2 * drivers/pci/pcie/aer/aerdrv_core.c
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
8 * This file implements the core part of PCI-Express AER. When an pci-express
9 * error is delivered, an error message will be collected and printed to
10 * console, then, an error recovery procedure will be executed by following
11 * the pci error recovery rules.
13 * Copyright (C) 2006 Intel Corp.
14 * Tom Long Nguyen (tom.l.nguyen@intel.com)
15 * Zhang Yanmin (yanmin.zhang@intel.com)
19 #include <linux/module.h>
20 #include <linux/pci.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
24 #include <linux/suspend.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
27 #include <linux/kfifo.h>
30 static bool forceload;
31 static bool nosourceid;
32 module_param(forceload, bool, 0);
33 module_param(nosourceid, bool, 0);
35 #define PCI_EXP_AER_FLAGS (PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
36 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
38 int pci_enable_pcie_error_reporting(struct pci_dev *dev)
40 if (pcie_aer_get_firmware_first(dev))
43 if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
46 return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
48 EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
50 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
52 if (pcie_aer_get_firmware_first(dev))
55 return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
58 EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
60 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
65 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
69 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
71 pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
75 EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
78 * add_error_device - list device to be handled
79 * @e_info: pointer to error info
80 * @dev: pointer to pci_dev to be added
82 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
84 if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
85 e_info->dev[e_info->error_dev_num] = dev;
86 e_info->error_dev_num++;
93 * is_error_source - check whether the device is source of reported error
94 * @dev: pointer to pci_dev to be checked
95 * @e_info: pointer to reported error info
97 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
104 * When bus id is equal to 0, it might be a bad id
105 * reported by root port.
107 if (!nosourceid && (PCI_BUS_NUM(e_info->id) != 0)) {
108 /* Device ID match? */
109 if (e_info->id == ((dev->bus->number << 8) | dev->devfn))
112 /* Continue id comparing if there is no multiple error */
113 if (!e_info->multi_error_valid)
120 * 2) bus id is equal to 0. Some ports might lose the bus
121 * id of error source id;
122 * 3) There are multiple errors and prior id comparing fails;
123 * We check AER status registers to find possible reporter.
125 if (atomic_read(&dev->enable_cnt) == 0)
128 /* Check if AER is enabled */
129 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, ®16);
130 if (!(reg16 & PCI_EXP_AER_FLAGS))
133 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
137 /* Check if error is recorded */
138 if (e_info->severity == AER_CORRECTABLE) {
139 pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status);
140 pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &mask);
142 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
143 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask);
151 static int find_device_iter(struct pci_dev *dev, void *data)
153 struct aer_err_info *e_info = (struct aer_err_info *)data;
155 if (is_error_source(dev, e_info)) {
156 /* List this device */
157 if (add_error_device(e_info, dev)) {
158 /* We cannot handle more... Stop iteration */
159 /* TODO: Should print error message here? */
163 /* If there is only a single error, stop iteration */
164 if (!e_info->multi_error_valid)
171 * find_source_device - search through device hierarchy for source device
172 * @parent: pointer to Root Port pci_dev data structure
173 * @e_info: including detailed error information such like id
175 * Return true if found.
177 * Invoked by DPC when error is detected at the Root Port.
178 * Caller of this function must set id, severity, and multi_error_valid of
179 * struct aer_err_info pointed by @e_info properly. This function must fill
180 * e_info->error_dev_num and e_info->dev[], based on the given information.
182 static bool find_source_device(struct pci_dev *parent,
183 struct aer_err_info *e_info)
185 struct pci_dev *dev = parent;
188 /* Must reset in this function */
189 e_info->error_dev_num = 0;
191 /* Is Root Port an agent that sends error message? */
192 result = find_device_iter(dev, e_info);
196 pci_walk_bus(parent->subordinate, find_device_iter, e_info);
198 if (!e_info->error_dev_num) {
199 dev_printk(KERN_DEBUG, &parent->dev,
200 "can't find device of ID%04x\n",
207 static int report_error_detected(struct pci_dev *dev, void *data)
209 pci_ers_result_t vote;
210 const struct pci_error_handlers *err_handler;
211 struct aer_broadcast_data *result_data;
212 result_data = (struct aer_broadcast_data *) data;
214 device_lock(&dev->dev);
215 dev->error_state = result_data->state;
218 !dev->driver->err_handler ||
219 !dev->driver->err_handler->error_detected) {
220 if (result_data->state == pci_channel_io_frozen &&
221 !(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)) {
223 * In case of fatal recovery, if one of down-
224 * stream device has no driver. We might be
225 * unable to recover because a later insmod
226 * of a driver for this device is unaware of
229 dev_printk(KERN_DEBUG, &dev->dev, "device has %s\n",
231 "no AER-aware driver" : "no driver");
235 * If there's any device in the subtree that does not
236 * have an error_detected callback, returning
237 * PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of
238 * the subsequent mmio_enabled/slot_reset/resume
239 * callbacks of "any" device in the subtree. All the
240 * devices in the subtree are left in the error state
244 if (!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
245 vote = PCI_ERS_RESULT_NO_AER_DRIVER;
247 vote = PCI_ERS_RESULT_NONE;
249 err_handler = dev->driver->err_handler;
250 vote = err_handler->error_detected(dev, result_data->state);
253 result_data->result = merge_result(result_data->result, vote);
254 device_unlock(&dev->dev);
258 static int report_mmio_enabled(struct pci_dev *dev, void *data)
260 pci_ers_result_t vote;
261 const struct pci_error_handlers *err_handler;
262 struct aer_broadcast_data *result_data;
263 result_data = (struct aer_broadcast_data *) data;
265 device_lock(&dev->dev);
267 !dev->driver->err_handler ||
268 !dev->driver->err_handler->mmio_enabled)
271 err_handler = dev->driver->err_handler;
272 vote = err_handler->mmio_enabled(dev);
273 result_data->result = merge_result(result_data->result, vote);
275 device_unlock(&dev->dev);
279 static int report_slot_reset(struct pci_dev *dev, void *data)
281 pci_ers_result_t vote;
282 const struct pci_error_handlers *err_handler;
283 struct aer_broadcast_data *result_data;
284 result_data = (struct aer_broadcast_data *) data;
286 device_lock(&dev->dev);
288 !dev->driver->err_handler ||
289 !dev->driver->err_handler->slot_reset)
292 err_handler = dev->driver->err_handler;
293 vote = err_handler->slot_reset(dev);
294 result_data->result = merge_result(result_data->result, vote);
296 device_unlock(&dev->dev);
300 static int report_resume(struct pci_dev *dev, void *data)
302 const struct pci_error_handlers *err_handler;
304 device_lock(&dev->dev);
305 dev->error_state = pci_channel_io_normal;
308 !dev->driver->err_handler ||
309 !dev->driver->err_handler->resume)
312 err_handler = dev->driver->err_handler;
313 err_handler->resume(dev);
315 device_unlock(&dev->dev);
320 * broadcast_error_message - handle message broadcast to downstream drivers
321 * @dev: pointer to from where in a hierarchy message is broadcasted down
322 * @state: error state
323 * @error_mesg: message to print
324 * @cb: callback to be broadcasted
326 * Invoked during error recovery process. Once being invoked, the content
327 * of error severity will be broadcasted to all downstream drivers in a
328 * hierarchy in question.
330 static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
331 enum pci_channel_state state,
333 int (*cb)(struct pci_dev *, void *))
335 struct aer_broadcast_data result_data;
337 dev_printk(KERN_DEBUG, &dev->dev, "broadcast %s message\n", error_mesg);
338 result_data.state = state;
339 if (cb == report_error_detected)
340 result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
342 result_data.result = PCI_ERS_RESULT_RECOVERED;
344 if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
346 * If the error is reported by a bridge, we think this error
347 * is related to the downstream link of the bridge, so we
348 * do error recovery on all subordinates of the bridge instead
349 * of the bridge and clear the error status of the bridge.
351 if (cb == report_error_detected)
352 dev->error_state = state;
353 pci_walk_bus(dev->subordinate, cb, &result_data);
354 if (cb == report_resume) {
355 pci_cleanup_aer_uncorrect_error_status(dev);
356 dev->error_state = pci_channel_io_normal;
360 * If the error is reported by an end point, we think this
361 * error is related to the upstream link of the end point.
363 pci_walk_bus(dev->bus, cb, &result_data);
366 return result_data.result;
370 * aer_do_secondary_bus_reset - perform secondary bus reset
371 * @dev: pointer to bridge's pci_dev data structure
373 * Invoked when performing link reset at Root Port or Downstream Port.
375 void aer_do_secondary_bus_reset(struct pci_dev *dev)
379 /* Assert Secondary Bus Reset */
380 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
381 p2p_ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
382 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
385 * we should send hot reset message for 2ms to allow it time to
386 * propagate to all downstream ports
390 /* De-assert Secondary Bus Reset */
391 p2p_ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
392 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
395 * System software must wait for at least 100ms from the end
396 * of a reset of one or more device before it is permitted
397 * to issue Configuration Requests to those devices.
403 * default_reset_link - default reset function
404 * @dev: pointer to pci_dev data structure
406 * Invoked when performing link reset on a Downstream Port or a
407 * Root Port with no aer driver.
409 static pci_ers_result_t default_reset_link(struct pci_dev *dev)
411 aer_do_secondary_bus_reset(dev);
412 dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n");
413 return PCI_ERS_RESULT_RECOVERED;
416 static int find_aer_service_iter(struct device *device, void *data)
418 struct pcie_port_service_driver *service_driver, **drv;
420 drv = (struct pcie_port_service_driver **) data;
422 if (device->bus == &pcie_port_bus_type && device->driver) {
423 service_driver = to_service_driver(device->driver);
424 if (service_driver->service == PCIE_PORT_SERVICE_AER) {
425 *drv = service_driver;
433 static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev)
435 struct pcie_port_service_driver *drv = NULL;
437 device_for_each_child(&dev->dev, &drv, find_aer_service_iter);
442 static pci_ers_result_t reset_link(struct pci_dev *dev)
444 struct pci_dev *udev;
445 pci_ers_result_t status;
446 struct pcie_port_service_driver *driver;
448 if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
449 /* Reset this port for all subordinates */
452 /* Reset the upstream component (likely downstream port) */
453 udev = dev->bus->self;
456 /* Use the aer driver of the component firstly */
457 driver = find_aer_service(udev);
459 if (driver && driver->reset_link) {
460 status = driver->reset_link(udev);
461 } else if (pci_pcie_type(udev) == PCI_EXP_TYPE_DOWNSTREAM ||
462 pci_pcie_type(udev) == PCI_EXP_TYPE_ROOT_PORT) {
463 status = default_reset_link(udev);
465 dev_printk(KERN_DEBUG, &dev->dev,
466 "no link-reset support at upstream device %s\n",
468 return PCI_ERS_RESULT_DISCONNECT;
471 if (status != PCI_ERS_RESULT_RECOVERED) {
472 dev_printk(KERN_DEBUG, &dev->dev,
473 "link reset at upstream device %s failed\n",
475 return PCI_ERS_RESULT_DISCONNECT;
482 * do_recovery - handle nonfatal/fatal error recovery process
483 * @dev: pointer to a pci_dev data structure of agent detecting an error
484 * @severity: error severity type
486 * Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
487 * error detected message to all downstream drivers within a hierarchy in
488 * question and return the returned code.
490 static void do_recovery(struct pci_dev *dev, int severity)
492 pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED;
493 enum pci_channel_state state;
495 if (severity == AER_FATAL)
496 state = pci_channel_io_frozen;
498 state = pci_channel_io_normal;
500 status = broadcast_error_message(dev,
503 report_error_detected);
505 if (severity == AER_FATAL) {
506 result = reset_link(dev);
507 if (result != PCI_ERS_RESULT_RECOVERED)
511 if (status == PCI_ERS_RESULT_CAN_RECOVER)
512 status = broadcast_error_message(dev,
515 report_mmio_enabled);
517 if (status == PCI_ERS_RESULT_NEED_RESET) {
519 * TODO: Should call platform-specific
520 * functions to reset slot before calling
521 * drivers' slot_reset callbacks?
523 status = broadcast_error_message(dev,
529 if (status != PCI_ERS_RESULT_RECOVERED)
532 broadcast_error_message(dev,
537 dev_info(&dev->dev, "AER: Device recovery successful\n");
541 /* TODO: Should kernel panic here? */
542 dev_info(&dev->dev, "AER: Device recovery failed\n");
546 * handle_error_source - handle logging error into an event log
547 * @aerdev: pointer to pcie_device data structure of the root port
548 * @dev: pointer to pci_dev data structure of error source device
549 * @info: comprehensive error information
551 * Invoked when an error being detected by Root Port.
553 static void handle_error_source(struct pcie_device *aerdev,
555 struct aer_err_info *info)
559 if (info->severity == AER_CORRECTABLE) {
561 * Correctable error does not need software intevention.
562 * No need to go through error recovery process.
564 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
566 pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,
569 do_recovery(dev, info->severity);
572 #ifdef CONFIG_ACPI_APEI_PCIEAER
573 static void aer_recover_work_func(struct work_struct *work);
575 #define AER_RECOVER_RING_ORDER 4
576 #define AER_RECOVER_RING_SIZE (1 << AER_RECOVER_RING_ORDER)
578 struct aer_recover_entry
584 struct aer_capability_regs *regs;
587 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
588 AER_RECOVER_RING_SIZE);
590 * Mutual exclusion for writers of aer_recover_ring, reader side don't
591 * need lock, because there is only one reader and lock is not needed
592 * between reader and writer.
594 static DEFINE_SPINLOCK(aer_recover_ring_lock);
595 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
597 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
598 int severity, struct aer_capability_regs *aer_regs)
601 struct aer_recover_entry entry = {
605 .severity = severity,
609 spin_lock_irqsave(&aer_recover_ring_lock, flags);
610 if (kfifo_put(&aer_recover_ring, &entry))
611 schedule_work(&aer_recover_work);
613 pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n",
614 domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
615 spin_unlock_irqrestore(&aer_recover_ring_lock, flags);
617 EXPORT_SYMBOL_GPL(aer_recover_queue);
619 static void aer_recover_work_func(struct work_struct *work)
621 struct aer_recover_entry entry;
622 struct pci_dev *pdev;
624 while (kfifo_get(&aer_recover_ring, &entry)) {
625 pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
628 pr_err("AER recover: Can not find pci_dev for %04x:%02x:%02x:%x\n",
629 entry.domain, entry.bus,
630 PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
633 cper_print_aer(pdev, entry.severity, entry.regs);
634 do_recovery(pdev, entry.severity);
641 * get_device_error_info - read error status from dev and store it to info
642 * @dev: pointer to the device expected to have a error record
643 * @info: pointer to structure to store the error record
645 * Return 1 on success, 0 on error.
647 * Note that @info is reused among all error devices. Clear fields properly.
649 static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
653 /* Must reset in this function */
655 info->tlp_header_valid = 0;
657 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
659 /* The device might not support AER */
663 if (info->severity == AER_CORRECTABLE) {
664 pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS,
666 pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK,
668 if (!(info->status & ~info->mask))
670 } else if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE ||
671 info->severity == AER_NONFATAL) {
673 /* Link is still healthy for IO reads */
674 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS,
676 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK,
678 if (!(info->status & ~info->mask))
681 /* Get First Error Pointer */
682 pci_read_config_dword(dev, pos + PCI_ERR_CAP, &temp);
683 info->first_error = PCI_ERR_CAP_FEP(temp);
685 if (info->status & AER_LOG_TLP_MASKS) {
686 info->tlp_header_valid = 1;
687 pci_read_config_dword(dev,
688 pos + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
689 pci_read_config_dword(dev,
690 pos + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
691 pci_read_config_dword(dev,
692 pos + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
693 pci_read_config_dword(dev,
694 pos + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
701 static inline void aer_process_err_devices(struct pcie_device *p_device,
702 struct aer_err_info *e_info)
706 /* Report all before handle them, not to lost records by reset etc. */
707 for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
708 if (get_device_error_info(e_info->dev[i], e_info))
709 aer_print_error(e_info->dev[i], e_info);
711 for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
712 if (get_device_error_info(e_info->dev[i], e_info))
713 handle_error_source(p_device, e_info->dev[i], e_info);
718 * aer_isr_one_error - consume an error detected by root port
719 * @p_device: pointer to error root port service device
720 * @e_src: pointer to an error source
722 static void aer_isr_one_error(struct pcie_device *p_device,
723 struct aer_err_source *e_src)
725 struct aer_err_info *e_info;
727 /* struct aer_err_info might be big, so we allocate it with slab */
728 e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL);
730 dev_printk(KERN_DEBUG, &p_device->port->dev,
731 "Can't allocate mem when processing AER errors\n");
736 * There is a possibility that both correctable error and
737 * uncorrectable error being logged. Report correctable error first.
739 if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
740 e_info->id = ERR_COR_ID(e_src->id);
741 e_info->severity = AER_CORRECTABLE;
743 if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
744 e_info->multi_error_valid = 1;
746 e_info->multi_error_valid = 0;
748 aer_print_port_info(p_device->port, e_info);
750 if (find_source_device(p_device->port, e_info))
751 aer_process_err_devices(p_device, e_info);
754 if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
755 e_info->id = ERR_UNCOR_ID(e_src->id);
757 if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
758 e_info->severity = AER_FATAL;
760 e_info->severity = AER_NONFATAL;
762 if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
763 e_info->multi_error_valid = 1;
765 e_info->multi_error_valid = 0;
767 aer_print_port_info(p_device->port, e_info);
769 if (find_source_device(p_device->port, e_info))
770 aer_process_err_devices(p_device, e_info);
777 * get_e_source - retrieve an error source
778 * @rpc: pointer to the root port which holds an error
779 * @e_src: pointer to store retrieved error source
781 * Return 1 if an error source is retrieved, otherwise 0.
783 * Invoked by DPC handler to consume an error.
785 static int get_e_source(struct aer_rpc *rpc, struct aer_err_source *e_src)
789 /* Lock access to Root error producer/consumer index */
790 spin_lock_irqsave(&rpc->e_lock, flags);
791 if (rpc->prod_idx == rpc->cons_idx) {
792 spin_unlock_irqrestore(&rpc->e_lock, flags);
796 *e_src = rpc->e_sources[rpc->cons_idx];
798 if (rpc->cons_idx == AER_ERROR_SOURCES_MAX)
800 spin_unlock_irqrestore(&rpc->e_lock, flags);
806 * aer_isr - consume errors detected by root port
807 * @work: definition of this work item
809 * Invoked, as DPC, when root port records new detected error
811 void aer_isr(struct work_struct *work)
813 struct aer_rpc *rpc = container_of(work, struct aer_rpc, dpc_handler);
814 struct pcie_device *p_device = rpc->rpd;
815 struct aer_err_source uninitialized_var(e_src);
817 mutex_lock(&rpc->rpc_mutex);
818 while (get_e_source(rpc, &e_src))
819 aer_isr_one_error(p_device, &e_src);
820 mutex_unlock(&rpc->rpc_mutex);
822 wake_up(&rpc->wait_release);
826 * aer_init - provide AER initialization
827 * @dev: pointer to AER pcie device
829 * Invoked when AER service driver is loaded.
831 int aer_init(struct pcie_device *dev)
834 dev_printk(KERN_DEBUG, &dev->device,
835 "aerdrv forceload requested.\n");
836 pcie_aer_force_firmware_first(dev->port, 0);