summaryrefslogtreecommitdiff
path: root/drivers/nvme/host/apple.c
blob: ff8b083dc5c6d862912874960ac76a6abe5dd3c8 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Apple ANS NVM Express device driver
 * Copyright The Asahi Linux Contributors
 *
 * Based on the pci.c NVM Express device driver
 * Copyright (c) 2011-2014, Intel Corporation.
 * and on the rdma.c NVMe over Fabrics RDMA host code.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 */

#include <linux/async.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/interrupt.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/jiffies.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/once.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/soc/apple/rtkit.h>
#include <linux/soc/apple/sart.h>
#include <linux/reset.h>
#include <linux/time64.h>

#include "nvme.h"

#define APPLE_ANS_BOOT_TIMEOUT	  USEC_PER_SEC
#define APPLE_ANS_MAX_QUEUE_DEPTH 64

#define APPLE_ANS_COPROC_CPU_CONTROL	 0x44
#define APPLE_ANS_COPROC_CPU_CONTROL_RUN BIT(4)

#define APPLE_ANS_ACQ_DB  0x1004
#define APPLE_ANS_IOCQ_DB 0x100c

#define APPLE_ANS_MAX_PEND_CMDS_CTRL 0x1210

#define APPLE_ANS_BOOT_STATUS	 0x1300
#define APPLE_ANS_BOOT_STATUS_OK 0xde71ce55

#define APPLE_ANS_UNKNOWN_CTRL	 0x24008
#define APPLE_ANS_PRP_NULL_CHECK BIT(11)

#define APPLE_ANS_LINEAR_SQ_CTRL 0x24908
#define APPLE_ANS_LINEAR_SQ_EN	 BIT(0)

#define APPLE_ANS_LINEAR_ASQ_DB	 0x2490c
#define APPLE_ANS_LINEAR_IOSQ_DB 0x24910

#define APPLE_NVMMU_NUM_TCBS	  0x28100
#define APPLE_NVMMU_ASQ_TCB_BASE  0x28108
#define APPLE_NVMMU_IOSQ_TCB_BASE 0x28110
#define APPLE_NVMMU_TCB_INVAL	  0x28118
#define APPLE_NVMMU_TCB_STAT	  0x28120

/*
 * This controller is a bit weird in the way command tags works: Both the
 * admin and the IO queue share the same tag space. Additionally, tags
 * cannot be higher than 0x40 which effectively limits the combined
 * queue depth to 0x40. Instead of wasting half of that on the admin queue
 * which gets much less traffic we instead reduce its size here.
 * The controller also doesn't support async event such that no space must
 * be reserved for NVME_NR_AEN_COMMANDS.
 */
#define APPLE_NVME_AQ_DEPTH	   2
#define APPLE_NVME_AQ_MQ_TAG_DEPTH (APPLE_NVME_AQ_DEPTH - 1)

/*
 * These can be higher, but we need to ensure that any command doesn't
 * require an sg allocation that needs more than a page of data.
 */
#define NVME_MAX_KB_SZ 4096
#define NVME_MAX_SEGS  127

/*
 * This controller comes with an embedded IOMMU known as NVMMU.
 * The NVMMU is pointed to an array of TCBs indexed by the command tag.
 * Each command must be configured inside this structure before it's allowed
 * to execute, including commands that don't require DMA transfers.
 *
 * An exception to this are Apple's vendor-specific commands (opcode 0xD8 on the
 * admin queue): Those commands must still be added to the NVMMU but the DMA
 * buffers cannot be represented as PRPs and must instead be allowed using SART.
 *
 * Programming the PRPs to the same values as those in the submission queue
 * looks rather silly at first. This hardware is however designed for a kernel
 * that runs the NVMMU code in a higher exception level than the NVMe driver.
 * In that setting the NVMe driver first programs the submission queue entry
 * and then executes a hypercall to the code that is allowed to program the
 * NVMMU. The NVMMU driver then creates a shadow copy of the PRPs while
 * verifying that they don't point to kernel text, data, pagetables, or similar
 * protected areas before programming the TCB to point to this shadow copy.
 * Since Linux doesn't do any of that we may as well just point both the queue
 * and the TCB PRP pointer to the same memory.
 */
struct apple_nvmmu_tcb {
	u8 opcode;

#define APPLE_ANS_TCB_DMA_FROM_DEVICE BIT(0)
#define APPLE_ANS_TCB_DMA_TO_DEVICE   BIT(1)
	u8 dma_flags;

	u8 command_id;
	u8 _unk0;
	__le16 length;
	u8 _unk1[18];
	__le64 prp1;
	__le64 prp2;
	u8 _unk2[16];
	u8 aes_iv[8];
	u8 _aes_unk[64];
};

/*
 * The Apple NVMe controller only supports a single admin and a single IO queue
 * which are both limited to 64 entries and share a single interrupt.
 *
 * The completion queue works as usual. The submission "queue" instead is
 * an array indexed by the command tag on this hardware. Commands must also be
 * present in the NVMMU's tcb array. They are triggered by writing their tag to
 * a MMIO register.
 */
struct apple_nvme_queue {
	struct nvme_command *sqes;
	struct nvme_completion *cqes;
	struct apple_nvmmu_tcb *tcbs;

	dma_addr_t sq_dma_addr;
	dma_addr_t cq_dma_addr;
	dma_addr_t tcb_dma_addr;

	u32 __iomem *sq_db;
	u32 __iomem *cq_db;

	u16 cq_head;
	u8 cq_phase;

	bool is_adminq;
	bool enabled;
};

/*
 * The apple_nvme_iod describes the data in an I/O.
 *
 * The sg pointer contains the list of PRP chunk allocations in addition
 * to the actual struct scatterlist.
 */
struct apple_nvme_iod {
	struct nvme_request req;
	struct nvme_command cmd;
	struct apple_nvme_queue *q;
	int npages; /* In the PRP list. 0 means small pool in use */
	int nents; /* Used in scatterlist */
	dma_addr_t first_dma;
	unsigned int dma_len; /* length of single DMA segment mapping */
	struct scatterlist *sg;
};

struct apple_nvme {
	struct device *dev;

	void __iomem *mmio_coproc;
	void __iomem *mmio_nvme;

	struct device **pd_dev;
	struct device_link **pd_link;
	int pd_count;

	struct apple_sart *sart;
	struct apple_rtkit *rtk;
	struct reset_control *reset;

	struct dma_pool *prp_page_pool;
	struct dma_pool *prp_small_pool;
	mempool_t *iod_mempool;

	struct nvme_ctrl ctrl;
	struct work_struct remove_work;

	struct apple_nvme_queue adminq;
	struct apple_nvme_queue ioq;

	struct blk_mq_tag_set admin_tagset;
	struct blk_mq_tag_set tagset;

	int irq;
	spinlock_t lock;
};

static_assert(sizeof(struct nvme_command) == 64);
static_assert(sizeof(struct apple_nvmmu_tcb) == 128);

static inline struct apple_nvme *ctrl_to_apple_nvme(struct nvme_ctrl *ctrl)
{
	return container_of(ctrl, struct apple_nvme, ctrl);
}

static inline struct apple_nvme *queue_to_apple_nvme(struct apple_nvme_queue *q)
{
	if (q->is_adminq)
		return container_of(q, struct apple_nvme, adminq);
	else
		return container_of(q, struct apple_nvme, ioq);
}

static unsigned int apple_nvme_queue_depth(struct apple_nvme_queue *q)
{
	if (q->is_adminq)
		return APPLE_NVME_AQ_DEPTH;
	else
		return APPLE_ANS_MAX_QUEUE_DEPTH;
}

static void apple_nvme_rtkit_crashed(void *cookie)
{
	struct apple_nvme *anv = cookie;

	dev_warn(anv->dev, "RTKit crashed; unable to recover without a reboot");
	nvme_reset_ctrl(&anv->ctrl);
}

static int apple_nvme_sart_dma_setup(void *cookie,
				     struct apple_rtkit_shmem *bfr)
{
	struct apple_nvme *anv = cookie;
	int ret;

	if (bfr->iova)
		return -EINVAL;
	if (!bfr->size)
		return -EINVAL;

	bfr->buffer =
		dma_alloc_coherent(anv->dev, bfr->size, &bfr->iova, GFP_KERNEL);
	if (!bfr->buffer)
		return -ENOMEM;

	ret = apple_sart_add_allowed_region(anv->sart, bfr->iova, bfr->size);
	if (ret) {
		dma_free_coherent(anv->dev, bfr->size, bfr->buffer, bfr->iova);
		bfr->buffer = NULL;
		return -ENOMEM;
	}

	return 0;
}

static void apple_nvme_sart_dma_destroy(void *cookie,
					struct apple_rtkit_shmem *bfr)
{
	struct apple_nvme *anv = cookie;

	apple_sart_remove_allowed_region(anv->sart, bfr->iova, bfr->size);
	dma_free_coherent(anv->dev, bfr->size, bfr->buffer, bfr->iova);
}

static const struct apple_rtkit_ops apple_nvme_rtkit_ops = {
	.crashed = apple_nvme_rtkit_crashed,
	.shmem_setup = apple_nvme_sart_dma_setup,
	.shmem_destroy = apple_nvme_sart_dma_destroy,
};

static void apple_nvmmu_inval(struct apple_nvme_queue *q, unsigned int tag)
{
	struct apple_nvme *anv = queue_to_apple_nvme(q);

	writel(tag, anv->mmio_nvme + APPLE_NVMMU_TCB_INVAL);
	if (readl(anv->mmio_nvme + APPLE_NVMMU_TCB_STAT))
		dev_warn_ratelimited(anv->dev,
				     "NVMMU TCB invalidation failed\n");
}

static void apple_nvme_submit_cmd(struct apple_nvme_queue *q,
				  struct nvme_command *cmd)
{
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	u32 tag = nvme_tag_from_cid(cmd->common.command_id);
	struct apple_nvmmu_tcb *tcb = &q->tcbs[tag];

	tcb->opcode = cmd->common.opcode;
	tcb->prp1 = cmd->common.dptr.prp1;
	tcb->prp2 = cmd->common.dptr.prp2;
	tcb->length = cmd->rw.length;
	tcb->command_id = tag;

	if (nvme_is_write(cmd))
		tcb->dma_flags = APPLE_ANS_TCB_DMA_TO_DEVICE;
	else
		tcb->dma_flags = APPLE_ANS_TCB_DMA_FROM_DEVICE;

	memcpy(&q->sqes[tag], cmd, sizeof(*cmd));

	/*
	 * This lock here doesn't make much sense at a first glace but
	 * removing it will result in occasional missed completetion
	 * interrupts even though the commands still appear on the CQ.
	 * It's unclear why this happens but our best guess is that
	 * there is a bug in the firmware triggered when a new command
	 * is issued while we're inside the irq handler between the
	 * NVMMU invalidation (and making the tag available again)
	 * and the final CQ update.
	 */
	spin_lock_irq(&anv->lock);
	writel(tag, q->sq_db);
	spin_unlock_irq(&anv->lock);
}

/*
 * From pci.c:
 * Will slightly overestimate the number of pages needed.  This is OK
 * as it only leads to a small amount of wasted memory for the lifetime of
 * the I/O.
 */
static inline size_t apple_nvme_iod_alloc_size(void)
{
	const unsigned int nprps = DIV_ROUND_UP(
		NVME_MAX_KB_SZ + NVME_CTRL_PAGE_SIZE, NVME_CTRL_PAGE_SIZE);
	const int npages = DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
	const size_t alloc_size = sizeof(__le64 *) * npages +
				  sizeof(struct scatterlist) * NVME_MAX_SEGS;

	return alloc_size;
}

static void **apple_nvme_iod_list(struct request *req)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);

	return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
}

static void apple_nvme_free_prps(struct apple_nvme *anv, struct request *req)
{
	const int last_prp = NVME_CTRL_PAGE_SIZE / sizeof(__le64) - 1;
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	dma_addr_t dma_addr = iod->first_dma;
	int i;

	for (i = 0; i < iod->npages; i++) {
		__le64 *prp_list = apple_nvme_iod_list(req)[i];
		dma_addr_t next_dma_addr = le64_to_cpu(prp_list[last_prp]);

		dma_pool_free(anv->prp_page_pool, prp_list, dma_addr);
		dma_addr = next_dma_addr;
	}
}

static void apple_nvme_unmap_data(struct apple_nvme *anv, struct request *req)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);

	if (iod->dma_len) {
		dma_unmap_page(anv->dev, iod->first_dma, iod->dma_len,
			       rq_dma_dir(req));
		return;
	}

	WARN_ON_ONCE(!iod->nents);

	dma_unmap_sg(anv->dev, iod->sg, iod->nents, rq_dma_dir(req));
	if (iod->npages == 0)
		dma_pool_free(anv->prp_small_pool, apple_nvme_iod_list(req)[0],
			      iod->first_dma);
	else
		apple_nvme_free_prps(anv, req);
	mempool_free(iod->sg, anv->iod_mempool);
}

static void apple_nvme_print_sgl(struct scatterlist *sgl, int nents)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sgl, sg, nents, i) {
		dma_addr_t phys = sg_phys(sg);

		pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d dma_address:%pad dma_length:%d\n",
			i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
			sg_dma_len(sg));
	}
}

static blk_status_t apple_nvme_setup_prps(struct apple_nvme *anv,
					  struct request *req,
					  struct nvme_rw_command *cmnd)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	struct dma_pool *pool;
	int length = blk_rq_payload_bytes(req);
	struct scatterlist *sg = iod->sg;
	int dma_len = sg_dma_len(sg);
	u64 dma_addr = sg_dma_address(sg);
	int offset = dma_addr & (NVME_CTRL_PAGE_SIZE - 1);
	__le64 *prp_list;
	void **list = apple_nvme_iod_list(req);
	dma_addr_t prp_dma;
	int nprps, i;

	length -= (NVME_CTRL_PAGE_SIZE - offset);
	if (length <= 0) {
		iod->first_dma = 0;
		goto done;
	}

	dma_len -= (NVME_CTRL_PAGE_SIZE - offset);
	if (dma_len) {
		dma_addr += (NVME_CTRL_PAGE_SIZE - offset);
	} else {
		sg = sg_next(sg);
		dma_addr = sg_dma_address(sg);
		dma_len = sg_dma_len(sg);
	}

	if (length <= NVME_CTRL_PAGE_SIZE) {
		iod->first_dma = dma_addr;
		goto done;
	}

	nprps = DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE);
	if (nprps <= (256 / 8)) {
		pool = anv->prp_small_pool;
		iod->npages = 0;
	} else {
		pool = anv->prp_page_pool;
		iod->npages = 1;
	}

	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
	if (!prp_list) {
		iod->first_dma = dma_addr;
		iod->npages = -1;
		return BLK_STS_RESOURCE;
	}
	list[0] = prp_list;
	iod->first_dma = prp_dma;
	i = 0;
	for (;;) {
		if (i == NVME_CTRL_PAGE_SIZE >> 3) {
			__le64 *old_prp_list = prp_list;

			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
			if (!prp_list)
				goto free_prps;
			list[iod->npages++] = prp_list;
			prp_list[0] = old_prp_list[i - 1];
			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
			i = 1;
		}
		prp_list[i++] = cpu_to_le64(dma_addr);
		dma_len -= NVME_CTRL_PAGE_SIZE;
		dma_addr += NVME_CTRL_PAGE_SIZE;
		length -= NVME_CTRL_PAGE_SIZE;
		if (length <= 0)
			break;
		if (dma_len > 0)
			continue;
		if (unlikely(dma_len < 0))
			goto bad_sgl;
		sg = sg_next(sg);
		dma_addr = sg_dma_address(sg);
		dma_len = sg_dma_len(sg);
	}
done:
	cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
	cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
	return BLK_STS_OK;
free_prps:
	apple_nvme_free_prps(anv, req);
	return BLK_STS_RESOURCE;
bad_sgl:
	WARN(DO_ONCE(apple_nvme_print_sgl, iod->sg, iod->nents),
	     "Invalid SGL for payload:%d nents:%d\n", blk_rq_payload_bytes(req),
	     iod->nents);
	return BLK_STS_IOERR;
}

static blk_status_t apple_nvme_setup_prp_simple(struct apple_nvme *anv,
						struct request *req,
						struct nvme_rw_command *cmnd,
						struct bio_vec *bv)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	unsigned int offset = bv->bv_offset & (NVME_CTRL_PAGE_SIZE - 1);
	unsigned int first_prp_len = NVME_CTRL_PAGE_SIZE - offset;

	iod->first_dma = dma_map_bvec(anv->dev, bv, rq_dma_dir(req), 0);
	if (dma_mapping_error(anv->dev, iod->first_dma))
		return BLK_STS_RESOURCE;
	iod->dma_len = bv->bv_len;

	cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma);
	if (bv->bv_len > first_prp_len)
		cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len);
	return BLK_STS_OK;
}

static blk_status_t apple_nvme_map_data(struct apple_nvme *anv,
					struct request *req,
					struct nvme_command *cmnd)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	blk_status_t ret = BLK_STS_RESOURCE;
	int nr_mapped;

	if (blk_rq_nr_phys_segments(req) == 1) {
		struct bio_vec bv = req_bvec(req);

		if (bv.bv_offset + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2)
			return apple_nvme_setup_prp_simple(anv, req, &cmnd->rw,
							   &bv);
	}

	iod->dma_len = 0;
	iod->sg = mempool_alloc(anv->iod_mempool, GFP_ATOMIC);
	if (!iod->sg)
		return BLK_STS_RESOURCE;
	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
	if (!iod->nents)
		goto out_free_sg;

	nr_mapped = dma_map_sg_attrs(anv->dev, iod->sg, iod->nents,
				     rq_dma_dir(req), DMA_ATTR_NO_WARN);
	if (!nr_mapped)
		goto out_free_sg;

	ret = apple_nvme_setup_prps(anv, req, &cmnd->rw);
	if (ret != BLK_STS_OK)
		goto out_unmap_sg;
	return BLK_STS_OK;

out_unmap_sg:
	dma_unmap_sg(anv->dev, iod->sg, iod->nents, rq_dma_dir(req));
out_free_sg:
	mempool_free(iod->sg, anv->iod_mempool);
	return ret;
}

static __always_inline void apple_nvme_unmap_rq(struct request *req)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	struct apple_nvme *anv = queue_to_apple_nvme(iod->q);

	if (blk_rq_nr_phys_segments(req))
		apple_nvme_unmap_data(anv, req);
}

static void apple_nvme_complete_rq(struct request *req)
{
	apple_nvme_unmap_rq(req);
	nvme_complete_rq(req);
}

static void apple_nvme_complete_batch(struct io_comp_batch *iob)
{
	nvme_complete_batch(iob, apple_nvme_unmap_rq);
}

static inline bool apple_nvme_cqe_pending(struct apple_nvme_queue *q)
{
	struct nvme_completion *hcqe = &q->cqes[q->cq_head];

	return (le16_to_cpu(READ_ONCE(hcqe->status)) & 1) == q->cq_phase;
}

static inline struct blk_mq_tags *
apple_nvme_queue_tagset(struct apple_nvme *anv, struct apple_nvme_queue *q)
{
	if (q->is_adminq)
		return anv->admin_tagset.tags[0];
	else
		return anv->tagset.tags[0];
}

static inline void apple_nvme_handle_cqe(struct apple_nvme_queue *q,
					 struct io_comp_batch *iob, u16 idx)
{
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	struct nvme_completion *cqe = &q->cqes[idx];
	__u16 command_id = READ_ONCE(cqe->command_id);
	struct request *req;

	apple_nvmmu_inval(q, command_id);

	req = nvme_find_rq(apple_nvme_queue_tagset(anv, q), command_id);
	if (unlikely(!req)) {
		dev_warn(anv->dev, "invalid id %d completed", command_id);
		return;
	}

	if (!nvme_try_complete_req(req, cqe->status, cqe->result) &&
	    !blk_mq_add_to_batch(req, iob, nvme_req(req)->status,
				 apple_nvme_complete_batch))
		apple_nvme_complete_rq(req);
}

static inline void apple_nvme_update_cq_head(struct apple_nvme_queue *q)
{
	u32 tmp = q->cq_head + 1;

	if (tmp == apple_nvme_queue_depth(q)) {
		q->cq_head = 0;
		q->cq_phase ^= 1;
	} else {
		q->cq_head = tmp;
	}
}

static bool apple_nvme_poll_cq(struct apple_nvme_queue *q,
			       struct io_comp_batch *iob)
{
	bool found = false;

	while (apple_nvme_cqe_pending(q)) {
		found = true;

		/*
		 * load-load control dependency between phase and the rest of
		 * the cqe requires a full read memory barrier
		 */
		dma_rmb();
		apple_nvme_handle_cqe(q, iob, q->cq_head);
		apple_nvme_update_cq_head(q);
	}

	if (found)
		writel(q->cq_head, q->cq_db);

	return found;
}

static bool apple_nvme_handle_cq(struct apple_nvme_queue *q, bool force)
{
	bool found;
	DEFINE_IO_COMP_BATCH(iob);

	if (!READ_ONCE(q->enabled) && !force)
		return false;

	found = apple_nvme_poll_cq(q, &iob);

	if (!rq_list_empty(iob.req_list))
		apple_nvme_complete_batch(&iob);

	return found;
}

static irqreturn_t apple_nvme_irq(int irq, void *data)
{
	struct apple_nvme *anv = data;
	bool handled = false;
	unsigned long flags;

	spin_lock_irqsave(&anv->lock, flags);
	if (apple_nvme_handle_cq(&anv->ioq, false))
		handled = true;
	if (apple_nvme_handle_cq(&anv->adminq, false))
		handled = true;
	spin_unlock_irqrestore(&anv->lock, flags);

	if (handled)
		return IRQ_HANDLED;
	return IRQ_NONE;
}

static int apple_nvme_create_cq(struct apple_nvme *anv)
{
	struct nvme_command c = {};

	/*
	 * Note: we (ab)use the fact that the prp fields survive if no data
	 * is attached to the request.
	 */
	c.create_cq.opcode = nvme_admin_create_cq;
	c.create_cq.prp1 = cpu_to_le64(anv->ioq.cq_dma_addr);
	c.create_cq.cqid = cpu_to_le16(1);
	c.create_cq.qsize = cpu_to_le16(APPLE_ANS_MAX_QUEUE_DEPTH - 1);
	c.create_cq.cq_flags = cpu_to_le16(NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED);
	c.create_cq.irq_vector = cpu_to_le16(0);

	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
}

static int apple_nvme_remove_cq(struct apple_nvme *anv)
{
	struct nvme_command c = {};

	c.delete_queue.opcode = nvme_admin_delete_cq;
	c.delete_queue.qid = cpu_to_le16(1);

	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
}

static int apple_nvme_create_sq(struct apple_nvme *anv)
{
	struct nvme_command c = {};

	/*
	 * Note: we (ab)use the fact that the prp fields survive if no data
	 * is attached to the request.
	 */
	c.create_sq.opcode = nvme_admin_create_sq;
	c.create_sq.prp1 = cpu_to_le64(anv->ioq.sq_dma_addr);
	c.create_sq.sqid = cpu_to_le16(1);
	c.create_sq.qsize = cpu_to_le16(APPLE_ANS_MAX_QUEUE_DEPTH - 1);
	c.create_sq.sq_flags = cpu_to_le16(NVME_QUEUE_PHYS_CONTIG);
	c.create_sq.cqid = cpu_to_le16(1);

	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
}

static int apple_nvme_remove_sq(struct apple_nvme *anv)
{
	struct nvme_command c = {};

	c.delete_queue.opcode = nvme_admin_delete_sq;
	c.delete_queue.qid = cpu_to_le16(1);

	return nvme_submit_sync_cmd(anv->ctrl.admin_q, &c, NULL, 0);
}

static blk_status_t apple_nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
					const struct blk_mq_queue_data *bd)
{
	struct nvme_ns *ns = hctx->queue->queuedata;
	struct apple_nvme_queue *q = hctx->driver_data;
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	struct request *req = bd->rq;
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	struct nvme_command *cmnd = &iod->cmd;
	blk_status_t ret;

	iod->npages = -1;
	iod->nents = 0;

	/*
	 * We should not need to do this, but we're still using this to
	 * ensure we can drain requests on a dying queue.
	 */
	if (unlikely(!READ_ONCE(q->enabled)))
		return BLK_STS_IOERR;

	if (!nvme_check_ready(&anv->ctrl, req, true))
		return nvme_fail_nonready_command(&anv->ctrl, req);

	ret = nvme_setup_cmd(ns, req);
	if (ret)
		return ret;

	if (blk_rq_nr_phys_segments(req)) {
		ret = apple_nvme_map_data(anv, req, cmnd);
		if (ret)
			goto out_free_cmd;
	}

	blk_mq_start_request(req);
	apple_nvme_submit_cmd(q, cmnd);
	return BLK_STS_OK;

out_free_cmd:
	nvme_cleanup_cmd(req);
	return ret;
}

static int apple_nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
				unsigned int hctx_idx)
{
	hctx->driver_data = data;
	return 0;
}

static int apple_nvme_init_request(struct blk_mq_tag_set *set,
				   struct request *req, unsigned int hctx_idx,
				   unsigned int numa_node)
{
	struct apple_nvme_queue *q = set->driver_data;
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	struct nvme_request *nreq = nvme_req(req);

	iod->q = q;
	nreq->ctrl = &anv->ctrl;
	nreq->cmd = &iod->cmd;

	return 0;
}

static void apple_nvme_disable(struct apple_nvme *anv, bool shutdown)
{
	u32 csts = readl(anv->mmio_nvme + NVME_REG_CSTS);
	bool dead = false, freeze = false;
	unsigned long flags;

	if (apple_rtkit_is_crashed(anv->rtk))
		dead = true;
	if (!(csts & NVME_CSTS_RDY))
		dead = true;
	if (csts & NVME_CSTS_CFS)
		dead = true;

	if (anv->ctrl.state == NVME_CTRL_LIVE ||
	    anv->ctrl.state == NVME_CTRL_RESETTING) {
		freeze = true;
		nvme_start_freeze(&anv->ctrl);
	}

	/*
	 * Give the controller a chance to complete all entered requests if
	 * doing a safe shutdown.
	 */
	if (!dead && shutdown && freeze)
		nvme_wait_freeze_timeout(&anv->ctrl, NVME_IO_TIMEOUT);

	nvme_stop_queues(&anv->ctrl);

	if (!dead) {
		if (READ_ONCE(anv->ioq.enabled)) {
			apple_nvme_remove_sq(anv);
			apple_nvme_remove_cq(anv);
		}

		if (shutdown)
			nvme_shutdown_ctrl(&anv->ctrl);
		nvme_disable_ctrl(&anv->ctrl);
	}

	WRITE_ONCE(anv->ioq.enabled, false);
	WRITE_ONCE(anv->adminq.enabled, false);
	mb(); /* ensure that nvme_queue_rq() sees that enabled is cleared */
	nvme_stop_admin_queue(&anv->ctrl);

	/* last chance to complete any requests before nvme_cancel_request */
	spin_lock_irqsave(&anv->lock, flags);
	apple_nvme_handle_cq(&anv->ioq, true);
	apple_nvme_handle_cq(&anv->adminq, true);
	spin_unlock_irqrestore(&anv->lock, flags);

	nvme_cancel_tagset(&anv->ctrl);
	nvme_cancel_admin_tagset(&anv->ctrl);

	/*
	 * The driver will not be starting up queues again if shutting down so
	 * must flush all entered requests to their failed completion to avoid
	 * deadlocking blk-mq hot-cpu notifier.
	 */
	if (shutdown) {
		nvme_start_queues(&anv->ctrl);
		nvme_start_admin_queue(&anv->ctrl);
	}
}

static enum blk_eh_timer_return apple_nvme_timeout(struct request *req)
{
	struct apple_nvme_iod *iod = blk_mq_rq_to_pdu(req);
	struct apple_nvme_queue *q = iod->q;
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	unsigned long flags;
	u32 csts = readl(anv->mmio_nvme + NVME_REG_CSTS);

	if (anv->ctrl.state != NVME_CTRL_LIVE) {
		/*
		 * From rdma.c:
		 * If we are resetting, connecting or deleting we should
		 * complete immediately because we may block controller
		 * teardown or setup sequence
		 * - ctrl disable/shutdown fabrics requests
		 * - connect requests
		 * - initialization admin requests
		 * - I/O requests that entered after unquiescing and
		 *   the controller stopped responding
		 *
		 * All other requests should be cancelled by the error
		 * recovery work, so it's fine that we fail it here.
		 */
		dev_warn(anv->dev,
			 "I/O %d(aq:%d) timeout while not in live state\n",
			 req->tag, q->is_adminq);
		if (blk_mq_request_started(req) &&
		    !blk_mq_request_completed(req)) {
			nvme_req(req)->status = NVME_SC_HOST_ABORTED_CMD;
			nvme_req(req)->flags |= NVME_REQ_CANCELLED;
			blk_mq_complete_request(req);
		}
		return BLK_EH_DONE;
	}

	/* check if we just missed an interrupt if we're still alive */
	if (!apple_rtkit_is_crashed(anv->rtk) && !(csts & NVME_CSTS_CFS)) {
		spin_lock_irqsave(&anv->lock, flags);
		apple_nvme_handle_cq(q, false);
		spin_unlock_irqrestore(&anv->lock, flags);
		if (blk_mq_request_completed(req)) {
			dev_warn(anv->dev,
				 "I/O %d(aq:%d) timeout: completion polled\n",
				 req->tag, q->is_adminq);
			return BLK_EH_DONE;
		}
	}

	/*
	 * aborting commands isn't supported which leaves a full reset as our
	 * only option here
	 */
	dev_warn(anv->dev, "I/O %d(aq:%d) timeout: resetting controller\n",
		 req->tag, q->is_adminq);
	nvme_req(req)->flags |= NVME_REQ_CANCELLED;
	apple_nvme_disable(anv, false);
	nvme_reset_ctrl(&anv->ctrl);
	return BLK_EH_DONE;
}

static int apple_nvme_poll(struct blk_mq_hw_ctx *hctx,
			   struct io_comp_batch *iob)
{
	struct apple_nvme_queue *q = hctx->driver_data;
	struct apple_nvme *anv = queue_to_apple_nvme(q);
	bool found;
	unsigned long flags;

	spin_lock_irqsave(&anv->lock, flags);
	found = apple_nvme_poll_cq(q, iob);
	spin_unlock_irqrestore(&anv->lock, flags);

	return found;
}

static const struct blk_mq_ops apple_nvme_mq_admin_ops = {
	.queue_rq = apple_nvme_queue_rq,
	.complete = apple_nvme_complete_rq,
	.init_hctx = apple_nvme_init_hctx,
	.init_request = apple_nvme_init_request,
	.timeout = apple_nvme_timeout,
};

static const struct blk_mq_ops apple_nvme_mq_ops = {
	.queue_rq = apple_nvme_queue_rq,
	.complete = apple_nvme_complete_rq,
	.init_hctx = apple_nvme_init_hctx,
	.init_request = apple_nvme_init_request,
	.timeout = apple_nvme_timeout,
	.poll = apple_nvme_poll,
};

static void apple_nvme_init_queue(struct apple_nvme_queue *q)
{
	unsigned int depth = apple_nvme_queue_depth(q);

	q->cq_head = 0;
	q->cq_phase = 1;
	memset(q->tcbs, 0,
	       APPLE_ANS_MAX_QUEUE_DEPTH * sizeof(struct apple_nvmmu_tcb));
	memset(q->cqes, 0, depth * sizeof(struct nvme_completion));
	WRITE_ONCE(q->enabled, true);
	wmb(); /* ensure the first interrupt sees the initialization */
}

static void apple_nvme_reset_work(struct work_struct *work)
{
	unsigned int nr_io_queues = 1;
	int ret;
	u32 boot_status, aqa;
	struct apple_nvme *anv =
		container_of(work, struct apple_nvme, ctrl.reset_work);

	if (anv->ctrl.state != NVME_CTRL_RESETTING) {
		dev_warn(anv->dev, "ctrl state %d is not RESETTING\n",
			 anv->ctrl.state);
		ret = -ENODEV;
		goto out;
	}

	/* there's unfortunately no known way to recover if RTKit crashed :( */
	if (apple_rtkit_is_crashed(anv->rtk)) {
		dev_err(anv->dev,
			"RTKit has crashed without any way to recover.");
		ret = -EIO;
		goto out;
	}

	if (anv->ctrl.ctrl_config & NVME_CC_ENABLE)
		apple_nvme_disable(anv, false);

	/* RTKit must be shut down cleanly for the (soft)-reset to work */
	if (apple_rtkit_is_running(anv->rtk)) {
		dev_dbg(anv->dev, "Trying to shut down RTKit before reset.");
		ret = apple_rtkit_shutdown(anv->rtk);
		if (ret)
			goto out;
	}

	writel(0, anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);

	ret = reset_control_assert(anv->reset);
	if (ret)
		goto out;

	ret = apple_rtkit_reinit(anv->rtk);
	if (ret)
		goto out;

	ret = reset_control_deassert(anv->reset);
	if (ret)
		goto out;

	writel(APPLE_ANS_COPROC_CPU_CONTROL_RUN,
	       anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);
	ret = apple_rtkit_boot(anv->rtk);
	if (ret) {
		dev_err(anv->dev, "ANS did not boot");
		goto out;
	}

	ret = readl_poll_timeout(anv->mmio_nvme + APPLE_ANS_BOOT_STATUS,
				 boot_status,
				 boot_status == APPLE_ANS_BOOT_STATUS_OK,
				 USEC_PER_MSEC, APPLE_ANS_BOOT_TIMEOUT);
	if (ret) {
		dev_err(anv->dev, "ANS did not initialize");
		goto out;
	}

	dev_dbg(anv->dev, "ANS booted successfully.");

	/*
	 * Limit the max command size to prevent iod->sg allocations going
	 * over a single page.
	 */
	anv->ctrl.max_hw_sectors = min_t(u32, NVME_MAX_KB_SZ << 1,
					 dma_max_mapping_size(anv->dev) >> 9);
	anv->ctrl.max_segments = NVME_MAX_SEGS;

	dma_set_max_seg_size(anv->dev, 0xffffffff);

	/*
	 * Enable NVMMU and linear submission queues.
	 * While we could keep those disabled and pretend this is slightly
	 * more common NVMe controller we'd still need some quirks (e.g.
	 * sq entries will be 128 bytes) and Apple might drop support for
	 * that mode in the future.
	 */
	writel(APPLE_ANS_LINEAR_SQ_EN,
	       anv->mmio_nvme + APPLE_ANS_LINEAR_SQ_CTRL);

	/* Allow as many pending command as possible for both queues */
	writel(APPLE_ANS_MAX_QUEUE_DEPTH | (APPLE_ANS_MAX_QUEUE_DEPTH << 16),
	       anv->mmio_nvme + APPLE_ANS_MAX_PEND_CMDS_CTRL);

	/* Setup the NVMMU for the maximum admin and IO queue depth */
	writel(APPLE_ANS_MAX_QUEUE_DEPTH - 1,
	       anv->mmio_nvme + APPLE_NVMMU_NUM_TCBS);

	/*
	 * This is probably a chicken bit: without it all commands where any PRP
	 * is set to zero (including those that don't use that field) fail and
	 * the co-processor complains about "completed with err BAD_CMD-" or
	 * a "NULL_PRP_PTR_ERR" in the syslog
	 */
	writel(readl(anv->mmio_nvme + APPLE_ANS_UNKNOWN_CTRL) &
		       ~APPLE_ANS_PRP_NULL_CHECK,
	       anv->mmio_nvme + APPLE_ANS_UNKNOWN_CTRL);

	/* Setup the admin queue */
	aqa = APPLE_NVME_AQ_DEPTH - 1;
	aqa |= aqa << 16;
	writel(aqa, anv->mmio_nvme + NVME_REG_AQA);
	writeq(anv->adminq.sq_dma_addr, anv->mmio_nvme + NVME_REG_ASQ);
	writeq(anv->adminq.cq_dma_addr, anv->mmio_nvme + NVME_REG_ACQ);

	/* Setup NVMMU for both queues */
	writeq(anv->adminq.tcb_dma_addr,
	       anv->mmio_nvme + APPLE_NVMMU_ASQ_TCB_BASE);
	writeq(anv->ioq.tcb_dma_addr,
	       anv->mmio_nvme + APPLE_NVMMU_IOSQ_TCB_BASE);

	anv->ctrl.sqsize =
		APPLE_ANS_MAX_QUEUE_DEPTH - 1; /* 0's based queue depth */
	anv->ctrl.cap = readq(anv->mmio_nvme + NVME_REG_CAP);

	dev_dbg(anv->dev, "Enabling controller now");
	ret = nvme_enable_ctrl(&anv->ctrl);
	if (ret)
		goto out;

	dev_dbg(anv->dev, "Starting admin queue");
	apple_nvme_init_queue(&anv->adminq);
	nvme_start_admin_queue(&anv->ctrl);

	if (!nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_CONNECTING)) {
		dev_warn(anv->ctrl.device,
			 "failed to mark controller CONNECTING\n");
		ret = -ENODEV;
		goto out;
	}

	ret = nvme_init_ctrl_finish(&anv->ctrl);
	if (ret)
		goto out;

	dev_dbg(anv->dev, "Creating IOCQ");
	ret = apple_nvme_create_cq(anv);
	if (ret)
		goto out;
	dev_dbg(anv->dev, "Creating IOSQ");
	ret = apple_nvme_create_sq(anv);
	if (ret)
		goto out_remove_cq;

	apple_nvme_init_queue(&anv->ioq);
	nr_io_queues = 1;
	ret = nvme_set_queue_count(&anv->ctrl, &nr_io_queues);
	if (ret)
		goto out_remove_sq;
	if (nr_io_queues != 1) {
		ret = -ENXIO;
		goto out_remove_sq;
	}

	anv->ctrl.queue_count = nr_io_queues + 1;

	nvme_start_queues(&anv->ctrl);
	nvme_wait_freeze(&anv->ctrl);
	blk_mq_update_nr_hw_queues(&anv->tagset, 1);
	nvme_unfreeze(&anv->ctrl);

	if (!nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_LIVE)) {
		dev_warn(anv->ctrl.device,
			 "failed to mark controller live state\n");
		ret = -ENODEV;
		goto out_remove_sq;
	}

	nvme_start_ctrl(&anv->ctrl);

	dev_dbg(anv->dev, "ANS boot and NVMe init completed.");
	return;

out_remove_sq:
	apple_nvme_remove_sq(anv);
out_remove_cq:
	apple_nvme_remove_cq(anv);
out:
	dev_warn(anv->ctrl.device, "Reset failure status: %d\n", ret);
	nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_DELETING);
	nvme_get_ctrl(&anv->ctrl);
	apple_nvme_disable(anv, false);
	nvme_kill_queues(&anv->ctrl);
	if (!queue_work(nvme_wq, &anv->remove_work))
		nvme_put_ctrl(&anv->ctrl);
}

static void apple_nvme_remove_dead_ctrl_work(struct work_struct *work)
{
	struct apple_nvme *anv =
		container_of(work, struct apple_nvme, remove_work);

	nvme_put_ctrl(&anv->ctrl);
	device_release_driver(anv->dev);
}

static int apple_nvme_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
{
	*val = readl(ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
	return 0;
}

static int apple_nvme_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
{
	writel(val, ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
	return 0;
}

static int apple_nvme_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
{
	*val = readq(ctrl_to_apple_nvme(ctrl)->mmio_nvme + off);
	return 0;
}

static int apple_nvme_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
{
	struct device *dev = ctrl_to_apple_nvme(ctrl)->dev;

	return snprintf(buf, size, "%s\n", dev_name(dev));
}

static void apple_nvme_free_ctrl(struct nvme_ctrl *ctrl)
{
	struct apple_nvme *anv = ctrl_to_apple_nvme(ctrl);

	if (anv->ctrl.admin_q)
		blk_put_queue(anv->ctrl.admin_q);
	put_device(anv->dev);
}

static const struct nvme_ctrl_ops nvme_ctrl_ops = {
	.name = "apple-nvme",
	.module = THIS_MODULE,
	.flags = 0,
	.reg_read32 = apple_nvme_reg_read32,
	.reg_write32 = apple_nvme_reg_write32,
	.reg_read64 = apple_nvme_reg_read64,
	.free_ctrl = apple_nvme_free_ctrl,
	.get_address = apple_nvme_get_address,
};

static void apple_nvme_async_probe(void *data, async_cookie_t cookie)
{
	struct apple_nvme *anv = data;

	flush_work(&anv->ctrl.reset_work);
	flush_work(&anv->ctrl.scan_work);
	nvme_put_ctrl(&anv->ctrl);
}

static void devm_apple_nvme_put_tag_set(void *data)
{
	blk_mq_free_tag_set(data);
}

static int apple_nvme_alloc_tagsets(struct apple_nvme *anv)
{
	int ret;

	anv->admin_tagset.ops = &apple_nvme_mq_admin_ops;
	anv->admin_tagset.nr_hw_queues = 1;
	anv->admin_tagset.queue_depth = APPLE_NVME_AQ_MQ_TAG_DEPTH;
	anv->admin_tagset.timeout = NVME_ADMIN_TIMEOUT;
	anv->admin_tagset.numa_node = NUMA_NO_NODE;
	anv->admin_tagset.cmd_size = sizeof(struct apple_nvme_iod);
	anv->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
	anv->admin_tagset.driver_data = &anv->adminq;

	ret = blk_mq_alloc_tag_set(&anv->admin_tagset);
	if (ret)
		return ret;
	ret = devm_add_action_or_reset(anv->dev, devm_apple_nvme_put_tag_set,
				       &anv->admin_tagset);
	if (ret)
		return ret;

	anv->tagset.ops = &apple_nvme_mq_ops;
	anv->tagset.nr_hw_queues = 1;
	anv->tagset.nr_maps = 1;
	/*
	 * Tags are used as an index to the NVMMU and must be unique across
	 * both queues. The admin queue gets the first APPLE_NVME_AQ_DEPTH which
	 * must be marked as reserved in the IO queue.
	 */
	anv->tagset.reserved_tags = APPLE_NVME_AQ_DEPTH;
	anv->tagset.queue_depth = APPLE_ANS_MAX_QUEUE_DEPTH - 1;
	anv->tagset.timeout = NVME_IO_TIMEOUT;
	anv->tagset.numa_node = NUMA_NO_NODE;
	anv->tagset.cmd_size = sizeof(struct apple_nvme_iod);
	anv->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
	anv->tagset.driver_data = &anv->ioq;

	ret = blk_mq_alloc_tag_set(&anv->tagset);
	if (ret)
		return ret;
	ret = devm_add_action_or_reset(anv->dev, devm_apple_nvme_put_tag_set,
					&anv->tagset);
	if (ret)
		return ret;

	anv->ctrl.admin_tagset = &anv->admin_tagset;
	anv->ctrl.tagset = &anv->tagset;

	return 0;
}

static int apple_nvme_queue_alloc(struct apple_nvme *anv,
				  struct apple_nvme_queue *q)
{
	unsigned int depth = apple_nvme_queue_depth(q);

	q->cqes = dmam_alloc_coherent(anv->dev,
				      depth * sizeof(struct nvme_completion),
				      &q->cq_dma_addr, GFP_KERNEL);
	if (!q->cqes)
		return -ENOMEM;

	q->sqes = dmam_alloc_coherent(anv->dev,
				      depth * sizeof(struct nvme_command),
				      &q->sq_dma_addr, GFP_KERNEL);
	if (!q->sqes)
		return -ENOMEM;

	/*
	 * We need the maximum queue depth here because the NVMMU only has a
	 * single depth configuration shared between both queues.
	 */
	q->tcbs = dmam_alloc_coherent(anv->dev,
				      APPLE_ANS_MAX_QUEUE_DEPTH *
					      sizeof(struct apple_nvmmu_tcb),
				      &q->tcb_dma_addr, GFP_KERNEL);
	if (!q->tcbs)
		return -ENOMEM;

	/*
	 * initialize phase to make sure the allocated and empty memory
	 * doesn't look like a full cq already.
	 */
	q->cq_phase = 1;
	return 0;
}

static void apple_nvme_detach_genpd(struct apple_nvme *anv)
{
	int i;

	if (anv->pd_count <= 1)
		return;

	for (i = anv->pd_count - 1; i >= 0; i--) {
		if (anv->pd_link[i])
			device_link_del(anv->pd_link[i]);
		if (!IS_ERR_OR_NULL(anv->pd_dev[i]))
			dev_pm_domain_detach(anv->pd_dev[i], true);
	}
}

static int apple_nvme_attach_genpd(struct apple_nvme *anv)
{
	struct device *dev = anv->dev;
	int i;

	anv->pd_count = of_count_phandle_with_args(
		dev->of_node, "power-domains", "#power-domain-cells");
	if (anv->pd_count <= 1)
		return 0;

	anv->pd_dev = devm_kcalloc(dev, anv->pd_count, sizeof(*anv->pd_dev),
				   GFP_KERNEL);
	if (!anv->pd_dev)
		return -ENOMEM;

	anv->pd_link = devm_kcalloc(dev, anv->pd_count, sizeof(*anv->pd_link),
				    GFP_KERNEL);
	if (!anv->pd_link)
		return -ENOMEM;

	for (i = 0; i < anv->pd_count; i++) {
		anv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
		if (IS_ERR(anv->pd_dev[i])) {
			apple_nvme_detach_genpd(anv);
			return PTR_ERR(anv->pd_dev[i]);
		}

		anv->pd_link[i] = device_link_add(dev, anv->pd_dev[i],
						  DL_FLAG_STATELESS |
						  DL_FLAG_PM_RUNTIME |
						  DL_FLAG_RPM_ACTIVE);
		if (!anv->pd_link[i]) {
			apple_nvme_detach_genpd(anv);
			return -EINVAL;
		}
	}

	return 0;
}

static void devm_apple_nvme_mempool_destroy(void *data)
{
	mempool_destroy(data);
}

static int apple_nvme_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct apple_nvme *anv;
	int ret;

	anv = devm_kzalloc(dev, sizeof(*anv), GFP_KERNEL);
	if (!anv)
		return -ENOMEM;

	anv->dev = get_device(dev);
	anv->adminq.is_adminq = true;
	platform_set_drvdata(pdev, anv);

	ret = apple_nvme_attach_genpd(anv);
	if (ret < 0) {
		dev_err_probe(dev, ret, "Failed to attach power domains");
		goto put_dev;
	}
	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) {
		ret = -ENXIO;
		goto put_dev;
	}

	anv->irq = platform_get_irq(pdev, 0);
	if (anv->irq < 0) {
		ret = anv->irq;
		goto put_dev;
	}
	if (!anv->irq) {
		ret = -ENXIO;
		goto put_dev;
	}

	anv->mmio_coproc = devm_platform_ioremap_resource_byname(pdev, "ans");
	if (IS_ERR(anv->mmio_coproc)) {
		ret = PTR_ERR(anv->mmio_coproc);
		goto put_dev;
	}
	anv->mmio_nvme = devm_platform_ioremap_resource_byname(pdev, "nvme");
	if (IS_ERR(anv->mmio_nvme)) {
		ret = PTR_ERR(anv->mmio_nvme);
		goto put_dev;
	}

	anv->adminq.sq_db = anv->mmio_nvme + APPLE_ANS_LINEAR_ASQ_DB;
	anv->adminq.cq_db = anv->mmio_nvme + APPLE_ANS_ACQ_DB;
	anv->ioq.sq_db = anv->mmio_nvme + APPLE_ANS_LINEAR_IOSQ_DB;
	anv->ioq.cq_db = anv->mmio_nvme + APPLE_ANS_IOCQ_DB;

	anv->sart = devm_apple_sart_get(dev);
	if (IS_ERR(anv->sart)) {
		ret = dev_err_probe(dev, PTR_ERR(anv->sart),
				    "Failed to initialize SART");
		goto put_dev;
	}

	anv->reset = devm_reset_control_array_get_exclusive(anv->dev);
	if (IS_ERR(anv->reset)) {
		ret = dev_err_probe(dev, PTR_ERR(anv->reset),
				    "Failed to get reset control");
		goto put_dev;
	}

	INIT_WORK(&anv->ctrl.reset_work, apple_nvme_reset_work);
	INIT_WORK(&anv->remove_work, apple_nvme_remove_dead_ctrl_work);
	spin_lock_init(&anv->lock);

	ret = apple_nvme_queue_alloc(anv, &anv->adminq);
	if (ret)
		goto put_dev;
	ret = apple_nvme_queue_alloc(anv, &anv->ioq);
	if (ret)
		goto put_dev;

	anv->prp_page_pool = dmam_pool_create("prp list page", anv->dev,
					      NVME_CTRL_PAGE_SIZE,
					      NVME_CTRL_PAGE_SIZE, 0);
	if (!anv->prp_page_pool) {
		ret = -ENOMEM;
		goto put_dev;
	}

	anv->prp_small_pool =
		dmam_pool_create("prp list 256", anv->dev, 256, 256, 0);
	if (!anv->prp_small_pool) {
		ret = -ENOMEM;
		goto put_dev;
	}

	WARN_ON_ONCE(apple_nvme_iod_alloc_size() > PAGE_SIZE);
	anv->iod_mempool =
		mempool_create_kmalloc_pool(1, apple_nvme_iod_alloc_size());
	if (!anv->iod_mempool) {
		ret = -ENOMEM;
		goto put_dev;
	}
	ret = devm_add_action_or_reset(anv->dev,
			devm_apple_nvme_mempool_destroy, anv->iod_mempool);
	if (ret)
		goto put_dev;

	ret = apple_nvme_alloc_tagsets(anv);
	if (ret)
		goto put_dev;

	ret = devm_request_irq(anv->dev, anv->irq, apple_nvme_irq, 0,
			       "nvme-apple", anv);
	if (ret) {
		dev_err_probe(dev, ret, "Failed to request IRQ");
		goto put_dev;
	}

	anv->rtk =
		devm_apple_rtkit_init(dev, anv, NULL, 0, &apple_nvme_rtkit_ops);
	if (IS_ERR(anv->rtk)) {
		ret = dev_err_probe(dev, PTR_ERR(anv->rtk),
				    "Failed to initialize RTKit");
		goto put_dev;
	}

	ret = nvme_init_ctrl(&anv->ctrl, anv->dev, &nvme_ctrl_ops,
			     NVME_QUIRK_SKIP_CID_GEN);
	if (ret) {
		dev_err_probe(dev, ret, "Failed to initialize nvme_ctrl");
		goto put_dev;
	}

	anv->ctrl.admin_q = blk_mq_init_queue(&anv->admin_tagset);
	if (IS_ERR(anv->ctrl.admin_q)) {
		ret = -ENOMEM;
		goto put_dev;
	}

	if (!blk_get_queue(anv->ctrl.admin_q)) {
		nvme_start_admin_queue(&anv->ctrl);
		blk_mq_destroy_queue(anv->ctrl.admin_q);
		anv->ctrl.admin_q = NULL;
		ret = -ENODEV;
		goto put_dev;
	}

	nvme_reset_ctrl(&anv->ctrl);
	async_schedule(apple_nvme_async_probe, anv);

	return 0;

put_dev:
	put_device(anv->dev);
	return ret;
}

static int apple_nvme_remove(struct platform_device *pdev)
{
	struct apple_nvme *anv = platform_get_drvdata(pdev);

	nvme_change_ctrl_state(&anv->ctrl, NVME_CTRL_DELETING);
	flush_work(&anv->ctrl.reset_work);
	nvme_stop_ctrl(&anv->ctrl);
	nvme_remove_namespaces(&anv->ctrl);
	apple_nvme_disable(anv, true);
	nvme_uninit_ctrl(&anv->ctrl);

	if (apple_rtkit_is_running(anv->rtk))
		apple_rtkit_shutdown(anv->rtk);

	apple_nvme_detach_genpd(anv);

	return 0;
}

static void apple_nvme_shutdown(struct platform_device *pdev)
{
	struct apple_nvme *anv = platform_get_drvdata(pdev);

	apple_nvme_disable(anv, true);
	if (apple_rtkit_is_running(anv->rtk))
		apple_rtkit_shutdown(anv->rtk);
}

static int apple_nvme_resume(struct device *dev)
{
	struct apple_nvme *anv = dev_get_drvdata(dev);

	return nvme_reset_ctrl(&anv->ctrl);
}

static int apple_nvme_suspend(struct device *dev)
{
	struct apple_nvme *anv = dev_get_drvdata(dev);
	int ret = 0;

	apple_nvme_disable(anv, true);

	if (apple_rtkit_is_running(anv->rtk))
		ret = apple_rtkit_shutdown(anv->rtk);

	writel(0, anv->mmio_coproc + APPLE_ANS_COPROC_CPU_CONTROL);

	return ret;
}

static DEFINE_SIMPLE_DEV_PM_OPS(apple_nvme_pm_ops, apple_nvme_suspend,
				apple_nvme_resume);

static const struct of_device_id apple_nvme_of_match[] = {
	{ .compatible = "apple,nvme-ans2" },
	{},
};
MODULE_DEVICE_TABLE(of, apple_nvme_of_match);

static struct platform_driver apple_nvme_driver = {
	.driver = {
		.name = "nvme-apple",
		.of_match_table = apple_nvme_of_match,
		.pm = pm_sleep_ptr(&apple_nvme_pm_ops),
	},
	.probe = apple_nvme_probe,
	.remove = apple_nvme_remove,
	.shutdown = apple_nvme_shutdown,
};
module_platform_driver(apple_nvme_driver);

MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
MODULE_LICENSE("GPL");