drivers/lightnvm/rrpc.c

   1 /*
   2  * Copyright (C) 2015 IT University of Copenhagen
   3  * Initial release: Matias Bjorling <m@bjorling.me>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License version
   7  * 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
  15  */
  16
  17 #include "rrpc.h"
  18
  19 static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
  20 static DECLARE_RWSEM(rrpc_lock);
  21
  22 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
  23                                 struct nvm_rq *rqd, unsigned long flags);
  24
  25 #define rrpc_for_each_lun(rrpc, rlun, i) \
  26                 for ((i) = 0, rlun = &(rrpc)->luns[0]; \
  27                         (i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)])
  28
  29 static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
  30 {
  31         struct rrpc_block *rblk = a->rblk;
  32         unsigned int pg_offset;
  33
  34         lockdep_assert_held(&rrpc->rev_lock);
  35
  36         if (a->addr == ADDR_EMPTY || !rblk)
  37                 return;
  38
  39         spin_lock(&rblk->lock);
  40
  41         div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset);
  42         WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
  43         rblk->nr_invalid_pages++;
  44
  45         spin_unlock(&rblk->lock);
  46
  47         rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY;
  48 }
  49
  50 static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
  51                                                                 unsigned len)
  52 {
  53         sector_t i;
  54
  55         spin_lock(&rrpc->rev_lock);
  56         for (i = slba; i < slba + len; i++) {
  57                 struct rrpc_addr *gp = &rrpc->trans_map[i];
  58
  59                 rrpc_page_invalidate(rrpc, gp);
  60                 gp->rblk = NULL;
  61         }
  62         spin_unlock(&rrpc->rev_lock);
  63 }
  64
  65 static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc,
  66                                         sector_t laddr, unsigned int pages)
  67 {
  68         struct nvm_rq *rqd;
  69         struct rrpc_inflight_rq *inf;
  70
  71         rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC);
  72         if (!rqd)
  73                 return ERR_PTR(-ENOMEM);
  74
  75         inf = rrpc_get_inflight_rq(rqd);
  76         if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) {
  77                 mempool_free(rqd, rrpc->rq_pool);
  78                 return NULL;
  79         }
  80
  81         return rqd;
  82 }
  83
  84 static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd)
  85 {
  86         struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd);
  87
  88         rrpc_unlock_laddr(rrpc, inf);
  89
  90         mempool_free(rqd, rrpc->rq_pool);
  91 }
  92
  93 static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)
  94 {
  95         sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
  96         sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
  97         struct nvm_rq *rqd;
  98
  99         do {
 100                 rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
 101                 schedule();
 102         } while (!rqd);
 103
 104         if (IS_ERR(rqd)) {
 105                 pr_err("rrpc: unable to acquire inflight IO\n");
 106                 bio_io_error(bio);
 107                 return;
 108         }
 109
 110         rrpc_invalidate_range(rrpc, slba, len);
 111         rrpc_inflight_laddr_release(rrpc, rqd);
 112 }
 113
 114 static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
 115 {
 116         return (rblk->next_page == rrpc->dev->pgs_per_blk);
 117 }
 118
 119 static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 120 {
 121         struct nvm_block *blk = rblk->parent;
 122
 123         return blk->id * rrpc->dev->pgs_per_blk;
 124 }
 125
 126 static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
 127                                                         struct ppa_addr r)
 128 {
 129         struct ppa_addr l;
 130         int secs, pgs, blks, luns;
 131         sector_t ppa = r.ppa;
 132
 133         l.ppa = 0;
 134
 135         div_u64_rem(ppa, dev->sec_per_pg, &secs);
 136         l.g.sec = secs;
 137
 138         sector_div(ppa, dev->sec_per_pg);
 139         div_u64_rem(ppa, dev->sec_per_blk, &pgs);
 140         l.g.pg = pgs;
 141
 142         sector_div(ppa, dev->pgs_per_blk);
 143         div_u64_rem(ppa, dev->blks_per_lun, &blks);
 144         l.g.blk = blks;
 145
 146         sector_div(ppa, dev->blks_per_lun);
 147         div_u64_rem(ppa, dev->luns_per_chnl, &luns);
 148         l.g.lun = luns;
 149
 150         sector_div(ppa, dev->luns_per_chnl);
 151         l.g.ch = ppa;
 152
 153         return l;
 154 }
 155
 156 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 157 {
 158         struct ppa_addr paddr;
 159
 160         paddr.ppa = addr;
 161         return linear_to_generic_addr(dev, paddr);
 162 }
 163
 164 /* requires lun->lock taken */
 165 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
 166 {
 167         struct rrpc *rrpc = rlun->rrpc;
 168
 169         BUG_ON(!rblk);
 170
 171         if (rlun->cur) {
 172                 spin_lock(&rlun->cur->lock);
 173                 WARN_ON(!block_is_full(rrpc, rlun->cur));
 174                 spin_unlock(&rlun->cur->lock);
 175         }
 176         rlun->cur = rblk;
 177 }
 178
 179 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 180                                                         unsigned long flags)
 181 {
 182         struct nvm_block *blk;
 183         struct rrpc_block *rblk;
 184
 185         blk = nvm_get_blk(rrpc->dev, rlun->parent, flags);
 186         if (!blk)
 187                 return NULL;
 188
 189         rblk = &rlun->blocks[blk->id];
 190         blk->priv = rblk;
 191
 192         bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
 193         rblk->next_page = 0;
 194         rblk->nr_invalid_pages = 0;
 195         atomic_set(&rblk->data_cmnt_size, 0);
 196
 197         return rblk;
 198 }
 199
 200 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 201 {
 202         nvm_put_blk(rrpc->dev, rblk->parent);
 203 }
 204
 205 static void rrpc_put_blks(struct rrpc *rrpc)
 206 {
 207         struct rrpc_lun *rlun;
 208         int i;
 209
 210         for (i = 0; i < rrpc->nr_luns; i++) {
 211                 rlun = &rrpc->luns[i];
 212                 if (rlun->cur)
 213                         rrpc_put_blk(rrpc, rlun->cur);
 214                 if (rlun->gc_cur)
 215                         rrpc_put_blk(rrpc, rlun->gc_cur);
 216         }
 217 }
 218
 219 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 220 {
 221         int next = atomic_inc_return(&rrpc->next_lun);
 222
 223         return &rrpc->luns[next % rrpc->nr_luns];
 224 }
 225
 226 static void rrpc_gc_kick(struct rrpc *rrpc)
 227 {
 228         struct rrpc_lun *rlun;
 229         unsigned int i;
 230
 231         for (i = 0; i < rrpc->nr_luns; i++) {
 232                 rlun = &rrpc->luns[i];
 233                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 234         }
 235 }
 236
 237 /*
 238  * timed GC every interval.
 239  */
 240 static void rrpc_gc_timer(unsigned long data)
 241 {
 242         struct rrpc *rrpc = (struct rrpc *)data;
 243
 244         rrpc_gc_kick(rrpc);
 245         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 246 }
 247
 248 static void rrpc_end_sync_bio(struct bio *bio)
 249 {
 250         struct completion *waiting = bio->bi_private;
 251
 252         if (bio->bi_error)
 253                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 254
 255         complete(waiting);
 256 }
 257
 258 /*
 259  * rrpc_move_valid_pages -- migrate live data off the block
 260  * @rrpc: the 'rrpc' structure
 261  * @block: the block from which to migrate live pages
 262  *
 263  * Description:
 264  *   GC algorithms may call this function to migrate remaining live
 265  *   pages off the block prior to erasing it. This function blocks
 266  *   further execution until the operation is complete.
 267  */
 268 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 269 {
 270         struct request_queue *q = rrpc->dev->q;
 271         struct rrpc_rev_addr *rev;
 272         struct nvm_rq *rqd;
 273         struct bio *bio;
 274         struct page *page;
 275         int slot;
 276         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 277         u64 phys_addr;
 278         DECLARE_COMPLETION_ONSTACK(wait);
 279
 280         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 281                 return 0;
 282
 283         bio = bio_alloc(GFP_NOIO, 1);
 284         if (!bio) {
 285                 pr_err("nvm: could not alloc bio to gc\n");
 286                 return -ENOMEM;
 287         }
 288
 289         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 290         if (!page) {
 291                 bio_put(bio);
 292                 return -ENOMEM;
 293         }
 294
 295         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 296                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 297
 298                 /* Lock laddr */
 299                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 300
 301 try:
 302                 spin_lock(&rrpc->rev_lock);
 303                 /* Get logical address from physical to logical table */
 304                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 305                 /* already updated by previous regular write */
 306                 if (rev->addr == ADDR_EMPTY) {
 307                         spin_unlock(&rrpc->rev_lock);
 308                         continue;
 309                 }
 310
 311                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 312                 if (IS_ERR_OR_NULL(rqd)) {
 313                         spin_unlock(&rrpc->rev_lock);
 314                         schedule();
 315                         goto try;
 316                 }
 317
 318                 spin_unlock(&rrpc->rev_lock);
 319
 320                 /* Perform read to do GC */
 321                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 322                 bio->bi_rw = READ;
 323                 bio->bi_private = &wait;
 324                 bio->bi_end_io = rrpc_end_sync_bio;
 325
 326                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 327                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 328
 329                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 330                         pr_err("rrpc: gc read failed.\n");
 331                         rrpc_inflight_laddr_release(rrpc, rqd);
 332                         goto finished;
 333                 }
 334                 wait_for_completion_io(&wait);
 335
 336                 bio_reset(bio);
 337                 reinit_completion(&wait);
 338
 339                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 340                 bio->bi_rw = WRITE;
 341                 bio->bi_private = &wait;
 342                 bio->bi_end_io = rrpc_end_sync_bio;
 343
 344                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 345
 346                 /* turn the command around and write the data back to a new
 347                  * address
 348                  */
 349                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 350                         pr_err("rrpc: gc write failed.\n");
 351                         rrpc_inflight_laddr_release(rrpc, rqd);
 352                         goto finished;
 353                 }
 354                 wait_for_completion_io(&wait);
 355
 356                 rrpc_inflight_laddr_release(rrpc, rqd);
 357
 358                 bio_reset(bio);
 359         }
 360
 361 finished:
 362         mempool_free(page, rrpc->page_pool);
 363         bio_put(bio);
 364
 365         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 366                 pr_err("nvm: failed to garbage collect block\n");
 367                 return -EIO;
 368         }
 369
 370         return 0;
 371 }
 372
 373 static void rrpc_block_gc(struct work_struct *work)
 374 {
 375         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 376                                                                         ws_gc);
 377         struct rrpc *rrpc = gcb->rrpc;
 378         struct rrpc_block *rblk = gcb->rblk;
 379         struct nvm_dev *dev = rrpc->dev;
 380
 381         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 382
 383         if (rrpc_move_valid_pages(rrpc, rblk))
 384                 goto done;
 385
 386         nvm_erase_blk(dev, rblk->parent);
 387         rrpc_put_blk(rrpc, rblk);
 388 done:
 389         mempool_free(gcb, rrpc->gcb_pool);
 390 }
 391
 392 /* the block with highest number of invalid pages, will be in the beginning
 393  * of the list
 394  */
 395 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 396                                                         struct rrpc_block *rb)
 397 {
 398         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 399                 return ra;
 400
 401         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 402 }
 403
 404 /* linearly find the block with highest number of invalid pages
 405  * requires lun->lock
 406  */
 407 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 408 {
 409         struct list_head *prio_list = &rlun->prio_list;
 410         struct rrpc_block *rblock, *max;
 411
 412         BUG_ON(list_empty(prio_list));
 413
 414         max = list_first_entry(prio_list, struct rrpc_block, prio);
 415         list_for_each_entry(rblock, prio_list, prio)
 416                 max = rblock_max_invalid(max, rblock);
 417
 418         return max;
 419 }
 420
 421 static void rrpc_lun_gc(struct work_struct *work)
 422 {
 423         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 424         struct rrpc *rrpc = rlun->rrpc;
 425         struct nvm_lun *lun = rlun->parent;
 426         struct rrpc_block_gc *gcb;
 427         unsigned int nr_blocks_need;
 428
 429         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 430
 431         if (nr_blocks_need < rrpc->nr_luns)
 432                 nr_blocks_need = rrpc->nr_luns;
 433
 434         spin_lock(&rlun->lock);
 435         while (nr_blocks_need > lun->nr_free_blocks &&
 436                                         !list_empty(&rlun->prio_list)) {
 437                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 438                 struct nvm_block *block = rblock->parent;
 439
 440                 if (!rblock->nr_invalid_pages)
 441                         break;
 442
 443                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 444                 if (!gcb)
 445                         break;
 446
 447                 list_del_init(&rblock->prio);
 448
 449                 BUG_ON(!block_is_full(rrpc, rblock));
 450
 451                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 452
 453                 gcb->rrpc = rrpc;
 454                 gcb->rblk = rblock;
 455                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 456
 457                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 458
 459                 nr_blocks_need--;
 460         }
 461         spin_unlock(&rlun->lock);
 462
 463         /* TODO: Hint that request queue can be started again */
 464 }
 465
 466 static void rrpc_gc_queue(struct work_struct *work)
 467 {
 468         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 469                                                                         ws_gc);
 470         struct rrpc *rrpc = gcb->rrpc;
 471         struct rrpc_block *rblk = gcb->rblk;
 472         struct nvm_lun *lun = rblk->parent->lun;
 473         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 474
 475         spin_lock(&rlun->lock);
 476         list_add_tail(&rblk->prio, &rlun->prio_list);
 477         spin_unlock(&rlun->lock);
 478
 479         mempool_free(gcb, rrpc->gcb_pool);
 480         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 481                                                         rblk->parent->id);
 482 }
 483
 484 static const struct block_device_operations rrpc_fops = {
 485         .owner          = THIS_MODULE,
 486 };
 487
 488 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 489 {
 490         unsigned int i;
 491         struct rrpc_lun *rlun, *max_free;
 492
 493         if (!is_gc)
 494                 return get_next_lun(rrpc);
 495
 496         /* during GC, we don't care about RR, instead we want to make
 497          * sure that we maintain evenness between the block luns.
 498          */
 499         max_free = &rrpc->luns[0];
 500         /* prevent GC-ing lun from devouring pages of a lun with
 501          * little free blocks. We don't take the lock as we only need an
 502          * estimate.
 503          */
 504         rrpc_for_each_lun(rrpc, rlun, i) {
 505                 if (rlun->parent->nr_free_blocks >
 506                                         max_free->parent->nr_free_blocks)
 507                         max_free = rlun;
 508         }
 509
 510         return max_free;
 511 }
 512
 513 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 514                                         struct rrpc_block *rblk, u64 paddr)
 515 {
 516         struct rrpc_addr *gp;
 517         struct rrpc_rev_addr *rev;
 518
 519         BUG_ON(laddr >= rrpc->nr_pages);
 520
 521         gp = &rrpc->trans_map[laddr];
 522         spin_lock(&rrpc->rev_lock);
 523         if (gp->rblk)
 524                 rrpc_page_invalidate(rrpc, gp);
 525
 526         gp->addr = paddr;
 527         gp->rblk = rblk;
 528
 529         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 530         rev->addr = laddr;
 531         spin_unlock(&rrpc->rev_lock);
 532
 533         return gp;
 534 }
 535
 536 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 537 {
 538         u64 addr = ADDR_EMPTY;
 539
 540         spin_lock(&rblk->lock);
 541         if (block_is_full(rrpc, rblk))
 542                 goto out;
 543
 544         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 545
 546         rblk->next_page++;
 547 out:
 548         spin_unlock(&rblk->lock);
 549         return addr;
 550 }
 551
 552 /* Simple round-robin Logical to physical address translation.
 553  *
 554  * Retrieve the mapping using the active append point. Then update the ap for
 555  * the next write to the disk.
 556  *
 557  * Returns rrpc_addr with the physical address and block. Remember to return to
 558  * rrpc->addr_cache when request is finished.
 559  */
 560 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 561                                                                 int is_gc)
 562 {
 563         struct rrpc_lun *rlun;
 564         struct rrpc_block *rblk;
 565         struct nvm_lun *lun;
 566         u64 paddr;
 567
 568         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 569         lun = rlun->parent;
 570
 571         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 572                 return NULL;
 573
 574         spin_lock(&rlun->lock);
 575
 576         rblk = rlun->cur;
 577 retry:
 578         paddr = rrpc_alloc_addr(rrpc, rblk);
 579
 580         if (paddr == ADDR_EMPTY) {
 581                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 582                 if (rblk) {
 583                         rrpc_set_lun_cur(rlun, rblk);
 584                         goto retry;
 585                 }
 586
 587                 if (is_gc) {
 588                         /* retry from emergency gc block */
 589                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 590                         if (paddr == ADDR_EMPTY) {
 591                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 592                                 if (!rblk) {
 593                                         pr_err("rrpc: no more blocks");
 594                                         goto err;
 595                                 }
 596
 597                                 rlun->gc_cur = rblk;
 598                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 599                         }
 600                         rblk = rlun->gc_cur;
 601                 }
 602         }
 603
 604         spin_unlock(&rlun->lock);
 605         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 606 err:
 607         spin_unlock(&rlun->lock);
 608         return NULL;
 609 }
 610
 611 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 612 {
 613         struct rrpc_block_gc *gcb;
 614
 615         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 616         if (!gcb) {
 617                 pr_err("rrpc: unable to queue block for gc.");
 618                 return;
 619         }
 620
 621         gcb->rrpc = rrpc;
 622         gcb->rblk = rblk;
 623
 624         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 625         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 626 }
 627
 628 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 629                                                 sector_t laddr, uint8_t npages)
 630 {
 631         struct rrpc_addr *p;
 632         struct rrpc_block *rblk;
 633         struct nvm_lun *lun;
 634         int cmnt_size, i;
 635
 636         for (i = 0; i < npages; i++) {
 637                 p = &rrpc->trans_map[laddr + i];
 638                 rblk = p->rblk;
 639                 lun = rblk->parent->lun;
 640
 641                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 642                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
 643                         rrpc_run_gc(rrpc, rblk);
 644         }
 645 }
 646
 647 static int rrpc_end_io(struct nvm_rq *rqd, int error)
 648 {
 649         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 650         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 651         uint8_t npages = rqd->nr_pages;
 652         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 653
 654         if (bio_data_dir(rqd->bio) == WRITE)
 655                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 656
 657         bio_put(rqd->bio);
 658
 659         if (rrqd->flags & NVM_IOTYPE_GC)
 660                 return 0;
 661
 662         rrpc_unlock_rq(rrpc, rqd);
 663
 664         if (npages > 1)
 665                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 666         if (rqd->metadata)
 667                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 668
 669         mempool_free(rqd, rrpc->rq_pool);
 670
 671         return 0;
 672 }
 673
 674 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 675                         struct nvm_rq *rqd, unsigned long flags, int npages)
 676 {
 677         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 678         struct rrpc_addr *gp;
 679         sector_t laddr = rrpc_get_laddr(bio);
 680         int is_gc = flags & NVM_IOTYPE_GC;
 681         int i;
 682
 683         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 684                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 685                 return NVM_IO_REQUEUE;
 686         }
 687
 688         for (i = 0; i < npages; i++) {
 689                 /* We assume that mapping occurs at 4KB granularity */
 690                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 691                 gp = &rrpc->trans_map[laddr + i];
 692
 693                 if (gp->rblk) {
 694                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 695                                                                 gp->addr);
 696                 } else {
 697                         BUG_ON(is_gc);
 698                         rrpc_unlock_laddr(rrpc, r);
 699                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 700                                                         rqd->dma_ppa_list);
 701                         return NVM_IO_DONE;
 702                 }
 703         }
 704
 705         rqd->opcode = NVM_OP_HBREAD;
 706
 707         return NVM_IO_OK;
 708 }
 709
 710 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 711                                                         unsigned long flags)
 712 {
 713         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 714         int is_gc = flags & NVM_IOTYPE_GC;
 715         sector_t laddr = rrpc_get_laddr(bio);
 716         struct rrpc_addr *gp;
 717
 718         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 719                 return NVM_IO_REQUEUE;
 720
 721         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 722         gp = &rrpc->trans_map[laddr];
 723
 724         if (gp->rblk) {
 725                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 726         } else {
 727                 BUG_ON(is_gc);
 728                 rrpc_unlock_rq(rrpc, rqd);
 729                 return NVM_IO_DONE;
 730         }
 731
 732         rqd->opcode = NVM_OP_HBREAD;
 733         rrqd->addr = gp;
 734
 735         return NVM_IO_OK;
 736 }
 737
 738 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 739                         struct nvm_rq *rqd, unsigned long flags, int npages)
 740 {
 741         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 742         struct rrpc_addr *p;
 743         sector_t laddr = rrpc_get_laddr(bio);
 744         int is_gc = flags & NVM_IOTYPE_GC;
 745         int i;
 746
 747         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 748                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 749                 return NVM_IO_REQUEUE;
 750         }
 751
 752         for (i = 0; i < npages; i++) {
 753                 /* We assume that mapping occurs at 4KB granularity */
 754                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 755                 if (!p) {
 756                         BUG_ON(is_gc);
 757                         rrpc_unlock_laddr(rrpc, r);
 758                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 759                                                         rqd->dma_ppa_list);
 760                         rrpc_gc_kick(rrpc);
 761                         return NVM_IO_REQUEUE;
 762                 }
 763
 764                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 765                                                                 p->addr);
 766         }
 767
 768         rqd->opcode = NVM_OP_HBWRITE;
 769
 770         return NVM_IO_OK;
 771 }
 772
 773 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 774                                 struct nvm_rq *rqd, unsigned long flags)
 775 {
 776         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 777         struct rrpc_addr *p;
 778         int is_gc = flags & NVM_IOTYPE_GC;
 779         sector_t laddr = rrpc_get_laddr(bio);
 780
 781         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 782                 return NVM_IO_REQUEUE;
 783
 784         p = rrpc_map_page(rrpc, laddr, is_gc);
 785         if (!p) {
 786                 BUG_ON(is_gc);
 787                 rrpc_unlock_rq(rrpc, rqd);
 788                 rrpc_gc_kick(rrpc);
 789                 return NVM_IO_REQUEUE;
 790         }
 791
 792         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 793         rqd->opcode = NVM_OP_HBWRITE;
 794         rrqd->addr = p;
 795
 796         return NVM_IO_OK;
 797 }
 798
 799 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 800                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 801 {
 802         if (npages > 1) {
 803                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 804                                                         &rqd->dma_ppa_list);
 805                 if (!rqd->ppa_list) {
 806                         pr_err("rrpc: not able to allocate ppa list\n");
 807                         return NVM_IO_ERR;
 808                 }
 809
 810                 if (bio_rw(bio) == WRITE)
 811                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 812                                                                         npages);
 813
 814                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 815         }
 816
 817         if (bio_rw(bio) == WRITE)
 818                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 819
 820         return rrpc_read_rq(rrpc, bio, rqd, flags);
 821 }
 822
 823 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 824                                 struct nvm_rq *rqd, unsigned long flags)
 825 {
 826         int err;
 827         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 828         uint8_t nr_pages = rrpc_get_pages(bio);
 829         int bio_size = bio_sectors(bio) << 9;
 830
 831         if (bio_size < rrpc->dev->sec_size)
 832                 return NVM_IO_ERR;
 833         else if (bio_size > rrpc->dev->max_rq_size)
 834                 return NVM_IO_ERR;
 835
 836         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 837         if (err)
 838                 return err;
 839
 840         bio_get(bio);
 841         rqd->bio = bio;
 842         rqd->ins = &rrpc->instance;
 843         rqd->nr_pages = nr_pages;
 844         rrq->flags = flags;
 845
 846         err = nvm_submit_io(rrpc->dev, rqd);
 847         if (err) {
 848                 pr_err("rrpc: I/O submission failed: %d\n", err);
 849                 bio_put(bio);
 850                 if (!(flags & NVM_IOTYPE_GC)) {
 851                         rrpc_unlock_rq(rrpc, rqd);
 852                         if (rqd->nr_pages > 1)
 853                                 nvm_dev_dma_free(rrpc->dev,
 854                         rqd->ppa_list, rqd->dma_ppa_list);
 855                 }
 856                 return NVM_IO_ERR;
 857         }
 858
 859         return NVM_IO_OK;
 860 }
 861
 862 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 863 {
 864         struct rrpc *rrpc = q->queuedata;
 865         struct nvm_rq *rqd;
 866         int err;
 867
 868         if (bio->bi_rw & REQ_DISCARD) {
 869                 rrpc_discard(rrpc, bio);
 870                 return BLK_QC_T_NONE;
 871         }
 872
 873         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 874         if (!rqd) {
 875                 pr_err_ratelimited("rrpc: not able to queue bio.");
 876                 bio_io_error(bio);
 877                 return BLK_QC_T_NONE;
 878         }
 879         memset(rqd, 0, sizeof(struct nvm_rq));
 880
 881         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 882         switch (err) {
 883         case NVM_IO_OK:
 884                 return BLK_QC_T_NONE;
 885         case NVM_IO_ERR:
 886                 bio_io_error(bio);
 887                 break;
 888         case NVM_IO_DONE:
 889                 bio_endio(bio);
 890                 break;
 891         case NVM_IO_REQUEUE:
 892                 spin_lock(&rrpc->bio_lock);
 893                 bio_list_add(&rrpc->requeue_bios, bio);
 894                 spin_unlock(&rrpc->bio_lock);
 895                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 896                 break;
 897         }
 898
 899         mempool_free(rqd, rrpc->rq_pool);
 900         return BLK_QC_T_NONE;
 901 }
 902
 903 static void rrpc_requeue(struct work_struct *work)
 904 {
 905         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 906         struct bio_list bios;
 907         struct bio *bio;
 908
 909         bio_list_init(&bios);
 910
 911         spin_lock(&rrpc->bio_lock);
 912         bio_list_merge(&bios, &rrpc->requeue_bios);
 913         bio_list_init(&rrpc->requeue_bios);
 914         spin_unlock(&rrpc->bio_lock);
 915
 916         while ((bio = bio_list_pop(&bios)))
 917                 rrpc_make_rq(rrpc->disk->queue, bio);
 918 }
 919
 920 static void rrpc_gc_free(struct rrpc *rrpc)
 921 {
 922         struct rrpc_lun *rlun;
 923         int i;
 924
 925         if (rrpc->krqd_wq)
 926                 destroy_workqueue(rrpc->krqd_wq);
 927
 928         if (rrpc->kgc_wq)
 929                 destroy_workqueue(rrpc->kgc_wq);
 930
 931         if (!rrpc->luns)
 932                 return;
 933
 934         for (i = 0; i < rrpc->nr_luns; i++) {
 935                 rlun = &rrpc->luns[i];
 936
 937                 if (!rlun->blocks)
 938                         break;
 939                 vfree(rlun->blocks);
 940         }
 941 }
 942
 943 static int rrpc_gc_init(struct rrpc *rrpc)
 944 {
 945         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 946                                                                 rrpc->nr_luns);
 947         if (!rrpc->krqd_wq)
 948                 return -ENOMEM;
 949
 950         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 951         if (!rrpc->kgc_wq)
 952                 return -ENOMEM;
 953
 954         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 955
 956         return 0;
 957 }
 958
 959 static void rrpc_map_free(struct rrpc *rrpc)
 960 {
 961         vfree(rrpc->rev_trans_map);
 962         vfree(rrpc->trans_map);
 963 }
 964
 965 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 966 {
 967         struct rrpc *rrpc = (struct rrpc *)private;
 968         struct nvm_dev *dev = rrpc->dev;
 969         struct rrpc_addr *addr = rrpc->trans_map + slba;
 970         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
 971         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 972         u64 elba = slba + nlb;
 973         u64 i;
 974
 975         if (unlikely(elba > dev->total_pages)) {
 976                 pr_err("nvm: L2P data from device is out of bounds!\n");
 977                 return -EINVAL;
 978         }
 979
 980         for (i = 0; i < nlb; i++) {
 981                 u64 pba = le64_to_cpu(entries[i]);
 982                 /* LNVM treats address-spaces as silos, LBA and PBA are
 983                  * equally large and zero-indexed.
 984                  */
 985                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 986                         pr_err("nvm: L2P data entry is out of bounds!\n");
 987                         return -EINVAL;
 988                 }
 989
 990                 /* Address zero is a special one. The first page on a disk is
 991                  * protected. As it often holds internal device boot
 992                  * information.
 993                  */
 994                 if (!pba)
 995                         continue;
 996
 997                 addr[i].addr = pba;
 998                 raddr[pba].addr = slba + i;
 999         }
1000
1001         return 0;
1002 }
1003
1004 static int rrpc_map_init(struct rrpc *rrpc)
1005 {
1006         struct nvm_dev *dev = rrpc->dev;
1007         sector_t i;
1008         int ret;
1009
1010         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
1011         if (!rrpc->trans_map)
1012                 return -ENOMEM;
1013
1014         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1015                                                         * rrpc->nr_pages);
1016         if (!rrpc->rev_trans_map)
1017                 return -ENOMEM;
1018
1019         for (i = 0; i < rrpc->nr_pages; i++) {
1020                 struct rrpc_addr *p = &rrpc->trans_map[i];
1021                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1022
1023                 p->addr = ADDR_EMPTY;
1024                 r->addr = ADDR_EMPTY;
1025         }
1026
1027         if (!dev->ops->get_l2p_tbl)
1028                 return 0;
1029
1030         /* Bring up the mapping table from device */
1031         ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
1032                                                         rrpc_l2p_update, rrpc);
1033         if (ret) {
1034                 pr_err("nvm: rrpc: could not read L2P table.\n");
1035                 return -EINVAL;
1036         }
1037
1038         return 0;
1039 }
1040
1041
1042 /* Minimum pages needed within a lun */
1043 #define PAGE_POOL_SIZE 16
1044 #define ADDR_POOL_SIZE 64
1045
1046 static int rrpc_core_init(struct rrpc *rrpc)
1047 {
1048         down_write(&rrpc_lock);
1049         if (!rrpc_gcb_cache) {
1050                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1051                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1052                 if (!rrpc_gcb_cache) {
1053                         up_write(&rrpc_lock);
1054                         return -ENOMEM;
1055                 }
1056
1057                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1058                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1059                                 0, 0, NULL);
1060                 if (!rrpc_rq_cache) {
1061                         kmem_cache_destroy(rrpc_gcb_cache);
1062                         up_write(&rrpc_lock);
1063                         return -ENOMEM;
1064                 }
1065         }
1066         up_write(&rrpc_lock);
1067
1068         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1069         if (!rrpc->page_pool)
1070                 return -ENOMEM;
1071
1072         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1073                                                                 rrpc_gcb_cache);
1074         if (!rrpc->gcb_pool)
1075                 return -ENOMEM;
1076
1077         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1078         if (!rrpc->rq_pool)
1079                 return -ENOMEM;
1080
1081         spin_lock_init(&rrpc->inflights.lock);
1082         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1083
1084         return 0;
1085 }
1086
1087 static void rrpc_core_free(struct rrpc *rrpc)
1088 {
1089         mempool_destroy(rrpc->page_pool);
1090         mempool_destroy(rrpc->gcb_pool);
1091         mempool_destroy(rrpc->rq_pool);
1092 }
1093
1094 static void rrpc_luns_free(struct rrpc *rrpc)
1095 {
1096         kfree(rrpc->luns);
1097 }
1098
1099 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1100 {
1101         struct nvm_dev *dev = rrpc->dev;
1102         struct rrpc_lun *rlun;
1103         int i, j;
1104
1105         spin_lock_init(&rrpc->rev_lock);
1106
1107         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1108                                                                 GFP_KERNEL);
1109         if (!rrpc->luns)
1110                 return -ENOMEM;
1111
1112         /* 1:1 mapping */
1113         for (i = 0; i < rrpc->nr_luns; i++) {
1114                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1115
1116                 if (dev->pgs_per_blk >
1117                                 MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1118                         pr_err("rrpc: number of pages per block too high.");
1119                         goto err;
1120                 }
1121
1122                 rlun = &rrpc->luns[i];
1123                 rlun->rrpc = rrpc;
1124                 rlun->parent = lun;
1125                 INIT_LIST_HEAD(&rlun->prio_list);
1126                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1127                 spin_lock_init(&rlun->lock);
1128
1129                 rrpc->total_blocks += dev->blks_per_lun;
1130                 rrpc->nr_pages += dev->sec_per_lun;
1131
1132                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1133                                                 rrpc->dev->blks_per_lun);
1134                 if (!rlun->blocks)
1135                         goto err;
1136
1137                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1138                         struct rrpc_block *rblk = &rlun->blocks[j];
1139                         struct nvm_block *blk = &lun->blocks[j];
1140
1141                         rblk->parent = blk;
1142                         INIT_LIST_HEAD(&rblk->prio);
1143                         spin_lock_init(&rblk->lock);
1144                 }
1145         }
1146
1147         return 0;
1148 err:
1149         return -ENOMEM;
1150 }
1151
1152 static void rrpc_free(struct rrpc *rrpc)
1153 {
1154         rrpc_gc_free(rrpc);
1155         rrpc_map_free(rrpc);
1156         rrpc_core_free(rrpc);
1157         rrpc_luns_free(rrpc);
1158
1159         kfree(rrpc);
1160 }
1161
1162 static void rrpc_exit(void *private)
1163 {
1164         struct rrpc *rrpc = private;
1165
1166         del_timer(&rrpc->gc_timer);
1167
1168         flush_workqueue(rrpc->krqd_wq);
1169         flush_workqueue(rrpc->kgc_wq);
1170
1171         rrpc_free(rrpc);
1172 }
1173
1174 static sector_t rrpc_capacity(void *private)
1175 {
1176         struct rrpc *rrpc = private;
1177         struct nvm_dev *dev = rrpc->dev;
1178         sector_t reserved, provisioned;
1179
1180         /* cur, gc, and two emergency blocks for each lun */
1181         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1182         provisioned = rrpc->nr_pages - reserved;
1183
1184         if (reserved > rrpc->nr_pages) {
1185                 pr_err("rrpc: not enough space available to expose storage.\n");
1186                 return 0;
1187         }
1188
1189         sector_div(provisioned, 10);
1190         return provisioned * 9 * NR_PHY_IN_LOG;
1191 }
1192
1193 /*
1194  * Looks up the logical address from reverse trans map and check if its valid by
1195  * comparing the logical to physical address with the physical address.
1196  * Returns 0 on free, otherwise 1 if in use
1197  */
1198 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1199 {
1200         struct nvm_dev *dev = rrpc->dev;
1201         int offset;
1202         struct rrpc_addr *laddr;
1203         u64 paddr, pladdr;
1204
1205         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1206                 paddr = block_to_addr(rrpc, rblk) + offset;
1207
1208                 pladdr = rrpc->rev_trans_map[paddr].addr;
1209                 if (pladdr == ADDR_EMPTY)
1210                         continue;
1211
1212                 laddr = &rrpc->trans_map[pladdr];
1213
1214                 if (paddr == laddr->addr) {
1215                         laddr->rblk = rblk;
1216                 } else {
1217                         set_bit(offset, rblk->invalid_pages);
1218                         rblk->nr_invalid_pages++;
1219                 }
1220         }
1221 }
1222
1223 static int rrpc_blocks_init(struct rrpc *rrpc)
1224 {
1225         struct rrpc_lun *rlun;
1226         struct rrpc_block *rblk;
1227         int lun_iter, blk_iter;
1228
1229         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1230                 rlun = &rrpc->luns[lun_iter];
1231
1232                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1233                                                                 blk_iter++) {
1234                         rblk = &rlun->blocks[blk_iter];
1235                         rrpc_block_map_update(rrpc, rblk);
1236                 }
1237         }
1238
1239         return 0;
1240 }
1241
1242 static int rrpc_luns_configure(struct rrpc *rrpc)
1243 {
1244         struct rrpc_lun *rlun;
1245         struct rrpc_block *rblk;
1246         int i;
1247
1248         for (i = 0; i < rrpc->nr_luns; i++) {
1249                 rlun = &rrpc->luns[i];
1250
1251                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1252                 if (!rblk)
1253                         goto err;
1254
1255                 rrpc_set_lun_cur(rlun, rblk);
1256
1257                 /* Emergency gc block */
1258                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1259                 if (!rblk)
1260                         goto err;
1261                 rlun->gc_cur = rblk;
1262         }
1263
1264         return 0;
1265 err:
1266         rrpc_put_blks(rrpc);
1267         return -EINVAL;
1268 }
1269
1270 static struct nvm_tgt_type tt_rrpc;
1271
1272 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1273                                                 int lun_begin, int lun_end)
1274 {
1275         struct request_queue *bqueue = dev->q;
1276         struct request_queue *tqueue = tdisk->queue;
1277         struct rrpc *rrpc;
1278         int ret;
1279
1280         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1281                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1282                                                         dev->identity.dom);
1283                 return ERR_PTR(-EINVAL);
1284         }
1285
1286         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1287         if (!rrpc)
1288                 return ERR_PTR(-ENOMEM);
1289
1290         rrpc->instance.tt = &tt_rrpc;
1291         rrpc->dev = dev;
1292         rrpc->disk = tdisk;
1293
1294         bio_list_init(&rrpc->requeue_bios);
1295         spin_lock_init(&rrpc->bio_lock);
1296         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1297
1298         rrpc->nr_luns = lun_end - lun_begin + 1;
1299
1300         /* simple round-robin strategy */
1301         atomic_set(&rrpc->next_lun, -1);
1302
1303         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1304         if (ret) {
1305                 pr_err("nvm: rrpc: could not initialize luns\n");
1306                 goto err;
1307         }
1308
1309         rrpc->poffset = dev->sec_per_lun * lun_begin;
1310         rrpc->lun_offset = lun_begin;
1311
1312         ret = rrpc_core_init(rrpc);
1313         if (ret) {
1314                 pr_err("nvm: rrpc: could not initialize core\n");
1315                 goto err;
1316         }
1317
1318         ret = rrpc_map_init(rrpc);
1319         if (ret) {
1320                 pr_err("nvm: rrpc: could not initialize maps\n");
1321                 goto err;
1322         }
1323
1324         ret = rrpc_blocks_init(rrpc);
1325         if (ret) {
1326                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1327                 goto err;
1328         }
1329
1330         ret = rrpc_luns_configure(rrpc);
1331         if (ret) {
1332                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1333                 goto err;
1334         }
1335
1336         ret = rrpc_gc_init(rrpc);
1337         if (ret) {
1338                 pr_err("nvm: rrpc: could not initialize gc\n");
1339                 goto err;
1340         }
1341
1342         /* inherit the size from the underlying device */
1343         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1344         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1345
1346         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1347                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1348
1349         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1350
1351         return rrpc;
1352 err:
1353         rrpc_free(rrpc);
1354         return ERR_PTR(ret);
1355 }
1356
1357 /* round robin, page-based FTL, and cost-based GC */
1358 static struct nvm_tgt_type tt_rrpc = {
1359         .name           = "rrpc",
1360         .version        = {1, 0, 0},
1361
1362         .make_rq        = rrpc_make_rq,
1363         .capacity       = rrpc_capacity,
1364         .end_io         = rrpc_end_io,
1365
1366         .init           = rrpc_init,
1367         .exit           = rrpc_exit,
1368 };
1369
1370 static int __init rrpc_module_init(void)
1371 {
1372         return nvm_register_target(&tt_rrpc);
1373 }
1374
1375 static void rrpc_module_exit(void)
1376 {
1377         nvm_unregister_target(&tt_rrpc);
1378 }
1379
1380 module_init(rrpc_module_init);
1381 module_exit(rrpc_module_exit);
1382 MODULE_LICENSE("GPL v2");
1383 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");