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