cregit-Linux how code gets into the kernel

Release 4.14 arch/powerpc/kernel/eeh_driver.c

Directory: arch/powerpc/kernel
/*
 * 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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/**
 * 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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/**
 * 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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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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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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/**
 * 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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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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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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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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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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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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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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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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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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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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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;
}


Contributors
PersonTokensPropCommitsCommitProp
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, eeh_report_resume, NULL);

	return false;

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 (frozen_bus) {
		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(frozen_bus);
			pci_unlock_rescan_remove();

			/* The passed PE should no longer be used */
			return true;
		}
	}
	return false;
}


Contributors
PersonTokensPropCommitsCommitProp
Linas Vepstas31148.22%1333.33%


Gavin Shan19029.46%1846.15%


Wei Yang8613.33%25.13%


Russell Currey406.20%37.69%


Rafael J. Wysocki81.24%12.56%


Paul Mackerras81.24%12.56%


Al Viro20.31%12.56%


Total645100.00%39100.00%



/**
 * 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.
 */



static 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() can make the PE stale if it
                         * determines that the PE cannot possibly be recovered.
                         * Don't modify the PE state if that's the case.
                         */
			if (eeh_handle_normal_event(pe))
				continue;

			eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
		} 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);
}


Contributors
PersonTokensPropCommitsCommitProp
Gavin Shan27685.71%654.55%


Russell Currey4012.42%436.36%


Rafael J. Wysocki61.86%19.09%


Total322100.00%11100.00%



/**
 * eeh_handle_event - Reset a PCI device after hard lockup.
 * @pe: EEH 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_event(struct eeh_pe *pe)
{
	if (pe)
		eeh_handle_normal_event(pe);
	else
		eeh_handle_special_event();
}

Contributors
PersonTokensPropCommitsCommitProp
Gavin Shan23100.00%1100.00%


Total23100.00%1100.00%




Overall Contributors
PersonTokensPropCommitsCommitProp
Gavin Shan185754.31%4248.84%


Linas Vepstas80923.66%1922.09%


Wei Yang46313.54%22.33%


Mike Mason962.81%22.33%


Russell Currey842.46%66.98%


Rafael J. Wysocki361.05%11.16%


Yanmin Zhang280.82%11.16%


Thomas Gleixner120.35%22.33%


Thadeu Lima de Souza Cascardo100.29%11.16%


Paul Mackerras90.26%11.16%


Andrew Donnellan60.18%22.33%


Michael Ellerman20.06%22.33%


Al Viro20.06%11.16%


Olaf Hering20.06%11.16%


Björn Helgaas10.03%11.16%


Alexey Kardashevskiy10.03%11.16%


Brian King10.03%11.16%


Total3419100.00%86100.00%


Directory: arch/powerpc/kernel



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