summaryrefslogtreecommitdiff
path: root/drivers/nvme/host/core.c
blob: 8c2ddd5025ab6afe4adec11f42d150ac9ff529a5 (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
/*
 * NVM Express device driver
 * Copyright (c) 2011-2014, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list_sort.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/pr.h>
#include <linux/ptrace.h>
#include <linux/nvme_ioctl.h>
#include <linux/t10-pi.h>
#include <scsi/sg.h>
#include <asm/unaligned.h>

#include "nvme.h"

#define NVME_MINORS		(1U << MINORBITS)

static int nvme_major;
module_param(nvme_major, int, 0);

static int nvme_char_major;
module_param(nvme_char_major, int, 0);

static LIST_HEAD(nvme_ctrl_list);
DEFINE_SPINLOCK(dev_list_lock);

static struct class *nvme_class;

static void nvme_free_ns(struct kref *kref)
{
	struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);

	if (ns->type == NVME_NS_LIGHTNVM)
		nvme_nvm_unregister(ns->queue, ns->disk->disk_name);

	spin_lock(&dev_list_lock);
	ns->disk->private_data = NULL;
	spin_unlock(&dev_list_lock);

	put_disk(ns->disk);
	ida_simple_remove(&ns->ctrl->ns_ida, ns->instance);
	nvme_put_ctrl(ns->ctrl);
	kfree(ns);
}

static void nvme_put_ns(struct nvme_ns *ns)
{
	kref_put(&ns->kref, nvme_free_ns);
}

static struct nvme_ns *nvme_get_ns_from_disk(struct gendisk *disk)
{
	struct nvme_ns *ns;

	spin_lock(&dev_list_lock);
	ns = disk->private_data;
	if (ns && !kref_get_unless_zero(&ns->kref))
		ns = NULL;
	spin_unlock(&dev_list_lock);

	return ns;
}

void nvme_requeue_req(struct request *req)
{
	unsigned long flags;

	blk_mq_requeue_request(req);
	spin_lock_irqsave(req->q->queue_lock, flags);
	if (!blk_queue_stopped(req->q))
		blk_mq_kick_requeue_list(req->q);
	spin_unlock_irqrestore(req->q->queue_lock, flags);
}

struct request *nvme_alloc_request(struct request_queue *q,
		struct nvme_command *cmd, unsigned int flags)
{
	bool write = cmd->common.opcode & 1;
	struct request *req;

	req = blk_mq_alloc_request(q, write, flags);
	if (IS_ERR(req))
		return req;

	req->cmd_type = REQ_TYPE_DRV_PRIV;
	req->cmd_flags |= REQ_FAILFAST_DRIVER;
	req->__data_len = 0;
	req->__sector = (sector_t) -1;
	req->bio = req->biotail = NULL;

	req->cmd = (unsigned char *)cmd;
	req->cmd_len = sizeof(struct nvme_command);
	req->special = (void *)0;

	return req;
}

/*
 * Returns 0 on success.  If the result is negative, it's a Linux error code;
 * if the result is positive, it's an NVM Express status code
 */
int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
		void *buffer, unsigned bufflen, u32 *result, unsigned timeout)
{
	struct request *req;
	int ret;

	req = nvme_alloc_request(q, cmd, 0);
	if (IS_ERR(req))
		return PTR_ERR(req);

	req->timeout = timeout ? timeout : ADMIN_TIMEOUT;

	if (buffer && bufflen) {
		ret = blk_rq_map_kern(q, req, buffer, bufflen, GFP_KERNEL);
		if (ret)
			goto out;
	}

	blk_execute_rq(req->q, NULL, req, 0);
	if (result)
		*result = (u32)(uintptr_t)req->special;
	ret = req->errors;
 out:
	blk_mq_free_request(req);
	return ret;
}

int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
		void *buffer, unsigned bufflen)
{
	return __nvme_submit_sync_cmd(q, cmd, buffer, bufflen, NULL, 0);
}

int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
		void __user *ubuffer, unsigned bufflen,
		void __user *meta_buffer, unsigned meta_len, u32 meta_seed,
		u32 *result, unsigned timeout)
{
	bool write = cmd->common.opcode & 1;
	struct nvme_ns *ns = q->queuedata;
	struct gendisk *disk = ns ? ns->disk : NULL;
	struct request *req;
	struct bio *bio = NULL;
	void *meta = NULL;
	int ret;

	req = nvme_alloc_request(q, cmd, 0);
	if (IS_ERR(req))
		return PTR_ERR(req);

	req->timeout = timeout ? timeout : ADMIN_TIMEOUT;

	if (ubuffer && bufflen) {
		ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen,
				GFP_KERNEL);
		if (ret)
			goto out;
		bio = req->bio;

		if (!disk)
			goto submit;
		bio->bi_bdev = bdget_disk(disk, 0);
		if (!bio->bi_bdev) {
			ret = -ENODEV;
			goto out_unmap;
		}

		if (meta_buffer) {
			struct bio_integrity_payload *bip;

			meta = kmalloc(meta_len, GFP_KERNEL);
			if (!meta) {
				ret = -ENOMEM;
				goto out_unmap;
			}

			if (write) {
				if (copy_from_user(meta, meta_buffer,
						meta_len)) {
					ret = -EFAULT;
					goto out_free_meta;
				}
			}

			bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
			if (IS_ERR(bip)) {
				ret = PTR_ERR(bip);
				goto out_free_meta;
			}

			bip->bip_iter.bi_size = meta_len;
			bip->bip_iter.bi_sector = meta_seed;

			ret = bio_integrity_add_page(bio, virt_to_page(meta),
					meta_len, offset_in_page(meta));
			if (ret != meta_len) {
				ret = -ENOMEM;
				goto out_free_meta;
			}
		}
	}
 submit:
	blk_execute_rq(req->q, disk, req, 0);
	ret = req->errors;
	if (result)
		*result = (u32)(uintptr_t)req->special;
	if (meta && !ret && !write) {
		if (copy_to_user(meta_buffer, meta, meta_len))
			ret = -EFAULT;
	}
 out_free_meta:
	kfree(meta);
 out_unmap:
	if (bio) {
		if (disk && bio->bi_bdev)
			bdput(bio->bi_bdev);
		blk_rq_unmap_user(bio);
	}
 out:
	blk_mq_free_request(req);
	return ret;
}

int nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
		void __user *ubuffer, unsigned bufflen, u32 *result,
		unsigned timeout)
{
	return __nvme_submit_user_cmd(q, cmd, ubuffer, bufflen, NULL, 0, 0,
			result, timeout);
}

int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
{
	struct nvme_command c = { };
	int error;

	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
	c.identify.opcode = nvme_admin_identify;
	c.identify.cns = cpu_to_le32(1);

	*id = kmalloc(sizeof(struct nvme_id_ctrl), GFP_KERNEL);
	if (!*id)
		return -ENOMEM;

	error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
			sizeof(struct nvme_id_ctrl));
	if (error)
		kfree(*id);
	return error;
}

static int nvme_identify_ns_list(struct nvme_ctrl *dev, unsigned nsid, __le32 *ns_list)
{
	struct nvme_command c = { };

	c.identify.opcode = nvme_admin_identify;
	c.identify.cns = cpu_to_le32(2);
	c.identify.nsid = cpu_to_le32(nsid);
	return nvme_submit_sync_cmd(dev->admin_q, &c, ns_list, 0x1000);
}

int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
		struct nvme_id_ns **id)
{
	struct nvme_command c = { };
	int error;

	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
	c.identify.opcode = nvme_admin_identify,
	c.identify.nsid = cpu_to_le32(nsid),

	*id = kmalloc(sizeof(struct nvme_id_ns), GFP_KERNEL);
	if (!*id)
		return -ENOMEM;

	error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
			sizeof(struct nvme_id_ns));
	if (error)
		kfree(*id);
	return error;
}

int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
					dma_addr_t dma_addr, u32 *result)
{
	struct nvme_command c;

	memset(&c, 0, sizeof(c));
	c.features.opcode = nvme_admin_get_features;
	c.features.nsid = cpu_to_le32(nsid);
	c.features.prp1 = cpu_to_le64(dma_addr);
	c.features.fid = cpu_to_le32(fid);

	return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0, result, 0);
}

int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
					dma_addr_t dma_addr, u32 *result)
{
	struct nvme_command c;

	memset(&c, 0, sizeof(c));
	c.features.opcode = nvme_admin_set_features;
	c.features.prp1 = cpu_to_le64(dma_addr);
	c.features.fid = cpu_to_le32(fid);
	c.features.dword11 = cpu_to_le32(dword11);

	return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0, result, 0);
}

int nvme_get_log_page(struct nvme_ctrl *dev, struct nvme_smart_log **log)
{
	struct nvme_command c = { };
	int error;

	c.common.opcode = nvme_admin_get_log_page,
	c.common.nsid = cpu_to_le32(0xFFFFFFFF),
	c.common.cdw10[0] = cpu_to_le32(
			(((sizeof(struct nvme_smart_log) / 4) - 1) << 16) |
			 NVME_LOG_SMART),

	*log = kmalloc(sizeof(struct nvme_smart_log), GFP_KERNEL);
	if (!*log)
		return -ENOMEM;

	error = nvme_submit_sync_cmd(dev->admin_q, &c, *log,
			sizeof(struct nvme_smart_log));
	if (error)
		kfree(*log);
	return error;
}

int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count)
{
	u32 q_count = (*count - 1) | ((*count - 1) << 16);
	u32 result;
	int status, nr_io_queues;

	status = nvme_set_features(ctrl, NVME_FEAT_NUM_QUEUES, q_count, 0,
			&result);
	if (status)
		return status;

	nr_io_queues = min(result & 0xffff, result >> 16) + 1;
	*count = min(*count, nr_io_queues);
	return 0;
}

static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
{
	struct nvme_user_io io;
	struct nvme_command c;
	unsigned length, meta_len;
	void __user *metadata;

	if (copy_from_user(&io, uio, sizeof(io)))
		return -EFAULT;

	switch (io.opcode) {
	case nvme_cmd_write:
	case nvme_cmd_read:
	case nvme_cmd_compare:
		break;
	default:
		return -EINVAL;
	}

	length = (io.nblocks + 1) << ns->lba_shift;
	meta_len = (io.nblocks + 1) * ns->ms;
	metadata = (void __user *)(uintptr_t)io.metadata;

	if (ns->ext) {
		length += meta_len;
		meta_len = 0;
	} else if (meta_len) {
		if ((io.metadata & 3) || !io.metadata)
			return -EINVAL;
	}

	memset(&c, 0, sizeof(c));
	c.rw.opcode = io.opcode;
	c.rw.flags = io.flags;
	c.rw.nsid = cpu_to_le32(ns->ns_id);
	c.rw.slba = cpu_to_le64(io.slba);
	c.rw.length = cpu_to_le16(io.nblocks);
	c.rw.control = cpu_to_le16(io.control);
	c.rw.dsmgmt = cpu_to_le32(io.dsmgmt);
	c.rw.reftag = cpu_to_le32(io.reftag);
	c.rw.apptag = cpu_to_le16(io.apptag);
	c.rw.appmask = cpu_to_le16(io.appmask);

	return __nvme_submit_user_cmd(ns->queue, &c,
			(void __user *)(uintptr_t)io.addr, length,
			metadata, meta_len, io.slba, NULL, 0);
}

static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
			struct nvme_passthru_cmd __user *ucmd)
{
	struct nvme_passthru_cmd cmd;
	struct nvme_command c;
	unsigned timeout = 0;
	int status;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
		return -EFAULT;

	memset(&c, 0, sizeof(c));
	c.common.opcode = cmd.opcode;
	c.common.flags = cmd.flags;
	c.common.nsid = cpu_to_le32(cmd.nsid);
	c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
	c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
	c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
	c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
	c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
	c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
	c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
	c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);

	if (cmd.timeout_ms)
		timeout = msecs_to_jiffies(cmd.timeout_ms);

	status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
			(void __user *)(uintptr_t)cmd.addr, cmd.data_len,
			&cmd.result, timeout);
	if (status >= 0) {
		if (put_user(cmd.result, &ucmd->result))
			return -EFAULT;
	}

	return status;
}

static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
		unsigned int cmd, unsigned long arg)
{
	struct nvme_ns *ns = bdev->bd_disk->private_data;

	switch (cmd) {
	case NVME_IOCTL_ID:
		force_successful_syscall_return();
		return ns->ns_id;
	case NVME_IOCTL_ADMIN_CMD:
		return nvme_user_cmd(ns->ctrl, NULL, (void __user *)arg);
	case NVME_IOCTL_IO_CMD:
		return nvme_user_cmd(ns->ctrl, ns, (void __user *)arg);
	case NVME_IOCTL_SUBMIT_IO:
		return nvme_submit_io(ns, (void __user *)arg);
#ifdef CONFIG_BLK_DEV_NVME_SCSI
	case SG_GET_VERSION_NUM:
		return nvme_sg_get_version_num((void __user *)arg);
	case SG_IO:
		return nvme_sg_io(ns, (void __user *)arg);
#endif
	default:
		return -ENOTTY;
	}
}

#ifdef CONFIG_COMPAT
static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
			unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case SG_IO:
		return -ENOIOCTLCMD;
	}
	return nvme_ioctl(bdev, mode, cmd, arg);
}
#else
#define nvme_compat_ioctl	NULL
#endif

static int nvme_open(struct block_device *bdev, fmode_t mode)
{
	return nvme_get_ns_from_disk(bdev->bd_disk) ? 0 : -ENXIO;
}

static void nvme_release(struct gendisk *disk, fmode_t mode)
{
	nvme_put_ns(disk->private_data);
}

static int nvme_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	/* some standard values */
	geo->heads = 1 << 6;
	geo->sectors = 1 << 5;
	geo->cylinders = get_capacity(bdev->bd_disk) >> 11;
	return 0;
}

#ifdef CONFIG_BLK_DEV_INTEGRITY
static void nvme_init_integrity(struct nvme_ns *ns)
{
	struct blk_integrity integrity;

	switch (ns->pi_type) {
	case NVME_NS_DPS_PI_TYPE3:
		integrity.profile = &t10_pi_type3_crc;
		break;
	case NVME_NS_DPS_PI_TYPE1:
	case NVME_NS_DPS_PI_TYPE2:
		integrity.profile = &t10_pi_type1_crc;
		break;
	default:
		integrity.profile = NULL;
		break;
	}
	integrity.tuple_size = ns->ms;
	blk_integrity_register(ns->disk, &integrity);
	blk_queue_max_integrity_segments(ns->queue, 1);
}
#else
static void nvme_init_integrity(struct nvme_ns *ns)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */

static void nvme_config_discard(struct nvme_ns *ns)
{
	u32 logical_block_size = queue_logical_block_size(ns->queue);
	ns->queue->limits.discard_zeroes_data = 0;
	ns->queue->limits.discard_alignment = logical_block_size;
	ns->queue->limits.discard_granularity = logical_block_size;
	blk_queue_max_discard_sectors(ns->queue, 0xffffffff);
	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);
}

static int nvme_revalidate_disk(struct gendisk *disk)
{
	struct nvme_ns *ns = disk->private_data;
	struct nvme_id_ns *id;
	u8 lbaf, pi_type;
	u16 old_ms;
	unsigned short bs;

	if (nvme_identify_ns(ns->ctrl, ns->ns_id, &id)) {
		dev_warn(ns->ctrl->dev, "%s: Identify failure nvme%dn%d\n",
				__func__, ns->ctrl->instance, ns->ns_id);
		return -ENODEV;
	}
	if (id->ncap == 0) {
		kfree(id);
		return -ENODEV;
	}

	if (nvme_nvm_ns_supported(ns, id) && ns->type != NVME_NS_LIGHTNVM) {
		if (nvme_nvm_register(ns->queue, disk->disk_name)) {
			dev_warn(ns->ctrl->dev,
				"%s: LightNVM init failure\n", __func__);
			kfree(id);
			return -ENODEV;
		}
		ns->type = NVME_NS_LIGHTNVM;
	}

	if (ns->ctrl->vs >= NVME_VS(1, 1))
		memcpy(ns->eui, id->eui64, sizeof(ns->eui));
	if (ns->ctrl->vs >= NVME_VS(1, 2))
		memcpy(ns->uuid, id->nguid, sizeof(ns->uuid));

	old_ms = ns->ms;
	lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
	ns->lba_shift = id->lbaf[lbaf].ds;
	ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
	ns->ext = ns->ms && (id->flbas & NVME_NS_FLBAS_META_EXT);

	/*
	 * If identify namespace failed, use default 512 byte block size so
	 * block layer can use before failing read/write for 0 capacity.
	 */
	if (ns->lba_shift == 0)
		ns->lba_shift = 9;
	bs = 1 << ns->lba_shift;
	/* XXX: PI implementation requires metadata equal t10 pi tuple size */
	pi_type = ns->ms == sizeof(struct t10_pi_tuple) ?
					id->dps & NVME_NS_DPS_PI_MASK : 0;

	blk_mq_freeze_queue(disk->queue);
	if (blk_get_integrity(disk) && (ns->pi_type != pi_type ||
				ns->ms != old_ms ||
				bs != queue_logical_block_size(disk->queue) ||
				(ns->ms && ns->ext)))
		blk_integrity_unregister(disk);

	ns->pi_type = pi_type;
	blk_queue_logical_block_size(ns->queue, bs);

	if (ns->ms && !blk_get_integrity(disk) && !ns->ext)
		nvme_init_integrity(ns);
	if (ns->ms && !(ns->ms == 8 && ns->pi_type) && !blk_get_integrity(disk))
		set_capacity(disk, 0);
	else
		set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));

	if (ns->ctrl->oncs & NVME_CTRL_ONCS_DSM)
		nvme_config_discard(ns);
	blk_mq_unfreeze_queue(disk->queue);

	kfree(id);
	return 0;
}

static char nvme_pr_type(enum pr_type type)
{
	switch (type) {
	case PR_WRITE_EXCLUSIVE:
		return 1;
	case PR_EXCLUSIVE_ACCESS:
		return 2;
	case PR_WRITE_EXCLUSIVE_REG_ONLY:
		return 3;
	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
		return 4;
	case PR_WRITE_EXCLUSIVE_ALL_REGS:
		return 5;
	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
		return 6;
	default:
		return 0;
	}
};

static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
				u64 key, u64 sa_key, u8 op)
{
	struct nvme_ns *ns = bdev->bd_disk->private_data;
	struct nvme_command c;
	u8 data[16] = { 0, };

	put_unaligned_le64(key, &data[0]);
	put_unaligned_le64(sa_key, &data[8]);

	memset(&c, 0, sizeof(c));
	c.common.opcode = op;
	c.common.nsid = cpu_to_le32(ns->ns_id);
	c.common.cdw10[0] = cpu_to_le32(cdw10);

	return nvme_submit_sync_cmd(ns->queue, &c, data, 16);
}

static int nvme_pr_register(struct block_device *bdev, u64 old,
		u64 new, unsigned flags)
{
	u32 cdw10;

	if (flags & ~PR_FL_IGNORE_KEY)
		return -EOPNOTSUPP;

	cdw10 = old ? 2 : 0;
	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
}

static int nvme_pr_reserve(struct block_device *bdev, u64 key,
		enum pr_type type, unsigned flags)
{
	u32 cdw10;

	if (flags & ~PR_FL_IGNORE_KEY)
		return -EOPNOTSUPP;

	cdw10 = nvme_pr_type(type) << 8;
	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
}

static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
		enum pr_type type, bool abort)
{
	u32 cdw10 = nvme_pr_type(type) << 8 | abort ? 2 : 1;
	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
}

static int nvme_pr_clear(struct block_device *bdev, u64 key)
{
	u32 cdw10 = 1 | (key ? 1 << 3 : 0);
	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_register);
}

static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
{
	u32 cdw10 = nvme_pr_type(type) << 8 | key ? 1 << 3 : 0;
	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
}

static const struct pr_ops nvme_pr_ops = {
	.pr_register	= nvme_pr_register,
	.pr_reserve	= nvme_pr_reserve,
	.pr_release	= nvme_pr_release,
	.pr_preempt	= nvme_pr_preempt,
	.pr_clear	= nvme_pr_clear,
};

static const struct block_device_operations nvme_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= nvme_ioctl,
	.compat_ioctl	= nvme_compat_ioctl,
	.open		= nvme_open,
	.release	= nvme_release,
	.getgeo		= nvme_getgeo,
	.revalidate_disk= nvme_revalidate_disk,
	.pr_ops		= &nvme_pr_ops,
};

static int nvme_wait_ready(struct nvme_ctrl *ctrl, u64 cap, bool enabled)
{
	unsigned long timeout =
		((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
	u32 csts, bit = enabled ? NVME_CSTS_RDY : 0;
	int ret;

	while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
		if ((csts & NVME_CSTS_RDY) == bit)
			break;

		msleep(100);
		if (fatal_signal_pending(current))
			return -EINTR;
		if (time_after(jiffies, timeout)) {
			dev_err(ctrl->dev,
				"Device not ready; aborting %s\n", enabled ?
						"initialisation" : "reset");
			return -ENODEV;
		}
	}

	return ret;
}

/*
 * If the device has been passed off to us in an enabled state, just clear
 * the enabled bit.  The spec says we should set the 'shutdown notification
 * bits', but doing so may cause the device to complete commands to the
 * admin queue ... and we don't know what memory that might be pointing at!
 */
int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap)
{
	int ret;

	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
	ctrl->ctrl_config &= ~NVME_CC_ENABLE;

	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
	if (ret)
		return ret;
	return nvme_wait_ready(ctrl, cap, false);
}

int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap)
{
	/*
	 * Default to a 4K page size, with the intention to update this
	 * path in the future to accomodate architectures with differing
	 * kernel and IO page sizes.
	 */
	unsigned dev_page_min = NVME_CAP_MPSMIN(cap) + 12, page_shift = 12;
	int ret;

	if (page_shift < dev_page_min) {
		dev_err(ctrl->dev,
			"Minimum device page size %u too large for host (%u)\n",
			1 << dev_page_min, 1 << page_shift);
		return -ENODEV;
	}

	ctrl->page_size = 1 << page_shift;

	ctrl->ctrl_config = NVME_CC_CSS_NVM;
	ctrl->ctrl_config |= (page_shift - 12) << NVME_CC_MPS_SHIFT;
	ctrl->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
	ctrl->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
	ctrl->ctrl_config |= NVME_CC_ENABLE;

	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
	if (ret)
		return ret;
	return nvme_wait_ready(ctrl, cap, true);
}

int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl)
{
	unsigned long timeout = SHUTDOWN_TIMEOUT + jiffies;
	u32 csts;
	int ret;

	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
	ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;

	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
	if (ret)
		return ret;

	while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
		if ((csts & NVME_CSTS_SHST_MASK) == NVME_CSTS_SHST_CMPLT)
			break;

		msleep(100);
		if (fatal_signal_pending(current))
			return -EINTR;
		if (time_after(jiffies, timeout)) {
			dev_err(ctrl->dev,
				"Device shutdown incomplete; abort shutdown\n");
			return -ENODEV;
		}
	}

	return ret;
}

/*
 * Initialize the cached copies of the Identify data and various controller
 * register in our nvme_ctrl structure.  This should be called as soon as
 * the admin queue is fully up and running.
 */
int nvme_init_identify(struct nvme_ctrl *ctrl)
{
	struct nvme_id_ctrl *id;
	u64 cap;
	int ret, page_shift;

	ret = ctrl->ops->reg_read32(ctrl, NVME_REG_VS, &ctrl->vs);
	if (ret) {
		dev_err(ctrl->dev, "Reading VS failed (%d)\n", ret);
		return ret;
	}

	ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &cap);
	if (ret) {
		dev_err(ctrl->dev, "Reading CAP failed (%d)\n", ret);
		return ret;
	}
	page_shift = NVME_CAP_MPSMIN(cap) + 12;

	if (ctrl->vs >= NVME_VS(1, 1))
		ctrl->subsystem = NVME_CAP_NSSRC(cap);

	ret = nvme_identify_ctrl(ctrl, &id);
	if (ret) {
		dev_err(ctrl->dev, "Identify Controller failed (%d)\n", ret);
		return -EIO;
	}

	ctrl->oncs = le16_to_cpup(&id->oncs);
	atomic_set(&ctrl->abort_limit, id->acl + 1);
	ctrl->vwc = id->vwc;
	memcpy(ctrl->serial, id->sn, sizeof(id->sn));
	memcpy(ctrl->model, id->mn, sizeof(id->mn));
	memcpy(ctrl->firmware_rev, id->fr, sizeof(id->fr));
	if (id->mdts)
		ctrl->max_hw_sectors = 1 << (id->mdts + page_shift - 9);
	else
		ctrl->max_hw_sectors = UINT_MAX;

	if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) && id->vs[3]) {
		unsigned int max_hw_sectors;

		ctrl->stripe_size = 1 << (id->vs[3] + page_shift);
		max_hw_sectors = ctrl->stripe_size >> (page_shift - 9);
		if (ctrl->max_hw_sectors) {
			ctrl->max_hw_sectors = min(max_hw_sectors,
							ctrl->max_hw_sectors);
		} else {
			ctrl->max_hw_sectors = max_hw_sectors;
		}
	}

	kfree(id);
	return 0;
}

static int nvme_dev_open(struct inode *inode, struct file *file)
{
	struct nvme_ctrl *ctrl;
	int instance = iminor(inode);
	int ret = -ENODEV;

	spin_lock(&dev_list_lock);
	list_for_each_entry(ctrl, &nvme_ctrl_list, node) {
		if (ctrl->instance != instance)
			continue;

		if (!ctrl->admin_q) {
			ret = -EWOULDBLOCK;
			break;
		}
		if (!kref_get_unless_zero(&ctrl->kref))
			break;
		file->private_data = ctrl;
		ret = 0;
		break;
	}
	spin_unlock(&dev_list_lock);

	return ret;
}

static int nvme_dev_release(struct inode *inode, struct file *file)
{
	nvme_put_ctrl(file->private_data);
	return 0;
}

static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp)
{
	struct nvme_ns *ns;
	int ret;

	mutex_lock(&ctrl->namespaces_mutex);
	if (list_empty(&ctrl->namespaces)) {
		ret = -ENOTTY;
		goto out_unlock;
	}

	ns = list_first_entry(&ctrl->namespaces, struct nvme_ns, list);
	if (ns != list_last_entry(&ctrl->namespaces, struct nvme_ns, list)) {
		dev_warn(ctrl->dev,
			"NVME_IOCTL_IO_CMD not supported when multiple namespaces present!\n");
		ret = -EINVAL;
		goto out_unlock;
	}

	dev_warn(ctrl->dev,
		"using deprecated NVME_IOCTL_IO_CMD ioctl on the char device!\n");
	kref_get(&ns->kref);
	mutex_unlock(&ctrl->namespaces_mutex);

	ret = nvme_user_cmd(ctrl, ns, argp);
	nvme_put_ns(ns);
	return ret;

out_unlock:
	mutex_unlock(&ctrl->namespaces_mutex);
	return ret;
}

static long nvme_dev_ioctl(struct file *file, unsigned int cmd,
		unsigned long arg)
{
	struct nvme_ctrl *ctrl = file->private_data;
	void __user *argp = (void __user *)arg;

	switch (cmd) {
	case NVME_IOCTL_ADMIN_CMD:
		return nvme_user_cmd(ctrl, NULL, argp);
	case NVME_IOCTL_IO_CMD:
		return nvme_dev_user_cmd(ctrl, argp);
	case NVME_IOCTL_RESET:
		dev_warn(ctrl->dev, "resetting controller\n");
		return ctrl->ops->reset_ctrl(ctrl);
	case NVME_IOCTL_SUBSYS_RESET:
		return nvme_reset_subsystem(ctrl);
	default:
		return -ENOTTY;
	}
}

static const struct file_operations nvme_dev_fops = {
	.owner		= THIS_MODULE,
	.open		= nvme_dev_open,
	.release	= nvme_dev_release,
	.unlocked_ioctl	= nvme_dev_ioctl,
	.compat_ioctl	= nvme_dev_ioctl,
};

static ssize_t nvme_sysfs_reset(struct device *dev,
				struct device_attribute *attr, const char *buf,
				size_t count)
{
	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
	int ret;

	ret = ctrl->ops->reset_ctrl(ctrl);
	if (ret < 0)
		return ret;
	return count;
}
static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);

static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
								char *buf)
{
	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
	return sprintf(buf, "%pU\n", ns->uuid);
}
static DEVICE_ATTR(uuid, S_IRUGO, uuid_show, NULL);

static ssize_t eui_show(struct device *dev, struct device_attribute *attr,
								char *buf)
{
	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
	return sprintf(buf, "%8phd\n", ns->eui);
}
static DEVICE_ATTR(eui, S_IRUGO, eui_show, NULL);

static ssize_t nsid_show(struct device *dev, struct device_attribute *attr,
								char *buf)
{
	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
	return sprintf(buf, "%d\n", ns->ns_id);
}
static DEVICE_ATTR(nsid, S_IRUGO, nsid_show, NULL);

static struct attribute *nvme_ns_attrs[] = {
	&dev_attr_uuid.attr,
	&dev_attr_eui.attr,
	&dev_attr_nsid.attr,
	NULL,
};

static umode_t nvme_attrs_are_visible(struct kobject *kobj,
		struct attribute *a, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct nvme_ns *ns = dev_to_disk(dev)->private_data;

	if (a == &dev_attr_uuid.attr) {
		if (!memchr_inv(ns->uuid, 0, sizeof(ns->uuid)))
			return 0;
	}
	if (a == &dev_attr_eui.attr) {
		if (!memchr_inv(ns->eui, 0, sizeof(ns->eui)))
			return 0;
	}
	return a->mode;
}

static const struct attribute_group nvme_ns_attr_group = {
	.attrs		= nvme_ns_attrs,
	.is_visible	= nvme_attrs_are_visible,
};

#define nvme_show_function(field)						\
static ssize_t  field##_show(struct device *dev,				\
			    struct device_attribute *attr, char *buf)		\
{										\
        struct nvme_ctrl *ctrl = dev_get_drvdata(dev);				\
        return sprintf(buf, "%.*s\n", (int)sizeof(ctrl->field), ctrl->field);	\
}										\
static DEVICE_ATTR(field, S_IRUGO, field##_show, NULL);

nvme_show_function(model);
nvme_show_function(serial);
nvme_show_function(firmware_rev);

static struct attribute *nvme_dev_attrs[] = {
	&dev_attr_reset_controller.attr,
	&dev_attr_model.attr,
	&dev_attr_serial.attr,
	&dev_attr_firmware_rev.attr,
	NULL
};

static struct attribute_group nvme_dev_attrs_group = {
	.attrs = nvme_dev_attrs,
};

static const struct attribute_group *nvme_dev_attr_groups[] = {
	&nvme_dev_attrs_group,
	NULL,
};

static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
{
	struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
	struct nvme_ns *nsb = container_of(b, struct nvme_ns, list);

	return nsa->ns_id - nsb->ns_id;
}

static struct nvme_ns *nvme_find_ns(struct nvme_ctrl *ctrl, unsigned nsid)
{
	struct nvme_ns *ns;

	lockdep_assert_held(&ctrl->namespaces_mutex);

	list_for_each_entry(ns, &ctrl->namespaces, list) {
		if (ns->ns_id == nsid)
			return ns;
		if (ns->ns_id > nsid)
			break;
	}
	return NULL;
}

static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
{
	struct nvme_ns *ns;
	struct gendisk *disk;
	int node = dev_to_node(ctrl->dev);

	lockdep_assert_held(&ctrl->namespaces_mutex);

	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
	if (!ns)
		return;

	ns->instance = ida_simple_get(&ctrl->ns_ida, 1, 0, GFP_KERNEL);
	if (ns->instance < 0)
		goto out_free_ns;

	ns->queue = blk_mq_init_queue(ctrl->tagset);
	if (IS_ERR(ns->queue))
		goto out_release_instance;
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
	ns->queue->queuedata = ns;
	ns->ctrl = ctrl;

	disk = alloc_disk_node(0, node);
	if (!disk)
		goto out_free_queue;

	kref_init(&ns->kref);
	ns->ns_id = nsid;
	ns->disk = disk;
	ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */

	blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
	if (ctrl->max_hw_sectors) {
		blk_queue_max_hw_sectors(ns->queue, ctrl->max_hw_sectors);
		blk_queue_max_segments(ns->queue,
			(ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1);
	}
	if (ctrl->stripe_size)
		blk_queue_chunk_sectors(ns->queue, ctrl->stripe_size >> 9);
	if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
		blk_queue_flush(ns->queue, REQ_FLUSH | REQ_FUA);
	blk_queue_virt_boundary(ns->queue, ctrl->page_size - 1);

	disk->major = nvme_major;
	disk->first_minor = 0;
	disk->fops = &nvme_fops;
	disk->private_data = ns;
	disk->queue = ns->queue;
	disk->driverfs_dev = ctrl->device;
	disk->flags = GENHD_FL_EXT_DEVT;
	sprintf(disk->disk_name, "nvme%dn%d", ctrl->instance, ns->instance);

	if (nvme_revalidate_disk(ns->disk))
		goto out_free_disk;

	list_add_tail(&ns->list, &ctrl->namespaces);
	kref_get(&ctrl->kref);
	if (ns->type == NVME_NS_LIGHTNVM)
		return;

	add_disk(ns->disk);
	if (sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
					&nvme_ns_attr_group))
		pr_warn("%s: failed to create sysfs group for identification\n",
			ns->disk->disk_name);
	return;
 out_free_disk:
	kfree(disk);
 out_free_queue:
	blk_cleanup_queue(ns->queue);
 out_release_instance:
	ida_simple_remove(&ctrl->ns_ida, ns->instance);
 out_free_ns:
	kfree(ns);
}

static void nvme_ns_remove(struct nvme_ns *ns)
{
	bool kill;

	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))
		return;

	kill = nvme_io_incapable(ns->ctrl) &&
			!blk_queue_dying(ns->queue);
	if (kill) {
		blk_set_queue_dying(ns->queue);

		/*
		 * The controller was shutdown first if we got here through
		 * device removal. The shutdown may requeue outstanding
		 * requests. These need to be aborted immediately so
		 * del_gendisk doesn't block indefinitely for their completion.
		 */
		blk_mq_abort_requeue_list(ns->queue);
	}
	if (ns->disk->flags & GENHD_FL_UP) {
		if (blk_get_integrity(ns->disk))
			blk_integrity_unregister(ns->disk);
		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
					&nvme_ns_attr_group);
		del_gendisk(ns->disk);
	}
	if (kill || !blk_queue_dying(ns->queue)) {
		blk_mq_abort_requeue_list(ns->queue);
		blk_cleanup_queue(ns->queue);
	}
	mutex_lock(&ns->ctrl->namespaces_mutex);
	list_del_init(&ns->list);
	mutex_unlock(&ns->ctrl->namespaces_mutex);
	nvme_put_ns(ns);
}

static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid)
{
	struct nvme_ns *ns;

	ns = nvme_find_ns(ctrl, nsid);
	if (ns) {
		if (revalidate_disk(ns->disk))
			nvme_ns_remove(ns);
	} else
		nvme_alloc_ns(ctrl, nsid);
}

static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn)
{
	struct nvme_ns *ns;
	__le32 *ns_list;
	unsigned i, j, nsid, prev = 0, num_lists = DIV_ROUND_UP(nn, 1024);
	int ret = 0;

	ns_list = kzalloc(0x1000, GFP_KERNEL);
	if (!ns_list)
		return -ENOMEM;

	for (i = 0; i < num_lists; i++) {
		ret = nvme_identify_ns_list(ctrl, prev, ns_list);
		if (ret)
			goto out;

		for (j = 0; j < min(nn, 1024U); j++) {
			nsid = le32_to_cpu(ns_list[j]);
			if (!nsid)
				goto out;

			nvme_validate_ns(ctrl, nsid);

			while (++prev < nsid) {
				ns = nvme_find_ns(ctrl, prev);
				if (ns)
					nvme_ns_remove(ns);
			}
		}
		nn -= j;
	}
 out:
	kfree(ns_list);
	return ret;
}

static void __nvme_scan_namespaces(struct nvme_ctrl *ctrl, unsigned nn)
{
	struct nvme_ns *ns, *next;
	unsigned i;

	lockdep_assert_held(&ctrl->namespaces_mutex);

	for (i = 1; i <= nn; i++)
		nvme_validate_ns(ctrl, i);

	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) {
		if (ns->ns_id > nn)
			nvme_ns_remove(ns);
	}
}

void nvme_scan_namespaces(struct nvme_ctrl *ctrl)
{
	struct nvme_id_ctrl *id;
	unsigned nn;

	if (nvme_identify_ctrl(ctrl, &id))
		return;

	mutex_lock(&ctrl->namespaces_mutex);
	nn = le32_to_cpu(id->nn);
	if (ctrl->vs >= NVME_VS(1, 1) &&
	    !(ctrl->quirks & NVME_QUIRK_IDENTIFY_CNS)) {
		if (!nvme_scan_ns_list(ctrl, nn))
			goto done;
	}
	__nvme_scan_namespaces(ctrl, le32_to_cpup(&id->nn));
 done:
	list_sort(NULL, &ctrl->namespaces, ns_cmp);
	mutex_unlock(&ctrl->namespaces_mutex);
	kfree(id);
}

void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
{
	struct nvme_ns *ns, *next;

	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list)
		nvme_ns_remove(ns);
}

static DEFINE_IDA(nvme_instance_ida);

static int nvme_set_instance(struct nvme_ctrl *ctrl)
{
	int instance, error;

	do {
		if (!ida_pre_get(&nvme_instance_ida, GFP_KERNEL))
			return -ENODEV;

		spin_lock(&dev_list_lock);
		error = ida_get_new(&nvme_instance_ida, &instance);
		spin_unlock(&dev_list_lock);
	} while (error == -EAGAIN);

	if (error)
		return -ENODEV;

	ctrl->instance = instance;
	return 0;
}

static void nvme_release_instance(struct nvme_ctrl *ctrl)
{
	spin_lock(&dev_list_lock);
	ida_remove(&nvme_instance_ida, ctrl->instance);
	spin_unlock(&dev_list_lock);
}

void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)
 {
	device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));

	spin_lock(&dev_list_lock);
	list_del(&ctrl->node);
	spin_unlock(&dev_list_lock);
}

static void nvme_free_ctrl(struct kref *kref)
{
	struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);

	put_device(ctrl->device);
	nvme_release_instance(ctrl);
	ida_destroy(&ctrl->ns_ida);

	ctrl->ops->free_ctrl(ctrl);
}

void nvme_put_ctrl(struct nvme_ctrl *ctrl)
{
	kref_put(&ctrl->kref, nvme_free_ctrl);
}

/*
 * Initialize a NVMe controller structures.  This needs to be called during
 * earliest initialization so that we have the initialized structured around
 * during probing.
 */
int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
		const struct nvme_ctrl_ops *ops, unsigned long quirks)
{
	int ret;

	INIT_LIST_HEAD(&ctrl->namespaces);
	mutex_init(&ctrl->namespaces_mutex);
	kref_init(&ctrl->kref);
	ctrl->dev = dev;
	ctrl->ops = ops;
	ctrl->quirks = quirks;

	ret = nvme_set_instance(ctrl);
	if (ret)
		goto out;

	ctrl->device = device_create_with_groups(nvme_class, ctrl->dev,
				MKDEV(nvme_char_major, ctrl->instance),
				dev, nvme_dev_attr_groups,
				"nvme%d", ctrl->instance);
	if (IS_ERR(ctrl->device)) {
		ret = PTR_ERR(ctrl->device);
		goto out_release_instance;
	}
	get_device(ctrl->device);
	dev_set_drvdata(ctrl->device, ctrl);
	ida_init(&ctrl->ns_ida);

	spin_lock(&dev_list_lock);
	list_add_tail(&ctrl->node, &nvme_ctrl_list);
	spin_unlock(&dev_list_lock);

	return 0;
out_release_instance:
	nvme_release_instance(ctrl);
out:
	return ret;
}

void nvme_stop_queues(struct nvme_ctrl *ctrl)
{
	struct nvme_ns *ns;

	mutex_lock(&ctrl->namespaces_mutex);
	list_for_each_entry(ns, &ctrl->namespaces, list) {
		spin_lock_irq(ns->queue->queue_lock);
		queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);
		spin_unlock_irq(ns->queue->queue_lock);

		blk_mq_cancel_requeue_work(ns->queue);
		blk_mq_stop_hw_queues(ns->queue);
	}
	mutex_unlock(&ctrl->namespaces_mutex);
}

void nvme_start_queues(struct nvme_ctrl *ctrl)
{
	struct nvme_ns *ns;

	mutex_lock(&ctrl->namespaces_mutex);
	list_for_each_entry(ns, &ctrl->namespaces, list) {
		queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);
		blk_mq_start_stopped_hw_queues(ns->queue, true);
		blk_mq_kick_requeue_list(ns->queue);
	}
	mutex_unlock(&ctrl->namespaces_mutex);
}

int __init nvme_core_init(void)
{
	int result;

	result = register_blkdev(nvme_major, "nvme");
	if (result < 0)
		return result;
	else if (result > 0)
		nvme_major = result;

	result = __register_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme",
							&nvme_dev_fops);
	if (result < 0)
		goto unregister_blkdev;
	else if (result > 0)
		nvme_char_major = result;

	nvme_class = class_create(THIS_MODULE, "nvme");
	if (IS_ERR(nvme_class)) {
		result = PTR_ERR(nvme_class);
		goto unregister_chrdev;
	}

	return 0;

 unregister_chrdev:
	__unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
 unregister_blkdev:
	unregister_blkdev(nvme_major, "nvme");
	return result;
}

void nvme_core_exit(void)
{
	unregister_blkdev(nvme_major, "nvme");
	class_destroy(nvme_class);
	__unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
}