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 gen_nvm *gn, struct ppa_addr ppa,
 133                                                         u8 *blks, int nr_blks)
 134 {
 135         struct nvm_dev *dev = gn->dev;
 136         struct gen_lun *lun;
 137         struct nvm_block *blk;
 138         int i;
 139
 140         nr_blks = nvm_bb_tbl_fold(dev, blks, nr_blks);
 141         if (nr_blks < 0)
 142                 return nr_blks;
 143
 144         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
 145
 146         for (i = 0; i < nr_blks; i++) {
 147                 if (blks[i] == 0)
 148                         continue;
 149
 150                 blk = &lun->vlun.blocks[i];
 151                 list_move_tail(&blk->list, &lun->bb_list);
 152                 lun->vlun.nr_bad_blocks++;
 153                 lun->vlun.nr_free_blocks--;
 154         }
 155
 156         return 0;
 157 }
 158
 159 static int gennvm_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
 160 {
 161         struct nvm_dev *dev = private;
 162         struct gen_nvm *gn = dev->mp;
 163         u64 elba = slba + nlb;
 164         struct gen_lun *lun;
 165         struct nvm_block *blk;
 166         u64 i;
 167         int lun_id;
 168
 169         if (unlikely(elba > dev->total_secs)) {
 170                 pr_err("gennvm: L2P data from device is out of bounds!\n");
 171                 return -EINVAL;
 172         }
 173
 174         for (i = 0; i < nlb; i++) {
 175                 u64 pba = le64_to_cpu(entries[i]);
 176
 177                 if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
 178                         pr_err("gennvm: L2P data entry is out of bounds!\n");
 179                         return -EINVAL;
 180                 }
 181
 182                 /* Address zero is a special one. The first page on a disk is
 183                  * protected. It often holds internal device boot
 184                  * information.
 185                  */
 186                 if (!pba)
 187                         continue;
 188
 189                 /* resolve block from physical address */
 190                 lun_id = div_u64(pba, dev->sec_per_lun);
 191                 lun = &gn->luns[lun_id];
 192
 193                 /* Calculate block offset into lun */
 194                 pba = pba - (dev->sec_per_lun * lun_id);
 195                 blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
 196
 197                 if (!blk->state) {
 198                         /* at this point, we don't know anything about the
 199                          * block. It's up to the FTL on top to re-etablish the
 200                          * block state. The block is assumed to be open.
 201                          */
 202                         list_move_tail(&blk->list, &lun->used_list);
 203                         blk->state = NVM_BLK_ST_OPEN;
 204                         lun->vlun.nr_free_blocks--;
 205                         lun->vlun.nr_open_blocks++;
 206                 }
 207         }
 208
 209         return 0;
 210 }
 211
 212 static int gennvm_blocks_init(struct nvm_dev *dev, struct gen_nvm *gn)
 213 {
 214         struct gen_lun *lun;
 215         struct nvm_block *block;
 216         sector_t lun_iter, blk_iter, cur_block_id = 0;
 217         int ret, nr_blks;
 218         u8 *blks;
 219
 220         nr_blks = dev->blks_per_lun * dev->plane_mode;
 221         blks = kmalloc(nr_blks, GFP_KERNEL);
 222         if (!blks)
 223                 return -ENOMEM;
 224
 225         gennvm_for_each_lun(gn, lun, lun_iter) {
 226                 lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
 227                                                         dev->blks_per_lun);
 228                 if (!lun->vlun.blocks) {
 229                         kfree(blks);
 230                         return -ENOMEM;
 231                 }
 232
 233                 for (blk_iter = 0; blk_iter < dev->blks_per_lun; blk_iter++) {
 234                         block = &lun->vlun.blocks[blk_iter];
 235
 236                         INIT_LIST_HEAD(&block->list);
 237
 238                         block->lun = &lun->vlun;
 239                         block->id = cur_block_id++;
 240
 241                         /* First block is reserved for device */
 242                         if (unlikely(lun_iter == 0 && blk_iter == 0)) {
 243                                 lun->vlun.nr_free_blocks--;
 244                                 continue;
 245                         }
 246
 247                         list_add_tail(&block->list, &lun->free_list);
 248                 }
 249
 250                 if (dev->ops->get_bb_tbl) {
 251                         struct ppa_addr ppa;
 252
 253                         ppa.ppa = 0;
 254                         ppa.g.ch = lun->vlun.chnl_id;
 255                         ppa.g.lun = lun->vlun.lun_id;
 256
 257                         ret = nvm_get_bb_tbl(dev, ppa, blks);
 258                         if (ret)
 259                                 pr_err("gennvm: could not get BB table\n");
 260
 261                         ret = gennvm_block_bb(gn, ppa, blks, nr_blks);
 262                         if (ret)
 263                                 pr_err("gennvm: BB table map failed\n");
 264                 }
 265         }
 266
 267         if ((dev->identity.dom & NVM_RSP_L2P) && dev->ops->get_l2p_tbl) {
 268                 ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_secs,
 269                                                         gennvm_block_map, dev);
 270                 if (ret) {
 271                         pr_err("gennvm: could not read L2P table.\n");
 272                         pr_warn("gennvm: default block initialization");
 273                 }
 274         }
 275
 276         kfree(blks);
 277         return 0;
 278 }
 279
 280 static void gennvm_free(struct nvm_dev *dev)
 281 {
 282         gennvm_blocks_free(dev);
 283         gennvm_luns_free(dev);
 284         kfree(dev->mp);
 285         dev->mp = NULL;
 286 }
 287
 288 static int gennvm_register(struct nvm_dev *dev)
 289 {
 290         struct gen_nvm *gn;
 291         int ret;
 292
 293         if (!try_module_get(THIS_MODULE))
 294                 return -ENODEV;
 295
 296         gn = kzalloc(sizeof(struct gen_nvm), GFP_KERNEL);
 297         if (!gn)
 298                 return -ENOMEM;
 299
 300         gn->dev = dev;
 301         gn->nr_luns = dev->nr_luns;
 302         INIT_LIST_HEAD(&gn->area_list);
 303         dev->mp = gn;
 304
 305         ret = gennvm_luns_init(dev, gn);
 306         if (ret) {
 307                 pr_err("gennvm: could not initialize luns\n");
 308                 goto err;
 309         }
 310
 311         ret = gennvm_blocks_init(dev, gn);
 312         if (ret) {
 313                 pr_err("gennvm: could not initialize blocks\n");
 314                 goto err;
 315         }
 316
 317         return 1;
 318 err:
 319         gennvm_free(dev);
 320         module_put(THIS_MODULE);
 321         return ret;
 322 }
 323
 324 static void gennvm_unregister(struct nvm_dev *dev)
 325 {
 326         gennvm_free(dev);
 327         module_put(THIS_MODULE);
 328 }
 329
 330 static struct nvm_block *gennvm_get_blk_unlocked(struct nvm_dev *dev,
 331                                 struct nvm_lun *vlun, unsigned long flags)
 332 {
 333         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 334         struct nvm_block *blk = NULL;
 335         int is_gc = flags & NVM_IOTYPE_GC;
 336
 337         assert_spin_locked(&vlun->lock);
 338
 339         if (list_empty(&lun->free_list)) {
 340                 pr_err_ratelimited("gennvm: lun %u have no free pages available",
 341                                                                 lun->vlun.id);
 342                 goto out;
 343         }
 344
 345         if (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks)
 346                 goto out;
 347
 348         blk = list_first_entry(&lun->free_list, struct nvm_block, list);
 349         list_move_tail(&blk->list, &lun->used_list);
 350         blk->state = NVM_BLK_ST_OPEN;
 351
 352         lun->vlun.nr_free_blocks--;
 353         lun->vlun.nr_open_blocks++;
 354
 355 out:
 356         return blk;
 357 }
 358
 359 static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 360                                 struct nvm_lun *vlun, unsigned long flags)
 361 {
 362         struct nvm_block *blk;
 363
 364         spin_lock(&vlun->lock);
 365         blk = gennvm_get_blk_unlocked(dev, vlun, flags);
 366         spin_unlock(&vlun->lock);
 367         return blk;
 368 }
 369
 370 static void gennvm_put_blk_unlocked(struct nvm_dev *dev, struct nvm_block *blk)
 371 {
 372         struct nvm_lun *vlun = blk->lun;
 373         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 374
 375         assert_spin_locked(&vlun->lock);
 376
 377         if (blk->state & NVM_BLK_ST_OPEN) {
 378                 list_move_tail(&blk->list, &lun->free_list);
 379                 lun->vlun.nr_open_blocks--;
 380                 lun->vlun.nr_free_blocks++;
 381                 blk->state = NVM_BLK_ST_FREE;
 382         } else if (blk->state & NVM_BLK_ST_CLOSED) {
 383                 list_move_tail(&blk->list, &lun->free_list);
 384                 lun->vlun.nr_closed_blocks--;
 385                 lun->vlun.nr_free_blocks++;
 386                 blk->state = NVM_BLK_ST_FREE;
 387         } else if (blk->state & NVM_BLK_ST_BAD) {
 388                 list_move_tail(&blk->list, &lun->bb_list);
 389                 lun->vlun.nr_bad_blocks++;
 390                 blk->state = NVM_BLK_ST_BAD;
 391         } else {
 392                 WARN_ON_ONCE(1);
 393                 pr_err("gennvm: erroneous block type (%lu -> %u)\n",
 394                                                         blk->id, blk->state);
 395                 list_move_tail(&blk->list, &lun->bb_list);
 396                 lun->vlun.nr_bad_blocks++;
 397                 blk->state = NVM_BLK_ST_BAD;
 398         }
 399 }
 400
 401 static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 402 {
 403         struct nvm_lun *vlun = blk->lun;
 404
 405         spin_lock(&vlun->lock);
 406         gennvm_put_blk_unlocked(dev, blk);
 407         spin_unlock(&vlun->lock);
 408 }
 409
 410 static void gennvm_mark_blk(struct nvm_dev *dev, struct ppa_addr ppa, int type)
 411 {
 412         struct gen_nvm *gn = dev->mp;
 413         struct gen_lun *lun;
 414         struct nvm_block *blk;
 415
 416         pr_debug("gennvm: ppa  (ch: %u lun: %u blk: %u pg: %u) -> %u\n",
 417                         ppa.g.ch, ppa.g.lun, ppa.g.blk, ppa.g.pg, type);
 418
 419         if (unlikely(ppa.g.ch > dev->nr_chnls ||
 420                                         ppa.g.lun > dev->luns_per_chnl ||
 421                                         ppa.g.blk > dev->blks_per_lun)) {
 422                 WARN_ON_ONCE(1);
 423                 pr_err("gennvm: ppa broken (ch: %u > %u lun: %u > %u blk: %u > %u",
 424                                 ppa.g.ch, dev->nr_chnls,
 425                                 ppa.g.lun, dev->luns_per_chnl,
 426                                 ppa.g.blk, dev->blks_per_lun);
 427                 return;
 428         }
 429
 430         lun = &gn->luns[ppa.g.lun * ppa.g.ch];
 431         blk = &lun->vlun.blocks[ppa.g.blk];
 432
 433         /* will be moved to bb list on put_blk from target */
 434         blk->state = type;
 435 }
 436
 437 /*
 438  * mark block bad in gennvm. It is expected that the target recovers separately
 439  */
 440 static void gennvm_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
 441 {
 442         int bit = -1;
 443         int max_secs = dev->ops->max_phys_sect;
 444         void *comp_bits = &rqd->ppa_status;
 445
 446         nvm_addr_to_generic_mode(dev, rqd);
 447
 448         /* look up blocks and mark them as bad */
 449         if (rqd->nr_ppas == 1) {
 450                 gennvm_mark_blk(dev, rqd->ppa_addr, NVM_BLK_ST_BAD);
 451                 return;
 452         }
 453
 454         while ((bit = find_next_bit(comp_bits, max_secs, bit + 1)) < max_secs)
 455                 gennvm_mark_blk(dev, rqd->ppa_list[bit], NVM_BLK_ST_BAD);
 456 }
 457
 458 static void gennvm_end_io(struct nvm_rq *rqd)
 459 {
 460         struct nvm_tgt_instance *ins = rqd->ins;
 461
 462         if (rqd->error == NVM_RSP_ERR_FAILWRITE)
 463                 gennvm_mark_blk_bad(rqd->dev, rqd);
 464
 465         ins->tt->end_io(rqd);
 466 }
 467
 468 static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 469 {
 470         if (!dev->ops->submit_io)
 471                 return -ENODEV;
 472
 473         /* Convert address space */
 474         nvm_generic_to_addr_mode(dev, rqd);
 475
 476         rqd->dev = dev;
 477         rqd->end_io = gennvm_end_io;
 478         return dev->ops->submit_io(dev, rqd);
 479 }
 480
 481 static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 482                                                         unsigned long flags)
 483 {
 484         struct ppa_addr addr = block_to_ppa(dev, blk);
 485
 486         return nvm_erase_ppa(dev, &addr, 1);
 487 }
 488
 489 static int gennvm_reserve_lun(struct nvm_dev *dev, int lunid)
 490 {
 491         return test_and_set_bit(lunid, dev->lun_map);
 492 }
 493
 494 static void gennvm_release_lun(struct nvm_dev *dev, int lunid)
 495 {
 496         WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
 497 }
 498
 499 static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
 500 {
 501         struct gen_nvm *gn = dev->mp;
 502
 503         if (unlikely(lunid >= dev->nr_luns))
 504                 return NULL;
 505
 506         return &gn->luns[lunid].vlun;
 507 }
 508
 509 static void gennvm_lun_info_print(struct nvm_dev *dev)
 510 {
 511         struct gen_nvm *gn = dev->mp;
 512         struct gen_lun *lun;
 513         unsigned int i;
 514
 515
 516         gennvm_for_each_lun(gn, lun, i) {
 517                 spin_lock(&lun->vlun.lock);
 518
 519                 pr_info("%s: lun%8u\t%u\t%u\t%u\t%u\n",
 520                                 dev->name, i,
 521                                 lun->vlun.nr_free_blocks,
 522                                 lun->vlun.nr_open_blocks,
 523                                 lun->vlun.nr_closed_blocks,
 524                                 lun->vlun.nr_bad_blocks);
 525
 526                 spin_unlock(&lun->vlun.lock);
 527         }
 528 }
 529
 530 static struct nvmm_type gennvm = {
 531         .name                   = "gennvm",
 532         .version                = {0, 1, 0},
 533
 534         .register_mgr           = gennvm_register,
 535         .unregister_mgr         = gennvm_unregister,
 536
 537         .get_blk_unlocked       = gennvm_get_blk_unlocked,
 538         .put_blk_unlocked       = gennvm_put_blk_unlocked,
 539
 540         .get_blk                = gennvm_get_blk,
 541         .put_blk                = gennvm_put_blk,
 542
 543         .submit_io              = gennvm_submit_io,
 544         .erase_blk              = gennvm_erase_blk,
 545
 546         .mark_blk               = gennvm_mark_blk,
 547
 548         .get_lun                = gennvm_get_lun,
 549         .reserve_lun            = gennvm_reserve_lun,
 550         .release_lun            = gennvm_release_lun,
 551         .lun_info_print         = gennvm_lun_info_print,
 552
 553         .get_area               = gennvm_get_area,
 554         .put_area               = gennvm_put_area,
 555
 556 };
 557
 558 static int __init gennvm_module_init(void)
 559 {
 560         return nvm_register_mgr(&gennvm);
 561 }
 562
 563 static void gennvm_module_exit(void)
 564 {
 565         nvm_unregister_mgr(&gennvm);
 566 }
 567
 568 module_init(gennvm_module_init);
 569 module_exit(gennvm_module_exit);
 570 MODULE_LICENSE("GPL v2");
 571 MODULE_DESCRIPTION("Generic media manager for Open-Channel SSDs");