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