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_lun *lun = rlun->parent;
 183         struct nvm_block *blk;
 184         struct rrpc_block *rblk;
 185
 186         spin_lock(&lun->lock);
 187         blk = nvm_get_blk_unlocked(rrpc->dev, rlun->parent, flags);
 188         if (!blk) {
 189                 pr_err("nvm: rrpc: cannot get new block from media manager\n");
 190                 spin_unlock(&lun->lock);
 191                 return NULL;
 192         }
 193
 194         rblk = &rlun->blocks[blk->id];
 195         list_add_tail(&rblk->list, &rlun->open_list);
 196         spin_unlock(&lun->lock);
 197
 198         blk->priv = rblk;
 199         bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
 200         rblk->next_page = 0;
 201         rblk->nr_invalid_pages = 0;
 202         atomic_set(&rblk->data_cmnt_size, 0);
 203
 204         return rblk;
 205 }
 206
 207 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 208 {
 209         struct rrpc_lun *rlun = rblk->rlun;
 210         struct nvm_lun *lun = rlun->parent;
 211
 212         spin_lock(&lun->lock);
 213         nvm_put_blk_unlocked(rrpc->dev, rblk->parent);
 214         list_del(&rblk->list);
 215         spin_unlock(&lun->lock);
 216 }
 217
 218 static void rrpc_put_blks(struct rrpc *rrpc)
 219 {
 220         struct rrpc_lun *rlun;
 221         int i;
 222
 223         for (i = 0; i < rrpc->nr_luns; i++) {
 224                 rlun = &rrpc->luns[i];
 225                 if (rlun->cur)
 226                         rrpc_put_blk(rrpc, rlun->cur);
 227                 if (rlun->gc_cur)
 228                         rrpc_put_blk(rrpc, rlun->gc_cur);
 229         }
 230 }
 231
 232 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 233 {
 234         int next = atomic_inc_return(&rrpc->next_lun);
 235
 236         return &rrpc->luns[next % rrpc->nr_luns];
 237 }
 238
 239 static void rrpc_gc_kick(struct rrpc *rrpc)
 240 {
 241         struct rrpc_lun *rlun;
 242         unsigned int i;
 243
 244         for (i = 0; i < rrpc->nr_luns; i++) {
 245                 rlun = &rrpc->luns[i];
 246                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 247         }
 248 }
 249
 250 /*
 251  * timed GC every interval.
 252  */
 253 static void rrpc_gc_timer(unsigned long data)
 254 {
 255         struct rrpc *rrpc = (struct rrpc *)data;
 256
 257         rrpc_gc_kick(rrpc);
 258         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 259 }
 260
 261 static void rrpc_end_sync_bio(struct bio *bio)
 262 {
 263         struct completion *waiting = bio->bi_private;
 264
 265         if (bio->bi_error)
 266                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 267
 268         complete(waiting);
 269 }
 270
 271 /*
 272  * rrpc_move_valid_pages -- migrate live data off the block
 273  * @rrpc: the 'rrpc' structure
 274  * @block: the block from which to migrate live pages
 275  *
 276  * Description:
 277  *   GC algorithms may call this function to migrate remaining live
 278  *   pages off the block prior to erasing it. This function blocks
 279  *   further execution until the operation is complete.
 280  */
 281 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 282 {
 283         struct request_queue *q = rrpc->dev->q;
 284         struct rrpc_rev_addr *rev;
 285         struct nvm_rq *rqd;
 286         struct bio *bio;
 287         struct page *page;
 288         int slot;
 289         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 290         u64 phys_addr;
 291         DECLARE_COMPLETION_ONSTACK(wait);
 292
 293         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 294                 return 0;
 295
 296         bio = bio_alloc(GFP_NOIO, 1);
 297         if (!bio) {
 298                 pr_err("nvm: could not alloc bio to gc\n");
 299                 return -ENOMEM;
 300         }
 301
 302         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 303         if (!page)
 304                 return -ENOMEM;
 305
 306         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 307                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 308
 309                 /* Lock laddr */
 310                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 311
 312 try:
 313                 spin_lock(&rrpc->rev_lock);
 314                 /* Get logical address from physical to logical table */
 315                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 316                 /* already updated by previous regular write */
 317                 if (rev->addr == ADDR_EMPTY) {
 318                         spin_unlock(&rrpc->rev_lock);
 319                         continue;
 320                 }
 321
 322                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 323                 if (IS_ERR_OR_NULL(rqd)) {
 324                         spin_unlock(&rrpc->rev_lock);
 325                         schedule();
 326                         goto try;
 327                 }
 328
 329                 spin_unlock(&rrpc->rev_lock);
 330
 331                 /* Perform read to do GC */
 332                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 333                 bio->bi_rw = READ;
 334                 bio->bi_private = &wait;
 335                 bio->bi_end_io = rrpc_end_sync_bio;
 336
 337                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 338                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 339
 340                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 341                         pr_err("rrpc: gc read failed.\n");
 342                         rrpc_inflight_laddr_release(rrpc, rqd);
 343                         goto finished;
 344                 }
 345                 wait_for_completion_io(&wait);
 346                 if (bio->bi_error) {
 347                         rrpc_inflight_laddr_release(rrpc, rqd);
 348                         goto finished;
 349                 }
 350
 351                 bio_reset(bio);
 352                 reinit_completion(&wait);
 353
 354                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 355                 bio->bi_rw = WRITE;
 356                 bio->bi_private = &wait;
 357                 bio->bi_end_io = rrpc_end_sync_bio;
 358
 359                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 360
 361                 /* turn the command around and write the data back to a new
 362                  * address
 363                  */
 364                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 365                         pr_err("rrpc: gc write failed.\n");
 366                         rrpc_inflight_laddr_release(rrpc, rqd);
 367                         goto finished;
 368                 }
 369                 wait_for_completion_io(&wait);
 370
 371                 rrpc_inflight_laddr_release(rrpc, rqd);
 372                 if (bio->bi_error)
 373                         goto finished;
 374
 375                 bio_reset(bio);
 376         }
 377
 378 finished:
 379         mempool_free(page, rrpc->page_pool);
 380         bio_put(bio);
 381
 382         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 383                 pr_err("nvm: failed to garbage collect block\n");
 384                 return -EIO;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static void rrpc_block_gc(struct work_struct *work)
 391 {
 392         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 393                                                                         ws_gc);
 394         struct rrpc *rrpc = gcb->rrpc;
 395         struct rrpc_block *rblk = gcb->rblk;
 396         struct nvm_dev *dev = rrpc->dev;
 397         struct nvm_lun *lun = rblk->parent->lun;
 398         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 399
 400         mempool_free(gcb, rrpc->gcb_pool);
 401         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 402
 403         if (rrpc_move_valid_pages(rrpc, rblk))
 404                 goto put_back;
 405
 406         if (nvm_erase_blk(dev, rblk->parent))
 407                 goto put_back;
 408
 409         rrpc_put_blk(rrpc, rblk);
 410
 411         return;
 412
 413 put_back:
 414         spin_lock(&rlun->lock);
 415         list_add_tail(&rblk->prio, &rlun->prio_list);
 416         spin_unlock(&rlun->lock);
 417 }
 418
 419 /* the block with highest number of invalid pages, will be in the beginning
 420  * of the list
 421  */
 422 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 423                                                         struct rrpc_block *rb)
 424 {
 425         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 426                 return ra;
 427
 428         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 429 }
 430
 431 /* linearly find the block with highest number of invalid pages
 432  * requires lun->lock
 433  */
 434 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 435 {
 436         struct list_head *prio_list = &rlun->prio_list;
 437         struct rrpc_block *rblock, *max;
 438
 439         BUG_ON(list_empty(prio_list));
 440
 441         max = list_first_entry(prio_list, struct rrpc_block, prio);
 442         list_for_each_entry(rblock, prio_list, prio)
 443                 max = rblock_max_invalid(max, rblock);
 444
 445         return max;
 446 }
 447
 448 static void rrpc_lun_gc(struct work_struct *work)
 449 {
 450         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 451         struct rrpc *rrpc = rlun->rrpc;
 452         struct nvm_lun *lun = rlun->parent;
 453         struct rrpc_block_gc *gcb;
 454         unsigned int nr_blocks_need;
 455
 456         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 457
 458         if (nr_blocks_need < rrpc->nr_luns)
 459                 nr_blocks_need = rrpc->nr_luns;
 460
 461         spin_lock(&rlun->lock);
 462         while (nr_blocks_need > lun->nr_free_blocks &&
 463                                         !list_empty(&rlun->prio_list)) {
 464                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 465                 struct nvm_block *block = rblock->parent;
 466
 467                 if (!rblock->nr_invalid_pages)
 468                         break;
 469
 470                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 471                 if (!gcb)
 472                         break;
 473
 474                 list_del_init(&rblock->prio);
 475
 476                 BUG_ON(!block_is_full(rrpc, rblock));
 477
 478                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 479
 480                 gcb->rrpc = rrpc;
 481                 gcb->rblk = rblock;
 482                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 483
 484                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 485
 486                 nr_blocks_need--;
 487         }
 488         spin_unlock(&rlun->lock);
 489
 490         /* TODO: Hint that request queue can be started again */
 491 }
 492
 493 static void rrpc_gc_queue(struct work_struct *work)
 494 {
 495         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 496                                                                         ws_gc);
 497         struct rrpc *rrpc = gcb->rrpc;
 498         struct rrpc_block *rblk = gcb->rblk;
 499         struct nvm_lun *lun = rblk->parent->lun;
 500         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 501
 502         spin_lock(&rlun->lock);
 503         list_add_tail(&rblk->prio, &rlun->prio_list);
 504         spin_unlock(&rlun->lock);
 505
 506         mempool_free(gcb, rrpc->gcb_pool);
 507         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 508                                                         rblk->parent->id);
 509 }
 510
 511 static const struct block_device_operations rrpc_fops = {
 512         .owner          = THIS_MODULE,
 513 };
 514
 515 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 516 {
 517         unsigned int i;
 518         struct rrpc_lun *rlun, *max_free;
 519
 520         if (!is_gc)
 521                 return get_next_lun(rrpc);
 522
 523         /* during GC, we don't care about RR, instead we want to make
 524          * sure that we maintain evenness between the block luns.
 525          */
 526         max_free = &rrpc->luns[0];
 527         /* prevent GC-ing lun from devouring pages of a lun with
 528          * little free blocks. We don't take the lock as we only need an
 529          * estimate.
 530          */
 531         rrpc_for_each_lun(rrpc, rlun, i) {
 532                 if (rlun->parent->nr_free_blocks >
 533                                         max_free->parent->nr_free_blocks)
 534                         max_free = rlun;
 535         }
 536
 537         return max_free;
 538 }
 539
 540 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 541                                         struct rrpc_block *rblk, u64 paddr)
 542 {
 543         struct rrpc_addr *gp;
 544         struct rrpc_rev_addr *rev;
 545
 546         BUG_ON(laddr >= rrpc->nr_pages);
 547
 548         gp = &rrpc->trans_map[laddr];
 549         spin_lock(&rrpc->rev_lock);
 550         if (gp->rblk)
 551                 rrpc_page_invalidate(rrpc, gp);
 552
 553         gp->addr = paddr;
 554         gp->rblk = rblk;
 555
 556         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 557         rev->addr = laddr;
 558         spin_unlock(&rrpc->rev_lock);
 559
 560         return gp;
 561 }
 562
 563 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 564 {
 565         u64 addr = ADDR_EMPTY;
 566
 567         spin_lock(&rblk->lock);
 568         if (block_is_full(rrpc, rblk))
 569                 goto out;
 570
 571         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 572
 573         rblk->next_page++;
 574 out:
 575         spin_unlock(&rblk->lock);
 576         return addr;
 577 }
 578
 579 /* Simple round-robin Logical to physical address translation.
 580  *
 581  * Retrieve the mapping using the active append point. Then update the ap for
 582  * the next write to the disk.
 583  *
 584  * Returns rrpc_addr with the physical address and block. Remember to return to
 585  * rrpc->addr_cache when request is finished.
 586  */
 587 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 588                                                                 int is_gc)
 589 {
 590         struct rrpc_lun *rlun;
 591         struct rrpc_block *rblk;
 592         struct nvm_lun *lun;
 593         u64 paddr;
 594
 595         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 596         lun = rlun->parent;
 597
 598         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 599                 return NULL;
 600
 601         spin_lock(&rlun->lock);
 602
 603         rblk = rlun->cur;
 604 retry:
 605         paddr = rrpc_alloc_addr(rrpc, rblk);
 606
 607         if (paddr == ADDR_EMPTY) {
 608                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 609                 if (rblk) {
 610                         rrpc_set_lun_cur(rlun, rblk);
 611                         goto retry;
 612                 }
 613
 614                 if (is_gc) {
 615                         /* retry from emergency gc block */
 616                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 617                         if (paddr == ADDR_EMPTY) {
 618                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 619                                 if (!rblk) {
 620                                         pr_err("rrpc: no more blocks");
 621                                         goto err;
 622                                 }
 623
 624                                 rlun->gc_cur = rblk;
 625                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 626                         }
 627                         rblk = rlun->gc_cur;
 628                 }
 629         }
 630
 631         spin_unlock(&rlun->lock);
 632         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 633 err:
 634         spin_unlock(&rlun->lock);
 635         return NULL;
 636 }
 637
 638 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 639 {
 640         struct rrpc_block_gc *gcb;
 641
 642         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 643         if (!gcb) {
 644                 pr_err("rrpc: unable to queue block for gc.");
 645                 return;
 646         }
 647
 648         gcb->rrpc = rrpc;
 649         gcb->rblk = rblk;
 650
 651         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 652         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 653 }
 654
 655 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 656                                                 sector_t laddr, uint8_t npages)
 657 {
 658         struct rrpc_addr *p;
 659         struct rrpc_block *rblk;
 660         struct nvm_lun *lun;
 661         int cmnt_size, i;
 662
 663         for (i = 0; i < npages; i++) {
 664                 p = &rrpc->trans_map[laddr + i];
 665                 rblk = p->rblk;
 666                 lun = rblk->parent->lun;
 667
 668                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 669                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk)) {
 670                         struct nvm_block *blk = rblk->parent;
 671                         struct rrpc_lun *rlun = rblk->rlun;
 672
 673                         spin_lock(&lun->lock);
 674                         lun->nr_open_blocks--;
 675                         lun->nr_closed_blocks++;
 676                         blk->state &= ~NVM_BLK_ST_OPEN;
 677                         blk->state |= NVM_BLK_ST_CLOSED;
 678                         list_move_tail(&rblk->list, &rlun->closed_list);
 679                         spin_unlock(&lun->lock);
 680
 681                         rrpc_run_gc(rrpc, rblk);
 682                 }
 683         }
 684 }
 685
 686 static void rrpc_end_io(struct nvm_rq *rqd)
 687 {
 688         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 689         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 690         uint8_t npages = rqd->nr_pages;
 691         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 692
 693         if (bio_data_dir(rqd->bio) == WRITE)
 694                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 695
 696         bio_put(rqd->bio);
 697
 698         if (rrqd->flags & NVM_IOTYPE_GC)
 699                 return;
 700
 701         rrpc_unlock_rq(rrpc, rqd);
 702
 703         if (npages > 1)
 704                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 705         if (rqd->metadata)
 706                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 707
 708         mempool_free(rqd, rrpc->rq_pool);
 709 }
 710
 711 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 712                         struct nvm_rq *rqd, unsigned long flags, int npages)
 713 {
 714         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 715         struct rrpc_addr *gp;
 716         sector_t laddr = rrpc_get_laddr(bio);
 717         int is_gc = flags & NVM_IOTYPE_GC;
 718         int i;
 719
 720         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 721                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 722                 return NVM_IO_REQUEUE;
 723         }
 724
 725         for (i = 0; i < npages; i++) {
 726                 /* We assume that mapping occurs at 4KB granularity */
 727                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 728                 gp = &rrpc->trans_map[laddr + i];
 729
 730                 if (gp->rblk) {
 731                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 732                                                                 gp->addr);
 733                 } else {
 734                         BUG_ON(is_gc);
 735                         rrpc_unlock_laddr(rrpc, r);
 736                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 737                                                         rqd->dma_ppa_list);
 738                         return NVM_IO_DONE;
 739                 }
 740         }
 741
 742         rqd->opcode = NVM_OP_HBREAD;
 743
 744         return NVM_IO_OK;
 745 }
 746
 747 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 748                                                         unsigned long flags)
 749 {
 750         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 751         int is_gc = flags & NVM_IOTYPE_GC;
 752         sector_t laddr = rrpc_get_laddr(bio);
 753         struct rrpc_addr *gp;
 754
 755         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 756                 return NVM_IO_REQUEUE;
 757
 758         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 759         gp = &rrpc->trans_map[laddr];
 760
 761         if (gp->rblk) {
 762                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 763         } else {
 764                 BUG_ON(is_gc);
 765                 rrpc_unlock_rq(rrpc, rqd);
 766                 return NVM_IO_DONE;
 767         }
 768
 769         rqd->opcode = NVM_OP_HBREAD;
 770         rrqd->addr = gp;
 771
 772         return NVM_IO_OK;
 773 }
 774
 775 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 776                         struct nvm_rq *rqd, unsigned long flags, int npages)
 777 {
 778         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 779         struct rrpc_addr *p;
 780         sector_t laddr = rrpc_get_laddr(bio);
 781         int is_gc = flags & NVM_IOTYPE_GC;
 782         int i;
 783
 784         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 785                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 786                 return NVM_IO_REQUEUE;
 787         }
 788
 789         for (i = 0; i < npages; i++) {
 790                 /* We assume that mapping occurs at 4KB granularity */
 791                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 792                 if (!p) {
 793                         BUG_ON(is_gc);
 794                         rrpc_unlock_laddr(rrpc, r);
 795                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 796                                                         rqd->dma_ppa_list);
 797                         rrpc_gc_kick(rrpc);
 798                         return NVM_IO_REQUEUE;
 799                 }
 800
 801                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 802                                                                 p->addr);
 803         }
 804
 805         rqd->opcode = NVM_OP_HBWRITE;
 806
 807         return NVM_IO_OK;
 808 }
 809
 810 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 811                                 struct nvm_rq *rqd, unsigned long flags)
 812 {
 813         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 814         struct rrpc_addr *p;
 815         int is_gc = flags & NVM_IOTYPE_GC;
 816         sector_t laddr = rrpc_get_laddr(bio);
 817
 818         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 819                 return NVM_IO_REQUEUE;
 820
 821         p = rrpc_map_page(rrpc, laddr, is_gc);
 822         if (!p) {
 823                 BUG_ON(is_gc);
 824                 rrpc_unlock_rq(rrpc, rqd);
 825                 rrpc_gc_kick(rrpc);
 826                 return NVM_IO_REQUEUE;
 827         }
 828
 829         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 830         rqd->opcode = NVM_OP_HBWRITE;
 831         rrqd->addr = p;
 832
 833         return NVM_IO_OK;
 834 }
 835
 836 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 837                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 838 {
 839         if (npages > 1) {
 840                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 841                                                         &rqd->dma_ppa_list);
 842                 if (!rqd->ppa_list) {
 843                         pr_err("rrpc: not able to allocate ppa list\n");
 844                         return NVM_IO_ERR;
 845                 }
 846
 847                 if (bio_rw(bio) == WRITE)
 848                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 849                                                                         npages);
 850
 851                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 852         }
 853
 854         if (bio_rw(bio) == WRITE)
 855                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 856
 857         return rrpc_read_rq(rrpc, bio, rqd, flags);
 858 }
 859
 860 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 861                                 struct nvm_rq *rqd, unsigned long flags)
 862 {
 863         int err;
 864         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 865         uint8_t nr_pages = rrpc_get_pages(bio);
 866         int bio_size = bio_sectors(bio) << 9;
 867
 868         if (bio_size < rrpc->dev->sec_size)
 869                 return NVM_IO_ERR;
 870         else if (bio_size > rrpc->dev->max_rq_size)
 871                 return NVM_IO_ERR;
 872
 873         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 874         if (err)
 875                 return err;
 876
 877         bio_get(bio);
 878         rqd->bio = bio;
 879         rqd->ins = &rrpc->instance;
 880         rqd->nr_pages = nr_pages;
 881         rrq->flags = flags;
 882
 883         err = nvm_submit_io(rrpc->dev, rqd);
 884         if (err) {
 885                 pr_err("rrpc: I/O submission failed: %d\n", err);
 886                 bio_put(bio);
 887                 if (!(flags & NVM_IOTYPE_GC)) {
 888                         rrpc_unlock_rq(rrpc, rqd);
 889                         if (rqd->nr_pages > 1)
 890                                 nvm_dev_dma_free(rrpc->dev,
 891                         rqd->ppa_list, rqd->dma_ppa_list);
 892                 }
 893                 return NVM_IO_ERR;
 894         }
 895
 896         return NVM_IO_OK;
 897 }
 898
 899 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 900 {
 901         struct rrpc *rrpc = q->queuedata;
 902         struct nvm_rq *rqd;
 903         int err;
 904
 905         if (bio->bi_rw & REQ_DISCARD) {
 906                 rrpc_discard(rrpc, bio);
 907                 return BLK_QC_T_NONE;
 908         }
 909
 910         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 911         if (!rqd) {
 912                 pr_err_ratelimited("rrpc: not able to queue bio.");
 913                 bio_io_error(bio);
 914                 return BLK_QC_T_NONE;
 915         }
 916         memset(rqd, 0, sizeof(struct nvm_rq));
 917
 918         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 919         switch (err) {
 920         case NVM_IO_OK:
 921                 return BLK_QC_T_NONE;
 922         case NVM_IO_ERR:
 923                 bio_io_error(bio);
 924                 break;
 925         case NVM_IO_DONE:
 926                 bio_endio(bio);
 927                 break;
 928         case NVM_IO_REQUEUE:
 929                 spin_lock(&rrpc->bio_lock);
 930                 bio_list_add(&rrpc->requeue_bios, bio);
 931                 spin_unlock(&rrpc->bio_lock);
 932                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 933                 break;
 934         }
 935
 936         mempool_free(rqd, rrpc->rq_pool);
 937         return BLK_QC_T_NONE;
 938 }
 939
 940 static void rrpc_requeue(struct work_struct *work)
 941 {
 942         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 943         struct bio_list bios;
 944         struct bio *bio;
 945
 946         bio_list_init(&bios);
 947
 948         spin_lock(&rrpc->bio_lock);
 949         bio_list_merge(&bios, &rrpc->requeue_bios);
 950         bio_list_init(&rrpc->requeue_bios);
 951         spin_unlock(&rrpc->bio_lock);
 952
 953         while ((bio = bio_list_pop(&bios)))
 954                 rrpc_make_rq(rrpc->disk->queue, bio);
 955 }
 956
 957 static void rrpc_gc_free(struct rrpc *rrpc)
 958 {
 959         struct rrpc_lun *rlun;
 960         int i;
 961
 962         if (rrpc->krqd_wq)
 963                 destroy_workqueue(rrpc->krqd_wq);
 964
 965         if (rrpc->kgc_wq)
 966                 destroy_workqueue(rrpc->kgc_wq);
 967
 968         if (!rrpc->luns)
 969                 return;
 970
 971         for (i = 0; i < rrpc->nr_luns; i++) {
 972                 rlun = &rrpc->luns[i];
 973
 974                 if (!rlun->blocks)
 975                         break;
 976                 vfree(rlun->blocks);
 977         }
 978 }
 979
 980 static int rrpc_gc_init(struct rrpc *rrpc)
 981 {
 982         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 983                                                                 rrpc->nr_luns);
 984         if (!rrpc->krqd_wq)
 985                 return -ENOMEM;
 986
 987         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 988         if (!rrpc->kgc_wq)
 989                 return -ENOMEM;
 990
 991         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 992
 993         return 0;
 994 }
 995
 996 static void rrpc_map_free(struct rrpc *rrpc)
 997 {
 998         vfree(rrpc->rev_trans_map);
 999         vfree(rrpc->trans_map);
1000 }
1001
1002 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
1003 {
1004         struct rrpc *rrpc = (struct rrpc *)private;
1005         struct nvm_dev *dev = rrpc->dev;
1006         struct rrpc_addr *addr = rrpc->trans_map + slba;
1007         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
1008         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
1009         u64 elba = slba + nlb;
1010         u64 i;
1011
1012         if (unlikely(elba > dev->total_pages)) {
1013                 pr_err("nvm: L2P data from device is out of bounds!\n");
1014                 return -EINVAL;
1015         }
1016
1017         for (i = 0; i < nlb; i++) {
1018                 u64 pba = le64_to_cpu(entries[i]);
1019                 /* LNVM treats address-spaces as silos, LBA and PBA are
1020                  * equally large and zero-indexed.
1021                  */
1022                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
1023                         pr_err("nvm: L2P data entry is out of bounds!\n");
1024                         return -EINVAL;
1025                 }
1026
1027                 /* Address zero is a special one. The first page on a disk is
1028                  * protected. As it often holds internal device boot
1029                  * information.
1030                  */
1031                 if (!pba)
1032                         continue;
1033
1034                 addr[i].addr = pba;
1035                 raddr[pba].addr = slba + i;
1036         }
1037
1038         return 0;
1039 }
1040
1041 static int rrpc_map_init(struct rrpc *rrpc)
1042 {
1043         struct nvm_dev *dev = rrpc->dev;
1044         sector_t i;
1045         int ret;
1046
1047         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
1048         if (!rrpc->trans_map)
1049                 return -ENOMEM;
1050
1051         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1052                                                         * rrpc->nr_pages);
1053         if (!rrpc->rev_trans_map)
1054                 return -ENOMEM;
1055
1056         for (i = 0; i < rrpc->nr_pages; i++) {
1057                 struct rrpc_addr *p = &rrpc->trans_map[i];
1058                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1059
1060                 p->addr = ADDR_EMPTY;
1061                 r->addr = ADDR_EMPTY;
1062         }
1063
1064         if (!dev->ops->get_l2p_tbl)
1065                 return 0;
1066
1067         /* Bring up the mapping table from device */
1068         ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
1069                                                         rrpc_l2p_update, rrpc);
1070         if (ret) {
1071                 pr_err("nvm: rrpc: could not read L2P table.\n");
1072                 return -EINVAL;
1073         }
1074
1075         return 0;
1076 }
1077
1078
1079 /* Minimum pages needed within a lun */
1080 #define PAGE_POOL_SIZE 16
1081 #define ADDR_POOL_SIZE 64
1082
1083 static int rrpc_core_init(struct rrpc *rrpc)
1084 {
1085         down_write(&rrpc_lock);
1086         if (!rrpc_gcb_cache) {
1087                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1088                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1089                 if (!rrpc_gcb_cache) {
1090                         up_write(&rrpc_lock);
1091                         return -ENOMEM;
1092                 }
1093
1094                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1095                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1096                                 0, 0, NULL);
1097                 if (!rrpc_rq_cache) {
1098                         kmem_cache_destroy(rrpc_gcb_cache);
1099                         up_write(&rrpc_lock);
1100                         return -ENOMEM;
1101                 }
1102         }
1103         up_write(&rrpc_lock);
1104
1105         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1106         if (!rrpc->page_pool)
1107                 return -ENOMEM;
1108
1109         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1110                                                                 rrpc_gcb_cache);
1111         if (!rrpc->gcb_pool)
1112                 return -ENOMEM;
1113
1114         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1115         if (!rrpc->rq_pool)
1116                 return -ENOMEM;
1117
1118         spin_lock_init(&rrpc->inflights.lock);
1119         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1120
1121         return 0;
1122 }
1123
1124 static void rrpc_core_free(struct rrpc *rrpc)
1125 {
1126         mempool_destroy(rrpc->page_pool);
1127         mempool_destroy(rrpc->gcb_pool);
1128         mempool_destroy(rrpc->rq_pool);
1129 }
1130
1131 static void rrpc_luns_free(struct rrpc *rrpc)
1132 {
1133         kfree(rrpc->luns);
1134 }
1135
1136 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1137 {
1138         struct nvm_dev *dev = rrpc->dev;
1139         struct rrpc_lun *rlun;
1140         int i, j;
1141
1142         if (dev->pgs_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1143                 pr_err("rrpc: number of pages per block too high.");
1144                 return -EINVAL;
1145         }
1146
1147         spin_lock_init(&rrpc->rev_lock);
1148
1149         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1150                                                                 GFP_KERNEL);
1151         if (!rrpc->luns)
1152                 return -ENOMEM;
1153
1154         /* 1:1 mapping */
1155         for (i = 0; i < rrpc->nr_luns; i++) {
1156                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1157
1158                 rlun = &rrpc->luns[i];
1159                 rlun->rrpc = rrpc;
1160                 rlun->parent = lun;
1161                 INIT_LIST_HEAD(&rlun->prio_list);
1162                 INIT_LIST_HEAD(&rlun->open_list);
1163                 INIT_LIST_HEAD(&rlun->closed_list);
1164
1165                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1166                 spin_lock_init(&rlun->lock);
1167
1168                 rrpc->total_blocks += dev->blks_per_lun;
1169                 rrpc->nr_pages += dev->sec_per_lun;
1170
1171                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1172                                                 rrpc->dev->blks_per_lun);
1173                 if (!rlun->blocks)
1174                         goto err;
1175
1176                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1177                         struct rrpc_block *rblk = &rlun->blocks[j];
1178                         struct nvm_block *blk = &lun->blocks[j];
1179
1180                         rblk->parent = blk;
1181                         rblk->rlun = rlun;
1182                         INIT_LIST_HEAD(&rblk->prio);
1183                         spin_lock_init(&rblk->lock);
1184                 }
1185         }
1186
1187         return 0;
1188 err:
1189         return -ENOMEM;
1190 }
1191
1192 static void rrpc_free(struct rrpc *rrpc)
1193 {
1194         rrpc_gc_free(rrpc);
1195         rrpc_map_free(rrpc);
1196         rrpc_core_free(rrpc);
1197         rrpc_luns_free(rrpc);
1198
1199         kfree(rrpc);
1200 }
1201
1202 static void rrpc_exit(void *private)
1203 {
1204         struct rrpc *rrpc = private;
1205
1206         del_timer(&rrpc->gc_timer);
1207
1208         flush_workqueue(rrpc->krqd_wq);
1209         flush_workqueue(rrpc->kgc_wq);
1210
1211         rrpc_free(rrpc);
1212 }
1213
1214 static sector_t rrpc_capacity(void *private)
1215 {
1216         struct rrpc *rrpc = private;
1217         struct nvm_dev *dev = rrpc->dev;
1218         sector_t reserved, provisioned;
1219
1220         /* cur, gc, and two emergency blocks for each lun */
1221         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1222         provisioned = rrpc->nr_pages - reserved;
1223
1224         if (reserved > rrpc->nr_pages) {
1225                 pr_err("rrpc: not enough space available to expose storage.\n");
1226                 return 0;
1227         }
1228
1229         sector_div(provisioned, 10);
1230         return provisioned * 9 * NR_PHY_IN_LOG;
1231 }
1232
1233 /*
1234  * Looks up the logical address from reverse trans map and check if its valid by
1235  * comparing the logical to physical address with the physical address.
1236  * Returns 0 on free, otherwise 1 if in use
1237  */
1238 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1239 {
1240         struct nvm_dev *dev = rrpc->dev;
1241         int offset;
1242         struct rrpc_addr *laddr;
1243         u64 paddr, pladdr;
1244
1245         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1246                 paddr = block_to_addr(rrpc, rblk) + offset;
1247
1248                 pladdr = rrpc->rev_trans_map[paddr].addr;
1249                 if (pladdr == ADDR_EMPTY)
1250                         continue;
1251
1252                 laddr = &rrpc->trans_map[pladdr];
1253
1254                 if (paddr == laddr->addr) {
1255                         laddr->rblk = rblk;
1256                 } else {
1257                         set_bit(offset, rblk->invalid_pages);
1258                         rblk->nr_invalid_pages++;
1259                 }
1260         }
1261 }
1262
1263 static int rrpc_blocks_init(struct rrpc *rrpc)
1264 {
1265         struct rrpc_lun *rlun;
1266         struct rrpc_block *rblk;
1267         int lun_iter, blk_iter;
1268
1269         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1270                 rlun = &rrpc->luns[lun_iter];
1271
1272                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1273                                                                 blk_iter++) {
1274                         rblk = &rlun->blocks[blk_iter];
1275                         rrpc_block_map_update(rrpc, rblk);
1276                 }
1277         }
1278
1279         return 0;
1280 }
1281
1282 static int rrpc_luns_configure(struct rrpc *rrpc)
1283 {
1284         struct rrpc_lun *rlun;
1285         struct rrpc_block *rblk;
1286         int i;
1287
1288         for (i = 0; i < rrpc->nr_luns; i++) {
1289                 rlun = &rrpc->luns[i];
1290
1291                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1292                 if (!rblk)
1293                         goto err;
1294
1295                 rrpc_set_lun_cur(rlun, rblk);
1296
1297                 /* Emergency gc block */
1298                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1299                 if (!rblk)
1300                         goto err;
1301                 rlun->gc_cur = rblk;
1302         }
1303
1304         return 0;
1305 err:
1306         rrpc_put_blks(rrpc);
1307         return -EINVAL;
1308 }
1309
1310 static struct nvm_tgt_type tt_rrpc;
1311
1312 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1313                                                 int lun_begin, int lun_end)
1314 {
1315         struct request_queue *bqueue = dev->q;
1316         struct request_queue *tqueue = tdisk->queue;
1317         struct rrpc *rrpc;
1318         int ret;
1319
1320         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1321                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1322                                                         dev->identity.dom);
1323                 return ERR_PTR(-EINVAL);
1324         }
1325
1326         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1327         if (!rrpc)
1328                 return ERR_PTR(-ENOMEM);
1329
1330         rrpc->instance.tt = &tt_rrpc;
1331         rrpc->dev = dev;
1332         rrpc->disk = tdisk;
1333
1334         bio_list_init(&rrpc->requeue_bios);
1335         spin_lock_init(&rrpc->bio_lock);
1336         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1337
1338         rrpc->nr_luns = lun_end - lun_begin + 1;
1339
1340         /* simple round-robin strategy */
1341         atomic_set(&rrpc->next_lun, -1);
1342
1343         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1344         if (ret) {
1345                 pr_err("nvm: rrpc: could not initialize luns\n");
1346                 goto err;
1347         }
1348
1349         rrpc->poffset = dev->sec_per_lun * lun_begin;
1350         rrpc->lun_offset = lun_begin;
1351
1352         ret = rrpc_core_init(rrpc);
1353         if (ret) {
1354                 pr_err("nvm: rrpc: could not initialize core\n");
1355                 goto err;
1356         }
1357
1358         ret = rrpc_map_init(rrpc);
1359         if (ret) {
1360                 pr_err("nvm: rrpc: could not initialize maps\n");
1361                 goto err;
1362         }
1363
1364         ret = rrpc_blocks_init(rrpc);
1365         if (ret) {
1366                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1367                 goto err;
1368         }
1369
1370         ret = rrpc_luns_configure(rrpc);
1371         if (ret) {
1372                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1373                 goto err;
1374         }
1375
1376         ret = rrpc_gc_init(rrpc);
1377         if (ret) {
1378                 pr_err("nvm: rrpc: could not initialize gc\n");
1379                 goto err;
1380         }
1381
1382         /* inherit the size from the underlying device */
1383         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1384         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1385
1386         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1387                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1388
1389         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1390
1391         return rrpc;
1392 err:
1393         rrpc_free(rrpc);
1394         return ERR_PTR(ret);
1395 }
1396
1397 /* round robin, page-based FTL, and cost-based GC */
1398 static struct nvm_tgt_type tt_rrpc = {
1399         .name           = "rrpc",
1400         .version        = {1, 0, 0},
1401
1402         .make_rq        = rrpc_make_rq,
1403         .capacity       = rrpc_capacity,
1404         .end_io         = rrpc_end_io,
1405
1406         .init           = rrpc_init,
1407         .exit           = rrpc_exit,
1408 };
1409
1410 static int __init rrpc_module_init(void)
1411 {
1412         return nvm_register_target(&tt_rrpc);
1413 }
1414
1415 static void rrpc_module_exit(void)
1416 {
1417         nvm_unregister_target(&tt_rrpc);
1418 }
1419
1420 module_init(rrpc_module_init);
1421 module_exit(rrpc_module_exit);
1422 MODULE_LICENSE("GPL v2");
1423 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");