summaryrefslogtreecommitdiff
path: root/include/linux/lightnvm.h
blob: 0908abda9c1b33fc1b3e50420872155486c9a995 (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
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef NVM_H
#define NVM_H

#include <linux/blkdev.h>
#include <linux/types.h>
#include <uapi/linux/lightnvm.h>

enum {
	NVM_IO_OK = 0,
	NVM_IO_REQUEUE = 1,
	NVM_IO_DONE = 2,
	NVM_IO_ERR = 3,

	NVM_IOTYPE_NONE = 0,
	NVM_IOTYPE_GC = 1,
};

/* common format */
#define NVM_GEN_CH_BITS  (8)
#define NVM_GEN_LUN_BITS (8)
#define NVM_GEN_BLK_BITS (16)
#define NVM_GEN_RESERVED (32)

/* 1.2 format */
#define NVM_12_PG_BITS  (16)
#define NVM_12_PL_BITS  (4)
#define NVM_12_SEC_BITS (4)
#define NVM_12_RESERVED (8)

/* 2.0 format */
#define NVM_20_SEC_BITS (24)
#define NVM_20_RESERVED (8)

enum {
	NVM_OCSSD_SPEC_12 = 12,
	NVM_OCSSD_SPEC_20 = 20,
};

struct ppa_addr {
	/* Generic structure for all addresses */
	union {
		/* generic device format */
		struct {
			u64 ch		: NVM_GEN_CH_BITS;
			u64 lun		: NVM_GEN_LUN_BITS;
			u64 blk		: NVM_GEN_BLK_BITS;
			u64 reserved	: NVM_GEN_RESERVED;
		} a;

		/* 1.2 device format */
		struct {
			u64 ch		: NVM_GEN_CH_BITS;
			u64 lun		: NVM_GEN_LUN_BITS;
			u64 blk		: NVM_GEN_BLK_BITS;
			u64 pg		: NVM_12_PG_BITS;
			u64 pl		: NVM_12_PL_BITS;
			u64 sec		: NVM_12_SEC_BITS;
			u64 reserved	: NVM_12_RESERVED;
		} g;

		/* 2.0 device format */
		struct {
			u64 grp		: NVM_GEN_CH_BITS;
			u64 pu		: NVM_GEN_LUN_BITS;
			u64 chk		: NVM_GEN_BLK_BITS;
			u64 sec		: NVM_20_SEC_BITS;
			u64 reserved	: NVM_20_RESERVED;
		} m;

		struct {
			u64 line	: 63;
			u64 is_cached	: 1;
		} c;

		u64 ppa;
	};
};

struct nvm_rq;
struct nvm_id;
struct nvm_dev;
struct nvm_tgt_dev;
struct nvm_chk_meta;

typedef int (nvm_id_fn)(struct nvm_dev *);
typedef int (nvm_op_bb_tbl_fn)(struct nvm_dev *, struct ppa_addr, u8 *);
typedef int (nvm_op_set_bb_fn)(struct nvm_dev *, struct ppa_addr *, int, int);
typedef int (nvm_get_chk_meta_fn)(struct nvm_dev *, sector_t, int,
							struct nvm_chk_meta *);
typedef int (nvm_submit_io_fn)(struct nvm_dev *, struct nvm_rq *, void *);
typedef void *(nvm_create_dma_pool_fn)(struct nvm_dev *, char *, int);
typedef void (nvm_destroy_dma_pool_fn)(void *);
typedef void *(nvm_dev_dma_alloc_fn)(struct nvm_dev *, void *, gfp_t,
								dma_addr_t *);
typedef void (nvm_dev_dma_free_fn)(void *, void*, dma_addr_t);

struct nvm_dev_ops {
	nvm_id_fn		*identity;
	nvm_op_bb_tbl_fn	*get_bb_tbl;
	nvm_op_set_bb_fn	*set_bb_tbl;

	nvm_get_chk_meta_fn	*get_chk_meta;

	nvm_submit_io_fn	*submit_io;

	nvm_create_dma_pool_fn	*create_dma_pool;
	nvm_destroy_dma_pool_fn	*destroy_dma_pool;
	nvm_dev_dma_alloc_fn	*dev_dma_alloc;
	nvm_dev_dma_free_fn	*dev_dma_free;
};

#ifdef CONFIG_NVM

#include <linux/file.h>
#include <linux/dmapool.h>

enum {
	/* HW Responsibilities */
	NVM_RSP_L2P	= 1 << 0,
	NVM_RSP_ECC	= 1 << 1,

	/* Physical Adressing Mode */
	NVM_ADDRMODE_LINEAR	= 0,
	NVM_ADDRMODE_CHANNEL	= 1,

	/* Plane programming mode for LUN */
	NVM_PLANE_SINGLE	= 1,
	NVM_PLANE_DOUBLE	= 2,
	NVM_PLANE_QUAD		= 4,

	/* Status codes */
	NVM_RSP_SUCCESS		= 0x0,
	NVM_RSP_NOT_CHANGEABLE	= 0x1,
	NVM_RSP_ERR_FAILWRITE	= 0x40ff,
	NVM_RSP_ERR_EMPTYPAGE	= 0x42ff,
	NVM_RSP_ERR_FAILECC	= 0x4281,
	NVM_RSP_ERR_FAILCRC	= 0x4004,
	NVM_RSP_WARN_HIGHECC	= 0x4700,

	/* Device opcodes */
	NVM_OP_PWRITE		= 0x91,
	NVM_OP_PREAD		= 0x92,
	NVM_OP_ERASE		= 0x90,

	/* PPA Command Flags */
	NVM_IO_SNGL_ACCESS	= 0x0,
	NVM_IO_DUAL_ACCESS	= 0x1,
	NVM_IO_QUAD_ACCESS	= 0x2,

	/* NAND Access Modes */
	NVM_IO_SUSPEND		= 0x80,
	NVM_IO_SLC_MODE		= 0x100,
	NVM_IO_SCRAMBLE_ENABLE	= 0x200,

	/* Block Types */
	NVM_BLK_T_FREE		= 0x0,
	NVM_BLK_T_BAD		= 0x1,
	NVM_BLK_T_GRWN_BAD	= 0x2,
	NVM_BLK_T_DEV		= 0x4,
	NVM_BLK_T_HOST		= 0x8,

	/* Memory capabilities */
	NVM_ID_CAP_SLC		= 0x1,
	NVM_ID_CAP_CMD_SUSPEND	= 0x2,
	NVM_ID_CAP_SCRAMBLE	= 0x4,
	NVM_ID_CAP_ENCRYPT	= 0x8,

	/* Memory types */
	NVM_ID_FMTYPE_SLC	= 0,
	NVM_ID_FMTYPE_MLC	= 1,

	/* Device capabilities */
	NVM_ID_DCAP_BBLKMGMT	= 0x1,
	NVM_UD_DCAP_ECC		= 0x2,
};

struct nvm_id_lp_mlc {
	u16	num_pairs;
	u8	pairs[886];
};

struct nvm_id_lp_tbl {
	__u8	id[8];
	struct nvm_id_lp_mlc mlc;
};

struct nvm_addrf_12 {
	u8	ch_len;
	u8	lun_len;
	u8	blk_len;
	u8	pg_len;
	u8	pln_len;
	u8	sec_len;

	u8	ch_offset;
	u8	lun_offset;
	u8	blk_offset;
	u8	pg_offset;
	u8	pln_offset;
	u8	sec_offset;

	u64	ch_mask;
	u64	lun_mask;
	u64	blk_mask;
	u64	pg_mask;
	u64	pln_mask;
	u64	sec_mask;
};

struct nvm_addrf {
	u8	ch_len;
	u8	lun_len;
	u8	chk_len;
	u8	sec_len;
	u8	rsv_len[2];

	u8	ch_offset;
	u8	lun_offset;
	u8	chk_offset;
	u8	sec_offset;
	u8	rsv_off[2];

	u64	ch_mask;
	u64	lun_mask;
	u64	chk_mask;
	u64	sec_mask;
	u64	rsv_mask[2];
};

enum {
	/* Chunk states */
	NVM_CHK_ST_FREE =	1 << 0,
	NVM_CHK_ST_CLOSED =	1 << 1,
	NVM_CHK_ST_OPEN =	1 << 2,
	NVM_CHK_ST_OFFLINE =	1 << 3,

	/* Chunk types */
	NVM_CHK_TP_W_SEQ =	1 << 0,
	NVM_CHK_TP_W_RAN =	1 << 1,
	NVM_CHK_TP_SZ_SPEC =	1 << 4,
};

/*
 * Note: The structure size is linked to nvme_nvm_chk_meta such that the same
 * buffer can be used when converting from little endian to cpu addressing.
 */
struct nvm_chk_meta {
	u8	state;
	u8	type;
	u8	wi;
	u8	rsvd[5];
	u64	slba;
	u64	cnlb;
	u64	wp;
};

struct nvm_target {
	struct list_head list;
	struct nvm_tgt_dev *dev;
	struct nvm_tgt_type *type;
	struct gendisk *disk;
};

#define ADDR_EMPTY (~0ULL)

#define NVM_TARGET_DEFAULT_OP (101)
#define NVM_TARGET_MIN_OP (3)
#define NVM_TARGET_MAX_OP (80)

#define NVM_VERSION_MAJOR 1
#define NVM_VERSION_MINOR 0
#define NVM_VERSION_PATCH 0

#define NVM_MAX_VLBA (64) /* max logical blocks in a vector command */

struct nvm_rq;
typedef void (nvm_end_io_fn)(struct nvm_rq *);

struct nvm_rq {
	struct nvm_tgt_dev *dev;

	struct bio *bio;

	union {
		struct ppa_addr ppa_addr;
		dma_addr_t dma_ppa_list;
	};

	struct ppa_addr *ppa_list;

	void *meta_list;
	dma_addr_t dma_meta_list;

	nvm_end_io_fn *end_io;

	uint8_t opcode;
	uint16_t nr_ppas;
	uint16_t flags;

	u64 ppa_status; /* ppa media status */
	int error;

	int is_seq; /* Sequential hint flag. 1.2 only */

	void *private;
};

static inline struct nvm_rq *nvm_rq_from_pdu(void *pdu)
{
	return pdu - sizeof(struct nvm_rq);
}

static inline void *nvm_rq_to_pdu(struct nvm_rq *rqdata)
{
	return rqdata + 1;
}

static inline struct ppa_addr *nvm_rq_to_ppa_list(struct nvm_rq *rqd)
{
	return (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
}

enum {
	NVM_BLK_ST_FREE =	0x1,	/* Free block */
	NVM_BLK_ST_TGT =	0x2,	/* Block in use by target */
	NVM_BLK_ST_BAD =	0x8,	/* Bad block */
};

/* Instance geometry */
struct nvm_geo {
	/* device reported version */
	u8	major_ver_id;
	u8	minor_ver_id;

	/* kernel short version */
	u8	version;

	/* instance specific geometry */
	int num_ch;
	int num_lun;		/* per channel */

	/* calculated values */
	int all_luns;		/* across channels */
	int all_chunks;		/* across channels */

	int op;			/* over-provision in instance */

	sector_t total_secs;	/* across channels */

	/* chunk geometry */
	u32	num_chk;	/* chunks per lun */
	u32	clba;		/* sectors per chunk */
	u16	csecs;		/* sector size */
	u16	sos;		/* out-of-band area size */
	bool	ext;		/* metadata in extended data buffer */
	u32	mdts;		/* Max data transfer size*/

	/* device write constrains */
	u32	ws_min;		/* minimum write size */
	u32	ws_opt;		/* optimal write size */
	u32	mw_cunits;	/* distance required for successful read */
	u32	maxoc;		/* maximum open chunks */
	u32	maxocpu;	/* maximum open chunks per parallel unit */

	/* device capabilities */
	u32	mccap;

	/* device timings */
	u32	trdt;		/* Avg. Tread (ns) */
	u32	trdm;		/* Max Tread (ns) */
	u32	tprt;		/* Avg. Tprog (ns) */
	u32	tprm;		/* Max Tprog (ns) */
	u32	tbet;		/* Avg. Terase (ns) */
	u32	tbem;		/* Max Terase (ns) */

	/* generic address format */
	struct nvm_addrf addrf;

	/* 1.2 compatibility */
	u8	vmnt;
	u32	cap;
	u32	dom;

	u8	mtype;
	u8	fmtype;

	u16	cpar;
	u32	mpos;

	u8	num_pln;
	u8	pln_mode;
	u16	num_pg;
	u16	fpg_sz;
};

/* sub-device structure */
struct nvm_tgt_dev {
	/* Device information */
	struct nvm_geo geo;

	/* Base ppas for target LUNs */
	struct ppa_addr *luns;

	struct request_queue *q;

	struct nvm_dev *parent;
	void *map;
};

struct nvm_dev {
	struct nvm_dev_ops *ops;

	struct list_head devices;

	/* Device information */
	struct nvm_geo geo;

	unsigned long *lun_map;
	void *dma_pool;

	/* Backend device */
	struct request_queue *q;
	char name[DISK_NAME_LEN];
	void *private_data;

	struct kref ref;
	void *rmap;

	struct mutex mlock;
	spinlock_t lock;

	/* target management */
	struct list_head area_list;
	struct list_head targets;
};

static inline struct ppa_addr generic_to_dev_addr(struct nvm_dev *dev,
						  struct ppa_addr r)
{
	struct nvm_geo *geo = &dev->geo;
	struct ppa_addr l;

	if (geo->version == NVM_OCSSD_SPEC_12) {
		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&geo->addrf;

		l.ppa = ((u64)r.g.ch) << ppaf->ch_offset;
		l.ppa |= ((u64)r.g.lun) << ppaf->lun_offset;
		l.ppa |= ((u64)r.g.blk) << ppaf->blk_offset;
		l.ppa |= ((u64)r.g.pg) << ppaf->pg_offset;
		l.ppa |= ((u64)r.g.pl) << ppaf->pln_offset;
		l.ppa |= ((u64)r.g.sec) << ppaf->sec_offset;
	} else {
		struct nvm_addrf *lbaf = &geo->addrf;

		l.ppa = ((u64)r.m.grp) << lbaf->ch_offset;
		l.ppa |= ((u64)r.m.pu) << lbaf->lun_offset;
		l.ppa |= ((u64)r.m.chk) << lbaf->chk_offset;
		l.ppa |= ((u64)r.m.sec) << lbaf->sec_offset;
	}

	return l;
}

static inline struct ppa_addr dev_to_generic_addr(struct nvm_dev *dev,
						  struct ppa_addr r)
{
	struct nvm_geo *geo = &dev->geo;
	struct ppa_addr l;

	l.ppa = 0;

	if (geo->version == NVM_OCSSD_SPEC_12) {
		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&geo->addrf;

		l.g.ch = (r.ppa & ppaf->ch_mask) >> ppaf->ch_offset;
		l.g.lun = (r.ppa & ppaf->lun_mask) >> ppaf->lun_offset;
		l.g.blk = (r.ppa & ppaf->blk_mask) >> ppaf->blk_offset;
		l.g.pg = (r.ppa & ppaf->pg_mask) >> ppaf->pg_offset;
		l.g.pl = (r.ppa & ppaf->pln_mask) >> ppaf->pln_offset;
		l.g.sec = (r.ppa & ppaf->sec_mask) >> ppaf->sec_offset;
	} else {
		struct nvm_addrf *lbaf = &geo->addrf;

		l.m.grp = (r.ppa & lbaf->ch_mask) >> lbaf->ch_offset;
		l.m.pu = (r.ppa & lbaf->lun_mask) >> lbaf->lun_offset;
		l.m.chk = (r.ppa & lbaf->chk_mask) >> lbaf->chk_offset;
		l.m.sec = (r.ppa & lbaf->sec_mask) >> lbaf->sec_offset;
	}

	return l;
}

static inline u64 dev_to_chunk_addr(struct nvm_dev *dev, void *addrf,
				    struct ppa_addr p)
{
	struct nvm_geo *geo = &dev->geo;
	u64 caddr;

	if (geo->version == NVM_OCSSD_SPEC_12) {
		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)addrf;

		caddr = (u64)p.g.pg << ppaf->pg_offset;
		caddr |= (u64)p.g.pl << ppaf->pln_offset;
		caddr |= (u64)p.g.sec << ppaf->sec_offset;
	} else {
		caddr = p.m.sec;
	}

	return caddr;
}

static inline struct ppa_addr nvm_ppa32_to_ppa64(struct nvm_dev *dev,
						 void *addrf, u32 ppa32)
{
	struct ppa_addr ppa64;

	ppa64.ppa = 0;

	if (ppa32 == -1) {
		ppa64.ppa = ADDR_EMPTY;
	} else if (ppa32 & (1U << 31)) {
		ppa64.c.line = ppa32 & ((~0U) >> 1);
		ppa64.c.is_cached = 1;
	} else {
		struct nvm_geo *geo = &dev->geo;

		if (geo->version == NVM_OCSSD_SPEC_12) {
			struct nvm_addrf_12 *ppaf = addrf;

			ppa64.g.ch = (ppa32 & ppaf->ch_mask) >>
							ppaf->ch_offset;
			ppa64.g.lun = (ppa32 & ppaf->lun_mask) >>
							ppaf->lun_offset;
			ppa64.g.blk = (ppa32 & ppaf->blk_mask) >>
							ppaf->blk_offset;
			ppa64.g.pg = (ppa32 & ppaf->pg_mask) >>
							ppaf->pg_offset;
			ppa64.g.pl = (ppa32 & ppaf->pln_mask) >>
							ppaf->pln_offset;
			ppa64.g.sec = (ppa32 & ppaf->sec_mask) >>
							ppaf->sec_offset;
		} else {
			struct nvm_addrf *lbaf = addrf;

			ppa64.m.grp = (ppa32 & lbaf->ch_mask) >>
							lbaf->ch_offset;
			ppa64.m.pu = (ppa32 & lbaf->lun_mask) >>
							lbaf->lun_offset;
			ppa64.m.chk = (ppa32 & lbaf->chk_mask) >>
							lbaf->chk_offset;
			ppa64.m.sec = (ppa32 & lbaf->sec_mask) >>
							lbaf->sec_offset;
		}
	}

	return ppa64;
}

static inline u32 nvm_ppa64_to_ppa32(struct nvm_dev *dev,
				     void *addrf, struct ppa_addr ppa64)
{
	u32 ppa32 = 0;

	if (ppa64.ppa == ADDR_EMPTY) {
		ppa32 = ~0U;
	} else if (ppa64.c.is_cached) {
		ppa32 |= ppa64.c.line;
		ppa32 |= 1U << 31;
	} else {
		struct nvm_geo *geo = &dev->geo;

		if (geo->version == NVM_OCSSD_SPEC_12) {
			struct nvm_addrf_12 *ppaf = addrf;

			ppa32 |= ppa64.g.ch << ppaf->ch_offset;
			ppa32 |= ppa64.g.lun << ppaf->lun_offset;
			ppa32 |= ppa64.g.blk << ppaf->blk_offset;
			ppa32 |= ppa64.g.pg << ppaf->pg_offset;
			ppa32 |= ppa64.g.pl << ppaf->pln_offset;
			ppa32 |= ppa64.g.sec << ppaf->sec_offset;
		} else {
			struct nvm_addrf *lbaf = addrf;

			ppa32 |= ppa64.m.grp << lbaf->ch_offset;
			ppa32 |= ppa64.m.pu << lbaf->lun_offset;
			ppa32 |= ppa64.m.chk << lbaf->chk_offset;
			ppa32 |= ppa64.m.sec << lbaf->sec_offset;
		}
	}

	return ppa32;
}

static inline int nvm_next_ppa_in_chk(struct nvm_tgt_dev *dev,
				      struct ppa_addr *ppa)
{
	struct nvm_geo *geo = &dev->geo;
	int last = 0;

	if (geo->version == NVM_OCSSD_SPEC_12) {
		int sec = ppa->g.sec;

		sec++;
		if (sec == geo->ws_min) {
			int pg = ppa->g.pg;

			sec = 0;
			pg++;
			if (pg == geo->num_pg) {
				int pl = ppa->g.pl;

				pg = 0;
				pl++;
				if (pl == geo->num_pln)
					last = 1;

				ppa->g.pl = pl;
			}
			ppa->g.pg = pg;
		}
		ppa->g.sec = sec;
	} else {
		ppa->m.sec++;
		if (ppa->m.sec == geo->clba)
			last = 1;
	}

	return last;
}

typedef sector_t (nvm_tgt_capacity_fn)(void *);
typedef void *(nvm_tgt_init_fn)(struct nvm_tgt_dev *, struct gendisk *,
				int flags);
typedef void (nvm_tgt_exit_fn)(void *, bool);
typedef int (nvm_tgt_sysfs_init_fn)(struct gendisk *);
typedef void (nvm_tgt_sysfs_exit_fn)(struct gendisk *);

enum {
	NVM_TGT_F_DEV_L2P = 0,
	NVM_TGT_F_HOST_L2P = 1 << 0,
};

struct nvm_tgt_type {
	const char *name;
	unsigned int version[3];
	int flags;

	/* target entry points */
	const struct block_device_operations *bops;
	nvm_tgt_capacity_fn *capacity;

	/* module-specific init/teardown */
	nvm_tgt_init_fn *init;
	nvm_tgt_exit_fn *exit;

	/* sysfs */
	nvm_tgt_sysfs_init_fn *sysfs_init;
	nvm_tgt_sysfs_exit_fn *sysfs_exit;

	/* For internal use */
	struct list_head list;
	struct module *owner;
};

extern int nvm_register_tgt_type(struct nvm_tgt_type *);
extern void nvm_unregister_tgt_type(struct nvm_tgt_type *);

extern void *nvm_dev_dma_alloc(struct nvm_dev *, gfp_t, dma_addr_t *);
extern void nvm_dev_dma_free(struct nvm_dev *, void *, dma_addr_t);

extern struct nvm_dev *nvm_alloc_dev(int);
extern int nvm_register(struct nvm_dev *);
extern void nvm_unregister(struct nvm_dev *);

extern int nvm_get_chunk_meta(struct nvm_tgt_dev *, struct ppa_addr,
			      int, struct nvm_chk_meta *);
extern int nvm_set_chunk_meta(struct nvm_tgt_dev *, struct ppa_addr *,
			      int, int);
extern int nvm_submit_io(struct nvm_tgt_dev *, struct nvm_rq *, void *);
extern int nvm_submit_io_sync(struct nvm_tgt_dev *, struct nvm_rq *, void *);
extern void nvm_end_io(struct nvm_rq *);

#else /* CONFIG_NVM */
struct nvm_dev_ops;

static inline struct nvm_dev *nvm_alloc_dev(int node)
{
	return ERR_PTR(-EINVAL);
}
static inline int nvm_register(struct nvm_dev *dev)
{
	return -EINVAL;
}
static inline void nvm_unregister(struct nvm_dev *dev) {}
#endif /* CONFIG_NVM */
#endif /* LIGHTNVM.H */