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1225 lines
32 KiB
1225 lines
32 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* PCI Error Recovery Driver for RPA-compliant PPC64 platform. |
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* Copyright IBM Corp. 2004 2005 |
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* Copyright Linas Vepstas <[email protected]> 2004, 2005 |
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* |
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* Send comments and feedback to Linas Vepstas <[email protected]> |
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*/ |
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#include <linux/delay.h> |
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#include <linux/interrupt.h> |
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#include <linux/irq.h> |
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#include <linux/module.h> |
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#include <linux/pci.h> |
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#include <linux/pci_hotplug.h> |
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#include <asm/eeh.h> |
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#include <asm/eeh_event.h> |
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#include <asm/ppc-pci.h> |
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#include <asm/pci-bridge.h> |
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#include <asm/prom.h> |
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#include <asm/rtas.h> |
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|
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struct eeh_rmv_data { |
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struct list_head removed_vf_list; |
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int removed_dev_count; |
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}; |
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|
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static int eeh_result_priority(enum pci_ers_result result) |
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{ |
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switch (result) { |
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case PCI_ERS_RESULT_NONE: |
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return 1; |
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case PCI_ERS_RESULT_NO_AER_DRIVER: |
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return 2; |
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case PCI_ERS_RESULT_RECOVERED: |
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return 3; |
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case PCI_ERS_RESULT_CAN_RECOVER: |
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return 4; |
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case PCI_ERS_RESULT_DISCONNECT: |
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return 5; |
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case PCI_ERS_RESULT_NEED_RESET: |
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return 6; |
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default: |
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WARN_ONCE(1, "Unknown pci_ers_result value: %d\n", (int)result); |
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return 0; |
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} |
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}; |
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|
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static const char *pci_ers_result_name(enum pci_ers_result result) |
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{ |
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switch (result) { |
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case PCI_ERS_RESULT_NONE: |
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return "none"; |
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case PCI_ERS_RESULT_CAN_RECOVER: |
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return "can recover"; |
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case PCI_ERS_RESULT_NEED_RESET: |
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return "need reset"; |
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case PCI_ERS_RESULT_DISCONNECT: |
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return "disconnect"; |
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case PCI_ERS_RESULT_RECOVERED: |
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return "recovered"; |
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case PCI_ERS_RESULT_NO_AER_DRIVER: |
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return "no AER driver"; |
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default: |
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WARN_ONCE(1, "Unknown result type: %d\n", (int)result); |
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return "unknown"; |
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} |
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}; |
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|
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static enum pci_ers_result pci_ers_merge_result(enum pci_ers_result old, |
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enum pci_ers_result new) |
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{ |
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if (eeh_result_priority(new) > eeh_result_priority(old)) |
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return new; |
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return old; |
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} |
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|
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static bool eeh_dev_removed(struct eeh_dev *edev) |
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{ |
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return !edev || (edev->mode & EEH_DEV_REMOVED); |
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} |
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|
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static bool eeh_edev_actionable(struct eeh_dev *edev) |
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{ |
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if (!edev->pdev) |
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return false; |
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if (edev->pdev->error_state == pci_channel_io_perm_failure) |
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return false; |
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if (eeh_dev_removed(edev)) |
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return false; |
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if (eeh_pe_passed(edev->pe)) |
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return false; |
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|
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return true; |
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} |
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|
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/** |
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* eeh_pcid_get - Get the PCI device driver |
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* @pdev: PCI device |
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* |
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* The function is used to retrieve the PCI device driver for |
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* the indicated PCI device. Besides, we will increase the reference |
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* of the PCI device driver to prevent that being unloaded on |
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* the fly. Otherwise, kernel crash would be seen. |
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*/ |
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static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev) |
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{ |
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if (!pdev || !pdev->driver) |
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return NULL; |
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|
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if (!try_module_get(pdev->driver->driver.owner)) |
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return NULL; |
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return pdev->driver; |
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} |
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|
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/** |
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* eeh_pcid_put - Dereference on the PCI device driver |
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* @pdev: PCI device |
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* |
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* The function is called to do dereference on the PCI device |
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* driver of the indicated PCI device. |
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*/ |
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static inline void eeh_pcid_put(struct pci_dev *pdev) |
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{ |
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if (!pdev || !pdev->driver) |
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return; |
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|
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module_put(pdev->driver->driver.owner); |
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} |
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|
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/** |
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* eeh_disable_irq - Disable interrupt for the recovering device |
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* @dev: PCI device |
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* |
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* This routine must be called when reporting temporary or permanent |
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* error to the particular PCI device to disable interrupt of that |
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* device. If the device has enabled MSI or MSI-X interrupt, we needn't |
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* do real work because EEH should freeze DMA transfers for those PCI |
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* devices encountering EEH errors, which includes MSI or MSI-X. |
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*/ |
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static void eeh_disable_irq(struct eeh_dev *edev) |
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{ |
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/* Don't disable MSI and MSI-X interrupts. They are |
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* effectively disabled by the DMA Stopped state |
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* when an EEH error occurs. |
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*/ |
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if (edev->pdev->msi_enabled || edev->pdev->msix_enabled) |
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return; |
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|
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if (!irq_has_action(edev->pdev->irq)) |
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return; |
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edev->mode |= EEH_DEV_IRQ_DISABLED; |
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disable_irq_nosync(edev->pdev->irq); |
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} |
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|
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/** |
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* eeh_enable_irq - Enable interrupt for the recovering device |
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* @dev: PCI device |
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* |
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* This routine must be called to enable interrupt while failed |
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* device could be resumed. |
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*/ |
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static void eeh_enable_irq(struct eeh_dev *edev) |
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{ |
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if ((edev->mode) & EEH_DEV_IRQ_DISABLED) { |
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edev->mode &= ~EEH_DEV_IRQ_DISABLED; |
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/* |
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* FIXME !!!!! |
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* |
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* This is just ass backwards. This maze has |
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* unbalanced irq_enable/disable calls. So instead of |
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* finding the root cause it works around the warning |
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* in the irq_enable code by conditionally calling |
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* into it. |
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* |
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* That's just wrong.The warning in the core code is |
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* there to tell people to fix their asymmetries in |
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* their own code, not by abusing the core information |
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* to avoid it. |
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* |
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* I so wish that the assymetry would be the other way |
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* round and a few more irq_disable calls render that |
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* shit unusable forever. |
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* |
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* tglx |
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*/ |
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if (irqd_irq_disabled(irq_get_irq_data(edev->pdev->irq))) |
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enable_irq(edev->pdev->irq); |
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} |
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} |
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|
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static void eeh_dev_save_state(struct eeh_dev *edev, void *userdata) |
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{ |
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struct pci_dev *pdev; |
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|
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if (!edev) |
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return; |
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|
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/* |
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* We cannot access the config space on some adapters. |
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* Otherwise, it will cause fenced PHB. We don't save |
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* the content in their config space and will restore |
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* from the initial config space saved when the EEH |
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* device is created. |
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*/ |
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if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) |
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return; |
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|
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pdev = eeh_dev_to_pci_dev(edev); |
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if (!pdev) |
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return; |
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pci_save_state(pdev); |
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} |
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|
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static void eeh_set_channel_state(struct eeh_pe *root, pci_channel_state_t s) |
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{ |
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struct eeh_pe *pe; |
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struct eeh_dev *edev, *tmp; |
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|
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eeh_for_each_pe(root, pe) |
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eeh_pe_for_each_dev(pe, edev, tmp) |
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if (eeh_edev_actionable(edev)) |
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edev->pdev->error_state = s; |
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} |
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|
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static void eeh_set_irq_state(struct eeh_pe *root, bool enable) |
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{ |
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struct eeh_pe *pe; |
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struct eeh_dev *edev, *tmp; |
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eeh_for_each_pe(root, pe) { |
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eeh_pe_for_each_dev(pe, edev, tmp) { |
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if (!eeh_edev_actionable(edev)) |
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continue; |
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|
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if (!eeh_pcid_get(edev->pdev)) |
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continue; |
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if (enable) |
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eeh_enable_irq(edev); |
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else |
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eeh_disable_irq(edev); |
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|
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eeh_pcid_put(edev->pdev); |
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} |
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} |
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} |
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typedef enum pci_ers_result (*eeh_report_fn)(struct eeh_dev *, |
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struct pci_dev *, |
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struct pci_driver *); |
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static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn, |
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enum pci_ers_result *result) |
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{ |
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struct pci_dev *pdev; |
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struct pci_driver *driver; |
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enum pci_ers_result new_result; |
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pci_lock_rescan_remove(); |
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pdev = edev->pdev; |
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if (pdev) |
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get_device(&pdev->dev); |
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pci_unlock_rescan_remove(); |
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if (!pdev) { |
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eeh_edev_info(edev, "no device"); |
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return; |
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} |
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device_lock(&pdev->dev); |
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if (eeh_edev_actionable(edev)) { |
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driver = eeh_pcid_get(pdev); |
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|
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if (!driver) |
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eeh_edev_info(edev, "no driver"); |
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else if (!driver->err_handler) |
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eeh_edev_info(edev, "driver not EEH aware"); |
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else if (edev->mode & EEH_DEV_NO_HANDLER) |
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eeh_edev_info(edev, "driver bound too late"); |
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else { |
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new_result = fn(edev, pdev, driver); |
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eeh_edev_info(edev, "%s driver reports: '%s'", |
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driver->name, |
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pci_ers_result_name(new_result)); |
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if (result) |
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*result = pci_ers_merge_result(*result, |
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new_result); |
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} |
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if (driver) |
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eeh_pcid_put(pdev); |
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} else { |
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eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!pdev, |
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!eeh_dev_removed(edev), !eeh_pe_passed(edev->pe)); |
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} |
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device_unlock(&pdev->dev); |
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if (edev->pdev != pdev) |
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eeh_edev_warn(edev, "Device changed during processing!\n"); |
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put_device(&pdev->dev); |
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} |
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|
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static void eeh_pe_report(const char *name, struct eeh_pe *root, |
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eeh_report_fn fn, enum pci_ers_result *result) |
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{ |
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struct eeh_pe *pe; |
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struct eeh_dev *edev, *tmp; |
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|
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pr_info("EEH: Beginning: '%s'\n", name); |
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eeh_for_each_pe(root, pe) eeh_pe_for_each_dev(pe, edev, tmp) |
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eeh_pe_report_edev(edev, fn, result); |
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if (result) |
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pr_info("EEH: Finished:'%s' with aggregate recovery state:'%s'\n", |
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name, pci_ers_result_name(*result)); |
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else |
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pr_info("EEH: Finished:'%s'", name); |
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} |
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|
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/** |
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* eeh_report_error - Report pci error to each device driver |
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* @edev: eeh device |
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* @driver: device's PCI driver |
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* |
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* Report an EEH error to each device driver. |
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*/ |
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static enum pci_ers_result eeh_report_error(struct eeh_dev *edev, |
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struct pci_dev *pdev, |
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struct pci_driver *driver) |
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{ |
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enum pci_ers_result rc; |
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if (!driver->err_handler->error_detected) |
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return PCI_ERS_RESULT_NONE; |
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eeh_edev_info(edev, "Invoking %s->error_detected(IO frozen)", |
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driver->name); |
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rc = driver->err_handler->error_detected(pdev, pci_channel_io_frozen); |
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|
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edev->in_error = true; |
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pci_uevent_ers(pdev, PCI_ERS_RESULT_NONE); |
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return rc; |
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} |
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|
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/** |
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* eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled |
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* @edev: eeh device |
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* @driver: device's PCI driver |
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* |
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* Tells each device driver that IO ports, MMIO and config space I/O |
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* are now enabled. |
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*/ |
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static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev, |
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struct pci_dev *pdev, |
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struct pci_driver *driver) |
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{ |
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if (!driver->err_handler->mmio_enabled) |
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return PCI_ERS_RESULT_NONE; |
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eeh_edev_info(edev, "Invoking %s->mmio_enabled()", driver->name); |
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return driver->err_handler->mmio_enabled(pdev); |
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} |
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|
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/** |
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* eeh_report_reset - Tell device that slot has been reset |
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* @edev: eeh device |
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* @driver: device's PCI driver |
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* |
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* This routine must be called while EEH tries to reset particular |
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* PCI device so that the associated PCI device driver could take |
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* some actions, usually to save data the driver needs so that the |
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* driver can work again while the device is recovered. |
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*/ |
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static enum pci_ers_result eeh_report_reset(struct eeh_dev *edev, |
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struct pci_dev *pdev, |
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struct pci_driver *driver) |
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{ |
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if (!driver->err_handler->slot_reset || !edev->in_error) |
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return PCI_ERS_RESULT_NONE; |
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eeh_edev_info(edev, "Invoking %s->slot_reset()", driver->name); |
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return driver->err_handler->slot_reset(pdev); |
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} |
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|
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static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata) |
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{ |
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struct pci_dev *pdev; |
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|
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if (!edev) |
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return; |
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|
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/* |
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* The content in the config space isn't saved because |
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* the blocked config space on some adapters. We have |
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* to restore the initial saved config space when the |
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* EEH device is created. |
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*/ |
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if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) { |
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if (list_is_last(&edev->entry, &edev->pe->edevs)) |
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eeh_pe_restore_bars(edev->pe); |
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|
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return; |
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} |
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|
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pdev = eeh_dev_to_pci_dev(edev); |
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if (!pdev) |
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return; |
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|
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pci_restore_state(pdev); |
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} |
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|
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/** |
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* eeh_report_resume - Tell device to resume normal operations |
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* @edev: eeh device |
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* @driver: device's PCI driver |
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* |
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* This routine must be called to notify the device driver that it |
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* could resume so that the device driver can do some initialization |
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* to make the recovered device work again. |
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*/ |
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static enum pci_ers_result eeh_report_resume(struct eeh_dev *edev, |
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struct pci_dev *pdev, |
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struct pci_driver *driver) |
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{ |
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if (!driver->err_handler->resume || !edev->in_error) |
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return PCI_ERS_RESULT_NONE; |
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|
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eeh_edev_info(edev, "Invoking %s->resume()", driver->name); |
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driver->err_handler->resume(pdev); |
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|
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pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_RECOVERED); |
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#ifdef CONFIG_PCI_IOV |
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if (eeh_ops->notify_resume) |
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eeh_ops->notify_resume(edev); |
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#endif |
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return PCI_ERS_RESULT_NONE; |
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} |
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|
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/** |
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* eeh_report_failure - Tell device driver that device is dead. |
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* @edev: eeh device |
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* @driver: device's PCI driver |
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* |
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* This informs the device driver that the device is permanently |
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* dead, and that no further recovery attempts will be made on it. |
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*/ |
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static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev, |
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struct pci_dev *pdev, |
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struct pci_driver *driver) |
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{ |
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enum pci_ers_result rc; |
|
|
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if (!driver->err_handler->error_detected) |
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return PCI_ERS_RESULT_NONE; |
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|
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eeh_edev_info(edev, "Invoking %s->error_detected(permanent failure)", |
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driver->name); |
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rc = driver->err_handler->error_detected(pdev, |
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pci_channel_io_perm_failure); |
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|
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pci_uevent_ers(pdev, PCI_ERS_RESULT_DISCONNECT); |
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return rc; |
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} |
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|
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static void *eeh_add_virt_device(struct eeh_dev *edev) |
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{ |
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struct pci_driver *driver; |
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struct pci_dev *dev = eeh_dev_to_pci_dev(edev); |
|
|
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if (!(edev->physfn)) { |
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eeh_edev_warn(edev, "Not for VF\n"); |
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return NULL; |
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} |
|
|
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driver = eeh_pcid_get(dev); |
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if (driver) { |
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if (driver->err_handler) { |
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eeh_pcid_put(dev); |
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return NULL; |
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} |
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eeh_pcid_put(dev); |
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} |
|
|
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#ifdef CONFIG_PCI_IOV |
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pci_iov_add_virtfn(edev->physfn, edev->vf_index); |
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#endif |
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return NULL; |
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} |
|
|
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static void eeh_rmv_device(struct eeh_dev *edev, void *userdata) |
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{ |
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struct pci_driver *driver; |
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struct pci_dev *dev = eeh_dev_to_pci_dev(edev); |
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struct eeh_rmv_data *rmv_data = (struct eeh_rmv_data *)userdata; |
|
|
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/* |
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* Actually, we should remove the PCI bridges as well. |
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* However, that's lots of complexity to do that, |
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* particularly some of devices under the bridge might |
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* support EEH. So we just care about PCI devices for |
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* simplicity here. |
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*/ |
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if (!eeh_edev_actionable(edev) || |
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(dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) |
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return; |
|
|
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if (rmv_data) { |
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driver = eeh_pcid_get(dev); |
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if (driver) { |
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if (driver->err_handler && |
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driver->err_handler->error_detected && |
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driver->err_handler->slot_reset) { |
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eeh_pcid_put(dev); |
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return; |
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} |
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eeh_pcid_put(dev); |
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} |
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} |
|
|
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/* Remove it from PCI subsystem */ |
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pr_info("EEH: Removing %s without EEH sensitive driver\n", |
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pci_name(dev)); |
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edev->mode |= EEH_DEV_DISCONNECTED; |
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if (rmv_data) |
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rmv_data->removed_dev_count++; |
|
|
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if (edev->physfn) { |
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#ifdef CONFIG_PCI_IOV |
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pci_iov_remove_virtfn(edev->physfn, edev->vf_index); |
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edev->pdev = NULL; |
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#endif |
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if (rmv_data) |
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list_add(&edev->rmv_entry, &rmv_data->removed_vf_list); |
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} else { |
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pci_lock_rescan_remove(); |
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pci_stop_and_remove_bus_device(dev); |
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pci_unlock_rescan_remove(); |
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} |
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} |
|
|
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static void *eeh_pe_detach_dev(struct eeh_pe *pe, void *userdata) |
|
{ |
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struct eeh_dev *edev, *tmp; |
|
|
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eeh_pe_for_each_dev(pe, edev, tmp) { |
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if (!(edev->mode & EEH_DEV_DISCONNECTED)) |
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continue; |
|
|
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edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED); |
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eeh_pe_tree_remove(edev); |
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} |
|
|
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return NULL; |
|
} |
|
|
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/* |
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* 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 |
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* for 3 times as well. |
|
*/ |
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static int eeh_clear_pe_frozen_state(struct eeh_pe *root, bool include_passed) |
|
{ |
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struct eeh_pe *pe; |
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int i; |
|
|
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eeh_for_each_pe(root, pe) { |
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if (include_passed || !eeh_pe_passed(pe)) { |
|
for (i = 0; i < 3; i++) |
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if (!eeh_unfreeze_pe(pe)) |
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break; |
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if (i >= 3) |
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return -EIO; |
|
} |
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} |
|
eeh_pe_state_clear(root, EEH_PE_ISOLATED, include_passed); |
|
return 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, true); |
|
if (ret) { |
|
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); |
|
return ret; |
|
} |
|
|
|
/* Unfreeze the PE */ |
|
ret = eeh_clear_pe_frozen_state(pe, true); |
|
if (ret) { |
|
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); |
|
return ret; |
|
} |
|
|
|
/* Restore device state */ |
|
eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL); |
|
|
|
/* Clear recovery mode */ |
|
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* eeh_reset_device - Perform actual reset of a pci slot |
|
* @driver_eeh_aware: Does the device's driver provide EEH support? |
|
* @pe: EEH PE |
|
* @bus: PCI bus corresponding to the isolcated slot |
|
* @rmv_data: Optional, list to record removed devices |
|
* |
|
* This routine must be called to do reset on the indicated PE. |
|
* During the reset, udev might be invoked because those affected |
|
* PCI devices will be removed and then added. |
|
*/ |
|
static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, |
|
struct eeh_rmv_data *rmv_data, |
|
bool driver_eeh_aware) |
|
{ |
|
time64_t tstamp; |
|
int cnt, rc; |
|
struct eeh_dev *edev; |
|
struct eeh_pe *tmp_pe; |
|
bool any_passed = false; |
|
|
|
eeh_for_each_pe(pe, tmp_pe) |
|
any_passed |= eeh_pe_passed(tmp_pe); |
|
|
|
/* pcibios will clear the counter; save the value */ |
|
cnt = pe->freeze_count; |
|
tstamp = pe->tstamp; |
|
|
|
/* |
|
* We don't remove the corresponding PE instances because |
|
* we need the information afterwords. The attached EEH |
|
* devices are expected to be attached soon when calling |
|
* into pci_hp_add_devices(). |
|
*/ |
|
eeh_pe_state_mark(pe, EEH_PE_KEEP); |
|
if (any_passed || driver_eeh_aware || (pe->type & EEH_PE_VF)) { |
|
eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data); |
|
} else { |
|
pci_lock_rescan_remove(); |
|
pci_hp_remove_devices(bus); |
|
pci_unlock_rescan_remove(); |
|
} |
|
|
|
/* |
|
* Reset the pci controller. (Asserts RST#; resets config space). |
|
* Reconfigure bridges and devices. Don't try to bring the system |
|
* up if the reset failed for some reason. |
|
* |
|
* During the reset, it's very dangerous to have uncontrolled PCI |
|
* config accesses. So we prefer to block them. However, controlled |
|
* PCI config accesses initiated from EEH itself are allowed. |
|
*/ |
|
rc = eeh_pe_reset_full(pe, false); |
|
if (rc) |
|
return rc; |
|
|
|
pci_lock_rescan_remove(); |
|
|
|
/* Restore PE */ |
|
eeh_ops->configure_bridge(pe); |
|
eeh_pe_restore_bars(pe); |
|
|
|
/* Clear frozen state */ |
|
rc = eeh_clear_pe_frozen_state(pe, false); |
|
if (rc) { |
|
pci_unlock_rescan_remove(); |
|
return rc; |
|
} |
|
|
|
/* Give the system 5 seconds to finish running the user-space |
|
* hotplug shutdown scripts, e.g. ifdown for ethernet. Yes, |
|
* this is a hack, but if we don't do this, and try to bring |
|
* the device up before the scripts have taken it down, |
|
* potentially weird things happen. |
|
*/ |
|
if (!driver_eeh_aware || rmv_data->removed_dev_count) { |
|
pr_info("EEH: Sleep 5s ahead of %s hotplug\n", |
|
(driver_eeh_aware ? "partial" : "complete")); |
|
ssleep(5); |
|
|
|
/* |
|
* The EEH device is still connected with its parent |
|
* PE. We should disconnect it so the binding can be |
|
* rebuilt when adding PCI devices. |
|
*/ |
|
edev = list_first_entry(&pe->edevs, struct eeh_dev, entry); |
|
eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL); |
|
if (pe->type & EEH_PE_VF) { |
|
eeh_add_virt_device(edev); |
|
} else { |
|
if (!driver_eeh_aware) |
|
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true); |
|
pci_hp_add_devices(bus); |
|
} |
|
} |
|
eeh_pe_state_clear(pe, EEH_PE_KEEP, true); |
|
|
|
pe->tstamp = tstamp; |
|
pe->freeze_count = cnt; |
|
|
|
pci_unlock_rescan_remove(); |
|
return 0; |
|
} |
|
|
|
/* The longest amount of time to wait for a pci device |
|
* to come back on line, in seconds. |
|
*/ |
|
#define MAX_WAIT_FOR_RECOVERY 300 |
|
|
|
|
|
/* Walks the PE tree after processing an event to remove any stale PEs. |
|
* |
|
* NB: This needs to be recursive to ensure the leaf PEs get removed |
|
* before their parents do. Although this is possible to do recursively |
|
* we don't since this is easier to read and we need to garantee |
|
* the leaf nodes will be handled first. |
|
*/ |
|
static void eeh_pe_cleanup(struct eeh_pe *pe) |
|
{ |
|
struct eeh_pe *child_pe, *tmp; |
|
|
|
list_for_each_entry_safe(child_pe, tmp, &pe->child_list, child) |
|
eeh_pe_cleanup(child_pe); |
|
|
|
if (pe->state & EEH_PE_KEEP) |
|
return; |
|
|
|
if (!(pe->state & EEH_PE_INVALID)) |
|
return; |
|
|
|
if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) { |
|
list_del(&pe->child); |
|
kfree(pe); |
|
} |
|
} |
|
|
|
/** |
|
* eeh_check_slot_presence - Check if a device is still present in a slot |
|
* @pdev: pci_dev to check |
|
* |
|
* This function may return a false positive if we can't determine the slot's |
|
* presence state. This might happen for for PCIe slots if the PE containing |
|
* the upstream bridge is also frozen, or the bridge is part of the same PE |
|
* as the device. |
|
* |
|
* This shouldn't happen often, but you might see it if you hotplug a PCIe |
|
* switch. |
|
*/ |
|
static bool eeh_slot_presence_check(struct pci_dev *pdev) |
|
{ |
|
const struct hotplug_slot_ops *ops; |
|
struct pci_slot *slot; |
|
u8 state; |
|
int rc; |
|
|
|
if (!pdev) |
|
return false; |
|
|
|
if (pdev->error_state == pci_channel_io_perm_failure) |
|
return false; |
|
|
|
slot = pdev->slot; |
|
if (!slot || !slot->hotplug) |
|
return true; |
|
|
|
ops = slot->hotplug->ops; |
|
if (!ops || !ops->get_adapter_status) |
|
return true; |
|
|
|
/* set the attention indicator while we've got the slot ops */ |
|
if (ops->set_attention_status) |
|
ops->set_attention_status(slot->hotplug, 1); |
|
|
|
rc = ops->get_adapter_status(slot->hotplug, &state); |
|
if (rc) |
|
return true; |
|
|
|
return !!state; |
|
} |
|
|
|
static void eeh_clear_slot_attention(struct pci_dev *pdev) |
|
{ |
|
const struct hotplug_slot_ops *ops; |
|
struct pci_slot *slot; |
|
|
|
if (!pdev) |
|
return; |
|
|
|
if (pdev->error_state == pci_channel_io_perm_failure) |
|
return; |
|
|
|
slot = pdev->slot; |
|
if (!slot || !slot->hotplug) |
|
return; |
|
|
|
ops = slot->hotplug->ops; |
|
if (!ops || !ops->set_attention_status) |
|
return; |
|
|
|
ops->set_attention_status(slot->hotplug, 0); |
|
} |
|
|
|
/** |
|
* eeh_handle_normal_event - Handle EEH events on a specific PE |
|
* @pe: EEH PE - which should not be used after we return, as it may |
|
* have been invalidated. |
|
* |
|
* Attempts to recover the given PE. If recovery fails or the PE has failed |
|
* too many times, remove the PE. |
|
* |
|
* While PHB detects address or data parity errors on particular PCI |
|
* slot, the associated PE will be frozen. Besides, DMA's occurring |
|
* to wild addresses (which usually happen due to bugs in device |
|
* drivers or in PCI adapter firmware) can cause EEH error. #SERR, |
|
* #PERR or other misc PCI-related errors also can trigger EEH errors. |
|
* |
|
* Recovery process consists of unplugging the device driver (which |
|
* generated hotplug events to userspace), then issuing a PCI #RST to |
|
* the device, then reconfiguring the PCI config space for all bridges |
|
* & devices under this slot, and then finally restarting the device |
|
* drivers (which cause a second set of hotplug events to go out to |
|
* userspace). |
|
*/ |
|
void eeh_handle_normal_event(struct eeh_pe *pe) |
|
{ |
|
struct pci_bus *bus; |
|
struct eeh_dev *edev, *tmp; |
|
struct eeh_pe *tmp_pe; |
|
int rc = 0; |
|
enum pci_ers_result result = PCI_ERS_RESULT_NONE; |
|
struct eeh_rmv_data rmv_data = |
|
{LIST_HEAD_INIT(rmv_data.removed_vf_list), 0}; |
|
int devices = 0; |
|
|
|
bus = eeh_pe_bus_get(pe); |
|
if (!bus) { |
|
pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n", |
|
__func__, pe->phb->global_number, pe->addr); |
|
return; |
|
} |
|
|
|
/* |
|
* When devices are hot-removed we might get an EEH due to |
|
* a driver attempting to touch the MMIO space of a removed |
|
* device. In this case we don't have a device to recover |
|
* so suppress the event if we can't find any present devices. |
|
* |
|
* The hotplug driver should take care of tearing down the |
|
* device itself. |
|
*/ |
|
eeh_for_each_pe(pe, tmp_pe) |
|
eeh_pe_for_each_dev(tmp_pe, edev, tmp) |
|
if (eeh_slot_presence_check(edev->pdev)) |
|
devices++; |
|
|
|
if (!devices) { |
|
pr_debug("EEH: Frozen PHB#%x-PE#%x is empty!\n", |
|
pe->phb->global_number, pe->addr); |
|
goto out; /* nothing to recover */ |
|
} |
|
|
|
/* Log the event */ |
|
if (pe->type & EEH_PE_PHB) { |
|
pr_err("EEH: Recovering PHB#%x, location: %s\n", |
|
pe->phb->global_number, eeh_pe_loc_get(pe)); |
|
} else { |
|
struct eeh_pe *phb_pe = eeh_phb_pe_get(pe->phb); |
|
|
|
pr_err("EEH: Recovering PHB#%x-PE#%x\n", |
|
pe->phb->global_number, pe->addr); |
|
pr_err("EEH: PE location: %s, PHB location: %s\n", |
|
eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe)); |
|
} |
|
|
|
#ifdef CONFIG_STACKTRACE |
|
/* |
|
* Print the saved stack trace now that we've verified there's |
|
* something to recover. |
|
*/ |
|
if (pe->trace_entries) { |
|
void **ptrs = (void **) pe->stack_trace; |
|
int i; |
|
|
|
pr_err("EEH: Frozen PHB#%x-PE#%x detected\n", |
|
pe->phb->global_number, pe->addr); |
|
|
|
/* FIXME: Use the same format as dump_stack() */ |
|
pr_err("EEH: Call Trace:\n"); |
|
for (i = 0; i < pe->trace_entries; i++) |
|
pr_err("EEH: [%pK] %pS\n", ptrs[i], ptrs[i]); |
|
|
|
pe->trace_entries = 0; |
|
} |
|
#endif /* CONFIG_STACKTRACE */ |
|
|
|
eeh_pe_update_time_stamp(pe); |
|
pe->freeze_count++; |
|
if (pe->freeze_count > eeh_max_freezes) { |
|
pr_err("EEH: PHB#%x-PE#%x has failed %d times in the last hour and has been permanently disabled.\n", |
|
pe->phb->global_number, pe->addr, |
|
pe->freeze_count); |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} |
|
|
|
eeh_for_each_pe(pe, tmp_pe) |
|
eeh_pe_for_each_dev(tmp_pe, edev, tmp) |
|
edev->mode &= ~EEH_DEV_NO_HANDLER; |
|
|
|
/* Walk the various device drivers attached to this slot through |
|
* a reset sequence, giving each an opportunity to do what it needs |
|
* to accomplish the reset. Each child gets a report of the |
|
* status ... if any child can't handle the reset, then the entire |
|
* slot is dlpar removed and added. |
|
* |
|
* When the PHB is fenced, we have to issue a reset to recover from |
|
* the error. Override the result if necessary to have partially |
|
* hotplug for this case. |
|
*/ |
|
if (result != PCI_ERS_RESULT_DISCONNECT) { |
|
pr_warn("EEH: This PCI device has failed %d times in the last hour and will be permanently disabled after %d failures.\n", |
|
pe->freeze_count, eeh_max_freezes); |
|
pr_info("EEH: Notify device drivers to shutdown\n"); |
|
eeh_set_channel_state(pe, pci_channel_io_frozen); |
|
eeh_set_irq_state(pe, false); |
|
eeh_pe_report("error_detected(IO frozen)", pe, |
|
eeh_report_error, &result); |
|
if ((pe->type & EEH_PE_PHB) && |
|
result != PCI_ERS_RESULT_NONE && |
|
result != PCI_ERS_RESULT_NEED_RESET) |
|
result = PCI_ERS_RESULT_NEED_RESET; |
|
} |
|
|
|
/* Get the current PCI slot state. This can take a long time, |
|
* sometimes over 300 seconds for certain systems. |
|
*/ |
|
if (result != PCI_ERS_RESULT_DISCONNECT) { |
|
rc = eeh_wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000); |
|
if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) { |
|
pr_warn("EEH: Permanent failure\n"); |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} |
|
} |
|
|
|
/* Since rtas may enable MMIO when posting the error log, |
|
* don't post the error log until after all dev drivers |
|
* have been informed. |
|
*/ |
|
if (result != PCI_ERS_RESULT_DISCONNECT) { |
|
pr_info("EEH: Collect temporary log\n"); |
|
eeh_slot_error_detail(pe, EEH_LOG_TEMP); |
|
} |
|
|
|
/* If all device drivers were EEH-unaware, then shut |
|
* down all of the device drivers, and hope they |
|
* go down willingly, without panicing the system. |
|
*/ |
|
if (result == PCI_ERS_RESULT_NONE) { |
|
pr_info("EEH: Reset with hotplug activity\n"); |
|
rc = eeh_reset_device(pe, bus, NULL, false); |
|
if (rc) { |
|
pr_warn("%s: Unable to reset, err=%d\n", |
|
__func__, rc); |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} |
|
} |
|
|
|
/* If all devices reported they can proceed, then re-enable MMIO */ |
|
if (result == PCI_ERS_RESULT_CAN_RECOVER) { |
|
pr_info("EEH: Enable I/O for affected devices\n"); |
|
rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); |
|
|
|
if (rc < 0) { |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} else if (rc) { |
|
result = PCI_ERS_RESULT_NEED_RESET; |
|
} else { |
|
pr_info("EEH: Notify device drivers to resume I/O\n"); |
|
eeh_pe_report("mmio_enabled", pe, |
|
eeh_report_mmio_enabled, &result); |
|
} |
|
} |
|
|
|
/* If all devices reported they can proceed, then re-enable DMA */ |
|
if (result == PCI_ERS_RESULT_CAN_RECOVER) { |
|
pr_info("EEH: Enabled DMA for affected devices\n"); |
|
rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA); |
|
|
|
if (rc < 0) { |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} else if (rc) { |
|
result = PCI_ERS_RESULT_NEED_RESET; |
|
} else { |
|
/* |
|
* We didn't do PE reset for the case. The PE |
|
* is still in frozen state. Clear it before |
|
* resuming the PE. |
|
*/ |
|
eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); |
|
result = PCI_ERS_RESULT_RECOVERED; |
|
} |
|
} |
|
|
|
/* If any device called out for a reset, then reset the slot */ |
|
if (result == PCI_ERS_RESULT_NEED_RESET) { |
|
pr_info("EEH: Reset without hotplug activity\n"); |
|
rc = eeh_reset_device(pe, bus, &rmv_data, true); |
|
if (rc) { |
|
pr_warn("%s: Cannot reset, err=%d\n", |
|
__func__, rc); |
|
result = PCI_ERS_RESULT_DISCONNECT; |
|
} else { |
|
result = PCI_ERS_RESULT_NONE; |
|
eeh_set_channel_state(pe, pci_channel_io_normal); |
|
eeh_set_irq_state(pe, true); |
|
eeh_pe_report("slot_reset", pe, eeh_report_reset, |
|
&result); |
|
} |
|
} |
|
|
|
if ((result == PCI_ERS_RESULT_RECOVERED) || |
|
(result == PCI_ERS_RESULT_NONE)) { |
|
/* |
|
* For those hot removed VFs, we should add back them after PF |
|
* get recovered properly. |
|
*/ |
|
list_for_each_entry_safe(edev, tmp, &rmv_data.removed_vf_list, |
|
rmv_entry) { |
|
eeh_add_virt_device(edev); |
|
list_del(&edev->rmv_entry); |
|
} |
|
|
|
/* Tell all device drivers that they can resume operations */ |
|
pr_info("EEH: Notify device driver to resume\n"); |
|
eeh_set_channel_state(pe, pci_channel_io_normal); |
|
eeh_set_irq_state(pe, true); |
|
eeh_pe_report("resume", pe, eeh_report_resume, NULL); |
|
eeh_for_each_pe(pe, tmp_pe) { |
|
eeh_pe_for_each_dev(tmp_pe, edev, tmp) { |
|
edev->mode &= ~EEH_DEV_NO_HANDLER; |
|
edev->in_error = false; |
|
} |
|
} |
|
|
|
pr_info("EEH: Recovery successful.\n"); |
|
} else { |
|
/* |
|
* About 90% of all real-life EEH failures in the field |
|
* are due to poorly seated PCI cards. Only 10% or so are |
|
* due to actual, failed cards. |
|
*/ |
|
pr_err("EEH: Unable to recover from failure from PHB#%x-PE#%x.\n" |
|
"Please try reseating or replacing it\n", |
|
pe->phb->global_number, pe->addr); |
|
|
|
eeh_slot_error_detail(pe, EEH_LOG_PERM); |
|
|
|
/* Notify all devices that they're about to go down. */ |
|
eeh_set_channel_state(pe, pci_channel_io_perm_failure); |
|
eeh_set_irq_state(pe, false); |
|
eeh_pe_report("error_detected(permanent failure)", pe, |
|
eeh_report_failure, NULL); |
|
|
|
/* Mark the PE to be removed permanently */ |
|
eeh_pe_state_mark(pe, EEH_PE_REMOVED); |
|
|
|
/* |
|
* Shut down the device drivers for good. We mark |
|
* all removed devices correctly to avoid access |
|
* the their PCI config any more. |
|
*/ |
|
if (pe->type & EEH_PE_VF) { |
|
eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL); |
|
eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED); |
|
} else { |
|
eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true); |
|
eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED); |
|
|
|
pci_lock_rescan_remove(); |
|
pci_hp_remove_devices(bus); |
|
pci_unlock_rescan_remove(); |
|
/* The passed PE should no longer be used */ |
|
return; |
|
} |
|
} |
|
|
|
out: |
|
/* |
|
* Clean up any PEs without devices. While marked as EEH_PE_RECOVERYING |
|
* we don't want to modify the PE tree structure so we do it here. |
|
*/ |
|
eeh_pe_cleanup(pe); |
|
|
|
/* clear the slot attention LED for all recovered devices */ |
|
eeh_for_each_pe(pe, tmp_pe) |
|
eeh_pe_for_each_dev(tmp_pe, edev, tmp) |
|
eeh_clear_slot_attention(edev->pdev); |
|
|
|
eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true); |
|
} |
|
|
|
/** |
|
* eeh_handle_special_event - Handle EEH events without a specific failing PE |
|
* |
|
* Called when an EEH event is detected but can't be narrowed down to a |
|
* specific PE. Iterates through possible failures and handles them as |
|
* necessary. |
|
*/ |
|
void eeh_handle_special_event(void) |
|
{ |
|
struct eeh_pe *pe, *phb_pe, *tmp_pe; |
|
struct eeh_dev *edev, *tmp_edev; |
|
struct pci_bus *bus; |
|
struct pci_controller *hose; |
|
unsigned long flags; |
|
int rc; |
|
|
|
|
|
do { |
|
rc = eeh_ops->next_error(&pe); |
|
|
|
switch (rc) { |
|
case EEH_NEXT_ERR_DEAD_IOC: |
|
/* Mark all PHBs in dead state */ |
|
eeh_serialize_lock(&flags); |
|
|
|
/* Purge all events */ |
|
eeh_remove_event(NULL, true); |
|
|
|
list_for_each_entry(hose, &hose_list, list_node) { |
|
phb_pe = eeh_phb_pe_get(hose); |
|
if (!phb_pe) continue; |
|
|
|
eeh_pe_mark_isolated(phb_pe); |
|
} |
|
|
|
eeh_serialize_unlock(flags); |
|
|
|
break; |
|
case EEH_NEXT_ERR_FROZEN_PE: |
|
case EEH_NEXT_ERR_FENCED_PHB: |
|
case EEH_NEXT_ERR_DEAD_PHB: |
|
/* Mark the PE in fenced state */ |
|
eeh_serialize_lock(&flags); |
|
|
|
/* Purge all events of the PHB */ |
|
eeh_remove_event(pe, true); |
|
|
|
if (rc != EEH_NEXT_ERR_DEAD_PHB) |
|
eeh_pe_state_mark(pe, EEH_PE_RECOVERING); |
|
eeh_pe_mark_isolated(pe); |
|
|
|
eeh_serialize_unlock(flags); |
|
|
|
break; |
|
case EEH_NEXT_ERR_NONE: |
|
return; |
|
default: |
|
pr_warn("%s: Invalid value %d from next_error()\n", |
|
__func__, rc); |
|
return; |
|
} |
|
|
|
/* |
|
* For fenced PHB and frozen PE, it's handled as normal |
|
* event. We have to remove the affected PHBs for dead |
|
* PHB and IOC |
|
*/ |
|
if (rc == EEH_NEXT_ERR_FROZEN_PE || |
|
rc == EEH_NEXT_ERR_FENCED_PHB) { |
|
eeh_pe_state_mark(pe, EEH_PE_RECOVERING); |
|
eeh_handle_normal_event(pe); |
|
} else { |
|
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); |
|
|
|
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; |
|
|
|
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); |
|
}
|
|
|