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