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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PCI Error Recovery Driver for RPA-compliant PPC64 platform.
4 * Copyright IBM Corp. 2004 2005
5 * Copyright Linas Vepstas <linas@linas.org> 2004, 2005
6 *
7 * Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
8 */
9#include <linux/delay.h>
10#include <linux/interrupt.h>
11#include <linux/irq.h>
12#include <linux/module.h>
13#include <linux/pci.h>
14#include <linux/pci_hotplug.h>
15#include <asm/eeh.h>
16#include <asm/eeh_event.h>
17#include <asm/ppc-pci.h>
18#include <asm/pci-bridge.h>
19#include <asm/prom.h>
20#include <asm/rtas.h>
21
22struct eeh_rmv_data {
23 struct list_head removed_vf_list;
24 int removed_dev_count;
25};
26
27static int eeh_result_priority(enum pci_ers_result result)
28{
29 switch (result) {
30 case PCI_ERS_RESULT_NONE:
31 return 1;
32 case PCI_ERS_RESULT_NO_AER_DRIVER:
33 return 2;
34 case PCI_ERS_RESULT_RECOVERED:
35 return 3;
36 case PCI_ERS_RESULT_CAN_RECOVER:
37 return 4;
38 case PCI_ERS_RESULT_DISCONNECT:
39 return 5;
40 case PCI_ERS_RESULT_NEED_RESET:
41 return 6;
42 default:
43 WARN_ONCE(1, "Unknown pci_ers_result value: %d\n", (int)result);
44 return 0;
45 }
46};
47
48static const char *pci_ers_result_name(enum pci_ers_result result)
49{
50 switch (result) {
51 case PCI_ERS_RESULT_NONE:
52 return "none";
53 case PCI_ERS_RESULT_CAN_RECOVER:
54 return "can recover";
55 case PCI_ERS_RESULT_NEED_RESET:
56 return "need reset";
57 case PCI_ERS_RESULT_DISCONNECT:
58 return "disconnect";
59 case PCI_ERS_RESULT_RECOVERED:
60 return "recovered";
61 case PCI_ERS_RESULT_NO_AER_DRIVER:
62 return "no AER driver";
63 default:
64 WARN_ONCE(1, "Unknown result type: %d\n", (int)result);
65 return "unknown";
66 }
67};
68
69static enum pci_ers_result pci_ers_merge_result(enum pci_ers_result old,
70 enum pci_ers_result new)
71{
72 if (eeh_result_priority(new) > eeh_result_priority(old))
73 return new;
74 return old;
75}
76
77static bool eeh_dev_removed(struct eeh_dev *edev)
78{
79 return !edev || (edev->mode & EEH_DEV_REMOVED);
80}
81
82static bool eeh_edev_actionable(struct eeh_dev *edev)
83{
84 if (!edev->pdev)
85 return false;
86 if (edev->pdev->error_state == pci_channel_io_perm_failure)
87 return false;
88 if (eeh_dev_removed(edev))
89 return false;
90 if (eeh_pe_passed(edev->pe))
91 return false;
92
93 return true;
94}
95
96/**
97 * eeh_pcid_get - Get the PCI device driver
98 * @pdev: PCI device
99 *
100 * The function is used to retrieve the PCI device driver for
101 * the indicated PCI device. Besides, we will increase the reference
102 * of the PCI device driver to prevent that being unloaded on
103 * the fly. Otherwise, kernel crash would be seen.
104 */
105static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
106{
107 if (!pdev || !pdev->driver)
108 return NULL;
109
110 if (!try_module_get(pdev->driver->driver.owner))
111 return NULL;
112
113 return pdev->driver;
114}
115
116/**
117 * eeh_pcid_put - Dereference on the PCI device driver
118 * @pdev: PCI device
119 *
120 * The function is called to do dereference on the PCI device
121 * driver of the indicated PCI device.
122 */
123static inline void eeh_pcid_put(struct pci_dev *pdev)
124{
125 if (!pdev || !pdev->driver)
126 return;
127
128 module_put(pdev->driver->driver.owner);
129}
130
131/**
132 * eeh_disable_irq - Disable interrupt for the recovering device
133 * @dev: PCI device
134 *
135 * This routine must be called when reporting temporary or permanent
136 * error to the particular PCI device to disable interrupt of that
137 * device. If the device has enabled MSI or MSI-X interrupt, we needn't
138 * do real work because EEH should freeze DMA transfers for those PCI
139 * devices encountering EEH errors, which includes MSI or MSI-X.
140 */
141static void eeh_disable_irq(struct eeh_dev *edev)
142{
143 /* Don't disable MSI and MSI-X interrupts. They are
144 * effectively disabled by the DMA Stopped state
145 * when an EEH error occurs.
146 */
147 if (edev->pdev->msi_enabled || edev->pdev->msix_enabled)
148 return;
149
150 if (!irq_has_action(edev->pdev->irq))
151 return;
152
153 edev->mode |= EEH_DEV_IRQ_DISABLED;
154 disable_irq_nosync(edev->pdev->irq);
155}
156
157/**
158 * eeh_enable_irq - Enable interrupt for the recovering device
159 * @dev: PCI device
160 *
161 * This routine must be called to enable interrupt while failed
162 * device could be resumed.
163 */
164static void eeh_enable_irq(struct eeh_dev *edev)
165{
166 if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
167 edev->mode &= ~EEH_DEV_IRQ_DISABLED;
168 /*
169 * FIXME !!!!!
170 *
171 * This is just ass backwards. This maze has
172 * unbalanced irq_enable/disable calls. So instead of
173 * finding the root cause it works around the warning
174 * in the irq_enable code by conditionally calling
175 * into it.
176 *
177 * That's just wrong.The warning in the core code is
178 * there to tell people to fix their asymmetries in
179 * their own code, not by abusing the core information
180 * to avoid it.
181 *
182 * I so wish that the assymetry would be the other way
183 * round and a few more irq_disable calls render that
184 * shit unusable forever.
185 *
186 * tglx
187 */
188 if (irqd_irq_disabled(irq_get_irq_data(edev->pdev->irq)))
189 enable_irq(edev->pdev->irq);
190 }
191}
192
193static void eeh_dev_save_state(struct eeh_dev *edev, void *userdata)
194{
195 struct pci_dev *pdev;
196
197 if (!edev)
198 return;
199
200 /*
201 * We cannot access the config space on some adapters.
202 * Otherwise, it will cause fenced PHB. We don't save
203 * the content in their config space and will restore
204 * from the initial config space saved when the EEH
205 * device is created.
206 */
207 if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED))
208 return;
209
210 pdev = eeh_dev_to_pci_dev(edev);
211 if (!pdev)
212 return;
213
214 pci_save_state(pdev);
215}
216
217static void eeh_set_channel_state(struct eeh_pe *root, pci_channel_state_t s)
218{
219 struct eeh_pe *pe;
220 struct eeh_dev *edev, *tmp;
221
222 eeh_for_each_pe(root, pe)
223 eeh_pe_for_each_dev(pe, edev, tmp)
224 if (eeh_edev_actionable(edev))
225 edev->pdev->error_state = s;
226}
227
228static void eeh_set_irq_state(struct eeh_pe *root, bool enable)
229{
230 struct eeh_pe *pe;
231 struct eeh_dev *edev, *tmp;
232
233 eeh_for_each_pe(root, pe) {
234 eeh_pe_for_each_dev(pe, edev, tmp) {
235 if (!eeh_edev_actionable(edev))
236 continue;
237
238 if (!eeh_pcid_get(edev->pdev))
239 continue;
240
241 if (enable)
242 eeh_enable_irq(edev);
243 else
244 eeh_disable_irq(edev);
245
246 eeh_pcid_put(edev->pdev);
247 }
248 }
249}
250
251typedef enum pci_ers_result (*eeh_report_fn)(struct eeh_dev *,
252 struct pci_dev *,
253 struct pci_driver *);
254static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn,
255 enum pci_ers_result *result)
256{
257 struct pci_dev *pdev;
258 struct pci_driver *driver;
259 enum pci_ers_result new_result;
260
261 pci_lock_rescan_remove();
262 pdev = edev->pdev;
263 if (pdev)
264 get_device(&pdev->dev);
265 pci_unlock_rescan_remove();
266 if (!pdev) {
267 eeh_edev_info(edev, "no device");
268 return;
269 }
270 device_lock(&pdev->dev);
271 if (eeh_edev_actionable(edev)) {
272 driver = eeh_pcid_get(pdev);
273
274 if (!driver)
275 eeh_edev_info(edev, "no driver");
276 else if (!driver->err_handler)
277 eeh_edev_info(edev, "driver not EEH aware");
278 else if (edev->mode & EEH_DEV_NO_HANDLER)
279 eeh_edev_info(edev, "driver bound too late");
280 else {
281 new_result = fn(edev, pdev, driver);
282 eeh_edev_info(edev, "%s driver reports: '%s'",
283 driver->name,
284 pci_ers_result_name(new_result));
285 if (result)
286 *result = pci_ers_merge_result(*result,
287 new_result);
288 }
289 if (driver)
290 eeh_pcid_put(pdev);
291 } else {
292 eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!pdev,
293 !eeh_dev_removed(edev), !eeh_pe_passed(edev->pe));
294 }
295 device_unlock(&pdev->dev);
296 if (edev->pdev != pdev)
297 eeh_edev_warn(edev, "Device changed during processing!\n");
298 put_device(&pdev->dev);
299}
300
301static void eeh_pe_report(const char *name, struct eeh_pe *root,
302 eeh_report_fn fn, enum pci_ers_result *result)
303{
304 struct eeh_pe *pe;
305 struct eeh_dev *edev, *tmp;
306
307 pr_info("EEH: Beginning: '%s'\n", name);
308 eeh_for_each_pe(root, pe) eeh_pe_for_each_dev(pe, edev, tmp)
309 eeh_pe_report_edev(edev, fn, result);
310 if (result)
311 pr_info("EEH: Finished:'%s' with aggregate recovery state:'%s'\n",
312 name, pci_ers_result_name(*result));
313 else
314 pr_info("EEH: Finished:'%s'", name);
315}
316
317/**
318 * eeh_report_error - Report pci error to each device driver
319 * @edev: eeh device
320 * @driver: device's PCI driver
321 *
322 * Report an EEH error to each device driver.
323 */
324static enum pci_ers_result eeh_report_error(struct eeh_dev *edev,
325 struct pci_dev *pdev,
326 struct pci_driver *driver)
327{
328 enum pci_ers_result rc;
329
330 if (!driver->err_handler->error_detected)
331 return PCI_ERS_RESULT_NONE;
332
333 eeh_edev_info(edev, "Invoking %s->error_detected(IO frozen)",
334 driver->name);
335 rc = driver->err_handler->error_detected(pdev, pci_channel_io_frozen);
336
337 edev->in_error = true;
338 pci_uevent_ers(pdev, PCI_ERS_RESULT_NONE);
339 return rc;
340}
341
342/**
343 * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
344 * @edev: eeh device
345 * @driver: device's PCI driver
346 *
347 * Tells each device driver that IO ports, MMIO and config space I/O
348 * are now enabled.
349 */
350static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev,
351 struct pci_dev *pdev,
352 struct pci_driver *driver)
353{
354 if (!driver->err_handler->mmio_enabled)
355 return PCI_ERS_RESULT_NONE;
356 eeh_edev_info(edev, "Invoking %s->mmio_enabled()", driver->name);
357 return driver->err_handler->mmio_enabled(pdev);
358}
359
360/**
361 * eeh_report_reset - Tell device that slot has been reset
362 * @edev: eeh device
363 * @driver: device's PCI driver
364 *
365 * This routine must be called while EEH tries to reset particular
366 * PCI device so that the associated PCI device driver could take
367 * some actions, usually to save data the driver needs so that the
368 * driver can work again while the device is recovered.
369 */
370static enum pci_ers_result eeh_report_reset(struct eeh_dev *edev,
371 struct pci_dev *pdev,
372 struct pci_driver *driver)
373{
374 if (!driver->err_handler->slot_reset || !edev->in_error)
375 return PCI_ERS_RESULT_NONE;
376 eeh_edev_info(edev, "Invoking %s->slot_reset()", driver->name);
377 return driver->err_handler->slot_reset(pdev);
378}
379
380static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata)
381{
382 struct pci_dev *pdev;
383
384 if (!edev)
385 return;
386
387 /*
388 * The content in the config space isn't saved because
389 * the blocked config space on some adapters. We have
390 * to restore the initial saved config space when the
391 * EEH device is created.
392 */
393 if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED)) {
394 if (list_is_last(&edev->entry, &edev->pe->edevs))
395 eeh_pe_restore_bars(edev->pe);
396
397 return;
398 }
399
400 pdev = eeh_dev_to_pci_dev(edev);
401 if (!pdev)
402 return;
403
404 pci_restore_state(pdev);
405}
406
407/**
408 * eeh_report_resume - Tell device to resume normal operations
409 * @edev: eeh device
410 * @driver: device's PCI driver
411 *
412 * This routine must be called to notify the device driver that it
413 * could resume so that the device driver can do some initialization
414 * to make the recovered device work again.
415 */
416static enum pci_ers_result eeh_report_resume(struct eeh_dev *edev,
417 struct pci_dev *pdev,
418 struct pci_driver *driver)
419{
420 if (!driver->err_handler->resume || !edev->in_error)
421 return PCI_ERS_RESULT_NONE;
422
423 eeh_edev_info(edev, "Invoking %s->resume()", driver->name);
424 driver->err_handler->resume(pdev);
425
426 pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_RECOVERED);
427#ifdef CONFIG_PCI_IOV
428 if (eeh_ops->notify_resume)
429 eeh_ops->notify_resume(edev);
430#endif
431 return PCI_ERS_RESULT_NONE;
432}
433
434/**
435 * eeh_report_failure - Tell device driver that device is dead.
436 * @edev: eeh device
437 * @driver: device's PCI driver
438 *
439 * This informs the device driver that the device is permanently
440 * dead, and that no further recovery attempts will be made on it.
441 */
442static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev,
443 struct pci_dev *pdev,
444 struct pci_driver *driver)
445{
446 enum pci_ers_result rc;
447
448 if (!driver->err_handler->error_detected)
449 return PCI_ERS_RESULT_NONE;
450
451 eeh_edev_info(edev, "Invoking %s->error_detected(permanent failure)",
452 driver->name);
453 rc = driver->err_handler->error_detected(pdev,
454 pci_channel_io_perm_failure);
455
456 pci_uevent_ers(pdev, PCI_ERS_RESULT_DISCONNECT);
457 return rc;
458}
459
460static void *eeh_add_virt_device(struct eeh_dev *edev)
461{
462 struct pci_driver *driver;
463 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
464
465 if (!(edev->physfn)) {
466 eeh_edev_warn(edev, "Not for VF\n");
467 return NULL;
468 }
469
470 driver = eeh_pcid_get(dev);
471 if (driver) {
472 if (driver->err_handler) {
473 eeh_pcid_put(dev);
474 return NULL;
475 }
476 eeh_pcid_put(dev);
477 }
478
479#ifdef CONFIG_PCI_IOV
480 pci_iov_add_virtfn(edev->physfn, edev->vf_index);
481#endif
482 return NULL;
483}
484
485static void eeh_rmv_device(struct eeh_dev *edev, void *userdata)
486{
487 struct pci_driver *driver;
488 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
489 struct eeh_rmv_data *rmv_data = (struct eeh_rmv_data *)userdata;
490
491 /*
492 * Actually, we should remove the PCI bridges as well.
493 * However, that's lots of complexity to do that,
494 * particularly some of devices under the bridge might
495 * support EEH. So we just care about PCI devices for
496 * simplicity here.
497 */
498 if (!eeh_edev_actionable(edev) ||
499 (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE))
500 return;
501
502 if (rmv_data) {
503 driver = eeh_pcid_get(dev);
504 if (driver) {
505 if (driver->err_handler &&
506 driver->err_handler->error_detected &&
507 driver->err_handler->slot_reset) {
508 eeh_pcid_put(dev);
509 return;
510 }
511 eeh_pcid_put(dev);
512 }
513 }
514
515 /* Remove it from PCI subsystem */
516 pr_info("EEH: Removing %s without EEH sensitive driver\n",
517 pci_name(dev));
518 edev->mode |= EEH_DEV_DISCONNECTED;
519 if (rmv_data)
520 rmv_data->removed_dev_count++;
521
522 if (edev->physfn) {
523#ifdef CONFIG_PCI_IOV
524 pci_iov_remove_virtfn(edev->physfn, edev->vf_index);
525 edev->pdev = NULL;
526#endif
527 if (rmv_data)
528 list_add(&edev->rmv_entry, &rmv_data->removed_vf_list);
529 } else {
530 pci_lock_rescan_remove();
531 pci_stop_and_remove_bus_device(dev);
532 pci_unlock_rescan_remove();
533 }
534}
535
536static void *eeh_pe_detach_dev(struct eeh_pe *pe, void *userdata)
537{
538 struct eeh_dev *edev, *tmp;
539
540 eeh_pe_for_each_dev(pe, edev, tmp) {
541 if (!(edev->mode & EEH_DEV_DISCONNECTED))
542 continue;
543
544 edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED);
545 eeh_pe_tree_remove(edev);
546 }
547
548 return NULL;
549}
550
551/*
552 * Explicitly clear PE's frozen state for PowerNV where
553 * we have frozen PE until BAR restore is completed. It's
554 * harmless to clear it for pSeries. To be consistent with
555 * PE reset (for 3 times), we try to clear the frozen state
556 * for 3 times as well.
557 */
558static int eeh_clear_pe_frozen_state(struct eeh_pe *root, bool include_passed)
559{
560 struct eeh_pe *pe;
561 int i;
562
563 eeh_for_each_pe(root, pe) {
564 if (include_passed || !eeh_pe_passed(pe)) {
565 for (i = 0; i < 3; i++)
566 if (!eeh_unfreeze_pe(pe))
567 break;
568 if (i >= 3)
569 return -EIO;
570 }
571 }
572 eeh_pe_state_clear(root, EEH_PE_ISOLATED, include_passed);
573 return 0;
574}
575
576int eeh_pe_reset_and_recover(struct eeh_pe *pe)
577{
578 int ret;
579
580 /* Bail if the PE is being recovered */
581 if (pe->state & EEH_PE_RECOVERING)
582 return 0;
583
584 /* Put the PE into recovery mode */
585 eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
586
587 /* Save states */
588 eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL);
589
590 /* Issue reset */
591 ret = eeh_pe_reset_full(pe, true);
592 if (ret) {
593 eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
594 return ret;
595 }
596
597 /* Unfreeze the PE */
598 ret = eeh_clear_pe_frozen_state(pe, true);
599 if (ret) {
600 eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
601 return ret;
602 }
603
604 /* Restore device state */
605 eeh_pe_dev_traverse(pe, eeh_dev_restore_state, NULL);
606
607 /* Clear recovery mode */
608 eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
609
610 return 0;
611}
612
613/**
614 * eeh_reset_device - Perform actual reset of a pci slot
615 * @driver_eeh_aware: Does the device's driver provide EEH support?
616 * @pe: EEH PE
617 * @bus: PCI bus corresponding to the isolcated slot
618 * @rmv_data: Optional, list to record removed devices
619 *
620 * This routine must be called to do reset on the indicated PE.
621 * During the reset, udev might be invoked because those affected
622 * PCI devices will be removed and then added.
623 */
624static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
625 struct eeh_rmv_data *rmv_data,
626 bool driver_eeh_aware)
627{
628 time64_t tstamp;
629 int cnt, rc;
630 struct eeh_dev *edev;
631 struct eeh_pe *tmp_pe;
632 bool any_passed = false;
633
634 eeh_for_each_pe(pe, tmp_pe)
635 any_passed |= eeh_pe_passed(tmp_pe);
636
637 /* pcibios will clear the counter; save the value */
638 cnt = pe->freeze_count;
639 tstamp = pe->tstamp;
640
641 /*
642 * We don't remove the corresponding PE instances because
643 * we need the information afterwords. The attached EEH
644 * devices are expected to be attached soon when calling
645 * into pci_hp_add_devices().
646 */
647 eeh_pe_state_mark(pe, EEH_PE_KEEP);
648 if (any_passed || driver_eeh_aware || (pe->type & EEH_PE_VF)) {
649 eeh_pe_dev_traverse(pe, eeh_rmv_device, rmv_data);
650 } else {
651 pci_lock_rescan_remove();
652 pci_hp_remove_devices(bus);
653 pci_unlock_rescan_remove();
654 }
655
656 /*
657 * Reset the pci controller. (Asserts RST#; resets config space).
658 * Reconfigure bridges and devices. Don't try to bring the system
659 * up if the reset failed for some reason.
660 *
661 * During the reset, it's very dangerous to have uncontrolled PCI
662 * config accesses. So we prefer to block them. However, controlled
663 * PCI config accesses initiated from EEH itself are allowed.
664 */
665 rc = eeh_pe_reset_full(pe, false);
666 if (rc)
667 return rc;
668
669 pci_lock_rescan_remove();
670
671 /* Restore PE */
672 eeh_ops->configure_bridge(pe);
673 eeh_pe_restore_bars(pe);
674
675 /* Clear frozen state */
676 rc = eeh_clear_pe_frozen_state(pe, false);
677 if (rc) {
678 pci_unlock_rescan_remove();
679 return rc;
680 }
681
682 /* Give the system 5 seconds to finish running the user-space
683 * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,
684 * this is a hack, but if we don't do this, and try to bring
685 * the device up before the scripts have taken it down,
686 * potentially weird things happen.
687 */
688 if (!driver_eeh_aware || rmv_data->removed_dev_count) {
689 pr_info("EEH: Sleep 5s ahead of %s hotplug\n",
690 (driver_eeh_aware ? "partial" : "complete"));
691 ssleep(5);
692
693 /*
694 * The EEH device is still connected with its parent
695 * PE. We should disconnect it so the binding can be
696 * rebuilt when adding PCI devices.
697 */
698 edev = list_first_entry(&pe->edevs, struct eeh_dev, entry);
699 eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
700 if (pe->type & EEH_PE_VF) {
701 eeh_add_virt_device(edev);
702 } else {
703 if (!driver_eeh_aware)
704 eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
705 pci_hp_add_devices(bus);
706 }
707 }
708 eeh_pe_state_clear(pe, EEH_PE_KEEP, true);
709
710 pe->tstamp = tstamp;
711 pe->freeze_count = cnt;
712
713 pci_unlock_rescan_remove();
714 return 0;
715}
716
717/* The longest amount of time to wait for a pci device
718 * to come back on line, in seconds.
719 */
720#define MAX_WAIT_FOR_RECOVERY 300
721
722
723/* Walks the PE tree after processing an event to remove any stale PEs.
724 *
725 * NB: This needs to be recursive to ensure the leaf PEs get removed
726 * before their parents do. Although this is possible to do recursively
727 * we don't since this is easier to read and we need to garantee
728 * the leaf nodes will be handled first.
729 */
730static void eeh_pe_cleanup(struct eeh_pe *pe)
731{
732 struct eeh_pe *child_pe, *tmp;
733
734 list_for_each_entry_safe(child_pe, tmp, &pe->child_list, child)
735 eeh_pe_cleanup(child_pe);
736
737 if (pe->state & EEH_PE_KEEP)
738 return;
739
740 if (!(pe->state & EEH_PE_INVALID))
741 return;
742
743 if (list_empty(&pe->edevs) && list_empty(&pe->child_list)) {
744 list_del(&pe->child);
745 kfree(pe);
746 }
747}
748
749/**
750 * eeh_check_slot_presence - Check if a device is still present in a slot
751 * @pdev: pci_dev to check
752 *
753 * This function may return a false positive if we can't determine the slot's
754 * presence state. This might happen for for PCIe slots if the PE containing
755 * the upstream bridge is also frozen, or the bridge is part of the same PE
756 * as the device.
757 *
758 * This shouldn't happen often, but you might see it if you hotplug a PCIe
759 * switch.
760 */
761static bool eeh_slot_presence_check(struct pci_dev *pdev)
762{
763 const struct hotplug_slot_ops *ops;
764 struct pci_slot *slot;
765 u8 state;
766 int rc;
767
768 if (!pdev)
769 return false;
770
771 if (pdev->error_state == pci_channel_io_perm_failure)
772 return false;
773
774 slot = pdev->slot;
775 if (!slot || !slot->hotplug)
776 return true;
777
778 ops = slot->hotplug->ops;
779 if (!ops || !ops->get_adapter_status)
780 return true;
781
782 /* set the attention indicator while we've got the slot ops */
783 if (ops->set_attention_status)
784 ops->set_attention_status(slot->hotplug, 1);
785
786 rc = ops->get_adapter_status(slot->hotplug, &state);
787 if (rc)
788 return true;
789
790 return !!state;
791}
792
793static void eeh_clear_slot_attention(struct pci_dev *pdev)
794{
795 const struct hotplug_slot_ops *ops;
796 struct pci_slot *slot;
797
798 if (!pdev)
799 return;
800
801 if (pdev->error_state == pci_channel_io_perm_failure)
802 return;
803
804 slot = pdev->slot;
805 if (!slot || !slot->hotplug)
806 return;
807
808 ops = slot->hotplug->ops;
809 if (!ops || !ops->set_attention_status)
810 return;
811
812 ops->set_attention_status(slot->hotplug, 0);
813}
814
815/**
816 * eeh_handle_normal_event - Handle EEH events on a specific PE
817 * @pe: EEH PE - which should not be used after we return, as it may
818 * have been invalidated.
819 *
820 * Attempts to recover the given PE. If recovery fails or the PE has failed
821 * too many times, remove the PE.
822 *
823 * While PHB detects address or data parity errors on particular PCI
824 * slot, the associated PE will be frozen. Besides, DMA's occurring
825 * to wild addresses (which usually happen due to bugs in device
826 * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
827 * #PERR or other misc PCI-related errors also can trigger EEH errors.
828 *
829 * Recovery process consists of unplugging the device driver (which
830 * generated hotplug events to userspace), then issuing a PCI #RST to
831 * the device, then reconfiguring the PCI config space for all bridges
832 * & devices under this slot, and then finally restarting the device
833 * drivers (which cause a second set of hotplug events to go out to
834 * userspace).
835 */
836void eeh_handle_normal_event(struct eeh_pe *pe)
837{
838 struct pci_bus *bus;
839 struct eeh_dev *edev, *tmp;
840 struct eeh_pe *tmp_pe;
841 int rc = 0;
842 enum pci_ers_result result = PCI_ERS_RESULT_NONE;
843 struct eeh_rmv_data rmv_data =
844 {LIST_HEAD_INIT(rmv_data.removed_vf_list), 0};
845 int devices = 0;
846
847 bus = eeh_pe_bus_get(pe);
848 if (!bus) {
849 pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n",
850 __func__, pe->phb->global_number, pe->addr);
851 return;
852 }
853
854 /*
855 * When devices are hot-removed we might get an EEH due to
856 * a driver attempting to touch the MMIO space of a removed
857 * device. In this case we don't have a device to recover
858 * so suppress the event if we can't find any present devices.
859 *
860 * The hotplug driver should take care of tearing down the
861 * device itself.
862 */
863 eeh_for_each_pe(pe, tmp_pe)
864 eeh_pe_for_each_dev(tmp_pe, edev, tmp)
865 if (eeh_slot_presence_check(edev->pdev))
866 devices++;
867
868 if (!devices) {
869 pr_debug("EEH: Frozen PHB#%x-PE#%x is empty!\n",
870 pe->phb->global_number, pe->addr);
871 goto out; /* nothing to recover */
872 }
873
874 /* Log the event */
875 if (pe->type & EEH_PE_PHB) {
876 pr_err("EEH: Recovering PHB#%x, location: %s\n",
877 pe->phb->global_number, eeh_pe_loc_get(pe));
878 } else {
879 struct eeh_pe *phb_pe = eeh_phb_pe_get(pe->phb);
880
881 pr_err("EEH: Recovering PHB#%x-PE#%x\n",
882 pe->phb->global_number, pe->addr);
883 pr_err("EEH: PE location: %s, PHB location: %s\n",
884 eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe));
885 }
886
887#ifdef CONFIG_STACKTRACE
888 /*
889 * Print the saved stack trace now that we've verified there's
890 * something to recover.
891 */
892 if (pe->trace_entries) {
893 void **ptrs = (void **) pe->stack_trace;
894 int i;
895
896 pr_err("EEH: Frozen PHB#%x-PE#%x detected\n",
897 pe->phb->global_number, pe->addr);
898
899 /* FIXME: Use the same format as dump_stack() */
900 pr_err("EEH: Call Trace:\n");
901 for (i = 0; i < pe->trace_entries; i++)
902 pr_err("EEH: [%pK] %pS\n", ptrs[i], ptrs[i]);
903
904 pe->trace_entries = 0;
905 }
906#endif /* CONFIG_STACKTRACE */
907
908 eeh_pe_update_time_stamp(pe);
909 pe->freeze_count++;
910 if (pe->freeze_count > eeh_max_freezes) {
911 pr_err("EEH: PHB#%x-PE#%x has failed %d times in the last hour and has been permanently disabled.\n",
912 pe->phb->global_number, pe->addr,
913 pe->freeze_count);
914 result = PCI_ERS_RESULT_DISCONNECT;
915 }
916
917 eeh_for_each_pe(pe, tmp_pe)
918 eeh_pe_for_each_dev(tmp_pe, edev, tmp)
919 edev->mode &= ~EEH_DEV_NO_HANDLER;
920
921 /* Walk the various device drivers attached to this slot through
922 * a reset sequence, giving each an opportunity to do what it needs
923 * to accomplish the reset. Each child gets a report of the
924 * status ... if any child can't handle the reset, then the entire
925 * slot is dlpar removed and added.
926 *
927 * When the PHB is fenced, we have to issue a reset to recover from
928 * the error. Override the result if necessary to have partially
929 * hotplug for this case.
930 */
931 if (result != PCI_ERS_RESULT_DISCONNECT) {
932 pr_warn("EEH: This PCI device has failed %d times in the last hour and will be permanently disabled after %d failures.\n",
933 pe->freeze_count, eeh_max_freezes);
934 pr_info("EEH: Notify device drivers to shutdown\n");
935 eeh_set_channel_state(pe, pci_channel_io_frozen);
936 eeh_set_irq_state(pe, false);
937 eeh_pe_report("error_detected(IO frozen)", pe,
938 eeh_report_error, &result);
939 if ((pe->type & EEH_PE_PHB) &&
940 result != PCI_ERS_RESULT_NONE &&
941 result != PCI_ERS_RESULT_NEED_RESET)
942 result = PCI_ERS_RESULT_NEED_RESET;
943 }
944
945 /* Get the current PCI slot state. This can take a long time,
946 * sometimes over 300 seconds for certain systems.
947 */
948 if (result != PCI_ERS_RESULT_DISCONNECT) {
949 rc = eeh_wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
950 if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
951 pr_warn("EEH: Permanent failure\n");
952 result = PCI_ERS_RESULT_DISCONNECT;
953 }
954 }
955
956 /* Since rtas may enable MMIO when posting the error log,
957 * don't post the error log until after all dev drivers
958 * have been informed.
959 */
960 if (result != PCI_ERS_RESULT_DISCONNECT) {
961 pr_info("EEH: Collect temporary log\n");
962 eeh_slot_error_detail(pe, EEH_LOG_TEMP);
963 }
964
965 /* If all device drivers were EEH-unaware, then shut
966 * down all of the device drivers, and hope they
967 * go down willingly, without panicing the system.
968 */
969 if (result == PCI_ERS_RESULT_NONE) {
970 pr_info("EEH: Reset with hotplug activity\n");
971 rc = eeh_reset_device(pe, bus, NULL, false);
972 if (rc) {
973 pr_warn("%s: Unable to reset, err=%d\n",
974 __func__, rc);
975 result = PCI_ERS_RESULT_DISCONNECT;
976 }
977 }
978
979 /* If all devices reported they can proceed, then re-enable MMIO */
980 if (result == PCI_ERS_RESULT_CAN_RECOVER) {
981 pr_info("EEH: Enable I/O for affected devices\n");
982 rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
983
984 if (rc < 0) {
985 result = PCI_ERS_RESULT_DISCONNECT;
986 } else if (rc) {
987 result = PCI_ERS_RESULT_NEED_RESET;
988 } else {
989 pr_info("EEH: Notify device drivers to resume I/O\n");
990 eeh_pe_report("mmio_enabled", pe,
991 eeh_report_mmio_enabled, &result);
992 }
993 }
994
995 /* If all devices reported they can proceed, then re-enable DMA */
996 if (result == PCI_ERS_RESULT_CAN_RECOVER) {
997 pr_info("EEH: Enabled DMA for affected devices\n");
998 rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
999
1000 if (rc < 0) {
1001 result = PCI_ERS_RESULT_DISCONNECT;
1002 } else if (rc) {
1003 result = PCI_ERS_RESULT_NEED_RESET;
1004 } else {
1005 /*
1006 * We didn't do PE reset for the case. The PE
1007 * is still in frozen state. Clear it before
1008 * resuming the PE.
1009 */
1010 eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
1011 result = PCI_ERS_RESULT_RECOVERED;
1012 }
1013 }
1014
1015 /* If any device called out for a reset, then reset the slot */
1016 if (result == PCI_ERS_RESULT_NEED_RESET) {
1017 pr_info("EEH: Reset without hotplug activity\n");
1018 rc = eeh_reset_device(pe, bus, &rmv_data, true);
1019 if (rc) {
1020 pr_warn("%s: Cannot reset, err=%d\n",
1021 __func__, rc);
1022 result = PCI_ERS_RESULT_DISCONNECT;
1023 } else {
1024 result = PCI_ERS_RESULT_NONE;
1025 eeh_set_channel_state(pe, pci_channel_io_normal);
1026 eeh_set_irq_state(pe, true);
1027 eeh_pe_report("slot_reset", pe, eeh_report_reset,
1028 &result);
1029 }
1030 }
1031
1032 if ((result == PCI_ERS_RESULT_RECOVERED) ||
1033 (result == PCI_ERS_RESULT_NONE)) {
1034 /*
1035 * For those hot removed VFs, we should add back them after PF
1036 * get recovered properly.
1037 */
1038 list_for_each_entry_safe(edev, tmp, &rmv_data.removed_vf_list,
1039 rmv_entry) {
1040 eeh_add_virt_device(edev);
1041 list_del(&edev->rmv_entry);
1042 }
1043
1044 /* Tell all device drivers that they can resume operations */
1045 pr_info("EEH: Notify device driver to resume\n");
1046 eeh_set_channel_state(pe, pci_channel_io_normal);
1047 eeh_set_irq_state(pe, true);
1048 eeh_pe_report("resume", pe, eeh_report_resume, NULL);
1049 eeh_for_each_pe(pe, tmp_pe) {
1050 eeh_pe_for_each_dev(tmp_pe, edev, tmp) {
1051 edev->mode &= ~EEH_DEV_NO_HANDLER;
1052 edev->in_error = false;
1053 }
1054 }
1055
1056 pr_info("EEH: Recovery successful.\n");
1057 } else {
1058 /*
1059 * About 90% of all real-life EEH failures in the field
1060 * are due to poorly seated PCI cards. Only 10% or so are
1061 * due to actual, failed cards.
1062 */
1063 pr_err("EEH: Unable to recover from failure from PHB#%x-PE#%x.\n"
1064 "Please try reseating or replacing it\n",
1065 pe->phb->global_number, pe->addr);
1066
1067 eeh_slot_error_detail(pe, EEH_LOG_PERM);
1068
1069 /* Notify all devices that they're about to go down. */
1070 eeh_set_channel_state(pe, pci_channel_io_perm_failure);
1071 eeh_set_irq_state(pe, false);
1072 eeh_pe_report("error_detected(permanent failure)", pe,
1073 eeh_report_failure, NULL);
1074
1075 /* Mark the PE to be removed permanently */
1076 eeh_pe_state_mark(pe, EEH_PE_REMOVED);
1077
1078 /*
1079 * Shut down the device drivers for good. We mark
1080 * all removed devices correctly to avoid access
1081 * the their PCI config any more.
1082 */
1083 if (pe->type & EEH_PE_VF) {
1084 eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL);
1085 eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
1086 } else {
1087 eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
1088 eeh_pe_dev_mode_mark(pe, EEH_DEV_REMOVED);
1089
1090 pci_lock_rescan_remove();
1091 pci_hp_remove_devices(bus);
1092 pci_unlock_rescan_remove();
1093 /* The passed PE should no longer be used */
1094 return;
1095 }
1096 }
1097
1098out:
1099 /*
1100 * Clean up any PEs without devices. While marked as EEH_PE_RECOVERYING
1101 * we don't want to modify the PE tree structure so we do it here.
1102 */
1103 eeh_pe_cleanup(pe);
1104
1105 /* clear the slot attention LED for all recovered devices */
1106 eeh_for_each_pe(pe, tmp_pe)
1107 eeh_pe_for_each_dev(tmp_pe, edev, tmp)
1108 eeh_clear_slot_attention(edev->pdev);
1109
1110 eeh_pe_state_clear(pe, EEH_PE_RECOVERING, true);
1111}
1112
1113/**
1114 * eeh_handle_special_event - Handle EEH events without a specific failing PE
1115 *
1116 * Called when an EEH event is detected but can't be narrowed down to a
1117 * specific PE. Iterates through possible failures and handles them as
1118 * necessary.
1119 */
1120void eeh_handle_special_event(void)
1121{
1122 struct eeh_pe *pe, *phb_pe, *tmp_pe;
1123 struct eeh_dev *edev, *tmp_edev;
1124 struct pci_bus *bus;
1125 struct pci_controller *hose;
1126 unsigned long flags;
1127 int rc;
1128
1129
1130 do {
1131 rc = eeh_ops->next_error(&pe);
1132
1133 switch (rc) {
1134 case EEH_NEXT_ERR_DEAD_IOC:
1135 /* Mark all PHBs in dead state */
1136 eeh_serialize_lock(&flags);
1137
1138 /* Purge all events */
1139 eeh_remove_event(NULL, true);
1140
1141 list_for_each_entry(hose, &hose_list, list_node) {
1142 phb_pe = eeh_phb_pe_get(hose);
1143 if (!phb_pe) continue;
1144
1145 eeh_pe_mark_isolated(phb_pe);
1146 }
1147
1148 eeh_serialize_unlock(flags);
1149
1150 break;
1151 case EEH_NEXT_ERR_FROZEN_PE:
1152 case EEH_NEXT_ERR_FENCED_PHB:
1153 case EEH_NEXT_ERR_DEAD_PHB:
1154 /* Mark the PE in fenced state */
1155 eeh_serialize_lock(&flags);
1156
1157 /* Purge all events of the PHB */
1158 eeh_remove_event(pe, true);
1159
1160 if (rc != EEH_NEXT_ERR_DEAD_PHB)
1161 eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
1162 eeh_pe_mark_isolated(pe);
1163
1164 eeh_serialize_unlock(flags);
1165
1166 break;
1167 case EEH_NEXT_ERR_NONE:
1168 return;
1169 default:
1170 pr_warn("%s: Invalid value %d from next_error()\n",
1171 __func__, rc);
1172 return;
1173 }
1174
1175 /*
1176 * For fenced PHB and frozen PE, it's handled as normal
1177 * event. We have to remove the affected PHBs for dead
1178 * PHB and IOC
1179 */
1180 if (rc == EEH_NEXT_ERR_FROZEN_PE ||
1181 rc == EEH_NEXT_ERR_FENCED_PHB) {
1182 eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
1183 eeh_handle_normal_event(pe);
1184 } else {
1185 eeh_for_each_pe(pe, tmp_pe)
1186 eeh_pe_for_each_dev(tmp_pe, edev, tmp_edev)
1187 edev->mode &= ~EEH_DEV_NO_HANDLER;
1188
1189 /* Notify all devices to be down */
1190 eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
1191 eeh_set_channel_state(pe, pci_channel_io_perm_failure);
1192 eeh_pe_report(
1193 "error_detected(permanent failure)", pe,
1194 eeh_report_failure, NULL);
1195
1196 pci_lock_rescan_remove();
1197 list_for_each_entry(hose, &hose_list, list_node) {
1198 phb_pe = eeh_phb_pe_get(hose);
1199 if (!phb_pe ||
1200 !(phb_pe->state & EEH_PE_ISOLATED) ||
1201 (phb_pe->state & EEH_PE_RECOVERING))
1202 continue;
1203
1204 bus = eeh_pe_bus_get(phb_pe);
1205 if (!bus) {
1206 pr_err("%s: Cannot find PCI bus for "
1207 "PHB#%x-PE#%x\n",
1208 __func__,
1209 pe->phb->global_number,
1210 pe->addr);
1211 break;
1212 }
1213 pci_hp_remove_devices(bus);
1214 }
1215 pci_unlock_rescan_remove();
1216 }
1217
1218 /*
1219 * If we have detected dead IOC, we needn't proceed
1220 * any more since all PHBs would have been removed
1221 */
1222 if (rc == EEH_NEXT_ERR_DEAD_IOC)
1223 break;
1224 } while (rc != EEH_NEXT_ERR_NONE);
1225}
1/*
2 * PCI Error Recovery Driver for RPA-compliant PPC64 platform.
3 * Copyright IBM Corp. 2004 2005
4 * Copyright Linas Vepstas <linas@linas.org> 2004, 2005
5 *
6 * All rights reserved.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or (at
11 * your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
16 * NON INFRINGEMENT. See the GNU General Public License for more
17 * details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 *
23 * Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
24 */
25#include <linux/delay.h>
26#include <linux/interrupt.h>
27#include <linux/irq.h>
28#include <linux/module.h>
29#include <linux/pci.h>
30#include <asm/eeh.h>
31#include <asm/eeh_event.h>
32#include <asm/ppc-pci.h>
33#include <asm/pci-bridge.h>
34#include <asm/prom.h>
35#include <asm/rtas.h>
36
37/**
38 * eeh_pcid_name - Retrieve name of PCI device driver
39 * @pdev: PCI device
40 *
41 * This routine is used to retrieve the name of PCI device driver
42 * if that's valid.
43 */
44static inline const char *eeh_pcid_name(struct pci_dev *pdev)
45{
46 if (pdev && pdev->dev.driver)
47 return pdev->dev.driver->name;
48 return "";
49}
50
51/**
52 * eeh_pcid_get - Get the PCI device driver
53 * @pdev: PCI device
54 *
55 * The function is used to retrieve the PCI device driver for
56 * the indicated PCI device. Besides, we will increase the reference
57 * of the PCI device driver to prevent that being unloaded on
58 * the fly. Otherwise, kernel crash would be seen.
59 */
60static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
61{
62 if (!pdev || !pdev->driver)
63 return NULL;
64
65 if (!try_module_get(pdev->driver->driver.owner))
66 return NULL;
67
68 return pdev->driver;
69}
70
71/**
72 * eeh_pcid_put - Dereference on the PCI device driver
73 * @pdev: PCI device
74 *
75 * The function is called to do dereference on the PCI device
76 * driver of the indicated PCI device.
77 */
78static inline void eeh_pcid_put(struct pci_dev *pdev)
79{
80 if (!pdev || !pdev->driver)
81 return;
82
83 module_put(pdev->driver->driver.owner);
84}
85
86#if 0
87static void print_device_node_tree(struct pci_dn *pdn, int dent)
88{
89 int i;
90 struct device_node *pc;
91
92 if (!pdn)
93 return;
94 for (i = 0; i < dent; i++)
95 printk(" ");
96 printk("dn=%s mode=%x \tcfg_addr=%x pe_addr=%x \tfull=%s\n",
97 pdn->node->name, pdn->eeh_mode, pdn->eeh_config_addr,
98 pdn->eeh_pe_config_addr, pdn->node->full_name);
99 dent += 3;
100 pc = pdn->node->child;
101 while (pc) {
102 print_device_node_tree(PCI_DN(pc), dent);
103 pc = pc->sibling;
104 }
105}
106#endif
107
108/**
109 * eeh_disable_irq - Disable interrupt for the recovering device
110 * @dev: PCI device
111 *
112 * This routine must be called when reporting temporary or permanent
113 * error to the particular PCI device to disable interrupt of that
114 * device. If the device has enabled MSI or MSI-X interrupt, we needn't
115 * do real work because EEH should freeze DMA transfers for those PCI
116 * devices encountering EEH errors, which includes MSI or MSI-X.
117 */
118static void eeh_disable_irq(struct pci_dev *dev)
119{
120 struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
121
122 /* Don't disable MSI and MSI-X interrupts. They are
123 * effectively disabled by the DMA Stopped state
124 * when an EEH error occurs.
125 */
126 if (dev->msi_enabled || dev->msix_enabled)
127 return;
128
129 if (!irq_has_action(dev->irq))
130 return;
131
132 edev->mode |= EEH_DEV_IRQ_DISABLED;
133 disable_irq_nosync(dev->irq);
134}
135
136/**
137 * eeh_enable_irq - Enable interrupt for the recovering device
138 * @dev: PCI device
139 *
140 * This routine must be called to enable interrupt while failed
141 * device could be resumed.
142 */
143static void eeh_enable_irq(struct pci_dev *dev)
144{
145 struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
146
147 if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
148 edev->mode &= ~EEH_DEV_IRQ_DISABLED;
149 /*
150 * FIXME !!!!!
151 *
152 * This is just ass backwards. This maze has
153 * unbalanced irq_enable/disable calls. So instead of
154 * finding the root cause it works around the warning
155 * in the irq_enable code by conditionally calling
156 * into it.
157 *
158 * That's just wrong.The warning in the core code is
159 * there to tell people to fix their assymetries in
160 * their own code, not by abusing the core information
161 * to avoid it.
162 *
163 * I so wish that the assymetry would be the other way
164 * round and a few more irq_disable calls render that
165 * shit unusable forever.
166 *
167 * tglx
168 */
169 if (irqd_irq_disabled(irq_get_irq_data(dev->irq)))
170 enable_irq(dev->irq);
171 }
172}
173
174/**
175 * eeh_report_error - Report pci error to each device driver
176 * @data: eeh device
177 * @userdata: return value
178 *
179 * Report an EEH error to each device driver, collect up and
180 * merge the device driver responses. Cumulative response
181 * passed back in "userdata".
182 */
183static void *eeh_report_error(void *data, void *userdata)
184{
185 struct eeh_dev *edev = (struct eeh_dev *)data;
186 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
187 enum pci_ers_result rc, *res = userdata;
188 struct pci_driver *driver;
189
190 /* We might not have the associated PCI device,
191 * then we should continue for next one.
192 */
193 if (!dev) return NULL;
194 dev->error_state = pci_channel_io_frozen;
195
196 driver = eeh_pcid_get(dev);
197 if (!driver) return NULL;
198
199 eeh_disable_irq(dev);
200
201 if (!driver->err_handler ||
202 !driver->err_handler->error_detected) {
203 eeh_pcid_put(dev);
204 return NULL;
205 }
206
207 rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen);
208
209 /* A driver that needs a reset trumps all others */
210 if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
211 if (*res == PCI_ERS_RESULT_NONE) *res = rc;
212
213 eeh_pcid_put(dev);
214 return NULL;
215}
216
217/**
218 * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled
219 * @data: eeh device
220 * @userdata: return value
221 *
222 * Tells each device driver that IO ports, MMIO and config space I/O
223 * are now enabled. Collects up and merges the device driver responses.
224 * Cumulative response passed back in "userdata".
225 */
226static void *eeh_report_mmio_enabled(void *data, void *userdata)
227{
228 struct eeh_dev *edev = (struct eeh_dev *)data;
229 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
230 enum pci_ers_result rc, *res = userdata;
231 struct pci_driver *driver;
232
233 driver = eeh_pcid_get(dev);
234 if (!driver) return NULL;
235
236 if (!driver->err_handler ||
237 !driver->err_handler->mmio_enabled ||
238 (edev->mode & EEH_DEV_NO_HANDLER)) {
239 eeh_pcid_put(dev);
240 return NULL;
241 }
242
243 rc = driver->err_handler->mmio_enabled(dev);
244
245 /* A driver that needs a reset trumps all others */
246 if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
247 if (*res == PCI_ERS_RESULT_NONE) *res = rc;
248
249 eeh_pcid_put(dev);
250 return NULL;
251}
252
253/**
254 * eeh_report_reset - Tell device that slot has been reset
255 * @data: eeh device
256 * @userdata: return value
257 *
258 * This routine must be called while EEH tries to reset particular
259 * PCI device so that the associated PCI device driver could take
260 * some actions, usually to save data the driver needs so that the
261 * driver can work again while the device is recovered.
262 */
263static void *eeh_report_reset(void *data, void *userdata)
264{
265 struct eeh_dev *edev = (struct eeh_dev *)data;
266 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
267 enum pci_ers_result rc, *res = userdata;
268 struct pci_driver *driver;
269
270 if (!dev) return NULL;
271 dev->error_state = pci_channel_io_normal;
272
273 driver = eeh_pcid_get(dev);
274 if (!driver) return NULL;
275
276 eeh_enable_irq(dev);
277
278 if (!driver->err_handler ||
279 !driver->err_handler->slot_reset ||
280 (edev->mode & EEH_DEV_NO_HANDLER)) {
281 eeh_pcid_put(dev);
282 return NULL;
283 }
284
285 rc = driver->err_handler->slot_reset(dev);
286 if ((*res == PCI_ERS_RESULT_NONE) ||
287 (*res == PCI_ERS_RESULT_RECOVERED)) *res = rc;
288 if (*res == PCI_ERS_RESULT_DISCONNECT &&
289 rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
290
291 eeh_pcid_put(dev);
292 return NULL;
293}
294
295/**
296 * eeh_report_resume - Tell device to resume normal operations
297 * @data: eeh device
298 * @userdata: return value
299 *
300 * This routine must be called to notify the device driver that it
301 * could resume so that the device driver can do some initialization
302 * to make the recovered device work again.
303 */
304static void *eeh_report_resume(void *data, void *userdata)
305{
306 struct eeh_dev *edev = (struct eeh_dev *)data;
307 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
308 struct pci_driver *driver;
309
310 if (!dev) return NULL;
311 dev->error_state = pci_channel_io_normal;
312
313 driver = eeh_pcid_get(dev);
314 if (!driver) return NULL;
315
316 eeh_enable_irq(dev);
317
318 if (!driver->err_handler ||
319 !driver->err_handler->resume ||
320 (edev->mode & EEH_DEV_NO_HANDLER)) {
321 edev->mode &= ~EEH_DEV_NO_HANDLER;
322 eeh_pcid_put(dev);
323 return NULL;
324 }
325
326 driver->err_handler->resume(dev);
327
328 eeh_pcid_put(dev);
329 return NULL;
330}
331
332/**
333 * eeh_report_failure - Tell device driver that device is dead.
334 * @data: eeh device
335 * @userdata: return value
336 *
337 * This informs the device driver that the device is permanently
338 * dead, and that no further recovery attempts will be made on it.
339 */
340static void *eeh_report_failure(void *data, void *userdata)
341{
342 struct eeh_dev *edev = (struct eeh_dev *)data;
343 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
344 struct pci_driver *driver;
345
346 if (!dev) return NULL;
347 dev->error_state = pci_channel_io_perm_failure;
348
349 driver = eeh_pcid_get(dev);
350 if (!driver) return NULL;
351
352 eeh_disable_irq(dev);
353
354 if (!driver->err_handler ||
355 !driver->err_handler->error_detected) {
356 eeh_pcid_put(dev);
357 return NULL;
358 }
359
360 driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
361
362 eeh_pcid_put(dev);
363 return NULL;
364}
365
366static void *eeh_rmv_device(void *data, void *userdata)
367{
368 struct pci_driver *driver;
369 struct eeh_dev *edev = (struct eeh_dev *)data;
370 struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
371 int *removed = (int *)userdata;
372
373 /*
374 * Actually, we should remove the PCI bridges as well.
375 * However, that's lots of complexity to do that,
376 * particularly some of devices under the bridge might
377 * support EEH. So we just care about PCI devices for
378 * simplicity here.
379 */
380 if (!dev || (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
381 return NULL;
382
383 driver = eeh_pcid_get(dev);
384 if (driver) {
385 eeh_pcid_put(dev);
386 if (driver->err_handler)
387 return NULL;
388 }
389
390 /* Remove it from PCI subsystem */
391 pr_debug("EEH: Removing %s without EEH sensitive driver\n",
392 pci_name(dev));
393 edev->bus = dev->bus;
394 edev->mode |= EEH_DEV_DISCONNECTED;
395 (*removed)++;
396
397 pci_lock_rescan_remove();
398 pci_stop_and_remove_bus_device(dev);
399 pci_unlock_rescan_remove();
400
401 return NULL;
402}
403
404static void *eeh_pe_detach_dev(void *data, void *userdata)
405{
406 struct eeh_pe *pe = (struct eeh_pe *)data;
407 struct eeh_dev *edev, *tmp;
408
409 eeh_pe_for_each_dev(pe, edev, tmp) {
410 if (!(edev->mode & EEH_DEV_DISCONNECTED))
411 continue;
412
413 edev->mode &= ~(EEH_DEV_DISCONNECTED | EEH_DEV_IRQ_DISABLED);
414 eeh_rmv_from_parent_pe(edev);
415 }
416
417 return NULL;
418}
419
420/**
421 * eeh_reset_device - Perform actual reset of a pci slot
422 * @pe: EEH PE
423 * @bus: PCI bus corresponding to the isolcated slot
424 *
425 * This routine must be called to do reset on the indicated PE.
426 * During the reset, udev might be invoked because those affected
427 * PCI devices will be removed and then added.
428 */
429static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus)
430{
431 struct pci_bus *frozen_bus = eeh_pe_bus_get(pe);
432 struct timeval tstamp;
433 int cnt, rc, removed = 0;
434
435 /* pcibios will clear the counter; save the value */
436 cnt = pe->freeze_count;
437 tstamp = pe->tstamp;
438
439 /*
440 * We don't remove the corresponding PE instances because
441 * we need the information afterwords. The attached EEH
442 * devices are expected to be attached soon when calling
443 * into pcibios_add_pci_devices().
444 */
445 eeh_pe_state_mark(pe, EEH_PE_KEEP);
446 if (bus) {
447 pci_lock_rescan_remove();
448 pcibios_remove_pci_devices(bus);
449 pci_unlock_rescan_remove();
450 } else if (frozen_bus) {
451 eeh_pe_dev_traverse(pe, eeh_rmv_device, &removed);
452 }
453
454 /* Reset the pci controller. (Asserts RST#; resets config space).
455 * Reconfigure bridges and devices. Don't try to bring the system
456 * up if the reset failed for some reason.
457 */
458 rc = eeh_reset_pe(pe);
459 if (rc)
460 return rc;
461
462 pci_lock_rescan_remove();
463
464 /* Restore PE */
465 eeh_ops->configure_bridge(pe);
466 eeh_pe_restore_bars(pe);
467
468 /* Give the system 5 seconds to finish running the user-space
469 * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,
470 * this is a hack, but if we don't do this, and try to bring
471 * the device up before the scripts have taken it down,
472 * potentially weird things happen.
473 */
474 if (bus) {
475 pr_info("EEH: Sleep 5s ahead of complete hotplug\n");
476 ssleep(5);
477
478 /*
479 * The EEH device is still connected with its parent
480 * PE. We should disconnect it so the binding can be
481 * rebuilt when adding PCI devices.
482 */
483 eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
484 pcibios_add_pci_devices(bus);
485 } else if (frozen_bus && removed) {
486 pr_info("EEH: Sleep 5s ahead of partial hotplug\n");
487 ssleep(5);
488
489 eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL);
490 pcibios_add_pci_devices(frozen_bus);
491 }
492 eeh_pe_state_clear(pe, EEH_PE_KEEP);
493
494 pe->tstamp = tstamp;
495 pe->freeze_count = cnt;
496
497 pci_unlock_rescan_remove();
498 return 0;
499}
500
501/* The longest amount of time to wait for a pci device
502 * to come back on line, in seconds.
503 */
504#define MAX_WAIT_FOR_RECOVERY 300
505
506static void eeh_handle_normal_event(struct eeh_pe *pe)
507{
508 struct pci_bus *frozen_bus;
509 int rc = 0;
510 enum pci_ers_result result = PCI_ERS_RESULT_NONE;
511
512 frozen_bus = eeh_pe_bus_get(pe);
513 if (!frozen_bus) {
514 pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n",
515 __func__, pe->phb->global_number, pe->addr);
516 return;
517 }
518
519 eeh_pe_update_time_stamp(pe);
520 pe->freeze_count++;
521 if (pe->freeze_count > EEH_MAX_ALLOWED_FREEZES)
522 goto excess_failures;
523 pr_warning("EEH: This PCI device has failed %d times in the last hour\n",
524 pe->freeze_count);
525
526 /* Walk the various device drivers attached to this slot through
527 * a reset sequence, giving each an opportunity to do what it needs
528 * to accomplish the reset. Each child gets a report of the
529 * status ... if any child can't handle the reset, then the entire
530 * slot is dlpar removed and added.
531 */
532 pr_info("EEH: Notify device drivers to shutdown\n");
533 eeh_pe_dev_traverse(pe, eeh_report_error, &result);
534
535 /* Get the current PCI slot state. This can take a long time,
536 * sometimes over 3 seconds for certain systems.
537 */
538 rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
539 if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
540 pr_warning("EEH: Permanent failure\n");
541 goto hard_fail;
542 }
543
544 /* Since rtas may enable MMIO when posting the error log,
545 * don't post the error log until after all dev drivers
546 * have been informed.
547 */
548 pr_info("EEH: Collect temporary log\n");
549 eeh_slot_error_detail(pe, EEH_LOG_TEMP);
550
551 /* If all device drivers were EEH-unaware, then shut
552 * down all of the device drivers, and hope they
553 * go down willingly, without panicing the system.
554 */
555 if (result == PCI_ERS_RESULT_NONE) {
556 pr_info("EEH: Reset with hotplug activity\n");
557 rc = eeh_reset_device(pe, frozen_bus);
558 if (rc) {
559 pr_warning("%s: Unable to reset, err=%d\n",
560 __func__, rc);
561 goto hard_fail;
562 }
563 }
564
565 /* If all devices reported they can proceed, then re-enable MMIO */
566 if (result == PCI_ERS_RESULT_CAN_RECOVER) {
567 pr_info("EEH: Enable I/O for affected devices\n");
568 rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
569
570 if (rc < 0)
571 goto hard_fail;
572 if (rc) {
573 result = PCI_ERS_RESULT_NEED_RESET;
574 } else {
575 pr_info("EEH: Notify device drivers to resume I/O\n");
576 result = PCI_ERS_RESULT_NONE;
577 eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result);
578 }
579 }
580
581 /* If all devices reported they can proceed, then re-enable DMA */
582 if (result == PCI_ERS_RESULT_CAN_RECOVER) {
583 pr_info("EEH: Enabled DMA for affected devices\n");
584 rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
585
586 if (rc < 0)
587 goto hard_fail;
588 if (rc)
589 result = PCI_ERS_RESULT_NEED_RESET;
590 else
591 result = PCI_ERS_RESULT_RECOVERED;
592 }
593
594 /* If any device has a hard failure, then shut off everything. */
595 if (result == PCI_ERS_RESULT_DISCONNECT) {
596 pr_warning("EEH: Device driver gave up\n");
597 goto hard_fail;
598 }
599
600 /* If any device called out for a reset, then reset the slot */
601 if (result == PCI_ERS_RESULT_NEED_RESET) {
602 pr_info("EEH: Reset without hotplug activity\n");
603 rc = eeh_reset_device(pe, NULL);
604 if (rc) {
605 pr_warning("%s: Cannot reset, err=%d\n",
606 __func__, rc);
607 goto hard_fail;
608 }
609
610 pr_info("EEH: Notify device drivers "
611 "the completion of reset\n");
612 result = PCI_ERS_RESULT_NONE;
613 eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
614 }
615
616 /* All devices should claim they have recovered by now. */
617 if ((result != PCI_ERS_RESULT_RECOVERED) &&
618 (result != PCI_ERS_RESULT_NONE)) {
619 pr_warning("EEH: Not recovered\n");
620 goto hard_fail;
621 }
622
623 /* Tell all device drivers that they can resume operations */
624 pr_info("EEH: Notify device driver to resume\n");
625 eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
626
627 return;
628
629excess_failures:
630 /*
631 * About 90% of all real-life EEH failures in the field
632 * are due to poorly seated PCI cards. Only 10% or so are
633 * due to actual, failed cards.
634 */
635 pr_err("EEH: PHB#%d-PE#%x has failed %d times in the\n"
636 "last hour and has been permanently disabled.\n"
637 "Please try reseating or replacing it.\n",
638 pe->phb->global_number, pe->addr,
639 pe->freeze_count);
640 goto perm_error;
641
642hard_fail:
643 pr_err("EEH: Unable to recover from failure from PHB#%d-PE#%x.\n"
644 "Please try reseating or replacing it\n",
645 pe->phb->global_number, pe->addr);
646
647perm_error:
648 eeh_slot_error_detail(pe, EEH_LOG_PERM);
649
650 /* Notify all devices that they're about to go down. */
651 eeh_pe_dev_traverse(pe, eeh_report_failure, NULL);
652
653 /* Shut down the device drivers for good. */
654 if (frozen_bus) {
655 pci_lock_rescan_remove();
656 pcibios_remove_pci_devices(frozen_bus);
657 pci_unlock_rescan_remove();
658 }
659}
660
661static void eeh_handle_special_event(void)
662{
663 struct eeh_pe *pe, *phb_pe;
664 struct pci_bus *bus;
665 struct pci_controller *hose;
666 unsigned long flags;
667 int rc;
668
669
670 do {
671 rc = eeh_ops->next_error(&pe);
672
673 switch (rc) {
674 case EEH_NEXT_ERR_DEAD_IOC:
675 /* Mark all PHBs in dead state */
676 eeh_serialize_lock(&flags);
677
678 /* Purge all events */
679 eeh_remove_event(NULL);
680
681 list_for_each_entry(hose, &hose_list, list_node) {
682 phb_pe = eeh_phb_pe_get(hose);
683 if (!phb_pe) continue;
684
685 eeh_pe_state_mark(phb_pe,
686 EEH_PE_ISOLATED | EEH_PE_PHB_DEAD);
687 }
688
689 eeh_serialize_unlock(flags);
690
691 break;
692 case EEH_NEXT_ERR_FROZEN_PE:
693 case EEH_NEXT_ERR_FENCED_PHB:
694 case EEH_NEXT_ERR_DEAD_PHB:
695 /* Mark the PE in fenced state */
696 eeh_serialize_lock(&flags);
697
698 /* Purge all events of the PHB */
699 eeh_remove_event(pe);
700
701 if (rc == EEH_NEXT_ERR_DEAD_PHB)
702 eeh_pe_state_mark(pe,
703 EEH_PE_ISOLATED | EEH_PE_PHB_DEAD);
704 else
705 eeh_pe_state_mark(pe,
706 EEH_PE_ISOLATED | EEH_PE_RECOVERING);
707
708 eeh_serialize_unlock(flags);
709
710 break;
711 case EEH_NEXT_ERR_NONE:
712 return;
713 default:
714 pr_warn("%s: Invalid value %d from next_error()\n",
715 __func__, rc);
716 return;
717 }
718
719 /*
720 * For fenced PHB and frozen PE, it's handled as normal
721 * event. We have to remove the affected PHBs for dead
722 * PHB and IOC
723 */
724 if (rc == EEH_NEXT_ERR_FROZEN_PE ||
725 rc == EEH_NEXT_ERR_FENCED_PHB) {
726 eeh_handle_normal_event(pe);
727 } else {
728 pci_lock_rescan_remove();
729 list_for_each_entry(hose, &hose_list, list_node) {
730 phb_pe = eeh_phb_pe_get(hose);
731 if (!phb_pe ||
732 !(phb_pe->state & EEH_PE_PHB_DEAD))
733 continue;
734
735 /* Notify all devices to be down */
736 bus = eeh_pe_bus_get(phb_pe);
737 eeh_pe_dev_traverse(pe,
738 eeh_report_failure, NULL);
739 pcibios_remove_pci_devices(bus);
740 }
741 pci_unlock_rescan_remove();
742 }
743
744 /*
745 * If we have detected dead IOC, we needn't proceed
746 * any more since all PHBs would have been removed
747 */
748 if (rc == EEH_NEXT_ERR_DEAD_IOC)
749 break;
750 } while (rc != EEH_NEXT_ERR_NONE);
751}
752
753/**
754 * eeh_handle_event - Reset a PCI device after hard lockup.
755 * @pe: EEH PE
756 *
757 * While PHB detects address or data parity errors on particular PCI
758 * slot, the associated PE will be frozen. Besides, DMA's occurring
759 * to wild addresses (which usually happen due to bugs in device
760 * drivers or in PCI adapter firmware) can cause EEH error. #SERR,
761 * #PERR or other misc PCI-related errors also can trigger EEH errors.
762 *
763 * Recovery process consists of unplugging the device driver (which
764 * generated hotplug events to userspace), then issuing a PCI #RST to
765 * the device, then reconfiguring the PCI config space for all bridges
766 * & devices under this slot, and then finally restarting the device
767 * drivers (which cause a second set of hotplug events to go out to
768 * userspace).
769 */
770void eeh_handle_event(struct eeh_pe *pe)
771{
772 if (pe)
773 eeh_handle_normal_event(pe);
774 else
775 eeh_handle_special_event();
776}