aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/pseries/eeh_pe.c
blob: 9d4a9e8562b2229a7791bb8b069dc13c9c2c9a73 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
/*
 * The file intends to implement PE based on the information from
 * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device.
 * All the PEs should be organized as hierarchy tree. The first level
 * of the tree will be associated to existing PHBs since the particular
 * PE is only meaningful in one PHB domain.
 *
 * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>

#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>

static LIST_HEAD(eeh_phb_pe);

/**
 * eeh_pe_alloc - Allocate PE
 * @phb: PCI controller
 * @type: PE type
 *
 * Allocate PE instance dynamically.
 */
static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
{
	struct eeh_pe *pe;

	/* Allocate PHB PE */
	pe = kzalloc(sizeof(struct eeh_pe), GFP_KERNEL);
	if (!pe) return NULL;

	/* Initialize PHB PE */
	pe->type = type;
	pe->phb = phb;
	INIT_LIST_HEAD(&pe->child_list);
	INIT_LIST_HEAD(&pe->child);
	INIT_LIST_HEAD(&pe->edevs);

	return pe;
}

/**
 * eeh_phb_pe_create - Create PHB PE
 * @phb: PCI controller
 *
 * The function should be called while the PHB is detected during
 * system boot or PCI hotplug in order to create PHB PE.
 */
int eeh_phb_pe_create(struct pci_controller *phb)
{
	struct eeh_pe *pe;

	/* Allocate PHB PE */
	pe = eeh_pe_alloc(phb, EEH_PE_PHB);
	if (!pe) {
		pr_err("%s: out of memory!\n", __func__);
		return -ENOMEM;
	}

	/* Put it into the list */
	eeh_lock();
	list_add_tail(&pe->child, &eeh_phb_pe);
	eeh_unlock();

	pr_debug("EEH: Add PE for PHB#%d\n", phb->global_number);

	return 0;
}

/**
 * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
 * @phb: PCI controller
 *
 * The overall PEs form hierarchy tree. The first layer of the
 * hierarchy tree is composed of PHB PEs. The function is used
 * to retrieve the corresponding PHB PE according to the given PHB.
 */
static struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
{
	struct eeh_pe *pe;

	list_for_each_entry(pe, &eeh_phb_pe, child) {
		/*
		 * Actually, we needn't check the type since
		 * the PE for PHB has been determined when that
		 * was created.
		 */
		if ((pe->type & EEH_PE_PHB) && pe->phb == phb)
			return pe;
	}

	return NULL;
}

/**
 * eeh_pe_next - Retrieve the next PE in the tree
 * @pe: current PE
 * @root: root PE
 *
 * The function is used to retrieve the next PE in the
 * hierarchy PE tree.
 */
static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe,
				  struct eeh_pe *root)
{
	struct list_head *next = pe->child_list.next;

	if (next == &pe->child_list) {
		while (1) {
			if (pe == root)
				return NULL;
			next = pe->child.next;
			if (next != &pe->parent->child_list)
				break;
			pe = pe->parent;
		}
	}

	return list_entry(next, struct eeh_pe, child);
}

/**
 * eeh_pe_traverse - Traverse PEs in the specified PHB
 * @root: root PE
 * @fn: callback
 * @flag: extra parameter to callback
 *
 * The function is used to traverse the specified PE and its
 * child PEs. The traversing is to be terminated once the
 * callback returns something other than NULL, or no more PEs
 * to be traversed.
 */
static void *eeh_pe_traverse(struct eeh_pe *root,
			eeh_traverse_func fn, void *flag)
{
	struct eeh_pe *pe;
	void *ret;

	for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
		ret = fn(pe, flag);
		if (ret) return ret;
	}

	return NULL;
}

/**
 * eeh_pe_dev_traverse - Traverse the devices from the PE
 * @root: EEH PE
 * @fn: function callback
 * @flag: extra parameter to callback
 *
 * The function is used to traverse the devices of the specified
 * PE and its child PEs.
 */
void *eeh_pe_dev_traverse(struct eeh_pe *root,
		eeh_traverse_func fn, void *flag)
{
	struct eeh_pe *pe;
	struct eeh_dev *edev;
	void *ret;

	if (!root) {
		pr_warning("%s: Invalid PE %p\n", __func__, root);
		return NULL;
	}

	eeh_lock();

	/* Traverse root PE */
	for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
		eeh_pe_for_each_dev(pe, edev) {
			ret = fn(edev, flag);
			if (ret) {
				eeh_unlock();
				return ret;
			}
		}
	}

	eeh_unlock();

	return NULL;
}

/**
 * __eeh_pe_get - Check the PE address
 * @data: EEH PE
 * @flag: EEH device
 *
 * For one particular PE, it can be identified by PE address
 * or tranditional BDF address. BDF address is composed of
 * Bus/Device/Function number. The extra data referred by flag
 * indicates which type of address should be used.
 */
static void *__eeh_pe_get(void *data, void *flag)
{
	struct eeh_pe *pe = (struct eeh_pe *)data;
	struct eeh_dev *edev = (struct eeh_dev *)flag;

	/* Unexpected PHB PE */
	if (pe->type & EEH_PE_PHB)
		return NULL;

	/* We prefer PE address */
	if (edev->pe_config_addr &&
	   (edev->pe_config_addr == pe->addr))
		return pe;

	/* Try BDF address */
	if (edev->pe_config_addr &&
	   (edev->config_addr == pe->config_addr))
		return pe;

	return NULL;
}

/**
 * eeh_pe_get - Search PE based on the given address
 * @edev: EEH device
 *
 * Search the corresponding PE based on the specified address which
 * is included in the eeh device. The function is used to check if
 * the associated PE has been created against the PE address. It's
 * notable that the PE address has 2 format: traditional PE address
 * which is composed of PCI bus/device/function number, or unified
 * PE address.
 */
static struct eeh_pe *eeh_pe_get(struct eeh_dev *edev)
{
	struct eeh_pe *root = eeh_phb_pe_get(edev->phb);
	struct eeh_pe *pe;

	pe = eeh_pe_traverse(root, __eeh_pe_get, edev);

	return pe;
}

/**
 * eeh_pe_get_parent - Retrieve the parent PE
 * @edev: EEH device
 *
 * The whole PEs existing in the system are organized as hierarchy
 * tree. The function is used to retrieve the parent PE according
 * to the parent EEH device.
 */
static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
{
	struct device_node *dn;
	struct eeh_dev *parent;

	/*
	 * It might have the case for the indirect parent
	 * EEH device already having associated PE, but
	 * the direct parent EEH device doesn't have yet.
	 */
	dn = edev->dn->parent;
	while (dn) {
		/* We're poking out of PCI territory */
		if (!PCI_DN(dn)) return NULL;

		parent = of_node_to_eeh_dev(dn);
		/* We're poking out of PCI territory */
		if (!parent) return NULL;

		if (parent->pe)
			return parent->pe;

		dn = dn->parent;
	}

	return NULL;
}

/**
 * eeh_add_to_parent_pe - Add EEH device to parent PE
 * @edev: EEH device
 *
 * Add EEH device to the parent PE. If the parent PE already
 * exists, the PE type will be changed to EEH_PE_BUS. Otherwise,
 * we have to create new PE to hold the EEH device and the new
 * PE will be linked to its parent PE as well.
 */
int eeh_add_to_parent_pe(struct eeh_dev *edev)
{
	struct eeh_pe *pe, *parent;

	eeh_lock();

	/*
	 * Search the PE has been existing or not according
	 * to the PE address. If that has been existing, the
	 * PE should be composed of PCI bus and its subordinate
	 * components.
	 */
	pe = eeh_pe_get(edev);
	if (pe && !(pe->type & EEH_PE_INVALID)) {
		if (!edev->pe_config_addr) {
			eeh_unlock();
			pr_err("%s: PE with addr 0x%x already exists\n",
				__func__, edev->config_addr);
			return -EEXIST;
		}

		/* Mark the PE as type of PCI bus */
		pe->type = EEH_PE_BUS;
		edev->pe = pe;

		/* Put the edev to PE */
		list_add_tail(&edev->list, &pe->edevs);
		eeh_unlock();
		pr_debug("EEH: Add %s to Bus PE#%x\n",
			edev->dn->full_name, pe->addr);

		return 0;
	} else if (pe && (pe->type & EEH_PE_INVALID)) {
		list_add_tail(&edev->list, &pe->edevs);
		edev->pe = pe;
		/*
		 * We're running to here because of PCI hotplug caused by
		 * EEH recovery. We need clear EEH_PE_INVALID until the top.
		 */
		parent = pe;
		while (parent) {
			if (!(parent->type & EEH_PE_INVALID))
				break;
			parent->type &= ~EEH_PE_INVALID;
			parent = parent->parent;
		}
		eeh_unlock();
		pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n",
			edev->dn->full_name, pe->addr, pe->parent->addr);

		return 0;
	}

	/* Create a new EEH PE */
	pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE);
	if (!pe) {
		eeh_unlock();
		pr_err("%s: out of memory!\n", __func__);
		return -ENOMEM;
	}
	pe->addr	= edev->pe_config_addr;
	pe->config_addr	= edev->config_addr;

	/*
	 * Put the new EEH PE into hierarchy tree. If the parent
	 * can't be found, the newly created PE will be attached
	 * to PHB directly. Otherwise, we have to associate the
	 * PE with its parent.
	 */
	parent = eeh_pe_get_parent(edev);
	if (!parent) {
		parent = eeh_phb_pe_get(edev->phb);
		if (!parent) {
			eeh_unlock();
			pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
				__func__, edev->phb->global_number);
			edev->pe = NULL;
			kfree(pe);
			return -EEXIST;
		}
	}
	pe->parent = parent;

	/*
	 * Put the newly created PE into the child list and
	 * link the EEH device accordingly.
	 */
	list_add_tail(&pe->child, &parent->child_list);
	list_add_tail(&edev->list, &pe->edevs);
	edev->pe = pe;
	eeh_unlock();
	pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n",
		edev->dn->full_name, pe->addr, pe->parent->addr);

	return 0;
}

/**
 * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE
 * @edev: EEH device
 * @purge_pe: remove PE or not
 *
 * The PE hierarchy tree might be changed when doing PCI hotplug.
 * Also, the PCI devices or buses could be removed from the system
 * during EEH recovery. So we have to call the function remove the
 * corresponding PE accordingly if necessary.
 */
int eeh_rmv_from_parent_pe(struct eeh_dev *edev, int purge_pe)
{
	struct eeh_pe *pe, *parent, *child;
	int cnt;

	if (!edev->pe) {
		pr_warning("%s: No PE found for EEH device %s\n",
			__func__, edev->dn->full_name);
		return -EEXIST;
	}

	eeh_lock();

	/* Remove the EEH device */
	pe = edev->pe;
	edev->pe = NULL;
	list_del(&edev->list);

	/*
	 * Check if the parent PE includes any EEH devices.
	 * If not, we should delete that. Also, we should
	 * delete the parent PE if it doesn't have associated
	 * child PEs and EEH devices.
	 */
	while (1) {
		parent = pe->parent;
		if (pe->type & EEH_PE_PHB)
			break;

		if (purge_pe) {
			if (list_empty(&pe->edevs) &&
			    list_empty(&pe->child_list)) {
				list_del(&pe->child);
				kfree(pe);
			} else {
				break;
			}
		} else {
			if (list_empty(&pe->edevs)) {
				cnt = 0;
				list_for_each_entry(child, &pe->child_list, child) {
					if (!(child->type & EEH_PE_INVALID)) {
						cnt++;
						break;
					}
				}

				if (!cnt)
					pe->type |= EEH_PE_INVALID;
				else
					break;
			}
		}

		pe = parent;
	}

	eeh_unlock();

	return 0;
}

/**
 * __eeh_pe_state_mark - Mark the state for the PE
 * @data: EEH PE
 * @flag: state
 *
 * The function is used to mark the indicated state for the given
 * PE. Also, the associated PCI devices will be put into IO frozen
 * state as well.
 */
static void *__eeh_pe_state_mark(void *data, void *flag)
{
	struct eeh_pe *pe = (struct eeh_pe *)data;
	int state = *((int *)flag);
	struct eeh_dev *tmp;
	struct pci_dev *pdev;

	/*
	 * Mark the PE with the indicated state. Also,
	 * the associated PCI device will be put into
	 * I/O frozen state to avoid I/O accesses from
	 * the PCI device driver.
	 */
	pe->state |= state;
	eeh_pe_for_each_dev(pe, tmp) {
		pdev = eeh_dev_to_pci_dev(tmp);
		if (pdev)
			pdev->error_state = pci_channel_io_frozen;
	}

	return NULL;
}

/**
 * eeh_pe_state_mark - Mark specified state for PE and its associated device
 * @pe: EEH PE
 *
 * EEH error affects the current PE and its child PEs. The function
 * is used to mark appropriate state for the affected PEs and the
 * associated devices.
 */
void eeh_pe_state_mark(struct eeh_pe *pe, int state)
{
	eeh_lock();
	eeh_pe_traverse(pe, __eeh_pe_state_mark, &state);
	eeh_unlock();
}

/**
 * __eeh_pe_state_clear - Clear state for the PE
 * @data: EEH PE
 * @flag: state
 *
 * The function is used to clear the indicated state from the
 * given PE. Besides, we also clear the check count of the PE
 * as well.
 */
static void *__eeh_pe_state_clear(void *data, void *flag)
{
	struct eeh_pe *pe = (struct eeh_pe *)data;
	int state = *((int *)flag);

	pe->state &= ~state;
	pe->check_count = 0;

	return NULL;
}

/**
 * eeh_pe_state_clear - Clear state for the PE and its children
 * @pe: PE
 * @state: state to be cleared
 *
 * When the PE and its children has been recovered from error,
 * we need clear the error state for that. The function is used
 * for the purpose.
 */
void eeh_pe_state_clear(struct eeh_pe *pe, int state)
{
	eeh_lock();
	eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
	eeh_unlock();
}

/**
 * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
 * @data: EEH device
 * @flag: Unused
 *
 * Loads the PCI configuration space base address registers,
 * the expansion ROM base address, the latency timer, and etc.
 * from the saved values in the device node.
 */
static void *eeh_restore_one_device_bars(void *data, void *flag)
{
	int i;
	u32 cmd;
	struct eeh_dev *edev = (struct eeh_dev *)data;
	struct device_node *dn = eeh_dev_to_of_node(edev);

	for (i = 4; i < 10; i++)
		eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]);
	/* 12 == Expansion ROM Address */
	eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]);

#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])

	eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1,
		SAVED_BYTE(PCI_CACHE_LINE_SIZE));
	eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1,
		SAVED_BYTE(PCI_LATENCY_TIMER));

	/* max latency, min grant, interrupt pin and line */
	eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]);

	/*
	 * Restore PERR & SERR bits, some devices require it,
	 * don't touch the other command bits
	 */
	eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd);
	if (edev->config_space[1] & PCI_COMMAND_PARITY)
		cmd |= PCI_COMMAND_PARITY;
	else
		cmd &= ~PCI_COMMAND_PARITY;
	if (edev->config_space[1] & PCI_COMMAND_SERR)
		cmd |= PCI_COMMAND_SERR;
	else
		cmd &= ~PCI_COMMAND_SERR;
	eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd);

	return NULL;
}

/**
 * eeh_pe_restore_bars - Restore the PCI config space info
 * @pe: EEH PE
 *
 * This routine performs a recursive walk to the children
 * of this device as well.
 */
void eeh_pe_restore_bars(struct eeh_pe *pe)
{
	/*
	 * We needn't take the EEH lock since eeh_pe_dev_traverse()
	 * will take that.
	 */
	eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
}

/**
 * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
 * @pe: EEH PE
 *
 * Retrieve the PCI bus according to the given PE. Basically,
 * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
 * primary PCI bus will be retrieved. The parent bus will be
 * returned for BUS PE. However, we don't have associated PCI
 * bus for DEVICE PE.
 */
struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
{
	struct pci_bus *bus = NULL;
	struct eeh_dev *edev;
	struct pci_dev *pdev;

	eeh_lock();

	if (pe->type & EEH_PE_PHB) {
		bus = pe->phb->bus;
	} else if (pe->type & EEH_PE_BUS ||
		   pe->type & EEH_PE_DEVICE) {
		edev = list_first_entry(&pe->edevs, struct eeh_dev, list);
		pdev = eeh_dev_to_pci_dev(edev);
		if (pdev)
			bus = pdev->bus;
	}

	eeh_unlock();

	return bus;
}