kernel/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 void gennvm_blocks_free(struct nvm_dev *dev)
  24 {
  25         struct gen_nvm *gn = dev->mp;
  26         struct gen_lun *lun;
  27         int i;
  28
  29         gennvm_for_each_lun(gn, lun, i) {
  30                 if (!lun->vlun.blocks)
  31                         break;
  32                 vfree(lun->vlun.blocks);
  33         }
  34 }
  35
  36 static void gennvm_luns_free(struct nvm_dev *dev)
  37 {
  38         struct gen_nvm *gn = dev->mp;
  39
  40         kfree(gn->luns);
  41 }
  42
  43 static int gennvm_luns_init(struct nvm_dev *dev, struct gen_nvm *gn)
  44 {
  45         struct gen_lun *lun;
  46         int i;
  47
  48         gn->luns = kcalloc(dev->nr_luns, sizeof(struct gen_lun), GFP_KERNEL);
  49         if (!gn->luns)
  50                 return -ENOMEM;
  51
  52         gennvm_for_each_lun(gn, lun, i) {
  53                 spin_lock_init(&lun->vlun.lock);
  54                 INIT_LIST_HEAD(&lun->free_list);
  55                 INIT_LIST_HEAD(&lun->used_list);
  56                 INIT_LIST_HEAD(&lun->bb_list);
  57
  58                 lun->reserved_blocks = 2; /* for GC only */
  59                 lun->vlun.id = i;
  60                 lun->vlun.lun_id = i % dev->luns_per_chnl;
  61                 lun->vlun.chnl_id = i / dev->luns_per_chnl;
  62                 lun->vlun.nr_free_blocks = dev->blks_per_lun;
  63                 lun->vlun.nr_inuse_blocks = 0;
  64                 lun->vlun.nr_bad_blocks = 0;
  65         }
  66         return 0;
  67 }
  68
  69 static int gennvm_block_bb(struct ppa_addr ppa, int nr_blocks, u8 *blks,
  70                                                                 void *private)
  71 {
  72         struct gen_nvm *gn = private;
  73         struct nvm_dev *dev = gn->dev;
  74         struct gen_lun *lun;
  75         struct nvm_block *blk;
  76         int i;
  77
  78         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
  79
  80         for (i = 0; i < nr_blocks; i++) {
  81                 if (blks[i] == 0)
  82                         continue;
  83
  84                 blk = &lun->vlun.blocks[i];
  85                 if (!blk) {
  86                         pr_err("gennvm: BB data is out of bounds.\n");
  87                         return -EINVAL;
  88                 }
  89
  90                 list_move_tail(&blk->list, &lun->bb_list);
  91                 lun->vlun.nr_bad_blocks++;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int gennvm_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
  98 {
  99         struct nvm_dev *dev = private;
 100         struct gen_nvm *gn = dev->mp;
 101         sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
 102         u64 elba = slba + nlb;
 103         struct gen_lun *lun;
 104         struct nvm_block *blk;
 105         u64 i;
 106         int lun_id;
 107
 108         if (unlikely(elba > dev->total_pages)) {
 109                 pr_err("gennvm: L2P data from device is out of bounds!\n");
 110                 return -EINVAL;
 111         }
 112
 113         for (i = 0; i < nlb; i++) {
 114                 u64 pba = le64_to_cpu(entries[i]);
 115
 116                 if (unlikely(pba >= max_pages && pba != U64_MAX)) {
 117                         pr_err("gennvm: L2P data entry is out of bounds!\n");
 118                         return -EINVAL;
 119                 }
 120
 121                 /* Address zero is a special one. The first page on a disk is
 122                  * protected. It often holds internal device boot
 123                  * information.
 124                  */
 125                 if (!pba)
 126                         continue;
 127
 128                 /* resolve block from physical address */
 129                 lun_id = div_u64(pba, dev->sec_per_lun);
 130                 lun = &gn->luns[lun_id];
 131
 132                 /* Calculate block offset into lun */
 133                 pba = pba - (dev->sec_per_lun * lun_id);
 134                 blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
 135
 136                 if (!blk->type) {
 137                         /* at this point, we don't know anything about the
 138                          * block. It's up to the FTL on top to re-etablish the
 139                          * block state
 140                          */
 141                         list_move_tail(&blk->list, &lun->used_list);
 142                         blk->type = 1;
 143                         lun->vlun.nr_free_blocks--;
 144                         lun->vlun.nr_inuse_blocks++;
 145                 }
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int gennvm_blocks_init(struct nvm_dev *dev, struct gen_nvm *gn)
 152 {
 153         struct gen_lun *lun;
 154         struct nvm_block *block;
 155         sector_t lun_iter, blk_iter, cur_block_id = 0;
 156         int ret;
 157
 158         gennvm_for_each_lun(gn, lun, lun_iter) {
 159                 lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
 160                                                         dev->blks_per_lun);
 161                 if (!lun->vlun.blocks)
 162                         return -ENOMEM;
 163
 164                 for (blk_iter = 0; blk_iter < dev->blks_per_lun; blk_iter++) {
 165                         block = &lun->vlun.blocks[blk_iter];
 166
 167                         INIT_LIST_HEAD(&block->list);
 168
 169                         block->lun = &lun->vlun;
 170                         block->id = cur_block_id++;
 171
 172                         /* First block is reserved for device */
 173                         if (unlikely(lun_iter == 0 && blk_iter == 0)) {
 174                                 lun->vlun.nr_free_blocks--;
 175                                 continue;
 176                         }
 177
 178                         list_add_tail(&block->list, &lun->free_list);
 179                 }
 180
 181                 if (dev->ops->get_bb_tbl) {
 182                         struct ppa_addr ppa;
 183
 184                         ppa.ppa = 0;
 185                         ppa.g.ch = lun->vlun.chnl_id;
 186                         ppa.g.lun = lun->vlun.id;
 187                         ppa = generic_to_dev_addr(dev, ppa);
 188
 189                         ret = dev->ops->get_bb_tbl(dev, ppa,
 190                                                 dev->blks_per_lun,
 191                                                 gennvm_block_bb, gn);
 192                         if (ret)
 193                                 pr_err("gennvm: could not read BB table\n");
 194                 }
 195         }
 196
 197         if (dev->ops->get_l2p_tbl) {
 198                 ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
 199                                                         gennvm_block_map, dev);
 200                 if (ret) {
 201                         pr_err("gennvm: could not read L2P table.\n");
 202                         pr_warn("gennvm: default block initialization");
 203                 }
 204         }
 205
 206         return 0;
 207 }
 208
 209 static void gennvm_free(struct nvm_dev *dev)
 210 {
 211         gennvm_blocks_free(dev);
 212         gennvm_luns_free(dev);
 213         kfree(dev->mp);
 214         dev->mp = NULL;
 215 }
 216
 217 static int gennvm_register(struct nvm_dev *dev)
 218 {
 219         struct gen_nvm *gn;
 220         int ret;
 221
 222         if (!try_module_get(THIS_MODULE))
 223                 return -ENODEV;
 224
 225         gn = kzalloc(sizeof(struct gen_nvm), GFP_KERNEL);
 226         if (!gn)
 227                 return -ENOMEM;
 228
 229         gn->dev = dev;
 230         gn->nr_luns = dev->nr_luns;
 231         dev->mp = gn;
 232
 233         ret = gennvm_luns_init(dev, gn);
 234         if (ret) {
 235                 pr_err("gennvm: could not initialize luns\n");
 236                 goto err;
 237         }
 238
 239         ret = gennvm_blocks_init(dev, gn);
 240         if (ret) {
 241                 pr_err("gennvm: could not initialize blocks\n");
 242                 goto err;
 243         }
 244
 245         return 1;
 246 err:
 247         gennvm_free(dev);
 248         module_put(THIS_MODULE);
 249         return ret;
 250 }
 251
 252 static void gennvm_unregister(struct nvm_dev *dev)
 253 {
 254         gennvm_free(dev);
 255         module_put(THIS_MODULE);
 256 }
 257
 258 static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 259                                 struct nvm_lun *vlun, unsigned long flags)
 260 {
 261         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 262         struct nvm_block *blk = NULL;
 263         int is_gc = flags & NVM_IOTYPE_GC;
 264
 265         spin_lock(&vlun->lock);
 266
 267         if (list_empty(&lun->free_list)) {
 268                 pr_err_ratelimited("gennvm: lun %u have no free pages available",
 269                                                                 lun->vlun.id);
 270                 goto out;
 271         }
 272
 273         if (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks)
 274                 goto out;
 275
 276         blk = list_first_entry(&lun->free_list, struct nvm_block, list);
 277         list_move_tail(&blk->list, &lun->used_list);
 278         blk->type = 1;
 279
 280         lun->vlun.nr_free_blocks--;
 281         lun->vlun.nr_inuse_blocks++;
 282
 283 out:
 284         spin_unlock(&vlun->lock);
 285         return blk;
 286 }
 287
 288 static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 289 {
 290         struct nvm_lun *vlun = blk->lun;
 291         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 292
 293         spin_lock(&vlun->lock);
 294
 295         switch (blk->type) {
 296         case 1:
 297                 list_move_tail(&blk->list, &lun->free_list);
 298                 lun->vlun.nr_free_blocks++;
 299                 lun->vlun.nr_inuse_blocks--;
 300                 blk->type = 0;
 301                 break;
 302         case 2:
 303                 list_move_tail(&blk->list, &lun->bb_list);
 304                 lun->vlun.nr_bad_blocks++;
 305                 lun->vlun.nr_inuse_blocks--;
 306                 break;
 307         default:
 308                 WARN_ON_ONCE(1);
 309                 pr_err("gennvm: erroneous block type (%lu -> %u)\n",
 310                                                         blk->id, blk->type);
 311                 list_move_tail(&blk->list, &lun->bb_list);
 312                 lun->vlun.nr_bad_blocks++;
 313                 lun->vlun.nr_inuse_blocks--;
 314         }
 315
 316         spin_unlock(&vlun->lock);
 317 }
 318
 319 static void gennvm_addr_to_generic_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
 320 {
 321         int i;
 322
 323         if (rqd->nr_pages > 1) {
 324                 for (i = 0; i < rqd->nr_pages; i++)
 325                         rqd->ppa_list[i] = dev_to_generic_addr(dev,
 326                                                         rqd->ppa_list[i]);
 327         } else {
 328                 rqd->ppa_addr = dev_to_generic_addr(dev, rqd->ppa_addr);
 329         }
 330 }
 331
 332 static void gennvm_generic_to_addr_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
 333 {
 334         int i;
 335
 336         if (rqd->nr_pages > 1) {
 337                 for (i = 0; i < rqd->nr_pages; i++)
 338                         rqd->ppa_list[i] = generic_to_dev_addr(dev,
 339                                                         rqd->ppa_list[i]);
 340         } else {
 341                 rqd->ppa_addr = generic_to_dev_addr(dev, rqd->ppa_addr);
 342         }
 343 }
 344
 345 static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 346 {
 347         if (!dev->ops->submit_io)
 348                 return 0;
 349
 350         /* Convert address space */
 351         gennvm_generic_to_addr_mode(dev, rqd);
 352
 353         rqd->dev = dev;
 354         return dev->ops->submit_io(dev, rqd);
 355 }
 356
 357 static void gennvm_blk_set_type(struct nvm_dev *dev, struct ppa_addr *ppa,
 358                                                                 int type)
 359 {
 360         struct gen_nvm *gn = dev->mp;
 361         struct gen_lun *lun;
 362         struct nvm_block *blk;
 363
 364         if (unlikely(ppa->g.ch > dev->nr_chnls ||
 365                                         ppa->g.lun > dev->luns_per_chnl ||
 366                                         ppa->g.blk > dev->blks_per_lun)) {
 367                 WARN_ON_ONCE(1);
 368                 pr_err("gennvm: ppa broken (ch: %u > %u lun: %u > %u blk: %u > %u",
 369                                 ppa->g.ch, dev->nr_chnls,
 370                                 ppa->g.lun, dev->luns_per_chnl,
 371                                 ppa->g.blk, dev->blks_per_lun);
 372                 return;
 373         }
 374
 375         lun = &gn->luns[ppa->g.lun * ppa->g.ch];
 376         blk = &lun->vlun.blocks[ppa->g.blk];
 377
 378         /* will be moved to bb list on put_blk from target */
 379         blk->type = type;
 380 }
 381
 382 /* mark block bad. It is expected the target recover from the error. */
 383 static void gennvm_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
 384 {
 385         int i;
 386
 387         if (!dev->ops->set_bb_tbl)
 388                 return;
 389
 390         if (dev->ops->set_bb_tbl(dev, rqd, 1))
 391                 return;
 392
 393         gennvm_addr_to_generic_mode(dev, rqd);
 394
 395         /* look up blocks and mark them as bad */
 396         if (rqd->nr_pages > 1)
 397                 for (i = 0; i < rqd->nr_pages; i++)
 398                         gennvm_blk_set_type(dev, &rqd->ppa_list[i], 2);
 399         else
 400                 gennvm_blk_set_type(dev, &rqd->ppa_addr, 2);
 401 }
 402
 403 static int gennvm_end_io(struct nvm_rq *rqd, int error)
 404 {
 405         struct nvm_tgt_instance *ins = rqd->ins;
 406         int ret = 0;
 407
 408         switch (error) {
 409         case NVM_RSP_SUCCESS:
 410                 break;
 411         case NVM_RSP_ERR_EMPTYPAGE:
 412                 break;
 413         case NVM_RSP_ERR_FAILWRITE:
 414                 gennvm_mark_blk_bad(rqd->dev, rqd);
 415         default:
 416                 ret++;
 417         }
 418
 419         ret += ins->tt->end_io(rqd, error);
 420
 421         return ret;
 422 }
 423
 424 static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 425                                                         unsigned long flags)
 426 {
 427         int plane_cnt = 0, pl_idx, ret;
 428         struct ppa_addr addr;
 429         struct nvm_rq rqd;
 430
 431         if (!dev->ops->erase_block)
 432                 return 0;
 433
 434         addr = block_to_ppa(dev, blk);
 435
 436         if (dev->plane_mode == NVM_PLANE_SINGLE) {
 437                 rqd.nr_pages = 1;
 438                 rqd.ppa_addr = addr;
 439         } else {
 440                 plane_cnt = (1 << dev->plane_mode);
 441                 rqd.nr_pages = plane_cnt;
 442
 443                 rqd.ppa_list = nvm_dev_dma_alloc(dev, GFP_KERNEL,
 444                                                         &rqd.dma_ppa_list);
 445                 if (!rqd.ppa_list) {
 446                         pr_err("gennvm: failed to allocate dma memory\n");
 447                         return -ENOMEM;
 448                 }
 449
 450                 for (pl_idx = 0; pl_idx < plane_cnt; pl_idx++) {
 451                         addr.g.pl = pl_idx;
 452                         rqd.ppa_list[pl_idx] = addr;
 453                 }
 454         }
 455
 456         gennvm_generic_to_addr_mode(dev, &rqd);
 457
 458         ret = dev->ops->erase_block(dev, &rqd);
 459
 460         if (plane_cnt)
 461                 nvm_dev_dma_free(dev, rqd.ppa_list, rqd.dma_ppa_list);
 462
 463         return ret;
 464 }
 465
 466 static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
 467 {
 468         struct gen_nvm *gn = dev->mp;
 469
 470         return &gn->luns[lunid].vlun;
 471 }
 472
 473 static void gennvm_lun_info_print(struct nvm_dev *dev)
 474 {
 475         struct gen_nvm *gn = dev->mp;
 476         struct gen_lun *lun;
 477         unsigned int i;
 478
 479
 480         gennvm_for_each_lun(gn, lun, i) {
 481                 spin_lock(&lun->vlun.lock);
 482
 483                 pr_info("%s: lun%8u\t%u\t%u\t%u\n",
 484                                 dev->name, i,
 485                                 lun->vlun.nr_free_blocks,
 486                                 lun->vlun.nr_inuse_blocks,
 487                                 lun->vlun.nr_bad_blocks);
 488
 489                 spin_unlock(&lun->vlun.lock);
 490         }
 491 }
 492
 493 static struct nvmm_type gennvm = {
 494         .name           = "gennvm",
 495         .version        = {0, 1, 0},
 496
 497         .register_mgr   = gennvm_register,
 498         .unregister_mgr = gennvm_unregister,
 499
 500         .get_blk        = gennvm_get_blk,
 501         .put_blk        = gennvm_put_blk,
 502
 503         .submit_io      = gennvm_submit_io,
 504         .end_io         = gennvm_end_io,
 505         .erase_blk      = gennvm_erase_blk,
 506
 507         .get_lun        = gennvm_get_lun,
 508         .lun_info_print = gennvm_lun_info_print,
 509 };
 510
 511 static int __init gennvm_module_init(void)
 512 {
 513         return nvm_register_mgr(&gennvm);
 514 }
 515
 516 static void gennvm_module_exit(void)
 517 {
 518         nvm_unregister_mgr(&gennvm);
 519 }
 520
 521 module_init(gennvm_module_init);
 522 module_exit(gennvm_module_exit);
 523 MODULE_LICENSE("GPL v2");
 524 MODULE_DESCRIPTION("Generic media manager for Open-Channel SSDs");