aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/i915_guc_submission.c
blob: 4462112725ef9e639dc080dcc89a60fc00095eec (plain) (blame)
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
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */
#include <linux/firmware.h>
#include <linux/circ_buf.h>
#include <linux/debugfs.h>
#include <linux/relay.h>
#include "i915_drv.h"
#include "intel_guc.h"

/**
 * DOC: GuC-based command submission
 *
 * i915_guc_client:
 * We use the term client to avoid confusion with contexts. A i915_guc_client is
 * equivalent to GuC object guc_context_desc. This context descriptor is
 * allocated from a pool of 1024 entries. Kernel driver will allocate doorbell
 * and workqueue for it. Also the process descriptor (guc_process_desc), which
 * is mapped to client space. So the client can write Work Item then ring the
 * doorbell.
 *
 * To simplify the implementation, we allocate one gem object that contains all
 * pages for doorbell, process descriptor and workqueue.
 *
 * The Scratch registers:
 * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes
 * a value to the action register (SOFT_SCRATCH_0) along with any data. It then
 * triggers an interrupt on the GuC via another register write (0xC4C8).
 * Firmware writes a success/fail code back to the action register after
 * processes the request. The kernel driver polls waiting for this update and
 * then proceeds.
 * See host2guc_action()
 *
 * Doorbells:
 * Doorbells are interrupts to uKernel. A doorbell is a single cache line (QW)
 * mapped into process space.
 *
 * Work Items:
 * There are several types of work items that the host may place into a
 * workqueue, each with its own requirements and limitations. Currently only
 * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which
 * represents in-order queue. The kernel driver packs ring tail pointer and an
 * ELSP context descriptor dword into Work Item.
 * See guc_wq_item_append()
 *
 */

/*
 * Read GuC command/status register (SOFT_SCRATCH_0)
 * Return true if it contains a response rather than a command
 */
static inline bool host2guc_action_response(struct drm_i915_private *dev_priv,
					    u32 *status)
{
	u32 val = I915_READ(SOFT_SCRATCH(0));
	*status = val;
	return GUC2HOST_IS_RESPONSE(val);
}

static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 status;
	int i;
	int ret;

	if (WARN_ON(len < 1 || len > 15))
		return -EINVAL;

	mutex_lock(&guc->action_lock);
	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);

	dev_priv->guc.action_count += 1;
	dev_priv->guc.action_cmd = data[0];

	for (i = 0; i < len; i++)
		I915_WRITE(SOFT_SCRATCH(i), data[i]);

	POSTING_READ(SOFT_SCRATCH(i - 1));

	I915_WRITE(HOST2GUC_INTERRUPT, HOST2GUC_TRIGGER);

	/*
	 * Fast commands should complete in less than 10us, so sample quickly
	 * up to that length of time, then switch to a slower sleep-wait loop.
	 * No HOST2GUC command should ever take longer than 10ms.
	 */
	ret = wait_for_us(host2guc_action_response(dev_priv, &status), 10);
	if (ret)
		ret = wait_for(host2guc_action_response(dev_priv, &status), 10);
	if (status != GUC2HOST_STATUS_SUCCESS) {
		/*
		 * Either the GuC explicitly returned an error (which
		 * we convert to -EIO here) or no response at all was
		 * received within the timeout limit (-ETIMEDOUT)
		 */
		if (ret != -ETIMEDOUT)
			ret = -EIO;

		DRM_WARN("Action 0x%X failed; ret=%d status=0x%08X response=0x%08X\n",
			 data[0], ret, status, I915_READ(SOFT_SCRATCH(15)));

		dev_priv->guc.action_fail += 1;
		dev_priv->guc.action_err = ret;
	}
	dev_priv->guc.action_status = status;

	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
	mutex_unlock(&guc->action_lock);

	return ret;
}

/*
 * Tell the GuC to allocate or deallocate a specific doorbell
 */

static int host2guc_allocate_doorbell(struct intel_guc *guc,
				      struct i915_guc_client *client)
{
	u32 data[2];

	data[0] = HOST2GUC_ACTION_ALLOCATE_DOORBELL;
	data[1] = client->ctx_index;

	return host2guc_action(guc, data, 2);
}

static int host2guc_release_doorbell(struct intel_guc *guc,
				     struct i915_guc_client *client)
{
	u32 data[2];

	data[0] = HOST2GUC_ACTION_DEALLOCATE_DOORBELL;
	data[1] = client->ctx_index;

	return host2guc_action(guc, data, 2);
}

static int host2guc_sample_forcewake(struct intel_guc *guc,
				     struct i915_guc_client *client)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 data[2];

	data[0] = HOST2GUC_ACTION_SAMPLE_FORCEWAKE;
	/* WaRsDisableCoarsePowerGating:skl,bxt */
	if (!intel_enable_rc6() || NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
		data[1] = 0;
	else
		/* bit 0 and 1 are for Render and Media domain separately */
		data[1] = GUC_FORCEWAKE_RENDER | GUC_FORCEWAKE_MEDIA;

	return host2guc_action(guc, data, ARRAY_SIZE(data));
}

static int host2guc_logbuffer_flush_complete(struct intel_guc *guc)
{
	u32 data[1];

	data[0] = HOST2GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE;

	return host2guc_action(guc, data, 1);
}

static int host2guc_force_logbuffer_flush(struct intel_guc *guc)
{
	u32 data[2];

	data[0] = HOST2GUC_ACTION_FORCE_LOG_BUFFER_FLUSH;
	data[1] = 0;

	return host2guc_action(guc, data, 2);
}

static int host2guc_logging_control(struct intel_guc *guc, u32 control_val)
{
	u32 data[2];

	data[0] = HOST2GUC_ACTION_UK_LOG_ENABLE_LOGGING;
	data[1] = control_val;

	return host2guc_action(guc, data, 2);
}

/*
 * Initialise, update, or clear doorbell data shared with the GuC
 *
 * These functions modify shared data and so need access to the mapped
 * client object which contains the page being used for the doorbell
 */

static int guc_update_doorbell_id(struct intel_guc *guc,
				  struct i915_guc_client *client,
				  u16 new_id)
{
	struct sg_table *sg = guc->ctx_pool_vma->pages;
	void *doorbell_bitmap = guc->doorbell_bitmap;
	struct guc_doorbell_info *doorbell;
	struct guc_context_desc desc;
	size_t len;

	doorbell = client->vaddr + client->doorbell_offset;

	if (client->doorbell_id != GUC_INVALID_DOORBELL_ID &&
	    test_bit(client->doorbell_id, doorbell_bitmap)) {
		/* Deactivate the old doorbell */
		doorbell->db_status = GUC_DOORBELL_DISABLED;
		(void)host2guc_release_doorbell(guc, client);
		__clear_bit(client->doorbell_id, doorbell_bitmap);
	}

	/* Update the GuC's idea of the doorbell ID */
	len = sg_pcopy_to_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
			     sizeof(desc) * client->ctx_index);
	if (len != sizeof(desc))
		return -EFAULT;
	desc.db_id = new_id;
	len = sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
			     sizeof(desc) * client->ctx_index);
	if (len != sizeof(desc))
		return -EFAULT;

	client->doorbell_id = new_id;
	if (new_id == GUC_INVALID_DOORBELL_ID)
		return 0;

	/* Activate the new doorbell */
	__set_bit(new_id, doorbell_bitmap);
	doorbell->cookie = 0;
	doorbell->db_status = GUC_DOORBELL_ENABLED;
	return host2guc_allocate_doorbell(guc, client);
}

static int guc_init_doorbell(struct intel_guc *guc,
			      struct i915_guc_client *client,
			      uint16_t db_id)
{
	return guc_update_doorbell_id(guc, client, db_id);
}

static void guc_disable_doorbell(struct intel_guc *guc,
				 struct i915_guc_client *client)
{
	(void)guc_update_doorbell_id(guc, client, GUC_INVALID_DOORBELL_ID);

	/* XXX: wait for any interrupts */
	/* XXX: wait for workqueue to drain */
}

static uint16_t
select_doorbell_register(struct intel_guc *guc, uint32_t priority)
{
	/*
	 * The bitmap tracks which doorbell registers are currently in use.
	 * It is split into two halves; the first half is used for normal
	 * priority contexts, the second half for high-priority ones.
	 * Note that logically higher priorities are numerically less than
	 * normal ones, so the test below means "is it high-priority?"
	 */
	const bool hi_pri = (priority <= GUC_CTX_PRIORITY_HIGH);
	const uint16_t half = GUC_MAX_DOORBELLS / 2;
	const uint16_t start = hi_pri ? half : 0;
	const uint16_t end = start + half;
	uint16_t id;

	id = find_next_zero_bit(guc->doorbell_bitmap, end, start);
	if (id == end)
		id = GUC_INVALID_DOORBELL_ID;

	DRM_DEBUG_DRIVER("assigned %s priority doorbell id 0x%x\n",
			hi_pri ? "high" : "normal", id);

	return id;
}

/*
 * Select, assign and relase doorbell cachelines
 *
 * These functions track which doorbell cachelines are in use.
 * The data they manipulate is protected by the host2guc lock.
 */

static uint32_t select_doorbell_cacheline(struct intel_guc *guc)
{
	const uint32_t cacheline_size = cache_line_size();
	uint32_t offset;

	/* Doorbell uses a single cache line within a page */
	offset = offset_in_page(guc->db_cacheline);

	/* Moving to next cache line to reduce contention */
	guc->db_cacheline += cacheline_size;

	DRM_DEBUG_DRIVER("selected doorbell cacheline 0x%x, next 0x%x, linesize %u\n",
			offset, guc->db_cacheline, cacheline_size);

	return offset;
}

/*
 * Initialise the process descriptor shared with the GuC firmware.
 */
static void guc_proc_desc_init(struct intel_guc *guc,
			       struct i915_guc_client *client)
{
	struct guc_process_desc *desc;

	desc = client->vaddr + client->proc_desc_offset;

	memset(desc, 0, sizeof(*desc));

	/*
	 * XXX: pDoorbell and WQVBaseAddress are pointers in process address
	 * space for ring3 clients (set them as in mmap_ioctl) or kernel
	 * space for kernel clients (map on demand instead? May make debug
	 * easier to have it mapped).
	 */
	desc->wq_base_addr = 0;
	desc->db_base_addr = 0;

	desc->context_id = client->ctx_index;
	desc->wq_size_bytes = client->wq_size;
	desc->wq_status = WQ_STATUS_ACTIVE;
	desc->priority = client->priority;
}

/*
 * Initialise/clear the context descriptor shared with the GuC firmware.
 *
 * This descriptor tells the GuC where (in GGTT space) to find the important
 * data structures relating to this client (doorbell, process descriptor,
 * write queue, etc).
 */

static void guc_ctx_desc_init(struct intel_guc *guc,
			      struct i915_guc_client *client)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct intel_engine_cs *engine;
	struct i915_gem_context *ctx = client->owner;
	struct guc_context_desc desc;
	struct sg_table *sg;
	unsigned int tmp;
	u32 gfx_addr;

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

	desc.attribute = GUC_CTX_DESC_ATTR_ACTIVE | GUC_CTX_DESC_ATTR_KERNEL;
	desc.context_id = client->ctx_index;
	desc.priority = client->priority;
	desc.db_id = client->doorbell_id;

	for_each_engine_masked(engine, dev_priv, client->engines, tmp) {
		struct intel_context *ce = &ctx->engine[engine->id];
		uint32_t guc_engine_id = engine->guc_id;
		struct guc_execlist_context *lrc = &desc.lrc[guc_engine_id];

		/* TODO: We have a design issue to be solved here. Only when we
		 * receive the first batch, we know which engine is used by the
		 * user. But here GuC expects the lrc and ring to be pinned. It
		 * is not an issue for default context, which is the only one
		 * for now who owns a GuC client. But for future owner of GuC
		 * client, need to make sure lrc is pinned prior to enter here.
		 */
		if (!ce->state)
			break;	/* XXX: continue? */

		lrc->context_desc = lower_32_bits(ce->lrc_desc);

		/* The state page is after PPHWSP */
		lrc->ring_lcra =
			i915_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE;
		lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) |
				(guc_engine_id << GUC_ELC_ENGINE_OFFSET);

		lrc->ring_begin = i915_ggtt_offset(ce->ring->vma);
		lrc->ring_end = lrc->ring_begin + ce->ring->size - 1;
		lrc->ring_next_free_location = lrc->ring_begin;
		lrc->ring_current_tail_pointer_value = 0;

		desc.engines_used |= (1 << guc_engine_id);
	}

	DRM_DEBUG_DRIVER("Host engines 0x%x => GuC engines used 0x%x\n",
			client->engines, desc.engines_used);
	WARN_ON(desc.engines_used == 0);

	/*
	 * The doorbell, process descriptor, and workqueue are all parts
	 * of the client object, which the GuC will reference via the GGTT
	 */
	gfx_addr = i915_ggtt_offset(client->vma);
	desc.db_trigger_phy = sg_dma_address(client->vma->pages->sgl) +
				client->doorbell_offset;
	desc.db_trigger_cpu =
		(uintptr_t)client->vaddr + client->doorbell_offset;
	desc.db_trigger_uk = gfx_addr + client->doorbell_offset;
	desc.process_desc = gfx_addr + client->proc_desc_offset;
	desc.wq_addr = gfx_addr + client->wq_offset;
	desc.wq_size = client->wq_size;

	/*
	 * XXX: Take LRCs from an existing context if this is not an
	 * IsKMDCreatedContext client
	 */
	desc.desc_private = (uintptr_t)client;

	/* Pool context is pinned already */
	sg = guc->ctx_pool_vma->pages;
	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
			     sizeof(desc) * client->ctx_index);
}

static void guc_ctx_desc_fini(struct intel_guc *guc,
			      struct i915_guc_client *client)
{
	struct guc_context_desc desc;
	struct sg_table *sg;

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

	sg = guc->ctx_pool_vma->pages;
	sg_pcopy_from_buffer(sg->sgl, sg->nents, &desc, sizeof(desc),
			     sizeof(desc) * client->ctx_index);
}

/**
 * i915_guc_wq_reserve() - reserve space in the GuC's workqueue
 * @request:	request associated with the commands
 *
 * Return:	0 if space is available
 *		-EAGAIN if space is not currently available
 *
 * This function must be called (and must return 0) before a request
 * is submitted to the GuC via i915_guc_submit() below. Once a result
 * of 0 has been returned, it must be balanced by a corresponding
 * call to submit().
 *
 * Reservation allows the caller to determine in advance that space
 * will be available for the next submission before committing resources
 * to it, and helps avoid late failures with complicated recovery paths.
 */
int i915_guc_wq_reserve(struct drm_i915_gem_request *request)
{
	const size_t wqi_size = sizeof(struct guc_wq_item);
	struct i915_guc_client *gc = request->i915->guc.execbuf_client;
	struct guc_process_desc *desc = gc->vaddr + gc->proc_desc_offset;
	u32 freespace;
	int ret;

	spin_lock(&gc->wq_lock);
	freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size);
	freespace -= gc->wq_rsvd;
	if (likely(freespace >= wqi_size)) {
		gc->wq_rsvd += wqi_size;
		ret = 0;
	} else {
		gc->no_wq_space++;
		ret = -EAGAIN;
	}
	spin_unlock(&gc->wq_lock);

	return ret;
}

void i915_guc_wq_unreserve(struct drm_i915_gem_request *request)
{
	const size_t wqi_size = sizeof(struct guc_wq_item);
	struct i915_guc_client *gc = request->i915->guc.execbuf_client;

	GEM_BUG_ON(READ_ONCE(gc->wq_rsvd) < wqi_size);

	spin_lock(&gc->wq_lock);
	gc->wq_rsvd -= wqi_size;
	spin_unlock(&gc->wq_lock);
}

/* Construct a Work Item and append it to the GuC's Work Queue */
static void guc_wq_item_append(struct i915_guc_client *gc,
			       struct drm_i915_gem_request *rq)
{
	/* wqi_len is in DWords, and does not include the one-word header */
	const size_t wqi_size = sizeof(struct guc_wq_item);
	const u32 wqi_len = wqi_size/sizeof(u32) - 1;
	struct intel_engine_cs *engine = rq->engine;
	struct guc_process_desc *desc;
	struct guc_wq_item *wqi;
	u32 freespace, tail, wq_off;

	desc = gc->vaddr + gc->proc_desc_offset;

	/* Free space is guaranteed, see i915_guc_wq_reserve() above */
	freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size);
	GEM_BUG_ON(freespace < wqi_size);

	/* The GuC firmware wants the tail index in QWords, not bytes */
	tail = rq->tail;
	GEM_BUG_ON(tail & 7);
	tail >>= 3;
	GEM_BUG_ON(tail > WQ_RING_TAIL_MAX);

	/* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
	 * should not have the case where structure wqi is across page, neither
	 * wrapped to the beginning. This simplifies the implementation below.
	 *
	 * XXX: if not the case, we need save data to a temp wqi and copy it to
	 * workqueue buffer dw by dw.
	 */
	BUILD_BUG_ON(wqi_size != 16);
	GEM_BUG_ON(gc->wq_rsvd < wqi_size);

	/* postincrement WQ tail for next time */
	wq_off = gc->wq_tail;
	GEM_BUG_ON(wq_off & (wqi_size - 1));
	gc->wq_tail += wqi_size;
	gc->wq_tail &= gc->wq_size - 1;
	gc->wq_rsvd -= wqi_size;

	/* WQ starts from the page after doorbell / process_desc */
	wqi = gc->vaddr + wq_off + GUC_DB_SIZE;

	/* Now fill in the 4-word work queue item */
	wqi->header = WQ_TYPE_INORDER |
			(wqi_len << WQ_LEN_SHIFT) |
			(engine->guc_id << WQ_TARGET_SHIFT) |
			WQ_NO_WCFLUSH_WAIT;

	/* The GuC wants only the low-order word of the context descriptor */
	wqi->context_desc = (u32)intel_lr_context_descriptor(rq->ctx, engine);

	wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT;
	wqi->fence_id = rq->global_seqno;
}

static int guc_ring_doorbell(struct i915_guc_client *gc)
{
	struct guc_process_desc *desc;
	union guc_doorbell_qw db_cmp, db_exc, db_ret;
	union guc_doorbell_qw *db;
	int attempt = 2, ret = -EAGAIN;

	desc = gc->vaddr + gc->proc_desc_offset;

	/* Update the tail so it is visible to GuC */
	desc->tail = gc->wq_tail;

	/* current cookie */
	db_cmp.db_status = GUC_DOORBELL_ENABLED;
	db_cmp.cookie = gc->cookie;

	/* cookie to be updated */
	db_exc.db_status = GUC_DOORBELL_ENABLED;
	db_exc.cookie = gc->cookie + 1;
	if (db_exc.cookie == 0)
		db_exc.cookie = 1;

	/* pointer of current doorbell cacheline */
	db = gc->vaddr + gc->doorbell_offset;

	while (attempt--) {
		/* lets ring the doorbell */
		db_ret.value_qw = atomic64_cmpxchg((atomic64_t *)db,
			db_cmp.value_qw, db_exc.value_qw);

		/* if the exchange was successfully executed */
		if (db_ret.value_qw == db_cmp.value_qw) {
			/* db was successfully rung */
			gc->cookie = db_exc.cookie;
			ret = 0;
			break;
		}

		/* XXX: doorbell was lost and need to acquire it again */
		if (db_ret.db_status == GUC_DOORBELL_DISABLED)
			break;

		DRM_WARN("Cookie mismatch. Expected %d, found %d\n",
			 db_cmp.cookie, db_ret.cookie);

		/* update the cookie to newly read cookie from GuC */
		db_cmp.cookie = db_ret.cookie;
		db_exc.cookie = db_ret.cookie + 1;
		if (db_exc.cookie == 0)
			db_exc.cookie = 1;
	}

	return ret;
}

/**
 * i915_guc_submit() - Submit commands through GuC
 * @rq:		request associated with the commands
 *
 * Return:	0 on success, otherwise an errno.
 * 		(Note: nonzero really shouldn't happen!)
 *
 * The caller must have already called i915_guc_wq_reserve() above with
 * a result of 0 (success), guaranteeing that there is space in the work
 * queue for the new request, so enqueuing the item cannot fail.
 *
 * Bad Things Will Happen if the caller violates this protocol e.g. calls
 * submit() when _reserve() says there's no space, or calls _submit()
 * a different number of times from (successful) calls to _reserve().
 *
 * The only error here arises if the doorbell hardware isn't functioning
 * as expected, which really shouln't happen.
 */
static void i915_guc_submit(struct drm_i915_gem_request *rq)
{
	struct drm_i915_private *dev_priv = rq->i915;
	struct intel_engine_cs *engine = rq->engine;
	unsigned int engine_id = engine->id;
	struct intel_guc *guc = &rq->i915->guc;
	struct i915_guc_client *client = guc->execbuf_client;
	int b_ret;

	/* We keep the previous context alive until we retire the following
	 * request. This ensures that any the context object is still pinned
	 * for any residual writes the HW makes into it on the context switch
	 * into the next object following the breadcrumb. Otherwise, we may
	 * retire the context too early.
	 */
	rq->previous_context = engine->last_context;
	engine->last_context = rq->ctx;

	i915_gem_request_submit(rq);

	spin_lock(&client->wq_lock);
	guc_wq_item_append(client, rq);

	/* WA to flush out the pending GMADR writes to ring buffer. */
	if (i915_vma_is_map_and_fenceable(rq->ring->vma))
		POSTING_READ_FW(GUC_STATUS);

	b_ret = guc_ring_doorbell(client);

	client->submissions[engine_id] += 1;
	client->retcode = b_ret;
	if (b_ret)
		client->b_fail += 1;

	guc->submissions[engine_id] += 1;
	guc->last_seqno[engine_id] = rq->global_seqno;
	spin_unlock(&client->wq_lock);
}

/*
 * Everything below here is concerned with setup & teardown, and is
 * therefore not part of the somewhat time-critical batch-submission
 * path of i915_guc_submit() above.
 */

/**
 * guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
 * @guc:	the guc
 * @size:	size of area to allocate (both virtual space and memory)
 *
 * This is a wrapper to create an object for use with the GuC. In order to
 * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
 * both some backing storage and a range inside the Global GTT. We must pin
 * it in the GGTT somewhere other than than [0, GUC_WOPCM_TOP) because that
 * range is reserved inside GuC.
 *
 * Return:	A i915_vma if successful, otherwise an ERR_PTR.
 */
static struct i915_vma *guc_allocate_vma(struct intel_guc *guc, u32 size)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	int ret;

	obj = i915_gem_object_create(&dev_priv->drm, size);
	if (IS_ERR(obj))
		return ERR_CAST(obj);

	vma = i915_vma_create(obj, &dev_priv->ggtt.base, NULL);
	if (IS_ERR(vma))
		goto err;

	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
			   PIN_GLOBAL | PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
	if (ret) {
		vma = ERR_PTR(ret);
		goto err;
	}

	/* Invalidate GuC TLB to let GuC take the latest updates to GTT. */
	I915_WRITE(GEN8_GTCR, GEN8_GTCR_INVALIDATE);

	return vma;

err:
	i915_gem_object_put(obj);
	return vma;
}

static void
guc_client_free(struct drm_i915_private *dev_priv,
		struct i915_guc_client *client)
{
	struct intel_guc *guc = &dev_priv->guc;

	if (!client)
		return;

	/*
	 * XXX: wait for any outstanding submissions before freeing memory.
	 * Be sure to drop any locks
	 */

	if (client->vaddr) {
		/*
		 * If we got as far as setting up a doorbell, make sure we
		 * shut it down before unmapping & deallocating the memory.
		 */
		guc_disable_doorbell(guc, client);

		i915_gem_object_unpin_map(client->vma->obj);
	}

	i915_vma_unpin_and_release(&client->vma);

	if (client->ctx_index != GUC_INVALID_CTX_ID) {
		guc_ctx_desc_fini(guc, client);
		ida_simple_remove(&guc->ctx_ids, client->ctx_index);
	}

	kfree(client);
}

/* Check that a doorbell register is in the expected state */
static bool guc_doorbell_check(struct intel_guc *guc, uint16_t db_id)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	i915_reg_t drbreg = GEN8_DRBREGL(db_id);
	uint32_t value = I915_READ(drbreg);
	bool enabled = (value & GUC_DOORBELL_ENABLED) != 0;
	bool expected = test_bit(db_id, guc->doorbell_bitmap);

	if (enabled == expected)
		return true;

	DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) 0x%x, should be %s\n",
			 db_id, drbreg.reg, value,
			 expected ? "active" : "inactive");

	return false;
}

/*
 * Borrow the first client to set up & tear down each unused doorbell
 * in turn, to ensure that all doorbell h/w is (re)initialised.
 */
static void guc_init_doorbell_hw(struct intel_guc *guc)
{
	struct i915_guc_client *client = guc->execbuf_client;
	uint16_t db_id;
	int i, err;

	/* Save client's original doorbell selection */
	db_id = client->doorbell_id;

	for (i = 0; i < GUC_MAX_DOORBELLS; ++i) {
		/* Skip if doorbell is OK */
		if (guc_doorbell_check(guc, i))
			continue;

		err = guc_update_doorbell_id(guc, client, i);
		if (err)
			DRM_DEBUG_DRIVER("Doorbell %d update failed, err %d\n",
					i, err);
	}

	/* Restore to original value */
	err = guc_update_doorbell_id(guc, client, db_id);
	if (err)
		DRM_WARN("Failed to restore doorbell to %d, err %d\n",
			 db_id, err);

	/* Read back & verify all doorbell registers */
	for (i = 0; i < GUC_MAX_DOORBELLS; ++i)
		(void)guc_doorbell_check(guc, i);
}

/**
 * guc_client_alloc() - Allocate an i915_guc_client
 * @dev_priv:	driver private data structure
 * @engines:	The set of engines to enable for this client
 * @priority:	four levels priority _CRITICAL, _HIGH, _NORMAL and _LOW
 * 		The kernel client to replace ExecList submission is created with
 * 		NORMAL priority. Priority of a client for scheduler can be HIGH,
 * 		while a preemption context can use CRITICAL.
 * @ctx:	the context that owns the client (we use the default render
 * 		context)
 *
 * Return:	An i915_guc_client object if success, else NULL.
 */
static struct i915_guc_client *
guc_client_alloc(struct drm_i915_private *dev_priv,
		 uint32_t engines,
		 uint32_t priority,
		 struct i915_gem_context *ctx)
{
	struct i915_guc_client *client;
	struct intel_guc *guc = &dev_priv->guc;
	struct i915_vma *vma;
	void *vaddr;
	uint16_t db_id;

	client = kzalloc(sizeof(*client), GFP_KERNEL);
	if (!client)
		return NULL;

	client->owner = ctx;
	client->guc = guc;
	client->engines = engines;
	client->priority = priority;
	client->doorbell_id = GUC_INVALID_DOORBELL_ID;

	client->ctx_index = (uint32_t)ida_simple_get(&guc->ctx_ids, 0,
			GUC_MAX_GPU_CONTEXTS, GFP_KERNEL);
	if (client->ctx_index >= GUC_MAX_GPU_CONTEXTS) {
		client->ctx_index = GUC_INVALID_CTX_ID;
		goto err;
	}

	/* The first page is doorbell/proc_desc. Two followed pages are wq. */
	vma = guc_allocate_vma(guc, GUC_DB_SIZE + GUC_WQ_SIZE);
	if (IS_ERR(vma))
		goto err;

	/* We'll keep just the first (doorbell/proc) page permanently kmap'd. */
	client->vma = vma;

	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
	if (IS_ERR(vaddr))
		goto err;

	client->vaddr = vaddr;

	spin_lock_init(&client->wq_lock);
	client->wq_offset = GUC_DB_SIZE;
	client->wq_size = GUC_WQ_SIZE;

	db_id = select_doorbell_register(guc, client->priority);
	if (db_id == GUC_INVALID_DOORBELL_ID)
		/* XXX: evict a doorbell instead? */
		goto err;

	client->doorbell_offset = select_doorbell_cacheline(guc);

	/*
	 * Since the doorbell only requires a single cacheline, we can save
	 * space by putting the application process descriptor in the same
	 * page. Use the half of the page that doesn't include the doorbell.
	 */
	if (client->doorbell_offset >= (GUC_DB_SIZE / 2))
		client->proc_desc_offset = 0;
	else
		client->proc_desc_offset = (GUC_DB_SIZE / 2);

	guc_proc_desc_init(guc, client);
	guc_ctx_desc_init(guc, client);
	if (guc_init_doorbell(guc, client, db_id))
		goto err;

	DRM_DEBUG_DRIVER("new priority %u client %p for engine(s) 0x%x: ctx_index %u\n",
		priority, client, client->engines, client->ctx_index);
	DRM_DEBUG_DRIVER("doorbell id %u, cacheline offset 0x%x\n",
		client->doorbell_id, client->doorbell_offset);

	return client;

err:
	guc_client_free(dev_priv, client);
	return NULL;
}

/*
 * Sub buffer switch callback. Called whenever relay has to switch to a new
 * sub buffer, relay stays on the same sub buffer if 0 is returned.
 */
static int subbuf_start_callback(struct rchan_buf *buf,
				 void *subbuf,
				 void *prev_subbuf,
				 size_t prev_padding)
{
	/* Use no-overwrite mode by default, where relay will stop accepting
	 * new data if there are no empty sub buffers left.
	 * There is no strict synchronization enforced by relay between Consumer
	 * and Producer. In overwrite mode, there is a possibility of getting
	 * inconsistent/garbled data, the producer could be writing on to the
	 * same sub buffer from which Consumer is reading. This can't be avoided
	 * unless Consumer is fast enough and can always run in tandem with
	 * Producer.
	 */
	if (relay_buf_full(buf))
		return 0;

	return 1;
}

/*
 * file_create() callback. Creates relay file in debugfs.
 */
static struct dentry *create_buf_file_callback(const char *filename,
					       struct dentry *parent,
					       umode_t mode,
					       struct rchan_buf *buf,
					       int *is_global)
{
	struct dentry *buf_file;

	/* This to enable the use of a single buffer for the relay channel and
	 * correspondingly have a single file exposed to User, through which
	 * it can collect the logs in order without any post-processing.
	 * Need to set 'is_global' even if parent is NULL for early logging.
	 */
	*is_global = 1;

	if (!parent)
		return NULL;

	/* Not using the channel filename passed as an argument, since for each
	 * channel relay appends the corresponding CPU number to the filename
	 * passed in relay_open(). This should be fine as relay just needs a
	 * dentry of the file associated with the channel buffer and that file's
	 * name need not be same as the filename passed as an argument.
	 */
	buf_file = debugfs_create_file("guc_log", mode,
				       parent, buf, &relay_file_operations);
	return buf_file;
}

/*
 * file_remove() default callback. Removes relay file in debugfs.
 */
static int remove_buf_file_callback(struct dentry *dentry)
{
	debugfs_remove(dentry);
	return 0;
}

/* relay channel callbacks */
static struct rchan_callbacks relay_callbacks = {
	.subbuf_start = subbuf_start_callback,
	.create_buf_file = create_buf_file_callback,
	.remove_buf_file = remove_buf_file_callback,
};

static void guc_log_remove_relay_file(struct intel_guc *guc)
{
	relay_close(guc->log.relay_chan);
}

static int guc_log_create_relay_channel(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct rchan *guc_log_relay_chan;
	size_t n_subbufs, subbuf_size;

	/* Keep the size of sub buffers same as shared log buffer */
	subbuf_size = guc->log.vma->obj->base.size;

	/* Store up to 8 snapshots, which is large enough to buffer sufficient
	 * boot time logs and provides enough leeway to User, in terms of
	 * latency, for consuming the logs from relay. Also doesn't take
	 * up too much memory.
	 */
	n_subbufs = 8;

	guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
					n_subbufs, &relay_callbacks, dev_priv);
	if (!guc_log_relay_chan) {
		DRM_ERROR("Couldn't create relay chan for GuC logging\n");
		return -ENOMEM;
	}

	GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
	guc->log.relay_chan = guc_log_relay_chan;
	return 0;
}

static int guc_log_create_relay_file(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct dentry *log_dir;
	int ret;

	/* For now create the log file in /sys/kernel/debug/dri/0 dir */
	log_dir = dev_priv->drm.primary->debugfs_root;

	/* If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
	 * not mounted and so can't create the relay file.
	 * The relay API seems to fit well with debugfs only, for availing relay
	 * there are 3 requirements which can be met for debugfs file only in a
	 * straightforward/clean manner :-
	 * i)   Need the associated dentry pointer of the file, while opening the
	 *      relay channel.
	 * ii)  Should be able to use 'relay_file_operations' fops for the file.
	 * iii) Set the 'i_private' field of file's inode to the pointer of
	 *	relay channel buffer.
	 */
	if (!log_dir) {
		DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
		return -ENODEV;
	}

	ret = relay_late_setup_files(guc->log.relay_chan, "guc_log", log_dir);
	if (ret) {
		DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
		return ret;
	}

	return 0;
}

static void guc_move_to_next_buf(struct intel_guc *guc)
{
	/* Make sure the updates made in the sub buffer are visible when
	 * Consumer sees the following update to offset inside the sub buffer.
	 */
	smp_wmb();

	/* All data has been written, so now move the offset of sub buffer. */
	relay_reserve(guc->log.relay_chan, guc->log.vma->obj->base.size);

	/* Switch to the next sub buffer */
	relay_flush(guc->log.relay_chan);
}

static void *guc_get_write_buffer(struct intel_guc *guc)
{
	if (!guc->log.relay_chan)
		return NULL;

	/* Just get the base address of a new sub buffer and copy data into it
	 * ourselves. NULL will be returned in no-overwrite mode, if all sub
	 * buffers are full. Could have used the relay_write() to indirectly
	 * copy the data, but that would have been bit convoluted, as we need to
	 * write to only certain locations inside a sub buffer which cannot be
	 * done without using relay_reserve() along with relay_write(). So its
	 * better to use relay_reserve() alone.
	 */
	return relay_reserve(guc->log.relay_chan, 0);
}

static bool
guc_check_log_buf_overflow(struct intel_guc *guc,
			   enum guc_log_buffer_type type, unsigned int full_cnt)
{
	unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
	bool overflow = false;

	if (full_cnt != prev_full_cnt) {
		overflow = true;

		guc->log.prev_overflow_count[type] = full_cnt;
		guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;

		if (full_cnt < prev_full_cnt) {
			/* buffer_full_cnt is a 4 bit counter */
			guc->log.total_overflow_count[type] += 16;
		}
		DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
	}

	return overflow;
}

static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
{
	switch (type) {
	case GUC_ISR_LOG_BUFFER:
		return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
	case GUC_DPC_LOG_BUFFER:
		return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
	case GUC_CRASH_DUMP_LOG_BUFFER:
		return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
	default:
		MISSING_CASE(type);
	}

	return 0;
}

static void guc_read_update_log_buffer(struct intel_guc *guc)
{
	unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
	struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
	struct guc_log_buffer_state log_buf_state_local;
	enum guc_log_buffer_type type;
	void *src_data, *dst_data;
	bool new_overflow;

	if (WARN_ON(!guc->log.buf_addr))
		return;

	/* Get the pointer to shared GuC log buffer */
	log_buf_state = src_data = guc->log.buf_addr;

	/* Get the pointer to local buffer to store the logs */
	log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);

	/* Actual logs are present from the 2nd page */
	src_data += PAGE_SIZE;
	dst_data += PAGE_SIZE;

	for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
		/* Make a copy of the state structure, inside GuC log buffer
		 * (which is uncached mapped), on the stack to avoid reading
		 * from it multiple times.
		 */
		memcpy(&log_buf_state_local, log_buf_state,
		       sizeof(struct guc_log_buffer_state));
		buffer_size = guc_get_log_buffer_size(type);
		read_offset = log_buf_state_local.read_ptr;
		write_offset = log_buf_state_local.sampled_write_ptr;
		full_cnt = log_buf_state_local.buffer_full_cnt;

		/* Bookkeeping stuff */
		guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
		new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);

		/* Update the state of shared log buffer */
		log_buf_state->read_ptr = write_offset;
		log_buf_state->flush_to_file = 0;
		log_buf_state++;

		if (unlikely(!log_buf_snapshot_state))
			continue;

		/* First copy the state structure in snapshot buffer */
		memcpy(log_buf_snapshot_state, &log_buf_state_local,
		       sizeof(struct guc_log_buffer_state));

		/* The write pointer could have been updated by GuC firmware,
		 * after sending the flush interrupt to Host, for consistency
		 * set write pointer value to same value of sampled_write_ptr
		 * in the snapshot buffer.
		 */
		log_buf_snapshot_state->write_ptr = write_offset;
		log_buf_snapshot_state++;

		/* Now copy the actual logs. */
		if (unlikely(new_overflow)) {
			/* copy the whole buffer in case of overflow */
			read_offset = 0;
			write_offset = buffer_size;
		} else if (unlikely((read_offset > buffer_size) ||
				    (write_offset > buffer_size))) {
			DRM_ERROR("invalid log buffer state\n");
			/* copy whole buffer as offsets are unreliable */
			read_offset = 0;
			write_offset = buffer_size;
		}

		/* Just copy the newly written data */
		if (read_offset > write_offset) {
			i915_memcpy_from_wc(dst_data, src_data, write_offset);
			bytes_to_copy = buffer_size - read_offset;
		} else {
			bytes_to_copy = write_offset - read_offset;
		}
		i915_memcpy_from_wc(dst_data + read_offset,
				    src_data + read_offset, bytes_to_copy);

		src_data += buffer_size;
		dst_data += buffer_size;
	}

	if (log_buf_snapshot_state)
		guc_move_to_next_buf(guc);
	else {
		/* Used rate limited to avoid deluge of messages, logs might be
		 * getting consumed by User at a slow rate.
		 */
		DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
		guc->log.capture_miss_count++;
	}
}

static void guc_capture_logs_work(struct work_struct *work)
{
	struct drm_i915_private *dev_priv =
		container_of(work, struct drm_i915_private, guc.log.flush_work);

	i915_guc_capture_logs(dev_priv);
}

static void guc_log_cleanup(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	lockdep_assert_held(&dev_priv->drm.struct_mutex);

	/* First disable the flush interrupt */
	gen9_disable_guc_interrupts(dev_priv);

	if (guc->log.flush_wq)
		destroy_workqueue(guc->log.flush_wq);

	guc->log.flush_wq = NULL;

	if (guc->log.relay_chan)
		guc_log_remove_relay_file(guc);

	guc->log.relay_chan = NULL;

	if (guc->log.buf_addr)
		i915_gem_object_unpin_map(guc->log.vma->obj);

	guc->log.buf_addr = NULL;
}

static int guc_log_create_extras(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	void *vaddr;
	int ret;

	lockdep_assert_held(&dev_priv->drm.struct_mutex);

	/* Nothing to do */
	if (i915.guc_log_level < 0)
		return 0;

	if (!guc->log.buf_addr) {
		/* Create a WC (Uncached for read) vmalloc mapping of log
		 * buffer pages, so that we can directly get the data
		 * (up-to-date) from memory.
		 */
		vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
		if (IS_ERR(vaddr)) {
			ret = PTR_ERR(vaddr);
			DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
			return ret;
		}

		guc->log.buf_addr = vaddr;
	}

	if (!guc->log.relay_chan) {
		/* Create a relay channel, so that we have buffers for storing
		 * the GuC firmware logs, the channel will be linked with a file
		 * later on when debugfs is registered.
		 */
		ret = guc_log_create_relay_channel(guc);
		if (ret)
			return ret;
	}

	if (!guc->log.flush_wq) {
		INIT_WORK(&guc->log.flush_work, guc_capture_logs_work);

		 /*
		 * GuC log buffer flush work item has to do register access to
		 * send the ack to GuC and this work item, if not synced before
		 * suspend, can potentially get executed after the GFX device is
		 * suspended.
		 * By marking the WQ as freezable, we don't have to bother about
		 * flushing of this work item from the suspend hooks, the pending
		 * work item if any will be either executed before the suspend
		 * or scheduled later on resume. This way the handling of work
		 * item can be kept same between system suspend & rpm suspend.
		 */
		guc->log.flush_wq = alloc_ordered_workqueue("i915-guc_log",
							    WQ_HIGHPRI | WQ_FREEZABLE);
		if (guc->log.flush_wq == NULL) {
			DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
			return -ENOMEM;
		}
	}

	return 0;
}

static void guc_log_create(struct intel_guc *guc)
{
	struct i915_vma *vma;
	unsigned long offset;
	uint32_t size, flags;

	if (i915.guc_log_level > GUC_LOG_VERBOSITY_MAX)
		i915.guc_log_level = GUC_LOG_VERBOSITY_MAX;

	/* The first page is to save log buffer state. Allocate one
	 * extra page for others in case for overlap */
	size = (1 + GUC_LOG_DPC_PAGES + 1 +
		GUC_LOG_ISR_PAGES + 1 +
		GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;

	vma = guc->log.vma;
	if (!vma) {
		/* We require SSE 4.1 for fast reads from the GuC log buffer and
		 * it should be present on the chipsets supporting GuC based
		 * submisssions.
		 */
		if (WARN_ON(!i915_memcpy_from_wc(NULL, NULL, 0))) {
			/* logging will not be enabled */
			i915.guc_log_level = -1;
			return;
		}

		vma = guc_allocate_vma(guc, size);
		if (IS_ERR(vma)) {
			/* logging will be off */
			i915.guc_log_level = -1;
			return;
		}

		guc->log.vma = vma;

		if (guc_log_create_extras(guc)) {
			guc_log_cleanup(guc);
			i915_vma_unpin_and_release(&guc->log.vma);
			i915.guc_log_level = -1;
			return;
		}
	}

	/* each allocated unit is a page */
	flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
		(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
		(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
		(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);

	offset = i915_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
	guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
}

static int guc_log_late_setup(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	int ret;

	lockdep_assert_held(&dev_priv->drm.struct_mutex);

	if (i915.guc_log_level < 0)
		return -EINVAL;

	/* If log_level was set as -1 at boot time, then setup needed to
	 * handle log buffer flush interrupts would not have been done yet,
	 * so do that now.
	 */
	ret = guc_log_create_extras(guc);
	if (ret)
		goto err;

	ret = guc_log_create_relay_file(guc);
	if (ret)
		goto err;

	return 0;
err:
	guc_log_cleanup(guc);
	/* logging will remain off */
	i915.guc_log_level = -1;
	return ret;
}

static void guc_policies_init(struct guc_policies *policies)
{
	struct guc_policy *policy;
	u32 p, i;

	policies->dpc_promote_time = 500000;
	policies->max_num_work_items = POLICY_MAX_NUM_WI;

	for (p = 0; p < GUC_CTX_PRIORITY_NUM; p++) {
		for (i = GUC_RENDER_ENGINE; i < GUC_MAX_ENGINES_NUM; i++) {
			policy = &policies->policy[p][i];

			policy->execution_quantum = 1000000;
			policy->preemption_time = 500000;
			policy->fault_time = 250000;
			policy->policy_flags = 0;
		}
	}

	policies->is_valid = 1;
}

static void guc_addon_create(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct i915_vma *vma;
	struct guc_ads *ads;
	struct guc_policies *policies;
	struct guc_mmio_reg_state *reg_state;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;
	struct page *page;
	u32 size;

	/* The ads obj includes the struct itself and buffers passed to GuC */
	size = sizeof(struct guc_ads) + sizeof(struct guc_policies) +
			sizeof(struct guc_mmio_reg_state) +
			GUC_S3_SAVE_SPACE_PAGES * PAGE_SIZE;

	vma = guc->ads_vma;
	if (!vma) {
		vma = guc_allocate_vma(guc, PAGE_ALIGN(size));
		if (IS_ERR(vma))
			return;

		guc->ads_vma = vma;
	}

	page = i915_vma_first_page(vma);
	ads = kmap(page);

	/*
	 * The GuC requires a "Golden Context" when it reinitialises
	 * engines after a reset. Here we use the Render ring default
	 * context, which must already exist and be pinned in the GGTT,
	 * so its address won't change after we've told the GuC where
	 * to find it.
	 */
	engine = dev_priv->engine[RCS];
	ads->golden_context_lrca = engine->status_page.ggtt_offset;

	for_each_engine(engine, dev_priv, id)
		ads->eng_state_size[engine->guc_id] = intel_lr_context_size(engine);

	/* GuC scheduling policies */
	policies = (void *)ads + sizeof(struct guc_ads);
	guc_policies_init(policies);

	ads->scheduler_policies =
		i915_ggtt_offset(vma) + sizeof(struct guc_ads);

	/* MMIO reg state */
	reg_state = (void *)policies + sizeof(struct guc_policies);

	for_each_engine(engine, dev_priv, id) {
		reg_state->mmio_white_list[engine->guc_id].mmio_start =
			engine->mmio_base + GUC_MMIO_WHITE_LIST_START;

		/* Nothing to be saved or restored for now. */
		reg_state->mmio_white_list[engine->guc_id].count = 0;
	}

	ads->reg_state_addr = ads->scheduler_policies +
			sizeof(struct guc_policies);

	ads->reg_state_buffer = ads->reg_state_addr +
			sizeof(struct guc_mmio_reg_state);

	kunmap(page);
}

/*
 * Set up the memory resources to be shared with the GuC.  At this point,
 * we require just one object that can be mapped through the GGTT.
 */
int i915_guc_submission_init(struct drm_i915_private *dev_priv)
{
	const size_t ctxsize = sizeof(struct guc_context_desc);
	const size_t poolsize = GUC_MAX_GPU_CONTEXTS * ctxsize;
	const size_t gemsize = round_up(poolsize, PAGE_SIZE);
	struct intel_guc *guc = &dev_priv->guc;
	struct i915_vma *vma;

	/* Wipe bitmap & delete client in case of reinitialisation */
	bitmap_clear(guc->doorbell_bitmap, 0, GUC_MAX_DOORBELLS);
	i915_guc_submission_disable(dev_priv);

	if (!i915.enable_guc_submission)
		return 0; /* not enabled  */

	if (guc->ctx_pool_vma)
		return 0; /* already allocated */

	vma = guc_allocate_vma(guc, gemsize);
	if (IS_ERR(vma))
		return PTR_ERR(vma);

	guc->ctx_pool_vma = vma;
	ida_init(&guc->ctx_ids);
	mutex_init(&guc->action_lock);
	guc_log_create(guc);
	guc_addon_create(guc);

	return 0;
}

int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
{
	struct intel_guc *guc = &dev_priv->guc;
	struct drm_i915_gem_request *request;
	struct i915_guc_client *client;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;

	/* client for execbuf submission */
	client = guc_client_alloc(dev_priv,
				  INTEL_INFO(dev_priv)->ring_mask,
				  GUC_CTX_PRIORITY_KMD_NORMAL,
				  dev_priv->kernel_context);
	if (!client) {
		DRM_ERROR("Failed to create normal GuC client!\n");
		return -ENOMEM;
	}

	guc->execbuf_client = client;
	host2guc_sample_forcewake(guc, client);
	guc_init_doorbell_hw(guc);

	/* Take over from manual control of ELSP (execlists) */
	for_each_engine(engine, dev_priv, id) {
		engine->submit_request = i915_guc_submit;
		engine->schedule = NULL;

		/* Replay the current set of previously submitted requests */
		list_for_each_entry(request,
				    &engine->timeline->requests, link) {
			client->wq_rsvd += sizeof(struct guc_wq_item);
			if (i915_sw_fence_done(&request->submit))
				i915_guc_submit(request);
		}
	}

	return 0;
}

void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
{
	struct intel_guc *guc = &dev_priv->guc;

	if (!guc->execbuf_client)
		return;

	/* Revert back to manual ELSP submission */
	intel_execlists_enable_submission(dev_priv);

	guc_client_free(dev_priv, guc->execbuf_client);
	guc->execbuf_client = NULL;
}

void i915_guc_submission_fini(struct drm_i915_private *dev_priv)
{
	struct intel_guc *guc = &dev_priv->guc;

	i915_vma_unpin_and_release(&guc->ads_vma);
	i915_vma_unpin_and_release(&guc->log.vma);

	if (guc->ctx_pool_vma)
		ida_destroy(&guc->ctx_ids);
	i915_vma_unpin_and_release(&guc->ctx_pool_vma);
}

/**
 * intel_guc_suspend() - notify GuC entering suspend state
 * @dev:	drm device
 */
int intel_guc_suspend(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = to_i915(dev);
	struct intel_guc *guc = &dev_priv->guc;
	struct i915_gem_context *ctx;
	u32 data[3];

	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
		return 0;

	gen9_disable_guc_interrupts(dev_priv);

	ctx = dev_priv->kernel_context;

	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
	/* any value greater than GUC_POWER_D0 */
	data[1] = GUC_POWER_D1;
	/* first page is shared data with GuC */
	data[2] = i915_ggtt_offset(ctx->engine[RCS].state);

	return host2guc_action(guc, data, ARRAY_SIZE(data));
}


/**
 * intel_guc_resume() - notify GuC resuming from suspend state
 * @dev:	drm device
 */
int intel_guc_resume(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = to_i915(dev);
	struct intel_guc *guc = &dev_priv->guc;
	struct i915_gem_context *ctx;
	u32 data[3];

	if (guc->guc_fw.guc_fw_load_status != GUC_FIRMWARE_SUCCESS)
		return 0;

	if (i915.guc_log_level >= 0)
		gen9_enable_guc_interrupts(dev_priv);

	ctx = dev_priv->kernel_context;

	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
	data[1] = GUC_POWER_D0;
	/* first page is shared data with GuC */
	data[2] = i915_ggtt_offset(ctx->engine[RCS].state);

	return host2guc_action(guc, data, ARRAY_SIZE(data));
}

void i915_guc_capture_logs(struct drm_i915_private *dev_priv)
{
	guc_read_update_log_buffer(&dev_priv->guc);

	/* Generally device is expected to be active only at this
	 * time, so get/put should be really quick.
	 */
	intel_runtime_pm_get(dev_priv);
	host2guc_logbuffer_flush_complete(&dev_priv->guc);
	intel_runtime_pm_put(dev_priv);
}

void i915_guc_flush_logs(struct drm_i915_private *dev_priv)
{
	if (!i915.enable_guc_submission || (i915.guc_log_level < 0))
		return;

	/* First disable the interrupts, will be renabled afterwards */
	gen9_disable_guc_interrupts(dev_priv);

	/* Before initiating the forceful flush, wait for any pending/ongoing
	 * flush to complete otherwise forceful flush may not actually happen.
	 */
	flush_work(&dev_priv->guc.log.flush_work);

	/* Ask GuC to update the log buffer state */
	host2guc_force_logbuffer_flush(&dev_priv->guc);

	/* GuC would have updated log buffer by now, so capture it */
	i915_guc_capture_logs(dev_priv);
}

void i915_guc_unregister(struct drm_i915_private *dev_priv)
{
	if (!i915.enable_guc_submission)
		return;

	mutex_lock(&dev_priv->drm.struct_mutex);
	guc_log_cleanup(&dev_priv->guc);
	mutex_unlock(&dev_priv->drm.struct_mutex);
}

void i915_guc_register(struct drm_i915_private *dev_priv)
{
	if (!i915.enable_guc_submission)
		return;

	mutex_lock(&dev_priv->drm.struct_mutex);
	guc_log_late_setup(&dev_priv->guc);
	mutex_unlock(&dev_priv->drm.struct_mutex);
}

int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
{
	union guc_log_control log_param;
	int ret;

	log_param.value = control_val;

	if (log_param.verbosity < GUC_LOG_VERBOSITY_MIN ||
	    log_param.verbosity > GUC_LOG_VERBOSITY_MAX)
		return -EINVAL;

	/* This combination doesn't make sense & won't have any effect */
	if (!log_param.logging_enabled && (i915.guc_log_level < 0))
		return 0;

	ret = host2guc_logging_control(&dev_priv->guc, log_param.value);
	if (ret < 0) {
		DRM_DEBUG_DRIVER("host2guc action failed %d\n", ret);
		return ret;
	}

	i915.guc_log_level = log_param.verbosity;

	/* If log_level was set as -1 at boot time, then the relay channel file
	 * wouldn't have been created by now and interrupts also would not have
	 * been enabled.
	 */
	if (!dev_priv->guc.log.relay_chan) {
		ret = guc_log_late_setup(&dev_priv->guc);
		if (!ret)
			gen9_enable_guc_interrupts(dev_priv);
	} else if (!log_param.logging_enabled) {
		/* Once logging is disabled, GuC won't generate logs & send an
		 * interrupt. But there could be some data in the log buffer
		 * which is yet to be captured. So request GuC to update the log
		 * buffer state and then collect the left over logs.
		 */
		i915_guc_flush_logs(dev_priv);

		/* As logging is disabled, update log level to reflect that */
		i915.guc_log_level = -1;
	} else {
		/* In case interrupts were disabled, enable them now */
		gen9_enable_guc_interrupts(dev_priv);
	}

	return ret;
}