aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/vmw_pvscsi.c
blob: 53a3eb6c0634ed286efa7049d1aba0785aa0d101 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
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
/*
 * Linux driver for VMware's para-virtualized SCSI HBA.
 *
 * Copyright (C) 2008-2014, VMware, Inc. All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; version 2 of the License and no later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained by: Arvind Kumar <arvindkumar@vmware.com>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/pci.h>

#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>

#include "vmw_pvscsi.h"

#define PVSCSI_LINUX_DRIVER_DESC "VMware PVSCSI driver"

MODULE_DESCRIPTION(PVSCSI_LINUX_DRIVER_DESC);
MODULE_AUTHOR("VMware, Inc.");
MODULE_LICENSE("GPL");
MODULE_VERSION(PVSCSI_DRIVER_VERSION_STRING);

#define PVSCSI_DEFAULT_NUM_PAGES_PER_RING	8
#define PVSCSI_DEFAULT_NUM_PAGES_MSG_RING	1
#define PVSCSI_DEFAULT_QUEUE_DEPTH		254
#define SGL_SIZE				PAGE_SIZE

struct pvscsi_sg_list {
	struct PVSCSISGElement sge[PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT];
};

struct pvscsi_ctx {
	/*
	 * The index of the context in cmd_map serves as the context ID for a
	 * 1-to-1 mapping completions back to requests.
	 */
	struct scsi_cmnd	*cmd;
	struct pvscsi_sg_list	*sgl;
	struct list_head	list;
	dma_addr_t		dataPA;
	dma_addr_t		sensePA;
	dma_addr_t		sglPA;
	struct completion	*abort_cmp;
};

struct pvscsi_adapter {
	char				*mmioBase;
	unsigned int			irq;
	u8				rev;
	bool				use_msi;
	bool				use_msix;
	bool				use_msg;
	bool				use_req_threshold;

	spinlock_t			hw_lock;

	struct workqueue_struct		*workqueue;
	struct work_struct		work;

	struct PVSCSIRingReqDesc	*req_ring;
	unsigned			req_pages;
	unsigned			req_depth;
	dma_addr_t			reqRingPA;

	struct PVSCSIRingCmpDesc	*cmp_ring;
	unsigned			cmp_pages;
	dma_addr_t			cmpRingPA;

	struct PVSCSIRingMsgDesc	*msg_ring;
	unsigned			msg_pages;
	dma_addr_t			msgRingPA;

	struct PVSCSIRingsState		*rings_state;
	dma_addr_t			ringStatePA;

	struct pci_dev			*dev;
	struct Scsi_Host		*host;

	struct list_head		cmd_pool;
	struct pvscsi_ctx		*cmd_map;
};


/* Command line parameters */
static int pvscsi_ring_pages;
static int pvscsi_msg_ring_pages = PVSCSI_DEFAULT_NUM_PAGES_MSG_RING;
static int pvscsi_cmd_per_lun    = PVSCSI_DEFAULT_QUEUE_DEPTH;
static bool pvscsi_disable_msi;
static bool pvscsi_disable_msix;
static bool pvscsi_use_msg       = true;
static bool pvscsi_use_req_threshold = true;

#define PVSCSI_RW (S_IRUSR | S_IWUSR)

module_param_named(ring_pages, pvscsi_ring_pages, int, PVSCSI_RW);
MODULE_PARM_DESC(ring_pages, "Number of pages per req/cmp ring - (default="
		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_PER_RING)
		 "[up to 16 targets],"
		 __stringify(PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
		 "[for 16+ targets])");

module_param_named(msg_ring_pages, pvscsi_msg_ring_pages, int, PVSCSI_RW);
MODULE_PARM_DESC(msg_ring_pages, "Number of pages for the msg ring - (default="
		 __stringify(PVSCSI_DEFAULT_NUM_PAGES_MSG_RING) ")");

module_param_named(cmd_per_lun, pvscsi_cmd_per_lun, int, PVSCSI_RW);
MODULE_PARM_DESC(cmd_per_lun, "Maximum commands per lun - (default="
		 __stringify(PVSCSI_DEFAULT_QUEUE_DEPTH) ")");

module_param_named(disable_msi, pvscsi_disable_msi, bool, PVSCSI_RW);
MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");

module_param_named(disable_msix, pvscsi_disable_msix, bool, PVSCSI_RW);
MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");

module_param_named(use_msg, pvscsi_use_msg, bool, PVSCSI_RW);
MODULE_PARM_DESC(use_msg, "Use msg ring when available - (default=1)");

module_param_named(use_req_threshold, pvscsi_use_req_threshold,
		   bool, PVSCSI_RW);
MODULE_PARM_DESC(use_req_threshold, "Use driver-based request coalescing if configured - (default=1)");

static const struct pci_device_id pvscsi_pci_tbl[] = {
	{ PCI_VDEVICE(VMWARE, PCI_DEVICE_ID_VMWARE_PVSCSI) },
	{ 0 }
};

MODULE_DEVICE_TABLE(pci, pvscsi_pci_tbl);

static struct device *
pvscsi_dev(const struct pvscsi_adapter *adapter)
{
	return &(adapter->dev->dev);
}

static struct pvscsi_ctx *
pvscsi_find_context(const struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
{
	struct pvscsi_ctx *ctx, *end;

	end = &adapter->cmd_map[adapter->req_depth];
	for (ctx = adapter->cmd_map; ctx < end; ctx++)
		if (ctx->cmd == cmd)
			return ctx;

	return NULL;
}

static struct pvscsi_ctx *
pvscsi_acquire_context(struct pvscsi_adapter *adapter, struct scsi_cmnd *cmd)
{
	struct pvscsi_ctx *ctx;

	if (list_empty(&adapter->cmd_pool))
		return NULL;

	ctx = list_first_entry(&adapter->cmd_pool, struct pvscsi_ctx, list);
	ctx->cmd = cmd;
	list_del(&ctx->list);

	return ctx;
}

static void pvscsi_release_context(struct pvscsi_adapter *adapter,
				   struct pvscsi_ctx *ctx)
{
	ctx->cmd = NULL;
	ctx->abort_cmp = NULL;
	list_add(&ctx->list, &adapter->cmd_pool);
}

/*
 * Map a pvscsi_ctx struct to a context ID field value; we map to a simple
 * non-zero integer. ctx always points to an entry in cmd_map array, hence
 * the return value is always >=1.
 */
static u64 pvscsi_map_context(const struct pvscsi_adapter *adapter,
			      const struct pvscsi_ctx *ctx)
{
	return ctx - adapter->cmd_map + 1;
}

static struct pvscsi_ctx *
pvscsi_get_context(const struct pvscsi_adapter *adapter, u64 context)
{
	return &adapter->cmd_map[context - 1];
}

static void pvscsi_reg_write(const struct pvscsi_adapter *adapter,
			     u32 offset, u32 val)
{
	writel(val, adapter->mmioBase + offset);
}

static u32 pvscsi_reg_read(const struct pvscsi_adapter *adapter, u32 offset)
{
	return readl(adapter->mmioBase + offset);
}

static u32 pvscsi_read_intr_status(const struct pvscsi_adapter *adapter)
{
	return pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_INTR_STATUS);
}

static void pvscsi_write_intr_status(const struct pvscsi_adapter *adapter,
				     u32 val)
{
	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_STATUS, val);
}

static void pvscsi_unmask_intr(const struct pvscsi_adapter *adapter)
{
	u32 intr_bits;

	intr_bits = PVSCSI_INTR_CMPL_MASK;
	if (adapter->use_msg)
		intr_bits |= PVSCSI_INTR_MSG_MASK;

	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, intr_bits);
}

static void pvscsi_mask_intr(const struct pvscsi_adapter *adapter)
{
	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_INTR_MASK, 0);
}

static void pvscsi_write_cmd_desc(const struct pvscsi_adapter *adapter,
				  u32 cmd, const void *desc, size_t len)
{
	const u32 *ptr = desc;
	size_t i;

	len /= sizeof(*ptr);
	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND, cmd);
	for (i = 0; i < len; i++)
		pvscsi_reg_write(adapter,
				 PVSCSI_REG_OFFSET_COMMAND_DATA, ptr[i]);
}

static void pvscsi_abort_cmd(const struct pvscsi_adapter *adapter,
			     const struct pvscsi_ctx *ctx)
{
	struct PVSCSICmdDescAbortCmd cmd = { 0 };

	cmd.target = ctx->cmd->device->id;
	cmd.context = pvscsi_map_context(adapter, ctx);

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ABORT_CMD, &cmd, sizeof(cmd));
}

static void pvscsi_kick_rw_io(const struct pvscsi_adapter *adapter)
{
	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_RW_IO, 0);
}

static void pvscsi_process_request_ring(const struct pvscsi_adapter *adapter)
{
	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_KICK_NON_RW_IO, 0);
}

static int scsi_is_rw(unsigned char op)
{
	return op == READ_6  || op == WRITE_6 ||
	       op == READ_10 || op == WRITE_10 ||
	       op == READ_12 || op == WRITE_12 ||
	       op == READ_16 || op == WRITE_16;
}

static void pvscsi_kick_io(const struct pvscsi_adapter *adapter,
			   unsigned char op)
{
	if (scsi_is_rw(op)) {
		struct PVSCSIRingsState *s = adapter->rings_state;

		if (!adapter->use_req_threshold ||
		    s->reqProdIdx - s->reqConsIdx >= s->reqCallThreshold)
			pvscsi_kick_rw_io(adapter);
	} else {
		pvscsi_process_request_ring(adapter);
	}
}

static void ll_adapter_reset(const struct pvscsi_adapter *adapter)
{
	dev_dbg(pvscsi_dev(adapter), "Adapter Reset on %p\n", adapter);

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_ADAPTER_RESET, NULL, 0);
}

static void ll_bus_reset(const struct pvscsi_adapter *adapter)
{
	dev_dbg(pvscsi_dev(adapter), "Resetting bus on %p\n", adapter);

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_BUS, NULL, 0);
}

static void ll_device_reset(const struct pvscsi_adapter *adapter, u32 target)
{
	struct PVSCSICmdDescResetDevice cmd = { 0 };

	dev_dbg(pvscsi_dev(adapter), "Resetting device: target=%u\n", target);

	cmd.target = target;

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_RESET_DEVICE,
			      &cmd, sizeof(cmd));
}

static void pvscsi_create_sg(struct pvscsi_ctx *ctx,
			     struct scatterlist *sg, unsigned count)
{
	unsigned i;
	struct PVSCSISGElement *sge;

	BUG_ON(count > PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT);

	sge = &ctx->sgl->sge[0];
	for (i = 0; i < count; i++, sg++) {
		sge[i].addr   = sg_dma_address(sg);
		sge[i].length = sg_dma_len(sg);
		sge[i].flags  = 0;
	}
}

/*
 * Map all data buffers for a command into PCI space and
 * setup the scatter/gather list if needed.
 */
static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
			       struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd,
			       struct PVSCSIRingReqDesc *e)
{
	unsigned count;
	unsigned bufflen = scsi_bufflen(cmd);
	struct scatterlist *sg;

	e->dataLen = bufflen;
	e->dataAddr = 0;
	if (bufflen == 0)
		return;

	sg = scsi_sglist(cmd);
	count = scsi_sg_count(cmd);
	if (count != 0) {
		int segs = scsi_dma_map(cmd);
		if (segs > 1) {
			pvscsi_create_sg(ctx, sg, segs);

			e->flags |= PVSCSI_FLAG_CMD_WITH_SG_LIST;
			ctx->sglPA = pci_map_single(adapter->dev, ctx->sgl,
						    SGL_SIZE, PCI_DMA_TODEVICE);
			e->dataAddr = ctx->sglPA;
		} else
			e->dataAddr = sg_dma_address(sg);
	} else {
		/*
		 * In case there is no S/G list, scsi_sglist points
		 * directly to the buffer.
		 */
		ctx->dataPA = pci_map_single(adapter->dev, sg, bufflen,
					     cmd->sc_data_direction);
		e->dataAddr = ctx->dataPA;
	}
}

static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
				 struct pvscsi_ctx *ctx)
{
	struct scsi_cmnd *cmd;
	unsigned bufflen;

	cmd = ctx->cmd;
	bufflen = scsi_bufflen(cmd);

	if (bufflen != 0) {
		unsigned count = scsi_sg_count(cmd);

		if (count != 0) {
			scsi_dma_unmap(cmd);
			if (ctx->sglPA) {
				pci_unmap_single(adapter->dev, ctx->sglPA,
						 SGL_SIZE, PCI_DMA_TODEVICE);
				ctx->sglPA = 0;
			}
		} else
			pci_unmap_single(adapter->dev, ctx->dataPA, bufflen,
					 cmd->sc_data_direction);
	}
	if (cmd->sense_buffer)
		pci_unmap_single(adapter->dev, ctx->sensePA,
				 SCSI_SENSE_BUFFERSIZE, PCI_DMA_FROMDEVICE);
}

static int pvscsi_allocate_rings(struct pvscsi_adapter *adapter)
{
	adapter->rings_state = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
						    &adapter->ringStatePA);
	if (!adapter->rings_state)
		return -ENOMEM;

	adapter->req_pages = min(PVSCSI_MAX_NUM_PAGES_REQ_RING,
				 pvscsi_ring_pages);
	adapter->req_depth = adapter->req_pages
					* PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
	adapter->req_ring = pci_alloc_consistent(adapter->dev,
						 adapter->req_pages * PAGE_SIZE,
						 &adapter->reqRingPA);
	if (!adapter->req_ring)
		return -ENOMEM;

	adapter->cmp_pages = min(PVSCSI_MAX_NUM_PAGES_CMP_RING,
				 pvscsi_ring_pages);
	adapter->cmp_ring = pci_alloc_consistent(adapter->dev,
						 adapter->cmp_pages * PAGE_SIZE,
						 &adapter->cmpRingPA);
	if (!adapter->cmp_ring)
		return -ENOMEM;

	BUG_ON(!IS_ALIGNED(adapter->ringStatePA, PAGE_SIZE));
	BUG_ON(!IS_ALIGNED(adapter->reqRingPA, PAGE_SIZE));
	BUG_ON(!IS_ALIGNED(adapter->cmpRingPA, PAGE_SIZE));

	if (!adapter->use_msg)
		return 0;

	adapter->msg_pages = min(PVSCSI_MAX_NUM_PAGES_MSG_RING,
				 pvscsi_msg_ring_pages);
	adapter->msg_ring = pci_alloc_consistent(adapter->dev,
						 adapter->msg_pages * PAGE_SIZE,
						 &adapter->msgRingPA);
	if (!adapter->msg_ring)
		return -ENOMEM;
	BUG_ON(!IS_ALIGNED(adapter->msgRingPA, PAGE_SIZE));

	return 0;
}

static void pvscsi_setup_all_rings(const struct pvscsi_adapter *adapter)
{
	struct PVSCSICmdDescSetupRings cmd = { 0 };
	dma_addr_t base;
	unsigned i;

	cmd.ringsStatePPN   = adapter->ringStatePA >> PAGE_SHIFT;
	cmd.reqRingNumPages = adapter->req_pages;
	cmd.cmpRingNumPages = adapter->cmp_pages;

	base = adapter->reqRingPA;
	for (i = 0; i < adapter->req_pages; i++) {
		cmd.reqRingPPNs[i] = base >> PAGE_SHIFT;
		base += PAGE_SIZE;
	}

	base = adapter->cmpRingPA;
	for (i = 0; i < adapter->cmp_pages; i++) {
		cmd.cmpRingPPNs[i] = base >> PAGE_SHIFT;
		base += PAGE_SIZE;
	}

	memset(adapter->rings_state, 0, PAGE_SIZE);
	memset(adapter->req_ring, 0, adapter->req_pages * PAGE_SIZE);
	memset(adapter->cmp_ring, 0, adapter->cmp_pages * PAGE_SIZE);

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_RINGS,
			      &cmd, sizeof(cmd));

	if (adapter->use_msg) {
		struct PVSCSICmdDescSetupMsgRing cmd_msg = { 0 };

		cmd_msg.numPages = adapter->msg_pages;

		base = adapter->msgRingPA;
		for (i = 0; i < adapter->msg_pages; i++) {
			cmd_msg.ringPPNs[i] = base >> PAGE_SHIFT;
			base += PAGE_SIZE;
		}
		memset(adapter->msg_ring, 0, adapter->msg_pages * PAGE_SIZE);

		pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_SETUP_MSG_RING,
				      &cmd_msg, sizeof(cmd_msg));
	}
}

static int pvscsi_change_queue_depth(struct scsi_device *sdev,
				     int qdepth,
				     int reason)
{
	int max_depth;
	struct Scsi_Host *shost = sdev->host;

	if (reason != SCSI_QDEPTH_DEFAULT)
		/*
		 * We support only changing default.
		 */
		return -EOPNOTSUPP;

	max_depth = shost->can_queue;
	if (!sdev->tagged_supported)
		max_depth = 1;
	if (qdepth > max_depth)
		qdepth = max_depth;
	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);

	if (sdev->inquiry_len > 7)
		sdev_printk(KERN_INFO, sdev,
			    "qdepth(%d), tagged(%d), simple(%d), scsi_level(%d), cmd_que(%d)\n",
			    sdev->queue_depth, sdev->tagged_supported,
			    sdev->simple_tags,
			    sdev->scsi_level, (sdev->inquiry[7] & 2) >> 1);
	return sdev->queue_depth;
}

/*
 * Pull a completion descriptor off and pass the completion back
 * to the SCSI mid layer.
 */
static void pvscsi_complete_request(struct pvscsi_adapter *adapter,
				    const struct PVSCSIRingCmpDesc *e)
{
	struct pvscsi_ctx *ctx;
	struct scsi_cmnd *cmd;
	struct completion *abort_cmp;
	u32 btstat = e->hostStatus;
	u32 sdstat = e->scsiStatus;

	ctx = pvscsi_get_context(adapter, e->context);
	cmd = ctx->cmd;
	abort_cmp = ctx->abort_cmp;
	pvscsi_unmap_buffers(adapter, ctx);
	pvscsi_release_context(adapter, ctx);
	if (abort_cmp) {
		/*
		 * The command was requested to be aborted. Just signal that
		 * the request completed and swallow the actual cmd completion
		 * here. The abort handler will post a completion for this
		 * command indicating that it got successfully aborted.
		 */
		complete(abort_cmp);
		return;
	}

	cmd->result = 0;
	if (sdstat != SAM_STAT_GOOD &&
	    (btstat == BTSTAT_SUCCESS ||
	     btstat == BTSTAT_LINKED_COMMAND_COMPLETED ||
	     btstat == BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG)) {
		cmd->result = (DID_OK << 16) | sdstat;
		if (sdstat == SAM_STAT_CHECK_CONDITION && cmd->sense_buffer)
			cmd->result |= (DRIVER_SENSE << 24);
	} else
		switch (btstat) {
		case BTSTAT_SUCCESS:
		case BTSTAT_LINKED_COMMAND_COMPLETED:
		case BTSTAT_LINKED_COMMAND_COMPLETED_WITH_FLAG:
			/* If everything went fine, let's move on..  */
			cmd->result = (DID_OK << 16);
			break;

		case BTSTAT_DATARUN:
		case BTSTAT_DATA_UNDERRUN:
			/* Report residual data in underruns */
			scsi_set_resid(cmd, scsi_bufflen(cmd) - e->dataLen);
			cmd->result = (DID_ERROR << 16);
			break;

		case BTSTAT_SELTIMEO:
			/* Our emulation returns this for non-connected devs */
			cmd->result = (DID_BAD_TARGET << 16);
			break;

		case BTSTAT_LUNMISMATCH:
		case BTSTAT_TAGREJECT:
		case BTSTAT_BADMSG:
			cmd->result = (DRIVER_INVALID << 24);
			/* fall through */

		case BTSTAT_HAHARDWARE:
		case BTSTAT_INVPHASE:
		case BTSTAT_HATIMEOUT:
		case BTSTAT_NORESPONSE:
		case BTSTAT_DISCONNECT:
		case BTSTAT_HASOFTWARE:
		case BTSTAT_BUSFREE:
		case BTSTAT_SENSFAILED:
			cmd->result |= (DID_ERROR << 16);
			break;

		case BTSTAT_SENTRST:
		case BTSTAT_RECVRST:
		case BTSTAT_BUSRESET:
			cmd->result = (DID_RESET << 16);
			break;

		case BTSTAT_ABORTQUEUE:
			cmd->result = (DID_ABORT << 16);
			break;

		case BTSTAT_SCSIPARITY:
			cmd->result = (DID_PARITY << 16);
			break;

		default:
			cmd->result = (DID_ERROR << 16);
			scmd_printk(KERN_DEBUG, cmd,
				    "Unknown completion status: 0x%x\n",
				    btstat);
	}

	dev_dbg(&cmd->device->sdev_gendev,
		"cmd=%p %x ctx=%p result=0x%x status=0x%x,%x\n",
		cmd, cmd->cmnd[0], ctx, cmd->result, btstat, sdstat);

	cmd->scsi_done(cmd);
}

/*
 * barrier usage : Since the PVSCSI device is emulated, there could be cases
 * where we may want to serialize some accesses between the driver and the
 * emulation layer. We use compiler barriers instead of the more expensive
 * memory barriers because PVSCSI is only supported on X86 which has strong
 * memory access ordering.
 */
static void pvscsi_process_completion_ring(struct pvscsi_adapter *adapter)
{
	struct PVSCSIRingsState *s = adapter->rings_state;
	struct PVSCSIRingCmpDesc *ring = adapter->cmp_ring;
	u32 cmp_entries = s->cmpNumEntriesLog2;

	while (s->cmpConsIdx != s->cmpProdIdx) {
		struct PVSCSIRingCmpDesc *e = ring + (s->cmpConsIdx &
						      MASK(cmp_entries));
		/*
		 * This barrier() ensures that *e is not dereferenced while
		 * the device emulation still writes data into the slot.
		 * Since the device emulation advances s->cmpProdIdx only after
		 * updating the slot we want to check it first.
		 */
		barrier();
		pvscsi_complete_request(adapter, e);
		/*
		 * This barrier() ensures that compiler doesn't reorder write
		 * to s->cmpConsIdx before the read of (*e) inside
		 * pvscsi_complete_request. Otherwise, device emulation may
		 * overwrite *e before we had a chance to read it.
		 */
		barrier();
		s->cmpConsIdx++;
	}
}

/*
 * Translate a Linux SCSI request into a request ring entry.
 */
static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
			     struct pvscsi_ctx *ctx, struct scsi_cmnd *cmd)
{
	struct PVSCSIRingsState *s;
	struct PVSCSIRingReqDesc *e;
	struct scsi_device *sdev;
	u32 req_entries;

	s = adapter->rings_state;
	sdev = cmd->device;
	req_entries = s->reqNumEntriesLog2;

	/*
	 * If this condition holds, we might have room on the request ring, but
	 * we might not have room on the completion ring for the response.
	 * However, we have already ruled out this possibility - we would not
	 * have successfully allocated a context if it were true, since we only
	 * have one context per request entry.  Check for it anyway, since it
	 * would be a serious bug.
	 */
	if (s->reqProdIdx - s->cmpConsIdx >= 1 << req_entries) {
		scmd_printk(KERN_ERR, cmd, "vmw_pvscsi: "
			    "ring full: reqProdIdx=%d cmpConsIdx=%d\n",
			    s->reqProdIdx, s->cmpConsIdx);
		return -1;
	}

	e = adapter->req_ring + (s->reqProdIdx & MASK(req_entries));

	e->bus    = sdev->channel;
	e->target = sdev->id;
	memset(e->lun, 0, sizeof(e->lun));
	e->lun[1] = sdev->lun;

	if (cmd->sense_buffer) {
		ctx->sensePA = pci_map_single(adapter->dev, cmd->sense_buffer,
					      SCSI_SENSE_BUFFERSIZE,
					      PCI_DMA_FROMDEVICE);
		e->senseAddr = ctx->sensePA;
		e->senseLen = SCSI_SENSE_BUFFERSIZE;
	} else {
		e->senseLen  = 0;
		e->senseAddr = 0;
	}
	e->cdbLen   = cmd->cmd_len;
	e->vcpuHint = smp_processor_id();
	memcpy(e->cdb, cmd->cmnd, e->cdbLen);

	e->tag = SIMPLE_QUEUE_TAG;
	if (sdev->tagged_supported &&
	    (cmd->tag == HEAD_OF_QUEUE_TAG ||
	     cmd->tag == ORDERED_QUEUE_TAG))
		e->tag = cmd->tag;

	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
		e->flags = PVSCSI_FLAG_CMD_DIR_TOHOST;
	else if (cmd->sc_data_direction == DMA_TO_DEVICE)
		e->flags = PVSCSI_FLAG_CMD_DIR_TODEVICE;
	else if (cmd->sc_data_direction == DMA_NONE)
		e->flags = PVSCSI_FLAG_CMD_DIR_NONE;
	else
		e->flags = 0;

	pvscsi_map_buffers(adapter, ctx, cmd, e);

	e->context = pvscsi_map_context(adapter, ctx);

	barrier();

	s->reqProdIdx++;

	return 0;
}

static int pvscsi_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
	struct Scsi_Host *host = cmd->device->host;
	struct pvscsi_adapter *adapter = shost_priv(host);
	struct pvscsi_ctx *ctx;
	unsigned long flags;

	spin_lock_irqsave(&adapter->hw_lock, flags);

	ctx = pvscsi_acquire_context(adapter, cmd);
	if (!ctx || pvscsi_queue_ring(adapter, ctx, cmd) != 0) {
		if (ctx)
			pvscsi_release_context(adapter, ctx);
		spin_unlock_irqrestore(&adapter->hw_lock, flags);
		return SCSI_MLQUEUE_HOST_BUSY;
	}

	cmd->scsi_done = done;

	dev_dbg(&cmd->device->sdev_gendev,
		"queued cmd %p, ctx %p, op=%x\n", cmd, ctx, cmd->cmnd[0]);

	spin_unlock_irqrestore(&adapter->hw_lock, flags);

	pvscsi_kick_io(adapter, cmd->cmnd[0]);

	return 0;
}

static DEF_SCSI_QCMD(pvscsi_queue)

static int pvscsi_abort(struct scsi_cmnd *cmd)
{
	struct pvscsi_adapter *adapter = shost_priv(cmd->device->host);
	struct pvscsi_ctx *ctx;
	unsigned long flags;
	int result = SUCCESS;
	DECLARE_COMPLETION_ONSTACK(abort_cmp);

	scmd_printk(KERN_DEBUG, cmd, "task abort on host %u, %p\n",
		    adapter->host->host_no, cmd);

	spin_lock_irqsave(&adapter->hw_lock, flags);

	/*
	 * Poll the completion ring first - we might be trying to abort
	 * a command that is waiting to be dispatched in the completion ring.
	 */
	pvscsi_process_completion_ring(adapter);

	/*
	 * If there is no context for the command, it either already succeeded
	 * or else was never properly issued.  Not our problem.
	 */
	ctx = pvscsi_find_context(adapter, cmd);
	if (!ctx) {
		scmd_printk(KERN_DEBUG, cmd, "Failed to abort cmd %p\n", cmd);
		goto out;
	}

	/*
	 * Mark that the command has been requested to be aborted and issue
	 * the abort.
	 */
	ctx->abort_cmp = &abort_cmp;

	pvscsi_abort_cmd(adapter, ctx);
	spin_unlock_irqrestore(&adapter->hw_lock, flags);
	/* Wait for 2 secs for the completion. */
	wait_for_completion_timeout(&abort_cmp, msecs_to_jiffies(2000));
	spin_lock_irqsave(&adapter->hw_lock, flags);

	if (!completion_done(&abort_cmp)) {
		/*
		 * Failed to abort the command, unmark the fact that it
		 * was requested to be aborted.
		 */
		ctx->abort_cmp = NULL;
		result = FAILED;
		scmd_printk(KERN_DEBUG, cmd,
			    "Failed to get completion for aborted cmd %p\n",
			    cmd);
		goto out;
	}

	/*
	 * Successfully aborted the command.
	 */
	cmd->result = (DID_ABORT << 16);
	cmd->scsi_done(cmd);

out:
	spin_unlock_irqrestore(&adapter->hw_lock, flags);
	return result;
}

/*
 * Abort all outstanding requests.  This is only safe to use if the completion
 * ring will never be walked again or the device has been reset, because it
 * destroys the 1-1 mapping between context field passed to emulation and our
 * request structure.
 */
static void pvscsi_reset_all(struct pvscsi_adapter *adapter)
{
	unsigned i;

	for (i = 0; i < adapter->req_depth; i++) {
		struct pvscsi_ctx *ctx = &adapter->cmd_map[i];
		struct scsi_cmnd *cmd = ctx->cmd;
		if (cmd) {
			scmd_printk(KERN_ERR, cmd,
				    "Forced reset on cmd %p\n", cmd);
			pvscsi_unmap_buffers(adapter, ctx);
			pvscsi_release_context(adapter, ctx);
			cmd->result = (DID_RESET << 16);
			cmd->scsi_done(cmd);
		}
	}
}

static int pvscsi_host_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host = cmd->device->host;
	struct pvscsi_adapter *adapter = shost_priv(host);
	unsigned long flags;
	bool use_msg;

	scmd_printk(KERN_INFO, cmd, "SCSI Host reset\n");

	spin_lock_irqsave(&adapter->hw_lock, flags);

	use_msg = adapter->use_msg;

	if (use_msg) {
		adapter->use_msg = 0;
		spin_unlock_irqrestore(&adapter->hw_lock, flags);

		/*
		 * Now that we know that the ISR won't add more work on the
		 * workqueue we can safely flush any outstanding work.
		 */
		flush_workqueue(adapter->workqueue);
		spin_lock_irqsave(&adapter->hw_lock, flags);
	}

	/*
	 * We're going to tear down the entire ring structure and set it back
	 * up, so stalling new requests until all completions are flushed and
	 * the rings are back in place.
	 */

	pvscsi_process_request_ring(adapter);

	ll_adapter_reset(adapter);

	/*
	 * Now process any completions.  Note we do this AFTER adapter reset,
	 * which is strange, but stops races where completions get posted
	 * between processing the ring and issuing the reset.  The backend will
	 * not touch the ring memory after reset, so the immediately pre-reset
	 * completion ring state is still valid.
	 */
	pvscsi_process_completion_ring(adapter);

	pvscsi_reset_all(adapter);
	adapter->use_msg = use_msg;
	pvscsi_setup_all_rings(adapter);
	pvscsi_unmask_intr(adapter);

	spin_unlock_irqrestore(&adapter->hw_lock, flags);

	return SUCCESS;
}

static int pvscsi_bus_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host = cmd->device->host;
	struct pvscsi_adapter *adapter = shost_priv(host);
	unsigned long flags;

	scmd_printk(KERN_INFO, cmd, "SCSI Bus reset\n");

	/*
	 * We don't want to queue new requests for this bus after
	 * flushing all pending requests to emulation, since new
	 * requests could then sneak in during this bus reset phase,
	 * so take the lock now.
	 */
	spin_lock_irqsave(&adapter->hw_lock, flags);

	pvscsi_process_request_ring(adapter);
	ll_bus_reset(adapter);
	pvscsi_process_completion_ring(adapter);

	spin_unlock_irqrestore(&adapter->hw_lock, flags);

	return SUCCESS;
}

static int pvscsi_device_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host = cmd->device->host;
	struct pvscsi_adapter *adapter = shost_priv(host);
	unsigned long flags;

	scmd_printk(KERN_INFO, cmd, "SCSI device reset on scsi%u:%u\n",
		    host->host_no, cmd->device->id);

	/*
	 * We don't want to queue new requests for this device after flushing
	 * all pending requests to emulation, since new requests could then
	 * sneak in during this device reset phase, so take the lock now.
	 */
	spin_lock_irqsave(&adapter->hw_lock, flags);

	pvscsi_process_request_ring(adapter);
	ll_device_reset(adapter, cmd->device->id);
	pvscsi_process_completion_ring(adapter);

	spin_unlock_irqrestore(&adapter->hw_lock, flags);

	return SUCCESS;
}

static struct scsi_host_template pvscsi_template;

static const char *pvscsi_info(struct Scsi_Host *host)
{
	struct pvscsi_adapter *adapter = shost_priv(host);
	static char buf[256];

	sprintf(buf, "VMware PVSCSI storage adapter rev %d, req/cmp/msg rings: "
		"%u/%u/%u pages, cmd_per_lun=%u", adapter->rev,
		adapter->req_pages, adapter->cmp_pages, adapter->msg_pages,
		pvscsi_template.cmd_per_lun);

	return buf;
}

static struct scsi_host_template pvscsi_template = {
	.module				= THIS_MODULE,
	.name				= "VMware PVSCSI Host Adapter",
	.proc_name			= "vmw_pvscsi",
	.info				= pvscsi_info,
	.queuecommand			= pvscsi_queue,
	.this_id			= -1,
	.sg_tablesize			= PVSCSI_MAX_NUM_SG_ENTRIES_PER_SEGMENT,
	.dma_boundary			= UINT_MAX,
	.max_sectors			= 0xffff,
	.use_clustering			= ENABLE_CLUSTERING,
	.change_queue_depth		= pvscsi_change_queue_depth,
	.eh_abort_handler		= pvscsi_abort,
	.eh_device_reset_handler	= pvscsi_device_reset,
	.eh_bus_reset_handler		= pvscsi_bus_reset,
	.eh_host_reset_handler		= pvscsi_host_reset,
};

static void pvscsi_process_msg(const struct pvscsi_adapter *adapter,
			       const struct PVSCSIRingMsgDesc *e)
{
	struct PVSCSIRingsState *s = adapter->rings_state;
	struct Scsi_Host *host = adapter->host;
	struct scsi_device *sdev;

	printk(KERN_INFO "vmw_pvscsi: msg type: 0x%x - MSG RING: %u/%u (%u) \n",
	       e->type, s->msgProdIdx, s->msgConsIdx, s->msgNumEntriesLog2);

	BUILD_BUG_ON(PVSCSI_MSG_LAST != 2);

	if (e->type == PVSCSI_MSG_DEV_ADDED) {
		struct PVSCSIMsgDescDevStatusChanged *desc;
		desc = (struct PVSCSIMsgDescDevStatusChanged *)e;

		printk(KERN_INFO
		       "vmw_pvscsi: msg: device added at scsi%u:%u:%u\n",
		       desc->bus, desc->target, desc->lun[1]);

		if (!scsi_host_get(host))
			return;

		sdev = scsi_device_lookup(host, desc->bus, desc->target,
					  desc->lun[1]);
		if (sdev) {
			printk(KERN_INFO "vmw_pvscsi: device already exists\n");
			scsi_device_put(sdev);
		} else
			scsi_add_device(adapter->host, desc->bus,
					desc->target, desc->lun[1]);

		scsi_host_put(host);
	} else if (e->type == PVSCSI_MSG_DEV_REMOVED) {
		struct PVSCSIMsgDescDevStatusChanged *desc;
		desc = (struct PVSCSIMsgDescDevStatusChanged *)e;

		printk(KERN_INFO
		       "vmw_pvscsi: msg: device removed at scsi%u:%u:%u\n",
		       desc->bus, desc->target, desc->lun[1]);

		if (!scsi_host_get(host))
			return;

		sdev = scsi_device_lookup(host, desc->bus, desc->target,
					  desc->lun[1]);
		if (sdev) {
			scsi_remove_device(sdev);
			scsi_device_put(sdev);
		} else
			printk(KERN_INFO
			       "vmw_pvscsi: failed to lookup scsi%u:%u:%u\n",
			       desc->bus, desc->target, desc->lun[1]);

		scsi_host_put(host);
	}
}

static int pvscsi_msg_pending(const struct pvscsi_adapter *adapter)
{
	struct PVSCSIRingsState *s = adapter->rings_state;

	return s->msgProdIdx != s->msgConsIdx;
}

static void pvscsi_process_msg_ring(const struct pvscsi_adapter *adapter)
{
	struct PVSCSIRingsState *s = adapter->rings_state;
	struct PVSCSIRingMsgDesc *ring = adapter->msg_ring;
	u32 msg_entries = s->msgNumEntriesLog2;

	while (pvscsi_msg_pending(adapter)) {
		struct PVSCSIRingMsgDesc *e = ring + (s->msgConsIdx &
						      MASK(msg_entries));

		barrier();
		pvscsi_process_msg(adapter, e);
		barrier();
		s->msgConsIdx++;
	}
}

static void pvscsi_msg_workqueue_handler(struct work_struct *data)
{
	struct pvscsi_adapter *adapter;

	adapter = container_of(data, struct pvscsi_adapter, work);

	pvscsi_process_msg_ring(adapter);
}

static int pvscsi_setup_msg_workqueue(struct pvscsi_adapter *adapter)
{
	char name[32];

	if (!pvscsi_use_msg)
		return 0;

	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
			 PVSCSI_CMD_SETUP_MSG_RING);

	if (pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS) == -1)
		return 0;

	snprintf(name, sizeof(name),
		 "vmw_pvscsi_wq_%u", adapter->host->host_no);

	adapter->workqueue = create_singlethread_workqueue(name);
	if (!adapter->workqueue) {
		printk(KERN_ERR "vmw_pvscsi: failed to create work queue\n");
		return 0;
	}
	INIT_WORK(&adapter->work, pvscsi_msg_workqueue_handler);

	return 1;
}

static bool pvscsi_setup_req_threshold(struct pvscsi_adapter *adapter,
				      bool enable)
{
	u32 val;

	if (!pvscsi_use_req_threshold)
		return false;

	pvscsi_reg_write(adapter, PVSCSI_REG_OFFSET_COMMAND,
			 PVSCSI_CMD_SETUP_REQCALLTHRESHOLD);
	val = pvscsi_reg_read(adapter, PVSCSI_REG_OFFSET_COMMAND_STATUS);
	if (val == -1) {
		printk(KERN_INFO "vmw_pvscsi: device does not support req_threshold\n");
		return false;
	} else {
		struct PVSCSICmdDescSetupReqCall cmd_msg = { 0 };
		cmd_msg.enable = enable;
		printk(KERN_INFO
		       "vmw_pvscsi: %sabling reqCallThreshold\n",
			enable ? "en" : "dis");
		pvscsi_write_cmd_desc(adapter,
				      PVSCSI_CMD_SETUP_REQCALLTHRESHOLD,
				      &cmd_msg, sizeof(cmd_msg));
		return pvscsi_reg_read(adapter,
				       PVSCSI_REG_OFFSET_COMMAND_STATUS) != 0;
	}
}

static irqreturn_t pvscsi_isr(int irq, void *devp)
{
	struct pvscsi_adapter *adapter = devp;
	int handled;

	if (adapter->use_msi || adapter->use_msix)
		handled = true;
	else {
		u32 val = pvscsi_read_intr_status(adapter);
		handled = (val & PVSCSI_INTR_ALL_SUPPORTED) != 0;
		if (handled)
			pvscsi_write_intr_status(devp, val);
	}

	if (handled) {
		unsigned long flags;

		spin_lock_irqsave(&adapter->hw_lock, flags);

		pvscsi_process_completion_ring(adapter);
		if (adapter->use_msg && pvscsi_msg_pending(adapter))
			queue_work(adapter->workqueue, &adapter->work);

		spin_unlock_irqrestore(&adapter->hw_lock, flags);
	}

	return IRQ_RETVAL(handled);
}

static void pvscsi_free_sgls(const struct pvscsi_adapter *adapter)
{
	struct pvscsi_ctx *ctx = adapter->cmd_map;
	unsigned i;

	for (i = 0; i < adapter->req_depth; ++i, ++ctx)
		free_pages((unsigned long)ctx->sgl, get_order(SGL_SIZE));
}

static int pvscsi_setup_msix(const struct pvscsi_adapter *adapter,
			     unsigned int *irq)
{
	struct msix_entry entry = { 0, PVSCSI_VECTOR_COMPLETION };
	int ret;

	ret = pci_enable_msix_exact(adapter->dev, &entry, 1);
	if (ret)
		return ret;

	*irq = entry.vector;

	return 0;
}

static void pvscsi_shutdown_intr(struct pvscsi_adapter *adapter)
{
	if (adapter->irq) {
		free_irq(adapter->irq, adapter);
		adapter->irq = 0;
	}
	if (adapter->use_msi) {
		pci_disable_msi(adapter->dev);
		adapter->use_msi = 0;
	} else if (adapter->use_msix) {
		pci_disable_msix(adapter->dev);
		adapter->use_msix = 0;
	}
}

static void pvscsi_release_resources(struct pvscsi_adapter *adapter)
{
	pvscsi_shutdown_intr(adapter);

	if (adapter->workqueue)
		destroy_workqueue(adapter->workqueue);

	if (adapter->mmioBase)
		pci_iounmap(adapter->dev, adapter->mmioBase);

	pci_release_regions(adapter->dev);

	if (adapter->cmd_map) {
		pvscsi_free_sgls(adapter);
		kfree(adapter->cmd_map);
	}

	if (adapter->rings_state)
		pci_free_consistent(adapter->dev, PAGE_SIZE,
				    adapter->rings_state, adapter->ringStatePA);

	if (adapter->req_ring)
		pci_free_consistent(adapter->dev,
				    adapter->req_pages * PAGE_SIZE,
				    adapter->req_ring, adapter->reqRingPA);

	if (adapter->cmp_ring)
		pci_free_consistent(adapter->dev,
				    adapter->cmp_pages * PAGE_SIZE,
				    adapter->cmp_ring, adapter->cmpRingPA);

	if (adapter->msg_ring)
		pci_free_consistent(adapter->dev,
				    adapter->msg_pages * PAGE_SIZE,
				    adapter->msg_ring, adapter->msgRingPA);
}

/*
 * Allocate scatter gather lists.
 *
 * These are statically allocated.  Trying to be clever was not worth it.
 *
 * Dynamic allocation can fail, and we can't go deep into the memory
 * allocator, since we're a SCSI driver, and trying too hard to allocate
 * memory might generate disk I/O.  We also don't want to fail disk I/O
 * in that case because we can't get an allocation - the I/O could be
 * trying to swap out data to free memory.  Since that is pathological,
 * just use a statically allocated scatter list.
 *
 */
static int pvscsi_allocate_sg(struct pvscsi_adapter *adapter)
{
	struct pvscsi_ctx *ctx;
	int i;

	ctx = adapter->cmd_map;
	BUILD_BUG_ON(sizeof(struct pvscsi_sg_list) > SGL_SIZE);

	for (i = 0; i < adapter->req_depth; ++i, ++ctx) {
		ctx->sgl = (void *)__get_free_pages(GFP_KERNEL,
						    get_order(SGL_SIZE));
		ctx->sglPA = 0;
		BUG_ON(!IS_ALIGNED(((unsigned long)ctx->sgl), PAGE_SIZE));
		if (!ctx->sgl) {
			for (; i >= 0; --i, --ctx) {
				free_pages((unsigned long)ctx->sgl,
					   get_order(SGL_SIZE));
				ctx->sgl = NULL;
			}
			return -ENOMEM;
		}
	}

	return 0;
}

/*
 * Query the device, fetch the config info and return the
 * maximum number of targets on the adapter. In case of
 * failure due to any reason return default i.e. 16.
 */
static u32 pvscsi_get_max_targets(struct pvscsi_adapter *adapter)
{
	struct PVSCSICmdDescConfigCmd cmd;
	struct PVSCSIConfigPageHeader *header;
	struct device *dev;
	dma_addr_t configPagePA;
	void *config_page;
	u32 numPhys = 16;

	dev = pvscsi_dev(adapter);
	config_page = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
					   &configPagePA);
	if (!config_page) {
		dev_warn(dev, "vmw_pvscsi: failed to allocate memory for config page\n");
		goto exit;
	}
	BUG_ON(configPagePA & ~PAGE_MASK);

	/* Fetch config info from the device. */
	cmd.configPageAddress = ((u64)PVSCSI_CONFIG_CONTROLLER_ADDRESS) << 32;
	cmd.configPageNum = PVSCSI_CONFIG_PAGE_CONTROLLER;
	cmd.cmpAddr = configPagePA;
	cmd._pad = 0;

	/*
	 * Mark the completion page header with error values. If the device
	 * completes the command successfully, it sets the status values to
	 * indicate success.
	 */
	header = config_page;
	memset(header, 0, sizeof *header);
	header->hostStatus = BTSTAT_INVPARAM;
	header->scsiStatus = SDSTAT_CHECK;

	pvscsi_write_cmd_desc(adapter, PVSCSI_CMD_CONFIG, &cmd, sizeof cmd);

	if (header->hostStatus == BTSTAT_SUCCESS &&
	    header->scsiStatus == SDSTAT_GOOD) {
		struct PVSCSIConfigPageController *config;

		config = config_page;
		numPhys = config->numPhys;
	} else
		dev_warn(dev, "vmw_pvscsi: PVSCSI_CMD_CONFIG failed. hostStatus = 0x%x, scsiStatus = 0x%x\n",
			 header->hostStatus, header->scsiStatus);
	pci_free_consistent(adapter->dev, PAGE_SIZE, config_page, configPagePA);
exit:
	return numPhys;
}

static int pvscsi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct pvscsi_adapter *adapter;
	struct pvscsi_adapter adapter_temp;
	struct Scsi_Host *host = NULL;
	unsigned int i;
	unsigned long flags = 0;
	int error;
	u32 max_id;

	error = -ENODEV;

	if (pci_enable_device(pdev))
		return error;

	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) == 0 &&
	    pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) == 0) {
		printk(KERN_INFO "vmw_pvscsi: using 64bit dma\n");
	} else if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) == 0 &&
		   pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)) == 0) {
		printk(KERN_INFO "vmw_pvscsi: using 32bit dma\n");
	} else {
		printk(KERN_ERR "vmw_pvscsi: failed to set DMA mask\n");
		goto out_disable_device;
	}

	/*
	 * Let's use a temp pvscsi_adapter struct until we find the number of
	 * targets on the adapter, after that we will switch to the real
	 * allocated struct.
	 */
	adapter = &adapter_temp;
	memset(adapter, 0, sizeof(*adapter));
	adapter->dev  = pdev;
	adapter->rev = pdev->revision;

	if (pci_request_regions(pdev, "vmw_pvscsi")) {
		printk(KERN_ERR "vmw_pvscsi: pci memory selection failed\n");
		goto out_disable_device;
	}

	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		if ((pci_resource_flags(pdev, i) & PCI_BASE_ADDRESS_SPACE_IO))
			continue;

		if (pci_resource_len(pdev, i) < PVSCSI_MEM_SPACE_SIZE)
			continue;

		break;
	}

	if (i == DEVICE_COUNT_RESOURCE) {
		printk(KERN_ERR
		       "vmw_pvscsi: adapter has no suitable MMIO region\n");
		goto out_release_resources_and_disable;
	}

	adapter->mmioBase = pci_iomap(pdev, i, PVSCSI_MEM_SPACE_SIZE);

	if (!adapter->mmioBase) {
		printk(KERN_ERR
		       "vmw_pvscsi: can't iomap for BAR %d memsize %lu\n",
		       i, PVSCSI_MEM_SPACE_SIZE);
		goto out_release_resources_and_disable;
	}

	pci_set_master(pdev);

	/*
	 * Ask the device for max number of targets before deciding the
	 * default pvscsi_ring_pages value.
	 */
	max_id = pvscsi_get_max_targets(adapter);
	printk(KERN_INFO "vmw_pvscsi: max_id: %u\n", max_id);

	if (pvscsi_ring_pages == 0)
		/*
		 * Set the right default value. Up to 16 it is 8, above it is
		 * max.
		 */
		pvscsi_ring_pages = (max_id > 16) ?
			PVSCSI_SETUP_RINGS_MAX_NUM_PAGES :
			PVSCSI_DEFAULT_NUM_PAGES_PER_RING;
	printk(KERN_INFO
	       "vmw_pvscsi: setting ring_pages to %d\n",
	       pvscsi_ring_pages);

	pvscsi_template.can_queue =
		min(PVSCSI_MAX_NUM_PAGES_REQ_RING, pvscsi_ring_pages) *
		PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
	pvscsi_template.cmd_per_lun =
		min(pvscsi_template.can_queue, pvscsi_cmd_per_lun);
	host = scsi_host_alloc(&pvscsi_template, sizeof(struct pvscsi_adapter));
	if (!host) {
		printk(KERN_ERR "vmw_pvscsi: failed to allocate host\n");
		goto out_release_resources_and_disable;
	}

	/*
	 * Let's use the real pvscsi_adapter struct here onwards.
	 */
	adapter = shost_priv(host);
	memset(adapter, 0, sizeof(*adapter));
	adapter->dev  = pdev;
	adapter->host = host;
	/*
	 * Copy back what we already have to the allocated adapter struct.
	 */
	adapter->rev = adapter_temp.rev;
	adapter->mmioBase = adapter_temp.mmioBase;

	spin_lock_init(&adapter->hw_lock);
	host->max_channel = 0;
	host->max_lun     = 1;
	host->max_cmd_len = 16;
	host->max_id      = max_id;

	pci_set_drvdata(pdev, host);

	ll_adapter_reset(adapter);

	adapter->use_msg = pvscsi_setup_msg_workqueue(adapter);

	error = pvscsi_allocate_rings(adapter);
	if (error) {
		printk(KERN_ERR "vmw_pvscsi: unable to allocate ring memory\n");
		goto out_release_resources;
	}

	/*
	 * From this point on we should reset the adapter if anything goes
	 * wrong.
	 */
	pvscsi_setup_all_rings(adapter);

	adapter->cmd_map = kcalloc(adapter->req_depth,
				   sizeof(struct pvscsi_ctx), GFP_KERNEL);
	if (!adapter->cmd_map) {
		printk(KERN_ERR "vmw_pvscsi: failed to allocate memory.\n");
		error = -ENOMEM;
		goto out_reset_adapter;
	}

	INIT_LIST_HEAD(&adapter->cmd_pool);
	for (i = 0; i < adapter->req_depth; i++) {
		struct pvscsi_ctx *ctx = adapter->cmd_map + i;
		list_add(&ctx->list, &adapter->cmd_pool);
	}

	error = pvscsi_allocate_sg(adapter);
	if (error) {
		printk(KERN_ERR "vmw_pvscsi: unable to allocate s/g table\n");
		goto out_reset_adapter;
	}

	if (!pvscsi_disable_msix &&
	    pvscsi_setup_msix(adapter, &adapter->irq) == 0) {
		printk(KERN_INFO "vmw_pvscsi: using MSI-X\n");
		adapter->use_msix = 1;
	} else if (!pvscsi_disable_msi && pci_enable_msi(pdev) == 0) {
		printk(KERN_INFO "vmw_pvscsi: using MSI\n");
		adapter->use_msi = 1;
		adapter->irq = pdev->irq;
	} else {
		printk(KERN_INFO "vmw_pvscsi: using INTx\n");
		adapter->irq = pdev->irq;
		flags = IRQF_SHARED;
	}

	adapter->use_req_threshold = pvscsi_setup_req_threshold(adapter, true);
	printk(KERN_DEBUG "vmw_pvscsi: driver-based request coalescing %sabled\n",
	       adapter->use_req_threshold ? "en" : "dis");

	error = request_irq(adapter->irq, pvscsi_isr, flags,
			    "vmw_pvscsi", adapter);
	if (error) {
		printk(KERN_ERR
		       "vmw_pvscsi: unable to request IRQ: %d\n", error);
		adapter->irq = 0;
		goto out_reset_adapter;
	}

	error = scsi_add_host(host, &pdev->dev);
	if (error) {
		printk(KERN_ERR
		       "vmw_pvscsi: scsi_add_host failed: %d\n", error);
		goto out_reset_adapter;
	}

	dev_info(&pdev->dev, "VMware PVSCSI rev %d host #%u\n",
		 adapter->rev, host->host_no);

	pvscsi_unmask_intr(adapter);

	scsi_scan_host(host);

	return 0;

out_reset_adapter:
	ll_adapter_reset(adapter);
out_release_resources:
	pvscsi_release_resources(adapter);
	scsi_host_put(host);
out_disable_device:
	pci_disable_device(pdev);

	return error;

out_release_resources_and_disable:
	pvscsi_release_resources(adapter);
	goto out_disable_device;
}

static void __pvscsi_shutdown(struct pvscsi_adapter *adapter)
{
	pvscsi_mask_intr(adapter);

	if (adapter->workqueue)
		flush_workqueue(adapter->workqueue);

	pvscsi_shutdown_intr(adapter);

	pvscsi_process_request_ring(adapter);
	pvscsi_process_completion_ring(adapter);
	ll_adapter_reset(adapter);
}

static void pvscsi_shutdown(struct pci_dev *dev)
{
	struct Scsi_Host *host = pci_get_drvdata(dev);
	struct pvscsi_adapter *adapter = shost_priv(host);

	__pvscsi_shutdown(adapter);
}

static void pvscsi_remove(struct pci_dev *pdev)
{
	struct Scsi_Host *host = pci_get_drvdata(pdev);
	struct pvscsi_adapter *adapter = shost_priv(host);

	scsi_remove_host(host);

	__pvscsi_shutdown(adapter);
	pvscsi_release_resources(adapter);

	scsi_host_put(host);

	pci_disable_device(pdev);
}

static struct pci_driver pvscsi_pci_driver = {
	.name		= "vmw_pvscsi",
	.id_table	= pvscsi_pci_tbl,
	.probe		= pvscsi_probe,
	.remove		= pvscsi_remove,
	.shutdown       = pvscsi_shutdown,
};

static int __init pvscsi_init(void)
{
	pr_info("%s - version %s\n",
		PVSCSI_LINUX_DRIVER_DESC, PVSCSI_DRIVER_VERSION_STRING);
	return pci_register_driver(&pvscsi_pci_driver);
}

static void __exit pvscsi_exit(void)
{
	pci_unregister_driver(&pvscsi_pci_driver);
}

module_init(pvscsi_init);
module_exit(pvscsi_exit);

Privacy Policy