/* * 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 PCI-Express AER. When an pci-express * 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 #include #include #include #include #include #include #include "aerdrv.h" static int forceload; static int nosourceid; module_param(forceload, bool, 0); module_param(nosourceid, bool, 0); int pci_enable_pcie_error_reporting(struct pci_dev *dev) { u16 reg16 = 0; int pos; if (dev->aer_firmware_first) return -EIO; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); if (!pos) return -EIO; pos = pci_pcie_cap(dev); if (!pos) return -EIO; pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, ®16); reg16 = reg16 | PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE; pci_write_config_word(dev, pos+PCI_EXP_DEVCTL, reg16); return 0; } EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting); int pci_disable_pcie_error_reporting(struct pci_dev *dev) { u16 reg16 = 0; int pos; if (dev->aer_firmware_first) return -EIO; pos = pci_pcie_cap(dev); if (!pos) return -EIO; pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, ®16); reg16 = reg16 & ~(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE); pci_write_config_word(dev, pos+PCI_EXP_DEVCTL, reg16); return 0; } EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting); int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev) { int pos; u32 status; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); 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); static int set_device_error_reporting(struct pci_dev *dev, void *data) { bool enable = *((bool *)data); if ((dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) || (dev->pcie_type == PCI_EXP_TYPE_UPSTREAM) || (dev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)) { if (enable) pci_enable_pcie_error_reporting(dev); else pci_disable_pcie_error_reporting(dev); } if (enable) pcie_set_ecrc_checking(dev); return 0; } /** * set_downstream_devices_error_reporting - enable/disable the error reporting bits on the root port and its downstream ports. * @dev: pointer to root port's pci_dev data structure * @enable: true = enable error reporting, false = disable error reporting. */ static void set_downstream_devices_error_reporting(struct pci_dev *dev, bool enable) { set_device_error_reporting(dev, &enable); if (!dev->subordinate) return; pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable); } static inline int compare_device_id(struct pci_dev *dev, struct aer_err_info *e_info) { if (e_info->id == ((dev->bus->number << 8) | dev->devfn)) { /* * Device ID match */ return 1; } return 0; } 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 1; } return 0; } #define PCI_BUS(x) (((x) >> 8) & 0xff) static int find_device_iter(struct pci_dev *dev, void *data) { int pos; u32 status; u32 mask; u16 reg16; int result; struct aer_err_info *e_info = (struct aer_err_info *)data; /* * When bus id is equal to 0, it might be a bad id * reported by root port. */ if (!nosourceid && (PCI_BUS(e_info->id) != 0)) { result = compare_device_id(dev, e_info); if (result) add_error_device(e_info, dev); /* * If there is no multiple error, we stop * or continue based on the id comparing. */ if (!e_info->multi_error_valid) return result; /* * If there are multiple errors and id does match, * We need continue to search other devices under * the root port. Return 0 means that. */ if (result) return 0; } /* * When either * 1) nosourceid==y; * 2) bus id is equal to 0. Some ports might lose the bus * id of error source id; * 3) There are multiple errors and prior id comparing fails; * We check AER status registers to find the initial reporter. */ if (atomic_read(&dev->enable_cnt) == 0) return 0; pos = pci_pcie_cap(dev); if (!pos) return 0; /* Check if AER is enabled */ pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, ®16); if (!(reg16 & ( PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE))) return 0; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); if (!pos) return 0; status = 0; mask = 0; 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); if (status & ~mask) { add_error_device(e_info, dev); goto added; } } 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) { add_error_device(e_info, dev); goto added; } } return 0; added: if (e_info->multi_error_valid) return 0; else return 1; } /** * find_source_device - search through device hierarchy for source device * @parent: pointer to Root Port pci_dev data structure * @err_info: including detailed error information such like id * * Invoked when error is detected at the Root Port. */ static void find_source_device(struct pci_dev *parent, struct aer_err_info *e_info) { struct pci_dev *dev = parent; int result; /* Is Root Port an agent that sends error message? */ result = find_device_iter(dev, e_info); if (result) return; pci_walk_bus(parent->subordinate, find_device_iter, e_info); } static int report_error_detected(struct pci_dev *dev, void *data) { pci_ers_result_t vote; struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; 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"); } return 0; } err_handler = dev->driver->err_handler; vote = err_handler->error_detected(dev, result_data->state); result_data->result = merge_result(result_data->result, vote); return 0; } static int report_mmio_enabled(struct pci_dev *dev, void *data) { pci_ers_result_t vote; struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->mmio_enabled) return 0; err_handler = dev->driver->err_handler; vote = err_handler->mmio_enabled(dev); result_data->result = merge_result(result_data->result, vote); return 0; } static int report_slot_reset(struct pci_dev *dev, void *data) { pci_ers_result_t vote; struct pci_error_handlers *err_handler; struct aer_broadcast_data *result_data; result_data = (struct aer_broadcast_data *) data; if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->slot_reset) return 0; err_handler = dev->driver->err_handler; vote = err_handler->slot_reset(dev); result_data->result = merge_result(result_data->result, vote); return 0; } static int report_resume(struct pci_dev *dev, void *data) { struct pci_error_handlers *err_handler; dev->error_state = pci_channel_io_normal; if (!dev->driver || !dev->driver->err_handler || !dev->driver->err_handler->resume) return 0; err_handler = dev->driver->err_handler; err_handler->resume(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. */ pci_walk_bus(dev->bus, cb, &result_data); } return result_data.result; } struct find_aer_service_data { struct pcie_port_service_driver *aer_driver; int is_downstream; }; static int find_aer_service_iter(struct device *device, void *data) { struct device_driver *driver; struct pcie_port_service_driver *service_driver; struct find_aer_service_data *result; result = (struct find_aer_service_data *) data; if (device->bus == &pcie_port_bus_type) { struct pcie_device *pcie = to_pcie_device(device); if (pcie->port->pcie_type == PCI_EXP_TYPE_DOWNSTREAM) result->is_downstream = 1; driver = device->driver; if (driver) { service_driver = to_service_driver(driver); if (service_driver->service == PCIE_PORT_SERVICE_AER) { result->aer_driver = service_driver; return 1; } } } return 0; } static void find_aer_service(struct pci_dev *dev, struct find_aer_service_data *data) { int retval; retval = device_for_each_child(&dev->dev, data, find_aer_service_iter); } static pci_ers_result_t reset_link(struct pcie_device *aerdev, struct pci_dev *dev) { struct pci_dev *udev; pci_ers_result_t status; struct find_aer_service_data data; if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) udev = dev; else udev = dev->bus->self; data.is_downstream = 0; data.aer_driver = NULL; find_aer_service(udev, &data); /* * Use the aer driver of the error agent firstly. * If it hasn't the aer driver, use the root port's */ if (!data.aer_driver || !data.aer_driver->reset_link) { if (data.is_downstream && aerdev->device.driver && to_service_driver(aerdev->device.driver)->reset_link) { data.aer_driver = to_service_driver(aerdev->device.driver); } else { dev_printk(KERN_DEBUG, &dev->dev, "no link-reset " "support\n"); return PCI_ERS_RESULT_DISCONNECT; } } status = data.aer_driver->reset_link(udev); 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 * @aerdev: pointer to a pcie_device data structure of root port * @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 pci_ers_result_t do_recovery(struct pcie_device *aerdev, 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(aerdev, dev); if (result != PCI_ERS_RESULT_RECOVERED) { /* TODO: Should panic here? */ return result; } } 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) broadcast_error_message(dev, state, "resume", report_resume); return status; } /** * 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) { pci_ers_result_t status = 0; int pos; if (info->severity == AER_CORRECTABLE) { /* * Correctable error does not need software intevention. * No need to go through error recovery process. */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); if (pos) pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, info->status); } else { status = do_recovery(aerdev, dev, info->severity); if (status == PCI_ERS_RESULT_RECOVERED) { dev_printk(KERN_DEBUG, &dev->dev, "AER driver " "successfully recovered\n"); } else { /* TODO: Should kernel panic here? */ dev_printk(KERN_DEBUG, &dev->dev, "AER driver didn't " "recover\n"); } } } /** * aer_enable_rootport - enable Root Port's interrupts when receiving messages * @rpc: pointer to a Root Port data structure * * Invoked when PCIe bus loads AER service driver. */ void aer_enable_rootport(struct aer_rpc *rpc) { struct pci_dev *pdev = rpc->rpd->port; int pos, aer_pos; u16 reg16; u32 reg32; pos = pci_pcie_cap(pdev); /* Clear PCIe Capability's Device Status */ pci_read_config_word(pdev, pos+PCI_EXP_DEVSTA, ®16); pci_write_config_word(pdev, pos+PCI_EXP_DEVSTA, reg16); /* Disable system error generation in response to error messages */ pci_read_config_word(pdev, pos + PCI_EXP_RTCTL, ®16); reg16 &= ~(SYSTEM_ERROR_INTR_ON_MESG_MASK); pci_write_config_word(pdev, pos + PCI_EXP_RTCTL, reg16); aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR); /* Clear error status */ pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32); pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32); pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32); /* * Enable error reporting for the root port device and downstream port * devices. */ set_downstream_devices_error_reporting(pdev, true); /* Enable Root Port's interrupt in response to error messages */ pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, ROOT_PORT_INTR_ON_MESG_MASK); } /** * disable_root_aer - disable Root Port's interrupts when receiving messages * @rpc: pointer to a Root Port data structure * * Invoked when PCIe bus unloads AER service driver. */ static void disable_root_aer(struct aer_rpc *rpc) { struct pci_dev *pdev = rpc->rpd->port; u32 reg32; int pos; /* * Disable error reporting for the root port device and downstream port * devices. */ set_downstream_devices_error_reporting(pdev, false); pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR); /* Disable Root's interrupt in response to error messages */ pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, 0); /* Clear Root's error status reg */ pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, ®32); pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32); } /** * get_e_source - retrieve an error source * @rpc: pointer to the root port which holds an error * * Invoked by DPC handler to consume an error. */ static struct aer_err_source *get_e_source(struct aer_rpc *rpc) { struct aer_err_source *e_source; 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 NULL; } e_source = &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 e_source; } /** * 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. */ static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info) { int pos, temp; info->status = 0; info->tlp_header_valid = 0; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); /* 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; if (!e_info->dev[0]) { dev_printk(KERN_DEBUG, &p_device->port->dev, "can't find device of ID%04x\n", e_info->id); } /* 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_err_info *e_info; int i; /* struct aer_err_info might be big, so we allocate it with slab */ e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL); if (e_info == NULL) { dev_printk(KERN_DEBUG, &p_device->port->dev, "Can't allocate mem when processing AER errors\n"); return; } /* * There is a possibility that both correctable error and * uncorrectable error being logged. Report correctable error first. */ for (i = 1; i & ROOT_ERR_STATUS_MASKS ; i <<= 2) { if (i > 4) break; if (!(e_src->status & i)) continue; memset(e_info, 0, sizeof(struct aer_err_info)); /* Init comprehensive error information */ if (i & PCI_ERR_ROOT_COR_RCV) { e_info->id = ERR_COR_ID(e_src->id); e_info->severity = AER_CORRECTABLE; } else { e_info->id = ERR_UNCOR_ID(e_src->id); e_info->severity = ((e_src->status >> 6) & 1); } if (e_src->status & (PCI_ERR_ROOT_MULTI_COR_RCV | PCI_ERR_ROOT_MULTI_UNCOR_RCV)) e_info->multi_error_valid = 1; aer_print_port_info(p_device->port, e_info); find_source_device(p_device->port, e_info); aer_process_err_devices(p_device, e_info); } kfree(e_info); } /** * 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 *e_src; mutex_lock(&rpc->rpc_mutex); e_src = get_e_source(rpc); while (e_src) { aer_isr_one_error(p_device, e_src); e_src = get_e_source(rpc); } mutex_unlock(&rpc->rpc_mutex); wake_up(&rpc->wait_release); } /** * aer_delete_rootport - disable root port aer and delete service data * @rpc: pointer to a root port device being deleted * * Invoked when AER service unloaded on a specific Root Port */ void aer_delete_rootport(struct aer_rpc *rpc) { /* Disable root port AER itself */ disable_root_aer(rpc); kfree(rpc); } /** * aer_init - provide AER initialization * @dev: pointer to AER pcie device * * Invoked when AER service driver is loaded. */ int aer_init(struct pcie_device *dev) { if (dev->port->aer_firmware_first) { dev_printk(KERN_DEBUG, &dev->device, "PCIe errors handled by platform firmware.\n"); goto out; } if (aer_osc_setup(dev)) goto out; return 0; out: if (forceload) { dev_printk(KERN_DEBUG, &dev->device, "aerdrv forceload requested.\n"); dev->port->aer_firmware_first = 0; return 0; } return -ENXIO; }