linux_dsm_epyc7002/arch/powerpc/kernel/eeh_driver.c
Sam Bobroff de84ffc3cc powerpc/eeh: differentiate duplicate detection message
Currently when an EEH error is detected, the system log receives the
same (or almost the same) message twice:

  EEH: PHB#0 failure detected, location: N/A
  EEH: PHB#0 failure detected, location: N/A
or
  EEH: eeh_dev_check_failure: Frozen PHB#0-PE#0 detected
  EEH: Frozen PHB#0-PE#0 detected

This looks like a bug, but in fact the messages are from different
functions and mean slightly different things.  So keep both but change
one of the messages slightly, so that it's clear they are different:

  EEH: PHB#0 failure detected, location: N/A
  EEH: Recovering PHB#0, location: N/A
or
  EEH: eeh_dev_check_failure: Frozen PHB#0-PE#0 detected
  EEH: Recovering PHB#0-PE#0

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/43817cb6e6631b0828b9a6e266f60d1f8ca8eb22.1571288375.git.sbobroff@linux.ibm.com
2019-11-13 16:58:10 +11:00

1233 lines
33 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright IBM Corp. 2004 2005
* Copyright Linas Vepstas <linas@linas.org> 2004, 2005
*
* Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.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>
struct eeh_rmv_data {
struct list_head removed_vf_list;
int removed_dev_count;
};
static int eeh_result_priority(enum pci_ers_result result)
{
switch (result) {
case PCI_ERS_RESULT_NONE:
return 1;
case PCI_ERS_RESULT_NO_AER_DRIVER:
return 2;
case PCI_ERS_RESULT_RECOVERED:
return 3;
case PCI_ERS_RESULT_CAN_RECOVER:
return 4;
case PCI_ERS_RESULT_DISCONNECT:
return 5;
case PCI_ERS_RESULT_NEED_RESET:
return 6;
default:
WARN_ONCE(1, "Unknown pci_ers_result value: %d\n", (int)result);
return 0;
}
};
static const char *pci_ers_result_name(enum pci_ers_result result)
{
switch (result) {
case PCI_ERS_RESULT_NONE:
return "none";
case PCI_ERS_RESULT_CAN_RECOVER:
return "can recover";
case PCI_ERS_RESULT_NEED_RESET:
return "need reset";
case PCI_ERS_RESULT_DISCONNECT:
return "disconnect";
case PCI_ERS_RESULT_RECOVERED:
return "recovered";
case PCI_ERS_RESULT_NO_AER_DRIVER:
return "no AER driver";
default:
WARN_ONCE(1, "Unknown result type: %d\n", (int)result);
return "unknown";
}
};
static enum pci_ers_result pci_ers_merge_result(enum pci_ers_result old,
enum pci_ers_result new)
{
if (eeh_result_priority(new) > eeh_result_priority(old))
return new;
return old;
}
static bool eeh_dev_removed(struct eeh_dev *edev)
{
return !edev || (edev->mode & EEH_DEV_REMOVED);
}
static bool eeh_edev_actionable(struct eeh_dev *edev)
{
if (!edev->pdev)
return false;
if (edev->pdev->error_state == pci_channel_io_perm_failure)
return false;
if (eeh_dev_removed(edev))
return false;
if (eeh_pe_passed(edev->pe))
return false;
return true;
}
/**
* eeh_pcid_get - Get the PCI device driver
* @pdev: PCI device
*
* The function is used to retrieve the PCI device driver for
* the indicated PCI device. Besides, we will increase the reference
* of the PCI device driver to prevent that being unloaded on
* the fly. Otherwise, kernel crash would be seen.
*/
static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
{
if (!pdev || !pdev->driver)
return NULL;
if (!try_module_get(pdev->driver->driver.owner))
return NULL;
return pdev->driver;
}
/**
* eeh_pcid_put - Dereference on the PCI device driver
* @pdev: PCI device
*
* The function is called to do dereference on the PCI device
* driver of the indicated PCI device.
*/
static inline void eeh_pcid_put(struct pci_dev *pdev)
{
if (!pdev || !pdev->driver)
return;
module_put(pdev->driver->driver.owner);
}
/**
* eeh_disable_irq - Disable interrupt for the recovering device
* @dev: PCI device
*
* This routine must be called when reporting temporary or permanent
* error to the particular PCI device to disable interrupt of that
* device. If the device has enabled MSI or MSI-X interrupt, we needn't
* do real work because EEH should freeze DMA transfers for those PCI
* devices encountering EEH errors, which includes MSI or MSI-X.
*/
static void eeh_disable_irq(struct eeh_dev *edev)
{
/* Don't disable MSI and MSI-X interrupts. They are
* effectively disabled by the DMA Stopped state
* when an EEH error occurs.
*/
if (edev->pdev->msi_enabled || edev->pdev->msix_enabled)
return;
if (!irq_has_action(edev->pdev->irq))
return;
edev->mode |= EEH_DEV_IRQ_DISABLED;
disable_irq_nosync(edev->pdev->irq);
}
/**
* eeh_enable_irq - Enable interrupt for the recovering device
* @dev: PCI device
*
* This routine must be called to enable interrupt while failed
* device could be resumed.
*/
static void eeh_enable_irq(struct eeh_dev *edev)
{
if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
edev->mode &= ~EEH_DEV_IRQ_DISABLED;
/*
* FIXME !!!!!
*
* This is just ass backwards. This maze has
* unbalanced irq_enable/disable calls. So instead of
* finding the root cause it works around the warning
* in the irq_enable code by conditionally calling
* into it.
*
* That's just wrong.The warning in the core code is
* there to tell people to fix their asymmetries in
* their own code, not by abusing the core information
* to avoid it.
*
* I so wish that the assymetry would be the other way
* round and a few more irq_disable calls render that
* shit unusable forever.
*
* tglx
*/
if (irqd_irq_disabled(irq_get_irq_data(edev->pdev->irq)))
enable_irq(edev->pdev->irq);
}
}
static void eeh_dev_save_state(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *pdev;
if (!edev)
return;
/*
* We cannot access the config space on some adapters.
* Otherwise, it will cause fenced PHB. We don't save
* the content in their config space and will restore
* from the initial config space saved when the EEH
* device is created.
*/
if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED))
return;
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
return;
pci_save_state(pdev);
}
static void eeh_set_channel_state(struct eeh_pe *root, enum pci_channel_state s)
{
struct eeh_pe *pe;
struct eeh_dev *edev, *tmp;
eeh_for_each_pe(root, pe)
eeh_pe_for_each_dev(pe, edev, tmp)
if (eeh_edev_actionable(edev))
edev->pdev->error_state = s;
}
static void eeh_set_irq_state(struct eeh_pe *root, bool enable)
{
struct eeh_pe *pe;
struct eeh_dev *edev, *tmp;
eeh_for_each_pe(root, pe) {
eeh_pe_for_each_dev(pe, edev, tmp) {
if (!eeh_edev_actionable(edev))
continue;
if (!eeh_pcid_get(edev->pdev))
continue;
if (enable)
eeh_enable_irq(edev);
else
eeh_disable_irq(edev);
eeh_pcid_put(edev->pdev);
}
}
}
typedef enum pci_ers_result (*eeh_report_fn)(struct eeh_dev *,
struct pci_dev *,
struct pci_driver *);
static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn,
enum pci_ers_result *result)
{
struct pci_dev *pdev;
struct pci_driver *driver;
enum pci_ers_result new_result;
pci_lock_rescan_remove();
pdev = edev->pdev;
if (pdev)
get_device(&pdev->dev);
pci_unlock_rescan_remove();
if (!pdev) {
eeh_edev_info(edev, "no device");
return;
}
device_lock(&pdev->dev);
if (eeh_edev_actionable(edev)) {
driver = eeh_pcid_get(pdev);
if (!driver)
eeh_edev_info(edev, "no driver");
else if (!driver->err_handler)
eeh_edev_info(edev, "driver not EEH aware");
else if (edev->mode & EEH_DEV_NO_HANDLER)
eeh_edev_info(edev, "driver bound too late");
else {
new_result = fn(edev, pdev, driver);
eeh_edev_info(edev, "%s driver reports: '%s'",
driver->name,
pci_ers_result_name(new_result));
if (result)
*result = pci_ers_merge_result(*result,
new_result);
}
if (driver)
eeh_pcid_put(pdev);
} else {
eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!pdev,
!eeh_dev_removed(edev), !eeh_pe_passed(edev->pe));
}
device_unlock(&pdev->dev);
if (edev->pdev != pdev)
eeh_edev_warn(edev, "Device changed during processing!\n");
put_device(&pdev->dev);
}
static void eeh_pe_report(const char *name, struct eeh_pe *root,
eeh_report_fn fn, enum pci_ers_result *result)
{
struct eeh_pe *pe;
struct eeh_dev *edev, *tmp;
pr_info("EEH: Beginning: '%s'\n", name);
eeh_for_each_pe(root, pe) eeh_pe_for_each_dev(pe, edev, tmp)
eeh_pe_report_edev(edev, fn, result);
if (result)
pr_info("EEH: Finished:'%s' with aggregate recovery state:'%s'\n",
name, pci_ers_result_name(*result));
else
pr_info("EEH: Finished:'%s'", name);
}
/**
* eeh_report_error - Report pci error to each device driver
* @edev: eeh device
* @driver: device's PCI driver
*
* Report an EEH error to each device driver.
*/
static enum pci_ers_result eeh_report_error(struct eeh_dev *edev,
struct pci_dev *pdev,
struct pci_driver *driver)
{
enum pci_ers_result rc;
if (!driver->err_handler->error_detected)
return PCI_ERS_RESULT_NONE;
eeh_edev_info(edev, "Invoking %s->error_detected(IO frozen)",
driver->name);
rc = driver->err_handler->error_detected(pdev, pci_channel_io_frozen);
edev->in_error = true;
pci_uevent_ers(pdev, PCI_ERS_RESULT_NONE);
return rc;
}
/**
* eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
* @edev: eeh device
* @driver: device's PCI driver
*
* Tells each device driver that IO ports, MMIO and config space I/O
* are now enabled.
*/
static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev,
struct pci_dev *pdev,
struct pci_driver *driver)
{
if (!driver->err_handler->mmio_enabled)
return PCI_ERS_RESULT_NONE;
eeh_edev_info(edev, "Invoking %s->mmio_enabled()", driver->name);
return driver->err_handler->mmio_enabled(pdev);
}
/**
* eeh_report_reset - Tell device that slot has been reset
* @edev: eeh device
* @driver: device's PCI driver
*
* This routine must be called while EEH tries to reset particular
* PCI device so that the associated PCI device driver could take
* some actions, usually to save data the driver needs so that the
* driver can work again while the device is recovered.
*/
static enum pci_ers_result eeh_report_reset(struct eeh_dev *edev,
struct pci_dev *pdev,
struct pci_driver *driver)
{
if (!driver->err_handler->slot_reset || !edev->in_error)
return PCI_ERS_RESULT_NONE;
eeh_edev_info(edev, "Invoking %s->slot_reset()", driver->name);
return driver->err_handler->slot_reset(pdev);
}
static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *pdev;
if (!edev)
return;
/*
* The content in the config space isn't saved because
* the blocked config space on some adapters. We have
* to restore the initial saved config space when the
* EEH device is created.
*/
if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) {
if (list_is_last(&edev->entry, &edev->pe->edevs))
eeh_pe_restore_bars(edev->pe);
return;
}
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
return;
pci_restore_state(pdev);
}
/**
* eeh_report_resume - Tell device to resume normal operations
* @edev: eeh device
* @driver: device's PCI driver
*
* This routine must be called to notify the device driver that it
* could resume so that the device driver can do some initialization
* to make the recovered device work again.
*/
static enum pci_ers_result eeh_report_resume(struct eeh_dev *edev,
struct pci_dev *pdev,
struct pci_driver *driver)
{
if (!driver->err_handler->resume || !edev->in_error)
return PCI_ERS_RESULT_NONE;
eeh_edev_info(edev, "Invoking %s->resume()", driver->name);
driver->err_handler->resume(pdev);
pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_RECOVERED);
#ifdef CONFIG_PCI_IOV
if (eeh_ops->notify_resume && eeh_dev_to_pdn(edev))
eeh_ops->notify_resume(eeh_dev_to_pdn(edev));
#endif
return PCI_ERS_RESULT_NONE;
}
/**
* eeh_report_failure - Tell device driver that device is dead.
* @edev: eeh device
* @driver: device's PCI driver
*
* This informs the device driver that the device is permanently
* dead, and that no further recovery attempts will be made on it.
*/
static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev,
struct pci_dev *pdev,
struct pci_driver *driver)
{
enum pci_ers_result rc;
if (!driver->err_handler->error_detected)
return PCI_ERS_RESULT_NONE;
eeh_edev_info(edev, "Invoking %s->error_detected(permanent failure)",
driver->name);
rc = driver->err_handler->error_detected(pdev,
pci_channel_io_perm_failure);
pci_uevent_ers(pdev, PCI_ERS_RESULT_DISCONNECT);
return rc;
}
static void *eeh_add_virt_device(struct eeh_dev *edev)
{
struct pci_driver *driver;
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
if (!(edev->physfn)) {
eeh_edev_warn(edev, "Not for VF\n");
return NULL;
}
driver = eeh_pcid_get(dev);
if (driver) {
if (driver->err_handler) {
eeh_pcid_put(dev);
return NULL;
}
eeh_pcid_put(dev);
}
#ifdef CONFIG_PCI_IOV
pci_iov_add_virtfn(edev->physfn, eeh_dev_to_pdn(edev)->vf_index);
#endif
return NULL;
}
static void eeh_rmv_device(struct eeh_dev *edev, void *userdata)
{
struct pci_driver *driver;
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
struct eeh_rmv_data *rmv_data = (struct eeh_rmv_data *)userdata;
/*
* Actually, we should remove the PCI bridges as well.
* However, that's lots of complexity to do that,
* particularly some of devices under the bridge might
* support EEH. So we just care about PCI devices for
* simplicity here.
*/
if (!eeh_edev_actionable(edev) ||
(dev->hdr_type == PCI_HEADER_TYPE_BRIDGE))
return;
if (rmv_data) {
driver = eeh_pcid_get(dev);
if (driver) {
if (driver->err_handler &&
driver->err_handler->error_detected &&
driver->err_handler->slot_reset) {
eeh_pcid_put(dev);
return;
}
eeh_pcid_put(dev);
}
}
/* Remove it from PCI subsystem */
pr_info("EEH: Removing %s without EEH sensitive driver\n",
pci_name(dev));
edev->mode |= EEH_DEV_DISCONNECTED;
if (rmv_data)
rmv_data->removed_dev_count++;
if (edev->physfn) {
#ifdef CONFIG_PCI_IOV
struct pci_dn *pdn = eeh_dev_to_pdn(edev);
pci_iov_remove_virtfn(edev->physfn, pdn->vf_index);
edev->pdev = NULL;
/*
* We have to set the VF PE number to invalid one, which is
* required to plug the VF successfully.
*/
pdn->pe_number = IODA_INVALID_PE;
#endif
if (rmv_data)
list_add(&edev->rmv_entry, &rmv_data->removed_vf_list);
} else {
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(dev);
pci_unlock_rescan_remove();
}
}
static void *eeh_pe_detach_dev(struct eeh_pe *pe, void *userdata)
{
struct eeh_dev *edev, *tmp;
eeh_pe_for_each_dev(pe, edev, tmp) {
if (!(edev->mode & EEH_DEV_DISCONNECTED))
continue;
edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED);
eeh_rmv_from_parent_pe(edev);
}
return NULL;
}
/*
* Explicitly clear PE's frozen state for PowerNV where
* we have frozen PE until BAR restore is completed. It's
* harmless to clear it for pSeries. To be consistent with
* PE reset (for 3 times), we try to clear the frozen state
* for 3 times as well.
*/
static int eeh_clear_pe_frozen_state(struct eeh_pe *root, bool include_passed)
{
struct eeh_pe *pe;
int i;
eeh_for_each_pe(root, pe) {
if (include_passed || !eeh_pe_passed(pe)) {
for (i = 0; i < 3; i++)
if (!eeh_unfreeze_pe(pe))
break;
if (i >= 3)
return -EIO;
}
}
eeh_pe_state_clear(root, EEH_PE_ISOLATED, include_passed);
return 0;
}
int eeh_pe_reset_and_recover(struct eeh_pe *pe)
{
int ret;
/* Bail if the PE is being recovered */
if (pe->state & EEH_PE_RECOVERING)
return 0;
/* Put the PE into recovery mode */
eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
/* Save states */
eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL);
/* Issue reset */
ret = eeh_pe_reset_full(pe, true);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
return ret;
}
/* Unfreeze the PE */
ret = eeh_clear_pe_frozen_state(pe, true);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
return ret;
}
/* Restore device state */
eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL);
/* Clear recovery mode */
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
return 0;
}
/**
* eeh_reset_device - Perform actual reset of a pci slot
* @driver_eeh_aware: Does the device's driver provide EEH support?
* @pe: EEH PE
* @bus: PCI bus corresponding to the isolcated slot
* @rmv_data: Optional, list to record removed devices
*
* This routine must be called to do reset on the indicated PE.
* During the reset, udev might be invoked because those affected
* PCI devices will be removed and then added.
*/
static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
struct eeh_rmv_data *rmv_data,
bool driver_eeh_aware)
{
time64_t tstamp;
int cnt, rc;
struct eeh_dev *edev;
struct eeh_pe *tmp_pe;
bool any_passed = false;
eeh_for_each_pe(pe, tmp_pe)
any_passed |= eeh_pe_passed(tmp_pe);
/* pcibios will clear the counter; save the value */
cnt = pe->freeze_count;
tstamp = pe->tstamp;
/*
* We don't remove the corresponding PE instances because
* we need the information afterwords. The attached EEH
* devices are expected to be attached soon when calling
* into pci_hp_add_devices().
*/
eeh_pe_state_mark(pe, EEH_PE_KEEP);
if (any_passed || driver_eeh_aware || (pe->type & EEH_PE_VF)) {
eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data);
} else {
pci_lock_rescan_remove();
pci_hp_remove_devices(bus);
pci_unlock_rescan_remove();
}
/*
* Reset the pci controller. (Asserts RST#; resets config space).
* Reconfigure bridges and devices. Don't try to bring the system
* up if the reset failed for some reason.
*
* During the reset, it's very dangerous to have uncontrolled PCI
* config accesses. So we prefer to block them. However, controlled
* PCI config accesses initiated from EEH itself are allowed.
*/
rc = eeh_pe_reset_full(pe, false);
if (rc)
return rc;
pci_lock_rescan_remove();
/* Restore PE */
eeh_ops->configure_bridge(pe);
eeh_pe_restore_bars(pe);
/* Clear frozen state */
rc = eeh_clear_pe_frozen_state(pe, false);
if (rc) {
pci_unlock_rescan_remove();
return rc;
}
/* 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 (!driver_eeh_aware || rmv_data->removed_dev_count) {
pr_info("EEH: Sleep 5s ahead of %s hotplug\n",
(driver_eeh_aware ? "partial" : "complete"));
ssleep(5);
/*
* The EEH device is still connected with its parent
* PE. We should disconnect it so the binding can be
* rebuilt when adding PCI devices.
*/
edev = list_first_entry(&pe->edevs, struct eeh_dev, entry);
eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
if (pe->type & EEH_PE_VF) {
eeh_add_virt_device(edev);
} else {
if (!driver_eeh_aware)
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
pci_hp_add_devices(bus);
}
}
eeh_pe_state_clear(pe, EEH_PE_KEEP, true);
pe->tstamp = tstamp;
pe->freeze_count = cnt;
pci_unlock_rescan_remove();
return 0;
}
/* The longest amount of time to wait for a pci device
* to come back on line, in seconds.
*/
#define MAX_WAIT_FOR_RECOVERY 300
/* Walks the PE tree after processing an event to remove any stale PEs.
*
* NB: This needs to be recursive to ensure the leaf PEs get removed
* before their parents do. Although this is possible to do recursively
* we don't since this is easier to read and we need to garantee
* the leaf nodes will be handled first.
*/
static void eeh_pe_cleanup(struct eeh_pe *pe)
{
struct eeh_pe *child_pe, *tmp;
list_for_each_entry_safe(child_pe, tmp, &pe->child_list, child)
eeh_pe_cleanup(child_pe);
if (pe->state & EEH_PE_KEEP)
return;
if (!(pe->state & EEH_PE_INVALID))
return;
if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) {
list_del(&pe->child);
kfree(pe);
}
}
/**
* eeh_check_slot_presence - Check if a device is still present in a slot
* @pdev: pci_dev to check
*
* This function may return a false positive if we can't determine the slot's
* presence state. This might happen for for PCIe slots if the PE containing
* the upstream bridge is also frozen, or the bridge is part of the same PE
* as the device.
*
* This shouldn't happen often, but you might see it if you hotplug a PCIe
* switch.
*/
static bool eeh_slot_presence_check(struct pci_dev *pdev)
{
const struct hotplug_slot_ops *ops;
struct pci_slot *slot;
u8 state;
int rc;
if (!pdev)
return false;
if (pdev->error_state == pci_channel_io_perm_failure)
return false;
slot = pdev->slot;
if (!slot || !slot->hotplug)
return true;
ops = slot->hotplug->ops;
if (!ops || !ops->get_adapter_status)
return true;
/* set the attention indicator while we've got the slot ops */
if (ops->set_attention_status)
ops->set_attention_status(slot->hotplug, 1);
rc = ops->get_adapter_status(slot->hotplug, &state);
if (rc)
return true;
return !!state;
}
static void eeh_clear_slot_attention(struct pci_dev *pdev)
{
const struct hotplug_slot_ops *ops;
struct pci_slot *slot;
if (!pdev)
return;
if (pdev->error_state == pci_channel_io_perm_failure)
return;
slot = pdev->slot;
if (!slot || !slot->hotplug)
return;
ops = slot->hotplug->ops;
if (!ops || !ops->set_attention_status)
return;
ops->set_attention_status(slot->hotplug, 0);
}
/**
* eeh_handle_normal_event - Handle EEH events on a specific PE
* @pe: EEH PE - which should not be used after we return, as it may
* have been invalidated.
*
* Attempts to recover the given PE. If recovery fails or the PE has failed
* too many times, remove the PE.
*
* While PHB detects address or data parity errors on particular PCI
* slot, the associated PE will be frozen. Besides, DMA's occurring
* to wild addresses (which usually happen due to bugs in device
* drivers or in PCI adapter firmware) can cause EEH error. #SERR,
* #PERR or other misc PCI-related errors also can trigger EEH errors.
*
* 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).
*/
void eeh_handle_normal_event(struct eeh_pe *pe)
{
struct pci_bus *bus;
struct eeh_dev *edev, *tmp;
struct eeh_pe *tmp_pe;
int rc = 0;
enum pci_ers_result result = PCI_ERS_RESULT_NONE;
struct eeh_rmv_data rmv_data =
{LIST_HEAD_INIT(rmv_data.removed_vf_list), 0};
int devices = 0;
bus = eeh_pe_bus_get(pe);
if (!bus) {
pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n",
__func__, pe->phb->global_number, pe->addr);
return;
}
/*
* When devices are hot-removed we might get an EEH due to
* a driver attempting to touch the MMIO space of a removed
* device. In this case we don't have a device to recover
* so suppress the event if we can't find any present devices.
*
* The hotplug driver should take care of tearing down the
* device itself.
*/
eeh_for_each_pe(pe, tmp_pe)
eeh_pe_for_each_dev(tmp_pe, edev, tmp)
if (eeh_slot_presence_check(edev->pdev))
devices++;
if (!devices) {
pr_debug("EEH: Frozen PHB#%x-PE#%x is empty!\n",
pe->phb->global_number, pe->addr);
goto out; /* nothing to recover */
}
/* Log the event */
if (pe->type & EEH_PE_PHB) {
pr_err("EEH: Recovering PHB#%x, location: %s\n",
pe->phb->global_number, eeh_pe_loc_get(pe));
} else {
struct eeh_pe *phb_pe = eeh_phb_pe_get(pe->phb);
pr_err("EEH: Recovering PHB#%x-PE#%x\n",
pe->phb->global_number, pe->addr);
pr_err("EEH: PE location: %s, PHB location: %s\n",
eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe));
}
#ifdef CONFIG_STACKTRACE
/*
* Print the saved stack trace now that we've verified there's
* something to recover.
*/
if (pe->trace_entries) {
void **ptrs = (void **) pe->stack_trace;
int i;
pr_err("EEH: Frozen PHB#%x-PE#%x detected\n",
pe->phb->global_number, pe->addr);
/* FIXME: Use the same format as dump_stack() */
pr_err("EEH: Call Trace:\n");
for (i = 0; i < pe->trace_entries; i++)
pr_err("EEH: [%pK] %pS\n", ptrs[i], ptrs[i]);
pe->trace_entries = 0;
}
#endif /* CONFIG_STACKTRACE */
eeh_pe_update_time_stamp(pe);
pe->freeze_count++;
if (pe->freeze_count > eeh_max_freezes) {
pr_err("EEH: PHB#%x-PE#%x has failed %d times in the last hour and has been permanently disabled.\n",
pe->phb->global_number, pe->addr,
pe->freeze_count);
result = PCI_ERS_RESULT_DISCONNECT;
}
eeh_for_each_pe(pe, tmp_pe)
eeh_pe_for_each_dev(tmp_pe, edev, tmp)
edev->mode &= ~EEH_DEV_NO_HANDLER;
/* 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.
*
* When the PHB is fenced, we have to issue a reset to recover from
* the error. Override the result if necessary to have partially
* hotplug for this case.
*/
if (result != PCI_ERS_RESULT_DISCONNECT) {
pr_warn("EEH: This PCI device has failed %d times in the last hour and will be permanently disabled after %d failures.\n",
pe->freeze_count, eeh_max_freezes);
pr_info("EEH: Notify device drivers to shutdown\n");
eeh_set_channel_state(pe, pci_channel_io_frozen);
eeh_set_irq_state(pe, false);
eeh_pe_report("error_detected(IO frozen)", pe,
eeh_report_error, &result);
if ((pe->type & EEH_PE_PHB) &&
result != PCI_ERS_RESULT_NONE &&
result != PCI_ERS_RESULT_NEED_RESET)
result = PCI_ERS_RESULT_NEED_RESET;
}
/* Get the current PCI slot state. This can take a long time,
* sometimes over 300 seconds for certain systems.
*/
if (result != PCI_ERS_RESULT_DISCONNECT) {
rc = eeh_wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
pr_warn("EEH: Permanent failure\n");
result = PCI_ERS_RESULT_DISCONNECT;
}
}
/* Since rtas may enable MMIO when posting the error log,
* don't post the error log until after all dev drivers
* have been informed.
*/
if (result != PCI_ERS_RESULT_DISCONNECT) {
pr_info("EEH: Collect temporary log\n");
eeh_slot_error_detail(pe, EEH_LOG_TEMP);
}
/* 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 == PCI_ERS_RESULT_NONE) {
pr_info("EEH: Reset with hotplug activity\n");
rc = eeh_reset_device(pe, bus, NULL, false);
if (rc) {
pr_warn("%s: Unable to reset, err=%d\n",
__func__, rc);
result = PCI_ERS_RESULT_DISCONNECT;
}
}
/* If all devices reported they can proceed, then re-enable MMIO */
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
pr_info("EEH: Enable I/O for affected devices\n");
rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
if (rc < 0) {
result = PCI_ERS_RESULT_DISCONNECT;
} else if (rc) {
result = PCI_ERS_RESULT_NEED_RESET;
} else {
pr_info("EEH: Notify device drivers to resume I/O\n");
eeh_pe_report("mmio_enabled", pe,
eeh_report_mmio_enabled, &result);
}
}
/* If all devices reported they can proceed, then re-enable DMA */
if (result == PCI_ERS_RESULT_CAN_RECOVER) {
pr_info("EEH: Enabled DMA for affected devices\n");
rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
if (rc < 0) {
result = PCI_ERS_RESULT_DISCONNECT;
} else if (rc) {
result = PCI_ERS_RESULT_NEED_RESET;
} else {
/*
* We didn't do PE reset for the case. The PE
* is still in frozen state. Clear it before
* resuming the PE.
*/
eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
result = PCI_ERS_RESULT_RECOVERED;
}
}
/* If any device called out for a reset, then reset the slot */
if (result == PCI_ERS_RESULT_NEED_RESET) {
pr_info("EEH: Reset without hotplug activity\n");
rc = eeh_reset_device(pe, bus, &rmv_data, true);
if (rc) {
pr_warn("%s: Cannot reset, err=%d\n",
__func__, rc);
result = PCI_ERS_RESULT_DISCONNECT;
} else {
result = PCI_ERS_RESULT_NONE;
eeh_set_channel_state(pe, pci_channel_io_normal);
eeh_set_irq_state(pe, true);
eeh_pe_report("slot_reset", pe, eeh_report_reset,
&result);
}
}
if ((result == PCI_ERS_RESULT_RECOVERED) ||
(result == PCI_ERS_RESULT_NONE)) {
/*
* For those hot removed VFs, we should add back them after PF
* get recovered properly.
*/
list_for_each_entry_safe(edev, tmp, &rmv_data.removed_vf_list,
rmv_entry) {
eeh_add_virt_device(edev);
list_del(&edev->rmv_entry);
}
/* Tell all device drivers that they can resume operations */
pr_info("EEH: Notify device driver to resume\n");
eeh_set_channel_state(pe, pci_channel_io_normal);
eeh_set_irq_state(pe, true);
eeh_pe_report("resume", pe, eeh_report_resume, NULL);
eeh_for_each_pe(pe, tmp_pe) {
eeh_pe_for_each_dev(tmp_pe, edev, tmp) {
edev->mode &= ~EEH_DEV_NO_HANDLER;
edev->in_error = false;
}
}
pr_info("EEH: Recovery successful.\n");
} else {
/*
* 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.
*/
pr_err("EEH: Unable to recover from failure from PHB#%x-PE#%x.\n"
"Please try reseating or replacing it\n",
pe->phb->global_number, pe->addr);
eeh_slot_error_detail(pe, EEH_LOG_PERM);
/* Notify all devices that they're about to go down. */
eeh_set_channel_state(pe, pci_channel_io_perm_failure);
eeh_set_irq_state(pe, false);
eeh_pe_report("error_detected(permanent failure)", pe,
eeh_report_failure, NULL);
/* Mark the PE to be removed permanently */
eeh_pe_state_mark(pe, EEH_PE_REMOVED);
/*
* Shut down the device drivers for good. We mark
* all removed devices correctly to avoid access
* the their PCI config any more.
*/
if (pe->type & EEH_PE_VF) {
eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
} else {
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
pci_lock_rescan_remove();
pci_hp_remove_devices(bus);
pci_unlock_rescan_remove();
/* The passed PE should no longer be used */
return;
}
}
out:
/*
* Clean up any PEs without devices. While marked as EEH_PE_RECOVERYING
* we don't want to modify the PE tree structure so we do it here.
*/
eeh_pe_cleanup(pe);
/* clear the slot attention LED for all recovered devices */
eeh_for_each_pe(pe, tmp_pe)
eeh_pe_for_each_dev(tmp_pe, edev, tmp)
eeh_clear_slot_attention(edev->pdev);
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
}
/**
* eeh_handle_special_event - Handle EEH events without a specific failing PE
*
* Called when an EEH event is detected but can't be narrowed down to a
* specific PE. Iterates through possible failures and handles them as
* necessary.
*/
void eeh_handle_special_event(void)
{
struct eeh_pe *pe, *phb_pe, *tmp_pe;
struct eeh_dev *edev, *tmp_edev;
struct pci_bus *bus;
struct pci_controller *hose;
unsigned long flags;
int rc;
do {
rc = eeh_ops->next_error(&pe);
switch (rc) {
case EEH_NEXT_ERR_DEAD_IOC:
/* Mark all PHBs in dead state */
eeh_serialize_lock(&flags);
/* Purge all events */
eeh_remove_event(NULL, true);
list_for_each_entry(hose, &hose_list, list_node) {
phb_pe = eeh_phb_pe_get(hose);
if (!phb_pe) continue;
eeh_pe_mark_isolated(phb_pe);
}
eeh_serialize_unlock(flags);
break;
case EEH_NEXT_ERR_FROZEN_PE:
case EEH_NEXT_ERR_FENCED_PHB:
case EEH_NEXT_ERR_DEAD_PHB:
/* Mark the PE in fenced state */
eeh_serialize_lock(&flags);
/* Purge all events of the PHB */
eeh_remove_event(pe, true);
if (rc != EEH_NEXT_ERR_DEAD_PHB)
eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
eeh_pe_mark_isolated(pe);
eeh_serialize_unlock(flags);
break;
case EEH_NEXT_ERR_NONE:
return;
default:
pr_warn("%s: Invalid value %d from next_error()\n",
__func__, rc);
return;
}
/*
* For fenced PHB and frozen PE, it's handled as normal
* event. We have to remove the affected PHBs for dead
* PHB and IOC
*/
if (rc == EEH_NEXT_ERR_FROZEN_PE ||
rc == EEH_NEXT_ERR_FENCED_PHB) {
eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
eeh_handle_normal_event(pe);
} else {
pci_lock_rescan_remove();
list_for_each_entry(hose, &hose_list, list_node) {
phb_pe = eeh_phb_pe_get(hose);
if (!phb_pe ||
!(phb_pe->state & EEH_PE_ISOLATED) ||
(phb_pe->state & EEH_PE_RECOVERING))
continue;
eeh_for_each_pe(pe, tmp_pe)
eeh_pe_for_each_dev(tmp_pe, edev, tmp_edev)
edev->mode &= ~EEH_DEV_NO_HANDLER;
/* Notify all devices to be down */
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
eeh_set_channel_state(pe, pci_channel_io_perm_failure);
eeh_pe_report(
"error_detected(permanent failure)", pe,
eeh_report_failure, NULL);
bus = eeh_pe_bus_get(phb_pe);
if (!bus) {
pr_err("%s: Cannot find PCI bus for "
"PHB#%x-PE#%x\n",
__func__,
pe->phb->global_number,
pe->addr);
break;
}
pci_hp_remove_devices(bus);
}
pci_unlock_rescan_remove();
}
/*
* If we have detected dead IOC, we needn't proceed
* any more since all PHBs would have been removed
*/
if (rc == EEH_NEXT_ERR_DEAD_IOC)
break;
} while (rc != EEH_NEXT_ERR_NONE);
}