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 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->sec_per_blk);
 117 }
 118
 119 /* Calculate relative addr for the given block, considering instantiated LUNs */
 120 static u64 block_to_rel_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 121 {
 122         struct nvm_block *blk = rblk->parent;
 123         int lun_blk = blk->id % (rrpc->dev->blks_per_lun * rrpc->nr_luns);
 124
 125         return lun_blk * rrpc->dev->sec_per_blk;
 126 }
 127
 128 /* Calculate global addr for the given block */
 129 static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 130 {
 131         struct nvm_block *blk = rblk->parent;
 132
 133         return blk->id * rrpc->dev->sec_per_blk;
 134 }
 135
 136 static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
 137                                                         struct ppa_addr r)
 138 {
 139         struct ppa_addr l;
 140         int secs, pgs, blks, luns;
 141         sector_t ppa = r.ppa;
 142
 143         l.ppa = 0;
 144
 145         div_u64_rem(ppa, dev->sec_per_pg, &secs);
 146         l.g.sec = secs;
 147
 148         sector_div(ppa, dev->sec_per_pg);
 149         div_u64_rem(ppa, dev->pgs_per_blk, &pgs);
 150         l.g.pg = pgs;
 151
 152         sector_div(ppa, dev->pgs_per_blk);
 153         div_u64_rem(ppa, dev->blks_per_lun, &blks);
 154         l.g.blk = blks;
 155
 156         sector_div(ppa, dev->blks_per_lun);
 157         div_u64_rem(ppa, dev->luns_per_chnl, &luns);
 158         l.g.lun = luns;
 159
 160         sector_div(ppa, dev->luns_per_chnl);
 161         l.g.ch = ppa;
 162
 163         return l;
 164 }
 165
 166 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 167 {
 168         struct ppa_addr paddr;
 169
 170         paddr.ppa = addr;
 171         return linear_to_generic_addr(dev, paddr);
 172 }
 173
 174 /* requires lun->lock taken */
 175 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
 176 {
 177         struct rrpc *rrpc = rlun->rrpc;
 178
 179         BUG_ON(!rblk);
 180
 181         if (rlun->cur) {
 182                 spin_lock(&rlun->cur->lock);
 183                 WARN_ON(!block_is_full(rrpc, rlun->cur));
 184                 spin_unlock(&rlun->cur->lock);
 185         }
 186         rlun->cur = rblk;
 187 }
 188
 189 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 190                                                         unsigned long flags)
 191 {
 192         struct nvm_lun *lun = rlun->parent;
 193         struct nvm_block *blk;
 194         struct rrpc_block *rblk;
 195
 196         spin_lock(&lun->lock);
 197         blk = nvm_get_blk_unlocked(rrpc->dev, rlun->parent, flags);
 198         if (!blk) {
 199                 pr_err("nvm: rrpc: cannot get new block from media manager\n");
 200                 spin_unlock(&lun->lock);
 201                 return NULL;
 202         }
 203
 204         rblk = rrpc_get_rblk(rlun, blk->id);
 205         list_add_tail(&rblk->list, &rlun->open_list);
 206         spin_unlock(&lun->lock);
 207
 208         blk->priv = rblk;
 209         bitmap_zero(rblk->invalid_pages, rrpc->dev->sec_per_blk);
 210         rblk->next_page = 0;
 211         rblk->nr_invalid_pages = 0;
 212         atomic_set(&rblk->data_cmnt_size, 0);
 213
 214         return rblk;
 215 }
 216
 217 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 218 {
 219         struct rrpc_lun *rlun = rblk->rlun;
 220         struct nvm_lun *lun = rlun->parent;
 221
 222         spin_lock(&lun->lock);
 223         nvm_put_blk_unlocked(rrpc->dev, rblk->parent);
 224         list_del(&rblk->list);
 225         spin_unlock(&lun->lock);
 226 }
 227
 228 static void rrpc_put_blks(struct rrpc *rrpc)
 229 {
 230         struct rrpc_lun *rlun;
 231         int i;
 232
 233         for (i = 0; i < rrpc->nr_luns; i++) {
 234                 rlun = &rrpc->luns[i];
 235                 if (rlun->cur)
 236                         rrpc_put_blk(rrpc, rlun->cur);
 237                 if (rlun->gc_cur)
 238                         rrpc_put_blk(rrpc, rlun->gc_cur);
 239         }
 240 }
 241
 242 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 243 {
 244         int next = atomic_inc_return(&rrpc->next_lun);
 245
 246         return &rrpc->luns[next % rrpc->nr_luns];
 247 }
 248
 249 static void rrpc_gc_kick(struct rrpc *rrpc)
 250 {
 251         struct rrpc_lun *rlun;
 252         unsigned int i;
 253
 254         for (i = 0; i < rrpc->nr_luns; i++) {
 255                 rlun = &rrpc->luns[i];
 256                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 257         }
 258 }
 259
 260 /*
 261  * timed GC every interval.
 262  */
 263 static void rrpc_gc_timer(unsigned long data)
 264 {
 265         struct rrpc *rrpc = (struct rrpc *)data;
 266
 267         rrpc_gc_kick(rrpc);
 268         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 269 }
 270
 271 static void rrpc_end_sync_bio(struct bio *bio)
 272 {
 273         struct completion *waiting = bio->bi_private;
 274
 275         if (bio->bi_error)
 276                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 277
 278         complete(waiting);
 279 }
 280
 281 /*
 282  * rrpc_move_valid_pages -- migrate live data off the block
 283  * @rrpc: the 'rrpc' structure
 284  * @block: the block from which to migrate live pages
 285  *
 286  * Description:
 287  *   GC algorithms may call this function to migrate remaining live
 288  *   pages off the block prior to erasing it. This function blocks
 289  *   further execution until the operation is complete.
 290  */
 291 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 292 {
 293         struct request_queue *q = rrpc->dev->q;
 294         struct rrpc_rev_addr *rev;
 295         struct nvm_rq *rqd;
 296         struct bio *bio;
 297         struct page *page;
 298         int slot;
 299         int nr_sec_per_blk = rrpc->dev->sec_per_blk;
 300         u64 phys_addr;
 301         DECLARE_COMPLETION_ONSTACK(wait);
 302
 303         if (bitmap_full(rblk->invalid_pages, nr_sec_per_blk))
 304                 return 0;
 305
 306         bio = bio_alloc(GFP_NOIO, 1);
 307         if (!bio) {
 308                 pr_err("nvm: could not alloc bio to gc\n");
 309                 return -ENOMEM;
 310         }
 311
 312         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 313         if (!page) {
 314                 bio_put(bio);
 315                 return -ENOMEM;
 316         }
 317
 318         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 319                                             nr_sec_per_blk)) < nr_sec_per_blk) {
 320
 321                 /* Lock laddr */
 322                 phys_addr = rblk->parent->id * nr_sec_per_blk + slot;
 323
 324 try:
 325                 spin_lock(&rrpc->rev_lock);
 326                 /* Get logical address from physical to logical table */
 327                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 328                 /* already updated by previous regular write */
 329                 if (rev->addr == ADDR_EMPTY) {
 330                         spin_unlock(&rrpc->rev_lock);
 331                         continue;
 332                 }
 333
 334                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 335                 if (IS_ERR_OR_NULL(rqd)) {
 336                         spin_unlock(&rrpc->rev_lock);
 337                         schedule();
 338                         goto try;
 339                 }
 340
 341                 spin_unlock(&rrpc->rev_lock);
 342
 343                 /* Perform read to do GC */
 344                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 345                 bio->bi_rw = READ;
 346                 bio->bi_private = &wait;
 347                 bio->bi_end_io = rrpc_end_sync_bio;
 348
 349                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 350                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 351
 352                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 353                         pr_err("rrpc: gc read failed.\n");
 354                         rrpc_inflight_laddr_release(rrpc, rqd);
 355                         goto finished;
 356                 }
 357                 wait_for_completion_io(&wait);
 358                 if (bio->bi_error) {
 359                         rrpc_inflight_laddr_release(rrpc, rqd);
 360                         goto finished;
 361                 }
 362
 363                 bio_reset(bio);
 364                 reinit_completion(&wait);
 365
 366                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 367                 bio->bi_rw = WRITE;
 368                 bio->bi_private = &wait;
 369                 bio->bi_end_io = rrpc_end_sync_bio;
 370
 371                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 372
 373                 /* turn the command around and write the data back to a new
 374                  * address
 375                  */
 376                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 377                         pr_err("rrpc: gc write failed.\n");
 378                         rrpc_inflight_laddr_release(rrpc, rqd);
 379                         goto finished;
 380                 }
 381                 wait_for_completion_io(&wait);
 382
 383                 rrpc_inflight_laddr_release(rrpc, rqd);
 384                 if (bio->bi_error)
 385                         goto finished;
 386
 387                 bio_reset(bio);
 388         }
 389
 390 finished:
 391         mempool_free(page, rrpc->page_pool);
 392         bio_put(bio);
 393
 394         if (!bitmap_full(rblk->invalid_pages, nr_sec_per_blk)) {
 395                 pr_err("nvm: failed to garbage collect block\n");
 396                 return -EIO;
 397         }
 398
 399         return 0;
 400 }
 401
 402 static void rrpc_block_gc(struct work_struct *work)
 403 {
 404         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 405                                                                         ws_gc);
 406         struct rrpc *rrpc = gcb->rrpc;
 407         struct rrpc_block *rblk = gcb->rblk;
 408         struct rrpc_lun *rlun = rblk->rlun;
 409         struct nvm_dev *dev = rrpc->dev;
 410
 411         mempool_free(gcb, rrpc->gcb_pool);
 412         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 413
 414         if (rrpc_move_valid_pages(rrpc, rblk))
 415                 goto put_back;
 416
 417         if (nvm_erase_blk(dev, rblk->parent))
 418                 goto put_back;
 419
 420         rrpc_put_blk(rrpc, rblk);
 421
 422         return;
 423
 424 put_back:
 425         spin_lock(&rlun->lock);
 426         list_add_tail(&rblk->prio, &rlun->prio_list);
 427         spin_unlock(&rlun->lock);
 428 }
 429
 430 /* the block with highest number of invalid pages, will be in the beginning
 431  * of the list
 432  */
 433 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 434                                                         struct rrpc_block *rb)
 435 {
 436         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 437                 return ra;
 438
 439         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 440 }
 441
 442 /* linearly find the block with highest number of invalid pages
 443  * requires lun->lock
 444  */
 445 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 446 {
 447         struct list_head *prio_list = &rlun->prio_list;
 448         struct rrpc_block *rblock, *max;
 449
 450         BUG_ON(list_empty(prio_list));
 451
 452         max = list_first_entry(prio_list, struct rrpc_block, prio);
 453         list_for_each_entry(rblock, prio_list, prio)
 454                 max = rblock_max_invalid(max, rblock);
 455
 456         return max;
 457 }
 458
 459 static void rrpc_lun_gc(struct work_struct *work)
 460 {
 461         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 462         struct rrpc *rrpc = rlun->rrpc;
 463         struct nvm_lun *lun = rlun->parent;
 464         struct rrpc_block_gc *gcb;
 465         unsigned int nr_blocks_need;
 466
 467         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 468
 469         if (nr_blocks_need < rrpc->nr_luns)
 470                 nr_blocks_need = rrpc->nr_luns;
 471
 472         spin_lock(&rlun->lock);
 473         while (nr_blocks_need > lun->nr_free_blocks &&
 474                                         !list_empty(&rlun->prio_list)) {
 475                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 476                 struct nvm_block *block = rblock->parent;
 477
 478                 if (!rblock->nr_invalid_pages)
 479                         break;
 480
 481                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 482                 if (!gcb)
 483                         break;
 484
 485                 list_del_init(&rblock->prio);
 486
 487                 BUG_ON(!block_is_full(rrpc, rblock));
 488
 489                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 490
 491                 gcb->rrpc = rrpc;
 492                 gcb->rblk = rblock;
 493                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 494
 495                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 496
 497                 nr_blocks_need--;
 498         }
 499         spin_unlock(&rlun->lock);
 500
 501         /* TODO: Hint that request queue can be started again */
 502 }
 503
 504 static void rrpc_gc_queue(struct work_struct *work)
 505 {
 506         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 507                                                                         ws_gc);
 508         struct rrpc *rrpc = gcb->rrpc;
 509         struct rrpc_block *rblk = gcb->rblk;
 510         struct rrpc_lun *rlun = rblk->rlun;
 511         struct nvm_lun *lun = rblk->parent->lun;
 512         struct nvm_block *blk = rblk->parent;
 513
 514         spin_lock(&rlun->lock);
 515         list_add_tail(&rblk->prio, &rlun->prio_list);
 516         spin_unlock(&rlun->lock);
 517
 518         spin_lock(&lun->lock);
 519         lun->nr_open_blocks--;
 520         lun->nr_closed_blocks++;
 521         blk->state &= ~NVM_BLK_ST_OPEN;
 522         blk->state |= NVM_BLK_ST_CLOSED;
 523         list_move_tail(&rblk->list, &rlun->closed_list);
 524         spin_unlock(&lun->lock);
 525
 526         mempool_free(gcb, rrpc->gcb_pool);
 527         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 528                                                         rblk->parent->id);
 529 }
 530
 531 static const struct block_device_operations rrpc_fops = {
 532         .owner          = THIS_MODULE,
 533 };
 534
 535 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 536 {
 537         unsigned int i;
 538         struct rrpc_lun *rlun, *max_free;
 539
 540         if (!is_gc)
 541                 return get_next_lun(rrpc);
 542
 543         /* during GC, we don't care about RR, instead we want to make
 544          * sure that we maintain evenness between the block luns.
 545          */
 546         max_free = &rrpc->luns[0];
 547         /* prevent GC-ing lun from devouring pages of a lun with
 548          * little free blocks. We don't take the lock as we only need an
 549          * estimate.
 550          */
 551         rrpc_for_each_lun(rrpc, rlun, i) {
 552                 if (rlun->parent->nr_free_blocks >
 553                                         max_free->parent->nr_free_blocks)
 554                         max_free = rlun;
 555         }
 556
 557         return max_free;
 558 }
 559
 560 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 561                                         struct rrpc_block *rblk, u64 paddr)
 562 {
 563         struct rrpc_addr *gp;
 564         struct rrpc_rev_addr *rev;
 565
 566         BUG_ON(laddr >= rrpc->nr_sects);
 567
 568         gp = &rrpc->trans_map[laddr];
 569         spin_lock(&rrpc->rev_lock);
 570         if (gp->rblk)
 571                 rrpc_page_invalidate(rrpc, gp);
 572
 573         gp->addr = paddr;
 574         gp->rblk = rblk;
 575
 576         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 577         rev->addr = laddr;
 578         spin_unlock(&rrpc->rev_lock);
 579
 580         return gp;
 581 }
 582
 583 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 584 {
 585         u64 addr = ADDR_EMPTY;
 586
 587         spin_lock(&rblk->lock);
 588         if (block_is_full(rrpc, rblk))
 589                 goto out;
 590
 591         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 592
 593         rblk->next_page++;
 594 out:
 595         spin_unlock(&rblk->lock);
 596         return addr;
 597 }
 598
 599 /* Simple round-robin Logical to physical address translation.
 600  *
 601  * Retrieve the mapping using the active append point. Then update the ap for
 602  * the next write to the disk.
 603  *
 604  * Returns rrpc_addr with the physical address and block. Remember to return to
 605  * rrpc->addr_cache when request is finished.
 606  */
 607 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 608                                                                 int is_gc)
 609 {
 610         struct rrpc_lun *rlun;
 611         struct rrpc_block *rblk;
 612         struct nvm_lun *lun;
 613         u64 paddr;
 614
 615         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 616         lun = rlun->parent;
 617
 618         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 619                 return NULL;
 620
 621         spin_lock(&rlun->lock);
 622
 623         rblk = rlun->cur;
 624 retry:
 625         paddr = rrpc_alloc_addr(rrpc, rblk);
 626
 627         if (paddr == ADDR_EMPTY) {
 628                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 629                 if (rblk) {
 630                         rrpc_set_lun_cur(rlun, rblk);
 631                         goto retry;
 632                 }
 633
 634                 if (is_gc) {
 635                         /* retry from emergency gc block */
 636                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 637                         if (paddr == ADDR_EMPTY) {
 638                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 639                                 if (!rblk) {
 640                                         pr_err("rrpc: no more blocks");
 641                                         goto err;
 642                                 }
 643
 644                                 rlun->gc_cur = rblk;
 645                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 646                         }
 647                         rblk = rlun->gc_cur;
 648                 }
 649         }
 650
 651         spin_unlock(&rlun->lock);
 652         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 653 err:
 654         spin_unlock(&rlun->lock);
 655         return NULL;
 656 }
 657
 658 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 659 {
 660         struct rrpc_block_gc *gcb;
 661
 662         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 663         if (!gcb) {
 664                 pr_err("rrpc: unable to queue block for gc.");
 665                 return;
 666         }
 667
 668         gcb->rrpc = rrpc;
 669         gcb->rblk = rblk;
 670
 671         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 672         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 673 }
 674
 675 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 676                                                 sector_t laddr, uint8_t npages)
 677 {
 678         struct rrpc_addr *p;
 679         struct rrpc_block *rblk;
 680         struct nvm_lun *lun;
 681         int cmnt_size, i;
 682
 683         for (i = 0; i < npages; i++) {
 684                 p = &rrpc->trans_map[laddr + i];
 685                 rblk = p->rblk;
 686                 lun = rblk->parent->lun;
 687
 688                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 689                 if (unlikely(cmnt_size == rrpc->dev->sec_per_blk))
 690                         rrpc_run_gc(rrpc, rblk);
 691         }
 692 }
 693
 694 static void rrpc_end_io(struct nvm_rq *rqd)
 695 {
 696         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 697         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 698         uint8_t npages = rqd->nr_ppas;
 699         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 700
 701         if (bio_data_dir(rqd->bio) == WRITE)
 702                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 703
 704         bio_put(rqd->bio);
 705
 706         if (rrqd->flags & NVM_IOTYPE_GC)
 707                 return;
 708
 709         rrpc_unlock_rq(rrpc, rqd);
 710
 711         if (npages > 1)
 712                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 713
 714         mempool_free(rqd, rrpc->rq_pool);
 715 }
 716
 717 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 718                         struct nvm_rq *rqd, unsigned long flags, int npages)
 719 {
 720         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 721         struct rrpc_addr *gp;
 722         sector_t laddr = rrpc_get_laddr(bio);
 723         int is_gc = flags & NVM_IOTYPE_GC;
 724         int i;
 725
 726         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 727                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 728                 return NVM_IO_REQUEUE;
 729         }
 730
 731         for (i = 0; i < npages; i++) {
 732                 /* We assume that mapping occurs at 4KB granularity */
 733                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_sects));
 734                 gp = &rrpc->trans_map[laddr + i];
 735
 736                 if (gp->rblk) {
 737                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 738                                                                 gp->addr);
 739                 } else {
 740                         BUG_ON(is_gc);
 741                         rrpc_unlock_laddr(rrpc, r);
 742                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 743                                                         rqd->dma_ppa_list);
 744                         return NVM_IO_DONE;
 745                 }
 746         }
 747
 748         rqd->opcode = NVM_OP_HBREAD;
 749
 750         return NVM_IO_OK;
 751 }
 752
 753 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 754                                                         unsigned long flags)
 755 {
 756         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 757         int is_gc = flags & NVM_IOTYPE_GC;
 758         sector_t laddr = rrpc_get_laddr(bio);
 759         struct rrpc_addr *gp;
 760
 761         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 762                 return NVM_IO_REQUEUE;
 763
 764         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_sects));
 765         gp = &rrpc->trans_map[laddr];
 766
 767         if (gp->rblk) {
 768                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 769         } else {
 770                 BUG_ON(is_gc);
 771                 rrpc_unlock_rq(rrpc, rqd);
 772                 return NVM_IO_DONE;
 773         }
 774
 775         rqd->opcode = NVM_OP_HBREAD;
 776         rrqd->addr = gp;
 777
 778         return NVM_IO_OK;
 779 }
 780
 781 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 782                         struct nvm_rq *rqd, unsigned long flags, int npages)
 783 {
 784         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 785         struct rrpc_addr *p;
 786         sector_t laddr = rrpc_get_laddr(bio);
 787         int is_gc = flags & NVM_IOTYPE_GC;
 788         int i;
 789
 790         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 791                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 792                 return NVM_IO_REQUEUE;
 793         }
 794
 795         for (i = 0; i < npages; i++) {
 796                 /* We assume that mapping occurs at 4KB granularity */
 797                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 798                 if (!p) {
 799                         BUG_ON(is_gc);
 800                         rrpc_unlock_laddr(rrpc, r);
 801                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 802                                                         rqd->dma_ppa_list);
 803                         rrpc_gc_kick(rrpc);
 804                         return NVM_IO_REQUEUE;
 805                 }
 806
 807                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 808                                                                 p->addr);
 809         }
 810
 811         rqd->opcode = NVM_OP_HBWRITE;
 812
 813         return NVM_IO_OK;
 814 }
 815
 816 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 817                                 struct nvm_rq *rqd, unsigned long flags)
 818 {
 819         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 820         struct rrpc_addr *p;
 821         int is_gc = flags & NVM_IOTYPE_GC;
 822         sector_t laddr = rrpc_get_laddr(bio);
 823
 824         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 825                 return NVM_IO_REQUEUE;
 826
 827         p = rrpc_map_page(rrpc, laddr, is_gc);
 828         if (!p) {
 829                 BUG_ON(is_gc);
 830                 rrpc_unlock_rq(rrpc, rqd);
 831                 rrpc_gc_kick(rrpc);
 832                 return NVM_IO_REQUEUE;
 833         }
 834
 835         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 836         rqd->opcode = NVM_OP_HBWRITE;
 837         rrqd->addr = p;
 838
 839         return NVM_IO_OK;
 840 }
 841
 842 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 843                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 844 {
 845         if (npages > 1) {
 846                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 847                                                         &rqd->dma_ppa_list);
 848                 if (!rqd->ppa_list) {
 849                         pr_err("rrpc: not able to allocate ppa list\n");
 850                         return NVM_IO_ERR;
 851                 }
 852
 853                 if (bio_rw(bio) == WRITE)
 854                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 855                                                                         npages);
 856
 857                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 858         }
 859
 860         if (bio_rw(bio) == WRITE)
 861                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 862
 863         return rrpc_read_rq(rrpc, bio, rqd, flags);
 864 }
 865
 866 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 867                                 struct nvm_rq *rqd, unsigned long flags)
 868 {
 869         int err;
 870         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 871         uint8_t nr_pages = rrpc_get_pages(bio);
 872         int bio_size = bio_sectors(bio) << 9;
 873
 874         if (bio_size < rrpc->dev->sec_size)
 875                 return NVM_IO_ERR;
 876         else if (bio_size > rrpc->dev->max_rq_size)
 877                 return NVM_IO_ERR;
 878
 879         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 880         if (err)
 881                 return err;
 882
 883         bio_get(bio);
 884         rqd->bio = bio;
 885         rqd->ins = &rrpc->instance;
 886         rqd->nr_ppas = nr_pages;
 887         rrq->flags = flags;
 888
 889         err = nvm_submit_io(rrpc->dev, rqd);
 890         if (err) {
 891                 pr_err("rrpc: I/O submission failed: %d\n", err);
 892                 bio_put(bio);
 893                 if (!(flags & NVM_IOTYPE_GC)) {
 894                         rrpc_unlock_rq(rrpc, rqd);
 895                         if (rqd->nr_ppas > 1)
 896                                 nvm_dev_dma_free(rrpc->dev,
 897                         rqd->ppa_list, rqd->dma_ppa_list);
 898                 }
 899                 return NVM_IO_ERR;
 900         }
 901
 902         return NVM_IO_OK;
 903 }
 904
 905 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 906 {
 907         struct rrpc *rrpc = q->queuedata;
 908         struct nvm_rq *rqd;
 909         int err;
 910
 911         if (bio->bi_rw & REQ_DISCARD) {
 912                 rrpc_discard(rrpc, bio);
 913                 return BLK_QC_T_NONE;
 914         }
 915
 916         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 917         if (!rqd) {
 918                 pr_err_ratelimited("rrpc: not able to queue bio.");
 919                 bio_io_error(bio);
 920                 return BLK_QC_T_NONE;
 921         }
 922         memset(rqd, 0, sizeof(struct nvm_rq));
 923
 924         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 925         switch (err) {
 926         case NVM_IO_OK:
 927                 return BLK_QC_T_NONE;
 928         case NVM_IO_ERR:
 929                 bio_io_error(bio);
 930                 break;
 931         case NVM_IO_DONE:
 932                 bio_endio(bio);
 933                 break;
 934         case NVM_IO_REQUEUE:
 935                 spin_lock(&rrpc->bio_lock);
 936                 bio_list_add(&rrpc->requeue_bios, bio);
 937                 spin_unlock(&rrpc->bio_lock);
 938                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 939                 break;
 940         }
 941
 942         mempool_free(rqd, rrpc->rq_pool);
 943         return BLK_QC_T_NONE;
 944 }
 945
 946 static void rrpc_requeue(struct work_struct *work)
 947 {
 948         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 949         struct bio_list bios;
 950         struct bio *bio;
 951
 952         bio_list_init(&bios);
 953
 954         spin_lock(&rrpc->bio_lock);
 955         bio_list_merge(&bios, &rrpc->requeue_bios);
 956         bio_list_init(&rrpc->requeue_bios);
 957         spin_unlock(&rrpc->bio_lock);
 958
 959         while ((bio = bio_list_pop(&bios)))
 960                 rrpc_make_rq(rrpc->disk->queue, bio);
 961 }
 962
 963 static void rrpc_gc_free(struct rrpc *rrpc)
 964 {
 965         if (rrpc->krqd_wq)
 966                 destroy_workqueue(rrpc->krqd_wq);
 967
 968         if (rrpc->kgc_wq)
 969                 destroy_workqueue(rrpc->kgc_wq);
 970 }
 971
 972 static int rrpc_gc_init(struct rrpc *rrpc)
 973 {
 974         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 975                                                                 rrpc->nr_luns);
 976         if (!rrpc->krqd_wq)
 977                 return -ENOMEM;
 978
 979         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 980         if (!rrpc->kgc_wq)
 981                 return -ENOMEM;
 982
 983         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 984
 985         return 0;
 986 }
 987
 988 static void rrpc_map_free(struct rrpc *rrpc)
 989 {
 990         vfree(rrpc->rev_trans_map);
 991         vfree(rrpc->trans_map);
 992 }
 993
 994 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 995 {
 996         struct rrpc *rrpc = (struct rrpc *)private;
 997         struct nvm_dev *dev = rrpc->dev;
 998         struct rrpc_addr *addr = rrpc->trans_map + slba;
 999         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
1000         u64 elba = slba + nlb;
1001         u64 i;
1002
1003         if (unlikely(elba > dev->total_secs)) {
1004                 pr_err("nvm: L2P data from device is out of bounds!\n");
1005                 return -EINVAL;
1006         }
1007
1008         for (i = 0; i < nlb; i++) {
1009                 u64 pba = le64_to_cpu(entries[i]);
1010                 unsigned int mod;
1011                 /* LNVM treats address-spaces as silos, LBA and PBA are
1012                  * equally large and zero-indexed.
1013                  */
1014                 if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
1015                         pr_err("nvm: L2P data entry is out of bounds!\n");
1016                         return -EINVAL;
1017                 }
1018
1019                 /* Address zero is a special one. The first page on a disk is
1020                  * protected. As it often holds internal device boot
1021                  * information.
1022                  */
1023                 if (!pba)
1024                         continue;
1025
1026                 div_u64_rem(pba, rrpc->nr_sects, &mod);
1027
1028                 addr[i].addr = pba;
1029                 raddr[mod].addr = slba + i;
1030         }
1031
1032         return 0;
1033 }
1034
1035 static int rrpc_map_init(struct rrpc *rrpc)
1036 {
1037         struct nvm_dev *dev = rrpc->dev;
1038         sector_t i;
1039         int ret;
1040
1041         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_sects);
1042         if (!rrpc->trans_map)
1043                 return -ENOMEM;
1044
1045         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1046                                                         * rrpc->nr_sects);
1047         if (!rrpc->rev_trans_map)
1048                 return -ENOMEM;
1049
1050         for (i = 0; i < rrpc->nr_sects; i++) {
1051                 struct rrpc_addr *p = &rrpc->trans_map[i];
1052                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1053
1054                 p->addr = ADDR_EMPTY;
1055                 r->addr = ADDR_EMPTY;
1056         }
1057
1058         if (!dev->ops->get_l2p_tbl)
1059                 return 0;
1060
1061         /* Bring up the mapping table from device */
1062         ret = dev->ops->get_l2p_tbl(dev, rrpc->soffset, rrpc->nr_sects,
1063                                         rrpc_l2p_update, rrpc);
1064         if (ret) {
1065                 pr_err("nvm: rrpc: could not read L2P table.\n");
1066                 return -EINVAL;
1067         }
1068
1069         return 0;
1070 }
1071
1072 /* Minimum pages needed within a lun */
1073 #define PAGE_POOL_SIZE 16
1074 #define ADDR_POOL_SIZE 64
1075
1076 static int rrpc_core_init(struct rrpc *rrpc)
1077 {
1078         down_write(&rrpc_lock);
1079         if (!rrpc_gcb_cache) {
1080                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1081                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1082                 if (!rrpc_gcb_cache) {
1083                         up_write(&rrpc_lock);
1084                         return -ENOMEM;
1085                 }
1086
1087                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1088                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1089                                 0, 0, NULL);
1090                 if (!rrpc_rq_cache) {
1091                         kmem_cache_destroy(rrpc_gcb_cache);
1092                         up_write(&rrpc_lock);
1093                         return -ENOMEM;
1094                 }
1095         }
1096         up_write(&rrpc_lock);
1097
1098         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1099         if (!rrpc->page_pool)
1100                 return -ENOMEM;
1101
1102         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1103                                                                 rrpc_gcb_cache);
1104         if (!rrpc->gcb_pool)
1105                 return -ENOMEM;
1106
1107         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1108         if (!rrpc->rq_pool)
1109                 return -ENOMEM;
1110
1111         spin_lock_init(&rrpc->inflights.lock);
1112         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1113
1114         return 0;
1115 }
1116
1117 static void rrpc_core_free(struct rrpc *rrpc)
1118 {
1119         mempool_destroy(rrpc->page_pool);
1120         mempool_destroy(rrpc->gcb_pool);
1121         mempool_destroy(rrpc->rq_pool);
1122 }
1123
1124 static void rrpc_luns_free(struct rrpc *rrpc)
1125 {
1126         struct nvm_dev *dev = rrpc->dev;
1127         struct nvm_lun *lun;
1128         struct rrpc_lun *rlun;
1129         int i;
1130
1131         if (!rrpc->luns)
1132                 return;
1133
1134         for (i = 0; i < rrpc->nr_luns; i++) {
1135                 rlun = &rrpc->luns[i];
1136                 lun = rlun->parent;
1137                 if (!lun)
1138                         break;
1139                 dev->mt->release_lun(dev, lun->id);
1140                 vfree(rlun->blocks);
1141         }
1142
1143         kfree(rrpc->luns);
1144 }
1145
1146 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1147 {
1148         struct nvm_dev *dev = rrpc->dev;
1149         struct rrpc_lun *rlun;
1150         int i, j, ret = -EINVAL;
1151
1152         if (dev->sec_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1153                 pr_err("rrpc: number of pages per block too high.");
1154                 return -EINVAL;
1155         }
1156
1157         spin_lock_init(&rrpc->rev_lock);
1158
1159         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1160                                                                 GFP_KERNEL);
1161         if (!rrpc->luns)
1162                 return -ENOMEM;
1163
1164         /* 1:1 mapping */
1165         for (i = 0; i < rrpc->nr_luns; i++) {
1166                 int lunid = lun_begin + i;
1167                 struct nvm_lun *lun;
1168
1169                 if (dev->mt->reserve_lun(dev, lunid)) {
1170                         pr_err("rrpc: lun %u is already allocated\n", lunid);
1171                         goto err;
1172                 }
1173
1174                 lun = dev->mt->get_lun(dev, lunid);
1175                 if (!lun)
1176                         goto err;
1177
1178                 rlun = &rrpc->luns[i];
1179                 rlun->parent = lun;
1180                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1181                                                 rrpc->dev->blks_per_lun);
1182                 if (!rlun->blocks) {
1183                         ret = -ENOMEM;
1184                         goto err;
1185                 }
1186
1187                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1188                         struct rrpc_block *rblk = &rlun->blocks[j];
1189                         struct nvm_block *blk = &lun->blocks[j];
1190
1191                         rblk->parent = blk;
1192                         rblk->rlun = rlun;
1193                         INIT_LIST_HEAD(&rblk->prio);
1194                         spin_lock_init(&rblk->lock);
1195                 }
1196
1197                 rlun->rrpc = rrpc;
1198                 INIT_LIST_HEAD(&rlun->prio_list);
1199                 INIT_LIST_HEAD(&rlun->open_list);
1200                 INIT_LIST_HEAD(&rlun->closed_list);
1201
1202                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1203                 spin_lock_init(&rlun->lock);
1204         }
1205
1206         return 0;
1207 err:
1208         return ret;
1209 }
1210
1211 /* returns 0 on success and stores the beginning address in *begin */
1212 static int rrpc_area_init(struct rrpc *rrpc, sector_t *begin)
1213 {
1214         struct nvm_dev *dev = rrpc->dev;
1215         struct nvmm_type *mt = dev->mt;
1216         sector_t size = rrpc->nr_sects * dev->sec_size;
1217         int ret;
1218
1219         size >>= 9;
1220
1221         ret = mt->get_area(dev, begin, size);
1222         if (!ret)
1223                 *begin >>= (ilog2(dev->sec_size) - 9);
1224
1225         return ret;
1226 }
1227
1228 static void rrpc_area_free(struct rrpc *rrpc)
1229 {
1230         struct nvm_dev *dev = rrpc->dev;
1231         struct nvmm_type *mt = dev->mt;
1232         sector_t begin = rrpc->soffset << (ilog2(dev->sec_size) - 9);
1233
1234         mt->put_area(dev, begin);
1235 }
1236
1237 static void rrpc_free(struct rrpc *rrpc)
1238 {
1239         rrpc_gc_free(rrpc);
1240         rrpc_map_free(rrpc);
1241         rrpc_core_free(rrpc);
1242         rrpc_luns_free(rrpc);
1243         rrpc_area_free(rrpc);
1244
1245         kfree(rrpc);
1246 }
1247
1248 static void rrpc_exit(void *private)
1249 {
1250         struct rrpc *rrpc = private;
1251
1252         del_timer(&rrpc->gc_timer);
1253
1254         flush_workqueue(rrpc->krqd_wq);
1255         flush_workqueue(rrpc->kgc_wq);
1256
1257         rrpc_free(rrpc);
1258 }
1259
1260 static sector_t rrpc_capacity(void *private)
1261 {
1262         struct rrpc *rrpc = private;
1263         struct nvm_dev *dev = rrpc->dev;
1264         sector_t reserved, provisioned;
1265
1266         /* cur, gc, and two emergency blocks for each lun */
1267         reserved = rrpc->nr_luns * dev->sec_per_blk * 4;
1268         provisioned = rrpc->nr_sects - reserved;
1269
1270         if (reserved > rrpc->nr_sects) {
1271                 pr_err("rrpc: not enough space available to expose storage.\n");
1272                 return 0;
1273         }
1274
1275         sector_div(provisioned, 10);
1276         return provisioned * 9 * NR_PHY_IN_LOG;
1277 }
1278
1279 /*
1280  * Looks up the logical address from reverse trans map and check if its valid by
1281  * comparing the logical to physical address with the physical address.
1282  * Returns 0 on free, otherwise 1 if in use
1283  */
1284 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1285 {
1286         struct nvm_dev *dev = rrpc->dev;
1287         int offset;
1288         struct rrpc_addr *laddr;
1289         u64 bpaddr, paddr, pladdr;
1290
1291         bpaddr = block_to_rel_addr(rrpc, rblk);
1292         for (offset = 0; offset < dev->sec_per_blk; offset++) {
1293                 paddr = bpaddr + offset;
1294
1295                 pladdr = rrpc->rev_trans_map[paddr].addr;
1296                 if (pladdr == ADDR_EMPTY)
1297                         continue;
1298
1299                 laddr = &rrpc->trans_map[pladdr];
1300
1301                 if (paddr == laddr->addr) {
1302                         laddr->rblk = rblk;
1303                 } else {
1304                         set_bit(offset, rblk->invalid_pages);
1305                         rblk->nr_invalid_pages++;
1306                 }
1307         }
1308 }
1309
1310 static int rrpc_blocks_init(struct rrpc *rrpc)
1311 {
1312         struct rrpc_lun *rlun;
1313         struct rrpc_block *rblk;
1314         int lun_iter, blk_iter;
1315
1316         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1317                 rlun = &rrpc->luns[lun_iter];
1318
1319                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1320                                                                 blk_iter++) {
1321                         rblk = &rlun->blocks[blk_iter];
1322                         rrpc_block_map_update(rrpc, rblk);
1323                 }
1324         }
1325
1326         return 0;
1327 }
1328
1329 static int rrpc_luns_configure(struct rrpc *rrpc)
1330 {
1331         struct rrpc_lun *rlun;
1332         struct rrpc_block *rblk;
1333         int i;
1334
1335         for (i = 0; i < rrpc->nr_luns; i++) {
1336                 rlun = &rrpc->luns[i];
1337
1338                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1339                 if (!rblk)
1340                         goto err;
1341
1342                 rrpc_set_lun_cur(rlun, rblk);
1343
1344                 /* Emergency gc block */
1345                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1346                 if (!rblk)
1347                         goto err;
1348                 rlun->gc_cur = rblk;
1349         }
1350
1351         return 0;
1352 err:
1353         rrpc_put_blks(rrpc);
1354         return -EINVAL;
1355 }
1356
1357 static struct nvm_tgt_type tt_rrpc;
1358
1359 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1360                                                 int lun_begin, int lun_end)
1361 {
1362         struct request_queue *bqueue = dev->q;
1363         struct request_queue *tqueue = tdisk->queue;
1364         struct rrpc *rrpc;
1365         sector_t soffset;
1366         int ret;
1367
1368         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1369                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1370                                                         dev->identity.dom);
1371                 return ERR_PTR(-EINVAL);
1372         }
1373
1374         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1375         if (!rrpc)
1376                 return ERR_PTR(-ENOMEM);
1377
1378         rrpc->instance.tt = &tt_rrpc;
1379         rrpc->dev = dev;
1380         rrpc->disk = tdisk;
1381
1382         bio_list_init(&rrpc->requeue_bios);
1383         spin_lock_init(&rrpc->bio_lock);
1384         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1385
1386         rrpc->nr_luns = lun_end - lun_begin + 1;
1387         rrpc->total_blocks = (unsigned long)dev->blks_per_lun * rrpc->nr_luns;
1388         rrpc->nr_sects = (unsigned long long)dev->sec_per_lun * rrpc->nr_luns;
1389
1390         /* simple round-robin strategy */
1391         atomic_set(&rrpc->next_lun, -1);
1392
1393         ret = rrpc_area_init(rrpc, &soffset);
1394         if (ret < 0) {
1395                 pr_err("nvm: rrpc: could not initialize area\n");
1396                 return ERR_PTR(ret);
1397         }
1398         rrpc->soffset = soffset;
1399
1400         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1401         if (ret) {
1402                 pr_err("nvm: rrpc: could not initialize luns\n");
1403                 goto err;
1404         }
1405
1406         rrpc->poffset = dev->sec_per_lun * lun_begin;
1407         rrpc->lun_offset = lun_begin;
1408
1409         ret = rrpc_core_init(rrpc);
1410         if (ret) {
1411                 pr_err("nvm: rrpc: could not initialize core\n");
1412                 goto err;
1413         }
1414
1415         ret = rrpc_map_init(rrpc);
1416         if (ret) {
1417                 pr_err("nvm: rrpc: could not initialize maps\n");
1418                 goto err;
1419         }
1420
1421         ret = rrpc_blocks_init(rrpc);
1422         if (ret) {
1423                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1424                 goto err;
1425         }
1426
1427         ret = rrpc_luns_configure(rrpc);
1428         if (ret) {
1429                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1430                 goto err;
1431         }
1432
1433         ret = rrpc_gc_init(rrpc);
1434         if (ret) {
1435                 pr_err("nvm: rrpc: could not initialize gc\n");
1436                 goto err;
1437         }
1438
1439         /* inherit the size from the underlying device */
1440         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1441         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1442
1443         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1444                         rrpc->nr_luns, (unsigned long long)rrpc->nr_sects);
1445
1446         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1447
1448         return rrpc;
1449 err:
1450         rrpc_free(rrpc);
1451         return ERR_PTR(ret);
1452 }
1453
1454 /* round robin, page-based FTL, and cost-based GC */
1455 static struct nvm_tgt_type tt_rrpc = {
1456         .name           = "rrpc",
1457         .version        = {1, 0, 0},
1458
1459         .make_rq        = rrpc_make_rq,
1460         .capacity       = rrpc_capacity,
1461         .end_io         = rrpc_end_io,
1462
1463         .init           = rrpc_init,
1464         .exit           = rrpc_exit,
1465 };
1466
1467 static int __init rrpc_module_init(void)
1468 {
1469         return nvm_register_tgt_type(&tt_rrpc);
1470 }
1471
1472 static void rrpc_module_exit(void)
1473 {
1474         nvm_unregister_tgt_type(&tt_rrpc);
1475 }
1476
1477 module_init(rrpc_module_init);
1478 module_exit(rrpc_module_exit);
1479 MODULE_LICENSE("GPL v2");
1480 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");