drivers/lightnvm/rrpc.c

   1 /*
   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
  19 static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
  20 static DECLARE_RWSEM(rrpc_lock);
  21
  22 static 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
  29 static 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
  50 static 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
  65 static 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
  84 static 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
  93 static 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
 114 static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
 115 {
 116         return (rblk->next_page == rrpc->dev->pgs_per_blk);
 117 }
 118
 119 static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 120 {
 121         struct nvm_block *blk = rblk->parent;
 122
 123         return blk->id * rrpc->dev->pgs_per_blk;
 124 }
 125
 126 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 127 {
 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 */
 135 static 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
 149 static 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
 170 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 171 {
 172         nvm_put_blk(rrpc->dev, rblk->parent);
 173 }
 174
 175 static 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
 182 static 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  */
 196 static 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
 204 static 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  */
 224 static 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;
 233         u64 phys_addr;
 234         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
 253 try:
 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
 313 finished:
 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
 325 static 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);
 340 done:
 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  */
 347 static 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  */
 359 static 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
 373 static 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
 418 static 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
 436 static const struct block_device_operations rrpc_fops = {
 437         .owner          = THIS_MODULE,
 438 };
 439
 440 static 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
 465 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 466                                         struct rrpc_block *rblk, u64 paddr)
 467 {
 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
 488 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 489 {
 490         u64 addr = ADDR_EMPTY;
 491
 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++;
 499 out:
 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  */
 512 static 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;
 518         u64 paddr;
 519
 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;
 529 retry:
 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);
 558 err:
 559         spin_unlock(&rlun->lock);
 560         return NULL;
 561 }
 562
 563 static 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
 580 static 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
 599 static 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
 625 static 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
 661 static 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
 689 static 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
 724 static 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
 750 static 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
 774 static 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
 806 static void rrpc_make_rq(struct request_queue *q, struct bio *bio)
 807 {
 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);
 814                 return;
 815         }
 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);
 821                 return;
 822         }
 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:
 828                 return;
 829         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);
 844 }
 845
 846 static void rrpc_requeue(struct work_struct *work)
 847 {
 848         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 849         struct bio_list bios;
 850         struct bio *bio;
 851
 852         bio_list_init(&bios);
 853
 854         spin_lock(&rrpc->bio_lock);
 855         bio_list_merge(&bios, &rrpc->requeue_bios);
 856         bio_list_init(&rrpc->requeue_bios);
 857         spin_unlock(&rrpc->bio_lock);
 858
 859         while ((bio = bio_list_pop(&bios)))
 860                 rrpc_make_rq(rrpc->disk->queue, bio);
 861 }
 862
 863 static void rrpc_gc_free(struct rrpc *rrpc)
 864 {
 865         struct rrpc_lun *rlun;
 866         int i;
 867
 868         if (rrpc->krqd_wq)
 869                 destroy_workqueue(rrpc->krqd_wq);
 870
 871         if (rrpc->kgc_wq)
 872                 destroy_workqueue(rrpc->kgc_wq);
 873
 874         if (!rrpc->luns)
 875                 return;
 876
 877         for (i = 0; i < rrpc->nr_luns; i++) {
 878                 rlun = &rrpc->luns[i];
 879
 880                 if (!rlun->blocks)
 881                         break;
 882                 vfree(rlun->blocks);
 883         }
 884 }
 885
 886 static int rrpc_gc_init(struct rrpc *rrpc)
 887 {
 888         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 889                                                                 rrpc->nr_luns);
 890         if (!rrpc->krqd_wq)
 891                 return -ENOMEM;
 892
 893         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 894         if (!rrpc->kgc_wq)
 895                 return -ENOMEM;
 896
 897         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 898
 899         return 0;
 900 }
 901
 902 static void rrpc_map_free(struct rrpc *rrpc)
 903 {
 904         vfree(rrpc->rev_trans_map);
 905         vfree(rrpc->trans_map);
 906 }
 907
 908 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 909 {
 910         struct rrpc *rrpc = (struct rrpc *)private;
 911         struct nvm_dev *dev = rrpc->dev;
 912         struct rrpc_addr *addr = rrpc->trans_map + slba;
 913         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
 914         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 915         u64 elba = slba + nlb;
 916         u64 i;
 917
 918         if (unlikely(elba > dev->total_pages)) {
 919                 pr_err("nvm: L2P data from device is out of bounds!\n");
 920                 return -EINVAL;
 921         }
 922
 923         for (i = 0; i < nlb; i++) {
 924                 u64 pba = le64_to_cpu(entries[i]);
 925                 /* LNVM treats address-spaces as silos, LBA and PBA are
 926                  * equally large and zero-indexed.
 927                  */
 928                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 929                         pr_err("nvm: L2P data entry is out of bounds!\n");
 930                         return -EINVAL;
 931                 }
 932
 933                 /* Address zero is a special one. The first page on a disk is
 934                  * protected. As it often holds internal device boot
 935                  * information.
 936                  */
 937                 if (!pba)
 938                         continue;
 939
 940                 addr[i].addr = pba;
 941                 raddr[pba].addr = slba + i;
 942         }
 943
 944         return 0;
 945 }
 946
 947 static int rrpc_map_init(struct rrpc *rrpc)
 948 {
 949         struct nvm_dev *dev = rrpc->dev;
 950         sector_t i;
 951         int ret;
 952
 953         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
 954         if (!rrpc->trans_map)
 955                 return -ENOMEM;
 956
 957         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
 958                                                         * rrpc->nr_pages);
 959         if (!rrpc->rev_trans_map)
 960                 return -ENOMEM;
 961
 962         for (i = 0; i < rrpc->nr_pages; i++) {
 963                 struct rrpc_addr *p = &rrpc->trans_map[i];
 964                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
 965
 966                 p->addr = ADDR_EMPTY;
 967                 r->addr = ADDR_EMPTY;
 968         }
 969
 970         if (!dev->ops->get_l2p_tbl)
 971                 return 0;
 972
 973         /* Bring up the mapping table from device */
 974         ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
 975                                                         rrpc_l2p_update, rrpc);
 976         if (ret) {
 977                 pr_err("nvm: rrpc: could not read L2P table.\n");
 978                 return -EINVAL;
 979         }
 980
 981         return 0;
 982 }
 983
 984
 985 /* Minimum pages needed within a lun */
 986 #define PAGE_POOL_SIZE 16
 987 #define ADDR_POOL_SIZE 64
 988
 989 static int rrpc_core_init(struct rrpc *rrpc)
 990 {
 991         down_write(&rrpc_lock);
 992         if (!rrpc_gcb_cache) {
 993                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
 994                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
 995                 if (!rrpc_gcb_cache) {
 996                         up_write(&rrpc_lock);
 997                         return -ENOMEM;
 998                 }
 999
1000                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1001                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1002                                 0, 0, NULL);
1003                 if (!rrpc_rq_cache) {
1004                         kmem_cache_destroy(rrpc_gcb_cache);
1005                         up_write(&rrpc_lock);
1006                         return -ENOMEM;
1007                 }
1008         }
1009         up_write(&rrpc_lock);
1010
1011         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1012         if (!rrpc->page_pool)
1013                 return -ENOMEM;
1014
1015         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1016                                                                 rrpc_gcb_cache);
1017         if (!rrpc->gcb_pool)
1018                 return -ENOMEM;
1019
1020         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1021         if (!rrpc->rq_pool)
1022                 return -ENOMEM;
1023
1024         spin_lock_init(&rrpc->inflights.lock);
1025         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1026
1027         return 0;
1028 }
1029
1030 static void rrpc_core_free(struct rrpc *rrpc)
1031 {
1032         mempool_destroy(rrpc->page_pool);
1033         mempool_destroy(rrpc->gcb_pool);
1034         mempool_destroy(rrpc->rq_pool);
1035 }
1036
1037 static void rrpc_luns_free(struct rrpc *rrpc)
1038 {
1039         kfree(rrpc->luns);
1040 }
1041
1042 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1043 {
1044         struct nvm_dev *dev = rrpc->dev;
1045         struct rrpc_lun *rlun;
1046         int i, j;
1047
1048         spin_lock_init(&rrpc->rev_lock);
1049
1050         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1051                                                                 GFP_KERNEL);
1052         if (!rrpc->luns)
1053                 return -ENOMEM;
1054
1055         /* 1:1 mapping */
1056         for (i = 0; i < rrpc->nr_luns; i++) {
1057                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1058
1059                 if (dev->pgs_per_blk >
1060                                 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1061                         pr_err("rrpc: number of pages per block too high.");
1062                         goto err;
1063                 }
1064
1065                 rlun = &rrpc->luns[i];
1066                 rlun->rrpc = rrpc;
1067                 rlun->parent = lun;
1068                 INIT_LIST_HEAD(&rlun->prio_list);
1069                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1070                 spin_lock_init(&rlun->lock);
1071
1072                 rrpc->total_blocks += dev->blks_per_lun;
1073                 rrpc->nr_pages += dev->sec_per_lun;
1074
1075                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1076                                                 rrpc->dev->blks_per_lun);
1077                 if (!rlun->blocks)
1078                         goto err;
1079
1080                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1081                         struct rrpc_block *rblk = &rlun->blocks[j];
1082                         struct nvm_block *blk = &lun->blocks[j];
1083
1084                         rblk->parent = blk;
1085                         INIT_LIST_HEAD(&rblk->prio);
1086                         spin_lock_init(&rblk->lock);
1087                 }
1088         }
1089
1090         return 0;
1091 err:
1092         return -ENOMEM;
1093 }
1094
1095 static void rrpc_free(struct rrpc *rrpc)
1096 {
1097         rrpc_gc_free(rrpc);
1098         rrpc_map_free(rrpc);
1099         rrpc_core_free(rrpc);
1100         rrpc_luns_free(rrpc);
1101
1102         kfree(rrpc);
1103 }
1104
1105 static void rrpc_exit(void *private)
1106 {
1107         struct rrpc *rrpc = private;
1108
1109         del_timer(&rrpc->gc_timer);
1110
1111         flush_workqueue(rrpc->krqd_wq);
1112         flush_workqueue(rrpc->kgc_wq);
1113
1114         rrpc_free(rrpc);
1115 }
1116
1117 static sector_t rrpc_capacity(void *private)
1118 {
1119         struct rrpc *rrpc = private;
1120         struct nvm_dev *dev = rrpc->dev;
1121         sector_t reserved, provisioned;
1122
1123         /* cur, gc, and two emergency blocks for each lun */
1124         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1125         provisioned = rrpc->nr_pages - reserved;
1126
1127         if (reserved > rrpc->nr_pages) {
1128                 pr_err("rrpc: not enough space available to expose storage.\n");
1129                 return 0;
1130         }
1131
1132         sector_div(provisioned, 10);
1133         return provisioned * 9 * NR_PHY_IN_LOG;
1134 }
1135
1136 /*
1137  * Looks up the logical address from reverse trans map and check if its valid by
1138  * comparing the logical to physical address with the physical address.
1139  * Returns 0 on free, otherwise 1 if in use
1140  */
1141 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1142 {
1143         struct nvm_dev *dev = rrpc->dev;
1144         int offset;
1145         struct rrpc_addr *laddr;
1146         u64 paddr, pladdr;
1147
1148         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1149                 paddr = block_to_addr(rrpc, rblk) + offset;
1150
1151                 pladdr = rrpc->rev_trans_map[paddr].addr;
1152                 if (pladdr == ADDR_EMPTY)
1153                         continue;
1154
1155                 laddr = &rrpc->trans_map[pladdr];
1156
1157                 if (paddr == laddr->addr) {
1158                         laddr->rblk = rblk;
1159                 } else {
1160                         set_bit(offset, rblk->invalid_pages);
1161                         rblk->nr_invalid_pages++;
1162                 }
1163         }
1164 }
1165
1166 static int rrpc_blocks_init(struct rrpc *rrpc)
1167 {
1168         struct rrpc_lun *rlun;
1169         struct rrpc_block *rblk;
1170         int lun_iter, blk_iter;
1171
1172         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1173                 rlun = &rrpc->luns[lun_iter];
1174
1175                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1176                                                                 blk_iter++) {
1177                         rblk = &rlun->blocks[blk_iter];
1178                         rrpc_block_map_update(rrpc, rblk);
1179                 }
1180         }
1181
1182         return 0;
1183 }
1184
1185 static int rrpc_luns_configure(struct rrpc *rrpc)
1186 {
1187         struct rrpc_lun *rlun;
1188         struct rrpc_block *rblk;
1189         int i;
1190
1191         for (i = 0; i < rrpc->nr_luns; i++) {
1192                 rlun = &rrpc->luns[i];
1193
1194                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1195                 if (!rblk)
1196                         return -EINVAL;
1197
1198                 rrpc_set_lun_cur(rlun, rblk);
1199
1200                 /* Emergency gc block */
1201                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1202                 if (!rblk)
1203                         return -EINVAL;
1204                 rlun->gc_cur = rblk;
1205         }
1206
1207         return 0;
1208 }
1209
1210 static struct nvm_tgt_type tt_rrpc;
1211
1212 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1213                                                 int lun_begin, int lun_end)
1214 {
1215         struct request_queue *bqueue = dev->q;
1216         struct request_queue *tqueue = tdisk->queue;
1217         struct rrpc *rrpc;
1218         int ret;
1219
1220         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1221                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1222                                                         dev->identity.dom);
1223                 return ERR_PTR(-EINVAL);
1224         }
1225
1226         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1227         if (!rrpc)
1228                 return ERR_PTR(-ENOMEM);
1229
1230         rrpc->instance.tt = &tt_rrpc;
1231         rrpc->dev = dev;
1232         rrpc->disk = tdisk;
1233
1234         bio_list_init(&rrpc->requeue_bios);
1235         spin_lock_init(&rrpc->bio_lock);
1236         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1237
1238         rrpc->nr_luns = lun_end - lun_begin + 1;
1239
1240         /* simple round-robin strategy */
1241         atomic_set(&rrpc->next_lun, -1);
1242
1243         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1244         if (ret) {
1245                 pr_err("nvm: rrpc: could not initialize luns\n");
1246                 goto err;
1247         }
1248
1249         rrpc->poffset = dev->sec_per_lun * lun_begin;
1250         rrpc->lun_offset = lun_begin;
1251
1252         ret = rrpc_core_init(rrpc);
1253         if (ret) {
1254                 pr_err("nvm: rrpc: could not initialize core\n");
1255                 goto err;
1256         }
1257
1258         ret = rrpc_map_init(rrpc);
1259         if (ret) {
1260                 pr_err("nvm: rrpc: could not initialize maps\n");
1261                 goto err;
1262         }
1263
1264         ret = rrpc_blocks_init(rrpc);
1265         if (ret) {
1266                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1267                 goto err;
1268         }
1269
1270         ret = rrpc_luns_configure(rrpc);
1271         if (ret) {
1272                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1273                 goto err;
1274         }
1275
1276         ret = rrpc_gc_init(rrpc);
1277         if (ret) {
1278                 pr_err("nvm: rrpc: could not initialize gc\n");
1279                 goto err;
1280         }
1281
1282         /* inherit the size from the underlying device */
1283         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1284         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1285
1286         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1287                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1288
1289         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1290
1291         return rrpc;
1292 err:
1293         rrpc_free(rrpc);
1294         return ERR_PTR(ret);
1295 }
1296
1297 /* round robin, page-based FTL, and cost-based GC */
1298 static struct nvm_tgt_type tt_rrpc = {
1299         .name           = "rrpc",
1300         .version        = {1, 0, 0},
1301
1302         .make_rq        = rrpc_make_rq,
1303         .capacity       = rrpc_capacity,
1304         .end_io         = rrpc_end_io,
1305
1306         .init           = rrpc_init,
1307         .exit           = rrpc_exit,
1308 };
1309
1310 static int __init rrpc_module_init(void)
1311 {
1312         return nvm_register_target(&tt_rrpc);
1313 }
1314
1315 static void rrpc_module_exit(void)
1316 {
1317         nvm_unregister_target(&tt_rrpc);
1318 }
1319
1320 module_init(rrpc_module_init);
1321 module_exit(rrpc_module_exit);
1322 MODULE_LICENSE("GPL v2");
1323 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");