/*
* 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 <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 edev_list;
int removed;
};
/**
* 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 pci_dev *dev)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
/* Don't disable MSI and MSI-X interrupts. They are
* effectively disabled by the DMA Stopped state
* when an EEH error occurs.
*/
if (dev->msi_enabled || dev->msix_enabled)
return;
if (!irq_has_action(dev->irq))
return;
edev->mode |= EEH_DEV_IRQ_DISABLED;
disable_irq_nosync(dev->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 pci_dev *dev)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
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(dev->irq)))
enable_irq(dev->irq);
}
}
static bool eeh_dev_removed(struct eeh_dev *edev)
{
/* EEH device removed ? */
if (!edev || (edev->mode & EEH_DEV_REMOVED))
return true;
return false;
}
static void *eeh_dev_save_state(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *pdev;
if (!edev)
return NULL;
/*
* 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 NULL;
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
return NULL;
pci_save_state(pdev);
return NULL;
}
/**
* eeh_report_error - Report pci error to each device driver
* @data: eeh device
* @userdata: return value
*
* Report an EEH error to each device driver, collect up and
* merge the device driver responses. Cumulative response
* passed back in "userdata".
*/
static void *eeh_report_error(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
enum pci_ers_result rc, *res = userdata;
struct pci_driver *driver;
if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe))
return NULL;
device_lock(&dev->dev);
dev->error_state = pci_channel_io_frozen;
driver = eeh_pcid_get(dev);
if (!driver) goto out_no_dev;
eeh_disable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->error_detected)
goto out;
rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen);
/* A driver that needs a reset trumps all others */
if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
if (*res == PCI_ERS_RESULT_NONE) *res = rc;
edev->in_error = true;
pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
out:
eeh_pcid_put(dev);
out_no_dev:
device_unlock(&dev->dev);
return NULL;
}
/**
* eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
* @data: eeh device
* @userdata: return value
*
* Tells each device driver that IO ports, MMIO and config space I/O
* are now enabled. Collects up and merges the device driver responses.
* Cumulative response passed back in "userdata".
*/
static void *eeh_report_mmio_enabled(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
enum pci_ers_result rc, *res = userdata;
struct pci_driver *driver;
if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe))
return NULL;
device_lock(&dev->dev);
driver = eeh_pcid_get(dev);
if (!driver) goto out_no_dev;
if (!driver->err_handler ||
!driver->err_handler->mmio_enabled ||
(edev->mode & EEH_DEV_NO_HANDLER))
goto out;
rc = driver->err_handler->mmio_enabled(dev);
/* A driver that needs a reset trumps all others */
if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
if (*res == PCI_ERS_RESULT_NONE) *res = rc;
out:
eeh_pcid_put(dev);
out_no_dev:
device_unlock(&dev->dev);
return NULL;
}
/**
* eeh_report_reset - Tell device that slot has been reset
* @data: eeh device
* @userdata: return value
*
* 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 void *eeh_report_reset(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
enum pci_ers_result rc, *res = userdata;
struct pci_driver *driver;
if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe))
return NULL;
device_lock(&dev->dev);
dev->error_state = pci_channel_io_normal;
driver = eeh_pcid_get(dev);
if (!driver) goto out_no_dev;
eeh_enable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->slot_reset ||
(edev->mode & EEH_DEV_NO_HANDLER) ||
(!edev->in_error))
goto out;
rc = driver->err_handler->slot_reset(dev);
if ((*res == PCI_ERS_RESULT_NONE) ||
(*res == PCI_ERS_RESULT_RECOVERED)) *res = rc;
if (*res == PCI_ERS_RESULT_DISCONNECT &&
rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
out:
eeh_pcid_put(dev);
out_no_dev:
device_unlock(&dev->dev);
return NULL;
}
static void *eeh_dev_restore_state(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *pdev;
if (!edev)
return NULL;
/*
* 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->list, &edev->pe->edevs))
eeh_pe_restore_bars(edev->pe);
return NULL;
}
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
return NULL;
pci_restore_state(pdev);
return NULL;
}
/**
* eeh_report_resume - Tell device to resume normal operations
* @data: eeh device
* @userdata: return value
*
* 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 void *eeh_report_resume(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
bool was_in_error;
struct pci_driver *driver;
if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe))
return NULL;
device_lock(&dev->dev);
dev->error_state = pci_channel_io_normal;
driver = eeh_pcid_get(dev);
if (!driver) goto out_no_dev;
was_in_error = edev->in_error;
edev->in_error = false;
eeh_enable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->resume ||
(edev->mode & EEH_DEV_NO_HANDLER) || !was_in_error) {
edev->mode &= ~EEH_DEV_NO_HANDLER;
goto out;
}
driver->err_handler->resume(dev);
pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
out:
eeh_pcid_put(dev);
#ifdef CONFIG_PCI_IOV
if (eeh_ops->notify_resume && eeh_dev_to_pdn(edev))
eeh_ops->notify_resume(eeh_dev_to_pdn(edev));
#endif
out_no_dev:
device_unlock(&dev->dev);
return NULL;
}
/**
* eeh_report_failure - Tell device driver that device is dead.
* @data: eeh device
* @userdata: return value
*
* This informs the device driver that the device is permanently
* dead, and that no further recovery attempts will be made on it.
*/
static void *eeh_report_failure(struct eeh_dev *edev, void *userdata)
{
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
struct pci_driver *driver;
if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe))
return NULL;
device_lock(&dev->dev);
dev->error_state = pci_channel_io_perm_failure;
driver = eeh_pcid_get(dev);
if (!driver) goto out_no_dev;
eeh_disable_irq(dev);
if (!driver->err_handler ||
!driver->err_handler->error_detected)
goto out;
driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
out:
eeh_pcid_put(dev);
out_no_dev:
device_unlock(&dev->dev);
return NULL;
}
static void *eeh_add_virt_device(void *data, void *userdata)
{
struct pci_driver *driver;
struct eeh_dev *edev = (struct eeh_dev *)data;
struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
struct pci_dn *pdn = eeh_dev_to_pdn(edev);
if (!(edev->physfn)) {
pr_warn("%s: EEH dev %04x:%02x:%02x.%01x not for VF\n",
__func__, pdn->phb->global_number, pdn->busno,
PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
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, pdn->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;
int *removed = rmv_data ? &rmv_data->removed : NULL;
/*
* 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 (!dev || (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE))
return NULL;
/*
* We rely on count-based pcibios_release_device() to
* detach permanently offlined PEs. Unfortunately, that's
* not reliable enough. We might have the permanently
* offlined PEs attached, but we needn't take care of
* them and their child devices.
*/
if (eeh_dev_removed(edev))
return NULL;
if (removed) {
if (eeh_pe_passed(edev->pe))
return NULL;
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 NULL;
}
eeh_pcid_put(dev);
}
}
/* Remove it from PCI subsystem */
pr_debug("EEH: Removing %s without EEH sensitive driver\n",
pci_name(dev));
edev->bus = dev->bus;
edev->mode |= EEH_DEV_DISCONNECTED;
if (removed)
(*removed)++;
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_list, &rmv_data->edev_list);
} else {
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(dev);
pci_unlock_rescan_remove();
}
return NULL;
}
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 void *__eeh_clear_pe_frozen_state(struct eeh_pe *pe, void *flag)
{
bool clear_sw_state = *(bool *)flag;
int i, rc = 1;
for (i = 0; rc && i < 3; i++)
rc = eeh_unfreeze_pe(pe, clear_sw_state);
/* Stop immediately on any errors */
if (rc) {
pr_warn("%s: Failure %d unfreezing PHB#%x-PE#%x\n",
__func__, rc, pe->phb->global_number, pe->addr);
return (void *)pe;
}
return NULL;
}
static int eeh_clear_pe_frozen_state(struct eeh_pe *pe,
bool clear_sw_state)
{
void *rc;
rc = eeh_pe_traverse(pe, __eeh_clear_pe_frozen_state, &clear_sw_state);
if (!rc)
eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
return rc ? -EIO : 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);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
return ret;
}
/* Unfreeze the PE */
ret = eeh_clear_pe_frozen_state(pe, true);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
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);
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;
/* 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 (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);
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) {
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, list);
eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
if (pe->type & EEH_PE_VF) {
eeh_add_virt_device(edev, NULL);
} else {
if (!driver_eeh_aware)
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
pci_hp_add_devices(bus);
}
}
eeh_pe_state_clear(pe, EEH_PE_KEEP);
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
/**
* 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;
int rc = 0;
enum pci_ers_result result = PCI_ERS_RESULT_NONE;
struct eeh_rmv_data rmv_data = {LIST_HEAD_INIT(rmv_data.edev_list), 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;
}
eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
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);
goto hard_fail;
}
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);
/* 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.
*/
pr_info("EEH: Notify device drivers to shutdown\n");
eeh_pe_dev_traverse(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.
*/
rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
pr_warn("EEH: Permanent failure\n");
goto hard_fail;
}
/* Since rtas may enable MMIO when posting the error log,
* don't post the error log until after all dev drivers
* have been informed.
*/
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);
goto hard_fail;
}
}
/* 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)
goto hard_fail;
if (rc) {
result = PCI_ERS_RESULT_NEED_RESET;
} else {
pr_info("EEH: Notify device drivers to resume I/O\n");
eeh_pe_dev_traverse(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)
goto hard_fail;
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);
result = PCI_ERS_RESULT_RECOVERED;
}
}
/* If any device has a hard failure, then shut off everything. */
if (result == PCI_ERS_RESULT_DISCONNECT) {
pr_warn("EEH: Device driver gave up\n");
goto hard_fail;
}
/* 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);
goto hard_fail;
}
pr_info("EEH: Notify device drivers "
"the completion of reset\n");
result = PCI_ERS_RESULT_NONE;
eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
}
/* All devices should claim they have recovered by now. */
if ((result != PCI_ERS_RESULT_RECOVERED) &&
(result != PCI_ERS_RESULT_NONE)) {
pr_warn("EEH: Not recovered\n");
goto hard_fail;
}
/*
* For those hot removed VFs, we should add back them after PF get
* recovered properly.
*/
list_for_each_entry_safe(edev, tmp, &rmv_data.edev_list, rmv_list) {
eeh_add_virt_device(edev, NULL);
list_del(&edev->rmv_list);
}
/* Tell all device drivers that they can resume operations */
pr_info("EEH: Notify device driver to resume\n");
eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
pr_info("EEH: Recovery successful.\n");
goto final;
hard_fail:
/*
* 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_pe_dev_traverse(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);
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;
}
final:
eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
}
/**
* 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;
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_state_mark(phb_pe, EEH_PE_ISOLATED);
}
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_ISOLATED);
else
eeh_pe_state_mark(pe,
EEH_PE_ISOLATED | EEH_PE_RECOVERING);
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_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;
/* Notify all devices to be down */
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
eeh_pe_dev_traverse(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);
}
