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