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 > 256) {
 312                 pr_info("nvm: max sectors supported is 256.\n");
 313                 ret = -EINVAL;
 314                 goto err_init;
 315         }
 316
 317         if (dev->ops->max_phys_sect > 1) {
 318                 dev->ppalist_pool = dev->ops->create_dma_pool(dev->q,
 319                                                                 "ppalist");
 320                 if (!dev->ppalist_pool) {
 321                         pr_err("nvm: could not create ppa pool\n");
 322                         ret = -ENOMEM;
 323                         goto err_init;
 324                 }
 325         }
 326
 327         down_write(&nvm_lock);
 328         list_add(&dev->devices, &nvm_devices);
 329         up_write(&nvm_lock);
 330
 331         return 0;
 332 err_init:
 333         kfree(dev);
 334         return ret;
 335 }
 336 EXPORT_SYMBOL(nvm_register);
 337
 338 void nvm_unregister(char *disk_name)
 339 {
 340         struct nvm_dev *dev = nvm_find_nvm_dev(disk_name);
 341
 342         if (!dev) {
 343                 pr_err("nvm: could not find device %s to unregister\n",
 344                                                                 disk_name);
 345                 return;
 346         }
 347
 348         down_write(&nvm_lock);
 349         list_del(&dev->devices);
 350         up_write(&nvm_lock);
 351
 352         nvm_exit(dev);
 353         kfree(dev);
 354 }
 355 EXPORT_SYMBOL(nvm_unregister);
 356
 357 static const struct block_device_operations nvm_fops = {
 358         .owner          = THIS_MODULE,
 359 };
 360
 361 static int nvm_create_target(struct nvm_dev *dev,
 362                                                 struct nvm_ioctl_create *create)
 363 {
 364         struct nvm_ioctl_create_simple *s = &create->conf.s;
 365         struct request_queue *tqueue;
 366         struct nvmm_type *mt;
 367         struct gendisk *tdisk;
 368         struct nvm_tgt_type *tt;
 369         struct nvm_target *t;
 370         void *targetdata;
 371         int ret = 0;
 372
 373         if (!dev->mt) {
 374                 /* register with device with a supported NVM manager */
 375                 list_for_each_entry(mt, &nvm_mgrs, list) {
 376                         ret = mt->register_mgr(dev);
 377                         if (ret < 0)
 378                                 return ret; /* initialization failed */
 379                         if (ret > 0) {
 380                                 dev->mt = mt;
 381                                 break; /* successfully initialized */
 382                         }
 383                 }
 384
 385                 if (!ret) {
 386                         pr_info("nvm: no compatible nvm manager found.\n");
 387                         return -ENODEV;
 388                 }
 389         }
 390
 391         tt = nvm_find_target_type(create->tgttype);
 392         if (!tt) {
 393                 pr_err("nvm: target type %s not found\n", create->tgttype);
 394                 return -EINVAL;
 395         }
 396
 397         down_write(&nvm_lock);
 398         list_for_each_entry(t, &dev->online_targets, list) {
 399                 if (!strcmp(create->tgtname, t->disk->disk_name)) {
 400                         pr_err("nvm: target name already exists.\n");
 401                         up_write(&nvm_lock);
 402                         return -EINVAL;
 403                 }
 404         }
 405         up_write(&nvm_lock);
 406
 407         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 408         if (!t)
 409                 return -ENOMEM;
 410
 411         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
 412         if (!tqueue)
 413                 goto err_t;
 414         blk_queue_make_request(tqueue, tt->make_rq);
 415
 416         tdisk = alloc_disk(0);
 417         if (!tdisk)
 418                 goto err_queue;
 419
 420         sprintf(tdisk->disk_name, "%s", create->tgtname);
 421         tdisk->flags = GENHD_FL_EXT_DEVT;
 422         tdisk->major = 0;
 423         tdisk->first_minor = 0;
 424         tdisk->fops = &nvm_fops;
 425         tdisk->queue = tqueue;
 426
 427         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
 428         if (IS_ERR(targetdata))
 429                 goto err_init;
 430
 431         tdisk->private_data = targetdata;
 432         tqueue->queuedata = targetdata;
 433
 434         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
 435
 436         set_capacity(tdisk, tt->capacity(targetdata));
 437         add_disk(tdisk);
 438
 439         t->type = tt;
 440         t->disk = tdisk;
 441
 442         down_write(&nvm_lock);
 443         list_add_tail(&t->list, &dev->online_targets);
 444         up_write(&nvm_lock);
 445
 446         return 0;
 447 err_init:
 448         put_disk(tdisk);
 449 err_queue:
 450         blk_cleanup_queue(tqueue);
 451 err_t:
 452         kfree(t);
 453         return -ENOMEM;
 454 }
 455
 456 static void nvm_remove_target(struct nvm_target *t)
 457 {
 458         struct nvm_tgt_type *tt = t->type;
 459         struct gendisk *tdisk = t->disk;
 460         struct request_queue *q = tdisk->queue;
 461
 462         lockdep_assert_held(&nvm_lock);
 463
 464         del_gendisk(tdisk);
 465         blk_cleanup_queue(q);
 466
 467         if (tt->exit)
 468                 tt->exit(tdisk->private_data);
 469
 470         put_disk(tdisk);
 471
 472         list_del(&t->list);
 473         kfree(t);
 474 }
 475
 476 static int __nvm_configure_create(struct nvm_ioctl_create *create)
 477 {
 478         struct nvm_dev *dev;
 479         struct nvm_ioctl_create_simple *s;
 480
 481         dev = nvm_find_nvm_dev(create->dev);
 482         if (!dev) {
 483                 pr_err("nvm: device not found\n");
 484                 return -EINVAL;
 485         }
 486
 487         if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
 488                 pr_err("nvm: config type not valid\n");
 489                 return -EINVAL;
 490         }
 491         s = &create->conf.s;
 492
 493         if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
 494                 pr_err("nvm: lun out of bound (%u:%u > %u)\n",
 495                         s->lun_begin, s->lun_end, dev->nr_luns);
 496                 return -EINVAL;
 497         }
 498
 499         return nvm_create_target(dev, create);
 500 }
 501
 502 static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
 503 {
 504         struct nvm_target *t = NULL;
 505         struct nvm_dev *dev;
 506         int ret = -1;
 507
 508         down_write(&nvm_lock);
 509         list_for_each_entry(dev, &nvm_devices, devices)
 510                 list_for_each_entry(t, &dev->online_targets, list) {
 511                         if (!strcmp(remove->tgtname, t->disk->disk_name)) {
 512                                 nvm_remove_target(t);
 513                                 ret = 0;
 514                                 break;
 515                         }
 516                 }
 517         up_write(&nvm_lock);
 518
 519         if (ret) {
 520                 pr_err("nvm: target \"%s\" doesn't exist.\n", remove->tgtname);
 521                 return -EINVAL;
 522         }
 523
 524         return 0;
 525 }
 526
 527 #ifdef CONFIG_NVM_DEBUG
 528 static int nvm_configure_show(const char *val)
 529 {
 530         struct nvm_dev *dev;
 531         char opcode, devname[DISK_NAME_LEN];
 532         int ret;
 533
 534         ret = sscanf(val, "%c %32s", &opcode, devname);
 535         if (ret != 2) {
 536                 pr_err("nvm: invalid command. Use \"opcode devicename\".\n");
 537                 return -EINVAL;
 538         }
 539
 540         dev = nvm_find_nvm_dev(devname);
 541         if (!dev) {
 542                 pr_err("nvm: device not found\n");
 543                 return -EINVAL;
 544         }
 545
 546         if (!dev->mt)
 547                 return 0;
 548
 549         dev->mt->lun_info_print(dev);
 550
 551         return 0;
 552 }
 553
 554 static int nvm_configure_remove(const char *val)
 555 {
 556         struct nvm_ioctl_remove remove;
 557         char opcode;
 558         int ret;
 559
 560         ret = sscanf(val, "%c %256s", &opcode, remove.tgtname);
 561         if (ret != 2) {
 562                 pr_err("nvm: invalid command. Use \"d targetname\".\n");
 563                 return -EINVAL;
 564         }
 565
 566         remove.flags = 0;
 567
 568         return __nvm_configure_remove(&remove);
 569 }
 570
 571 static int nvm_configure_create(const char *val)
 572 {
 573         struct nvm_ioctl_create create;
 574         char opcode;
 575         int lun_begin, lun_end, ret;
 576
 577         ret = sscanf(val, "%c %256s %256s %48s %u:%u", &opcode, create.dev,
 578                                                 create.tgtname, create.tgttype,
 579                                                 &lun_begin, &lun_end);
 580         if (ret != 6) {
 581                 pr_err("nvm: invalid command. Use \"opcode device name tgttype lun_begin:lun_end\".\n");
 582                 return -EINVAL;
 583         }
 584
 585         create.flags = 0;
 586         create.conf.type = NVM_CONFIG_TYPE_SIMPLE;
 587         create.conf.s.lun_begin = lun_begin;
 588         create.conf.s.lun_end = lun_end;
 589
 590         return __nvm_configure_create(&create);
 591 }
 592
 593
 594 /* Exposes administrative interface through /sys/module/lnvm/configure_by_str */
 595 static int nvm_configure_by_str_event(const char *val,
 596                                         const struct kernel_param *kp)
 597 {
 598         char opcode;
 599         int ret;
 600
 601         ret = sscanf(val, "%c", &opcode);
 602         if (ret != 1) {
 603                 pr_err("nvm: string must have the format of \"cmd ...\"\n");
 604                 return -EINVAL;
 605         }
 606
 607         switch (opcode) {
 608         case 'a':
 609                 return nvm_configure_create(val);
 610         case 'd':
 611                 return nvm_configure_remove(val);
 612         case 's':
 613                 return nvm_configure_show(val);
 614         default:
 615                 pr_err("nvm: invalid command\n");
 616                 return -EINVAL;
 617         }
 618
 619         return 0;
 620 }
 621
 622 static int nvm_configure_get(char *buf, const struct kernel_param *kp)
 623 {
 624         int sz = 0;
 625         char *buf_start = buf;
 626         struct nvm_dev *dev;
 627
 628         buf += sprintf(buf, "available devices:\n");
 629         down_write(&nvm_lock);
 630         list_for_each_entry(dev, &nvm_devices, devices) {
 631                 if (sz > 4095 - DISK_NAME_LEN)
 632                         break;
 633                 buf += sprintf(buf, " %32s\n", dev->name);
 634         }
 635         up_write(&nvm_lock);
 636
 637         return buf - buf_start - 1;
 638 }
 639
 640 static const struct kernel_param_ops nvm_configure_by_str_event_param_ops = {
 641         .set    = nvm_configure_by_str_event,
 642         .get    = nvm_configure_get,
 643 };
 644
 645 #undef MODULE_PARAM_PREFIX
 646 #define MODULE_PARAM_PREFIX     "lnvm."
 647
 648 module_param_cb(configure_debug, &nvm_configure_by_str_event_param_ops, NULL,
 649                                                                         0644);
 650
 651 #endif /* CONFIG_NVM_DEBUG */
 652
 653 static long nvm_ioctl_info(struct file *file, void __user *arg)
 654 {
 655         struct nvm_ioctl_info *info;
 656         struct nvm_tgt_type *tt;
 657         int tgt_iter = 0;
 658
 659         if (!capable(CAP_SYS_ADMIN))
 660                 return -EPERM;
 661
 662         info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
 663         if (IS_ERR(info))
 664                 return -EFAULT;
 665
 666         info->version[0] = NVM_VERSION_MAJOR;
 667         info->version[1] = NVM_VERSION_MINOR;
 668         info->version[2] = NVM_VERSION_PATCH;
 669
 670         down_write(&nvm_lock);
 671         list_for_each_entry(tt, &nvm_targets, list) {
 672                 struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 673
 674                 tgt->version[0] = tt->version[0];
 675                 tgt->version[1] = tt->version[1];
 676                 tgt->version[2] = tt->version[2];
 677                 strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
 678
 679                 tgt_iter++;
 680         }
 681
 682         info->tgtsize = tgt_iter;
 683         up_write(&nvm_lock);
 684
 685         if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info))) {
 686                 kfree(info);
 687                 return -EFAULT;
 688         }
 689
 690         kfree(info);
 691         return 0;
 692 }
 693
 694 static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
 695 {
 696         struct nvm_ioctl_get_devices *devices;
 697         struct nvm_dev *dev;
 698         int i = 0;
 699
 700         if (!capable(CAP_SYS_ADMIN))
 701                 return -EPERM;
 702
 703         devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
 704         if (!devices)
 705                 return -ENOMEM;
 706
 707         down_write(&nvm_lock);
 708         list_for_each_entry(dev, &nvm_devices, devices) {
 709                 struct nvm_ioctl_device_info *info = &devices->info[i];
 710
 711                 sprintf(info->devname, "%s", dev->name);
 712                 if (dev->mt) {
 713                         info->bmversion[0] = dev->mt->version[0];
 714                         info->bmversion[1] = dev->mt->version[1];
 715                         info->bmversion[2] = dev->mt->version[2];
 716                         sprintf(info->bmname, "%s", dev->mt->name);
 717                 } else {
 718                         sprintf(info->bmname, "none");
 719                 }
 720
 721                 i++;
 722                 if (i > 31) {
 723                         pr_err("nvm: max 31 devices can be reported.\n");
 724                         break;
 725                 }
 726         }
 727         up_write(&nvm_lock);
 728
 729         devices->nr_devices = i;
 730
 731         if (copy_to_user(arg, devices,
 732                          sizeof(struct nvm_ioctl_get_devices))) {
 733                 kfree(devices);
 734                 return -EFAULT;
 735         }
 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);