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->sec_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 int 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         while (1) {
 100                 rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
 101                 if (rqd)
 102                         break;
 103
 104                 schedule();
 105         }
 106
 107         if (IS_ERR(rqd)) {
 108                 pr_err("rrpc: unable to acquire inflight IO\n");
 109                 bio_io_error(bio);
 110                 return;
 111         }
 112
 113         rrpc_invalidate_range(rrpc, slba, len);
 114         rrpc_inflight_laddr_release(rrpc, rqd);
 115 }
 116
 117 static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
 118 {
 119         return (rblk->next_page == rrpc->dev->sec_per_blk);
 120 }
 121
 122 /* Calculate relative addr for the given block, considering instantiated LUNs */
 123 static u64 block_to_rel_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 124 {
 125         struct nvm_block *blk = rblk->parent;
 126         int lun_blk = blk->id % (rrpc->dev->blks_per_lun * rrpc->nr_luns);
 127
 128         return lun_blk * rrpc->dev->sec_per_blk;
 129 }
 130
 131 /* Calculate global addr for the given block */
 132 static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 133 {
 134         struct nvm_block *blk = rblk->parent;
 135
 136         return blk->id * rrpc->dev->sec_per_blk;
 137 }
 138
 139 static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
 140                                                         struct ppa_addr r)
 141 {
 142         struct ppa_addr l;
 143         int secs, pgs, blks, luns;
 144         sector_t ppa = r.ppa;
 145
 146         l.ppa = 0;
 147
 148         div_u64_rem(ppa, dev->sec_per_pg, &secs);
 149         l.g.sec = secs;
 150
 151         sector_div(ppa, dev->sec_per_pg);
 152         div_u64_rem(ppa, dev->pgs_per_blk, &pgs);
 153         l.g.pg = pgs;
 154
 155         sector_div(ppa, dev->pgs_per_blk);
 156         div_u64_rem(ppa, dev->blks_per_lun, &blks);
 157         l.g.blk = blks;
 158
 159         sector_div(ppa, dev->blks_per_lun);
 160         div_u64_rem(ppa, dev->luns_per_chnl, &luns);
 161         l.g.lun = luns;
 162
 163         sector_div(ppa, dev->luns_per_chnl);
 164         l.g.ch = ppa;
 165
 166         return l;
 167 }
 168
 169 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 170 {
 171         struct ppa_addr paddr;
 172
 173         paddr.ppa = addr;
 174         return linear_to_generic_addr(dev, paddr);
 175 }
 176
 177 /* requires lun->lock taken */
 178 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *new_rblk,
 179                                                 struct rrpc_block **cur_rblk)
 180 {
 181         struct rrpc *rrpc = rlun->rrpc;
 182
 183         if (*cur_rblk) {
 184                 spin_lock(&(*cur_rblk)->lock);
 185                 WARN_ON(!block_is_full(rrpc, *cur_rblk));
 186                 spin_unlock(&(*cur_rblk)->lock);
 187         }
 188         *cur_rblk = new_rblk;
 189 }
 190
 191 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 192                                                         unsigned long flags)
 193 {
 194         struct nvm_block *blk;
 195         struct rrpc_block *rblk;
 196
 197         blk = nvm_get_blk(rrpc->dev, rlun->parent, flags);
 198         if (!blk) {
 199                 pr_err("nvm: rrpc: cannot get new block from media manager\n");
 200                 return NULL;
 201         }
 202
 203         rblk = rrpc_get_rblk(rlun, blk->id);
 204         blk->priv = rblk;
 205         bitmap_zero(rblk->invalid_pages, rrpc->dev->sec_per_blk);
 206         rblk->next_page = 0;
 207         rblk->nr_invalid_pages = 0;
 208         atomic_set(&rblk->data_cmnt_size, 0);
 209
 210         return rblk;
 211 }
 212
 213 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 214 {
 215         nvm_put_blk(rrpc->dev, rblk->parent);
 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_sec_per_blk = rrpc->dev->sec_per_blk;
 290         u64 phys_addr;
 291         DECLARE_COMPLETION_ONSTACK(wait);
 292
 293         if (bitmap_full(rblk->invalid_pages, nr_sec_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                 bio_put(bio);
 305                 return -ENOMEM;
 306         }
 307
 308         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 309                                             nr_sec_per_blk)) < nr_sec_per_blk) {
 310
 311                 /* Lock laddr */
 312                 phys_addr = rblk->parent->id * nr_sec_per_blk + slot;
 313
 314 try:
 315                 spin_lock(&rrpc->rev_lock);
 316                 /* Get logical address from physical to logical table */
 317                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 318                 /* already updated by previous regular write */
 319                 if (rev->addr == ADDR_EMPTY) {
 320                         spin_unlock(&rrpc->rev_lock);
 321                         continue;
 322                 }
 323
 324                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 325                 if (IS_ERR_OR_NULL(rqd)) {
 326                         spin_unlock(&rrpc->rev_lock);
 327                         schedule();
 328                         goto try;
 329                 }
 330
 331                 spin_unlock(&rrpc->rev_lock);
 332
 333                 /* Perform read to do GC */
 334                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 335                 bio_set_op_attrs(bio,  REQ_OP_READ, 0);
 336                 bio->bi_private = &wait;
 337                 bio->bi_end_io = rrpc_end_sync_bio;
 338
 339                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 340                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 341
 342                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 343                         pr_err("rrpc: gc read failed.\n");
 344                         rrpc_inflight_laddr_release(rrpc, rqd);
 345                         goto finished;
 346                 }
 347                 wait_for_completion_io(&wait);
 348                 if (bio->bi_error) {
 349                         rrpc_inflight_laddr_release(rrpc, rqd);
 350                         goto finished;
 351                 }
 352
 353                 bio_reset(bio);
 354                 reinit_completion(&wait);
 355
 356                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 357                 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 358                 bio->bi_private = &wait;
 359                 bio->bi_end_io = rrpc_end_sync_bio;
 360
 361                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 362
 363                 /* turn the command around and write the data back to a new
 364                  * address
 365                  */
 366                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 367                         pr_err("rrpc: gc write failed.\n");
 368                         rrpc_inflight_laddr_release(rrpc, rqd);
 369                         goto finished;
 370                 }
 371                 wait_for_completion_io(&wait);
 372
 373                 rrpc_inflight_laddr_release(rrpc, rqd);
 374                 if (bio->bi_error)
 375                         goto finished;
 376
 377                 bio_reset(bio);
 378         }
 379
 380 finished:
 381         mempool_free(page, rrpc->page_pool);
 382         bio_put(bio);
 383
 384         if (!bitmap_full(rblk->invalid_pages, nr_sec_per_blk)) {
 385                 pr_err("nvm: failed to garbage collect block\n");
 386                 return -EIO;
 387         }
 388
 389         return 0;
 390 }
 391
 392 static void rrpc_block_gc(struct work_struct *work)
 393 {
 394         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 395                                                                         ws_gc);
 396         struct rrpc *rrpc = gcb->rrpc;
 397         struct rrpc_block *rblk = gcb->rblk;
 398         struct rrpc_lun *rlun = rblk->rlun;
 399         struct nvm_dev *dev = rrpc->dev;
 400
 401         mempool_free(gcb, rrpc->gcb_pool);
 402         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 403
 404         if (rrpc_move_valid_pages(rrpc, rblk))
 405                 goto put_back;
 406
 407         if (nvm_erase_blk(dev, rblk->parent))
 408                 goto put_back;
 409
 410         rrpc_put_blk(rrpc, rblk);
 411
 412         return;
 413
 414 put_back:
 415         spin_lock(&rlun->lock);
 416         list_add_tail(&rblk->prio, &rlun->prio_list);
 417         spin_unlock(&rlun->lock);
 418 }
 419
 420 /* the block with highest number of invalid pages, will be in the beginning
 421  * of the list
 422  */
 423 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 424                                                         struct rrpc_block *rb)
 425 {
 426         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 427                 return ra;
 428
 429         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 430 }
 431
 432 /* linearly find the block with highest number of invalid pages
 433  * requires lun->lock
 434  */
 435 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 436 {
 437         struct list_head *prio_list = &rlun->prio_list;
 438         struct rrpc_block *rblock, *max;
 439
 440         BUG_ON(list_empty(prio_list));
 441
 442         max = list_first_entry(prio_list, struct rrpc_block, prio);
 443         list_for_each_entry(rblock, prio_list, prio)
 444                 max = rblock_max_invalid(max, rblock);
 445
 446         return max;
 447 }
 448
 449 static void rrpc_lun_gc(struct work_struct *work)
 450 {
 451         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 452         struct rrpc *rrpc = rlun->rrpc;
 453         struct nvm_lun *lun = rlun->parent;
 454         struct rrpc_block_gc *gcb;
 455         unsigned int nr_blocks_need;
 456
 457         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 458
 459         if (nr_blocks_need < rrpc->nr_luns)
 460                 nr_blocks_need = rrpc->nr_luns;
 461
 462         spin_lock(&rlun->lock);
 463         while (nr_blocks_need > lun->nr_free_blocks &&
 464                                         !list_empty(&rlun->prio_list)) {
 465                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 466                 struct nvm_block *block = rblock->parent;
 467
 468                 if (!rblock->nr_invalid_pages)
 469                         break;
 470
 471                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 472                 if (!gcb)
 473                         break;
 474
 475                 list_del_init(&rblock->prio);
 476
 477                 BUG_ON(!block_is_full(rrpc, rblock));
 478
 479                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 480
 481                 gcb->rrpc = rrpc;
 482                 gcb->rblk = rblock;
 483                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 484
 485                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 486
 487                 nr_blocks_need--;
 488         }
 489         spin_unlock(&rlun->lock);
 490
 491         /* TODO: Hint that request queue can be started again */
 492 }
 493
 494 static void rrpc_gc_queue(struct work_struct *work)
 495 {
 496         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 497                                                                         ws_gc);
 498         struct rrpc *rrpc = gcb->rrpc;
 499         struct rrpc_block *rblk = gcb->rblk;
 500         struct rrpc_lun *rlun = rblk->rlun;
 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_sects);
 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 /* Map logical address to a physical page. The mapping implements a round robin
 580  * approach and allocates a page from the next lun available.
 581  *
 582  * Returns rrpc_addr with the physical address and block. Returns NULL if no
 583  * blocks in the next rlun are available.
 584  */
 585 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 586                                                                 int is_gc)
 587 {
 588         struct rrpc_lun *rlun;
 589         struct rrpc_block *rblk, **cur_rblk;
 590         struct nvm_lun *lun;
 591         u64 paddr;
 592         int gc_force = 0;
 593
 594         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 595         lun = rlun->parent;
 596
 597         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 598                 return NULL;
 599
 600         /*
 601          * page allocation steps:
 602          * 1. Try to allocate new page from current rblk
 603          * 2a. If succeed, proceed to map it in and return
 604          * 2b. If fail, first try to allocate a new block from media manger,
 605          *     and then retry step 1. Retry until the normal block pool is
 606          *     exhausted.
 607          * 3. If exhausted, and garbage collector is requesting the block,
 608          *    go to the reserved block and retry step 1.
 609          *    In the case that this fails as well, or it is not GC
 610          *    requesting, report not able to retrieve a block and let the
 611          *    caller handle further processing.
 612          */
 613
 614         spin_lock(&rlun->lock);
 615         cur_rblk = &rlun->cur;
 616         rblk = rlun->cur;
 617 retry:
 618         paddr = rrpc_alloc_addr(rrpc, rblk);
 619
 620         if (paddr != ADDR_EMPTY)
 621                 goto done;
 622
 623         if (!list_empty(&rlun->wblk_list)) {
 624 new_blk:
 625                 rblk = list_first_entry(&rlun->wblk_list, struct rrpc_block,
 626                                                                         prio);
 627                 rrpc_set_lun_cur(rlun, rblk, cur_rblk);
 628                 list_del(&rblk->prio);
 629                 goto retry;
 630         }
 631         spin_unlock(&rlun->lock);
 632
 633         rblk = rrpc_get_blk(rrpc, rlun, gc_force);
 634         if (rblk) {
 635                 spin_lock(&rlun->lock);
 636                 list_add_tail(&rblk->prio, &rlun->wblk_list);
 637                 /*
 638                  * another thread might already have added a new block,
 639                  * Therefore, make sure that one is used, instead of the
 640                  * one just added.
 641                  */
 642                 goto new_blk;
 643         }
 644
 645         if (unlikely(is_gc) && !gc_force) {
 646                 /* retry from emergency gc block */
 647                 cur_rblk = &rlun->gc_cur;
 648                 rblk = rlun->gc_cur;
 649                 gc_force = 1;
 650                 spin_lock(&rlun->lock);
 651                 goto retry;
 652         }
 653
 654         pr_err("rrpc: failed to allocate new block\n");
 655         return NULL;
 656 done:
 657         spin_unlock(&rlun->lock);
 658         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 659 }
 660
 661 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 662 {
 663         struct rrpc_block_gc *gcb;
 664
 665         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 666         if (!gcb) {
 667                 pr_err("rrpc: unable to queue block for gc.");
 668                 return;
 669         }
 670
 671         gcb->rrpc = rrpc;
 672         gcb->rblk = rblk;
 673
 674         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 675         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 676 }
 677
 678 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 679                                                 sector_t laddr, uint8_t npages)
 680 {
 681         struct rrpc_addr *p;
 682         struct rrpc_block *rblk;
 683         struct nvm_lun *lun;
 684         int cmnt_size, i;
 685
 686         for (i = 0; i < npages; i++) {
 687                 p = &rrpc->trans_map[laddr + i];
 688                 rblk = p->rblk;
 689                 lun = rblk->parent->lun;
 690
 691                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 692                 if (unlikely(cmnt_size == rrpc->dev->sec_per_blk))
 693                         rrpc_run_gc(rrpc, rblk);
 694         }
 695 }
 696
 697 static void rrpc_end_io(struct nvm_rq *rqd)
 698 {
 699         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 700         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 701         uint8_t npages = rqd->nr_ppas;
 702         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 703
 704         if (bio_data_dir(rqd->bio) == WRITE)
 705                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 706
 707         bio_put(rqd->bio);
 708
 709         if (rrqd->flags & NVM_IOTYPE_GC)
 710                 return;
 711
 712         rrpc_unlock_rq(rrpc, rqd);
 713
 714         if (npages > 1)
 715                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 716
 717         mempool_free(rqd, rrpc->rq_pool);
 718 }
 719
 720 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 721                         struct nvm_rq *rqd, unsigned long flags, int npages)
 722 {
 723         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 724         struct rrpc_addr *gp;
 725         sector_t laddr = rrpc_get_laddr(bio);
 726         int is_gc = flags & NVM_IOTYPE_GC;
 727         int i;
 728
 729         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 730                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 731                 return NVM_IO_REQUEUE;
 732         }
 733
 734         for (i = 0; i < npages; i++) {
 735                 /* We assume that mapping occurs at 4KB granularity */
 736                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_sects));
 737                 gp = &rrpc->trans_map[laddr + i];
 738
 739                 if (gp->rblk) {
 740                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 741                                                                 gp->addr);
 742                 } else {
 743                         BUG_ON(is_gc);
 744                         rrpc_unlock_laddr(rrpc, r);
 745                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 746                                                         rqd->dma_ppa_list);
 747                         return NVM_IO_DONE;
 748                 }
 749         }
 750
 751         rqd->opcode = NVM_OP_HBREAD;
 752
 753         return NVM_IO_OK;
 754 }
 755
 756 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 757                                                         unsigned long flags)
 758 {
 759         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 760         int is_gc = flags & NVM_IOTYPE_GC;
 761         sector_t laddr = rrpc_get_laddr(bio);
 762         struct rrpc_addr *gp;
 763
 764         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 765                 return NVM_IO_REQUEUE;
 766
 767         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_sects));
 768         gp = &rrpc->trans_map[laddr];
 769
 770         if (gp->rblk) {
 771                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 772         } else {
 773                 BUG_ON(is_gc);
 774                 rrpc_unlock_rq(rrpc, rqd);
 775                 return NVM_IO_DONE;
 776         }
 777
 778         rqd->opcode = NVM_OP_HBREAD;
 779         rrqd->addr = gp;
 780
 781         return NVM_IO_OK;
 782 }
 783
 784 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 785                         struct nvm_rq *rqd, unsigned long flags, int npages)
 786 {
 787         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 788         struct rrpc_addr *p;
 789         sector_t laddr = rrpc_get_laddr(bio);
 790         int is_gc = flags & NVM_IOTYPE_GC;
 791         int i;
 792
 793         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 794                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 795                 return NVM_IO_REQUEUE;
 796         }
 797
 798         for (i = 0; i < npages; i++) {
 799                 /* We assume that mapping occurs at 4KB granularity */
 800                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 801                 if (!p) {
 802                         BUG_ON(is_gc);
 803                         rrpc_unlock_laddr(rrpc, r);
 804                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 805                                                         rqd->dma_ppa_list);
 806                         rrpc_gc_kick(rrpc);
 807                         return NVM_IO_REQUEUE;
 808                 }
 809
 810                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 811                                                                 p->addr);
 812         }
 813
 814         rqd->opcode = NVM_OP_HBWRITE;
 815
 816         return NVM_IO_OK;
 817 }
 818
 819 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 820                                 struct nvm_rq *rqd, unsigned long flags)
 821 {
 822         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 823         struct rrpc_addr *p;
 824         int is_gc = flags & NVM_IOTYPE_GC;
 825         sector_t laddr = rrpc_get_laddr(bio);
 826
 827         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 828                 return NVM_IO_REQUEUE;
 829
 830         p = rrpc_map_page(rrpc, laddr, is_gc);
 831         if (!p) {
 832                 BUG_ON(is_gc);
 833                 rrpc_unlock_rq(rrpc, rqd);
 834                 rrpc_gc_kick(rrpc);
 835                 return NVM_IO_REQUEUE;
 836         }
 837
 838         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 839         rqd->opcode = NVM_OP_HBWRITE;
 840         rrqd->addr = p;
 841
 842         return NVM_IO_OK;
 843 }
 844
 845 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 846                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 847 {
 848         if (npages > 1) {
 849                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 850                                                         &rqd->dma_ppa_list);
 851                 if (!rqd->ppa_list) {
 852                         pr_err("rrpc: not able to allocate ppa list\n");
 853                         return NVM_IO_ERR;
 854                 }
 855
 856                 if (bio_op(bio) == REQ_OP_WRITE)
 857                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 858                                                                         npages);
 859
 860                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 861         }
 862
 863         if (bio_op(bio) == REQ_OP_WRITE)
 864                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 865
 866         return rrpc_read_rq(rrpc, bio, rqd, flags);
 867 }
 868
 869 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 870                                 struct nvm_rq *rqd, unsigned long flags)
 871 {
 872         int err;
 873         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 874         uint8_t nr_pages = rrpc_get_pages(bio);
 875         int bio_size = bio_sectors(bio) << 9;
 876
 877         if (bio_size < rrpc->dev->sec_size)
 878                 return NVM_IO_ERR;
 879         else if (bio_size > rrpc->dev->max_rq_size)
 880                 return NVM_IO_ERR;
 881
 882         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 883         if (err)
 884                 return err;
 885
 886         bio_get(bio);
 887         rqd->bio = bio;
 888         rqd->ins = &rrpc->instance;
 889         rqd->nr_ppas = nr_pages;
 890         rrq->flags = flags;
 891
 892         err = nvm_submit_io(rrpc->dev, rqd);
 893         if (err) {
 894                 pr_err("rrpc: I/O submission failed: %d\n", err);
 895                 bio_put(bio);
 896                 if (!(flags & NVM_IOTYPE_GC)) {
 897                         rrpc_unlock_rq(rrpc, rqd);
 898                         if (rqd->nr_ppas > 1)
 899                                 nvm_dev_dma_free(rrpc->dev,
 900                         rqd->ppa_list, rqd->dma_ppa_list);
 901                 }
 902                 return NVM_IO_ERR;
 903         }
 904
 905         return NVM_IO_OK;
 906 }
 907
 908 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 909 {
 910         struct rrpc *rrpc = q->queuedata;
 911         struct nvm_rq *rqd;
 912         int err;
 913
 914         if (bio_op(bio) == REQ_OP_DISCARD) {
 915                 rrpc_discard(rrpc, bio);
 916                 return BLK_QC_T_NONE;
 917         }
 918
 919         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 920         if (!rqd) {
 921                 pr_err_ratelimited("rrpc: not able to queue bio.");
 922                 bio_io_error(bio);
 923                 return BLK_QC_T_NONE;
 924         }
 925         memset(rqd, 0, sizeof(struct nvm_rq));
 926
 927         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 928         switch (err) {
 929         case NVM_IO_OK:
 930                 return BLK_QC_T_NONE;
 931         case NVM_IO_ERR:
 932                 bio_io_error(bio);
 933                 break;
 934         case NVM_IO_DONE:
 935                 bio_endio(bio);
 936                 break;
 937         case NVM_IO_REQUEUE:
 938                 spin_lock(&rrpc->bio_lock);
 939                 bio_list_add(&rrpc->requeue_bios, bio);
 940                 spin_unlock(&rrpc->bio_lock);
 941                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 942                 break;
 943         }
 944
 945         mempool_free(rqd, rrpc->rq_pool);
 946         return BLK_QC_T_NONE;
 947 }
 948
 949 static void rrpc_requeue(struct work_struct *work)
 950 {
 951         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 952         struct bio_list bios;
 953         struct bio *bio;
 954
 955         bio_list_init(&bios);
 956
 957         spin_lock(&rrpc->bio_lock);
 958         bio_list_merge(&bios, &rrpc->requeue_bios);
 959         bio_list_init(&rrpc->requeue_bios);
 960         spin_unlock(&rrpc->bio_lock);
 961
 962         while ((bio = bio_list_pop(&bios)))
 963                 rrpc_make_rq(rrpc->disk->queue, bio);
 964 }
 965
 966 static void rrpc_gc_free(struct rrpc *rrpc)
 967 {
 968         if (rrpc->krqd_wq)
 969                 destroy_workqueue(rrpc->krqd_wq);
 970
 971         if (rrpc->kgc_wq)
 972                 destroy_workqueue(rrpc->kgc_wq);
 973 }
 974
 975 static int rrpc_gc_init(struct rrpc *rrpc)
 976 {
 977         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 978                                                                 rrpc->nr_luns);
 979         if (!rrpc->krqd_wq)
 980                 return -ENOMEM;
 981
 982         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 983         if (!rrpc->kgc_wq)
 984                 return -ENOMEM;
 985
 986         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 987
 988         return 0;
 989 }
 990
 991 static void rrpc_map_free(struct rrpc *rrpc)
 992 {
 993         vfree(rrpc->rev_trans_map);
 994         vfree(rrpc->trans_map);
 995 }
 996
 997 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 998 {
 999         struct rrpc *rrpc = (struct rrpc *)private;
1000         struct nvm_dev *dev = rrpc->dev;
1001         struct rrpc_addr *addr = rrpc->trans_map + slba;
1002         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
1003         u64 elba = slba + nlb;
1004         u64 i;
1005
1006         if (unlikely(elba > dev->total_secs)) {
1007                 pr_err("nvm: L2P data from device is out of bounds!\n");
1008                 return -EINVAL;
1009         }
1010
1011         for (i = 0; i < nlb; i++) {
1012                 u64 pba = le64_to_cpu(entries[i]);
1013                 unsigned int mod;
1014                 /* LNVM treats address-spaces as silos, LBA and PBA are
1015                  * equally large and zero-indexed.
1016                  */
1017                 if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
1018                         pr_err("nvm: L2P data entry is out of bounds!\n");
1019                         return -EINVAL;
1020                 }
1021
1022                 /* Address zero is a special one. The first page on a disk is
1023                  * protected. As it often holds internal device boot
1024                  * information.
1025                  */
1026                 if (!pba)
1027                         continue;
1028
1029                 div_u64_rem(pba, rrpc->nr_sects, &mod);
1030
1031                 addr[i].addr = pba;
1032                 raddr[mod].addr = slba + i;
1033         }
1034
1035         return 0;
1036 }
1037
1038 static int rrpc_map_init(struct rrpc *rrpc)
1039 {
1040         struct nvm_dev *dev = rrpc->dev;
1041         sector_t i;
1042         int ret;
1043
1044         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_sects);
1045         if (!rrpc->trans_map)
1046                 return -ENOMEM;
1047
1048         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1049                                                         * rrpc->nr_sects);
1050         if (!rrpc->rev_trans_map)
1051                 return -ENOMEM;
1052
1053         for (i = 0; i < rrpc->nr_sects; i++) {
1054                 struct rrpc_addr *p = &rrpc->trans_map[i];
1055                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1056
1057                 p->addr = ADDR_EMPTY;
1058                 r->addr = ADDR_EMPTY;
1059         }
1060
1061         if (!dev->ops->get_l2p_tbl)
1062                 return 0;
1063
1064         /* Bring up the mapping table from device */
1065         ret = dev->ops->get_l2p_tbl(dev, rrpc->soffset, rrpc->nr_sects,
1066                                         rrpc_l2p_update, rrpc);
1067         if (ret) {
1068                 pr_err("nvm: rrpc: could not read L2P table.\n");
1069                 return -EINVAL;
1070         }
1071
1072         return 0;
1073 }
1074
1075 /* Minimum pages needed within a lun */
1076 #define PAGE_POOL_SIZE 16
1077 #define ADDR_POOL_SIZE 64
1078
1079 static int rrpc_core_init(struct rrpc *rrpc)
1080 {
1081         down_write(&rrpc_lock);
1082         if (!rrpc_gcb_cache) {
1083                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1084                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1085                 if (!rrpc_gcb_cache) {
1086                         up_write(&rrpc_lock);
1087                         return -ENOMEM;
1088                 }
1089
1090                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1091                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1092                                 0, 0, NULL);
1093                 if (!rrpc_rq_cache) {
1094                         kmem_cache_destroy(rrpc_gcb_cache);
1095                         up_write(&rrpc_lock);
1096                         return -ENOMEM;
1097                 }
1098         }
1099         up_write(&rrpc_lock);
1100
1101         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1102         if (!rrpc->page_pool)
1103                 return -ENOMEM;
1104
1105         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1106                                                                 rrpc_gcb_cache);
1107         if (!rrpc->gcb_pool)
1108                 return -ENOMEM;
1109
1110         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1111         if (!rrpc->rq_pool)
1112                 return -ENOMEM;
1113
1114         spin_lock_init(&rrpc->inflights.lock);
1115         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1116
1117         return 0;
1118 }
1119
1120 static void rrpc_core_free(struct rrpc *rrpc)
1121 {
1122         mempool_destroy(rrpc->page_pool);
1123         mempool_destroy(rrpc->gcb_pool);
1124         mempool_destroy(rrpc->rq_pool);
1125 }
1126
1127 static void rrpc_luns_free(struct rrpc *rrpc)
1128 {
1129         struct nvm_dev *dev = rrpc->dev;
1130         struct nvm_lun *lun;
1131         struct rrpc_lun *rlun;
1132         int i;
1133
1134         if (!rrpc->luns)
1135                 return;
1136
1137         for (i = 0; i < rrpc->nr_luns; i++) {
1138                 rlun = &rrpc->luns[i];
1139                 lun = rlun->parent;
1140                 if (!lun)
1141                         break;
1142                 dev->mt->release_lun(dev, lun->id);
1143                 vfree(rlun->blocks);
1144         }
1145
1146         kfree(rrpc->luns);
1147 }
1148
1149 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1150 {
1151         struct nvm_dev *dev = rrpc->dev;
1152         struct rrpc_lun *rlun;
1153         int i, j, ret = -EINVAL;
1154
1155         if (dev->sec_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1156                 pr_err("rrpc: number of pages per block too high.");
1157                 return -EINVAL;
1158         }
1159
1160         spin_lock_init(&rrpc->rev_lock);
1161
1162         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1163                                                                 GFP_KERNEL);
1164         if (!rrpc->luns)
1165                 return -ENOMEM;
1166
1167         /* 1:1 mapping */
1168         for (i = 0; i < rrpc->nr_luns; i++) {
1169                 int lunid = lun_begin + i;
1170                 struct nvm_lun *lun;
1171
1172                 if (dev->mt->reserve_lun(dev, lunid)) {
1173                         pr_err("rrpc: lun %u is already allocated\n", lunid);
1174                         goto err;
1175                 }
1176
1177                 lun = dev->mt->get_lun(dev, lunid);
1178                 if (!lun)
1179                         goto err;
1180
1181                 rlun = &rrpc->luns[i];
1182                 rlun->parent = lun;
1183                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1184                                                 rrpc->dev->blks_per_lun);
1185                 if (!rlun->blocks) {
1186                         ret = -ENOMEM;
1187                         goto err;
1188                 }
1189
1190                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1191                         struct rrpc_block *rblk = &rlun->blocks[j];
1192                         struct nvm_block *blk = &lun->blocks[j];
1193
1194                         rblk->parent = blk;
1195                         rblk->rlun = rlun;
1196                         INIT_LIST_HEAD(&rblk->prio);
1197                         spin_lock_init(&rblk->lock);
1198                 }
1199
1200                 rlun->rrpc = rrpc;
1201                 INIT_LIST_HEAD(&rlun->prio_list);
1202                 INIT_LIST_HEAD(&rlun->wblk_list);
1203
1204                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1205                 spin_lock_init(&rlun->lock);
1206         }
1207
1208         return 0;
1209 err:
1210         return ret;
1211 }
1212
1213 /* returns 0 on success and stores the beginning address in *begin */
1214 static int rrpc_area_init(struct rrpc *rrpc, sector_t *begin)
1215 {
1216         struct nvm_dev *dev = rrpc->dev;
1217         struct nvmm_type *mt = dev->mt;
1218         sector_t size = rrpc->nr_sects * dev->sec_size;
1219         int ret;
1220
1221         size >>= 9;
1222
1223         ret = mt->get_area(dev, begin, size);
1224         if (!ret)
1225                 *begin >>= (ilog2(dev->sec_size) - 9);
1226
1227         return ret;
1228 }
1229
1230 static void rrpc_area_free(struct rrpc *rrpc)
1231 {
1232         struct nvm_dev *dev = rrpc->dev;
1233         struct nvmm_type *mt = dev->mt;
1234         sector_t begin = rrpc->soffset << (ilog2(dev->sec_size) - 9);
1235
1236         mt->put_area(dev, begin);
1237 }
1238
1239 static void rrpc_free(struct rrpc *rrpc)
1240 {
1241         rrpc_gc_free(rrpc);
1242         rrpc_map_free(rrpc);
1243         rrpc_core_free(rrpc);
1244         rrpc_luns_free(rrpc);
1245         rrpc_area_free(rrpc);
1246
1247         kfree(rrpc);
1248 }
1249
1250 static void rrpc_exit(void *private)
1251 {
1252         struct rrpc *rrpc = private;
1253
1254         del_timer(&rrpc->gc_timer);
1255
1256         flush_workqueue(rrpc->krqd_wq);
1257         flush_workqueue(rrpc->kgc_wq);
1258
1259         rrpc_free(rrpc);
1260 }
1261
1262 static sector_t rrpc_capacity(void *private)
1263 {
1264         struct rrpc *rrpc = private;
1265         struct nvm_dev *dev = rrpc->dev;
1266         sector_t reserved, provisioned;
1267
1268         /* cur, gc, and two emergency blocks for each lun */
1269         reserved = rrpc->nr_luns * dev->sec_per_blk * 4;
1270         provisioned = rrpc->nr_sects - reserved;
1271
1272         if (reserved > rrpc->nr_sects) {
1273                 pr_err("rrpc: not enough space available to expose storage.\n");
1274                 return 0;
1275         }
1276
1277         sector_div(provisioned, 10);
1278         return provisioned * 9 * NR_PHY_IN_LOG;
1279 }
1280
1281 /*
1282  * Looks up the logical address from reverse trans map and check if its valid by
1283  * comparing the logical to physical address with the physical address.
1284  * Returns 0 on free, otherwise 1 if in use
1285  */
1286 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1287 {
1288         struct nvm_dev *dev = rrpc->dev;
1289         int offset;
1290         struct rrpc_addr *laddr;
1291         u64 bpaddr, paddr, pladdr;
1292
1293         bpaddr = block_to_rel_addr(rrpc, rblk);
1294         for (offset = 0; offset < dev->sec_per_blk; offset++) {
1295                 paddr = bpaddr + offset;
1296
1297                 pladdr = rrpc->rev_trans_map[paddr].addr;
1298                 if (pladdr == ADDR_EMPTY)
1299                         continue;
1300
1301                 laddr = &rrpc->trans_map[pladdr];
1302
1303                 if (paddr == laddr->addr) {
1304                         laddr->rblk = rblk;
1305                 } else {
1306                         set_bit(offset, rblk->invalid_pages);
1307                         rblk->nr_invalid_pages++;
1308                 }
1309         }
1310 }
1311
1312 static int rrpc_blocks_init(struct rrpc *rrpc)
1313 {
1314         struct rrpc_lun *rlun;
1315         struct rrpc_block *rblk;
1316         int lun_iter, blk_iter;
1317
1318         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1319                 rlun = &rrpc->luns[lun_iter];
1320
1321                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1322                                                                 blk_iter++) {
1323                         rblk = &rlun->blocks[blk_iter];
1324                         rrpc_block_map_update(rrpc, rblk);
1325                 }
1326         }
1327
1328         return 0;
1329 }
1330
1331 static int rrpc_luns_configure(struct rrpc *rrpc)
1332 {
1333         struct rrpc_lun *rlun;
1334         struct rrpc_block *rblk;
1335         int i;
1336
1337         for (i = 0; i < rrpc->nr_luns; i++) {
1338                 rlun = &rrpc->luns[i];
1339
1340                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1341                 if (!rblk)
1342                         goto err;
1343                 rrpc_set_lun_cur(rlun, rblk, &rlun->cur);
1344
1345                 /* Emergency gc block */
1346                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1347                 if (!rblk)
1348                         goto err;
1349                 rrpc_set_lun_cur(rlun, rblk, &rlun->gc_cur);
1350         }
1351
1352         return 0;
1353 err:
1354         rrpc_put_blks(rrpc);
1355         return -EINVAL;
1356 }
1357
1358 static struct nvm_tgt_type tt_rrpc;
1359
1360 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1361                                                 int lun_begin, int lun_end)
1362 {
1363         struct request_queue *bqueue = dev->q;
1364         struct request_queue *tqueue = tdisk->queue;
1365         struct rrpc *rrpc;
1366         sector_t soffset;
1367         int ret;
1368
1369         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1370                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1371                                                         dev->identity.dom);
1372                 return ERR_PTR(-EINVAL);
1373         }
1374
1375         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1376         if (!rrpc)
1377                 return ERR_PTR(-ENOMEM);
1378
1379         rrpc->instance.tt = &tt_rrpc;
1380         rrpc->dev = dev;
1381         rrpc->disk = tdisk;
1382
1383         bio_list_init(&rrpc->requeue_bios);
1384         spin_lock_init(&rrpc->bio_lock);
1385         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1386
1387         rrpc->nr_luns = lun_end - lun_begin + 1;
1388         rrpc->total_blocks = (unsigned long)dev->blks_per_lun * rrpc->nr_luns;
1389         rrpc->nr_sects = (unsigned long long)dev->sec_per_lun * rrpc->nr_luns;
1390
1391         /* simple round-robin strategy */
1392         atomic_set(&rrpc->next_lun, -1);
1393
1394         ret = rrpc_area_init(rrpc, &soffset);
1395         if (ret < 0) {
1396                 pr_err("nvm: rrpc: could not initialize area\n");
1397                 return ERR_PTR(ret);
1398         }
1399         rrpc->soffset = soffset;
1400
1401         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1402         if (ret) {
1403                 pr_err("nvm: rrpc: could not initialize luns\n");
1404                 goto err;
1405         }
1406
1407         rrpc->poffset = dev->sec_per_lun * lun_begin;
1408         rrpc->lun_offset = lun_begin;
1409
1410         ret = rrpc_core_init(rrpc);
1411         if (ret) {
1412                 pr_err("nvm: rrpc: could not initialize core\n");
1413                 goto err;
1414         }
1415
1416         ret = rrpc_map_init(rrpc);
1417         if (ret) {
1418                 pr_err("nvm: rrpc: could not initialize maps\n");
1419                 goto err;
1420         }
1421
1422         ret = rrpc_blocks_init(rrpc);
1423         if (ret) {
1424                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1425                 goto err;
1426         }
1427
1428         ret = rrpc_luns_configure(rrpc);
1429         if (ret) {
1430                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1431                 goto err;
1432         }
1433
1434         ret = rrpc_gc_init(rrpc);
1435         if (ret) {
1436                 pr_err("nvm: rrpc: could not initialize gc\n");
1437                 goto err;
1438         }
1439
1440         /* inherit the size from the underlying device */
1441         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1442         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1443
1444         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1445                         rrpc->nr_luns, (unsigned long long)rrpc->nr_sects);
1446
1447         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1448
1449         return rrpc;
1450 err:
1451         rrpc_free(rrpc);
1452         return ERR_PTR(ret);
1453 }
1454
1455 /* round robin, page-based FTL, and cost-based GC */
1456 static struct nvm_tgt_type tt_rrpc = {
1457         .name           = "rrpc",
1458         .version        = {1, 0, 0},
1459
1460         .make_rq        = rrpc_make_rq,
1461         .capacity       = rrpc_capacity,
1462         .end_io         = rrpc_end_io,
1463
1464         .init           = rrpc_init,
1465         .exit           = rrpc_exit,
1466 };
1467
1468 static int __init rrpc_module_init(void)
1469 {
1470         return nvm_register_tgt_type(&tt_rrpc);
1471 }
1472
1473 static void rrpc_module_exit(void)
1474 {
1475         nvm_unregister_tgt_type(&tt_rrpc);
1476 }
1477
1478 module_init(rrpc_module_init);
1479 module_exit(rrpc_module_exit);
1480 MODULE_LICENSE("GPL v2");
1481 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");