drivers/nvme/host/core.c

   1 /*
   2  * NVM Express device driver
   3  * Copyright (c) 2011-2014, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14
  15 #include <linux/blkdev.h>
  16 #include <linux/blk-mq.h>
  17 #include <linux/delay.h>
  18 #include <linux/errno.h>
  19 #include <linux/hdreg.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/list_sort.h>
  23 #include <linux/slab.h>
  24 #include <linux/types.h>
  25 #include <linux/pr.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/nvme_ioctl.h>
  28 #include <linux/t10-pi.h>
  29 #include <scsi/sg.h>
  30 #include <asm/unaligned.h>
  31
  32 #include "nvme.h"
  33
  34 #define NVME_MINORS             (1U << MINORBITS)
  35
  36 static int nvme_major;
  37 module_param(nvme_major, int, 0);
  38
  39 static int nvme_char_major;
  40 module_param(nvme_char_major, int, 0);
  41
  42 static LIST_HEAD(nvme_ctrl_list);
  43 DEFINE_SPINLOCK(dev_list_lock);
  44
  45 static struct class *nvme_class;
  46
  47 static void nvme_free_ns(struct kref *kref)
  48 {
  49         struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
  50
  51         if (ns->type == NVME_NS_LIGHTNVM)
  52                 nvme_nvm_unregister(ns->queue, ns->disk->disk_name);
  53
  54         spin_lock(&dev_list_lock);
  55         ns->disk->private_data = NULL;
  56         spin_unlock(&dev_list_lock);
  57
  58         nvme_put_ctrl(ns->ctrl);
  59         put_disk(ns->disk);
  60         kfree(ns);
  61 }
  62
  63 static void nvme_put_ns(struct nvme_ns *ns)
  64 {
  65         kref_put(&ns->kref, nvme_free_ns);
  66 }
  67
  68 static struct nvme_ns *nvme_get_ns_from_disk(struct gendisk *disk)
  69 {
  70         struct nvme_ns *ns;
  71
  72         spin_lock(&dev_list_lock);
  73         ns = disk->private_data;
  74         if (ns && !kref_get_unless_zero(&ns->kref))
  75                 ns = NULL;
  76         spin_unlock(&dev_list_lock);
  77
  78         return ns;
  79 }
  80
  81 struct request *nvme_alloc_request(struct request_queue *q,
  82                 struct nvme_command *cmd, unsigned int flags)
  83 {
  84         bool write = cmd->common.opcode & 1;
  85         struct request *req;
  86
  87         req = blk_mq_alloc_request(q, write, flags);
  88         if (IS_ERR(req))
  89                 return req;
  90
  91         req->cmd_type = REQ_TYPE_DRV_PRIV;
  92         req->cmd_flags |= REQ_FAILFAST_DRIVER;
  93         req->__data_len = 0;
  94         req->__sector = (sector_t) -1;
  95         req->bio = req->biotail = NULL;
  96
  97         req->cmd = (unsigned char *)cmd;
  98         req->cmd_len = sizeof(struct nvme_command);
  99         req->special = (void *)0;
 100
 101         return req;
 102 }
 103
 104 /*
 105  * Returns 0 on success.  If the result is negative, it's a Linux error code;
 106  * if the result is positive, it's an NVM Express status code
 107  */
 108 int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 109                 void *buffer, unsigned bufflen, u32 *result, unsigned timeout)
 110 {
 111         struct request *req;
 112         int ret;
 113
 114         req = nvme_alloc_request(q, cmd, 0);
 115         if (IS_ERR(req))
 116                 return PTR_ERR(req);
 117
 118         req->timeout = timeout ? timeout : ADMIN_TIMEOUT;
 119
 120         if (buffer && bufflen) {
 121                 ret = blk_rq_map_kern(q, req, buffer, bufflen, GFP_KERNEL);
 122                 if (ret)
 123                         goto out;
 124         }
 125
 126         blk_execute_rq(req->q, NULL, req, 0);
 127         if (result)
 128                 *result = (u32)(uintptr_t)req->special;
 129         ret = req->errors;
 130  out:
 131         blk_mq_free_request(req);
 132         return ret;
 133 }
 134
 135 int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 136                 void *buffer, unsigned bufflen)
 137 {
 138         return __nvme_submit_sync_cmd(q, cmd, buffer, bufflen, NULL, 0);
 139 }
 140
 141 int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 142                 void __user *ubuffer, unsigned bufflen,
 143                 void __user *meta_buffer, unsigned meta_len, u32 meta_seed,
 144                 u32 *result, unsigned timeout)
 145 {
 146         bool write = cmd->common.opcode & 1;
 147         struct nvme_ns *ns = q->queuedata;
 148         struct gendisk *disk = ns ? ns->disk : NULL;
 149         struct request *req;
 150         struct bio *bio = NULL;
 151         void *meta = NULL;
 152         int ret;
 153
 154         req = nvme_alloc_request(q, cmd, 0);
 155         if (IS_ERR(req))
 156                 return PTR_ERR(req);
 157
 158         req->timeout = timeout ? timeout : ADMIN_TIMEOUT;
 159
 160         if (ubuffer && bufflen) {
 161                 ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen,
 162                                 GFP_KERNEL);
 163                 if (ret)
 164                         goto out;
 165                 bio = req->bio;
 166
 167                 if (!disk)
 168                         goto submit;
 169                 bio->bi_bdev = bdget_disk(disk, 0);
 170                 if (!bio->bi_bdev) {
 171                         ret = -ENODEV;
 172                         goto out_unmap;
 173                 }
 174
 175                 if (meta_buffer) {
 176                         struct bio_integrity_payload *bip;
 177
 178                         meta = kmalloc(meta_len, GFP_KERNEL);
 179                         if (!meta) {
 180                                 ret = -ENOMEM;
 181                                 goto out_unmap;
 182                         }
 183
 184                         if (write) {
 185                                 if (copy_from_user(meta, meta_buffer,
 186                                                 meta_len)) {
 187                                         ret = -EFAULT;
 188                                         goto out_free_meta;
 189                                 }
 190                         }
 191
 192                         bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
 193                         if (IS_ERR(bip)) {
 194                                 ret = PTR_ERR(bip);
 195                                 goto out_free_meta;
 196                         }
 197
 198                         bip->bip_iter.bi_size = meta_len;
 199                         bip->bip_iter.bi_sector = meta_seed;
 200
 201                         ret = bio_integrity_add_page(bio, virt_to_page(meta),
 202                                         meta_len, offset_in_page(meta));
 203                         if (ret != meta_len) {
 204                                 ret = -ENOMEM;
 205                                 goto out_free_meta;
 206                         }
 207                 }
 208         }
 209  submit:
 210         blk_execute_rq(req->q, disk, req, 0);
 211         ret = req->errors;
 212         if (result)
 213                 *result = (u32)(uintptr_t)req->special;
 214         if (meta && !ret && !write) {
 215                 if (copy_to_user(meta_buffer, meta, meta_len))
 216                         ret = -EFAULT;
 217         }
 218  out_free_meta:
 219         kfree(meta);
 220  out_unmap:
 221         if (bio) {
 222                 if (disk && bio->bi_bdev)
 223                         bdput(bio->bi_bdev);
 224                 blk_rq_unmap_user(bio);
 225         }
 226  out:
 227         blk_mq_free_request(req);
 228         return ret;
 229 }
 230
 231 int nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 232                 void __user *ubuffer, unsigned bufflen, u32 *result,
 233                 unsigned timeout)
 234 {
 235         return __nvme_submit_user_cmd(q, cmd, ubuffer, bufflen, NULL, 0, 0,
 236                         result, timeout);
 237 }
 238
 239 int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
 240 {
 241         struct nvme_command c = { };
 242         int error;
 243
 244         /* gcc-4.4.4 (at least) has issues with initializers and anon unions */
 245         c.identify.opcode = nvme_admin_identify;
 246         c.identify.cns = cpu_to_le32(1);
 247
 248         *id = kmalloc(sizeof(struct nvme_id_ctrl), GFP_KERNEL);
 249         if (!*id)
 250                 return -ENOMEM;
 251
 252         error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
 253                         sizeof(struct nvme_id_ctrl));
 254         if (error)
 255                 kfree(*id);
 256         return error;
 257 }
 258
 259 int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
 260                 struct nvme_id_ns **id)
 261 {
 262         struct nvme_command c = { };
 263         int error;
 264
 265         /* gcc-4.4.4 (at least) has issues with initializers and anon unions */
 266         c.identify.opcode = nvme_admin_identify,
 267         c.identify.nsid = cpu_to_le32(nsid),
 268
 269         *id = kmalloc(sizeof(struct nvme_id_ns), GFP_KERNEL);
 270         if (!*id)
 271                 return -ENOMEM;
 272
 273         error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
 274                         sizeof(struct nvme_id_ns));
 275         if (error)
 276                 kfree(*id);
 277         return error;
 278 }
 279
 280 int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
 281                                         dma_addr_t dma_addr, u32 *result)
 282 {
 283         struct nvme_command c;
 284
 285         memset(&c, 0, sizeof(c));
 286         c.features.opcode = nvme_admin_get_features;
 287         c.features.nsid = cpu_to_le32(nsid);
 288         c.features.prp1 = cpu_to_le64(dma_addr);
 289         c.features.fid = cpu_to_le32(fid);
 290
 291         return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0, result, 0);
 292 }
 293
 294 int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
 295                                         dma_addr_t dma_addr, u32 *result)
 296 {
 297         struct nvme_command c;
 298
 299         memset(&c, 0, sizeof(c));
 300         c.features.opcode = nvme_admin_set_features;
 301         c.features.prp1 = cpu_to_le64(dma_addr);
 302         c.features.fid = cpu_to_le32(fid);
 303         c.features.dword11 = cpu_to_le32(dword11);
 304
 305         return __nvme_submit_sync_cmd(dev->admin_q, &c, NULL, 0, result, 0);
 306 }
 307
 308 int nvme_get_log_page(struct nvme_ctrl *dev, struct nvme_smart_log **log)
 309 {
 310         struct nvme_command c = { };
 311         int error;
 312
 313         c.common.opcode = nvme_admin_get_log_page,
 314         c.common.nsid = cpu_to_le32(0xFFFFFFFF),
 315         c.common.cdw10[0] = cpu_to_le32(
 316                         (((sizeof(struct nvme_smart_log) / 4) - 1) << 16) |
 317                          NVME_LOG_SMART),
 318
 319         *log = kmalloc(sizeof(struct nvme_smart_log), GFP_KERNEL);
 320         if (!*log)
 321                 return -ENOMEM;
 322
 323         error = nvme_submit_sync_cmd(dev->admin_q, &c, *log,
 324                         sizeof(struct nvme_smart_log));
 325         if (error)
 326                 kfree(*log);
 327         return error;
 328 }
 329
 330 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count)
 331 {
 332         u32 q_count = (*count - 1) | ((*count - 1) << 16);
 333         u32 result;
 334         int status, nr_io_queues;
 335
 336         status = nvme_set_features(ctrl, NVME_FEAT_NUM_QUEUES, q_count, 0,
 337                         &result);
 338         if (status)
 339                 return status;
 340
 341         nr_io_queues = min(result & 0xffff, result >> 16) + 1;
 342         *count = min(*count, nr_io_queues);
 343         return 0;
 344 }
 345
 346 static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 347 {
 348         struct nvme_user_io io;
 349         struct nvme_command c;
 350         unsigned length, meta_len;
 351         void __user *metadata;
 352
 353         if (copy_from_user(&io, uio, sizeof(io)))
 354                 return -EFAULT;
 355
 356         switch (io.opcode) {
 357         case nvme_cmd_write:
 358         case nvme_cmd_read:
 359         case nvme_cmd_compare:
 360                 break;
 361         default:
 362                 return -EINVAL;
 363         }
 364
 365         length = (io.nblocks + 1) << ns->lba_shift;
 366         meta_len = (io.nblocks + 1) * ns->ms;
 367         metadata = (void __user *)(uintptr_t)io.metadata;
 368
 369         if (ns->ext) {
 370                 length += meta_len;
 371                 meta_len = 0;
 372         } else if (meta_len) {
 373                 if ((io.metadata & 3) || !io.metadata)
 374                         return -EINVAL;
 375         }
 376
 377         memset(&c, 0, sizeof(c));
 378         c.rw.opcode = io.opcode;
 379         c.rw.flags = io.flags;
 380         c.rw.nsid = cpu_to_le32(ns->ns_id);
 381         c.rw.slba = cpu_to_le64(io.slba);
 382         c.rw.length = cpu_to_le16(io.nblocks);
 383         c.rw.control = cpu_to_le16(io.control);
 384         c.rw.dsmgmt = cpu_to_le32(io.dsmgmt);
 385         c.rw.reftag = cpu_to_le32(io.reftag);
 386         c.rw.apptag = cpu_to_le16(io.apptag);
 387         c.rw.appmask = cpu_to_le16(io.appmask);
 388
 389         return __nvme_submit_user_cmd(ns->queue, &c,
 390                         (void __user *)(uintptr_t)io.addr, length,
 391                         metadata, meta_len, io.slba, NULL, 0);
 392 }
 393
 394 static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 395                         struct nvme_passthru_cmd __user *ucmd)
 396 {
 397         struct nvme_passthru_cmd cmd;
 398         struct nvme_command c;
 399         unsigned timeout = 0;
 400         int status;
 401
 402         if (!capable(CAP_SYS_ADMIN))
 403                 return -EACCES;
 404         if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
 405                 return -EFAULT;
 406
 407         memset(&c, 0, sizeof(c));
 408         c.common.opcode = cmd.opcode;
 409         c.common.flags = cmd.flags;
 410         c.common.nsid = cpu_to_le32(cmd.nsid);
 411         c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
 412         c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
 413         c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
 414         c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
 415         c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
 416         c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
 417         c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
 418         c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);
 419
 420         if (cmd.timeout_ms)
 421                 timeout = msecs_to_jiffies(cmd.timeout_ms);
 422
 423         status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
 424                         (void __user *)(uintptr_t)cmd.addr, cmd.data_len,
 425                         &cmd.result, timeout);
 426         if (status >= 0) {
 427                 if (put_user(cmd.result, &ucmd->result))
 428                         return -EFAULT;
 429         }
 430
 431         return status;
 432 }
 433
 434 static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
 435                 unsigned int cmd, unsigned long arg)
 436 {
 437         struct nvme_ns *ns = bdev->bd_disk->private_data;
 438
 439         switch (cmd) {
 440         case NVME_IOCTL_ID:
 441                 force_successful_syscall_return();
 442                 return ns->ns_id;
 443         case NVME_IOCTL_ADMIN_CMD:
 444                 return nvme_user_cmd(ns->ctrl, NULL, (void __user *)arg);
 445         case NVME_IOCTL_IO_CMD:
 446                 return nvme_user_cmd(ns->ctrl, ns, (void __user *)arg);
 447         case NVME_IOCTL_SUBMIT_IO:
 448                 return nvme_submit_io(ns, (void __user *)arg);
 449         case SG_GET_VERSION_NUM:
 450                 return nvme_sg_get_version_num((void __user *)arg);
 451         case SG_IO:
 452                 return nvme_sg_io(ns, (void __user *)arg);
 453         default:
 454                 return -ENOTTY;
 455         }
 456 }
 457
 458 #ifdef CONFIG_COMPAT
 459 static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
 460                         unsigned int cmd, unsigned long arg)
 461 {
 462         switch (cmd) {
 463         case SG_IO:
 464                 return -ENOIOCTLCMD;
 465         }
 466         return nvme_ioctl(bdev, mode, cmd, arg);
 467 }
 468 #else
 469 #define nvme_compat_ioctl       NULL
 470 #endif
 471
 472 static int nvme_open(struct block_device *bdev, fmode_t mode)
 473 {
 474         return nvme_get_ns_from_disk(bdev->bd_disk) ? 0 : -ENXIO;
 475 }
 476
 477 static void nvme_release(struct gendisk *disk, fmode_t mode)
 478 {
 479         nvme_put_ns(disk->private_data);
 480 }
 481
 482 static int nvme_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 483 {
 484         /* some standard values */
 485         geo->heads = 1 << 6;
 486         geo->sectors = 1 << 5;
 487         geo->cylinders = get_capacity(bdev->bd_disk) >> 11;
 488         return 0;
 489 }
 490
 491 #ifdef CONFIG_BLK_DEV_INTEGRITY
 492 static void nvme_init_integrity(struct nvme_ns *ns)
 493 {
 494         struct blk_integrity integrity;
 495
 496         switch (ns->pi_type) {
 497         case NVME_NS_DPS_PI_TYPE3:
 498                 integrity.profile = &t10_pi_type3_crc;
 499                 break;
 500         case NVME_NS_DPS_PI_TYPE1:
 501         case NVME_NS_DPS_PI_TYPE2:
 502                 integrity.profile = &t10_pi_type1_crc;
 503                 break;
 504         default:
 505                 integrity.profile = NULL;
 506                 break;
 507         }
 508         integrity.tuple_size = ns->ms;
 509         blk_integrity_register(ns->disk, &integrity);
 510         blk_queue_max_integrity_segments(ns->queue, 1);
 511 }
 512 #else
 513 static void nvme_init_integrity(struct nvme_ns *ns)
 514 {
 515 }
 516 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 517
 518 static void nvme_config_discard(struct nvme_ns *ns)
 519 {
 520         u32 logical_block_size = queue_logical_block_size(ns->queue);
 521         ns->queue->limits.discard_zeroes_data = 0;
 522         ns->queue->limits.discard_alignment = logical_block_size;
 523         ns->queue->limits.discard_granularity = logical_block_size;
 524         blk_queue_max_discard_sectors(ns->queue, 0xffffffff);
 525         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);
 526 }
 527
 528 static int nvme_revalidate_disk(struct gendisk *disk)
 529 {
 530         struct nvme_ns *ns = disk->private_data;
 531         struct nvme_id_ns *id;
 532         u8 lbaf, pi_type;
 533         u16 old_ms;
 534         unsigned short bs;
 535
 536         if (nvme_identify_ns(ns->ctrl, ns->ns_id, &id)) {
 537                 dev_warn(ns->ctrl->dev, "%s: Identify failure nvme%dn%d\n",
 538                                 __func__, ns->ctrl->instance, ns->ns_id);
 539                 return -ENODEV;
 540         }
 541         if (id->ncap == 0) {
 542                 kfree(id);
 543                 return -ENODEV;
 544         }
 545
 546         if (nvme_nvm_ns_supported(ns, id) && ns->type != NVME_NS_LIGHTNVM) {
 547                 if (nvme_nvm_register(ns->queue, disk->disk_name)) {
 548                         dev_warn(ns->ctrl->dev,
 549                                 "%s: LightNVM init failure\n", __func__);
 550                         kfree(id);
 551                         return -ENODEV;
 552                 }
 553                 ns->type = NVME_NS_LIGHTNVM;
 554         }
 555
 556         old_ms = ns->ms;
 557         lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
 558         ns->lba_shift = id->lbaf[lbaf].ds;
 559         ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
 560         ns->ext = ns->ms && (id->flbas & NVME_NS_FLBAS_META_EXT);
 561
 562         /*
 563          * If identify namespace failed, use default 512 byte block size so
 564          * block layer can use before failing read/write for 0 capacity.
 565          */
 566         if (ns->lba_shift == 0)
 567                 ns->lba_shift = 9;
 568         bs = 1 << ns->lba_shift;
 569
 570         /* XXX: PI implementation requires metadata equal t10 pi tuple size */
 571         pi_type = ns->ms == sizeof(struct t10_pi_tuple) ?
 572                                         id->dps & NVME_NS_DPS_PI_MASK : 0;
 573
 574         blk_mq_freeze_queue(disk->queue);
 575         if (blk_get_integrity(disk) && (ns->pi_type != pi_type ||
 576                                 ns->ms != old_ms ||
 577                                 bs != queue_logical_block_size(disk->queue) ||
 578                                 (ns->ms && ns->ext)))
 579                 blk_integrity_unregister(disk);
 580
 581         ns->pi_type = pi_type;
 582         blk_queue_logical_block_size(ns->queue, bs);
 583
 584         if (ns->ms && !ns->ext)
 585                 nvme_init_integrity(ns);
 586
 587         if (ns->ms && !(ns->ms == 8 && ns->pi_type) && !blk_get_integrity(disk))
 588                 set_capacity(disk, 0);
 589         else
 590                 set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
 591
 592         if (ns->ctrl->oncs & NVME_CTRL_ONCS_DSM)
 593                 nvme_config_discard(ns);
 594         blk_mq_unfreeze_queue(disk->queue);
 595
 596         kfree(id);
 597         return 0;
 598 }
 599
 600 static char nvme_pr_type(enum pr_type type)
 601 {
 602         switch (type) {
 603         case PR_WRITE_EXCLUSIVE:
 604                 return 1;
 605         case PR_EXCLUSIVE_ACCESS:
 606                 return 2;
 607         case PR_WRITE_EXCLUSIVE_REG_ONLY:
 608                 return 3;
 609         case PR_EXCLUSIVE_ACCESS_REG_ONLY:
 610                 return 4;
 611         case PR_WRITE_EXCLUSIVE_ALL_REGS:
 612                 return 5;
 613         case PR_EXCLUSIVE_ACCESS_ALL_REGS:
 614                 return 6;
 615         default:
 616                 return 0;
 617         }
 618 };
 619
 620 static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
 621                                 u64 key, u64 sa_key, u8 op)
 622 {
 623         struct nvme_ns *ns = bdev->bd_disk->private_data;
 624         struct nvme_command c;
 625         u8 data[16] = { 0, };
 626
 627         put_unaligned_le64(key, &data[0]);
 628         put_unaligned_le64(sa_key, &data[8]);
 629
 630         memset(&c, 0, sizeof(c));
 631         c.common.opcode = op;
 632         c.common.nsid = cpu_to_le32(ns->ns_id);
 633         c.common.cdw10[0] = cpu_to_le32(cdw10);
 634
 635         return nvme_submit_sync_cmd(ns->queue, &c, data, 16);
 636 }
 637
 638 static int nvme_pr_register(struct block_device *bdev, u64 old,
 639                 u64 new, unsigned flags)
 640 {
 641         u32 cdw10;
 642
 643         if (flags & ~PR_FL_IGNORE_KEY)
 644                 return -EOPNOTSUPP;
 645
 646         cdw10 = old ? 2 : 0;
 647         cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
 648         cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
 649         return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
 650 }
 651
 652 static int nvme_pr_reserve(struct block_device *bdev, u64 key,
 653                 enum pr_type type, unsigned flags)
 654 {
 655         u32 cdw10;
 656
 657         if (flags & ~PR_FL_IGNORE_KEY)
 658                 return -EOPNOTSUPP;
 659
 660         cdw10 = nvme_pr_type(type) << 8;
 661         cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
 662         return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
 663 }
 664
 665 static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
 666                 enum pr_type type, bool abort)
 667 {
 668         u32 cdw10 = nvme_pr_type(type) << 8 | abort ? 2 : 1;
 669         return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
 670 }
 671
 672 static int nvme_pr_clear(struct block_device *bdev, u64 key)
 673 {
 674         u32 cdw10 = 1 | key ? 1 << 3 : 0;
 675         return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_register);
 676 }
 677
 678 static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
 679 {
 680         u32 cdw10 = nvme_pr_type(type) << 8 | key ? 1 << 3 : 0;
 681         return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
 682 }
 683
 684 static const struct pr_ops nvme_pr_ops = {
 685         .pr_register    = nvme_pr_register,
 686         .pr_reserve     = nvme_pr_reserve,
 687         .pr_release     = nvme_pr_release,
 688         .pr_preempt     = nvme_pr_preempt,
 689         .pr_clear       = nvme_pr_clear,
 690 };
 691
 692 static const struct block_device_operations nvme_fops = {
 693         .owner          = THIS_MODULE,
 694         .ioctl          = nvme_ioctl,
 695         .compat_ioctl   = nvme_compat_ioctl,
 696         .open           = nvme_open,
 697         .release        = nvme_release,
 698         .getgeo         = nvme_getgeo,
 699         .revalidate_disk= nvme_revalidate_disk,
 700         .pr_ops         = &nvme_pr_ops,
 701 };
 702
 703 static int nvme_wait_ready(struct nvme_ctrl *ctrl, u64 cap, bool enabled)
 704 {
 705         unsigned long timeout =
 706                 ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
 707         u32 csts, bit = enabled ? NVME_CSTS_RDY : 0;
 708         int ret;
 709
 710         while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
 711                 if ((csts & NVME_CSTS_RDY) == bit)
 712                         break;
 713
 714                 msleep(100);
 715                 if (fatal_signal_pending(current))
 716                         return -EINTR;
 717                 if (time_after(jiffies, timeout)) {
 718                         dev_err(ctrl->dev,
 719                                 "Device not ready; aborting %s\n", enabled ?
 720                                                 "initialisation" : "reset");
 721                         return -ENODEV;
 722                 }
 723         }
 724
 725         return ret;
 726 }
 727
 728 /*
 729  * If the device has been passed off to us in an enabled state, just clear
 730  * the enabled bit.  The spec says we should set the 'shutdown notification
 731  * bits', but doing so may cause the device to complete commands to the
 732  * admin queue ... and we don't know what memory that might be pointing at!
 733  */
 734 int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap)
 735 {
 736         int ret;
 737
 738         ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
 739         ctrl->ctrl_config &= ~NVME_CC_ENABLE;
 740
 741         ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
 742         if (ret)
 743                 return ret;
 744         return nvme_wait_ready(ctrl, cap, false);
 745 }
 746
 747 int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap)
 748 {
 749         /*
 750          * Default to a 4K page size, with the intention to update this
 751          * path in the future to accomodate architectures with differing
 752          * kernel and IO page sizes.
 753          */
 754         unsigned dev_page_min = NVME_CAP_MPSMIN(cap) + 12, page_shift = 12;
 755         int ret;
 756
 757         if (page_shift < dev_page_min) {
 758                 dev_err(ctrl->dev,
 759                         "Minimum device page size %u too large for host (%u)\n",
 760                         1 << dev_page_min, 1 << page_shift);
 761                 return -ENODEV;
 762         }
 763
 764         ctrl->page_size = 1 << page_shift;
 765
 766         ctrl->ctrl_config = NVME_CC_CSS_NVM;
 767         ctrl->ctrl_config |= (page_shift - 12) << NVME_CC_MPS_SHIFT;
 768         ctrl->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
 769         ctrl->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
 770         ctrl->ctrl_config |= NVME_CC_ENABLE;
 771
 772         ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
 773         if (ret)
 774                 return ret;
 775         return nvme_wait_ready(ctrl, cap, true);
 776 }
 777
 778 int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl)
 779 {
 780         unsigned long timeout = SHUTDOWN_TIMEOUT + jiffies;
 781         u32 csts;
 782         int ret;
 783
 784         ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
 785         ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
 786
 787         ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
 788         if (ret)
 789                 return ret;
 790
 791         while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
 792                 if ((csts & NVME_CSTS_SHST_MASK) == NVME_CSTS_SHST_CMPLT)
 793                         break;
 794
 795                 msleep(100);
 796                 if (fatal_signal_pending(current))
 797                         return -EINTR;
 798                 if (time_after(jiffies, timeout)) {
 799                         dev_err(ctrl->dev,
 800                                 "Device shutdown incomplete; abort shutdown\n");
 801                         return -ENODEV;
 802                 }
 803         }
 804
 805         return ret;
 806 }
 807
 808 /*
 809  * Initialize the cached copies of the Identify data and various controller
 810  * register in our nvme_ctrl structure.  This should be called as soon as
 811  * the admin queue is fully up and running.
 812  */
 813 int nvme_init_identify(struct nvme_ctrl *ctrl)
 814 {
 815         struct nvme_id_ctrl *id;
 816         u64 cap;
 817         int ret, page_shift;
 818
 819         ret = ctrl->ops->reg_read32(ctrl, NVME_REG_VS, &ctrl->vs);
 820         if (ret) {
 821                 dev_err(ctrl->dev, "Reading VS failed (%d)\n", ret);
 822                 return ret;
 823         }
 824
 825         ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &cap);
 826         if (ret) {
 827                 dev_err(ctrl->dev, "Reading CAP failed (%d)\n", ret);
 828                 return ret;
 829         }
 830         page_shift = NVME_CAP_MPSMIN(cap) + 12;
 831
 832         if (ctrl->vs >= NVME_VS(1, 1))
 833                 ctrl->subsystem = NVME_CAP_NSSRC(cap);
 834
 835         ret = nvme_identify_ctrl(ctrl, &id);
 836         if (ret) {
 837                 dev_err(ctrl->dev, "Identify Controller failed (%d)\n", ret);
 838                 return -EIO;
 839         }
 840
 841         ctrl->oncs = le16_to_cpup(&id->oncs);
 842         ctrl->abort_limit = id->acl + 1;
 843         ctrl->vwc = id->vwc;
 844         memcpy(ctrl->serial, id->sn, sizeof(id->sn));
 845         memcpy(ctrl->model, id->mn, sizeof(id->mn));
 846         memcpy(ctrl->firmware_rev, id->fr, sizeof(id->fr));
 847         if (id->mdts)
 848                 ctrl->max_hw_sectors = 1 << (id->mdts + page_shift - 9);
 849         else
 850                 ctrl->max_hw_sectors = UINT_MAX;
 851
 852         if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) && id->vs[3]) {
 853                 unsigned int max_hw_sectors;
 854
 855                 ctrl->stripe_size = 1 << (id->vs[3] + page_shift);
 856                 max_hw_sectors = ctrl->stripe_size >> (page_shift - 9);
 857                 if (ctrl->max_hw_sectors) {
 858                         ctrl->max_hw_sectors = min(max_hw_sectors,
 859                                                         ctrl->max_hw_sectors);
 860                 } else {
 861                         ctrl->max_hw_sectors = max_hw_sectors;
 862                 }
 863         }
 864
 865         kfree(id);
 866         return 0;
 867 }
 868
 869 static int nvme_dev_open(struct inode *inode, struct file *file)
 870 {
 871         struct nvme_ctrl *ctrl;
 872         int instance = iminor(inode);
 873         int ret = -ENODEV;
 874
 875         spin_lock(&dev_list_lock);
 876         list_for_each_entry(ctrl, &nvme_ctrl_list, node) {
 877                 if (ctrl->instance != instance)
 878                         continue;
 879
 880                 if (!ctrl->admin_q) {
 881                         ret = -EWOULDBLOCK;
 882                         break;
 883                 }
 884                 if (!kref_get_unless_zero(&ctrl->kref))
 885                         break;
 886                 file->private_data = ctrl;
 887                 ret = 0;
 888                 break;
 889         }
 890         spin_unlock(&dev_list_lock);
 891
 892         return ret;
 893 }
 894
 895 static int nvme_dev_release(struct inode *inode, struct file *file)
 896 {
 897         nvme_put_ctrl(file->private_data);
 898         return 0;
 899 }
 900
 901 static long nvme_dev_ioctl(struct file *file, unsigned int cmd,
 902                 unsigned long arg)
 903 {
 904         struct nvme_ctrl *ctrl = file->private_data;
 905         void __user *argp = (void __user *)arg;
 906         struct nvme_ns *ns;
 907
 908         switch (cmd) {
 909         case NVME_IOCTL_ADMIN_CMD:
 910                 return nvme_user_cmd(ctrl, NULL, argp);
 911         case NVME_IOCTL_IO_CMD:
 912                 if (list_empty(&ctrl->namespaces))
 913                         return -ENOTTY;
 914                 ns = list_first_entry(&ctrl->namespaces, struct nvme_ns, list);
 915                 return nvme_user_cmd(ctrl, ns, argp);
 916         case NVME_IOCTL_RESET:
 917                 dev_warn(ctrl->dev, "resetting controller\n");
 918                 return ctrl->ops->reset_ctrl(ctrl);
 919         case NVME_IOCTL_SUBSYS_RESET:
 920                 return nvme_reset_subsystem(ctrl);
 921         default:
 922                 return -ENOTTY;
 923         }
 924 }
 925
 926 static const struct file_operations nvme_dev_fops = {
 927         .owner          = THIS_MODULE,
 928         .open           = nvme_dev_open,
 929         .release        = nvme_dev_release,
 930         .unlocked_ioctl = nvme_dev_ioctl,
 931         .compat_ioctl   = nvme_dev_ioctl,
 932 };
 933
 934 static ssize_t nvme_sysfs_reset(struct device *dev,
 935                                 struct device_attribute *attr, const char *buf,
 936                                 size_t count)
 937 {
 938         struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
 939         int ret;
 940
 941         ret = ctrl->ops->reset_ctrl(ctrl);
 942         if (ret < 0)
 943                 return ret;
 944         return count;
 945 }
 946 static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
 947
 948 static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
 949 {
 950         struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
 951         struct nvme_ns *nsb = container_of(b, struct nvme_ns, list);
 952
 953         return nsa->ns_id - nsb->ns_id;
 954 }
 955
 956 static struct nvme_ns *nvme_find_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 957 {
 958         struct nvme_ns *ns;
 959
 960         list_for_each_entry(ns, &ctrl->namespaces, list) {
 961                 if (ns->ns_id == nsid)
 962                         return ns;
 963                 if (ns->ns_id > nsid)
 964                         break;
 965         }
 966         return NULL;
 967 }
 968
 969 static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 970 {
 971         struct nvme_ns *ns;
 972         struct gendisk *disk;
 973         int node = dev_to_node(ctrl->dev);
 974
 975         ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
 976         if (!ns)
 977                 return;
 978
 979         ns->queue = blk_mq_init_queue(ctrl->tagset);
 980         if (IS_ERR(ns->queue))
 981                 goto out_free_ns;
 982         queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);
 983         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
 984         ns->queue->queuedata = ns;
 985         ns->ctrl = ctrl;
 986
 987         disk = alloc_disk_node(0, node);
 988         if (!disk)
 989                 goto out_free_queue;
 990
 991         kref_init(&ns->kref);
 992         ns->ns_id = nsid;
 993         ns->disk = disk;
 994         ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */
 995         list_add_tail(&ns->list, &ctrl->namespaces);
 996
 997         blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
 998         if (ctrl->max_hw_sectors) {
 999                 blk_queue_max_hw_sectors(ns->queue, ctrl->max_hw_sectors);
1000                 blk_queue_max_segments(ns->queue,
1001                         (ctrl->max_hw_sectors / (ctrl->page_size >> 9)) + 1);
1002         }
1003         if (ctrl->stripe_size)
1004                 blk_queue_chunk_sectors(ns->queue, ctrl->stripe_size >> 9);
1005         if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
1006                 blk_queue_flush(ns->queue, REQ_FLUSH | REQ_FUA);
1007         blk_queue_virt_boundary(ns->queue, ctrl->page_size - 1);
1008
1009         disk->major = nvme_major;
1010         disk->first_minor = 0;
1011         disk->fops = &nvme_fops;
1012         disk->private_data = ns;
1013         disk->queue = ns->queue;
1014         disk->driverfs_dev = ctrl->device;
1015         disk->flags = GENHD_FL_EXT_DEVT;
1016         sprintf(disk->disk_name, "nvme%dn%d", ctrl->instance, nsid);
1017
1018         /*
1019          * Initialize capacity to 0 until we establish the namespace format and
1020          * setup integrity extentions if necessary. The revalidate_disk after
1021          * add_disk allows the driver to register with integrity if the format
1022          * requires it.
1023          */
1024         set_capacity(disk, 0);
1025         if (nvme_revalidate_disk(ns->disk))
1026                 goto out_free_disk;
1027
1028         kref_get(&ctrl->kref);
1029         if (ns->type != NVME_NS_LIGHTNVM) {
1030                 add_disk(ns->disk);
1031                 if (ns->ms) {
1032                         struct block_device *bd = bdget_disk(ns->disk, 0);
1033                         if (!bd)
1034                                 return;
1035                         if (blkdev_get(bd, FMODE_READ, NULL)) {
1036                                 bdput(bd);
1037                                 return;
1038                         }
1039                         blkdev_reread_part(bd);
1040                         blkdev_put(bd, FMODE_READ);
1041                 }
1042         }
1043
1044         return;
1045  out_free_disk:
1046         kfree(disk);
1047         list_del(&ns->list);
1048  out_free_queue:
1049         blk_cleanup_queue(ns->queue);
1050  out_free_ns:
1051         kfree(ns);
1052 }
1053
1054 static void nvme_ns_remove(struct nvme_ns *ns)
1055 {
1056         bool kill = nvme_io_incapable(ns->ctrl) &&
1057                         !blk_queue_dying(ns->queue);
1058
1059         if (kill)
1060                 blk_set_queue_dying(ns->queue);
1061         if (ns->disk->flags & GENHD_FL_UP) {
1062                 if (blk_get_integrity(ns->disk))
1063                         blk_integrity_unregister(ns->disk);
1064                 del_gendisk(ns->disk);
1065         }
1066         if (kill || !blk_queue_dying(ns->queue)) {
1067                 blk_mq_abort_requeue_list(ns->queue);
1068                 blk_cleanup_queue(ns->queue);
1069         }
1070         list_del_init(&ns->list);
1071         nvme_put_ns(ns);
1072 }
1073
1074 static void __nvme_scan_namespaces(struct nvme_ctrl *ctrl, unsigned nn)
1075 {
1076         struct nvme_ns *ns, *next;
1077         unsigned i;
1078
1079         for (i = 1; i <= nn; i++) {
1080                 ns = nvme_find_ns(ctrl, i);
1081                 if (ns) {
1082                         if (revalidate_disk(ns->disk))
1083                                 nvme_ns_remove(ns);
1084                 } else
1085                         nvme_alloc_ns(ctrl, i);
1086         }
1087         list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) {
1088                 if (ns->ns_id > nn)
1089                         nvme_ns_remove(ns);
1090         }
1091         list_sort(NULL, &ctrl->namespaces, ns_cmp);
1092 }
1093
1094 void nvme_scan_namespaces(struct nvme_ctrl *ctrl)
1095 {
1096         struct nvme_id_ctrl *id;
1097
1098         if (nvme_identify_ctrl(ctrl, &id))
1099                 return;
1100         __nvme_scan_namespaces(ctrl, le32_to_cpup(&id->nn));
1101         kfree(id);
1102 }
1103
1104 void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
1105 {
1106         struct nvme_ns *ns, *next;
1107
1108         list_for_each_entry_safe(ns, next, &ctrl->namespaces, list)
1109                 nvme_ns_remove(ns);
1110 }
1111
1112 static DEFINE_IDA(nvme_instance_ida);
1113
1114 static int nvme_set_instance(struct nvme_ctrl *ctrl)
1115 {
1116         int instance, error;
1117
1118         do {
1119                 if (!ida_pre_get(&nvme_instance_ida, GFP_KERNEL))
1120                         return -ENODEV;
1121
1122                 spin_lock(&dev_list_lock);
1123                 error = ida_get_new(&nvme_instance_ida, &instance);
1124                 spin_unlock(&dev_list_lock);
1125         } while (error == -EAGAIN);
1126
1127         if (error)
1128                 return -ENODEV;
1129
1130         ctrl->instance = instance;
1131         return 0;
1132 }
1133
1134 static void nvme_release_instance(struct nvme_ctrl *ctrl)
1135 {
1136         spin_lock(&dev_list_lock);
1137         ida_remove(&nvme_instance_ida, ctrl->instance);
1138         spin_unlock(&dev_list_lock);
1139 }
1140
1141 static void nvme_free_ctrl(struct kref *kref)
1142 {
1143         struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);
1144
1145         spin_lock(&dev_list_lock);
1146         list_del(&ctrl->node);
1147         spin_unlock(&dev_list_lock);
1148
1149         put_device(ctrl->device);
1150         nvme_release_instance(ctrl);
1151         device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));
1152
1153         ctrl->ops->free_ctrl(ctrl);
1154 }
1155
1156 void nvme_put_ctrl(struct nvme_ctrl *ctrl)
1157 {
1158         kref_put(&ctrl->kref, nvme_free_ctrl);
1159 }
1160
1161 /*
1162  * Initialize a NVMe controller structures.  This needs to be called during
1163  * earliest initialization so that we have the initialized structured around
1164  * during probing.
1165  */
1166 int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
1167                 const struct nvme_ctrl_ops *ops, unsigned long quirks)
1168 {
1169         int ret;
1170
1171         INIT_LIST_HEAD(&ctrl->namespaces);
1172         kref_init(&ctrl->kref);
1173         ctrl->dev = dev;
1174         ctrl->ops = ops;
1175         ctrl->quirks = quirks;
1176
1177         ret = nvme_set_instance(ctrl);
1178         if (ret)
1179                 goto out;
1180
1181         ctrl->device = device_create(nvme_class, ctrl->dev,
1182                                 MKDEV(nvme_char_major, ctrl->instance),
1183                                 dev, "nvme%d", ctrl->instance);
1184         if (IS_ERR(ctrl->device)) {
1185                 ret = PTR_ERR(ctrl->device);
1186                 goto out_release_instance;
1187         }
1188         get_device(ctrl->device);
1189         dev_set_drvdata(ctrl->device, ctrl);
1190
1191         ret = device_create_file(ctrl->device, &dev_attr_reset_controller);
1192         if (ret)
1193                 goto out_put_device;
1194
1195         spin_lock(&dev_list_lock);
1196         list_add_tail(&ctrl->node, &nvme_ctrl_list);
1197         spin_unlock(&dev_list_lock);
1198
1199         return 0;
1200
1201 out_put_device:
1202         put_device(ctrl->device);
1203         device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));
1204 out_release_instance:
1205         nvme_release_instance(ctrl);
1206 out:
1207         return ret;
1208 }
1209
1210 int __init nvme_core_init(void)
1211 {
1212         int result;
1213
1214         result = register_blkdev(nvme_major, "nvme");
1215         if (result < 0)
1216                 return result;
1217         else if (result > 0)
1218                 nvme_major = result;
1219
1220         result = __register_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme",
1221                                                         &nvme_dev_fops);
1222         if (result < 0)
1223                 goto unregister_blkdev;
1224         else if (result > 0)
1225                 nvme_char_major = result;
1226
1227         nvme_class = class_create(THIS_MODULE, "nvme");
1228         if (IS_ERR(nvme_class)) {
1229                 result = PTR_ERR(nvme_class);
1230                 goto unregister_chrdev;
1231         }
1232
1233         return 0;
1234
1235  unregister_chrdev:
1236         __unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
1237  unregister_blkdev:
1238         unregister_blkdev(nvme_major, "nvme");
1239         return result;
1240 }
1241
1242 void nvme_core_exit(void)
1243 {
1244         unregister_blkdev(nvme_major, "nvme");
1245         class_destroy(nvme_class);
1246         __unregister_chrdev(nvme_char_major, 0, NVME_MINORS, "nvme");
1247 }