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