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