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 linear_to_generic_addr(struct nvm_dev *dev,
 127                                                         struct ppa_addr r)
 128 {
 129         struct ppa_addr l;
 130         int secs, pgs, blks, luns;
 131         sector_t ppa = r.ppa;
 132
 133         l.ppa = 0;
 134
 135         div_u64_rem(ppa, dev->sec_per_pg, &secs);
 136         l.g.sec = secs;
 137
 138         sector_div(ppa, dev->sec_per_pg);
 139         div_u64_rem(ppa, dev->sec_per_blk, &pgs);
 140         l.g.pg = pgs;
 141
 142         sector_div(ppa, dev->pgs_per_blk);
 143         div_u64_rem(ppa, dev->blks_per_lun, &blks);
 144         l.g.blk = blks;
 145
 146         sector_div(ppa, dev->blks_per_lun);
 147         div_u64_rem(ppa, dev->luns_per_chnl, &luns);
 148         l.g.lun = luns;
 149
 150         sector_div(ppa, dev->luns_per_chnl);
 151         l.g.ch = ppa;
 152
 153         return l;
 154 }
 155
 156 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 157 {
 158         struct ppa_addr paddr;
 159
 160         paddr.ppa = addr;
 161         return linear_to_generic_addr(dev, paddr);
 162 }
 163
 164 /* requires lun->lock taken */
 165 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
 166 {
 167         struct rrpc *rrpc = rlun->rrpc;
 168
 169         BUG_ON(!rblk);
 170
 171         if (rlun->cur) {
 172                 spin_lock(&rlun->cur->lock);
 173                 WARN_ON(!block_is_full(rrpc, rlun->cur));
 174                 spin_unlock(&rlun->cur->lock);
 175         }
 176         rlun->cur = rblk;
 177 }
 178
 179 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 180                                                         unsigned long flags)
 181 {
 182         struct nvm_block *blk;
 183         struct rrpc_block *rblk;
 184
 185         blk = nvm_get_blk(rrpc->dev, rlun->parent, 0);
 186         if (!blk)
 187                 return NULL;
 188
 189         rblk = &rlun->blocks[blk->id];
 190         blk->priv = rblk;
 191
 192         bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
 193         rblk->next_page = 0;
 194         rblk->nr_invalid_pages = 0;
 195         atomic_set(&rblk->data_cmnt_size, 0);
 196
 197         return rblk;
 198 }
 199
 200 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 201 {
 202         nvm_put_blk(rrpc->dev, rblk->parent);
 203 }
 204
 205 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 206 {
 207         int next = atomic_inc_return(&rrpc->next_lun);
 208
 209         return &rrpc->luns[next % rrpc->nr_luns];
 210 }
 211
 212 static void rrpc_gc_kick(struct rrpc *rrpc)
 213 {
 214         struct rrpc_lun *rlun;
 215         unsigned int i;
 216
 217         for (i = 0; i < rrpc->nr_luns; i++) {
 218                 rlun = &rrpc->luns[i];
 219                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 220         }
 221 }
 222
 223 /*
 224  * timed GC every interval.
 225  */
 226 static void rrpc_gc_timer(unsigned long data)
 227 {
 228         struct rrpc *rrpc = (struct rrpc *)data;
 229
 230         rrpc_gc_kick(rrpc);
 231         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 232 }
 233
 234 static void rrpc_end_sync_bio(struct bio *bio)
 235 {
 236         struct completion *waiting = bio->bi_private;
 237
 238         if (bio->bi_error)
 239                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 240
 241         complete(waiting);
 242 }
 243
 244 /*
 245  * rrpc_move_valid_pages -- migrate live data off the block
 246  * @rrpc: the 'rrpc' structure
 247  * @block: the block from which to migrate live pages
 248  *
 249  * Description:
 250  *   GC algorithms may call this function to migrate remaining live
 251  *   pages off the block prior to erasing it. This function blocks
 252  *   further execution until the operation is complete.
 253  */
 254 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 255 {
 256         struct request_queue *q = rrpc->dev->q;
 257         struct rrpc_rev_addr *rev;
 258         struct nvm_rq *rqd;
 259         struct bio *bio;
 260         struct page *page;
 261         int slot;
 262         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 263         u64 phys_addr;
 264         DECLARE_COMPLETION_ONSTACK(wait);
 265
 266         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 267                 return 0;
 268
 269         bio = bio_alloc(GFP_NOIO, 1);
 270         if (!bio) {
 271                 pr_err("nvm: could not alloc bio to gc\n");
 272                 return -ENOMEM;
 273         }
 274
 275         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 276
 277         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 278                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 279
 280                 /* Lock laddr */
 281                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 282
 283 try:
 284                 spin_lock(&rrpc->rev_lock);
 285                 /* Get logical address from physical to logical table */
 286                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 287                 /* already updated by previous regular write */
 288                 if (rev->addr == ADDR_EMPTY) {
 289                         spin_unlock(&rrpc->rev_lock);
 290                         continue;
 291                 }
 292
 293                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 294                 if (IS_ERR_OR_NULL(rqd)) {
 295                         spin_unlock(&rrpc->rev_lock);
 296                         schedule();
 297                         goto try;
 298                 }
 299
 300                 spin_unlock(&rrpc->rev_lock);
 301
 302                 /* Perform read to do GC */
 303                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 304                 bio->bi_rw = READ;
 305                 bio->bi_private = &wait;
 306                 bio->bi_end_io = rrpc_end_sync_bio;
 307
 308                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 309                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 310
 311                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 312                         pr_err("rrpc: gc read failed.\n");
 313                         rrpc_inflight_laddr_release(rrpc, rqd);
 314                         goto finished;
 315                 }
 316                 wait_for_completion_io(&wait);
 317
 318                 bio_reset(bio);
 319                 reinit_completion(&wait);
 320
 321                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 322                 bio->bi_rw = WRITE;
 323                 bio->bi_private = &wait;
 324                 bio->bi_end_io = rrpc_end_sync_bio;
 325
 326                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 327
 328                 /* turn the command around and write the data back to a new
 329                  * address
 330                  */
 331                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 332                         pr_err("rrpc: gc write failed.\n");
 333                         rrpc_inflight_laddr_release(rrpc, rqd);
 334                         goto finished;
 335                 }
 336                 wait_for_completion_io(&wait);
 337
 338                 rrpc_inflight_laddr_release(rrpc, rqd);
 339
 340                 bio_reset(bio);
 341         }
 342
 343 finished:
 344         mempool_free(page, rrpc->page_pool);
 345         bio_put(bio);
 346
 347         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 348                 pr_err("nvm: failed to garbage collect block\n");
 349                 return -EIO;
 350         }
 351
 352         return 0;
 353 }
 354
 355 static void rrpc_block_gc(struct work_struct *work)
 356 {
 357         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 358                                                                         ws_gc);
 359         struct rrpc *rrpc = gcb->rrpc;
 360         struct rrpc_block *rblk = gcb->rblk;
 361         struct nvm_dev *dev = rrpc->dev;
 362
 363         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 364
 365         if (rrpc_move_valid_pages(rrpc, rblk))
 366                 goto done;
 367
 368         nvm_erase_blk(dev, rblk->parent);
 369         rrpc_put_blk(rrpc, rblk);
 370 done:
 371         mempool_free(gcb, rrpc->gcb_pool);
 372 }
 373
 374 /* the block with highest number of invalid pages, will be in the beginning
 375  * of the list
 376  */
 377 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 378                                                         struct rrpc_block *rb)
 379 {
 380         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 381                 return ra;
 382
 383         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 384 }
 385
 386 /* linearly find the block with highest number of invalid pages
 387  * requires lun->lock
 388  */
 389 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 390 {
 391         struct list_head *prio_list = &rlun->prio_list;
 392         struct rrpc_block *rblock, *max;
 393
 394         BUG_ON(list_empty(prio_list));
 395
 396         max = list_first_entry(prio_list, struct rrpc_block, prio);
 397         list_for_each_entry(rblock, prio_list, prio)
 398                 max = rblock_max_invalid(max, rblock);
 399
 400         return max;
 401 }
 402
 403 static void rrpc_lun_gc(struct work_struct *work)
 404 {
 405         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 406         struct rrpc *rrpc = rlun->rrpc;
 407         struct nvm_lun *lun = rlun->parent;
 408         struct rrpc_block_gc *gcb;
 409         unsigned int nr_blocks_need;
 410
 411         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 412
 413         if (nr_blocks_need < rrpc->nr_luns)
 414                 nr_blocks_need = rrpc->nr_luns;
 415
 416         spin_lock(&lun->lock);
 417         while (nr_blocks_need > lun->nr_free_blocks &&
 418                                         !list_empty(&rlun->prio_list)) {
 419                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 420                 struct nvm_block *block = rblock->parent;
 421
 422                 if (!rblock->nr_invalid_pages)
 423                         break;
 424
 425                 list_del_init(&rblock->prio);
 426
 427                 BUG_ON(!block_is_full(rrpc, rblock));
 428
 429                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 430
 431                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 432                 if (!gcb)
 433                         break;
 434
 435                 gcb->rrpc = rrpc;
 436                 gcb->rblk = rblock;
 437                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 438
 439                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 440
 441                 nr_blocks_need--;
 442         }
 443         spin_unlock(&lun->lock);
 444
 445         /* TODO: Hint that request queue can be started again */
 446 }
 447
 448 static void rrpc_gc_queue(struct work_struct *work)
 449 {
 450         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 451                                                                         ws_gc);
 452         struct rrpc *rrpc = gcb->rrpc;
 453         struct rrpc_block *rblk = gcb->rblk;
 454         struct nvm_lun *lun = rblk->parent->lun;
 455         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 456
 457         spin_lock(&rlun->lock);
 458         list_add_tail(&rblk->prio, &rlun->prio_list);
 459         spin_unlock(&rlun->lock);
 460
 461         mempool_free(gcb, rrpc->gcb_pool);
 462         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 463                                                         rblk->parent->id);
 464 }
 465
 466 static const struct block_device_operations rrpc_fops = {
 467         .owner          = THIS_MODULE,
 468 };
 469
 470 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 471 {
 472         unsigned int i;
 473         struct rrpc_lun *rlun, *max_free;
 474
 475         if (!is_gc)
 476                 return get_next_lun(rrpc);
 477
 478         /* during GC, we don't care about RR, instead we want to make
 479          * sure that we maintain evenness between the block luns.
 480          */
 481         max_free = &rrpc->luns[0];
 482         /* prevent GC-ing lun from devouring pages of a lun with
 483          * little free blocks. We don't take the lock as we only need an
 484          * estimate.
 485          */
 486         rrpc_for_each_lun(rrpc, rlun, i) {
 487                 if (rlun->parent->nr_free_blocks >
 488                                         max_free->parent->nr_free_blocks)
 489                         max_free = rlun;
 490         }
 491
 492         return max_free;
 493 }
 494
 495 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 496                                         struct rrpc_block *rblk, u64 paddr)
 497 {
 498         struct rrpc_addr *gp;
 499         struct rrpc_rev_addr *rev;
 500
 501         BUG_ON(laddr >= rrpc->nr_pages);
 502
 503         gp = &rrpc->trans_map[laddr];
 504         spin_lock(&rrpc->rev_lock);
 505         if (gp->rblk)
 506                 rrpc_page_invalidate(rrpc, gp);
 507
 508         gp->addr = paddr;
 509         gp->rblk = rblk;
 510
 511         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 512         rev->addr = laddr;
 513         spin_unlock(&rrpc->rev_lock);
 514
 515         return gp;
 516 }
 517
 518 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 519 {
 520         u64 addr = ADDR_EMPTY;
 521
 522         spin_lock(&rblk->lock);
 523         if (block_is_full(rrpc, rblk))
 524                 goto out;
 525
 526         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 527
 528         rblk->next_page++;
 529 out:
 530         spin_unlock(&rblk->lock);
 531         return addr;
 532 }
 533
 534 /* Simple round-robin Logical to physical address translation.
 535  *
 536  * Retrieve the mapping using the active append point. Then update the ap for
 537  * the next write to the disk.
 538  *
 539  * Returns rrpc_addr with the physical address and block. Remember to return to
 540  * rrpc->addr_cache when request is finished.
 541  */
 542 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 543                                                                 int is_gc)
 544 {
 545         struct rrpc_lun *rlun;
 546         struct rrpc_block *rblk;
 547         struct nvm_lun *lun;
 548         u64 paddr;
 549
 550         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 551         lun = rlun->parent;
 552
 553         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 554                 return NULL;
 555
 556         spin_lock(&rlun->lock);
 557
 558         rblk = rlun->cur;
 559 retry:
 560         paddr = rrpc_alloc_addr(rrpc, rblk);
 561
 562         if (paddr == ADDR_EMPTY) {
 563                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 564                 if (rblk) {
 565                         rrpc_set_lun_cur(rlun, rblk);
 566                         goto retry;
 567                 }
 568
 569                 if (is_gc) {
 570                         /* retry from emergency gc block */
 571                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 572                         if (paddr == ADDR_EMPTY) {
 573                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 574                                 if (!rblk) {
 575                                         pr_err("rrpc: no more blocks");
 576                                         goto err;
 577                                 }
 578
 579                                 rlun->gc_cur = rblk;
 580                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 581                         }
 582                         rblk = rlun->gc_cur;
 583                 }
 584         }
 585
 586         spin_unlock(&rlun->lock);
 587         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 588 err:
 589         spin_unlock(&rlun->lock);
 590         return NULL;
 591 }
 592
 593 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 594 {
 595         struct rrpc_block_gc *gcb;
 596
 597         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 598         if (!gcb) {
 599                 pr_err("rrpc: unable to queue block for gc.");
 600                 return;
 601         }
 602
 603         gcb->rrpc = rrpc;
 604         gcb->rblk = rblk;
 605
 606         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 607         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 608 }
 609
 610 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 611                                                 sector_t laddr, uint8_t npages)
 612 {
 613         struct rrpc_addr *p;
 614         struct rrpc_block *rblk;
 615         struct nvm_lun *lun;
 616         int cmnt_size, i;
 617
 618         for (i = 0; i < npages; i++) {
 619                 p = &rrpc->trans_map[laddr + i];
 620                 rblk = p->rblk;
 621                 lun = rblk->parent->lun;
 622
 623                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 624                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
 625                         rrpc_run_gc(rrpc, rblk);
 626         }
 627 }
 628
 629 static int rrpc_end_io(struct nvm_rq *rqd, int error)
 630 {
 631         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 632         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 633         uint8_t npages = rqd->nr_pages;
 634         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 635
 636         if (bio_data_dir(rqd->bio) == WRITE)
 637                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 638
 639         if (rrqd->flags & NVM_IOTYPE_GC)
 640                 return 0;
 641
 642         rrpc_unlock_rq(rrpc, rqd);
 643         bio_put(rqd->bio);
 644
 645         if (npages > 1)
 646                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 647         if (rqd->metadata)
 648                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 649
 650         mempool_free(rqd, rrpc->rq_pool);
 651
 652         return 0;
 653 }
 654
 655 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 656                         struct nvm_rq *rqd, unsigned long flags, int npages)
 657 {
 658         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 659         struct rrpc_addr *gp;
 660         sector_t laddr = rrpc_get_laddr(bio);
 661         int is_gc = flags & NVM_IOTYPE_GC;
 662         int i;
 663
 664         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 665                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 666                 return NVM_IO_REQUEUE;
 667         }
 668
 669         for (i = 0; i < npages; i++) {
 670                 /* We assume that mapping occurs at 4KB granularity */
 671                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 672                 gp = &rrpc->trans_map[laddr + i];
 673
 674                 if (gp->rblk) {
 675                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 676                                                                 gp->addr);
 677                 } else {
 678                         BUG_ON(is_gc);
 679                         rrpc_unlock_laddr(rrpc, r);
 680                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 681                                                         rqd->dma_ppa_list);
 682                         return NVM_IO_DONE;
 683                 }
 684         }
 685
 686         rqd->opcode = NVM_OP_HBREAD;
 687
 688         return NVM_IO_OK;
 689 }
 690
 691 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 692                                                         unsigned long flags)
 693 {
 694         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 695         int is_gc = flags & NVM_IOTYPE_GC;
 696         sector_t laddr = rrpc_get_laddr(bio);
 697         struct rrpc_addr *gp;
 698
 699         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 700                 return NVM_IO_REQUEUE;
 701
 702         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 703         gp = &rrpc->trans_map[laddr];
 704
 705         if (gp->rblk) {
 706                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 707         } else {
 708                 BUG_ON(is_gc);
 709                 rrpc_unlock_rq(rrpc, rqd);
 710                 return NVM_IO_DONE;
 711         }
 712
 713         rqd->opcode = NVM_OP_HBREAD;
 714         rrqd->addr = gp;
 715
 716         return NVM_IO_OK;
 717 }
 718
 719 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 720                         struct nvm_rq *rqd, unsigned long flags, int npages)
 721 {
 722         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 723         struct rrpc_addr *p;
 724         sector_t laddr = rrpc_get_laddr(bio);
 725         int is_gc = flags & NVM_IOTYPE_GC;
 726         int i;
 727
 728         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 729                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 730                 return NVM_IO_REQUEUE;
 731         }
 732
 733         for (i = 0; i < npages; i++) {
 734                 /* We assume that mapping occurs at 4KB granularity */
 735                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 736                 if (!p) {
 737                         BUG_ON(is_gc);
 738                         rrpc_unlock_laddr(rrpc, r);
 739                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 740                                                         rqd->dma_ppa_list);
 741                         rrpc_gc_kick(rrpc);
 742                         return NVM_IO_REQUEUE;
 743                 }
 744
 745                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 746                                                                 p->addr);
 747         }
 748
 749         rqd->opcode = NVM_OP_HBWRITE;
 750
 751         return NVM_IO_OK;
 752 }
 753
 754 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 755                                 struct nvm_rq *rqd, unsigned long flags)
 756 {
 757         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 758         struct rrpc_addr *p;
 759         int is_gc = flags & NVM_IOTYPE_GC;
 760         sector_t laddr = rrpc_get_laddr(bio);
 761
 762         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 763                 return NVM_IO_REQUEUE;
 764
 765         p = rrpc_map_page(rrpc, laddr, is_gc);
 766         if (!p) {
 767                 BUG_ON(is_gc);
 768                 rrpc_unlock_rq(rrpc, rqd);
 769                 rrpc_gc_kick(rrpc);
 770                 return NVM_IO_REQUEUE;
 771         }
 772
 773         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 774         rqd->opcode = NVM_OP_HBWRITE;
 775         rrqd->addr = p;
 776
 777         return NVM_IO_OK;
 778 }
 779
 780 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 781                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 782 {
 783         if (npages > 1) {
 784                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 785                                                         &rqd->dma_ppa_list);
 786                 if (!rqd->ppa_list) {
 787                         pr_err("rrpc: not able to allocate ppa list\n");
 788                         return NVM_IO_ERR;
 789                 }
 790
 791                 if (bio_rw(bio) == WRITE)
 792                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 793                                                                         npages);
 794
 795                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 796         }
 797
 798         if (bio_rw(bio) == WRITE)
 799                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 800
 801         return rrpc_read_rq(rrpc, bio, rqd, flags);
 802 }
 803
 804 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 805                                 struct nvm_rq *rqd, unsigned long flags)
 806 {
 807         int err;
 808         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 809         uint8_t nr_pages = rrpc_get_pages(bio);
 810         int bio_size = bio_sectors(bio) << 9;
 811
 812         if (bio_size < rrpc->dev->sec_size)
 813                 return NVM_IO_ERR;
 814         else if (bio_size > rrpc->dev->max_rq_size)
 815                 return NVM_IO_ERR;
 816
 817         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 818         if (err)
 819                 return err;
 820
 821         bio_get(bio);
 822         rqd->bio = bio;
 823         rqd->ins = &rrpc->instance;
 824         rqd->nr_pages = nr_pages;
 825         rrq->flags = flags;
 826
 827         err = nvm_submit_io(rrpc->dev, rqd);
 828         if (err) {
 829                 pr_err("rrpc: I/O submission failed: %d\n", err);
 830                 return NVM_IO_ERR;
 831         }
 832
 833         return NVM_IO_OK;
 834 }
 835
 836 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 837 {
 838         struct rrpc *rrpc = q->queuedata;
 839         struct nvm_rq *rqd;
 840         int err;
 841
 842         if (bio->bi_rw & REQ_DISCARD) {
 843                 rrpc_discard(rrpc, bio);
 844                 return BLK_QC_T_NONE;
 845         }
 846
 847         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 848         if (!rqd) {
 849                 pr_err_ratelimited("rrpc: not able to queue bio.");
 850                 bio_io_error(bio);
 851                 return BLK_QC_T_NONE;
 852         }
 853         memset(rqd, 0, sizeof(struct nvm_rq));
 854
 855         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 856         switch (err) {
 857         case NVM_IO_OK:
 858                 return BLK_QC_T_NONE;
 859         case NVM_IO_ERR:
 860                 bio_io_error(bio);
 861                 break;
 862         case NVM_IO_DONE:
 863                 bio_endio(bio);
 864                 break;
 865         case NVM_IO_REQUEUE:
 866                 spin_lock(&rrpc->bio_lock);
 867                 bio_list_add(&rrpc->requeue_bios, bio);
 868                 spin_unlock(&rrpc->bio_lock);
 869                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 870                 break;
 871         }
 872
 873         mempool_free(rqd, rrpc->rq_pool);
 874         return BLK_QC_T_NONE;
 875 }
 876
 877 static void rrpc_requeue(struct work_struct *work)
 878 {
 879         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 880         struct bio_list bios;
 881         struct bio *bio;
 882
 883         bio_list_init(&bios);
 884
 885         spin_lock(&rrpc->bio_lock);
 886         bio_list_merge(&bios, &rrpc->requeue_bios);
 887         bio_list_init(&rrpc->requeue_bios);
 888         spin_unlock(&rrpc->bio_lock);
 889
 890         while ((bio = bio_list_pop(&bios)))
 891                 rrpc_make_rq(rrpc->disk->queue, bio);
 892 }
 893
 894 static void rrpc_gc_free(struct rrpc *rrpc)
 895 {
 896         struct rrpc_lun *rlun;
 897         int i;
 898
 899         if (rrpc->krqd_wq)
 900                 destroy_workqueue(rrpc->krqd_wq);
 901
 902         if (rrpc->kgc_wq)
 903                 destroy_workqueue(rrpc->kgc_wq);
 904
 905         if (!rrpc->luns)
 906                 return;
 907
 908         for (i = 0; i < rrpc->nr_luns; i++) {
 909                 rlun = &rrpc->luns[i];
 910
 911                 if (!rlun->blocks)
 912                         break;
 913                 vfree(rlun->blocks);
 914         }
 915 }
 916
 917 static int rrpc_gc_init(struct rrpc *rrpc)
 918 {
 919         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 920                                                                 rrpc->nr_luns);
 921         if (!rrpc->krqd_wq)
 922                 return -ENOMEM;
 923
 924         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 925         if (!rrpc->kgc_wq)
 926                 return -ENOMEM;
 927
 928         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 929
 930         return 0;
 931 }
 932
 933 static void rrpc_map_free(struct rrpc *rrpc)
 934 {
 935         vfree(rrpc->rev_trans_map);
 936         vfree(rrpc->trans_map);
 937 }
 938
 939 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 940 {
 941         struct rrpc *rrpc = (struct rrpc *)private;
 942         struct nvm_dev *dev = rrpc->dev;
 943         struct rrpc_addr *addr = rrpc->trans_map + slba;
 944         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
 945         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 946         u64 elba = slba + nlb;
 947         u64 i;
 948
 949         if (unlikely(elba > dev->total_pages)) {
 950                 pr_err("nvm: L2P data from device is out of bounds!\n");
 951                 return -EINVAL;
 952         }
 953
 954         for (i = 0; i < nlb; i++) {
 955                 u64 pba = le64_to_cpu(entries[i]);
 956                 /* LNVM treats address-spaces as silos, LBA and PBA are
 957                  * equally large and zero-indexed.
 958                  */
 959                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 960                         pr_err("nvm: L2P data entry is out of bounds!\n");
 961                         return -EINVAL;
 962                 }
 963
 964                 /* Address zero is a special one. The first page on a disk is
 965                  * protected. As it often holds internal device boot
 966                  * information.
 967                  */
 968                 if (!pba)
 969                         continue;
 970
 971                 addr[i].addr = pba;
 972                 raddr[pba].addr = slba + i;
 973         }
 974
 975         return 0;
 976 }
 977
 978 static int rrpc_map_init(struct rrpc *rrpc)
 979 {
 980         struct nvm_dev *dev = rrpc->dev;
 981         sector_t i;
 982         int ret;
 983
 984         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
 985         if (!rrpc->trans_map)
 986                 return -ENOMEM;
 987
 988         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
 989                                                         * rrpc->nr_pages);
 990         if (!rrpc->rev_trans_map)
 991                 return -ENOMEM;
 992
 993         for (i = 0; i < rrpc->nr_pages; i++) {
 994                 struct rrpc_addr *p = &rrpc->trans_map[i];
 995                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
 996
 997                 p->addr = ADDR_EMPTY;
 998                 r->addr = ADDR_EMPTY;
 999         }
1000
1001         if (!dev->ops->get_l2p_tbl)
1002                 return 0;
1003
1004         /* Bring up the mapping table from device */
1005         ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
1006                                                         rrpc_l2p_update, rrpc);
1007         if (ret) {
1008                 pr_err("nvm: rrpc: could not read L2P table.\n");
1009                 return -EINVAL;
1010         }
1011
1012         return 0;
1013 }
1014
1015
1016 /* Minimum pages needed within a lun */
1017 #define PAGE_POOL_SIZE 16
1018 #define ADDR_POOL_SIZE 64
1019
1020 static int rrpc_core_init(struct rrpc *rrpc)
1021 {
1022         down_write(&rrpc_lock);
1023         if (!rrpc_gcb_cache) {
1024                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1025                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1026                 if (!rrpc_gcb_cache) {
1027                         up_write(&rrpc_lock);
1028                         return -ENOMEM;
1029                 }
1030
1031                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1032                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1033                                 0, 0, NULL);
1034                 if (!rrpc_rq_cache) {
1035                         kmem_cache_destroy(rrpc_gcb_cache);
1036                         up_write(&rrpc_lock);
1037                         return -ENOMEM;
1038                 }
1039         }
1040         up_write(&rrpc_lock);
1041
1042         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1043         if (!rrpc->page_pool)
1044                 return -ENOMEM;
1045
1046         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1047                                                                 rrpc_gcb_cache);
1048         if (!rrpc->gcb_pool)
1049                 return -ENOMEM;
1050
1051         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1052         if (!rrpc->rq_pool)
1053                 return -ENOMEM;
1054
1055         spin_lock_init(&rrpc->inflights.lock);
1056         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1057
1058         return 0;
1059 }
1060
1061 static void rrpc_core_free(struct rrpc *rrpc)
1062 {
1063         mempool_destroy(rrpc->page_pool);
1064         mempool_destroy(rrpc->gcb_pool);
1065         mempool_destroy(rrpc->rq_pool);
1066 }
1067
1068 static void rrpc_luns_free(struct rrpc *rrpc)
1069 {
1070         kfree(rrpc->luns);
1071 }
1072
1073 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1074 {
1075         struct nvm_dev *dev = rrpc->dev;
1076         struct rrpc_lun *rlun;
1077         int i, j;
1078
1079         spin_lock_init(&rrpc->rev_lock);
1080
1081         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1082                                                                 GFP_KERNEL);
1083         if (!rrpc->luns)
1084                 return -ENOMEM;
1085
1086         /* 1:1 mapping */
1087         for (i = 0; i < rrpc->nr_luns; i++) {
1088                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1089
1090                 if (dev->pgs_per_blk >
1091                                 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1092                         pr_err("rrpc: number of pages per block too high.");
1093                         goto err;
1094                 }
1095
1096                 rlun = &rrpc->luns[i];
1097                 rlun->rrpc = rrpc;
1098                 rlun->parent = lun;
1099                 INIT_LIST_HEAD(&rlun->prio_list);
1100                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1101                 spin_lock_init(&rlun->lock);
1102
1103                 rrpc->total_blocks += dev->blks_per_lun;
1104                 rrpc->nr_pages += dev->sec_per_lun;
1105
1106                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1107                                                 rrpc->dev->blks_per_lun);
1108                 if (!rlun->blocks)
1109                         goto err;
1110
1111                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1112                         struct rrpc_block *rblk = &rlun->blocks[j];
1113                         struct nvm_block *blk = &lun->blocks[j];
1114
1115                         rblk->parent = blk;
1116                         INIT_LIST_HEAD(&rblk->prio);
1117                         spin_lock_init(&rblk->lock);
1118                 }
1119         }
1120
1121         return 0;
1122 err:
1123         return -ENOMEM;
1124 }
1125
1126 static void rrpc_free(struct rrpc *rrpc)
1127 {
1128         rrpc_gc_free(rrpc);
1129         rrpc_map_free(rrpc);
1130         rrpc_core_free(rrpc);
1131         rrpc_luns_free(rrpc);
1132
1133         kfree(rrpc);
1134 }
1135
1136 static void rrpc_exit(void *private)
1137 {
1138         struct rrpc *rrpc = private;
1139
1140         del_timer(&rrpc->gc_timer);
1141
1142         flush_workqueue(rrpc->krqd_wq);
1143         flush_workqueue(rrpc->kgc_wq);
1144
1145         rrpc_free(rrpc);
1146 }
1147
1148 static sector_t rrpc_capacity(void *private)
1149 {
1150         struct rrpc *rrpc = private;
1151         struct nvm_dev *dev = rrpc->dev;
1152         sector_t reserved, provisioned;
1153
1154         /* cur, gc, and two emergency blocks for each lun */
1155         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1156         provisioned = rrpc->nr_pages - reserved;
1157
1158         if (reserved > rrpc->nr_pages) {
1159                 pr_err("rrpc: not enough space available to expose storage.\n");
1160                 return 0;
1161         }
1162
1163         sector_div(provisioned, 10);
1164         return provisioned * 9 * NR_PHY_IN_LOG;
1165 }
1166
1167 /*
1168  * Looks up the logical address from reverse trans map and check if its valid by
1169  * comparing the logical to physical address with the physical address.
1170  * Returns 0 on free, otherwise 1 if in use
1171  */
1172 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1173 {
1174         struct nvm_dev *dev = rrpc->dev;
1175         int offset;
1176         struct rrpc_addr *laddr;
1177         u64 paddr, pladdr;
1178
1179         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1180                 paddr = block_to_addr(rrpc, rblk) + offset;
1181
1182                 pladdr = rrpc->rev_trans_map[paddr].addr;
1183                 if (pladdr == ADDR_EMPTY)
1184                         continue;
1185
1186                 laddr = &rrpc->trans_map[pladdr];
1187
1188                 if (paddr == laddr->addr) {
1189                         laddr->rblk = rblk;
1190                 } else {
1191                         set_bit(offset, rblk->invalid_pages);
1192                         rblk->nr_invalid_pages++;
1193                 }
1194         }
1195 }
1196
1197 static int rrpc_blocks_init(struct rrpc *rrpc)
1198 {
1199         struct rrpc_lun *rlun;
1200         struct rrpc_block *rblk;
1201         int lun_iter, blk_iter;
1202
1203         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1204                 rlun = &rrpc->luns[lun_iter];
1205
1206                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1207                                                                 blk_iter++) {
1208                         rblk = &rlun->blocks[blk_iter];
1209                         rrpc_block_map_update(rrpc, rblk);
1210                 }
1211         }
1212
1213         return 0;
1214 }
1215
1216 static int rrpc_luns_configure(struct rrpc *rrpc)
1217 {
1218         struct rrpc_lun *rlun;
1219         struct rrpc_block *rblk;
1220         int i;
1221
1222         for (i = 0; i < rrpc->nr_luns; i++) {
1223                 rlun = &rrpc->luns[i];
1224
1225                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1226                 if (!rblk)
1227                         return -EINVAL;
1228
1229                 rrpc_set_lun_cur(rlun, rblk);
1230
1231                 /* Emergency gc block */
1232                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1233                 if (!rblk)
1234                         return -EINVAL;
1235                 rlun->gc_cur = rblk;
1236         }
1237
1238         return 0;
1239 }
1240
1241 static struct nvm_tgt_type tt_rrpc;
1242
1243 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1244                                                 int lun_begin, int lun_end)
1245 {
1246         struct request_queue *bqueue = dev->q;
1247         struct request_queue *tqueue = tdisk->queue;
1248         struct rrpc *rrpc;
1249         int ret;
1250
1251         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1252                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1253                                                         dev->identity.dom);
1254                 return ERR_PTR(-EINVAL);
1255         }
1256
1257         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1258         if (!rrpc)
1259                 return ERR_PTR(-ENOMEM);
1260
1261         rrpc->instance.tt = &tt_rrpc;
1262         rrpc->dev = dev;
1263         rrpc->disk = tdisk;
1264
1265         bio_list_init(&rrpc->requeue_bios);
1266         spin_lock_init(&rrpc->bio_lock);
1267         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1268
1269         rrpc->nr_luns = lun_end - lun_begin + 1;
1270
1271         /* simple round-robin strategy */
1272         atomic_set(&rrpc->next_lun, -1);
1273
1274         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1275         if (ret) {
1276                 pr_err("nvm: rrpc: could not initialize luns\n");
1277                 goto err;
1278         }
1279
1280         rrpc->poffset = dev->sec_per_lun * lun_begin;
1281         rrpc->lun_offset = lun_begin;
1282
1283         ret = rrpc_core_init(rrpc);
1284         if (ret) {
1285                 pr_err("nvm: rrpc: could not initialize core\n");
1286                 goto err;
1287         }
1288
1289         ret = rrpc_map_init(rrpc);
1290         if (ret) {
1291                 pr_err("nvm: rrpc: could not initialize maps\n");
1292                 goto err;
1293         }
1294
1295         ret = rrpc_blocks_init(rrpc);
1296         if (ret) {
1297                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1298                 goto err;
1299         }
1300
1301         ret = rrpc_luns_configure(rrpc);
1302         if (ret) {
1303                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1304                 goto err;
1305         }
1306
1307         ret = rrpc_gc_init(rrpc);
1308         if (ret) {
1309                 pr_err("nvm: rrpc: could not initialize gc\n");
1310                 goto err;
1311         }
1312
1313         /* inherit the size from the underlying device */
1314         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1315         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1316
1317         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1318                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1319
1320         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1321
1322         return rrpc;
1323 err:
1324         rrpc_free(rrpc);
1325         return ERR_PTR(ret);
1326 }
1327
1328 /* round robin, page-based FTL, and cost-based GC */
1329 static struct nvm_tgt_type tt_rrpc = {
1330         .name           = "rrpc",
1331         .version        = {1, 0, 0},
1332
1333         .make_rq        = rrpc_make_rq,
1334         .capacity       = rrpc_capacity,
1335         .end_io         = rrpc_end_io,
1336
1337         .init           = rrpc_init,
1338         .exit           = rrpc_exit,
1339 };
1340
1341 static int __init rrpc_module_init(void)
1342 {
1343         return nvm_register_target(&tt_rrpc);
1344 }
1345
1346 static void rrpc_module_exit(void)
1347 {
1348         nvm_unregister_target(&tt_rrpc);
1349 }
1350
1351 module_init(rrpc_module_init);
1352 module_exit(rrpc_module_exit);
1353 MODULE_LICENSE("GPL v2");
1354 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");