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 void nvm_core_free(struct nvm_dev *dev)
 164 {
 165         kfree(dev);
 166 }
 167
 168 static int nvm_core_init(struct nvm_dev *dev)
 169 {
 170         struct nvm_id *id = &dev->identity;
 171         struct nvm_id_group *grp = &id->groups[0];
 172
 173         /* device values */
 174         dev->nr_chnls = grp->num_ch;
 175         dev->luns_per_chnl = grp->num_lun;
 176         dev->pgs_per_blk = grp->num_pg;
 177         dev->blks_per_lun = grp->num_blk;
 178         dev->nr_planes = grp->num_pln;
 179         dev->sec_size = grp->csecs;
 180         dev->oob_size = grp->sos;
 181         dev->sec_per_pg = grp->fpg_sz / grp->csecs;
 182         dev->addr_mode = id->ppat;
 183         dev->addr_format = id->ppaf;
 184
 185         dev->plane_mode = NVM_PLANE_SINGLE;
 186         dev->max_rq_size = dev->ops->max_phys_sect * dev->sec_size;
 187
 188         if (grp->mtype != 0) {
 189                 pr_err("nvm: memory type not supported\n");
 190                 return -EINVAL;
 191         }
 192
 193         if (grp->fmtype != 0 && grp->fmtype != 1) {
 194                 pr_err("nvm: flash type not supported\n");
 195                 return -EINVAL;
 196         }
 197
 198         if (grp->mpos & 0x020202)
 199                 dev->plane_mode = NVM_PLANE_DOUBLE;
 200         if (grp->mpos & 0x040404)
 201                 dev->plane_mode = NVM_PLANE_QUAD;
 202
 203         /* calculated values */
 204         dev->sec_per_pl = dev->sec_per_pg * dev->nr_planes;
 205         dev->sec_per_blk = dev->sec_per_pl * dev->pgs_per_blk;
 206         dev->sec_per_lun = dev->sec_per_blk * dev->blks_per_lun;
 207         dev->nr_luns = dev->luns_per_chnl * dev->nr_chnls;
 208
 209         dev->total_blocks = dev->nr_planes *
 210                                 dev->blks_per_lun *
 211                                 dev->luns_per_chnl *
 212                                 dev->nr_chnls;
 213         dev->total_pages = dev->total_blocks * dev->pgs_per_blk;
 214         INIT_LIST_HEAD(&dev->online_targets);
 215
 216         return 0;
 217 }
 218
 219 static void nvm_free(struct nvm_dev *dev)
 220 {
 221         if (!dev)
 222                 return;
 223
 224         if (dev->mt)
 225                 dev->mt->unregister_mgr(dev);
 226
 227         nvm_core_free(dev);
 228 }
 229
 230 static int nvm_init(struct nvm_dev *dev)
 231 {
 232         struct nvmm_type *mt;
 233         int ret = 0;
 234
 235         if (!dev->q || !dev->ops)
 236                 return -EINVAL;
 237
 238         if (dev->ops->identity(dev->q, &dev->identity)) {
 239                 pr_err("nvm: device could not be identified\n");
 240                 ret = -EINVAL;
 241                 goto err;
 242         }
 243
 244         pr_debug("nvm: ver:%x nvm_vendor:%x groups:%u\n",
 245                         dev->identity.ver_id, dev->identity.vmnt,
 246                                                         dev->identity.cgrps);
 247
 248         if (dev->identity.ver_id != 1) {
 249                 pr_err("nvm: device not supported by kernel.");
 250                 goto err;
 251         }
 252
 253         if (dev->identity.cgrps != 1) {
 254                 pr_err("nvm: only one group configuration supported.");
 255                 goto err;
 256         }
 257
 258         ret = nvm_core_init(dev);
 259         if (ret) {
 260                 pr_err("nvm: could not initialize core structures.\n");
 261                 goto err;
 262         }
 263
 264         /* register with device with a supported manager */
 265         list_for_each_entry(mt, &nvm_mgrs, list) {
 266                 ret = mt->register_mgr(dev);
 267                 if (ret < 0)
 268                         goto err; /* initialization failed */
 269                 if (ret > 0) {
 270                         dev->mt = mt;
 271                         break; /* successfully initialized */
 272                 }
 273         }
 274
 275         if (!ret) {
 276                 pr_info("nvm: no compatible manager found.\n");
 277                 return 0;
 278         }
 279
 280         pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",
 281                         dev->name, dev->sec_per_pg, dev->nr_planes,
 282                         dev->pgs_per_blk, dev->blks_per_lun, dev->nr_luns,
 283                         dev->nr_chnls);
 284         return 0;
 285 err:
 286         nvm_free(dev);
 287         pr_err("nvm: failed to initialize nvm\n");
 288         return ret;
 289 }
 290
 291 static void nvm_exit(struct nvm_dev *dev)
 292 {
 293         if (dev->ppalist_pool)
 294                 dev->ops->destroy_dma_pool(dev->ppalist_pool);
 295         nvm_free(dev);
 296
 297         pr_info("nvm: successfully unloaded\n");
 298 }
 299
 300 int nvm_register(struct request_queue *q, char *disk_name,
 301                                                         struct nvm_dev_ops *ops)
 302 {
 303         struct nvm_dev *dev;
 304         int ret;
 305
 306         if (!ops->identity)
 307                 return -EINVAL;
 308
 309         dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);
 310         if (!dev)
 311                 return -ENOMEM;
 312
 313         dev->q = q;
 314         dev->ops = ops;
 315         strncpy(dev->name, disk_name, DISK_NAME_LEN);
 316
 317         ret = nvm_init(dev);
 318         if (ret)
 319                 goto err_init;
 320
 321         down_write(&nvm_lock);
 322         list_add(&dev->devices, &nvm_devices);
 323         up_write(&nvm_lock);
 324
 325         if (dev->ops->max_phys_sect > 1) {
 326                 dev->ppalist_pool = dev->ops->create_dma_pool(dev->q,
 327                                                                 "ppalist");
 328                 if (!dev->ppalist_pool) {
 329                         pr_err("nvm: could not create ppa pool\n");
 330                         return -ENOMEM;
 331                 }
 332         } else if (dev->ops->max_phys_sect > 256) {
 333                 pr_info("nvm: max sectors supported is 256.\n");
 334                 return -EINVAL;
 335         }
 336
 337         return 0;
 338 err_init:
 339         kfree(dev);
 340         return ret;
 341 }
 342 EXPORT_SYMBOL(nvm_register);
 343
 344 void nvm_unregister(char *disk_name)
 345 {
 346         struct nvm_dev *dev = nvm_find_nvm_dev(disk_name);
 347
 348         if (!dev) {
 349                 pr_err("nvm: could not find device %s to unregister\n",
 350                                                                 disk_name);
 351                 return;
 352         }
 353
 354         nvm_exit(dev);
 355
 356         down_write(&nvm_lock);
 357         list_del(&dev->devices);
 358         up_write(&nvm_lock);
 359 }
 360 EXPORT_SYMBOL(nvm_unregister);
 361
 362 static const struct block_device_operations nvm_fops = {
 363         .owner          = THIS_MODULE,
 364 };
 365
 366 static int nvm_create_target(struct nvm_dev *dev,
 367                                                 struct nvm_ioctl_create *create)
 368 {
 369         struct nvm_ioctl_create_simple *s = &create->conf.s;
 370         struct request_queue *tqueue;
 371         struct nvmm_type *mt;
 372         struct gendisk *tdisk;
 373         struct nvm_tgt_type *tt;
 374         struct nvm_target *t;
 375         void *targetdata;
 376         int ret = 0;
 377
 378         if (!dev->mt) {
 379                 /* register with device with a supported NVM manager */
 380                 list_for_each_entry(mt, &nvm_mgrs, list) {
 381                         ret = mt->register_mgr(dev);
 382                         if (ret < 0)
 383                                 return ret; /* initialization failed */
 384                         if (ret > 0) {
 385                                 dev->mt = mt;
 386                                 break; /* successfully initialized */
 387                         }
 388                 }
 389
 390                 if (!ret) {
 391                         pr_info("nvm: no compatible nvm manager found.\n");
 392                         return -ENODEV;
 393                 }
 394         }
 395
 396         tt = nvm_find_target_type(create->tgttype);
 397         if (!tt) {
 398                 pr_err("nvm: target type %s not found\n", create->tgttype);
 399                 return -EINVAL;
 400         }
 401
 402         down_write(&nvm_lock);
 403         list_for_each_entry(t, &dev->online_targets, list) {
 404                 if (!strcmp(create->tgtname, t->disk->disk_name)) {
 405                         pr_err("nvm: target name already exists.\n");
 406                         up_write(&nvm_lock);
 407                         return -EINVAL;
 408                 }
 409         }
 410         up_write(&nvm_lock);
 411
 412         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 413         if (!t)
 414                 return -ENOMEM;
 415
 416         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
 417         if (!tqueue)
 418                 goto err_t;
 419         blk_queue_make_request(tqueue, tt->make_rq);
 420
 421         tdisk = alloc_disk(0);
 422         if (!tdisk)
 423                 goto err_queue;
 424
 425         sprintf(tdisk->disk_name, "%s", create->tgtname);
 426         tdisk->flags = GENHD_FL_EXT_DEVT;
 427         tdisk->major = 0;
 428         tdisk->first_minor = 0;
 429         tdisk->fops = &nvm_fops;
 430         tdisk->queue = tqueue;
 431
 432         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
 433         if (IS_ERR(targetdata))
 434                 goto err_init;
 435
 436         tdisk->private_data = targetdata;
 437         tqueue->queuedata = targetdata;
 438
 439         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
 440
 441         set_capacity(tdisk, tt->capacity(targetdata));
 442         add_disk(tdisk);
 443
 444         t->type = tt;
 445         t->disk = tdisk;
 446
 447         down_write(&nvm_lock);
 448         list_add_tail(&t->list, &dev->online_targets);
 449         up_write(&nvm_lock);
 450
 451         return 0;
 452 err_init:
 453         put_disk(tdisk);
 454 err_queue:
 455         blk_cleanup_queue(tqueue);
 456 err_t:
 457         kfree(t);
 458         return -ENOMEM;
 459 }
 460
 461 static void nvm_remove_target(struct nvm_target *t)
 462 {
 463         struct nvm_tgt_type *tt = t->type;
 464         struct gendisk *tdisk = t->disk;
 465         struct request_queue *q = tdisk->queue;
 466
 467         lockdep_assert_held(&nvm_lock);
 468
 469         del_gendisk(tdisk);
 470         if (tt->exit)
 471                 tt->exit(tdisk->private_data);
 472
 473         blk_cleanup_queue(q);
 474
 475         put_disk(tdisk);
 476
 477         list_del(&t->list);
 478         kfree(t);
 479 }
 480
 481 static int __nvm_configure_create(struct nvm_ioctl_create *create)
 482 {
 483         struct nvm_dev *dev;
 484         struct nvm_ioctl_create_simple *s;
 485
 486         dev = nvm_find_nvm_dev(create->dev);
 487         if (!dev) {
 488                 pr_err("nvm: device not found\n");
 489                 return -EINVAL;
 490         }
 491
 492         if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
 493                 pr_err("nvm: config type not valid\n");
 494                 return -EINVAL;
 495         }
 496         s = &create->conf.s;
 497
 498         if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
 499                 pr_err("nvm: lun out of bound (%u:%u > %u)\n",
 500                         s->lun_begin, s->lun_end, dev->nr_luns);
 501                 return -EINVAL;
 502         }
 503
 504         return nvm_create_target(dev, create);
 505 }
 506
 507 static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
 508 {
 509         struct nvm_target *t = NULL;
 510         struct nvm_dev *dev;
 511         int ret = -1;
 512
 513         down_write(&nvm_lock);
 514         list_for_each_entry(dev, &nvm_devices, devices)
 515                 list_for_each_entry(t, &dev->online_targets, list) {
 516                         if (!strcmp(remove->tgtname, t->disk->disk_name)) {
 517                                 nvm_remove_target(t);
 518                                 ret = 0;
 519                                 break;
 520                         }
 521                 }
 522         up_write(&nvm_lock);
 523
 524         if (ret) {
 525                 pr_err("nvm: target \"%s\" doesn't exist.\n", remove->tgtname);
 526                 return -EINVAL;
 527         }
 528
 529         return 0;
 530 }
 531
 532 #ifdef CONFIG_NVM_DEBUG
 533 static int nvm_configure_show(const char *val)
 534 {
 535         struct nvm_dev *dev;
 536         char opcode, devname[DISK_NAME_LEN];
 537         int ret;
 538
 539         ret = sscanf(val, "%c %32s", &opcode, devname);
 540         if (ret != 2) {
 541                 pr_err("nvm: invalid command. Use \"opcode devicename\".\n");
 542                 return -EINVAL;
 543         }
 544
 545         dev = nvm_find_nvm_dev(devname);
 546         if (!dev) {
 547                 pr_err("nvm: device not found\n");
 548                 return -EINVAL;
 549         }
 550
 551         if (!dev->mt)
 552                 return 0;
 553
 554         dev->mt->free_blocks_print(dev);
 555
 556         return 0;
 557 }
 558
 559 static int nvm_configure_remove(const char *val)
 560 {
 561         struct nvm_ioctl_remove remove;
 562         char opcode;
 563         int ret;
 564
 565         ret = sscanf(val, "%c %256s", &opcode, remove.tgtname);
 566         if (ret != 2) {
 567                 pr_err("nvm: invalid command. Use \"d targetname\".\n");
 568                 return -EINVAL;
 569         }
 570
 571         remove.flags = 0;
 572
 573         return __nvm_configure_remove(&remove);
 574 }
 575
 576 static int nvm_configure_create(const char *val)
 577 {
 578         struct nvm_ioctl_create create;
 579         char opcode;
 580         int lun_begin, lun_end, ret;
 581
 582         ret = sscanf(val, "%c %256s %256s %48s %u:%u", &opcode, create.dev,
 583                                                 create.tgtname, create.tgttype,
 584                                                 &lun_begin, &lun_end);
 585         if (ret != 6) {
 586                 pr_err("nvm: invalid command. Use \"opcode device name tgttype lun_begin:lun_end\".\n");
 587                 return -EINVAL;
 588         }
 589
 590         create.flags = 0;
 591         create.conf.type = NVM_CONFIG_TYPE_SIMPLE;
 592         create.conf.s.lun_begin = lun_begin;
 593         create.conf.s.lun_end = lun_end;
 594
 595         return __nvm_configure_create(&create);
 596 }
 597
 598
 599 /* Exposes administrative interface through /sys/module/lnvm/configure_by_str */
 600 static int nvm_configure_by_str_event(const char *val,
 601                                         const struct kernel_param *kp)
 602 {
 603         char opcode;
 604         int ret;
 605
 606         ret = sscanf(val, "%c", &opcode);
 607         if (ret != 1) {
 608                 pr_err("nvm: string must have the format of \"cmd ...\"\n");
 609                 return -EINVAL;
 610         }
 611
 612         switch (opcode) {
 613         case 'a':
 614                 return nvm_configure_create(val);
 615         case 'd':
 616                 return nvm_configure_remove(val);
 617         case 's':
 618                 return nvm_configure_show(val);
 619         default:
 620                 pr_err("nvm: invalid command\n");
 621                 return -EINVAL;
 622         }
 623
 624         return 0;
 625 }
 626
 627 static int nvm_configure_get(char *buf, const struct kernel_param *kp)
 628 {
 629         int sz = 0;
 630         char *buf_start = buf;
 631         struct nvm_dev *dev;
 632
 633         buf += sprintf(buf, "available devices:\n");
 634         down_write(&nvm_lock);
 635         list_for_each_entry(dev, &nvm_devices, devices) {
 636                 if (sz > 4095 - DISK_NAME_LEN)
 637                         break;
 638                 buf += sprintf(buf, " %32s\n", dev->name);
 639         }
 640         up_write(&nvm_lock);
 641
 642         return buf - buf_start - 1;
 643 }
 644
 645 static const struct kernel_param_ops nvm_configure_by_str_event_param_ops = {
 646         .set    = nvm_configure_by_str_event,
 647         .get    = nvm_configure_get,
 648 };
 649
 650 #undef MODULE_PARAM_PREFIX
 651 #define MODULE_PARAM_PREFIX     "lnvm."
 652
 653 module_param_cb(configure_debug, &nvm_configure_by_str_event_param_ops, NULL,
 654                                                                         0644);
 655
 656 #endif /* CONFIG_NVM_DEBUG */
 657
 658 static long nvm_ioctl_info(struct file *file, void __user *arg)
 659 {
 660         struct nvm_ioctl_info *info;
 661         struct nvm_tgt_type *tt;
 662         int tgt_iter = 0;
 663
 664         if (!capable(CAP_SYS_ADMIN))
 665                 return -EPERM;
 666
 667         info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
 668         if (IS_ERR(info))
 669                 return -EFAULT;
 670
 671         info->version[0] = NVM_VERSION_MAJOR;
 672         info->version[1] = NVM_VERSION_MINOR;
 673         info->version[2] = NVM_VERSION_PATCH;
 674
 675         down_write(&nvm_lock);
 676         list_for_each_entry(tt, &nvm_targets, list) {
 677                 struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 678
 679                 tgt->version[0] = tt->version[0];
 680                 tgt->version[1] = tt->version[1];
 681                 tgt->version[2] = tt->version[2];
 682                 strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
 683
 684                 tgt_iter++;
 685         }
 686
 687         info->tgtsize = tgt_iter;
 688         up_write(&nvm_lock);
 689
 690         if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info)))
 691                 return -EFAULT;
 692
 693         kfree(info);
 694         return 0;
 695 }
 696
 697 static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
 698 {
 699         struct nvm_ioctl_get_devices *devices;
 700         struct nvm_dev *dev;
 701         int i = 0;
 702
 703         if (!capable(CAP_SYS_ADMIN))
 704                 return -EPERM;
 705
 706         devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
 707         if (!devices)
 708                 return -ENOMEM;
 709
 710         down_write(&nvm_lock);
 711         list_for_each_entry(dev, &nvm_devices, devices) {
 712                 struct nvm_ioctl_device_info *info = &devices->info[i];
 713
 714                 sprintf(info->devname, "%s", dev->name);
 715                 if (dev->mt) {
 716                         info->bmversion[0] = dev->mt->version[0];
 717                         info->bmversion[1] = dev->mt->version[1];
 718                         info->bmversion[2] = dev->mt->version[2];
 719                         sprintf(info->bmname, "%s", dev->mt->name);
 720                 } else {
 721                         sprintf(info->bmname, "none");
 722                 }
 723
 724                 i++;
 725                 if (i > 31) {
 726                         pr_err("nvm: max 31 devices can be reported.\n");
 727                         break;
 728                 }
 729         }
 730         up_write(&nvm_lock);
 731
 732         devices->nr_devices = i;
 733
 734         if (copy_to_user(arg, devices, sizeof(struct nvm_ioctl_get_devices)))
 735                 return -EFAULT;
 736
 737         kfree(devices);
 738         return 0;
 739 }
 740
 741 static long nvm_ioctl_dev_create(struct file *file, void __user *arg)
 742 {
 743         struct nvm_ioctl_create create;
 744
 745         if (!capable(CAP_SYS_ADMIN))
 746                 return -EPERM;
 747
 748         if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
 749                 return -EFAULT;
 750
 751         create.dev[DISK_NAME_LEN - 1] = '\0';
 752         create.tgttype[NVM_TTYPE_NAME_MAX - 1] = '\0';
 753         create.tgtname[DISK_NAME_LEN - 1] = '\0';
 754
 755         if (create.flags != 0) {
 756                 pr_err("nvm: no flags supported\n");
 757                 return -EINVAL;
 758         }
 759
 760         return __nvm_configure_create(&create);
 761 }
 762
 763 static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
 764 {
 765         struct nvm_ioctl_remove remove;
 766
 767         if (!capable(CAP_SYS_ADMIN))
 768                 return -EPERM;
 769
 770         if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
 771                 return -EFAULT;
 772
 773         remove.tgtname[DISK_NAME_LEN - 1] = '\0';
 774
 775         if (remove.flags != 0) {
 776                 pr_err("nvm: no flags supported\n");
 777                 return -EINVAL;
 778         }
 779
 780         return __nvm_configure_remove(&remove);
 781 }
 782
 783 static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 784 {
 785         void __user *argp = (void __user *)arg;
 786
 787         switch (cmd) {
 788         case NVM_INFO:
 789                 return nvm_ioctl_info(file, argp);
 790         case NVM_GET_DEVICES:
 791                 return nvm_ioctl_get_devices(file, argp);
 792         case NVM_DEV_CREATE:
 793                 return nvm_ioctl_dev_create(file, argp);
 794         case NVM_DEV_REMOVE:
 795                 return nvm_ioctl_dev_remove(file, argp);
 796         }
 797         return 0;
 798 }
 799
 800 static const struct file_operations _ctl_fops = {
 801         .open = nonseekable_open,
 802         .unlocked_ioctl = nvm_ctl_ioctl,
 803         .owner = THIS_MODULE,
 804         .llseek  = noop_llseek,
 805 };
 806
 807 static struct miscdevice _nvm_misc = {
 808         .minor          = MISC_DYNAMIC_MINOR,
 809         .name           = "lightnvm",
 810         .nodename       = "lightnvm/control",
 811         .fops           = &_ctl_fops,
 812 };
 813
 814 MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
 815
 816 static int __init nvm_mod_init(void)
 817 {
 818         int ret;
 819
 820         ret = misc_register(&_nvm_misc);
 821         if (ret)
 822                 pr_err("nvm: misc_register failed for control device");
 823
 824         return ret;
 825 }
 826
 827 static void __exit nvm_mod_exit(void)
 828 {
 829         misc_deregister(&_nvm_misc);
 830 }
 831
 832 MODULE_AUTHOR("Matias Bjorling <m@bjorling.me>");
 833 MODULE_LICENSE("GPL v2");
 834 MODULE_VERSION("0.1");
 835 module_init(nvm_mod_init);
 836 module_exit(nvm_mod_exit);