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