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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 eeh_ops->read_config(edev, cap + PCI_EXP_LNKCAP, 4, &val);
675 if (!(val & PCI_EXP_LNKCAP_DLLLARC)) {
676 eeh_edev_dbg(edev, "No link reporting capability (0x%08x) \n", val);
677 msleep(1000);
678 return;
679 }
680
681 /* Wait the link is up until timeout (5s) */
682 timeout = 0;
683 while (timeout < 5000) {
684 msleep(20);
685 timeout += 20;
686
687 eeh_ops->read_config(edev, cap + PCI_EXP_LNKSTA, 2, &val);
688 if (val & PCI_EXP_LNKSTA_DLLLA)
689 break;
690 }
691
692 if (val & PCI_EXP_LNKSTA_DLLLA)
693 eeh_edev_dbg(edev, "Link up (%s)\n",
694 (val & PCI_EXP_LNKSTA_CLS_2_5GB) ? "2.5GB" : "5GB");
695 else
696 eeh_edev_dbg(edev, "Link not ready (0x%04x)\n", val);
697}
698
699#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
700#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
701
702static void eeh_restore_bridge_bars(struct eeh_dev *edev)
703{
704 int i;
705
706 /*
707 * Device BARs: 0x10 - 0x18
708 * Bus numbers and windows: 0x18 - 0x30
709 */
710 for (i = 4; i < 13; i++)
711 eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]);
712 /* Rom: 0x38 */
713 eeh_ops->write_config(edev, 14*4, 4, edev->config_space[14]);
714
715 /* Cache line & Latency timer: 0xC 0xD */
716 eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1,
717 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
718 eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1,
719 SAVED_BYTE(PCI_LATENCY_TIMER));
720 /* Max latency, min grant, interrupt ping and line: 0x3C */
721 eeh_ops->write_config(edev, 15*4, 4, edev->config_space[15]);
722
723 /* PCI Command: 0x4 */
724 eeh_ops->write_config(edev, PCI_COMMAND, 4, edev->config_space[1] |
725 PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
726
727 /* Check the PCIe link is ready */
728 eeh_bridge_check_link(edev);
729}
730
731static void eeh_restore_device_bars(struct eeh_dev *edev)
732{
733 int i;
734 u32 cmd;
735
736 for (i = 4; i < 10; i++)
737 eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]);
738 /* 12 == Expansion ROM Address */
739 eeh_ops->write_config(edev, 12*4, 4, edev->config_space[12]);
740
741 eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1,
742 SAVED_BYTE(PCI_CACHE_LINE_SIZE));
743 eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1,
744 SAVED_BYTE(PCI_LATENCY_TIMER));
745
746 /* max latency, min grant, interrupt pin and line */
747 eeh_ops->write_config(edev, 15*4, 4, edev->config_space[15]);
748
749 /*
750 * Restore PERR & SERR bits, some devices require it,
751 * don't touch the other command bits
752 */
753 eeh_ops->read_config(edev, PCI_COMMAND, 4, &cmd);
754 if (edev->config_space[1] & PCI_COMMAND_PARITY)
755 cmd |= PCI_COMMAND_PARITY;
756 else
757 cmd &= ~PCI_COMMAND_PARITY;
758 if (edev->config_space[1] & PCI_COMMAND_SERR)
759 cmd |= PCI_COMMAND_SERR;
760 else
761 cmd &= ~PCI_COMMAND_SERR;
762 eeh_ops->write_config(edev, PCI_COMMAND, 4, cmd);
763}
764
765/**
766 * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
767 * @data: EEH device
768 * @flag: Unused
769 *
770 * Loads the PCI configuration space base address registers,
771 * the expansion ROM base address, the latency timer, and etc.
772 * from the saved values in the device node.
773 */
774static void eeh_restore_one_device_bars(struct eeh_dev *edev, void *flag)
775{
776 /* Do special restore for bridges */
777 if (edev->mode & EEH_DEV_BRIDGE)
778 eeh_restore_bridge_bars(edev);
779 else
780 eeh_restore_device_bars(edev);
781
782 if (eeh_ops->restore_config)
783 eeh_ops->restore_config(edev);
784}
785
786/**
787 * eeh_pe_restore_bars - Restore the PCI config space info
788 * @pe: EEH PE
789 *
790 * This routine performs a recursive walk to the children
791 * of this device as well.
792 */
793void eeh_pe_restore_bars(struct eeh_pe *pe)
794{
795 /*
796 * We needn't take the EEH lock since eeh_pe_dev_traverse()
797 * will take that.
798 */
799 eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
800}
801
802/**
803 * eeh_pe_loc_get - Retrieve location code binding to the given PE
804 * @pe: EEH PE
805 *
806 * Retrieve the location code of the given PE. If the primary PE bus
807 * is root bus, we will grab location code from PHB device tree node
808 * or root port. Otherwise, the upstream bridge's device tree node
809 * of the primary PE bus will be checked for the location code.
810 */
811const char *eeh_pe_loc_get(struct eeh_pe *pe)
812{
813 struct pci_bus *bus = eeh_pe_bus_get(pe);
814 struct device_node *dn;
815 const char *loc = NULL;
816
817 while (bus) {
818 dn = pci_bus_to_OF_node(bus);
819 if (!dn) {
820 bus = bus->parent;
821 continue;
822 }
823
824 if (pci_is_root_bus(bus))
825 loc = of_get_property(dn, "ibm,io-base-loc-code", NULL);
826 else
827 loc = of_get_property(dn, "ibm,slot-location-code",
828 NULL);
829
830 if (loc)
831 return loc;
832
833 bus = bus->parent;
834 }
835
836 return "N/A";
837}
838
839/**
840 * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
841 * @pe: EEH PE
842 *
843 * Retrieve the PCI bus according to the given PE. Basically,
844 * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
845 * primary PCI bus will be retrieved. The parent bus will be
846 * returned for BUS PE. However, we don't have associated PCI
847 * bus for DEVICE PE.
848 */
849struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
850{
851 struct eeh_dev *edev;
852 struct pci_dev *pdev;
853
854 if (pe->type & EEH_PE_PHB)
855 return pe->phb->bus;
856
857 /* The primary bus might be cached during probe time */
858 if (pe->state & EEH_PE_PRI_BUS)
859 return pe->bus;
860
861 /* Retrieve the parent PCI bus of first (top) PCI device */
862 edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry);
863 pdev = eeh_dev_to_pci_dev(edev);
864 if (pdev)
865 return pdev->bus;
866
867 return NULL;
868}
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
22static int eeh_pe_aux_size = 0;
23static 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 */
31void 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 */
46static 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 */
79int 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 */
106int 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 */
157struct 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 */
182struct 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 */
211void *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 */
234void 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 */
262struct eeh_pe_get_flag {
263 int pe_no;
264 int config_addr;
265};
266
267static 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 */
309struct 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 */
329static 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 */
367int 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 */
470int 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 */
557void 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 */
583void 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}
591EXPORT_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 */
601void 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}
619EXPORT_SYMBOL_GPL(eeh_pe_mark_isolated);
620
621static 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 */
634void 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 */
649void 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 */
699static 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
770static 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
800static 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 */
844static 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 */
865void 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 */
883const 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 */
921struct 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}