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 general nvm manager for Open-Channel SSDs.
  19  */
  20
  21 #include "gennvm.h"
  22
  23 static struct nvm_target *gen_find_target(struct gen_dev *gn, const char *name)
  24 {
  25         struct nvm_target *tgt;
  26
  27         list_for_each_entry(tgt, &gn->targets, list)
  28                 if (!strcmp(name, tgt->disk->disk_name))
  29                         return tgt;
  30
  31         return NULL;
  32 }
  33
  34 static const struct block_device_operations gen_fops = {
  35         .owner          = THIS_MODULE,
  36 };
  37
  38 static int gen_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
  39 {
  40         struct gen_dev *gn = dev->mp;
  41         struct nvm_ioctl_create_simple *s = &create->conf.s;
  42         struct request_queue *tqueue;
  43         struct gendisk *tdisk;
  44         struct nvm_tgt_type *tt;
  45         struct nvm_target *t;
  46         void *targetdata;
  47
  48         tt = nvm_find_target_type(create->tgttype, 1);
  49         if (!tt) {
  50                 pr_err("nvm: target type %s not found\n", create->tgttype);
  51                 return -EINVAL;
  52         }
  53
  54         mutex_lock(&gn->lock);
  55         t = gen_find_target(gn, create->tgtname);
  56         if (t) {
  57                 pr_err("nvm: target name already exists.\n");
  58                 mutex_unlock(&gn->lock);
  59                 return -EINVAL;
  60         }
  61         mutex_unlock(&gn->lock);
  62
  63         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
  64         if (!t)
  65                 return -ENOMEM;
  66
  67         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
  68         if (!tqueue)
  69                 goto err_t;
  70         blk_queue_make_request(tqueue, tt->make_rq);
  71
  72         tdisk = alloc_disk(0);
  73         if (!tdisk)
  74                 goto err_queue;
  75
  76         sprintf(tdisk->disk_name, "%s", create->tgtname);
  77         tdisk->flags = GENHD_FL_EXT_DEVT;
  78         tdisk->major = 0;
  79         tdisk->first_minor = 0;
  80         tdisk->fops = &gen_fops;
  81         tdisk->queue = tqueue;
  82
  83         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
  84         if (IS_ERR(targetdata))
  85                 goto err_init;
  86
  87         tdisk->private_data = targetdata;
  88         tqueue->queuedata = targetdata;
  89
  90         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
  91
  92         set_capacity(tdisk, tt->capacity(targetdata));
  93         add_disk(tdisk);
  94
  95         t->type = tt;
  96         t->disk = tdisk;
  97         t->dev = dev;
  98
  99         mutex_lock(&gn->lock);
 100         list_add_tail(&t->list, &gn->targets);
 101         mutex_unlock(&gn->lock);
 102
 103         return 0;
 104 err_init:
 105         put_disk(tdisk);
 106 err_queue:
 107         blk_cleanup_queue(tqueue);
 108 err_t:
 109         kfree(t);
 110         return -ENOMEM;
 111 }
 112
 113 static void __gen_remove_target(struct nvm_target *t)
 114 {
 115         struct nvm_tgt_type *tt = t->type;
 116         struct gendisk *tdisk = t->disk;
 117         struct request_queue *q = tdisk->queue;
 118
 119         del_gendisk(tdisk);
 120         blk_cleanup_queue(q);
 121
 122         if (tt->exit)
 123                 tt->exit(tdisk->private_data);
 124
 125         put_disk(tdisk);
 126
 127         list_del(&t->list);
 128         kfree(t);
 129 }
 130
 131 /**
 132  * gen_remove_tgt - Removes a target from the media manager
 133  * @dev:        device
 134  * @remove:     ioctl structure with target name to remove.
 135  *
 136  * Returns:
 137  * 0: on success
 138  * 1: on not found
 139  * <0: on error
 140  */
 141 static int gen_remove_tgt(struct nvm_dev *dev, struct nvm_ioctl_remove *remove)
 142 {
 143         struct gen_dev *gn = dev->mp;
 144         struct nvm_target *t;
 145
 146         if (!gn)
 147                 return 1;
 148
 149         mutex_lock(&gn->lock);
 150         t = gen_find_target(gn, remove->tgtname);
 151         if (!t) {
 152                 mutex_unlock(&gn->lock);
 153                 return 1;
 154         }
 155         __gen_remove_target(t);
 156         mutex_unlock(&gn->lock);
 157
 158         return 0;
 159 }
 160
 161 static int gen_get_area(struct nvm_dev *dev, sector_t *lba, sector_t len)
 162 {
 163         struct gen_dev *gn = dev->mp;
 164         struct gen_area *area, *prev, *next;
 165         sector_t begin = 0;
 166         sector_t max_sectors = (dev->sec_size * dev->total_secs) >> 9;
 167
 168         if (len > max_sectors)
 169                 return -EINVAL;
 170
 171         area = kmalloc(sizeof(struct gen_area), GFP_KERNEL);
 172         if (!area)
 173                 return -ENOMEM;
 174
 175         prev = NULL;
 176
 177         spin_lock(&dev->lock);
 178         list_for_each_entry(next, &gn->area_list, list) {
 179                 if (begin + len > next->begin) {
 180                         begin = next->end;
 181                         prev = next;
 182                         continue;
 183                 }
 184                 break;
 185         }
 186
 187         if ((begin + len) > max_sectors) {
 188                 spin_unlock(&dev->lock);
 189                 kfree(area);
 190                 return -EINVAL;
 191         }
 192
 193         area->begin = *lba = begin;
 194         area->end = begin + len;
 195
 196         if (prev) /* insert into sorted order */
 197                 list_add(&area->list, &prev->list);
 198         else
 199                 list_add(&area->list, &gn->area_list);
 200         spin_unlock(&dev->lock);
 201
 202         return 0;
 203 }
 204
 205 static void gen_put_area(struct nvm_dev *dev, sector_t begin)
 206 {
 207         struct gen_dev *gn = dev->mp;
 208         struct gen_area *area;
 209
 210         spin_lock(&dev->lock);
 211         list_for_each_entry(area, &gn->area_list, list) {
 212                 if (area->begin != begin)
 213                         continue;
 214
 215                 list_del(&area->list);
 216                 spin_unlock(&dev->lock);
 217                 kfree(area);
 218                 return;
 219         }
 220         spin_unlock(&dev->lock);
 221 }
 222
 223 static void gen_blocks_free(struct nvm_dev *dev)
 224 {
 225         struct gen_dev *gn = dev->mp;
 226         struct gen_lun *lun;
 227         int i;
 228
 229         gen_for_each_lun(gn, lun, i) {
 230                 if (!lun->vlun.blocks)
 231                         break;
 232                 vfree(lun->vlun.blocks);
 233         }
 234 }
 235
 236 static void gen_luns_free(struct nvm_dev *dev)
 237 {
 238         struct gen_dev *gn = dev->mp;
 239
 240         kfree(gn->luns);
 241 }
 242
 243 static int gen_luns_init(struct nvm_dev *dev, struct gen_dev *gn)
 244 {
 245         struct gen_lun *lun;
 246         int i;
 247
 248         gn->luns = kcalloc(dev->nr_luns, sizeof(struct gen_lun), GFP_KERNEL);
 249         if (!gn->luns)
 250                 return -ENOMEM;
 251
 252         gen_for_each_lun(gn, lun, i) {
 253                 spin_lock_init(&lun->vlun.lock);
 254                 INIT_LIST_HEAD(&lun->free_list);
 255                 INIT_LIST_HEAD(&lun->used_list);
 256                 INIT_LIST_HEAD(&lun->bb_list);
 257
 258                 lun->reserved_blocks = 2; /* for GC only */
 259                 lun->vlun.id = i;
 260                 lun->vlun.lun_id = i % dev->luns_per_chnl;
 261                 lun->vlun.chnl_id = i / dev->luns_per_chnl;
 262                 lun->vlun.nr_free_blocks = dev->blks_per_lun;
 263         }
 264         return 0;
 265 }
 266
 267 static int gen_block_bb(struct gen_dev *gn, struct ppa_addr ppa,
 268                                                         u8 *blks, int nr_blks)
 269 {
 270         struct nvm_dev *dev = gn->dev;
 271         struct gen_lun *lun;
 272         struct nvm_block *blk;
 273         int i;
 274
 275         nr_blks = nvm_bb_tbl_fold(dev, blks, nr_blks);
 276         if (nr_blks < 0)
 277                 return nr_blks;
 278
 279         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
 280
 281         for (i = 0; i < nr_blks; i++) {
 282                 if (blks[i] == 0)
 283                         continue;
 284
 285                 blk = &lun->vlun.blocks[i];
 286                 list_move_tail(&blk->list, &lun->bb_list);
 287                 lun->vlun.nr_free_blocks--;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int gen_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
 294 {
 295         struct nvm_dev *dev = private;
 296         struct gen_dev *gn = dev->mp;
 297         u64 elba = slba + nlb;
 298         struct gen_lun *lun;
 299         struct nvm_block *blk;
 300         u64 i;
 301         int lun_id;
 302
 303         if (unlikely(elba > dev->total_secs)) {
 304                 pr_err("gen: L2P data from device is out of bounds!\n");
 305                 return -EINVAL;
 306         }
 307
 308         for (i = 0; i < nlb; i++) {
 309                 u64 pba = le64_to_cpu(entries[i]);
 310
 311                 if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
 312                         pr_err("gen: L2P data entry is out of bounds!\n");
 313                         return -EINVAL;
 314                 }
 315
 316                 /* Address zero is a special one. The first page on a disk is
 317                  * protected. It often holds internal device boot
 318                  * information.
 319                  */
 320                 if (!pba)
 321                         continue;
 322
 323                 /* resolve block from physical address */
 324                 lun_id = div_u64(pba, dev->sec_per_lun);
 325                 lun = &gn->luns[lun_id];
 326
 327                 /* Calculate block offset into lun */
 328                 pba = pba - (dev->sec_per_lun * lun_id);
 329                 blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
 330
 331                 if (!blk->state) {
 332                         /* at this point, we don't know anything about the
 333                          * block. It's up to the FTL on top to re-etablish the
 334                          * block state. The block is assumed to be open.
 335                          */
 336                         list_move_tail(&blk->list, &lun->used_list);
 337                         blk->state = NVM_BLK_ST_TGT;
 338                         lun->vlun.nr_free_blocks--;
 339                 }
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int gen_blocks_init(struct nvm_dev *dev, struct gen_dev *gn)
 346 {
 347         struct gen_lun *lun;
 348         struct nvm_block *block;
 349         sector_t lun_iter, blk_iter, cur_block_id = 0;
 350         int ret, nr_blks;
 351         u8 *blks;
 352
 353         nr_blks = dev->blks_per_lun * dev->plane_mode;
 354         blks = kmalloc(nr_blks, GFP_KERNEL);
 355         if (!blks)
 356                 return -ENOMEM;
 357
 358         gen_for_each_lun(gn, lun, lun_iter) {
 359                 lun->vlun.blocks = vzalloc(sizeof(struct nvm_block) *
 360                                                         dev->blks_per_lun);
 361                 if (!lun->vlun.blocks) {
 362                         kfree(blks);
 363                         return -ENOMEM;
 364                 }
 365
 366                 for (blk_iter = 0; blk_iter < dev->blks_per_lun; blk_iter++) {
 367                         block = &lun->vlun.blocks[blk_iter];
 368
 369                         INIT_LIST_HEAD(&block->list);
 370
 371                         block->lun = &lun->vlun;
 372                         block->id = cur_block_id++;
 373
 374                         /* First block is reserved for device */
 375                         if (unlikely(lun_iter == 0 && blk_iter == 0)) {
 376                                 lun->vlun.nr_free_blocks--;
 377                                 continue;
 378                         }
 379
 380                         list_add_tail(&block->list, &lun->free_list);
 381                 }
 382
 383                 if (dev->ops->get_bb_tbl) {
 384                         struct ppa_addr ppa;
 385
 386                         ppa.ppa = 0;
 387                         ppa.g.ch = lun->vlun.chnl_id;
 388                         ppa.g.lun = lun->vlun.lun_id;
 389
 390                         ret = nvm_get_bb_tbl(dev, ppa, blks);
 391                         if (ret)
 392                                 pr_err("gen: could not get BB table\n");
 393
 394                         ret = gen_block_bb(gn, ppa, blks, nr_blks);
 395                         if (ret)
 396                                 pr_err("gen: BB table map failed\n");
 397                 }
 398         }
 399
 400         if ((dev->identity.dom & NVM_RSP_L2P) && dev->ops->get_l2p_tbl) {
 401                 ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_secs,
 402                                                         gen_block_map, dev);
 403                 if (ret) {
 404                         pr_err("gen: could not read L2P table.\n");
 405                         pr_warn("gen: default block initialization");
 406                 }
 407         }
 408
 409         kfree(blks);
 410         return 0;
 411 }
 412
 413 static void gen_free(struct nvm_dev *dev)
 414 {
 415         gen_blocks_free(dev);
 416         gen_luns_free(dev);
 417         kfree(dev->mp);
 418         dev->mp = NULL;
 419 }
 420
 421 static int gen_register(struct nvm_dev *dev)
 422 {
 423         struct gen_dev *gn;
 424         int ret;
 425
 426         if (!try_module_get(THIS_MODULE))
 427                 return -ENODEV;
 428
 429         gn = kzalloc(sizeof(struct gen_dev), GFP_KERNEL);
 430         if (!gn)
 431                 return -ENOMEM;
 432
 433         gn->dev = dev;
 434         gn->nr_luns = dev->nr_luns;
 435         INIT_LIST_HEAD(&gn->area_list);
 436         mutex_init(&gn->lock);
 437         INIT_LIST_HEAD(&gn->targets);
 438         dev->mp = gn;
 439
 440         ret = gen_luns_init(dev, gn);
 441         if (ret) {
 442                 pr_err("gen: could not initialize luns\n");
 443                 goto err;
 444         }
 445
 446         ret = gen_blocks_init(dev, gn);
 447         if (ret) {
 448                 pr_err("gen: could not initialize blocks\n");
 449                 goto err;
 450         }
 451
 452         return 1;
 453 err:
 454         gen_free(dev);
 455         module_put(THIS_MODULE);
 456         return ret;
 457 }
 458
 459 static void gen_unregister(struct nvm_dev *dev)
 460 {
 461         struct gen_dev *gn = dev->mp;
 462         struct nvm_target *t, *tmp;
 463
 464         mutex_lock(&gn->lock);
 465         list_for_each_entry_safe(t, tmp, &gn->targets, list) {
 466                 if (t->dev != dev)
 467                         continue;
 468                 __gen_remove_target(t);
 469         }
 470         mutex_unlock(&gn->lock);
 471
 472         gen_free(dev);
 473         module_put(THIS_MODULE);
 474 }
 475
 476 static struct nvm_block *gen_get_blk(struct nvm_dev *dev,
 477                                 struct nvm_lun *vlun, unsigned long flags)
 478 {
 479         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 480         struct nvm_block *blk = NULL;
 481         int is_gc = flags & NVM_IOTYPE_GC;
 482
 483         spin_lock(&vlun->lock);
 484         if (list_empty(&lun->free_list)) {
 485                 pr_err_ratelimited("gen: lun %u have no free pages available",
 486                                                                 lun->vlun.id);
 487                 goto out;
 488         }
 489
 490         if (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks)
 491                 goto out;
 492
 493         blk = list_first_entry(&lun->free_list, struct nvm_block, list);
 494
 495         list_move_tail(&blk->list, &lun->used_list);
 496         blk->state = NVM_BLK_ST_TGT;
 497         lun->vlun.nr_free_blocks--;
 498 out:
 499         spin_unlock(&vlun->lock);
 500         return blk;
 501 }
 502
 503 static void gen_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 504 {
 505         struct nvm_lun *vlun = blk->lun;
 506         struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
 507
 508         spin_lock(&vlun->lock);
 509         if (blk->state & NVM_BLK_ST_TGT) {
 510                 list_move_tail(&blk->list, &lun->free_list);
 511                 lun->vlun.nr_free_blocks++;
 512                 blk->state = NVM_BLK_ST_FREE;
 513         } else if (blk->state & NVM_BLK_ST_BAD) {
 514                 list_move_tail(&blk->list, &lun->bb_list);
 515                 blk->state = NVM_BLK_ST_BAD;
 516         } else {
 517                 WARN_ON_ONCE(1);
 518                 pr_err("gen: erroneous block type (%lu -> %u)\n",
 519                                                         blk->id, blk->state);
 520                 list_move_tail(&blk->list, &lun->bb_list);
 521         }
 522         spin_unlock(&vlun->lock);
 523 }
 524
 525 static void gen_mark_blk(struct nvm_dev *dev, struct ppa_addr ppa, int type)
 526 {
 527         struct gen_dev *gn = dev->mp;
 528         struct gen_lun *lun;
 529         struct nvm_block *blk;
 530
 531         pr_debug("gen: ppa  (ch: %u lun: %u blk: %u pg: %u) -> %u\n",
 532                         ppa.g.ch, ppa.g.lun, ppa.g.blk, ppa.g.pg, type);
 533
 534         if (unlikely(ppa.g.ch > dev->nr_chnls ||
 535                                         ppa.g.lun > dev->luns_per_chnl ||
 536                                         ppa.g.blk > dev->blks_per_lun)) {
 537                 WARN_ON_ONCE(1);
 538                 pr_err("gen: ppa broken (ch: %u > %u lun: %u > %u blk: %u > %u",
 539                                 ppa.g.ch, dev->nr_chnls,
 540                                 ppa.g.lun, dev->luns_per_chnl,
 541                                 ppa.g.blk, dev->blks_per_lun);
 542                 return;
 543         }
 544
 545         lun = &gn->luns[(dev->luns_per_chnl * ppa.g.ch) + ppa.g.lun];
 546         blk = &lun->vlun.blocks[ppa.g.blk];
 547
 548         /* will be moved to bb list on put_blk from target */
 549         blk->state = type;
 550 }
 551
 552 /*
 553  * mark block bad in gen. It is expected that the target recovers separately
 554  */
 555 static void gen_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
 556 {
 557         int bit = -1;
 558         int max_secs = dev->ops->max_phys_sect;
 559         void *comp_bits = &rqd->ppa_status;
 560
 561         nvm_addr_to_generic_mode(dev, rqd);
 562
 563         /* look up blocks and mark them as bad */
 564         if (rqd->nr_ppas == 1) {
 565                 gen_mark_blk(dev, rqd->ppa_addr, NVM_BLK_ST_BAD);
 566                 return;
 567         }
 568
 569         while ((bit = find_next_bit(comp_bits, max_secs, bit + 1)) < max_secs)
 570                 gen_mark_blk(dev, rqd->ppa_list[bit], NVM_BLK_ST_BAD);
 571 }
 572
 573 static void gen_end_io(struct nvm_rq *rqd)
 574 {
 575         struct nvm_tgt_instance *ins = rqd->ins;
 576
 577         if (rqd->error == NVM_RSP_ERR_FAILWRITE)
 578                 gen_mark_blk_bad(rqd->dev, rqd);
 579
 580         ins->tt->end_io(rqd);
 581 }
 582
 583 static int gen_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 584 {
 585         if (!dev->ops->submit_io)
 586                 return -ENODEV;
 587
 588         /* Convert address space */
 589         nvm_generic_to_addr_mode(dev, rqd);
 590
 591         rqd->dev = dev;
 592         rqd->end_io = gen_end_io;
 593         return dev->ops->submit_io(dev, rqd);
 594 }
 595
 596 static int gen_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 597                                                         unsigned long flags)
 598 {
 599         struct ppa_addr addr = block_to_ppa(dev, blk);
 600
 601         return nvm_erase_ppa(dev, &addr, 1);
 602 }
 603
 604 static int gen_reserve_lun(struct nvm_dev *dev, int lunid)
 605 {
 606         return test_and_set_bit(lunid, dev->lun_map);
 607 }
 608
 609 static void gen_release_lun(struct nvm_dev *dev, int lunid)
 610 {
 611         WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
 612 }
 613
 614 static struct nvm_lun *gen_get_lun(struct nvm_dev *dev, int lunid)
 615 {
 616         struct gen_dev *gn = dev->mp;
 617
 618         if (unlikely(lunid >= dev->nr_luns))
 619                 return NULL;
 620
 621         return &gn->luns[lunid].vlun;
 622 }
 623
 624 static void gen_lun_info_print(struct nvm_dev *dev)
 625 {
 626         struct gen_dev *gn = dev->mp;
 627         struct gen_lun *lun;
 628         unsigned int i;
 629
 630
 631         gen_for_each_lun(gn, lun, i) {
 632                 spin_lock(&lun->vlun.lock);
 633
 634                 pr_info("%s: lun%8u\t%u\n", dev->name, i,
 635                                                 lun->vlun.nr_free_blocks);
 636
 637                 spin_unlock(&lun->vlun.lock);
 638         }
 639 }
 640
 641 static struct nvmm_type gen = {
 642         .name                   = "gennvm",
 643         .version                = {0, 1, 0},
 644
 645         .register_mgr           = gen_register,
 646         .unregister_mgr         = gen_unregister,
 647
 648         .create_tgt             = gen_create_tgt,
 649         .remove_tgt             = gen_remove_tgt,
 650
 651         .get_blk                = gen_get_blk,
 652         .put_blk                = gen_put_blk,
 653
 654         .submit_io              = gen_submit_io,
 655         .erase_blk              = gen_erase_blk,
 656
 657         .mark_blk               = gen_mark_blk,
 658
 659         .get_lun                = gen_get_lun,
 660         .reserve_lun            = gen_reserve_lun,
 661         .release_lun            = gen_release_lun,
 662         .lun_info_print         = gen_lun_info_print,
 663
 664         .get_area               = gen_get_area,
 665         .put_area               = gen_put_area,
 666
 667 };
 668
 669 static int __init gen_module_init(void)
 670 {
 671         return nvm_register_mgr(&gen);
 672 }
 673
 674 static void gen_module_exit(void)
 675 {
 676         nvm_unregister_mgr(&gen);
 677 }
 678
 679 module_init(gen_module_init);
 680 module_exit(gen_module_exit);
 681 MODULE_LICENSE("GPL v2");
 682 MODULE_DESCRIPTION("General media manager for Open-Channel SSDs");