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OpenCloudOS-Kernel/arch/powerpc/platforms/pseries/eeh.c

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/*
* Copyright IBM Corporation 2001, 2005, 2006
* Copyright Dave Engebretsen & Todd Inglett 2001
* Copyright Linas Vepstas 2005, 2006
* Copyright 2001-2012 IBM Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/atomic.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
#include <asm/rtas.h>
/** Overview:
* EEH, or "Extended Error Handling" is a PCI bridge technology for
* dealing with PCI bus errors that can't be dealt with within the
* usual PCI framework, except by check-stopping the CPU. Systems
* that are designed for high-availability/reliability cannot afford
* to crash due to a "mere" PCI error, thus the need for EEH.
* An EEH-capable bridge operates by converting a detected error
* into a "slot freeze", taking the PCI adapter off-line, making
* the slot behave, from the OS'es point of view, as if the slot
* were "empty": all reads return 0xff's and all writes are silently
* ignored. EEH slot isolation events can be triggered by parity
* errors on the address or data busses (e.g. during posted writes),
* which in turn might be caused by low voltage on the bus, dust,
* vibration, humidity, radioactivity or plain-old failed hardware.
*
* Note, however, that one of the leading causes of EEH slot
* freeze events are buggy device drivers, buggy device microcode,
* or buggy device hardware. This is because any attempt by the
* device to bus-master data to a memory address that is not
* assigned to the device will trigger a slot freeze. (The idea
* is to prevent devices-gone-wild from corrupting system memory).
* Buggy hardware/drivers will have a miserable time co-existing
* with EEH.
*
* Ideally, a PCI device driver, when suspecting that an isolation
* event has occurred (e.g. by reading 0xff's), will then ask EEH
* whether this is the case, and then take appropriate steps to
* reset the PCI slot, the PCI device, and then resume operations.
* However, until that day, the checking is done here, with the
* eeh_check_failure() routine embedded in the MMIO macros. If
* the slot is found to be isolated, an "EEH Event" is synthesized
* and sent out for processing.
*/
/* If a device driver keeps reading an MMIO register in an interrupt
* handler after a slot isolation event, it might be broken.
* This sets the threshold for how many read attempts we allow
* before printing an error message.
*/
#define EEH_MAX_FAILS 2100000
/* Time to wait for a PCI slot to report status, in milliseconds */
#define PCI_BUS_RESET_WAIT_MSEC (60*1000)
/* Platform dependent EEH operations */
struct eeh_ops *eeh_ops = NULL;
int eeh_subsystem_enabled;
EXPORT_SYMBOL(eeh_subsystem_enabled);
/* Lock to avoid races due to multiple reports of an error */
static DEFINE_RAW_SPINLOCK(confirm_error_lock);
/* Buffer for reporting pci register dumps. Its here in BSS, and
* not dynamically alloced, so that it ends up in RMO where RTAS
* can access it.
*/
#define EEH_PCI_REGS_LOG_LEN 4096
static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN];
/*
* The struct is used to maintain the EEH global statistic
* information. Besides, the EEH global statistics will be
* exported to user space through procfs
*/
struct eeh_stats {
u64 no_device; /* PCI device not found */
u64 no_dn; /* OF node not found */
u64 no_cfg_addr; /* Config address not found */
u64 ignored_check; /* EEH check skipped */
u64 total_mmio_ffs; /* Total EEH checks */
u64 false_positives; /* Unnecessary EEH checks */
u64 slot_resets; /* PE reset */
};
static struct eeh_stats eeh_stats;
#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
/**
* eeh_gather_pci_data - Copy assorted PCI config space registers to buff
* @edev: device to report data for
* @buf: point to buffer in which to log
* @len: amount of room in buffer
*
* This routine captures assorted PCI configuration space data,
* and puts them into a buffer for RTAS error logging.
*/
static size_t eeh_gather_pci_data(struct eeh_dev *edev, char * buf, size_t len)
{
struct device_node *dn = eeh_dev_to_of_node(edev);
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
u32 cfg;
int cap, i;
int n = 0;
n += scnprintf(buf+n, len-n, "%s\n", dn->full_name);
printk(KERN_WARNING "EEH: of node=%s\n", dn->full_name);
eeh_ops->read_config(dn, PCI_VENDOR_ID, 4, &cfg);
n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg);
printk(KERN_WARNING "EEH: PCI device/vendor: %08x\n", cfg);
eeh_ops->read_config(dn, PCI_COMMAND, 4, &cfg);
n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI cmd/status register: %08x\n", cfg);
if (!dev) {
printk(KERN_WARNING "EEH: no PCI device for this of node\n");
return n;
}
/* Gather bridge-specific registers */
if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) {
eeh_ops->read_config(dn, PCI_SEC_STATUS, 2, &cfg);
n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg);
printk(KERN_WARNING "EEH: Bridge secondary status: %04x\n", cfg);
eeh_ops->read_config(dn, PCI_BRIDGE_CONTROL, 2, &cfg);
n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg);
printk(KERN_WARNING "EEH: Bridge control: %04x\n", cfg);
}
/* Dump out the PCI-X command and status regs */
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (cap) {
eeh_ops->read_config(dn, cap, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI-X cmd: %08x\n", cfg);
eeh_ops->read_config(dn, cap+4, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI-X status: %08x\n", cfg);
}
/* If PCI-E capable, dump PCI-E cap 10, and the AER */
cap = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e cap10:\n");
printk(KERN_WARNING
"EEH: PCI-E capabilities and status follow:\n");
for (i=0; i<=8; i++) {
eeh_ops->read_config(dn, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
printk(KERN_WARNING "EEH: PCI-E %02x: %08x\n", i, cfg);
}
cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e AER:\n");
printk(KERN_WARNING
"EEH: PCI-E AER capability register set follows:\n");
for (i=0; i<14; i++) {
eeh_ops->read_config(dn, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
printk(KERN_WARNING "EEH: PCI-E AER %02x: %08x\n", i, cfg);
}
}
}
/* Gather status on devices under the bridge */
if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) {
struct device_node *child;
for_each_child_of_node(dn, child) {
if (of_node_to_eeh_dev(child))
n += eeh_gather_pci_data(of_node_to_eeh_dev(child), buf+n, len-n);
}
}
return n;
}
/**
* eeh_slot_error_detail - Generate combined log including driver log and error log
* @edev: device to report error log for
* @severity: temporary or permanent error log
*
* This routine should be called to generate the combined log, which
* is comprised of driver log and error log. The driver log is figured
* out from the config space of the corresponding PCI device, while
* the error log is fetched through platform dependent function call.
*/
void eeh_slot_error_detail(struct eeh_dev *edev, int severity)
{
size_t loglen = 0;
pci_regs_buf[0] = 0;
eeh_pci_enable(edev, EEH_OPT_THAW_MMIO);
eeh_ops->configure_bridge(eeh_dev_to_of_node(edev));
eeh_restore_bars(edev);
loglen = eeh_gather_pci_data(edev, pci_regs_buf, EEH_PCI_REGS_LOG_LEN);
eeh_ops->get_log(eeh_dev_to_of_node(edev), severity, pci_regs_buf, loglen);
}
/**
* eeh_token_to_phys - Convert EEH address token to phys address
* @token: I/O token, should be address in the form 0xA....
*
* This routine should be called to convert virtual I/O address
* to physical one.
*/
static inline unsigned long eeh_token_to_phys(unsigned long token)
{
pte_t *ptep;
unsigned long pa;
ptep = find_linux_pte(init_mm.pgd, token);
if (!ptep)
return token;
pa = pte_pfn(*ptep) << PAGE_SHIFT;
return pa | (token & (PAGE_SIZE-1));
}
/**
* eeh_find_device_pe - Retrieve the PE for the given device
* @dn: device node
*
* Return the PE under which this device lies
*/
struct device_node *eeh_find_device_pe(struct device_node *dn)
{
while (dn->parent && of_node_to_eeh_dev(dn->parent) &&
(of_node_to_eeh_dev(dn->parent)->mode & EEH_MODE_SUPPORTED)) {
dn = dn->parent;
}
return dn;
}
/**
* __eeh_mark_slot - Mark all child devices as failed
* @parent: parent device
* @mode_flag: failure flag
*
* Mark all devices that are children of this device as failed.
* Mark the device driver too, so that it can see the failure
* immediately; this is critical, since some drivers poll
* status registers in interrupts ... If a driver is polling,
* and the slot is frozen, then the driver can deadlock in
* an interrupt context, which is bad.
*/
static void __eeh_mark_slot(struct device_node *parent, int mode_flag)
{
struct device_node *dn;
for_each_child_of_node(parent, dn) {
if (of_node_to_eeh_dev(dn)) {
/* Mark the pci device driver too */
struct pci_dev *dev = of_node_to_eeh_dev(dn)->pdev;
of_node_to_eeh_dev(dn)->mode |= mode_flag;
if (dev && dev->driver)
dev->error_state = pci_channel_io_frozen;
__eeh_mark_slot(dn, mode_flag);
}
}
}
/**
* eeh_mark_slot - Mark the indicated device and its children as failed
* @dn: parent device
* @mode_flag: failure flag
*
* Mark the indicated device and its child devices as failed.
* The device drivers are marked as failed as well.
*/
void eeh_mark_slot(struct device_node *dn, int mode_flag)
{
struct pci_dev *dev;
dn = eeh_find_device_pe(dn);
/* Back up one, since config addrs might be shared */
if (!pcibios_find_pci_bus(dn) && of_node_to_eeh_dev(dn->parent))
dn = dn->parent;
of_node_to_eeh_dev(dn)->mode |= mode_flag;
/* Mark the pci device too */
dev = of_node_to_eeh_dev(dn)->pdev;
if (dev)
dev->error_state = pci_channel_io_frozen;
__eeh_mark_slot(dn, mode_flag);
}
/**
* __eeh_clear_slot - Clear failure flag for the child devices
* @parent: parent device
* @mode_flag: flag to be cleared
*
* Clear failure flag for the child devices.
*/
static void __eeh_clear_slot(struct device_node *parent, int mode_flag)
{
struct device_node *dn;
for_each_child_of_node(parent, dn) {
if (of_node_to_eeh_dev(dn)) {
of_node_to_eeh_dev(dn)->mode &= ~mode_flag;
of_node_to_eeh_dev(dn)->check_count = 0;
__eeh_clear_slot(dn, mode_flag);
}
}
}
/**
* eeh_clear_slot - Clear failure flag for the indicated device and its children
* @dn: parent device
* @mode_flag: flag to be cleared
*
* Clear failure flag for the indicated device and its children.
*/
void eeh_clear_slot(struct device_node *dn, int mode_flag)
{
unsigned long flags;
raw_spin_lock_irqsave(&confirm_error_lock, flags);
dn = eeh_find_device_pe(dn);
/* Back up one, since config addrs might be shared */
if (!pcibios_find_pci_bus(dn) && of_node_to_eeh_dev(dn->parent))
dn = dn->parent;
of_node_to_eeh_dev(dn)->mode &= ~mode_flag;
of_node_to_eeh_dev(dn)->check_count = 0;
__eeh_clear_slot(dn, mode_flag);
raw_spin_unlock_irqrestore(&confirm_error_lock, flags);
}
/**
* eeh_dn_check_failure - Check if all 1's data is due to EEH slot freeze
* @dn: device node
* @dev: pci device, if known
*
* Check for an EEH failure for the given device node. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze. This routine
* will query firmware for the EEH status.
*
* Returns 0 if there has not been an EEH error; otherwise returns
* a non-zero value and queues up a slot isolation event notification.
*
* It is safe to call this routine in an interrupt context.
*/
int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
{
int ret;
unsigned long flags;
struct eeh_dev *edev;
int rc = 0;
const char *location;
eeh_stats.total_mmio_ffs++;
if (!eeh_subsystem_enabled)
return 0;
if (!dn) {
eeh_stats.no_dn++;
return 0;
}
dn = eeh_find_device_pe(dn);
edev = of_node_to_eeh_dev(dn);
/* Access to IO BARs might get this far and still not want checking. */
if (!(edev->mode & EEH_MODE_SUPPORTED) ||
edev->mode & EEH_MODE_NOCHECK) {
eeh_stats.ignored_check++;
pr_debug("EEH: Ignored check (%x) for %s %s\n",
edev->mode, eeh_pci_name(dev), dn->full_name);
return 0;
}
if (!edev->config_addr && !edev->pe_config_addr) {
eeh_stats.no_cfg_addr++;
return 0;
}
/* If we already have a pending isolation event for this
* slot, we know it's bad already, we don't need to check.
* Do this checking under a lock; as multiple PCI devices
* in one slot might report errors simultaneously, and we
* only want one error recovery routine running.
*/
raw_spin_lock_irqsave(&confirm_error_lock, flags);
rc = 1;
if (edev->mode & EEH_MODE_ISOLATED) {
edev->check_count++;
if (edev->check_count % EEH_MAX_FAILS == 0) {
location = of_get_property(dn, "ibm,loc-code", NULL);
printk(KERN_ERR "EEH: %d reads ignored for recovering device at "
"location=%s driver=%s pci addr=%s\n",
edev->check_count, location,
eeh_driver_name(dev), eeh_pci_name(dev));
printk(KERN_ERR "EEH: Might be infinite loop in %s driver\n",
eeh_driver_name(dev));
dump_stack();
}
goto dn_unlock;
}
/*
* Now test for an EEH failure. This is VERY expensive.
* Note that the eeh_config_addr may be a parent device
* in the case of a device behind a bridge, or it may be
* function zero of a multi-function device.
* In any case they must share a common PHB.
*/
ret = eeh_ops->get_state(dn, NULL);
/* Note that config-io to empty slots may fail;
* they are empty when they don't have children.
* We will punt with the following conditions: Failure to get
* PE's state, EEH not support and Permanently unavailable
* state, PE is in good state.
*/
if ((ret < 0) ||
(ret == EEH_STATE_NOT_SUPPORT) ||
(ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) ==
(EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) {
eeh_stats.false_positives++;
edev->false_positives ++;
rc = 0;
goto dn_unlock;
}
eeh_stats.slot_resets++;
/* Avoid repeated reports of this failure, including problems
* with other functions on this device, and functions under
* bridges.
*/
eeh_mark_slot(dn, EEH_MODE_ISOLATED);
raw_spin_unlock_irqrestore(&confirm_error_lock, flags);
eeh_send_failure_event(edev);
/* Most EEH events are due to device driver bugs. Having
* a stack trace will help the device-driver authors figure
* out what happened. So print that out.
*/
dump_stack();
return 1;
dn_unlock:
raw_spin_unlock_irqrestore(&confirm_error_lock, flags);
return rc;
}
EXPORT_SYMBOL_GPL(eeh_dn_check_failure);
/**
* eeh_check_failure - Check if all 1's data is due to EEH slot freeze
* @token: I/O token, should be address in the form 0xA....
* @val: value, should be all 1's (XXX why do we need this arg??)
*
* Check for an EEH failure at the given token address. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze event. This routine
* will query firmware for the EEH status.
*
* Note this routine is safe to call in an interrupt context.
*/
unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val)
{
unsigned long addr;
struct pci_dev *dev;
struct device_node *dn;
/* Finding the phys addr + pci device; this is pretty quick. */
addr = eeh_token_to_phys((unsigned long __force) token);
dev = pci_addr_cache_get_device(addr);
if (!dev) {
eeh_stats.no_device++;
return val;
}
dn = pci_device_to_OF_node(dev);
eeh_dn_check_failure(dn, dev);
pci_dev_put(dev);
return val;
}
EXPORT_SYMBOL(eeh_check_failure);
/**
* eeh_pci_enable - Enable MMIO or DMA transfers for this slot
* @edev: pci device node
*
* This routine should be called to reenable frozen MMIO or DMA
* so that it would work correctly again. It's useful while doing
* recovery or log collection on the indicated device.
*/
int eeh_pci_enable(struct eeh_dev *edev, int function)
{
int rc;
struct device_node *dn = eeh_dev_to_of_node(edev);
rc = eeh_ops->set_option(dn, function);
if (rc)
printk(KERN_WARNING "EEH: Unexpected state change %d, err=%d dn=%s\n",
function, rc, dn->full_name);
rc = eeh_ops->wait_state(dn, PCI_BUS_RESET_WAIT_MSEC);
if (rc > 0 && (rc & EEH_STATE_MMIO_ENABLED) &&
(function == EEH_OPT_THAW_MMIO))
return 0;
return rc;
}
/**
* pcibios_set_pcie_slot_reset - Set PCI-E reset state
* @dev: pci device struct
* @state: reset state to enter
*
* Return value:
* 0 if success
*/
int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
{
struct device_node *dn = pci_device_to_OF_node(dev);
switch (state) {
case pcie_deassert_reset:
eeh_ops->reset(dn, EEH_RESET_DEACTIVATE);
break;
case pcie_hot_reset:
eeh_ops->reset(dn, EEH_RESET_HOT);
break;
case pcie_warm_reset:
eeh_ops->reset(dn, EEH_RESET_FUNDAMENTAL);
break;
default:
return -EINVAL;
};
return 0;
}
/**
* __eeh_set_pe_freset - Check the required reset for child devices
* @parent: parent device
* @freset: return value
*
* Each device might have its preferred reset type: fundamental or
* hot reset. The routine is used to collect the information from
* the child devices so that they could be reset accordingly.
*/
void __eeh_set_pe_freset(struct device_node *parent, unsigned int *freset)
{
struct device_node *dn;
for_each_child_of_node(parent, dn) {
if (of_node_to_eeh_dev(dn)) {
struct pci_dev *dev = of_node_to_eeh_dev(dn)->pdev;
if (dev && dev->driver)
*freset |= dev->needs_freset;
__eeh_set_pe_freset(dn, freset);
}
}
}
/**
* eeh_set_pe_freset - Check the required reset for the indicated device and its children
* @dn: parent device
* @freset: return value
*
* Each device might have its preferred reset type: fundamental or
* hot reset. The routine is used to collected the information for
* the indicated device and its children so that the bunch of the
* devices could be reset properly.
*/
void eeh_set_pe_freset(struct device_node *dn, unsigned int *freset)
{
struct pci_dev *dev;
dn = eeh_find_device_pe(dn);
/* Back up one, since config addrs might be shared */
if (!pcibios_find_pci_bus(dn) && of_node_to_eeh_dev(dn->parent))
dn = dn->parent;
dev = of_node_to_eeh_dev(dn)->pdev;
if (dev)
*freset |= dev->needs_freset;
__eeh_set_pe_freset(dn, freset);
}
/**
* eeh_reset_pe_once - Assert the pci #RST line for 1/4 second
* @edev: pci device node to be reset.
*
* Assert the PCI #RST line for 1/4 second.
*/
static void eeh_reset_pe_once(struct eeh_dev *edev)
{
unsigned int freset = 0;
struct device_node *dn = eeh_dev_to_of_node(edev);
/* Determine type of EEH reset required for
* Partitionable Endpoint, a hot-reset (1)
* or a fundamental reset (3).
* A fundamental reset required by any device under
* Partitionable Endpoint trumps hot-reset.
*/
eeh_set_pe_freset(dn, &freset);
if (freset)
eeh_ops->reset(dn, EEH_RESET_FUNDAMENTAL);
else
eeh_ops->reset(dn, EEH_RESET_HOT);
/* The PCI bus requires that the reset be held high for at least
* a 100 milliseconds. We wait a bit longer 'just in case'.
*/
#define PCI_BUS_RST_HOLD_TIME_MSEC 250
msleep(PCI_BUS_RST_HOLD_TIME_MSEC);
/* We might get hit with another EEH freeze as soon as the
* pci slot reset line is dropped. Make sure we don't miss
* these, and clear the flag now.
*/
eeh_clear_slot(dn, EEH_MODE_ISOLATED);
eeh_ops->reset(dn, EEH_RESET_DEACTIVATE);
/* After a PCI slot has been reset, the PCI Express spec requires
* a 1.5 second idle time for the bus to stabilize, before starting
* up traffic.
*/
#define PCI_BUS_SETTLE_TIME_MSEC 1800
msleep(PCI_BUS_SETTLE_TIME_MSEC);
}
/**
* eeh_reset_pe - Reset the indicated PE
* @edev: PCI device associated EEH device
*
* This routine should be called to reset indicated device, including
* PE. A PE might include multiple PCI devices and sometimes PCI bridges
* might be involved as well.
*/
int eeh_reset_pe(struct eeh_dev *edev)
{
int i, rc;
struct device_node *dn = eeh_dev_to_of_node(edev);
/* Take three shots at resetting the bus */
for (i=0; i<3; i++) {
eeh_reset_pe_once(edev);
rc = eeh_ops->wait_state(dn, PCI_BUS_RESET_WAIT_MSEC);
if (rc == (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE))
return 0;
if (rc < 0) {
printk(KERN_ERR "EEH: unrecoverable slot failure %s\n",
dn->full_name);
return -1;
}
printk(KERN_ERR "EEH: bus reset %d failed on slot %s, rc=%d\n",
i+1, dn->full_name, rc);
}
return -1;
}
/** Save and restore of PCI BARs
*
* Although firmware will set up BARs during boot, it doesn't
* set up device BAR's after a device reset, although it will,
* if requested, set up bridge configuration. Thus, we need to
* configure the PCI devices ourselves.
*/
/**
* eeh_restore_one_device_bars - Restore the Base Address Registers for one device
* @edev: PCI device associated EEH device
*
* Loads the PCI configuration space base address registers,
* the expansion ROM base address, the latency timer, and etc.
* from the saved values in the device node.
*/
static inline void eeh_restore_one_device_bars(struct eeh_dev *edev)
{
int i;
u32 cmd;
struct device_node *dn = eeh_dev_to_of_node(edev);
if (!edev->phb)
return;
for (i=4; i<10; i++) {
eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]);
}
/* 12 == Expansion ROM Address */
eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]);
#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1,
SAVED_BYTE(PCI_CACHE_LINE_SIZE));
eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1,
SAVED_BYTE(PCI_LATENCY_TIMER));
/* max latency, min grant, interrupt pin and line */
eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]);
/* Restore PERR & SERR bits, some devices require it,
* don't touch the other command bits
*/
eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd);
if (edev->config_space[1] & PCI_COMMAND_PARITY)
cmd |= PCI_COMMAND_PARITY;
else
cmd &= ~PCI_COMMAND_PARITY;
if (edev->config_space[1] & PCI_COMMAND_SERR)
cmd |= PCI_COMMAND_SERR;
else
cmd &= ~PCI_COMMAND_SERR;
eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd);
}
/**
* eeh_restore_bars - Restore the PCI config space info
* @edev: EEH device
*
* This routine performs a recursive walk to the children
* of this device as well.
*/
void eeh_restore_bars(struct eeh_dev *edev)
{
struct device_node *dn;
if (!edev)
return;
if ((edev->mode & EEH_MODE_SUPPORTED) && !IS_BRIDGE(edev->class_code))
eeh_restore_one_device_bars(edev);
for_each_child_of_node(eeh_dev_to_of_node(edev), dn)
eeh_restore_bars(of_node_to_eeh_dev(dn));
}
/**
* eeh_save_bars - Save device bars
* @edev: PCI device associated EEH device
*
* Save the values of the device bars. Unlike the restore
* routine, this routine is *not* recursive. This is because
* PCI devices are added individually; but, for the restore,
* an entire slot is reset at a time.
*/
static void eeh_save_bars(struct eeh_dev *edev)
{
int i;
struct device_node *dn;
if (!edev)
return;
dn = eeh_dev_to_of_node(edev);
for (i = 0; i < 16; i++)
eeh_ops->read_config(dn, i * 4, 4, &edev->config_space[i]);
}
/**
* eeh_early_enable - Early enable EEH on the indicated device
* @dn: device node
* @data: BUID
*
* Enable EEH functionality on the specified PCI device. The function
* is expected to be called before real PCI probing is done. However,
* the PHBs have been initialized at this point.
*/
static void *eeh_early_enable(struct device_node *dn, void *data)
{
int ret;
const u32 *class_code = of_get_property(dn, "class-code", NULL);
const u32 *vendor_id = of_get_property(dn, "vendor-id", NULL);
const u32 *device_id = of_get_property(dn, "device-id", NULL);
const u32 *regs;
int enable;
struct eeh_dev *edev = of_node_to_eeh_dev(dn);
edev->class_code = 0;
edev->mode = 0;
edev->check_count = 0;
edev->freeze_count = 0;
edev->false_positives = 0;
if (!of_device_is_available(dn))
return NULL;
/* Ignore bad nodes. */
if (!class_code || !vendor_id || !device_id)
return NULL;
/* There is nothing to check on PCI to ISA bridges */
if (dn->type && !strcmp(dn->type, "isa")) {
edev->mode |= EEH_MODE_NOCHECK;
return NULL;
}
edev->class_code = *class_code;
/* Ok... see if this device supports EEH. Some do, some don't,
* and the only way to find out is to check each and every one.
*/
regs = of_get_property(dn, "reg", NULL);
if (regs) {
/* First register entry is addr (00BBSS00) */
/* Try to enable eeh */
ret = eeh_ops->set_option(dn, EEH_OPT_ENABLE);
enable = 0;
if (ret == 0) {
edev->config_addr = regs[0];
/* If the newer, better, ibm,get-config-addr-info is supported,
* then use that instead.
*/
edev->pe_config_addr = eeh_ops->get_pe_addr(dn);
/* Some older systems (Power4) allow the
* ibm,set-eeh-option call to succeed even on nodes
* where EEH is not supported. Verify support
* explicitly.
*/
ret = eeh_ops->get_state(dn, NULL);
if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)
enable = 1;
}
if (enable) {
eeh_subsystem_enabled = 1;
edev->mode |= EEH_MODE_SUPPORTED;
pr_debug("EEH: %s: eeh enabled, config=%x pe_config=%x\n",
dn->full_name, edev->config_addr,
edev->pe_config_addr);
} else {
/* This device doesn't support EEH, but it may have an
* EEH parent, in which case we mark it as supported.
*/
if (dn->parent && of_node_to_eeh_dev(dn->parent) &&
(of_node_to_eeh_dev(dn->parent)->mode & EEH_MODE_SUPPORTED)) {
/* Parent supports EEH. */
edev->mode |= EEH_MODE_SUPPORTED;
edev->config_addr = of_node_to_eeh_dev(dn->parent)->config_addr;
return NULL;
}
}
} else {
printk(KERN_WARNING "EEH: %s: unable to get reg property.\n",
dn->full_name);
}
eeh_save_bars(edev);
return NULL;
}
/**
* eeh_ops_register - Register platform dependent EEH operations
* @ops: platform dependent EEH operations
*
* Register the platform dependent EEH operation callback
* functions. The platform should call this function before
* any other EEH operations.
*/
int __init eeh_ops_register(struct eeh_ops *ops)
{
if (!ops->name) {
pr_warning("%s: Invalid EEH ops name for %p\n",
__func__, ops);
return -EINVAL;
}
if (eeh_ops && eeh_ops != ops) {
pr_warning("%s: EEH ops of platform %s already existing (%s)\n",
__func__, eeh_ops->name, ops->name);
return -EEXIST;
}
eeh_ops = ops;
return 0;
}
/**
* eeh_ops_unregister - Unreigster platform dependent EEH operations
* @name: name of EEH platform operations
*
* Unregister the platform dependent EEH operation callback
* functions.
*/
int __exit eeh_ops_unregister(const char *name)
{
if (!name || !strlen(name)) {
pr_warning("%s: Invalid EEH ops name\n",
__func__);
return -EINVAL;
}
if (eeh_ops && !strcmp(eeh_ops->name, name)) {
eeh_ops = NULL;
return 0;
}
return -EEXIST;
}
/**
* eeh_init - EEH initialization
*
* Initialize EEH by trying to enable it for all of the adapters in the system.
* As a side effect we can determine here if eeh is supported at all.
* Note that we leave EEH on so failed config cycles won't cause a machine
* check. If a user turns off EEH for a particular adapter they are really
* telling Linux to ignore errors. Some hardware (e.g. POWER5) won't
* grant access to a slot if EEH isn't enabled, and so we always enable
* EEH for all slots/all devices.
*
* The eeh-force-off option disables EEH checking globally, for all slots.
* Even if force-off is set, the EEH hardware is still enabled, so that
* newer systems can boot.
*/
void __init eeh_init(void)
{
struct device_node *phb, *np;
int ret;
/* call platform initialization function */
if (!eeh_ops) {
pr_warning("%s: Platform EEH operation not found\n",
__func__);
return;
} else if ((ret = eeh_ops->init())) {
pr_warning("%s: Failed to call platform init function (%d)\n",
__func__, ret);
return;
}
raw_spin_lock_init(&confirm_error_lock);
np = of_find_node_by_path("/rtas");
if (np == NULL)
return;
/* Enable EEH for all adapters. Note that eeh requires buid's */
for (phb = of_find_node_by_name(NULL, "pci"); phb;
phb = of_find_node_by_name(phb, "pci")) {
unsigned long buid;
buid = get_phb_buid(phb);
if (buid == 0 || !of_node_to_eeh_dev(phb))
continue;
traverse_pci_devices(phb, eeh_early_enable, NULL);
}
if (eeh_subsystem_enabled)
printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n");
else
printk(KERN_WARNING "EEH: No capable adapters found\n");
}
/**
* eeh_add_device_early - Enable EEH for the indicated device_node
* @dn: device node for which to set up EEH
*
* This routine must be used to perform EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
* This routine must be called before any i/o is performed to the
* adapter (inluding any config-space i/o).
* Whether this actually enables EEH or not for this device depends
* on the CEC architecture, type of the device, on earlier boot
* command-line arguments & etc.
*/
static void eeh_add_device_early(struct device_node *dn)
{
struct pci_controller *phb;
if (!dn || !of_node_to_eeh_dev(dn))
return;
phb = of_node_to_eeh_dev(dn)->phb;
/* USB Bus children of PCI devices will not have BUID's */
if (NULL == phb || 0 == phb->buid)
return;
eeh_early_enable(dn, NULL);
}
/**
* eeh_add_device_tree_early - Enable EEH for the indicated device
* @dn: device node
*
* This routine must be used to perform EEH initialization for the
* indicated PCI device that was added after system boot (e.g.
* hotplug, dlpar).
*/
void eeh_add_device_tree_early(struct device_node *dn)
{
struct device_node *sib;
for_each_child_of_node(dn, sib)
eeh_add_device_tree_early(sib);
eeh_add_device_early(dn);
}
EXPORT_SYMBOL_GPL(eeh_add_device_tree_early);
/**
* eeh_add_device_late - Perform EEH initialization for the indicated pci device
* @dev: pci device for which to set up EEH
*
* This routine must be used to complete EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
*/
static void eeh_add_device_late(struct pci_dev *dev)
{
struct device_node *dn;
struct eeh_dev *edev;
if (!dev || !eeh_subsystem_enabled)
return;
pr_debug("EEH: Adding device %s\n", pci_name(dev));
dn = pci_device_to_OF_node(dev);
edev = pci_dev_to_eeh_dev(dev);
if (edev->pdev == dev) {
pr_debug("EEH: Already referenced !\n");
return;
}
WARN_ON(edev->pdev);
pci_dev_get(dev);
edev->pdev = dev;
dev->dev.archdata.edev = edev;
pci_addr_cache_insert_device(dev);
eeh_sysfs_add_device(dev);
}
/**
* eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus
* @bus: PCI bus
*
* This routine must be used to perform EEH initialization for PCI
* devices which are attached to the indicated PCI bus. The PCI bus
* is added after system boot through hotplug or dlpar.
*/
void eeh_add_device_tree_late(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
eeh_add_device_late(dev);
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
struct pci_bus *subbus = dev->subordinate;
if (subbus)
eeh_add_device_tree_late(subbus);
}
}
}
EXPORT_SYMBOL_GPL(eeh_add_device_tree_late);
/**
* eeh_remove_device - Undo EEH setup for the indicated pci device
* @dev: pci device to be removed
*
* This routine should be called when a device is removed from
* a running system (e.g. by hotplug or dlpar). It unregisters
* the PCI device from the EEH subsystem. I/O errors affecting
* this device will no longer be detected after this call; thus,
* i/o errors affecting this slot may leave this device unusable.
*/
static void eeh_remove_device(struct pci_dev *dev)
{
struct eeh_dev *edev;
if (!dev || !eeh_subsystem_enabled)
return;
edev = pci_dev_to_eeh_dev(dev);
/* Unregister the device with the EEH/PCI address search system */
pr_debug("EEH: Removing device %s\n", pci_name(dev));
if (!edev || !edev->pdev) {
pr_debug("EEH: Not referenced !\n");
return;
}
edev->pdev = NULL;
dev->dev.archdata.edev = NULL;
pci_dev_put(dev);
pci_addr_cache_remove_device(dev);
eeh_sysfs_remove_device(dev);
}
/**
* eeh_remove_bus_device - Undo EEH setup for the indicated PCI device
* @dev: PCI device
*
* This routine must be called when a device is removed from the
* running system through hotplug or dlpar. The corresponding
* PCI address cache will be removed.
*/
void eeh_remove_bus_device(struct pci_dev *dev)
{
struct pci_bus *bus = dev->subordinate;
struct pci_dev *child, *tmp;
eeh_remove_device(dev);
if (bus && dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
list_for_each_entry_safe(child, tmp, &bus->devices, bus_list)
eeh_remove_bus_device(child);
}
}
EXPORT_SYMBOL_GPL(eeh_remove_bus_device);
static int proc_eeh_show(struct seq_file *m, void *v)
{
if (0 == eeh_subsystem_enabled) {
seq_printf(m, "EEH Subsystem is globally disabled\n");
seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs);
} else {
seq_printf(m, "EEH Subsystem is enabled\n");
seq_printf(m,
"no device=%llu\n"
"no device node=%llu\n"
"no config address=%llu\n"
"check not wanted=%llu\n"
"eeh_total_mmio_ffs=%llu\n"
"eeh_false_positives=%llu\n"
"eeh_slot_resets=%llu\n",
eeh_stats.no_device,
eeh_stats.no_dn,
eeh_stats.no_cfg_addr,
eeh_stats.ignored_check,
eeh_stats.total_mmio_ffs,
eeh_stats.false_positives,
eeh_stats.slot_resets);
}
return 0;
}
static int proc_eeh_open(struct inode *inode, struct file *file)
{
return single_open(file, proc_eeh_show, NULL);
}
static const struct file_operations proc_eeh_operations = {
.open = proc_eeh_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init eeh_init_proc(void)
{
if (machine_is(pseries))
proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations);
return 0;
}
__initcall(eeh_init_proc);
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