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, 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 struct nvmm_type *nvm_init_mgr(struct nvm_dev *dev)
 101 {
 102         struct nvmm_type *mt;
 103         int ret;
 104
 105         lockdep_assert_held(&nvm_lock);
 106
 107         list_for_each_entry(mt, &nvm_mgrs, list) {
 108                 ret = mt->register_mgr(dev);
 109                 if (ret < 0) {
 110                         pr_err("nvm: media mgr failed to init (%d) on dev %s\n",
 111                                                                 ret, dev->name);
 112                         return NULL; /* initialization failed */
 113                 } else if (ret > 0)
 114                         return mt;
 115         }
 116
 117         return NULL;
 118 }
 119
 120 int nvm_register_mgr(struct nvmm_type *mt)
 121 {
 122         struct nvm_dev *dev;
 123         int ret = 0;
 124
 125         down_write(&nvm_lock);
 126         if (nvm_find_mgr_type(mt->name)) {
 127                 ret = -EEXIST;
 128                 goto finish;
 129         } else {
 130                 list_add(&mt->list, &nvm_mgrs);
 131         }
 132
 133         /* try to register media mgr if any device have none configured */
 134         list_for_each_entry(dev, &nvm_devices, devices) {
 135                 if (dev->mt)
 136                         continue;
 137
 138                 dev->mt = nvm_init_mgr(dev);
 139         }
 140 finish:
 141         up_write(&nvm_lock);
 142
 143         return ret;
 144 }
 145 EXPORT_SYMBOL(nvm_register_mgr);
 146
 147 void nvm_unregister_mgr(struct nvmm_type *mt)
 148 {
 149         if (!mt)
 150                 return;
 151
 152         down_write(&nvm_lock);
 153         list_del(&mt->list);
 154         up_write(&nvm_lock);
 155 }
 156 EXPORT_SYMBOL(nvm_unregister_mgr);
 157
 158 static struct nvm_dev *nvm_find_nvm_dev(const char *name)
 159 {
 160         struct nvm_dev *dev;
 161
 162         list_for_each_entry(dev, &nvm_devices, devices)
 163                 if (!strcmp(name, dev->name))
 164                         return dev;
 165
 166         return NULL;
 167 }
 168
 169 struct nvm_block *nvm_get_blk(struct nvm_dev *dev, struct nvm_lun *lun,
 170                                                         unsigned long flags)
 171 {
 172         return dev->mt->get_blk(dev, lun, flags);
 173 }
 174 EXPORT_SYMBOL(nvm_get_blk);
 175
 176 /* Assumes that all valid pages have already been moved on release to bm */
 177 void nvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
 178 {
 179         return dev->mt->put_blk(dev, blk);
 180 }
 181 EXPORT_SYMBOL(nvm_put_blk);
 182
 183 int nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 184 {
 185         return dev->mt->submit_io(dev, rqd);
 186 }
 187 EXPORT_SYMBOL(nvm_submit_io);
 188
 189 int nvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk)
 190 {
 191         return dev->mt->erase_blk(dev, blk, 0);
 192 }
 193 EXPORT_SYMBOL(nvm_erase_blk);
 194
 195 static int nvm_core_init(struct nvm_dev *dev)
 196 {
 197         struct nvm_id *id = &dev->identity;
 198         struct nvm_id_group *grp = &id->groups[0];
 199
 200         /* device values */
 201         dev->nr_chnls = grp->num_ch;
 202         dev->luns_per_chnl = grp->num_lun;
 203         dev->pgs_per_blk = grp->num_pg;
 204         dev->blks_per_lun = grp->num_blk;
 205         dev->nr_planes = grp->num_pln;
 206         dev->sec_size = grp->csecs;
 207         dev->oob_size = grp->sos;
 208         dev->sec_per_pg = grp->fpg_sz / grp->csecs;
 209         memcpy(&dev->ppaf, &id->ppaf, sizeof(struct nvm_addr_format));
 210
 211         dev->plane_mode = NVM_PLANE_SINGLE;
 212         dev->max_rq_size = dev->ops->max_phys_sect * dev->sec_size;
 213
 214         if (grp->mtype != 0) {
 215                 pr_err("nvm: memory type not supported\n");
 216                 return -EINVAL;
 217         }
 218
 219         if (grp->fmtype != 0 && grp->fmtype != 1) {
 220                 pr_err("nvm: flash type not supported\n");
 221                 return -EINVAL;
 222         }
 223
 224         if (grp->mpos & 0x020202)
 225                 dev->plane_mode = NVM_PLANE_DOUBLE;
 226         if (grp->mpos & 0x040404)
 227                 dev->plane_mode = NVM_PLANE_QUAD;
 228
 229         /* calculated values */
 230         dev->sec_per_pl = dev->sec_per_pg * dev->nr_planes;
 231         dev->sec_per_blk = dev->sec_per_pl * dev->pgs_per_blk;
 232         dev->sec_per_lun = dev->sec_per_blk * dev->blks_per_lun;
 233         dev->nr_luns = dev->luns_per_chnl * dev->nr_chnls;
 234
 235         dev->total_blocks = dev->nr_planes *
 236                                 dev->blks_per_lun *
 237                                 dev->luns_per_chnl *
 238                                 dev->nr_chnls;
 239         dev->total_pages = dev->total_blocks * dev->pgs_per_blk;
 240         INIT_LIST_HEAD(&dev->online_targets);
 241
 242         return 0;
 243 }
 244
 245 static void nvm_free(struct nvm_dev *dev)
 246 {
 247         if (!dev)
 248                 return;
 249
 250         if (dev->mt)
 251                 dev->mt->unregister_mgr(dev);
 252 }
 253
 254 static int nvm_init(struct nvm_dev *dev)
 255 {
 256         int ret = -EINVAL;
 257
 258         if (!dev->q || !dev->ops)
 259                 return ret;
 260
 261         if (dev->ops->identity(dev, &dev->identity)) {
 262                 pr_err("nvm: device could not be identified\n");
 263                 goto err;
 264         }
 265
 266         pr_debug("nvm: ver:%x nvm_vendor:%x groups:%u\n",
 267                         dev->identity.ver_id, dev->identity.vmnt,
 268                                                         dev->identity.cgrps);
 269
 270         if (dev->identity.ver_id != 1) {
 271                 pr_err("nvm: device not supported by kernel.");
 272                 goto err;
 273         }
 274
 275         if (dev->identity.cgrps != 1) {
 276                 pr_err("nvm: only one group configuration supported.");
 277                 goto err;
 278         }
 279
 280         ret = nvm_core_init(dev);
 281         if (ret) {
 282                 pr_err("nvm: could not initialize core structures.\n");
 283                 goto err;
 284         }
 285
 286         pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",
 287                         dev->name, dev->sec_per_pg, dev->nr_planes,
 288                         dev->pgs_per_blk, dev->blks_per_lun, dev->nr_luns,
 289                         dev->nr_chnls);
 290         return 0;
 291 err:
 292         pr_err("nvm: failed to initialize nvm\n");
 293         return ret;
 294 }
 295
 296 static void nvm_exit(struct nvm_dev *dev)
 297 {
 298         if (dev->ppalist_pool)
 299                 dev->ops->destroy_dma_pool(dev->ppalist_pool);
 300         nvm_free(dev);
 301
 302         pr_info("nvm: successfully unloaded\n");
 303 }
 304
 305 int nvm_register(struct request_queue *q, char *disk_name,
 306                                                         struct nvm_dev_ops *ops)
 307 {
 308         struct nvm_dev *dev;
 309         int ret;
 310
 311         if (!ops->identity)
 312                 return -EINVAL;
 313
 314         dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);
 315         if (!dev)
 316                 return -ENOMEM;
 317
 318         dev->q = q;
 319         dev->ops = ops;
 320         strncpy(dev->name, disk_name, DISK_NAME_LEN);
 321
 322         ret = nvm_init(dev);
 323         if (ret)
 324                 goto err_init;
 325
 326         if (dev->ops->max_phys_sect > 256) {
 327                 pr_info("nvm: max sectors supported is 256.\n");
 328                 ret = -EINVAL;
 329                 goto err_init;
 330         }
 331
 332         if (dev->ops->max_phys_sect > 1) {
 333                 dev->ppalist_pool = dev->ops->create_dma_pool(dev, "ppalist");
 334                 if (!dev->ppalist_pool) {
 335                         pr_err("nvm: could not create ppa pool\n");
 336                         ret = -ENOMEM;
 337                         goto err_init;
 338                 }
 339         }
 340
 341         /* register device with a supported media manager */
 342         down_write(&nvm_lock);
 343         dev->mt = nvm_init_mgr(dev);
 344         list_add(&dev->devices, &nvm_devices);
 345         up_write(&nvm_lock);
 346
 347         return 0;
 348 err_init:
 349         kfree(dev);
 350         return ret;
 351 }
 352 EXPORT_SYMBOL(nvm_register);
 353
 354 void nvm_unregister(char *disk_name)
 355 {
 356         struct nvm_dev *dev;
 357
 358         down_write(&nvm_lock);
 359         dev = nvm_find_nvm_dev(disk_name);
 360         if (!dev) {
 361                 pr_err("nvm: could not find device %s to unregister\n",
 362                                                                 disk_name);
 363                 up_write(&nvm_lock);
 364                 return;
 365         }
 366
 367         list_del(&dev->devices);
 368         up_write(&nvm_lock);
 369
 370         nvm_exit(dev);
 371         kfree(dev);
 372 }
 373 EXPORT_SYMBOL(nvm_unregister);
 374
 375 static const struct block_device_operations nvm_fops = {
 376         .owner          = THIS_MODULE,
 377 };
 378
 379 static int nvm_create_target(struct nvm_dev *dev,
 380                                                 struct nvm_ioctl_create *create)
 381 {
 382         struct nvm_ioctl_create_simple *s = &create->conf.s;
 383         struct request_queue *tqueue;
 384         struct gendisk *tdisk;
 385         struct nvm_tgt_type *tt;
 386         struct nvm_target *t;
 387         void *targetdata;
 388
 389         if (!dev->mt) {
 390                 pr_info("nvm: device has no media manager registered.\n");
 391                 return -ENODEV;
 392         }
 393
 394         down_write(&nvm_lock);
 395         tt = nvm_find_target_type(create->tgttype);
 396         if (!tt) {
 397                 pr_err("nvm: target type %s not found\n", create->tgttype);
 398                 up_write(&nvm_lock);
 399                 return -EINVAL;
 400         }
 401
 402         list_for_each_entry(t, &dev->online_targets, list) {
 403                 if (!strcmp(create->tgtname, t->disk->disk_name)) {
 404                         pr_err("nvm: target name already exists.\n");
 405                         up_write(&nvm_lock);
 406                         return -EINVAL;
 407                 }
 408         }
 409         up_write(&nvm_lock);
 410
 411         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 412         if (!t)
 413                 return -ENOMEM;
 414
 415         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
 416         if (!tqueue)
 417                 goto err_t;
 418         blk_queue_make_request(tqueue, tt->make_rq);
 419
 420         tdisk = alloc_disk(0);
 421         if (!tdisk)
 422                 goto err_queue;
 423
 424         sprintf(tdisk->disk_name, "%s", create->tgtname);
 425         tdisk->flags = GENHD_FL_EXT_DEVT;
 426         tdisk->major = 0;
 427         tdisk->first_minor = 0;
 428         tdisk->fops = &nvm_fops;
 429         tdisk->queue = tqueue;
 430
 431         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
 432         if (IS_ERR(targetdata))
 433                 goto err_init;
 434
 435         tdisk->private_data = targetdata;
 436         tqueue->queuedata = targetdata;
 437
 438         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
 439
 440         set_capacity(tdisk, tt->capacity(targetdata));
 441         add_disk(tdisk);
 442
 443         t->type = tt;
 444         t->disk = tdisk;
 445
 446         down_write(&nvm_lock);
 447         list_add_tail(&t->list, &dev->online_targets);
 448         up_write(&nvm_lock);
 449
 450         return 0;
 451 err_init:
 452         put_disk(tdisk);
 453 err_queue:
 454         blk_cleanup_queue(tqueue);
 455 err_t:
 456         kfree(t);
 457         return -ENOMEM;
 458 }
 459
 460 static void nvm_remove_target(struct nvm_target *t)
 461 {
 462         struct nvm_tgt_type *tt = t->type;
 463         struct gendisk *tdisk = t->disk;
 464         struct request_queue *q = tdisk->queue;
 465
 466         lockdep_assert_held(&nvm_lock);
 467
 468         del_gendisk(tdisk);
 469         blk_cleanup_queue(q);
 470
 471         if (tt->exit)
 472                 tt->exit(tdisk->private_data);
 473
 474         put_disk(tdisk);
 475
 476         list_del(&t->list);
 477         kfree(t);
 478 }
 479
 480 static int __nvm_configure_create(struct nvm_ioctl_create *create)
 481 {
 482         struct nvm_dev *dev;
 483         struct nvm_ioctl_create_simple *s;
 484
 485         down_write(&nvm_lock);
 486         dev = nvm_find_nvm_dev(create->dev);
 487         up_write(&nvm_lock);
 488         if (!dev) {
 489                 pr_err("nvm: device not found\n");
 490                 return -EINVAL;
 491         }
 492
 493         if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
 494                 pr_err("nvm: config type not valid\n");
 495                 return -EINVAL;
 496         }
 497         s = &create->conf.s;
 498
 499         if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
 500                 pr_err("nvm: lun out of bound (%u:%u > %u)\n",
 501                         s->lun_begin, s->lun_end, dev->nr_luns);
 502                 return -EINVAL;
 503         }
 504
 505         return nvm_create_target(dev, create);
 506 }
 507
 508 static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
 509 {
 510         struct nvm_target *t = NULL;
 511         struct nvm_dev *dev;
 512         int ret = -1;
 513
 514         down_write(&nvm_lock);
 515         list_for_each_entry(dev, &nvm_devices, devices)
 516                 list_for_each_entry(t, &dev->online_targets, list) {
 517                         if (!strcmp(remove->tgtname, t->disk->disk_name)) {
 518                                 nvm_remove_target(t);
 519                                 ret = 0;
 520                                 break;
 521                         }
 522                 }
 523         up_write(&nvm_lock);
 524
 525         if (ret) {
 526                 pr_err("nvm: target \"%s\" doesn't exist.\n", remove->tgtname);
 527                 return -EINVAL;
 528         }
 529
 530         return 0;
 531 }
 532
 533 #ifdef CONFIG_NVM_DEBUG
 534 static int nvm_configure_show(const char *val)
 535 {
 536         struct nvm_dev *dev;
 537         char opcode, devname[DISK_NAME_LEN];
 538         int ret;
 539
 540         ret = sscanf(val, "%c %32s", &opcode, devname);
 541         if (ret != 2) {
 542                 pr_err("nvm: invalid command. Use \"opcode devicename\".\n");
 543                 return -EINVAL;
 544         }
 545
 546         down_write(&nvm_lock);
 547         dev = nvm_find_nvm_dev(devname);
 548         up_write(&nvm_lock);
 549         if (!dev) {
 550                 pr_err("nvm: device not found\n");
 551                 return -EINVAL;
 552         }
 553
 554         if (!dev->mt)
 555                 return 0;
 556
 557         dev->mt->lun_info_print(dev);
 558
 559         return 0;
 560 }
 561
 562 static int nvm_configure_remove(const char *val)
 563 {
 564         struct nvm_ioctl_remove remove;
 565         char opcode;
 566         int ret;
 567
 568         ret = sscanf(val, "%c %256s", &opcode, remove.tgtname);
 569         if (ret != 2) {
 570                 pr_err("nvm: invalid command. Use \"d targetname\".\n");
 571                 return -EINVAL;
 572         }
 573
 574         remove.flags = 0;
 575
 576         return __nvm_configure_remove(&remove);
 577 }
 578
 579 static int nvm_configure_create(const char *val)
 580 {
 581         struct nvm_ioctl_create create;
 582         char opcode;
 583         int lun_begin, lun_end, ret;
 584
 585         ret = sscanf(val, "%c %256s %256s %48s %u:%u", &opcode, create.dev,
 586                                                 create.tgtname, create.tgttype,
 587                                                 &lun_begin, &lun_end);
 588         if (ret != 6) {
 589                 pr_err("nvm: invalid command. Use \"opcode device name tgttype lun_begin:lun_end\".\n");
 590                 return -EINVAL;
 591         }
 592
 593         create.flags = 0;
 594         create.conf.type = NVM_CONFIG_TYPE_SIMPLE;
 595         create.conf.s.lun_begin = lun_begin;
 596         create.conf.s.lun_end = lun_end;
 597
 598         return __nvm_configure_create(&create);
 599 }
 600
 601
 602 /* Exposes administrative interface through /sys/module/lnvm/configure_by_str */
 603 static int nvm_configure_by_str_event(const char *val,
 604                                         const struct kernel_param *kp)
 605 {
 606         char opcode;
 607         int ret;
 608
 609         ret = sscanf(val, "%c", &opcode);
 610         if (ret != 1) {
 611                 pr_err("nvm: string must have the format of \"cmd ...\"\n");
 612                 return -EINVAL;
 613         }
 614
 615         switch (opcode) {
 616         case 'a':
 617                 return nvm_configure_create(val);
 618         case 'd':
 619                 return nvm_configure_remove(val);
 620         case 's':
 621                 return nvm_configure_show(val);
 622         default:
 623                 pr_err("nvm: invalid command\n");
 624                 return -EINVAL;
 625         }
 626
 627         return 0;
 628 }
 629
 630 static int nvm_configure_get(char *buf, const struct kernel_param *kp)
 631 {
 632         int sz = 0;
 633         char *buf_start = buf;
 634         struct nvm_dev *dev;
 635
 636         buf += sprintf(buf, "available devices:\n");
 637         down_write(&nvm_lock);
 638         list_for_each_entry(dev, &nvm_devices, devices) {
 639                 if (sz > 4095 - DISK_NAME_LEN)
 640                         break;
 641                 buf += sprintf(buf, " %32s\n", dev->name);
 642         }
 643         up_write(&nvm_lock);
 644
 645         return buf - buf_start - 1;
 646 }
 647
 648 static const struct kernel_param_ops nvm_configure_by_str_event_param_ops = {
 649         .set    = nvm_configure_by_str_event,
 650         .get    = nvm_configure_get,
 651 };
 652
 653 #undef MODULE_PARAM_PREFIX
 654 #define MODULE_PARAM_PREFIX     "lnvm."
 655
 656 module_param_cb(configure_debug, &nvm_configure_by_str_event_param_ops, NULL,
 657                                                                         0644);
 658
 659 #endif /* CONFIG_NVM_DEBUG */
 660
 661 static long nvm_ioctl_info(struct file *file, void __user *arg)
 662 {
 663         struct nvm_ioctl_info *info;
 664         struct nvm_tgt_type *tt;
 665         int tgt_iter = 0;
 666
 667         if (!capable(CAP_SYS_ADMIN))
 668                 return -EPERM;
 669
 670         info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
 671         if (IS_ERR(info))
 672                 return -EFAULT;
 673
 674         info->version[0] = NVM_VERSION_MAJOR;
 675         info->version[1] = NVM_VERSION_MINOR;
 676         info->version[2] = NVM_VERSION_PATCH;
 677
 678         down_write(&nvm_lock);
 679         list_for_each_entry(tt, &nvm_targets, list) {
 680                 struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 681
 682                 tgt->version[0] = tt->version[0];
 683                 tgt->version[1] = tt->version[1];
 684                 tgt->version[2] = tt->version[2];
 685                 strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
 686
 687                 tgt_iter++;
 688         }
 689
 690         info->tgtsize = tgt_iter;
 691         up_write(&nvm_lock);
 692
 693         if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info))) {
 694                 kfree(info);
 695                 return -EFAULT;
 696         }
 697
 698         kfree(info);
 699         return 0;
 700 }
 701
 702 static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
 703 {
 704         struct nvm_ioctl_get_devices *devices;
 705         struct nvm_dev *dev;
 706         int i = 0;
 707
 708         if (!capable(CAP_SYS_ADMIN))
 709                 return -EPERM;
 710
 711         devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
 712         if (!devices)
 713                 return -ENOMEM;
 714
 715         down_write(&nvm_lock);
 716         list_for_each_entry(dev, &nvm_devices, devices) {
 717                 struct nvm_ioctl_device_info *info = &devices->info[i];
 718
 719                 sprintf(info->devname, "%s", dev->name);
 720                 if (dev->mt) {
 721                         info->bmversion[0] = dev->mt->version[0];
 722                         info->bmversion[1] = dev->mt->version[1];
 723                         info->bmversion[2] = dev->mt->version[2];
 724                         sprintf(info->bmname, "%s", dev->mt->name);
 725                 } else {
 726                         sprintf(info->bmname, "none");
 727                 }
 728
 729                 i++;
 730                 if (i > 31) {
 731                         pr_err("nvm: max 31 devices can be reported.\n");
 732                         break;
 733                 }
 734         }
 735         up_write(&nvm_lock);
 736
 737         devices->nr_devices = i;
 738
 739         if (copy_to_user(arg, devices,
 740                          sizeof(struct nvm_ioctl_get_devices))) {
 741                 kfree(devices);
 742                 return -EFAULT;
 743         }
 744
 745         kfree(devices);
 746         return 0;
 747 }
 748
 749 static long nvm_ioctl_dev_create(struct file *file, void __user *arg)
 750 {
 751         struct nvm_ioctl_create create;
 752
 753         if (!capable(CAP_SYS_ADMIN))
 754                 return -EPERM;
 755
 756         if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
 757                 return -EFAULT;
 758
 759         create.dev[DISK_NAME_LEN - 1] = '\0';
 760         create.tgttype[NVM_TTYPE_NAME_MAX - 1] = '\0';
 761         create.tgtname[DISK_NAME_LEN - 1] = '\0';
 762
 763         if (create.flags != 0) {
 764                 pr_err("nvm: no flags supported\n");
 765                 return -EINVAL;
 766         }
 767
 768         return __nvm_configure_create(&create);
 769 }
 770
 771 static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
 772 {
 773         struct nvm_ioctl_remove remove;
 774
 775         if (!capable(CAP_SYS_ADMIN))
 776                 return -EPERM;
 777
 778         if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
 779                 return -EFAULT;
 780
 781         remove.tgtname[DISK_NAME_LEN - 1] = '\0';
 782
 783         if (remove.flags != 0) {
 784                 pr_err("nvm: no flags supported\n");
 785                 return -EINVAL;
 786         }
 787
 788         return __nvm_configure_remove(&remove);
 789 }
 790
 791 static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 792 {
 793         void __user *argp = (void __user *)arg;
 794
 795         switch (cmd) {
 796         case NVM_INFO:
 797                 return nvm_ioctl_info(file, argp);
 798         case NVM_GET_DEVICES:
 799                 return nvm_ioctl_get_devices(file, argp);
 800         case NVM_DEV_CREATE:
 801                 return nvm_ioctl_dev_create(file, argp);
 802         case NVM_DEV_REMOVE:
 803                 return nvm_ioctl_dev_remove(file, argp);
 804         }
 805         return 0;
 806 }
 807
 808 static const struct file_operations _ctl_fops = {
 809         .open = nonseekable_open,
 810         .unlocked_ioctl = nvm_ctl_ioctl,
 811         .owner = THIS_MODULE,
 812         .llseek  = noop_llseek,
 813 };
 814
 815 static struct miscdevice _nvm_misc = {
 816         .minor          = MISC_DYNAMIC_MINOR,
 817         .name           = "lightnvm",
 818         .nodename       = "lightnvm/control",
 819         .fops           = &_ctl_fops,
 820 };
 821
 822 MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
 823
 824 static int __init nvm_mod_init(void)
 825 {
 826         int ret;
 827
 828         ret = misc_register(&_nvm_misc);
 829         if (ret)
 830                 pr_err("nvm: misc_register failed for control device");
 831
 832         return ret;
 833 }
 834
 835 static void __exit nvm_mod_exit(void)
 836 {
 837         misc_deregister(&_nvm_misc);
 838 }
 839
 840 MODULE_AUTHOR("Matias Bjorling <m@bjorling.me>");
 841 MODULE_LICENSE("GPL v2");
 842 MODULE_VERSION("0.1");
 843 module_init(nvm_mod_init);
 844 module_exit(nvm_mod_exit);