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 void nvm_addr_to_generic_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
 196 {
 197         int i;
 198
 199         if (rqd->nr_pages > 1) {
 200                 for (i = 0; i < rqd->nr_pages; i++)
 201                         rqd->ppa_list[i] = dev_to_generic_addr(dev,
 202                                                         rqd->ppa_list[i]);
 203         } else {
 204                 rqd->ppa_addr = dev_to_generic_addr(dev, rqd->ppa_addr);
 205         }
 206 }
 207 EXPORT_SYMBOL(nvm_addr_to_generic_mode);
 208
 209 void nvm_generic_to_addr_mode(struct nvm_dev *dev, struct nvm_rq *rqd)
 210 {
 211         int i;
 212
 213         if (rqd->nr_pages > 1) {
 214                 for (i = 0; i < rqd->nr_pages; i++)
 215                         rqd->ppa_list[i] = generic_to_dev_addr(dev,
 216                                                         rqd->ppa_list[i]);
 217         } else {
 218                 rqd->ppa_addr = generic_to_dev_addr(dev, rqd->ppa_addr);
 219         }
 220 }
 221 EXPORT_SYMBOL(nvm_generic_to_addr_mode);
 222
 223 int nvm_erase_ppa(struct nvm_dev *dev, struct ppa_addr ppa)
 224 {
 225         int plane_cnt = 0, pl_idx, ret;
 226         struct nvm_rq rqd;
 227
 228         if (!dev->ops->erase_block)
 229                 return 0;
 230
 231         if (dev->plane_mode == NVM_PLANE_SINGLE) {
 232                 rqd.nr_pages = 1;
 233                 rqd.ppa_addr = ppa;
 234         } else {
 235                 plane_cnt = (1 << dev->plane_mode);
 236                 rqd.nr_pages = plane_cnt;
 237
 238                 rqd.ppa_list = nvm_dev_dma_alloc(dev, GFP_KERNEL,
 239                                                         &rqd.dma_ppa_list);
 240                 if (!rqd.ppa_list) {
 241                         pr_err("nvm: failed to allocate dma memory\n");
 242                         return -ENOMEM;
 243                 }
 244
 245                 for (pl_idx = 0; pl_idx < plane_cnt; pl_idx++) {
 246                         ppa.g.pl = pl_idx;
 247                         rqd.ppa_list[pl_idx] = ppa;
 248                 }
 249         }
 250
 251         nvm_generic_to_addr_mode(dev, &rqd);
 252
 253         ret = dev->ops->erase_block(dev, &rqd);
 254
 255         if (plane_cnt)
 256                 nvm_dev_dma_free(dev, rqd.ppa_list, rqd.dma_ppa_list);
 257
 258         return ret;
 259 }
 260 EXPORT_SYMBOL(nvm_erase_ppa);
 261
 262 static int nvm_core_init(struct nvm_dev *dev)
 263 {
 264         struct nvm_id *id = &dev->identity;
 265         struct nvm_id_group *grp = &id->groups[0];
 266
 267         /* device values */
 268         dev->nr_chnls = grp->num_ch;
 269         dev->luns_per_chnl = grp->num_lun;
 270         dev->pgs_per_blk = grp->num_pg;
 271         dev->blks_per_lun = grp->num_blk;
 272         dev->nr_planes = grp->num_pln;
 273         dev->sec_size = grp->csecs;
 274         dev->oob_size = grp->sos;
 275         dev->sec_per_pg = grp->fpg_sz / grp->csecs;
 276         memcpy(&dev->ppaf, &id->ppaf, sizeof(struct nvm_addr_format));
 277
 278         dev->plane_mode = NVM_PLANE_SINGLE;
 279         dev->max_rq_size = dev->ops->max_phys_sect * dev->sec_size;
 280
 281         if (grp->mtype != 0) {
 282                 pr_err("nvm: memory type not supported\n");
 283                 return -EINVAL;
 284         }
 285
 286         if (grp->fmtype != 0 && grp->fmtype != 1) {
 287                 pr_err("nvm: flash type not supported\n");
 288                 return -EINVAL;
 289         }
 290
 291         if (grp->mpos & 0x020202)
 292                 dev->plane_mode = NVM_PLANE_DOUBLE;
 293         if (grp->mpos & 0x040404)
 294                 dev->plane_mode = NVM_PLANE_QUAD;
 295
 296         /* calculated values */
 297         dev->sec_per_pl = dev->sec_per_pg * dev->nr_planes;
 298         dev->sec_per_blk = dev->sec_per_pl * dev->pgs_per_blk;
 299         dev->sec_per_lun = dev->sec_per_blk * dev->blks_per_lun;
 300         dev->nr_luns = dev->luns_per_chnl * dev->nr_chnls;
 301
 302         dev->total_blocks = dev->nr_planes *
 303                                 dev->blks_per_lun *
 304                                 dev->luns_per_chnl *
 305                                 dev->nr_chnls;
 306         dev->total_pages = dev->total_blocks * dev->pgs_per_blk;
 307         INIT_LIST_HEAD(&dev->online_targets);
 308
 309         return 0;
 310 }
 311
 312 static void nvm_free(struct nvm_dev *dev)
 313 {
 314         if (!dev)
 315                 return;
 316
 317         if (dev->mt)
 318                 dev->mt->unregister_mgr(dev);
 319 }
 320
 321 static int nvm_init(struct nvm_dev *dev)
 322 {
 323         int ret = -EINVAL;
 324
 325         if (!dev->q || !dev->ops)
 326                 return ret;
 327
 328         if (dev->ops->identity(dev, &dev->identity)) {
 329                 pr_err("nvm: device could not be identified\n");
 330                 goto err;
 331         }
 332
 333         pr_debug("nvm: ver:%x nvm_vendor:%x groups:%u\n",
 334                         dev->identity.ver_id, dev->identity.vmnt,
 335                                                         dev->identity.cgrps);
 336
 337         if (dev->identity.ver_id != 1) {
 338                 pr_err("nvm: device not supported by kernel.");
 339                 goto err;
 340         }
 341
 342         if (dev->identity.cgrps != 1) {
 343                 pr_err("nvm: only one group configuration supported.");
 344                 goto err;
 345         }
 346
 347         ret = nvm_core_init(dev);
 348         if (ret) {
 349                 pr_err("nvm: could not initialize core structures.\n");
 350                 goto err;
 351         }
 352
 353         pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",
 354                         dev->name, dev->sec_per_pg, dev->nr_planes,
 355                         dev->pgs_per_blk, dev->blks_per_lun, dev->nr_luns,
 356                         dev->nr_chnls);
 357         return 0;
 358 err:
 359         pr_err("nvm: failed to initialize nvm\n");
 360         return ret;
 361 }
 362
 363 static void nvm_exit(struct nvm_dev *dev)
 364 {
 365         if (dev->ppalist_pool)
 366                 dev->ops->destroy_dma_pool(dev->ppalist_pool);
 367         nvm_free(dev);
 368
 369         pr_info("nvm: successfully unloaded\n");
 370 }
 371
 372 int nvm_register(struct request_queue *q, char *disk_name,
 373                                                         struct nvm_dev_ops *ops)
 374 {
 375         struct nvm_dev *dev;
 376         int ret;
 377
 378         if (!ops->identity)
 379                 return -EINVAL;
 380
 381         dev = kzalloc(sizeof(struct nvm_dev), GFP_KERNEL);
 382         if (!dev)
 383                 return -ENOMEM;
 384
 385         dev->q = q;
 386         dev->ops = ops;
 387         strncpy(dev->name, disk_name, DISK_NAME_LEN);
 388
 389         ret = nvm_init(dev);
 390         if (ret)
 391                 goto err_init;
 392
 393         if (dev->ops->max_phys_sect > 256) {
 394                 pr_info("nvm: max sectors supported is 256.\n");
 395                 ret = -EINVAL;
 396                 goto err_init;
 397         }
 398
 399         if (dev->ops->max_phys_sect > 1) {
 400                 dev->ppalist_pool = dev->ops->create_dma_pool(dev, "ppalist");
 401                 if (!dev->ppalist_pool) {
 402                         pr_err("nvm: could not create ppa pool\n");
 403                         ret = -ENOMEM;
 404                         goto err_init;
 405                 }
 406         }
 407
 408         /* register device with a supported media manager */
 409         down_write(&nvm_lock);
 410         dev->mt = nvm_init_mgr(dev);
 411         list_add(&dev->devices, &nvm_devices);
 412         up_write(&nvm_lock);
 413
 414         return 0;
 415 err_init:
 416         kfree(dev);
 417         return ret;
 418 }
 419 EXPORT_SYMBOL(nvm_register);
 420
 421 void nvm_unregister(char *disk_name)
 422 {
 423         struct nvm_dev *dev;
 424
 425         down_write(&nvm_lock);
 426         dev = nvm_find_nvm_dev(disk_name);
 427         if (!dev) {
 428                 pr_err("nvm: could not find device %s to unregister\n",
 429                                                                 disk_name);
 430                 up_write(&nvm_lock);
 431                 return;
 432         }
 433
 434         list_del(&dev->devices);
 435         up_write(&nvm_lock);
 436
 437         nvm_exit(dev);
 438         kfree(dev);
 439 }
 440 EXPORT_SYMBOL(nvm_unregister);
 441
 442 static const struct block_device_operations nvm_fops = {
 443         .owner          = THIS_MODULE,
 444 };
 445
 446 static int nvm_create_target(struct nvm_dev *dev,
 447                                                 struct nvm_ioctl_create *create)
 448 {
 449         struct nvm_ioctl_create_simple *s = &create->conf.s;
 450         struct request_queue *tqueue;
 451         struct gendisk *tdisk;
 452         struct nvm_tgt_type *tt;
 453         struct nvm_target *t;
 454         void *targetdata;
 455
 456         if (!dev->mt) {
 457                 pr_info("nvm: device has no media manager registered.\n");
 458                 return -ENODEV;
 459         }
 460
 461         down_write(&nvm_lock);
 462         tt = nvm_find_target_type(create->tgttype);
 463         if (!tt) {
 464                 pr_err("nvm: target type %s not found\n", create->tgttype);
 465                 up_write(&nvm_lock);
 466                 return -EINVAL;
 467         }
 468
 469         list_for_each_entry(t, &dev->online_targets, list) {
 470                 if (!strcmp(create->tgtname, t->disk->disk_name)) {
 471                         pr_err("nvm: target name already exists.\n");
 472                         up_write(&nvm_lock);
 473                         return -EINVAL;
 474                 }
 475         }
 476         up_write(&nvm_lock);
 477
 478         t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 479         if (!t)
 480                 return -ENOMEM;
 481
 482         tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
 483         if (!tqueue)
 484                 goto err_t;
 485         blk_queue_make_request(tqueue, tt->make_rq);
 486
 487         tdisk = alloc_disk(0);
 488         if (!tdisk)
 489                 goto err_queue;
 490
 491         sprintf(tdisk->disk_name, "%s", create->tgtname);
 492         tdisk->flags = GENHD_FL_EXT_DEVT;
 493         tdisk->major = 0;
 494         tdisk->first_minor = 0;
 495         tdisk->fops = &nvm_fops;
 496         tdisk->queue = tqueue;
 497
 498         targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
 499         if (IS_ERR(targetdata))
 500                 goto err_init;
 501
 502         tdisk->private_data = targetdata;
 503         tqueue->queuedata = targetdata;
 504
 505         blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
 506
 507         set_capacity(tdisk, tt->capacity(targetdata));
 508         add_disk(tdisk);
 509
 510         t->type = tt;
 511         t->disk = tdisk;
 512
 513         down_write(&nvm_lock);
 514         list_add_tail(&t->list, &dev->online_targets);
 515         up_write(&nvm_lock);
 516
 517         return 0;
 518 err_init:
 519         put_disk(tdisk);
 520 err_queue:
 521         blk_cleanup_queue(tqueue);
 522 err_t:
 523         kfree(t);
 524         return -ENOMEM;
 525 }
 526
 527 static void nvm_remove_target(struct nvm_target *t)
 528 {
 529         struct nvm_tgt_type *tt = t->type;
 530         struct gendisk *tdisk = t->disk;
 531         struct request_queue *q = tdisk->queue;
 532
 533         lockdep_assert_held(&nvm_lock);
 534
 535         del_gendisk(tdisk);
 536         blk_cleanup_queue(q);
 537
 538         if (tt->exit)
 539                 tt->exit(tdisk->private_data);
 540
 541         put_disk(tdisk);
 542
 543         list_del(&t->list);
 544         kfree(t);
 545 }
 546
 547 static int __nvm_configure_create(struct nvm_ioctl_create *create)
 548 {
 549         struct nvm_dev *dev;
 550         struct nvm_ioctl_create_simple *s;
 551
 552         down_write(&nvm_lock);
 553         dev = nvm_find_nvm_dev(create->dev);
 554         up_write(&nvm_lock);
 555         if (!dev) {
 556                 pr_err("nvm: device not found\n");
 557                 return -EINVAL;
 558         }
 559
 560         if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
 561                 pr_err("nvm: config type not valid\n");
 562                 return -EINVAL;
 563         }
 564         s = &create->conf.s;
 565
 566         if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
 567                 pr_err("nvm: lun out of bound (%u:%u > %u)\n",
 568                         s->lun_begin, s->lun_end, dev->nr_luns);
 569                 return -EINVAL;
 570         }
 571
 572         return nvm_create_target(dev, create);
 573 }
 574
 575 static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
 576 {
 577         struct nvm_target *t = NULL;
 578         struct nvm_dev *dev;
 579         int ret = -1;
 580
 581         down_write(&nvm_lock);
 582         list_for_each_entry(dev, &nvm_devices, devices)
 583                 list_for_each_entry(t, &dev->online_targets, list) {
 584                         if (!strcmp(remove->tgtname, t->disk->disk_name)) {
 585                                 nvm_remove_target(t);
 586                                 ret = 0;
 587                                 break;
 588                         }
 589                 }
 590         up_write(&nvm_lock);
 591
 592         if (ret) {
 593                 pr_err("nvm: target \"%s\" doesn't exist.\n", remove->tgtname);
 594                 return -EINVAL;
 595         }
 596
 597         return 0;
 598 }
 599
 600 #ifdef CONFIG_NVM_DEBUG
 601 static int nvm_configure_show(const char *val)
 602 {
 603         struct nvm_dev *dev;
 604         char opcode, devname[DISK_NAME_LEN];
 605         int ret;
 606
 607         ret = sscanf(val, "%c %32s", &opcode, devname);
 608         if (ret != 2) {
 609                 pr_err("nvm: invalid command. Use \"opcode devicename\".\n");
 610                 return -EINVAL;
 611         }
 612
 613         down_write(&nvm_lock);
 614         dev = nvm_find_nvm_dev(devname);
 615         up_write(&nvm_lock);
 616         if (!dev) {
 617                 pr_err("nvm: device not found\n");
 618                 return -EINVAL;
 619         }
 620
 621         if (!dev->mt)
 622                 return 0;
 623
 624         dev->mt->lun_info_print(dev);
 625
 626         return 0;
 627 }
 628
 629 static int nvm_configure_remove(const char *val)
 630 {
 631         struct nvm_ioctl_remove remove;
 632         char opcode;
 633         int ret;
 634
 635         ret = sscanf(val, "%c %256s", &opcode, remove.tgtname);
 636         if (ret != 2) {
 637                 pr_err("nvm: invalid command. Use \"d targetname\".\n");
 638                 return -EINVAL;
 639         }
 640
 641         remove.flags = 0;
 642
 643         return __nvm_configure_remove(&remove);
 644 }
 645
 646 static int nvm_configure_create(const char *val)
 647 {
 648         struct nvm_ioctl_create create;
 649         char opcode;
 650         int lun_begin, lun_end, ret;
 651
 652         ret = sscanf(val, "%c %256s %256s %48s %u:%u", &opcode, create.dev,
 653                                                 create.tgtname, create.tgttype,
 654                                                 &lun_begin, &lun_end);
 655         if (ret != 6) {
 656                 pr_err("nvm: invalid command. Use \"opcode device name tgttype lun_begin:lun_end\".\n");
 657                 return -EINVAL;
 658         }
 659
 660         create.flags = 0;
 661         create.conf.type = NVM_CONFIG_TYPE_SIMPLE;
 662         create.conf.s.lun_begin = lun_begin;
 663         create.conf.s.lun_end = lun_end;
 664
 665         return __nvm_configure_create(&create);
 666 }
 667
 668
 669 /* Exposes administrative interface through /sys/module/lnvm/configure_by_str */
 670 static int nvm_configure_by_str_event(const char *val,
 671                                         const struct kernel_param *kp)
 672 {
 673         char opcode;
 674         int ret;
 675
 676         ret = sscanf(val, "%c", &opcode);
 677         if (ret != 1) {
 678                 pr_err("nvm: string must have the format of \"cmd ...\"\n");
 679                 return -EINVAL;
 680         }
 681
 682         switch (opcode) {
 683         case 'a':
 684                 return nvm_configure_create(val);
 685         case 'd':
 686                 return nvm_configure_remove(val);
 687         case 's':
 688                 return nvm_configure_show(val);
 689         default:
 690                 pr_err("nvm: invalid command\n");
 691                 return -EINVAL;
 692         }
 693
 694         return 0;
 695 }
 696
 697 static int nvm_configure_get(char *buf, const struct kernel_param *kp)
 698 {
 699         int sz = 0;
 700         char *buf_start = buf;
 701         struct nvm_dev *dev;
 702
 703         buf += sprintf(buf, "available devices:\n");
 704         down_write(&nvm_lock);
 705         list_for_each_entry(dev, &nvm_devices, devices) {
 706                 if (sz > 4095 - DISK_NAME_LEN)
 707                         break;
 708                 buf += sprintf(buf, " %32s\n", dev->name);
 709         }
 710         up_write(&nvm_lock);
 711
 712         return buf - buf_start - 1;
 713 }
 714
 715 static const struct kernel_param_ops nvm_configure_by_str_event_param_ops = {
 716         .set    = nvm_configure_by_str_event,
 717         .get    = nvm_configure_get,
 718 };
 719
 720 #undef MODULE_PARAM_PREFIX
 721 #define MODULE_PARAM_PREFIX     "lnvm."
 722
 723 module_param_cb(configure_debug, &nvm_configure_by_str_event_param_ops, NULL,
 724                                                                         0644);
 725
 726 #endif /* CONFIG_NVM_DEBUG */
 727
 728 static long nvm_ioctl_info(struct file *file, void __user *arg)
 729 {
 730         struct nvm_ioctl_info *info;
 731         struct nvm_tgt_type *tt;
 732         int tgt_iter = 0;
 733
 734         if (!capable(CAP_SYS_ADMIN))
 735                 return -EPERM;
 736
 737         info = memdup_user(arg, sizeof(struct nvm_ioctl_info));
 738         if (IS_ERR(info))
 739                 return -EFAULT;
 740
 741         info->version[0] = NVM_VERSION_MAJOR;
 742         info->version[1] = NVM_VERSION_MINOR;
 743         info->version[2] = NVM_VERSION_PATCH;
 744
 745         down_write(&nvm_lock);
 746         list_for_each_entry(tt, &nvm_targets, list) {
 747                 struct nvm_ioctl_info_tgt *tgt = &info->tgts[tgt_iter];
 748
 749                 tgt->version[0] = tt->version[0];
 750                 tgt->version[1] = tt->version[1];
 751                 tgt->version[2] = tt->version[2];
 752                 strncpy(tgt->tgtname, tt->name, NVM_TTYPE_NAME_MAX);
 753
 754                 tgt_iter++;
 755         }
 756
 757         info->tgtsize = tgt_iter;
 758         up_write(&nvm_lock);
 759
 760         if (copy_to_user(arg, info, sizeof(struct nvm_ioctl_info))) {
 761                 kfree(info);
 762                 return -EFAULT;
 763         }
 764
 765         kfree(info);
 766         return 0;
 767 }
 768
 769 static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
 770 {
 771         struct nvm_ioctl_get_devices *devices;
 772         struct nvm_dev *dev;
 773         int i = 0;
 774
 775         if (!capable(CAP_SYS_ADMIN))
 776                 return -EPERM;
 777
 778         devices = kzalloc(sizeof(struct nvm_ioctl_get_devices), GFP_KERNEL);
 779         if (!devices)
 780                 return -ENOMEM;
 781
 782         down_write(&nvm_lock);
 783         list_for_each_entry(dev, &nvm_devices, devices) {
 784                 struct nvm_ioctl_device_info *info = &devices->info[i];
 785
 786                 sprintf(info->devname, "%s", dev->name);
 787                 if (dev->mt) {
 788                         info->bmversion[0] = dev->mt->version[0];
 789                         info->bmversion[1] = dev->mt->version[1];
 790                         info->bmversion[2] = dev->mt->version[2];
 791                         sprintf(info->bmname, "%s", dev->mt->name);
 792                 } else {
 793                         sprintf(info->bmname, "none");
 794                 }
 795
 796                 i++;
 797                 if (i > 31) {
 798                         pr_err("nvm: max 31 devices can be reported.\n");
 799                         break;
 800                 }
 801         }
 802         up_write(&nvm_lock);
 803
 804         devices->nr_devices = i;
 805
 806         if (copy_to_user(arg, devices,
 807                          sizeof(struct nvm_ioctl_get_devices))) {
 808                 kfree(devices);
 809                 return -EFAULT;
 810         }
 811
 812         kfree(devices);
 813         return 0;
 814 }
 815
 816 static long nvm_ioctl_dev_create(struct file *file, void __user *arg)
 817 {
 818         struct nvm_ioctl_create create;
 819
 820         if (!capable(CAP_SYS_ADMIN))
 821                 return -EPERM;
 822
 823         if (copy_from_user(&create, arg, sizeof(struct nvm_ioctl_create)))
 824                 return -EFAULT;
 825
 826         create.dev[DISK_NAME_LEN - 1] = '\0';
 827         create.tgttype[NVM_TTYPE_NAME_MAX - 1] = '\0';
 828         create.tgtname[DISK_NAME_LEN - 1] = '\0';
 829
 830         if (create.flags != 0) {
 831                 pr_err("nvm: no flags supported\n");
 832                 return -EINVAL;
 833         }
 834
 835         return __nvm_configure_create(&create);
 836 }
 837
 838 static long nvm_ioctl_dev_remove(struct file *file, void __user *arg)
 839 {
 840         struct nvm_ioctl_remove remove;
 841
 842         if (!capable(CAP_SYS_ADMIN))
 843                 return -EPERM;
 844
 845         if (copy_from_user(&remove, arg, sizeof(struct nvm_ioctl_remove)))
 846                 return -EFAULT;
 847
 848         remove.tgtname[DISK_NAME_LEN - 1] = '\0';
 849
 850         if (remove.flags != 0) {
 851                 pr_err("nvm: no flags supported\n");
 852                 return -EINVAL;
 853         }
 854
 855         return __nvm_configure_remove(&remove);
 856 }
 857
 858 static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 859 {
 860         void __user *argp = (void __user *)arg;
 861
 862         switch (cmd) {
 863         case NVM_INFO:
 864                 return nvm_ioctl_info(file, argp);
 865         case NVM_GET_DEVICES:
 866                 return nvm_ioctl_get_devices(file, argp);
 867         case NVM_DEV_CREATE:
 868                 return nvm_ioctl_dev_create(file, argp);
 869         case NVM_DEV_REMOVE:
 870                 return nvm_ioctl_dev_remove(file, argp);
 871         }
 872         return 0;
 873 }
 874
 875 static const struct file_operations _ctl_fops = {
 876         .open = nonseekable_open,
 877         .unlocked_ioctl = nvm_ctl_ioctl,
 878         .owner = THIS_MODULE,
 879         .llseek  = noop_llseek,
 880 };
 881
 882 static struct miscdevice _nvm_misc = {
 883         .minor          = MISC_DYNAMIC_MINOR,
 884         .name           = "lightnvm",
 885         .nodename       = "lightnvm/control",
 886         .fops           = &_ctl_fops,
 887 };
 888
 889 MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
 890
 891 static int __init nvm_mod_init(void)
 892 {
 893         int ret;
 894
 895         ret = misc_register(&_nvm_misc);
 896         if (ret)
 897                 pr_err("nvm: misc_register failed for control device");
 898
 899         return ret;
 900 }
 901
 902 static void __exit nvm_mod_exit(void)
 903 {
 904         misc_deregister(&_nvm_misc);
 905 }
 906
 907 MODULE_AUTHOR("Matias Bjorling <m@bjorling.me>");
 908 MODULE_LICENSE("GPL v2");
 909 MODULE_VERSION("0.1");
 910 module_init(nvm_mod_init);
 911 module_exit(nvm_mod_exit);