blob: 254239746020b5f0334b27fa7550a82ee3d9b97b [file] [log] [blame]
Vishal Verma5212e112015-06-25 04:20:32 -04001/*
2 * Block Translation Table
3 * Copyright (c) 2014-2015, Intel Corporation.
4 *
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.
8 *
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
12 * more details.
13 */
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>
24#include <linux/fs.h>
25#include <linux/nd.h>
26#include "btt.h"
27#include "nd.h"
28
29enum log_ent_request {
30 LOG_NEW_ENT = 0,
31 LOG_OLD_ENT
32};
33
34static int btt_major;
35
36static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
37 void *buf, size_t n)
38{
39 struct nd_btt *nd_btt = arena->nd_btt;
40 struct nd_namespace_common *ndns = nd_btt->ndns;
41
42 /* arena offsets are 4K from the base of the device */
43 offset += SZ_4K;
44 return nvdimm_read_bytes(ndns, offset, buf, n);
45}
46
47static int arena_write_bytes(struct arena_info *arena, resource_size_t offset,
48 void *buf, size_t n)
49{
50 struct nd_btt *nd_btt = arena->nd_btt;
51 struct nd_namespace_common *ndns = nd_btt->ndns;
52
53 /* arena offsets are 4K from the base of the device */
54 offset += SZ_4K;
55 return nvdimm_write_bytes(ndns, offset, buf, n);
56}
57
58static int btt_info_write(struct arena_info *arena, struct btt_sb *super)
59{
60 int ret;
61
62 ret = arena_write_bytes(arena, arena->info2off, super,
63 sizeof(struct btt_sb));
64 if (ret)
65 return ret;
66
67 return arena_write_bytes(arena, arena->infooff, super,
68 sizeof(struct btt_sb));
69}
70
71static int btt_info_read(struct arena_info *arena, struct btt_sb *super)
72{
73 WARN_ON(!super);
74 return arena_read_bytes(arena, arena->infooff, super,
75 sizeof(struct btt_sb));
76}
77
78/*
79 * 'raw' version of btt_map write
80 * Assumptions:
81 * mapping is in little-endian
82 * mapping contains 'E' and 'Z' flags as desired
83 */
84static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping)
85{
86 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
87
88 WARN_ON(lba >= arena->external_nlba);
89 return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE);
90}
91
92static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping,
93 u32 z_flag, u32 e_flag)
94{
95 u32 ze;
96 __le32 mapping_le;
97
98 /*
99 * This 'mapping' is supposed to be just the LBA mapping, without
100 * any flags set, so strip the flag bits.
101 */
102 mapping &= MAP_LBA_MASK;
103
104 ze = (z_flag << 1) + e_flag;
105 switch (ze) {
106 case 0:
107 /*
108 * We want to set neither of the Z or E flags, and
109 * in the actual layout, this means setting the bit
110 * positions of both to '1' to indicate a 'normal'
111 * map entry
112 */
113 mapping |= MAP_ENT_NORMAL;
114 break;
115 case 1:
116 mapping |= (1 << MAP_ERR_SHIFT);
117 break;
118 case 2:
119 mapping |= (1 << MAP_TRIM_SHIFT);
120 break;
121 default:
122 /*
123 * The case where Z and E are both sent in as '1' could be
124 * construed as a valid 'normal' case, but we decide not to,
125 * to avoid confusion
126 */
127 WARN_ONCE(1, "Invalid use of Z and E flags\n");
128 return -EIO;
129 }
130
131 mapping_le = cpu_to_le32(mapping);
132 return __btt_map_write(arena, lba, mapping_le);
133}
134
135static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping,
136 int *trim, int *error)
137{
138 int ret;
139 __le32 in;
140 u32 raw_mapping, postmap, ze, z_flag, e_flag;
141 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
142
143 WARN_ON(lba >= arena->external_nlba);
144
145 ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE);
146 if (ret)
147 return ret;
148
149 raw_mapping = le32_to_cpu(in);
150
151 z_flag = (raw_mapping & MAP_TRIM_MASK) >> MAP_TRIM_SHIFT;
152 e_flag = (raw_mapping & MAP_ERR_MASK) >> MAP_ERR_SHIFT;
153 ze = (z_flag << 1) + e_flag;
154 postmap = raw_mapping & MAP_LBA_MASK;
155
156 /* Reuse the {z,e}_flag variables for *trim and *error */
157 z_flag = 0;
158 e_flag = 0;
159
160 switch (ze) {
161 case 0:
162 /* Initial state. Return postmap = premap */
163 *mapping = lba;
164 break;
165 case 1:
166 *mapping = postmap;
167 e_flag = 1;
168 break;
169 case 2:
170 *mapping = postmap;
171 z_flag = 1;
172 break;
173 case 3:
174 *mapping = postmap;
175 break;
176 default:
177 return -EIO;
178 }
179
180 if (trim)
181 *trim = z_flag;
182 if (error)
183 *error = e_flag;
184
185 return ret;
186}
187
188static int btt_log_read_pair(struct arena_info *arena, u32 lane,
189 struct log_entry *ent)
190{
191 WARN_ON(!ent);
192 return arena_read_bytes(arena,
193 arena->logoff + (2 * lane * LOG_ENT_SIZE), ent,
194 2 * LOG_ENT_SIZE);
195}
196
197static struct dentry *debugfs_root;
198
199static void arena_debugfs_init(struct arena_info *a, struct dentry *parent,
200 int idx)
201{
202 char dirname[32];
203 struct dentry *d;
204
205 /* If for some reason, parent bttN was not created, exit */
206 if (!parent)
207 return;
208
209 snprintf(dirname, 32, "arena%d", idx);
210 d = debugfs_create_dir(dirname, parent);
211 if (IS_ERR_OR_NULL(d))
212 return;
213 a->debugfs_dir = d;
214
215 debugfs_create_x64("size", S_IRUGO, d, &a->size);
216 debugfs_create_x64("external_lba_start", S_IRUGO, d,
217 &a->external_lba_start);
218 debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba);
219 debugfs_create_u32("internal_lbasize", S_IRUGO, d,
220 &a->internal_lbasize);
221 debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba);
222 debugfs_create_u32("external_lbasize", S_IRUGO, d,
223 &a->external_lbasize);
224 debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree);
225 debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major);
226 debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor);
227 debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff);
228 debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff);
229 debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff);
230 debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff);
231 debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff);
232 debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off);
233 debugfs_create_x32("flags", S_IRUGO, d, &a->flags);
234}
235
236static void btt_debugfs_init(struct btt *btt)
237{
238 int i = 0;
239 struct arena_info *arena;
240
241 btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev),
242 debugfs_root);
243 if (IS_ERR_OR_NULL(btt->debugfs_dir))
244 return;
245
246 list_for_each_entry(arena, &btt->arena_list, list) {
247 arena_debugfs_init(arena, btt->debugfs_dir, i);
248 i++;
249 }
250}
251
252/*
253 * This function accepts two log entries, and uses the
254 * sequence number to find the 'older' entry.
255 * It also updates the sequence number in this old entry to
256 * make it the 'new' one if the mark_flag is set.
257 * Finally, it returns which of the entries was the older one.
258 *
259 * TODO The logic feels a bit kludge-y. make it better..
260 */
261static int btt_log_get_old(struct log_entry *ent)
262{
263 int old;
264
265 /*
266 * the first ever time this is seen, the entry goes into [0]
267 * the next time, the following logic works out to put this
268 * (next) entry into [1]
269 */
270 if (ent[0].seq == 0) {
271 ent[0].seq = cpu_to_le32(1);
272 return 0;
273 }
274
275 if (ent[0].seq == ent[1].seq)
276 return -EINVAL;
277 if (le32_to_cpu(ent[0].seq) + le32_to_cpu(ent[1].seq) > 5)
278 return -EINVAL;
279
280 if (le32_to_cpu(ent[0].seq) < le32_to_cpu(ent[1].seq)) {
281 if (le32_to_cpu(ent[1].seq) - le32_to_cpu(ent[0].seq) == 1)
282 old = 0;
283 else
284 old = 1;
285 } else {
286 if (le32_to_cpu(ent[0].seq) - le32_to_cpu(ent[1].seq) == 1)
287 old = 1;
288 else
289 old = 0;
290 }
291
292 return old;
293}
294
295static struct device *to_dev(struct arena_info *arena)
296{
297 return &arena->nd_btt->dev;
298}
299
300/*
301 * This function copies the desired (old/new) log entry into ent if
302 * it is not NULL. It returns the sub-slot number (0 or 1)
303 * where the desired log entry was found. Negative return values
304 * indicate errors.
305 */
306static int btt_log_read(struct arena_info *arena, u32 lane,
307 struct log_entry *ent, int old_flag)
308{
309 int ret;
310 int old_ent, ret_ent;
311 struct log_entry log[2];
312
313 ret = btt_log_read_pair(arena, lane, log);
314 if (ret)
315 return -EIO;
316
317 old_ent = btt_log_get_old(log);
318 if (old_ent < 0 || old_ent > 1) {
319 dev_info(to_dev(arena),
320 "log corruption (%d): lane %d seq [%d, %d]\n",
321 old_ent, lane, log[0].seq, log[1].seq);
322 /* TODO set error state? */
323 return -EIO;
324 }
325
326 ret_ent = (old_flag ? old_ent : (1 - old_ent));
327
328 if (ent != NULL)
329 memcpy(ent, &log[ret_ent], LOG_ENT_SIZE);
330
331 return ret_ent;
332}
333
334/*
335 * This function commits a log entry to media
336 * It does _not_ prepare the freelist entry for the next write
337 * btt_flog_write is the wrapper for updating the freelist elements
338 */
339static int __btt_log_write(struct arena_info *arena, u32 lane,
340 u32 sub, struct log_entry *ent)
341{
342 int ret;
343 /*
344 * Ignore the padding in log_entry for calculating log_half.
345 * The entry is 'committed' when we write the sequence number,
346 * and we want to ensure that that is the last thing written.
347 * We don't bother writing the padding as that would be extra
348 * media wear and write amplification
349 */
350 unsigned int log_half = (LOG_ENT_SIZE - 2 * sizeof(u64)) / 2;
351 u64 ns_off = arena->logoff + (((2 * lane) + sub) * LOG_ENT_SIZE);
352 void *src = ent;
353
354 /* split the 16B write into atomic, durable halves */
355 ret = arena_write_bytes(arena, ns_off, src, log_half);
356 if (ret)
357 return ret;
358
359 ns_off += log_half;
360 src += log_half;
361 return arena_write_bytes(arena, ns_off, src, log_half);
362}
363
364static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
365 struct log_entry *ent)
366{
367 int ret;
368
369 ret = __btt_log_write(arena, lane, sub, ent);
370 if (ret)
371 return ret;
372
373 /* prepare the next free entry */
374 arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
375 if (++(arena->freelist[lane].seq) == 4)
376 arena->freelist[lane].seq = 1;
377 arena->freelist[lane].block = le32_to_cpu(ent->old_map);
378
379 return ret;
380}
381
382/*
383 * This function initializes the BTT map to the initial state, which is
384 * all-zeroes, and indicates an identity mapping
385 */
386static int btt_map_init(struct arena_info *arena)
387{
388 int ret = -EINVAL;
389 void *zerobuf;
390 size_t offset = 0;
391 size_t chunk_size = SZ_2M;
392 size_t mapsize = arena->logoff - arena->mapoff;
393
394 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
395 if (!zerobuf)
396 return -ENOMEM;
397
398 while (mapsize) {
399 size_t size = min(mapsize, chunk_size);
400
401 ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,
402 size);
403 if (ret)
404 goto free;
405
406 offset += size;
407 mapsize -= size;
408 cond_resched();
409 }
410
411 free:
412 kfree(zerobuf);
413 return ret;
414}
415
416/*
417 * This function initializes the BTT log with 'fake' entries pointing
418 * to the initial reserved set of blocks as being free
419 */
420static int btt_log_init(struct arena_info *arena)
421{
422 int ret;
423 u32 i;
424 struct log_entry log, zerolog;
425
426 memset(&zerolog, 0, sizeof(zerolog));
427
428 for (i = 0; i < arena->nfree; i++) {
429 log.lba = cpu_to_le32(i);
430 log.old_map = cpu_to_le32(arena->external_nlba + i);
431 log.new_map = cpu_to_le32(arena->external_nlba + i);
432 log.seq = cpu_to_le32(LOG_SEQ_INIT);
433 ret = __btt_log_write(arena, i, 0, &log);
434 if (ret)
435 return ret;
436 ret = __btt_log_write(arena, i, 1, &zerolog);
437 if (ret)
438 return ret;
439 }
440
441 return 0;
442}
443
444static int btt_freelist_init(struct arena_info *arena)
445{
446 int old, new, ret;
447 u32 i, map_entry;
448 struct log_entry log_new, log_old;
449
450 arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
451 GFP_KERNEL);
452 if (!arena->freelist)
453 return -ENOMEM;
454
455 for (i = 0; i < arena->nfree; i++) {
456 old = btt_log_read(arena, i, &log_old, LOG_OLD_ENT);
457 if (old < 0)
458 return old;
459
460 new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
461 if (new < 0)
462 return new;
463
464 /* sub points to the next one to be overwritten */
465 arena->freelist[i].sub = 1 - new;
466 arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
467 arena->freelist[i].block = le32_to_cpu(log_new.old_map);
468
469 /* This implies a newly created or untouched flog entry */
470 if (log_new.old_map == log_new.new_map)
471 continue;
472
473 /* Check if map recovery is needed */
474 ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
475 NULL, NULL);
476 if (ret)
477 return ret;
478 if ((le32_to_cpu(log_new.new_map) != map_entry) &&
479 (le32_to_cpu(log_new.old_map) == map_entry)) {
480 /*
481 * Last transaction wrote the flog, but wasn't able
482 * to complete the map write. So fix up the map.
483 */
484 ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
485 le32_to_cpu(log_new.new_map), 0, 0);
486 if (ret)
487 return ret;
488 }
489
490 }
491
492 return 0;
493}
494
495static int btt_rtt_init(struct arena_info *arena)
496{
497 arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL);
498 if (arena->rtt == NULL)
499 return -ENOMEM;
500
501 return 0;
502}
503
504static int btt_maplocks_init(struct arena_info *arena)
505{
506 u32 i;
507
508 arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
509 GFP_KERNEL);
510 if (!arena->map_locks)
511 return -ENOMEM;
512
513 for (i = 0; i < arena->nfree; i++)
514 spin_lock_init(&arena->map_locks[i].lock);
515
516 return 0;
517}
518
519static struct arena_info *alloc_arena(struct btt *btt, size_t size,
520 size_t start, size_t arena_off)
521{
522 struct arena_info *arena;
523 u64 logsize, mapsize, datasize;
524 u64 available = size;
525
526 arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL);
527 if (!arena)
528 return NULL;
529 arena->nd_btt = btt->nd_btt;
530
531 if (!size)
532 return arena;
533
534 arena->size = size;
535 arena->external_lba_start = start;
536 arena->external_lbasize = btt->lbasize;
537 arena->internal_lbasize = roundup(arena->external_lbasize,
538 INT_LBASIZE_ALIGNMENT);
539 arena->nfree = BTT_DEFAULT_NFREE;
540 arena->version_major = 1;
541 arena->version_minor = 1;
542
543 if (available % BTT_PG_SIZE)
544 available -= (available % BTT_PG_SIZE);
545
546 /* Two pages are reserved for the super block and its copy */
547 available -= 2 * BTT_PG_SIZE;
548
549 /* The log takes a fixed amount of space based on nfree */
550 logsize = roundup(2 * arena->nfree * sizeof(struct log_entry),
551 BTT_PG_SIZE);
552 available -= logsize;
553
554 /* Calculate optimal split between map and data area */
555 arena->internal_nlba = div_u64(available - BTT_PG_SIZE,
556 arena->internal_lbasize + MAP_ENT_SIZE);
557 arena->external_nlba = arena->internal_nlba - arena->nfree;
558
559 mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE);
560 datasize = available - mapsize;
561
562 /* 'Absolute' values, relative to start of storage space */
563 arena->infooff = arena_off;
564 arena->dataoff = arena->infooff + BTT_PG_SIZE;
565 arena->mapoff = arena->dataoff + datasize;
566 arena->logoff = arena->mapoff + mapsize;
567 arena->info2off = arena->logoff + logsize;
568 return arena;
569}
570
571static void free_arenas(struct btt *btt)
572{
573 struct arena_info *arena, *next;
574
575 list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
576 list_del(&arena->list);
577 kfree(arena->rtt);
578 kfree(arena->map_locks);
579 kfree(arena->freelist);
580 debugfs_remove_recursive(arena->debugfs_dir);
581 kfree(arena);
582 }
583}
584
585/*
Vishal Verma5212e112015-06-25 04:20:32 -0400586 * This function reads an existing valid btt superblock and
587 * populates the corresponding arena_info struct
588 */
589static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
590 u64 arena_off)
591{
592 arena->internal_nlba = le32_to_cpu(super->internal_nlba);
593 arena->internal_lbasize = le32_to_cpu(super->internal_lbasize);
594 arena->external_nlba = le32_to_cpu(super->external_nlba);
595 arena->external_lbasize = le32_to_cpu(super->external_lbasize);
596 arena->nfree = le32_to_cpu(super->nfree);
597 arena->version_major = le16_to_cpu(super->version_major);
598 arena->version_minor = le16_to_cpu(super->version_minor);
599
600 arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off +
601 le64_to_cpu(super->nextoff));
602 arena->infooff = arena_off;
603 arena->dataoff = arena_off + le64_to_cpu(super->dataoff);
604 arena->mapoff = arena_off + le64_to_cpu(super->mapoff);
605 arena->logoff = arena_off + le64_to_cpu(super->logoff);
606 arena->info2off = arena_off + le64_to_cpu(super->info2off);
607
Dan Williams5e329402015-07-11 10:02:46 -0400608 arena->size = (le64_to_cpu(super->nextoff) > 0)
609 ? (le64_to_cpu(super->nextoff))
610 : (arena->info2off - arena->infooff + BTT_PG_SIZE);
Vishal Verma5212e112015-06-25 04:20:32 -0400611
612 arena->flags = le32_to_cpu(super->flags);
613}
614
615static int discover_arenas(struct btt *btt)
616{
617 int ret = 0;
618 struct arena_info *arena;
619 struct btt_sb *super;
620 size_t remaining = btt->rawsize;
621 u64 cur_nlba = 0;
622 size_t cur_off = 0;
623 int num_arenas = 0;
624
625 super = kzalloc(sizeof(*super), GFP_KERNEL);
626 if (!super)
627 return -ENOMEM;
628
629 while (remaining) {
630 /* Alloc memory for arena */
631 arena = alloc_arena(btt, 0, 0, 0);
632 if (!arena) {
633 ret = -ENOMEM;
634 goto out_super;
635 }
636
637 arena->infooff = cur_off;
638 ret = btt_info_read(arena, super);
639 if (ret)
640 goto out;
641
Vishal Vermaab45e762015-07-29 14:58:08 -0600642 if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
Vishal Verma5212e112015-06-25 04:20:32 -0400643 if (remaining == btt->rawsize) {
644 btt->init_state = INIT_NOTFOUND;
645 dev_info(to_dev(arena), "No existing arenas\n");
646 goto out;
647 } else {
648 dev_info(to_dev(arena),
649 "Found corrupted metadata!\n");
650 ret = -ENODEV;
651 goto out;
652 }
653 }
654
655 arena->external_lba_start = cur_nlba;
656 parse_arena_meta(arena, super, cur_off);
657
658 ret = btt_freelist_init(arena);
659 if (ret)
660 goto out;
661
662 ret = btt_rtt_init(arena);
663 if (ret)
664 goto out;
665
666 ret = btt_maplocks_init(arena);
667 if (ret)
668 goto out;
669
670 list_add_tail(&arena->list, &btt->arena_list);
671
672 remaining -= arena->size;
673 cur_off += arena->size;
674 cur_nlba += arena->external_nlba;
675 num_arenas++;
676
677 if (arena->nextoff == 0)
678 break;
679 }
680 btt->num_arenas = num_arenas;
681 btt->nlba = cur_nlba;
682 btt->init_state = INIT_READY;
683
684 kfree(super);
685 return ret;
686
687 out:
688 kfree(arena);
689 free_arenas(btt);
690 out_super:
691 kfree(super);
692 return ret;
693}
694
695static int create_arenas(struct btt *btt)
696{
697 size_t remaining = btt->rawsize;
698 size_t cur_off = 0;
699
700 while (remaining) {
701 struct arena_info *arena;
702 size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining);
703
704 remaining -= arena_size;
705 if (arena_size < ARENA_MIN_SIZE)
706 break;
707
708 arena = alloc_arena(btt, arena_size, btt->nlba, cur_off);
709 if (!arena) {
710 free_arenas(btt);
711 return -ENOMEM;
712 }
713 btt->nlba += arena->external_nlba;
714 if (remaining >= ARENA_MIN_SIZE)
715 arena->nextoff = arena->size;
716 else
717 arena->nextoff = 0;
718 cur_off += arena_size;
719 list_add_tail(&arena->list, &btt->arena_list);
720 }
721
722 return 0;
723}
724
725/*
726 * This function completes arena initialization by writing
727 * all the metadata.
728 * It is only called for an uninitialized arena when a write
729 * to that arena occurs for the first time.
730 */
Vishal Vermafbde1412015-07-29 14:58:07 -0600731static int btt_arena_write_layout(struct arena_info *arena)
Vishal Verma5212e112015-06-25 04:20:32 -0400732{
733 int ret;
Dan Williamse1455742015-07-30 17:57:47 -0400734 u64 sum;
Vishal Verma5212e112015-06-25 04:20:32 -0400735 struct btt_sb *super;
Vishal Vermafbde1412015-07-29 14:58:07 -0600736 struct nd_btt *nd_btt = arena->nd_btt;
Vishal Verma6ec68952015-07-29 14:58:09 -0600737 const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
Vishal Verma5212e112015-06-25 04:20:32 -0400738
739 ret = btt_map_init(arena);
740 if (ret)
741 return ret;
742
743 ret = btt_log_init(arena);
744 if (ret)
745 return ret;
746
747 super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
748 if (!super)
749 return -ENOMEM;
750
751 strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
Vishal Vermafbde1412015-07-29 14:58:07 -0600752 memcpy(super->uuid, nd_btt->uuid, 16);
Vishal Verma6ec68952015-07-29 14:58:09 -0600753 memcpy(super->parent_uuid, parent_uuid, 16);
Vishal Verma5212e112015-06-25 04:20:32 -0400754 super->flags = cpu_to_le32(arena->flags);
755 super->version_major = cpu_to_le16(arena->version_major);
756 super->version_minor = cpu_to_le16(arena->version_minor);
757 super->external_lbasize = cpu_to_le32(arena->external_lbasize);
758 super->external_nlba = cpu_to_le32(arena->external_nlba);
759 super->internal_lbasize = cpu_to_le32(arena->internal_lbasize);
760 super->internal_nlba = cpu_to_le32(arena->internal_nlba);
761 super->nfree = cpu_to_le32(arena->nfree);
762 super->infosize = cpu_to_le32(sizeof(struct btt_sb));
763 super->nextoff = cpu_to_le64(arena->nextoff);
764 /*
765 * Subtract arena->infooff (arena start) so numbers are relative
766 * to 'this' arena
767 */
768 super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff);
769 super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff);
770 super->logoff = cpu_to_le64(arena->logoff - arena->infooff);
771 super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
772
773 super->flags = 0;
Dan Williamse1455742015-07-30 17:57:47 -0400774 sum = nd_sb_checksum((struct nd_gen_sb *) super);
775 super->checksum = cpu_to_le64(sum);
Vishal Verma5212e112015-06-25 04:20:32 -0400776
777 ret = btt_info_write(arena, super);
778
779 kfree(super);
780 return ret;
781}
782
783/*
784 * This function completes the initialization for the BTT namespace
785 * such that it is ready to accept IOs
786 */
787static int btt_meta_init(struct btt *btt)
788{
789 int ret = 0;
790 struct arena_info *arena;
791
792 mutex_lock(&btt->init_lock);
793 list_for_each_entry(arena, &btt->arena_list, list) {
Vishal Vermafbde1412015-07-29 14:58:07 -0600794 ret = btt_arena_write_layout(arena);
Vishal Verma5212e112015-06-25 04:20:32 -0400795 if (ret)
796 goto unlock;
797
798 ret = btt_freelist_init(arena);
799 if (ret)
800 goto unlock;
801
802 ret = btt_rtt_init(arena);
803 if (ret)
804 goto unlock;
805
806 ret = btt_maplocks_init(arena);
807 if (ret)
808 goto unlock;
809 }
810
811 btt->init_state = INIT_READY;
812
813 unlock:
814 mutex_unlock(&btt->init_lock);
815 return ret;
816}
817
Vishal Verma41cd8b72015-06-25 04:21:52 -0400818static u32 btt_meta_size(struct btt *btt)
819{
820 return btt->lbasize - btt->sector_size;
821}
822
Vishal Verma5212e112015-06-25 04:20:32 -0400823/*
824 * This function calculates the arena in which the given LBA lies
825 * by doing a linear walk. This is acceptable since we expect only
826 * a few arenas. If we have backing devices that get much larger,
827 * we can construct a balanced binary tree of arenas at init time
828 * so that this range search becomes faster.
829 */
830static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap,
831 struct arena_info **arena)
832{
833 struct arena_info *arena_list;
834 __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size);
835
836 list_for_each_entry(arena_list, &btt->arena_list, list) {
837 if (lba < arena_list->external_nlba) {
838 *arena = arena_list;
839 *premap = lba;
840 return 0;
841 }
842 lba -= arena_list->external_nlba;
843 }
844
845 return -EIO;
846}
847
848/*
849 * The following (lock_map, unlock_map) are mostly just to improve
850 * readability, since they index into an array of locks
851 */
852static void lock_map(struct arena_info *arena, u32 premap)
853 __acquires(&arena->map_locks[idx].lock)
854{
855 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
856
857 spin_lock(&arena->map_locks[idx].lock);
858}
859
860static void unlock_map(struct arena_info *arena, u32 premap)
861 __releases(&arena->map_locks[idx].lock)
862{
863 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
864
865 spin_unlock(&arena->map_locks[idx].lock);
866}
867
868static u64 to_namespace_offset(struct arena_info *arena, u64 lba)
869{
870 return arena->dataoff + ((u64)lba * arena->internal_lbasize);
871}
872
873static int btt_data_read(struct arena_info *arena, struct page *page,
874 unsigned int off, u32 lba, u32 len)
875{
876 int ret;
877 u64 nsoff = to_namespace_offset(arena, lba);
878 void *mem = kmap_atomic(page);
879
880 ret = arena_read_bytes(arena, nsoff, mem + off, len);
881 kunmap_atomic(mem);
882
883 return ret;
884}
885
886static int btt_data_write(struct arena_info *arena, u32 lba,
887 struct page *page, unsigned int off, u32 len)
888{
889 int ret;
890 u64 nsoff = to_namespace_offset(arena, lba);
891 void *mem = kmap_atomic(page);
892
893 ret = arena_write_bytes(arena, nsoff, mem + off, len);
894 kunmap_atomic(mem);
895
896 return ret;
897}
898
899static void zero_fill_data(struct page *page, unsigned int off, u32 len)
900{
901 void *mem = kmap_atomic(page);
902
903 memset(mem + off, 0, len);
904 kunmap_atomic(mem);
905}
906
Vishal Verma41cd8b72015-06-25 04:21:52 -0400907#ifdef CONFIG_BLK_DEV_INTEGRITY
908static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
909 struct arena_info *arena, u32 postmap, int rw)
910{
911 unsigned int len = btt_meta_size(btt);
912 u64 meta_nsoff;
913 int ret = 0;
914
915 if (bip == NULL)
916 return 0;
917
918 meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
919
920 while (len) {
921 unsigned int cur_len;
922 struct bio_vec bv;
923 void *mem;
924
925 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
926 /*
927 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
928 * .bv_offset already adjusted for iter->bi_bvec_done, and we
929 * can use those directly
930 */
931
932 cur_len = min(len, bv.bv_len);
933 mem = kmap_atomic(bv.bv_page);
934 if (rw)
935 ret = arena_write_bytes(arena, meta_nsoff,
936 mem + bv.bv_offset, cur_len);
937 else
938 ret = arena_read_bytes(arena, meta_nsoff,
939 mem + bv.bv_offset, cur_len);
940
941 kunmap_atomic(mem);
942 if (ret)
943 return ret;
944
945 len -= cur_len;
946 meta_nsoff += cur_len;
947 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
948 }
949
950 return ret;
951}
952
953#else /* CONFIG_BLK_DEV_INTEGRITY */
954static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
955 struct arena_info *arena, u32 postmap, int rw)
956{
957 return 0;
958}
959#endif
960
961static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
962 struct page *page, unsigned int off, sector_t sector,
963 unsigned int len)
Vishal Verma5212e112015-06-25 04:20:32 -0400964{
965 int ret = 0;
966 int t_flag, e_flag;
967 struct arena_info *arena = NULL;
968 u32 lane = 0, premap, postmap;
969
970 while (len) {
971 u32 cur_len;
972
973 lane = nd_region_acquire_lane(btt->nd_region);
974
975 ret = lba_to_arena(btt, sector, &premap, &arena);
976 if (ret)
977 goto out_lane;
978
979 cur_len = min(btt->sector_size, len);
980
981 ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag);
982 if (ret)
983 goto out_lane;
984
985 /*
986 * We loop to make sure that the post map LBA didn't change
987 * from under us between writing the RTT and doing the actual
988 * read.
989 */
990 while (1) {
991 u32 new_map;
992
993 if (t_flag) {
994 zero_fill_data(page, off, cur_len);
995 goto out_lane;
996 }
997
998 if (e_flag) {
999 ret = -EIO;
1000 goto out_lane;
1001 }
1002
1003 arena->rtt[lane] = RTT_VALID | postmap;
1004 /*
1005 * Barrier to make sure this write is not reordered
1006 * to do the verification map_read before the RTT store
1007 */
1008 barrier();
1009
1010 ret = btt_map_read(arena, premap, &new_map, &t_flag,
1011 &e_flag);
1012 if (ret)
1013 goto out_rtt;
1014
1015 if (postmap == new_map)
1016 break;
1017
1018 postmap = new_map;
1019 }
1020
1021 ret = btt_data_read(arena, page, off, postmap, cur_len);
1022 if (ret)
1023 goto out_rtt;
1024
Vishal Verma41cd8b72015-06-25 04:21:52 -04001025 if (bip) {
1026 ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
1027 if (ret)
1028 goto out_rtt;
1029 }
1030
Vishal Verma5212e112015-06-25 04:20:32 -04001031 arena->rtt[lane] = RTT_INVALID;
1032 nd_region_release_lane(btt->nd_region, lane);
1033
1034 len -= cur_len;
1035 off += cur_len;
1036 sector += btt->sector_size >> SECTOR_SHIFT;
1037 }
1038
1039 return 0;
1040
1041 out_rtt:
1042 arena->rtt[lane] = RTT_INVALID;
1043 out_lane:
1044 nd_region_release_lane(btt->nd_region, lane);
1045 return ret;
1046}
1047
Vishal Verma41cd8b72015-06-25 04:21:52 -04001048static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
1049 sector_t sector, struct page *page, unsigned int off,
1050 unsigned int len)
Vishal Verma5212e112015-06-25 04:20:32 -04001051{
1052 int ret = 0;
1053 struct arena_info *arena = NULL;
1054 u32 premap = 0, old_postmap, new_postmap, lane = 0, i;
1055 struct log_entry log;
1056 int sub;
1057
1058 while (len) {
1059 u32 cur_len;
1060
1061 lane = nd_region_acquire_lane(btt->nd_region);
1062
1063 ret = lba_to_arena(btt, sector, &premap, &arena);
1064 if (ret)
1065 goto out_lane;
1066 cur_len = min(btt->sector_size, len);
1067
1068 if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) {
1069 ret = -EIO;
1070 goto out_lane;
1071 }
1072
1073 new_postmap = arena->freelist[lane].block;
1074
1075 /* Wait if the new block is being read from */
1076 for (i = 0; i < arena->nfree; i++)
1077 while (arena->rtt[i] == (RTT_VALID | new_postmap))
1078 cpu_relax();
1079
1080
1081 if (new_postmap >= arena->internal_nlba) {
1082 ret = -EIO;
1083 goto out_lane;
Vishal Verma41cd8b72015-06-25 04:21:52 -04001084 }
1085
1086 ret = btt_data_write(arena, new_postmap, page, off, cur_len);
Vishal Verma5212e112015-06-25 04:20:32 -04001087 if (ret)
1088 goto out_lane;
1089
Vishal Verma41cd8b72015-06-25 04:21:52 -04001090 if (bip) {
1091 ret = btt_rw_integrity(btt, bip, arena, new_postmap,
1092 WRITE);
1093 if (ret)
1094 goto out_lane;
1095 }
1096
Vishal Verma5212e112015-06-25 04:20:32 -04001097 lock_map(arena, premap);
1098 ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL);
1099 if (ret)
1100 goto out_map;
1101 if (old_postmap >= arena->internal_nlba) {
1102 ret = -EIO;
1103 goto out_map;
1104 }
1105
1106 log.lba = cpu_to_le32(premap);
1107 log.old_map = cpu_to_le32(old_postmap);
1108 log.new_map = cpu_to_le32(new_postmap);
1109 log.seq = cpu_to_le32(arena->freelist[lane].seq);
1110 sub = arena->freelist[lane].sub;
1111 ret = btt_flog_write(arena, lane, sub, &log);
1112 if (ret)
1113 goto out_map;
1114
1115 ret = btt_map_write(arena, premap, new_postmap, 0, 0);
1116 if (ret)
1117 goto out_map;
1118
1119 unlock_map(arena, premap);
1120 nd_region_release_lane(btt->nd_region, lane);
1121
1122 len -= cur_len;
1123 off += cur_len;
1124 sector += btt->sector_size >> SECTOR_SHIFT;
1125 }
1126
1127 return 0;
1128
1129 out_map:
1130 unlock_map(arena, premap);
1131 out_lane:
1132 nd_region_release_lane(btt->nd_region, lane);
1133 return ret;
1134}
1135
Vishal Verma41cd8b72015-06-25 04:21:52 -04001136static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
1137 struct page *page, unsigned int len, unsigned int off,
1138 int rw, sector_t sector)
Vishal Verma5212e112015-06-25 04:20:32 -04001139{
1140 int ret;
1141
1142 if (rw == READ) {
Vishal Verma41cd8b72015-06-25 04:21:52 -04001143 ret = btt_read_pg(btt, bip, page, off, sector, len);
Vishal Verma5212e112015-06-25 04:20:32 -04001144 flush_dcache_page(page);
1145 } else {
1146 flush_dcache_page(page);
Vishal Verma41cd8b72015-06-25 04:21:52 -04001147 ret = btt_write_pg(btt, bip, sector, page, off, len);
Vishal Verma5212e112015-06-25 04:20:32 -04001148 }
1149
1150 return ret;
1151}
1152
1153static void btt_make_request(struct request_queue *q, struct bio *bio)
1154{
Vishal Verma41cd8b72015-06-25 04:21:52 -04001155 struct bio_integrity_payload *bip = bio_integrity(bio);
Vishal Verma5212e112015-06-25 04:20:32 -04001156 struct btt *btt = q->queuedata;
1157 struct bvec_iter iter;
Dan Williamsf0dc0892015-05-16 12:28:53 -04001158 unsigned long start;
Vishal Verma5212e112015-06-25 04:20:32 -04001159 struct bio_vec bvec;
1160 int err = 0, rw;
Dan Williamsf0dc0892015-05-16 12:28:53 -04001161 bool do_acct;
Vishal Verma5212e112015-06-25 04:20:32 -04001162
Vishal Verma41cd8b72015-06-25 04:21:52 -04001163 /*
1164 * bio_integrity_enabled also checks if the bio already has an
1165 * integrity payload attached. If it does, we *don't* do a
1166 * bio_integrity_prep here - the payload has been generated by
1167 * another kernel subsystem, and we just pass it through.
1168 */
1169 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
Christoph Hellwig4246a0b2015-07-20 15:29:37 +02001170 bio->bi_error = -EIO;
Vishal Verma41cd8b72015-06-25 04:21:52 -04001171 goto out;
1172 }
1173
Dan Williamsf0dc0892015-05-16 12:28:53 -04001174 do_acct = nd_iostat_start(bio, &start);
Vishal Verma5212e112015-06-25 04:20:32 -04001175 rw = bio_data_dir(bio);
1176 bio_for_each_segment(bvec, bio, iter) {
1177 unsigned int len = bvec.bv_len;
1178
1179 BUG_ON(len > PAGE_SIZE);
1180 /* Make sure len is in multiples of sector size. */
1181 /* XXX is this right? */
1182 BUG_ON(len < btt->sector_size);
1183 BUG_ON(len % btt->sector_size);
1184
Vishal Verma41cd8b72015-06-25 04:21:52 -04001185 err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
Vishal Verma5212e112015-06-25 04:20:32 -04001186 rw, iter.bi_sector);
1187 if (err) {
1188 dev_info(&btt->nd_btt->dev,
1189 "io error in %s sector %lld, len %d,\n",
1190 (rw == READ) ? "READ" : "WRITE",
1191 (unsigned long long) iter.bi_sector, len);
Christoph Hellwig4246a0b2015-07-20 15:29:37 +02001192 bio->bi_error = err;
Dan Williamsf0dc0892015-05-16 12:28:53 -04001193 break;
Vishal Verma5212e112015-06-25 04:20:32 -04001194 }
1195 }
Dan Williamsf0dc0892015-05-16 12:28:53 -04001196 if (do_acct)
1197 nd_iostat_end(bio, start);
Vishal Verma5212e112015-06-25 04:20:32 -04001198
1199out:
Christoph Hellwig4246a0b2015-07-20 15:29:37 +02001200 bio_endio(bio);
Vishal Verma5212e112015-06-25 04:20:32 -04001201}
1202
1203static int btt_rw_page(struct block_device *bdev, sector_t sector,
1204 struct page *page, int rw)
1205{
1206 struct btt *btt = bdev->bd_disk->private_data;
1207
Vishal Verma41cd8b72015-06-25 04:21:52 -04001208 btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector);
Vishal Verma5212e112015-06-25 04:20:32 -04001209 page_endio(page, rw & WRITE, 0);
1210 return 0;
1211}
1212
1213
1214static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo)
1215{
1216 /* some standard values */
1217 geo->heads = 1 << 6;
1218 geo->sectors = 1 << 5;
1219 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
1220 return 0;
1221}
1222
1223static const struct block_device_operations btt_fops = {
1224 .owner = THIS_MODULE,
1225 .rw_page = btt_rw_page,
1226 .getgeo = btt_getgeo,
Dan Williams58138822015-06-23 20:08:34 -04001227 .revalidate_disk = nvdimm_revalidate_disk,
Vishal Verma5212e112015-06-25 04:20:32 -04001228};
1229
1230static int btt_blk_init(struct btt *btt)
1231{
1232 struct nd_btt *nd_btt = btt->nd_btt;
1233 struct nd_namespace_common *ndns = nd_btt->ndns;
1234
1235 /* create a new disk and request queue for btt */
1236 btt->btt_queue = blk_alloc_queue(GFP_KERNEL);
1237 if (!btt->btt_queue)
1238 return -ENOMEM;
1239
1240 btt->btt_disk = alloc_disk(0);
1241 if (!btt->btt_disk) {
1242 blk_cleanup_queue(btt->btt_queue);
1243 return -ENOMEM;
1244 }
1245
1246 nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
1247 btt->btt_disk->driverfs_dev = &btt->nd_btt->dev;
1248 btt->btt_disk->major = btt_major;
1249 btt->btt_disk->first_minor = 0;
1250 btt->btt_disk->fops = &btt_fops;
1251 btt->btt_disk->private_data = btt;
1252 btt->btt_disk->queue = btt->btt_queue;
1253 btt->btt_disk->flags = GENHD_FL_EXT_DEVT;
1254
1255 blk_queue_make_request(btt->btt_queue, btt_make_request);
1256 blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
1257 blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX);
1258 blk_queue_bounce_limit(btt->btt_queue, BLK_BOUNCE_ANY);
1259 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, btt->btt_queue);
1260 btt->btt_queue->queuedata = btt;
1261
Vishal Verma41cd8b72015-06-25 04:21:52 -04001262 set_capacity(btt->btt_disk, 0);
Vishal Verma5212e112015-06-25 04:20:32 -04001263 add_disk(btt->btt_disk);
Vishal Verma41cd8b72015-06-25 04:21:52 -04001264 if (btt_meta_size(btt)) {
1265 int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
1266
1267 if (rc) {
1268 del_gendisk(btt->btt_disk);
1269 put_disk(btt->btt_disk);
1270 blk_cleanup_queue(btt->btt_queue);
1271 return rc;
1272 }
1273 }
1274 set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
Dan Williams58138822015-06-23 20:08:34 -04001275 revalidate_disk(btt->btt_disk);
Vishal Verma5212e112015-06-25 04:20:32 -04001276
1277 return 0;
1278}
1279
1280static void btt_blk_cleanup(struct btt *btt)
1281{
Vishal Verma41cd8b72015-06-25 04:21:52 -04001282 blk_integrity_unregister(btt->btt_disk);
Vishal Verma5212e112015-06-25 04:20:32 -04001283 del_gendisk(btt->btt_disk);
1284 put_disk(btt->btt_disk);
1285 blk_cleanup_queue(btt->btt_queue);
1286}
1287
1288/**
1289 * btt_init - initialize a block translation table for the given device
1290 * @nd_btt: device with BTT geometry and backing device info
1291 * @rawsize: raw size in bytes of the backing device
1292 * @lbasize: lba size of the backing device
1293 * @uuid: A uuid for the backing device - this is stored on media
1294 * @maxlane: maximum number of parallel requests the device can handle
1295 *
1296 * Initialize a Block Translation Table on a backing device to provide
1297 * single sector power fail atomicity.
1298 *
1299 * Context:
1300 * Might sleep.
1301 *
1302 * Returns:
1303 * Pointer to a new struct btt on success, NULL on failure.
1304 */
1305static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
1306 u32 lbasize, u8 *uuid, struct nd_region *nd_region)
1307{
1308 int ret;
1309 struct btt *btt;
1310 struct device *dev = &nd_btt->dev;
1311
1312 btt = kzalloc(sizeof(struct btt), GFP_KERNEL);
1313 if (!btt)
1314 return NULL;
1315
1316 btt->nd_btt = nd_btt;
1317 btt->rawsize = rawsize;
1318 btt->lbasize = lbasize;
1319 btt->sector_size = ((lbasize >= 4096) ? 4096 : 512);
1320 INIT_LIST_HEAD(&btt->arena_list);
1321 mutex_init(&btt->init_lock);
1322 btt->nd_region = nd_region;
1323
1324 ret = discover_arenas(btt);
1325 if (ret) {
1326 dev_err(dev, "init: error in arena_discover: %d\n", ret);
1327 goto out_free;
1328 }
1329
Dan Williams58138822015-06-23 20:08:34 -04001330 if (btt->init_state != INIT_READY && nd_region->ro) {
1331 dev_info(dev, "%s is read-only, unable to init btt metadata\n",
1332 dev_name(&nd_region->dev));
1333 goto out_free;
1334 } else if (btt->init_state != INIT_READY) {
Vishal Verma5212e112015-06-25 04:20:32 -04001335 btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
1336 ((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
1337 dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
1338 btt->num_arenas, rawsize);
1339
1340 ret = create_arenas(btt);
1341 if (ret) {
1342 dev_info(dev, "init: create_arenas: %d\n", ret);
1343 goto out_free;
1344 }
1345
1346 ret = btt_meta_init(btt);
1347 if (ret) {
1348 dev_err(dev, "init: error in meta_init: %d\n", ret);
Dan Williams58138822015-06-23 20:08:34 -04001349 goto out_free;
Vishal Verma5212e112015-06-25 04:20:32 -04001350 }
1351 }
1352
1353 ret = btt_blk_init(btt);
1354 if (ret) {
1355 dev_err(dev, "init: error in blk_init: %d\n", ret);
1356 goto out_free;
1357 }
1358
1359 btt_debugfs_init(btt);
1360
1361 return btt;
1362
1363 out_free:
1364 kfree(btt);
1365 return NULL;
1366}
1367
1368/**
1369 * btt_fini - de-initialize a BTT
1370 * @btt: the BTT handle that was generated by btt_init
1371 *
1372 * De-initialize a Block Translation Table on device removal
1373 *
1374 * Context:
1375 * Might sleep.
1376 */
1377static void btt_fini(struct btt *btt)
1378{
1379 if (btt) {
1380 btt_blk_cleanup(btt);
1381 free_arenas(btt);
1382 debugfs_remove_recursive(btt->debugfs_dir);
1383 kfree(btt);
1384 }
1385}
1386
1387int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
1388{
1389 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1390 struct nd_region *nd_region;
1391 struct btt *btt;
1392 size_t rawsize;
1393
1394 if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize)
1395 return -ENODEV;
1396
1397 rawsize = nvdimm_namespace_capacity(ndns) - SZ_4K;
1398 if (rawsize < ARENA_MIN_SIZE) {
1399 return -ENXIO;
1400 }
1401 nd_region = to_nd_region(nd_btt->dev.parent);
1402 btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid,
1403 nd_region);
1404 if (!btt)
1405 return -ENOMEM;
1406 nd_btt->btt = btt;
1407
1408 return 0;
1409}
1410EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
1411
1412int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns)
1413{
1414 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1415 struct btt *btt = nd_btt->btt;
1416
1417 btt_fini(btt);
1418 nd_btt->btt = NULL;
1419
1420 return 0;
1421}
1422EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
1423
1424static int __init nd_btt_init(void)
1425{
1426 int rc;
1427
Vishal Verma5212e112015-06-25 04:20:32 -04001428 btt_major = register_blkdev(0, "btt");
1429 if (btt_major < 0)
1430 return btt_major;
1431
1432 debugfs_root = debugfs_create_dir("btt", NULL);
1433 if (IS_ERR_OR_NULL(debugfs_root)) {
1434 rc = -ENXIO;
1435 goto err_debugfs;
1436 }
1437
1438 return 0;
1439
1440 err_debugfs:
1441 unregister_blkdev(btt_major, "btt");
1442
1443 return rc;
1444}
1445
1446static void __exit nd_btt_exit(void)
1447{
1448 debugfs_remove_recursive(debugfs_root);
1449 unregister_blkdev(btt_major, "btt");
1450}
1451
1452MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
1453MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
1454MODULE_LICENSE("GPL v2");
1455module_init(nd_btt_init);
1456module_exit(nd_btt_exit);