?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / nvdimm / btt.c
blob0d04ea3d9fd74ae20666a705d44209d7ed6643a4
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Block Translation Table
4 * Copyright (c) 2014-2015, Intel Corporation.
5 */
6 #include <linux/highmem.h>
7 #include <linux/debugfs.h>
8 #include <linux/blkdev.h>
9 #include <linux/module.h>
10 #include <linux/device.h>
11 #include <linux/mutex.h>
12 #include <linux/hdreg.h>
13 #include <linux/genhd.h>
14 #include <linux/sizes.h>
15 #include <linux/ndctl.h>
16 #include <linux/fs.h>
17 #include <linux/nd.h>
18 #include <linux/backing-dev.h>
19 #include "btt.h"
20 #include "nd.h"
21
22 enum log_ent_request {
23 LOG_NEW_ENT = 0,
24 LOG_OLD_ENT
25 };
26
27 static struct device *to_dev(struct arena_info *arena)
28 {
29 return &arena->nd_btt->dev;
30 }
31
32 static u64 adjust_initial_offset(struct nd_btt *nd_btt, u64 offset)
33 {
34 return offset + nd_btt->initial_offset;
35 }
36
37 static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
38 void *buf, size_t n, unsigned long flags)
39 {
40 struct nd_btt *nd_btt = arena->nd_btt;
41 struct nd_namespace_common *ndns = nd_btt->ndns;
42
43 /* arena offsets may be shifted from the base of the device */
44 offset = adjust_initial_offset(nd_btt, offset);
45 return nvdimm_read_bytes(ndns, offset, buf, n, flags);
46 }
47
48 static int arena_write_bytes(struct arena_info *arena, resource_size_t offset,
49 void *buf, size_t n, unsigned long flags)
50 {
51 struct nd_btt *nd_btt = arena->nd_btt;
52 struct nd_namespace_common *ndns = nd_btt->ndns;
53
54 /* arena offsets may be shifted from the base of the device */
55 offset = adjust_initial_offset(nd_btt, offset);
56 return nvdimm_write_bytes(ndns, offset, buf, n, flags);
57 }
58
59 static int btt_info_write(struct arena_info *arena, struct btt_sb *super)
60 {
61 int ret;
62
63 /*
64 * infooff and info2off should always be at least 512B aligned.
65 * We rely on that to make sure rw_bytes does error clearing
66 * correctly, so make sure that is the case.
67 */
68 dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->infooff, 512),
69 "arena->infooff: %#llx is unaligned\n", arena->infooff);
70 dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->info2off, 512),
71 "arena->info2off: %#llx is unaligned\n", arena->info2off);
72
73 ret = arena_write_bytes(arena, arena->info2off, super,
74 sizeof(struct btt_sb), 0);
75 if (ret)
76 return ret;
77
78 return arena_write_bytes(arena, arena->infooff, super,
79 sizeof(struct btt_sb), 0);
80 }
81
82 static int btt_info_read(struct arena_info *arena, struct btt_sb *super)
83 {
84 return arena_read_bytes(arena, arena->infooff, super,
85 sizeof(struct btt_sb), 0);
86 }
87
88 /*
89 * 'raw' version of btt_map write
90 * Assumptions:
91 * mapping is in little-endian
92 * mapping contains 'E' and 'Z' flags as desired
93 */
94 static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping,
95 unsigned long flags)
96 {
97 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
98
99 if (unlikely(lba >= arena->external_nlba))
100 dev_err_ratelimited(to_dev(arena),
101 "%s: lba %#x out of range (max: %#x)\n",
102 __func__, lba, arena->external_nlba);
103 return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE, flags);
104 }
105
106 static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping,
107 u32 z_flag, u32 e_flag, unsigned long rwb_flags)
108 {
109 u32 ze;
110 __le32 mapping_le;
111
112 /*
113 * This 'mapping' is supposed to be just the LBA mapping, without
114 * any flags set, so strip the flag bits.
115 */
116 mapping = ent_lba(mapping);
117
118 ze = (z_flag << 1) + e_flag;
119 switch (ze) {
120 case 0:
121 /*
122 * We want to set neither of the Z or E flags, and
123 * in the actual layout, this means setting the bit
124 * positions of both to '1' to indicate a 'normal'
125 * map entry
126 */
127 mapping |= MAP_ENT_NORMAL;
128 break;
129 case 1:
130 mapping |= (1 << MAP_ERR_SHIFT);
131 break;
132 case 2:
133 mapping |= (1 << MAP_TRIM_SHIFT);
134 break;
135 default:
136 /*
137 * The case where Z and E are both sent in as '1' could be
138 * construed as a valid 'normal' case, but we decide not to,
139 * to avoid confusion
140 */
141 dev_err_ratelimited(to_dev(arena),
142 "Invalid use of Z and E flags\n");
143 return -EIO;
144 }
145
146 mapping_le = cpu_to_le32(mapping);
147 return __btt_map_write(arena, lba, mapping_le, rwb_flags);
148 }
149
150 static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping,
151 int *trim, int *error, unsigned long rwb_flags)
152 {
153 int ret;
154 __le32 in;
155 u32 raw_mapping, postmap, ze, z_flag, e_flag;
156 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
157
158 if (unlikely(lba >= arena->external_nlba))
159 dev_err_ratelimited(to_dev(arena),
160 "%s: lba %#x out of range (max: %#x)\n",
161 __func__, lba, arena->external_nlba);
162
163 ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE, rwb_flags);
164 if (ret)
165 return ret;
166
167 raw_mapping = le32_to_cpu(in);
168
169 z_flag = ent_z_flag(raw_mapping);
170 e_flag = ent_e_flag(raw_mapping);
171 ze = (z_flag << 1) + e_flag;
172 postmap = ent_lba(raw_mapping);
173
174 /* Reuse the {z,e}_flag variables for *trim and *error */
175 z_flag = 0;
176 e_flag = 0;
177
178 switch (ze) {
179 case 0:
180 /* Initial state. Return postmap = premap */
181 *mapping = lba;
182 break;
183 case 1:
184 *mapping = postmap;
185 e_flag = 1;
186 break;
187 case 2:
188 *mapping = postmap;
189 z_flag = 1;
190 break;
191 case 3:
192 *mapping = postmap;
193 break;
194 default:
195 return -EIO;
196 }
197
198 if (trim)
199 *trim = z_flag;
200 if (error)
201 *error = e_flag;
202
203 return ret;
204 }
205
206 static int btt_log_group_read(struct arena_info *arena, u32 lane,
207 struct log_group *log)
208 {
209 return arena_read_bytes(arena,
210 arena->logoff + (lane * LOG_GRP_SIZE), log,
211 LOG_GRP_SIZE, 0);
212 }
213
214 static struct dentry *debugfs_root;
215
216 static void arena_debugfs_init(struct arena_info *a, struct dentry *parent,
217 int idx)
218 {
219 char dirname[32];
220 struct dentry *d;
221
222 /* If for some reason, parent bttN was not created, exit */
223 if (!parent)
224 return;
225
226 snprintf(dirname, 32, "arena%d", idx);
227 d = debugfs_create_dir(dirname, parent);
228 if (IS_ERR_OR_NULL(d))
229 return;
230 a->debugfs_dir = d;
231
232 debugfs_create_x64("size", S_IRUGO, d, &a->size);
233 debugfs_create_x64("external_lba_start", S_IRUGO, d,
234 &a->external_lba_start);
235 debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba);
236 debugfs_create_u32("internal_lbasize", S_IRUGO, d,
237 &a->internal_lbasize);
238 debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba);
239 debugfs_create_u32("external_lbasize", S_IRUGO, d,
240 &a->external_lbasize);
241 debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree);
242 debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major);
243 debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor);
244 debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff);
245 debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff);
246 debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff);
247 debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff);
248 debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff);
249 debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off);
250 debugfs_create_x32("flags", S_IRUGO, d, &a->flags);
251 debugfs_create_u32("log_index_0", S_IRUGO, d, &a->log_index[0]);
252 debugfs_create_u32("log_index_1", S_IRUGO, d, &a->log_index[1]);
253 }
254
255 static void btt_debugfs_init(struct btt *btt)
256 {
257 int i = 0;
258 struct arena_info *arena;
259
260 btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev),
261 debugfs_root);
262 if (IS_ERR_OR_NULL(btt->debugfs_dir))
263 return;
264
265 list_for_each_entry(arena, &btt->arena_list, list) {
266 arena_debugfs_init(arena, btt->debugfs_dir, i);
267 i++;
268 }
269 }
270
271 static u32 log_seq(struct log_group *log, int log_idx)
272 {
273 return le32_to_cpu(log->ent[log_idx].seq);
274 }
275
276 /*
277 * This function accepts two log entries, and uses the
278 * sequence number to find the 'older' entry.
279 * It also updates the sequence number in this old entry to
280 * make it the 'new' one if the mark_flag is set.
281 * Finally, it returns which of the entries was the older one.
282 *
283 * TODO The logic feels a bit kludge-y. make it better..
284 */
285 static int btt_log_get_old(struct arena_info *a, struct log_group *log)
286 {
287 int idx0 = a->log_index[0];
288 int idx1 = a->log_index[1];
289 int old;
290
291 /*
292 * the first ever time this is seen, the entry goes into [0]
293 * the next time, the following logic works out to put this
294 * (next) entry into [1]
295 */
296 if (log_seq(log, idx0) == 0) {
297 log->ent[idx0].seq = cpu_to_le32(1);
298 return 0;
299 }
300
301 if (log_seq(log, idx0) == log_seq(log, idx1))
302 return -EINVAL;
303 if (log_seq(log, idx0) + log_seq(log, idx1) > 5)
304 return -EINVAL;
305
306 if (log_seq(log, idx0) < log_seq(log, idx1)) {
307 if ((log_seq(log, idx1) - log_seq(log, idx0)) == 1)
308 old = 0;
309 else
310 old = 1;
311 } else {
312 if ((log_seq(log, idx0) - log_seq(log, idx1)) == 1)
313 old = 1;
314 else
315 old = 0;
316 }
317
318 return old;
319 }
320
321 /*
322 * This function copies the desired (old/new) log entry into ent if
323 * it is not NULL. It returns the sub-slot number (0 or 1)
324 * where the desired log entry was found. Negative return values
325 * indicate errors.
326 */
327 static int btt_log_read(struct arena_info *arena, u32 lane,
328 struct log_entry *ent, int old_flag)
329 {
330 int ret;
331 int old_ent, ret_ent;
332 struct log_group log;
333
334 ret = btt_log_group_read(arena, lane, &log);
335 if (ret)
336 return -EIO;
337
338 old_ent = btt_log_get_old(arena, &log);
339 if (old_ent < 0 || old_ent > 1) {
340 dev_err(to_dev(arena),
341 "log corruption (%d): lane %d seq [%d, %d]\n",
342 old_ent, lane, log.ent[arena->log_index[0]].seq,
343 log.ent[arena->log_index[1]].seq);
344 /* TODO set error state? */
345 return -EIO;
346 }
347
348 ret_ent = (old_flag ? old_ent : (1 - old_ent));
349
350 if (ent != NULL)
351 memcpy(ent, &log.ent[arena->log_index[ret_ent]], LOG_ENT_SIZE);
352
353 return ret_ent;
354 }
355
356 /*
357 * This function commits a log entry to media
358 * It does _not_ prepare the freelist entry for the next write
359 * btt_flog_write is the wrapper for updating the freelist elements
360 */
361 static int __btt_log_write(struct arena_info *arena, u32 lane,
362 u32 sub, struct log_entry *ent, unsigned long flags)
363 {
364 int ret;
365 u32 group_slot = arena->log_index[sub];
366 unsigned int log_half = LOG_ENT_SIZE / 2;
367 void *src = ent;
368 u64 ns_off;
369
370 ns_off = arena->logoff + (lane * LOG_GRP_SIZE) +
371 (group_slot * LOG_ENT_SIZE);
372 /* split the 16B write into atomic, durable halves */
373 ret = arena_write_bytes(arena, ns_off, src, log_half, flags);
374 if (ret)
375 return ret;
376
377 ns_off += log_half;
378 src += log_half;
379 return arena_write_bytes(arena, ns_off, src, log_half, flags);
380 }
381
382 static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
383 struct log_entry *ent)
384 {
385 int ret;
386
387 ret = __btt_log_write(arena, lane, sub, ent, NVDIMM_IO_ATOMIC);
388 if (ret)
389 return ret;
390
391 /* prepare the next free entry */
392 arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
393 if (++(arena->freelist[lane].seq) == 4)
394 arena->freelist[lane].seq = 1;
395 if (ent_e_flag(le32_to_cpu(ent->old_map)))
396 arena->freelist[lane].has_err = 1;
397 arena->freelist[lane].block = ent_lba(le32_to_cpu(ent->old_map));
398
399 return ret;
400 }
401
402 /*
403 * This function initializes the BTT map to the initial state, which is
404 * all-zeroes, and indicates an identity mapping
405 */
406 static int btt_map_init(struct arena_info *arena)
407 {
408 int ret = -EINVAL;
409 void *zerobuf;
410 size_t offset = 0;
411 size_t chunk_size = SZ_2M;
412 size_t mapsize = arena->logoff - arena->mapoff;
413
414 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
415 if (!zerobuf)
416 return -ENOMEM;
417
418 /*
419 * mapoff should always be at least 512B aligned. We rely on that to
420 * make sure rw_bytes does error clearing correctly, so make sure that
421 * is the case.
422 */
423 dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->mapoff, 512),
424 "arena->mapoff: %#llx is unaligned\n", arena->mapoff);
425
426 while (mapsize) {
427 size_t size = min(mapsize, chunk_size);
428
429 dev_WARN_ONCE(to_dev(arena), size < 512,
430 "chunk size: %#zx is unaligned\n", size);
431 ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,
432 size, 0);
433 if (ret)
434 goto free;
435
436 offset += size;
437 mapsize -= size;
438 cond_resched();
439 }
440
441 free:
442 kfree(zerobuf);
443 return ret;
444 }
445
446 /*
447 * This function initializes the BTT log with 'fake' entries pointing
448 * to the initial reserved set of blocks as being free
449 */
450 static int btt_log_init(struct arena_info *arena)
451 {
452 size_t logsize = arena->info2off - arena->logoff;
453 size_t chunk_size = SZ_4K, offset = 0;
454 struct log_entry ent;
455 void *zerobuf;
456 int ret;
457 u32 i;
458
459 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
460 if (!zerobuf)
461 return -ENOMEM;
462 /*
463 * logoff should always be at least 512B aligned. We rely on that to
464 * make sure rw_bytes does error clearing correctly, so make sure that
465 * is the case.
466 */
467 dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->logoff, 512),
468 "arena->logoff: %#llx is unaligned\n", arena->logoff);
469
470 while (logsize) {
471 size_t size = min(logsize, chunk_size);
472
473 dev_WARN_ONCE(to_dev(arena), size < 512,
474 "chunk size: %#zx is unaligned\n", size);
475 ret = arena_write_bytes(arena, arena->logoff + offset, zerobuf,
476 size, 0);
477 if (ret)
478 goto free;
479
480 offset += size;
481 logsize -= size;
482 cond_resched();
483 }
484
485 for (i = 0; i < arena->nfree; i++) {
486 ent.lba = cpu_to_le32(i);
487 ent.old_map = cpu_to_le32(arena->external_nlba + i);
488 ent.new_map = cpu_to_le32(arena->external_nlba + i);
489 ent.seq = cpu_to_le32(LOG_SEQ_INIT);
490 ret = __btt_log_write(arena, i, 0, &ent, 0);
491 if (ret)
492 goto free;
493 }
494
495 free:
496 kfree(zerobuf);
497 return ret;
498 }
499
500 static u64 to_namespace_offset(struct arena_info *arena, u64 lba)
501 {
502 return arena->dataoff + ((u64)lba * arena->internal_lbasize);
503 }
504
505 static int arena_clear_freelist_error(struct arena_info *arena, u32 lane)
506 {
507 int ret = 0;
508
509 if (arena->freelist[lane].has_err) {
510 void *zero_page = page_address(ZERO_PAGE(0));
511 u32 lba = arena->freelist[lane].block;
512 u64 nsoff = to_namespace_offset(arena, lba);
513 unsigned long len = arena->sector_size;
514
515 mutex_lock(&arena->err_lock);
516
517 while (len) {
518 unsigned long chunk = min(len, PAGE_SIZE);
519
520 ret = arena_write_bytes(arena, nsoff, zero_page,
521 chunk, 0);
522 if (ret)
523 break;
524 len -= chunk;
525 nsoff += chunk;
526 if (len == 0)
527 arena->freelist[lane].has_err = 0;
528 }
529 mutex_unlock(&arena->err_lock);
530 }
531 return ret;
532 }
533
534 static int btt_freelist_init(struct arena_info *arena)
535 {
536 int new, ret;
537 struct log_entry log_new;
538 u32 i, map_entry, log_oldmap, log_newmap;
539
540 arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
541 GFP_KERNEL);
542 if (!arena->freelist)
543 return -ENOMEM;
544
545 for (i = 0; i < arena->nfree; i++) {
546 new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
547 if (new < 0)
548 return new;
549
550 /* old and new map entries with any flags stripped out */
551 log_oldmap = ent_lba(le32_to_cpu(log_new.old_map));
552 log_newmap = ent_lba(le32_to_cpu(log_new.new_map));
553
554 /* sub points to the next one to be overwritten */
555 arena->freelist[i].sub = 1 - new;
556 arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
557 arena->freelist[i].block = log_oldmap;
558
559 /*
560 * FIXME: if error clearing fails during init, we want to make
561 * the BTT read-only
562 */
563 if (ent_e_flag(le32_to_cpu(log_new.old_map)) &&
564 !ent_normal(le32_to_cpu(log_new.old_map))) {
565 arena->freelist[i].has_err = 1;
566 ret = arena_clear_freelist_error(arena, i);
567 if (ret)
568 dev_err_ratelimited(to_dev(arena),
569 "Unable to clear known errors\n");
570 }
571
572 /* This implies a newly created or untouched flog entry */
573 if (log_oldmap == log_newmap)
574 continue;
575
576 /* Check if map recovery is needed */
577 ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
578 NULL, NULL, 0);
579 if (ret)
580 return ret;
581
582 /*
583 * The map_entry from btt_read_map is stripped of any flag bits,
584 * so use the stripped out versions from the log as well for
585 * testing whether recovery is needed. For restoration, use the
586 * 'raw' version of the log entries as that captured what we
587 * were going to write originally.
588 */
589 if ((log_newmap != map_entry) && (log_oldmap == map_entry)) {
590 /*
591 * Last transaction wrote the flog, but wasn't able
592 * to complete the map write. So fix up the map.
593 */
594 ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
595 le32_to_cpu(log_new.new_map), 0, 0, 0);
596 if (ret)
597 return ret;
598 }
599 }
600
601 return 0;
602 }
603
604 static bool ent_is_padding(struct log_entry *ent)
605 {
606 return (ent->lba == 0) && (ent->old_map == 0) && (ent->new_map == 0)
607 && (ent->seq == 0);
608 }
609
610 /*
611 * Detecting valid log indices: We read a log group (see the comments in btt.h
612 * for a description of a 'log_group' and its 'slots'), and iterate over its
613 * four slots. We expect that a padding slot will be all-zeroes, and use this
614 * to detect a padding slot vs. an actual entry.
615 *
616 * If a log_group is in the initial state, i.e. hasn't been used since the
617 * creation of this BTT layout, it will have three of the four slots with
618 * zeroes. We skip over these log_groups for the detection of log_index. If
619 * all log_groups are in the initial state (i.e. the BTT has never been
620 * written to), it is safe to assume the 'new format' of log entries in slots
621 * (0, 1).
622 */
623 static int log_set_indices(struct arena_info *arena)
624 {
625 bool idx_set = false, initial_state = true;
626 int ret, log_index[2] = {-1, -1};
627 u32 i, j, next_idx = 0;
628 struct log_group log;
629 u32 pad_count = 0;
630
631 for (i = 0; i < arena->nfree; i++) {
632 ret = btt_log_group_read(arena, i, &log);
633 if (ret < 0)
634 return ret;
635
636 for (j = 0; j < 4; j++) {
637 if (!idx_set) {
638 if (ent_is_padding(&log.ent[j])) {
639 pad_count++;
640 continue;
641 } else {
642 /* Skip if index has been recorded */
643 if ((next_idx == 1) &&
644 (j == log_index[0]))
645 continue;
646 /* valid entry, record index */
647 log_index[next_idx] = j;
648 next_idx++;
649 }
650 if (next_idx == 2) {
651 /* two valid entries found */
652 idx_set = true;
653 } else if (next_idx > 2) {
654 /* too many valid indices */
655 return -ENXIO;
656 }
657 } else {
658 /*
659 * once the indices have been set, just verify
660 * that all subsequent log groups are either in
661 * their initial state or follow the same
662 * indices.
663 */
664 if (j == log_index[0]) {
665 /* entry must be 'valid' */
666 if (ent_is_padding(&log.ent[j]))
667 return -ENXIO;
668 } else if (j == log_index[1]) {
669 ;
670 /*
671 * log_index[1] can be padding if the
672 * lane never got used and it is still
673 * in the initial state (three 'padding'
674 * entries)
675 */
676 } else {
677 /* entry must be invalid (padding) */
678 if (!ent_is_padding(&log.ent[j]))
679 return -ENXIO;
680 }
681 }
682 }
683 /*
684 * If any of the log_groups have more than one valid,
685 * non-padding entry, then the we are no longer in the
686 * initial_state
687 */
688 if (pad_count < 3)
689 initial_state = false;
690 pad_count = 0;
691 }
692
693 if (!initial_state && !idx_set)
694 return -ENXIO;
695
696 /*
697 * If all the entries in the log were in the initial state,
698 * assume new padding scheme
699 */
700 if (initial_state)
701 log_index[1] = 1;
702
703 /*
704 * Only allow the known permutations of log/padding indices,
705 * i.e. (0, 1), and (0, 2)
706 */
707 if ((log_index[0] == 0) && ((log_index[1] == 1) || (log_index[1] == 2)))
708 ; /* known index possibilities */
709 else {
710 dev_err(to_dev(arena), "Found an unknown padding scheme\n");
711 return -ENXIO;
712 }
713
714 arena->log_index[0] = log_index[0];
715 arena->log_index[1] = log_index[1];
716 dev_dbg(to_dev(arena), "log_index_0 = %d\n", log_index[0]);
717 dev_dbg(to_dev(arena), "log_index_1 = %d\n", log_index[1]);
718 return 0;
719 }
720
721 static int btt_rtt_init(struct arena_info *arena)
722 {
723 arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL);
724 if (arena->rtt == NULL)
725 return -ENOMEM;
726
727 return 0;
728 }
729
730 static int btt_maplocks_init(struct arena_info *arena)
731 {
732 u32 i;
733
734 arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
735 GFP_KERNEL);
736 if (!arena->map_locks)
737 return -ENOMEM;
738
739 for (i = 0; i < arena->nfree; i++)
740 spin_lock_init(&arena->map_locks[i].lock);
741
742 return 0;
743 }
744
745 static struct arena_info *alloc_arena(struct btt *btt, size_t size,
746 size_t start, size_t arena_off)
747 {
748 struct arena_info *arena;
749 u64 logsize, mapsize, datasize;
750 u64 available = size;
751
752 arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL);
753 if (!arena)
754 return NULL;
755 arena->nd_btt = btt->nd_btt;
756 arena->sector_size = btt->sector_size;
757 mutex_init(&arena->err_lock);
758
759 if (!size)
760 return arena;
761
762 arena->size = size;
763 arena->external_lba_start = start;
764 arena->external_lbasize = btt->lbasize;
765 arena->internal_lbasize = roundup(arena->external_lbasize,
766 INT_LBASIZE_ALIGNMENT);
767 arena->nfree = BTT_DEFAULT_NFREE;
768 arena->version_major = btt->nd_btt->version_major;
769 arena->version_minor = btt->nd_btt->version_minor;
770
771 if (available % BTT_PG_SIZE)
772 available -= (available % BTT_PG_SIZE);
773
774 /* Two pages are reserved for the super block and its copy */
775 available -= 2 * BTT_PG_SIZE;
776
777 /* The log takes a fixed amount of space based on nfree */
778 logsize = roundup(arena->nfree * LOG_GRP_SIZE, BTT_PG_SIZE);
779 available -= logsize;
780
781 /* Calculate optimal split between map and data area */
782 arena->internal_nlba = div_u64(available - BTT_PG_SIZE,
783 arena->internal_lbasize + MAP_ENT_SIZE);
784 arena->external_nlba = arena->internal_nlba - arena->nfree;
785
786 mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE);
787 datasize = available - mapsize;
788
789 /* 'Absolute' values, relative to start of storage space */
790 arena->infooff = arena_off;
791 arena->dataoff = arena->infooff + BTT_PG_SIZE;
792 arena->mapoff = arena->dataoff + datasize;
793 arena->logoff = arena->mapoff + mapsize;
794 arena->info2off = arena->logoff + logsize;
795
796 /* Default log indices are (0,1) */
797 arena->log_index[0] = 0;
798 arena->log_index[1] = 1;
799 return arena;
800 }
801
802 static void free_arenas(struct btt *btt)
803 {
804 struct arena_info *arena, *next;
805
806 list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
807 list_del(&arena->list);
808 kfree(arena->rtt);
809 kfree(arena->map_locks);
810 kfree(arena->freelist);
811 debugfs_remove_recursive(arena->debugfs_dir);
812 kfree(arena);
813 }
814 }
815
816 /*
817 * This function reads an existing valid btt superblock and
818 * populates the corresponding arena_info struct
819 */
820 static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
821 u64 arena_off)
822 {
823 arena->internal_nlba = le32_to_cpu(super->internal_nlba);
824 arena->internal_lbasize = le32_to_cpu(super->internal_lbasize);
825 arena->external_nlba = le32_to_cpu(super->external_nlba);
826 arena->external_lbasize = le32_to_cpu(super->external_lbasize);
827 arena->nfree = le32_to_cpu(super->nfree);
828 arena->version_major = le16_to_cpu(super->version_major);
829 arena->version_minor = le16_to_cpu(super->version_minor);
830
831 arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off +
832 le64_to_cpu(super->nextoff));
833 arena->infooff = arena_off;
834 arena->dataoff = arena_off + le64_to_cpu(super->dataoff);
835 arena->mapoff = arena_off + le64_to_cpu(super->mapoff);
836 arena->logoff = arena_off + le64_to_cpu(super->logoff);
837 arena->info2off = arena_off + le64_to_cpu(super->info2off);
838
839 arena->size = (le64_to_cpu(super->nextoff) > 0)
840 ? (le64_to_cpu(super->nextoff))
841 : (arena->info2off - arena->infooff + BTT_PG_SIZE);
842
843 arena->flags = le32_to_cpu(super->flags);
844 }
845
846 static int discover_arenas(struct btt *btt)
847 {
848 int ret = 0;
849 struct arena_info *arena;
850 struct btt_sb *super;
851 size_t remaining = btt->rawsize;
852 u64 cur_nlba = 0;
853 size_t cur_off = 0;
854 int num_arenas = 0;
855
856 super = kzalloc(sizeof(*super), GFP_KERNEL);
857 if (!super)
858 return -ENOMEM;
859
860 while (remaining) {
861 /* Alloc memory for arena */
862 arena = alloc_arena(btt, 0, 0, 0);
863 if (!arena) {
864 ret = -ENOMEM;
865 goto out_super;
866 }
867
868 arena->infooff = cur_off;
869 ret = btt_info_read(arena, super);
870 if (ret)
871 goto out;
872
873 if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
874 if (remaining == btt->rawsize) {
875 btt->init_state = INIT_NOTFOUND;
876 dev_info(to_dev(arena), "No existing arenas\n");
877 goto out;
878 } else {
879 dev_err(to_dev(arena),
880 "Found corrupted metadata!\n");
881 ret = -ENODEV;
882 goto out;
883 }
884 }
885
886 arena->external_lba_start = cur_nlba;
887 parse_arena_meta(arena, super, cur_off);
888
889 ret = log_set_indices(arena);
890 if (ret) {
891 dev_err(to_dev(arena),
892 "Unable to deduce log/padding indices\n");
893 goto out;
894 }
895
896 ret = btt_freelist_init(arena);
897 if (ret)
898 goto out;
899
900 ret = btt_rtt_init(arena);
901 if (ret)
902 goto out;
903
904 ret = btt_maplocks_init(arena);
905 if (ret)
906 goto out;
907
908 list_add_tail(&arena->list, &btt->arena_list);
909
910 remaining -= arena->size;
911 cur_off += arena->size;
912 cur_nlba += arena->external_nlba;
913 num_arenas++;
914
915 if (arena->nextoff == 0)
916 break;
917 }
918 btt->num_arenas = num_arenas;
919 btt->nlba = cur_nlba;
920 btt->init_state = INIT_READY;
921
922 kfree(super);
923 return ret;
924
925 out:
926 kfree(arena);
927 free_arenas(btt);
928 out_super:
929 kfree(super);
930 return ret;
931 }
932
933 static int create_arenas(struct btt *btt)
934 {
935 size_t remaining = btt->rawsize;
936 size_t cur_off = 0;
937
938 while (remaining) {
939 struct arena_info *arena;
940 size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining);
941
942 remaining -= arena_size;
943 if (arena_size < ARENA_MIN_SIZE)
944 break;
945
946 arena = alloc_arena(btt, arena_size, btt->nlba, cur_off);
947 if (!arena) {
948 free_arenas(btt);
949 return -ENOMEM;
950 }
951 btt->nlba += arena->external_nlba;
952 if (remaining >= ARENA_MIN_SIZE)
953 arena->nextoff = arena->size;
954 else
955 arena->nextoff = 0;
956 cur_off += arena_size;
957 list_add_tail(&arena->list, &btt->arena_list);
958 }
959
960 return 0;
961 }
962
963 /*
964 * This function completes arena initialization by writing
965 * all the metadata.
966 * It is only called for an uninitialized arena when a write
967 * to that arena occurs for the first time.
968 */
969 static int btt_arena_write_layout(struct arena_info *arena)
970 {
971 int ret;
972 u64 sum;
973 struct btt_sb *super;
974 struct nd_btt *nd_btt = arena->nd_btt;
975 const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
976
977 ret = btt_map_init(arena);
978 if (ret)
979 return ret;
980
981 ret = btt_log_init(arena);
982 if (ret)
983 return ret;
984
985 super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
986 if (!super)
987 return -ENOMEM;
988
989 strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
990 memcpy(super->uuid, nd_btt->uuid, 16);
991 memcpy(super->parent_uuid, parent_uuid, 16);
992 super->flags = cpu_to_le32(arena->flags);
993 super->version_major = cpu_to_le16(arena->version_major);
994 super->version_minor = cpu_to_le16(arena->version_minor);
995 super->external_lbasize = cpu_to_le32(arena->external_lbasize);
996 super->external_nlba = cpu_to_le32(arena->external_nlba);
997 super->internal_lbasize = cpu_to_le32(arena->internal_lbasize);
998 super->internal_nlba = cpu_to_le32(arena->internal_nlba);
999 super->nfree = cpu_to_le32(arena->nfree);
1000 super->infosize = cpu_to_le32(sizeof(struct btt_sb));
1001 super->nextoff = cpu_to_le64(arena->nextoff);
1002 /*
1003 * Subtract arena->infooff (arena start) so numbers are relative
1004 * to 'this' arena
1005 */
1006 super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff);
1007 super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff);
1008 super->logoff = cpu_to_le64(arena->logoff - arena->infooff);
1009 super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
1010
1011 super->flags = 0;
1012 sum = nd_sb_checksum((struct nd_gen_sb *) super);
1013 super->checksum = cpu_to_le64(sum);
1014
1015 ret = btt_info_write(arena, super);
1016
1017 kfree(super);
1018 return ret;
1019 }
1020
1021 /*
1022 * This function completes the initialization for the BTT namespace
1023 * such that it is ready to accept IOs
1024 */
1025 static int btt_meta_init(struct btt *btt)
1026 {
1027 int ret = 0;
1028 struct arena_info *arena;
1029
1030 mutex_lock(&btt->init_lock);
1031 list_for_each_entry(arena, &btt->arena_list, list) {
1032 ret = btt_arena_write_layout(arena);
1033 if (ret)
1034 goto unlock;
1035
1036 ret = btt_freelist_init(arena);
1037 if (ret)
1038 goto unlock;
1039
1040 ret = btt_rtt_init(arena);
1041 if (ret)
1042 goto unlock;
1043
1044 ret = btt_maplocks_init(arena);
1045 if (ret)
1046 goto unlock;
1047 }
1048
1049 btt->init_state = INIT_READY;
1050
1051 unlock:
1052 mutex_unlock(&btt->init_lock);
1053 return ret;
1054 }
1055
1056 static u32 btt_meta_size(struct btt *btt)
1057 {
1058 return btt->lbasize - btt->sector_size;
1059 }
1060
1061 /*
1062 * This function calculates the arena in which the given LBA lies
1063 * by doing a linear walk. This is acceptable since we expect only
1064 * a few arenas. If we have backing devices that get much larger,
1065 * we can construct a balanced binary tree of arenas at init time
1066 * so that this range search becomes faster.
1067 */
1068 static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap,
1069 struct arena_info **arena)
1070 {
1071 struct arena_info *arena_list;
1072 __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size);
1073
1074 list_for_each_entry(arena_list, &btt->arena_list, list) {
1075 if (lba < arena_list->external_nlba) {
1076 *arena = arena_list;
1077 *premap = lba;
1078 return 0;
1079 }
1080 lba -= arena_list->external_nlba;
1081 }
1082
1083 return -EIO;
1084 }
1085
1086 /*
1087 * The following (lock_map, unlock_map) are mostly just to improve
1088 * readability, since they index into an array of locks
1089 */
1090 static void lock_map(struct arena_info *arena, u32 premap)
1091 __acquires(&arena->map_locks[idx].lock)
1092 {
1093 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
1094
1095 spin_lock(&arena->map_locks[idx].lock);
1096 }
1097
1098 static void unlock_map(struct arena_info *arena, u32 premap)
1099 __releases(&arena->map_locks[idx].lock)
1100 {
1101 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
1102
1103 spin_unlock(&arena->map_locks[idx].lock);
1104 }
1105
1106 static int btt_data_read(struct arena_info *arena, struct page *page,
1107 unsigned int off, u32 lba, u32 len)
1108 {
1109 int ret;
1110 u64 nsoff = to_namespace_offset(arena, lba);
1111 void *mem = kmap_atomic(page);
1112
1113 ret = arena_read_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
1114 kunmap_atomic(mem);
1115
1116 return ret;
1117 }
1118
1119 static int btt_data_write(struct arena_info *arena, u32 lba,
1120 struct page *page, unsigned int off, u32 len)
1121 {
1122 int ret;
1123 u64 nsoff = to_namespace_offset(arena, lba);
1124 void *mem = kmap_atomic(page);
1125
1126 ret = arena_write_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
1127 kunmap_atomic(mem);
1128
1129 return ret;
1130 }
1131
1132 static void zero_fill_data(struct page *page, unsigned int off, u32 len)
1133 {
1134 void *mem = kmap_atomic(page);
1135
1136 memset(mem + off, 0, len);
1137 kunmap_atomic(mem);
1138 }
1139
1140 #ifdef CONFIG_BLK_DEV_INTEGRITY
1141 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
1142 struct arena_info *arena, u32 postmap, int rw)
1143 {
1144 unsigned int len = btt_meta_size(btt);
1145 u64 meta_nsoff;
1146 int ret = 0;
1147
1148 if (bip == NULL)
1149 return 0;
1150
1151 meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
1152
1153 while (len) {
1154 unsigned int cur_len;
1155 struct bio_vec bv;
1156 void *mem;
1157
1158 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
1159 /*
1160 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
1161 * .bv_offset already adjusted for iter->bi_bvec_done, and we
1162 * can use those directly
1163 */
1164
1165 cur_len = min(len, bv.bv_len);
1166 mem = kmap_atomic(bv.bv_page);
1167 if (rw)
1168 ret = arena_write_bytes(arena, meta_nsoff,
1169 mem + bv.bv_offset, cur_len,
1170 NVDIMM_IO_ATOMIC);
1171 else
1172 ret = arena_read_bytes(arena, meta_nsoff,
1173 mem + bv.bv_offset, cur_len,
1174 NVDIMM_IO_ATOMIC);
1175
1176 kunmap_atomic(mem);
1177 if (ret)
1178 return ret;
1179
1180 len -= cur_len;
1181 meta_nsoff += cur_len;
1182 if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
1183 return -EIO;
1184 }
1185
1186 return ret;
1187 }
1188
1189 #else /* CONFIG_BLK_DEV_INTEGRITY */
1190 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
1191 struct arena_info *arena, u32 postmap, int rw)
1192 {
1193 return 0;
1194 }
1195 #endif
1196
1197 static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
1198 struct page *page, unsigned int off, sector_t sector,
1199 unsigned int len)
1200 {
1201 int ret = 0;
1202 int t_flag, e_flag;
1203 struct arena_info *arena = NULL;
1204 u32 lane = 0, premap, postmap;
1205
1206 while (len) {
1207 u32 cur_len;
1208
1209 lane = nd_region_acquire_lane(btt->nd_region);
1210
1211 ret = lba_to_arena(btt, sector, &premap, &arena);
1212 if (ret)
1213 goto out_lane;
1214
1215 cur_len = min(btt->sector_size, len);
1216
1217 ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag,
1218 NVDIMM_IO_ATOMIC);
1219 if (ret)
1220 goto out_lane;
1221
1222 /*
1223 * We loop to make sure that the post map LBA didn't change
1224 * from under us between writing the RTT and doing the actual
1225 * read.
1226 */
1227 while (1) {
1228 u32 new_map;
1229 int new_t, new_e;
1230
1231 if (t_flag) {
1232 zero_fill_data(page, off, cur_len);
1233 goto out_lane;
1234 }
1235
1236 if (e_flag) {
1237 ret = -EIO;
1238 goto out_lane;
1239 }
1240
1241 arena->rtt[lane] = RTT_VALID | postmap;
1242 /*
1243 * Barrier to make sure this write is not reordered
1244 * to do the verification map_read before the RTT store
1245 */
1246 barrier();
1247
1248 ret = btt_map_read(arena, premap, &new_map, &new_t,
1249 &new_e, NVDIMM_IO_ATOMIC);
1250 if (ret)
1251 goto out_rtt;
1252
1253 if ((postmap == new_map) && (t_flag == new_t) &&
1254 (e_flag == new_e))
1255 break;
1256
1257 postmap = new_map;
1258 t_flag = new_t;
1259 e_flag = new_e;
1260 }
1261
1262 ret = btt_data_read(arena, page, off, postmap, cur_len);
1263 if (ret) {
1264 /* Media error - set the e_flag */
1265 if (btt_map_write(arena, premap, postmap, 0, 1, NVDIMM_IO_ATOMIC))
1266 dev_warn_ratelimited(to_dev(arena),
1267 "Error persistently tracking bad blocks at %#x\n",
1268 premap);
1269 goto out_rtt;
1270 }
1271
1272 if (bip) {
1273 ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
1274 if (ret)
1275 goto out_rtt;
1276 }
1277
1278 arena->rtt[lane] = RTT_INVALID;
1279 nd_region_release_lane(btt->nd_region, lane);
1280
1281 len -= cur_len;
1282 off += cur_len;
1283 sector += btt->sector_size >> SECTOR_SHIFT;
1284 }
1285
1286 return 0;
1287
1288 out_rtt:
1289 arena->rtt[lane] = RTT_INVALID;
1290 out_lane:
1291 nd_region_release_lane(btt->nd_region, lane);
1292 return ret;
1293 }
1294
1295 /*
1296 * Normally, arena_{read,write}_bytes will take care of the initial offset
1297 * adjustment, but in the case of btt_is_badblock, where we query is_bad_pmem,
1298 * we need the final, raw namespace offset here
1299 */
1300 static bool btt_is_badblock(struct btt *btt, struct arena_info *arena,
1301 u32 postmap)
1302 {
1303 u64 nsoff = adjust_initial_offset(arena->nd_btt,
1304 to_namespace_offset(arena, postmap));
1305 sector_t phys_sector = nsoff >> 9;
1306
1307 return is_bad_pmem(btt->phys_bb, phys_sector, arena->internal_lbasize);
1308 }
1309
1310 static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
1311 sector_t sector, struct page *page, unsigned int off,
1312 unsigned int len)
1313 {
1314 int ret = 0;
1315 struct arena_info *arena = NULL;
1316 u32 premap = 0, old_postmap, new_postmap, lane = 0, i;
1317 struct log_entry log;
1318 int sub;
1319
1320 while (len) {
1321 u32 cur_len;
1322 int e_flag;
1323
1324 retry:
1325 lane = nd_region_acquire_lane(btt->nd_region);
1326
1327 ret = lba_to_arena(btt, sector, &premap, &arena);
1328 if (ret)
1329 goto out_lane;
1330 cur_len = min(btt->sector_size, len);
1331
1332 if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) {
1333 ret = -EIO;
1334 goto out_lane;
1335 }
1336
1337 if (btt_is_badblock(btt, arena, arena->freelist[lane].block))
1338 arena->freelist[lane].has_err = 1;
1339
1340 if (mutex_is_locked(&arena->err_lock)
1341 || arena->freelist[lane].has_err) {
1342 nd_region_release_lane(btt->nd_region, lane);
1343
1344 ret = arena_clear_freelist_error(arena, lane);
1345 if (ret)
1346 return ret;
1347
1348 /* OK to acquire a different lane/free block */
1349 goto retry;
1350 }
1351
1352 new_postmap = arena->freelist[lane].block;
1353
1354 /* Wait if the new block is being read from */
1355 for (i = 0; i < arena->nfree; i++)
1356 while (arena->rtt[i] == (RTT_VALID | new_postmap))
1357 cpu_relax();
1358
1359
1360 if (new_postmap >= arena->internal_nlba) {
1361 ret = -EIO;
1362 goto out_lane;
1363 }
1364
1365 ret = btt_data_write(arena, new_postmap, page, off, cur_len);
1366 if (ret)
1367 goto out_lane;
1368
1369 if (bip) {
1370 ret = btt_rw_integrity(btt, bip, arena, new_postmap,
1371 WRITE);
1372 if (ret)
1373 goto out_lane;
1374 }
1375
1376 lock_map(arena, premap);
1377 ret = btt_map_read(arena, premap, &old_postmap, NULL, &e_flag,
1378 NVDIMM_IO_ATOMIC);
1379 if (ret)
1380 goto out_map;
1381 if (old_postmap >= arena->internal_nlba) {
1382 ret = -EIO;
1383 goto out_map;
1384 }
1385 if (e_flag)
1386 set_e_flag(old_postmap);
1387
1388 log.lba = cpu_to_le32(premap);
1389 log.old_map = cpu_to_le32(old_postmap);
1390 log.new_map = cpu_to_le32(new_postmap);
1391 log.seq = cpu_to_le32(arena->freelist[lane].seq);
1392 sub = arena->freelist[lane].sub;
1393 ret = btt_flog_write(arena, lane, sub, &log);
1394 if (ret)
1395 goto out_map;
1396
1397 ret = btt_map_write(arena, premap, new_postmap, 0, 0,
1398 NVDIMM_IO_ATOMIC);
1399 if (ret)
1400 goto out_map;
1401
1402 unlock_map(arena, premap);
1403 nd_region_release_lane(btt->nd_region, lane);
1404
1405 if (e_flag) {
1406 ret = arena_clear_freelist_error(arena, lane);
1407 if (ret)
1408 return ret;
1409 }
1410
1411 len -= cur_len;
1412 off += cur_len;
1413 sector += btt->sector_size >> SECTOR_SHIFT;
1414 }
1415
1416 return 0;
1417
1418 out_map:
1419 unlock_map(arena, premap);
1420 out_lane:
1421 nd_region_release_lane(btt->nd_region, lane);
1422 return ret;
1423 }
1424
1425 static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
1426 struct page *page, unsigned int len, unsigned int off,
1427 unsigned int op, sector_t sector)
1428 {
1429 int ret;
1430
1431 if (!op_is_write(op)) {
1432 ret = btt_read_pg(btt, bip, page, off, sector, len);
1433 flush_dcache_page(page);
1434 } else {
1435 flush_dcache_page(page);
1436 ret = btt_write_pg(btt, bip, sector, page, off, len);
1437 }
1438
1439 return ret;
1440 }
1441
1442 static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
1443 {
1444 struct bio_integrity_payload *bip = bio_integrity(bio);
1445 struct btt *btt = q->queuedata;
1446 struct bvec_iter iter;
1447 unsigned long start;
1448 struct bio_vec bvec;
1449 int err = 0;
1450 bool do_acct;
1451
1452 if (!bio_integrity_prep(bio))
1453 return BLK_QC_T_NONE;
1454
1455 do_acct = nd_iostat_start(bio, &start);
1456 bio_for_each_segment(bvec, bio, iter) {
1457 unsigned int len = bvec.bv_len;
1458
1459 if (len > PAGE_SIZE || len < btt->sector_size ||
1460 len % btt->sector_size) {
1461 dev_err_ratelimited(&btt->nd_btt->dev,
1462 "unaligned bio segment (len: %d)\n", len);
1463 bio->bi_status = BLK_STS_IOERR;
1464 break;
1465 }
1466
1467 err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
1468 bio_op(bio), iter.bi_sector);
1469 if (err) {
1470 dev_err(&btt->nd_btt->dev,
1471 "io error in %s sector %lld, len %d,\n",
1472 (op_is_write(bio_op(bio))) ? "WRITE" :
1473 "READ",
1474 (unsigned long long) iter.bi_sector, len);
1475 bio->bi_status = errno_to_blk_status(err);
1476 break;
1477 }
1478 }
1479 if (do_acct)
1480 nd_iostat_end(bio, start);
1481
1482 bio_endio(bio);
1483 return BLK_QC_T_NONE;
1484 }
1485
1486 static int btt_rw_page(struct block_device *bdev, sector_t sector,
1487 struct page *page, unsigned int op)
1488 {
1489 struct btt *btt = bdev->bd_disk->private_data;
1490 int rc;
1491 unsigned int len;
1492
1493 len = hpage_nr_pages(page) * PAGE_SIZE;
1494 rc = btt_do_bvec(btt, NULL, page, len, 0, op, sector);
1495 if (rc == 0)
1496 page_endio(page, op_is_write(op), 0);
1497
1498 return rc;
1499 }
1500
1501
1502 static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo)
1503 {
1504 /* some standard values */
1505 geo->heads = 1 << 6;
1506 geo->sectors = 1 << 5;
1507 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
1508 return 0;
1509 }
1510
1511 static const struct block_device_operations btt_fops = {
1512 .owner = THIS_MODULE,
1513 .rw_page = btt_rw_page,
1514 .getgeo = btt_getgeo,
1515 .revalidate_disk = nvdimm_revalidate_disk,
1516 };
1517
1518 static int btt_blk_init(struct btt *btt)
1519 {
1520 struct nd_btt *nd_btt = btt->nd_btt;
1521 struct nd_namespace_common *ndns = nd_btt->ndns;
1522
1523 /* create a new disk and request queue for btt */
1524 btt->btt_queue = blk_alloc_queue(GFP_KERNEL);
1525 if (!btt->btt_queue)
1526 return -ENOMEM;
1527
1528 btt->btt_disk = alloc_disk(0);
1529 if (!btt->btt_disk) {
1530 blk_cleanup_queue(btt->btt_queue);
1531 return -ENOMEM;
1532 }
1533
1534 nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
1535 btt->btt_disk->first_minor = 0;
1536 btt->btt_disk->fops = &btt_fops;
1537 btt->btt_disk->private_data = btt;
1538 btt->btt_disk->queue = btt->btt_queue;
1539 btt->btt_disk->flags = GENHD_FL_EXT_DEVT;
1540 btt->btt_disk->queue->backing_dev_info->capabilities |=
1541 BDI_CAP_SYNCHRONOUS_IO;
1542
1543 blk_queue_make_request(btt->btt_queue, btt_make_request);
1544 blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
1545 blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX);
1546 blk_queue_flag_set(QUEUE_FLAG_NONROT, btt->btt_queue);
1547 btt->btt_queue->queuedata = btt;
1548
1549 if (btt_meta_size(btt)) {
1550 int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
1551
1552 if (rc) {
1553 del_gendisk(btt->btt_disk);
1554 put_disk(btt->btt_disk);
1555 blk_cleanup_queue(btt->btt_queue);
1556 return rc;
1557 }
1558 }
1559 set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
1560 device_add_disk(&btt->nd_btt->dev, btt->btt_disk, NULL);
1561 btt->nd_btt->size = btt->nlba * (u64)btt->sector_size;
1562 revalidate_disk(btt->btt_disk);
1563
1564 return 0;
1565 }
1566
1567 static void btt_blk_cleanup(struct btt *btt)
1568 {
1569 del_gendisk(btt->btt_disk);
1570 put_disk(btt->btt_disk);
1571 blk_cleanup_queue(btt->btt_queue);
1572 }
1573
1574 /**
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
1581 *
1582 * Initialize a Block Translation Table on a backing device to provide
1583 * single sector power fail atomicity.
1584 *
1585 * Context:
1586 * Might sleep.
1587 *
1588 * Returns:
1589 * Pointer to a new struct btt on success, NULL on failure.
1590 */
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)
1593 {
1594 int ret;
1595 struct btt *btt;
1596 struct nd_namespace_io *nsio;
1597 struct device *dev = &nd_btt->dev;
1598
1599 btt = devm_kzalloc(dev, sizeof(struct btt), GFP_KERNEL);
1600 if (!btt)
1601 return NULL;
1602
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;
1612
1613 ret = discover_arenas(btt);
1614 if (ret) {
1615 dev_err(dev, "init: error in arena_discover: %d\n", ret);
1616 return NULL;
1617 }
1618
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));
1622 return NULL;
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);
1628
1629 ret = create_arenas(btt);
1630 if (ret) {
1631 dev_info(dev, "init: create_arenas: %d\n", ret);
1632 return NULL;
1633 }
1634
1635 ret = btt_meta_init(btt);
1636 if (ret) {
1637 dev_err(dev, "init: error in meta_init: %d\n", ret);
1638 return NULL;
1639 }
1640 }
1641
1642 ret = btt_blk_init(btt);
1643 if (ret) {
1644 dev_err(dev, "init: error in blk_init: %d\n", ret);
1645 return NULL;
1646 }
1647
1648 btt_debugfs_init(btt);
1649
1650 return btt;
1651 }
1652
1653 /**
1654 * btt_fini - de-initialize a BTT
1655 * @btt: the BTT handle that was generated by btt_init
1656 *
1657 * De-initialize a Block Translation Table on device removal
1658 *
1659 * Context:
1660 * Might sleep.
1661 */
1662 static void btt_fini(struct btt *btt)
1663 {
1664 if (btt) {
1665 btt_blk_cleanup(btt);
1666 free_arenas(btt);
1667 debugfs_remove_recursive(btt->debugfs_dir);
1668 }
1669 }
1670
1671 int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
1672 {
1673 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1674 struct nd_region *nd_region;
1675 struct btt_sb *btt_sb;
1676 struct btt *btt;
1677 size_t size, rawsize;
1678 int rc;
1679
1680 if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) {
1681 dev_dbg(&nd_btt->dev, "incomplete btt configuration\n");
1682 return -ENODEV;
1683 }
1684
1685 btt_sb = devm_kzalloc(&nd_btt->dev, sizeof(*btt_sb), GFP_KERNEL);
1686 if (!btt_sb)
1687 return -ENOMEM;
1688
1689 size = nvdimm_namespace_capacity(ndns);
1690 rc = devm_namespace_enable(&nd_btt->dev, ndns, size);
1691 if (rc)
1692 return rc;
1693
1694 /*
1695 * If this returns < 0, that is ok as it just means there wasn't
1696 * an existing BTT, and we're creating a new one. We still need to
1697 * call this as we need the version dependent fields in nd_btt to be
1698 * set correctly based on the holder class
1699 */
1700 nd_btt_version(nd_btt, ndns, btt_sb);
1701
1702 rawsize = size - nd_btt->initial_offset;
1703 if (rawsize < ARENA_MIN_SIZE) {
1704 dev_dbg(&nd_btt->dev, "%s must be at least %ld bytes\n",
1705 dev_name(&ndns->dev),
1706 ARENA_MIN_SIZE + nd_btt->initial_offset);
1707 return -ENXIO;
1708 }
1709 nd_region = to_nd_region(nd_btt->dev.parent);
1710 btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid,
1711 nd_region);
1712 if (!btt)
1713 return -ENOMEM;
1714 nd_btt->btt = btt;
1715
1716 return 0;
1717 }
1718 EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
1719
1720 int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt)
1721 {
1722 struct btt *btt = nd_btt->btt;
1723
1724 btt_fini(btt);
1725 nd_btt->btt = NULL;
1726
1727 return 0;
1728 }
1729 EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
1730
1731 static int __init nd_btt_init(void)
1732 {
1733 int rc = 0;
1734
1735 debugfs_root = debugfs_create_dir("btt", NULL);
1736 if (IS_ERR_OR_NULL(debugfs_root))
1737 rc = -ENXIO;
1738
1739 return rc;
1740 }
1741
1742 static void __exit nd_btt_exit(void)
1743 {
1744 debugfs_remove_recursive(debugfs_root);
1745 }
1746
1747 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
1748 MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
1749 MODULE_LICENSE("GPL v2");
1750 module_init(nd_btt_init);
1751 module_exit(nd_btt_exit);
Linux with added FPC-III support