summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
blob: 847490bbb2e2c6020d2a35cc2b9e9b930914ea1b (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
/**************************************************************************
 *
 * Copyright © 2015 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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 <drm/ttm/ttm_bo_api.h>

#include "vmwgfx_drv.h"

/*
 * Size of inline command buffers. Try to make sure that a page size is a
 * multiple of the DMA pool allocation size.
 */
#define VMW_CMDBUF_INLINE_ALIGN 64
#define VMW_CMDBUF_INLINE_SIZE \
	(1024 - ALIGN(sizeof(SVGACBHeader), VMW_CMDBUF_INLINE_ALIGN))

/**
 * struct vmw_cmdbuf_context - Command buffer context queues
 *
 * @submitted: List of command buffers that have been submitted to the
 * manager but not yet submitted to hardware.
 * @hw_submitted: List of command buffers submitted to hardware.
 * @preempted: List of preempted command buffers.
 * @num_hw_submitted: Number of buffers currently being processed by hardware
 */
struct vmw_cmdbuf_context {
	struct list_head submitted;
	struct list_head hw_submitted;
	struct list_head preempted;
	unsigned num_hw_submitted;
	bool block_submission;
};

/**
 * struct vmw_cmdbuf_man: - Command buffer manager
 *
 * @cur_mutex: Mutex protecting the command buffer used for incremental small
 * kernel command submissions, @cur.
 * @space_mutex: Mutex to protect against starvation when we allocate
 * main pool buffer space.
 * @error_mutex: Mutex to serialize the work queue error handling.
 * Note this is not needed if the same workqueue handler
 * can't race with itself...
 * @work: A struct work_struct implementeing command buffer error handling.
 * Immutable.
 * @dev_priv: Pointer to the device private struct. Immutable.
 * @ctx: Array of command buffer context queues. The queues and the context
 * data is protected by @lock.
 * @error: List of command buffers that have caused device errors.
 * Protected by @lock.
 * @mm: Range manager for the command buffer space. Manager allocations and
 * frees are protected by @lock.
 * @cmd_space: Buffer object for the command buffer space, unless we were
 * able to make a contigous coherent DMA memory allocation, @handle. Immutable.
 * @map_obj: Mapping state for @cmd_space. Immutable.
 * @map: Pointer to command buffer space. May be a mapped buffer object or
 * a contigous coherent DMA memory allocation. Immutable.
 * @cur: Command buffer for small kernel command submissions. Protected by
 * the @cur_mutex.
 * @cur_pos: Space already used in @cur. Protected by @cur_mutex.
 * @default_size: Default size for the @cur command buffer. Immutable.
 * @max_hw_submitted: Max number of in-flight command buffers the device can
 * handle. Immutable.
 * @lock: Spinlock protecting command submission queues.
 * @header: Pool of DMA memory for device command buffer headers.
 * Internal protection.
 * @dheaders: Pool of DMA memory for device command buffer headers with trailing
 * space for inline data. Internal protection.
 * @alloc_queue: Wait queue for processes waiting to allocate command buffer
 * space.
 * @idle_queue: Wait queue for processes waiting for command buffer idle.
 * @irq_on: Whether the process function has requested irq to be turned on.
 * Protected by @lock.
 * @using_mob: Whether the command buffer space is a MOB or a contigous DMA
 * allocation. Immutable.
 * @has_pool: Has a large pool of DMA memory which allows larger allocations.
 * Typically this is false only during bootstrap.
 * @handle: DMA address handle for the command buffer space if @using_mob is
 * false. Immutable.
 * @size: The size of the command buffer space. Immutable.
 */
struct vmw_cmdbuf_man {
	struct mutex cur_mutex;
	struct mutex space_mutex;
	struct mutex error_mutex;
	struct work_struct work;
	struct vmw_private *dev_priv;
	struct vmw_cmdbuf_context ctx[SVGA_CB_CONTEXT_MAX];
	struct list_head error;
	struct drm_mm mm;
	struct ttm_buffer_object *cmd_space;
	struct ttm_bo_kmap_obj map_obj;
	u8 *map;
	struct vmw_cmdbuf_header *cur;
	size_t cur_pos;
	size_t default_size;
	unsigned max_hw_submitted;
	spinlock_t lock;
	struct dma_pool *headers;
	struct dma_pool *dheaders;
	wait_queue_head_t alloc_queue;
	wait_queue_head_t idle_queue;
	bool irq_on;
	bool using_mob;
	bool has_pool;
	dma_addr_t handle;
	size_t size;
};

/**
 * struct vmw_cmdbuf_header - Command buffer metadata
 *
 * @man: The command buffer manager.
 * @cb_header: Device command buffer header, allocated from a DMA pool.
 * @cb_context: The device command buffer context.
 * @list: List head for attaching to the manager lists.
 * @node: The range manager node.
 * @handle. The DMA address of @cb_header. Handed to the device on command
 * buffer submission.
 * @cmd: Pointer to the command buffer space of this buffer.
 * @size: Size of the command buffer space of this buffer.
 * @reserved: Reserved space of this buffer.
 * @inline_space: Whether inline command buffer space is used.
 */
struct vmw_cmdbuf_header {
	struct vmw_cmdbuf_man *man;
	SVGACBHeader *cb_header;
	SVGACBContext cb_context;
	struct list_head list;
	struct drm_mm_node node;
	dma_addr_t handle;
	u8 *cmd;
	size_t size;
	size_t reserved;
	bool inline_space;
};

/**
 * struct vmw_cmdbuf_dheader - Device command buffer header with inline
 * command buffer space.
 *
 * @cb_header: Device command buffer header.
 * @cmd: Inline command buffer space.
 */
struct vmw_cmdbuf_dheader {
	SVGACBHeader cb_header;
	u8 cmd[VMW_CMDBUF_INLINE_SIZE] __aligned(VMW_CMDBUF_INLINE_ALIGN);
};

/**
 * struct vmw_cmdbuf_alloc_info - Command buffer space allocation metadata
 *
 * @page_size: Size of requested command buffer space in pages.
 * @node: Pointer to the range manager node.
 * @done: True if this allocation has succeeded.
 */
struct vmw_cmdbuf_alloc_info {
	size_t page_size;
	struct drm_mm_node *node;
	bool done;
};

/* Loop over each context in the command buffer manager. */
#define for_each_cmdbuf_ctx(_man, _i, _ctx)				\
	for (_i = 0, _ctx = &(_man)->ctx[0]; (_i) < SVGA_CB_CONTEXT_MAX; \
	     ++(_i), ++(_ctx))

static int vmw_cmdbuf_startstop(struct vmw_cmdbuf_man *man, u32 context,
				bool enable);
static int vmw_cmdbuf_preempt(struct vmw_cmdbuf_man *man, u32 context);

/**
 * vmw_cmdbuf_cur_lock - Helper to lock the cur_mutex.
 *
 * @man: The range manager.
 * @interruptible: Whether to wait interruptible when locking.
 */
static int vmw_cmdbuf_cur_lock(struct vmw_cmdbuf_man *man, bool interruptible)
{
	if (interruptible) {
		if (mutex_lock_interruptible(&man->cur_mutex))
			return -ERESTARTSYS;
	} else {
		mutex_lock(&man->cur_mutex);
	}

	return 0;
}

/**
 * vmw_cmdbuf_cur_unlock - Helper to unlock the cur_mutex.
 *
 * @man: The range manager.
 */
static void vmw_cmdbuf_cur_unlock(struct vmw_cmdbuf_man *man)
{
	mutex_unlock(&man->cur_mutex);
}

/**
 * vmw_cmdbuf_header_inline_free - Free a struct vmw_cmdbuf_header that has
 * been used for the device context with inline command buffers.
 * Need not be called locked.
 *
 * @header: Pointer to the header to free.
 */
static void vmw_cmdbuf_header_inline_free(struct vmw_cmdbuf_header *header)
{
	struct vmw_cmdbuf_dheader *dheader;

	if (WARN_ON_ONCE(!header->inline_space))
		return;

	dheader = container_of(header->cb_header, struct vmw_cmdbuf_dheader,
			       cb_header);
	dma_pool_free(header->man->dheaders, dheader, header->handle);
	kfree(header);
}

/**
 * __vmw_cmdbuf_header_free - Free a struct vmw_cmdbuf_header  and its
 * associated structures.
 *
 * header: Pointer to the header to free.
 *
 * For internal use. Must be called with man::lock held.
 */
static void __vmw_cmdbuf_header_free(struct vmw_cmdbuf_header *header)
{
	struct vmw_cmdbuf_man *man = header->man;

	lockdep_assert_held_once(&man->lock);

	if (header->inline_space) {
		vmw_cmdbuf_header_inline_free(header);
		return;
	}

	drm_mm_remove_node(&header->node);
	wake_up_all(&man->alloc_queue);
	if (header->cb_header)
		dma_pool_free(man->headers, header->cb_header,
			      header->handle);
	kfree(header);
}

/**
 * vmw_cmdbuf_header_free - Free a struct vmw_cmdbuf_header  and its
 * associated structures.
 *
 * @header: Pointer to the header to free.
 */
void vmw_cmdbuf_header_free(struct vmw_cmdbuf_header *header)
{
	struct vmw_cmdbuf_man *man = header->man;

	/* Avoid locking if inline_space */
	if (header->inline_space) {
		vmw_cmdbuf_header_inline_free(header);
		return;
	}
	spin_lock(&man->lock);
	__vmw_cmdbuf_header_free(header);
	spin_unlock(&man->lock);
}


/**
 * vmw_cmbuf_header_submit: Submit a command buffer to hardware.
 *
 * @header: The header of the buffer to submit.
 */
static int vmw_cmdbuf_header_submit(struct vmw_cmdbuf_header *header)
{
	struct vmw_cmdbuf_man *man = header->man;
	u32 val;

	val = upper_32_bits(header->handle);
	vmw_write(man->dev_priv, SVGA_REG_COMMAND_HIGH, val);

	val = lower_32_bits(header->handle);
	val |= header->cb_context & SVGA_CB_CONTEXT_MASK;
	vmw_write(man->dev_priv, SVGA_REG_COMMAND_LOW, val);

	return header->cb_header->status;
}

/**
 * vmw_cmdbuf_ctx_init: Initialize a command buffer context.
 *
 * @ctx: The command buffer context to initialize
 */
static void vmw_cmdbuf_ctx_init(struct vmw_cmdbuf_context *ctx)
{
	INIT_LIST_HEAD(&ctx->hw_submitted);
	INIT_LIST_HEAD(&ctx->submitted);
	INIT_LIST_HEAD(&ctx->preempted);
	ctx->num_hw_submitted = 0;
}

/**
 * vmw_cmdbuf_ctx_submit: Submit command buffers from a command buffer
 * context.
 *
 * @man: The command buffer manager.
 * @ctx: The command buffer context.
 *
 * Submits command buffers to hardware until there are no more command
 * buffers to submit or the hardware can't handle more command buffers.
 */
static void vmw_cmdbuf_ctx_submit(struct vmw_cmdbuf_man *man,
				  struct vmw_cmdbuf_context *ctx)
{
	while (ctx->num_hw_submitted < man->max_hw_submitted &&
	       !list_empty(&ctx->submitted) &&
	       !ctx->block_submission) {
		struct vmw_cmdbuf_header *entry;
		SVGACBStatus status;

		entry = list_first_entry(&ctx->submitted,
					 struct vmw_cmdbuf_header,
					 list);

		status = vmw_cmdbuf_header_submit(entry);

		/* This should never happen */
		if (WARN_ON_ONCE(status == SVGA_CB_STATUS_QUEUE_FULL)) {
			entry->cb_header->status = SVGA_CB_STATUS_NONE;
			break;
		}

		list_del(&entry->list);
		list_add_tail(&entry->list, &ctx->hw_submitted);
		ctx->num_hw_submitted++;
	}

}

/**
 * vmw_cmdbuf_ctx_submit: Process a command buffer context.
 *
 * @man: The command buffer manager.
 * @ctx: The command buffer context.
 *
 * Submit command buffers to hardware if possible, and process finished
 * buffers. Typically freeing them, but on preemption or error take
 * appropriate action. Wake up waiters if appropriate.
 */
static void vmw_cmdbuf_ctx_process(struct vmw_cmdbuf_man *man,
				   struct vmw_cmdbuf_context *ctx,
				   int *notempty)
{
	struct vmw_cmdbuf_header *entry, *next;

	vmw_cmdbuf_ctx_submit(man, ctx);

	list_for_each_entry_safe(entry, next, &ctx->hw_submitted, list) {
		SVGACBStatus status = entry->cb_header->status;

		if (status == SVGA_CB_STATUS_NONE)
			break;

		list_del(&entry->list);
		wake_up_all(&man->idle_queue);
		ctx->num_hw_submitted--;
		switch (status) {
		case SVGA_CB_STATUS_COMPLETED:
			__vmw_cmdbuf_header_free(entry);
			break;
		case SVGA_CB_STATUS_COMMAND_ERROR:
			entry->cb_header->status = SVGA_CB_STATUS_NONE;
			list_add_tail(&entry->list, &man->error);
			schedule_work(&man->work);
			break;
		case SVGA_CB_STATUS_PREEMPTED:
			entry->cb_header->status = SVGA_CB_STATUS_NONE;
			list_add_tail(&entry->list, &ctx->preempted);
			break;
		case SVGA_CB_STATUS_CB_HEADER_ERROR:
			WARN_ONCE(true, "Command buffer header error.\n");
			__vmw_cmdbuf_header_free(entry);
			break;
		default:
			WARN_ONCE(true, "Undefined command buffer status.\n");
			__vmw_cmdbuf_header_free(entry);
			break;
		}
	}

	vmw_cmdbuf_ctx_submit(man, ctx);
	if (!list_empty(&ctx->submitted))
		(*notempty)++;
}

/**
 * vmw_cmdbuf_man_process - Process all command buffer contexts and
 * switch on and off irqs as appropriate.
 *
 * @man: The command buffer manager.
 *
 * Calls vmw_cmdbuf_ctx_process() on all contexts. If any context has
 * command buffers left that are not submitted to hardware, Make sure
 * IRQ handling is turned on. Otherwise, make sure it's turned off.
 */
static void vmw_cmdbuf_man_process(struct vmw_cmdbuf_man *man)
{
	int notempty;
	struct vmw_cmdbuf_context *ctx;
	int i;

retry:
	notempty = 0;
	for_each_cmdbuf_ctx(man, i, ctx)
		vmw_cmdbuf_ctx_process(man, ctx, &notempty);

	if (man->irq_on && !notempty) {
		vmw_generic_waiter_remove(man->dev_priv,
					  SVGA_IRQFLAG_COMMAND_BUFFER,
					  &man->dev_priv->cmdbuf_waiters);
		man->irq_on = false;
	} else if (!man->irq_on && notempty) {
		vmw_generic_waiter_add(man->dev_priv,
				       SVGA_IRQFLAG_COMMAND_BUFFER,
				       &man->dev_priv->cmdbuf_waiters);
		man->irq_on = true;

		/* Rerun in case we just missed an irq. */
		goto retry;
	}
}

/**
 * vmw_cmdbuf_ctx_add - Schedule a command buffer for submission on a
 * command buffer context
 *
 * @man: The command buffer manager.
 * @header: The header of the buffer to submit.
 * @cb_context: The command buffer context to use.
 *
 * This function adds @header to the "submitted" queue of the command
 * buffer context identified by @cb_context. It then calls the command buffer
 * manager processing to potentially submit the buffer to hardware.
 * @man->lock needs to be held when calling this function.
 */
static void vmw_cmdbuf_ctx_add(struct vmw_cmdbuf_man *man,
			       struct vmw_cmdbuf_header *header,
			       SVGACBContext cb_context)
{
	if (!(header->cb_header->flags & SVGA_CB_FLAG_DX_CONTEXT))
		header->cb_header->dxContext = 0;
	header->cb_context = cb_context;
	list_add_tail(&header->list, &man->ctx[cb_context].submitted);

	vmw_cmdbuf_man_process(man);
}

/**
 * vmw_cmdbuf_irqthread - The main part of the command buffer interrupt
 * handler implemented as a threaded irq task.
 *
 * @man: Pointer to the command buffer manager.
 *
 * The bottom half of the interrupt handler simply calls into the
 * command buffer processor to free finished buffers and submit any
 * queued buffers to hardware.
 */
void vmw_cmdbuf_irqthread(struct vmw_cmdbuf_man *man)
{
	spin_lock(&man->lock);
	vmw_cmdbuf_man_process(man);
	spin_unlock(&man->lock);
}

/**
 * vmw_cmdbuf_work_func - The deferred work function that handles
 * command buffer errors.
 *
 * @work: The work func closure argument.
 *
 * Restarting the command buffer context after an error requires process
 * context, so it is deferred to this work function.
 */
static void vmw_cmdbuf_work_func(struct work_struct *work)
{
	struct vmw_cmdbuf_man *man =
		container_of(work, struct vmw_cmdbuf_man, work);
	struct vmw_cmdbuf_header *entry, *next;
	uint32_t dummy;
	bool restart[SVGA_CB_CONTEXT_MAX];
	bool send_fence = false;
	struct list_head restart_head[SVGA_CB_CONTEXT_MAX];
	int i;
	struct vmw_cmdbuf_context *ctx;

	for_each_cmdbuf_ctx(man, i, ctx) {
		INIT_LIST_HEAD(&restart_head[i]);
		restart[i] = false;
	}

	mutex_lock(&man->error_mutex);
	spin_lock(&man->lock);
	list_for_each_entry_safe(entry, next, &man->error, list) {
		SVGACBHeader *cb_hdr = entry->cb_header;
		SVGA3dCmdHeader *header = (SVGA3dCmdHeader *)
			(entry->cmd + cb_hdr->errorOffset);
		u32 error_cmd_size, new_start_offset;
		const char *cmd_name;

		list_del_init(&entry->list);
		restart[entry->cb_context] = true;

		if (!vmw_cmd_describe(header, &error_cmd_size, &cmd_name)) {
			DRM_ERROR("Unknown command causing device error.\n");
			DRM_ERROR("Command buffer offset is %lu\n",
				  (unsigned long) cb_hdr->errorOffset);
			__vmw_cmdbuf_header_free(entry);
			send_fence = true;
			continue;
		}

		DRM_ERROR("Command \"%s\" causing device error.\n", cmd_name);
		DRM_ERROR("Command buffer offset is %lu\n",
			  (unsigned long) cb_hdr->errorOffset);
		DRM_ERROR("Command size is %lu\n",
			  (unsigned long) error_cmd_size);

		new_start_offset = cb_hdr->errorOffset + error_cmd_size;

		if (new_start_offset >= cb_hdr->length) {
			__vmw_cmdbuf_header_free(entry);
			send_fence = true;
			continue;
		}

		if (man->using_mob)
			cb_hdr->ptr.mob.mobOffset += new_start_offset;
		else
			cb_hdr->ptr.pa += (u64) new_start_offset;

		entry->cmd += new_start_offset;
		cb_hdr->length -= new_start_offset;
		cb_hdr->errorOffset = 0;
		list_add_tail(&entry->list, &restart_head[entry->cb_context]);
		man->ctx[entry->cb_context].block_submission = true;
	}
	spin_unlock(&man->lock);

	/* Preempt all contexts with errors */
	for_each_cmdbuf_ctx(man, i, ctx) {
		if (ctx->block_submission && vmw_cmdbuf_preempt(man, i))
			DRM_ERROR("Failed preempting command buffer "
				  "context %u.\n", i);
	}

	spin_lock(&man->lock);
	for_each_cmdbuf_ctx(man, i, ctx) {
		if (!ctx->block_submission)
			continue;

		/* Move preempted command buffers to the preempted queue. */
		vmw_cmdbuf_ctx_process(man, ctx, &dummy);

		/*
		 * Add the preempted queue after the command buffer
		 * that caused an error.
		 */
		list_splice_init(&ctx->preempted, restart_head[i].prev);

		/*
		 * Finally add all command buffers first in the submitted
		 * queue, to rerun them.
		 */
		list_splice_init(&restart_head[i], &ctx->submitted);

		ctx->block_submission = false;
	}

	vmw_cmdbuf_man_process(man);
	spin_unlock(&man->lock);

	for_each_cmdbuf_ctx(man, i, ctx) {
		if (restart[i] && vmw_cmdbuf_startstop(man, i, true))
			DRM_ERROR("Failed restarting command buffer "
				  "context %u.\n", i);
	}

	/* Send a new fence in case one was removed */
	if (send_fence) {
		vmw_fifo_send_fence(man->dev_priv, &dummy);
		wake_up_all(&man->idle_queue);
	}

	mutex_unlock(&man->error_mutex);
}

/**
 * vmw_cmdbuf_man idle - Check whether the command buffer manager is idle.
 *
 * @man: The command buffer manager.
 * @check_preempted: Check also the preempted queue for pending command buffers.
 *
 */
static bool vmw_cmdbuf_man_idle(struct vmw_cmdbuf_man *man,
				bool check_preempted)
{
	struct vmw_cmdbuf_context *ctx;
	bool idle = false;
	int i;

	spin_lock(&man->lock);
	vmw_cmdbuf_man_process(man);
	for_each_cmdbuf_ctx(man, i, ctx) {
		if (!list_empty(&ctx->submitted) ||
		    !list_empty(&ctx->hw_submitted) ||
		    (check_preempted && !list_empty(&ctx->preempted)))
			goto out_unlock;
	}

	idle = list_empty(&man->error);

out_unlock:
	spin_unlock(&man->lock);

	return idle;
}

/**
 * __vmw_cmdbuf_cur_flush - Flush the current command buffer for small kernel
 * command submissions
 *
 * @man: The command buffer manager.
 *
 * Flushes the current command buffer without allocating a new one. A new one
 * is automatically allocated when needed. Call with @man->cur_mutex held.
 */
static void __vmw_cmdbuf_cur_flush(struct vmw_cmdbuf_man *man)
{
	struct vmw_cmdbuf_header *cur = man->cur;

	WARN_ON(!mutex_is_locked(&man->cur_mutex));

	if (!cur)
		return;

	spin_lock(&man->lock);
	if (man->cur_pos == 0) {
		__vmw_cmdbuf_header_free(cur);
		goto out_unlock;
	}

	man->cur->cb_header->length = man->cur_pos;
	vmw_cmdbuf_ctx_add(man, man->cur, SVGA_CB_CONTEXT_0);
out_unlock:
	spin_unlock(&man->lock);
	man->cur = NULL;
	man->cur_pos = 0;
}

/**
 * vmw_cmdbuf_cur_flush - Flush the current command buffer for small kernel
 * command submissions
 *
 * @man: The command buffer manager.
 * @interruptible: Whether to sleep interruptible when sleeping.
 *
 * Flushes the current command buffer without allocating a new one. A new one
 * is automatically allocated when needed.
 */
int vmw_cmdbuf_cur_flush(struct vmw_cmdbuf_man *man,
			 bool interruptible)
{
	int ret = vmw_cmdbuf_cur_lock(man, interruptible);

	if (ret)
		return ret;

	__vmw_cmdbuf_cur_flush(man);
	vmw_cmdbuf_cur_unlock(man);

	return 0;
}

/**
 * vmw_cmdbuf_idle - Wait for command buffer manager idle.
 *
 * @man: The command buffer manager.
 * @interruptible: Sleep interruptible while waiting.
 * @timeout: Time out after this many ticks.
 *
 * Wait until the command buffer manager has processed all command buffers,
 * or until a timeout occurs. If a timeout occurs, the function will return
 * -EBUSY.
 */
int vmw_cmdbuf_idle(struct vmw_cmdbuf_man *man, bool interruptible,
		    unsigned long timeout)
{
	int ret;

	ret = vmw_cmdbuf_cur_flush(man, interruptible);
	vmw_generic_waiter_add(man->dev_priv,
			       SVGA_IRQFLAG_COMMAND_BUFFER,
			       &man->dev_priv->cmdbuf_waiters);

	if (interruptible) {
		ret = wait_event_interruptible_timeout
			(man->idle_queue, vmw_cmdbuf_man_idle(man, true),
			 timeout);
	} else {
		ret = wait_event_timeout
			(man->idle_queue, vmw_cmdbuf_man_idle(man, true),
			 timeout);
	}
	vmw_generic_waiter_remove(man->dev_priv,
				  SVGA_IRQFLAG_COMMAND_BUFFER,
				  &man->dev_priv->cmdbuf_waiters);
	if (ret == 0) {
		if (!vmw_cmdbuf_man_idle(man, true))
			ret = -EBUSY;
		else
			ret = 0;
	}
	if (ret > 0)
		ret = 0;

	return ret;
}

/**
 * vmw_cmdbuf_try_alloc - Try to allocate buffer space from the main pool.
 *
 * @man: The command buffer manager.
 * @info: Allocation info. Will hold the size on entry and allocated mm node
 * on successful return.
 *
 * Try to allocate buffer space from the main pool. Returns true if succeeded.
 * If a fatal error was hit, the error code is returned in @info->ret.
 */
static bool vmw_cmdbuf_try_alloc(struct vmw_cmdbuf_man *man,
				 struct vmw_cmdbuf_alloc_info *info)
{
	int ret;

	if (info->done)
		return true;
 
	memset(info->node, 0, sizeof(*info->node));
	spin_lock(&man->lock);
	ret = drm_mm_insert_node(&man->mm, info->node, info->page_size);
	if (ret) {
		vmw_cmdbuf_man_process(man);
		ret = drm_mm_insert_node(&man->mm, info->node, info->page_size);
	}

	spin_unlock(&man->lock);
	info->done = !ret;

	return info->done;
}

/**
 * vmw_cmdbuf_alloc_space - Allocate buffer space from the main pool.
 *
 * @man: The command buffer manager.
 * @node: Pointer to pre-allocated range-manager node.
 * @size: The size of the allocation.
 * @interruptible: Whether to sleep interruptible while waiting for space.
 *
 * This function allocates buffer space from the main pool, and if there is
 * no space available ATM, it turns on IRQ handling and sleeps waiting for it to
 * become available.
 */
static int vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,
				  struct drm_mm_node *node,
				  size_t size,
				  bool interruptible)
{
	struct vmw_cmdbuf_alloc_info info;

	info.page_size = PAGE_ALIGN(size) >> PAGE_SHIFT;
	info.node = node;
	info.done = false;

	/*
	 * To prevent starvation of large requests, only one allocating call
	 * at a time waiting for space.
	 */
	if (interruptible) {
		if (mutex_lock_interruptible(&man->space_mutex))
			return -ERESTARTSYS;
	} else {
		mutex_lock(&man->space_mutex);
	}

	/* Try to allocate space without waiting. */
	if (vmw_cmdbuf_try_alloc(man, &info))
		goto out_unlock;

	vmw_generic_waiter_add(man->dev_priv,
			       SVGA_IRQFLAG_COMMAND_BUFFER,
			       &man->dev_priv->cmdbuf_waiters);

	if (interruptible) {
		int ret;

		ret = wait_event_interruptible
			(man->alloc_queue, vmw_cmdbuf_try_alloc(man, &info));
		if (ret) {
			vmw_generic_waiter_remove
				(man->dev_priv, SVGA_IRQFLAG_COMMAND_BUFFER,
				 &man->dev_priv->cmdbuf_waiters);
			mutex_unlock(&man->space_mutex);
			return ret;
		}
	} else {
		wait_event(man->alloc_queue, vmw_cmdbuf_try_alloc(man, &info));
	}
	vmw_generic_waiter_remove(man->dev_priv,
				  SVGA_IRQFLAG_COMMAND_BUFFER,
				  &man->dev_priv->cmdbuf_waiters);

out_unlock:
	mutex_unlock(&man->space_mutex);

	return 0;
}

/**
 * vmw_cmdbuf_space_pool - Set up a command buffer header with command buffer
 * space from the main pool.
 *
 * @man: The command buffer manager.
 * @header: Pointer to the header to set up.
 * @size: The requested size of the buffer space.
 * @interruptible: Whether to sleep interruptible while waiting for space.
 */
static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man,
				 struct vmw_cmdbuf_header *header,
				 size_t size,
				 bool interruptible)
{
	SVGACBHeader *cb_hdr;
	size_t offset;
	int ret;

	if (!man->has_pool)
		return -ENOMEM;

	ret = vmw_cmdbuf_alloc_space(man, &header->node,  size, interruptible);

	if (ret)
		return ret;

	header->cb_header = dma_pool_zalloc(man->headers, GFP_KERNEL,
					    &header->handle);
	if (!header->cb_header) {
		ret = -ENOMEM;
		goto out_no_cb_header;
	}

	header->size = header->node.size << PAGE_SHIFT;
	cb_hdr = header->cb_header;
	offset = header->node.start << PAGE_SHIFT;
	header->cmd = man->map + offset;
	if (man->using_mob) {
		cb_hdr->flags = SVGA_CB_FLAG_MOB;
		cb_hdr->ptr.mob.mobid = man->cmd_space->mem.start;
		cb_hdr->ptr.mob.mobOffset = offset;
	} else {
		cb_hdr->ptr.pa = (u64)man->handle + (u64)offset;
	}

	return 0;

out_no_cb_header:
	spin_lock(&man->lock);
	drm_mm_remove_node(&header->node);
	spin_unlock(&man->lock);

	return ret;
}

/**
 * vmw_cmdbuf_space_inline - Set up a command buffer header with
 * inline command buffer space.
 *
 * @man: The command buffer manager.
 * @header: Pointer to the header to set up.
 * @size: The requested size of the buffer space.
 */
static int vmw_cmdbuf_space_inline(struct vmw_cmdbuf_man *man,
				   struct vmw_cmdbuf_header *header,
				   int size)
{
	struct vmw_cmdbuf_dheader *dheader;
	SVGACBHeader *cb_hdr;

	if (WARN_ON_ONCE(size > VMW_CMDBUF_INLINE_SIZE))
		return -ENOMEM;

	dheader = dma_pool_zalloc(man->dheaders, GFP_KERNEL,
				  &header->handle);
	if (!dheader)
		return -ENOMEM;

	header->inline_space = true;
	header->size = VMW_CMDBUF_INLINE_SIZE;
	cb_hdr = &dheader->cb_header;
	header->cb_header = cb_hdr;
	header->cmd = dheader->cmd;
	cb_hdr->status = SVGA_CB_STATUS_NONE;
	cb_hdr->flags = SVGA_CB_FLAG_NONE;
	cb_hdr->ptr.pa = (u64)header->handle +
		(u64)offsetof(struct vmw_cmdbuf_dheader, cmd);

	return 0;
}

/**
 * vmw_cmdbuf_alloc - Allocate a command buffer header complete with
 * command buffer space.
 *
 * @man: The command buffer manager.
 * @size: The requested size of the buffer space.
 * @interruptible: Whether to sleep interruptible while waiting for space.
 * @p_header: points to a header pointer to populate on successful return.
 *
 * Returns a pointer to command buffer space if successful. Otherwise
 * returns an error pointer. The header pointer returned in @p_header should
 * be used for upcoming calls to vmw_cmdbuf_reserve() and vmw_cmdbuf_commit().
 */
void *vmw_cmdbuf_alloc(struct vmw_cmdbuf_man *man,
		       size_t size, bool interruptible,
		       struct vmw_cmdbuf_header **p_header)
{
	struct vmw_cmdbuf_header *header;
	int ret = 0;

	*p_header = NULL;

	header = kzalloc(sizeof(*header), GFP_KERNEL);
	if (!header)
		return ERR_PTR(-ENOMEM);

	if (size <= VMW_CMDBUF_INLINE_SIZE)
		ret = vmw_cmdbuf_space_inline(man, header, size);
	else
		ret = vmw_cmdbuf_space_pool(man, header, size, interruptible);

	if (ret) {
		kfree(header);
		return ERR_PTR(ret);
	}

	header->man = man;
	INIT_LIST_HEAD(&header->list);
	header->cb_header->status = SVGA_CB_STATUS_NONE;
	*p_header = header;

	return header->cmd;
}

/**
 * vmw_cmdbuf_reserve_cur - Reserve space for commands in the current
 * command buffer.
 *
 * @man: The command buffer manager.
 * @size: The requested size of the commands.
 * @ctx_id: The context id if any. Otherwise set to SVGA3D_REG_INVALID.
 * @interruptible: Whether to sleep interruptible while waiting for space.
 *
 * Returns a pointer to command buffer space if successful. Otherwise
 * returns an error pointer.
 */
static void *vmw_cmdbuf_reserve_cur(struct vmw_cmdbuf_man *man,
				    size_t size,
				    int ctx_id,
				    bool interruptible)
{
	struct vmw_cmdbuf_header *cur;
	void *ret;

	if (vmw_cmdbuf_cur_lock(man, interruptible))
		return ERR_PTR(-ERESTARTSYS);

	cur = man->cur;
	if (cur && (size + man->cur_pos > cur->size ||
		    ((cur->cb_header->flags & SVGA_CB_FLAG_DX_CONTEXT) &&
		     ctx_id != cur->cb_header->dxContext)))
		__vmw_cmdbuf_cur_flush(man);

	if (!man->cur) {
		ret = vmw_cmdbuf_alloc(man,
				       max_t(size_t, size, man->default_size),
				       interruptible, &man->cur);
		if (IS_ERR(ret)) {
			vmw_cmdbuf_cur_unlock(man);
			return ret;
		}

		cur = man->cur;
	}

	if (ctx_id != SVGA3D_INVALID_ID) {
		cur->cb_header->flags |= SVGA_CB_FLAG_DX_CONTEXT;
		cur->cb_header->dxContext = ctx_id;
	}

	cur->reserved = size;

	return (void *) (man->cur->cmd + man->cur_pos);
}

/**
 * vmw_cmdbuf_commit_cur - Commit commands in the current command buffer.
 *
 * @man: The command buffer manager.
 * @size: The size of the commands actually written.
 * @flush: Whether to flush the command buffer immediately.
 */
static void vmw_cmdbuf_commit_cur(struct vmw_cmdbuf_man *man,
				  size_t size, bool flush)
{
	struct vmw_cmdbuf_header *cur = man->cur;

	WARN_ON(!mutex_is_locked(&man->cur_mutex));

	WARN_ON(size > cur->reserved);
	man->cur_pos += size;
	if (!size)
		cur->cb_header->flags &= ~SVGA_CB_FLAG_DX_CONTEXT;
	if (flush)
		__vmw_cmdbuf_cur_flush(man);
	vmw_cmdbuf_cur_unlock(man);
}

/**
 * vmw_cmdbuf_reserve - Reserve space for commands in a command buffer.
 *
 * @man: The command buffer manager.
 * @size: The requested size of the commands.
 * @ctx_id: The context id if any. Otherwise set to SVGA3D_REG_INVALID.
 * @interruptible: Whether to sleep interruptible while waiting for space.
 * @header: Header of the command buffer. NULL if the current command buffer
 * should be used.
 *
 * Returns a pointer to command buffer space if successful. Otherwise
 * returns an error pointer.
 */
void *vmw_cmdbuf_reserve(struct vmw_cmdbuf_man *man, size_t size,
			 int ctx_id, bool interruptible,
			 struct vmw_cmdbuf_header *header)
{
	if (!header)
		return vmw_cmdbuf_reserve_cur(man, size, ctx_id, interruptible);

	if (size > header->size)
		return ERR_PTR(-EINVAL);

	if (ctx_id != SVGA3D_INVALID_ID) {
		header->cb_header->flags |= SVGA_CB_FLAG_DX_CONTEXT;
		header->cb_header->dxContext = ctx_id;
	}

	header->reserved = size;
	return header->cmd;
}

/**
 * vmw_cmdbuf_commit - Commit commands in a command buffer.
 *
 * @man: The command buffer manager.
 * @size: The size of the commands actually written.
 * @header: Header of the command buffer. NULL if the current command buffer
 * should be used.
 * @flush: Whether to flush the command buffer immediately.
 */
void vmw_cmdbuf_commit(struct vmw_cmdbuf_man *man, size_t size,
		       struct vmw_cmdbuf_header *header, bool flush)
{
	if (!header) {
		vmw_cmdbuf_commit_cur(man, size, flush);
		return;
	}

	(void) vmw_cmdbuf_cur_lock(man, false);
	__vmw_cmdbuf_cur_flush(man);
	WARN_ON(size > header->reserved);
	man->cur = header;
	man->cur_pos = size;
	if (!size)
		header->cb_header->flags &= ~SVGA_CB_FLAG_DX_CONTEXT;
	if (flush)
		__vmw_cmdbuf_cur_flush(man);
	vmw_cmdbuf_cur_unlock(man);
}


/**
 * vmw_cmdbuf_send_device_command - Send a command through the device context.
 *
 * @man: The command buffer manager.
 * @command: Pointer to the command to send.
 * @size: Size of the command.
 *
 * Synchronously sends a device context command.
 */
static int vmw_cmdbuf_send_device_command(struct vmw_cmdbuf_man *man,
					  const void *command,
					  size_t size)
{
	struct vmw_cmdbuf_header *header;
	int status;
	void *cmd = vmw_cmdbuf_alloc(man, size, false, &header);

	if (IS_ERR(cmd))
		return PTR_ERR(cmd);

	memcpy(cmd, command, size);
	header->cb_header->length = size;
	header->cb_context = SVGA_CB_CONTEXT_DEVICE;
	spin_lock(&man->lock);
	status = vmw_cmdbuf_header_submit(header);
	spin_unlock(&man->lock);
	vmw_cmdbuf_header_free(header);

	if (status != SVGA_CB_STATUS_COMPLETED) {
		DRM_ERROR("Device context command failed with status %d\n",
			  status);
		return -EINVAL;
	}

	return 0;
}

/**
 * vmw_cmdbuf_preempt - Send a preempt command through the device
 * context.
 *
 * @man: The command buffer manager.
 *
 * Synchronously sends a preempt command.
 */
static int vmw_cmdbuf_preempt(struct vmw_cmdbuf_man *man, u32 context)
{
	struct {
		uint32 id;
		SVGADCCmdPreempt body;
	} __packed cmd;

	cmd.id = SVGA_DC_CMD_PREEMPT;
	cmd.body.context = SVGA_CB_CONTEXT_0 + context;
	cmd.body.ignoreIDZero = 0;

	return vmw_cmdbuf_send_device_command(man, &cmd, sizeof(cmd));
}


/**
 * vmw_cmdbuf_startstop - Send a start / stop command through the device
 * context.
 *
 * @man: The command buffer manager.
 * @enable: Whether to enable or disable the context.
 *
 * Synchronously sends a device start / stop context command.
 */
static int vmw_cmdbuf_startstop(struct vmw_cmdbuf_man *man, u32 context,
				bool enable)
{
	struct {
		uint32 id;
		SVGADCCmdStartStop body;
	} __packed cmd;

	cmd.id = SVGA_DC_CMD_START_STOP_CONTEXT;
	cmd.body.enable = (enable) ? 1 : 0;
	cmd.body.context = SVGA_CB_CONTEXT_0 + context;

	return vmw_cmdbuf_send_device_command(man, &cmd, sizeof(cmd));
}

/**
 * vmw_cmdbuf_set_pool_size - Set command buffer manager sizes
 *
 * @man: The command buffer manager.
 * @size: The size of the main space pool.
 * @default_size: The default size of the command buffer for small kernel
 * submissions.
 *
 * Set the size and allocate the main command buffer space pool,
 * as well as the default size of the command buffer for
 * small kernel submissions. If successful, this enables large command
 * submissions. Note that this function requires that rudimentary command
 * submission is already available and that the MOB memory manager is alive.
 * Returns 0 on success. Negative error code on failure.
 */
int vmw_cmdbuf_set_pool_size(struct vmw_cmdbuf_man *man,
			     size_t size, size_t default_size)
{
	struct vmw_private *dev_priv = man->dev_priv;
	bool dummy;
	int ret;

	if (man->has_pool)
		return -EINVAL;

	/* First, try to allocate a huge chunk of DMA memory */
	size = PAGE_ALIGN(size);
	man->map = dma_alloc_coherent(&dev_priv->dev->pdev->dev, size,
				      &man->handle, GFP_KERNEL);
	if (man->map) {
		man->using_mob = false;
	} else {
		/*
		 * DMA memory failed. If we can have command buffers in a
		 * MOB, try to use that instead. Note that this will
		 * actually call into the already enabled manager, when
		 * binding the MOB.
		 */
		if (!(dev_priv->capabilities & SVGA_CAP_DX))
			return -ENOMEM;

		ret = ttm_bo_create(&dev_priv->bdev, size, ttm_bo_type_device,
				    &vmw_mob_ne_placement, 0, false, NULL,
				    &man->cmd_space);
		if (ret)
			return ret;

		man->using_mob = true;
		ret = ttm_bo_kmap(man->cmd_space, 0, size >> PAGE_SHIFT,
				  &man->map_obj);
		if (ret)
			goto out_no_map;

		man->map = ttm_kmap_obj_virtual(&man->map_obj, &dummy);
	}

	man->size = size;
	drm_mm_init(&man->mm, 0, size >> PAGE_SHIFT);

	man->has_pool = true;

	/*
	 * For now, set the default size to VMW_CMDBUF_INLINE_SIZE to
	 * prevent deadlocks from happening when vmw_cmdbuf_space_pool()
	 * needs to wait for space and we block on further command
	 * submissions to be able to free up space.
	 */
	man->default_size = VMW_CMDBUF_INLINE_SIZE;
	DRM_INFO("Using command buffers with %s pool.\n",
		 (man->using_mob) ? "MOB" : "DMA");

	return 0;

out_no_map:
	if (man->using_mob)
		ttm_bo_unref(&man->cmd_space);

	return ret;
}

/**
 * vmw_cmdbuf_man_create: Create a command buffer manager and enable it for
 * inline command buffer submissions only.
 *
 * @dev_priv: Pointer to device private structure.
 *
 * Returns a pointer to a cummand buffer manager to success or error pointer
 * on failure. The command buffer manager will be enabled for submissions of
 * size VMW_CMDBUF_INLINE_SIZE only.
 */
struct vmw_cmdbuf_man *vmw_cmdbuf_man_create(struct vmw_private *dev_priv)
{
	struct vmw_cmdbuf_man *man;
	struct vmw_cmdbuf_context *ctx;
	unsigned int i;
	int ret;

	if (!(dev_priv->capabilities & SVGA_CAP_COMMAND_BUFFERS))
		return ERR_PTR(-ENOSYS);

	man = kzalloc(sizeof(*man), GFP_KERNEL);
	if (!man)
		return ERR_PTR(-ENOMEM);

	man->headers = dma_pool_create("vmwgfx cmdbuf",
				       &dev_priv->dev->pdev->dev,
				       sizeof(SVGACBHeader),
				       64, PAGE_SIZE);
	if (!man->headers) {
		ret = -ENOMEM;
		goto out_no_pool;
	}

	man->dheaders = dma_pool_create("vmwgfx inline cmdbuf",
					&dev_priv->dev->pdev->dev,
					sizeof(struct vmw_cmdbuf_dheader),
					64, PAGE_SIZE);
	if (!man->dheaders) {
		ret = -ENOMEM;
		goto out_no_dpool;
	}

	for_each_cmdbuf_ctx(man, i, ctx)
		vmw_cmdbuf_ctx_init(ctx);

	INIT_LIST_HEAD(&man->error);
	spin_lock_init(&man->lock);
	mutex_init(&man->cur_mutex);
	mutex_init(&man->space_mutex);
	mutex_init(&man->error_mutex);
	man->default_size = VMW_CMDBUF_INLINE_SIZE;
	init_waitqueue_head(&man->alloc_queue);
	init_waitqueue_head(&man->idle_queue);
	man->dev_priv = dev_priv;
	man->max_hw_submitted = SVGA_CB_MAX_QUEUED_PER_CONTEXT - 1;
	INIT_WORK(&man->work, &vmw_cmdbuf_work_func);
	vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_ERROR,
			       &dev_priv->error_waiters);
	for_each_cmdbuf_ctx(man, i, ctx) {
		ret = vmw_cmdbuf_startstop(man, i, true);
		if (ret) {
			DRM_ERROR("Failed starting command buffer "
				  "context %u.\n", i);
			vmw_cmdbuf_man_destroy(man);
			return ERR_PTR(ret);
		}
	}

	return man;

out_no_dpool:
	dma_pool_destroy(man->headers);
out_no_pool:
	kfree(man);

	return ERR_PTR(ret);
}

/**
 * vmw_cmdbuf_remove_pool - Take down the main buffer space pool.
 *
 * @man: Pointer to a command buffer manager.
 *
 * This function removes the main buffer space pool, and should be called
 * before MOB memory management is removed. When this function has been called,
 * only small command buffer submissions of size VMW_CMDBUF_INLINE_SIZE or
 * less are allowed, and the default size of the command buffer for small kernel
 * submissions is also set to this size.
 */
void vmw_cmdbuf_remove_pool(struct vmw_cmdbuf_man *man)
{
	if (!man->has_pool)
		return;

	man->has_pool = false;
	man->default_size = VMW_CMDBUF_INLINE_SIZE;
	(void) vmw_cmdbuf_idle(man, false, 10*HZ);
	if (man->using_mob) {
		(void) ttm_bo_kunmap(&man->map_obj);
		ttm_bo_unref(&man->cmd_space);
	} else {
		dma_free_coherent(&man->dev_priv->dev->pdev->dev,
				  man->size, man->map, man->handle);
	}
}

/**
 * vmw_cmdbuf_man_destroy - Take down a command buffer manager.
 *
 * @man: Pointer to a command buffer manager.
 *
 * This function idles and then destroys a command buffer manager.
 */
void vmw_cmdbuf_man_destroy(struct vmw_cmdbuf_man *man)
{
	struct vmw_cmdbuf_context *ctx;
	unsigned int i;

	WARN_ON_ONCE(man->has_pool);
	(void) vmw_cmdbuf_idle(man, false, 10*HZ);

	for_each_cmdbuf_ctx(man, i, ctx)
		if (vmw_cmdbuf_startstop(man, i, false))
			DRM_ERROR("Failed stopping command buffer "
				  "context %u.\n", i);

	vmw_generic_waiter_remove(man->dev_priv, SVGA_IRQFLAG_ERROR,
				  &man->dev_priv->error_waiters);
	(void) cancel_work_sync(&man->work);
	dma_pool_destroy(man->dheaders);
	dma_pool_destroy(man->headers);
	mutex_destroy(&man->cur_mutex);
	mutex_destroy(&man->space_mutex);
	mutex_destroy(&man->error_mutex);
	kfree(man);
}