drivers/lightnvm/rrpc.c

   1 /*
   2  * Copyright (C) 2015 IT University of Copenhagen
   3  * Initial release: Matias Bjorling <m@bjorling.me>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License version
   7  * 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
  15  */
  16
  17 #include "rrpc.h"
  18
  19 static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
  20 static DECLARE_RWSEM(rrpc_lock);
  21
  22 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
  23                                 struct nvm_rq *rqd, unsigned long flags);
  24
  25 #define rrpc_for_each_lun(rrpc, rlun, i) \
  26                 for ((i) = 0, rlun = &(rrpc)->luns[0]; \
  27                         (i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)])
  28
  29 static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
  30 {
  31         struct rrpc_block *rblk = a->rblk;
  32         unsigned int pg_offset;
  33
  34         lockdep_assert_held(&rrpc->rev_lock);
  35
  36         if (a->addr == ADDR_EMPTY || !rblk)
  37                 return;
  38
  39         spin_lock(&rblk->lock);
  40
  41         div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset);
  42         WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
  43         rblk->nr_invalid_pages++;
  44
  45         spin_unlock(&rblk->lock);
  46
  47         rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY;
  48 }
  49
  50 static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
  51                                                                 unsigned len)
  52 {
  53         sector_t i;
  54
  55         spin_lock(&rrpc->rev_lock);
  56         for (i = slba; i < slba + len; i++) {
  57                 struct rrpc_addr *gp = &rrpc->trans_map[i];
  58
  59                 rrpc_page_invalidate(rrpc, gp);
  60                 gp->rblk = NULL;
  61         }
  62         spin_unlock(&rrpc->rev_lock);
  63 }
  64
  65 static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc,
  66                                         sector_t laddr, unsigned int pages)
  67 {
  68         struct nvm_rq *rqd;
  69         struct rrpc_inflight_rq *inf;
  70
  71         rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC);
  72         if (!rqd)
  73                 return ERR_PTR(-ENOMEM);
  74
  75         inf = rrpc_get_inflight_rq(rqd);
  76         if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) {
  77                 mempool_free(rqd, rrpc->rq_pool);
  78                 return NULL;
  79         }
  80
  81         return rqd;
  82 }
  83
  84 static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd)
  85 {
  86         struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd);
  87
  88         rrpc_unlock_laddr(rrpc, inf);
  89
  90         mempool_free(rqd, rrpc->rq_pool);
  91 }
  92
  93 static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)
  94 {
  95         sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
  96         sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
  97         struct nvm_rq *rqd;
  98
  99         do {
 100                 rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
 101                 schedule();
 102         } while (!rqd);
 103
 104         if (IS_ERR(rqd)) {
 105                 pr_err("rrpc: unable to acquire inflight IO\n");
 106                 bio_io_error(bio);
 107                 return;
 108         }
 109
 110         rrpc_invalidate_range(rrpc, slba, len);
 111         rrpc_inflight_laddr_release(rrpc, rqd);
 112 }
 113
 114 static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
 115 {
 116         return (rblk->next_page == rrpc->dev->pgs_per_blk);
 117 }
 118
 119 static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 120 {
 121         struct nvm_block *blk = rblk->parent;
 122
 123         return blk->id * rrpc->dev->pgs_per_blk;
 124 }
 125
 126 static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
 127                                                         struct ppa_addr r)
 128 {
 129         struct ppa_addr l;
 130         int secs, pgs, blks, luns;
 131         sector_t ppa = r.ppa;
 132
 133         l.ppa = 0;
 134
 135         div_u64_rem(ppa, dev->sec_per_pg, &secs);
 136         l.g.sec = secs;
 137
 138         sector_div(ppa, dev->sec_per_pg);
 139         div_u64_rem(ppa, dev->sec_per_blk, &pgs);
 140         l.g.pg = pgs;
 141
 142         sector_div(ppa, dev->pgs_per_blk);
 143         div_u64_rem(ppa, dev->blks_per_lun, &blks);
 144         l.g.blk = blks;
 145
 146         sector_div(ppa, dev->blks_per_lun);
 147         div_u64_rem(ppa, dev->luns_per_chnl, &luns);
 148         l.g.lun = luns;
 149
 150         sector_div(ppa, dev->luns_per_chnl);
 151         l.g.ch = ppa;
 152
 153         return l;
 154 }
 155
 156 static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
 157 {
 158         struct ppa_addr paddr;
 159
 160         paddr.ppa = addr;
 161         return linear_to_generic_addr(dev, paddr);
 162 }
 163
 164 /* requires lun->lock taken */
 165 static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
 166 {
 167         struct rrpc *rrpc = rlun->rrpc;
 168
 169         BUG_ON(!rblk);
 170
 171         if (rlun->cur) {
 172                 spin_lock(&rlun->cur->lock);
 173                 WARN_ON(!block_is_full(rrpc, rlun->cur));
 174                 spin_unlock(&rlun->cur->lock);
 175         }
 176         rlun->cur = rblk;
 177 }
 178
 179 static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 180                                                         unsigned long flags)
 181 {
 182         struct nvm_lun *lun = rlun->parent;
 183         struct nvm_block *blk;
 184         struct rrpc_block *rblk;
 185
 186         spin_lock(&lun->lock);
 187         blk = nvm_get_blk_unlocked(rrpc->dev, rlun->parent, flags);
 188         if (!blk) {
 189                 pr_err("nvm: rrpc: cannot get new block from media manager\n");
 190                 spin_unlock(&lun->lock);
 191                 return NULL;
 192         }
 193
 194         rblk = &rlun->blocks[blk->id];
 195         list_add_tail(&rblk->list, &rlun->open_list);
 196         spin_unlock(&lun->lock);
 197
 198         blk->priv = rblk;
 199         bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
 200         rblk->next_page = 0;
 201         rblk->nr_invalid_pages = 0;
 202         atomic_set(&rblk->data_cmnt_size, 0);
 203
 204         return rblk;
 205 }
 206
 207 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 208 {
 209         struct rrpc_lun *rlun = rblk->rlun;
 210         struct nvm_lun *lun = rlun->parent;
 211
 212         spin_lock(&lun->lock);
 213         nvm_put_blk_unlocked(rrpc->dev, rblk->parent);
 214         list_del(&rblk->list);
 215         spin_unlock(&lun->lock);
 216 }
 217
 218 static void rrpc_put_blks(struct rrpc *rrpc)
 219 {
 220         struct rrpc_lun *rlun;
 221         int i;
 222
 223         for (i = 0; i < rrpc->nr_luns; i++) {
 224                 rlun = &rrpc->luns[i];
 225                 if (rlun->cur)
 226                         rrpc_put_blk(rrpc, rlun->cur);
 227                 if (rlun->gc_cur)
 228                         rrpc_put_blk(rrpc, rlun->gc_cur);
 229         }
 230 }
 231
 232 static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
 233 {
 234         int next = atomic_inc_return(&rrpc->next_lun);
 235
 236         return &rrpc->luns[next % rrpc->nr_luns];
 237 }
 238
 239 static void rrpc_gc_kick(struct rrpc *rrpc)
 240 {
 241         struct rrpc_lun *rlun;
 242         unsigned int i;
 243
 244         for (i = 0; i < rrpc->nr_luns; i++) {
 245                 rlun = &rrpc->luns[i];
 246                 queue_work(rrpc->krqd_wq, &rlun->ws_gc);
 247         }
 248 }
 249
 250 /*
 251  * timed GC every interval.
 252  */
 253 static void rrpc_gc_timer(unsigned long data)
 254 {
 255         struct rrpc *rrpc = (struct rrpc *)data;
 256
 257         rrpc_gc_kick(rrpc);
 258         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
 259 }
 260
 261 static void rrpc_end_sync_bio(struct bio *bio)
 262 {
 263         struct completion *waiting = bio->bi_private;
 264
 265         if (bio->bi_error)
 266                 pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
 267
 268         complete(waiting);
 269 }
 270
 271 /*
 272  * rrpc_move_valid_pages -- migrate live data off the block
 273  * @rrpc: the 'rrpc' structure
 274  * @block: the block from which to migrate live pages
 275  *
 276  * Description:
 277  *   GC algorithms may call this function to migrate remaining live
 278  *   pages off the block prior to erasing it. This function blocks
 279  *   further execution until the operation is complete.
 280  */
 281 static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 282 {
 283         struct request_queue *q = rrpc->dev->q;
 284         struct rrpc_rev_addr *rev;
 285         struct nvm_rq *rqd;
 286         struct bio *bio;
 287         struct page *page;
 288         int slot;
 289         int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
 290         u64 phys_addr;
 291         DECLARE_COMPLETION_ONSTACK(wait);
 292
 293         if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
 294                 return 0;
 295
 296         bio = bio_alloc(GFP_NOIO, 1);
 297         if (!bio) {
 298                 pr_err("nvm: could not alloc bio to gc\n");
 299                 return -ENOMEM;
 300         }
 301
 302         page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
 303         if (!page) {
 304                 bio_put(bio);
 305                 return -ENOMEM;
 306         }
 307
 308         while ((slot = find_first_zero_bit(rblk->invalid_pages,
 309                                             nr_pgs_per_blk)) < nr_pgs_per_blk) {
 310
 311                 /* Lock laddr */
 312                 phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
 313
 314 try:
 315                 spin_lock(&rrpc->rev_lock);
 316                 /* Get logical address from physical to logical table */
 317                 rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
 318                 /* already updated by previous regular write */
 319                 if (rev->addr == ADDR_EMPTY) {
 320                         spin_unlock(&rrpc->rev_lock);
 321                         continue;
 322                 }
 323
 324                 rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
 325                 if (IS_ERR_OR_NULL(rqd)) {
 326                         spin_unlock(&rrpc->rev_lock);
 327                         schedule();
 328                         goto try;
 329                 }
 330
 331                 spin_unlock(&rrpc->rev_lock);
 332
 333                 /* Perform read to do GC */
 334                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 335                 bio->bi_rw = READ;
 336                 bio->bi_private = &wait;
 337                 bio->bi_end_io = rrpc_end_sync_bio;
 338
 339                 /* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
 340                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 341
 342                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 343                         pr_err("rrpc: gc read failed.\n");
 344                         rrpc_inflight_laddr_release(rrpc, rqd);
 345                         goto finished;
 346                 }
 347                 wait_for_completion_io(&wait);
 348                 if (bio->bi_error) {
 349                         rrpc_inflight_laddr_release(rrpc, rqd);
 350                         goto finished;
 351                 }
 352
 353                 bio_reset(bio);
 354                 reinit_completion(&wait);
 355
 356                 bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
 357                 bio->bi_rw = WRITE;
 358                 bio->bi_private = &wait;
 359                 bio->bi_end_io = rrpc_end_sync_bio;
 360
 361                 bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
 362
 363                 /* turn the command around and write the data back to a new
 364                  * address
 365                  */
 366                 if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
 367                         pr_err("rrpc: gc write failed.\n");
 368                         rrpc_inflight_laddr_release(rrpc, rqd);
 369                         goto finished;
 370                 }
 371                 wait_for_completion_io(&wait);
 372
 373                 rrpc_inflight_laddr_release(rrpc, rqd);
 374                 if (bio->bi_error)
 375                         goto finished;
 376
 377                 bio_reset(bio);
 378         }
 379
 380 finished:
 381         mempool_free(page, rrpc->page_pool);
 382         bio_put(bio);
 383
 384         if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
 385                 pr_err("nvm: failed to garbage collect block\n");
 386                 return -EIO;
 387         }
 388
 389         return 0;
 390 }
 391
 392 static void rrpc_block_gc(struct work_struct *work)
 393 {
 394         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 395                                                                         ws_gc);
 396         struct rrpc *rrpc = gcb->rrpc;
 397         struct rrpc_block *rblk = gcb->rblk;
 398         struct nvm_dev *dev = rrpc->dev;
 399         struct nvm_lun *lun = rblk->parent->lun;
 400         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 401
 402         mempool_free(gcb, rrpc->gcb_pool);
 403         pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
 404
 405         if (rrpc_move_valid_pages(rrpc, rblk))
 406                 goto put_back;
 407
 408         if (nvm_erase_blk(dev, rblk->parent))
 409                 goto put_back;
 410
 411         rrpc_put_blk(rrpc, rblk);
 412
 413         return;
 414
 415 put_back:
 416         spin_lock(&rlun->lock);
 417         list_add_tail(&rblk->prio, &rlun->prio_list);
 418         spin_unlock(&rlun->lock);
 419 }
 420
 421 /* the block with highest number of invalid pages, will be in the beginning
 422  * of the list
 423  */
 424 static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
 425                                                         struct rrpc_block *rb)
 426 {
 427         if (ra->nr_invalid_pages == rb->nr_invalid_pages)
 428                 return ra;
 429
 430         return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
 431 }
 432
 433 /* linearly find the block with highest number of invalid pages
 434  * requires lun->lock
 435  */
 436 static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
 437 {
 438         struct list_head *prio_list = &rlun->prio_list;
 439         struct rrpc_block *rblock, *max;
 440
 441         BUG_ON(list_empty(prio_list));
 442
 443         max = list_first_entry(prio_list, struct rrpc_block, prio);
 444         list_for_each_entry(rblock, prio_list, prio)
 445                 max = rblock_max_invalid(max, rblock);
 446
 447         return max;
 448 }
 449
 450 static void rrpc_lun_gc(struct work_struct *work)
 451 {
 452         struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
 453         struct rrpc *rrpc = rlun->rrpc;
 454         struct nvm_lun *lun = rlun->parent;
 455         struct rrpc_block_gc *gcb;
 456         unsigned int nr_blocks_need;
 457
 458         nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
 459
 460         if (nr_blocks_need < rrpc->nr_luns)
 461                 nr_blocks_need = rrpc->nr_luns;
 462
 463         spin_lock(&rlun->lock);
 464         while (nr_blocks_need > lun->nr_free_blocks &&
 465                                         !list_empty(&rlun->prio_list)) {
 466                 struct rrpc_block *rblock = block_prio_find_max(rlun);
 467                 struct nvm_block *block = rblock->parent;
 468
 469                 if (!rblock->nr_invalid_pages)
 470                         break;
 471
 472                 gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 473                 if (!gcb)
 474                         break;
 475
 476                 list_del_init(&rblock->prio);
 477
 478                 BUG_ON(!block_is_full(rrpc, rblock));
 479
 480                 pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
 481
 482                 gcb->rrpc = rrpc;
 483                 gcb->rblk = rblock;
 484                 INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
 485
 486                 queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 487
 488                 nr_blocks_need--;
 489         }
 490         spin_unlock(&rlun->lock);
 491
 492         /* TODO: Hint that request queue can be started again */
 493 }
 494
 495 static void rrpc_gc_queue(struct work_struct *work)
 496 {
 497         struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
 498                                                                         ws_gc);
 499         struct rrpc *rrpc = gcb->rrpc;
 500         struct rrpc_block *rblk = gcb->rblk;
 501         struct nvm_lun *lun = rblk->parent->lun;
 502         struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
 503
 504         spin_lock(&rlun->lock);
 505         list_add_tail(&rblk->prio, &rlun->prio_list);
 506         spin_unlock(&rlun->lock);
 507
 508         mempool_free(gcb, rrpc->gcb_pool);
 509         pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
 510                                                         rblk->parent->id);
 511 }
 512
 513 static const struct block_device_operations rrpc_fops = {
 514         .owner          = THIS_MODULE,
 515 };
 516
 517 static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
 518 {
 519         unsigned int i;
 520         struct rrpc_lun *rlun, *max_free;
 521
 522         if (!is_gc)
 523                 return get_next_lun(rrpc);
 524
 525         /* during GC, we don't care about RR, instead we want to make
 526          * sure that we maintain evenness between the block luns.
 527          */
 528         max_free = &rrpc->luns[0];
 529         /* prevent GC-ing lun from devouring pages of a lun with
 530          * little free blocks. We don't take the lock as we only need an
 531          * estimate.
 532          */
 533         rrpc_for_each_lun(rrpc, rlun, i) {
 534                 if (rlun->parent->nr_free_blocks >
 535                                         max_free->parent->nr_free_blocks)
 536                         max_free = rlun;
 537         }
 538
 539         return max_free;
 540 }
 541
 542 static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 543                                         struct rrpc_block *rblk, u64 paddr)
 544 {
 545         struct rrpc_addr *gp;
 546         struct rrpc_rev_addr *rev;
 547
 548         BUG_ON(laddr >= rrpc->nr_pages);
 549
 550         gp = &rrpc->trans_map[laddr];
 551         spin_lock(&rrpc->rev_lock);
 552         if (gp->rblk)
 553                 rrpc_page_invalidate(rrpc, gp);
 554
 555         gp->addr = paddr;
 556         gp->rblk = rblk;
 557
 558         rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
 559         rev->addr = laddr;
 560         spin_unlock(&rrpc->rev_lock);
 561
 562         return gp;
 563 }
 564
 565 static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 566 {
 567         u64 addr = ADDR_EMPTY;
 568
 569         spin_lock(&rblk->lock);
 570         if (block_is_full(rrpc, rblk))
 571                 goto out;
 572
 573         addr = block_to_addr(rrpc, rblk) + rblk->next_page;
 574
 575         rblk->next_page++;
 576 out:
 577         spin_unlock(&rblk->lock);
 578         return addr;
 579 }
 580
 581 /* Simple round-robin Logical to physical address translation.
 582  *
 583  * Retrieve the mapping using the active append point. Then update the ap for
 584  * the next write to the disk.
 585  *
 586  * Returns rrpc_addr with the physical address and block. Remember to return to
 587  * rrpc->addr_cache when request is finished.
 588  */
 589 static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 590                                                                 int is_gc)
 591 {
 592         struct rrpc_lun *rlun;
 593         struct rrpc_block *rblk;
 594         struct nvm_lun *lun;
 595         u64 paddr;
 596
 597         rlun = rrpc_get_lun_rr(rrpc, is_gc);
 598         lun = rlun->parent;
 599
 600         if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
 601                 return NULL;
 602
 603         spin_lock(&rlun->lock);
 604
 605         rblk = rlun->cur;
 606 retry:
 607         paddr = rrpc_alloc_addr(rrpc, rblk);
 608
 609         if (paddr == ADDR_EMPTY) {
 610                 rblk = rrpc_get_blk(rrpc, rlun, 0);
 611                 if (rblk) {
 612                         rrpc_set_lun_cur(rlun, rblk);
 613                         goto retry;
 614                 }
 615
 616                 if (is_gc) {
 617                         /* retry from emergency gc block */
 618                         paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 619                         if (paddr == ADDR_EMPTY) {
 620                                 rblk = rrpc_get_blk(rrpc, rlun, 1);
 621                                 if (!rblk) {
 622                                         pr_err("rrpc: no more blocks");
 623                                         goto err;
 624                                 }
 625
 626                                 rlun->gc_cur = rblk;
 627                                 paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
 628                         }
 629                         rblk = rlun->gc_cur;
 630                 }
 631         }
 632
 633         spin_unlock(&rlun->lock);
 634         return rrpc_update_map(rrpc, laddr, rblk, paddr);
 635 err:
 636         spin_unlock(&rlun->lock);
 637         return NULL;
 638 }
 639
 640 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
 641 {
 642         struct rrpc_block_gc *gcb;
 643
 644         gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
 645         if (!gcb) {
 646                 pr_err("rrpc: unable to queue block for gc.");
 647                 return;
 648         }
 649
 650         gcb->rrpc = rrpc;
 651         gcb->rblk = rblk;
 652
 653         INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
 654         queue_work(rrpc->kgc_wq, &gcb->ws_gc);
 655 }
 656
 657 static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
 658                                                 sector_t laddr, uint8_t npages)
 659 {
 660         struct rrpc_addr *p;
 661         struct rrpc_block *rblk;
 662         struct nvm_lun *lun;
 663         int cmnt_size, i;
 664
 665         for (i = 0; i < npages; i++) {
 666                 p = &rrpc->trans_map[laddr + i];
 667                 rblk = p->rblk;
 668                 lun = rblk->parent->lun;
 669
 670                 cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
 671                 if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk)) {
 672                         struct nvm_block *blk = rblk->parent;
 673                         struct rrpc_lun *rlun = rblk->rlun;
 674
 675                         spin_lock(&lun->lock);
 676                         lun->nr_open_blocks--;
 677                         lun->nr_closed_blocks++;
 678                         blk->state &= ~NVM_BLK_ST_OPEN;
 679                         blk->state |= NVM_BLK_ST_CLOSED;
 680                         list_move_tail(&rblk->list, &rlun->closed_list);
 681                         spin_unlock(&lun->lock);
 682
 683                         rrpc_run_gc(rrpc, rblk);
 684                 }
 685         }
 686 }
 687
 688 static void rrpc_end_io(struct nvm_rq *rqd)
 689 {
 690         struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
 691         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 692         uint8_t npages = rqd->nr_pages;
 693         sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
 694
 695         if (bio_data_dir(rqd->bio) == WRITE)
 696                 rrpc_end_io_write(rrpc, rrqd, laddr, npages);
 697
 698         bio_put(rqd->bio);
 699
 700         if (rrqd->flags & NVM_IOTYPE_GC)
 701                 return;
 702
 703         rrpc_unlock_rq(rrpc, rqd);
 704
 705         if (npages > 1)
 706                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 707         if (rqd->metadata)
 708                 nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
 709
 710         mempool_free(rqd, rrpc->rq_pool);
 711 }
 712
 713 static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 714                         struct nvm_rq *rqd, unsigned long flags, int npages)
 715 {
 716         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 717         struct rrpc_addr *gp;
 718         sector_t laddr = rrpc_get_laddr(bio);
 719         int is_gc = flags & NVM_IOTYPE_GC;
 720         int i;
 721
 722         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 723                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 724                 return NVM_IO_REQUEUE;
 725         }
 726
 727         for (i = 0; i < npages; i++) {
 728                 /* We assume that mapping occurs at 4KB granularity */
 729                 BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
 730                 gp = &rrpc->trans_map[laddr + i];
 731
 732                 if (gp->rblk) {
 733                         rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 734                                                                 gp->addr);
 735                 } else {
 736                         BUG_ON(is_gc);
 737                         rrpc_unlock_laddr(rrpc, r);
 738                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 739                                                         rqd->dma_ppa_list);
 740                         return NVM_IO_DONE;
 741                 }
 742         }
 743
 744         rqd->opcode = NVM_OP_HBREAD;
 745
 746         return NVM_IO_OK;
 747 }
 748
 749 static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 750                                                         unsigned long flags)
 751 {
 752         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 753         int is_gc = flags & NVM_IOTYPE_GC;
 754         sector_t laddr = rrpc_get_laddr(bio);
 755         struct rrpc_addr *gp;
 756
 757         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 758                 return NVM_IO_REQUEUE;
 759
 760         BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
 761         gp = &rrpc->trans_map[laddr];
 762
 763         if (gp->rblk) {
 764                 rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
 765         } else {
 766                 BUG_ON(is_gc);
 767                 rrpc_unlock_rq(rrpc, rqd);
 768                 return NVM_IO_DONE;
 769         }
 770
 771         rqd->opcode = NVM_OP_HBREAD;
 772         rrqd->addr = gp;
 773
 774         return NVM_IO_OK;
 775 }
 776
 777 static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 778                         struct nvm_rq *rqd, unsigned long flags, int npages)
 779 {
 780         struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
 781         struct rrpc_addr *p;
 782         sector_t laddr = rrpc_get_laddr(bio);
 783         int is_gc = flags & NVM_IOTYPE_GC;
 784         int i;
 785
 786         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
 787                 nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
 788                 return NVM_IO_REQUEUE;
 789         }
 790
 791         for (i = 0; i < npages; i++) {
 792                 /* We assume that mapping occurs at 4KB granularity */
 793                 p = rrpc_map_page(rrpc, laddr + i, is_gc);
 794                 if (!p) {
 795                         BUG_ON(is_gc);
 796                         rrpc_unlock_laddr(rrpc, r);
 797                         nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
 798                                                         rqd->dma_ppa_list);
 799                         rrpc_gc_kick(rrpc);
 800                         return NVM_IO_REQUEUE;
 801                 }
 802
 803                 rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
 804                                                                 p->addr);
 805         }
 806
 807         rqd->opcode = NVM_OP_HBWRITE;
 808
 809         return NVM_IO_OK;
 810 }
 811
 812 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 813                                 struct nvm_rq *rqd, unsigned long flags)
 814 {
 815         struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
 816         struct rrpc_addr *p;
 817         int is_gc = flags & NVM_IOTYPE_GC;
 818         sector_t laddr = rrpc_get_laddr(bio);
 819
 820         if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
 821                 return NVM_IO_REQUEUE;
 822
 823         p = rrpc_map_page(rrpc, laddr, is_gc);
 824         if (!p) {
 825                 BUG_ON(is_gc);
 826                 rrpc_unlock_rq(rrpc, rqd);
 827                 rrpc_gc_kick(rrpc);
 828                 return NVM_IO_REQUEUE;
 829         }
 830
 831         rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
 832         rqd->opcode = NVM_OP_HBWRITE;
 833         rrqd->addr = p;
 834
 835         return NVM_IO_OK;
 836 }
 837
 838 static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
 839                         struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
 840 {
 841         if (npages > 1) {
 842                 rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
 843                                                         &rqd->dma_ppa_list);
 844                 if (!rqd->ppa_list) {
 845                         pr_err("rrpc: not able to allocate ppa list\n");
 846                         return NVM_IO_ERR;
 847                 }
 848
 849                 if (bio_rw(bio) == WRITE)
 850                         return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
 851                                                                         npages);
 852
 853                 return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
 854         }
 855
 856         if (bio_rw(bio) == WRITE)
 857                 return rrpc_write_rq(rrpc, bio, rqd, flags);
 858
 859         return rrpc_read_rq(rrpc, bio, rqd, flags);
 860 }
 861
 862 static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 863                                 struct nvm_rq *rqd, unsigned long flags)
 864 {
 865         int err;
 866         struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
 867         uint8_t nr_pages = rrpc_get_pages(bio);
 868         int bio_size = bio_sectors(bio) << 9;
 869
 870         if (bio_size < rrpc->dev->sec_size)
 871                 return NVM_IO_ERR;
 872         else if (bio_size > rrpc->dev->max_rq_size)
 873                 return NVM_IO_ERR;
 874
 875         err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
 876         if (err)
 877                 return err;
 878
 879         bio_get(bio);
 880         rqd->bio = bio;
 881         rqd->ins = &rrpc->instance;
 882         rqd->nr_pages = nr_pages;
 883         rrq->flags = flags;
 884
 885         err = nvm_submit_io(rrpc->dev, rqd);
 886         if (err) {
 887                 pr_err("rrpc: I/O submission failed: %d\n", err);
 888                 bio_put(bio);
 889                 if (!(flags & NVM_IOTYPE_GC)) {
 890                         rrpc_unlock_rq(rrpc, rqd);
 891                         if (rqd->nr_pages > 1)
 892                                 nvm_dev_dma_free(rrpc->dev,
 893                         rqd->ppa_list, rqd->dma_ppa_list);
 894                 }
 895                 return NVM_IO_ERR;
 896         }
 897
 898         return NVM_IO_OK;
 899 }
 900
 901 static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
 902 {
 903         struct rrpc *rrpc = q->queuedata;
 904         struct nvm_rq *rqd;
 905         int err;
 906
 907         if (bio->bi_rw & REQ_DISCARD) {
 908                 rrpc_discard(rrpc, bio);
 909                 return BLK_QC_T_NONE;
 910         }
 911
 912         rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
 913         if (!rqd) {
 914                 pr_err_ratelimited("rrpc: not able to queue bio.");
 915                 bio_io_error(bio);
 916                 return BLK_QC_T_NONE;
 917         }
 918         memset(rqd, 0, sizeof(struct nvm_rq));
 919
 920         err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
 921         switch (err) {
 922         case NVM_IO_OK:
 923                 return BLK_QC_T_NONE;
 924         case NVM_IO_ERR:
 925                 bio_io_error(bio);
 926                 break;
 927         case NVM_IO_DONE:
 928                 bio_endio(bio);
 929                 break;
 930         case NVM_IO_REQUEUE:
 931                 spin_lock(&rrpc->bio_lock);
 932                 bio_list_add(&rrpc->requeue_bios, bio);
 933                 spin_unlock(&rrpc->bio_lock);
 934                 queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
 935                 break;
 936         }
 937
 938         mempool_free(rqd, rrpc->rq_pool);
 939         return BLK_QC_T_NONE;
 940 }
 941
 942 static void rrpc_requeue(struct work_struct *work)
 943 {
 944         struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
 945         struct bio_list bios;
 946         struct bio *bio;
 947
 948         bio_list_init(&bios);
 949
 950         spin_lock(&rrpc->bio_lock);
 951         bio_list_merge(&bios, &rrpc->requeue_bios);
 952         bio_list_init(&rrpc->requeue_bios);
 953         spin_unlock(&rrpc->bio_lock);
 954
 955         while ((bio = bio_list_pop(&bios)))
 956                 rrpc_make_rq(rrpc->disk->queue, bio);
 957 }
 958
 959 static void rrpc_gc_free(struct rrpc *rrpc)
 960 {
 961         struct rrpc_lun *rlun;
 962         int i;
 963
 964         if (rrpc->krqd_wq)
 965                 destroy_workqueue(rrpc->krqd_wq);
 966
 967         if (rrpc->kgc_wq)
 968                 destroy_workqueue(rrpc->kgc_wq);
 969
 970         if (!rrpc->luns)
 971                 return;
 972
 973         for (i = 0; i < rrpc->nr_luns; i++) {
 974                 rlun = &rrpc->luns[i];
 975
 976                 if (!rlun->blocks)
 977                         break;
 978                 vfree(rlun->blocks);
 979         }
 980 }
 981
 982 static int rrpc_gc_init(struct rrpc *rrpc)
 983 {
 984         rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
 985                                                                 rrpc->nr_luns);
 986         if (!rrpc->krqd_wq)
 987                 return -ENOMEM;
 988
 989         rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
 990         if (!rrpc->kgc_wq)
 991                 return -ENOMEM;
 992
 993         setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
 994
 995         return 0;
 996 }
 997
 998 static void rrpc_map_free(struct rrpc *rrpc)
 999 {
1000         vfree(rrpc->rev_trans_map);
1001         vfree(rrpc->trans_map);
1002 }
1003
1004 static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
1005 {
1006         struct rrpc *rrpc = (struct rrpc *)private;
1007         struct nvm_dev *dev = rrpc->dev;
1008         struct rrpc_addr *addr = rrpc->trans_map + slba;
1009         struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
1010         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
1011         u64 elba = slba + nlb;
1012         u64 i;
1013
1014         if (unlikely(elba > dev->total_pages)) {
1015                 pr_err("nvm: L2P data from device is out of bounds!\n");
1016                 return -EINVAL;
1017         }
1018
1019         for (i = 0; i < nlb; i++) {
1020                 u64 pba = le64_to_cpu(entries[i]);
1021                 /* LNVM treats address-spaces as silos, LBA and PBA are
1022                  * equally large and zero-indexed.
1023                  */
1024                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
1025                         pr_err("nvm: L2P data entry is out of bounds!\n");
1026                         return -EINVAL;
1027                 }
1028
1029                 /* Address zero is a special one. The first page on a disk is
1030                  * protected. As it often holds internal device boot
1031                  * information.
1032                  */
1033                 if (!pba)
1034                         continue;
1035
1036                 addr[i].addr = pba;
1037                 raddr[pba].addr = slba + i;
1038         }
1039
1040         return 0;
1041 }
1042
1043 static int rrpc_map_init(struct rrpc *rrpc)
1044 {
1045         struct nvm_dev *dev = rrpc->dev;
1046         sector_t i;
1047         int ret;
1048
1049         rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
1050         if (!rrpc->trans_map)
1051                 return -ENOMEM;
1052
1053         rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
1054                                                         * rrpc->nr_pages);
1055         if (!rrpc->rev_trans_map)
1056                 return -ENOMEM;
1057
1058         for (i = 0; i < rrpc->nr_pages; i++) {
1059                 struct rrpc_addr *p = &rrpc->trans_map[i];
1060                 struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
1061
1062                 p->addr = ADDR_EMPTY;
1063                 r->addr = ADDR_EMPTY;
1064         }
1065
1066         if (!dev->ops->get_l2p_tbl)
1067                 return 0;
1068
1069         /* Bring up the mapping table from device */
1070         ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
1071                                                         rrpc_l2p_update, rrpc);
1072         if (ret) {
1073                 pr_err("nvm: rrpc: could not read L2P table.\n");
1074                 return -EINVAL;
1075         }
1076
1077         return 0;
1078 }
1079
1080
1081 /* Minimum pages needed within a lun */
1082 #define PAGE_POOL_SIZE 16
1083 #define ADDR_POOL_SIZE 64
1084
1085 static int rrpc_core_init(struct rrpc *rrpc)
1086 {
1087         down_write(&rrpc_lock);
1088         if (!rrpc_gcb_cache) {
1089                 rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
1090                                 sizeof(struct rrpc_block_gc), 0, 0, NULL);
1091                 if (!rrpc_gcb_cache) {
1092                         up_write(&rrpc_lock);
1093                         return -ENOMEM;
1094                 }
1095
1096                 rrpc_rq_cache = kmem_cache_create("rrpc_rq",
1097                                 sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
1098                                 0, 0, NULL);
1099                 if (!rrpc_rq_cache) {
1100                         kmem_cache_destroy(rrpc_gcb_cache);
1101                         up_write(&rrpc_lock);
1102                         return -ENOMEM;
1103                 }
1104         }
1105         up_write(&rrpc_lock);
1106
1107         rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
1108         if (!rrpc->page_pool)
1109                 return -ENOMEM;
1110
1111         rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
1112                                                                 rrpc_gcb_cache);
1113         if (!rrpc->gcb_pool)
1114                 return -ENOMEM;
1115
1116         rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
1117         if (!rrpc->rq_pool)
1118                 return -ENOMEM;
1119
1120         spin_lock_init(&rrpc->inflights.lock);
1121         INIT_LIST_HEAD(&rrpc->inflights.reqs);
1122
1123         return 0;
1124 }
1125
1126 static void rrpc_core_free(struct rrpc *rrpc)
1127 {
1128         mempool_destroy(rrpc->page_pool);
1129         mempool_destroy(rrpc->gcb_pool);
1130         mempool_destroy(rrpc->rq_pool);
1131 }
1132
1133 static void rrpc_luns_free(struct rrpc *rrpc)
1134 {
1135         kfree(rrpc->luns);
1136 }
1137
1138 static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
1139 {
1140         struct nvm_dev *dev = rrpc->dev;
1141         struct rrpc_lun *rlun;
1142         int i, j;
1143
1144         if (dev->pgs_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
1145                 pr_err("rrpc: number of pages per block too high.");
1146                 return -EINVAL;
1147         }
1148
1149         spin_lock_init(&rrpc->rev_lock);
1150
1151         rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
1152                                                                 GFP_KERNEL);
1153         if (!rrpc->luns)
1154                 return -ENOMEM;
1155
1156         /* 1:1 mapping */
1157         for (i = 0; i < rrpc->nr_luns; i++) {
1158                 struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
1159
1160                 rlun = &rrpc->luns[i];
1161                 rlun->rrpc = rrpc;
1162                 rlun->parent = lun;
1163                 INIT_LIST_HEAD(&rlun->prio_list);
1164                 INIT_LIST_HEAD(&rlun->open_list);
1165                 INIT_LIST_HEAD(&rlun->closed_list);
1166
1167                 INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
1168                 spin_lock_init(&rlun->lock);
1169
1170                 rrpc->total_blocks += dev->blks_per_lun;
1171                 rrpc->nr_pages += dev->sec_per_lun;
1172
1173                 rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
1174                                                 rrpc->dev->blks_per_lun);
1175                 if (!rlun->blocks)
1176                         goto err;
1177
1178                 for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
1179                         struct rrpc_block *rblk = &rlun->blocks[j];
1180                         struct nvm_block *blk = &lun->blocks[j];
1181
1182                         rblk->parent = blk;
1183                         rblk->rlun = rlun;
1184                         INIT_LIST_HEAD(&rblk->prio);
1185                         spin_lock_init(&rblk->lock);
1186                 }
1187         }
1188
1189         return 0;
1190 err:
1191         return -ENOMEM;
1192 }
1193
1194 static void rrpc_free(struct rrpc *rrpc)
1195 {
1196         rrpc_gc_free(rrpc);
1197         rrpc_map_free(rrpc);
1198         rrpc_core_free(rrpc);
1199         rrpc_luns_free(rrpc);
1200
1201         kfree(rrpc);
1202 }
1203
1204 static void rrpc_exit(void *private)
1205 {
1206         struct rrpc *rrpc = private;
1207
1208         del_timer(&rrpc->gc_timer);
1209
1210         flush_workqueue(rrpc->krqd_wq);
1211         flush_workqueue(rrpc->kgc_wq);
1212
1213         rrpc_free(rrpc);
1214 }
1215
1216 static sector_t rrpc_capacity(void *private)
1217 {
1218         struct rrpc *rrpc = private;
1219         struct nvm_dev *dev = rrpc->dev;
1220         sector_t reserved, provisioned;
1221
1222         /* cur, gc, and two emergency blocks for each lun */
1223         reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
1224         provisioned = rrpc->nr_pages - reserved;
1225
1226         if (reserved > rrpc->nr_pages) {
1227                 pr_err("rrpc: not enough space available to expose storage.\n");
1228                 return 0;
1229         }
1230
1231         sector_div(provisioned, 10);
1232         return provisioned * 9 * NR_PHY_IN_LOG;
1233 }
1234
1235 /*
1236  * Looks up the logical address from reverse trans map and check if its valid by
1237  * comparing the logical to physical address with the physical address.
1238  * Returns 0 on free, otherwise 1 if in use
1239  */
1240 static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
1241 {
1242         struct nvm_dev *dev = rrpc->dev;
1243         int offset;
1244         struct rrpc_addr *laddr;
1245         u64 paddr, pladdr;
1246
1247         for (offset = 0; offset < dev->pgs_per_blk; offset++) {
1248                 paddr = block_to_addr(rrpc, rblk) + offset;
1249
1250                 pladdr = rrpc->rev_trans_map[paddr].addr;
1251                 if (pladdr == ADDR_EMPTY)
1252                         continue;
1253
1254                 laddr = &rrpc->trans_map[pladdr];
1255
1256                 if (paddr == laddr->addr) {
1257                         laddr->rblk = rblk;
1258                 } else {
1259                         set_bit(offset, rblk->invalid_pages);
1260                         rblk->nr_invalid_pages++;
1261                 }
1262         }
1263 }
1264
1265 static int rrpc_blocks_init(struct rrpc *rrpc)
1266 {
1267         struct rrpc_lun *rlun;
1268         struct rrpc_block *rblk;
1269         int lun_iter, blk_iter;
1270
1271         for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
1272                 rlun = &rrpc->luns[lun_iter];
1273
1274                 for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
1275                                                                 blk_iter++) {
1276                         rblk = &rlun->blocks[blk_iter];
1277                         rrpc_block_map_update(rrpc, rblk);
1278                 }
1279         }
1280
1281         return 0;
1282 }
1283
1284 static int rrpc_luns_configure(struct rrpc *rrpc)
1285 {
1286         struct rrpc_lun *rlun;
1287         struct rrpc_block *rblk;
1288         int i;
1289
1290         for (i = 0; i < rrpc->nr_luns; i++) {
1291                 rlun = &rrpc->luns[i];
1292
1293                 rblk = rrpc_get_blk(rrpc, rlun, 0);
1294                 if (!rblk)
1295                         goto err;
1296
1297                 rrpc_set_lun_cur(rlun, rblk);
1298
1299                 /* Emergency gc block */
1300                 rblk = rrpc_get_blk(rrpc, rlun, 1);
1301                 if (!rblk)
1302                         goto err;
1303                 rlun->gc_cur = rblk;
1304         }
1305
1306         return 0;
1307 err:
1308         rrpc_put_blks(rrpc);
1309         return -EINVAL;
1310 }
1311
1312 static struct nvm_tgt_type tt_rrpc;
1313
1314 static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
1315                                                 int lun_begin, int lun_end)
1316 {
1317         struct request_queue *bqueue = dev->q;
1318         struct request_queue *tqueue = tdisk->queue;
1319         struct rrpc *rrpc;
1320         int ret;
1321
1322         if (!(dev->identity.dom & NVM_RSP_L2P)) {
1323                 pr_err("nvm: rrpc: device does not support l2p (%x)\n",
1324                                                         dev->identity.dom);
1325                 return ERR_PTR(-EINVAL);
1326         }
1327
1328         rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
1329         if (!rrpc)
1330                 return ERR_PTR(-ENOMEM);
1331
1332         rrpc->instance.tt = &tt_rrpc;
1333         rrpc->dev = dev;
1334         rrpc->disk = tdisk;
1335
1336         bio_list_init(&rrpc->requeue_bios);
1337         spin_lock_init(&rrpc->bio_lock);
1338         INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
1339
1340         rrpc->nr_luns = lun_end - lun_begin + 1;
1341
1342         /* simple round-robin strategy */
1343         atomic_set(&rrpc->next_lun, -1);
1344
1345         ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
1346         if (ret) {
1347                 pr_err("nvm: rrpc: could not initialize luns\n");
1348                 goto err;
1349         }
1350
1351         rrpc->poffset = dev->sec_per_lun * lun_begin;
1352         rrpc->lun_offset = lun_begin;
1353
1354         ret = rrpc_core_init(rrpc);
1355         if (ret) {
1356                 pr_err("nvm: rrpc: could not initialize core\n");
1357                 goto err;
1358         }
1359
1360         ret = rrpc_map_init(rrpc);
1361         if (ret) {
1362                 pr_err("nvm: rrpc: could not initialize maps\n");
1363                 goto err;
1364         }
1365
1366         ret = rrpc_blocks_init(rrpc);
1367         if (ret) {
1368                 pr_err("nvm: rrpc: could not initialize state for blocks\n");
1369                 goto err;
1370         }
1371
1372         ret = rrpc_luns_configure(rrpc);
1373         if (ret) {
1374                 pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
1375                 goto err;
1376         }
1377
1378         ret = rrpc_gc_init(rrpc);
1379         if (ret) {
1380                 pr_err("nvm: rrpc: could not initialize gc\n");
1381                 goto err;
1382         }
1383
1384         /* inherit the size from the underlying device */
1385         blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
1386         blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
1387
1388         pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
1389                         rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
1390
1391         mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
1392
1393         return rrpc;
1394 err:
1395         rrpc_free(rrpc);
1396         return ERR_PTR(ret);
1397 }
1398
1399 /* round robin, page-based FTL, and cost-based GC */
1400 static struct nvm_tgt_type tt_rrpc = {
1401         .name           = "rrpc",
1402         .version        = {1, 0, 0},
1403
1404         .make_rq        = rrpc_make_rq,
1405         .capacity       = rrpc_capacity,
1406         .end_io         = rrpc_end_io,
1407
1408         .init           = rrpc_init,
1409         .exit           = rrpc_exit,
1410 };
1411
1412 static int __init rrpc_module_init(void)
1413 {
1414         return nvm_register_target(&tt_rrpc);
1415 }
1416
1417 static void rrpc_module_exit(void)
1418 {
1419         nvm_unregister_target(&tt_rrpc);
1420 }
1421
1422 module_init(rrpc_module_init);
1423 module_exit(rrpc_module_exit);
1424 MODULE_LICENSE("GPL v2");
1425 MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");