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 sector_t block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 120 {
 121         struct nvm_block *blk = rblk->parent;
 122
 123         return blk->id * rrpc->dev->pgs_per_blk;
 124 }
 125
 126 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev,
 127                                                                 sector_t addr)
 128 {
 129         struct ppa_addr paddr;
 130
 131         paddr.ppa = addr;
 132         return __linear_to_generic_addr(dev, paddr);
 133 }
 134
 135 /* requires lun->lock taken */
 136 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
 137 {
 138         struct rrpc *rrpc = rlun->rrpc;
 139
 140         BUG_ON(!rblk);
 141
 142         if (rlun->cur) {
 143                 spin_lock(&rlun->cur->lock);
 144                 WARN_ON(!block_is_full(rrpc, rlun->cur));
 145                 spin_unlock(&rlun->cur->lock);
 146         }
 147         rlun->cur = rblk;
 148 }
 149
 150 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 151                                                         unsigned long flags)
 152 {
 153         struct nvm_block *blk;
 154         struct rrpc_block *rblk;
 155
 156         blk = nvm_get_blk(rrpc->dev, rlun->parent, 0);
 157         if (!blk)
 158                 return NULL;
 159
 160         rblk = &rlun->blocks[blk->id];
 161         blk->priv = rblk;
 162
 163         bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
 164         rblk->next_page = 0;
 165         rblk->nr_invalid_pages = 0;
 166         atomic_set(&rblk->data_cmnt_size, 0);
 167
 168         return rblk;
 169 }
 170
 171 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 172 {
 173         nvm_put_blk(rrpc->dev, rblk->parent);
 174 }
 175
 176 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 177 {
 178         int next = atomic_inc_return(&rrpc->next_lun);
 179
 180         return &rrpc->luns[next % rrpc->nr_luns];
 181 }
 182
 183 static void rrpc_gc_kick(struct rrpc *rrpc)
 184 {
 185         struct rrpc_lun *rlun;
 186         unsigned int i;
 187
 188         for (i = 0; i < rrpc->nr_luns; i++) {
 189                 rlun = &rrpc->luns[i];
 190                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 191         }
 192 }
 193
 194 /*
 195  * timed GC every interval.
 196  */
 197 static void rrpc_gc_timer(unsigned long data)
 198 {
 199         struct rrpc *rrpc = (struct rrpc *)data;
 200
 201         rrpc_gc_kick(rrpc);
 202         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 203 }
 204
 205 static void rrpc_end_sync_bio(struct bio *bio)
 206 {
 207         struct completion *waiting = bio->bi_private;
 208
 209         if (bio->bi_error)
 210                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 211
 212         complete(waiting);
 213 }
 214
 215 /*
 216  * rrpc_move_valid_pages -- migrate live data off the block
 217  * @rrpc: the 'rrpc' structure
 218  * @block: the block from which to migrate live pages
 219  *
 220  * Description:
 221  *   GC algorithms may call this function to migrate remaining live
 222  *   pages off the block prior to erasing it. This function blocks
 223  *   further execution until the operation is complete.
 224  */
 225 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 226 {
 227         struct request_queue *q = rrpc->dev->q;
 228         struct rrpc_rev_addr *rev;
 229         struct nvm_rq *rqd;
 230         struct bio *bio;
 231         struct page *page;
 232         int slot;
 233         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 234         sector_t phys_addr;
 235         DECLARE_COMPLETION_ONSTACK(wait);
 236
 237         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 238                 return 0;
 239
 240         bio = bio_alloc(GFP_NOIO, 1);
 241         if (!bio) {
 242                 pr_err("nvm: could not alloc bio to gc\n");
 243                 return -ENOMEM;
 244         }
 245
 246         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 247
 248         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 249                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 250
 251                 /* Lock laddr */
 252                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 253
 254 try:
 255                 spin_lock(&rrpc->rev_lock);
 256                 /* Get logical address from physical to logical table */
 257                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 258                 /* already updated by previous regular write */
 259                 if (rev->addr == ADDR_EMPTY) {
 260                         spin_unlock(&rrpc->rev_lock);
 261                         continue;
 262                 }
 263
 264                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 265                 if (IS_ERR_OR_NULL(rqd)) {
 266                         spin_unlock(&rrpc->rev_lock);
 267                         schedule();
 268                         goto try;
 269                 }
 270
 271                 spin_unlock(&rrpc->rev_lock);
 272
 273                 /* Perform read to do GC */
 274                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 275                 bio->bi_rw = READ;
 276                 bio->bi_private = &wait;
 277                 bio->bi_end_io = rrpc_end_sync_bio;
 278
 279                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 280                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 281
 282                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 283                         pr_err("rrpc: gc read failed.\n");
 284                         rrpc_inflight_laddr_release(rrpc, rqd);
 285                         goto finished;
 286                 }
 287                 wait_for_completion_io(&wait);
 288
 289                 bio_reset(bio);
 290                 reinit_completion(&wait);
 291
 292                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 293                 bio->bi_rw = WRITE;
 294                 bio->bi_private = &wait;
 295                 bio->bi_end_io = rrpc_end_sync_bio;
 296
 297                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 298
 299                 /* turn the command around and write the data back to a new
 300                  * address
 301                  */
 302                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 303                         pr_err("rrpc: gc write failed.\n");
 304                         rrpc_inflight_laddr_release(rrpc, rqd);
 305                         goto finished;
 306                 }
 307                 wait_for_completion_io(&wait);
 308
 309                 rrpc_inflight_laddr_release(rrpc, rqd);
 310
 311                 bio_reset(bio);
 312         }
 313
 314 finished:
 315         mempool_free(page, rrpc->page_pool);
 316         bio_put(bio);
 317
 318         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 319                 pr_err("nvm: failed to garbage collect block\n");
 320                 return -EIO;
 321         }
 322
 323         return 0;
 324 }
 325
 326 static void rrpc_block_gc(struct work_struct *work)
 327 {
 328         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 329                                                                         ws_gc);
 330         struct rrpc *rrpc = gcb->rrpc;
 331         struct rrpc_block *rblk = gcb->rblk;
 332         struct nvm_dev *dev = rrpc->dev;
 333
 334         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 335
 336         if (rrpc_move_valid_pages(rrpc, rblk))
 337                 goto done;
 338
 339         nvm_erase_blk(dev, rblk->parent);
 340         rrpc_put_blk(rrpc, rblk);
 341 done:
 342         mempool_free(gcb, rrpc->gcb_pool);
 343 }
 344
 345 /* the block with highest number of invalid pages, will be in the beginning
 346  * of the list
 347  */
 348 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 349                                                         struct rrpc_block *rb)
 350 {
 351         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 352                 return ra;
 353
 354         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 355 }
 356
 357 /* linearly find the block with highest number of invalid pages
 358  * requires lun->lock
 359  */
 360 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 361 {
 362         struct list_head *prio_list = &rlun->prio_list;
 363         struct rrpc_block *rblock, *max;
 364
 365         BUG_ON(list_empty(prio_list));
 366
 367         max = list_first_entry(prio_list, struct rrpc_block, prio);
 368         list_for_each_entry(rblock, prio_list, prio)
 369                 max = rblock_max_invalid(max, rblock);
 370
 371         return max;
 372 }
 373
 374 static void rrpc_lun_gc(struct work_struct *work)
 375 {
 376         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 377         struct rrpc *rrpc = rlun->rrpc;
 378         struct nvm_lun *lun = rlun->parent;
 379         struct rrpc_block_gc *gcb;
 380         unsigned int nr_blocks_need;
 381
 382         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 383
 384         if (nr_blocks_need < rrpc->nr_luns)
 385                 nr_blocks_need = rrpc->nr_luns;
 386
 387         spin_lock(&lun->lock);
 388         while (nr_blocks_need > lun->nr_free_blocks &&
 389                                         !list_empty(&rlun->prio_list)) {
 390                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 391                 struct nvm_block *block = rblock->parent;
 392
 393                 if (!rblock->nr_invalid_pages)
 394                         break;
 395
 396                 list_del_init(&rblock->prio);
 397
 398                 BUG_ON(!block_is_full(rrpc, rblock));
 399
 400                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 401
 402                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 403                 if (!gcb)
 404                         break;
 405
 406                 gcb->rrpc = rrpc;
 407                 gcb->rblk = rblock;
 408                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 409
 410                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 411
 412                 nr_blocks_need--;
 413         }
 414         spin_unlock(&lun->lock);
 415
 416         /* TODO: Hint that request queue can be started again */
 417 }
 418
 419 static void rrpc_gc_queue(struct work_struct *work)
 420 {
 421         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 422                                                                         ws_gc);
 423         struct rrpc *rrpc = gcb->rrpc;
 424         struct rrpc_block *rblk = gcb->rblk;
 425         struct nvm_lun *lun = rblk->parent->lun;
 426         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 427
 428         spin_lock(&rlun->lock);
 429         list_add_tail(&rblk->prio, &rlun->prio_list);
 430         spin_unlock(&rlun->lock);
 431
 432         mempool_free(gcb, rrpc->gcb_pool);
 433         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 434                                                         rblk->parent->id);
 435 }
 436
 437 static const struct block_device_operations rrpc_fops = {
 438         .owner          = THIS_MODULE,
 439 };
 440
 441 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 442 {
 443         unsigned int i;
 444         struct rrpc_lun *rlun, *max_free;
 445
 446         if (!is_gc)
 447                 return get_next_lun(rrpc);
 448
 449         /* during GC, we don't care about RR, instead we want to make
 450          * sure that we maintain evenness between the block luns.
 451          */
 452         max_free = &rrpc->luns[0];
 453         /* prevent GC-ing lun from devouring pages of a lun with
 454          * little free blocks. We don't take the lock as we only need an
 455          * estimate.
 456          */
 457         rrpc_for_each_lun(rrpc, rlun, i) {
 458                 if (rlun->parent->nr_free_blocks >
 459                                         max_free->parent->nr_free_blocks)
 460                         max_free = rlun;
 461         }
 462
 463         return max_free;
 464 }
 465
 466 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 467                                         struct rrpc_block *rblk, sector_t paddr)
 468 {
 469         struct rrpc_addr *gp;
 470         struct rrpc_rev_addr *rev;
 471
 472         BUG_ON(laddr >= rrpc->nr_pages);
 473
 474         gp = &rrpc->trans_map[laddr];
 475         spin_lock(&rrpc->rev_lock);
 476         if (gp->rblk)
 477                 rrpc_page_invalidate(rrpc, gp);
 478
 479         gp->addr = paddr;
 480         gp->rblk = rblk;
 481
 482         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 483         rev->addr = laddr;
 484         spin_unlock(&rrpc->rev_lock);
 485
 486         return gp;
 487 }
 488
 489 static sector_t rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 490 {
 491         sector_t addr = ADDR_EMPTY;
 492
 493         spin_lock(&rblk->lock);
 494         if (block_is_full(rrpc, rblk))
 495                 goto out;
 496
 497         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 498
 499         rblk->next_page++;
 500 out:
 501         spin_unlock(&rblk->lock);
 502         return addr;
 503 }
 504
 505 /* Simple round-robin Logical to physical address translation.
 506  *
 507  * Retrieve the mapping using the active append point. Then update the ap for
 508  * the next write to the disk.
 509  *
 510  * Returns rrpc_addr with the physical address and block. Remember to return to
 511  * rrpc->addr_cache when request is finished.
 512  */
 513 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 514                                                                 int is_gc)
 515 {
 516         struct rrpc_lun *rlun;
 517         struct rrpc_block *rblk;
 518         struct nvm_lun *lun;
 519         sector_t paddr;
 520
 521         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 522         lun = rlun->parent;
 523
 524         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 525                 return NULL;
 526
 527         spin_lock(&rlun->lock);
 528
 529         rblk = rlun->cur;
 530 retry:
 531         paddr = rrpc_alloc_addr(rrpc, rblk);
 532
 533         if (paddr == ADDR_EMPTY) {
 534                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 535                 if (rblk) {
 536                         rrpc_set_lun_cur(rlun, rblk);
 537                         goto retry;
 538                 }
 539
 540                 if (is_gc) {
 541                         /* retry from emergency gc block */
 542                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 543                         if (paddr == ADDR_EMPTY) {
 544                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 545                                 if (!rblk) {
 546                                         pr_err("rrpc: no more blocks");
 547                                         goto err;
 548                                 }
 549
 550                                 rlun->gc_cur = rblk;
 551                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 552                         }
 553                         rblk = rlun->gc_cur;
 554                 }
 555         }
 556
 557         spin_unlock(&rlun->lock);
 558         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 559 err:
 560         spin_unlock(&rlun->lock);
 561         return NULL;
 562 }
 563
 564 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 565 {
 566         struct rrpc_block_gc *gcb;
 567
 568         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 569         if (!gcb) {
 570                 pr_err("rrpc: unable to queue block for gc.");
 571                 return;
 572         }
 573
 574         gcb->rrpc = rrpc;
 575         gcb->rblk = rblk;
 576
 577         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 578         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 579 }
 580
 581 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 582                                                 sector_t laddr, uint8_t npages)
 583 {
 584         struct rrpc_addr *p;
 585         struct rrpc_block *rblk;
 586         struct nvm_lun *lun;
 587         int cmnt_size, i;
 588
 589         for (i = 0; i < npages; i++) {
 590                 p = &rrpc->trans_map[laddr + i];
 591                 rblk = p->rblk;
 592                 lun = rblk->parent->lun;
 593
 594                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 595                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
 596                         rrpc_run_gc(rrpc, rblk);
 597         }
 598 }
 599
 600 static int rrpc_end_io(struct nvm_rq *rqd, int error)
 601 {
 602         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 603         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 604         uint8_t npages = rqd->nr_pages;
 605         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 606
 607         if (bio_data_dir(rqd->bio) == WRITE)
 608                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 609
 610         if (rrqd->flags & NVM_IOTYPE_GC)
 611                 return 0;
 612
 613         rrpc_unlock_rq(rrpc, rqd);
 614         bio_put(rqd->bio);
 615
 616         if (npages > 1)
 617                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 618         if (rqd->metadata)
 619                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 620
 621         mempool_free(rqd, rrpc->rq_pool);
 622
 623         return 0;
 624 }
 625
 626 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 627                         struct nvm_rq *rqd, unsigned long flags, int npages)
 628 {
 629         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 630         struct rrpc_addr *gp;
 631         sector_t laddr = rrpc_get_laddr(bio);
 632         int is_gc = flags & NVM_IOTYPE_GC;
 633         int i;
 634
 635         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 636                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 637                 return NVM_IO_REQUEUE;
 638         }
 639
 640         for (i = 0; i < npages; i++) {
 641                 /* We assume that mapping occurs at 4KB granularity */
 642                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 643                 gp = &rrpc->trans_map[laddr + i];
 644
 645                 if (gp->rblk) {
 646                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 647                                                                 gp->addr);
 648                 } else {
 649                         BUG_ON(is_gc);
 650                         rrpc_unlock_laddr(rrpc, r);
 651                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 652                                                         rqd->dma_ppa_list);
 653                         return NVM_IO_DONE;
 654                 }
 655         }
 656
 657         rqd->opcode = NVM_OP_HBREAD;
 658
 659         return NVM_IO_OK;
 660 }
 661
 662 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 663                                                         unsigned long flags)
 664 {
 665         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 666         int is_gc = flags & NVM_IOTYPE_GC;
 667         sector_t laddr = rrpc_get_laddr(bio);
 668         struct rrpc_addr *gp;
 669
 670         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 671                 return NVM_IO_REQUEUE;
 672
 673         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 674         gp = &rrpc->trans_map[laddr];
 675
 676         if (gp->rblk) {
 677                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 678         } else {
 679                 BUG_ON(is_gc);
 680                 rrpc_unlock_rq(rrpc, rqd);
 681                 return NVM_IO_DONE;
 682         }
 683
 684         rqd->opcode = NVM_OP_HBREAD;
 685         rrqd->addr = gp;
 686
 687         return NVM_IO_OK;
 688 }
 689
 690 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 691                         struct nvm_rq *rqd, unsigned long flags, int npages)
 692 {
 693         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 694         struct rrpc_addr *p;
 695         sector_t laddr = rrpc_get_laddr(bio);
 696         int is_gc = flags & NVM_IOTYPE_GC;
 697         int i;
 698
 699         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 700                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 701                 return NVM_IO_REQUEUE;
 702         }
 703
 704         for (i = 0; i < npages; i++) {
 705                 /* We assume that mapping occurs at 4KB granularity */
 706                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 707                 if (!p) {
 708                         BUG_ON(is_gc);
 709                         rrpc_unlock_laddr(rrpc, r);
 710                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 711                                                         rqd->dma_ppa_list);
 712                         rrpc_gc_kick(rrpc);
 713                         return NVM_IO_REQUEUE;
 714                 }
 715
 716                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 717                                                                 p->addr);
 718         }
 719
 720         rqd->opcode = NVM_OP_HBWRITE;
 721
 722         return NVM_IO_OK;
 723 }
 724
 725 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 726                                 struct nvm_rq *rqd, unsigned long flags)
 727 {
 728         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 729         struct rrpc_addr *p;
 730         int is_gc = flags & NVM_IOTYPE_GC;
 731         sector_t laddr = rrpc_get_laddr(bio);
 732
 733         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 734                 return NVM_IO_REQUEUE;
 735
 736         p = rrpc_map_page(rrpc, laddr, is_gc);
 737         if (!p) {
 738                 BUG_ON(is_gc);
 739                 rrpc_unlock_rq(rrpc, rqd);
 740                 rrpc_gc_kick(rrpc);
 741                 return NVM_IO_REQUEUE;
 742         }
 743
 744         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 745         rqd->opcode = NVM_OP_HBWRITE;
 746         rrqd->addr = p;
 747
 748         return NVM_IO_OK;
 749 }
 750
 751 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 752                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 753 {
 754         if (npages > 1) {
 755                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 756                                                         &rqd->dma_ppa_list);
 757                 if (!rqd->ppa_list) {
 758                         pr_err("rrpc: not able to allocate ppa list\n");
 759                         return NVM_IO_ERR;
 760                 }
 761
 762                 if (bio_rw(bio) == WRITE)
 763                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 764                                                                         npages);
 765
 766                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 767         }
 768
 769         if (bio_rw(bio) == WRITE)
 770                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 771
 772         return rrpc_read_rq(rrpc, bio, rqd, flags);
 773 }
 774
 775 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 776                                 struct nvm_rq *rqd, unsigned long flags)
 777 {
 778         int err;
 779         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 780         uint8_t nr_pages = rrpc_get_pages(bio);
 781         int bio_size = bio_sectors(bio) << 9;
 782
 783         if (bio_size < rrpc->dev->sec_size)
 784                 return NVM_IO_ERR;
 785         else if (bio_size > rrpc->dev->max_rq_size)
 786                 return NVM_IO_ERR;
 787
 788         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 789         if (err)
 790                 return err;
 791
 792         bio_get(bio);
 793         rqd->bio = bio;
 794         rqd->ins = &rrpc->instance;
 795         rqd->nr_pages = nr_pages;
 796         rrq->flags = flags;
 797
 798         err = nvm_submit_io(rrpc->dev, rqd);
 799         if (err) {
 800                 pr_err("rrpc: I/O submission failed: %d\n", err);
 801                 return NVM_IO_ERR;
 802         }
 803
 804         return NVM_IO_OK;
 805 }
 806
 807 static void rrpc_make_rq(struct request_queue *q, struct bio *bio)
 808 {
 809         struct rrpc *rrpc = q->queuedata;
 810         struct nvm_rq *rqd;
 811         int err;
 812
 813         if (bio->bi_rw & REQ_DISCARD) {
 814                 rrpc_discard(rrpc, bio);
 815                 return;
 816         }
 817
 818         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 819         if (!rqd) {
 820                 pr_err_ratelimited("rrpc: not able to queue bio.");
 821                 bio_io_error(bio);
 822                 return;
 823         }
 824         memset(rqd, 0, sizeof(struct nvm_rq));
 825
 826         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 827         switch (err) {
 828         case NVM_IO_OK:
 829                 return;
 830         case NVM_IO_ERR:
 831                 bio_io_error(bio);
 832                 break;
 833         case NVM_IO_DONE:
 834                 bio_endio(bio);
 835                 break;
 836         case NVM_IO_REQUEUE:
 837                 spin_lock(&rrpc->bio_lock);
 838                 bio_list_add(&rrpc->requeue_bios, bio);
 839                 spin_unlock(&rrpc->bio_lock);
 840                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 841                 break;
 842         }
 843
 844         mempool_free(rqd, rrpc->rq_pool);
 845 }
 846
 847 static void rrpc_requeue(struct work_struct *work)
 848 {
 849         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 850         struct bio_list bios;
 851         struct bio *bio;
 852
 853         bio_list_init(&bios);
 854
 855         spin_lock(&rrpc->bio_lock);
 856         bio_list_merge(&bios, &rrpc->requeue_bios);
 857         bio_list_init(&rrpc->requeue_bios);
 858         spin_unlock(&rrpc->bio_lock);
 859
 860         while ((bio = bio_list_pop(&bios)))
 861                 rrpc_make_rq(rrpc->disk->queue, bio);
 862 }
 863
 864 static void rrpc_gc_free(struct rrpc *rrpc)
 865 {
 866         struct rrpc_lun *rlun;
 867         int i;
 868
 869         if (rrpc->krqd_wq)
 870                 destroy_workqueue(rrpc->krqd_wq);
 871
 872         if (rrpc->kgc_wq)
 873                 destroy_workqueue(rrpc->kgc_wq);
 874
 875         if (!rrpc->luns)
 876                 return;
 877
 878         for (i = 0; i < rrpc->nr_luns; i++) {
 879                 rlun = &rrpc->luns[i];
 880
 881                 if (!rlun->blocks)
 882                         break;
 883                 vfree(rlun->blocks);
 884         }
 885 }
 886
 887 static int rrpc_gc_init(struct rrpc *rrpc)
 888 {
 889         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 890                                                                 rrpc->nr_luns);
 891         if (!rrpc->krqd_wq)
 892                 return -ENOMEM;
 893
 894         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 895         if (!rrpc->kgc_wq)
 896                 return -ENOMEM;
 897
 898         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 899
 900         return 0;
 901 }
 902
 903 static void rrpc_map_free(struct rrpc *rrpc)
 904 {
 905         vfree(rrpc->rev_trans_map);
 906         vfree(rrpc->trans_map);
 907 }
 908
 909 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 910 {
 911         struct rrpc *rrpc = (struct rrpc *)private;
 912         struct nvm_dev *dev = rrpc->dev;
 913         struct rrpc_addr *addr = rrpc->trans_map + slba;
 914         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
 915         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 916         u64 elba = slba + nlb;
 917         u64 i;
 918
 919         if (unlikely(elba > dev->total_pages)) {
 920                 pr_err("nvm: L2P data from device is out of bounds!\n");
 921                 return -EINVAL;
 922         }
 923
 924         for (i = 0; i < nlb; i++) {
 925                 u64 pba = le64_to_cpu(entries[i]);
 926                 /* LNVM treats address-spaces as silos, LBA and PBA are
 927                  * equally large and zero-indexed.
 928                  */
 929                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 930                         pr_err("nvm: L2P data entry is out of bounds!\n");
 931                         return -EINVAL;
 932                 }
 933
 934                 /* Address zero is a special one. The first page on a disk is
 935                  * protected. As it often holds internal device boot
 936                  * information.
 937                  */
 938                 if (!pba)
 939                         continue;
 940
 941                 addr[i].addr = pba;
 942                 raddr[pba].addr = slba + i;
 943         }
 944
 945         return 0;
 946 }
 947
 948 static int rrpc_map_init(struct rrpc *rrpc)
 949 {
 950         struct nvm_dev *dev = rrpc->dev;
 951         sector_t i;
 952         int ret;
 953
 954         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
 955         if (!rrpc->trans_map)
 956                 return -ENOMEM;
 957
 958         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
 959                                                         * rrpc->nr_pages);
 960         if (!rrpc->rev_trans_map)
 961                 return -ENOMEM;
 962
 963         for (i = 0; i < rrpc->nr_pages; i++) {
 964                 struct rrpc_addr *p = &rrpc->trans_map[i];
 965                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
 966
 967                 p->addr = ADDR_EMPTY;
 968                 r->addr = ADDR_EMPTY;
 969         }
 970
 971         if (!dev->ops->get_l2p_tbl)
 972                 return 0;
 973
 974         /* Bring up the mapping table from device */
 975         ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
 976                                                         rrpc_l2p_update, rrpc);
 977         if (ret) {
 978                 pr_err("nvm: rrpc: could not read L2P table.\n");
 979                 return -EINVAL;
 980         }
 981
 982         return 0;
 983 }
 984
 985
 986 /* Minimum pages needed within a lun */
 987 #define PAGE_POOL_SIZE 16
 988 #define ADDR_POOL_SIZE 64
 989
 990 static int rrpc_core_init(struct rrpc *rrpc)
 991 {
 992         down_write(&rrpc_lock);
 993         if (!rrpc_gcb_cache) {
 994                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
 995                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
 996                 if (!rrpc_gcb_cache) {
 997                         up_write(&rrpc_lock);
 998                         return -ENOMEM;
 999                 }
1000
1001                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1002                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1003                                 0, 0, NULL);
1004                 if (!rrpc_rq_cache) {
1005                         kmem_cache_destroy(rrpc_gcb_cache);
1006                         up_write(&rrpc_lock);
1007                         return -ENOMEM;
1008                 }
1009         }
1010         up_write(&rrpc_lock);
1011
1012         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1013         if (!rrpc->page_pool)
1014                 return -ENOMEM;
1015
1016         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1017                                                                 rrpc_gcb_cache);
1018         if (!rrpc->gcb_pool)
1019                 return -ENOMEM;
1020
1021         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1022         if (!rrpc->rq_pool)
1023                 return -ENOMEM;
1024
1025         spin_lock_init(&rrpc->inflights.lock);
1026         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1027
1028         return 0;
1029 }
1030
1031 static void rrpc_core_free(struct rrpc *rrpc)
1032 {
1033         mempool_destroy(rrpc->page_pool);
1034         mempool_destroy(rrpc->gcb_pool);
1035         mempool_destroy(rrpc->rq_pool);
1036 }
1037
1038 static void rrpc_luns_free(struct rrpc *rrpc)
1039 {
1040         kfree(rrpc->luns);
1041 }
1042
1043 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1044 {
1045         struct nvm_dev *dev = rrpc->dev;
1046         struct rrpc_lun *rlun;
1047         int i, j;
1048
1049         spin_lock_init(&rrpc->rev_lock);
1050
1051         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1052                                                                 GFP_KERNEL);
1053         if (!rrpc->luns)
1054                 return -ENOMEM;
1055
1056         /* 1:1 mapping */
1057         for (i = 0; i < rrpc->nr_luns; i++) {
1058                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1059
1060                 if (dev->pgs_per_blk >
1061                                 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1062                         pr_err("rrpc: number of pages per block too high.");
1063                         goto err;
1064                 }
1065
1066                 rlun = &rrpc->luns[i];
1067                 rlun->rrpc = rrpc;
1068                 rlun->parent = lun;
1069                 INIT_LIST_HEAD(&rlun->prio_list);
1070                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1071                 spin_lock_init(&rlun->lock);
1072
1073                 rrpc->total_blocks += dev->blks_per_lun;
1074                 rrpc->nr_pages += dev->sec_per_lun;
1075
1076                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1077                                                 rrpc->dev->blks_per_lun);
1078                 if (!rlun->blocks)
1079                         goto err;
1080
1081                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1082                         struct rrpc_block *rblk = &rlun->blocks[j];
1083                         struct nvm_block *blk = &lun->blocks[j];
1084
1085                         rblk->parent = blk;
1086                         INIT_LIST_HEAD(&rblk->prio);
1087                         spin_lock_init(&rblk->lock);
1088                 }
1089         }
1090
1091         return 0;
1092 err:
1093         return -ENOMEM;
1094 }
1095
1096 static void rrpc_free(struct rrpc *rrpc)
1097 {
1098         rrpc_gc_free(rrpc);
1099         rrpc_map_free(rrpc);
1100         rrpc_core_free(rrpc);
1101         rrpc_luns_free(rrpc);
1102
1103         kfree(rrpc);
1104 }
1105
1106 static void rrpc_exit(void *private)
1107 {
1108         struct rrpc *rrpc = private;
1109
1110         del_timer(&rrpc->gc_timer);
1111
1112         flush_workqueue(rrpc->krqd_wq);
1113         flush_workqueue(rrpc->kgc_wq);
1114
1115         rrpc_free(rrpc);
1116 }
1117
1118 static sector_t rrpc_capacity(void *private)
1119 {
1120         struct rrpc *rrpc = private;
1121         struct nvm_dev *dev = rrpc->dev;
1122         sector_t reserved, provisioned;
1123
1124         /* cur, gc, and two emergency blocks for each lun */
1125         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1126         provisioned = rrpc->nr_pages - reserved;
1127
1128         if (reserved > rrpc->nr_pages) {
1129                 pr_err("rrpc: not enough space available to expose storage.\n");
1130                 return 0;
1131         }
1132
1133         sector_div(provisioned, 10);
1134         return provisioned * 9 * NR_PHY_IN_LOG;
1135 }
1136
1137 /*
1138  * Looks up the logical address from reverse trans map and check if its valid by
1139  * comparing the logical to physical address with the physical address.
1140  * Returns 0 on free, otherwise 1 if in use
1141  */
1142 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1143 {
1144         struct nvm_dev *dev = rrpc->dev;
1145         int offset;
1146         struct rrpc_addr *laddr;
1147         sector_t paddr, pladdr;
1148
1149         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1150                 paddr = block_to_addr(rrpc, rblk) + offset;
1151
1152                 pladdr = rrpc->rev_trans_map[paddr].addr;
1153                 if (pladdr == ADDR_EMPTY)
1154                         continue;
1155
1156                 laddr = &rrpc->trans_map[pladdr];
1157
1158                 if (paddr == laddr->addr) {
1159                         laddr->rblk = rblk;
1160                 } else {
1161                         set_bit(offset, rblk->invalid_pages);
1162                         rblk->nr_invalid_pages++;
1163                 }
1164         }
1165 }
1166
1167 static int rrpc_blocks_init(struct rrpc *rrpc)
1168 {
1169         struct rrpc_lun *rlun;
1170         struct rrpc_block *rblk;
1171         int lun_iter, blk_iter;
1172
1173         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1174                 rlun = &rrpc->luns[lun_iter];
1175
1176                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1177                                                                 blk_iter++) {
1178                         rblk = &rlun->blocks[blk_iter];
1179                         rrpc_block_map_update(rrpc, rblk);
1180                 }
1181         }
1182
1183         return 0;
1184 }
1185
1186 static int rrpc_luns_configure(struct rrpc *rrpc)
1187 {
1188         struct rrpc_lun *rlun;
1189         struct rrpc_block *rblk;
1190         int i;
1191
1192         for (i = 0; i < rrpc->nr_luns; i++) {
1193                 rlun = &rrpc->luns[i];
1194
1195                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1196                 if (!rblk)
1197                         return -EINVAL;
1198
1199                 rrpc_set_lun_cur(rlun, rblk);
1200
1201                 /* Emergency gc block */
1202                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1203                 if (!rblk)
1204                         return -EINVAL;
1205                 rlun->gc_cur = rblk;
1206         }
1207
1208         return 0;
1209 }
1210
1211 static struct nvm_tgt_type tt_rrpc;
1212
1213 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1214                                                 int lun_begin, int lun_end)
1215 {
1216         struct request_queue *bqueue = dev->q;
1217         struct request_queue *tqueue = tdisk->queue;
1218         struct rrpc *rrpc;
1219         int ret;
1220
1221         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1222                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1223                                                         dev->identity.dom);
1224                 return ERR_PTR(-EINVAL);
1225         }
1226
1227         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1228         if (!rrpc)
1229                 return ERR_PTR(-ENOMEM);
1230
1231         rrpc->instance.tt = &tt_rrpc;
1232         rrpc->dev = dev;
1233         rrpc->disk = tdisk;
1234
1235         bio_list_init(&rrpc->requeue_bios);
1236         spin_lock_init(&rrpc->bio_lock);
1237         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1238
1239         rrpc->nr_luns = lun_end - lun_begin + 1;
1240
1241         /* simple round-robin strategy */
1242         atomic_set(&rrpc->next_lun, -1);
1243
1244         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1245         if (ret) {
1246                 pr_err("nvm: rrpc: could not initialize luns\n");
1247                 goto err;
1248         }
1249
1250         rrpc->poffset = dev->sec_per_lun * lun_begin;
1251         rrpc->lun_offset = lun_begin;
1252
1253         ret = rrpc_core_init(rrpc);
1254         if (ret) {
1255                 pr_err("nvm: rrpc: could not initialize core\n");
1256                 goto err;
1257         }
1258
1259         ret = rrpc_map_init(rrpc);
1260         if (ret) {
1261                 pr_err("nvm: rrpc: could not initialize maps\n");
1262                 goto err;
1263         }
1264
1265         ret = rrpc_blocks_init(rrpc);
1266         if (ret) {
1267                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1268                 goto err;
1269         }
1270
1271         ret = rrpc_luns_configure(rrpc);
1272         if (ret) {
1273                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1274                 goto err;
1275         }
1276
1277         ret = rrpc_gc_init(rrpc);
1278         if (ret) {
1279                 pr_err("nvm: rrpc: could not initialize gc\n");
1280                 goto err;
1281         }
1282
1283         /* inherit the size from the underlying device */
1284         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1285         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1286
1287         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1288                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1289
1290         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1291
1292         return rrpc;
1293 err:
1294         rrpc_free(rrpc);
1295         return ERR_PTR(ret);
1296 }
1297
1298 /* round robin, page-based FTL, and cost-based GC */
1299 static struct nvm_tgt_type tt_rrpc = {
1300         .name           = "rrpc",
1301         .version        = {1, 0, 0},
1302
1303         .make_rq        = rrpc_make_rq,
1304         .capacity       = rrpc_capacity,
1305         .end_io         = rrpc_end_io,
1306
1307         .init           = rrpc_init,
1308         .exit           = rrpc_exit,
1309 };
1310
1311 static int __init rrpc_module_init(void)
1312 {
1313         return nvm_register_target(&tt_rrpc);
1314 }
1315
1316 static void rrpc_module_exit(void)
1317 {
1318         nvm_unregister_target(&tt_rrpc);
1319 }
1320
1321 module_init(rrpc_module_init);
1322 module_exit(rrpc_module_exit);
1323 MODULE_LICENSE("GPL v2");
1324 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");