/* * drivers/pci/pcie/aer/aerdrv_core.c * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * This file implements the core part of PCIe AER. When a PCIe * error is delivered, an error message will be collected and printed to * console, then, an error recovery procedure will be executed by following * the PCI error recovery rules. * * Copyright (C) 2006 Intel Corp. * Tom Long Nguyen (tom.l.nguyen@intel.com) * Zhang Yanmin (yanmin.zhang@intel.com) * */ #include <linux/module.h> #include <linux/pci.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/pm.h> #include <linux/suspend.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/kfifo.h> #include "aerdrv.h" #define PCI_EXP_AER_FLAGS (PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \ PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE) int pci_enable_pcie_error_reporting(struct pci_dev *dev) { if (pcie_aer_get_firmware_first(dev)) return -EIO; if (!dev->aer_cap) return -EIO; return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS); } EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting); int pci_disable_pcie_error_reporting(struct pci_dev *dev) { if (pcie_aer_get_firmware_first(dev)) return -EIO; return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS); } EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting); int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev) { int pos; u32 status; pos = dev->aer_cap; if (!pos) return -EIO; pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); if (status) pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status); return 0; } EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status); int pci_cleanup_aer_error_status_regs(struct pci_dev *dev) { int pos; u32 status; int port_type; if (!pci_is_pcie(dev)) return -ENODEV; pos = dev->aer_cap; if (!pos) return -EIO; port_type = pci_pcie_type(dev); if (port_type == PCI_EXP_TYPE_ROOT_PORT) { pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status); pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status); } pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status); pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, status); pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status); return 0; } int pci_aer_init(struct pci_dev *dev) { dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); return pci_cleanup_aer_error_status_regs(dev); } /** * add_error_device - list device to be handled * @e_info: pointer to error info * @dev: pointer to pci_dev to be added */ static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev) { if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) { e_info->dev[e_info->error_dev_num] = dev; e_info->error_dev_num++; return 0; } return -ENOSPC; } /** * is_error_source - check whether the device is source of reported error * @dev: pointer to pci_dev to be checked * @e_info: pointer to reported error info */ static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info) { int pos; u32 status, mask; u16 reg16; /* * When bus id is equal to 0, it might be a bad id * reported by root port. */ if ((PCI_BUS_NUM(e_info->id) != 0) && !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) { /* Device ID match? */ if (e_info->id == ((dev->bus->number << 8) | dev->devfn)) return true; /* Continue id comparing if there is no multiple error */ if (!e_info->multi_error_valid) return false; } /* * When either * 1) bus id is equal to 0. Some ports might lose the bus * id of error source id; * 2) bus flag PCI_BUS_FLAGS_NO_AERSID is set * 3) There are multiple errors and prior ID comparing fails; * We check AER status registers to find possible reporter. */ if (atomic_read(&dev->enable_cnt) == 0) return false; /* Check if AER is enabled */ pcie_capability_read_word(dev, PCI_EXP_DEVCTL, ®16); if (!(reg16 & PCI_EXP_AER_FLAGS)) return false; pos = dev->aer_cap; if (!pos) return false; /* Check if error is recorded */ if (e_info->severity == AER_CORRECTABLE) { pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status); pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &mask); } else { pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask); } if (status & ~mask) return true; return false; } static int find_device_iter(struct pci_dev *dev, void *data) { struct aer_err_info *e_info = (struct aer_err_info *)data; if (is_error_source(dev, e_info)) { /* List this device */ if (add_error_device(e_info, dev)) { /* We cannot handle more... Stop iteration */ /* TODO: Should print error message here? */ return 1; } /* If there is only a single error, stop iteration */ if (!e_info->multi_error_valid) return 1; } return 0; } /** * find_source_device - search through device hierarchy for source device * @parent: pointer to Root Port pci_dev data structure * @e_info: including detailed error information such like id * * Return true if found. * * Invoked by DPC when error is detected at the Root Port. * Caller of this function must set id, severity, and multi_error_valid of * struct aer_err_info pointed by @e_info properly. This function must fill * e_info->error_dev_num and e_info->dev[], based on the given information. */ static bool find_source_device(struct pci_dev *parent, struct aer_err_info *e_info) { struct pci_dev *dev = parent; int result; /* Must reset in this function */ e_info->error_dev_num = 0; /* Is Root Port an agent that sends error message? */ result = find_device_iter(dev, e_info); if (result) return true; pci_walk_bus(parent->subordinate, find_device_iter, e_info); if (!e_info->error_dev_num) { dev_printk(KERN_DEBUG, &parent->dev, "can't find device of ID%04x\n", e_info->id); return false; } return true; } static int report_error_detected(struct pci_dev *dev, void *data) { pci_ers_result_t vote; const struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; device_lock(&dev->dev); dev->error_state = result_data->state; if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->error_detected) { if (result_data->state == pci_channel_io_frozen && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) { /* * In case of fatal recovery, if one of down- * stream device has no driver. We might be * unable to recover because a later insmod * of a driver for this device is unaware of * its hw state. */ dev_printk(KERN_DEBUG, &dev->dev, "device has %s\n", dev->driver ? "no AER-aware driver" : "no driver"); } /* * If there's any device in the subtree that does not * have an error_detected callback, returning * PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of * the subsequent mmio_enabled/slot_reset/resume * callbacks of "any" device in the subtree. All the * devices in the subtree are left in the error state * without recovery. */ if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) vote = PCI_ERS_RESULT_NO_AER_DRIVER; else vote = PCI_ERS_RESULT_NONE; } else { err_handler = dev->driver->err_handler; vote = err_handler->error_detected(dev, result_data->state); pci_uevent_ers(dev, PCI_ERS_RESULT_NONE); } result_data->result = merge_result(result_data->result, vote); device_unlock(&dev->dev); return 0; } static int report_mmio_enabled(struct pci_dev *dev, void *data) { pci_ers_result_t vote; const struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; device_lock(&dev->dev); if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->mmio_enabled) goto out; err_handler = dev->driver->err_handler; vote = err_handler->mmio_enabled(dev); result_data->result = merge_result(result_data->result, vote); out: device_unlock(&dev->dev); return 0; } static int report_slot_reset(struct pci_dev *dev, void *data) { pci_ers_result_t vote; const struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; device_lock(&dev->dev); if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->slot_reset) goto out; err_handler = dev->driver->err_handler; vote = err_handler->slot_reset(dev); result_data->result = merge_result(result_data->result, vote); out: device_unlock(&dev->dev); return 0; } static int report_resume(struct pci_dev *dev, void *data) { const struct pci_error_handlers *err_handler; device_lock(&dev->dev); dev->error_state = pci_channel_io_normal; if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->resume) goto out; err_handler = dev->driver->err_handler; err_handler->resume(dev); pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED); out: device_unlock(&dev->dev); return 0; } /** * broadcast_error_message - handle message broadcast to downstream drivers * @dev: pointer to from where in a hierarchy message is broadcasted down * @state: error state * @error_mesg: message to print * @cb: callback to be broadcasted * * Invoked during error recovery process. Once being invoked, the content * of error severity will be broadcasted to all downstream drivers in a * hierarchy in question. */ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev, enum pci_channel_state state, char *error_mesg, int (*cb)(struct pci_dev *, void *)) { struct aer_broadcast_data result_data; dev_printk(KERN_DEBUG, &dev->dev, "broadcast %s message\n", error_mesg); result_data.state = state; if (cb == report_error_detected) result_data.result = PCI_ERS_RESULT_CAN_RECOVER; else result_data.result = PCI_ERS_RESULT_RECOVERED; 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. */ if (cb == report_error_detected) dev->error_state = state; pci_walk_bus(dev->subordinate, cb, &result_data); if (cb == report_resume) { pci_cleanup_aer_uncorrect_error_status(dev); dev->error_state = pci_channel_io_normal; } } else { /* * If the error is reported by an end point, we think this * error is related to the upstream link of the end point. */ if (state == pci_channel_io_normal) /* * the error is non fatal so the bus is ok, just invoke * the callback for the function that logged the error. */ cb(dev, &result_data); else pci_walk_bus(dev->bus, cb, &result_data); } return result_data.result; } /** * default_reset_link - default reset function * @dev: pointer to pci_dev data structure * * Invoked when performing link reset on a Downstream Port or a * Root Port with no aer driver. */ static pci_ers_result_t default_reset_link(struct pci_dev *dev) { pci_reset_bridge_secondary_bus(dev); dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n"); return PCI_ERS_RESULT_RECOVERED; } static int find_aer_service_iter(struct device *device, void *data) { struct pcie_port_service_driver *service_driver, **drv; drv = (struct pcie_port_service_driver **) data; if (device->bus == &pcie_port_bus_type && device->driver) { service_driver = to_service_driver(device->driver); if (service_driver->service == PCIE_PORT_SERVICE_AER) { *drv = service_driver; return 1; } } return 0; } static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev) { struct pcie_port_service_driver *drv = NULL; device_for_each_child(&dev->dev, &drv, find_aer_service_iter); return drv; } static pci_ers_result_t reset_link(struct pci_dev *dev) { struct pci_dev *udev; pci_ers_result_t status; struct pcie_port_service_driver *driver; if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { /* Reset this port for all subordinates */ udev = dev; } else { /* Reset the upstream component (likely downstream port) */ udev = dev->bus->self; } /* Use the aer driver of the component firstly */ driver = find_aer_service(udev); if (driver && driver->reset_link) { status = driver->reset_link(udev); } else if (udev->has_secondary_link) { status = default_reset_link(udev); } else { dev_printk(KERN_DEBUG, &dev->dev, "no link-reset support at upstream device %s\n", pci_name(udev)); return PCI_ERS_RESULT_DISCONNECT; } if (status != PCI_ERS_RESULT_RECOVERED) { dev_printk(KERN_DEBUG, &dev->dev, "link reset at upstream device %s failed\n", pci_name(udev)); return PCI_ERS_RESULT_DISCONNECT; } return status; } /** * do_recovery - handle nonfatal/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 * 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) { pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED; enum pci_channel_state state; if (severity == AER_FATAL) state = pci_channel_io_frozen; else 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, "mmio_enabled", report_mmio_enabled); if (status == PCI_ERS_RESULT_NEED_RESET) { /* * TODO: Should call platform-specific * functions to reset slot before calling * drivers' slot_reset callbacks? */ status = broadcast_error_message(dev, state, "slot_reset", report_slot_reset); } if (status != PCI_ERS_RESULT_RECOVERED) goto failed; broadcast_error_message(dev, state, "resume", report_resume); dev_info(&dev->dev, "AER: Device recovery successful\n"); return; failed: pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT); /* TODO: Should kernel panic here? */ dev_info(&dev->dev, "AER: Device recovery failed\n"); } /** * handle_error_source - handle logging error into an event log * @aerdev: pointer to pcie_device data structure of the root port * @dev: pointer to pci_dev data structure of error source device * @info: comprehensive error information * * Invoked when an error being detected by Root Port. */ static void handle_error_source(struct pcie_device *aerdev, struct pci_dev *dev, struct aer_err_info *info) { int pos; if (info->severity == AER_CORRECTABLE) { /* * Correctable error does not need software intervention. * No need to go through error recovery process. */ pos = dev->aer_cap; if (pos) pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, info->status); } else do_recovery(dev, info->severity); } #ifdef CONFIG_ACPI_APEI_PCIEAER static void aer_recover_work_func(struct work_struct *work); #define AER_RECOVER_RING_ORDER 4 #define AER_RECOVER_RING_SIZE (1 << AER_RECOVER_RING_ORDER) struct aer_recover_entry { u8 bus; u8 devfn; u16 domain; int severity; struct aer_capability_regs *regs; }; static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry, AER_RECOVER_RING_SIZE); /* * Mutual exclusion for writers of aer_recover_ring, reader side don't * need lock, because there is only one reader and lock is not needed * between reader and writer. */ static DEFINE_SPINLOCK(aer_recover_ring_lock); static DECLARE_WORK(aer_recover_work, aer_recover_work_func); void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn, int severity, struct aer_capability_regs *aer_regs) { unsigned long flags; struct aer_recover_entry entry = { .bus = bus, .devfn = devfn, .domain = domain, .severity = severity, .regs = aer_regs, }; spin_lock_irqsave(&aer_recover_ring_lock, flags); if (kfifo_put(&aer_recover_ring, entry)) schedule_work(&aer_recover_work); else pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n", domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn)); spin_unlock_irqrestore(&aer_recover_ring_lock, flags); } EXPORT_SYMBOL_GPL(aer_recover_queue); static void aer_recover_work_func(struct work_struct *work) { struct aer_recover_entry entry; struct pci_dev *pdev; while (kfifo_get(&aer_recover_ring, &entry)) { pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus, entry.devfn); if (!pdev) { pr_err("AER recover: Can not find pci_dev for %04x:%02x:%02x:%x\n", entry.domain, entry.bus, PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn)); continue; } cper_print_aer(pdev, entry.severity, entry.regs); do_recovery(pdev, entry.severity); pci_dev_put(pdev); } } #endif /** * get_device_error_info - read error status from dev and store it to info * @dev: pointer to the device expected to have a error record * @info: pointer to structure to store the error record * * Return 1 on success, 0 on error. * * Note that @info is reused among all error devices. Clear fields properly. */ static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info) { int pos, temp; /* Must reset in this function */ info->status = 0; info->tlp_header_valid = 0; pos = dev->aer_cap; /* The device might not support AER */ if (!pos) return 1; if (info->severity == AER_CORRECTABLE) { pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &info->status); pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &info->mask); if (!(info->status & ~info->mask)) return 0; } else if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || info->severity == AER_NONFATAL) { /* Link is still healthy for IO reads */ pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &info->status); pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &info->mask); if (!(info->status & ~info->mask)) return 0; /* Get First Error Pointer */ pci_read_config_dword(dev, pos + PCI_ERR_CAP, &temp); info->first_error = PCI_ERR_CAP_FEP(temp); if (info->status & AER_LOG_TLP_MASKS) { info->tlp_header_valid = 1; pci_read_config_dword(dev, pos + PCI_ERR_HEADER_LOG, &info->tlp.dw0); pci_read_config_dword(dev, pos + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1); pci_read_config_dword(dev, pos + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2); pci_read_config_dword(dev, pos + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3); } } return 1; } static inline void aer_process_err_devices(struct pcie_device *p_device, struct aer_err_info *e_info) { int i; /* Report all before handle them, not to lost records by reset etc. */ for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) { if (get_device_error_info(e_info->dev[i], e_info)) aer_print_error(e_info->dev[i], e_info); } for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) { if (get_device_error_info(e_info->dev[i], e_info)) handle_error_source(p_device, e_info->dev[i], e_info); } } /** * aer_isr_one_error - consume an error detected by root port * @p_device: pointer to error root port service device * @e_src: pointer to an error source */ static void aer_isr_one_error(struct pcie_device *p_device, struct aer_err_source *e_src) { struct aer_rpc *rpc = get_service_data(p_device); struct aer_err_info *e_info = &rpc->e_info; /* * There is a possibility that both correctable error and * uncorrectable error being logged. Report correctable error first. */ if (e_src->status & PCI_ERR_ROOT_COR_RCV) { e_info->id = ERR_COR_ID(e_src->id); e_info->severity = AER_CORRECTABLE; if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV) e_info->multi_error_valid = 1; else e_info->multi_error_valid = 0; aer_print_port_info(p_device->port, e_info); if (find_source_device(p_device->port, e_info)) aer_process_err_devices(p_device, e_info); } if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) { e_info->id = ERR_UNCOR_ID(e_src->id); if (e_src->status & PCI_ERR_ROOT_FATAL_RCV) e_info->severity = AER_FATAL; else e_info->severity = AER_NONFATAL; if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV) e_info->multi_error_valid = 1; else e_info->multi_error_valid = 0; aer_print_port_info(p_device->port, e_info); if (find_source_device(p_device->port, e_info)) aer_process_err_devices(p_device, e_info); } } /** * get_e_source - retrieve an error source * @rpc: pointer to the root port which holds an error * @e_src: pointer to store retrieved error source * * Return 1 if an error source is retrieved, otherwise 0. * * Invoked by DPC handler to consume an error. */ static int get_e_source(struct aer_rpc *rpc, struct aer_err_source *e_src) { unsigned long flags; /* Lock access to Root error producer/consumer index */ spin_lock_irqsave(&rpc->e_lock, flags); if (rpc->prod_idx == rpc->cons_idx) { spin_unlock_irqrestore(&rpc->e_lock, flags); return 0; } *e_src = rpc->e_sources[rpc->cons_idx]; rpc->cons_idx++; if (rpc->cons_idx == AER_ERROR_SOURCES_MAX) rpc->cons_idx = 0; spin_unlock_irqrestore(&rpc->e_lock, flags); return 1; } /** * aer_isr - consume errors detected by root port * @work: definition of this work item * * Invoked, as DPC, when root port records new detected error */ void aer_isr(struct work_struct *work) { struct aer_rpc *rpc = container_of(work, struct aer_rpc, dpc_handler); struct pcie_device *p_device = rpc->rpd; struct aer_err_source uninitialized_var(e_src); mutex_lock(&rpc->rpc_mutex); while (get_e_source(rpc, &e_src)) aer_isr_one_error(p_device, &e_src); mutex_unlock(&rpc->rpc_mutex); }