blob: 7ba64c87ba1c10306c9b96d132f0d2f869a628da [file] [log] [blame]
Matias Bjørlingae1519e2015-10-28 19:54:57 +01001/*
2 * Copyright (C) 2015 IT University of Copenhagen
3 * Initial release: Matias Bjorling <m@bjorling.me>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version
7 * 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
15 */
16
17#include "rrpc.h"
18
19static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
20static DECLARE_RWSEM(rrpc_lock);
21
22static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
23 struct nvm_rq *rqd, unsigned long flags);
24
25#define rrpc_for_each_lun(rrpc, rlun, i) \
26 for ((i) = 0, rlun = &(rrpc)->luns[0]; \
27 (i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)])
28
29static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
30{
31 struct rrpc_block *rblk = a->rblk;
32 unsigned int pg_offset;
33
34 lockdep_assert_held(&rrpc->rev_lock);
35
36 if (a->addr == ADDR_EMPTY || !rblk)
37 return;
38
39 spin_lock(&rblk->lock);
40
41 div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset);
42 WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
43 rblk->nr_invalid_pages++;
44
45 spin_unlock(&rblk->lock);
46
47 rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY;
48}
49
50static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
51 unsigned len)
52{
53 sector_t i;
54
55 spin_lock(&rrpc->rev_lock);
56 for (i = slba; i < slba + len; i++) {
57 struct rrpc_addr *gp = &rrpc->trans_map[i];
58
59 rrpc_page_invalidate(rrpc, gp);
60 gp->rblk = NULL;
61 }
62 spin_unlock(&rrpc->rev_lock);
63}
64
65static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc,
66 sector_t laddr, unsigned int pages)
67{
68 struct nvm_rq *rqd;
69 struct rrpc_inflight_rq *inf;
70
71 rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC);
72 if (!rqd)
73 return ERR_PTR(-ENOMEM);
74
75 inf = rrpc_get_inflight_rq(rqd);
76 if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) {
77 mempool_free(rqd, rrpc->rq_pool);
78 return NULL;
79 }
80
81 return rqd;
82}
83
84static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd)
85{
86 struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd);
87
88 rrpc_unlock_laddr(rrpc, inf);
89
90 mempool_free(rqd, rrpc->rq_pool);
91}
92
93static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)
94{
95 sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
96 sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
97 struct nvm_rq *rqd;
98
99 do {
100 rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
101 schedule();
102 } while (!rqd);
103
104 if (IS_ERR(rqd)) {
105 pr_err("rrpc: unable to acquire inflight IO\n");
106 bio_io_error(bio);
107 return;
108 }
109
110 rrpc_invalidate_range(rrpc, slba, len);
111 rrpc_inflight_laddr_release(rrpc, rqd);
112}
113
114static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
115{
116 return (rblk->next_page == rrpc->dev->pgs_per_blk);
117}
118
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100119static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100120{
121 struct nvm_block *blk = rblk->parent;
122
123 return blk->id * rrpc->dev->pgs_per_blk;
124}
125
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100126static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100127{
128 struct ppa_addr paddr;
129
130 paddr.ppa = addr;
131 return __linear_to_generic_addr(dev, paddr);
132}
133
134/* requires lun->lock taken */
135static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
136{
137 struct rrpc *rrpc = rlun->rrpc;
138
139 BUG_ON(!rblk);
140
141 if (rlun->cur) {
142 spin_lock(&rlun->cur->lock);
143 WARN_ON(!block_is_full(rrpc, rlun->cur));
144 spin_unlock(&rlun->cur->lock);
145 }
146 rlun->cur = rblk;
147}
148
149static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
150 unsigned long flags)
151{
152 struct nvm_block *blk;
153 struct rrpc_block *rblk;
154
155 blk = nvm_get_blk(rrpc->dev, rlun->parent, 0);
156 if (!blk)
157 return NULL;
158
159 rblk = &rlun->blocks[blk->id];
160 blk->priv = rblk;
161
162 bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
163 rblk->next_page = 0;
164 rblk->nr_invalid_pages = 0;
165 atomic_set(&rblk->data_cmnt_size, 0);
166
167 return rblk;
168}
169
170static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
171{
172 nvm_put_blk(rrpc->dev, rblk->parent);
173}
174
175static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
176{
177 int next = atomic_inc_return(&rrpc->next_lun);
178
179 return &rrpc->luns[next % rrpc->nr_luns];
180}
181
182static void rrpc_gc_kick(struct rrpc *rrpc)
183{
184 struct rrpc_lun *rlun;
185 unsigned int i;
186
187 for (i = 0; i < rrpc->nr_luns; i++) {
188 rlun = &rrpc->luns[i];
189 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
190 }
191}
192
193/*
194 * timed GC every interval.
195 */
196static void rrpc_gc_timer(unsigned long data)
197{
198 struct rrpc *rrpc = (struct rrpc *)data;
199
200 rrpc_gc_kick(rrpc);
201 mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
202}
203
204static void rrpc_end_sync_bio(struct bio *bio)
205{
206 struct completion *waiting = bio->bi_private;
207
208 if (bio->bi_error)
209 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
210
211 complete(waiting);
212}
213
214/*
215 * rrpc_move_valid_pages -- migrate live data off the block
216 * @rrpc: the 'rrpc' structure
217 * @block: the block from which to migrate live pages
218 *
219 * Description:
220 * GC algorithms may call this function to migrate remaining live
221 * pages off the block prior to erasing it. This function blocks
222 * further execution until the operation is complete.
223 */
224static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
225{
226 struct request_queue *q = rrpc->dev->q;
227 struct rrpc_rev_addr *rev;
228 struct nvm_rq *rqd;
229 struct bio *bio;
230 struct page *page;
231 int slot;
232 int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100233 u64 phys_addr;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100234 DECLARE_COMPLETION_ONSTACK(wait);
235
236 if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
237 return 0;
238
239 bio = bio_alloc(GFP_NOIO, 1);
240 if (!bio) {
241 pr_err("nvm: could not alloc bio to gc\n");
242 return -ENOMEM;
243 }
244
245 page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
246
247 while ((slot = find_first_zero_bit(rblk->invalid_pages,
248 nr_pgs_per_blk)) < nr_pgs_per_blk) {
249
250 /* Lock laddr */
251 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
252
253try:
254 spin_lock(&rrpc->rev_lock);
255 /* Get logical address from physical to logical table */
256 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
257 /* already updated by previous regular write */
258 if (rev->addr == ADDR_EMPTY) {
259 spin_unlock(&rrpc->rev_lock);
260 continue;
261 }
262
263 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
264 if (IS_ERR_OR_NULL(rqd)) {
265 spin_unlock(&rrpc->rev_lock);
266 schedule();
267 goto try;
268 }
269
270 spin_unlock(&rrpc->rev_lock);
271
272 /* Perform read to do GC */
273 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
274 bio->bi_rw = READ;
275 bio->bi_private = &wait;
276 bio->bi_end_io = rrpc_end_sync_bio;
277
278 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
279 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
280
281 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
282 pr_err("rrpc: gc read failed.\n");
283 rrpc_inflight_laddr_release(rrpc, rqd);
284 goto finished;
285 }
286 wait_for_completion_io(&wait);
287
288 bio_reset(bio);
289 reinit_completion(&wait);
290
291 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
292 bio->bi_rw = WRITE;
293 bio->bi_private = &wait;
294 bio->bi_end_io = rrpc_end_sync_bio;
295
296 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
297
298 /* turn the command around and write the data back to a new
299 * address
300 */
301 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
302 pr_err("rrpc: gc write failed.\n");
303 rrpc_inflight_laddr_release(rrpc, rqd);
304 goto finished;
305 }
306 wait_for_completion_io(&wait);
307
308 rrpc_inflight_laddr_release(rrpc, rqd);
309
310 bio_reset(bio);
311 }
312
313finished:
314 mempool_free(page, rrpc->page_pool);
315 bio_put(bio);
316
317 if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
318 pr_err("nvm: failed to garbage collect block\n");
319 return -EIO;
320 }
321
322 return 0;
323}
324
325static void rrpc_block_gc(struct work_struct *work)
326{
327 struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
328 ws_gc);
329 struct rrpc *rrpc = gcb->rrpc;
330 struct rrpc_block *rblk = gcb->rblk;
331 struct nvm_dev *dev = rrpc->dev;
332
333 pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
334
335 if (rrpc_move_valid_pages(rrpc, rblk))
336 goto done;
337
338 nvm_erase_blk(dev, rblk->parent);
339 rrpc_put_blk(rrpc, rblk);
340done:
341 mempool_free(gcb, rrpc->gcb_pool);
342}
343
344/* the block with highest number of invalid pages, will be in the beginning
345 * of the list
346 */
347static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
348 struct rrpc_block *rb)
349{
350 if (ra->nr_invalid_pages == rb->nr_invalid_pages)
351 return ra;
352
353 return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
354}
355
356/* linearly find the block with highest number of invalid pages
357 * requires lun->lock
358 */
359static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
360{
361 struct list_head *prio_list = &rlun->prio_list;
362 struct rrpc_block *rblock, *max;
363
364 BUG_ON(list_empty(prio_list));
365
366 max = list_first_entry(prio_list, struct rrpc_block, prio);
367 list_for_each_entry(rblock, prio_list, prio)
368 max = rblock_max_invalid(max, rblock);
369
370 return max;
371}
372
373static void rrpc_lun_gc(struct work_struct *work)
374{
375 struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
376 struct rrpc *rrpc = rlun->rrpc;
377 struct nvm_lun *lun = rlun->parent;
378 struct rrpc_block_gc *gcb;
379 unsigned int nr_blocks_need;
380
381 nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
382
383 if (nr_blocks_need < rrpc->nr_luns)
384 nr_blocks_need = rrpc->nr_luns;
385
386 spin_lock(&lun->lock);
387 while (nr_blocks_need > lun->nr_free_blocks &&
388 !list_empty(&rlun->prio_list)) {
389 struct rrpc_block *rblock = block_prio_find_max(rlun);
390 struct nvm_block *block = rblock->parent;
391
392 if (!rblock->nr_invalid_pages)
393 break;
394
395 list_del_init(&rblock->prio);
396
397 BUG_ON(!block_is_full(rrpc, rblock));
398
399 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
400
401 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
402 if (!gcb)
403 break;
404
405 gcb->rrpc = rrpc;
406 gcb->rblk = rblock;
407 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
408
409 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
410
411 nr_blocks_need--;
412 }
413 spin_unlock(&lun->lock);
414
415 /* TODO: Hint that request queue can be started again */
416}
417
418static void rrpc_gc_queue(struct work_struct *work)
419{
420 struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
421 ws_gc);
422 struct rrpc *rrpc = gcb->rrpc;
423 struct rrpc_block *rblk = gcb->rblk;
424 struct nvm_lun *lun = rblk->parent->lun;
425 struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
426
427 spin_lock(&rlun->lock);
428 list_add_tail(&rblk->prio, &rlun->prio_list);
429 spin_unlock(&rlun->lock);
430
431 mempool_free(gcb, rrpc->gcb_pool);
432 pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
433 rblk->parent->id);
434}
435
436static const struct block_device_operations rrpc_fops = {
437 .owner = THIS_MODULE,
438};
439
440static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
441{
442 unsigned int i;
443 struct rrpc_lun *rlun, *max_free;
444
445 if (!is_gc)
446 return get_next_lun(rrpc);
447
448 /* during GC, we don't care about RR, instead we want to make
449 * sure that we maintain evenness between the block luns.
450 */
451 max_free = &rrpc->luns[0];
452 /* prevent GC-ing lun from devouring pages of a lun with
453 * little free blocks. We don't take the lock as we only need an
454 * estimate.
455 */
456 rrpc_for_each_lun(rrpc, rlun, i) {
457 if (rlun->parent->nr_free_blocks >
458 max_free->parent->nr_free_blocks)
459 max_free = rlun;
460 }
461
462 return max_free;
463}
464
465static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100466 struct rrpc_block *rblk, u64 paddr)
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100467{
468 struct rrpc_addr *gp;
469 struct rrpc_rev_addr *rev;
470
471 BUG_ON(laddr >= rrpc->nr_pages);
472
473 gp = &rrpc->trans_map[laddr];
474 spin_lock(&rrpc->rev_lock);
475 if (gp->rblk)
476 rrpc_page_invalidate(rrpc, gp);
477
478 gp->addr = paddr;
479 gp->rblk = rblk;
480
481 rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
482 rev->addr = laddr;
483 spin_unlock(&rrpc->rev_lock);
484
485 return gp;
486}
487
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100488static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100489{
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100490 u64 addr = ADDR_EMPTY;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100491
492 spin_lock(&rblk->lock);
493 if (block_is_full(rrpc, rblk))
494 goto out;
495
496 addr = block_to_addr(rrpc, rblk) + rblk->next_page;
497
498 rblk->next_page++;
499out:
500 spin_unlock(&rblk->lock);
501 return addr;
502}
503
504/* Simple round-robin Logical to physical address translation.
505 *
506 * Retrieve the mapping using the active append point. Then update the ap for
507 * the next write to the disk.
508 *
509 * Returns rrpc_addr with the physical address and block. Remember to return to
510 * rrpc->addr_cache when request is finished.
511 */
512static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
513 int is_gc)
514{
515 struct rrpc_lun *rlun;
516 struct rrpc_block *rblk;
517 struct nvm_lun *lun;
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +0100518 u64 paddr;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100519
520 rlun = rrpc_get_lun_rr(rrpc, is_gc);
521 lun = rlun->parent;
522
523 if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
524 return NULL;
525
526 spin_lock(&rlun->lock);
527
528 rblk = rlun->cur;
529retry:
530 paddr = rrpc_alloc_addr(rrpc, rblk);
531
532 if (paddr == ADDR_EMPTY) {
533 rblk = rrpc_get_blk(rrpc, rlun, 0);
534 if (rblk) {
535 rrpc_set_lun_cur(rlun, rblk);
536 goto retry;
537 }
538
539 if (is_gc) {
540 /* retry from emergency gc block */
541 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
542 if (paddr == ADDR_EMPTY) {
543 rblk = rrpc_get_blk(rrpc, rlun, 1);
544 if (!rblk) {
545 pr_err("rrpc: no more blocks");
546 goto err;
547 }
548
549 rlun->gc_cur = rblk;
550 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
551 }
552 rblk = rlun->gc_cur;
553 }
554 }
555
556 spin_unlock(&rlun->lock);
557 return rrpc_update_map(rrpc, laddr, rblk, paddr);
558err:
559 spin_unlock(&rlun->lock);
560 return NULL;
561}
562
563static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
564{
565 struct rrpc_block_gc *gcb;
566
567 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
568 if (!gcb) {
569 pr_err("rrpc: unable to queue block for gc.");
570 return;
571 }
572
573 gcb->rrpc = rrpc;
574 gcb->rblk = rblk;
575
576 INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
577 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
578}
579
580static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
581 sector_t laddr, uint8_t npages)
582{
583 struct rrpc_addr *p;
584 struct rrpc_block *rblk;
585 struct nvm_lun *lun;
586 int cmnt_size, i;
587
588 for (i = 0; i < npages; i++) {
589 p = &rrpc->trans_map[laddr + i];
590 rblk = p->rblk;
591 lun = rblk->parent->lun;
592
593 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
594 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
595 rrpc_run_gc(rrpc, rblk);
596 }
597}
598
599static int rrpc_end_io(struct nvm_rq *rqd, int error)
600{
601 struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
602 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
603 uint8_t npages = rqd->nr_pages;
604 sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
605
606 if (bio_data_dir(rqd->bio) == WRITE)
607 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
608
609 if (rrqd->flags & NVM_IOTYPE_GC)
610 return 0;
611
612 rrpc_unlock_rq(rrpc, rqd);
613 bio_put(rqd->bio);
614
615 if (npages > 1)
616 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
617 if (rqd->metadata)
618 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
619
620 mempool_free(rqd, rrpc->rq_pool);
621
622 return 0;
623}
624
625static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
626 struct nvm_rq *rqd, unsigned long flags, int npages)
627{
628 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
629 struct rrpc_addr *gp;
630 sector_t laddr = rrpc_get_laddr(bio);
631 int is_gc = flags & NVM_IOTYPE_GC;
632 int i;
633
634 if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
635 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
636 return NVM_IO_REQUEUE;
637 }
638
639 for (i = 0; i < npages; i++) {
640 /* We assume that mapping occurs at 4KB granularity */
641 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
642 gp = &rrpc->trans_map[laddr + i];
643
644 if (gp->rblk) {
645 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
646 gp->addr);
647 } else {
648 BUG_ON(is_gc);
649 rrpc_unlock_laddr(rrpc, r);
650 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
651 rqd->dma_ppa_list);
652 return NVM_IO_DONE;
653 }
654 }
655
656 rqd->opcode = NVM_OP_HBREAD;
657
658 return NVM_IO_OK;
659}
660
661static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
662 unsigned long flags)
663{
664 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
665 int is_gc = flags & NVM_IOTYPE_GC;
666 sector_t laddr = rrpc_get_laddr(bio);
667 struct rrpc_addr *gp;
668
669 if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
670 return NVM_IO_REQUEUE;
671
672 BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
673 gp = &rrpc->trans_map[laddr];
674
675 if (gp->rblk) {
676 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
677 } else {
678 BUG_ON(is_gc);
679 rrpc_unlock_rq(rrpc, rqd);
680 return NVM_IO_DONE;
681 }
682
683 rqd->opcode = NVM_OP_HBREAD;
684 rrqd->addr = gp;
685
686 return NVM_IO_OK;
687}
688
689static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
690 struct nvm_rq *rqd, unsigned long flags, int npages)
691{
692 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
693 struct rrpc_addr *p;
694 sector_t laddr = rrpc_get_laddr(bio);
695 int is_gc = flags & NVM_IOTYPE_GC;
696 int i;
697
698 if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
699 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
700 return NVM_IO_REQUEUE;
701 }
702
703 for (i = 0; i < npages; i++) {
704 /* We assume that mapping occurs at 4KB granularity */
705 p = rrpc_map_page(rrpc, laddr + i, is_gc);
706 if (!p) {
707 BUG_ON(is_gc);
708 rrpc_unlock_laddr(rrpc, r);
709 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
710 rqd->dma_ppa_list);
711 rrpc_gc_kick(rrpc);
712 return NVM_IO_REQUEUE;
713 }
714
715 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
716 p->addr);
717 }
718
719 rqd->opcode = NVM_OP_HBWRITE;
720
721 return NVM_IO_OK;
722}
723
724static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
725 struct nvm_rq *rqd, unsigned long flags)
726{
727 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
728 struct rrpc_addr *p;
729 int is_gc = flags & NVM_IOTYPE_GC;
730 sector_t laddr = rrpc_get_laddr(bio);
731
732 if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
733 return NVM_IO_REQUEUE;
734
735 p = rrpc_map_page(rrpc, laddr, is_gc);
736 if (!p) {
737 BUG_ON(is_gc);
738 rrpc_unlock_rq(rrpc, rqd);
739 rrpc_gc_kick(rrpc);
740 return NVM_IO_REQUEUE;
741 }
742
743 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
744 rqd->opcode = NVM_OP_HBWRITE;
745 rrqd->addr = p;
746
747 return NVM_IO_OK;
748}
749
750static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
751 struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
752{
753 if (npages > 1) {
754 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
755 &rqd->dma_ppa_list);
756 if (!rqd->ppa_list) {
757 pr_err("rrpc: not able to allocate ppa list\n");
758 return NVM_IO_ERR;
759 }
760
761 if (bio_rw(bio) == WRITE)
762 return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
763 npages);
764
765 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
766 }
767
768 if (bio_rw(bio) == WRITE)
769 return rrpc_write_rq(rrpc, bio, rqd, flags);
770
771 return rrpc_read_rq(rrpc, bio, rqd, flags);
772}
773
774static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
775 struct nvm_rq *rqd, unsigned long flags)
776{
777 int err;
778 struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
779 uint8_t nr_pages = rrpc_get_pages(bio);
780 int bio_size = bio_sectors(bio) << 9;
781
782 if (bio_size < rrpc->dev->sec_size)
783 return NVM_IO_ERR;
784 else if (bio_size > rrpc->dev->max_rq_size)
785 return NVM_IO_ERR;
786
787 err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
788 if (err)
789 return err;
790
791 bio_get(bio);
792 rqd->bio = bio;
793 rqd->ins = &rrpc->instance;
794 rqd->nr_pages = nr_pages;
795 rrq->flags = flags;
796
797 err = nvm_submit_io(rrpc->dev, rqd);
798 if (err) {
799 pr_err("rrpc: I/O submission failed: %d\n", err);
800 return NVM_IO_ERR;
801 }
802
803 return NVM_IO_OK;
804}
805
Jens Axboedece1632015-11-05 10:41:16 -0700806static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100807{
808 struct rrpc *rrpc = q->queuedata;
809 struct nvm_rq *rqd;
810 int err;
811
812 if (bio->bi_rw & REQ_DISCARD) {
813 rrpc_discard(rrpc, bio);
Jens Axboedece1632015-11-05 10:41:16 -0700814 return BLK_QC_T_NONE;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100815 }
816
817 rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
818 if (!rqd) {
819 pr_err_ratelimited("rrpc: not able to queue bio.");
820 bio_io_error(bio);
Jens Axboedece1632015-11-05 10:41:16 -0700821 return BLK_QC_T_NONE;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100822 }
823 memset(rqd, 0, sizeof(struct nvm_rq));
824
825 err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
826 switch (err) {
827 case NVM_IO_OK:
Jens Axboedece1632015-11-05 10:41:16 -0700828 return BLK_QC_T_NONE;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100829 case NVM_IO_ERR:
830 bio_io_error(bio);
831 break;
832 case NVM_IO_DONE:
833 bio_endio(bio);
834 break;
835 case NVM_IO_REQUEUE:
836 spin_lock(&rrpc->bio_lock);
837 bio_list_add(&rrpc->requeue_bios, bio);
838 spin_unlock(&rrpc->bio_lock);
839 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
840 break;
841 }
842
843 mempool_free(rqd, rrpc->rq_pool);
Jens Axboedece1632015-11-05 10:41:16 -0700844 return BLK_QC_T_NONE;
Matias Bjørlingae1519e2015-10-28 19:54:57 +0100845}
846
847static void rrpc_requeue(struct work_struct *work)
848{
849 struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
850 struct bio_list bios;
851 struct bio *bio;
852
853 bio_list_init(&bios);
854
855 spin_lock(&rrpc->bio_lock);
856 bio_list_merge(&bios, &rrpc->requeue_bios);
857 bio_list_init(&rrpc->requeue_bios);
858 spin_unlock(&rrpc->bio_lock);
859
860 while ((bio = bio_list_pop(&bios)))
861 rrpc_make_rq(rrpc->disk->queue, bio);
862}
863
864static void rrpc_gc_free(struct rrpc *rrpc)
865{
866 struct rrpc_lun *rlun;
867 int i;
868
869 if (rrpc->krqd_wq)
870 destroy_workqueue(rrpc->krqd_wq);
871
872 if (rrpc->kgc_wq)
873 destroy_workqueue(rrpc->kgc_wq);
874
875 if (!rrpc->luns)
876 return;
877
878 for (i = 0; i < rrpc->nr_luns; i++) {
879 rlun = &rrpc->luns[i];
880
881 if (!rlun->blocks)
882 break;
883 vfree(rlun->blocks);
884 }
885}
886
887static int rrpc_gc_init(struct rrpc *rrpc)
888{
889 rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
890 rrpc->nr_luns);
891 if (!rrpc->krqd_wq)
892 return -ENOMEM;
893
894 rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
895 if (!rrpc->kgc_wq)
896 return -ENOMEM;
897
898 setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
899
900 return 0;
901}
902
903static void rrpc_map_free(struct rrpc *rrpc)
904{
905 vfree(rrpc->rev_trans_map);
906 vfree(rrpc->trans_map);
907}
908
909static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
910{
911 struct rrpc *rrpc = (struct rrpc *)private;
912 struct nvm_dev *dev = rrpc->dev;
913 struct rrpc_addr *addr = rrpc->trans_map + slba;
914 struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
915 sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
916 u64 elba = slba + nlb;
917 u64 i;
918
919 if (unlikely(elba > dev->total_pages)) {
920 pr_err("nvm: L2P data from device is out of bounds!\n");
921 return -EINVAL;
922 }
923
924 for (i = 0; i < nlb; i++) {
925 u64 pba = le64_to_cpu(entries[i]);
926 /* LNVM treats address-spaces as silos, LBA and PBA are
927 * equally large and zero-indexed.
928 */
929 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
930 pr_err("nvm: L2P data entry is out of bounds!\n");
931 return -EINVAL;
932 }
933
934 /* Address zero is a special one. The first page on a disk is
935 * protected. As it often holds internal device boot
936 * information.
937 */
938 if (!pba)
939 continue;
940
941 addr[i].addr = pba;
942 raddr[pba].addr = slba + i;
943 }
944
945 return 0;
946}
947
948static int rrpc_map_init(struct rrpc *rrpc)
949{
950 struct nvm_dev *dev = rrpc->dev;
951 sector_t i;
952 int ret;
953
954 rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
955 if (!rrpc->trans_map)
956 return -ENOMEM;
957
958 rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
959 * rrpc->nr_pages);
960 if (!rrpc->rev_trans_map)
961 return -ENOMEM;
962
963 for (i = 0; i < rrpc->nr_pages; i++) {
964 struct rrpc_addr *p = &rrpc->trans_map[i];
965 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
966
967 p->addr = ADDR_EMPTY;
968 r->addr = ADDR_EMPTY;
969 }
970
971 if (!dev->ops->get_l2p_tbl)
972 return 0;
973
974 /* Bring up the mapping table from device */
975 ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
976 rrpc_l2p_update, rrpc);
977 if (ret) {
978 pr_err("nvm: rrpc: could not read L2P table.\n");
979 return -EINVAL;
980 }
981
982 return 0;
983}
984
985
986/* Minimum pages needed within a lun */
987#define PAGE_POOL_SIZE 16
988#define ADDR_POOL_SIZE 64
989
990static int rrpc_core_init(struct rrpc *rrpc)
991{
992 down_write(&rrpc_lock);
993 if (!rrpc_gcb_cache) {
994 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
995 sizeof(struct rrpc_block_gc), 0, 0, NULL);
996 if (!rrpc_gcb_cache) {
997 up_write(&rrpc_lock);
998 return -ENOMEM;
999 }
1000
1001 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1002 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1003 0, 0, NULL);
1004 if (!rrpc_rq_cache) {
1005 kmem_cache_destroy(rrpc_gcb_cache);
1006 up_write(&rrpc_lock);
1007 return -ENOMEM;
1008 }
1009 }
1010 up_write(&rrpc_lock);
1011
1012 rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1013 if (!rrpc->page_pool)
1014 return -ENOMEM;
1015
1016 rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1017 rrpc_gcb_cache);
1018 if (!rrpc->gcb_pool)
1019 return -ENOMEM;
1020
1021 rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1022 if (!rrpc->rq_pool)
1023 return -ENOMEM;
1024
1025 spin_lock_init(&rrpc->inflights.lock);
1026 INIT_LIST_HEAD(&rrpc->inflights.reqs);
1027
1028 return 0;
1029}
1030
1031static void rrpc_core_free(struct rrpc *rrpc)
1032{
1033 mempool_destroy(rrpc->page_pool);
1034 mempool_destroy(rrpc->gcb_pool);
1035 mempool_destroy(rrpc->rq_pool);
1036}
1037
1038static void rrpc_luns_free(struct rrpc *rrpc)
1039{
1040 kfree(rrpc->luns);
1041}
1042
1043static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1044{
1045 struct nvm_dev *dev = rrpc->dev;
1046 struct rrpc_lun *rlun;
1047 int i, j;
1048
1049 spin_lock_init(&rrpc->rev_lock);
1050
1051 rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1052 GFP_KERNEL);
1053 if (!rrpc->luns)
1054 return -ENOMEM;
1055
1056 /* 1:1 mapping */
1057 for (i = 0; i < rrpc->nr_luns; i++) {
1058 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1059
1060 if (dev->pgs_per_blk >
1061 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1062 pr_err("rrpc: number of pages per block too high.");
1063 goto err;
1064 }
1065
1066 rlun = &rrpc->luns[i];
1067 rlun->rrpc = rrpc;
1068 rlun->parent = lun;
1069 INIT_LIST_HEAD(&rlun->prio_list);
1070 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1071 spin_lock_init(&rlun->lock);
1072
1073 rrpc->total_blocks += dev->blks_per_lun;
1074 rrpc->nr_pages += dev->sec_per_lun;
1075
1076 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1077 rrpc->dev->blks_per_lun);
1078 if (!rlun->blocks)
1079 goto err;
1080
1081 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1082 struct rrpc_block *rblk = &rlun->blocks[j];
1083 struct nvm_block *blk = &lun->blocks[j];
1084
1085 rblk->parent = blk;
1086 INIT_LIST_HEAD(&rblk->prio);
1087 spin_lock_init(&rblk->lock);
1088 }
1089 }
1090
1091 return 0;
1092err:
1093 return -ENOMEM;
1094}
1095
1096static void rrpc_free(struct rrpc *rrpc)
1097{
1098 rrpc_gc_free(rrpc);
1099 rrpc_map_free(rrpc);
1100 rrpc_core_free(rrpc);
1101 rrpc_luns_free(rrpc);
1102
1103 kfree(rrpc);
1104}
1105
1106static void rrpc_exit(void *private)
1107{
1108 struct rrpc *rrpc = private;
1109
1110 del_timer(&rrpc->gc_timer);
1111
1112 flush_workqueue(rrpc->krqd_wq);
1113 flush_workqueue(rrpc->kgc_wq);
1114
1115 rrpc_free(rrpc);
1116}
1117
1118static sector_t rrpc_capacity(void *private)
1119{
1120 struct rrpc *rrpc = private;
1121 struct nvm_dev *dev = rrpc->dev;
1122 sector_t reserved, provisioned;
1123
1124 /* cur, gc, and two emergency blocks for each lun */
1125 reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1126 provisioned = rrpc->nr_pages - reserved;
1127
1128 if (reserved > rrpc->nr_pages) {
1129 pr_err("rrpc: not enough space available to expose storage.\n");
1130 return 0;
1131 }
1132
1133 sector_div(provisioned, 10);
1134 return provisioned * 9 * NR_PHY_IN_LOG;
1135}
1136
1137/*
1138 * Looks up the logical address from reverse trans map and check if its valid by
1139 * comparing the logical to physical address with the physical address.
1140 * Returns 0 on free, otherwise 1 if in use
1141 */
1142static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1143{
1144 struct nvm_dev *dev = rrpc->dev;
1145 int offset;
1146 struct rrpc_addr *laddr;
Matias Bjørlingb7ceb7d2015-11-02 17:12:27 +01001147 u64 paddr, pladdr;
Matias Bjørlingae1519e2015-10-28 19:54:57 +01001148
1149 for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1150 paddr = block_to_addr(rrpc, rblk) + offset;
1151
1152 pladdr = rrpc->rev_trans_map[paddr].addr;
1153 if (pladdr == ADDR_EMPTY)
1154 continue;
1155
1156 laddr = &rrpc->trans_map[pladdr];
1157
1158 if (paddr == laddr->addr) {
1159 laddr->rblk = rblk;
1160 } else {
1161 set_bit(offset, rblk->invalid_pages);
1162 rblk->nr_invalid_pages++;
1163 }
1164 }
1165}
1166
1167static int rrpc_blocks_init(struct rrpc *rrpc)
1168{
1169 struct rrpc_lun *rlun;
1170 struct rrpc_block *rblk;
1171 int lun_iter, blk_iter;
1172
1173 for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1174 rlun = &rrpc->luns[lun_iter];
1175
1176 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1177 blk_iter++) {
1178 rblk = &rlun->blocks[blk_iter];
1179 rrpc_block_map_update(rrpc, rblk);
1180 }
1181 }
1182
1183 return 0;
1184}
1185
1186static int rrpc_luns_configure(struct rrpc *rrpc)
1187{
1188 struct rrpc_lun *rlun;
1189 struct rrpc_block *rblk;
1190 int i;
1191
1192 for (i = 0; i < rrpc->nr_luns; i++) {
1193 rlun = &rrpc->luns[i];
1194
1195 rblk = rrpc_get_blk(rrpc, rlun, 0);
1196 if (!rblk)
1197 return -EINVAL;
1198
1199 rrpc_set_lun_cur(rlun, rblk);
1200
1201 /* Emergency gc block */
1202 rblk = rrpc_get_blk(rrpc, rlun, 1);
1203 if (!rblk)
1204 return -EINVAL;
1205 rlun->gc_cur = rblk;
1206 }
1207
1208 return 0;
1209}
1210
1211static struct nvm_tgt_type tt_rrpc;
1212
1213static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1214 int lun_begin, int lun_end)
1215{
1216 struct request_queue *bqueue = dev->q;
1217 struct request_queue *tqueue = tdisk->queue;
1218 struct rrpc *rrpc;
1219 int ret;
1220
1221 if (!(dev->identity.dom & NVM_RSP_L2P)) {
1222 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1223 dev->identity.dom);
1224 return ERR_PTR(-EINVAL);
1225 }
1226
1227 rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1228 if (!rrpc)
1229 return ERR_PTR(-ENOMEM);
1230
1231 rrpc->instance.tt = &tt_rrpc;
1232 rrpc->dev = dev;
1233 rrpc->disk = tdisk;
1234
1235 bio_list_init(&rrpc->requeue_bios);
1236 spin_lock_init(&rrpc->bio_lock);
1237 INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1238
1239 rrpc->nr_luns = lun_end - lun_begin + 1;
1240
1241 /* simple round-robin strategy */
1242 atomic_set(&rrpc->next_lun, -1);
1243
1244 ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1245 if (ret) {
1246 pr_err("nvm: rrpc: could not initialize luns\n");
1247 goto err;
1248 }
1249
1250 rrpc->poffset = dev->sec_per_lun * lun_begin;
1251 rrpc->lun_offset = lun_begin;
1252
1253 ret = rrpc_core_init(rrpc);
1254 if (ret) {
1255 pr_err("nvm: rrpc: could not initialize core\n");
1256 goto err;
1257 }
1258
1259 ret = rrpc_map_init(rrpc);
1260 if (ret) {
1261 pr_err("nvm: rrpc: could not initialize maps\n");
1262 goto err;
1263 }
1264
1265 ret = rrpc_blocks_init(rrpc);
1266 if (ret) {
1267 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1268 goto err;
1269 }
1270
1271 ret = rrpc_luns_configure(rrpc);
1272 if (ret) {
1273 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1274 goto err;
1275 }
1276
1277 ret = rrpc_gc_init(rrpc);
1278 if (ret) {
1279 pr_err("nvm: rrpc: could not initialize gc\n");
1280 goto err;
1281 }
1282
1283 /* inherit the size from the underlying device */
1284 blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1285 blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1286
1287 pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1288 rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1289
1290 mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1291
1292 return rrpc;
1293err:
1294 rrpc_free(rrpc);
1295 return ERR_PTR(ret);
1296}
1297
1298/* round robin, page-based FTL, and cost-based GC */
1299static struct nvm_tgt_type tt_rrpc = {
1300 .name = "rrpc",
1301 .version = {1, 0, 0},
1302
1303 .make_rq = rrpc_make_rq,
1304 .capacity = rrpc_capacity,
1305 .end_io = rrpc_end_io,
1306
1307 .init = rrpc_init,
1308 .exit = rrpc_exit,
1309};
1310
1311static int __init rrpc_module_init(void)
1312{
1313 return nvm_register_target(&tt_rrpc);
1314}
1315
1316static void rrpc_module_exit(void)
1317{
1318 nvm_unregister_target(&tt_rrpc);
1319}
1320
1321module_init(rrpc_module_init);
1322module_exit(rrpc_module_exit);
1323MODULE_LICENSE("GPL v2");
1324MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");