summaryrefslogtreecommitdiff
path: root/drivers/pci/pci-acpi.c
blob: 260a06fb78a6132b27ba839b082625e4c2e44e9f (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
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
// SPDX-License-Identifier: GPL-2.0
/*
 * PCI support in ACPI
 *
 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
 * Copyright (C) 2004 Intel Corp.
 */

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irqdomain.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/pci_hotplug.h>
#include <linux/module.h>
#include <linux/pci-acpi.h>
#include <linux/pm_runtime.h>
#include <linux/pm_qos.h>
#include <linux/rwsem.h>
#include "pci.h"

/*
 * The GUID is defined in the PCI Firmware Specification available here:
 * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
 */
const guid_t pci_acpi_dsm_guid =
	GUID_INIT(0xe5c937d0, 0x3553, 0x4d7a,
		  0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d);

#if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
static int acpi_get_rc_addr(struct acpi_device *adev, struct resource *res)
{
	struct device *dev = &adev->dev;
	struct resource_entry *entry;
	struct list_head list;
	unsigned long flags;
	int ret;

	INIT_LIST_HEAD(&list);
	flags = IORESOURCE_MEM;
	ret = acpi_dev_get_resources(adev, &list,
				     acpi_dev_filter_resource_type_cb,
				     (void *) flags);
	if (ret < 0) {
		dev_err(dev, "failed to parse _CRS method, error code %d\n",
			ret);
		return ret;
	}

	if (ret == 0) {
		dev_err(dev, "no IO and memory resources present in _CRS\n");
		return -EINVAL;
	}

	entry = list_first_entry(&list, struct resource_entry, node);
	*res = *entry->res;
	acpi_dev_free_resource_list(&list);
	return 0;
}

static acpi_status acpi_match_rc(acpi_handle handle, u32 lvl, void *context,
				 void **retval)
{
	u16 *segment = context;
	unsigned long long uid;
	acpi_status status;

	status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
	if (ACPI_FAILURE(status) || uid != *segment)
		return AE_CTRL_DEPTH;

	*(acpi_handle *)retval = handle;
	return AE_CTRL_TERMINATE;
}

int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
			  struct resource *res)
{
	struct acpi_device *adev;
	acpi_status status;
	acpi_handle handle;
	int ret;

	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
	if (ACPI_FAILURE(status)) {
		dev_err(dev, "can't find _HID %s device to locate resources\n",
			hid);
		return -ENODEV;
	}

	ret = acpi_bus_get_device(handle, &adev);
	if (ret)
		return ret;

	ret = acpi_get_rc_addr(adev, res);
	if (ret) {
		dev_err(dev, "can't get resource from %s\n",
			dev_name(&adev->dev));
		return ret;
	}

	return 0;
}
#endif

phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
{
	acpi_status status = AE_NOT_EXIST;
	unsigned long long mcfg_addr;

	if (handle)
		status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
					       NULL, &mcfg_addr);
	if (ACPI_FAILURE(status))
		return 0;

	return (phys_addr_t)mcfg_addr;
}

/* _HPX PCI Setting Record (Type 0); same as _HPP */
struct hpx_type0 {
	u32 revision;		/* Not present in _HPP */
	u8  cache_line_size;	/* Not applicable to PCIe */
	u8  latency_timer;	/* Not applicable to PCIe */
	u8  enable_serr;
	u8  enable_perr;
};

static struct hpx_type0 pci_default_type0 = {
	.revision = 1,
	.cache_line_size = 8,
	.latency_timer = 0x40,
	.enable_serr = 0,
	.enable_perr = 0,
};

static void program_hpx_type0(struct pci_dev *dev, struct hpx_type0 *hpx)
{
	u16 pci_cmd, pci_bctl;

	if (!hpx)
		hpx = &pci_default_type0;

	if (hpx->revision > 1) {
		pci_warn(dev, "PCI settings rev %d not supported; using defaults\n",
			 hpx->revision);
		hpx = &pci_default_type0;
	}

	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, hpx->cache_line_size);
	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpx->latency_timer);
	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
	if (hpx->enable_serr)
		pci_cmd |= PCI_COMMAND_SERR;
	if (hpx->enable_perr)
		pci_cmd |= PCI_COMMAND_PARITY;
	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);

	/* Program bridge control value */
	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
				      hpx->latency_timer);
		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
		if (hpx->enable_perr)
			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
	}
}

static acpi_status decode_type0_hpx_record(union acpi_object *record,
					   struct hpx_type0 *hpx0)
{
	int i;
	union acpi_object *fields = record->package.elements;
	u32 revision = fields[1].integer.value;

	switch (revision) {
	case 1:
		if (record->package.count != 6)
			return AE_ERROR;
		for (i = 2; i < 6; i++)
			if (fields[i].type != ACPI_TYPE_INTEGER)
				return AE_ERROR;
		hpx0->revision        = revision;
		hpx0->cache_line_size = fields[2].integer.value;
		hpx0->latency_timer   = fields[3].integer.value;
		hpx0->enable_serr     = fields[4].integer.value;
		hpx0->enable_perr     = fields[5].integer.value;
		break;
	default:
		pr_warn("%s: Type 0 Revision %d record not supported\n",
		       __func__, revision);
		return AE_ERROR;
	}
	return AE_OK;
}

/* _HPX PCI-X Setting Record (Type 1) */
struct hpx_type1 {
	u32 revision;
	u8  max_mem_read;
	u8  avg_max_split;
	u16 tot_max_split;
};

static void program_hpx_type1(struct pci_dev *dev, struct hpx_type1 *hpx)
{
	int pos;

	if (!hpx)
		return;

	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
	if (!pos)
		return;

	pci_warn(dev, "PCI-X settings not supported\n");
}

static acpi_status decode_type1_hpx_record(union acpi_object *record,
					   struct hpx_type1 *hpx1)
{
	int i;
	union acpi_object *fields = record->package.elements;
	u32 revision = fields[1].integer.value;

	switch (revision) {
	case 1:
		if (record->package.count != 5)
			return AE_ERROR;
		for (i = 2; i < 5; i++)
			if (fields[i].type != ACPI_TYPE_INTEGER)
				return AE_ERROR;
		hpx1->revision      = revision;
		hpx1->max_mem_read  = fields[2].integer.value;
		hpx1->avg_max_split = fields[3].integer.value;
		hpx1->tot_max_split = fields[4].integer.value;
		break;
	default:
		pr_warn("%s: Type 1 Revision %d record not supported\n",
		       __func__, revision);
		return AE_ERROR;
	}
	return AE_OK;
}

static bool pcie_root_rcb_set(struct pci_dev *dev)
{
	struct pci_dev *rp = pcie_find_root_port(dev);
	u16 lnkctl;

	if (!rp)
		return false;

	pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl);
	if (lnkctl & PCI_EXP_LNKCTL_RCB)
		return true;

	return false;
}

/* _HPX PCI Express Setting Record (Type 2) */
struct hpx_type2 {
	u32 revision;
	u32 unc_err_mask_and;
	u32 unc_err_mask_or;
	u32 unc_err_sever_and;
	u32 unc_err_sever_or;
	u32 cor_err_mask_and;
	u32 cor_err_mask_or;
	u32 adv_err_cap_and;
	u32 adv_err_cap_or;
	u16 pci_exp_devctl_and;
	u16 pci_exp_devctl_or;
	u16 pci_exp_lnkctl_and;
	u16 pci_exp_lnkctl_or;
	u32 sec_unc_err_sever_and;
	u32 sec_unc_err_sever_or;
	u32 sec_unc_err_mask_and;
	u32 sec_unc_err_mask_or;
};

static void program_hpx_type2(struct pci_dev *dev, struct hpx_type2 *hpx)
{
	int pos;
	u32 reg32;

	if (!hpx)
		return;

	if (!pci_is_pcie(dev))
		return;

	if (hpx->revision > 1) {
		pci_warn(dev, "PCIe settings rev %d not supported\n",
			 hpx->revision);
		return;
	}

	/*
	 * Don't allow _HPX to change MPS or MRRS settings.  We manage
	 * those to make sure they're consistent with the rest of the
	 * platform.
	 */
	hpx->pci_exp_devctl_and |= PCI_EXP_DEVCTL_PAYLOAD |
				    PCI_EXP_DEVCTL_READRQ;
	hpx->pci_exp_devctl_or &= ~(PCI_EXP_DEVCTL_PAYLOAD |
				    PCI_EXP_DEVCTL_READRQ);

	/* Initialize Device Control Register */
	pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
			~hpx->pci_exp_devctl_and, hpx->pci_exp_devctl_or);

	/* Initialize Link Control Register */
	if (pcie_cap_has_lnkctl(dev)) {

		/*
		 * If the Root Port supports Read Completion Boundary of
		 * 128, set RCB to 128.  Otherwise, clear it.
		 */
		hpx->pci_exp_lnkctl_and |= PCI_EXP_LNKCTL_RCB;
		hpx->pci_exp_lnkctl_or &= ~PCI_EXP_LNKCTL_RCB;
		if (pcie_root_rcb_set(dev))
			hpx->pci_exp_lnkctl_or |= PCI_EXP_LNKCTL_RCB;

		pcie_capability_clear_and_set_word(dev, PCI_EXP_LNKCTL,
			~hpx->pci_exp_lnkctl_and, hpx->pci_exp_lnkctl_or);
	}

	/* Find Advanced Error Reporting Enhanced Capability */
	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
	if (!pos)
		return;

	/* Initialize Uncorrectable Error Mask Register */
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &reg32);
	reg32 = (reg32 & hpx->unc_err_mask_and) | hpx->unc_err_mask_or;
	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, reg32);

	/* Initialize Uncorrectable Error Severity Register */
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &reg32);
	reg32 = (reg32 & hpx->unc_err_sever_and) | hpx->unc_err_sever_or;
	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, reg32);

	/* Initialize Correctable Error Mask Register */
	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg32);
	reg32 = (reg32 & hpx->cor_err_mask_and) | hpx->cor_err_mask_or;
	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg32);

	/* Initialize Advanced Error Capabilities and Control Register */
	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
	reg32 = (reg32 & hpx->adv_err_cap_and) | hpx->adv_err_cap_or;

	/* Don't enable ECRC generation or checking if unsupported */
	if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
	if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);

	/*
	 * FIXME: The following two registers are not supported yet.
	 *
	 *   o Secondary Uncorrectable Error Severity Register
	 *   o Secondary Uncorrectable Error Mask Register
	 */
}

static acpi_status decode_type2_hpx_record(union acpi_object *record,
					   struct hpx_type2 *hpx2)
{
	int i;
	union acpi_object *fields = record->package.elements;
	u32 revision = fields[1].integer.value;

	switch (revision) {
	case 1:
		if (record->package.count != 18)
			return AE_ERROR;
		for (i = 2; i < 18; i++)
			if (fields[i].type != ACPI_TYPE_INTEGER)
				return AE_ERROR;
		hpx2->revision      = revision;
		hpx2->unc_err_mask_and      = fields[2].integer.value;
		hpx2->unc_err_mask_or       = fields[3].integer.value;
		hpx2->unc_err_sever_and     = fields[4].integer.value;
		hpx2->unc_err_sever_or      = fields[5].integer.value;
		hpx2->cor_err_mask_and      = fields[6].integer.value;
		hpx2->cor_err_mask_or       = fields[7].integer.value;
		hpx2->adv_err_cap_and       = fields[8].integer.value;
		hpx2->adv_err_cap_or        = fields[9].integer.value;
		hpx2->pci_exp_devctl_and    = fields[10].integer.value;
		hpx2->pci_exp_devctl_or     = fields[11].integer.value;
		hpx2->pci_exp_lnkctl_and    = fields[12].integer.value;
		hpx2->pci_exp_lnkctl_or     = fields[13].integer.value;
		hpx2->sec_unc_err_sever_and = fields[14].integer.value;
		hpx2->sec_unc_err_sever_or  = fields[15].integer.value;
		hpx2->sec_unc_err_mask_and  = fields[16].integer.value;
		hpx2->sec_unc_err_mask_or   = fields[17].integer.value;
		break;
	default:
		pr_warn("%s: Type 2 Revision %d record not supported\n",
		       __func__, revision);
		return AE_ERROR;
	}
	return AE_OK;
}

/* _HPX PCI Express Setting Record (Type 3) */
struct hpx_type3 {
	u16 device_type;
	u16 function_type;
	u16 config_space_location;
	u16 pci_exp_cap_id;
	u16 pci_exp_cap_ver;
	u16 pci_exp_vendor_id;
	u16 dvsec_id;
	u16 dvsec_rev;
	u16 match_offset;
	u32 match_mask_and;
	u32 match_value;
	u16 reg_offset;
	u32 reg_mask_and;
	u32 reg_mask_or;
};

enum hpx_type3_dev_type {
	HPX_TYPE_ENDPOINT	= BIT(0),
	HPX_TYPE_LEG_END	= BIT(1),
	HPX_TYPE_RC_END		= BIT(2),
	HPX_TYPE_RC_EC		= BIT(3),
	HPX_TYPE_ROOT_PORT	= BIT(4),
	HPX_TYPE_UPSTREAM	= BIT(5),
	HPX_TYPE_DOWNSTREAM	= BIT(6),
	HPX_TYPE_PCI_BRIDGE	= BIT(7),
	HPX_TYPE_PCIE_BRIDGE	= BIT(8),
};

static u16 hpx3_device_type(struct pci_dev *dev)
{
	u16 pcie_type = pci_pcie_type(dev);
	static const int pcie_to_hpx3_type[] = {
		[PCI_EXP_TYPE_ENDPOINT]    = HPX_TYPE_ENDPOINT,
		[PCI_EXP_TYPE_LEG_END]     = HPX_TYPE_LEG_END,
		[PCI_EXP_TYPE_RC_END]      = HPX_TYPE_RC_END,
		[PCI_EXP_TYPE_RC_EC]       = HPX_TYPE_RC_EC,
		[PCI_EXP_TYPE_ROOT_PORT]   = HPX_TYPE_ROOT_PORT,
		[PCI_EXP_TYPE_UPSTREAM]    = HPX_TYPE_UPSTREAM,
		[PCI_EXP_TYPE_DOWNSTREAM]  = HPX_TYPE_DOWNSTREAM,
		[PCI_EXP_TYPE_PCI_BRIDGE]  = HPX_TYPE_PCI_BRIDGE,
		[PCI_EXP_TYPE_PCIE_BRIDGE] = HPX_TYPE_PCIE_BRIDGE,
	};

	if (pcie_type >= ARRAY_SIZE(pcie_to_hpx3_type))
		return 0;

	return pcie_to_hpx3_type[pcie_type];
}

enum hpx_type3_fn_type {
	HPX_FN_NORMAL		= BIT(0),
	HPX_FN_SRIOV_PHYS	= BIT(1),
	HPX_FN_SRIOV_VIRT	= BIT(2),
};

static u8 hpx3_function_type(struct pci_dev *dev)
{
	if (dev->is_virtfn)
		return HPX_FN_SRIOV_VIRT;
	else if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV) > 0)
		return HPX_FN_SRIOV_PHYS;
	else
		return HPX_FN_NORMAL;
}

static bool hpx3_cap_ver_matches(u8 pcie_cap_id, u8 hpx3_cap_id)
{
	u8 cap_ver = hpx3_cap_id & 0xf;

	if ((hpx3_cap_id & BIT(4)) && cap_ver >= pcie_cap_id)
		return true;
	else if (cap_ver == pcie_cap_id)
		return true;

	return false;
}

enum hpx_type3_cfg_loc {
	HPX_CFG_PCICFG		= 0,
	HPX_CFG_PCIE_CAP	= 1,
	HPX_CFG_PCIE_CAP_EXT	= 2,
	HPX_CFG_VEND_CAP	= 3,
	HPX_CFG_DVSEC		= 4,
	HPX_CFG_MAX,
};

static void program_hpx_type3_register(struct pci_dev *dev,
				       const struct hpx_type3 *reg)
{
	u32 match_reg, write_reg, header, orig_value;
	u16 pos;

	if (!(hpx3_device_type(dev) & reg->device_type))
		return;

	if (!(hpx3_function_type(dev) & reg->function_type))
		return;

	switch (reg->config_space_location) {
	case HPX_CFG_PCICFG:
		pos = 0;
		break;
	case HPX_CFG_PCIE_CAP:
		pos = pci_find_capability(dev, reg->pci_exp_cap_id);
		if (pos == 0)
			return;

		break;
	case HPX_CFG_PCIE_CAP_EXT:
		pos = pci_find_ext_capability(dev, reg->pci_exp_cap_id);
		if (pos == 0)
			return;

		pci_read_config_dword(dev, pos, &header);
		if (!hpx3_cap_ver_matches(PCI_EXT_CAP_VER(header),
					  reg->pci_exp_cap_ver))
			return;

		break;
	case HPX_CFG_VEND_CAP:
	case HPX_CFG_DVSEC:
	default:
		pci_warn(dev, "Encountered _HPX type 3 with unsupported config space location");
		return;
	}

	pci_read_config_dword(dev, pos + reg->match_offset, &match_reg);

	if ((match_reg & reg->match_mask_and) != reg->match_value)
		return;

	pci_read_config_dword(dev, pos + reg->reg_offset, &write_reg);
	orig_value = write_reg;
	write_reg &= reg->reg_mask_and;
	write_reg |= reg->reg_mask_or;

	if (orig_value == write_reg)
		return;

	pci_write_config_dword(dev, pos + reg->reg_offset, write_reg);

	pci_dbg(dev, "Applied _HPX3 at [0x%x]: 0x%08x -> 0x%08x",
		pos, orig_value, write_reg);
}

static void program_hpx_type3(struct pci_dev *dev, struct hpx_type3 *hpx)
{
	if (!hpx)
		return;

	if (!pci_is_pcie(dev))
		return;

	program_hpx_type3_register(dev, hpx);
}

static void parse_hpx3_register(struct hpx_type3 *hpx3_reg,
				union acpi_object *reg_fields)
{
	hpx3_reg->device_type            = reg_fields[0].integer.value;
	hpx3_reg->function_type          = reg_fields[1].integer.value;
	hpx3_reg->config_space_location  = reg_fields[2].integer.value;
	hpx3_reg->pci_exp_cap_id         = reg_fields[3].integer.value;
	hpx3_reg->pci_exp_cap_ver        = reg_fields[4].integer.value;
	hpx3_reg->pci_exp_vendor_id      = reg_fields[5].integer.value;
	hpx3_reg->dvsec_id               = reg_fields[6].integer.value;
	hpx3_reg->dvsec_rev              = reg_fields[7].integer.value;
	hpx3_reg->match_offset           = reg_fields[8].integer.value;
	hpx3_reg->match_mask_and         = reg_fields[9].integer.value;
	hpx3_reg->match_value            = reg_fields[10].integer.value;
	hpx3_reg->reg_offset             = reg_fields[11].integer.value;
	hpx3_reg->reg_mask_and           = reg_fields[12].integer.value;
	hpx3_reg->reg_mask_or            = reg_fields[13].integer.value;
}

static acpi_status program_type3_hpx_record(struct pci_dev *dev,
					   union acpi_object *record)
{
	union acpi_object *fields = record->package.elements;
	u32 desc_count, expected_length, revision;
	union acpi_object *reg_fields;
	struct hpx_type3 hpx3;
	int i;

	revision = fields[1].integer.value;
	switch (revision) {
	case 1:
		desc_count = fields[2].integer.value;
		expected_length = 3 + desc_count * 14;

		if (record->package.count != expected_length)
			return AE_ERROR;

		for (i = 2; i < expected_length; i++)
			if (fields[i].type != ACPI_TYPE_INTEGER)
				return AE_ERROR;

		for (i = 0; i < desc_count; i++) {
			reg_fields = fields + 3 + i * 14;
			parse_hpx3_register(&hpx3, reg_fields);
			program_hpx_type3(dev, &hpx3);
		}

		break;
	default:
		printk(KERN_WARNING
			"%s: Type 3 Revision %d record not supported\n",
			__func__, revision);
		return AE_ERROR;
	}
	return AE_OK;
}

static acpi_status acpi_run_hpx(struct pci_dev *dev, acpi_handle handle)
{
	acpi_status status;
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *package, *record, *fields;
	struct hpx_type0 hpx0;
	struct hpx_type1 hpx1;
	struct hpx_type2 hpx2;
	u32 type;
	int i;

	status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
	if (ACPI_FAILURE(status))
		return status;

	package = (union acpi_object *)buffer.pointer;
	if (package->type != ACPI_TYPE_PACKAGE) {
		status = AE_ERROR;
		goto exit;
	}

	for (i = 0; i < package->package.count; i++) {
		record = &package->package.elements[i];
		if (record->type != ACPI_TYPE_PACKAGE) {
			status = AE_ERROR;
			goto exit;
		}

		fields = record->package.elements;
		if (fields[0].type != ACPI_TYPE_INTEGER ||
		    fields[1].type != ACPI_TYPE_INTEGER) {
			status = AE_ERROR;
			goto exit;
		}

		type = fields[0].integer.value;
		switch (type) {
		case 0:
			memset(&hpx0, 0, sizeof(hpx0));
			status = decode_type0_hpx_record(record, &hpx0);
			if (ACPI_FAILURE(status))
				goto exit;
			program_hpx_type0(dev, &hpx0);
			break;
		case 1:
			memset(&hpx1, 0, sizeof(hpx1));
			status = decode_type1_hpx_record(record, &hpx1);
			if (ACPI_FAILURE(status))
				goto exit;
			program_hpx_type1(dev, &hpx1);
			break;
		case 2:
			memset(&hpx2, 0, sizeof(hpx2));
			status = decode_type2_hpx_record(record, &hpx2);
			if (ACPI_FAILURE(status))
				goto exit;
			program_hpx_type2(dev, &hpx2);
			break;
		case 3:
			status = program_type3_hpx_record(dev, record);
			if (ACPI_FAILURE(status))
				goto exit;
			break;
		default:
			pr_err("%s: Type %d record not supported\n",
			       __func__, type);
			status = AE_ERROR;
			goto exit;
		}
	}
 exit:
	kfree(buffer.pointer);
	return status;
}

static acpi_status acpi_run_hpp(struct pci_dev *dev, acpi_handle handle)
{
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *package, *fields;
	struct hpx_type0 hpx0;
	int i;

	memset(&hpx0, 0, sizeof(hpx0));

	status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
	if (ACPI_FAILURE(status))
		return status;

	package = (union acpi_object *) buffer.pointer;
	if (package->type != ACPI_TYPE_PACKAGE ||
	    package->package.count != 4) {
		status = AE_ERROR;
		goto exit;
	}

	fields = package->package.elements;
	for (i = 0; i < 4; i++) {
		if (fields[i].type != ACPI_TYPE_INTEGER) {
			status = AE_ERROR;
			goto exit;
		}
	}

	hpx0.revision        = 1;
	hpx0.cache_line_size = fields[0].integer.value;
	hpx0.latency_timer   = fields[1].integer.value;
	hpx0.enable_serr     = fields[2].integer.value;
	hpx0.enable_perr     = fields[3].integer.value;

	program_hpx_type0(dev, &hpx0);

exit:
	kfree(buffer.pointer);
	return status;
}

/* pci_acpi_program_hp_params
 *
 * @dev - the pci_dev for which we want parameters
 */
int pci_acpi_program_hp_params(struct pci_dev *dev)
{
	acpi_status status;
	acpi_handle handle, phandle;
	struct pci_bus *pbus;

	if (acpi_pci_disabled)
		return -ENODEV;

	handle = NULL;
	for (pbus = dev->bus; pbus; pbus = pbus->parent) {
		handle = acpi_pci_get_bridge_handle(pbus);
		if (handle)
			break;
	}

	/*
	 * _HPP settings apply to all child buses, until another _HPP is
	 * encountered. If we don't find an _HPP for the input pci dev,
	 * look for it in the parent device scope since that would apply to
	 * this pci dev.
	 */
	while (handle) {
		status = acpi_run_hpx(dev, handle);
		if (ACPI_SUCCESS(status))
			return 0;
		status = acpi_run_hpp(dev, handle);
		if (ACPI_SUCCESS(status))
			return 0;
		if (acpi_is_root_bridge(handle))
			break;
		status = acpi_get_parent(handle, &phandle);
		if (ACPI_FAILURE(status))
			break;
		handle = phandle;
	}
	return -ENODEV;
}

/**
 * pciehp_is_native - Check whether a hotplug port is handled by the OS
 * @bridge: Hotplug port to check
 *
 * Returns true if the given @bridge is handled by the native PCIe hotplug
 * driver.
 */
bool pciehp_is_native(struct pci_dev *bridge)
{
	const struct pci_host_bridge *host;
	u32 slot_cap;

	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
		return false;

	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
		return false;

	if (pcie_ports_native)
		return true;

	host = pci_find_host_bridge(bridge->bus);
	return host->native_pcie_hotplug;
}

/**
 * shpchp_is_native - Check whether a hotplug port is handled by the OS
 * @bridge: Hotplug port to check
 *
 * Returns true if the given @bridge is handled by the native SHPC hotplug
 * driver.
 */
bool shpchp_is_native(struct pci_dev *bridge)
{
	return bridge->shpc_managed;
}

/**
 * pci_acpi_wake_bus - Root bus wakeup notification fork function.
 * @context: Device wakeup context.
 */
static void pci_acpi_wake_bus(struct acpi_device_wakeup_context *context)
{
	struct acpi_device *adev;
	struct acpi_pci_root *root;

	adev = container_of(context, struct acpi_device, wakeup.context);
	root = acpi_driver_data(adev);
	pci_pme_wakeup_bus(root->bus);
}

/**
 * pci_acpi_wake_dev - PCI device wakeup notification work function.
 * @context: Device wakeup context.
 */
static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
{
	struct pci_dev *pci_dev;

	pci_dev = to_pci_dev(context->dev);

	if (pci_dev->pme_poll)
		pci_dev->pme_poll = false;

	if (pci_dev->current_state == PCI_D3cold) {
		pci_wakeup_event(pci_dev);
		pm_request_resume(&pci_dev->dev);
		return;
	}

	/* Clear PME Status if set. */
	if (pci_dev->pme_support)
		pci_check_pme_status(pci_dev);

	pci_wakeup_event(pci_dev);
	pm_request_resume(&pci_dev->dev);

	pci_pme_wakeup_bus(pci_dev->subordinate);
}

/**
 * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
 * @dev: PCI root bridge ACPI device.
 */
acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
{
	return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
}

/**
 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 * @dev: ACPI device to add the notifier for.
 * @pci_dev: PCI device to check for the PME status if an event is signaled.
 */
acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
				     struct pci_dev *pci_dev)
{
	return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
}

/*
 * _SxD returns the D-state with the highest power
 * (lowest D-state number) supported in the S-state "x".
 *
 * If the devices does not have a _PRW
 * (Power Resources for Wake) supporting system wakeup from "x"
 * then the OS is free to choose a lower power (higher number
 * D-state) than the return value from _SxD.
 *
 * But if _PRW is enabled at S-state "x", the OS
 * must not choose a power lower than _SxD --
 * unless the device has an _SxW method specifying
 * the lowest power (highest D-state number) the device
 * may enter while still able to wake the system.
 *
 * ie. depending on global OS policy:
 *
 * if (_PRW at S-state x)
 *	choose from highest power _SxD to lowest power _SxW
 * else // no _PRW at S-state x
 *	choose highest power _SxD or any lower power
 */

static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
{
	int acpi_state, d_max;

	if (pdev->no_d3cold)
		d_max = ACPI_STATE_D3_HOT;
	else
		d_max = ACPI_STATE_D3_COLD;
	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
	if (acpi_state < 0)
		return PCI_POWER_ERROR;

	switch (acpi_state) {
	case ACPI_STATE_D0:
		return PCI_D0;
	case ACPI_STATE_D1:
		return PCI_D1;
	case ACPI_STATE_D2:
		return PCI_D2;
	case ACPI_STATE_D3_HOT:
		return PCI_D3hot;
	case ACPI_STATE_D3_COLD:
		return PCI_D3cold;
	}
	return PCI_POWER_ERROR;
}

static struct acpi_device *acpi_pci_find_companion(struct device *dev);

void pci_set_acpi_fwnode(struct pci_dev *dev)
{
	if (!dev_fwnode(&dev->dev) && !pci_dev_is_added(dev))
		ACPI_COMPANION_SET(&dev->dev,
				   acpi_pci_find_companion(&dev->dev));
}

/**
 * pci_dev_acpi_reset - do a function level reset using _RST method
 * @dev: device to reset
 * @probe: if true, return 0 if device supports _RST
 */
int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
{
	acpi_handle handle = ACPI_HANDLE(&dev->dev);

	if (!handle || !acpi_has_method(handle, "_RST"))
		return -ENOTTY;

	if (probe)
		return 0;

	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
		pci_warn(dev, "ACPI _RST failed\n");
		return -ENOTTY;
	}

	return 0;
}

static bool acpi_pci_power_manageable(struct pci_dev *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);

	if (!adev)
		return false;
	return acpi_device_power_manageable(adev);
}

static bool acpi_pci_bridge_d3(struct pci_dev *dev)
{
	const union acpi_object *obj;
	struct acpi_device *adev;
	struct pci_dev *rpdev;

	if (!dev->is_hotplug_bridge)
		return false;

	/* Assume D3 support if the bridge is power-manageable by ACPI. */
	if (acpi_pci_power_manageable(dev))
		return true;

	/*
	 * The ACPI firmware will provide the device-specific properties through
	 * _DSD configuration object. Look for the 'HotPlugSupportInD3' property
	 * for the root port and if it is set we know the hierarchy behind it
	 * supports D3 just fine.
	 */
	rpdev = pcie_find_root_port(dev);
	if (!rpdev)
		return false;

	adev = ACPI_COMPANION(&rpdev->dev);
	if (!adev)
		return false;

	if (acpi_dev_get_property(adev, "HotPlugSupportInD3",
				   ACPI_TYPE_INTEGER, &obj) < 0)
		return false;

	return obj->integer.value == 1;
}

static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
	static const u8 state_conv[] = {
		[PCI_D0] = ACPI_STATE_D0,
		[PCI_D1] = ACPI_STATE_D1,
		[PCI_D2] = ACPI_STATE_D2,
		[PCI_D3hot] = ACPI_STATE_D3_HOT,
		[PCI_D3cold] = ACPI_STATE_D3_COLD,
	};
	int error = -EINVAL;

	/* If the ACPI device has _EJ0, ignore the device */
	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
		return -ENODEV;

	switch (state) {
	case PCI_D3cold:
		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
				PM_QOS_FLAGS_ALL) {
			error = -EBUSY;
			break;
		}
		fallthrough;
	case PCI_D0:
	case PCI_D1:
	case PCI_D2:
	case PCI_D3hot:
		error = acpi_device_set_power(adev, state_conv[state]);
	}

	if (!error)
		pci_dbg(dev, "power state changed by ACPI to %s\n",
		        acpi_power_state_string(adev->power.state));

	return error;
}

static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
	static const pci_power_t state_conv[] = {
		[ACPI_STATE_D0]      = PCI_D0,
		[ACPI_STATE_D1]      = PCI_D1,
		[ACPI_STATE_D2]      = PCI_D2,
		[ACPI_STATE_D3_HOT]  = PCI_D3hot,
		[ACPI_STATE_D3_COLD] = PCI_D3cold,
	};
	int state;

	if (!adev || !acpi_device_power_manageable(adev))
		return PCI_UNKNOWN;

	state = adev->power.state;
	if (state == ACPI_STATE_UNKNOWN)
		return PCI_UNKNOWN;

	return state_conv[state];
}

static void acpi_pci_refresh_power_state(struct pci_dev *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);

	if (adev && acpi_device_power_manageable(adev))
		acpi_device_update_power(adev, NULL);
}

static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
{
	while (bus->parent) {
		if (acpi_pm_device_can_wakeup(&bus->self->dev))
			return acpi_pm_set_device_wakeup(&bus->self->dev, enable);

		bus = bus->parent;
	}

	/* We have reached the root bus. */
	if (bus->bridge) {
		if (acpi_pm_device_can_wakeup(bus->bridge))
			return acpi_pm_set_device_wakeup(bus->bridge, enable);
	}
	return 0;
}

static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
{
	if (acpi_pm_device_can_wakeup(&dev->dev))
		return acpi_pm_set_device_wakeup(&dev->dev, enable);

	return acpi_pci_propagate_wakeup(dev->bus, enable);
}

static bool acpi_pci_need_resume(struct pci_dev *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);

	/*
	 * In some cases (eg. Samsung 305V4A) leaving a bridge in suspend over
	 * system-wide suspend/resume confuses the platform firmware, so avoid
	 * doing that.  According to Section 16.1.6 of ACPI 6.2, endpoint
	 * devices are expected to be in D3 before invoking the S3 entry path
	 * from the firmware, so they should not be affected by this issue.
	 */
	if (pci_is_bridge(dev) && acpi_target_system_state() != ACPI_STATE_S0)
		return true;

	if (!adev || !acpi_device_power_manageable(adev))
		return false;

	if (adev->wakeup.flags.valid &&
	    device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
		return true;

	if (acpi_target_system_state() == ACPI_STATE_S0)
		return false;

	return !!adev->power.flags.dsw_present;
}

static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
	.bridge_d3 = acpi_pci_bridge_d3,
	.is_manageable = acpi_pci_power_manageable,
	.set_state = acpi_pci_set_power_state,
	.get_state = acpi_pci_get_power_state,
	.refresh_state = acpi_pci_refresh_power_state,
	.choose_state = acpi_pci_choose_state,
	.set_wakeup = acpi_pci_wakeup,
	.need_resume = acpi_pci_need_resume,
};

void acpi_pci_add_bus(struct pci_bus *bus)
{
	union acpi_object *obj;
	struct pci_host_bridge *bridge;

	if (acpi_pci_disabled || !bus->bridge || !ACPI_HANDLE(bus->bridge))
		return;

	acpi_pci_slot_enumerate(bus);
	acpiphp_enumerate_slots(bus);

	/*
	 * For a host bridge, check its _DSM for function 8 and if
	 * that is available, mark it in pci_host_bridge.
	 */
	if (!pci_is_root_bus(bus))
		return;

	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3,
				DSM_PCI_POWER_ON_RESET_DELAY, NULL);
	if (!obj)
		return;

	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
		bridge = pci_find_host_bridge(bus);
		bridge->ignore_reset_delay = 1;
	}
	ACPI_FREE(obj);
}

void acpi_pci_remove_bus(struct pci_bus *bus)
{
	if (acpi_pci_disabled || !bus->bridge)
		return;

	acpiphp_remove_slots(bus);
	acpi_pci_slot_remove(bus);
}

/* ACPI bus type */


static DECLARE_RWSEM(pci_acpi_companion_lookup_sem);
static struct acpi_device *(*pci_acpi_find_companion_hook)(struct pci_dev *);

/**
 * pci_acpi_set_companion_lookup_hook - Set ACPI companion lookup callback.
 * @func: ACPI companion lookup callback pointer or NULL.
 *
 * Set a special ACPI companion lookup callback for PCI devices whose companion
 * objects in the ACPI namespace have _ADR with non-standard bus-device-function
 * encodings.
 *
 * Return 0 on success or a negative error code on failure (in which case no
 * changes are made).
 *
 * The caller is responsible for the appropriate ordering of the invocations of
 * this function with respect to the enumeration of the PCI devices needing the
 * callback installed by it.
 */
int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_dev *))
{
	int ret;

	if (!func)
		return -EINVAL;

	down_write(&pci_acpi_companion_lookup_sem);

	if (pci_acpi_find_companion_hook) {
		ret = -EBUSY;
	} else {
		pci_acpi_find_companion_hook = func;
		ret = 0;
	}

	up_write(&pci_acpi_companion_lookup_sem);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_acpi_set_companion_lookup_hook);

/**
 * pci_acpi_clear_companion_lookup_hook - Clear ACPI companion lookup callback.
 *
 * Clear the special ACPI companion lookup callback previously set by
 * pci_acpi_set_companion_lookup_hook().  Block until the last running instance
 * of the callback returns before clearing it.
 *
 * The caller is responsible for the appropriate ordering of the invocations of
 * this function with respect to the enumeration of the PCI devices needing the
 * callback cleared by it.
 */
void pci_acpi_clear_companion_lookup_hook(void)
{
	down_write(&pci_acpi_companion_lookup_sem);

	pci_acpi_find_companion_hook = NULL;

	up_write(&pci_acpi_companion_lookup_sem);
}
EXPORT_SYMBOL_GPL(pci_acpi_clear_companion_lookup_hook);

static struct acpi_device *acpi_pci_find_companion(struct device *dev)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	struct acpi_device *adev;
	bool check_children;
	u64 addr;

	if (!dev->parent)
		return NULL;

	down_read(&pci_acpi_companion_lookup_sem);

	adev = pci_acpi_find_companion_hook ?
		pci_acpi_find_companion_hook(pci_dev) : NULL;

	up_read(&pci_acpi_companion_lookup_sem);

	if (adev)
		return adev;

	check_children = pci_is_bridge(pci_dev);
	/* Please ref to ACPI spec for the syntax of _ADR */
	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
				      check_children);

	/*
	 * There may be ACPI device objects in the ACPI namespace that are
	 * children of the device object representing the host bridge, but don't
	 * represent PCI devices.  Both _HID and _ADR may be present for them,
	 * even though that is against the specification (for example, see
	 * Section 6.1 of ACPI 6.3), but in many cases the _ADR returns 0 which
	 * appears to indicate that they should not be taken into consideration
	 * as potential companions of PCI devices on the root bus.
	 *
	 * To catch this special case, disregard the returned device object if
	 * it has a valid _HID, addr is 0 and the PCI device at hand is on the
	 * root bus.
	 */
	if (adev && adev->pnp.type.platform_id && !addr &&
	    pci_is_root_bus(pci_dev->bus))
		return NULL;

	return adev;
}

/**
 * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
 * @pdev: the PCI device whose delay is to be updated
 * @handle: ACPI handle of this device
 *
 * Update the d3hot_delay and d3cold_delay of a PCI device from the ACPI _DSM
 * control method of either the device itself or the PCI host bridge.
 *
 * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
 * host bridge.  If it returns one, the OS may assume that all devices in
 * the hierarchy have already completed power-on reset delays.
 *
 * Function 9, "Device Readiness Durations," applies only to the object
 * where it is located.  It returns delay durations required after various
 * events if the device requires less time than the spec requires.  Delays
 * from this function take precedence over the Reset Delay function.
 *
 * These _DSM functions are defined by the draft ECN of January 28, 2014,
 * titled "ACPI additions for FW latency optimizations."
 */
static void pci_acpi_optimize_delay(struct pci_dev *pdev,
				    acpi_handle handle)
{
	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
	int value;
	union acpi_object *obj, *elements;

	if (bridge->ignore_reset_delay)
		pdev->d3cold_delay = 0;

	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3,
				DSM_PCI_DEVICE_READINESS_DURATIONS, NULL);
	if (!obj)
		return;

	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
		elements = obj->package.elements;
		if (elements[0].type == ACPI_TYPE_INTEGER) {
			value = (int)elements[0].integer.value / 1000;
			if (value < PCI_PM_D3COLD_WAIT)
				pdev->d3cold_delay = value;
		}
		if (elements[3].type == ACPI_TYPE_INTEGER) {
			value = (int)elements[3].integer.value / 1000;
			if (value < PCI_PM_D3HOT_WAIT)
				pdev->d3hot_delay = value;
		}
	}
	ACPI_FREE(obj);
}

static void pci_acpi_set_external_facing(struct pci_dev *dev)
{
	u8 val;

	if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
		return;
	if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val))
		return;

	/*
	 * These root ports expose PCIe (including DMA) outside of the
	 * system.  Everything downstream from them is external.
	 */
	if (val)
		dev->external_facing = 1;
}

static void pci_acpi_setup(struct device *dev)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	struct acpi_device *adev = ACPI_COMPANION(dev);

	if (!adev)
		return;

	pci_acpi_optimize_delay(pci_dev, adev->handle);
	pci_acpi_set_external_facing(pci_dev);
	pci_acpi_add_edr_notifier(pci_dev);

	pci_acpi_add_pm_notifier(adev, pci_dev);
	if (!adev->wakeup.flags.valid)
		return;

	device_set_wakeup_capable(dev, true);
	/*
	 * For bridges that can do D3 we enable wake automatically (as
	 * we do for the power management itself in that case). The
	 * reason is that the bridge may have additional methods such as
	 * _DSW that need to be called.
	 */
	if (pci_dev->bridge_d3)
		device_wakeup_enable(dev);

	acpi_pci_wakeup(pci_dev, false);
	acpi_device_power_add_dependent(adev, dev);
}

static void pci_acpi_cleanup(struct device *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(dev);
	struct pci_dev *pci_dev = to_pci_dev(dev);

	if (!adev)
		return;

	pci_acpi_remove_edr_notifier(pci_dev);
	pci_acpi_remove_pm_notifier(adev);
	if (adev->wakeup.flags.valid) {
		acpi_device_power_remove_dependent(adev, dev);
		if (pci_dev->bridge_d3)
			device_wakeup_disable(dev);

		device_set_wakeup_capable(dev, false);
	}
}

static bool pci_acpi_bus_match(struct device *dev)
{
	return dev_is_pci(dev);
}

static struct acpi_bus_type acpi_pci_bus = {
	.name = "PCI",
	.match = pci_acpi_bus_match,
	.find_companion = acpi_pci_find_companion,
	.setup = pci_acpi_setup,
	.cleanup = pci_acpi_cleanup,
};


static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);

/**
 * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
 * @fn:       Callback matching a device to a fwnode that identifies a PCI
 *            MSI domain.
 *
 * This should be called by irqchip driver, which is the parent of
 * the MSI domain to provide callback interface to query fwnode.
 */
void
pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
{
	pci_msi_get_fwnode_cb = fn;
}

/**
 * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
 * @bus:      The PCI host bridge bus.
 *
 * This function uses the callback function registered by
 * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
 * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
 * This returns NULL on error or when the domain is not found.
 */
struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
{
	struct fwnode_handle *fwnode;

	if (!pci_msi_get_fwnode_cb)
		return NULL;

	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
	if (!fwnode)
		return NULL;

	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
}

static int __init acpi_pci_init(void)
{
	int ret;

	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
		pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
		pci_no_msi();
	}

	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
		pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
		pcie_no_aspm();
	}

	ret = register_acpi_bus_type(&acpi_pci_bus);
	if (ret)
		return 0;

	pci_set_platform_pm(&acpi_pci_platform_pm);
	acpi_pci_slot_init();
	acpiphp_init();

	return 0;
}
arch_initcall(acpi_pci_init);