diff options
| -rw-r--r-- | Documentation/PCI/pci-error-recovery.txt | 35 | ||||
| -rw-r--r-- | drivers/pci/pcie/aer/aerdrv.c | 5 | ||||
| -rw-r--r-- | drivers/pci/pcie/aer/aerdrv_core.c | 89 |
3 files changed, 96 insertions, 33 deletions
diff --git a/Documentation/PCI/pci-error-recovery.txt b/Documentation/PCI/pci-error-recovery.txt index 0b6bb3ef449e..688b69121e82 100644 --- a/Documentation/PCI/pci-error-recovery.txt +++ b/Documentation/PCI/pci-error-recovery.txt @@ -110,7 +110,7 @@ The actual steps taken by a platform to recover from a PCI error event will be platform-dependent, but will follow the general sequence described below. -STEP 0: Error Event +STEP 0: Error Event: ERR_NONFATAL ------------------- A PCI bus error is detected by the PCI hardware. On powerpc, the slot is isolated, in that all I/O is blocked: all reads return 0xffffffff, @@ -228,13 +228,7 @@ proceeds to either STEP3 (Link Reset) or to STEP 5 (Resume Operations). If any driver returned PCI_ERS_RESULT_NEED_RESET, then the platform proceeds to STEP 4 (Slot Reset) -STEP 3: Link Reset ------------------- -The platform resets the link. This is a PCI-Express specific step -and is done whenever a fatal error has been detected that can be -"solved" by resetting the link. - -STEP 4: Slot Reset +STEP 3: Slot Reset ------------------ In response to a return value of PCI_ERS_RESULT_NEED_RESET, the @@ -320,7 +314,7 @@ Failure). >>> However, it probably should. -STEP 5: Resume Operations +STEP 4: Resume Operations ------------------------- The platform will call the resume() callback on all affected device drivers if all drivers on the segment have returned @@ -332,7 +326,7 @@ a result code. At this point, if a new error happens, the platform will restart a new error recovery sequence. -STEP 6: Permanent Failure +STEP 5: Permanent Failure ------------------------- A "permanent failure" has occurred, and the platform cannot recover the device. The platform will call error_detected() with a @@ -355,6 +349,27 @@ errors. See the discussion in powerpc/eeh-pci-error-recovery.txt for additional detail on real-life experience of the causes of software errors. +STEP 0: Error Event: ERR_FATAL +------------------- +PCI bus error is detected by the PCI hardware. On powerpc, the slot is +isolated, in that all I/O is blocked: all reads return 0xffffffff, all +writes are ignored. + +STEP 1: Remove devices +-------------------- +Platform removes the devices depending on the error agent, it could be +this port for all subordinates or upstream component (likely downstream +port) + +STEP 2: Reset link +-------------------- +The platform resets the link. This is a PCI-Express specific step and is +done whenever a fatal error has been detected that can be "solved" by +resetting the link. + +STEP 3: Re-enumerate the devices +-------------------- +Initiates the re-enumeration. Conclusion; General Remarks --------------------------- diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c index 779b3879b1b5..377e576e4f41 100644 --- a/drivers/pci/pcie/aer/aerdrv.c +++ b/drivers/pci/pcie/aer/aerdrv.c @@ -353,10 +353,7 @@ static void aer_error_resume(struct pci_dev *dev) pos = dev->aer_cap; pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask); - if (dev->error_state == pci_channel_io_normal) - status &= ~mask; /* Clear corresponding nonfatal bits */ - else - status &= mask; /* Clear corresponding fatal bits */ + status &= ~mask; /* Clear corresponding nonfatal bits */ pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status); } diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index 0ea5acc40323..f64ebca09439 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -20,6 +20,7 @@ #include <linux/slab.h> #include <linux/kfifo.h> #include "aerdrv.h" +#include "../../pci.h" #define PCI_EXP_AER_FLAGS (PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \ PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE) @@ -475,35 +476,81 @@ static pci_ers_result_t reset_link(struct pci_dev *dev) } /** - * do_recovery - handle nonfatal/fatal error recovery process + * do_fatal_recovery - handle fatal error recovery process * @dev: pointer to a pci_dev data structure of agent detecting an error - * @severity: error severity type * - * Invoked when an error is nonfatal/fatal. Once being invoked, broadcast + * Invoked when an error is fatal. Once being invoked, removes the devices + * beneath this AER agent, followed by reset link e.g. secondary bus reset + * followed by re-enumeration of devices. + */ +static void do_fatal_recovery(struct pci_dev *dev) +{ + struct pci_dev *udev; + struct pci_bus *parent; + struct pci_dev *pdev, *temp; + pci_ers_result_t result; + + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) + udev = dev; + else + udev = dev->bus->self; + + parent = udev->subordinate; + pci_lock_rescan_remove(); + list_for_each_entry_safe_reverse(pdev, temp, &parent->devices, + bus_list) { + pci_dev_get(pdev); + pci_dev_set_disconnected(pdev, NULL); + if (pci_has_subordinate(pdev)) + pci_walk_bus(pdev->subordinate, + pci_dev_set_disconnected, NULL); + pci_stop_and_remove_bus_device(pdev); + pci_dev_put(pdev); + } + + result = reset_link(udev); + + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + /* + * If the error is reported by a bridge, we think this error + * is related to the downstream link of the bridge, so we + * do error recovery on all subordinates of the bridge instead + * of the bridge and clear the error status of the bridge. + */ + pci_cleanup_aer_uncorrect_error_status(dev); + } + + if (result == PCI_ERS_RESULT_RECOVERED) { + if (pcie_wait_for_link(udev, true)) + pci_rescan_bus(udev->bus); + } else { + pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT); + pci_info(dev, "AER: Device recovery from fatal error failed\n"); + } + + pci_unlock_rescan_remove(); +} + +/** + * do_nonfatal_recovery - handle nonfatal error recovery process + * @dev: pointer to a pci_dev data structure of agent detecting an error + * + * Invoked when an error is nonfatal. Once being invoked, broadcast * error detected message to all downstream drivers within a hierarchy in * question and return the returned code. */ -static void do_recovery(struct pci_dev *dev, int severity) +static void do_nonfatal_recovery(struct pci_dev *dev) { - pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED; + pci_ers_result_t status; enum pci_channel_state state; - if (severity == AER_FATAL) - state = pci_channel_io_frozen; - else - state = pci_channel_io_normal; + state = pci_channel_io_normal; status = broadcast_error_message(dev, state, "error_detected", report_error_detected); - if (severity == AER_FATAL) { - result = reset_link(dev); - if (result != PCI_ERS_RESULT_RECOVERED) - goto failed; - } - if (status == PCI_ERS_RESULT_CAN_RECOVER) status = broadcast_error_message(dev, state, @@ -562,8 +609,10 @@ static void handle_error_source(struct pcie_device *aerdev, if (pos) pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, info->status); - } else - do_recovery(dev, info->severity); + } else if (info->severity == AER_NONFATAL) + do_nonfatal_recovery(dev); + else if (info->severity == AER_FATAL) + do_fatal_recovery(dev); } #ifdef CONFIG_ACPI_APEI_PCIEAER @@ -627,8 +676,10 @@ static void aer_recover_work_func(struct work_struct *work) continue; } cper_print_aer(pdev, entry.severity, entry.regs); - if (entry.severity != AER_CORRECTABLE) - do_recovery(pdev, entry.severity); + if (entry.severity == AER_NONFATAL) + do_nonfatal_recovery(pdev); + else if (entry.severity == AER_FATAL) + do_fatal_recovery(pdev); pci_dev_put(pdev); } } |