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1/*
2 * The file intends to implement PE based on the information from
3 * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device.
4 * All the PEs should be organized as hierarchy tree. The first level
5 * of the tree will be associated to existing PHBs since the particular
6 * PE is only meaningful in one PHB domain.
7 *
8 * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include <linux/delay.h>
26#include <linux/export.h>
27#include <linux/gfp.h>
28#include <linux/kernel.h>
29#include <linux/pci.h>
30#include <linux/string.h>
31
32#include <asm/pci-bridge.h>
33#include <asm/ppc-pci.h>
34
35static int eeh_pe_aux_size = 0;
36static LIST_HEAD(eeh_phb_pe);
37
38/**
39 * eeh_set_pe_aux_size - Set PE auxillary data size
40 * @size: PE auxillary data size
41 *
42 * Set PE auxillary data size
43 */
44void eeh_set_pe_aux_size(int size)
45{
46 if (size < 0)
47 return;
48
49 eeh_pe_aux_size = size;
50}
51
52/**
53 * eeh_pe_alloc - Allocate PE
54 * @phb: PCI controller
55 * @type: PE type
56 *
57 * Allocate PE instance dynamically.
58 */
59static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
60{
61 struct eeh_pe *pe;
62 size_t alloc_size;
63
64 alloc_size = sizeof(struct eeh_pe);
65 if (eeh_pe_aux_size) {
66 alloc_size = ALIGN(alloc_size, cache_line_size());
67 alloc_size += eeh_pe_aux_size;
68 }
69
70 /* Allocate PHB PE */
71 pe = kzalloc(alloc_size, GFP_KERNEL);
72 if (!pe) return NULL;
73
74 /* Initialize PHB PE */
75 pe->type = type;
76 pe->phb = phb;
77 INIT_LIST_HEAD(&pe->child_list);
78 INIT_LIST_HEAD(&pe->child);
79 INIT_LIST_HEAD(&pe->edevs);
80
81 pe->data = (void *)pe + ALIGN(sizeof(struct eeh_pe),
82 cache_line_size());
83 return pe;
84}
85
86/**
87 * eeh_phb_pe_create - Create PHB PE
88 * @phb: PCI controller
89 *
90 * The function should be called while the PHB is detected during
91 * system boot or PCI hotplug in order to create PHB PE.
92 */
93int eeh_phb_pe_create(struct pci_controller *phb)
94{
95 struct eeh_pe *pe;
96
97 /* Allocate PHB PE */
98 pe = eeh_pe_alloc(phb, EEH_PE_PHB);
99 if (!pe) {
100 pr_err("%s: out of memory!\n", __func__);
101 return -ENOMEM;
102 }
103
104 /* Put it into the list */
105 list_add_tail(&pe->child, &eeh_phb_pe);
106
107 pr_debug("EEH: Add PE for PHB#%x\n", phb->global_number);
108
109 return 0;
110}
111
112/**
113 * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
114 * @phb: PCI controller
115 *
116 * The overall PEs form hierarchy tree. The first layer of the
117 * hierarchy tree is composed of PHB PEs. The function is used
118 * to retrieve the corresponding PHB PE according to the given PHB.
119 */
120struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
121{
122 struct eeh_pe *pe;
123
124 list_for_each_entry(pe, &eeh_phb_pe, child) {
125 /*
126 * Actually, we needn't check the type since
127 * the PE for PHB has been determined when that
128 * was created.
129 */
130 if ((pe->type & EEH_PE_PHB) && pe->phb == phb)
131 return pe;
132 }
133
134 return NULL;
135}
136
137/**
138 * eeh_pe_next - Retrieve the next PE in the tree
139 * @pe: current PE
140 * @root: root PE
141 *
142 * The function is used to retrieve the next PE in the
143 * hierarchy PE tree.
144 */
145static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe,
146 struct eeh_pe *root)
147{
148 struct list_head *next = pe->child_list.next;
149
150 if (next == &pe->child_list) {
151 while (1) {
152 if (pe == root)
153 return NULL;
154 next = pe->child.next;
155 if (next != &pe->parent->child_list)
156 break;
157 pe = pe->parent;
158 }
159 }
160
161 return list_entry(next, struct eeh_pe, child);
162}
163
164/**
165 * eeh_pe_traverse - Traverse PEs in the specified PHB
166 * @root: root PE
167 * @fn: callback
168 * @flag: extra parameter to callback
169 *
170 * The function is used to traverse the specified PE and its
171 * child PEs. The traversing is to be terminated once the
172 * callback returns something other than NULL, or no more PEs
173 * to be traversed.
174 */
175void *eeh_pe_traverse(struct eeh_pe *root,
176 eeh_traverse_func fn, void *flag)
177{
178 struct eeh_pe *pe;
179 void *ret;
180
181 for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
182 ret = fn(pe, flag);
183 if (ret) return ret;
184 }
185
186 return NULL;
187}
188
189/**
190 * eeh_pe_dev_traverse - Traverse the devices from the PE
191 * @root: EEH PE
192 * @fn: function callback
193 * @flag: extra parameter to callback
194 *
195 * The function is used to traverse the devices of the specified
196 * PE and its child PEs.
197 */
198void *eeh_pe_dev_traverse(struct eeh_pe *root,
199 eeh_traverse_func fn, void *flag)
200{
201 struct eeh_pe *pe;
202 struct eeh_dev *edev, *tmp;
203 void *ret;
204
205 if (!root) {
206 pr_warn("%s: Invalid PE %p\n",
207 __func__, root);
208 return NULL;
209 }
210
211 /* Traverse root PE */
212 for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
213 eeh_pe_for_each_dev(pe, edev, tmp) {
214 ret = fn(edev, flag);
215 if (ret)
216 return ret;
217 }
218 }
219
220 return NULL;
221}
222
223/**
224 * __eeh_pe_get - Check the PE address
225 * @data: EEH PE
226 * @flag: EEH device
227 *
228 * For one particular PE, it can be identified by PE address
229 * or tranditional BDF address. BDF address is composed of
230 * Bus/Device/Function number. The extra data referred by flag
231 * indicates which type of address should be used.
232 */
233struct eeh_pe_get_flag {
234 int pe_no;
235 int config_addr;
236};
237
238static void *__eeh_pe_get(void *data, void *flag)
239{
240 struct eeh_pe *pe = (struct eeh_pe *)data;
241 struct eeh_pe_get_flag *tmp = (struct eeh_pe_get_flag *) flag;
242
243 /* Unexpected PHB PE */
244 if (pe->type & EEH_PE_PHB)
245 return NULL;
246
247 /*
248 * We prefer PE address. For most cases, we should
249 * have non-zero PE address
250 */
251 if (eeh_has_flag(EEH_VALID_PE_ZERO)) {
252 if (tmp->pe_no == pe->addr)
253 return pe;
254 } else {
255 if (tmp->pe_no &&
256 (tmp->pe_no == pe->addr))
257 return pe;
258 }
259
260 /* Try BDF address */
261 if (tmp->config_addr &&
262 (tmp->config_addr == pe->config_addr))
263 return pe;
264
265 return NULL;
266}
267
268/**
269 * eeh_pe_get - Search PE based on the given address
270 * @phb: PCI controller
271 * @pe_no: PE number
272 * @config_addr: Config address
273 *
274 * Search the corresponding PE based on the specified address which
275 * is included in the eeh device. The function is used to check if
276 * the associated PE has been created against the PE address. It's
277 * notable that the PE address has 2 format: traditional PE address
278 * which is composed of PCI bus/device/function number, or unified
279 * PE address.
280 */
281struct eeh_pe *eeh_pe_get(struct pci_controller *phb,
282 int pe_no, int config_addr)
283{
284 struct eeh_pe *root = eeh_phb_pe_get(phb);
285 struct eeh_pe_get_flag tmp = { pe_no, config_addr };
286 struct eeh_pe *pe;
287
288 pe = eeh_pe_traverse(root, __eeh_pe_get, &tmp);
289
290 return pe;
291}
292
293/**
294 * eeh_pe_get_parent - Retrieve the parent PE
295 * @edev: EEH device
296 *
297 * The whole PEs existing in the system are organized as hierarchy
298 * tree. The function is used to retrieve the parent PE according
299 * to the parent EEH device.
300 */
301static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
302{
303 struct eeh_dev *parent;
304 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
305
306 /*
307 * It might have the case for the indirect parent
308 * EEH device already having associated PE, but
309 * the direct parent EEH device doesn't have yet.
310 */
311 if (edev->physfn)
312 pdn = pci_get_pdn(edev->physfn);
313 else
314 pdn = pdn ? pdn->parent : NULL;
315 while (pdn) {
316 /* We're poking out of PCI territory */
317 parent = pdn_to_eeh_dev(pdn);
318 if (!parent)
319 return NULL;
320
321 if (parent->pe)
322 return parent->pe;
323
324 pdn = pdn->parent;
325 }
326
327 return NULL;
328}
329
330/**
331 * eeh_add_to_parent_pe - Add EEH device to parent PE
332 * @edev: EEH device
333 *
334 * Add EEH device to the parent PE. If the parent PE already
335 * exists, the PE type will be changed to EEH_PE_BUS. Otherwise,
336 * we have to create new PE to hold the EEH device and the new
337 * PE will be linked to its parent PE as well.
338 */
339int eeh_add_to_parent_pe(struct eeh_dev *edev)
340{
341 struct eeh_pe *pe, *parent;
342 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
343 int config_addr = (pdn->busno << 8) | (pdn->devfn);
344
345 /* Check if the PE number is valid */
346 if (!eeh_has_flag(EEH_VALID_PE_ZERO) && !edev->pe_config_addr) {
347 pr_err("%s: Invalid PE#0 for edev 0x%x on PHB#%x\n",
348 __func__, config_addr, pdn->phb->global_number);
349 return -EINVAL;
350 }
351
352 /*
353 * Search the PE has been existing or not according
354 * to the PE address. If that has been existing, the
355 * PE should be composed of PCI bus and its subordinate
356 * components.
357 */
358 pe = eeh_pe_get(pdn->phb, edev->pe_config_addr, config_addr);
359 if (pe && !(pe->type & EEH_PE_INVALID)) {
360 /* Mark the PE as type of PCI bus */
361 pe->type = EEH_PE_BUS;
362 edev->pe = pe;
363
364 /* Put the edev to PE */
365 list_add_tail(&edev->list, &pe->edevs);
366 pr_debug("EEH: Add %04x:%02x:%02x.%01x to Bus PE#%x\n",
367 pdn->phb->global_number,
368 pdn->busno,
369 PCI_SLOT(pdn->devfn),
370 PCI_FUNC(pdn->devfn),
371 pe->addr);
372 return 0;
373 } else if (pe && (pe->type & EEH_PE_INVALID)) {
374 list_add_tail(&edev->list, &pe->edevs);
375 edev->pe = pe;
376 /*
377 * We're running to here because of PCI hotplug caused by
378 * EEH recovery. We need clear EEH_PE_INVALID until the top.
379 */
380 parent = pe;
381 while (parent) {
382 if (!(parent->type & EEH_PE_INVALID))
383 break;
384 parent->type &= ~(EEH_PE_INVALID | EEH_PE_KEEP);
385 parent = parent->parent;
386 }
387
388 pr_debug("EEH: Add %04x:%02x:%02x.%01x to Device "
389 "PE#%x, Parent PE#%x\n",
390 pdn->phb->global_number,
391 pdn->busno,
392 PCI_SLOT(pdn->devfn),
393 PCI_FUNC(pdn->devfn),
394 pe->addr, pe->parent->addr);
395 return 0;
396 }
397
398 /* Create a new EEH PE */
399 if (edev->physfn)
400 pe = eeh_pe_alloc(pdn->phb, EEH_PE_VF);
401 else
402 pe = eeh_pe_alloc(pdn->phb, EEH_PE_DEVICE);
403 if (!pe) {
404 pr_err("%s: out of memory!\n", __func__);
405 return -ENOMEM;
406 }
407 pe->addr = edev->pe_config_addr;
408 pe->config_addr = config_addr;
409
410 /*
411 * Put the new EEH PE into hierarchy tree. If the parent
412 * can't be found, the newly created PE will be attached
413 * to PHB directly. Otherwise, we have to associate the
414 * PE with its parent.
415 */
416 parent = eeh_pe_get_parent(edev);
417 if (!parent) {
418 parent = eeh_phb_pe_get(pdn->phb);
419 if (!parent) {
420 pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
421 __func__, pdn->phb->global_number);
422 edev->pe = NULL;
423 kfree(pe);
424 return -EEXIST;
425 }
426 }
427 pe->parent = parent;
428
429 /*
430 * Put the newly created PE into the child list and
431 * link the EEH device accordingly.
432 */
433 list_add_tail(&pe->child, &parent->child_list);
434 list_add_tail(&edev->list, &pe->edevs);
435 edev->pe = pe;
436 pr_debug("EEH: Add %04x:%02x:%02x.%01x to "
437 "Device PE#%x, Parent PE#%x\n",
438 pdn->phb->global_number,
439 pdn->busno,
440 PCI_SLOT(pdn->devfn),
441 PCI_FUNC(pdn->devfn),
442 pe->addr, pe->parent->addr);
443
444 return 0;
445}
446
447/**
448 * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE
449 * @edev: EEH device
450 *
451 * The PE hierarchy tree might be changed when doing PCI hotplug.
452 * Also, the PCI devices or buses could be removed from the system
453 * during EEH recovery. So we have to call the function remove the
454 * corresponding PE accordingly if necessary.
455 */
456int eeh_rmv_from_parent_pe(struct eeh_dev *edev)
457{
458 struct eeh_pe *pe, *parent, *child;
459 int cnt;
460 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
461
462 if (!edev->pe) {
463 pr_debug("%s: No PE found for device %04x:%02x:%02x.%01x\n",
464 __func__, pdn->phb->global_number,
465 pdn->busno,
466 PCI_SLOT(pdn->devfn),
467 PCI_FUNC(pdn->devfn));
468 return -EEXIST;
469 }
470
471 /* Remove the EEH device */
472 pe = eeh_dev_to_pe(edev);
473 edev->pe = NULL;
474 list_del(&edev->list);
475
476 /*
477 * Check if the parent PE includes any EEH devices.
478 * If not, we should delete that. Also, we should
479 * delete the parent PE if it doesn't have associated
480 * child PEs and EEH devices.
481 */
482 while (1) {
483 parent = pe->parent;
484 if (pe->type & EEH_PE_PHB)
485 break;
486
487 if (!(pe->state & EEH_PE_KEEP)) {
488 if (list_empty(&pe->edevs) &&
489 list_empty(&pe->child_list)) {
490 list_del(&pe->child);
491 kfree(pe);
492 } else {
493 break;
494 }
495 } else {
496 if (list_empty(&pe->edevs)) {
497 cnt = 0;
498 list_for_each_entry(child, &pe->child_list, child) {
499 if (!(child->type & EEH_PE_INVALID)) {
500 cnt++;
501 break;
502 }
503 }
504
505 if (!cnt)
506 pe->type |= EEH_PE_INVALID;
507 else
508 break;
509 }
510 }
511
512 pe = parent;
513 }
514
515 return 0;
516}
517
518/**
519 * eeh_pe_update_time_stamp - Update PE's frozen time stamp
520 * @pe: EEH PE
521 *
522 * We have time stamp for each PE to trace its time of getting
523 * frozen in last hour. The function should be called to update
524 * the time stamp on first error of the specific PE. On the other
525 * handle, we needn't account for errors happened in last hour.
526 */
527void eeh_pe_update_time_stamp(struct eeh_pe *pe)
528{
529 time64_t tstamp;
530
531 if (!pe) return;
532
533 if (pe->freeze_count <= 0) {
534 pe->freeze_count = 0;
535 pe->tstamp = ktime_get_seconds();
536 } else {
537 tstamp = ktime_get_seconds();
538 if (tstamp - pe->tstamp > 3600) {
539 pe->tstamp = tstamp;
540 pe->freeze_count = 0;
541 }
542 }
543}
544
545/**
546 * __eeh_pe_state_mark - Mark the state for the PE
547 * @data: EEH PE
548 * @flag: state
549 *
550 * The function is used to mark the indicated state for the given
551 * PE. Also, the associated PCI devices will be put into IO frozen
552 * state as well.
553 */
554static void *__eeh_pe_state_mark(void *data, void *flag)
555{
556 struct eeh_pe *pe = (struct eeh_pe *)data;
557 int state = *((int *)flag);
558 struct eeh_dev *edev, *tmp;
559 struct pci_dev *pdev;
560
561 /* Keep the state of permanently removed PE intact */
562 if (pe->state & EEH_PE_REMOVED)
563 return NULL;
564
565 pe->state |= state;
566
567 /* Offline PCI devices if applicable */
568 if (!(state & EEH_PE_ISOLATED))
569 return NULL;
570
571 eeh_pe_for_each_dev(pe, edev, tmp) {
572 pdev = eeh_dev_to_pci_dev(edev);
573 if (pdev)
574 pdev->error_state = pci_channel_io_frozen;
575 }
576
577 /* Block PCI config access if required */
578 if (pe->state & EEH_PE_CFG_RESTRICTED)
579 pe->state |= EEH_PE_CFG_BLOCKED;
580
581 return NULL;
582}
583
584/**
585 * eeh_pe_state_mark - Mark specified state for PE and its associated device
586 * @pe: EEH PE
587 *
588 * EEH error affects the current PE and its child PEs. The function
589 * is used to mark appropriate state for the affected PEs and the
590 * associated devices.
591 */
592void eeh_pe_state_mark(struct eeh_pe *pe, int state)
593{
594 eeh_pe_traverse(pe, __eeh_pe_state_mark, &state);
595}
596EXPORT_SYMBOL_GPL(eeh_pe_state_mark);
597
598static void *__eeh_pe_dev_mode_mark(void *data, void *flag)
599{
600 struct eeh_dev *edev = data;
601 int mode = *((int *)flag);
602
603 edev->mode |= mode;
604
605 return NULL;
606}
607
608/**
609 * eeh_pe_dev_state_mark - Mark state for all device under the PE
610 * @pe: EEH PE
611 *
612 * Mark specific state for all child devices of the PE.
613 */
614void eeh_pe_dev_mode_mark(struct eeh_pe *pe, int mode)
615{
616 eeh_pe_dev_traverse(pe, __eeh_pe_dev_mode_mark, &mode);
617}
618
619/**
620 * __eeh_pe_state_clear - Clear state for the PE
621 * @data: EEH PE
622 * @flag: state
623 *
624 * The function is used to clear the indicated state from the
625 * given PE. Besides, we also clear the check count of the PE
626 * as well.
627 */
628static void *__eeh_pe_state_clear(void *data, void *flag)
629{
630 struct eeh_pe *pe = (struct eeh_pe *)data;
631 int state = *((int *)flag);
632 struct eeh_dev *edev, *tmp;
633 struct pci_dev *pdev;
634
635 /* Keep the state of permanently removed PE intact */
636 if (pe->state & EEH_PE_REMOVED)
637 return NULL;
638
639 pe->state &= ~state;
640
641 /*
642 * Special treatment on clearing isolated state. Clear
643 * check count since last isolation and put all affected
644 * devices to normal state.
645 */
646 if (!(state & EEH_PE_ISOLATED))
647 return NULL;
648
649 pe->check_count = 0;
650 eeh_pe_for_each_dev(pe, edev, tmp) {
651 pdev = eeh_dev_to_pci_dev(edev);
652 if (!pdev)
653 continue;
654
655 pdev->error_state = pci_channel_io_normal;
656 }
657
658 /* Unblock PCI config access if required */
659 if (pe->state & EEH_PE_CFG_RESTRICTED)
660 pe->state &= ~EEH_PE_CFG_BLOCKED;
661
662 return NULL;
663}
664
665/**
666 * eeh_pe_state_clear - Clear state for the PE and its children
667 * @pe: PE
668 * @state: state to be cleared
669 *
670 * When the PE and its children has been recovered from error,
671 * we need clear the error state for that. The function is used
672 * for the purpose.
673 */
674void eeh_pe_state_clear(struct eeh_pe *pe, int state)
675{
676 eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
677}
678
679/**
680 * eeh_pe_state_mark_with_cfg - Mark PE state with unblocked config space
681 * @pe: PE
682 * @state: PE state to be set
683 *
684 * Set specified flag to PE and its child PEs. The PCI config space
685 * of some PEs is blocked automatically when EEH_PE_ISOLATED is set,
686 * which isn't needed in some situations. The function allows to set
687 * the specified flag to indicated PEs without blocking their PCI
688 * config space.
689 */
690void eeh_pe_state_mark_with_cfg(struct eeh_pe *pe, int state)
691{
692 eeh_pe_traverse(pe, __eeh_pe_state_mark, &state);
693 if (!(state & EEH_PE_ISOLATED))
694 return;
695
696 /* Clear EEH_PE_CFG_BLOCKED, which might be set just now */
697 state = EEH_PE_CFG_BLOCKED;
698 eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
699}
700
701/*
702 * Some PCI bridges (e.g. PLX bridges) have primary/secondary
703 * buses assigned explicitly by firmware, and we probably have
704 * lost that after reset. So we have to delay the check until
705 * the PCI-CFG registers have been restored for the parent
706 * bridge.
707 *
708 * Don't use normal PCI-CFG accessors, which probably has been
709 * blocked on normal path during the stage. So we need utilize
710 * eeh operations, which is always permitted.
711 */
712static void eeh_bridge_check_link(struct eeh_dev *edev)
713{
714 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
715 int cap;
716 uint32_t val;
717 int timeout = 0;
718
719 /*
720 * We only check root port and downstream ports of
721 * PCIe switches
722 */
723 if (!(edev->mode & (EEH_DEV_ROOT_PORT | EEH_DEV_DS_PORT)))
724 return;
725
726 pr_debug("%s: Check PCIe link for %04x:%02x:%02x.%01x ...\n",
727 __func__, pdn->phb->global_number,
728 pdn->busno,
729 PCI_SLOT(pdn->devfn),
730 PCI_FUNC(pdn->devfn));
731
732 /* Check slot status */
733 cap = edev->pcie_cap;
734 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTSTA, 2, &val);
735 if (!(val & PCI_EXP_SLTSTA_PDS)) {
736 pr_debug(" No card in the slot (0x%04x) !\n", val);
737 return;
738 }
739
740 /* Check power status if we have the capability */
741 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTCAP, 2, &val);
742 if (val & PCI_EXP_SLTCAP_PCP) {
743 eeh_ops->read_config(pdn, cap + PCI_EXP_SLTCTL, 2, &val);
744 if (val & PCI_EXP_SLTCTL_PCC) {
745 pr_debug(" In power-off state, power it on ...\n");
746 val &= ~(PCI_EXP_SLTCTL_PCC | PCI_EXP_SLTCTL_PIC);
747 val |= (0x0100 & PCI_EXP_SLTCTL_PIC);
748 eeh_ops->write_config(pdn, cap + PCI_EXP_SLTCTL, 2, val);
749 msleep(2 * 1000);
750 }
751 }
752
753 /* Enable link */
754 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKCTL, 2, &val);
755 val &= ~PCI_EXP_LNKCTL_LD;
756 eeh_ops->write_config(pdn, cap + PCI_EXP_LNKCTL, 2, val);
757
758 /* Check link */
759 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKCAP, 4, &val);
760 if (!(val & PCI_EXP_LNKCAP_DLLLARC)) {
761 pr_debug(" No link reporting capability (0x%08x) \n", val);
762 msleep(1000);
763 return;
764 }
765
766 /* Wait the link is up until timeout (5s) */
767 timeout = 0;
768 while (timeout < 5000) {
769 msleep(20);
770 timeout += 20;
771
772 eeh_ops->read_config(pdn, cap + PCI_EXP_LNKSTA, 2, &val);
773 if (val & PCI_EXP_LNKSTA_DLLLA)
774 break;
775 }
776
777 if (val & PCI_EXP_LNKSTA_DLLLA)
778 pr_debug(" Link up (%s)\n",
779 (val & PCI_EXP_LNKSTA_CLS_2_5GB) ? "2.5GB" : "5GB");
780 else
781 pr_debug(" Link not ready (0x%04x)\n", val);
782}
783
784#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
785#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
786
787static void eeh_restore_bridge_bars(struct eeh_dev *edev)
788{
789 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
790 int i;
791
792 /*
793 * Device BARs: 0x10 - 0x18
794 * Bus numbers and windows: 0x18 - 0x30
795 */
796 for (i = 4; i < 13; i++)
797 eeh_ops->write_config(pdn, i*4, 4, edev->config_space[i]);
798 /* Rom: 0x38 */
799 eeh_ops->write_config(pdn, 14*4, 4, edev->config_space[14]);
800
801 /* Cache line & Latency timer: 0xC 0xD */
802 eeh_ops->write_config(pdn, PCI_CACHE_LINE_SIZE, 1,
803 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
804 eeh_ops->write_config(pdn, PCI_LATENCY_TIMER, 1,
805 SAVED_BYTE(PCI_LATENCY_TIMER));
806 /* Max latency, min grant, interrupt ping and line: 0x3C */
807 eeh_ops->write_config(pdn, 15*4, 4, edev->config_space[15]);
808
809 /* PCI Command: 0x4 */
810 eeh_ops->write_config(pdn, PCI_COMMAND, 4, edev->config_space[1] |
811 PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
812
813 /* Check the PCIe link is ready */
814 eeh_bridge_check_link(edev);
815}
816
817static void eeh_restore_device_bars(struct eeh_dev *edev)
818{
819 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
820 int i;
821 u32 cmd;
822
823 for (i = 4; i < 10; i++)
824 eeh_ops->write_config(pdn, i*4, 4, edev->config_space[i]);
825 /* 12 == Expansion ROM Address */
826 eeh_ops->write_config(pdn, 12*4, 4, edev->config_space[12]);
827
828 eeh_ops->write_config(pdn, PCI_CACHE_LINE_SIZE, 1,
829 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
830 eeh_ops->write_config(pdn, PCI_LATENCY_TIMER, 1,
831 SAVED_BYTE(PCI_LATENCY_TIMER));
832
833 /* max latency, min grant, interrupt pin and line */
834 eeh_ops->write_config(pdn, 15*4, 4, edev->config_space[15]);
835
836 /*
837 * Restore PERR & SERR bits, some devices require it,
838 * don't touch the other command bits
839 */
840 eeh_ops->read_config(pdn, PCI_COMMAND, 4, &cmd);
841 if (edev->config_space[1] & PCI_COMMAND_PARITY)
842 cmd |= PCI_COMMAND_PARITY;
843 else
844 cmd &= ~PCI_COMMAND_PARITY;
845 if (edev->config_space[1] & PCI_COMMAND_SERR)
846 cmd |= PCI_COMMAND_SERR;
847 else
848 cmd &= ~PCI_COMMAND_SERR;
849 eeh_ops->write_config(pdn, PCI_COMMAND, 4, cmd);
850}
851
852/**
853 * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
854 * @data: EEH device
855 * @flag: Unused
856 *
857 * Loads the PCI configuration space base address registers,
858 * the expansion ROM base address, the latency timer, and etc.
859 * from the saved values in the device node.
860 */
861static void *eeh_restore_one_device_bars(void *data, void *flag)
862{
863 struct eeh_dev *edev = (struct eeh_dev *)data;
864 struct pci_dn *pdn = eeh_dev_to_pdn(edev);
865
866 /* Do special restore for bridges */
867 if (edev->mode & EEH_DEV_BRIDGE)
868 eeh_restore_bridge_bars(edev);
869 else
870 eeh_restore_device_bars(edev);
871
872 if (eeh_ops->restore_config && pdn)
873 eeh_ops->restore_config(pdn);
874
875 return NULL;
876}
877
878/**
879 * eeh_pe_restore_bars - Restore the PCI config space info
880 * @pe: EEH PE
881 *
882 * This routine performs a recursive walk to the children
883 * of this device as well.
884 */
885void eeh_pe_restore_bars(struct eeh_pe *pe)
886{
887 /*
888 * We needn't take the EEH lock since eeh_pe_dev_traverse()
889 * will take that.
890 */
891 eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
892}
893
894/**
895 * eeh_pe_loc_get - Retrieve location code binding to the given PE
896 * @pe: EEH PE
897 *
898 * Retrieve the location code of the given PE. If the primary PE bus
899 * is root bus, we will grab location code from PHB device tree node
900 * or root port. Otherwise, the upstream bridge's device tree node
901 * of the primary PE bus will be checked for the location code.
902 */
903const char *eeh_pe_loc_get(struct eeh_pe *pe)
904{
905 struct pci_bus *bus = eeh_pe_bus_get(pe);
906 struct device_node *dn;
907 const char *loc = NULL;
908
909 while (bus) {
910 dn = pci_bus_to_OF_node(bus);
911 if (!dn) {
912 bus = bus->parent;
913 continue;
914 }
915
916 if (pci_is_root_bus(bus))
917 loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
918 else
919 loc = of_get_property(dn, "ibm,slot-location-code",
920 NULL);
921
922 if (loc)
923 return loc;
924
925 bus = bus->parent;
926 }
927
928 return "N/A";
929}
930
931/**
932 * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
933 * @pe: EEH PE
934 *
935 * Retrieve the PCI bus according to the given PE. Basically,
936 * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
937 * primary PCI bus will be retrieved. The parent bus will be
938 * returned for BUS PE. However, we don't have associated PCI
939 * bus for DEVICE PE.
940 */
941struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
942{
943 struct eeh_dev *edev;
944 struct pci_dev *pdev;
945
946 if (pe->type & EEH_PE_PHB)
947 return pe->phb->bus;
948
949 /* The primary bus might be cached during probe time */
950 if (pe->state & EEH_PE_PRI_BUS)
951 return pe->bus;
952
953 /* Retrieve the parent PCI bus of first (top) PCI device */
954 edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, list);
955 pdev = eeh_dev_to_pci_dev(edev);
956 if (pdev)
957 return pdev->bus;
958
959 return NULL;
960}
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/of.h>
17#include <linux/pci.h>
18#include <linux/string.h>
19
20#include <asm/pci-bridge.h>
21#include <asm/ppc-pci.h>
22
23static int eeh_pe_aux_size = 0;
24static LIST_HEAD(eeh_phb_pe);
25
26/**
27 * eeh_set_pe_aux_size - Set PE auxillary data size
28 * @size: PE auxillary data size
29 *
30 * Set PE auxillary data size
31 */
32void eeh_set_pe_aux_size(int size)
33{
34 if (size < 0)
35 return;
36
37 eeh_pe_aux_size = size;
38}
39
40/**
41 * eeh_pe_alloc - Allocate PE
42 * @phb: PCI controller
43 * @type: PE type
44 *
45 * Allocate PE instance dynamically.
46 */
47static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
48{
49 struct eeh_pe *pe;
50 size_t alloc_size;
51
52 alloc_size = sizeof(struct eeh_pe);
53 if (eeh_pe_aux_size) {
54 alloc_size = ALIGN(alloc_size, cache_line_size());
55 alloc_size += eeh_pe_aux_size;
56 }
57
58 /* Allocate PHB PE */
59 pe = kzalloc(alloc_size, GFP_KERNEL);
60 if (!pe) return NULL;
61
62 /* Initialize PHB PE */
63 pe->type = type;
64 pe->phb = phb;
65 INIT_LIST_HEAD(&pe->child_list);
66 INIT_LIST_HEAD(&pe->edevs);
67
68 pe->data = (void *)pe + ALIGN(sizeof(struct eeh_pe),
69 cache_line_size());
70 return pe;
71}
72
73/**
74 * eeh_phb_pe_create - Create PHB PE
75 * @phb: PCI controller
76 *
77 * The function should be called while the PHB is detected during
78 * system boot or PCI hotplug in order to create PHB PE.
79 */
80int eeh_phb_pe_create(struct pci_controller *phb)
81{
82 struct eeh_pe *pe;
83
84 /* Allocate PHB PE */
85 pe = eeh_pe_alloc(phb, EEH_PE_PHB);
86 if (!pe) {
87 pr_err("%s: out of memory!\n", __func__);
88 return -ENOMEM;
89 }
90
91 /* Put it into the list */
92 list_add_tail(&pe->child, &eeh_phb_pe);
93
94 pr_debug("EEH: Add PE for PHB#%x\n", phb->global_number);
95
96 return 0;
97}
98
99/**
100 * eeh_wait_state - Wait for PE state
101 * @pe: EEH PE
102 * @max_wait: maximal period in millisecond
103 *
104 * Wait for the state of associated PE. It might take some time
105 * to retrieve the PE's state.
106 */
107int eeh_wait_state(struct eeh_pe *pe, int max_wait)
108{
109 int ret;
110 int mwait;
111
112 /*
113 * According to PAPR, the state of PE might be temporarily
114 * unavailable. Under the circumstance, we have to wait
115 * for indicated time determined by firmware. The maximal
116 * wait time is 5 minutes, which is acquired from the original
117 * EEH implementation. Also, the original implementation
118 * also defined the minimal wait time as 1 second.
119 */
120#define EEH_STATE_MIN_WAIT_TIME (1000)
121#define EEH_STATE_MAX_WAIT_TIME (300 * 1000)
122
123 while (1) {
124 ret = eeh_ops->get_state(pe, &mwait);
125
126 if (ret != EEH_STATE_UNAVAILABLE)
127 return ret;
128
129 if (max_wait <= 0) {
130 pr_warn("%s: Timeout when getting PE's state (%d)\n",
131 __func__, max_wait);
132 return EEH_STATE_NOT_SUPPORT;
133 }
134
135 if (mwait < EEH_STATE_MIN_WAIT_TIME) {
136 pr_warn("%s: Firmware returned bad wait value %d\n",
137 __func__, mwait);
138 mwait = EEH_STATE_MIN_WAIT_TIME;
139 } else if (mwait > EEH_STATE_MAX_WAIT_TIME) {
140 pr_warn("%s: Firmware returned too long wait value %d\n",
141 __func__, mwait);
142 mwait = EEH_STATE_MAX_WAIT_TIME;
143 }
144
145 msleep(min(mwait, max_wait));
146 max_wait -= mwait;
147 }
148}
149
150/**
151 * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
152 * @phb: PCI controller
153 *
154 * The overall PEs form hierarchy tree. The first layer of the
155 * hierarchy tree is composed of PHB PEs. The function is used
156 * to retrieve the corresponding PHB PE according to the given PHB.
157 */
158struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
159{
160 struct eeh_pe *pe;
161
162 list_for_each_entry(pe, &eeh_phb_pe, child) {
163 /*
164 * Actually, we needn't check the type since
165 * the PE for PHB has been determined when that
166 * was created.
167 */
168 if ((pe->type & EEH_PE_PHB) && pe->phb == phb)
169 return pe;
170 }
171
172 return NULL;
173}
174
175/**
176 * eeh_pe_next - Retrieve the next PE in the tree
177 * @pe: current PE
178 * @root: root PE
179 *
180 * The function is used to retrieve the next PE in the
181 * hierarchy PE tree.
182 */
183struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, struct eeh_pe *root)
184{
185 struct list_head *next = pe->child_list.next;
186
187 if (next == &pe->child_list) {
188 while (1) {
189 if (pe == root)
190 return NULL;
191 next = pe->child.next;
192 if (next != &pe->parent->child_list)
193 break;
194 pe = pe->parent;
195 }
196 }
197
198 return list_entry(next, struct eeh_pe, child);
199}
200
201/**
202 * eeh_pe_traverse - Traverse PEs in the specified PHB
203 * @root: root PE
204 * @fn: callback
205 * @flag: extra parameter to callback
206 *
207 * The function is used to traverse the specified PE and its
208 * child PEs. The traversing is to be terminated once the
209 * callback returns something other than NULL, or no more PEs
210 * to be traversed.
211 */
212void *eeh_pe_traverse(struct eeh_pe *root,
213 eeh_pe_traverse_func fn, void *flag)
214{
215 struct eeh_pe *pe;
216 void *ret;
217
218 eeh_for_each_pe(root, pe) {
219 ret = fn(pe, flag);
220 if (ret) return ret;
221 }
222
223 return NULL;
224}
225
226/**
227 * eeh_pe_dev_traverse - Traverse the devices from the PE
228 * @root: EEH PE
229 * @fn: function callback
230 * @flag: extra parameter to callback
231 *
232 * The function is used to traverse the devices of the specified
233 * PE and its child PEs.
234 */
235void eeh_pe_dev_traverse(struct eeh_pe *root,
236 eeh_edev_traverse_func fn, void *flag)
237{
238 struct eeh_pe *pe;
239 struct eeh_dev *edev, *tmp;
240
241 if (!root) {
242 pr_warn("%s: Invalid PE %p\n",
243 __func__, root);
244 return;
245 }
246
247 /* Traverse root PE */
248 eeh_for_each_pe(root, pe)
249 eeh_pe_for_each_dev(pe, edev, tmp)
250 fn(edev, flag);
251}
252
253/**
254 * __eeh_pe_get - Check the PE address
255 *
256 * For one particular PE, it can be identified by PE address
257 * or tranditional BDF address. BDF address is composed of
258 * Bus/Device/Function number. The extra data referred by flag
259 * indicates which type of address should be used.
260 */
261static void *__eeh_pe_get(struct eeh_pe *pe, void *flag)
262{
263 int *target_pe = flag;
264
265 /* PHB PEs are special and should be ignored */
266 if (pe->type & EEH_PE_PHB)
267 return NULL;
268
269 if (*target_pe == pe->addr)
270 return pe;
271
272 return NULL;
273}
274
275/**
276 * eeh_pe_get - Search PE based on the given address
277 * @phb: PCI controller
278 * @pe_no: PE number
279 *
280 * Search the corresponding PE based on the specified address which
281 * is included in the eeh device. The function is used to check if
282 * the associated PE has been created against the PE address. It's
283 * notable that the PE address has 2 format: traditional PE address
284 * which is composed of PCI bus/device/function number, or unified
285 * PE address.
286 */
287struct eeh_pe *eeh_pe_get(struct pci_controller *phb, int pe_no)
288{
289 struct eeh_pe *root = eeh_phb_pe_get(phb);
290
291 return eeh_pe_traverse(root, __eeh_pe_get, &pe_no);
292}
293
294/**
295 * eeh_pe_tree_insert - Add EEH device to parent PE
296 * @edev: EEH device
297 * @new_pe_parent: PE to create additional PEs under
298 *
299 * Add EEH device to the PE in edev->pe_config_addr. If a PE already
300 * exists with that address then @edev is added to that PE. Otherwise
301 * a new PE is created and inserted into the PE tree as a child of
302 * @new_pe_parent.
303 *
304 * If @new_pe_parent is NULL then the new PE will be inserted under
305 * directly under the PHB.
306 */
307int eeh_pe_tree_insert(struct eeh_dev *edev, struct eeh_pe *new_pe_parent)
308{
309 struct pci_controller *hose = edev->controller;
310 struct eeh_pe *pe, *parent;
311
312 /*
313 * Search the PE has been existing or not according
314 * to the PE address. If that has been existing, the
315 * PE should be composed of PCI bus and its subordinate
316 * components.
317 */
318 pe = eeh_pe_get(hose, edev->pe_config_addr);
319 if (pe) {
320 if (pe->type & EEH_PE_INVALID) {
321 list_add_tail(&edev->entry, &pe->edevs);
322 edev->pe = pe;
323 /*
324 * We're running to here because of PCI hotplug caused by
325 * EEH recovery. We need clear EEH_PE_INVALID until the top.
326 */
327 parent = pe;
328 while (parent) {
329 if (!(parent->type & EEH_PE_INVALID))
330 break;
331 parent->type &= ~EEH_PE_INVALID;
332 parent = parent->parent;
333 }
334
335 eeh_edev_dbg(edev, "Added to existing PE (parent: PE#%x)\n",
336 pe->parent->addr);
337 } else {
338 /* Mark the PE as type of PCI bus */
339 pe->type = EEH_PE_BUS;
340 edev->pe = pe;
341
342 /* Put the edev to PE */
343 list_add_tail(&edev->entry, &pe->edevs);
344 eeh_edev_dbg(edev, "Added to bus PE\n");
345 }
346 return 0;
347 }
348
349 /* Create a new EEH PE */
350 if (edev->physfn)
351 pe = eeh_pe_alloc(hose, EEH_PE_VF);
352 else
353 pe = eeh_pe_alloc(hose, EEH_PE_DEVICE);
354 if (!pe) {
355 pr_err("%s: out of memory!\n", __func__);
356 return -ENOMEM;
357 }
358
359 pe->addr = edev->pe_config_addr;
360
361 /*
362 * Put the new EEH PE into hierarchy tree. If the parent
363 * can't be found, the newly created PE will be attached
364 * to PHB directly. Otherwise, we have to associate the
365 * PE with its parent.
366 */
367 if (!new_pe_parent) {
368 new_pe_parent = eeh_phb_pe_get(hose);
369 if (!new_pe_parent) {
370 pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
371 __func__, hose->global_number);
372 edev->pe = NULL;
373 kfree(pe);
374 return -EEXIST;
375 }
376 }
377
378 /* link new PE into the tree */
379 pe->parent = new_pe_parent;
380 list_add_tail(&pe->child, &new_pe_parent->child_list);
381
382 /*
383 * Put the newly created PE into the child list and
384 * link the EEH device accordingly.
385 */
386 list_add_tail(&edev->entry, &pe->edevs);
387 edev->pe = pe;
388 eeh_edev_dbg(edev, "Added to new (parent: PE#%x)\n",
389 new_pe_parent->addr);
390
391 return 0;
392}
393
394/**
395 * eeh_pe_tree_remove - Remove one EEH device from the associated PE
396 * @edev: EEH device
397 *
398 * The PE hierarchy tree might be changed when doing PCI hotplug.
399 * Also, the PCI devices or buses could be removed from the system
400 * during EEH recovery. So we have to call the function remove the
401 * corresponding PE accordingly if necessary.
402 */
403int eeh_pe_tree_remove(struct eeh_dev *edev)
404{
405 struct eeh_pe *pe, *parent, *child;
406 bool keep, recover;
407 int cnt;
408
409 pe = eeh_dev_to_pe(edev);
410 if (!pe) {
411 eeh_edev_dbg(edev, "No PE found for device.\n");
412 return -EEXIST;
413 }
414
415 /* Remove the EEH device */
416 edev->pe = NULL;
417 list_del(&edev->entry);
418
419 /*
420 * Check if the parent PE includes any EEH devices.
421 * If not, we should delete that. Also, we should
422 * delete the parent PE if it doesn't have associated
423 * child PEs and EEH devices.
424 */
425 while (1) {
426 parent = pe->parent;
427
428 /* PHB PEs should never be removed */
429 if (pe->type & EEH_PE_PHB)
430 break;
431
432 /*
433 * XXX: KEEP is set while resetting a PE. I don't think it's
434 * ever set without RECOVERING also being set. I could
435 * be wrong though so catch that with a WARN.
436 */
437 keep = !!(pe->state & EEH_PE_KEEP);
438 recover = !!(pe->state & EEH_PE_RECOVERING);
439 WARN_ON(keep && !recover);
440
441 if (!keep && !recover) {
442 if (list_empty(&pe->edevs) &&
443 list_empty(&pe->child_list)) {
444 list_del(&pe->child);
445 kfree(pe);
446 } else {
447 break;
448 }
449 } else {
450 /*
451 * Mark the PE as invalid. At the end of the recovery
452 * process any invalid PEs will be garbage collected.
453 *
454 * We need to delay the free()ing of them since we can
455 * remove edev's while traversing the PE tree which
456 * might trigger the removal of a PE and we can't
457 * deal with that (yet).
458 */
459 if (list_empty(&pe->edevs)) {
460 cnt = 0;
461 list_for_each_entry(child, &pe->child_list, child) {
462 if (!(child->type & EEH_PE_INVALID)) {
463 cnt++;
464 break;
465 }
466 }
467
468 if (!cnt)
469 pe->type |= EEH_PE_INVALID;
470 else
471 break;
472 }
473 }
474
475 pe = parent;
476 }
477
478 return 0;
479}
480
481/**
482 * eeh_pe_update_time_stamp - Update PE's frozen time stamp
483 * @pe: EEH PE
484 *
485 * We have time stamp for each PE to trace its time of getting
486 * frozen in last hour. The function should be called to update
487 * the time stamp on first error of the specific PE. On the other
488 * handle, we needn't account for errors happened in last hour.
489 */
490void eeh_pe_update_time_stamp(struct eeh_pe *pe)
491{
492 time64_t tstamp;
493
494 if (!pe) return;
495
496 if (pe->freeze_count <= 0) {
497 pe->freeze_count = 0;
498 pe->tstamp = ktime_get_seconds();
499 } else {
500 tstamp = ktime_get_seconds();
501 if (tstamp - pe->tstamp > 3600) {
502 pe->tstamp = tstamp;
503 pe->freeze_count = 0;
504 }
505 }
506}
507
508/**
509 * eeh_pe_state_mark - Mark specified state for PE and its associated device
510 * @pe: EEH PE
511 *
512 * EEH error affects the current PE and its child PEs. The function
513 * is used to mark appropriate state for the affected PEs and the
514 * associated devices.
515 */
516void eeh_pe_state_mark(struct eeh_pe *root, int state)
517{
518 struct eeh_pe *pe;
519
520 eeh_for_each_pe(root, pe)
521 if (!(pe->state & EEH_PE_REMOVED))
522 pe->state |= state;
523}
524EXPORT_SYMBOL_GPL(eeh_pe_state_mark);
525
526/**
527 * eeh_pe_mark_isolated
528 * @pe: EEH PE
529 *
530 * Record that a PE has been isolated by marking the PE and it's children as
531 * EEH_PE_ISOLATED (and EEH_PE_CFG_BLOCKED, if required) and their PCI devices
532 * as pci_channel_io_frozen.
533 */
534void eeh_pe_mark_isolated(struct eeh_pe *root)
535{
536 struct eeh_pe *pe;
537 struct eeh_dev *edev;
538 struct pci_dev *pdev;
539
540 eeh_pe_state_mark(root, EEH_PE_ISOLATED);
541 eeh_for_each_pe(root, pe) {
542 list_for_each_entry(edev, &pe->edevs, entry) {
543 pdev = eeh_dev_to_pci_dev(edev);
544 if (pdev)
545 pdev->error_state = pci_channel_io_frozen;
546 }
547 /* Block PCI config access if required */
548 if (pe->state & EEH_PE_CFG_RESTRICTED)
549 pe->state |= EEH_PE_CFG_BLOCKED;
550 }
551}
552EXPORT_SYMBOL_GPL(eeh_pe_mark_isolated);
553
554static void __eeh_pe_dev_mode_mark(struct eeh_dev *edev, void *flag)
555{
556 int mode = *((int *)flag);
557
558 edev->mode |= mode;
559}
560
561/**
562 * eeh_pe_dev_state_mark - Mark state for all device under the PE
563 * @pe: EEH PE
564 *
565 * Mark specific state for all child devices of the PE.
566 */
567void eeh_pe_dev_mode_mark(struct eeh_pe *pe, int mode)
568{
569 eeh_pe_dev_traverse(pe, __eeh_pe_dev_mode_mark, &mode);
570}
571
572/**
573 * eeh_pe_state_clear - Clear state for the PE
574 * @data: EEH PE
575 * @state: state
576 * @include_passed: include passed-through devices?
577 *
578 * The function is used to clear the indicated state from the
579 * given PE. Besides, we also clear the check count of the PE
580 * as well.
581 */
582void eeh_pe_state_clear(struct eeh_pe *root, int state, bool include_passed)
583{
584 struct eeh_pe *pe;
585 struct eeh_dev *edev, *tmp;
586 struct pci_dev *pdev;
587
588 eeh_for_each_pe(root, pe) {
589 /* Keep the state of permanently removed PE intact */
590 if (pe->state & EEH_PE_REMOVED)
591 continue;
592
593 if (!include_passed && eeh_pe_passed(pe))
594 continue;
595
596 pe->state &= ~state;
597
598 /*
599 * Special treatment on clearing isolated state. Clear
600 * check count since last isolation and put all affected
601 * devices to normal state.
602 */
603 if (!(state & EEH_PE_ISOLATED))
604 continue;
605
606 pe->check_count = 0;
607 eeh_pe_for_each_dev(pe, edev, tmp) {
608 pdev = eeh_dev_to_pci_dev(edev);
609 if (!pdev)
610 continue;
611
612 pdev->error_state = pci_channel_io_normal;
613 }
614
615 /* Unblock PCI config access if required */
616 if (pe->state & EEH_PE_CFG_RESTRICTED)
617 pe->state &= ~EEH_PE_CFG_BLOCKED;
618 }
619}
620
621/*
622 * Some PCI bridges (e.g. PLX bridges) have primary/secondary
623 * buses assigned explicitly by firmware, and we probably have
624 * lost that after reset. So we have to delay the check until
625 * the PCI-CFG registers have been restored for the parent
626 * bridge.
627 *
628 * Don't use normal PCI-CFG accessors, which probably has been
629 * blocked on normal path during the stage. So we need utilize
630 * eeh operations, which is always permitted.
631 */
632static void eeh_bridge_check_link(struct eeh_dev *edev)
633{
634 int cap;
635 uint32_t val;
636 int timeout = 0;
637
638 /*
639 * We only check root port and downstream ports of
640 * PCIe switches
641 */
642 if (!(edev->mode & (EEH_DEV_ROOT_PORT | EEH_DEV_DS_PORT)))
643 return;
644
645 eeh_edev_dbg(edev, "Checking PCIe link...\n");
646
647 /* Check slot status */
648 cap = edev->pcie_cap;
649 eeh_ops->read_config(edev, cap + PCI_EXP_SLTSTA, 2, &val);
650 if (!(val & PCI_EXP_SLTSTA_PDS)) {
651 eeh_edev_dbg(edev, "No card in the slot (0x%04x) !\n", val);
652 return;
653 }
654
655 /* Check power status if we have the capability */
656 eeh_ops->read_config(edev, cap + PCI_EXP_SLTCAP, 2, &val);
657 if (val & PCI_EXP_SLTCAP_PCP) {
658 eeh_ops->read_config(edev, cap + PCI_EXP_SLTCTL, 2, &val);
659 if (val & PCI_EXP_SLTCTL_PCC) {
660 eeh_edev_dbg(edev, "In power-off state, power it on ...\n");
661 val &= ~(PCI_EXP_SLTCTL_PCC | PCI_EXP_SLTCTL_PIC);
662 val |= (0x0100 & PCI_EXP_SLTCTL_PIC);
663 eeh_ops->write_config(edev, cap + PCI_EXP_SLTCTL, 2, val);
664 msleep(2 * 1000);
665 }
666 }
667
668 /* Enable link */
669 eeh_ops->read_config(edev, cap + PCI_EXP_LNKCTL, 2, &val);
670 val &= ~PCI_EXP_LNKCTL_LD;
671 eeh_ops->write_config(edev, cap + PCI_EXP_LNKCTL, 2, val);
672
673 /* Check link */
674 if (!edev->pdev->link_active_reporting) {
675 eeh_edev_dbg(edev, "No link reporting capability\n");
676 msleep(1000);
677 return;
678 }
679
680 /* Wait the link is up until timeout (5s) */
681 timeout = 0;
682 while (timeout < 5000) {
683 msleep(20);
684 timeout += 20;
685
686 eeh_ops->read_config(edev, cap + PCI_EXP_LNKSTA, 2, &val);
687 if (val & PCI_EXP_LNKSTA_DLLLA)
688 break;
689 }
690
691 if (val & PCI_EXP_LNKSTA_DLLLA)
692 eeh_edev_dbg(edev, "Link up (%s)\n",
693 (val & PCI_EXP_LNKSTA_CLS_2_5GB) ? "2.5GB" : "5GB");
694 else
695 eeh_edev_dbg(edev, "Link not ready (0x%04x)\n", val);
696}
697
698#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
699#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
700
701static void eeh_restore_bridge_bars(struct eeh_dev *edev)
702{
703 int i;
704
705 /*
706 * Device BARs: 0x10 - 0x18
707 * Bus numbers and windows: 0x18 - 0x30
708 */
709 for (i = 4; i < 13; i++)
710 eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]);
711 /* Rom: 0x38 */
712 eeh_ops->write_config(edev, 14*4, 4, edev->config_space[14]);
713
714 /* Cache line & Latency timer: 0xC 0xD */
715 eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1,
716 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
717 eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1,
718 SAVED_BYTE(PCI_LATENCY_TIMER));
719 /* Max latency, min grant, interrupt ping and line: 0x3C */
720 eeh_ops->write_config(edev, 15*4, 4, edev->config_space[15]);
721
722 /* PCI Command: 0x4 */
723 eeh_ops->write_config(edev, PCI_COMMAND, 4, edev->config_space[1] |
724 PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
725
726 /* Check the PCIe link is ready */
727 eeh_bridge_check_link(edev);
728}
729
730static void eeh_restore_device_bars(struct eeh_dev *edev)
731{
732 int i;
733 u32 cmd;
734
735 for (i = 4; i < 10; i++)
736 eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]);
737 /* 12 == Expansion ROM Address */
738 eeh_ops->write_config(edev, 12*4, 4, edev->config_space[12]);
739
740 eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1,
741 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
742 eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1,
743 SAVED_BYTE(PCI_LATENCY_TIMER));
744
745 /* max latency, min grant, interrupt pin and line */
746 eeh_ops->write_config(edev, 15*4, 4, edev->config_space[15]);
747
748 /*
749 * Restore PERR & SERR bits, some devices require it,
750 * don't touch the other command bits
751 */
752 eeh_ops->read_config(edev, PCI_COMMAND, 4, &cmd);
753 if (edev->config_space[1] & PCI_COMMAND_PARITY)
754 cmd |= PCI_COMMAND_PARITY;
755 else
756 cmd &= ~PCI_COMMAND_PARITY;
757 if (edev->config_space[1] & PCI_COMMAND_SERR)
758 cmd |= PCI_COMMAND_SERR;
759 else
760 cmd &= ~PCI_COMMAND_SERR;
761 eeh_ops->write_config(edev, PCI_COMMAND, 4, cmd);
762}
763
764/**
765 * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
766 * @data: EEH device
767 * @flag: Unused
768 *
769 * Loads the PCI configuration space base address registers,
770 * the expansion ROM base address, the latency timer, and etc.
771 * from the saved values in the device node.
772 */
773static void eeh_restore_one_device_bars(struct eeh_dev *edev, void *flag)
774{
775 /* Do special restore for bridges */
776 if (edev->mode & EEH_DEV_BRIDGE)
777 eeh_restore_bridge_bars(edev);
778 else
779 eeh_restore_device_bars(edev);
780
781 if (eeh_ops->restore_config)
782 eeh_ops->restore_config(edev);
783}
784
785/**
786 * eeh_pe_restore_bars - Restore the PCI config space info
787 * @pe: EEH PE
788 *
789 * This routine performs a recursive walk to the children
790 * of this device as well.
791 */
792void eeh_pe_restore_bars(struct eeh_pe *pe)
793{
794 /*
795 * We needn't take the EEH lock since eeh_pe_dev_traverse()
796 * will take that.
797 */
798 eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
799}
800
801/**
802 * eeh_pe_loc_get - Retrieve location code binding to the given PE
803 * @pe: EEH PE
804 *
805 * Retrieve the location code of the given PE. If the primary PE bus
806 * is root bus, we will grab location code from PHB device tree node
807 * or root port. Otherwise, the upstream bridge's device tree node
808 * of the primary PE bus will be checked for the location code.
809 */
810const char *eeh_pe_loc_get(struct eeh_pe *pe)
811{
812 struct pci_bus *bus = eeh_pe_bus_get(pe);
813 struct device_node *dn;
814 const char *loc = NULL;
815
816 while (bus) {
817 dn = pci_bus_to_OF_node(bus);
818 if (!dn) {
819 bus = bus->parent;
820 continue;
821 }
822
823 if (pci_is_root_bus(bus))
824 loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
825 else
826 loc = of_get_property(dn, "ibm,slot-location-code",
827 NULL);
828
829 if (loc)
830 return loc;
831
832 bus = bus->parent;
833 }
834
835 return "N/A";
836}
837
838/**
839 * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
840 * @pe: EEH PE
841 *
842 * Retrieve the PCI bus according to the given PE. Basically,
843 * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
844 * primary PCI bus will be retrieved. The parent bus will be
845 * returned for BUS PE. However, we don't have associated PCI
846 * bus for DEVICE PE.
847 */
848struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
849{
850 struct eeh_dev *edev;
851 struct pci_dev *pdev;
852
853 if (pe->type & EEH_PE_PHB)
854 return pe->phb->bus;
855
856 /* The primary bus might be cached during probe time */
857 if (pe->state & EEH_PE_PRI_BUS)
858 return pe->bus;
859
860 /* Retrieve the parent PCI bus of first (top) PCI device */
861 edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry);
862 pdev = eeh_dev_to_pci_dev(edev);
863 if (pdev)
864 return pdev->bus;
865
866 return NULL;
867}