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, flags);
 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 void rrpc_put_blks(struct rrpc *rrpc)
 206 {
 207         struct rrpc_lun *rlun;
 208         int i;
 209
 210         for (i = 0; i < rrpc->nr_luns; i++) {
 211                 rlun = &rrpc->luns[i];
 212                 if (rlun->cur)
 213                         rrpc_put_blk(rrpc, rlun->cur);
 214                 if (rlun->gc_cur)
 215                         rrpc_put_blk(rrpc, rlun->gc_cur);
 216         }
 217 }
 218
 219 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 220 {
 221         int next = atomic_inc_return(&rrpc->next_lun);
 222
 223         return &rrpc->luns[next % rrpc->nr_luns];
 224 }
 225
 226 static void rrpc_gc_kick(struct rrpc *rrpc)
 227 {
 228         struct rrpc_lun *rlun;
 229         unsigned int i;
 230
 231         for (i = 0; i < rrpc->nr_luns; i++) {
 232                 rlun = &rrpc->luns[i];
 233                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 234         }
 235 }
 236
 237 /*
 238  * timed GC every interval.
 239  */
 240 static void rrpc_gc_timer(unsigned long data)
 241 {
 242         struct rrpc *rrpc = (struct rrpc *)data;
 243
 244         rrpc_gc_kick(rrpc);
 245         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 246 }
 247
 248 static void rrpc_end_sync_bio(struct bio *bio)
 249 {
 250         struct completion *waiting = bio->bi_private;
 251
 252         if (bio->bi_error)
 253                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 254
 255         complete(waiting);
 256 }
 257
 258 /*
 259  * rrpc_move_valid_pages -- migrate live data off the block
 260  * @rrpc: the 'rrpc' structure
 261  * @block: the block from which to migrate live pages
 262  *
 263  * Description:
 264  *   GC algorithms may call this function to migrate remaining live
 265  *   pages off the block prior to erasing it. This function blocks
 266  *   further execution until the operation is complete.
 267  */
 268 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 269 {
 270         struct request_queue *q = rrpc->dev->q;
 271         struct rrpc_rev_addr *rev;
 272         struct nvm_rq *rqd;
 273         struct bio *bio;
 274         struct page *page;
 275         int slot;
 276         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 277         u64 phys_addr;
 278         DECLARE_COMPLETION_ONSTACK(wait);
 279
 280         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 281                 return 0;
 282
 283         bio = bio_alloc(GFP_NOIO, 1);
 284         if (!bio) {
 285                 pr_err("nvm: could not alloc bio to gc\n");
 286                 return -ENOMEM;
 287         }
 288
 289         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 290         if (!page)
 291                 return -ENOMEM;
 292
 293         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 294                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 295
 296                 /* Lock laddr */
 297                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 298
 299 try:
 300                 spin_lock(&rrpc->rev_lock);
 301                 /* Get logical address from physical to logical table */
 302                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 303                 /* already updated by previous regular write */
 304                 if (rev->addr == ADDR_EMPTY) {
 305                         spin_unlock(&rrpc->rev_lock);
 306                         continue;
 307                 }
 308
 309                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 310                 if (IS_ERR_OR_NULL(rqd)) {
 311                         spin_unlock(&rrpc->rev_lock);
 312                         schedule();
 313                         goto try;
 314                 }
 315
 316                 spin_unlock(&rrpc->rev_lock);
 317
 318                 /* Perform read to do GC */
 319                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 320                 bio->bi_rw = READ;
 321                 bio->bi_private = &wait;
 322                 bio->bi_end_io = rrpc_end_sync_bio;
 323
 324                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 325                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 326
 327                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 328                         pr_err("rrpc: gc read failed.\n");
 329                         rrpc_inflight_laddr_release(rrpc, rqd);
 330                         goto finished;
 331                 }
 332                 wait_for_completion_io(&wait);
 333
 334                 bio_reset(bio);
 335                 reinit_completion(&wait);
 336
 337                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 338                 bio->bi_rw = WRITE;
 339                 bio->bi_private = &wait;
 340                 bio->bi_end_io = rrpc_end_sync_bio;
 341
 342                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 343
 344                 /* turn the command around and write the data back to a new
 345                  * address
 346                  */
 347                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 348                         pr_err("rrpc: gc write failed.\n");
 349                         rrpc_inflight_laddr_release(rrpc, rqd);
 350                         goto finished;
 351                 }
 352                 wait_for_completion_io(&wait);
 353
 354                 rrpc_inflight_laddr_release(rrpc, rqd);
 355
 356                 bio_reset(bio);
 357         }
 358
 359 finished:
 360         mempool_free(page, rrpc->page_pool);
 361         bio_put(bio);
 362
 363         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 364                 pr_err("nvm: failed to garbage collect block\n");
 365                 return -EIO;
 366         }
 367
 368         return 0;
 369 }
 370
 371 static void rrpc_block_gc(struct work_struct *work)
 372 {
 373         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 374                                                                         ws_gc);
 375         struct rrpc *rrpc = gcb->rrpc;
 376         struct rrpc_block *rblk = gcb->rblk;
 377         struct nvm_dev *dev = rrpc->dev;
 378
 379         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 380
 381         if (rrpc_move_valid_pages(rrpc, rblk))
 382                 goto done;
 383
 384         nvm_erase_blk(dev, rblk->parent);
 385         rrpc_put_blk(rrpc, rblk);
 386 done:
 387         mempool_free(gcb, rrpc->gcb_pool);
 388 }
 389
 390 /* the block with highest number of invalid pages, will be in the beginning
 391  * of the list
 392  */
 393 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 394                                                         struct rrpc_block *rb)
 395 {
 396         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 397                 return ra;
 398
 399         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 400 }
 401
 402 /* linearly find the block with highest number of invalid pages
 403  * requires lun->lock
 404  */
 405 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 406 {
 407         struct list_head *prio_list = &rlun->prio_list;
 408         struct rrpc_block *rblock, *max;
 409
 410         BUG_ON(list_empty(prio_list));
 411
 412         max = list_first_entry(prio_list, struct rrpc_block, prio);
 413         list_for_each_entry(rblock, prio_list, prio)
 414                 max = rblock_max_invalid(max, rblock);
 415
 416         return max;
 417 }
 418
 419 static void rrpc_lun_gc(struct work_struct *work)
 420 {
 421         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 422         struct rrpc *rrpc = rlun->rrpc;
 423         struct nvm_lun *lun = rlun->parent;
 424         struct rrpc_block_gc *gcb;
 425         unsigned int nr_blocks_need;
 426
 427         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 428
 429         if (nr_blocks_need < rrpc->nr_luns)
 430                 nr_blocks_need = rrpc->nr_luns;
 431
 432         spin_lock(&rlun->lock);
 433         while (nr_blocks_need > lun->nr_free_blocks &&
 434                                         !list_empty(&rlun->prio_list)) {
 435                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 436                 struct nvm_block *block = rblock->parent;
 437
 438                 if (!rblock->nr_invalid_pages)
 439                         break;
 440
 441                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 442                 if (!gcb)
 443                         break;
 444
 445                 list_del_init(&rblock->prio);
 446
 447                 BUG_ON(!block_is_full(rrpc, rblock));
 448
 449                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 450
 451                 gcb->rrpc = rrpc;
 452                 gcb->rblk = rblock;
 453                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 454
 455                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 456
 457                 nr_blocks_need--;
 458         }
 459         spin_unlock(&rlun->lock);
 460
 461         /* TODO: Hint that request queue can be started again */
 462 }
 463
 464 static void rrpc_gc_queue(struct work_struct *work)
 465 {
 466         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 467                                                                         ws_gc);
 468         struct rrpc *rrpc = gcb->rrpc;
 469         struct rrpc_block *rblk = gcb->rblk;
 470         struct nvm_lun *lun = rblk->parent->lun;
 471         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 472
 473         spin_lock(&rlun->lock);
 474         list_add_tail(&rblk->prio, &rlun->prio_list);
 475         spin_unlock(&rlun->lock);
 476
 477         mempool_free(gcb, rrpc->gcb_pool);
 478         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 479                                                         rblk->parent->id);
 480 }
 481
 482 static const struct block_device_operations rrpc_fops = {
 483         .owner          = THIS_MODULE,
 484 };
 485
 486 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 487 {
 488         unsigned int i;
 489         struct rrpc_lun *rlun, *max_free;
 490
 491         if (!is_gc)
 492                 return get_next_lun(rrpc);
 493
 494         /* during GC, we don't care about RR, instead we want to make
 495          * sure that we maintain evenness between the block luns.
 496          */
 497         max_free = &rrpc->luns[0];
 498         /* prevent GC-ing lun from devouring pages of a lun with
 499          * little free blocks. We don't take the lock as we only need an
 500          * estimate.
 501          */
 502         rrpc_for_each_lun(rrpc, rlun, i) {
 503                 if (rlun->parent->nr_free_blocks >
 504                                         max_free->parent->nr_free_blocks)
 505                         max_free = rlun;
 506         }
 507
 508         return max_free;
 509 }
 510
 511 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 512                                         struct rrpc_block *rblk, u64 paddr)
 513 {
 514         struct rrpc_addr *gp;
 515         struct rrpc_rev_addr *rev;
 516
 517         BUG_ON(laddr >= rrpc->nr_pages);
 518
 519         gp = &rrpc->trans_map[laddr];
 520         spin_lock(&rrpc->rev_lock);
 521         if (gp->rblk)
 522                 rrpc_page_invalidate(rrpc, gp);
 523
 524         gp->addr = paddr;
 525         gp->rblk = rblk;
 526
 527         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 528         rev->addr = laddr;
 529         spin_unlock(&rrpc->rev_lock);
 530
 531         return gp;
 532 }
 533
 534 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 535 {
 536         u64 addr = ADDR_EMPTY;
 537
 538         spin_lock(&rblk->lock);
 539         if (block_is_full(rrpc, rblk))
 540                 goto out;
 541
 542         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 543
 544         rblk->next_page++;
 545 out:
 546         spin_unlock(&rblk->lock);
 547         return addr;
 548 }
 549
 550 /* Simple round-robin Logical to physical address translation.
 551  *
 552  * Retrieve the mapping using the active append point. Then update the ap for
 553  * the next write to the disk.
 554  *
 555  * Returns rrpc_addr with the physical address and block. Remember to return to
 556  * rrpc->addr_cache when request is finished.
 557  */
 558 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 559                                                                 int is_gc)
 560 {
 561         struct rrpc_lun *rlun;
 562         struct rrpc_block *rblk;
 563         struct nvm_lun *lun;
 564         u64 paddr;
 565
 566         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 567         lun = rlun->parent;
 568
 569         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 570                 return NULL;
 571
 572         spin_lock(&rlun->lock);
 573
 574         rblk = rlun->cur;
 575 retry:
 576         paddr = rrpc_alloc_addr(rrpc, rblk);
 577
 578         if (paddr == ADDR_EMPTY) {
 579                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 580                 if (rblk) {
 581                         rrpc_set_lun_cur(rlun, rblk);
 582                         goto retry;
 583                 }
 584
 585                 if (is_gc) {
 586                         /* retry from emergency gc block */
 587                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 588                         if (paddr == ADDR_EMPTY) {
 589                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 590                                 if (!rblk) {
 591                                         pr_err("rrpc: no more blocks");
 592                                         goto err;
 593                                 }
 594
 595                                 rlun->gc_cur = rblk;
 596                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 597                         }
 598                         rblk = rlun->gc_cur;
 599                 }
 600         }
 601
 602         spin_unlock(&rlun->lock);
 603         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 604 err:
 605         spin_unlock(&rlun->lock);
 606         return NULL;
 607 }
 608
 609 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 610 {
 611         struct rrpc_block_gc *gcb;
 612
 613         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 614         if (!gcb) {
 615                 pr_err("rrpc: unable to queue block for gc.");
 616                 return;
 617         }
 618
 619         gcb->rrpc = rrpc;
 620         gcb->rblk = rblk;
 621
 622         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 623         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 624 }
 625
 626 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 627                                                 sector_t laddr, uint8_t npages)
 628 {
 629         struct rrpc_addr *p;
 630         struct rrpc_block *rblk;
 631         struct nvm_lun *lun;
 632         int cmnt_size, i;
 633
 634         for (i = 0; i < npages; i++) {
 635                 p = &rrpc->trans_map[laddr + i];
 636                 rblk = p->rblk;
 637                 lun = rblk->parent->lun;
 638
 639                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 640                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
 641                         rrpc_run_gc(rrpc, rblk);
 642         }
 643 }
 644
 645 static int rrpc_end_io(struct nvm_rq *rqd, int error)
 646 {
 647         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 648         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 649         uint8_t npages = rqd->nr_pages;
 650         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 651
 652         if (bio_data_dir(rqd->bio) == WRITE)
 653                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 654
 655         bio_put(rqd->bio);
 656
 657         if (rrqd->flags & NVM_IOTYPE_GC)
 658                 return 0;
 659
 660         rrpc_unlock_rq(rrpc, rqd);
 661
 662         if (npages > 1)
 663                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 664         if (rqd->metadata)
 665                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 666
 667         mempool_free(rqd, rrpc->rq_pool);
 668
 669         return 0;
 670 }
 671
 672 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 673                         struct nvm_rq *rqd, unsigned long flags, int npages)
 674 {
 675         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 676         struct rrpc_addr *gp;
 677         sector_t laddr = rrpc_get_laddr(bio);
 678         int is_gc = flags & NVM_IOTYPE_GC;
 679         int i;
 680
 681         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 682                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 683                 return NVM_IO_REQUEUE;
 684         }
 685
 686         for (i = 0; i < npages; i++) {
 687                 /* We assume that mapping occurs at 4KB granularity */
 688                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 689                 gp = &rrpc->trans_map[laddr + i];
 690
 691                 if (gp->rblk) {
 692                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 693                                                                 gp->addr);
 694                 } else {
 695                         BUG_ON(is_gc);
 696                         rrpc_unlock_laddr(rrpc, r);
 697                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 698                                                         rqd->dma_ppa_list);
 699                         return NVM_IO_DONE;
 700                 }
 701         }
 702
 703         rqd->opcode = NVM_OP_HBREAD;
 704
 705         return NVM_IO_OK;
 706 }
 707
 708 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 709                                                         unsigned long flags)
 710 {
 711         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 712         int is_gc = flags & NVM_IOTYPE_GC;
 713         sector_t laddr = rrpc_get_laddr(bio);
 714         struct rrpc_addr *gp;
 715
 716         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 717                 return NVM_IO_REQUEUE;
 718
 719         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 720         gp = &rrpc->trans_map[laddr];
 721
 722         if (gp->rblk) {
 723                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 724         } else {
 725                 BUG_ON(is_gc);
 726                 rrpc_unlock_rq(rrpc, rqd);
 727                 return NVM_IO_DONE;
 728         }
 729
 730         rqd->opcode = NVM_OP_HBREAD;
 731         rrqd->addr = gp;
 732
 733         return NVM_IO_OK;
 734 }
 735
 736 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 737                         struct nvm_rq *rqd, unsigned long flags, int npages)
 738 {
 739         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 740         struct rrpc_addr *p;
 741         sector_t laddr = rrpc_get_laddr(bio);
 742         int is_gc = flags & NVM_IOTYPE_GC;
 743         int i;
 744
 745         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 746                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 747                 return NVM_IO_REQUEUE;
 748         }
 749
 750         for (i = 0; i < npages; i++) {
 751                 /* We assume that mapping occurs at 4KB granularity */
 752                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 753                 if (!p) {
 754                         BUG_ON(is_gc);
 755                         rrpc_unlock_laddr(rrpc, r);
 756                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 757                                                         rqd->dma_ppa_list);
 758                         rrpc_gc_kick(rrpc);
 759                         return NVM_IO_REQUEUE;
 760                 }
 761
 762                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 763                                                                 p->addr);
 764         }
 765
 766         rqd->opcode = NVM_OP_HBWRITE;
 767
 768         return NVM_IO_OK;
 769 }
 770
 771 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 772                                 struct nvm_rq *rqd, unsigned long flags)
 773 {
 774         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 775         struct rrpc_addr *p;
 776         int is_gc = flags & NVM_IOTYPE_GC;
 777         sector_t laddr = rrpc_get_laddr(bio);
 778
 779         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 780                 return NVM_IO_REQUEUE;
 781
 782         p = rrpc_map_page(rrpc, laddr, is_gc);
 783         if (!p) {
 784                 BUG_ON(is_gc);
 785                 rrpc_unlock_rq(rrpc, rqd);
 786                 rrpc_gc_kick(rrpc);
 787                 return NVM_IO_REQUEUE;
 788         }
 789
 790         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 791         rqd->opcode = NVM_OP_HBWRITE;
 792         rrqd->addr = p;
 793
 794         return NVM_IO_OK;
 795 }
 796
 797 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 798                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 799 {
 800         if (npages > 1) {
 801                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 802                                                         &rqd->dma_ppa_list);
 803                 if (!rqd->ppa_list) {
 804                         pr_err("rrpc: not able to allocate ppa list\n");
 805                         return NVM_IO_ERR;
 806                 }
 807
 808                 if (bio_rw(bio) == WRITE)
 809                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 810                                                                         npages);
 811
 812                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 813         }
 814
 815         if (bio_rw(bio) == WRITE)
 816                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 817
 818         return rrpc_read_rq(rrpc, bio, rqd, flags);
 819 }
 820
 821 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 822                                 struct nvm_rq *rqd, unsigned long flags)
 823 {
 824         int err;
 825         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 826         uint8_t nr_pages = rrpc_get_pages(bio);
 827         int bio_size = bio_sectors(bio) << 9;
 828
 829         if (bio_size < rrpc->dev->sec_size)
 830                 return NVM_IO_ERR;
 831         else if (bio_size > rrpc->dev->max_rq_size)
 832                 return NVM_IO_ERR;
 833
 834         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 835         if (err)
 836                 return err;
 837
 838         bio_get(bio);
 839         rqd->bio = bio;
 840         rqd->ins = &rrpc->instance;
 841         rqd->nr_pages = nr_pages;
 842         rrq->flags = flags;
 843
 844         err = nvm_submit_io(rrpc->dev, rqd);
 845         if (err) {
 846                 pr_err("rrpc: I/O submission failed: %d\n", err);
 847                 bio_put(bio);
 848                 if (!(flags & NVM_IOTYPE_GC)) {
 849                         rrpc_unlock_rq(rrpc, rqd);
 850                         if (rqd->nr_pages > 1)
 851                                 nvm_dev_dma_free(rrpc->dev,
 852                         rqd->ppa_list, rqd->dma_ppa_list);
 853                 }
 854                 return NVM_IO_ERR;
 855         }
 856
 857         return NVM_IO_OK;
 858 }
 859
 860 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 861 {
 862         struct rrpc *rrpc = q->queuedata;
 863         struct nvm_rq *rqd;
 864         int err;
 865
 866         if (bio->bi_rw & REQ_DISCARD) {
 867                 rrpc_discard(rrpc, bio);
 868                 return BLK_QC_T_NONE;
 869         }
 870
 871         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 872         if (!rqd) {
 873                 pr_err_ratelimited("rrpc: not able to queue bio.");
 874                 bio_io_error(bio);
 875                 return BLK_QC_T_NONE;
 876         }
 877         memset(rqd, 0, sizeof(struct nvm_rq));
 878
 879         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 880         switch (err) {
 881         case NVM_IO_OK:
 882                 return BLK_QC_T_NONE;
 883         case NVM_IO_ERR:
 884                 bio_io_error(bio);
 885                 break;
 886         case NVM_IO_DONE:
 887                 bio_endio(bio);
 888                 break;
 889         case NVM_IO_REQUEUE:
 890                 spin_lock(&rrpc->bio_lock);
 891                 bio_list_add(&rrpc->requeue_bios, bio);
 892                 spin_unlock(&rrpc->bio_lock);
 893                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 894                 break;
 895         }
 896
 897         mempool_free(rqd, rrpc->rq_pool);
 898         return BLK_QC_T_NONE;
 899 }
 900
 901 static void rrpc_requeue(struct work_struct *work)
 902 {
 903         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 904         struct bio_list bios;
 905         struct bio *bio;
 906
 907         bio_list_init(&bios);
 908
 909         spin_lock(&rrpc->bio_lock);
 910         bio_list_merge(&bios, &rrpc->requeue_bios);
 911         bio_list_init(&rrpc->requeue_bios);
 912         spin_unlock(&rrpc->bio_lock);
 913
 914         while ((bio = bio_list_pop(&bios)))
 915                 rrpc_make_rq(rrpc->disk->queue, bio);
 916 }
 917
 918 static void rrpc_gc_free(struct rrpc *rrpc)
 919 {
 920         struct rrpc_lun *rlun;
 921         int i;
 922
 923         if (rrpc->krqd_wq)
 924                 destroy_workqueue(rrpc->krqd_wq);
 925
 926         if (rrpc->kgc_wq)
 927                 destroy_workqueue(rrpc->kgc_wq);
 928
 929         if (!rrpc->luns)
 930                 return;
 931
 932         for (i = 0; i < rrpc->nr_luns; i++) {
 933                 rlun = &rrpc->luns[i];
 934
 935                 if (!rlun->blocks)
 936                         break;
 937                 vfree(rlun->blocks);
 938         }
 939 }
 940
 941 static int rrpc_gc_init(struct rrpc *rrpc)
 942 {
 943         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 944                                                                 rrpc->nr_luns);
 945         if (!rrpc->krqd_wq)
 946                 return -ENOMEM;
 947
 948         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 949         if (!rrpc->kgc_wq)
 950                 return -ENOMEM;
 951
 952         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 953
 954         return 0;
 955 }
 956
 957 static void rrpc_map_free(struct rrpc *rrpc)
 958 {
 959         vfree(rrpc->rev_trans_map);
 960         vfree(rrpc->trans_map);
 961 }
 962
 963 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 964 {
 965         struct rrpc *rrpc = (struct rrpc *)private;
 966         struct nvm_dev *dev = rrpc->dev;
 967         struct rrpc_addr *addr = rrpc->trans_map + slba;
 968         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
 969         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 970         u64 elba = slba + nlb;
 971         u64 i;
 972
 973         if (unlikely(elba > dev->total_pages)) {
 974                 pr_err("nvm: L2P data from device is out of bounds!\n");
 975                 return -EINVAL;
 976         }
 977
 978         for (i = 0; i < nlb; i++) {
 979                 u64 pba = le64_to_cpu(entries[i]);
 980                 /* LNVM treats address-spaces as silos, LBA and PBA are
 981                  * equally large and zero-indexed.
 982                  */
 983                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 984                         pr_err("nvm: L2P data entry is out of bounds!\n");
 985                         return -EINVAL;
 986                 }
 987
 988                 /* Address zero is a special one. The first page on a disk is
 989                  * protected. As it often holds internal device boot
 990                  * information.
 991                  */
 992                 if (!pba)
 993                         continue;
 994
 995                 addr[i].addr = pba;
 996                 raddr[pba].addr = slba + i;
 997         }
 998
 999         return 0;
1000 }
1001
1002 static int rrpc_map_init(struct rrpc *rrpc)
1003 {
1004         struct nvm_dev *dev = rrpc->dev;
1005         sector_t i;
1006         int ret;
1007
1008         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
1009         if (!rrpc->trans_map)
1010                 return -ENOMEM;
1011
1012         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1013                                                         * rrpc->nr_pages);
1014         if (!rrpc->rev_trans_map)
1015                 return -ENOMEM;
1016
1017         for (i = 0; i < rrpc->nr_pages; i++) {
1018                 struct rrpc_addr *p = &rrpc->trans_map[i];
1019                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1020
1021                 p->addr = ADDR_EMPTY;
1022                 r->addr = ADDR_EMPTY;
1023         }
1024
1025         if (!dev->ops->get_l2p_tbl)
1026                 return 0;
1027
1028         /* Bring up the mapping table from device */
1029         ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
1030                                                         rrpc_l2p_update, rrpc);
1031         if (ret) {
1032                 pr_err("nvm: rrpc: could not read L2P table.\n");
1033                 return -EINVAL;
1034         }
1035
1036         return 0;
1037 }
1038
1039
1040 /* Minimum pages needed within a lun */
1041 #define PAGE_POOL_SIZE 16
1042 #define ADDR_POOL_SIZE 64
1043
1044 static int rrpc_core_init(struct rrpc *rrpc)
1045 {
1046         down_write(&rrpc_lock);
1047         if (!rrpc_gcb_cache) {
1048                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1049                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1050                 if (!rrpc_gcb_cache) {
1051                         up_write(&rrpc_lock);
1052                         return -ENOMEM;
1053                 }
1054
1055                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1056                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1057                                 0, 0, NULL);
1058                 if (!rrpc_rq_cache) {
1059                         kmem_cache_destroy(rrpc_gcb_cache);
1060                         up_write(&rrpc_lock);
1061                         return -ENOMEM;
1062                 }
1063         }
1064         up_write(&rrpc_lock);
1065
1066         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1067         if (!rrpc->page_pool)
1068                 return -ENOMEM;
1069
1070         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1071                                                                 rrpc_gcb_cache);
1072         if (!rrpc->gcb_pool)
1073                 return -ENOMEM;
1074
1075         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1076         if (!rrpc->rq_pool)
1077                 return -ENOMEM;
1078
1079         spin_lock_init(&rrpc->inflights.lock);
1080         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1081
1082         return 0;
1083 }
1084
1085 static void rrpc_core_free(struct rrpc *rrpc)
1086 {
1087         mempool_destroy(rrpc->page_pool);
1088         mempool_destroy(rrpc->gcb_pool);
1089         mempool_destroy(rrpc->rq_pool);
1090 }
1091
1092 static void rrpc_luns_free(struct rrpc *rrpc)
1093 {
1094         kfree(rrpc->luns);
1095 }
1096
1097 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1098 {
1099         struct nvm_dev *dev = rrpc->dev;
1100         struct rrpc_lun *rlun;
1101         int i, j;
1102
1103         spin_lock_init(&rrpc->rev_lock);
1104
1105         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1106                                                                 GFP_KERNEL);
1107         if (!rrpc->luns)
1108                 return -ENOMEM;
1109
1110         /* 1:1 mapping */
1111         for (i = 0; i < rrpc->nr_luns; i++) {
1112                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1113
1114                 if (dev->pgs_per_blk >
1115                                 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1116                         pr_err("rrpc: number of pages per block too high.");
1117                         goto err;
1118                 }
1119
1120                 rlun = &rrpc->luns[i];
1121                 rlun->rrpc = rrpc;
1122                 rlun->parent = lun;
1123                 INIT_LIST_HEAD(&rlun->prio_list);
1124                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1125                 spin_lock_init(&rlun->lock);
1126
1127                 rrpc->total_blocks += dev->blks_per_lun;
1128                 rrpc->nr_pages += dev->sec_per_lun;
1129
1130                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1131                                                 rrpc->dev->blks_per_lun);
1132                 if (!rlun->blocks)
1133                         goto err;
1134
1135                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1136                         struct rrpc_block *rblk = &rlun->blocks[j];
1137                         struct nvm_block *blk = &lun->blocks[j];
1138
1139                         rblk->parent = blk;
1140                         INIT_LIST_HEAD(&rblk->prio);
1141                         spin_lock_init(&rblk->lock);
1142                 }
1143         }
1144
1145         return 0;
1146 err:
1147         return -ENOMEM;
1148 }
1149
1150 static void rrpc_free(struct rrpc *rrpc)
1151 {
1152         rrpc_gc_free(rrpc);
1153         rrpc_map_free(rrpc);
1154         rrpc_core_free(rrpc);
1155         rrpc_luns_free(rrpc);
1156
1157         kfree(rrpc);
1158 }
1159
1160 static void rrpc_exit(void *private)
1161 {
1162         struct rrpc *rrpc = private;
1163
1164         del_timer(&rrpc->gc_timer);
1165
1166         flush_workqueue(rrpc->krqd_wq);
1167         flush_workqueue(rrpc->kgc_wq);
1168
1169         rrpc_free(rrpc);
1170 }
1171
1172 static sector_t rrpc_capacity(void *private)
1173 {
1174         struct rrpc *rrpc = private;
1175         struct nvm_dev *dev = rrpc->dev;
1176         sector_t reserved, provisioned;
1177
1178         /* cur, gc, and two emergency blocks for each lun */
1179         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1180         provisioned = rrpc->nr_pages - reserved;
1181
1182         if (reserved > rrpc->nr_pages) {
1183                 pr_err("rrpc: not enough space available to expose storage.\n");
1184                 return 0;
1185         }
1186
1187         sector_div(provisioned, 10);
1188         return provisioned * 9 * NR_PHY_IN_LOG;
1189 }
1190
1191 /*
1192  * Looks up the logical address from reverse trans map and check if its valid by
1193  * comparing the logical to physical address with the physical address.
1194  * Returns 0 on free, otherwise 1 if in use
1195  */
1196 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1197 {
1198         struct nvm_dev *dev = rrpc->dev;
1199         int offset;
1200         struct rrpc_addr *laddr;
1201         u64 paddr, pladdr;
1202
1203         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1204                 paddr = block_to_addr(rrpc, rblk) + offset;
1205
1206                 pladdr = rrpc->rev_trans_map[paddr].addr;
1207                 if (pladdr == ADDR_EMPTY)
1208                         continue;
1209
1210                 laddr = &rrpc->trans_map[pladdr];
1211
1212                 if (paddr == laddr->addr) {
1213                         laddr->rblk = rblk;
1214                 } else {
1215                         set_bit(offset, rblk->invalid_pages);
1216                         rblk->nr_invalid_pages++;
1217                 }
1218         }
1219 }
1220
1221 static int rrpc_blocks_init(struct rrpc *rrpc)
1222 {
1223         struct rrpc_lun *rlun;
1224         struct rrpc_block *rblk;
1225         int lun_iter, blk_iter;
1226
1227         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1228                 rlun = &rrpc->luns[lun_iter];
1229
1230                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1231                                                                 blk_iter++) {
1232                         rblk = &rlun->blocks[blk_iter];
1233                         rrpc_block_map_update(rrpc, rblk);
1234                 }
1235         }
1236
1237         return 0;
1238 }
1239
1240 static int rrpc_luns_configure(struct rrpc *rrpc)
1241 {
1242         struct rrpc_lun *rlun;
1243         struct rrpc_block *rblk;
1244         int i;
1245
1246         for (i = 0; i < rrpc->nr_luns; i++) {
1247                 rlun = &rrpc->luns[i];
1248
1249                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1250                 if (!rblk)
1251                         goto err;
1252
1253                 rrpc_set_lun_cur(rlun, rblk);
1254
1255                 /* Emergency gc block */
1256                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1257                 if (!rblk)
1258                         goto err;
1259                 rlun->gc_cur = rblk;
1260         }
1261
1262         return 0;
1263 err:
1264         rrpc_put_blks(rrpc);
1265         return -EINVAL;
1266 }
1267
1268 static struct nvm_tgt_type tt_rrpc;
1269
1270 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1271                                                 int lun_begin, int lun_end)
1272 {
1273         struct request_queue *bqueue = dev->q;
1274         struct request_queue *tqueue = tdisk->queue;
1275         struct rrpc *rrpc;
1276         int ret;
1277
1278         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1279                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1280                                                         dev->identity.dom);
1281                 return ERR_PTR(-EINVAL);
1282         }
1283
1284         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1285         if (!rrpc)
1286                 return ERR_PTR(-ENOMEM);
1287
1288         rrpc->instance.tt = &tt_rrpc;
1289         rrpc->dev = dev;
1290         rrpc->disk = tdisk;
1291
1292         bio_list_init(&rrpc->requeue_bios);
1293         spin_lock_init(&rrpc->bio_lock);
1294         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1295
1296         rrpc->nr_luns = lun_end - lun_begin + 1;
1297
1298         /* simple round-robin strategy */
1299         atomic_set(&rrpc->next_lun, -1);
1300
1301         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1302         if (ret) {
1303                 pr_err("nvm: rrpc: could not initialize luns\n");
1304                 goto err;
1305         }
1306
1307         rrpc->poffset = dev->sec_per_lun * lun_begin;
1308         rrpc->lun_offset = lun_begin;
1309
1310         ret = rrpc_core_init(rrpc);
1311         if (ret) {
1312                 pr_err("nvm: rrpc: could not initialize core\n");
1313                 goto err;
1314         }
1315
1316         ret = rrpc_map_init(rrpc);
1317         if (ret) {
1318                 pr_err("nvm: rrpc: could not initialize maps\n");
1319                 goto err;
1320         }
1321
1322         ret = rrpc_blocks_init(rrpc);
1323         if (ret) {
1324                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1325                 goto err;
1326         }
1327
1328         ret = rrpc_luns_configure(rrpc);
1329         if (ret) {
1330                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1331                 goto err;
1332         }
1333
1334         ret = rrpc_gc_init(rrpc);
1335         if (ret) {
1336                 pr_err("nvm: rrpc: could not initialize gc\n");
1337                 goto err;
1338         }
1339
1340         /* inherit the size from the underlying device */
1341         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1342         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1343
1344         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1345                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1346
1347         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1348
1349         return rrpc;
1350 err:
1351         rrpc_free(rrpc);
1352         return ERR_PTR(ret);
1353 }
1354
1355 /* round robin, page-based FTL, and cost-based GC */
1356 static struct nvm_tgt_type tt_rrpc = {
1357         .name           = "rrpc",
1358         .version        = {1, 0, 0},
1359
1360         .make_rq        = rrpc_make_rq,
1361         .capacity       = rrpc_capacity,
1362         .end_io         = rrpc_end_io,
1363
1364         .init           = rrpc_init,
1365         .exit           = rrpc_exit,
1366 };
1367
1368 static int __init rrpc_module_init(void)
1369 {
1370         return nvm_register_target(&tt_rrpc);
1371 }
1372
1373 static void rrpc_module_exit(void)
1374 {
1375         nvm_unregister_target(&tt_rrpc);
1376 }
1377
1378 module_init(rrpc_module_init);
1379 module_exit(rrpc_module_exit);
1380 MODULE_LICENSE("GPL v2");
1381 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");