[PATCH] powerpc: PCI Error Recovery: PPC64 core recovery routines

Various PCI bus errors can be signaled by newer PCI controllers.  The
core error recovery routines are architecture dependent.  This patch adds
a recovery infrastructure for the  PPC64 pSeries systems.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
(cherry picked from e8ca11b460c4c9c7fa6b529be221529ebd770e38 commit)
This commit is contained in:
Linas Vepstas 2005-11-03 18:52:49 -06:00 committed by Paul Mackerras
parent 977127174a
commit 77bd741561
7 changed files with 413 additions and 35 deletions

View file

@ -4,7 +4,7 @@ obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_IBMVIO) += vio.o
obj-$(CONFIG_XICS) += xics.o
obj-$(CONFIG_SCANLOG) += scanlog.o
obj-$(CONFIG_EEH) += eeh.o eeh_event.o
obj-$(CONFIG_EEH) += eeh.o eeh_driver.o eeh_event.o
obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o
obj-$(CONFIG_HVCS) += hvcserver.o

View file

@ -485,6 +485,11 @@ static void __eeh_mark_slot (struct device_node *dn, int mode_flag)
if (PCI_DN(dn)) {
PCI_DN(dn)->eeh_mode |= mode_flag;
/* Mark the pci device driver too */
struct pci_dev *dev = PCI_DN(dn)->pcidev;
if (dev && dev->driver)
dev->error_state = pci_channel_io_frozen;
if (dn->child)
__eeh_mark_slot (dn->child, mode_flag);
}
@ -544,6 +549,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
int rets[3];
unsigned long flags;
struct pci_dn *pdn;
enum pci_channel_state state;
int rc = 0;
__get_cpu_var(total_mmio_ffs)++;
@ -648,8 +654,13 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
eeh_mark_slot (dn, EEH_MODE_ISOLATED);
spin_unlock_irqrestore(&confirm_error_lock, flags);
eeh_send_failure_event (dn, dev, rets[0], rets[2]);
state = pci_channel_io_normal;
if ((rets[0] == 2) || (rets[0] == 4))
state = pci_channel_io_frozen;
if (rets[0] == 5)
state = pci_channel_io_perm_failure;
eeh_send_failure_event (dn, dev, state, rets[2]);
/* 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. */
@ -953,8 +964,10 @@ static void *early_enable_eeh(struct device_node *dn, void *data)
* But there are a few cases like display devices that make sense.
*/
enable = 1; /* i.e. we will do checking */
#if 0
if ((*class_code >> 16) == PCI_BASE_CLASS_DISPLAY)
enable = 0;
#endif
if (!enable)
pdn->eeh_mode |= EEH_MODE_NOCHECK;

View file

@ -0,0 +1,366 @@
/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright (C) 2004, 2005 Linas Vepstas <linas@linas.org>
*
* All rights reserved.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <linas@us.ibm.com>
*
*/
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/ppc-pci.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>
#include <asm/rtas.h>
static inline const char * pcid_name (struct pci_dev *pdev)
{
if (pdev->dev.driver)
return pdev->dev.driver->name;
return "";
}
/**
* Return the "partitionable endpoint" (pe) under which this device lies
*/
static struct device_node * find_device_pe(struct device_node *dn)
{
while ((dn->parent) && PCI_DN(dn->parent) &&
(PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) {
dn = dn->parent;
}
return dn;
}
#ifdef DEBUG
static void print_device_node_tree (struct pci_dn *pdn, int dent)
{
int i;
if (!pdn) return;
for (i=0;i<dent; i++)
printk(" ");
printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n",
pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr,
pdn->eeh_pe_config_addr, pdn->node->full_name);
dent += 3;
struct device_node *pc = pdn->node->child;
while (pc) {
print_device_node_tree(PCI_DN(pc), dent);
pc = pc->sibling;
}
}
#endif
/**
* irq_in_use - return true if this irq is being used
*/
static int irq_in_use(unsigned int irq)
{
int rc = 0;
unsigned long flags;
struct irq_desc *desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
if (desc->action)
rc = 1;
spin_unlock_irqrestore(&desc->lock, flags);
return rc;
}
/* ------------------------------------------------------- */
/** eeh_report_error - report an EEH error to each device,
* collect up and merge the device responses.
*/
static void eeh_report_error(struct pci_dev *dev, void *userdata)
{
enum pcierr_result rc, *res = userdata;
struct pci_driver *driver = dev->driver;
dev->error_state = pci_channel_io_frozen;
if (!driver)
return;
if (irq_in_use (dev->irq)) {
struct device_node *dn = pci_device_to_OF_node(dev);
PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->error_detected)
return;
rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen);
if (*res == PCIERR_RESULT_NONE) *res = rc;
if (*res == PCIERR_RESULT_NEED_RESET) return;
if (*res == PCIERR_RESULT_DISCONNECT &&
rc == PCIERR_RESULT_NEED_RESET) *res = rc;
}
/** eeh_report_reset -- tell this device that the pci slot
* has been reset.
*/
static void eeh_report_reset(struct pci_dev *dev, void *userdata)
{
struct pci_driver *driver = dev->driver;
struct device_node *dn = pci_device_to_OF_node(dev);
if (!driver)
return;
if ((PCI_DN(dn)->eeh_mode) & EEH_MODE_IRQ_DISABLED) {
PCI_DN(dn)->eeh_mode &= ~EEH_MODE_IRQ_DISABLED;
enable_irq(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->slot_reset)
return;
driver->err_handler->slot_reset(dev);
}
static void eeh_report_resume(struct pci_dev *dev, void *userdata)
{
struct pci_driver *driver = dev->driver;
dev->error_state = pci_channel_io_normal;
if (!driver)
return;
if (!driver->err_handler)
return;
if (!driver->err_handler->resume)
return;
driver->err_handler->resume(dev);
}
static void eeh_report_failure(struct pci_dev *dev, void *userdata)
{
struct pci_driver *driver = dev->driver;
dev->error_state = pci_channel_io_perm_failure;
if (!driver)
return;
if (irq_in_use (dev->irq)) {
struct device_node *dn = pci_device_to_OF_node(dev);
PCI_DN(dn)->eeh_mode |= EEH_MODE_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
if (!driver->err_handler)
return;
if (!driver->err_handler->error_detected)
return;
driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
}
/* ------------------------------------------------------- */
/**
* handle_eeh_events -- reset a PCI device after hard lockup.
*
* pSeries systems will isolate a PCI slot if the PCI-Host
* bridge detects address or data parity errors, DMA's
* occuring to wild addresses (which usually happen due to
* bugs in device drivers or in PCI adapter firmware).
* Slot isolations also occur if #SERR, #PERR or other misc
* PCI-related errors are detected.
*
* Recovery process consists of unplugging the device driver
* (which generated hotplug events to userspace), then issuing
* a PCI #RST to the device, then reconfiguring the PCI config
* space for all bridges & devices under this slot, and then
* finally restarting the device drivers (which cause a second
* set of hotplug events to go out to userspace).
*/
/**
* eeh_reset_device() -- perform actual reset of a pci slot
* Args: bus: pointer to the pci bus structure corresponding
* to the isolated slot. A non-null value will
* cause all devices under the bus to be removed
* and then re-added.
* pe_dn: pointer to a "Partionable Endpoint" device node.
* This is the top-level structure on which pci
* bus resets can be performed.
*/
static void eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
{
if (bus)
pcibios_remove_pci_devices(bus);
/* Reset the pci controller. (Asserts RST#; resets config space).
* Reconfigure bridges and devices */
rtas_set_slot_reset(pe_dn);
/* Walk over all functions on this device */
rtas_configure_bridge(pe_dn);
eeh_restore_bars(pe_dn);
/* Give the system 5 seconds to finish running the user-space
* hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,
* this is a hack, but if we don't do this, and try to bring
* the device up before the scripts have taken it down,
* potentially weird things happen.
*/
if (bus) {
ssleep (5);
pcibios_add_pci_devices(bus);
}
}
/* The longest amount of time to wait for a pci device
* to come back on line, in seconds.
*/
#define MAX_WAIT_FOR_RECOVERY 15
void handle_eeh_events (struct eeh_event *event)
{
struct device_node *frozen_dn;
struct pci_dn *frozen_pdn;
struct pci_bus *frozen_bus;
int perm_failure = 0;
frozen_dn = find_device_pe(event->dn);
frozen_bus = pcibios_find_pci_bus(frozen_dn);
if (!frozen_dn) {
printk(KERN_ERR "EEH: Error: Cannot find partition endpoint for %s\n",
pci_name(event->dev));
return;
}
/* There are two different styles for coming up with the PE.
* In the old style, it was the highest EEH-capable device
* which was always an EADS pci bridge. In the new style,
* there might not be any EADS bridges, and even when there are,
* the firmware marks them as "EEH incapable". So another
* two-step is needed to find the pci bus.. */
if (!frozen_bus)
frozen_bus = pcibios_find_pci_bus (frozen_dn->parent);
if (!frozen_bus) {
printk(KERN_ERR "EEH: Cannot find PCI bus for %s\n",
frozen_dn->full_name);
return;
}
#if 0
/* We may get "permanent failure" messages on empty slots.
* These are false alarms. Empty slots have no child dn. */
if ((event->state == pci_channel_io_perm_failure) && (frozen_device == NULL))
return;
#endif
frozen_pdn = PCI_DN(frozen_dn);
frozen_pdn->eeh_freeze_count++;
if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES)
perm_failure = 1;
/* If the reset state is a '5' and the time to reset is 0 (infinity)
* or is more then 15 seconds, then mark this as a permanent failure.
*/
if ((event->state == pci_channel_io_perm_failure) &&
((event->time_unavail <= 0) ||
(event->time_unavail > MAX_WAIT_FOR_RECOVERY*1000)))
{
perm_failure = 1;
}
/* Log the error with the rtas logger. */
if (perm_failure) {
/*
* About 90% of all real-life EEH failures in the field
* are due to poorly seated PCI cards. Only 10% or so are
* due to actual, failed cards.
*/
printk(KERN_ERR
"EEH: PCI device %s - %s has failed %d times \n"
"and has been permanently disabled. Please try reseating\n"
"this device or replacing it.\n",
pci_name (frozen_pdn->pcidev),
pcid_name(frozen_pdn->pcidev),
frozen_pdn->eeh_freeze_count);
eeh_slot_error_detail(frozen_pdn, 2 /* Permanent Error */);
/* Notify all devices that they're about to go down. */
pci_walk_bus(frozen_bus, eeh_report_failure, 0);
/* Shut down the device drivers for good. */
pcibios_remove_pci_devices(frozen_bus);
return;
}
eeh_slot_error_detail(frozen_pdn, 1 /* Temporary Error */);
printk(KERN_WARNING
"EEH: This PCI device has failed %d times since last reboot: %s - %s\n",
frozen_pdn->eeh_freeze_count,
pci_name (frozen_pdn->pcidev),
pcid_name(frozen_pdn->pcidev));
/* Walk the various device drivers attached to this slot through
* a reset sequence, giving each an opportunity to do what it needs
* to accomplish the reset. Each child gets a report of the
* status ... if any child can't handle the reset, then the entire
* slot is dlpar removed and added.
*/
enum pcierr_result result = PCIERR_RESULT_NONE;
pci_walk_bus(frozen_bus, eeh_report_error, &result);
/* If all device drivers were EEH-unaware, then shut
* down all of the device drivers, and hope they
* go down willingly, without panicing the system.
*/
if (result == PCIERR_RESULT_NONE) {
eeh_reset_device(frozen_pdn, frozen_bus);
}
/* If any device called out for a reset, then reset the slot */
if (result == PCIERR_RESULT_NEED_RESET) {
eeh_reset_device(frozen_pdn, NULL);
pci_walk_bus(frozen_bus, eeh_report_reset, 0);
}
/* If all devices reported they can proceed, the re-enable PIO */
if (result == PCIERR_RESULT_CAN_RECOVER) {
/* XXX Not supported; we brute-force reset the device */
eeh_reset_device(frozen_pdn, NULL);
pci_walk_bus(frozen_bus, eeh_report_reset, 0);
}
/* Tell all device drivers that they can resume operations */
pci_walk_bus(frozen_bus, eeh_report_resume, 0);
}
/* ---------- end of file ---------- */

View file

@ -21,6 +21,7 @@
#include <linux/list.h>
#include <linux/pci.h>
#include <asm/eeh_event.h>
#include <asm/ppc-pci.h>
/** Overview:
* EEH error states may be detected within exception handlers;
@ -36,31 +37,6 @@ LIST_HEAD(eeh_eventlist);
static void eeh_thread_launcher(void *);
DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);
/**
* eeh_panic - call panic() for an eeh event that cannot be handled.
* The philosophy of this routine is that it is better to panic and
* halt the OS than it is to risk possible data corruption by
* oblivious device drivers that don't know better.
*
* @dev pci device that had an eeh event
* @reset_state current reset state of the device slot
*/
static void eeh_panic(struct pci_dev *dev, int reset_state)
{
/*
* Since the panic_on_oops sysctl is used to halt the system
* in light of potential corruption, we can use it here.
*/
if (panic_on_oops) {
panic("EEH: MMIO failure (%d) on device:%s\n", reset_state,
pci_name(dev));
}
else {
printk(KERN_INFO "EEH: Ignored MMIO failure (%d) on device:%s\n",
reset_state, pci_name(dev));
}
}
/**
* eeh_event_handler - dispatch EEH events. The detection of a frozen
* slot can occur inside an interrupt, where it can be hard to do
@ -82,10 +58,16 @@ static int eeh_event_handler(void * dummy)
spin_lock_irqsave(&eeh_eventlist_lock, flags);
event = NULL;
/* Unqueue the event, get ready to process. */
if (!list_empty(&eeh_eventlist)) {
event = list_entry(eeh_eventlist.next, struct eeh_event, list);
list_del(&event->list);
}
if (event)
eeh_mark_slot(event->dn, EEH_MODE_RECOVERING);
spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
if (event == NULL)
break;
@ -93,8 +75,11 @@ static int eeh_event_handler(void * dummy)
printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
pci_name(event->dev));
eeh_panic (event->dev, event->state);
handle_eeh_events(event);
eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);
pci_dev_put(event->dev);
kfree(event);
}
@ -122,7 +107,7 @@ static void eeh_thread_launcher(void *dummy)
*/
int eeh_send_failure_event (struct device_node *dn,
struct pci_dev *dev,
int state,
enum pci_channel_state state,
int time_unavail)
{
unsigned long flags;

View file

@ -34,9 +34,11 @@ struct device_node;
extern int eeh_subsystem_enabled;
/* Values for eeh_mode bits in device_node */
#define EEH_MODE_SUPPORTED (1<<0)
#define EEH_MODE_NOCHECK (1<<1)
#define EEH_MODE_ISOLATED (1<<2)
#define EEH_MODE_SUPPORTED (1<<0)
#define EEH_MODE_NOCHECK (1<<1)
#define EEH_MODE_ISOLATED (1<<2)
#define EEH_MODE_RECOVERING (1<<3)
#define EEH_MODE_IRQ_DISABLED (1<<4)
/* Max number of EEH freezes allowed before we consider the device
* to be permanently disabled. */

View file

@ -30,7 +30,7 @@ struct eeh_event {
struct list_head list;
struct device_node *dn; /* struct device node */
struct pci_dev *dev; /* affected device */
int state;
enum pci_channel_state state; /* PCI bus state for the affected device */
int time_unavail; /* milliseconds until device might be available */
};
@ -47,8 +47,11 @@ struct eeh_event {
*/
int eeh_send_failure_event (struct device_node *dn,
struct pci_dev *dev,
int reset_state,
enum pci_channel_state state,
int time_unavail);
/* Main recovery function */
void handle_eeh_events (struct eeh_event *);
#endif /* __KERNEL__ */
#endif /* ASM_PPC64_EEH_EVENT_H */

View file

@ -52,6 +52,15 @@ extern unsigned long pci_probe_only;
/* ---- EEH internal-use-only related routines ---- */
#ifdef CONFIG_EEH
/**
* eeh_slot_error_detail -- record and EEH error condition to the log
* @severity: 1 if temporary, 2 if permanent failure.
*
* Obtains the the EEH error details from the RTAS subsystem,
* and then logs these details with the RTAS error log system.
*/
void eeh_slot_error_detail (struct pci_dn *pdn, int severity);
/**
* rtas_set_slot_reset -- unfreeze a frozen slot
*