1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * The file intends to implement PE based on the information from
4 * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device.
5 * All the PEs should be organized as hierarchy tree. The first level
6 * of the tree will be associated to existing PHBs since the particular
7 * PE is only meaningful in one PHB domain.
8 *
9 * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012.
10 */
11
12 #include <linux/delay.h>
13 #include <linux/export.h>
14 #include <linux/gfp.h>
15 #include <linux/kernel.h>
16 #include <linux/pci.h>
17 #include <linux/string.h>
18
19 #include <asm/pci-bridge.h>
20 #include <asm/ppc-pci.h>
21
22 static int eeh_pe_aux_size = 0;
23 static LIST_HEAD(eeh_phb_pe);
24
25 /**
26 * eeh_set_pe_aux_size - Set PE auxillary data size
27 * @size: PE auxillary data size
28 *
29 * Set PE auxillary data size
30 */
eeh_set_pe_aux_size(int size)31 void eeh_set_pe_aux_size(int size)
32 {
33 if (size < 0)
34 return;
35
36 eeh_pe_aux_size = size;
37 }
38
39 /**
40 * eeh_pe_alloc - Allocate PE
41 * @phb: PCI controller
42 * @type: PE type
43 *
44 * Allocate PE instance dynamically.
45 */
eeh_pe_alloc(struct pci_controller * phb,int type)46 static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
47 {
48 struct eeh_pe *pe;
49 size_t alloc_size;
50
51 alloc_size = sizeof(struct eeh_pe);
52 if (eeh_pe_aux_size) {
53 alloc_size = ALIGN(alloc_size, cache_line_size());
54 alloc_size += eeh_pe_aux_size;
55 }
56
57 /* Allocate PHB PE */
58 pe = kzalloc(alloc_size, GFP_KERNEL);
59 if (!pe) return NULL;
60
61 /* Initialize PHB PE */
62 pe->type = type;
63 pe->phb = phb;
64 INIT_LIST_HEAD(&pe->child_list);
65 INIT_LIST_HEAD(&pe->edevs);
66
67 pe->data = (void *)pe + ALIGN(sizeof(struct eeh_pe),
68 cache_line_size());
69 return pe;
70 }
71
72 /**
73 * eeh_phb_pe_create - Create PHB PE
74 * @phb: PCI controller
75 *
76 * The function should be called while the PHB is detected during
77 * system boot or PCI hotplug in order to create PHB PE.
78 */
eeh_phb_pe_create(struct pci_controller * phb)79 int eeh_phb_pe_create(struct pci_controller *phb)
80 {
81 struct eeh_pe *pe;
82
83 /* Allocate PHB PE */
84 pe = eeh_pe_alloc(phb, EEH_PE_PHB);
85 if (!pe) {
86 pr_err("%s: out of memory!\n", __func__);
87 return -ENOMEM;
88 }
89
90 /* Put it into the list */
91 list_add_tail(&pe->child, &eeh_phb_pe);
92
93 pr_debug("EEH: Add PE for PHB#%x\n", phb->global_number);
94
95 return 0;
96 }
97
98 /**
99 * eeh_wait_state - Wait for PE state
100 * @pe: EEH PE
101 * @max_wait: maximal period in millisecond
102 *
103 * Wait for the state of associated PE. It might take some time
104 * to retrieve the PE's state.
105 */
eeh_wait_state(struct eeh_pe * pe,int max_wait)106 int eeh_wait_state(struct eeh_pe *pe, int max_wait)
107 {
108 int ret;
109 int mwait;
110
111 /*
112 * According to PAPR, the state of PE might be temporarily
113 * unavailable. Under the circumstance, we have to wait
114 * for indicated time determined by firmware. The maximal
115 * wait time is 5 minutes, which is acquired from the original
116 * EEH implementation. Also, the original implementation
117 * also defined the minimal wait time as 1 second.
118 */
119 #define EEH_STATE_MIN_WAIT_TIME (1000)
120 #define EEH_STATE_MAX_WAIT_TIME (300 * 1000)
121
122 while (1) {
123 ret = eeh_ops->get_state(pe, &mwait);
124
125 if (ret != EEH_STATE_UNAVAILABLE)
126 return ret;
127
128 if (max_wait <= 0) {
129 pr_warn("%s: Timeout when getting PE's state (%d)\n",
130 __func__, max_wait);
131 return EEH_STATE_NOT_SUPPORT;
132 }
133
134 if (mwait < EEH_STATE_MIN_WAIT_TIME) {
135 pr_warn("%s: Firmware returned bad wait value %d\n",
136 __func__, mwait);
137 mwait = EEH_STATE_MIN_WAIT_TIME;
138 } else if (mwait > EEH_STATE_MAX_WAIT_TIME) {
139 pr_warn("%s: Firmware returned too long wait value %d\n",
140 __func__, mwait);
141 mwait = EEH_STATE_MAX_WAIT_TIME;
142 }
143
144 msleep(min(mwait, max_wait));
145 max_wait -= mwait;
146 }
147 }
148
149 /**
150 * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
151 * @phb: PCI controller
152 *
153 * The overall PEs form hierarchy tree. The first layer of the
154 * hierarchy tree is composed of PHB PEs. The function is used
155 * to retrieve the corresponding PHB PE according to the given PHB.
156 */
eeh_phb_pe_get(struct pci_controller * phb)157 struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
158 {
159 struct eeh_pe *pe;
160
161 list_for_each_entry(pe, &eeh_phb_pe, child) {
162 /*
163 * Actually, we needn't check the type since
164 * the PE for PHB has been determined when that
165 * was created.
166 */
167 if ((pe->type & EEH_PE_PHB) && pe->phb == phb)
168 return pe;
169 }
170
171 return NULL;
172 }
173
174 /**
175 * eeh_pe_next - Retrieve the next PE in the tree
176 * @pe: current PE
177 * @root: root PE
178 *
179 * The function is used to retrieve the next PE in the
180 * hierarchy PE tree.
181 */
eeh_pe_next(struct eeh_pe * pe,struct eeh_pe * root)182 struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, struct eeh_pe *root)
183 {
184 struct list_head *next = pe->child_list.next;
185
186 if (next == &pe->child_list) {
187 while (1) {
188 if (pe == root)
189 return NULL;
190 next = pe->child.next;
191 if (next != &pe->parent->child_list)
192 break;
193 pe = pe->parent;
194 }
195 }
196
197 return list_entry(next, struct eeh_pe, child);
198 }
199
200 /**
201 * eeh_pe_traverse - Traverse PEs in the specified PHB
202 * @root: root PE
203 * @fn: callback
204 * @flag: extra parameter to callback
205 *
206 * The function is used to traverse the specified PE and its
207 * child PEs. The traversing is to be terminated once the
208 * callback returns something other than NULL, or no more PEs
209 * to be traversed.
210 */
eeh_pe_traverse(struct eeh_pe * root,eeh_pe_traverse_func fn,void * flag)211 void *eeh_pe_traverse(struct eeh_pe *root,
212 eeh_pe_traverse_func fn, void *flag)
213 {
214 struct eeh_pe *pe;
215 void *ret;
216
217 eeh_for_each_pe(root, pe) {
218 ret = fn(pe, flag);
219 if (ret) return ret;
220 }
221
222 return NULL;
223 }
224
225 /**
226 * eeh_pe_dev_traverse - Traverse the devices from the PE
227 * @root: EEH PE
228 * @fn: function callback
229 * @flag: extra parameter to callback
230 *
231 * The function is used to traverse the devices of the specified
232 * PE and its child PEs.
233 */
eeh_pe_dev_traverse(struct eeh_pe * root,eeh_edev_traverse_func fn,void * flag)234 void eeh_pe_dev_traverse(struct eeh_pe *root,
235 eeh_edev_traverse_func fn, void *flag)
236 {
237 struct eeh_pe *pe;
238 struct eeh_dev *edev, *tmp;
239
240 if (!root) {
241 pr_warn("%s: Invalid PE %p\n",
242 __func__, root);
243 return;
244 }
245
246 /* Traverse root PE */
247 eeh_for_each_pe(root, pe)
248 eeh_pe_for_each_dev(pe, edev, tmp)
249 fn(edev, flag);
250 }
251
252 /**
253 * __eeh_pe_get - Check the PE address
254 * @data: EEH PE
255 * @flag: EEH device
256 *
257 * For one particular PE, it can be identified by PE address
258 * or tranditional BDF address. BDF address is composed of
259 * Bus/Device/Function number. The extra data referred by flag
260 * indicates which type of address should be used.
261 */
262 struct eeh_pe_get_flag {
263 int pe_no;
264 int config_addr;
265 };
266
__eeh_pe_get(struct eeh_pe * pe,void * flag)267 static void *__eeh_pe_get(struct eeh_pe *pe, void *flag)
268 {
269 struct eeh_pe_get_flag *tmp = (struct eeh_pe_get_flag *) flag;
270
271 /* Unexpected PHB PE */
272 if (pe->type & EEH_PE_PHB)
273 return NULL;
274
275 /*
276 * We prefer PE address. For most cases, we should
277 * have non-zero PE address
278 */
279 if (eeh_has_flag(EEH_VALID_PE_ZERO)) {
280 if (tmp->pe_no == pe->addr)
281 return pe;
282 } else {
283 if (tmp->pe_no &&
284 (tmp->pe_no == pe->addr))
285 return pe;
286 }
287
288 /* Try BDF address */
289 if (tmp->config_addr &&
290 (tmp->config_addr == pe->config_addr))
291 return pe;
292
293 return NULL;
294 }
295
296 /**
297 * eeh_pe_get - Search PE based on the given address
298 * @phb: PCI controller
299 * @pe_no: PE number
300 * @config_addr: Config address
301 *
302 * Search the corresponding PE based on the specified address which
303 * is included in the eeh device. The function is used to check if
304 * the associated PE has been created against the PE address. It's
305 * notable that the PE address has 2 format: traditional PE address
306 * which is composed of PCI bus/device/function number, or unified
307 * PE address.
308 */
eeh_pe_get(struct pci_controller * phb,int pe_no,int config_addr)309 struct eeh_pe *eeh_pe_get(struct pci_controller *phb,
310 int pe_no, int config_addr)
311 {
312 struct eeh_pe *root = eeh_phb_pe_get(phb);
313 struct eeh_pe_get_flag tmp = { pe_no, config_addr };
314 struct eeh_pe *pe;
315
316 pe = eeh_pe_traverse(root, __eeh_pe_get, &tmp);
317
318 return pe;
319 }
320
321 /**
322 * eeh_pe_get_parent - Retrieve the parent PE
323 * @edev: EEH device
324 *
325 * The whole PEs existing in the system are organized as hierarchy
326 * tree. The function is used to retrieve the parent PE according
327 * to the parent EEH device.
328 */
eeh_pe_get_parent(struct eeh_dev * edev)329 static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
330 {
331 struct eeh_dev *parent;
332 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
333
334 /*
335 * It might have the case for the indirect parent
336 * EEH device already having associated PE, but
337 * the direct parent EEH device doesn't have yet.
338 */
339 if (edev->physfn)
340 pdn = pci_get_pdn(edev->physfn);
341 else
342 pdn = pdn ? pdn->parent : NULL;
343 while (pdn) {
344 /* We're poking out of PCI territory */
345 parent = pdn_to_eeh_dev(pdn);
346 if (!parent)
347 return NULL;
348
349 if (parent->pe)
350 return parent->pe;
351
352 pdn = pdn->parent;
353 }
354
355 return NULL;
356 }
357
358 /**
359 * eeh_add_to_parent_pe - Add EEH device to parent PE
360 * @edev: EEH device
361 *
362 * Add EEH device to the parent PE. If the parent PE already
363 * exists, the PE type will be changed to EEH_PE_BUS. Otherwise,
364 * we have to create new PE to hold the EEH device and the new
365 * PE will be linked to its parent PE as well.
366 */
eeh_add_to_parent_pe(struct eeh_dev * edev)367 int eeh_add_to_parent_pe(struct eeh_dev *edev)
368 {
369 struct eeh_pe *pe, *parent;
370 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
371 int config_addr = (pdn->busno << 8) | (pdn->devfn);
372
373 /* Check if the PE number is valid */
374 if (!eeh_has_flag(EEH_VALID_PE_ZERO) && !edev->pe_config_addr) {
375 eeh_edev_err(edev, "PE#0 is invalid for this PHB!\n");
376 return -EINVAL;
377 }
378
379 /*
380 * Search the PE has been existing or not according
381 * to the PE address. If that has been existing, the
382 * PE should be composed of PCI bus and its subordinate
383 * components.
384 */
385 pe = eeh_pe_get(pdn->phb, edev->pe_config_addr, config_addr);
386 if (pe) {
387 if (pe->type & EEH_PE_INVALID) {
388 list_add_tail(&edev->entry, &pe->edevs);
389 edev->pe = pe;
390 /*
391 * We're running to here because of PCI hotplug caused by
392 * EEH recovery. We need clear EEH_PE_INVALID until the top.
393 */
394 parent = pe;
395 while (parent) {
396 if (!(parent->type & EEH_PE_INVALID))
397 break;
398 parent->type &= ~EEH_PE_INVALID;
399 parent = parent->parent;
400 }
401
402 eeh_edev_dbg(edev,
403 "Added to device PE (parent: PE#%x)\n",
404 pe->parent->addr);
405 } else {
406 /* Mark the PE as type of PCI bus */
407 pe->type = EEH_PE_BUS;
408 edev->pe = pe;
409
410 /* Put the edev to PE */
411 list_add_tail(&edev->entry, &pe->edevs);
412 eeh_edev_dbg(edev, "Added to bus PE\n");
413 }
414 return 0;
415 }
416
417 /* Create a new EEH PE */
418 if (edev->physfn)
419 pe = eeh_pe_alloc(pdn->phb, EEH_PE_VF);
420 else
421 pe = eeh_pe_alloc(pdn->phb, EEH_PE_DEVICE);
422 if (!pe) {
423 pr_err("%s: out of memory!\n", __func__);
424 return -ENOMEM;
425 }
426 pe->addr = edev->pe_config_addr;
427 pe->config_addr = config_addr;
428
429 /*
430 * Put the new EEH PE into hierarchy tree. If the parent
431 * can't be found, the newly created PE will be attached
432 * to PHB directly. Otherwise, we have to associate the
433 * PE with its parent.
434 */
435 parent = eeh_pe_get_parent(edev);
436 if (!parent) {
437 parent = eeh_phb_pe_get(pdn->phb);
438 if (!parent) {
439 pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
440 __func__, pdn->phb->global_number);
441 edev->pe = NULL;
442 kfree(pe);
443 return -EEXIST;
444 }
445 }
446 pe->parent = parent;
447
448 /*
449 * Put the newly created PE into the child list and
450 * link the EEH device accordingly.
451 */
452 list_add_tail(&pe->child, &parent->child_list);
453 list_add_tail(&edev->entry, &pe->edevs);
454 edev->pe = pe;
455 eeh_edev_dbg(edev, "Added to device PE (parent: PE#%x)\n",
456 pe->parent->addr);
457
458 return 0;
459 }
460
461 /**
462 * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE
463 * @edev: EEH device
464 *
465 * The PE hierarchy tree might be changed when doing PCI hotplug.
466 * Also, the PCI devices or buses could be removed from the system
467 * during EEH recovery. So we have to call the function remove the
468 * corresponding PE accordingly if necessary.
469 */
eeh_rmv_from_parent_pe(struct eeh_dev * edev)470 int eeh_rmv_from_parent_pe(struct eeh_dev *edev)
471 {
472 struct eeh_pe *pe, *parent, *child;
473 bool keep, recover;
474 int cnt;
475
476 pe = eeh_dev_to_pe(edev);
477 if (!pe) {
478 eeh_edev_dbg(edev, "No PE found for device.\n");
479 return -EEXIST;
480 }
481
482 /* Remove the EEH device */
483 edev->pe = NULL;
484 list_del(&edev->entry);
485
486 /*
487 * Check if the parent PE includes any EEH devices.
488 * If not, we should delete that. Also, we should
489 * delete the parent PE if it doesn't have associated
490 * child PEs and EEH devices.
491 */
492 while (1) {
493 parent = pe->parent;
494
495 /* PHB PEs should never be removed */
496 if (pe->type & EEH_PE_PHB)
497 break;
498
499 /*
500 * XXX: KEEP is set while resetting a PE. I don't think it's
501 * ever set without RECOVERING also being set. I could
502 * be wrong though so catch that with a WARN.
503 */
504 keep = !!(pe->state & EEH_PE_KEEP);
505 recover = !!(pe->state & EEH_PE_RECOVERING);
506 WARN_ON(keep && !recover);
507
508 if (!keep && !recover) {
509 if (list_empty(&pe->edevs) &&
510 list_empty(&pe->child_list)) {
511 list_del(&pe->child);
512 kfree(pe);
513 } else {
514 break;
515 }
516 } else {
517 /*
518 * Mark the PE as invalid. At the end of the recovery
519 * process any invalid PEs will be garbage collected.
520 *
521 * We need to delay the free()ing of them since we can
522 * remove edev's while traversing the PE tree which
523 * might trigger the removal of a PE and we can't
524 * deal with that (yet).
525 */
526 if (list_empty(&pe->edevs)) {
527 cnt = 0;
528 list_for_each_entry(child, &pe->child_list, child) {
529 if (!(child->type & EEH_PE_INVALID)) {
530 cnt++;
531 break;
532 }
533 }
534
535 if (!cnt)
536 pe->type |= EEH_PE_INVALID;
537 else
538 break;
539 }
540 }
541
542 pe = parent;
543 }
544
545 return 0;
546 }
547
548 /**
549 * eeh_pe_update_time_stamp - Update PE's frozen time stamp
550 * @pe: EEH PE
551 *
552 * We have time stamp for each PE to trace its time of getting
553 * frozen in last hour. The function should be called to update
554 * the time stamp on first error of the specific PE. On the other
555 * handle, we needn't account for errors happened in last hour.
556 */
eeh_pe_update_time_stamp(struct eeh_pe * pe)557 void eeh_pe_update_time_stamp(struct eeh_pe *pe)
558 {
559 time64_t tstamp;
560
561 if (!pe) return;
562
563 if (pe->freeze_count <= 0) {
564 pe->freeze_count = 0;
565 pe->tstamp = ktime_get_seconds();
566 } else {
567 tstamp = ktime_get_seconds();
568 if (tstamp - pe->tstamp > 3600) {
569 pe->tstamp = tstamp;
570 pe->freeze_count = 0;
571 }
572 }
573 }
574
575 /**
576 * eeh_pe_state_mark - Mark specified state for PE and its associated device
577 * @pe: EEH PE
578 *
579 * EEH error affects the current PE and its child PEs. The function
580 * is used to mark appropriate state for the affected PEs and the
581 * associated devices.
582 */
eeh_pe_state_mark(struct eeh_pe * root,int state)583 void eeh_pe_state_mark(struct eeh_pe *root, int state)
584 {
585 struct eeh_pe *pe;
586
587 eeh_for_each_pe(root, pe)
588 if (!(pe->state & EEH_PE_REMOVED))
589 pe->state |= state;
590 }
591 EXPORT_SYMBOL_GPL(eeh_pe_state_mark);
592
593 /**
594 * eeh_pe_mark_isolated
595 * @pe: EEH PE
596 *
597 * Record that a PE has been isolated by marking the PE and it's children as
598 * EEH_PE_ISOLATED (and EEH_PE_CFG_BLOCKED, if required) and their PCI devices
599 * as pci_channel_io_frozen.
600 */
eeh_pe_mark_isolated(struct eeh_pe * root)601 void eeh_pe_mark_isolated(struct eeh_pe *root)
602 {
603 struct eeh_pe *pe;
604 struct eeh_dev *edev;
605 struct pci_dev *pdev;
606
607 eeh_pe_state_mark(root, EEH_PE_ISOLATED);
608 eeh_for_each_pe(root, pe) {
609 list_for_each_entry(edev, &pe->edevs, entry) {
610 pdev = eeh_dev_to_pci_dev(edev);
611 if (pdev)
612 pdev->error_state = pci_channel_io_frozen;
613 }
614 /* Block PCI config access if required */
615 if (pe->state & EEH_PE_CFG_RESTRICTED)
616 pe->state |= EEH_PE_CFG_BLOCKED;
617 }
618 }
619 EXPORT_SYMBOL_GPL(eeh_pe_mark_isolated);
620
__eeh_pe_dev_mode_mark(struct eeh_dev * edev,void * flag)621 static void __eeh_pe_dev_mode_mark(struct eeh_dev *edev, void *flag)
622 {
623 int mode = *((int *)flag);
624
625 edev->mode |= mode;
626 }
627
628 /**
629 * eeh_pe_dev_state_mark - Mark state for all device under the PE
630 * @pe: EEH PE
631 *
632 * Mark specific state for all child devices of the PE.
633 */
eeh_pe_dev_mode_mark(struct eeh_pe * pe,int mode)634 void eeh_pe_dev_mode_mark(struct eeh_pe *pe, int mode)
635 {
636 eeh_pe_dev_traverse(pe, __eeh_pe_dev_mode_mark, &mode);
637 }
638
639 /**
640 * eeh_pe_state_clear - Clear state for the PE
641 * @data: EEH PE
642 * @state: state
643 * @include_passed: include passed-through devices?
644 *
645 * The function is used to clear the indicated state from the
646 * given PE. Besides, we also clear the check count of the PE
647 * as well.
648 */
eeh_pe_state_clear(struct eeh_pe * root,int state,bool include_passed)649 void eeh_pe_state_clear(struct eeh_pe *root, int state, bool include_passed)
650 {
651 struct eeh_pe *pe;
652 struct eeh_dev *edev, *tmp;
653 struct pci_dev *pdev;
654
655 eeh_for_each_pe(root, pe) {
656 /* Keep the state of permanently removed PE intact */
657 if (pe->state & EEH_PE_REMOVED)
658 continue;
659
660 if (!include_passed && eeh_pe_passed(pe))
661 continue;
662
663 pe->state &= ~state;
664
665 /*
666 * Special treatment on clearing isolated state. Clear
667 * check count since last isolation and put all affected
668 * devices to normal state.
669 */
670 if (!(state & EEH_PE_ISOLATED))
671 continue;
672
673 pe->check_count = 0;
674 eeh_pe_for_each_dev(pe, edev, tmp) {
675 pdev = eeh_dev_to_pci_dev(edev);
676 if (!pdev)
677 continue;
678
679 pdev->error_state = pci_channel_io_normal;
680 }
681
682 /* Unblock PCI config access if required */
683 if (pe->state & EEH_PE_CFG_RESTRICTED)
684 pe->state &= ~EEH_PE_CFG_BLOCKED;
685 }
686 }
687
688 /*
689 * Some PCI bridges (e.g. PLX bridges) have primary/secondary
690 * buses assigned explicitly by firmware, and we probably have
691 * lost that after reset. So we have to delay the check until
692 * the PCI-CFG registers have been restored for the parent
693 * bridge.
694 *
695 * Don't use normal PCI-CFG accessors, which probably has been
696 * blocked on normal path during the stage. So we need utilize
697 * eeh operations, which is always permitted.
698 */
eeh_bridge_check_link(struct eeh_dev * edev)699 static void eeh_bridge_check_link(struct eeh_dev *edev)
700 {
701 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
702 int cap;
703 uint32_t val;
704 int timeout = 0;
705
706 /*
707 * We only check root port and downstream ports of
708 * PCIe switches
709 */
710 if (!(edev->mode & (EEH_DEV_ROOT_PORT | EEH_DEV_DS_PORT)))
711 return;
712
713 eeh_edev_dbg(edev, "Checking PCIe link...\n");
714
715 /* Check slot status */
716 cap = edev->pcie_cap;
717 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTSTA, 2, &val);
718 if (!(val & PCI_EXP_SLTSTA_PDS)) {
719 eeh_edev_dbg(edev, "No card in the slot (0x%04x) !\n", val);
720 return;
721 }
722
723 /* Check power status if we have the capability */
724 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTCAP, 2, &val);
725 if (val & PCI_EXP_SLTCAP_PCP) {
726 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTCTL, 2, &val);
727 if (val & PCI_EXP_SLTCTL_PCC) {
728 eeh_edev_dbg(edev, "In power-off state, power it on ...\n");
729 val &= ~(PCI_EXP_SLTCTL_PCC | PCI_EXP_SLTCTL_PIC);
730 val |= (0x0100 & PCI_EXP_SLTCTL_PIC);
731 eeh_ops->write_config(pdn, cap + PCI_EXP_SLTCTL, 2, val);
732 msleep(2 * 1000);
733 }
734 }
735
736 /* Enable link */
737 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKCTL, 2, &val);
738 val &= ~PCI_EXP_LNKCTL_LD;
739 eeh_ops->write_config(pdn, cap + PCI_EXP_LNKCTL, 2, val);
740
741 /* Check link */
742 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKCAP, 4, &val);
743 if (!(val & PCI_EXP_LNKCAP_DLLLARC)) {
744 eeh_edev_dbg(edev, "No link reporting capability (0x%08x) \n", val);
745 msleep(1000);
746 return;
747 }
748
749 /* Wait the link is up until timeout (5s) */
750 timeout = 0;
751 while (timeout < 5000) {
752 msleep(20);
753 timeout += 20;
754
755 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKSTA, 2, &val);
756 if (val & PCI_EXP_LNKSTA_DLLLA)
757 break;
758 }
759
760 if (val & PCI_EXP_LNKSTA_DLLLA)
761 eeh_edev_dbg(edev, "Link up (%s)\n",
762 (val & PCI_EXP_LNKSTA_CLS_2_5GB) ? "2.5GB" : "5GB");
763 else
764 eeh_edev_dbg(edev, "Link not ready (0x%04x)\n", val);
765 }
766
767 #define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
768 #define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
769
eeh_restore_bridge_bars(struct eeh_dev * edev)770 static void eeh_restore_bridge_bars(struct eeh_dev *edev)
771 {
772 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
773 int i;
774
775 /*
776 * Device BARs: 0x10 - 0x18
777 * Bus numbers and windows: 0x18 - 0x30
778 */
779 for (i = 4; i < 13; i++)
780 eeh_ops->write_config(pdn, i*4, 4, edev->config_space[i]);
781 /* Rom: 0x38 */
782 eeh_ops->write_config(pdn, 14*4, 4, edev->config_space[14]);
783
784 /* Cache line & Latency timer: 0xC 0xD */
785 eeh_ops->write_config(pdn, PCI_CACHE_LINE_SIZE, 1,
786 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
787 eeh_ops->write_config(pdn, PCI_LATENCY_TIMER, 1,
788 SAVED_BYTE(PCI_LATENCY_TIMER));
789 /* Max latency, min grant, interrupt ping and line: 0x3C */
790 eeh_ops->write_config(pdn, 15*4, 4, edev->config_space[15]);
791
792 /* PCI Command: 0x4 */
793 eeh_ops->write_config(pdn, PCI_COMMAND, 4, edev->config_space[1] |
794 PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
795
796 /* Check the PCIe link is ready */
797 eeh_bridge_check_link(edev);
798 }
799
eeh_restore_device_bars(struct eeh_dev * edev)800 static void eeh_restore_device_bars(struct eeh_dev *edev)
801 {
802 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
803 int i;
804 u32 cmd;
805
806 for (i = 4; i < 10; i++)
807 eeh_ops->write_config(pdn, i*4, 4, edev->config_space[i]);
808 /* 12 == Expansion ROM Address */
809 eeh_ops->write_config(pdn, 12*4, 4, edev->config_space[12]);
810
811 eeh_ops->write_config(pdn, PCI_CACHE_LINE_SIZE, 1,
812 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
813 eeh_ops->write_config(pdn, PCI_LATENCY_TIMER, 1,
814 SAVED_BYTE(PCI_LATENCY_TIMER));
815
816 /* max latency, min grant, interrupt pin and line */
817 eeh_ops->write_config(pdn, 15*4, 4, edev->config_space[15]);
818
819 /*
820 * Restore PERR & SERR bits, some devices require it,
821 * don't touch the other command bits
822 */
823 eeh_ops->read_config(pdn, PCI_COMMAND, 4, &cmd);
824 if (edev->config_space[1] & PCI_COMMAND_PARITY)
825 cmd |= PCI_COMMAND_PARITY;
826 else
827 cmd &= ~PCI_COMMAND_PARITY;
828 if (edev->config_space[1] & PCI_COMMAND_SERR)
829 cmd |= PCI_COMMAND_SERR;
830 else
831 cmd &= ~PCI_COMMAND_SERR;
832 eeh_ops->write_config(pdn, PCI_COMMAND, 4, cmd);
833 }
834
835 /**
836 * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
837 * @data: EEH device
838 * @flag: Unused
839 *
840 * Loads the PCI configuration space base address registers,
841 * the expansion ROM base address, the latency timer, and etc.
842 * from the saved values in the device node.
843 */
eeh_restore_one_device_bars(struct eeh_dev * edev,void * flag)844 static void eeh_restore_one_device_bars(struct eeh_dev *edev, void *flag)
845 {
846 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
847
848 /* Do special restore for bridges */
849 if (edev->mode & EEH_DEV_BRIDGE)
850 eeh_restore_bridge_bars(edev);
851 else
852 eeh_restore_device_bars(edev);
853
854 if (eeh_ops->restore_config && pdn)
855 eeh_ops->restore_config(pdn);
856 }
857
858 /**
859 * eeh_pe_restore_bars - Restore the PCI config space info
860 * @pe: EEH PE
861 *
862 * This routine performs a recursive walk to the children
863 * of this device as well.
864 */
eeh_pe_restore_bars(struct eeh_pe * pe)865 void eeh_pe_restore_bars(struct eeh_pe *pe)
866 {
867 /*
868 * We needn't take the EEH lock since eeh_pe_dev_traverse()
869 * will take that.
870 */
871 eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
872 }
873
874 /**
875 * eeh_pe_loc_get - Retrieve location code binding to the given PE
876 * @pe: EEH PE
877 *
878 * Retrieve the location code of the given PE. If the primary PE bus
879 * is root bus, we will grab location code from PHB device tree node
880 * or root port. Otherwise, the upstream bridge's device tree node
881 * of the primary PE bus will be checked for the location code.
882 */
eeh_pe_loc_get(struct eeh_pe * pe)883 const char *eeh_pe_loc_get(struct eeh_pe *pe)
884 {
885 struct pci_bus *bus = eeh_pe_bus_get(pe);
886 struct device_node *dn;
887 const char *loc = NULL;
888
889 while (bus) {
890 dn = pci_bus_to_OF_node(bus);
891 if (!dn) {
892 bus = bus->parent;
893 continue;
894 }
895
896 if (pci_is_root_bus(bus))
897 loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
898 else
899 loc = of_get_property(dn, "ibm,slot-location-code",
900 NULL);
901
902 if (loc)
903 return loc;
904
905 bus = bus->parent;
906 }
907
908 return "N/A";
909 }
910
911 /**
912 * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
913 * @pe: EEH PE
914 *
915 * Retrieve the PCI bus according to the given PE. Basically,
916 * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
917 * primary PCI bus will be retrieved. The parent bus will be
918 * returned for BUS PE. However, we don't have associated PCI
919 * bus for DEVICE PE.
920 */
eeh_pe_bus_get(struct eeh_pe * pe)921 struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
922 {
923 struct eeh_dev *edev;
924 struct pci_dev *pdev;
925
926 if (pe->type & EEH_PE_PHB)
927 return pe->phb->bus;
928
929 /* The primary bus might be cached during probe time */
930 if (pe->state & EEH_PE_PRI_BUS)
931 return pe->bus;
932
933 /* Retrieve the parent PCI bus of first (top) PCI device */
934 edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry);
935 pdev = eeh_dev_to_pci_dev(edev);
936 if (pdev)
937 return pdev->bus;
938
939 return NULL;
940 }
941
