Commit Graph

24 Commits

Author SHA1 Message Date
Lukas Wunner f9a6c8ad49 PCI/ERR: Reduce compile time for CONFIG_PCIEAER=n
The sole non-static function in err.c, pcie_do_recovery(), is only
called from:

* aer.c (if CONFIG_PCIEAER=y)
* dpc.c (if CONFIG_PCIE_DPC=y, which depends on CONFIG_PCIEAER)
* edr.c (if CONFIG_PCIE_EDR=y, which depends on CONFIG_PCIE_DPC)

Thus, err.c need not be compiled if CONFIG_PCIEAER=n.

Also, pci_uevent_ers() and pcie_clear_device_status(), which are called
from err.c, can be #ifdef'ed away unless CONFIG_PCIEAER=y.

Since x86_64_defconfig doesn't enable CONFIG_PCIEAER, this change may
slightly reduce compile time for anyone doing a test build with that
config.

Link: https://lore.kernel.org/r/98f9041151268c1c035ab64cca320ad86803f64a.1627638184.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-10-16 09:16:59 -05:00
Bjorn Helgaas b4c7d2076b PCI/LINK: Remove bandwidth notification
The PCIe Bandwidth Change Notification feature logs messages when the link
bandwidth changes.  Some users have reported that these messages occur
often enough to significantly reduce NVMe performance.  GPUs also seem to
generate these messages.

We don't know why the link bandwidth changes, but in the reported cases
there's no indication that it's caused by hardware failures.

Remove the bandwidth change notifications for now.  Hopefully we can add
this back when we have a better understanding of why this happens and how
we can make the messages useful instead of overwhelming.

Link: https://lore.kernel.org/r/20200115221008.GA191037@google.com/
Link: https://lore.kernel.org/r/155605909349.3575.13433421148215616375.stgit@gimli.home/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206197
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-02-02 14:25:11 -06:00
Sean V Kelley 9065563198 PCI/ERR: Cache RCEC EA Capability offset in pci_init_capabilities()
Extend support for Root Complex Event Collectors by decoding and caching
the RCEC Endpoint Association Extended Capabilities when enumerating. Use
that cached information for later error source reporting. See PCIe r5.0,
sec 7.9.10.

Co-developed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Link: https://lore.kernel.org/r/20201121001036.8560-4-sean.v.kelley@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # non-native/no RCEC
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-12-04 11:18:50 -06:00
Kuppuswamy Sathyanarayanan ac1c8e35a3 PCI/DPC: Add Error Disconnect Recover (EDR) support
Error Disconnect Recover (EDR) is a feature that allows ACPI firmware to
notify OSPM that a device has been disconnected due to an error condition
(ACPI v6.3, sec 5.6.6).  OSPM advertises its support for EDR on PCI devices
via _OSC (see [1], sec 4.5.1, table 4-4).  The OSPM EDR notify handler
should invalidate software state associated with disconnected devices and
may attempt to recover them.  OSPM communicates the status of recovery to
the firmware via _OST (sec 6.3.5.2).

For PCIe, firmware may use Downstream Port Containment (DPC) to support
EDR.  Per [1], sec 4.5.1, table 4-6, even if firmware has retained control
of DPC, OSPM may read/write DPC control and status registers during the EDR
notification processing window, i.e., from the time it receives an EDR
notification until it clears the DPC Trigger Status.

Note that per [1], sec 4.5.1 and 4.5.2.4,

  1. If the OS supports EDR, it should advertise that to firmware by
     setting OSC_PCI_EDR_SUPPORT in _OSC Support.

  2. If the OS sets OSC_PCI_EXPRESS_DPC_CONTROL in _OSC Control to request
     control of the DPC capability, it must also set OSC_PCI_EDR_SUPPORT in
     _OSC Support.

Add an EDR notify handler to attempt recovery.

[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
    affecting PCI Firmware Specification, Rev. 3.2
    https://members.pcisig.com/wg/PCI-SIG/document/12888

[bhelgaas: squash add/enable patches into one]
Link: https://lore.kernel.org/r/90f91fe6d25c13f9d2255d2ce97ca15be307e1bb.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
2020-03-28 13:19:04 -05:00
Keith Busch 2078e1e7f7 PCI/LINK: Add Kconfig option (default off)
e8303bb7a7 ("PCI/LINK: Report degraded links via link bandwidth
notification") added dmesg logging whenever a link changes speed or width
to a state that is considered degraded.  Unfortunately, it cannot
differentiate signal integrity-related link changes from those
intentionally initiated by an endpoint driver, including drivers that may
live in userspace or VMs when making use of vfio-pci.  Some GPU drivers
actively manage the link state to save power, which generates a stream of
messages like this:

  vfio-pci 0000:07:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x16 link at 0000:00:02.0 (capable of 64.000 Gb/s with 5 GT/s x16 link)

Since we can't distinguish the intentional changes from the signal
integrity issues, leave the reporting turned off by default.  Add a Kconfig
option to turn it on if desired.

Fixes: e8303bb7a7 ("PCI/LINK: Report degraded links via link bandwidth notification")
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-05-02 08:34:32 -05:00
Alexandru Gagniuc e8303bb7a7 PCI/LINK: Report degraded links via link bandwidth notification
A warning is generated when a PCIe device is probed with a degraded link,
but there was no similar mechanism to warn when the link becomes degraded
after probing.  The Link Bandwidth Notification provides this mechanism.

Use the Link Bandwidth Management Interrupt to detect bandwidth changes,
and rescan the bandwidth, looking for the weakest point.  This is the same
logic used in probe().

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
2019-03-05 15:04:13 -06:00
Bjorn Helgaas 4696b828ca PCI/AER: Hoist aerdrv.c, aer_inject.c up to drivers/pci/pcie/
Hoist aerdrv.c, aer_inject.c up to drivers/pci/pcie/ so they're next to
other PCIe service drivers.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-06-11 08:11:39 -05:00
Oza Pawandeep 2e28bc84cf PCI/AER: Factor out error reporting to drivers/pci/pcie/err.c
Move the error reporting callbacks from aerdrv_core.c to err.c, where they
can be used by DPC in addition to AER.

As part of aerdrv_core.c, these callbacks were built under CONFIG_PCIEAER.
Moving them to the new err.c means they will now be built under
CONFIG_PCIEPORTBUS, so adjust the definition of pci_uevent_ers() to match.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: in reset_link(), initialize "driver" even if CONFIG_PCIEAER is
unset, update pci_uevent_ers() #ifdef wrapper]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-05-17 16:48:23 -05:00
Bjorn Helgaas 64ae499cf2 Merge branch 'pci/portdrv'
- move pcieport_if.h to drivers/pci/pcie/ to encapsulate it (Frederick
    Lawler)

  - merge pcieport_if.h into portdrv.h (Bjorn Helgaas)

  - move workaround for BIOS PME issue from portdrv to PCI core (Bjorn
    Helgaas)

  - completely disable portdrv with "pcie_ports=compat" (Bjorn Helgaas)

  - remove portdrv link order dependency (Bjorn Helgaas)

  - remove support for unused VC portdrv service (Bjorn Helgaas)

  - simplify portdrv feature permission checking (Bjorn Helgaas)

  - remove "pcie_hp=nomsi" parameter (use "pci=nomsi" instead) (Bjorn
    Helgaas)

  - remove unnecessary "pcie_ports=auto" parameter (Bjorn Helgaas)

  - use cached AER capability offset (Frederick Lawler)

  - don't enable DPC if BIOS hasn't granted AER control (Mika Westerberg)

  - rename pcie-dpc.c to dpc.c (Bjorn Helgaas)

* pci/portdrv:
  PCI/DPC: Rename from pcie-dpc.c to dpc.c
  PCI/DPC: Do not enable DPC if AER control is not allowed by the BIOS
  PCI/AER: Use cached AER Capability offset
  PCI/portdrv: Rename and reverse sense of pcie_ports_auto
  PCI/portdrv: Encapsulate pcie_ports_auto inside the port driver
  PCI/portdrv: Remove unnecessary "pcie_ports=auto" parameter
  PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter
  PCI/portdrv: Remove unnecessary include of <linux/pci-aspm.h>
  PCI/portdrv: Simplify PCIe feature permission checking
  PCI/portdrv: Remove unused PCIE_PORT_SERVICE_VC
  PCI/portdrv: Remove pcie_port_bus_type link order dependency
  PCI/portdrv: Disable port driver in compat mode
  PCI/PM: Clear PCIe PME Status bit for Root Complex Event Collectors
  PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver
  PCI/PM: Move pcie_clear_root_pme_status() to core
  PCI/portdrv: Merge pcieport_if.h into portdrv.h
  PCI/portdrv: Move pcieport_if.h to drivers/pci/pcie/

Conflicts:
	drivers/pci/pcie/Makefile
	drivers/pci/pcie/portdrv.h
2018-04-04 13:27:58 -05:00
Bjorn Helgaas e02602bd76 PCI/DPC: Rename from pcie-dpc.c to dpc.c
Rename pcie-dpc.c to dpc.c.  The path "drivers/pci/pcie/pcie-dpc.c" has
more occurrences of "pci" than necessary.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-31 17:48:57 -05:00
Bjorn Helgaas 02bfeb4842 PCI/portdrv: Simplify PCIe feature permission checking
Some PCIe features (AER, DPC, hotplug, PME) can be managed by either the
platform firmware or the OS, so the host bridge driver may have to request
permission from the platform before using them.  On ACPI systems, this is
done by negotiate_os_control() in acpi_pci_root_add().

The PCIe port driver later uses pcie_port_platform_notify() and
pcie_port_acpi_setup() to figure out whether it can use these features.
But all we need is a single bit for each service, so these interfaces are
needlessly complicated.

Simplify this by adding bits in the struct pci_host_bridge to show when the
OS has permission to use each feature:

  + unsigned int native_aer:1;       /* OS may use PCIe AER */
  + unsigned int native_hotplug:1;   /* OS may use PCIe hotplug */
  + unsigned int native_pme:1;       /* OS may use PCIe PME */

These are set when we create a host bridge, and the host bridge driver can
clear the bits corresponding to any feature the platform doesn't want us to
use.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-03-30 17:26:54 -05:00
Bjorn Helgaas c6c889d932 PCI/portdrv: Remove pcie_port_bus_type link order dependency
The pcie_port_bus_type must be registered before drivers that depend on it
can be registered.  Those drivers include:

  pcied_init()                # PCIe native hotplug driver
  aer_service_init()          # AER driver
  dpc_service_init()          # DPC driver
  pcie_pme_service_init()     # PME driver

Previously we registered pcie_port_bus_type from pcie_portdrv_init(), a
device_initcall.  The callers of pcie_port_service_register() (above) are
also device_initcalls.  This is fragile because the device_initcall
ordering depends on link order, which is not explicit.

Register pcie_port_bus_type from pci_driver_init() along with pci_bus_type.
This removes the link order dependency between portdrv and the pciehp, AER,
DPC, and PCIe PME drivers.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-03-30 17:26:53 -05:00
Bjorn Helgaas 3133e6dd07 PCI: Tidy Makefiles
Indent things so they line up neatly and remove extra blank lines and
superfluous comments.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-19 14:20:41 -05:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Jonathan Yong 9bb04a0c4e PCI: Add Precision Time Measurement (PTM) support
Add Precision Time Measurement (PTM) support (see PCIe r3.1, sec 6.22).

Enable PTM on PTM Root devices and switch ports.  This does not enable PTM
on endpoints.

There currently are no PTM-capable devices on the market, but it is
expected to be supported by the Intel Apollo Lake platform.

[bhelgaas: complete rework]
Signed-off-by: Jonathan Yong <jonathan.yong@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-08-15 13:44:08 -05:00
Keith Busch 26e5157133 PCI: Add Downstream Port Containment driver
Add driver for the PCI Express Downstream Port Containment extended
capability.  DPC is an optional capability to contain uncorrectable errors
below a port.

For more information on DPC, please see PCI Express Base Specification
Revision 4, section 7.31, or view the PCI-SIG DPC ECN here:

  https://pcisig.com/sites/default/files/specification_documents/ECN_DPC_2012-02-09_finalized.pdf

When a DPC event is triggered, the hardware disables downstream links, so
the DPC driver schedules removal for all devices below this port.  This may
happen concurrently with a PCIe hotplug driver if enabled.  When all
downstream devices are removed and the link state transitions to disabled,
the DPC driver clears the DPC status and interrupt bits so the link may
retrain for a newly connected device.

[bhelgaas: clear (not set) DPC_CTL bits on remove, whitespace cleanup]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
2016-05-03 10:39:24 -05:00
Rafael J. Wysocki 271fb719cc PCI: PCIe: Move PCIe PME code to the pcie directory
The PCIe PME code only consists of one file, so it doesn't need to
occupy its own directory.  Move it to drivers/pci/pcie/pme.c and
remove the contents of drivers/pci/pcie/pme .

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-24 13:47:48 -07:00
Rafael J. Wysocki 28eb5f274a PCI: PCIe: Ask BIOS for control of all native services at once
After commit 852972acff (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways.  First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time.  Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen.  For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).

Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously.  In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to.  If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.

Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).

Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-24 13:47:33 -07:00
Rafael J. Wysocki c7f486567c PCI PM: PCIe PME root port service driver
PCIe native PME detection mechanism is based on interrupts generated
by root ports or event collectors every time a PCIe device sends a
PME message upstream.

Once a PME message has been sent by an endpoint device and received
by its root port (or event collector in the case of root complex
integrated endpoints), the Requester ID from the message header is
registered in the root port's Root Status register.  At the same
time, the PME Status bit of the Root Status register is set to
indicate that there's a PME to handle.  If PCIe PME interrupt is
enabled for the root port, it generates an interrupt once the PME
Status has been set.  After receiving the interrupt, the kernel can
identify the PCIe device that generated the PME using the Requester
ID from the root port's Root Status register. [For details, see PCI
Express Base Specification, Rev. 2.0.]

Implement a driver for the PCIe PME root port service working in
accordance with the above description.

Based on a patch from Shaohua Li <shaohua.li@intel.com>.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-22 16:20:31 -08:00
Shaohua Li 7d715a6c1a 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>
2008-04-20 21:47:03 -07:00
Greg Kroah-Hartman cc3a1378b4 Revert "PCI: PCIE ASPM support"
This reverts commit 6c723d5bd8.

It caused build errors on non-x86 platforms, config file confusion, and
even some boot errors on some x86-64 boxes.  All around, not quite ready
for prime-time :(

Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-02 11:32:01 -08:00
Shaohua Li 6c723d5bd8 PCI: PCIE 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.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 15:04:30 -08:00
Zhang, Yanmin 6c2b374d74 PCI-Express AER implemetation: AER core and aerdriver
Patch 3 implements the core part of PCI-Express AER and aerdrv
port service driver.

When a root port service device is probed, the aerdrv will call
request_irq to register irq handler for AER error interrupt.

When a device sends an PCI-Express error message to the root port,
the root port will trigger an interrupt, by either MSI or IO-APIC,
then kernel would run the irq handler. The handler collects root
error status register and schedules a work. The work will call
the core part to process the error based on its type
(Correctable/non-fatal/fatal).

As for Correctable errors, the patch chooses to just clear the correctable
error status register of the device.

As for the non-fatal error, the patch follows generic PCI error handler
rules to call the error callback functions of the endpoint's driver. If
the device is a bridge, the patch chooses to broadcast the error to
downstream devices.

As for the fatal error, the patch resets the pci-express link and
follows generic PCI error handler rules to call the error callback
functions of the endpoint's driver. If the device is a bridge, the patch
chooses to broadcast the error to downstream devices.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-26 17:43:53 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00