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>
29 enum log_ent_request {
34 static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
35 void *buf, size_t n, unsigned long flags)
37 struct nd_btt *nd_btt = arena->nd_btt;
38 struct nd_namespace_common *ndns = nd_btt->ndns;
40 /* arena offsets may be shifted from the base of the device */
41 offset += arena->nd_btt->initial_offset;
42 return nvdimm_read_bytes(ndns, offset, buf, n, flags);
45 static int arena_write_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 += arena->nd_btt->initial_offset;
53 return nvdimm_write_bytes(ndns, offset, buf, n, flags);
56 static int btt_info_write(struct arena_info *arena, struct btt_sb *super)
61 * infooff and info2off should always be at least 512B aligned.
62 * We rely on that to make sure rw_bytes does error clearing
63 * correctly, so make sure that is the case.
65 WARN_ON_ONCE(!IS_ALIGNED(arena->infooff, 512));
66 WARN_ON_ONCE(!IS_ALIGNED(arena->info2off, 512));
68 ret = arena_write_bytes(arena, arena->info2off, super,
69 sizeof(struct btt_sb), 0);
73 return arena_write_bytes(arena, arena->infooff, super,
74 sizeof(struct btt_sb), 0);
77 static int btt_info_read(struct arena_info *arena, struct btt_sb *super)
80 return arena_read_bytes(arena, arena->infooff, super,
81 sizeof(struct btt_sb), 0);
85 * 'raw' version of btt_map write
87 * mapping is in little-endian
88 * mapping contains 'E' and 'Z' flags as desired
90 static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping,
93 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
95 WARN_ON(lba >= arena->external_nlba);
96 return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE, flags);
99 static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping,
100 u32 z_flag, u32 e_flag, unsigned long rwb_flags)
106 * This 'mapping' is supposed to be just the LBA mapping, without
107 * any flags set, so strip the flag bits.
109 mapping &= MAP_LBA_MASK;
111 ze = (z_flag << 1) + e_flag;
115 * We want to set neither of the Z or E flags, and
116 * in the actual layout, this means setting the bit
117 * positions of both to '1' to indicate a 'normal'
120 mapping |= MAP_ENT_NORMAL;
123 mapping |= (1 << MAP_ERR_SHIFT);
126 mapping |= (1 << MAP_TRIM_SHIFT);
130 * The case where Z and E are both sent in as '1' could be
131 * construed as a valid 'normal' case, but we decide not to,
134 WARN_ONCE(1, "Invalid use of Z and E flags\n");
138 mapping_le = cpu_to_le32(mapping);
139 return __btt_map_write(arena, lba, mapping_le, rwb_flags);
142 static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping,
143 int *trim, int *error, unsigned long rwb_flags)
147 u32 raw_mapping, postmap, ze, z_flag, e_flag;
148 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
150 WARN_ON(lba >= arena->external_nlba);
152 ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE, rwb_flags);
156 raw_mapping = le32_to_cpu(in);
158 z_flag = (raw_mapping & MAP_TRIM_MASK) >> MAP_TRIM_SHIFT;
159 e_flag = (raw_mapping & MAP_ERR_MASK) >> MAP_ERR_SHIFT;
160 ze = (z_flag << 1) + e_flag;
161 postmap = raw_mapping & MAP_LBA_MASK;
163 /* Reuse the {z,e}_flag variables for *trim and *error */
169 /* Initial state. Return postmap = premap */
195 static int btt_log_read_pair(struct arena_info *arena, u32 lane,
196 struct log_entry *ent)
199 return arena_read_bytes(arena,
200 arena->logoff + (2 * lane * LOG_ENT_SIZE), ent,
201 2 * LOG_ENT_SIZE, 0);
204 static struct dentry *debugfs_root;
206 static void arena_debugfs_init(struct arena_info *a, struct dentry *parent,
212 /* If for some reason, parent bttN was not created, exit */
216 snprintf(dirname, 32, "arena%d", idx);
217 d = debugfs_create_dir(dirname, parent);
218 if (IS_ERR_OR_NULL(d))
222 debugfs_create_x64("size", S_IRUGO, d, &a->size);
223 debugfs_create_x64("external_lba_start", S_IRUGO, d,
224 &a->external_lba_start);
225 debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba);
226 debugfs_create_u32("internal_lbasize", S_IRUGO, d,
227 &a->internal_lbasize);
228 debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba);
229 debugfs_create_u32("external_lbasize", S_IRUGO, d,
230 &a->external_lbasize);
231 debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree);
232 debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major);
233 debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor);
234 debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff);
235 debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff);
236 debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff);
237 debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff);
238 debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff);
239 debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off);
240 debugfs_create_x32("flags", S_IRUGO, d, &a->flags);
243 static void btt_debugfs_init(struct btt *btt)
246 struct arena_info *arena;
248 btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev),
250 if (IS_ERR_OR_NULL(btt->debugfs_dir))
253 list_for_each_entry(arena, &btt->arena_list, list) {
254 arena_debugfs_init(arena, btt->debugfs_dir, i);
260 * This function accepts two log entries, and uses the
261 * sequence number to find the 'older' entry.
262 * It also updates the sequence number in this old entry to
263 * make it the 'new' one if the mark_flag is set.
264 * Finally, it returns which of the entries was the older one.
266 * TODO The logic feels a bit kludge-y. make it better..
268 static int btt_log_get_old(struct log_entry *ent)
273 * the first ever time this is seen, the entry goes into [0]
274 * the next time, the following logic works out to put this
275 * (next) entry into [1]
277 if (ent[0].seq == 0) {
278 ent[0].seq = cpu_to_le32(1);
282 if (ent[0].seq == ent[1].seq)
284 if (le32_to_cpu(ent[0].seq) + le32_to_cpu(ent[1].seq) > 5)
287 if (le32_to_cpu(ent[0].seq) < le32_to_cpu(ent[1].seq)) {
288 if (le32_to_cpu(ent[1].seq) - le32_to_cpu(ent[0].seq) == 1)
293 if (le32_to_cpu(ent[0].seq) - le32_to_cpu(ent[1].seq) == 1)
302 static struct device *to_dev(struct arena_info *arena)
304 return &arena->nd_btt->dev;
308 * This function copies the desired (old/new) log entry into ent if
309 * it is not NULL. It returns the sub-slot number (0 or 1)
310 * where the desired log entry was found. Negative return values
313 static int btt_log_read(struct arena_info *arena, u32 lane,
314 struct log_entry *ent, int old_flag)
317 int old_ent, ret_ent;
318 struct log_entry log[2];
320 ret = btt_log_read_pair(arena, lane, log);
324 old_ent = btt_log_get_old(log);
325 if (old_ent < 0 || old_ent > 1) {
326 dev_err(to_dev(arena),
327 "log corruption (%d): lane %d seq [%d, %d]\n",
328 old_ent, lane, log[0].seq, log[1].seq);
329 /* TODO set error state? */
333 ret_ent = (old_flag ? old_ent : (1 - old_ent));
336 memcpy(ent, &log[ret_ent], LOG_ENT_SIZE);
342 * This function commits a log entry to media
343 * It does _not_ prepare the freelist entry for the next write
344 * btt_flog_write is the wrapper for updating the freelist elements
346 static int __btt_log_write(struct arena_info *arena, u32 lane,
347 u32 sub, struct log_entry *ent, unsigned long flags)
351 * Ignore the padding in log_entry for calculating log_half.
352 * The entry is 'committed' when we write the sequence number,
353 * and we want to ensure that that is the last thing written.
354 * We don't bother writing the padding as that would be extra
355 * media wear and write amplification
357 unsigned int log_half = (LOG_ENT_SIZE - 2 * sizeof(u64)) / 2;
358 u64 ns_off = arena->logoff + (((2 * lane) + sub) * LOG_ENT_SIZE);
361 /* split the 16B write into atomic, durable halves */
362 ret = arena_write_bytes(arena, ns_off, src, log_half, flags);
368 return arena_write_bytes(arena, ns_off, src, log_half, flags);
371 static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
372 struct log_entry *ent)
376 ret = __btt_log_write(arena, lane, sub, ent, NVDIMM_IO_ATOMIC);
380 /* prepare the next free entry */
381 arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
382 if (++(arena->freelist[lane].seq) == 4)
383 arena->freelist[lane].seq = 1;
384 arena->freelist[lane].block = le32_to_cpu(ent->old_map);
390 * This function initializes the BTT map to the initial state, which is
391 * all-zeroes, and indicates an identity mapping
393 static int btt_map_init(struct arena_info *arena)
398 size_t chunk_size = SZ_2M;
399 size_t mapsize = arena->logoff - arena->mapoff;
401 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
406 * mapoff should always be at least 512B aligned. We rely on that to
407 * make sure rw_bytes does error clearing correctly, so make sure that
410 WARN_ON_ONCE(!IS_ALIGNED(arena->mapoff, 512));
413 size_t size = min(mapsize, chunk_size);
415 WARN_ON_ONCE(size < 512);
416 ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,
432 * This function initializes the BTT log with 'fake' entries pointing
433 * to the initial reserved set of blocks as being free
435 static int btt_log_init(struct arena_info *arena)
437 size_t logsize = arena->info2off - arena->logoff;
438 size_t chunk_size = SZ_4K, offset = 0;
439 struct log_entry log;
444 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
448 * logoff should always be at least 512B aligned. We rely on that to
449 * make sure rw_bytes does error clearing correctly, so make sure that
452 WARN_ON_ONCE(!IS_ALIGNED(arena->logoff, 512));
455 size_t size = min(logsize, chunk_size);
457 WARN_ON_ONCE(size < 512);
458 ret = arena_write_bytes(arena, arena->logoff + offset, zerobuf,
468 for (i = 0; i < arena->nfree; i++) {
469 log.lba = cpu_to_le32(i);
470 log.old_map = cpu_to_le32(arena->external_nlba + i);
471 log.new_map = cpu_to_le32(arena->external_nlba + i);
472 log.seq = cpu_to_le32(LOG_SEQ_INIT);
473 ret = __btt_log_write(arena, i, 0, &log, 0);
483 static int btt_freelist_init(struct arena_info *arena)
487 struct log_entry log_new, log_old;
489 arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
491 if (!arena->freelist)
494 for (i = 0; i < arena->nfree; i++) {
495 old = btt_log_read(arena, i, &log_old, LOG_OLD_ENT);
499 new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
503 /* sub points to the next one to be overwritten */
504 arena->freelist[i].sub = 1 - new;
505 arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
506 arena->freelist[i].block = le32_to_cpu(log_new.old_map);
508 /* This implies a newly created or untouched flog entry */
509 if (log_new.old_map == log_new.new_map)
512 /* Check if map recovery is needed */
513 ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
517 if ((le32_to_cpu(log_new.new_map) != map_entry) &&
518 (le32_to_cpu(log_new.old_map) == map_entry)) {
520 * Last transaction wrote the flog, but wasn't able
521 * to complete the map write. So fix up the map.
523 ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
524 le32_to_cpu(log_new.new_map), 0, 0, 0);
534 static int btt_rtt_init(struct arena_info *arena)
536 arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL);
537 if (arena->rtt == NULL)
543 static int btt_maplocks_init(struct arena_info *arena)
547 arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
549 if (!arena->map_locks)
552 for (i = 0; i < arena->nfree; i++)
553 spin_lock_init(&arena->map_locks[i].lock);
558 static struct arena_info *alloc_arena(struct btt *btt, size_t size,
559 size_t start, size_t arena_off)
561 struct arena_info *arena;
562 u64 logsize, mapsize, datasize;
563 u64 available = size;
565 arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL);
568 arena->nd_btt = btt->nd_btt;
574 arena->external_lba_start = start;
575 arena->external_lbasize = btt->lbasize;
576 arena->internal_lbasize = roundup(arena->external_lbasize,
577 INT_LBASIZE_ALIGNMENT);
578 arena->nfree = BTT_DEFAULT_NFREE;
579 arena->version_major = btt->nd_btt->version_major;
580 arena->version_minor = btt->nd_btt->version_minor;
582 if (available % BTT_PG_SIZE)
583 available -= (available % BTT_PG_SIZE);
585 /* Two pages are reserved for the super block and its copy */
586 available -= 2 * BTT_PG_SIZE;
588 /* The log takes a fixed amount of space based on nfree */
589 logsize = roundup(2 * arena->nfree * sizeof(struct log_entry),
591 available -= logsize;
593 /* Calculate optimal split between map and data area */
594 arena->internal_nlba = div_u64(available - BTT_PG_SIZE,
595 arena->internal_lbasize + MAP_ENT_SIZE);
596 arena->external_nlba = arena->internal_nlba - arena->nfree;
598 mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE);
599 datasize = available - mapsize;
601 /* 'Absolute' values, relative to start of storage space */
602 arena->infooff = arena_off;
603 arena->dataoff = arena->infooff + BTT_PG_SIZE;
604 arena->mapoff = arena->dataoff + datasize;
605 arena->logoff = arena->mapoff + mapsize;
606 arena->info2off = arena->logoff + logsize;
610 static void free_arenas(struct btt *btt)
612 struct arena_info *arena, *next;
614 list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
615 list_del(&arena->list);
617 kfree(arena->map_locks);
618 kfree(arena->freelist);
619 debugfs_remove_recursive(arena->debugfs_dir);
625 * This function reads an existing valid btt superblock and
626 * populates the corresponding arena_info struct
628 static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
631 arena->internal_nlba = le32_to_cpu(super->internal_nlba);
632 arena->internal_lbasize = le32_to_cpu(super->internal_lbasize);
633 arena->external_nlba = le32_to_cpu(super->external_nlba);
634 arena->external_lbasize = le32_to_cpu(super->external_lbasize);
635 arena->nfree = le32_to_cpu(super->nfree);
636 arena->version_major = le16_to_cpu(super->version_major);
637 arena->version_minor = le16_to_cpu(super->version_minor);
639 arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off +
640 le64_to_cpu(super->nextoff));
641 arena->infooff = arena_off;
642 arena->dataoff = arena_off + le64_to_cpu(super->dataoff);
643 arena->mapoff = arena_off + le64_to_cpu(super->mapoff);
644 arena->logoff = arena_off + le64_to_cpu(super->logoff);
645 arena->info2off = arena_off + le64_to_cpu(super->info2off);
647 arena->size = (le64_to_cpu(super->nextoff) > 0)
648 ? (le64_to_cpu(super->nextoff))
649 : (arena->info2off - arena->infooff + BTT_PG_SIZE);
651 arena->flags = le32_to_cpu(super->flags);
654 static int discover_arenas(struct btt *btt)
657 struct arena_info *arena;
658 struct btt_sb *super;
659 size_t remaining = btt->rawsize;
664 super = kzalloc(sizeof(*super), GFP_KERNEL);
669 /* Alloc memory for arena */
670 arena = alloc_arena(btt, 0, 0, 0);
676 arena->infooff = cur_off;
677 ret = btt_info_read(arena, super);
681 if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
682 if (remaining == btt->rawsize) {
683 btt->init_state = INIT_NOTFOUND;
684 dev_info(to_dev(arena), "No existing arenas\n");
687 dev_err(to_dev(arena),
688 "Found corrupted metadata!\n");
694 arena->external_lba_start = cur_nlba;
695 parse_arena_meta(arena, super, cur_off);
697 ret = btt_freelist_init(arena);
701 ret = btt_rtt_init(arena);
705 ret = btt_maplocks_init(arena);
709 list_add_tail(&arena->list, &btt->arena_list);
711 remaining -= arena->size;
712 cur_off += arena->size;
713 cur_nlba += arena->external_nlba;
716 if (arena->nextoff == 0)
719 btt->num_arenas = num_arenas;
720 btt->nlba = cur_nlba;
721 btt->init_state = INIT_READY;
734 static int create_arenas(struct btt *btt)
736 size_t remaining = btt->rawsize;
740 struct arena_info *arena;
741 size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining);
743 remaining -= arena_size;
744 if (arena_size < ARENA_MIN_SIZE)
747 arena = alloc_arena(btt, arena_size, btt->nlba, cur_off);
752 btt->nlba += arena->external_nlba;
753 if (remaining >= ARENA_MIN_SIZE)
754 arena->nextoff = arena->size;
757 cur_off += arena_size;
758 list_add_tail(&arena->list, &btt->arena_list);
765 * This function completes arena initialization by writing
767 * It is only called for an uninitialized arena when a write
768 * to that arena occurs for the first time.
770 static int btt_arena_write_layout(struct arena_info *arena)
774 struct btt_sb *super;
775 struct nd_btt *nd_btt = arena->nd_btt;
776 const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
778 ret = btt_map_init(arena);
782 ret = btt_log_init(arena);
786 super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
790 strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
791 memcpy(super->uuid, nd_btt->uuid, 16);
792 memcpy(super->parent_uuid, parent_uuid, 16);
793 super->flags = cpu_to_le32(arena->flags);
794 super->version_major = cpu_to_le16(arena->version_major);
795 super->version_minor = cpu_to_le16(arena->version_minor);
796 super->external_lbasize = cpu_to_le32(arena->external_lbasize);
797 super->external_nlba = cpu_to_le32(arena->external_nlba);
798 super->internal_lbasize = cpu_to_le32(arena->internal_lbasize);
799 super->internal_nlba = cpu_to_le32(arena->internal_nlba);
800 super->nfree = cpu_to_le32(arena->nfree);
801 super->infosize = cpu_to_le32(sizeof(struct btt_sb));
802 super->nextoff = cpu_to_le64(arena->nextoff);
804 * Subtract arena->infooff (arena start) so numbers are relative
807 super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff);
808 super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff);
809 super->logoff = cpu_to_le64(arena->logoff - arena->infooff);
810 super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
813 sum = nd_sb_checksum((struct nd_gen_sb *) super);
814 super->checksum = cpu_to_le64(sum);
816 ret = btt_info_write(arena, super);
823 * This function completes the initialization for the BTT namespace
824 * such that it is ready to accept IOs
826 static int btt_meta_init(struct btt *btt)
829 struct arena_info *arena;
831 mutex_lock(&btt->init_lock);
832 list_for_each_entry(arena, &btt->arena_list, list) {
833 ret = btt_arena_write_layout(arena);
837 ret = btt_freelist_init(arena);
841 ret = btt_rtt_init(arena);
845 ret = btt_maplocks_init(arena);
850 btt->init_state = INIT_READY;
853 mutex_unlock(&btt->init_lock);
857 static u32 btt_meta_size(struct btt *btt)
859 return btt->lbasize - btt->sector_size;
863 * This function calculates the arena in which the given LBA lies
864 * by doing a linear walk. This is acceptable since we expect only
865 * a few arenas. If we have backing devices that get much larger,
866 * we can construct a balanced binary tree of arenas at init time
867 * so that this range search becomes faster.
869 static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap,
870 struct arena_info **arena)
872 struct arena_info *arena_list;
873 __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size);
875 list_for_each_entry(arena_list, &btt->arena_list, list) {
876 if (lba < arena_list->external_nlba) {
881 lba -= arena_list->external_nlba;
888 * The following (lock_map, unlock_map) are mostly just to improve
889 * readability, since they index into an array of locks
891 static void lock_map(struct arena_info *arena, u32 premap)
892 __acquires(&arena->map_locks[idx].lock)
894 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
896 spin_lock(&arena->map_locks[idx].lock);
899 static void unlock_map(struct arena_info *arena, u32 premap)
900 __releases(&arena->map_locks[idx].lock)
902 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
904 spin_unlock(&arena->map_locks[idx].lock);
907 static u64 to_namespace_offset(struct arena_info *arena, u64 lba)
909 return arena->dataoff + ((u64)lba * arena->internal_lbasize);
912 static int btt_data_read(struct arena_info *arena, struct page *page,
913 unsigned int off, u32 lba, u32 len)
916 u64 nsoff = to_namespace_offset(arena, lba);
917 void *mem = kmap_atomic(page);
919 ret = arena_read_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
925 static int btt_data_write(struct arena_info *arena, u32 lba,
926 struct page *page, unsigned int off, u32 len)
929 u64 nsoff = to_namespace_offset(arena, lba);
930 void *mem = kmap_atomic(page);
932 ret = arena_write_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
938 static void zero_fill_data(struct page *page, unsigned int off, u32 len)
940 void *mem = kmap_atomic(page);
942 memset(mem + off, 0, len);
946 #ifdef CONFIG_BLK_DEV_INTEGRITY
947 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
948 struct arena_info *arena, u32 postmap, int rw)
950 unsigned int len = btt_meta_size(btt);
957 meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
960 unsigned int cur_len;
964 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
966 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
967 * .bv_offset already adjusted for iter->bi_bvec_done, and we
968 * can use those directly
971 cur_len = min(len, bv.bv_len);
972 mem = kmap_atomic(bv.bv_page);
974 ret = arena_write_bytes(arena, meta_nsoff,
975 mem + bv.bv_offset, cur_len,
978 ret = arena_read_bytes(arena, meta_nsoff,
979 mem + bv.bv_offset, cur_len,
987 meta_nsoff += cur_len;
988 if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
995 #else /* CONFIG_BLK_DEV_INTEGRITY */
996 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
997 struct arena_info *arena, u32 postmap, int rw)
1003 static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
1004 struct page *page, unsigned int off, sector_t sector,
1009 struct arena_info *arena = NULL;
1010 u32 lane = 0, premap, postmap;
1015 lane = nd_region_acquire_lane(btt->nd_region);
1017 ret = lba_to_arena(btt, sector, &premap, &arena);
1021 cur_len = min(btt->sector_size, len);
1023 ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag,
1029 * We loop to make sure that the post map LBA didn't change
1030 * from under us between writing the RTT and doing the actual
1037 zero_fill_data(page, off, cur_len);
1046 arena->rtt[lane] = RTT_VALID | postmap;
1048 * Barrier to make sure this write is not reordered
1049 * to do the verification map_read before the RTT store
1053 ret = btt_map_read(arena, premap, &new_map, &t_flag,
1054 &e_flag, NVDIMM_IO_ATOMIC);
1058 if (postmap == new_map)
1064 ret = btt_data_read(arena, page, off, postmap, cur_len);
1069 ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
1074 arena->rtt[lane] = RTT_INVALID;
1075 nd_region_release_lane(btt->nd_region, lane);
1079 sector += btt->sector_size >> SECTOR_SHIFT;
1085 arena->rtt[lane] = RTT_INVALID;
1087 nd_region_release_lane(btt->nd_region, lane);
1091 static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
1092 sector_t sector, struct page *page, unsigned int off,
1096 struct arena_info *arena = NULL;
1097 u32 premap = 0, old_postmap, new_postmap, lane = 0, i;
1098 struct log_entry log;
1104 lane = nd_region_acquire_lane(btt->nd_region);
1106 ret = lba_to_arena(btt, sector, &premap, &arena);
1109 cur_len = min(btt->sector_size, len);
1111 if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) {
1116 new_postmap = arena->freelist[lane].block;
1118 /* Wait if the new block is being read from */
1119 for (i = 0; i < arena->nfree; i++)
1120 while (arena->rtt[i] == (RTT_VALID | new_postmap))
1124 if (new_postmap >= arena->internal_nlba) {
1129 ret = btt_data_write(arena, new_postmap, page, off, cur_len);
1134 ret = btt_rw_integrity(btt, bip, arena, new_postmap,
1140 lock_map(arena, premap);
1141 ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL,
1145 if (old_postmap >= arena->internal_nlba) {
1150 log.lba = cpu_to_le32(premap);
1151 log.old_map = cpu_to_le32(old_postmap);
1152 log.new_map = cpu_to_le32(new_postmap);
1153 log.seq = cpu_to_le32(arena->freelist[lane].seq);
1154 sub = arena->freelist[lane].sub;
1155 ret = btt_flog_write(arena, lane, sub, &log);
1159 ret = btt_map_write(arena, premap, new_postmap, 0, 0, 0);
1163 unlock_map(arena, premap);
1164 nd_region_release_lane(btt->nd_region, lane);
1168 sector += btt->sector_size >> SECTOR_SHIFT;
1174 unlock_map(arena, premap);
1176 nd_region_release_lane(btt->nd_region, lane);
1180 static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
1181 struct page *page, unsigned int len, unsigned int off,
1182 bool is_write, sector_t sector)
1187 ret = btt_read_pg(btt, bip, page, off, sector, len);
1188 flush_dcache_page(page);
1190 flush_dcache_page(page);
1191 ret = btt_write_pg(btt, bip, sector, page, off, len);
1197 static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
1199 struct bio_integrity_payload *bip = bio_integrity(bio);
1200 struct btt *btt = q->queuedata;
1201 struct bvec_iter iter;
1202 unsigned long start;
1203 struct bio_vec bvec;
1207 if (!bio_integrity_prep(bio))
1208 return BLK_QC_T_NONE;
1210 do_acct = nd_iostat_start(bio, &start);
1211 bio_for_each_segment(bvec, bio, iter) {
1212 unsigned int len = bvec.bv_len;
1214 BUG_ON(len > PAGE_SIZE);
1215 /* Make sure len is in multiples of sector size. */
1216 /* XXX is this right? */
1217 BUG_ON(len < btt->sector_size);
1218 BUG_ON(len % btt->sector_size);
1220 err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
1221 op_is_write(bio_op(bio)), iter.bi_sector);
1223 dev_err(&btt->nd_btt->dev,
1224 "io error in %s sector %lld, len %d,\n",
1225 (op_is_write(bio_op(bio))) ? "WRITE" :
1227 (unsigned long long) iter.bi_sector, len);
1228 bio->bi_status = errno_to_blk_status(err);
1233 nd_iostat_end(bio, start);
1236 return BLK_QC_T_NONE;
1239 static int btt_rw_page(struct block_device *bdev, sector_t sector,
1240 struct page *page, bool is_write)
1242 struct btt *btt = bdev->bd_disk->private_data;
1245 rc = btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector);
1247 page_endio(page, is_write, 0);
1253 static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo)
1255 /* some standard values */
1256 geo->heads = 1 << 6;
1257 geo->sectors = 1 << 5;
1258 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
1262 static const struct block_device_operations btt_fops = {
1263 .owner = THIS_MODULE,
1264 .rw_page = btt_rw_page,
1265 .getgeo = btt_getgeo,
1266 .revalidate_disk = nvdimm_revalidate_disk,
1269 static int btt_blk_init(struct btt *btt)
1271 struct nd_btt *nd_btt = btt->nd_btt;
1272 struct nd_namespace_common *ndns = nd_btt->ndns;
1274 /* create a new disk and request queue for btt */
1275 btt->btt_queue = blk_alloc_queue(GFP_KERNEL);
1276 if (!btt->btt_queue)
1279 btt->btt_disk = alloc_disk(0);
1280 if (!btt->btt_disk) {
1281 blk_cleanup_queue(btt->btt_queue);
1285 nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
1286 btt->btt_disk->first_minor = 0;
1287 btt->btt_disk->fops = &btt_fops;
1288 btt->btt_disk->private_data = btt;
1289 btt->btt_disk->queue = btt->btt_queue;
1290 btt->btt_disk->flags = GENHD_FL_EXT_DEVT;
1292 blk_queue_make_request(btt->btt_queue, btt_make_request);
1293 blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
1294 blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX);
1295 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, btt->btt_queue);
1296 btt->btt_queue->queuedata = btt;
1298 set_capacity(btt->btt_disk, 0);
1299 device_add_disk(&btt->nd_btt->dev, btt->btt_disk);
1300 if (btt_meta_size(btt)) {
1301 int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
1304 del_gendisk(btt->btt_disk);
1305 put_disk(btt->btt_disk);
1306 blk_cleanup_queue(btt->btt_queue);
1310 set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
1311 btt->nd_btt->size = btt->nlba * (u64)btt->sector_size;
1312 revalidate_disk(btt->btt_disk);
1317 static void btt_blk_cleanup(struct btt *btt)
1319 del_gendisk(btt->btt_disk);
1320 put_disk(btt->btt_disk);
1321 blk_cleanup_queue(btt->btt_queue);
1325 * btt_init - initialize a block translation table for the given device
1326 * @nd_btt: device with BTT geometry and backing device info
1327 * @rawsize: raw size in bytes of the backing device
1328 * @lbasize: lba size of the backing device
1329 * @uuid: A uuid for the backing device - this is stored on media
1330 * @maxlane: maximum number of parallel requests the device can handle
1332 * Initialize a Block Translation Table on a backing device to provide
1333 * single sector power fail atomicity.
1339 * Pointer to a new struct btt on success, NULL on failure.
1341 static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
1342 u32 lbasize, u8 *uuid, struct nd_region *nd_region)
1346 struct device *dev = &nd_btt->dev;
1348 btt = devm_kzalloc(dev, sizeof(struct btt), GFP_KERNEL);
1352 btt->nd_btt = nd_btt;
1353 btt->rawsize = rawsize;
1354 btt->lbasize = lbasize;
1355 btt->sector_size = ((lbasize >= 4096) ? 4096 : 512);
1356 INIT_LIST_HEAD(&btt->arena_list);
1357 mutex_init(&btt->init_lock);
1358 btt->nd_region = nd_region;
1360 ret = discover_arenas(btt);
1362 dev_err(dev, "init: error in arena_discover: %d\n", ret);
1366 if (btt->init_state != INIT_READY && nd_region->ro) {
1367 dev_warn(dev, "%s is read-only, unable to init btt metadata\n",
1368 dev_name(&nd_region->dev));
1370 } else if (btt->init_state != INIT_READY) {
1371 btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
1372 ((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
1373 dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
1374 btt->num_arenas, rawsize);
1376 ret = create_arenas(btt);
1378 dev_info(dev, "init: create_arenas: %d\n", ret);
1382 ret = btt_meta_init(btt);
1384 dev_err(dev, "init: error in meta_init: %d\n", ret);
1389 ret = btt_blk_init(btt);
1391 dev_err(dev, "init: error in blk_init: %d\n", ret);
1395 btt_debugfs_init(btt);
1401 * btt_fini - de-initialize a BTT
1402 * @btt: the BTT handle that was generated by btt_init
1404 * De-initialize a Block Translation Table on device removal
1409 static void btt_fini(struct btt *btt)
1412 btt_blk_cleanup(btt);
1414 debugfs_remove_recursive(btt->debugfs_dir);
1418 int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
1420 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1421 struct nd_region *nd_region;
1422 struct btt_sb *btt_sb;
1426 if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) {
1427 dev_dbg(&nd_btt->dev, "incomplete btt configuration\n");
1431 btt_sb = devm_kzalloc(&nd_btt->dev, sizeof(*btt_sb), GFP_KERNEL);
1434 * If this returns < 0, that is ok as it just means there wasn't
1435 * an existing BTT, and we're creating a new one. We still need to
1436 * call this as we need the version dependent fields in nd_btt to be
1437 * set correctly based on the holder class
1439 nd_btt_version(nd_btt, ndns, btt_sb);
1441 rawsize = nvdimm_namespace_capacity(ndns) - nd_btt->initial_offset;
1442 if (rawsize < ARENA_MIN_SIZE) {
1443 dev_dbg(&nd_btt->dev, "%s must be at least %ld bytes\n",
1444 dev_name(&ndns->dev),
1445 ARENA_MIN_SIZE + nd_btt->initial_offset);
1448 nd_region = to_nd_region(nd_btt->dev.parent);
1449 btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid,
1457 EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
1459 int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt)
1461 struct btt *btt = nd_btt->btt;
1468 EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
1470 static int __init nd_btt_init(void)
1474 debugfs_root = debugfs_create_dir("btt", NULL);
1475 if (IS_ERR_OR_NULL(debugfs_root))
1481 static void __exit nd_btt_exit(void)
1483 debugfs_remove_recursive(debugfs_root);
1486 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
1487 MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
1488 MODULE_LICENSE("GPL v2");
1489 module_init(nd_btt_init);
1490 module_exit(nd_btt_exit);