2 * Block Translation Table
3 * Copyright (c) 2014-2015, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 #include <linux/highmem.h>
15 #include <linux/debugfs.h>
16 #include <linux/blkdev.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/mutex.h>
20 #include <linux/hdreg.h>
21 #include <linux/genhd.h>
22 #include <linux/sizes.h>
23 #include <linux/ndctl.h>
26 #include <linux/backing-dev.h>
30 enum log_ent_request
{
35 static struct device
*to_dev(struct arena_info
*arena
)
37 return &arena
->nd_btt
->dev
;
40 static u64
adjust_initial_offset(struct nd_btt
*nd_btt
, u64 offset
)
42 return offset
+ nd_btt
->initial_offset
;
45 static int arena_read_bytes(struct arena_info
*arena
, resource_size_t offset
,
46 void *buf
, size_t n
, unsigned long flags
)
48 struct nd_btt
*nd_btt
= arena
->nd_btt
;
49 struct nd_namespace_common
*ndns
= nd_btt
->ndns
;
51 /* arena offsets may be shifted from the base of the device */
52 offset
= adjust_initial_offset(nd_btt
, offset
);
53 return nvdimm_read_bytes(ndns
, offset
, buf
, n
, flags
);
56 static int arena_write_bytes(struct arena_info
*arena
, resource_size_t offset
,
57 void *buf
, size_t n
, unsigned long flags
)
59 struct nd_btt
*nd_btt
= arena
->nd_btt
;
60 struct nd_namespace_common
*ndns
= nd_btt
->ndns
;
62 /* arena offsets may be shifted from the base of the device */
63 offset
= adjust_initial_offset(nd_btt
, offset
);
64 return nvdimm_write_bytes(ndns
, offset
, buf
, n
, flags
);
67 static int btt_info_write(struct arena_info
*arena
, struct btt_sb
*super
)
72 * infooff and info2off should always be at least 512B aligned.
73 * We rely on that to make sure rw_bytes does error clearing
74 * correctly, so make sure that is the case.
76 dev_WARN_ONCE(to_dev(arena
), !IS_ALIGNED(arena
->infooff
, 512),
77 "arena->infooff: %#llx is unaligned\n", arena
->infooff
);
78 dev_WARN_ONCE(to_dev(arena
), !IS_ALIGNED(arena
->info2off
, 512),
79 "arena->info2off: %#llx is unaligned\n", arena
->info2off
);
81 ret
= arena_write_bytes(arena
, arena
->info2off
, super
,
82 sizeof(struct btt_sb
), 0);
86 return arena_write_bytes(arena
, arena
->infooff
, super
,
87 sizeof(struct btt_sb
), 0);
90 static int btt_info_read(struct arena_info
*arena
, struct btt_sb
*super
)
92 return arena_read_bytes(arena
, arena
->infooff
, super
,
93 sizeof(struct btt_sb
), 0);
97 * 'raw' version of btt_map write
99 * mapping is in little-endian
100 * mapping contains 'E' and 'Z' flags as desired
102 static int __btt_map_write(struct arena_info
*arena
, u32 lba
, __le32 mapping
,
105 u64 ns_off
= arena
->mapoff
+ (lba
* MAP_ENT_SIZE
);
107 if (unlikely(lba
>= arena
->external_nlba
))
108 dev_err_ratelimited(to_dev(arena
),
109 "%s: lba %#x out of range (max: %#x)\n",
110 __func__
, lba
, arena
->external_nlba
);
111 return arena_write_bytes(arena
, ns_off
, &mapping
, MAP_ENT_SIZE
, flags
);
114 static int btt_map_write(struct arena_info
*arena
, u32 lba
, u32 mapping
,
115 u32 z_flag
, u32 e_flag
, unsigned long rwb_flags
)
121 * This 'mapping' is supposed to be just the LBA mapping, without
122 * any flags set, so strip the flag bits.
124 mapping
= ent_lba(mapping
);
126 ze
= (z_flag
<< 1) + e_flag
;
130 * We want to set neither of the Z or E flags, and
131 * in the actual layout, this means setting the bit
132 * positions of both to '1' to indicate a 'normal'
135 mapping
|= MAP_ENT_NORMAL
;
138 mapping
|= (1 << MAP_ERR_SHIFT
);
141 mapping
|= (1 << MAP_TRIM_SHIFT
);
145 * The case where Z and E are both sent in as '1' could be
146 * construed as a valid 'normal' case, but we decide not to,
149 dev_err_ratelimited(to_dev(arena
),
150 "Invalid use of Z and E flags\n");
154 mapping_le
= cpu_to_le32(mapping
);
155 return __btt_map_write(arena
, lba
, mapping_le
, rwb_flags
);
158 static int btt_map_read(struct arena_info
*arena
, u32 lba
, u32
*mapping
,
159 int *trim
, int *error
, unsigned long rwb_flags
)
163 u32 raw_mapping
, postmap
, ze
, z_flag
, e_flag
;
164 u64 ns_off
= arena
->mapoff
+ (lba
* MAP_ENT_SIZE
);
166 if (unlikely(lba
>= arena
->external_nlba
))
167 dev_err_ratelimited(to_dev(arena
),
168 "%s: lba %#x out of range (max: %#x)\n",
169 __func__
, lba
, arena
->external_nlba
);
171 ret
= arena_read_bytes(arena
, ns_off
, &in
, MAP_ENT_SIZE
, rwb_flags
);
175 raw_mapping
= le32_to_cpu(in
);
177 z_flag
= ent_z_flag(raw_mapping
);
178 e_flag
= ent_e_flag(raw_mapping
);
179 ze
= (z_flag
<< 1) + e_flag
;
180 postmap
= ent_lba(raw_mapping
);
182 /* Reuse the {z,e}_flag variables for *trim and *error */
188 /* Initial state. Return postmap = premap */
214 static int btt_log_group_read(struct arena_info
*arena
, u32 lane
,
215 struct log_group
*log
)
217 return arena_read_bytes(arena
,
218 arena
->logoff
+ (lane
* LOG_GRP_SIZE
), log
,
222 static struct dentry
*debugfs_root
;
224 static void arena_debugfs_init(struct arena_info
*a
, struct dentry
*parent
,
230 /* If for some reason, parent bttN was not created, exit */
234 snprintf(dirname
, 32, "arena%d", idx
);
235 d
= debugfs_create_dir(dirname
, parent
);
236 if (IS_ERR_OR_NULL(d
))
240 debugfs_create_x64("size", S_IRUGO
, d
, &a
->size
);
241 debugfs_create_x64("external_lba_start", S_IRUGO
, d
,
242 &a
->external_lba_start
);
243 debugfs_create_x32("internal_nlba", S_IRUGO
, d
, &a
->internal_nlba
);
244 debugfs_create_u32("internal_lbasize", S_IRUGO
, d
,
245 &a
->internal_lbasize
);
246 debugfs_create_x32("external_nlba", S_IRUGO
, d
, &a
->external_nlba
);
247 debugfs_create_u32("external_lbasize", S_IRUGO
, d
,
248 &a
->external_lbasize
);
249 debugfs_create_u32("nfree", S_IRUGO
, d
, &a
->nfree
);
250 debugfs_create_u16("version_major", S_IRUGO
, d
, &a
->version_major
);
251 debugfs_create_u16("version_minor", S_IRUGO
, d
, &a
->version_minor
);
252 debugfs_create_x64("nextoff", S_IRUGO
, d
, &a
->nextoff
);
253 debugfs_create_x64("infooff", S_IRUGO
, d
, &a
->infooff
);
254 debugfs_create_x64("dataoff", S_IRUGO
, d
, &a
->dataoff
);
255 debugfs_create_x64("mapoff", S_IRUGO
, d
, &a
->mapoff
);
256 debugfs_create_x64("logoff", S_IRUGO
, d
, &a
->logoff
);
257 debugfs_create_x64("info2off", S_IRUGO
, d
, &a
->info2off
);
258 debugfs_create_x32("flags", S_IRUGO
, d
, &a
->flags
);
259 debugfs_create_u32("log_index_0", S_IRUGO
, d
, &a
->log_index
[0]);
260 debugfs_create_u32("log_index_1", S_IRUGO
, d
, &a
->log_index
[1]);
263 static void btt_debugfs_init(struct btt
*btt
)
266 struct arena_info
*arena
;
268 btt
->debugfs_dir
= debugfs_create_dir(dev_name(&btt
->nd_btt
->dev
),
270 if (IS_ERR_OR_NULL(btt
->debugfs_dir
))
273 list_for_each_entry(arena
, &btt
->arena_list
, list
) {
274 arena_debugfs_init(arena
, btt
->debugfs_dir
, i
);
279 static u32
log_seq(struct log_group
*log
, int log_idx
)
281 return le32_to_cpu(log
->ent
[log_idx
].seq
);
285 * This function accepts two log entries, and uses the
286 * sequence number to find the 'older' entry.
287 * It also updates the sequence number in this old entry to
288 * make it the 'new' one if the mark_flag is set.
289 * Finally, it returns which of the entries was the older one.
291 * TODO The logic feels a bit kludge-y. make it better..
293 static int btt_log_get_old(struct arena_info
*a
, struct log_group
*log
)
295 int idx0
= a
->log_index
[0];
296 int idx1
= a
->log_index
[1];
300 * the first ever time this is seen, the entry goes into [0]
301 * the next time, the following logic works out to put this
302 * (next) entry into [1]
304 if (log_seq(log
, idx0
) == 0) {
305 log
->ent
[idx0
].seq
= cpu_to_le32(1);
309 if (log_seq(log
, idx0
) == log_seq(log
, idx1
))
311 if (log_seq(log
, idx0
) + log_seq(log
, idx1
) > 5)
314 if (log_seq(log
, idx0
) < log_seq(log
, idx1
)) {
315 if ((log_seq(log
, idx1
) - log_seq(log
, idx0
)) == 1)
320 if ((log_seq(log
, idx0
) - log_seq(log
, idx1
)) == 1)
330 * This function copies the desired (old/new) log entry into ent if
331 * it is not NULL. It returns the sub-slot number (0 or 1)
332 * where the desired log entry was found. Negative return values
335 static int btt_log_read(struct arena_info
*arena
, u32 lane
,
336 struct log_entry
*ent
, int old_flag
)
339 int old_ent
, ret_ent
;
340 struct log_group log
;
342 ret
= btt_log_group_read(arena
, lane
, &log
);
346 old_ent
= btt_log_get_old(arena
, &log
);
347 if (old_ent
< 0 || old_ent
> 1) {
348 dev_err(to_dev(arena
),
349 "log corruption (%d): lane %d seq [%d, %d]\n",
350 old_ent
, lane
, log
.ent
[arena
->log_index
[0]].seq
,
351 log
.ent
[arena
->log_index
[1]].seq
);
352 /* TODO set error state? */
356 ret_ent
= (old_flag
? old_ent
: (1 - old_ent
));
359 memcpy(ent
, &log
.ent
[arena
->log_index
[ret_ent
]], LOG_ENT_SIZE
);
365 * This function commits a log entry to media
366 * It does _not_ prepare the freelist entry for the next write
367 * btt_flog_write is the wrapper for updating the freelist elements
369 static int __btt_log_write(struct arena_info
*arena
, u32 lane
,
370 u32 sub
, struct log_entry
*ent
, unsigned long flags
)
373 u32 group_slot
= arena
->log_index
[sub
];
374 unsigned int log_half
= LOG_ENT_SIZE
/ 2;
378 ns_off
= arena
->logoff
+ (lane
* LOG_GRP_SIZE
) +
379 (group_slot
* LOG_ENT_SIZE
);
380 /* split the 16B write into atomic, durable halves */
381 ret
= arena_write_bytes(arena
, ns_off
, src
, log_half
, flags
);
387 return arena_write_bytes(arena
, ns_off
, src
, log_half
, flags
);
390 static int btt_flog_write(struct arena_info
*arena
, u32 lane
, u32 sub
,
391 struct log_entry
*ent
)
395 ret
= __btt_log_write(arena
, lane
, sub
, ent
, NVDIMM_IO_ATOMIC
);
399 /* prepare the next free entry */
400 arena
->freelist
[lane
].sub
= 1 - arena
->freelist
[lane
].sub
;
401 if (++(arena
->freelist
[lane
].seq
) == 4)
402 arena
->freelist
[lane
].seq
= 1;
403 if (ent_e_flag(ent
->old_map
))
404 arena
->freelist
[lane
].has_err
= 1;
405 arena
->freelist
[lane
].block
= le32_to_cpu(ent_lba(ent
->old_map
));
411 * This function initializes the BTT map to the initial state, which is
412 * all-zeroes, and indicates an identity mapping
414 static int btt_map_init(struct arena_info
*arena
)
419 size_t chunk_size
= SZ_2M
;
420 size_t mapsize
= arena
->logoff
- arena
->mapoff
;
422 zerobuf
= kzalloc(chunk_size
, GFP_KERNEL
);
427 * mapoff should always be at least 512B aligned. We rely on that to
428 * make sure rw_bytes does error clearing correctly, so make sure that
431 dev_WARN_ONCE(to_dev(arena
), !IS_ALIGNED(arena
->mapoff
, 512),
432 "arena->mapoff: %#llx is unaligned\n", arena
->mapoff
);
435 size_t size
= min(mapsize
, chunk_size
);
437 dev_WARN_ONCE(to_dev(arena
), size
< 512,
438 "chunk size: %#zx is unaligned\n", size
);
439 ret
= arena_write_bytes(arena
, arena
->mapoff
+ offset
, zerobuf
,
455 * This function initializes the BTT log with 'fake' entries pointing
456 * to the initial reserved set of blocks as being free
458 static int btt_log_init(struct arena_info
*arena
)
460 size_t logsize
= arena
->info2off
- arena
->logoff
;
461 size_t chunk_size
= SZ_4K
, offset
= 0;
462 struct log_entry ent
;
467 zerobuf
= kzalloc(chunk_size
, GFP_KERNEL
);
471 * logoff should always be at least 512B aligned. We rely on that to
472 * make sure rw_bytes does error clearing correctly, so make sure that
475 dev_WARN_ONCE(to_dev(arena
), !IS_ALIGNED(arena
->logoff
, 512),
476 "arena->logoff: %#llx is unaligned\n", arena
->logoff
);
479 size_t size
= min(logsize
, chunk_size
);
481 dev_WARN_ONCE(to_dev(arena
), size
< 512,
482 "chunk size: %#zx is unaligned\n", size
);
483 ret
= arena_write_bytes(arena
, arena
->logoff
+ offset
, zerobuf
,
493 for (i
= 0; i
< arena
->nfree
; i
++) {
494 ent
.lba
= cpu_to_le32(i
);
495 ent
.old_map
= cpu_to_le32(arena
->external_nlba
+ i
);
496 ent
.new_map
= cpu_to_le32(arena
->external_nlba
+ i
);
497 ent
.seq
= cpu_to_le32(LOG_SEQ_INIT
);
498 ret
= __btt_log_write(arena
, i
, 0, &ent
, 0);
508 static u64
to_namespace_offset(struct arena_info
*arena
, u64 lba
)
510 return arena
->dataoff
+ ((u64
)lba
* arena
->internal_lbasize
);
513 static int arena_clear_freelist_error(struct arena_info
*arena
, u32 lane
)
517 if (arena
->freelist
[lane
].has_err
) {
518 void *zero_page
= page_address(ZERO_PAGE(0));
519 u32 lba
= arena
->freelist
[lane
].block
;
520 u64 nsoff
= to_namespace_offset(arena
, lba
);
521 unsigned long len
= arena
->sector_size
;
523 mutex_lock(&arena
->err_lock
);
526 unsigned long chunk
= min(len
, PAGE_SIZE
);
528 ret
= arena_write_bytes(arena
, nsoff
, zero_page
,
535 arena
->freelist
[lane
].has_err
= 0;
537 mutex_unlock(&arena
->err_lock
);
542 static int btt_freelist_init(struct arena_info
*arena
)
546 struct log_entry log_new
, log_old
;
548 arena
->freelist
= kcalloc(arena
->nfree
, sizeof(struct free_entry
),
550 if (!arena
->freelist
)
553 for (i
= 0; i
< arena
->nfree
; i
++) {
554 old
= btt_log_read(arena
, i
, &log_old
, LOG_OLD_ENT
);
558 new = btt_log_read(arena
, i
, &log_new
, LOG_NEW_ENT
);
562 /* sub points to the next one to be overwritten */
563 arena
->freelist
[i
].sub
= 1 - new;
564 arena
->freelist
[i
].seq
= nd_inc_seq(le32_to_cpu(log_new
.seq
));
565 arena
->freelist
[i
].block
= le32_to_cpu(log_new
.old_map
);
568 * FIXME: if error clearing fails during init, we want to make
571 if (ent_e_flag(log_new
.old_map
)) {
572 ret
= arena_clear_freelist_error(arena
, i
);
574 dev_err_ratelimited(to_dev(arena
),
575 "Unable to clear known errors\n");
578 /* This implies a newly created or untouched flog entry */
579 if (log_new
.old_map
== log_new
.new_map
)
582 /* Check if map recovery is needed */
583 ret
= btt_map_read(arena
, le32_to_cpu(log_new
.lba
), &map_entry
,
587 if ((le32_to_cpu(log_new
.new_map
) != map_entry
) &&
588 (le32_to_cpu(log_new
.old_map
) == map_entry
)) {
590 * Last transaction wrote the flog, but wasn't able
591 * to complete the map write. So fix up the map.
593 ret
= btt_map_write(arena
, le32_to_cpu(log_new
.lba
),
594 le32_to_cpu(log_new
.new_map
), 0, 0, 0);
603 static bool ent_is_padding(struct log_entry
*ent
)
605 return (ent
->lba
== 0) && (ent
->old_map
== 0) && (ent
->new_map
== 0)
610 * Detecting valid log indices: We read a log group (see the comments in btt.h
611 * for a description of a 'log_group' and its 'slots'), and iterate over its
612 * four slots. We expect that a padding slot will be all-zeroes, and use this
613 * to detect a padding slot vs. an actual entry.
615 * If a log_group is in the initial state, i.e. hasn't been used since the
616 * creation of this BTT layout, it will have three of the four slots with
617 * zeroes. We skip over these log_groups for the detection of log_index. If
618 * all log_groups are in the initial state (i.e. the BTT has never been
619 * written to), it is safe to assume the 'new format' of log entries in slots
622 static int log_set_indices(struct arena_info
*arena
)
624 bool idx_set
= false, initial_state
= true;
625 int ret
, log_index
[2] = {-1, -1};
626 u32 i
, j
, next_idx
= 0;
627 struct log_group log
;
630 for (i
= 0; i
< arena
->nfree
; i
++) {
631 ret
= btt_log_group_read(arena
, i
, &log
);
635 for (j
= 0; j
< 4; j
++) {
637 if (ent_is_padding(&log
.ent
[j
])) {
641 /* Skip if index has been recorded */
642 if ((next_idx
== 1) &&
645 /* valid entry, record index */
646 log_index
[next_idx
] = j
;
650 /* two valid entries found */
652 } else if (next_idx
> 2) {
653 /* too many valid indices */
658 * once the indices have been set, just verify
659 * that all subsequent log groups are either in
660 * their initial state or follow the same
663 if (j
== log_index
[0]) {
664 /* entry must be 'valid' */
665 if (ent_is_padding(&log
.ent
[j
]))
667 } else if (j
== log_index
[1]) {
670 * log_index[1] can be padding if the
671 * lane never got used and it is still
672 * in the initial state (three 'padding'
676 /* entry must be invalid (padding) */
677 if (!ent_is_padding(&log
.ent
[j
]))
683 * If any of the log_groups have more than one valid,
684 * non-padding entry, then the we are no longer in the
688 initial_state
= false;
692 if (!initial_state
&& !idx_set
)
696 * If all the entries in the log were in the initial state,
697 * assume new padding scheme
703 * Only allow the known permutations of log/padding indices,
704 * i.e. (0, 1), and (0, 2)
706 if ((log_index
[0] == 0) && ((log_index
[1] == 1) || (log_index
[1] == 2)))
707 ; /* known index possibilities */
709 dev_err(to_dev(arena
), "Found an unknown padding scheme\n");
713 arena
->log_index
[0] = log_index
[0];
714 arena
->log_index
[1] = log_index
[1];
715 dev_dbg(to_dev(arena
), "log_index_0 = %d\n", log_index
[0]);
716 dev_dbg(to_dev(arena
), "log_index_1 = %d\n", log_index
[1]);
720 static int btt_rtt_init(struct arena_info
*arena
)
722 arena
->rtt
= kcalloc(arena
->nfree
, sizeof(u32
), GFP_KERNEL
);
723 if (arena
->rtt
== NULL
)
729 static int btt_maplocks_init(struct arena_info
*arena
)
733 arena
->map_locks
= kcalloc(arena
->nfree
, sizeof(struct aligned_lock
),
735 if (!arena
->map_locks
)
738 for (i
= 0; i
< arena
->nfree
; i
++)
739 spin_lock_init(&arena
->map_locks
[i
].lock
);
744 static struct arena_info
*alloc_arena(struct btt
*btt
, size_t size
,
745 size_t start
, size_t arena_off
)
747 struct arena_info
*arena
;
748 u64 logsize
, mapsize
, datasize
;
749 u64 available
= size
;
751 arena
= kzalloc(sizeof(struct arena_info
), GFP_KERNEL
);
754 arena
->nd_btt
= btt
->nd_btt
;
755 arena
->sector_size
= btt
->sector_size
;
756 mutex_init(&arena
->err_lock
);
762 arena
->external_lba_start
= start
;
763 arena
->external_lbasize
= btt
->lbasize
;
764 arena
->internal_lbasize
= roundup(arena
->external_lbasize
,
765 INT_LBASIZE_ALIGNMENT
);
766 arena
->nfree
= BTT_DEFAULT_NFREE
;
767 arena
->version_major
= btt
->nd_btt
->version_major
;
768 arena
->version_minor
= btt
->nd_btt
->version_minor
;
770 if (available
% BTT_PG_SIZE
)
771 available
-= (available
% BTT_PG_SIZE
);
773 /* Two pages are reserved for the super block and its copy */
774 available
-= 2 * BTT_PG_SIZE
;
776 /* The log takes a fixed amount of space based on nfree */
777 logsize
= roundup(arena
->nfree
* LOG_GRP_SIZE
, BTT_PG_SIZE
);
778 available
-= logsize
;
780 /* Calculate optimal split between map and data area */
781 arena
->internal_nlba
= div_u64(available
- BTT_PG_SIZE
,
782 arena
->internal_lbasize
+ MAP_ENT_SIZE
);
783 arena
->external_nlba
= arena
->internal_nlba
- arena
->nfree
;
785 mapsize
= roundup((arena
->external_nlba
* MAP_ENT_SIZE
), BTT_PG_SIZE
);
786 datasize
= available
- mapsize
;
788 /* 'Absolute' values, relative to start of storage space */
789 arena
->infooff
= arena_off
;
790 arena
->dataoff
= arena
->infooff
+ BTT_PG_SIZE
;
791 arena
->mapoff
= arena
->dataoff
+ datasize
;
792 arena
->logoff
= arena
->mapoff
+ mapsize
;
793 arena
->info2off
= arena
->logoff
+ logsize
;
795 /* Default log indices are (0,1) */
796 arena
->log_index
[0] = 0;
797 arena
->log_index
[1] = 1;
801 static void free_arenas(struct btt
*btt
)
803 struct arena_info
*arena
, *next
;
805 list_for_each_entry_safe(arena
, next
, &btt
->arena_list
, list
) {
806 list_del(&arena
->list
);
808 kfree(arena
->map_locks
);
809 kfree(arena
->freelist
);
810 debugfs_remove_recursive(arena
->debugfs_dir
);
816 * This function reads an existing valid btt superblock and
817 * populates the corresponding arena_info struct
819 static void parse_arena_meta(struct arena_info
*arena
, struct btt_sb
*super
,
822 arena
->internal_nlba
= le32_to_cpu(super
->internal_nlba
);
823 arena
->internal_lbasize
= le32_to_cpu(super
->internal_lbasize
);
824 arena
->external_nlba
= le32_to_cpu(super
->external_nlba
);
825 arena
->external_lbasize
= le32_to_cpu(super
->external_lbasize
);
826 arena
->nfree
= le32_to_cpu(super
->nfree
);
827 arena
->version_major
= le16_to_cpu(super
->version_major
);
828 arena
->version_minor
= le16_to_cpu(super
->version_minor
);
830 arena
->nextoff
= (super
->nextoff
== 0) ? 0 : (arena_off
+
831 le64_to_cpu(super
->nextoff
));
832 arena
->infooff
= arena_off
;
833 arena
->dataoff
= arena_off
+ le64_to_cpu(super
->dataoff
);
834 arena
->mapoff
= arena_off
+ le64_to_cpu(super
->mapoff
);
835 arena
->logoff
= arena_off
+ le64_to_cpu(super
->logoff
);
836 arena
->info2off
= arena_off
+ le64_to_cpu(super
->info2off
);
838 arena
->size
= (le64_to_cpu(super
->nextoff
) > 0)
839 ? (le64_to_cpu(super
->nextoff
))
840 : (arena
->info2off
- arena
->infooff
+ BTT_PG_SIZE
);
842 arena
->flags
= le32_to_cpu(super
->flags
);
845 static int discover_arenas(struct btt
*btt
)
848 struct arena_info
*arena
;
849 struct btt_sb
*super
;
850 size_t remaining
= btt
->rawsize
;
855 super
= kzalloc(sizeof(*super
), GFP_KERNEL
);
860 /* Alloc memory for arena */
861 arena
= alloc_arena(btt
, 0, 0, 0);
867 arena
->infooff
= cur_off
;
868 ret
= btt_info_read(arena
, super
);
872 if (!nd_btt_arena_is_valid(btt
->nd_btt
, super
)) {
873 if (remaining
== btt
->rawsize
) {
874 btt
->init_state
= INIT_NOTFOUND
;
875 dev_info(to_dev(arena
), "No existing arenas\n");
878 dev_err(to_dev(arena
),
879 "Found corrupted metadata!\n");
885 arena
->external_lba_start
= cur_nlba
;
886 parse_arena_meta(arena
, super
, cur_off
);
888 ret
= log_set_indices(arena
);
890 dev_err(to_dev(arena
),
891 "Unable to deduce log/padding indices\n");
895 ret
= btt_freelist_init(arena
);
899 ret
= btt_rtt_init(arena
);
903 ret
= btt_maplocks_init(arena
);
907 list_add_tail(&arena
->list
, &btt
->arena_list
);
909 remaining
-= arena
->size
;
910 cur_off
+= arena
->size
;
911 cur_nlba
+= arena
->external_nlba
;
914 if (arena
->nextoff
== 0)
917 btt
->num_arenas
= num_arenas
;
918 btt
->nlba
= cur_nlba
;
919 btt
->init_state
= INIT_READY
;
932 static int create_arenas(struct btt
*btt
)
934 size_t remaining
= btt
->rawsize
;
938 struct arena_info
*arena
;
939 size_t arena_size
= min_t(u64
, ARENA_MAX_SIZE
, remaining
);
941 remaining
-= arena_size
;
942 if (arena_size
< ARENA_MIN_SIZE
)
945 arena
= alloc_arena(btt
, arena_size
, btt
->nlba
, cur_off
);
950 btt
->nlba
+= arena
->external_nlba
;
951 if (remaining
>= ARENA_MIN_SIZE
)
952 arena
->nextoff
= arena
->size
;
955 cur_off
+= arena_size
;
956 list_add_tail(&arena
->list
, &btt
->arena_list
);
963 * This function completes arena initialization by writing
965 * It is only called for an uninitialized arena when a write
966 * to that arena occurs for the first time.
968 static int btt_arena_write_layout(struct arena_info
*arena
)
972 struct btt_sb
*super
;
973 struct nd_btt
*nd_btt
= arena
->nd_btt
;
974 const u8
*parent_uuid
= nd_dev_to_uuid(&nd_btt
->ndns
->dev
);
976 ret
= btt_map_init(arena
);
980 ret
= btt_log_init(arena
);
984 super
= kzalloc(sizeof(struct btt_sb
), GFP_NOIO
);
988 strncpy(super
->signature
, BTT_SIG
, BTT_SIG_LEN
);
989 memcpy(super
->uuid
, nd_btt
->uuid
, 16);
990 memcpy(super
->parent_uuid
, parent_uuid
, 16);
991 super
->flags
= cpu_to_le32(arena
->flags
);
992 super
->version_major
= cpu_to_le16(arena
->version_major
);
993 super
->version_minor
= cpu_to_le16(arena
->version_minor
);
994 super
->external_lbasize
= cpu_to_le32(arena
->external_lbasize
);
995 super
->external_nlba
= cpu_to_le32(arena
->external_nlba
);
996 super
->internal_lbasize
= cpu_to_le32(arena
->internal_lbasize
);
997 super
->internal_nlba
= cpu_to_le32(arena
->internal_nlba
);
998 super
->nfree
= cpu_to_le32(arena
->nfree
);
999 super
->infosize
= cpu_to_le32(sizeof(struct btt_sb
));
1000 super
->nextoff
= cpu_to_le64(arena
->nextoff
);
1002 * Subtract arena->infooff (arena start) so numbers are relative
1005 super
->dataoff
= cpu_to_le64(arena
->dataoff
- arena
->infooff
);
1006 super
->mapoff
= cpu_to_le64(arena
->mapoff
- arena
->infooff
);
1007 super
->logoff
= cpu_to_le64(arena
->logoff
- arena
->infooff
);
1008 super
->info2off
= cpu_to_le64(arena
->info2off
- arena
->infooff
);
1011 sum
= nd_sb_checksum((struct nd_gen_sb
*) super
);
1012 super
->checksum
= cpu_to_le64(sum
);
1014 ret
= btt_info_write(arena
, super
);
1021 * This function completes the initialization for the BTT namespace
1022 * such that it is ready to accept IOs
1024 static int btt_meta_init(struct btt
*btt
)
1027 struct arena_info
*arena
;
1029 mutex_lock(&btt
->init_lock
);
1030 list_for_each_entry(arena
, &btt
->arena_list
, list
) {
1031 ret
= btt_arena_write_layout(arena
);
1035 ret
= btt_freelist_init(arena
);
1039 ret
= btt_rtt_init(arena
);
1043 ret
= btt_maplocks_init(arena
);
1048 btt
->init_state
= INIT_READY
;
1051 mutex_unlock(&btt
->init_lock
);
1055 static u32
btt_meta_size(struct btt
*btt
)
1057 return btt
->lbasize
- btt
->sector_size
;
1061 * This function calculates the arena in which the given LBA lies
1062 * by doing a linear walk. This is acceptable since we expect only
1063 * a few arenas. If we have backing devices that get much larger,
1064 * we can construct a balanced binary tree of arenas at init time
1065 * so that this range search becomes faster.
1067 static int lba_to_arena(struct btt
*btt
, sector_t sector
, __u32
*premap
,
1068 struct arena_info
**arena
)
1070 struct arena_info
*arena_list
;
1071 __u64 lba
= div_u64(sector
<< SECTOR_SHIFT
, btt
->sector_size
);
1073 list_for_each_entry(arena_list
, &btt
->arena_list
, list
) {
1074 if (lba
< arena_list
->external_nlba
) {
1075 *arena
= arena_list
;
1079 lba
-= arena_list
->external_nlba
;
1086 * The following (lock_map, unlock_map) are mostly just to improve
1087 * readability, since they index into an array of locks
1089 static void lock_map(struct arena_info
*arena
, u32 premap
)
1090 __acquires(&arena
->map_locks
[idx
].lock
)
1092 u32 idx
= (premap
* MAP_ENT_SIZE
/ L1_CACHE_BYTES
) % arena
->nfree
;
1094 spin_lock(&arena
->map_locks
[idx
].lock
);
1097 static void unlock_map(struct arena_info
*arena
, u32 premap
)
1098 __releases(&arena
->map_locks
[idx
].lock
)
1100 u32 idx
= (premap
* MAP_ENT_SIZE
/ L1_CACHE_BYTES
) % arena
->nfree
;
1102 spin_unlock(&arena
->map_locks
[idx
].lock
);
1105 static int btt_data_read(struct arena_info
*arena
, struct page
*page
,
1106 unsigned int off
, u32 lba
, u32 len
)
1109 u64 nsoff
= to_namespace_offset(arena
, lba
);
1110 void *mem
= kmap_atomic(page
);
1112 ret
= arena_read_bytes(arena
, nsoff
, mem
+ off
, len
, NVDIMM_IO_ATOMIC
);
1118 static int btt_data_write(struct arena_info
*arena
, u32 lba
,
1119 struct page
*page
, unsigned int off
, u32 len
)
1122 u64 nsoff
= to_namespace_offset(arena
, lba
);
1123 void *mem
= kmap_atomic(page
);
1125 ret
= arena_write_bytes(arena
, nsoff
, mem
+ off
, len
, NVDIMM_IO_ATOMIC
);
1131 static void zero_fill_data(struct page
*page
, unsigned int off
, u32 len
)
1133 void *mem
= kmap_atomic(page
);
1135 memset(mem
+ off
, 0, len
);
1139 #ifdef CONFIG_BLK_DEV_INTEGRITY
1140 static int btt_rw_integrity(struct btt
*btt
, struct bio_integrity_payload
*bip
,
1141 struct arena_info
*arena
, u32 postmap
, int rw
)
1143 unsigned int len
= btt_meta_size(btt
);
1150 meta_nsoff
= to_namespace_offset(arena
, postmap
) + btt
->sector_size
;
1153 unsigned int cur_len
;
1157 bv
= bvec_iter_bvec(bip
->bip_vec
, bip
->bip_iter
);
1159 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
1160 * .bv_offset already adjusted for iter->bi_bvec_done, and we
1161 * can use those directly
1164 cur_len
= min(len
, bv
.bv_len
);
1165 mem
= kmap_atomic(bv
.bv_page
);
1167 ret
= arena_write_bytes(arena
, meta_nsoff
,
1168 mem
+ bv
.bv_offset
, cur_len
,
1171 ret
= arena_read_bytes(arena
, meta_nsoff
,
1172 mem
+ bv
.bv_offset
, cur_len
,
1180 meta_nsoff
+= cur_len
;
1181 if (!bvec_iter_advance(bip
->bip_vec
, &bip
->bip_iter
, cur_len
))
1188 #else /* CONFIG_BLK_DEV_INTEGRITY */
1189 static int btt_rw_integrity(struct btt
*btt
, struct bio_integrity_payload
*bip
,
1190 struct arena_info
*arena
, u32 postmap
, int rw
)
1196 static int btt_read_pg(struct btt
*btt
, struct bio_integrity_payload
*bip
,
1197 struct page
*page
, unsigned int off
, sector_t sector
,
1202 struct arena_info
*arena
= NULL
;
1203 u32 lane
= 0, premap
, postmap
;
1208 lane
= nd_region_acquire_lane(btt
->nd_region
);
1210 ret
= lba_to_arena(btt
, sector
, &premap
, &arena
);
1214 cur_len
= min(btt
->sector_size
, len
);
1216 ret
= btt_map_read(arena
, premap
, &postmap
, &t_flag
, &e_flag
,
1222 * We loop to make sure that the post map LBA didn't change
1223 * from under us between writing the RTT and doing the actual
1231 zero_fill_data(page
, off
, cur_len
);
1240 arena
->rtt
[lane
] = RTT_VALID
| postmap
;
1242 * Barrier to make sure this write is not reordered
1243 * to do the verification map_read before the RTT store
1247 ret
= btt_map_read(arena
, premap
, &new_map
, &new_t
,
1248 &new_e
, NVDIMM_IO_ATOMIC
);
1252 if ((postmap
== new_map
) && (t_flag
== new_t
) &&
1261 ret
= btt_data_read(arena
, page
, off
, postmap
, cur_len
);
1265 /* Media error - set the e_flag */
1266 rc
= btt_map_write(arena
, premap
, postmap
, 0, 1,
1272 ret
= btt_rw_integrity(btt
, bip
, arena
, postmap
, READ
);
1277 arena
->rtt
[lane
] = RTT_INVALID
;
1278 nd_region_release_lane(btt
->nd_region
, lane
);
1282 sector
+= btt
->sector_size
>> SECTOR_SHIFT
;
1288 arena
->rtt
[lane
] = RTT_INVALID
;
1290 nd_region_release_lane(btt
->nd_region
, lane
);
1295 * Normally, arena_{read,write}_bytes will take care of the initial offset
1296 * adjustment, but in the case of btt_is_badblock, where we query is_bad_pmem,
1297 * we need the final, raw namespace offset here
1299 static bool btt_is_badblock(struct btt
*btt
, struct arena_info
*arena
,
1302 u64 nsoff
= adjust_initial_offset(arena
->nd_btt
,
1303 to_namespace_offset(arena
, postmap
));
1304 sector_t phys_sector
= nsoff
>> 9;
1306 return is_bad_pmem(btt
->phys_bb
, phys_sector
, arena
->internal_lbasize
);
1309 static int btt_write_pg(struct btt
*btt
, struct bio_integrity_payload
*bip
,
1310 sector_t sector
, struct page
*page
, unsigned int off
,
1314 struct arena_info
*arena
= NULL
;
1315 u32 premap
= 0, old_postmap
, new_postmap
, lane
= 0, i
;
1316 struct log_entry log
;
1324 lane
= nd_region_acquire_lane(btt
->nd_region
);
1326 ret
= lba_to_arena(btt
, sector
, &premap
, &arena
);
1329 cur_len
= min(btt
->sector_size
, len
);
1331 if ((arena
->flags
& IB_FLAG_ERROR_MASK
) != 0) {
1336 if (btt_is_badblock(btt
, arena
, arena
->freelist
[lane
].block
))
1337 arena
->freelist
[lane
].has_err
= 1;
1339 if (mutex_is_locked(&arena
->err_lock
)
1340 || arena
->freelist
[lane
].has_err
) {
1341 nd_region_release_lane(btt
->nd_region
, lane
);
1343 ret
= arena_clear_freelist_error(arena
, lane
);
1347 /* OK to acquire a different lane/free block */
1351 new_postmap
= arena
->freelist
[lane
].block
;
1353 /* Wait if the new block is being read from */
1354 for (i
= 0; i
< arena
->nfree
; i
++)
1355 while (arena
->rtt
[i
] == (RTT_VALID
| new_postmap
))
1359 if (new_postmap
>= arena
->internal_nlba
) {
1364 ret
= btt_data_write(arena
, new_postmap
, page
, off
, cur_len
);
1369 ret
= btt_rw_integrity(btt
, bip
, arena
, new_postmap
,
1375 lock_map(arena
, premap
);
1376 ret
= btt_map_read(arena
, premap
, &old_postmap
, NULL
, &e_flag
,
1380 if (old_postmap
>= arena
->internal_nlba
) {
1385 set_e_flag(old_postmap
);
1387 log
.lba
= cpu_to_le32(premap
);
1388 log
.old_map
= cpu_to_le32(old_postmap
);
1389 log
.new_map
= cpu_to_le32(new_postmap
);
1390 log
.seq
= cpu_to_le32(arena
->freelist
[lane
].seq
);
1391 sub
= arena
->freelist
[lane
].sub
;
1392 ret
= btt_flog_write(arena
, lane
, sub
, &log
);
1396 ret
= btt_map_write(arena
, premap
, new_postmap
, 0, 0,
1401 unlock_map(arena
, premap
);
1402 nd_region_release_lane(btt
->nd_region
, lane
);
1405 ret
= arena_clear_freelist_error(arena
, lane
);
1412 sector
+= btt
->sector_size
>> SECTOR_SHIFT
;
1418 unlock_map(arena
, premap
);
1420 nd_region_release_lane(btt
->nd_region
, lane
);
1424 static int btt_do_bvec(struct btt
*btt
, struct bio_integrity_payload
*bip
,
1425 struct page
*page
, unsigned int len
, unsigned int off
,
1426 bool is_write
, sector_t sector
)
1431 ret
= btt_read_pg(btt
, bip
, page
, off
, sector
, len
);
1432 flush_dcache_page(page
);
1434 flush_dcache_page(page
);
1435 ret
= btt_write_pg(btt
, bip
, sector
, page
, off
, len
);
1441 static blk_qc_t
btt_make_request(struct request_queue
*q
, struct bio
*bio
)
1443 struct bio_integrity_payload
*bip
= bio_integrity(bio
);
1444 struct btt
*btt
= q
->queuedata
;
1445 struct bvec_iter iter
;
1446 unsigned long start
;
1447 struct bio_vec bvec
;
1451 if (!bio_integrity_prep(bio
))
1452 return BLK_QC_T_NONE
;
1454 do_acct
= nd_iostat_start(bio
, &start
);
1455 bio_for_each_segment(bvec
, bio
, iter
) {
1456 unsigned int len
= bvec
.bv_len
;
1458 if (len
> PAGE_SIZE
|| len
< btt
->sector_size
||
1459 len
% btt
->sector_size
) {
1460 dev_err_ratelimited(&btt
->nd_btt
->dev
,
1461 "unaligned bio segment (len: %d)\n", len
);
1462 bio
->bi_status
= BLK_STS_IOERR
;
1466 err
= btt_do_bvec(btt
, bip
, bvec
.bv_page
, len
, bvec
.bv_offset
,
1467 op_is_write(bio_op(bio
)), iter
.bi_sector
);
1469 dev_err(&btt
->nd_btt
->dev
,
1470 "io error in %s sector %lld, len %d,\n",
1471 (op_is_write(bio_op(bio
))) ? "WRITE" :
1473 (unsigned long long) iter
.bi_sector
, len
);
1474 bio
->bi_status
= errno_to_blk_status(err
);
1479 nd_iostat_end(bio
, start
);
1482 return BLK_QC_T_NONE
;
1485 static int btt_rw_page(struct block_device
*bdev
, sector_t sector
,
1486 struct page
*page
, bool is_write
)
1488 struct btt
*btt
= bdev
->bd_disk
->private_data
;
1492 len
= hpage_nr_pages(page
) * PAGE_SIZE
;
1493 rc
= btt_do_bvec(btt
, NULL
, page
, len
, 0, is_write
, sector
);
1495 page_endio(page
, is_write
, 0);
1501 static int btt_getgeo(struct block_device
*bd
, struct hd_geometry
*geo
)
1503 /* some standard values */
1504 geo
->heads
= 1 << 6;
1505 geo
->sectors
= 1 << 5;
1506 geo
->cylinders
= get_capacity(bd
->bd_disk
) >> 11;
1510 static const struct block_device_operations btt_fops
= {
1511 .owner
= THIS_MODULE
,
1512 .rw_page
= btt_rw_page
,
1513 .getgeo
= btt_getgeo
,
1514 .revalidate_disk
= nvdimm_revalidate_disk
,
1517 static int btt_blk_init(struct btt
*btt
)
1519 struct nd_btt
*nd_btt
= btt
->nd_btt
;
1520 struct nd_namespace_common
*ndns
= nd_btt
->ndns
;
1522 /* create a new disk and request queue for btt */
1523 btt
->btt_queue
= blk_alloc_queue(GFP_KERNEL
);
1524 if (!btt
->btt_queue
)
1527 btt
->btt_disk
= alloc_disk(0);
1528 if (!btt
->btt_disk
) {
1529 blk_cleanup_queue(btt
->btt_queue
);
1533 nvdimm_namespace_disk_name(ndns
, btt
->btt_disk
->disk_name
);
1534 btt
->btt_disk
->first_minor
= 0;
1535 btt
->btt_disk
->fops
= &btt_fops
;
1536 btt
->btt_disk
->private_data
= btt
;
1537 btt
->btt_disk
->queue
= btt
->btt_queue
;
1538 btt
->btt_disk
->flags
= GENHD_FL_EXT_DEVT
;
1539 btt
->btt_disk
->queue
->backing_dev_info
->capabilities
|=
1540 BDI_CAP_SYNCHRONOUS_IO
;
1542 blk_queue_make_request(btt
->btt_queue
, btt_make_request
);
1543 blk_queue_logical_block_size(btt
->btt_queue
, btt
->sector_size
);
1544 blk_queue_max_hw_sectors(btt
->btt_queue
, UINT_MAX
);
1545 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, btt
->btt_queue
);
1546 btt
->btt_queue
->queuedata
= btt
;
1548 set_capacity(btt
->btt_disk
, 0);
1549 device_add_disk(&btt
->nd_btt
->dev
, btt
->btt_disk
);
1550 if (btt_meta_size(btt
)) {
1551 int rc
= nd_integrity_init(btt
->btt_disk
, btt_meta_size(btt
));
1554 del_gendisk(btt
->btt_disk
);
1555 put_disk(btt
->btt_disk
);
1556 blk_cleanup_queue(btt
->btt_queue
);
1560 set_capacity(btt
->btt_disk
, btt
->nlba
* btt
->sector_size
>> 9);
1561 btt
->nd_btt
->size
= btt
->nlba
* (u64
)btt
->sector_size
;
1562 revalidate_disk(btt
->btt_disk
);
1567 static void btt_blk_cleanup(struct btt
*btt
)
1569 del_gendisk(btt
->btt_disk
);
1570 put_disk(btt
->btt_disk
);
1571 blk_cleanup_queue(btt
->btt_queue
);
1575 * btt_init - initialize a block translation table for the given device
1576 * @nd_btt: device with BTT geometry and backing device info
1577 * @rawsize: raw size in bytes of the backing device
1578 * @lbasize: lba size of the backing device
1579 * @uuid: A uuid for the backing device - this is stored on media
1580 * @maxlane: maximum number of parallel requests the device can handle
1582 * Initialize a Block Translation Table on a backing device to provide
1583 * single sector power fail atomicity.
1589 * Pointer to a new struct btt on success, NULL on failure.
1591 static struct btt
*btt_init(struct nd_btt
*nd_btt
, unsigned long long rawsize
,
1592 u32 lbasize
, u8
*uuid
, struct nd_region
*nd_region
)
1596 struct nd_namespace_io
*nsio
;
1597 struct device
*dev
= &nd_btt
->dev
;
1599 btt
= devm_kzalloc(dev
, sizeof(struct btt
), GFP_KERNEL
);
1603 btt
->nd_btt
= nd_btt
;
1604 btt
->rawsize
= rawsize
;
1605 btt
->lbasize
= lbasize
;
1606 btt
->sector_size
= ((lbasize
>= 4096) ? 4096 : 512);
1607 INIT_LIST_HEAD(&btt
->arena_list
);
1608 mutex_init(&btt
->init_lock
);
1609 btt
->nd_region
= nd_region
;
1610 nsio
= to_nd_namespace_io(&nd_btt
->ndns
->dev
);
1611 btt
->phys_bb
= &nsio
->bb
;
1613 ret
= discover_arenas(btt
);
1615 dev_err(dev
, "init: error in arena_discover: %d\n", ret
);
1619 if (btt
->init_state
!= INIT_READY
&& nd_region
->ro
) {
1620 dev_warn(dev
, "%s is read-only, unable to init btt metadata\n",
1621 dev_name(&nd_region
->dev
));
1623 } else if (btt
->init_state
!= INIT_READY
) {
1624 btt
->num_arenas
= (rawsize
/ ARENA_MAX_SIZE
) +
1625 ((rawsize
% ARENA_MAX_SIZE
) ? 1 : 0);
1626 dev_dbg(dev
, "init: %d arenas for %llu rawsize\n",
1627 btt
->num_arenas
, rawsize
);
1629 ret
= create_arenas(btt
);
1631 dev_info(dev
, "init: create_arenas: %d\n", ret
);
1635 ret
= btt_meta_init(btt
);
1637 dev_err(dev
, "init: error in meta_init: %d\n", ret
);
1642 ret
= btt_blk_init(btt
);
1644 dev_err(dev
, "init: error in blk_init: %d\n", ret
);
1648 btt_debugfs_init(btt
);
1654 * btt_fini - de-initialize a BTT
1655 * @btt: the BTT handle that was generated by btt_init
1657 * De-initialize a Block Translation Table on device removal
1662 static void btt_fini(struct btt
*btt
)
1665 btt_blk_cleanup(btt
);
1667 debugfs_remove_recursive(btt
->debugfs_dir
);
1671 int nvdimm_namespace_attach_btt(struct nd_namespace_common
*ndns
)
1673 struct nd_btt
*nd_btt
= to_nd_btt(ndns
->claim
);
1674 struct nd_region
*nd_region
;
1675 struct btt_sb
*btt_sb
;
1679 if (!nd_btt
->uuid
|| !nd_btt
->ndns
|| !nd_btt
->lbasize
) {
1680 dev_dbg(&nd_btt
->dev
, "incomplete btt configuration\n");
1684 btt_sb
= devm_kzalloc(&nd_btt
->dev
, sizeof(*btt_sb
), GFP_KERNEL
);
1689 * If this returns < 0, that is ok as it just means there wasn't
1690 * an existing BTT, and we're creating a new one. We still need to
1691 * call this as we need the version dependent fields in nd_btt to be
1692 * set correctly based on the holder class
1694 nd_btt_version(nd_btt
, ndns
, btt_sb
);
1696 rawsize
= nvdimm_namespace_capacity(ndns
) - nd_btt
->initial_offset
;
1697 if (rawsize
< ARENA_MIN_SIZE
) {
1698 dev_dbg(&nd_btt
->dev
, "%s must be at least %ld bytes\n",
1699 dev_name(&ndns
->dev
),
1700 ARENA_MIN_SIZE
+ nd_btt
->initial_offset
);
1703 nd_region
= to_nd_region(nd_btt
->dev
.parent
);
1704 btt
= btt_init(nd_btt
, rawsize
, nd_btt
->lbasize
, nd_btt
->uuid
,
1712 EXPORT_SYMBOL(nvdimm_namespace_attach_btt
);
1714 int nvdimm_namespace_detach_btt(struct nd_btt
*nd_btt
)
1716 struct btt
*btt
= nd_btt
->btt
;
1723 EXPORT_SYMBOL(nvdimm_namespace_detach_btt
);
1725 static int __init
nd_btt_init(void)
1729 debugfs_root
= debugfs_create_dir("btt", NULL
);
1730 if (IS_ERR_OR_NULL(debugfs_root
))
1736 static void __exit
nd_btt_exit(void)
1738 debugfs_remove_recursive(debugfs_root
);
1741 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT
);
1742 MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
1743 MODULE_LICENSE("GPL v2");
1744 module_init(nd_btt_init
);
1745 module_exit(nd_btt_exit
);