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