cregit-Linux how code gets into the kernel

Release 4.14 arch/powerpc/kernel/eeh_driver.c

/*
 * 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_name - Retrieve name of PCI device driver
 * @pdev: PCI device
 *
 * This routine is used to retrieve the name of PCI device driver
 * if that's valid.
 */

static inline const char *eeh_pcid_name(struct pci_dev *pdev) { if (pdev && pdev->dev.driver) return pdev->dev.driver->name; return ""; }

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Linas Vepstas3391.67%133.33%
Olaf Hering25.56%133.33%
Gavin Shan12.78%133.33%
Total36100.00%3100.00%

/** * 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; }

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Gavin Shan49100.00%1100.00%
Total49100.00%1100.00%

/** * 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); }

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Gavin Shan34100.00%1100.00%
Total34100.00%1100.00%

/** * 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); }

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Mike Mason4985.96%120.00%
Gavin Shan712.28%360.00%
Michael Ellerman11.75%120.00%
Total57100.00%5100.00%

/** * 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); } }

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PersonTokensPropCommitsCommitProp
Mike Mason3660.00%114.29%
Thomas Gleixner1220.00%228.57%
Gavin Shan1118.33%342.86%
Michael Ellerman11.67%114.29%
Total60100.00%7100.00%


static bool eeh_dev_removed(struct eeh_dev *edev) { /* EEH device removed ? */ if (!edev || (edev->mode & EEH_DEV_REMOVED)) return true; return false; }

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Gavin Shan31100.00%1100.00%
Total31100.00%1100.00%


static void *eeh_dev_save_state(void *data, void *userdata) { struct eeh_dev *edev = data; 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; }

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PersonTokensPropCommitsCommitProp
Gavin Shan78100.00%2100.00%
Total78100.00%2100.00%

/** * 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(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; 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; dev->error_state = pci_channel_io_frozen; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) { eeh_pcid_put(dev); return NULL; } 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; eeh_pcid_put(dev); return NULL; }

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PersonTokensPropCommitsCommitProp
Linas Vepstas9052.33%327.27%
Gavin Shan6839.53%436.36%
Wei Yang63.49%19.09%
Yanmin Zhang63.49%19.09%
Paul Mackerras10.58%19.09%
Mike Mason10.58%19.09%
Total172100.00%11100.00%

/** * 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(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; 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; driver = eeh_pcid_get(dev); if (!driver) return NULL; if (!driver->err_handler || !driver->err_handler->mmio_enabled || (edev->mode & EEH_DEV_NO_HANDLER)) { eeh_pcid_put(dev); return NULL; } 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; eeh_pcid_put(dev); return NULL; }

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PersonTokensPropCommitsCommitProp
Gavin Shan8351.55%555.56%
Linas Vepstas7445.96%333.33%
Yanmin Zhang42.48%111.11%
Total161100.00%9100.00%

/** * 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(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; 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; dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->slot_reset || (edev->mode & EEH_DEV_NO_HANDLER) || (!edev->in_error)) { eeh_pcid_put(dev); return NULL; } 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; eeh_pcid_put(dev); return NULL; }

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PersonTokensPropCommitsCommitProp
Linas Vepstas9549.48%325.00%
Gavin Shan7740.10%541.67%
Wei Yang73.65%18.33%
Mike Mason73.65%216.67%
Yanmin Zhang63.12%18.33%
Total192100.00%12100.00%


static void *eeh_dev_restore_state(void *data, void *userdata) { struct eeh_dev *edev = data; 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; }

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Gavin Shan104100.00%2100.00%
Total104100.00%2100.00%

/** * 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(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; 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; dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); if (!driver) return NULL; 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; eeh_pcid_put(dev); return NULL; } driver->err_handler->resume(dev); eeh_pcid_put(dev); return NULL; }

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PersonTokensPropCommitsCommitProp
Gavin Shan8552.47%550.00%
Linas Vepstas5232.10%220.00%
Wei Yang1811.11%110.00%
Yanmin Zhang63.70%110.00%
Mike Mason10.62%110.00%
Total162100.00%10100.00%

/** * 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(void *data, void *userdata) { struct eeh_dev *edev = (struct eeh_dev *)data; 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; dev->error_state = pci_channel_io_perm_failure; driver = eeh_pcid_get(dev); if (!driver) return NULL; eeh_disable_irq(dev); if (!driver->err_handler || !driver->err_handler->error_detected) { eeh_pcid_put(dev); return NULL; } driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); eeh_pcid_put(dev); return NULL; }

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PersonTokensPropCommitsCommitProp
Gavin Shan7053.44%457.14%
Linas Vepstas5340.46%114.29%
Yanmin Zhang64.58%114.29%
Mike Mason21.53%114.29%
Total131100.00%7100.00%


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) { eeh_pcid_put(dev); if (driver->err_handler) return NULL; } #ifdef CONFIG_PPC_POWERNV pci_iov_add_virtfn(edev->physfn, pdn->vf_index, 0); #endif return NULL; }

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Wei Yang14499.31%150.00%
Alexey Kardashevskiy10.69%150.00%
Total145100.00%2100.00%


static void *eeh_rmv_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 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; driver = eeh_pcid_get(dev); if (driver) { eeh_pcid_put(dev); if (removed && eeh_pe_passed(edev->pe)) return NULL; if (removed && driver->err_handler && driver->err_handler->error_detected && driver->err_handler->slot_reset) return NULL; } /* 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_PPC_POWERNV struct pci_dn *pdn = eeh_dev_to_pdn(edev); pci_iov_remove_virtfn(edev->physfn, pdn->vf_index, 0); 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; }

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Gavin Shan15858.96%450.00%
Wei Yang9334.70%112.50%
Thadeu Lima de Souza Cascardo103.73%112.50%
Rafael J. Wysocki62.24%112.50%
Björn Helgaas10.37%112.50%
Total268100.00%8100.00%


static void *eeh_pe_detach_dev(void *data, void *userdata) { struct eeh_pe *pe = (struct eeh_pe *)data; 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; }

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Gavin Shan76100.00%1100.00%
Total76100.00%1100.00%

/* * 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(void *data, void *flag) { struct eeh_pe *pe = (struct eeh_pe *)data; 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; }

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Gavin Shan104100.00%5100.00%
Total104100.00%5100.00%


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; }

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Gavin Shan50100.00%3100.00%
Total50100.00%3100.00%


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; }

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Gavin Shan11399.12%150.00%
Russell Currey10.88%150.00%
Total114100.00%2100.00%

/** * eeh_reset_device - Perform actual reset of a pci slot * @pe: EEH PE * @bus: PCI bus corresponding to the isolcated slot * * 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) { struct pci_bus *frozen_bus = eeh_pe_bus_get(pe); struct timeval 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 (bus) { if (pe->type & EEH_PE_VF) { eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL); } else { pci_lock_rescan_remove(); pci_hp_remove_devices(bus); pci_unlock_rescan_remove(); } } else if (frozen_bus) { eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data); } /* * 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 (bus) { pr_info("EEH: Sleep 5s ahead of complete hotplug\n"); 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 { eeh_pe_state_clear(pe, EEH_PE_PRI_BUS); pci_hp_add_devices(bus); } } else if (frozen_bus && rmv_data->removed) { pr_info("EEH: Sleep 5s ahead of partial hotplug\n"); ssleep(5); 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 pci_hp_add_devices(frozen_bus); } eeh_pe_state_clear(pe, EEH_PE_KEEP); pe->tstamp = tstamp; pe->freeze_count = cnt; pci_unlock_rescan_remove(); return 0; }

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Gavin Shan15345.13%1359.09%
Wei Yang9728.61%14.55%
Linas Vepstas6619.47%418.18%
Rafael J. Wysocki164.72%14.55%
Andrew Donnellan61.77%29.09%
Russell Currey10.29%14.55%
Total339100.00%22100.00%

/* 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 * * Attempts to recover the given PE. If recovery fails or the PE has failed * too many times, remove the PE. * * Returns true if @pe should no longer be used, else false. */
static bool eeh_handle_normal_event(struct eeh_pe *pe) { struct pci_bus *frozen_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}; frozen_bus = eeh_pe_bus_get(pe); if (!frozen_bus) { pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n", __func__, pe->phb->global_number, pe->addr); return false; } 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\n" "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\n", pe->freeze_count); /* 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, frozen_bus, NULL); 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, NULL, &rmv_data); 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