PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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/*
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* File: drivers/pci/pcie/aspm.c
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2009-12-03 19:49:24 +08:00
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* Enabling PCIe link L0s/L1 state and Clock Power Management
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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*
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* Copyright (C) 2007 Intel
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* Copyright (C) Zhang Yanmin (yanmin.zhang@intel.com)
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* Copyright (C) Shaohua Li (shaohua.li@intel.com)
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/pci.h>
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#include <linux/pci_regs.h>
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#include <linux/errno.h>
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#include <linux/pm.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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2008-12-09 20:05:09 +08:00
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#include <linux/jiffies.h>
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2009-01-06 07:21:04 +08:00
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#include <linux/delay.h>
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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#include <linux/pci-aspm.h>
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#include "../pci.h"
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#ifdef MODULE_PARAM_PREFIX
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#undef MODULE_PARAM_PREFIX
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#endif
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#define MODULE_PARAM_PREFIX "pcie_aspm."
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2009-08-19 10:02:13 +08:00
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/* Note: those are not register definitions */
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#define ASPM_STATE_L0S_UP (1) /* Upstream direction L0s state */
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#define ASPM_STATE_L0S_DW (2) /* Downstream direction L0s state */
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#define ASPM_STATE_L1 (4) /* L1 state */
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2017-01-03 14:34:11 +08:00
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#define ASPM_STATE_L1_1 (8) /* ASPM L1.1 state */
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#define ASPM_STATE_L1_2 (0x10) /* ASPM L1.2 state */
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#define ASPM_STATE_L1_1_PCIPM (0x20) /* PCI PM L1.1 state */
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#define ASPM_STATE_L1_2_PCIPM (0x40) /* PCI PM L1.2 state */
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#define ASPM_STATE_L1_SS_PCIPM (ASPM_STATE_L1_1_PCIPM | ASPM_STATE_L1_2_PCIPM)
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#define ASPM_STATE_L1_2_MASK (ASPM_STATE_L1_2 | ASPM_STATE_L1_2_PCIPM)
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#define ASPM_STATE_L1SS (ASPM_STATE_L1_1 | ASPM_STATE_L1_1_PCIPM |\
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ASPM_STATE_L1_2_MASK)
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2009-08-19 10:02:13 +08:00
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#define ASPM_STATE_L0S (ASPM_STATE_L0S_UP | ASPM_STATE_L0S_DW)
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2017-01-03 14:34:11 +08:00
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#define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1 | \
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ASPM_STATE_L1SS)
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2009-08-19 10:02:13 +08:00
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2017-01-03 14:34:13 +08:00
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/*
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* When L1 substates are enabled, the LTR L1.2 threshold is a timing parameter
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* that decides whether L1.1 or L1.2 is entered (Refer PCIe spec for details).
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* Not sure is there is a way to "calculate" this on the fly, but maybe we
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* could turn it into a parameter in future. This value has been taken from
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* the following files from Intel's coreboot (which is the only code I found
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* to have used this):
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* https://www.coreboot.org/pipermail/coreboot-gerrit/2015-March/021134.html
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* https://review.coreboot.org/#/c/8832/
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*/
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#define LTR_L1_2_THRESHOLD_BITS ((1 << 21) | (1 << 23) | (1 << 30))
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2009-08-19 10:02:13 +08:00
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2009-05-13 11:14:58 +08:00
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struct aspm_latency {
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u32 l0s; /* L0s latency (nsec) */
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u32 l1; /* L1 latency (nsec) */
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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};
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struct pcie_link_state {
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2009-05-13 11:17:04 +08:00
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struct pci_dev *pdev; /* Upstream component of the Link */
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2017-01-03 14:34:12 +08:00
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struct pci_dev *downstream; /* Downstream component, function 0 */
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2009-05-13 11:23:57 +08:00
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struct pcie_link_state *root; /* pointer to the root port link */
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2009-05-13 11:17:04 +08:00
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struct pcie_link_state *parent; /* pointer to the parent Link state */
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struct list_head sibling; /* node in link_list */
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struct list_head children; /* list of child link states */
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struct list_head link; /* node in parent's children list */
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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/* ASPM state */
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2017-01-03 14:34:11 +08:00
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u32 aspm_support:7; /* Supported ASPM state */
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u32 aspm_enabled:7; /* Enabled ASPM state */
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u32 aspm_capable:7; /* Capable ASPM state with latency */
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u32 aspm_default:7; /* Default ASPM state by BIOS */
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u32 aspm_disable:7; /* Disabled ASPM state */
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2009-05-13 11:12:43 +08:00
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2009-05-13 11:15:38 +08:00
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/* Clock PM state */
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u32 clkpm_capable:1; /* Clock PM capable? */
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u32 clkpm_enabled:1; /* Current Clock PM state */
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u32 clkpm_default:1; /* Default Clock PM state by BIOS */
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2009-08-19 10:02:13 +08:00
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/* Exit latencies */
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struct aspm_latency latency_up; /* Upstream direction exit latency */
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struct aspm_latency latency_dw; /* Downstream direction exit latency */
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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/*
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2009-05-13 11:14:58 +08:00
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* Endpoint acceptable latencies. A pcie downstream port only
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* has one slot under it, so at most there are 8 functions.
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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*/
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2009-05-13 11:14:58 +08:00
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struct aspm_latency acceptable[8];
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2017-01-03 14:34:13 +08:00
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/* L1 PM Substate info */
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struct {
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u32 up_cap_ptr; /* L1SS cap ptr in upstream dev */
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u32 dw_cap_ptr; /* L1SS cap ptr in downstream dev */
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u32 ctl1; /* value to be programmed in ctl1 */
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u32 ctl2; /* value to be programmed in ctl2 */
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} l1ss;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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};
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2011-11-11 05:38:33 +08:00
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static int aspm_disabled, aspm_force;
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2011-03-05 20:21:51 +08:00
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static bool aspm_support_enabled = true;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
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static DEFINE_MUTEX(aspm_lock);
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static LIST_HEAD(link_list);
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#define POLICY_DEFAULT 0 /* BIOS default setting */
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#define POLICY_PERFORMANCE 1 /* high performance */
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#define POLICY_POWERSAVE 2 /* high power saving */
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2017-01-03 14:34:11 +08:00
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#define POLICY_POWER_SUPERSAVE 3 /* possibly even more power saving */
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2012-02-03 23:18:13 +08:00
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#ifdef CONFIG_PCIEASPM_PERFORMANCE
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static int aspm_policy = POLICY_PERFORMANCE;
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#elif defined CONFIG_PCIEASPM_POWERSAVE
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static int aspm_policy = POLICY_POWERSAVE;
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2017-01-03 14:34:11 +08:00
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#elif defined CONFIG_PCIEASPM_POWER_SUPERSAVE
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static int aspm_policy = POLICY_POWER_SUPERSAVE;
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2012-02-03 23:18:13 +08:00
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#else
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
static int aspm_policy;
|
2012-02-03 23:18:13 +08:00
|
|
|
#endif
|
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
static const char *policy_str[] = {
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|
|
[POLICY_DEFAULT] = "default",
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|
|
[POLICY_PERFORMANCE] = "performance",
|
2017-01-03 14:34:11 +08:00
|
|
|
[POLICY_POWERSAVE] = "powersave",
|
|
|
|
[POLICY_POWER_SUPERSAVE] = "powersupersave"
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
};
|
|
|
|
|
2009-01-06 07:21:04 +08:00
|
|
|
#define LINK_RETRAIN_TIMEOUT HZ
|
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
static int policy_to_aspm_state(struct pcie_link_state *link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
|
|
|
switch (aspm_policy) {
|
|
|
|
case POLICY_PERFORMANCE:
|
|
|
|
/* Disable ASPM and Clock PM */
|
|
|
|
return 0;
|
|
|
|
case POLICY_POWERSAVE:
|
|
|
|
/* Enable ASPM L0s/L1 */
|
2017-01-03 14:34:11 +08:00
|
|
|
return (ASPM_STATE_L0S | ASPM_STATE_L1);
|
|
|
|
case POLICY_POWER_SUPERSAVE:
|
|
|
|
/* Enable Everything */
|
2009-08-19 10:02:13 +08:00
|
|
|
return ASPM_STATE_ALL;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
case POLICY_DEFAULT:
|
2009-05-13 11:17:44 +08:00
|
|
|
return link->aspm_default;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
static int policy_to_clkpm_state(struct pcie_link_state *link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
|
|
|
switch (aspm_policy) {
|
|
|
|
case POLICY_PERFORMANCE:
|
|
|
|
/* Disable ASPM and Clock PM */
|
|
|
|
return 0;
|
|
|
|
case POLICY_POWERSAVE:
|
2017-01-03 14:34:11 +08:00
|
|
|
case POLICY_POWER_SUPERSAVE:
|
|
|
|
/* Enable Clock PM */
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return 1;
|
|
|
|
case POLICY_DEFAULT:
|
2009-05-13 11:17:44 +08:00
|
|
|
return link->clkpm_default;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-05-13 11:20:10 +08:00
|
|
|
static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_dev *child;
|
|
|
|
struct pci_bus *linkbus = link->pdev->subordinate;
|
2015-06-11 03:00:21 +08:00
|
|
|
u32 val = enable ? PCI_EXP_LNKCTL_CLKREQ_EN : 0;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2015-06-11 03:00:21 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list)
|
|
|
|
pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
|
|
|
|
PCI_EXP_LNKCTL_CLKREQ_EN,
|
|
|
|
val);
|
2009-05-13 11:17:44 +08:00
|
|
|
link->clkpm_enabled = !!enable;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-05-13 11:20:10 +08:00
|
|
|
static void pcie_set_clkpm(struct pcie_link_state *link, int enable)
|
|
|
|
{
|
|
|
|
/* Don't enable Clock PM if the link is not Clock PM capable */
|
2016-05-24 17:32:10 +08:00
|
|
|
if (!link->clkpm_capable)
|
2010-12-07 03:00:56 +08:00
|
|
|
enable = 0;
|
2009-05-13 11:20:10 +08:00
|
|
|
/* Need nothing if the specified equals to current state */
|
|
|
|
if (link->clkpm_enabled == enable)
|
|
|
|
return;
|
|
|
|
pcie_set_clkpm_nocheck(link, enable);
|
|
|
|
}
|
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2012-07-24 17:20:12 +08:00
|
|
|
int capable = 1, enabled = 1;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
u32 reg32;
|
|
|
|
u16 reg16;
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_dev *child;
|
|
|
|
struct pci_bus *linkbus = link->pdev->subordinate;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
|
|
|
/* All functions should have the same cap and state, take the worst */
|
2009-05-13 11:17:44 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list) {
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_dword(child, PCI_EXP_LNKCAP, ®32);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (!(reg32 & PCI_EXP_LNKCAP_CLKPM)) {
|
|
|
|
capable = 0;
|
|
|
|
enabled = 0;
|
|
|
|
break;
|
|
|
|
}
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (!(reg16 & PCI_EXP_LNKCTL_CLKREQ_EN))
|
|
|
|
enabled = 0;
|
|
|
|
}
|
2009-05-13 11:17:44 +08:00
|
|
|
link->clkpm_enabled = enabled;
|
|
|
|
link->clkpm_default = enabled;
|
2009-05-13 11:18:22 +08:00
|
|
|
link->clkpm_capable = (blacklist) ? 0 : capable;
|
2008-12-19 09:27:42 +08:00
|
|
|
}
|
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/*
|
|
|
|
* pcie_aspm_configure_common_clock: check if the 2 ends of a link
|
|
|
|
* could use common clock. If they are, configure them to use the
|
|
|
|
* common clock. That will reduce the ASPM state exit latency.
|
|
|
|
*/
|
2009-05-13 11:17:44 +08:00
|
|
|
static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2012-07-24 17:20:12 +08:00
|
|
|
int same_clock = 1;
|
2009-05-13 11:17:44 +08:00
|
|
|
u16 reg16, parent_reg, child_reg[8];
|
2008-12-09 20:05:09 +08:00
|
|
|
unsigned long start_jiffies;
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_dev *child, *parent = link->pdev;
|
|
|
|
struct pci_bus *linkbus = parent->subordinate;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/*
|
2009-05-13 11:17:44 +08:00
|
|
|
* All functions of a slot should have the same Slot Clock
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
* Configuration, so just check one function
|
2009-05-13 11:17:44 +08:00
|
|
|
*/
|
|
|
|
child = list_entry(linkbus->devices.next, struct pci_dev, bus_list);
|
2009-11-11 13:36:52 +08:00
|
|
|
BUG_ON(!pci_is_pcie(child));
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
|
|
|
/* Check downstream component if bit Slot Clock Configuration is 1 */
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(child, PCI_EXP_LNKSTA, ®16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (!(reg16 & PCI_EXP_LNKSTA_SLC))
|
|
|
|
same_clock = 0;
|
|
|
|
|
|
|
|
/* Check upstream component if bit Slot Clock Configuration is 1 */
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (!(reg16 & PCI_EXP_LNKSTA_SLC))
|
|
|
|
same_clock = 0;
|
|
|
|
|
|
|
|
/* Configure downstream component, all functions */
|
2009-05-13 11:17:44 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list) {
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16);
|
2009-05-13 11:17:44 +08:00
|
|
|
child_reg[PCI_FUNC(child->devfn)] = reg16;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (same_clock)
|
|
|
|
reg16 |= PCI_EXP_LNKCTL_CCC;
|
|
|
|
else
|
|
|
|
reg16 &= ~PCI_EXP_LNKCTL_CCC;
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_write_word(child, PCI_EXP_LNKCTL, reg16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Configure upstream component */
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16);
|
2008-12-09 20:05:09 +08:00
|
|
|
parent_reg = reg16;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (same_clock)
|
|
|
|
reg16 |= PCI_EXP_LNKCTL_CCC;
|
|
|
|
else
|
|
|
|
reg16 &= ~PCI_EXP_LNKCTL_CCC;
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
/* Retrain link */
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
reg16 |= PCI_EXP_LNKCTL_RL;
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
/* Wait for link training end. Break out after waiting for timeout */
|
2008-12-09 20:05:09 +08:00
|
|
|
start_jiffies = jiffies;
|
2009-01-06 07:21:04 +08:00
|
|
|
for (;;) {
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(parent, PCI_EXP_LNKSTA, ®16);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
if (!(reg16 & PCI_EXP_LNKSTA_LT))
|
|
|
|
break;
|
2009-01-06 07:21:04 +08:00
|
|
|
if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
|
|
|
|
break;
|
|
|
|
msleep(1);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
2009-05-13 11:17:44 +08:00
|
|
|
if (!(reg16 & PCI_EXP_LNKSTA_LT))
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Training failed. Restore common clock configurations */
|
2012-10-28 16:05:49 +08:00
|
|
|
dev_err(&parent->dev, "ASPM: Could not configure common clock\n");
|
2012-07-24 17:20:12 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list)
|
|
|
|
pcie_capability_write_word(child, PCI_EXP_LNKCTL,
|
|
|
|
child_reg[PCI_FUNC(child->devfn)]);
|
|
|
|
pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_reg);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-05-13 11:21:48 +08:00
|
|
|
/* Convert L0s latency encoding to ns */
|
|
|
|
static u32 calc_l0s_latency(u32 encoding)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-05-13 11:21:48 +08:00
|
|
|
if (encoding == 0x7)
|
|
|
|
return (5 * 1000); /* > 4us */
|
|
|
|
return (64 << encoding);
|
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:21:48 +08:00
|
|
|
/* Convert L0s acceptable latency encoding to ns */
|
|
|
|
static u32 calc_l0s_acceptable(u32 encoding)
|
|
|
|
{
|
|
|
|
if (encoding == 0x7)
|
|
|
|
return -1U;
|
|
|
|
return (64 << encoding);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-05-13 11:21:48 +08:00
|
|
|
/* Convert L1 latency encoding to ns */
|
|
|
|
static u32 calc_l1_latency(u32 encoding)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-05-13 11:21:48 +08:00
|
|
|
if (encoding == 0x7)
|
|
|
|
return (65 * 1000); /* > 64us */
|
|
|
|
return (1000 << encoding);
|
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:21:48 +08:00
|
|
|
/* Convert L1 acceptable latency encoding to ns */
|
|
|
|
static u32 calc_l1_acceptable(u32 encoding)
|
|
|
|
{
|
|
|
|
if (encoding == 0x7)
|
|
|
|
return -1U;
|
|
|
|
return (1000 << encoding);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2017-01-03 14:34:13 +08:00
|
|
|
/* Convert L1SS T_pwr encoding to usec */
|
|
|
|
static u32 calc_l1ss_pwron(struct pci_dev *pdev, u32 scale, u32 val)
|
|
|
|
{
|
|
|
|
switch (scale) {
|
|
|
|
case 0:
|
|
|
|
return val * 2;
|
|
|
|
case 1:
|
|
|
|
return val * 10;
|
|
|
|
case 2:
|
|
|
|
return val * 100;
|
|
|
|
}
|
|
|
|
dev_err(&pdev->dev, "%s: Invalid T_PwrOn scale: %u\n",
|
|
|
|
__func__, scale);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-08-19 10:02:13 +08:00
|
|
|
struct aspm_register_info {
|
|
|
|
u32 support:2;
|
|
|
|
u32 enabled:2;
|
|
|
|
u32 latency_encoding_l0s;
|
|
|
|
u32 latency_encoding_l1;
|
2017-01-03 14:34:12 +08:00
|
|
|
|
|
|
|
/* L1 substates */
|
|
|
|
u32 l1ss_cap_ptr;
|
|
|
|
u32 l1ss_cap;
|
|
|
|
u32 l1ss_ctl1;
|
|
|
|
u32 l1ss_ctl2;
|
2009-08-19 10:02:13 +08:00
|
|
|
};
|
|
|
|
|
|
|
|
static void pcie_get_aspm_reg(struct pci_dev *pdev,
|
|
|
|
struct aspm_register_info *info)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
|
|
|
u16 reg16;
|
2009-08-19 10:02:13 +08:00
|
|
|
u32 reg32;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, ®32);
|
2009-08-19 10:02:13 +08:00
|
|
|
info->support = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10;
|
|
|
|
info->latency_encoding_l0s = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12;
|
|
|
|
info->latency_encoding_l1 = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15;
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, ®16);
|
2009-08-19 10:02:13 +08:00
|
|
|
info->enabled = reg16 & PCI_EXP_LNKCTL_ASPMC;
|
2017-01-03 14:34:12 +08:00
|
|
|
|
|
|
|
/* Read L1 PM substate capabilities */
|
|
|
|
info->l1ss_cap = info->l1ss_ctl1 = info->l1ss_ctl2 = 0;
|
|
|
|
info->l1ss_cap_ptr = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_L1SS);
|
|
|
|
if (!info->l1ss_cap_ptr)
|
|
|
|
return;
|
|
|
|
pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CAP,
|
|
|
|
&info->l1ss_cap);
|
|
|
|
if (!(info->l1ss_cap & PCI_L1SS_CAP_L1_PM_SS)) {
|
|
|
|
info->l1ss_cap = 0;
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
&info->l1ss_ctl1);
|
|
|
|
pci_read_config_dword(pdev, info->l1ss_cap_ptr + PCI_L1SS_CTL2,
|
|
|
|
&info->l1ss_ctl2);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-08-19 10:00:25 +08:00
|
|
|
static void pcie_aspm_check_latency(struct pci_dev *endpoint)
|
|
|
|
{
|
2009-08-19 10:02:13 +08:00
|
|
|
u32 latency, l1_switch_latency = 0;
|
2009-08-19 10:00:25 +08:00
|
|
|
struct aspm_latency *acceptable;
|
|
|
|
struct pcie_link_state *link;
|
|
|
|
|
|
|
|
/* Device not in D0 doesn't need latency check */
|
|
|
|
if ((endpoint->current_state != PCI_D0) &&
|
|
|
|
(endpoint->current_state != PCI_UNKNOWN))
|
|
|
|
return;
|
|
|
|
|
|
|
|
link = endpoint->bus->self->link_state;
|
|
|
|
acceptable = &link->acceptable[PCI_FUNC(endpoint->devfn)];
|
|
|
|
|
|
|
|
while (link) {
|
2009-08-19 10:02:13 +08:00
|
|
|
/* Check upstream direction L0s latency */
|
|
|
|
if ((link->aspm_capable & ASPM_STATE_L0S_UP) &&
|
|
|
|
(link->latency_up.l0s > acceptable->l0s))
|
|
|
|
link->aspm_capable &= ~ASPM_STATE_L0S_UP;
|
|
|
|
|
|
|
|
/* Check downstream direction L0s latency */
|
|
|
|
if ((link->aspm_capable & ASPM_STATE_L0S_DW) &&
|
|
|
|
(link->latency_dw.l0s > acceptable->l0s))
|
|
|
|
link->aspm_capable &= ~ASPM_STATE_L0S_DW;
|
2009-08-19 10:00:25 +08:00
|
|
|
/*
|
|
|
|
* Check L1 latency.
|
|
|
|
* Every switch on the path to root complex need 1
|
|
|
|
* more microsecond for L1. Spec doesn't mention L0s.
|
2017-01-03 14:34:15 +08:00
|
|
|
*
|
|
|
|
* The exit latencies for L1 substates are not advertised
|
|
|
|
* by a device. Since the spec also doesn't mention a way
|
|
|
|
* to determine max latencies introduced by enabling L1
|
|
|
|
* substates on the components, it is not clear how to do
|
|
|
|
* a L1 substate exit latency check. We assume that the
|
|
|
|
* L1 exit latencies advertised by a device include L1
|
|
|
|
* substate latencies (and hence do not do any check).
|
2009-08-19 10:00:25 +08:00
|
|
|
*/
|
2009-08-19 10:02:13 +08:00
|
|
|
latency = max_t(u32, link->latency_up.l1, link->latency_dw.l1);
|
|
|
|
if ((link->aspm_capable & ASPM_STATE_L1) &&
|
|
|
|
(latency + l1_switch_latency > acceptable->l1))
|
|
|
|
link->aspm_capable &= ~ASPM_STATE_L1;
|
2009-08-19 10:00:25 +08:00
|
|
|
l1_switch_latency += 1000;
|
|
|
|
|
|
|
|
link = link->parent;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2017-01-03 14:34:12 +08:00
|
|
|
/*
|
|
|
|
* The L1 PM substate capability is only implemented in function 0 in a
|
|
|
|
* multi function device.
|
|
|
|
*/
|
|
|
|
static struct pci_dev *pci_function_0(struct pci_bus *linkbus)
|
|
|
|
{
|
|
|
|
struct pci_dev *child;
|
|
|
|
|
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list)
|
|
|
|
if (PCI_FUNC(child->devfn) == 0)
|
|
|
|
return child;
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2017-01-03 14:34:13 +08:00
|
|
|
/* Calculate L1.2 PM substate timing parameters */
|
|
|
|
static void aspm_calc_l1ss_info(struct pcie_link_state *link,
|
|
|
|
struct aspm_register_info *upreg,
|
|
|
|
struct aspm_register_info *dwreg)
|
|
|
|
{
|
|
|
|
u32 val1, val2, scale1, scale2;
|
|
|
|
|
|
|
|
link->l1ss.up_cap_ptr = upreg->l1ss_cap_ptr;
|
|
|
|
link->l1ss.dw_cap_ptr = dwreg->l1ss_cap_ptr;
|
|
|
|
link->l1ss.ctl1 = link->l1ss.ctl2 = 0;
|
|
|
|
|
|
|
|
if (!(link->aspm_support & ASPM_STATE_L1_2_MASK))
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Choose the greater of the two T_cmn_mode_rstr_time */
|
|
|
|
val1 = (upreg->l1ss_cap >> 8) & 0xFF;
|
|
|
|
val2 = (upreg->l1ss_cap >> 8) & 0xFF;
|
|
|
|
if (val1 > val2)
|
|
|
|
link->l1ss.ctl1 |= val1 << 8;
|
|
|
|
else
|
|
|
|
link->l1ss.ctl1 |= val2 << 8;
|
|
|
|
/*
|
|
|
|
* We currently use LTR L1.2 threshold to be fixed constant picked from
|
|
|
|
* Intel's coreboot.
|
|
|
|
*/
|
|
|
|
link->l1ss.ctl1 |= LTR_L1_2_THRESHOLD_BITS;
|
|
|
|
|
|
|
|
/* Choose the greater of the two T_pwr_on */
|
|
|
|
val1 = (upreg->l1ss_cap >> 19) & 0x1F;
|
|
|
|
scale1 = (upreg->l1ss_cap >> 16) & 0x03;
|
|
|
|
val2 = (dwreg->l1ss_cap >> 19) & 0x1F;
|
|
|
|
scale2 = (dwreg->l1ss_cap >> 16) & 0x03;
|
|
|
|
|
|
|
|
if (calc_l1ss_pwron(link->pdev, scale1, val1) >
|
|
|
|
calc_l1ss_pwron(link->downstream, scale2, val2))
|
|
|
|
link->l1ss.ctl2 |= scale1 | (val1 << 3);
|
|
|
|
else
|
|
|
|
link->l1ss.ctl2 |= scale2 | (val2 << 3);
|
|
|
|
}
|
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2017-03-01 16:25:40 +08:00
|
|
|
struct pci_dev *child = link->downstream, *parent = link->pdev;
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_bus *linkbus = parent->subordinate;
|
2009-08-19 10:02:13 +08:00
|
|
|
struct aspm_register_info upreg, dwreg;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
if (blacklist) {
|
2009-08-19 09:59:52 +08:00
|
|
|
/* Set enabled/disable so that we will disable ASPM later */
|
2009-08-19 10:02:13 +08:00
|
|
|
link->aspm_enabled = ASPM_STATE_ALL;
|
|
|
|
link->aspm_disable = ASPM_STATE_ALL;
|
2009-05-13 11:18:22 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2016-11-18 06:25:01 +08:00
|
|
|
/* Get upstream/downstream components' register state */
|
|
|
|
pcie_get_aspm_reg(parent, &upreg);
|
|
|
|
pcie_get_aspm_reg(child, &dwreg);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If ASPM not supported, don't mess with the clocks and link,
|
|
|
|
* bail out now.
|
|
|
|
*/
|
|
|
|
if (!(upreg.support & dwreg.support))
|
|
|
|
return;
|
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
/* Configure common clock before checking latencies */
|
|
|
|
pcie_aspm_configure_common_clock(link);
|
|
|
|
|
2016-11-18 06:25:01 +08:00
|
|
|
/*
|
|
|
|
* Re-read upstream/downstream components' register state
|
|
|
|
* after clock configuration
|
|
|
|
*/
|
2009-08-19 10:02:13 +08:00
|
|
|
pcie_get_aspm_reg(parent, &upreg);
|
|
|
|
pcie_get_aspm_reg(child, &dwreg);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Setup L0s state
|
|
|
|
*
|
|
|
|
* Note that we must not enable L0s in either direction on a
|
|
|
|
* given link unless components on both sides of the link each
|
|
|
|
* support L0s.
|
|
|
|
*/
|
|
|
|
if (dwreg.support & upreg.support & PCIE_LINK_STATE_L0S)
|
|
|
|
link->aspm_support |= ASPM_STATE_L0S;
|
|
|
|
if (dwreg.enabled & PCIE_LINK_STATE_L0S)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L0S_UP;
|
|
|
|
if (upreg.enabled & PCIE_LINK_STATE_L0S)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L0S_DW;
|
|
|
|
link->latency_up.l0s = calc_l0s_latency(upreg.latency_encoding_l0s);
|
|
|
|
link->latency_dw.l0s = calc_l0s_latency(dwreg.latency_encoding_l0s);
|
|
|
|
|
|
|
|
/* Setup L1 state */
|
|
|
|
if (upreg.support & dwreg.support & PCIE_LINK_STATE_L1)
|
|
|
|
link->aspm_support |= ASPM_STATE_L1;
|
|
|
|
if (upreg.enabled & dwreg.enabled & PCIE_LINK_STATE_L1)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L1;
|
|
|
|
link->latency_up.l1 = calc_l1_latency(upreg.latency_encoding_l1);
|
|
|
|
link->latency_dw.l1 = calc_l1_latency(dwreg.latency_encoding_l1);
|
2009-05-13 11:17:44 +08:00
|
|
|
|
2017-01-03 14:34:12 +08:00
|
|
|
/* Setup L1 substate */
|
|
|
|
if (upreg.l1ss_cap & dwreg.l1ss_cap & PCI_L1SS_CAP_ASPM_L1_1)
|
|
|
|
link->aspm_support |= ASPM_STATE_L1_1;
|
|
|
|
if (upreg.l1ss_cap & dwreg.l1ss_cap & PCI_L1SS_CAP_ASPM_L1_2)
|
|
|
|
link->aspm_support |= ASPM_STATE_L1_2;
|
|
|
|
if (upreg.l1ss_cap & dwreg.l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_1)
|
|
|
|
link->aspm_support |= ASPM_STATE_L1_1_PCIPM;
|
|
|
|
if (upreg.l1ss_cap & dwreg.l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_2)
|
|
|
|
link->aspm_support |= ASPM_STATE_L1_2_PCIPM;
|
|
|
|
|
|
|
|
if (upreg.l1ss_ctl1 & dwreg.l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L1_1;
|
|
|
|
if (upreg.l1ss_ctl1 & dwreg.l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L1_2;
|
|
|
|
if (upreg.l1ss_ctl1 & dwreg.l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
|
|
|
|
if (upreg.l1ss_ctl1 & dwreg.l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
|
|
|
|
link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
|
|
|
|
|
2017-01-03 14:34:13 +08:00
|
|
|
if (link->aspm_support & ASPM_STATE_L1SS)
|
|
|
|
aspm_calc_l1ss_info(link, &upreg, &dwreg);
|
|
|
|
|
2009-08-19 09:57:31 +08:00
|
|
|
/* Save default state */
|
|
|
|
link->aspm_default = link->aspm_enabled;
|
2009-08-19 10:00:25 +08:00
|
|
|
|
|
|
|
/* Setup initial capable state. Will be updated later */
|
|
|
|
link->aspm_capable = link->aspm_support;
|
2009-08-19 09:59:52 +08:00
|
|
|
/*
|
|
|
|
* If the downstream component has pci bridge function, don't
|
|
|
|
* do ASPM for now.
|
|
|
|
*/
|
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list) {
|
2012-07-24 17:20:03 +08:00
|
|
|
if (pci_pcie_type(child) == PCI_EXP_TYPE_PCI_BRIDGE) {
|
2009-08-19 10:02:13 +08:00
|
|
|
link->aspm_disable = ASPM_STATE_ALL;
|
2009-08-19 09:59:52 +08:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
2009-08-19 09:57:31 +08:00
|
|
|
|
2009-08-19 10:01:37 +08:00
|
|
|
/* Get and check endpoint acceptable latencies */
|
2009-05-13 11:17:44 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list) {
|
2009-05-13 11:21:48 +08:00
|
|
|
u32 reg32, encoding;
|
2009-05-13 11:14:58 +08:00
|
|
|
struct aspm_latency *acceptable =
|
2009-05-13 11:17:44 +08:00
|
|
|
&link->acceptable[PCI_FUNC(child->devfn)];
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2012-07-24 17:20:03 +08:00
|
|
|
if (pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT &&
|
|
|
|
pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
continue;
|
|
|
|
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_dword(child, PCI_EXP_DEVCAP, ®32);
|
2009-08-19 10:00:25 +08:00
|
|
|
/* Calculate endpoint L0s acceptable latency */
|
2009-05-13 11:21:48 +08:00
|
|
|
encoding = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6;
|
|
|
|
acceptable->l0s = calc_l0s_acceptable(encoding);
|
2009-08-19 10:00:25 +08:00
|
|
|
/* Calculate endpoint L1 acceptable latency */
|
|
|
|
encoding = (reg32 & PCI_EXP_DEVCAP_L1) >> 9;
|
|
|
|
acceptable->l1 = calc_l1_acceptable(encoding);
|
|
|
|
|
|
|
|
pcie_aspm_check_latency(child);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2017-01-03 14:34:14 +08:00
|
|
|
static void pci_clear_and_set_dword(struct pci_dev *pdev, int pos,
|
|
|
|
u32 clear, u32 set)
|
|
|
|
{
|
|
|
|
u32 val;
|
|
|
|
|
|
|
|
pci_read_config_dword(pdev, pos, &val);
|
|
|
|
val &= ~clear;
|
|
|
|
val |= set;
|
|
|
|
pci_write_config_dword(pdev, pos, val);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Configure the ASPM L1 substates */
|
|
|
|
static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
|
|
|
|
{
|
|
|
|
u32 val, enable_req;
|
|
|
|
struct pci_dev *child = link->downstream, *parent = link->pdev;
|
|
|
|
u32 up_cap_ptr = link->l1ss.up_cap_ptr;
|
|
|
|
u32 dw_cap_ptr = link->l1ss.dw_cap_ptr;
|
|
|
|
|
|
|
|
enable_req = (link->aspm_enabled ^ state) & state;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Here are the rules specified in the PCIe spec for enabling L1SS:
|
|
|
|
* - When enabling L1.x, enable bit at parent first, then at child
|
|
|
|
* - When disabling L1.x, disable bit at child first, then at parent
|
|
|
|
* - When enabling ASPM L1.x, need to disable L1
|
|
|
|
* (at child followed by parent).
|
|
|
|
* - The ASPM/PCIPM L1.2 must be disabled while programming timing
|
|
|
|
* parameters
|
|
|
|
*
|
|
|
|
* To keep it simple, disable all L1SS bits first, and later enable
|
|
|
|
* what is needed.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* Disable all L1 substates */
|
|
|
|
pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
PCI_L1SS_CTL1_L1SS_MASK, 0);
|
|
|
|
pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
PCI_L1SS_CTL1_L1SS_MASK, 0);
|
|
|
|
/*
|
|
|
|
* If needed, disable L1, and it gets enabled later
|
|
|
|
* in pcie_config_aspm_link().
|
|
|
|
*/
|
|
|
|
if (enable_req & (ASPM_STATE_L1_1 | ASPM_STATE_L1_2)) {
|
|
|
|
pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL,
|
|
|
|
PCI_EXP_LNKCTL_ASPM_L1, 0);
|
|
|
|
pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL,
|
|
|
|
PCI_EXP_LNKCTL_ASPM_L1, 0);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (enable_req & ASPM_STATE_L1_2_MASK) {
|
|
|
|
|
|
|
|
/* Program T_pwr_on in both ports */
|
|
|
|
pci_write_config_dword(parent, up_cap_ptr + PCI_L1SS_CTL2,
|
|
|
|
link->l1ss.ctl2);
|
|
|
|
pci_write_config_dword(child, dw_cap_ptr + PCI_L1SS_CTL2,
|
|
|
|
link->l1ss.ctl2);
|
|
|
|
|
|
|
|
/* Program T_cmn_mode in parent */
|
|
|
|
pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
0xFF00, link->l1ss.ctl1);
|
|
|
|
|
|
|
|
/* Program LTR L1.2 threshold in both ports */
|
|
|
|
pci_clear_and_set_dword(parent, dw_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
0xE3FF0000, link->l1ss.ctl1);
|
|
|
|
pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
0xE3FF0000, link->l1ss.ctl1);
|
|
|
|
}
|
|
|
|
|
|
|
|
val = 0;
|
|
|
|
if (state & ASPM_STATE_L1_1)
|
|
|
|
val |= PCI_L1SS_CTL1_ASPM_L1_1;
|
|
|
|
if (state & ASPM_STATE_L1_2)
|
|
|
|
val |= PCI_L1SS_CTL1_ASPM_L1_2;
|
|
|
|
if (state & ASPM_STATE_L1_1_PCIPM)
|
|
|
|
val |= PCI_L1SS_CTL1_PCIPM_L1_1;
|
|
|
|
if (state & ASPM_STATE_L1_2_PCIPM)
|
|
|
|
val |= PCI_L1SS_CTL1_PCIPM_L1_2;
|
|
|
|
|
|
|
|
/* Enable what we need to enable */
|
|
|
|
pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
PCI_L1SS_CAP_L1_PM_SS, val);
|
|
|
|
pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1,
|
|
|
|
PCI_L1SS_CAP_L1_PM_SS, val);
|
|
|
|
}
|
|
|
|
|
2009-08-19 10:02:13 +08:00
|
|
|
static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2012-12-06 04:51:19 +08:00
|
|
|
pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
|
|
|
|
PCI_EXP_LNKCTL_ASPMC, val);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-08-19 10:01:37 +08:00
|
|
|
static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-08-19 10:02:13 +08:00
|
|
|
u32 upstream = 0, dwstream = 0;
|
2017-01-03 14:34:14 +08:00
|
|
|
struct pci_dev *child = link->downstream, *parent = link->pdev;
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_bus *linkbus = parent->subordinate;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2017-01-03 14:34:14 +08:00
|
|
|
/* Enable only the states that were not explicitly disabled */
|
2009-08-19 10:01:37 +08:00
|
|
|
state &= (link->aspm_capable & ~link->aspm_disable);
|
2017-01-03 14:34:14 +08:00
|
|
|
|
|
|
|
/* Can't enable any substates if L1 is not enabled */
|
|
|
|
if (!(state & ASPM_STATE_L1))
|
|
|
|
state &= ~ASPM_STATE_L1SS;
|
|
|
|
|
|
|
|
/* Spec says both ports must be in D0 before enabling PCI PM substates*/
|
|
|
|
if (parent->current_state != PCI_D0 || child->current_state != PCI_D0) {
|
|
|
|
state &= ~ASPM_STATE_L1_SS_PCIPM;
|
|
|
|
state |= (link->aspm_enabled & ASPM_STATE_L1_SS_PCIPM);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Nothing to do if the link is already in the requested state */
|
2009-08-19 09:59:52 +08:00
|
|
|
if (link->aspm_enabled == state)
|
|
|
|
return;
|
2009-08-19 10:02:13 +08:00
|
|
|
/* Convert ASPM state to upstream/downstream ASPM register state */
|
|
|
|
if (state & ASPM_STATE_L0S_UP)
|
2012-12-06 04:51:19 +08:00
|
|
|
dwstream |= PCI_EXP_LNKCTL_ASPM_L0S;
|
2009-08-19 10:02:13 +08:00
|
|
|
if (state & ASPM_STATE_L0S_DW)
|
2012-12-06 04:51:19 +08:00
|
|
|
upstream |= PCI_EXP_LNKCTL_ASPM_L0S;
|
2009-08-19 10:02:13 +08:00
|
|
|
if (state & ASPM_STATE_L1) {
|
2012-12-06 04:51:19 +08:00
|
|
|
upstream |= PCI_EXP_LNKCTL_ASPM_L1;
|
|
|
|
dwstream |= PCI_EXP_LNKCTL_ASPM_L1;
|
2009-08-19 10:02:13 +08:00
|
|
|
}
|
2017-01-03 14:34:14 +08:00
|
|
|
|
|
|
|
if (link->aspm_capable & ASPM_STATE_L1SS)
|
|
|
|
pcie_config_aspm_l1ss(link, state);
|
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/*
|
2009-05-13 11:17:44 +08:00
|
|
|
* Spec 2.0 suggests all functions should be configured the
|
|
|
|
* same setting for ASPM. Enabling ASPM L1 should be done in
|
|
|
|
* upstream component first and then downstream, and vice
|
|
|
|
* versa for disabling ASPM L1. Spec doesn't mention L0S.
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
*/
|
2009-08-19 10:02:13 +08:00
|
|
|
if (state & ASPM_STATE_L1)
|
|
|
|
pcie_config_aspm_dev(parent, upstream);
|
2009-05-13 11:17:44 +08:00
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list)
|
2009-08-19 10:02:13 +08:00
|
|
|
pcie_config_aspm_dev(child, dwstream);
|
|
|
|
if (!(state & ASPM_STATE_L1))
|
|
|
|
pcie_config_aspm_dev(parent, upstream);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
link->aspm_enabled = state;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-08-19 10:01:37 +08:00
|
|
|
static void pcie_config_aspm_path(struct pcie_link_state *link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-08-19 10:01:37 +08:00
|
|
|
while (link) {
|
|
|
|
pcie_config_aspm_link(link, policy_to_aspm_state(link));
|
|
|
|
link = link->parent;
|
2008-12-19 09:27:42 +08:00
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2009-05-13 11:17:44 +08:00
|
|
|
static void free_link_state(struct pcie_link_state *link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
2009-05-13 11:17:44 +08:00
|
|
|
link->pdev->link_state = NULL;
|
|
|
|
kfree(link);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2008-05-21 16:58:40 +08:00
|
|
|
static int pcie_aspm_sanity_check(struct pci_dev *pdev)
|
|
|
|
{
|
2009-05-13 11:23:09 +08:00
|
|
|
struct pci_dev *child;
|
2008-07-23 10:32:31 +08:00
|
|
|
u32 reg32;
|
2010-12-07 03:00:56 +08:00
|
|
|
|
2008-05-21 16:58:40 +08:00
|
|
|
/*
|
2009-12-03 19:49:24 +08:00
|
|
|
* Some functions in a slot might not all be PCIe functions,
|
2009-05-13 11:23:09 +08:00
|
|
|
* very strange. Disable ASPM for the whole slot
|
2008-05-21 16:58:40 +08:00
|
|
|
*/
|
2009-05-13 11:23:09 +08:00
|
|
|
list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
|
2012-07-24 17:20:12 +08:00
|
|
|
if (!pci_is_pcie(child))
|
2008-05-21 16:58:40 +08:00
|
|
|
return -EINVAL;
|
2012-03-27 22:17:41 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If ASPM is disabled then we're not going to change
|
|
|
|
* the BIOS state. It's safe to continue even if it's a
|
|
|
|
* pre-1.1 device
|
|
|
|
*/
|
|
|
|
|
|
|
|
if (aspm_disabled)
|
|
|
|
continue;
|
|
|
|
|
2008-07-23 10:32:31 +08:00
|
|
|
/*
|
|
|
|
* Disable ASPM for pre-1.1 PCIe device, we follow MS to use
|
|
|
|
* RBER bit to determine if a function is 1.1 version device
|
|
|
|
*/
|
2012-07-24 17:20:12 +08:00
|
|
|
pcie_capability_read_dword(child, PCI_EXP_DEVCAP, ®32);
|
2008-09-16 21:27:13 +08:00
|
|
|
if (!(reg32 & PCI_EXP_DEVCAP_RBER) && !aspm_force) {
|
2012-10-28 16:05:49 +08:00
|
|
|
dev_info(&child->dev, "disabling ASPM on pre-1.1 PCIe device. You can enable it with 'pcie_aspm=force'\n");
|
2008-07-23 10:32:31 +08:00
|
|
|
return -EINVAL;
|
|
|
|
}
|
2008-05-21 16:58:40 +08:00
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-08-19 10:01:37 +08:00
|
|
|
static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
|
2009-05-13 11:18:22 +08:00
|
|
|
{
|
|
|
|
struct pcie_link_state *link;
|
|
|
|
|
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL);
|
|
|
|
if (!link)
|
|
|
|
return NULL;
|
2017-01-28 05:00:45 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
INIT_LIST_HEAD(&link->sibling);
|
|
|
|
INIT_LIST_HEAD(&link->children);
|
|
|
|
INIT_LIST_HEAD(&link->link);
|
|
|
|
link->pdev = pdev;
|
2017-03-01 16:25:40 +08:00
|
|
|
link->downstream = pci_function_0(pdev->subordinate);
|
2017-01-28 05:00:45 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
|
|
|
|
* hierarchies.
|
|
|
|
*/
|
|
|
|
if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
|
|
|
|
pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE) {
|
|
|
|
link->root = link;
|
|
|
|
} else {
|
2009-05-13 11:18:22 +08:00
|
|
|
struct pcie_link_state *parent;
|
2017-01-28 05:00:45 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
parent = pdev->bus->parent->self->link_state;
|
|
|
|
if (!parent) {
|
|
|
|
kfree(link);
|
|
|
|
return NULL;
|
|
|
|
}
|
2017-01-28 05:00:45 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
link->parent = parent;
|
2017-01-28 05:00:45 +08:00
|
|
|
link->root = link->parent->root;
|
2009-05-13 11:18:22 +08:00
|
|
|
list_add(&link->link, &parent->children);
|
|
|
|
}
|
2009-05-13 11:23:57 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
list_add(&link->sibling, &link_list);
|
|
|
|
pdev->link_state = link;
|
|
|
|
return link;
|
|
|
|
}
|
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/*
|
|
|
|
* pcie_aspm_init_link_state: Initiate PCI express link state.
|
2013-11-15 02:28:18 +08:00
|
|
|
* It is called after the pcie and its children devices are scanned.
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
* @pdev: the root port or switch downstream port
|
|
|
|
*/
|
|
|
|
void pcie_aspm_init_link_state(struct pci_dev *pdev)
|
|
|
|
{
|
2009-05-13 11:18:22 +08:00
|
|
|
struct pcie_link_state *link;
|
2009-08-19 10:01:37 +08:00
|
|
|
int blacklist = !!pcie_aspm_sanity_check(pdev);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2013-01-16 04:31:28 +08:00
|
|
|
if (!aspm_support_enabled)
|
|
|
|
return;
|
|
|
|
|
2015-05-21 15:05:03 +08:00
|
|
|
if (pdev->link_state)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
2015-05-21 15:05:03 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* We allocate pcie_link_state for the component on the upstream
|
|
|
|
* end of a Link, so there's nothing to do unless this device has a
|
|
|
|
* Link on its secondary side.
|
|
|
|
*/
|
|
|
|
if (!pdev->has_secondary_link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
2009-05-13 11:18:22 +08:00
|
|
|
|
2009-06-08 09:27:25 +08:00
|
|
|
/* VIA has a strange chipset, root port is under a bridge */
|
2012-07-24 17:20:03 +08:00
|
|
|
if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT &&
|
2009-05-13 11:18:22 +08:00
|
|
|
pdev->bus->self)
|
2009-06-08 09:27:25 +08:00
|
|
|
return;
|
2009-05-13 11:18:22 +08:00
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
if (list_empty(&pdev->subordinate->devices))
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
mutex_lock(&aspm_lock);
|
2009-08-19 10:01:37 +08:00
|
|
|
link = alloc_pcie_link_state(pdev);
|
2009-05-13 11:18:22 +08:00
|
|
|
if (!link)
|
|
|
|
goto unlock;
|
|
|
|
/*
|
2009-08-19 10:01:37 +08:00
|
|
|
* Setup initial ASPM state. Note that we need to configure
|
|
|
|
* upstream links also because capable state of them can be
|
|
|
|
* update through pcie_aspm_cap_init().
|
2009-05-13 11:18:22 +08:00
|
|
|
*/
|
2009-08-19 10:01:37 +08:00
|
|
|
pcie_aspm_cap_init(link, blacklist);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
/* Setup initial Clock PM state */
|
2009-08-19 10:01:37 +08:00
|
|
|
pcie_clkpm_cap_init(link, blacklist);
|
2010-06-10 04:05:07 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* At this stage drivers haven't had an opportunity to change the
|
|
|
|
* link policy setting. Enabling ASPM on broken hardware can cripple
|
|
|
|
* it even before the driver has had a chance to disable ASPM, so
|
|
|
|
* default to a safe level right now. If we're enabling ASPM beyond
|
|
|
|
* the BIOS's expectation, we'll do so once pci_enable_device() is
|
|
|
|
* called.
|
|
|
|
*/
|
2017-01-03 14:34:11 +08:00
|
|
|
if (aspm_policy != POLICY_POWERSAVE &&
|
|
|
|
aspm_policy != POLICY_POWER_SUPERSAVE) {
|
2010-06-10 04:05:07 +08:00
|
|
|
pcie_config_aspm_path(link);
|
|
|
|
pcie_set_clkpm(link, policy_to_clkpm_state(link));
|
|
|
|
}
|
|
|
|
|
2009-05-13 11:18:22 +08:00
|
|
|
unlock:
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
out:
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
}
|
|
|
|
|
2009-08-19 10:00:25 +08:00
|
|
|
/* Recheck latencies and update aspm_capable for links under the root */
|
|
|
|
static void pcie_update_aspm_capable(struct pcie_link_state *root)
|
|
|
|
{
|
|
|
|
struct pcie_link_state *link;
|
|
|
|
BUG_ON(root->parent);
|
|
|
|
list_for_each_entry(link, &link_list, sibling) {
|
|
|
|
if (link->root != root)
|
|
|
|
continue;
|
|
|
|
link->aspm_capable = link->aspm_support;
|
|
|
|
}
|
|
|
|
list_for_each_entry(link, &link_list, sibling) {
|
|
|
|
struct pci_dev *child;
|
|
|
|
struct pci_bus *linkbus = link->pdev->subordinate;
|
|
|
|
if (link->root != root)
|
|
|
|
continue;
|
|
|
|
list_for_each_entry(child, &linkbus->devices, bus_list) {
|
2012-07-24 17:20:03 +08:00
|
|
|
if ((pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT) &&
|
|
|
|
(pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END))
|
2009-08-19 10:00:25 +08:00
|
|
|
continue;
|
|
|
|
pcie_aspm_check_latency(child);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/* @pdev: the endpoint device */
|
|
|
|
void pcie_aspm_exit_link_state(struct pci_dev *pdev)
|
|
|
|
{
|
|
|
|
struct pci_dev *parent = pdev->bus->self;
|
2009-08-19 10:01:37 +08:00
|
|
|
struct pcie_link_state *link, *root, *parent_link;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2013-02-01 07:29:25 +08:00
|
|
|
if (!parent || !parent->link_state)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
2009-08-19 09:58:46 +08:00
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
|
|
|
/*
|
|
|
|
* All PCIe functions are in one slot, remove one function will remove
|
2009-01-29 05:59:18 +08:00
|
|
|
* the whole slot, so just wait until we are the last function left.
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
*/
|
2009-01-29 05:59:18 +08:00
|
|
|
if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices))
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
goto out;
|
|
|
|
|
2009-08-19 09:58:46 +08:00
|
|
|
link = parent->link_state;
|
2009-08-19 10:00:25 +08:00
|
|
|
root = link->root;
|
2009-08-19 10:01:37 +08:00
|
|
|
parent_link = link->parent;
|
2009-08-19 09:58:46 +08:00
|
|
|
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/* All functions are removed, so just disable ASPM for the link */
|
2009-08-19 10:01:37 +08:00
|
|
|
pcie_config_aspm_link(link, 0);
|
2009-08-19 09:58:46 +08:00
|
|
|
list_del(&link->sibling);
|
|
|
|
list_del(&link->link);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
/* Clock PM is for endpoint device */
|
2009-08-19 09:58:46 +08:00
|
|
|
free_link_state(link);
|
2009-08-19 10:00:25 +08:00
|
|
|
|
|
|
|
/* Recheck latencies and configure upstream links */
|
2009-11-06 10:25:13 +08:00
|
|
|
if (parent_link) {
|
|
|
|
pcie_update_aspm_capable(root);
|
|
|
|
pcie_config_aspm_path(parent_link);
|
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
out:
|
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* @pdev: the root port or switch downstream port */
|
|
|
|
void pcie_aspm_pm_state_change(struct pci_dev *pdev)
|
|
|
|
{
|
2009-08-19 10:00:25 +08:00
|
|
|
struct pcie_link_state *link = pdev->link_state;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2015-05-19 11:41:34 +08:00
|
|
|
if (aspm_disabled || !link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
|
|
|
/*
|
2009-08-19 10:00:25 +08:00
|
|
|
* Devices changed PM state, we should recheck if latency
|
|
|
|
* meets all functions' requirement
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
*/
|
2009-08-19 10:00:25 +08:00
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
|
|
|
pcie_update_aspm_capable(link->root);
|
2009-08-19 10:01:37 +08:00
|
|
|
pcie_config_aspm_path(link);
|
2009-08-19 10:00:25 +08:00
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
2011-03-21 11:29:08 +08:00
|
|
|
void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
|
|
|
|
{
|
|
|
|
struct pcie_link_state *link = pdev->link_state;
|
|
|
|
|
2015-05-19 11:41:34 +08:00
|
|
|
if (aspm_disabled || !link)
|
2011-03-21 11:29:08 +08:00
|
|
|
return;
|
|
|
|
|
2017-01-03 14:34:11 +08:00
|
|
|
if (aspm_policy != POLICY_POWERSAVE &&
|
|
|
|
aspm_policy != POLICY_POWER_SUPERSAVE)
|
2011-03-21 11:29:08 +08:00
|
|
|
return;
|
|
|
|
|
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
|
|
|
pcie_config_aspm_path(link);
|
|
|
|
pcie_set_clkpm(link, policy_to_clkpm_state(link));
|
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
}
|
|
|
|
|
2015-05-21 01:13:05 +08:00
|
|
|
static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
{
|
|
|
|
struct pci_dev *parent = pdev->bus->self;
|
2009-08-19 09:59:52 +08:00
|
|
|
struct pcie_link_state *link;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2011-11-11 05:38:33 +08:00
|
|
|
if (!pci_is_pcie(pdev))
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
2011-11-11 05:38:33 +08:00
|
|
|
|
2015-05-21 15:05:03 +08:00
|
|
|
if (pdev->has_secondary_link)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
parent = pdev;
|
|
|
|
if (!parent || !parent->link_state)
|
|
|
|
return;
|
|
|
|
|
2013-05-22 00:56:51 +08:00
|
|
|
/*
|
|
|
|
* A driver requested that ASPM be disabled on this device, but
|
|
|
|
* if we don't have permission to manage ASPM (e.g., on ACPI
|
|
|
|
* systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and
|
|
|
|
* the _OSC method), we can't honor that request. Windows has
|
|
|
|
* a similar mechanism using "PciASPMOptOut", which is also
|
|
|
|
* ignored in this situation.
|
|
|
|
*/
|
2015-05-21 01:13:05 +08:00
|
|
|
if (aspm_disabled) {
|
2013-05-22 00:56:51 +08:00
|
|
|
dev_warn(&pdev->dev, "can't disable ASPM; OS doesn't have ASPM control\n");
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2011-05-13 08:11:47 +08:00
|
|
|
if (sem)
|
|
|
|
down_read(&pci_bus_sem);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
mutex_lock(&aspm_lock);
|
2009-08-19 09:59:52 +08:00
|
|
|
link = parent->link_state;
|
2009-08-19 10:02:13 +08:00
|
|
|
if (state & PCIE_LINK_STATE_L0S)
|
|
|
|
link->aspm_disable |= ASPM_STATE_L0S;
|
|
|
|
if (state & PCIE_LINK_STATE_L1)
|
|
|
|
link->aspm_disable |= ASPM_STATE_L1;
|
2009-08-19 10:01:37 +08:00
|
|
|
pcie_config_aspm_link(link, policy_to_aspm_state(link));
|
|
|
|
|
2009-05-13 11:20:10 +08:00
|
|
|
if (state & PCIE_LINK_STATE_CLKPM) {
|
2009-08-19 09:59:52 +08:00
|
|
|
link->clkpm_capable = 0;
|
|
|
|
pcie_set_clkpm(link, 0);
|
2009-05-13 11:20:10 +08:00
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
mutex_unlock(&aspm_lock);
|
2011-05-13 08:11:47 +08:00
|
|
|
if (sem)
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
}
|
|
|
|
|
|
|
|
void pci_disable_link_state_locked(struct pci_dev *pdev, int state)
|
|
|
|
{
|
2015-05-21 01:13:05 +08:00
|
|
|
__pci_disable_link_state(pdev, state, false);
|
2011-05-13 08:11:47 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(pci_disable_link_state_locked);
|
|
|
|
|
2013-05-28 16:03:22 +08:00
|
|
|
/**
|
|
|
|
* pci_disable_link_state - Disable device's link state, so the link will
|
|
|
|
* never enter specific states. Note that if the BIOS didn't grant ASPM
|
|
|
|
* control to the OS, this does nothing because we can't touch the LNKCTL
|
|
|
|
* register.
|
|
|
|
*
|
|
|
|
* @pdev: PCI device
|
|
|
|
* @state: ASPM link state to disable
|
|
|
|
*/
|
2011-05-13 08:11:47 +08:00
|
|
|
void pci_disable_link_state(struct pci_dev *pdev, int state)
|
|
|
|
{
|
2015-05-21 01:13:05 +08:00
|
|
|
__pci_disable_link_state(pdev, state, true);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(pci_disable_link_state);
|
|
|
|
|
|
|
|
static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
|
|
|
|
{
|
|
|
|
int i;
|
2009-08-19 10:01:37 +08:00
|
|
|
struct pcie_link_state *link;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2011-03-21 11:29:14 +08:00
|
|
|
if (aspm_disabled)
|
|
|
|
return -EPERM;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
for (i = 0; i < ARRAY_SIZE(policy_str); i++)
|
|
|
|
if (!strncmp(val, policy_str[i], strlen(policy_str[i])))
|
|
|
|
break;
|
|
|
|
if (i >= ARRAY_SIZE(policy_str))
|
|
|
|
return -EINVAL;
|
|
|
|
if (i == aspm_policy)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
|
|
|
aspm_policy = i;
|
2009-08-19 10:01:37 +08:00
|
|
|
list_for_each_entry(link, &link_list, sibling) {
|
|
|
|
pcie_config_aspm_link(link, policy_to_aspm_state(link));
|
|
|
|
pcie_set_clkpm(link, policy_to_clkpm_state(link));
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int pcie_aspm_get_policy(char *buffer, struct kernel_param *kp)
|
|
|
|
{
|
|
|
|
int i, cnt = 0;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(policy_str); i++)
|
|
|
|
if (i == aspm_policy)
|
|
|
|
cnt += sprintf(buffer + cnt, "[%s] ", policy_str[i]);
|
|
|
|
else
|
|
|
|
cnt += sprintf(buffer + cnt, "%s ", policy_str[i]);
|
|
|
|
return cnt;
|
|
|
|
}
|
|
|
|
|
|
|
|
module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy,
|
|
|
|
NULL, 0644);
|
|
|
|
|
|
|
|
#ifdef CONFIG_PCIEASPM_DEBUG
|
|
|
|
static ssize_t link_state_show(struct device *dev,
|
|
|
|
struct device_attribute *attr,
|
|
|
|
char *buf)
|
|
|
|
{
|
|
|
|
struct pci_dev *pci_device = to_pci_dev(dev);
|
|
|
|
struct pcie_link_state *link_state = pci_device->link_state;
|
|
|
|
|
2009-05-13 11:12:43 +08:00
|
|
|
return sprintf(buf, "%d\n", link_state->aspm_enabled);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t link_state_store(struct device *dev,
|
|
|
|
struct device_attribute *attr,
|
|
|
|
const char *buf,
|
|
|
|
size_t n)
|
|
|
|
{
|
2009-05-13 11:17:44 +08:00
|
|
|
struct pci_dev *pdev = to_pci_dev(dev);
|
2009-08-19 10:01:37 +08:00
|
|
|
struct pcie_link_state *link, *root = pdev->link_state->root;
|
2015-11-20 00:05:35 +08:00
|
|
|
u32 state;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2011-03-21 11:29:14 +08:00
|
|
|
if (aspm_disabled)
|
|
|
|
return -EPERM;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2015-11-20 00:05:35 +08:00
|
|
|
if (kstrtouint(buf, 10, &state))
|
|
|
|
return -EINVAL;
|
|
|
|
if ((state & ~ASPM_STATE_ALL) != 0)
|
|
|
|
return -EINVAL;
|
2009-08-19 10:02:13 +08:00
|
|
|
|
2009-08-19 10:01:37 +08:00
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
|
|
|
list_for_each_entry(link, &link_list, sibling) {
|
|
|
|
if (link->root != root)
|
|
|
|
continue;
|
|
|
|
pcie_config_aspm_link(link, state);
|
|
|
|
}
|
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
return n;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t clk_ctl_show(struct device *dev,
|
|
|
|
struct device_attribute *attr,
|
|
|
|
char *buf)
|
|
|
|
{
|
|
|
|
struct pci_dev *pci_device = to_pci_dev(dev);
|
|
|
|
struct pcie_link_state *link_state = pci_device->link_state;
|
|
|
|
|
2009-05-13 11:15:38 +08:00
|
|
|
return sprintf(buf, "%d\n", link_state->clkpm_enabled);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t clk_ctl_store(struct device *dev,
|
|
|
|
struct device_attribute *attr,
|
|
|
|
const char *buf,
|
|
|
|
size_t n)
|
|
|
|
{
|
2009-05-13 11:20:10 +08:00
|
|
|
struct pci_dev *pdev = to_pci_dev(dev);
|
2014-12-06 07:02:42 +08:00
|
|
|
bool state;
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2014-12-06 07:02:42 +08:00
|
|
|
if (strtobool(buf, &state))
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
down_read(&pci_bus_sem);
|
|
|
|
mutex_lock(&aspm_lock);
|
2014-12-06 07:02:42 +08:00
|
|
|
pcie_set_clkpm_nocheck(pdev->link_state, state);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
mutex_unlock(&aspm_lock);
|
|
|
|
up_read(&pci_bus_sem);
|
|
|
|
|
|
|
|
return n;
|
|
|
|
}
|
|
|
|
|
PCI/ASPM: Use permission-specific DEVICE_ATTR variants
Use DEVICE_ATTR_RW for read-write attributes. This simplifies the source
code, improves readability, and reduces the chance of inconsistencies.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@rw@
declarer name DEVICE_ATTR;
identifier x,x_show,x_store;
@@
DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store);
@script:ocaml@
x << rw.x;
x_show << rw.x_show;
x_store << rw.x_store;
@@
if not (x^"_show" = x_show && x^"_store" = x_store)
then Coccilib.include_match false
@@
declarer name DEVICE_ATTR_RW;
identifier rw.x,rw.x_show,rw.x_store;
@@
- DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store);
+ DEVICE_ATTR_RW(x);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-10-30 03:37:07 +08:00
|
|
|
static DEVICE_ATTR_RW(link_state);
|
|
|
|
static DEVICE_ATTR_RW(clk_ctl);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
|
|
|
static char power_group[] = "power";
|
|
|
|
void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
|
|
|
|
{
|
|
|
|
struct pcie_link_state *link_state = pdev->link_state;
|
|
|
|
|
2015-05-19 11:41:34 +08:00
|
|
|
if (!link_state)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
|
|
|
|
2009-05-13 11:12:43 +08:00
|
|
|
if (link_state->aspm_support)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
sysfs_add_file_to_group(&pdev->dev.kobj,
|
|
|
|
&dev_attr_link_state.attr, power_group);
|
2009-05-13 11:15:38 +08:00
|
|
|
if (link_state->clkpm_capable)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
sysfs_add_file_to_group(&pdev->dev.kobj,
|
|
|
|
&dev_attr_clk_ctl.attr, power_group);
|
|
|
|
}
|
|
|
|
|
|
|
|
void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
|
|
|
|
{
|
|
|
|
struct pcie_link_state *link_state = pdev->link_state;
|
|
|
|
|
2015-05-19 11:41:34 +08:00
|
|
|
if (!link_state)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return;
|
|
|
|
|
2009-05-13 11:12:43 +08:00
|
|
|
if (link_state->aspm_support)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
sysfs_remove_file_from_group(&pdev->dev.kobj,
|
|
|
|
&dev_attr_link_state.attr, power_group);
|
2009-05-13 11:15:38 +08:00
|
|
|
if (link_state->clkpm_capable)
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
sysfs_remove_file_from_group(&pdev->dev.kobj,
|
|
|
|
&dev_attr_clk_ctl.attr, power_group);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
static int __init pcie_aspm_disable(char *str)
|
|
|
|
{
|
2008-07-23 10:32:42 +08:00
|
|
|
if (!strcmp(str, "off")) {
|
2011-11-11 05:38:33 +08:00
|
|
|
aspm_policy = POLICY_DEFAULT;
|
2008-07-23 10:32:42 +08:00
|
|
|
aspm_disabled = 1;
|
2011-03-05 20:21:51 +08:00
|
|
|
aspm_support_enabled = false;
|
2008-07-23 10:32:42 +08:00
|
|
|
printk(KERN_INFO "PCIe ASPM is disabled\n");
|
|
|
|
} else if (!strcmp(str, "force")) {
|
|
|
|
aspm_force = 1;
|
2011-06-28 14:15:05 +08:00
|
|
|
printk(KERN_INFO "PCIe ASPM is forcibly enabled\n");
|
2008-07-23 10:32:42 +08:00
|
|
|
}
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2008-07-23 10:32:42 +08:00
|
|
|
__setup("pcie_aspm=", pcie_aspm_disable);
|
PCI: add PCI Express ASPM support
PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.
This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.
In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-25 09:46:41 +08:00
|
|
|
|
2008-07-23 10:32:24 +08:00
|
|
|
void pcie_no_aspm(void)
|
|
|
|
{
|
2011-11-11 05:38:33 +08:00
|
|
|
/*
|
|
|
|
* Disabling ASPM is intended to prevent the kernel from modifying
|
|
|
|
* existing hardware state, not to clear existing state. To that end:
|
|
|
|
* (a) set policy to POLICY_DEFAULT in order to avoid changing state
|
|
|
|
* (b) prevent userspace from changing policy
|
|
|
|
*/
|
|
|
|
if (!aspm_force) {
|
|
|
|
aspm_policy = POLICY_DEFAULT;
|
2008-07-23 10:32:42 +08:00
|
|
|
aspm_disabled = 1;
|
2011-11-11 05:38:33 +08:00
|
|
|
}
|
2008-07-23 10:32:24 +08:00
|
|
|
}
|
|
|
|
|
2011-03-05 20:21:51 +08:00
|
|
|
bool pcie_aspm_support_enabled(void)
|
|
|
|
{
|
|
|
|
return aspm_support_enabled;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(pcie_aspm_support_enabled);
|