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_open_blocks = 0;
  64                 lun->vlun.nr_closed_blocks = 0;
  65                 lun->vlun.nr_bad_blocks = 0;
  66         }
  67         return 0;
  68 }
  69
  70 static int gennvm_block_bb(struct ppa_addr ppa, int nr_blocks, u8 *blks,
  71                                                                 void *private)
  72 {
  73         struct gen_nvm *gn = private;
  74         struct nvm_dev *dev = gn->dev;
  75         struct gen_lun *lun;
  76         struct nvm_block *blk;
  77         int i;
  78
  79         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
  80
  81         for (i = 0; i < nr_blocks; i++) {
  82                 if (blks[i] == 0)
  83                         continue;
  84
  85                 blk = &lun->vlun.blocks[i];
  86                 if (!blk) {
  87                         pr_err("gennvm: BB data is out of bounds.\n");
  88                         return -EINVAL;
  89                 }
  90
  91                 list_move_tail(&blk->list, &lun->bb_list);
  92                 lun->vlun.nr_bad_blocks++;
  93                 lun->vlun.nr_free_blocks--;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static int gennvm_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
 100 {
 101         struct nvm_dev *dev = private;
 102         struct gen_nvm *gn = dev->mp;
 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_secs)) {
 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 >= dev->total_secs && 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->state) {
 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. The block is assumed to be open.
 141                          */
 142                         list_move_tail(&blk->list, &lun->used_list);
 143                         blk->state = NVM_BLK_ST_OPEN;
 144                         lun->vlun.nr_free_blocks--;
 145                         lun->vlun.nr_open_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_secs,
 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_unlocked(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         assert_spin_locked(&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->state = NVM_BLK_ST_OPEN;
 280
 281         lun->vlun.nr_free_blocks--;
 282         lun->vlun.nr_open_blocks++;
 283
 284 out:
 285         return blk;
 286 }
 287
 288 static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 289                                 struct nvm_lun *vlun, unsigned long flags)
 290 {
 291         struct nvm_block *blk;
 292
 293         spin_lock(&vlun->lock);
 294         blk = gennvm_get_blk_unlocked(dev, vlun, flags);
 295         spin_unlock(&vlun->lock);
 296         return blk;
 297 }
 298
 299 static void gennvm_put_blk_unlocked(struct nvm_dev *dev, struct nvm_block *blk)
 300 {
 301         struct nvm_lun *vlun = blk->lun;
 302         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 303
 304         assert_spin_locked(&vlun->lock);
 305
 306         if (blk->state & NVM_BLK_ST_OPEN) {
 307                 list_move_tail(&blk->list, &lun->free_list);
 308                 lun->vlun.nr_open_blocks--;
 309                 lun->vlun.nr_free_blocks++;
 310                 blk->state = NVM_BLK_ST_FREE;
 311         } else if (blk->state & NVM_BLK_ST_CLOSED) {
 312                 list_move_tail(&blk->list, &lun->free_list);
 313                 lun->vlun.nr_closed_blocks--;
 314                 lun->vlun.nr_free_blocks++;
 315                 blk->state = NVM_BLK_ST_FREE;
 316         } else if (blk->state & NVM_BLK_ST_BAD) {
 317                 list_move_tail(&blk->list, &lun->bb_list);
 318                 lun->vlun.nr_bad_blocks++;
 319                 blk->state = NVM_BLK_ST_BAD;
 320         } else {
 321                 WARN_ON_ONCE(1);
 322                 pr_err("gennvm: erroneous block type (%lu -> %u)\n",
 323                                                         blk->id, blk->state);
 324                 list_move_tail(&blk->list, &lun->bb_list);
 325                 lun->vlun.nr_bad_blocks++;
 326                 blk->state = NVM_BLK_ST_BAD;
 327         }
 328 }
 329
 330 static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 331 {
 332         struct nvm_lun *vlun = blk->lun;
 333
 334         spin_lock(&vlun->lock);
 335         gennvm_put_blk_unlocked(dev, blk);
 336         spin_unlock(&vlun->lock);
 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->state = 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, rqd, 1))
 373                 return;
 374
 375         nvm_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],
 381                                                 NVM_BLK_ST_BAD);
 382         else
 383                 gennvm_blk_set_type(dev, &rqd->ppa_addr, NVM_BLK_ST_BAD);
 384 }
 385
 386 static void gennvm_end_io(struct nvm_rq *rqd)
 387 {
 388         struct nvm_tgt_instance *ins = rqd->ins;
 389
 390         switch (rqd->error) {
 391         case NVM_RSP_SUCCESS:
 392         case NVM_RSP_ERR_EMPTYPAGE:
 393                 break;
 394         case NVM_RSP_ERR_FAILWRITE:
 395                 gennvm_mark_blk_bad(rqd->dev, rqd);
 396         }
 397
 398         ins->tt->end_io(rqd);
 399 }
 400
 401 static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 402 {
 403         if (!dev->ops->submit_io)
 404                 return -ENODEV;
 405
 406         /* Convert address space */
 407         nvm_generic_to_addr_mode(dev, rqd);
 408
 409         rqd->dev = dev;
 410         rqd->end_io = gennvm_end_io;
 411         return dev->ops->submit_io(dev, rqd);
 412 }
 413
 414 static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 415                                                         unsigned long flags)
 416 {
 417         struct ppa_addr addr = block_to_ppa(dev, blk);
 418
 419         return nvm_erase_ppa(dev, &addr, 1);
 420 }
 421
 422 static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
 423 {
 424         struct gen_nvm *gn = dev->mp;
 425
 426         return &gn->luns[lunid].vlun;
 427 }
 428
 429 static void gennvm_lun_info_print(struct nvm_dev *dev)
 430 {
 431         struct gen_nvm *gn = dev->mp;
 432         struct gen_lun *lun;
 433         unsigned int i;
 434
 435
 436         gennvm_for_each_lun(gn, lun, i) {
 437                 spin_lock(&lun->vlun.lock);
 438
 439                 pr_info("%s: lun%8u\t%u\t%u\t%u\t%u\n",
 440                                 dev->name, i,
 441                                 lun->vlun.nr_free_blocks,
 442                                 lun->vlun.nr_open_blocks,
 443                                 lun->vlun.nr_closed_blocks,
 444                                 lun->vlun.nr_bad_blocks);
 445
 446                 spin_unlock(&lun->vlun.lock);
 447         }
 448 }
 449
 450 static struct nvmm_type gennvm = {
 451         .name                   = "gennvm",
 452         .version                = {0, 1, 0},
 453
 454         .register_mgr           = gennvm_register,
 455         .unregister_mgr         = gennvm_unregister,
 456
 457         .get_blk_unlocked       = gennvm_get_blk_unlocked,
 458         .put_blk_unlocked       = gennvm_put_blk_unlocked,
 459
 460         .get_blk                = gennvm_get_blk,
 461         .put_blk                = gennvm_put_blk,
 462
 463         .submit_io              = gennvm_submit_io,
 464         .erase_blk              = gennvm_erase_blk,
 465
 466         .get_lun                = gennvm_get_lun,
 467         .lun_info_print         = gennvm_lun_info_print,
 468 };
 469
 470 static int __init gennvm_module_init(void)
 471 {
 472         return nvm_register_mgr(&gennvm);
 473 }
 474
 475 static void gennvm_module_exit(void)
 476 {
 477         nvm_unregister_mgr(&gennvm);
 478 }
 479
 480 module_init(gennvm_module_init);
 481 module_exit(gennvm_module_exit);
 482 MODULE_LICENSE("GPL v2");
 483 MODULE_DESCRIPTION("Generic media manager for Open-Channel SSDs");