drivers/lightnvm/core.c

   1 /*
   2  * Copyright (C) 2015 IT University of Copenhagen. All rights reserved.
   3  * Initial release: Matias Bjorling <m@bjorling.me>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License version
   7  * 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; see the file COPYING.  If not, write to
  16  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
  17  * USA.
  18  *
  19  */
  20
  21 #include <linux/blkdev.h>
  22 #include <linux/blk-mq.h>
  23 #include <linux/list.h>
  24 #include <linux/types.h>
  25 #include <linux/sem.h>
  26 #include <linux/bitmap.h>
  27 #include <linux/module.h>
  28 #include <linux/miscdevice.h>
  29 #include <linux/lightnvm.h>
  30 #include <uapi/linux/lightnvm.h>
  31
  32 static LIST_HEAD(nvm_targets);
  33 static LIST_HEAD(nvm_mgrs);
  34 static LIST_HEAD(nvm_devices);
  35 static DECLARE_RWSEM(nvm_lock);
  36
  37 static struct nvm_tgt_type *nvm_find_target_type(const char *name)
  38 {
  39         struct nvm_tgt_type *tt;
  40
  41         list_for_each_entry(tt, &nvm_targets, list)
  42                 if (!strcmp(name, tt->name))
  43                         return tt;
  44
  45         return NULL;
  46 }
  47
  48 int nvm_register_target(struct nvm_tgt_type *tt)
  49 {
  50         int ret = 0;
  51
  52         down_write(&nvm_lock);
  53         if (nvm_find_target_type(tt->name))
  54                 ret = -EEXIST;
  55         else
  56                 list_add(&tt->list, &nvm_targets);
  57         up_write(&nvm_lock);
  58
  59         return ret;
  60 }
  61 EXPORT_SYMBOL(nvm_register_target);
  62
  63 void nvm_unregister_target(struct nvm_tgt_type *tt)
  64 {
  65         if (!tt)
  66                 return;
  67
  68         down_write(&nvm_lock);
  69         list_del(&tt->list);
  70         up_write(&nvm_lock);
  71 }
  72 EXPORT_SYMBOL(nvm_unregister_target);
  73
  74 void *nvm_dev_dma_alloc(struct nvm_dev *dev, gfp_t mem_flags,
  75                                                         dma_addr_t *dma_handler)
  76 {
  77         return dev->ops->dev_dma_alloc(dev->q, dev->ppalist_pool, mem_flags,
  78                                                                 dma_handler);
  79 }
  80 EXPORT_SYMBOL(nvm_dev_dma_alloc);
  81
  82 void nvm_dev_dma_free(struct nvm_dev *dev, void *ppa_list,
  83                                                         dma_addr_t dma_handler)
  84 {
  85         dev->ops->dev_dma_free(dev->ppalist_pool, ppa_list, dma_handler);
  86 }
  87 EXPORT_SYMBOL(nvm_dev_dma_free);
  88
  89 static struct nvmm_type *nvm_find_mgr_type(const char *name)
  90 {
  91         struct nvmm_type *mt;
  92
  93         list_for_each_entry(mt, &nvm_mgrs, list)
  94                 if (!strcmp(name, mt->name))
  95                         return mt;
  96
  97         return NULL;
  98 }
  99
 100 int nvm_register_mgr(struct nvmm_type *mt)
 101 {
 102         int ret = 0;
 103
 104         down_write(&nvm_lock);
 105         if (nvm_find_mgr_type(mt->name))
 106                 ret = -EEXIST;
 107         else
 108                 list_add(&mt->list, &nvm_mgrs);
 109         up_write(&nvm_lock);
 110
 111         return ret;
 112 }
 113 EXPORT_SYMBOL(nvm_register_mgr);
 114
 115 void nvm_unregister_mgr(struct nvmm_type *mt)
 116 {
 117         if (!mt)
 118                 return;
 119
 120         down_write(&nvm_lock);
 121         list_del(&mt->list);
 122         up_write(&nvm_lock);
 123 }
 124 EXPORT_SYMBOL(nvm_unregister_mgr);
 125
 126 static struct nvm_dev *nvm_find_nvm_dev(const char *name)
 127 {
 128         struct nvm_dev *dev;
 129
 130         list_for_each_entry(dev, &nvm_devices, devices)
 131                 if (!strcmp(name, dev->name))
 132                         return dev;
 133
 134         return NULL;
 135 }
 136
 137 struct nvm_block *nvm_get_blk(struct nvm_dev *dev, struct nvm_lun *lun,
 138                                                         unsigned long flags)
 139 {
 140         return dev->mt->get_blk(dev, lun, flags);
 141 }
 142 EXPORT_SYMBOL(nvm_get_blk);
 143
 144 /* Assumes that all valid pages have already been moved on release to bm */
 145 void nvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 146 {
 147         return dev->mt->put_blk(dev, blk);
 148 }
 149 EXPORT_SYMBOL(nvm_put_blk);
 150
 151 int nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 152 {
 153         return dev->mt->submit_io(dev, rqd);
 154 }
 155 EXPORT_SYMBOL(nvm_submit_io);
 156
 157 int nvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk)
 158 {
 159         return dev->mt->erase_blk(dev, blk, 0);
 160 }
 161 EXPORT_SYMBOL(nvm_erase_blk);
 162
 163 static int nvm_core_init(struct nvm_dev *dev)
 164 {
 165         struct nvm_id *id = &dev->identity;
 166         struct nvm_id_group *grp = &id->groups[0];
 167
 168         /* device values */
 169         dev->nr_chnls = grp->num_ch;
 170         dev->luns_per_chnl = grp->num_lun;
 171         dev->pgs_per_blk = grp->num_pg;
 172         dev->blks_per_lun = grp->num_blk;
 173         dev->nr_planes = grp->num_pln;
 174         dev->sec_size = grp->csecs;
 175         dev->oob_size = grp->sos;
 176         dev->sec_per_pg = grp->fpg_sz / grp->csecs;
 177         dev->addr_mode = id->ppat;
 178         dev->addr_format = id->ppaf;
 179
 180         dev->plane_mode = NVM_PLANE_SINGLE;
 181         dev->max_rq_size = dev->ops->max_phys_sect * dev->sec_size;
 182
 183         if (grp->mtype != 0) {
 184                 pr_err("nvm: memory type not supported\n");
 185                 return -EINVAL;
 186         }
 187
 188         if (grp->fmtype != 0 && grp->fmtype != 1) {
 189                 pr_err("nvm: flash type not supported\n");
 190                 return -EINVAL;
 191         }
 192
 193         if (grp->mpos & 0x020202)
 194                 dev->plane_mode = NVM_PLANE_DOUBLE;
 195         if (grp->mpos & 0x040404)
 196                 dev->plane_mode = NVM_PLANE_QUAD;
 197
 198         /* calculated values */
 199         dev->sec_per_pl = dev->sec_per_pg * dev->nr_planes;
 200         dev->sec_per_blk = dev->sec_per_pl * dev->pgs_per_blk;
 201         dev->sec_per_lun = dev->sec_per_blk * dev->blks_per_lun;
 202         dev->nr_luns = dev->luns_per_chnl * dev->nr_chnls;
 203
 204         dev->total_blocks = dev->nr_planes *
 205                                 dev->blks_per_lun *
 206                                 dev->luns_per_chnl *
 207                                 dev->nr_chnls;
 208         dev->total_pages = dev->total_blocks * dev->pgs_per_blk;
 209         INIT_LIST_HEAD(&dev->online_targets);
 210
 211         return 0;
 212 }
 213
 214 static void nvm_free(struct nvm_dev *dev)
 215 {
 216         if (!dev)
 217                 return;
 218
 219         if (dev->mt)
 220                 dev->mt->unregister_mgr(dev);
 221 }
 222
 223 static int nvm_init(struct nvm_dev *dev)
 224 {
 225         struct nvmm_type *mt;
 226         int ret = 0;
 227
 228         if (!dev->q || !dev->ops)
 229                 return -EINVAL;
 230
 231         if (dev->ops->identity(dev->q, &dev->identity)) {
 232                 pr_err("nvm: device could not be identified\n");
 233                 ret = -EINVAL;
 234                 goto err;
 235         }
 236
 237         pr_debug("nvm: ver:%x nvm_vendor:%x groups:%u\n",
 238                         dev->identity.ver_id, dev->identity.vmnt,
 239                                                         dev->identity.cgrps);
 240
 241         if (dev->identity.ver_id != 1) {
 242                 pr_err("nvm: device not supported by kernel.");
 243                 goto err;
 244         }
 245
 246         if (dev->identity.cgrps != 1) {
 247                 pr_err("nvm: only one group configuration supported.");
 248                 goto err;
 249         }
 250
 251         ret = nvm_core_init(dev);
 252         if (ret) {
 253                 pr_err("nvm: could not initialize core structures.\n");
 254                 goto err;
 255         }
 256
 257         /* register with device with a supported manager */
 258         list_for_each_entry(mt, &nvm_mgrs, list) {
 259                 ret = mt->register_mgr(dev);
 260                 if (ret < 0)
 261                         goto err; /* initialization failed */
 262                 if (ret > 0) {
 263                         dev->mt = mt;
 264                         break; /* successfully initialized */
 265                 }
 266         }
 267
 268         if (!ret) {
 269                 pr_info("nvm: no compatible manager found.\n");
 270                 return 0;
 271         }
 272
 273         pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",
 274                         dev->name, dev->sec_per_pg, dev->nr_planes,
 275                         dev->pgs_per_blk, dev->blks_per_lun, dev->nr_luns,
 276                         dev->nr_chnls);
 277         return 0;
 278 err:
 279         nvm_free(dev);
 280         pr_err("nvm: failed to initialize nvm\n");
 281         return ret;
 282 }
 283
 284 static void nvm_exit(struct nvm_dev *dev)
 285 {
 286         if (dev->ppalist_pool)
 287                 dev->ops->destroy_dma_pool(dev->ppalist_pool);
 288         nvm_free(dev);
 289
 290         pr_info("nvm: successfully unloaded\n");
 291 }
 292
 293 int nvm_register(struct request_queue *q, char *disk_name,
 294                                                         struct nvm_dev_ops *ops)
 295 {
 296         struct nvm_dev *dev;
 297         int ret;
 298
 299         if (!ops->identity)
 300                 return -EINVAL;
 301
 302         dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);
 303         if (!dev)
 304                 return -ENOMEM;
 305
 306         dev->q = q;
 307         dev->ops = ops;
 308         strncpy(dev->name, disk_name, DISK_NAME_LEN);
 309
 310         ret = nvm_init(dev);
 311         if (ret)
 312                 goto err_init;
 313
 314         if (dev->ops->max_phys_sect > 1) {
 315                 dev->ppalist_pool = dev->ops->create_dma_pool(dev->q,
 316                                                                 "ppalist");
 317                 if (!dev->ppalist_pool) {
 318                         pr_err("nvm: could not create ppa pool\n");
 319                         return -ENOMEM;
 320                 }
 321         } else if (dev->ops->max_phys_sect > 256) {
 322                 pr_info("nvm: max sectors supported is 256.\n");
 323                 return -EINVAL;
 324         }
 325
 326         down_write(&nvm_lock);
 327         list_add(&dev->devices, &nvm_devices);
 328         up_write(&nvm_lock);
 329
 330         return 0;
 331 err_init:
 332         kfree(dev);
 333         return ret;
 334 }
 335 EXPORT_SYMBOL(nvm_register);
 336
 337 void nvm_unregister(char *disk_name)
 338 {
 339         struct nvm_dev *dev = nvm_find_nvm_dev(disk_name);
 340
 341         if (!dev) {
 342                 pr_err("nvm: could not find device %s to unregister\n",
 343                                                                 disk_name);
 344                 return;
 345         }
 346
 347         down_write(&nvm_lock);
 348         list_del(&dev->devices);
 349         up_write(&nvm_lock);
 350
 351         nvm_exit(dev);
 352         kfree(dev);
 353 }
 354 EXPORT_SYMBOL(nvm_unregister);
 355
 356 static const struct block_device_operations nvm_fops = {
 357         .owner          = THIS_MODULE,
 358 };
 359
 360 static int nvm_create_target(struct nvm_dev *dev,
 361                                                 struct nvm_ioctl_create *create)
 362 {
 363         struct nvm_ioctl_create_simple *s = &create->conf.s;
 364         struct request_queue *tqueue;
 365         struct nvmm_type *mt;
 366         struct gendisk *tdisk;
 367         struct nvm_tgt_type *tt;
 368         struct nvm_target *t;
 369         void *targetdata;
 370         int ret = 0;
 371
 372         if (!dev->mt) {
 373                 /* register with device with a supported NVM manager */
 374                 list_for_each_entry(mt, &nvm_mgrs, list) {
 375                         ret = mt->register_mgr(dev);
 376                         if (ret < 0)
 377                                 return ret; /* initialization failed */
 378                         if (ret > 0) {
 379                                 dev->mt = mt;
 380                                 break; /* successfully initialized */
 381                         }
 382                 }
 383
 384                 if (!ret) {
 385                         pr_info("nvm: no compatible nvm manager found.\n");
 386                         return -ENODEV;
 387                 }
 388         }
 389
 390         tt = nvm_find_target_type(create->tgttype);
 391         if (!tt) {
 392                 pr_err("nvm: target type %s not found\n", create->tgttype);
 393                 return -EINVAL;
 394         }
 395
 396         down_write(&nvm_lock);
 397         list_for_each_entry(t, &dev->online_targets, list) {
 398                 if (!strcmp(create->tgtname, t->disk->disk_name)) {
 399                         pr_err("nvm: target name already exists.\n");
 400                         up_write(&nvm_lock);
 401                         return -EINVAL;
 402                 }
 403         }
 404         up_write(&nvm_lock);
 405
 406         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 407         if (!t)
 408                 return -ENOMEM;
 409
 410         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
 411         if (!tqueue)
 412                 goto err_t;
 413         blk_queue_make_request(tqueue, tt->make_rq);
 414
 415         tdisk = alloc_disk(0);
 416         if (!tdisk)
 417                 goto err_queue;
 418
 419         sprintf(tdisk->disk_name, "%s", create->tgtname);
 420         tdisk->flags = GENHD_FL_EXT_DEVT;
 421         tdisk->major = 0;
 422         tdisk->first_minor = 0;
 423         tdisk->fops = &nvm_fops;
 424         tdisk->queue = tqueue;
 425
 426         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
 427         if (IS_ERR(targetdata))
 428                 goto err_init;
 429
 430         tdisk->private_data = targetdata;
 431         tqueue->queuedata = targetdata;
 432
 433         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
 434
 435         set_capacity(tdisk, tt->capacity(targetdata));
 436         add_disk(tdisk);
 437
 438         t->type = tt;
 439         t->disk = tdisk;
 440
 441         down_write(&nvm_lock);
 442         list_add_tail(&t->list, &dev->online_targets);
 443         up_write(&nvm_lock);
 444
 445         return 0;
 446 err_init:
 447         put_disk(tdisk);
 448 err_queue:
 449         blk_cleanup_queue(tqueue);
 450 err_t:
 451         kfree(t);
 452         return -ENOMEM;
 453 }
 454
 455 static void nvm_remove_target(struct nvm_target *t)
 456 {
 457         struct nvm_tgt_type *tt = t->type;
 458         struct gendisk *tdisk = t->disk;
 459         struct request_queue *q = tdisk->queue;
 460
 461         lockdep_assert_held(&nvm_lock);
 462
 463         del_gendisk(tdisk);
 464         if (tt->exit)
 465                 tt->exit(tdisk->private_data);
 466
 467         blk_cleanup_queue(q);
 468
 469         put_disk(tdisk);
 470
 471         list_del(&t->list);
 472         kfree(t);
 473 }
 474
 475 static int __nvm_configure_create(struct nvm_ioctl_create *create)
 476 {
 477         struct nvm_dev *dev;
 478         struct nvm_ioctl_create_simple *s;
 479
 480         dev = nvm_find_nvm_dev(create->dev);
 481         if (!dev) {
 482                 pr_err("nvm: device not found\n");
 483                 return -EINVAL;
 484         }
 485
 486         if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
 487                 pr_err("nvm: config type not valid\n");
 488                 return -EINVAL;
 489         }
 490         s = &create->conf.s;
 491
 492         if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
 493                 pr_err("nvm: lun out of bound (%u:%u > %u)\n",
 494                         s->lun_begin, s->lun_end, dev->nr_luns);
 495                 return -EINVAL;
 496         }
 497
 498         return nvm_create_target(dev, create);
 499 }
 500
 501 static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
 502 {
 503         struct nvm_target *t = NULL;
 504         struct nvm_dev *dev;
 505         int ret = -1;
 506
 507         down_write(&nvm_lock);
 508         list_for_each_entry(dev, &nvm_devices, devices)
 509                 list_for_each_entry(t, &dev->online_targets, list) {
 510                         if (!strcmp(remove->tgtname, t->disk->disk_name)) {
 511                                 nvm_remove_target(t);
 512                                 ret = 0;
 513                                 break;
 514                         }
 515                 }
 516         up_write(&nvm_lock);
 517
 518         if (ret) {
 519                 pr_err("nvm: target \"%s\" doesn't exist.\n", remove->tgtname);
 520                 return -EINVAL;
 521         }
 522
 523         return 0;
 524 }
 525
 526 #ifdef CONFIG_NVM_DEBUG
 527 static int nvm_configure_show(const char *val)
 528 {
 529         struct nvm_dev *dev;
 530         char opcode, devname[DISK_NAME_LEN];
 531         int ret;
 532
 533         ret = sscanf(val, "%c %32s", &opcode, devname);
 534         if (ret != 2) {
 535                 pr_err("nvm: invalid command. Use \"opcode devicename\".\n");
 536                 return -EINVAL;
 537         }
 538
 539         dev = nvm_find_nvm_dev(devname);
 540         if (!dev) {
 541                 pr_err("nvm: device not found\n");
 542                 return -EINVAL;
 543         }
 544
 545         if (!dev->mt)
 546                 return 0;
 547
 548         dev->mt->free_blocks_print(dev);
 549
 550         return 0;
 551 }
 552
 553 static int nvm_configure_remove(const char *val)
 554 {
 555         struct nvm_ioctl_remove remove;
 556         char opcode;
 557         int ret;
 558
 559         ret = sscanf(val, "%c %256s", &opcode, remove.tgtname);
 560         if (ret != 2) {
 561                 pr_err("nvm: invalid command. Use \"d targetname\".\n");
 562                 return -EINVAL;
 563         }
 564
 565         remove.flags = 0;
 566
 567         return __nvm_configure_remove(&remove);
 568 }
 569
 570 static int nvm_configure_create(const char *val)
 571 {
 572         struct nvm_ioctl_create create;
 573         char opcode;
 574         int lun_begin, lun_end, ret;
 575
 576         ret = sscanf(val, "%c %256s %256s %48s %u:%u", &opcode, create.dev,
 577                                                 create.tgtname, create.tgttype,
 578                                                 &lun_begin, &lun_end);
 579         if (ret != 6) {
 580                 pr_err("nvm: invalid command. Use \"opcode device name tgttype lun_begin:lun_end\".\n");
 581                 return -EINVAL;
 582         }
 583
 584         create.flags = 0;
 585         create.conf.type = NVM_CONFIG_TYPE_SIMPLE;
 586         create.conf.s.lun_begin = lun_begin;
 587         create.conf.s.lun_end = lun_end;
 588
 589         return __nvm_configure_create(&create);
 590 }
 591
 592
 593 /* Exposes administrative interface through /sys/module/lnvm/configure_by_str */
 594 static int nvm_configure_by_str_event(const char *val,
 595                                         const struct kernel_param *kp)
 596 {
 597         char opcode;
 598         int ret;
 599
 600         ret = sscanf(val, "%c", &opcode);
 601         if (ret != 1) {
 602                 pr_err("nvm: string must have the format of \"cmd ...\"\n");
 603                 return -EINVAL;
 604         }
 605
 606         switch (opcode) {
 607         case 'a':
 608                 return nvm_configure_create(val);
 609         case 'd':
 610                 return nvm_configure_remove(val);
 611         case 's':
 612                 return nvm_configure_show(val);
 613         default:
 614                 pr_err("nvm: invalid command\n");
 615                 return -EINVAL;
 616         }
 617
 618         return 0;
 619 }
 620
 621 static int nvm_configure_get(char *buf, const struct kernel_param *kp)
 622 {
 623         int sz = 0;
 624         char *buf_start = buf;
 625         struct nvm_dev *dev;
 626
 627         buf += sprintf(buf, "available devices:\n");
 628         down_write(&nvm_lock);
 629         list_for_each_entry(dev, &nvm_devices, devices) {
 630                 if (sz > 4095 - DISK_NAME_LEN)
 631                         break;
 632                 buf += sprintf(buf, " %32s\n", dev->name);
 633         }
 634         up_write(&nvm_lock);
 635
 636         return buf - buf_start - 1;
 637 }
 638
 639 static const struct kernel_param_ops nvm_configure_by_str_event_param_ops = {
 640         .set    = nvm_configure_by_str_event,
 641         .get    = nvm_configure_get,
 642 };
 643
 644 #undef MODULE_PARAM_PREFIX
 645 #define MODULE_PARAM_PREFIX     "lnvm."
 646
 647 module_param_cb(configure_debug, &nvm_configure_by_str_event_param_ops, NULL,
 648                                                                         0644);
 649
 650 #endif /* CONFIG_NVM_DEBUG */
 651
 652 static long nvm_ioctl_info(struct file *file, void __user *arg)
 653 {
 654         struct nvm_ioctl_info *info;
 655         struct nvm_tgt_type *tt;
 656         int tgt_iter = 0;
 657
 658         if (!capable(CAP_SYS_ADMIN))
 659                 return -EPERM;
 660
 661         info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
 662         if (IS_ERR(info))
 663                 return -EFAULT;
 664
 665         info->version[0] = NVM_VERSION_MAJOR;
 666         info->version[1] = NVM_VERSION_MINOR;
 667         info->version[2] = NVM_VERSION_PATCH;
 668
 669         down_write(&nvm_lock);
 670         list_for_each_entry(tt, &nvm_targets, list) {
 671                 struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 672
 673                 tgt->version[0] = tt->version[0];
 674                 tgt->version[1] = tt->version[1];
 675                 tgt->version[2] = tt->version[2];
 676                 strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
 677
 678                 tgt_iter++;
 679         }
 680
 681         info->tgtsize = tgt_iter;
 682         up_write(&nvm_lock);
 683
 684         if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info)))
 685                 return -EFAULT;
 686
 687         kfree(info);
 688         return 0;
 689 }
 690
 691 static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
 692 {
 693         struct nvm_ioctl_get_devices *devices;
 694         struct nvm_dev *dev;
 695         int i = 0;
 696
 697         if (!capable(CAP_SYS_ADMIN))
 698                 return -EPERM;
 699
 700         devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
 701         if (!devices)
 702                 return -ENOMEM;
 703
 704         down_write(&nvm_lock);
 705         list_for_each_entry(dev, &nvm_devices, devices) {
 706                 struct nvm_ioctl_device_info *info = &devices->info[i];
 707
 708                 sprintf(info->devname, "%s", dev->name);
 709                 if (dev->mt) {
 710                         info->bmversion[0] = dev->mt->version[0];
 711                         info->bmversion[1] = dev->mt->version[1];
 712                         info->bmversion[2] = dev->mt->version[2];
 713                         sprintf(info->bmname, "%s", dev->mt->name);
 714                 } else {
 715                         sprintf(info->bmname, "none");
 716                 }
 717
 718                 i++;
 719                 if (i > 31) {
 720                         pr_err("nvm: max 31 devices can be reported.\n");
 721                         break;
 722                 }
 723         }
 724         up_write(&nvm_lock);
 725
 726         devices->nr_devices = i;
 727
 728         if (copy_to_user(arg, devices, sizeof(struct nvm_ioctl_get_devices)))
 729                 return -EFAULT;
 730
 731         kfree(devices);
 732         return 0;
 733 }
 734
 735 static long nvm_ioctl_dev_create(struct file *file, void __user *arg)
 736 {
 737         struct nvm_ioctl_create create;
 738
 739         if (!capable(CAP_SYS_ADMIN))
 740                 return -EPERM;
 741
 742         if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
 743                 return -EFAULT;
 744
 745         create.dev[DISK_NAME_LEN - 1] = '\0';
 746         create.tgttype[NVM_TTYPE_NAME_MAX - 1] = '\0';
 747         create.tgtname[DISK_NAME_LEN - 1] = '\0';
 748
 749         if (create.flags != 0) {
 750                 pr_err("nvm: no flags supported\n");
 751                 return -EINVAL;
 752         }
 753
 754         return __nvm_configure_create(&create);
 755 }
 756
 757 static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
 758 {
 759         struct nvm_ioctl_remove remove;
 760
 761         if (!capable(CAP_SYS_ADMIN))
 762                 return -EPERM;
 763
 764         if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
 765                 return -EFAULT;
 766
 767         remove.tgtname[DISK_NAME_LEN - 1] = '\0';
 768
 769         if (remove.flags != 0) {
 770                 pr_err("nvm: no flags supported\n");
 771                 return -EINVAL;
 772         }
 773
 774         return __nvm_configure_remove(&remove);
 775 }
 776
 777 static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 778 {
 779         void __user *argp = (void __user *)arg;
 780
 781         switch (cmd) {
 782         case NVM_INFO:
 783                 return nvm_ioctl_info(file, argp);
 784         case NVM_GET_DEVICES:
 785                 return nvm_ioctl_get_devices(file, argp);
 786         case NVM_DEV_CREATE:
 787                 return nvm_ioctl_dev_create(file, argp);
 788         case NVM_DEV_REMOVE:
 789                 return nvm_ioctl_dev_remove(file, argp);
 790         }
 791         return 0;
 792 }
 793
 794 static const struct file_operations _ctl_fops = {
 795         .open = nonseekable_open,
 796         .unlocked_ioctl = nvm_ctl_ioctl,
 797         .owner = THIS_MODULE,
 798         .llseek  = noop_llseek,
 799 };
 800
 801 static struct miscdevice _nvm_misc = {
 802         .minor          = MISC_DYNAMIC_MINOR,
 803         .name           = "lightnvm",
 804         .nodename       = "lightnvm/control",
 805         .fops           = &_ctl_fops,
 806 };
 807
 808 MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
 809
 810 static int __init nvm_mod_init(void)
 811 {
 812         int ret;
 813
 814         ret = misc_register(&_nvm_misc);
 815         if (ret)
 816                 pr_err("nvm: misc_register failed for control device");
 817
 818         return ret;
 819 }
 820
 821 static void __exit nvm_mod_exit(void)
 822 {
 823         misc_deregister(&_nvm_misc);
 824 }
 825
 826 MODULE_AUTHOR("Matias Bjorling <m@bjorling.me>");
 827 MODULE_LICENSE("GPL v2");
 828 MODULE_VERSION("0.1");
 829 module_init(nvm_mod_init);
 830 module_exit(nvm_mod_exit);