drivers/lightnvm/gennvm.c

   1 /*
   2  * Copyright (C) 2015 Matias Bjorling <m@bjorling.me>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License version
   6  * 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
  16  * USA.
  17  *
  18  * Implementation of a generic nvm manager for Open-Channel SSDs.
  19  */
  20
  21 #include "gennvm.h"
  22
  23 static int gennvm_get_area(struct nvm_dev *dev, sector_t *lba, sector_t len)
  24 {
  25         struct gen_nvm *gn = dev->mp;
  26         struct gennvm_area *area, *prev, *next;
  27         sector_t begin = 0;
  28         sector_t max_sectors = (dev->sec_size * dev->total_secs) >> 9;
  29
  30         if (len > max_sectors)
  31                 return -EINVAL;
  32
  33         area = kmalloc(sizeof(struct gennvm_area), GFP_KERNEL);
  34         if (!area)
  35                 return -ENOMEM;
  36
  37         prev = NULL;
  38
  39         spin_lock(&dev->lock);
  40         list_for_each_entry(next, &gn->area_list, list) {
  41                 if (begin + len > next->begin) {
  42                         begin = next->end;
  43                         prev = next;
  44                         continue;
  45                 }
  46                 break;
  47         }
  48
  49         if ((begin + len) > max_sectors) {
  50                 spin_unlock(&dev->lock);
  51                 kfree(area);
  52                 return -EINVAL;
  53         }
  54
  55         area->begin = *lba = begin;
  56         area->end = begin + len;
  57
  58         if (prev) /* insert into sorted order */
  59                 list_add(&area->list, &prev->list);
  60         else
  61                 list_add(&area->list, &gn->area_list);
  62         spin_unlock(&dev->lock);
  63
  64         return 0;
  65 }
  66
  67 static void gennvm_put_area(struct nvm_dev *dev, sector_t begin)
  68 {
  69         struct gen_nvm *gn = dev->mp;
  70         struct gennvm_area *area;
  71
  72         spin_lock(&dev->lock);
  73         list_for_each_entry(area, &gn->area_list, list) {
  74                 if (area->begin != begin)
  75                         continue;
  76
  77                 list_del(&area->list);
  78                 spin_unlock(&dev->lock);
  79                 kfree(area);
  80                 return;
  81         }
  82         spin_unlock(&dev->lock);
  83 }
  84
  85 static void gennvm_blocks_free(struct nvm_dev *dev)
  86 {
  87         struct gen_nvm *gn = dev->mp;
  88         struct gen_lun *lun;
  89         int i;
  90
  91         gennvm_for_each_lun(gn, lun, i) {
  92                 if (!lun->vlun.blocks)
  93                         break;
  94                 vfree(lun->vlun.blocks);
  95         }
  96 }
  97
  98 static void gennvm_luns_free(struct nvm_dev *dev)
  99 {
 100         struct gen_nvm *gn = dev->mp;
 101
 102         kfree(gn->luns);
 103 }
 104
 105 static int gennvm_luns_init(struct nvm_dev *dev, struct gen_nvm *gn)
 106 {
 107         struct gen_lun *lun;
 108         int i;
 109
 110         gn->luns = kcalloc(dev->nr_luns, sizeof(struct gen_lun), GFP_KERNEL);
 111         if (!gn->luns)
 112                 return -ENOMEM;
 113
 114         gennvm_for_each_lun(gn, lun, i) {
 115                 spin_lock_init(&lun->vlun.lock);
 116                 INIT_LIST_HEAD(&lun->free_list);
 117                 INIT_LIST_HEAD(&lun->used_list);
 118                 INIT_LIST_HEAD(&lun->bb_list);
 119
 120                 lun->reserved_blocks = 2; /* for GC only */
 121                 lun->vlun.id = i;
 122                 lun->vlun.lun_id = i % dev->luns_per_chnl;
 123                 lun->vlun.chnl_id = i / dev->luns_per_chnl;
 124                 lun->vlun.nr_free_blocks = dev->blks_per_lun;
 125                 lun->vlun.nr_open_blocks = 0;
 126                 lun->vlun.nr_closed_blocks = 0;
 127                 lun->vlun.nr_bad_blocks = 0;
 128         }
 129         return 0;
 130 }
 131
 132 static int gennvm_block_bb(struct ppa_addr ppa, int nr_blocks, u8 *blks,
 133                                                                 void *private)
 134 {
 135         struct gen_nvm *gn = private;
 136         struct nvm_dev *dev = gn->dev;
 137         struct gen_lun *lun;
 138         struct nvm_block *blk;
 139         int i;
 140
 141         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
 142
 143         for (i = 0; i < nr_blocks; i++) {
 144                 if (blks[i] == 0)
 145                         continue;
 146
 147                 blk = &lun->vlun.blocks[i];
 148                 if (!blk) {
 149                         pr_err("gennvm: BB data is out of bounds.\n");
 150                         return -EINVAL;
 151                 }
 152
 153                 list_move_tail(&blk->list, &lun->bb_list);
 154                 lun->vlun.nr_bad_blocks++;
 155                 lun->vlun.nr_free_blocks--;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static int gennvm_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
 162 {
 163         struct nvm_dev *dev = private;
 164         struct gen_nvm *gn = dev->mp;
 165         u64 elba = slba + nlb;
 166         struct gen_lun *lun;
 167         struct nvm_block *blk;
 168         u64 i;
 169         int lun_id;
 170
 171         if (unlikely(elba > dev->total_secs)) {
 172                 pr_err("gennvm: L2P data from device is out of bounds!\n");
 173                 return -EINVAL;
 174         }
 175
 176         for (i = 0; i < nlb; i++) {
 177                 u64 pba = le64_to_cpu(entries[i]);
 178
 179                 if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
 180                         pr_err("gennvm: L2P data entry is out of bounds!\n");
 181                         return -EINVAL;
 182                 }
 183
 184                 /* Address zero is a special one. The first page on a disk is
 185                  * protected. It often holds internal device boot
 186                  * information.
 187                  */
 188                 if (!pba)
 189                         continue;
 190
 191                 /* resolve block from physical address */
 192                 lun_id = div_u64(pba, dev->sec_per_lun);
 193                 lun = &gn->luns[lun_id];
 194
 195                 /* Calculate block offset into lun */
 196                 pba = pba - (dev->sec_per_lun * lun_id);
 197                 blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
 198
 199                 if (!blk->state) {
 200                         /* at this point, we don't know anything about the
 201                          * block. It's up to the FTL on top to re-etablish the
 202                          * block state. The block is assumed to be open.
 203                          */
 204                         list_move_tail(&blk->list, &lun->used_list);
 205                         blk->state = NVM_BLK_ST_OPEN;
 206                         lun->vlun.nr_free_blocks--;
 207                         lun->vlun.nr_open_blocks++;
 208                 }
 209         }
 210
 211         return 0;
 212 }
 213
 214 static int gennvm_blocks_init(struct nvm_dev *dev, struct gen_nvm *gn)
 215 {
 216         struct gen_lun *lun;
 217         struct nvm_block *block;
 218         sector_t lun_iter, blk_iter, cur_block_id = 0;
 219         int ret;
 220
 221         gennvm_for_each_lun(gn, lun, lun_iter) {
 222                 lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
 223                                                         dev->blks_per_lun);
 224                 if (!lun->vlun.blocks)
 225                         return -ENOMEM;
 226
 227                 for (blk_iter = 0; blk_iter < dev->blks_per_lun; blk_iter++) {
 228                         block = &lun->vlun.blocks[blk_iter];
 229
 230                         INIT_LIST_HEAD(&block->list);
 231
 232                         block->lun = &lun->vlun;
 233                         block->id = cur_block_id++;
 234
 235                         /* First block is reserved for device */
 236                         if (unlikely(lun_iter == 0 && blk_iter == 0)) {
 237                                 lun->vlun.nr_free_blocks--;
 238                                 continue;
 239                         }
 240
 241                         list_add_tail(&block->list, &lun->free_list);
 242                 }
 243
 244                 if (dev->ops->get_bb_tbl) {
 245                         struct ppa_addr ppa;
 246
 247                         ppa.ppa = 0;
 248                         ppa.g.ch = lun->vlun.chnl_id;
 249                         ppa.g.lun = lun->vlun.id;
 250                         ppa = generic_to_dev_addr(dev, ppa);
 251
 252                         ret = dev->ops->get_bb_tbl(dev, ppa,
 253                                                 dev->blks_per_lun,
 254                                                 gennvm_block_bb, gn);
 255                         if (ret)
 256                                 pr_err("gennvm: could not read BB table\n");
 257                 }
 258         }
 259
 260         if ((dev->identity.dom & NVM_RSP_L2P) && dev->ops->get_l2p_tbl) {
 261                 ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_secs,
 262                                                         gennvm_block_map, dev);
 263                 if (ret) {
 264                         pr_err("gennvm: could not read L2P table.\n");
 265                         pr_warn("gennvm: default block initialization");
 266                 }
 267         }
 268
 269         return 0;
 270 }
 271
 272 static void gennvm_free(struct nvm_dev *dev)
 273 {
 274         gennvm_blocks_free(dev);
 275         gennvm_luns_free(dev);
 276         kfree(dev->mp);
 277         dev->mp = NULL;
 278 }
 279
 280 static int gennvm_register(struct nvm_dev *dev)
 281 {
 282         struct gen_nvm *gn;
 283         int ret;
 284
 285         if (!try_module_get(THIS_MODULE))
 286                 return -ENODEV;
 287
 288         gn = kzalloc(sizeof(struct gen_nvm), GFP_KERNEL);
 289         if (!gn)
 290                 return -ENOMEM;
 291
 292         gn->dev = dev;
 293         gn->nr_luns = dev->nr_luns;
 294         INIT_LIST_HEAD(&gn->area_list);
 295         dev->mp = gn;
 296
 297         ret = gennvm_luns_init(dev, gn);
 298         if (ret) {
 299                 pr_err("gennvm: could not initialize luns\n");
 300                 goto err;
 301         }
 302
 303         ret = gennvm_blocks_init(dev, gn);
 304         if (ret) {
 305                 pr_err("gennvm: could not initialize blocks\n");
 306                 goto err;
 307         }
 308
 309         return 1;
 310 err:
 311         gennvm_free(dev);
 312         module_put(THIS_MODULE);
 313         return ret;
 314 }
 315
 316 static void gennvm_unregister(struct nvm_dev *dev)
 317 {
 318         gennvm_free(dev);
 319         module_put(THIS_MODULE);
 320 }
 321
 322 static struct nvm_block *gennvm_get_blk_unlocked(struct nvm_dev *dev,
 323                                 struct nvm_lun *vlun, unsigned long flags)
 324 {
 325         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 326         struct nvm_block *blk = NULL;
 327         int is_gc = flags & NVM_IOTYPE_GC;
 328
 329         assert_spin_locked(&vlun->lock);
 330
 331         if (list_empty(&lun->free_list)) {
 332                 pr_err_ratelimited("gennvm: lun %u have no free pages available",
 333                                                                 lun->vlun.id);
 334                 goto out;
 335         }
 336
 337         if (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks)
 338                 goto out;
 339
 340         blk = list_first_entry(&lun->free_list, struct nvm_block, list);
 341         list_move_tail(&blk->list, &lun->used_list);
 342         blk->state = NVM_BLK_ST_OPEN;
 343
 344         lun->vlun.nr_free_blocks--;
 345         lun->vlun.nr_open_blocks++;
 346
 347 out:
 348         return blk;
 349 }
 350
 351 static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 352                                 struct nvm_lun *vlun, unsigned long flags)
 353 {
 354         struct nvm_block *blk;
 355
 356         spin_lock(&vlun->lock);
 357         blk = gennvm_get_blk_unlocked(dev, vlun, flags);
 358         spin_unlock(&vlun->lock);
 359         return blk;
 360 }
 361
 362 static void gennvm_put_blk_unlocked(struct nvm_dev *dev, struct nvm_block *blk)
 363 {
 364         struct nvm_lun *vlun = blk->lun;
 365         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 366
 367         assert_spin_locked(&vlun->lock);
 368
 369         if (blk->state & NVM_BLK_ST_OPEN) {
 370                 list_move_tail(&blk->list, &lun->free_list);
 371                 lun->vlun.nr_open_blocks--;
 372                 lun->vlun.nr_free_blocks++;
 373                 blk->state = NVM_BLK_ST_FREE;
 374         } else if (blk->state & NVM_BLK_ST_CLOSED) {
 375                 list_move_tail(&blk->list, &lun->free_list);
 376                 lun->vlun.nr_closed_blocks--;
 377                 lun->vlun.nr_free_blocks++;
 378                 blk->state = NVM_BLK_ST_FREE;
 379         } else if (blk->state & NVM_BLK_ST_BAD) {
 380                 list_move_tail(&blk->list, &lun->bb_list);
 381                 lun->vlun.nr_bad_blocks++;
 382                 blk->state = NVM_BLK_ST_BAD;
 383         } else {
 384                 WARN_ON_ONCE(1);
 385                 pr_err("gennvm: erroneous block type (%lu -> %u)\n",
 386                                                         blk->id, blk->state);
 387                 list_move_tail(&blk->list, &lun->bb_list);
 388                 lun->vlun.nr_bad_blocks++;
 389                 blk->state = NVM_BLK_ST_BAD;
 390         }
 391 }
 392
 393 static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 394 {
 395         struct nvm_lun *vlun = blk->lun;
 396
 397         spin_lock(&vlun->lock);
 398         gennvm_put_blk_unlocked(dev, blk);
 399         spin_unlock(&vlun->lock);
 400 }
 401
 402 static void gennvm_blk_set_type(struct nvm_dev *dev, struct ppa_addr *ppa,
 403                                                                 int type)
 404 {
 405         struct gen_nvm *gn = dev->mp;
 406         struct gen_lun *lun;
 407         struct nvm_block *blk;
 408
 409         if (unlikely(ppa->g.ch > dev->nr_chnls ||
 410                                         ppa->g.lun > dev->luns_per_chnl ||
 411                                         ppa->g.blk > dev->blks_per_lun)) {
 412                 WARN_ON_ONCE(1);
 413                 pr_err("gennvm: ppa broken (ch: %u > %u lun: %u > %u blk: %u > %u",
 414                                 ppa->g.ch, dev->nr_chnls,
 415                                 ppa->g.lun, dev->luns_per_chnl,
 416                                 ppa->g.blk, dev->blks_per_lun);
 417                 return;
 418         }
 419
 420         lun = &gn->luns[ppa->g.lun * ppa->g.ch];
 421         blk = &lun->vlun.blocks[ppa->g.blk];
 422
 423         /* will be moved to bb list on put_blk from target */
 424         blk->state = type;
 425 }
 426
 427 /* mark block bad. It is expected the target recover from the error. */
 428 static void gennvm_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
 429 {
 430         int i;
 431
 432         if (!dev->ops->set_bb_tbl)
 433                 return;
 434
 435         if (dev->ops->set_bb_tbl(dev, rqd, 1))
 436                 return;
 437
 438         nvm_addr_to_generic_mode(dev, rqd);
 439
 440         /* look up blocks and mark them as bad */
 441         if (rqd->nr_pages > 1)
 442                 for (i = 0; i < rqd->nr_pages; i++)
 443                         gennvm_blk_set_type(dev, &rqd->ppa_list[i],
 444                                                 NVM_BLK_ST_BAD);
 445         else
 446                 gennvm_blk_set_type(dev, &rqd->ppa_addr, NVM_BLK_ST_BAD);
 447 }
 448
 449 static void gennvm_end_io(struct nvm_rq *rqd)
 450 {
 451         struct nvm_tgt_instance *ins = rqd->ins;
 452
 453         switch (rqd->error) {
 454         case NVM_RSP_SUCCESS:
 455         case NVM_RSP_ERR_EMPTYPAGE:
 456                 break;
 457         case NVM_RSP_ERR_FAILWRITE:
 458                 gennvm_mark_blk_bad(rqd->dev, rqd);
 459         }
 460
 461         ins->tt->end_io(rqd);
 462 }
 463
 464 static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 465 {
 466         if (!dev->ops->submit_io)
 467                 return -ENODEV;
 468
 469         /* Convert address space */
 470         nvm_generic_to_addr_mode(dev, rqd);
 471
 472         rqd->dev = dev;
 473         rqd->end_io = gennvm_end_io;
 474         return dev->ops->submit_io(dev, rqd);
 475 }
 476
 477 static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 478                                                         unsigned long flags)
 479 {
 480         struct ppa_addr addr = block_to_ppa(dev, blk);
 481
 482         return nvm_erase_ppa(dev, &addr, 1);
 483 }
 484
 485 static int gennvm_reserve_lun(struct nvm_dev *dev, int lunid)
 486 {
 487         return test_and_set_bit(lunid, dev->lun_map);
 488 }
 489
 490 static void gennvm_release_lun(struct nvm_dev *dev, int lunid)
 491 {
 492         WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
 493 }
 494
 495 static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
 496 {
 497         struct gen_nvm *gn = dev->mp;
 498
 499         if (unlikely(lunid >= dev->nr_luns))
 500                 return NULL;
 501
 502         return &gn->luns[lunid].vlun;
 503 }
 504
 505 static void gennvm_lun_info_print(struct nvm_dev *dev)
 506 {
 507         struct gen_nvm *gn = dev->mp;
 508         struct gen_lun *lun;
 509         unsigned int i;
 510
 511
 512         gennvm_for_each_lun(gn, lun, i) {
 513                 spin_lock(&lun->vlun.lock);
 514
 515                 pr_info("%s: lun%8u\t%u\t%u\t%u\t%u\n",
 516                                 dev->name, i,
 517                                 lun->vlun.nr_free_blocks,
 518                                 lun->vlun.nr_open_blocks,
 519                                 lun->vlun.nr_closed_blocks,
 520                                 lun->vlun.nr_bad_blocks);
 521
 522                 spin_unlock(&lun->vlun.lock);
 523         }
 524 }
 525
 526 static struct nvmm_type gennvm = {
 527         .name                   = "gennvm",
 528         .version                = {0, 1, 0},
 529
 530         .register_mgr           = gennvm_register,
 531         .unregister_mgr         = gennvm_unregister,
 532
 533         .get_blk_unlocked       = gennvm_get_blk_unlocked,
 534         .put_blk_unlocked       = gennvm_put_blk_unlocked,
 535
 536         .get_blk                = gennvm_get_blk,
 537         .put_blk                = gennvm_put_blk,
 538
 539         .submit_io              = gennvm_submit_io,
 540         .erase_blk              = gennvm_erase_blk,
 541
 542         .get_lun                = gennvm_get_lun,
 543         .reserve_lun            = gennvm_reserve_lun,
 544         .release_lun            = gennvm_release_lun,
 545         .lun_info_print         = gennvm_lun_info_print,
 546
 547         .get_area               = gennvm_get_area,
 548         .put_area               = gennvm_put_area,
 549
 550 };
 551
 552 static int __init gennvm_module_init(void)
 553 {
 554         return nvm_register_mgr(&gennvm);
 555 }
 556
 557 static void gennvm_module_exit(void)
 558 {
 559         nvm_unregister_mgr(&gennvm);
 560 }
 561
 562 module_init(gennvm_module_init);
 563 module_exit(gennvm_module_exit);
 564 MODULE_LICENSE("GPL v2");
 565 MODULE_DESCRIPTION("Generic media manager for Open-Channel SSDs");