/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright IBM Corp. 2004 2005
* Copyright Linas Vepstas <linas@linas.org> 2004, 2005
*
* 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 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 [31mCONFIG_PCI_IOV[0m
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 [31mCONFIG_PCI_IOV[0m
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 [31mCONFIG_PCI_IOV[0m
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: PHB#%x failure detected, 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: Frozen PHB#%x-PE#%x detected\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 [31mCONFIG_STACKTRACE[0m
/*
* 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);
}