drivers/nvdimm/bus.c

   1 /*
   2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  */
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14 #include <linux/vmalloc.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/fcntl.h>
  19 #include <linux/async.h>
  20 #include <linux/genhd.h>
  21 #include <linux/ndctl.h>
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/fs.h>
  25 #include <linux/io.h>
  26 #include <linux/mm.h>
  27 #include <linux/nd.h>
  28 #include "nd-core.h"
  29 #include "nd.h"
  30
  31 int nvdimm_major;
  32 static int nvdimm_bus_major;
  33 static struct class *nd_class;
  34
  35 static int to_nd_device_type(struct device *dev)
  36 {
  37         if (is_nvdimm(dev))
  38                 return ND_DEVICE_DIMM;
  39         else if (is_nd_pmem(dev))
  40                 return ND_DEVICE_REGION_PMEM;
  41         else if (is_nd_blk(dev))
  42                 return ND_DEVICE_REGION_BLK;
  43         else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
  44                 return nd_region_to_nstype(to_nd_region(dev->parent));
  45
  46         return 0;
  47 }
  48
  49 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
  50 {
  51         /*
  52          * Ensure that region devices always have their numa node set as
  53          * early as possible.
  54          */
  55         if (is_nd_pmem(dev) || is_nd_blk(dev))
  56                 set_dev_node(dev, to_nd_region(dev)->numa_node);
  57         return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
  58                         to_nd_device_type(dev));
  59 }
  60
  61 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
  62 {
  63         struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
  64
  65         return test_bit(to_nd_device_type(dev), &nd_drv->type);
  66 }
  67
  68 static struct module *to_bus_provider(struct device *dev)
  69 {
  70         /* pin bus providers while regions are enabled */
  71         if (is_nd_pmem(dev) || is_nd_blk(dev)) {
  72                 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  73
  74                 return nvdimm_bus->module;
  75         }
  76         return NULL;
  77 }
  78
  79 static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
  80 {
  81         nvdimm_bus_lock(&nvdimm_bus->dev);
  82         nvdimm_bus->probe_active++;
  83         nvdimm_bus_unlock(&nvdimm_bus->dev);
  84 }
  85
  86 static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
  87 {
  88         nvdimm_bus_lock(&nvdimm_bus->dev);
  89         if (--nvdimm_bus->probe_active == 0)
  90                 wake_up(&nvdimm_bus->probe_wait);
  91         nvdimm_bus_unlock(&nvdimm_bus->dev);
  92 }
  93
  94 static int nvdimm_bus_probe(struct device *dev)
  95 {
  96         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
  97         struct module *provider = to_bus_provider(dev);
  98         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  99         int rc;
 100
 101         if (!try_module_get(provider))
 102                 return -ENXIO;
 103
 104         nvdimm_bus_probe_start(nvdimm_bus);
 105         rc = nd_drv->probe(dev);
 106         if (rc == 0)
 107                 nd_region_probe_success(nvdimm_bus, dev);
 108         else
 109                 nd_region_disable(nvdimm_bus, dev);
 110         nvdimm_bus_probe_end(nvdimm_bus);
 111
 112         dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
 113                         dev_name(dev), rc);
 114
 115         if (rc != 0)
 116                 module_put(provider);
 117         return rc;
 118 }
 119
 120 static int nvdimm_bus_remove(struct device *dev)
 121 {
 122         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 123         struct module *provider = to_bus_provider(dev);
 124         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 125         int rc;
 126
 127         rc = nd_drv->remove(dev);
 128         nd_region_disable(nvdimm_bus, dev);
 129
 130         dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
 131                         dev_name(dev), rc);
 132         module_put(provider);
 133         return rc;
 134 }
 135
 136 static struct bus_type nvdimm_bus_type = {
 137         .name = "nd",
 138         .uevent = nvdimm_bus_uevent,
 139         .match = nvdimm_bus_match,
 140         .probe = nvdimm_bus_probe,
 141         .remove = nvdimm_bus_remove,
 142 };
 143
 144 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 145
 146 void nd_synchronize(void)
 147 {
 148         async_synchronize_full_domain(&nd_async_domain);
 149 }
 150 EXPORT_SYMBOL_GPL(nd_synchronize);
 151
 152 static void nd_async_device_register(void *d, async_cookie_t cookie)
 153 {
 154         struct device *dev = d;
 155
 156         if (device_add(dev) != 0) {
 157                 dev_err(dev, "%s: failed\n", __func__);
 158                 put_device(dev);
 159         }
 160         put_device(dev);
 161         if (dev->parent)
 162                 put_device(dev->parent);
 163 }
 164
 165 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 166 {
 167         struct device *dev = d;
 168
 169         /* flush bus operations before delete */
 170         nvdimm_bus_lock(dev);
 171         nvdimm_bus_unlock(dev);
 172
 173         device_unregister(dev);
 174         put_device(dev);
 175 }
 176
 177 void __nd_device_register(struct device *dev)
 178 {
 179         dev->bus = &nvdimm_bus_type;
 180         if (dev->parent)
 181                 get_device(dev->parent);
 182         get_device(dev);
 183         async_schedule_domain(nd_async_device_register, dev,
 184                         &nd_async_domain);
 185 }
 186
 187 void nd_device_register(struct device *dev)
 188 {
 189         device_initialize(dev);
 190         __nd_device_register(dev);
 191 }
 192 EXPORT_SYMBOL(nd_device_register);
 193
 194 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 195 {
 196         switch (mode) {
 197         case ND_ASYNC:
 198                 get_device(dev);
 199                 async_schedule_domain(nd_async_device_unregister, dev,
 200                                 &nd_async_domain);
 201                 break;
 202         case ND_SYNC:
 203                 nd_synchronize();
 204                 device_unregister(dev);
 205                 break;
 206         }
 207 }
 208 EXPORT_SYMBOL(nd_device_unregister);
 209
 210 /**
 211  * __nd_driver_register() - register a region or a namespace driver
 212  * @nd_drv: driver to register
 213  * @owner: automatically set by nd_driver_register() macro
 214  * @mod_name: automatically set by nd_driver_register() macro
 215  */
 216 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 217                 const char *mod_name)
 218 {
 219         struct device_driver *drv = &nd_drv->drv;
 220
 221         if (!nd_drv->type) {
 222                 pr_debug("driver type bitmask not set (%pf)\n",
 223                                 __builtin_return_address(0));
 224                 return -EINVAL;
 225         }
 226
 227         if (!nd_drv->probe || !nd_drv->remove) {
 228                 pr_debug("->probe() and ->remove() must be specified\n");
 229                 return -EINVAL;
 230         }
 231
 232         drv->bus = &nvdimm_bus_type;
 233         drv->owner = owner;
 234         drv->mod_name = mod_name;
 235
 236         return driver_register(drv);
 237 }
 238 EXPORT_SYMBOL(__nd_driver_register);
 239
 240 int nvdimm_revalidate_disk(struct gendisk *disk)
 241 {
 242         struct device *dev = disk->driverfs_dev;
 243         struct nd_region *nd_region = to_nd_region(dev->parent);
 244         int disk_ro = get_disk_ro(disk);
 245
 246         /*
 247          * Upgrade to read-only if the region is read-only preserve as
 248          * read-only if the disk is already read-only.
 249          */
 250         if (disk_ro || nd_region->ro == disk_ro)
 251                 return 0;
 252
 253         dev_info(dev, "%s read-only, marking %s read-only\n",
 254                         dev_name(&nd_region->dev), disk->disk_name);
 255         set_disk_ro(disk, 1);
 256
 257         return 0;
 258
 259 }
 260 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 261
 262 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 263                 char *buf)
 264 {
 265         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 266                         to_nd_device_type(dev));
 267 }
 268 static DEVICE_ATTR_RO(modalias);
 269
 270 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 271                 char *buf)
 272 {
 273         return sprintf(buf, "%s\n", dev->type->name);
 274 }
 275 static DEVICE_ATTR_RO(devtype);
 276
 277 static struct attribute *nd_device_attributes[] = {
 278         &dev_attr_modalias.attr,
 279         &dev_attr_devtype.attr,
 280         NULL,
 281 };
 282
 283 /**
 284  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 285  */
 286 struct attribute_group nd_device_attribute_group = {
 287         .attrs = nd_device_attributes,
 288 };
 289 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 290
 291 static ssize_t numa_node_show(struct device *dev,
 292                 struct device_attribute *attr, char *buf)
 293 {
 294         return sprintf(buf, "%d\n", dev_to_node(dev));
 295 }
 296 static DEVICE_ATTR_RO(numa_node);
 297
 298 static struct attribute *nd_numa_attributes[] = {
 299         &dev_attr_numa_node.attr,
 300         NULL,
 301 };
 302
 303 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 304                 int n)
 305 {
 306         if (!IS_ENABLED(CONFIG_NUMA))
 307                 return 0;
 308
 309         return a->mode;
 310 }
 311
 312 /**
 313  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 314  */
 315 struct attribute_group nd_numa_attribute_group = {
 316         .attrs = nd_numa_attributes,
 317         .is_visible = nd_numa_attr_visible,
 318 };
 319 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 320
 321 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 322 {
 323         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 324         struct device *dev;
 325
 326         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 327                         "ndctl%d", nvdimm_bus->id);
 328
 329         if (IS_ERR(dev)) {
 330                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 331                                 nvdimm_bus->id, PTR_ERR(dev));
 332                 return PTR_ERR(dev);
 333         }
 334         return 0;
 335 }
 336
 337 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 338 {
 339         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 340 }
 341
 342 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 343         [ND_CMD_IMPLEMENTED] = { },
 344         [ND_CMD_SMART] = {
 345                 .out_num = 2,
 346                 .out_sizes = { 4, 128, },
 347         },
 348         [ND_CMD_SMART_THRESHOLD] = {
 349                 .out_num = 2,
 350                 .out_sizes = { 4, 8, },
 351         },
 352         [ND_CMD_DIMM_FLAGS] = {
 353                 .out_num = 2,
 354                 .out_sizes = { 4, 4 },
 355         },
 356         [ND_CMD_GET_CONFIG_SIZE] = {
 357                 .out_num = 3,
 358                 .out_sizes = { 4, 4, 4, },
 359         },
 360         [ND_CMD_GET_CONFIG_DATA] = {
 361                 .in_num = 2,
 362                 .in_sizes = { 4, 4, },
 363                 .out_num = 2,
 364                 .out_sizes = { 4, UINT_MAX, },
 365         },
 366         [ND_CMD_SET_CONFIG_DATA] = {
 367                 .in_num = 3,
 368                 .in_sizes = { 4, 4, UINT_MAX, },
 369                 .out_num = 1,
 370                 .out_sizes = { 4, },
 371         },
 372         [ND_CMD_VENDOR] = {
 373                 .in_num = 3,
 374                 .in_sizes = { 4, 4, UINT_MAX, },
 375                 .out_num = 3,
 376                 .out_sizes = { 4, 4, UINT_MAX, },
 377         },
 378 };
 379
 380 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 381 {
 382         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 383                 return &__nd_cmd_dimm_descs[cmd];
 384         return NULL;
 385 }
 386 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 387
 388 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 389         [ND_CMD_IMPLEMENTED] = { },
 390         [ND_CMD_ARS_CAP] = {
 391                 .in_num = 2,
 392                 .in_sizes = { 8, 8, },
 393                 .out_num = 2,
 394                 .out_sizes = { 4, 4, },
 395         },
 396         [ND_CMD_ARS_START] = {
 397                 .in_num = 4,
 398                 .in_sizes = { 8, 8, 2, 6, },
 399                 .out_num = 1,
 400                 .out_sizes = { 4, },
 401         },
 402         [ND_CMD_ARS_STATUS] = {
 403                 .out_num = 2,
 404                 .out_sizes = { 4, UINT_MAX, },
 405         },
 406 };
 407
 408 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 409 {
 410         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 411                 return &__nd_cmd_bus_descs[cmd];
 412         return NULL;
 413 }
 414 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 415
 416 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 417                 const struct nd_cmd_desc *desc, int idx, void *buf)
 418 {
 419         if (idx >= desc->in_num)
 420                 return UINT_MAX;
 421
 422         if (desc->in_sizes[idx] < UINT_MAX)
 423                 return desc->in_sizes[idx];
 424
 425         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 426                 struct nd_cmd_set_config_hdr *hdr = buf;
 427
 428                 return hdr->in_length;
 429         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 430                 struct nd_cmd_vendor_hdr *hdr = buf;
 431
 432                 return hdr->in_length;
 433         }
 434
 435         return UINT_MAX;
 436 }
 437 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 438
 439 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 440                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 441                 const u32 *out_field)
 442 {
 443         if (idx >= desc->out_num)
 444                 return UINT_MAX;
 445
 446         if (desc->out_sizes[idx] < UINT_MAX)
 447                 return desc->out_sizes[idx];
 448
 449         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 450                 return in_field[1];
 451         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 452                 return out_field[1];
 453         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
 454                 return ND_CMD_ARS_STATUS_MAX;
 455
 456         return UINT_MAX;
 457 }
 458 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 459
 460 void wait_nvdimm_bus_probe_idle(struct device *dev)
 461 {
 462         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 463
 464         do {
 465                 if (nvdimm_bus->probe_active == 0)
 466                         break;
 467                 nvdimm_bus_unlock(&nvdimm_bus->dev);
 468                 wait_event(nvdimm_bus->probe_wait,
 469                                 nvdimm_bus->probe_active == 0);
 470                 nvdimm_bus_lock(&nvdimm_bus->dev);
 471         } while (true);
 472 }
 473
 474 /* set_config requires an idle interleave set */
 475 static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
 476 {
 477         struct nvdimm_bus *nvdimm_bus;
 478
 479         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 480                 return 0;
 481
 482         nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
 483         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 484
 485         if (atomic_read(&nvdimm->busy))
 486                 return -EBUSY;
 487         return 0;
 488 }
 489
 490 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 491                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 492 {
 493         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 494         size_t buf_len = 0, in_len = 0, out_len = 0;
 495         static char out_env[ND_CMD_MAX_ENVELOPE];
 496         static char in_env[ND_CMD_MAX_ENVELOPE];
 497         const struct nd_cmd_desc *desc = NULL;
 498         unsigned int cmd = _IOC_NR(ioctl_cmd);
 499         void __user *p = (void __user *) arg;
 500         struct device *dev = &nvdimm_bus->dev;
 501         const char *cmd_name, *dimm_name;
 502         unsigned long dsm_mask;
 503         void *buf;
 504         int rc, i;
 505
 506         if (nvdimm) {
 507                 desc = nd_cmd_dimm_desc(cmd);
 508                 cmd_name = nvdimm_cmd_name(cmd);
 509                 dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 510                 dimm_name = dev_name(&nvdimm->dev);
 511         } else {
 512                 desc = nd_cmd_bus_desc(cmd);
 513                 cmd_name = nvdimm_bus_cmd_name(cmd);
 514                 dsm_mask = nd_desc->dsm_mask;
 515                 dimm_name = "bus";
 516         }
 517
 518         if (!desc || (desc->out_num + desc->in_num == 0) ||
 519                         !test_bit(cmd, &dsm_mask))
 520                 return -ENOTTY;
 521
 522         /* fail write commands (when read-only) */
 523         if (read_only)
 524                 switch (cmd) {
 525                 case ND_CMD_VENDOR:
 526                 case ND_CMD_SET_CONFIG_DATA:
 527                 case ND_CMD_ARS_START:
 528                         dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 529                                         nvdimm ? nvdimm_cmd_name(cmd)
 530                                         : nvdimm_bus_cmd_name(cmd));
 531                         return -EPERM;
 532                 default:
 533                         break;
 534                 }
 535
 536         /* process an input envelope */
 537         for (i = 0; i < desc->in_num; i++) {
 538                 u32 in_size, copy;
 539
 540                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 541                 if (in_size == UINT_MAX) {
 542                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 543                                         __func__, dimm_name, cmd_name, i);
 544                         return -ENXIO;
 545                 }
 546                 if (in_len < sizeof(in_env))
 547                         copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 548                 else
 549                         copy = 0;
 550                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 551                         return -EFAULT;
 552                 in_len += in_size;
 553         }
 554
 555         /* process an output envelope */
 556         for (i = 0; i < desc->out_num; i++) {
 557                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 558                                 (u32 *) in_env, (u32 *) out_env);
 559                 u32 copy;
 560
 561                 if (out_size == UINT_MAX) {
 562                         dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 563                                         __func__, dimm_name, cmd_name, i);
 564                         return -EFAULT;
 565                 }
 566                 if (out_len < sizeof(out_env))
 567                         copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 568                 else
 569                         copy = 0;
 570                 if (copy && copy_from_user(&out_env[out_len],
 571                                         p + in_len + out_len, copy))
 572                         return -EFAULT;
 573                 out_len += out_size;
 574         }
 575
 576         buf_len = out_len + in_len;
 577         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 578                 dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 579                                 dimm_name, cmd_name, buf_len,
 580                                 ND_IOCTL_MAX_BUFLEN);
 581                 return -EINVAL;
 582         }
 583
 584         buf = vmalloc(buf_len);
 585         if (!buf)
 586                 return -ENOMEM;
 587
 588         if (copy_from_user(buf, p, buf_len)) {
 589                 rc = -EFAULT;
 590                 goto out;
 591         }
 592
 593         nvdimm_bus_lock(&nvdimm_bus->dev);
 594         rc = nd_cmd_clear_to_send(nvdimm, cmd);
 595         if (rc)
 596                 goto out_unlock;
 597
 598         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
 599         if (rc < 0)
 600                 goto out_unlock;
 601         nvdimm_bus_unlock(&nvdimm_bus->dev);
 602
 603         if (copy_to_user(p, buf, buf_len))
 604                 rc = -EFAULT;
 605
 606         vfree(buf);
 607         return rc;
 608
 609  out_unlock:
 610         nvdimm_bus_unlock(&nvdimm_bus->dev);
 611  out:
 612         vfree(buf);
 613         return rc;
 614 }
 615
 616 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 617 {
 618         long id = (long) file->private_data;
 619         int rc = -ENXIO, read_only;
 620         struct nvdimm_bus *nvdimm_bus;
 621
 622         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 623         mutex_lock(&nvdimm_bus_list_mutex);
 624         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 625                 if (nvdimm_bus->id == id) {
 626                         rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
 627                         break;
 628                 }
 629         }
 630         mutex_unlock(&nvdimm_bus_list_mutex);
 631
 632         return rc;
 633 }
 634
 635 static int match_dimm(struct device *dev, void *data)
 636 {
 637         long id = (long) data;
 638
 639         if (is_nvdimm(dev)) {
 640                 struct nvdimm *nvdimm = to_nvdimm(dev);
 641
 642                 return nvdimm->id == id;
 643         }
 644
 645         return 0;
 646 }
 647
 648 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 649 {
 650         int rc = -ENXIO, read_only;
 651         struct nvdimm_bus *nvdimm_bus;
 652
 653         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 654         mutex_lock(&nvdimm_bus_list_mutex);
 655         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 656                 struct device *dev = device_find_child(&nvdimm_bus->dev,
 657                                 file->private_data, match_dimm);
 658                 struct nvdimm *nvdimm;
 659
 660                 if (!dev)
 661                         continue;
 662
 663                 nvdimm = to_nvdimm(dev);
 664                 rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
 665                 put_device(dev);
 666                 break;
 667         }
 668         mutex_unlock(&nvdimm_bus_list_mutex);
 669
 670         return rc;
 671 }
 672
 673 static int nd_open(struct inode *inode, struct file *file)
 674 {
 675         long minor = iminor(inode);
 676
 677         file->private_data = (void *) minor;
 678         return 0;
 679 }
 680
 681 static const struct file_operations nvdimm_bus_fops = {
 682         .owner = THIS_MODULE,
 683         .open = nd_open,
 684         .unlocked_ioctl = nd_ioctl,
 685         .compat_ioctl = nd_ioctl,
 686         .llseek = noop_llseek,
 687 };
 688
 689 static const struct file_operations nvdimm_fops = {
 690         .owner = THIS_MODULE,
 691         .open = nd_open,
 692         .unlocked_ioctl = nvdimm_ioctl,
 693         .compat_ioctl = nvdimm_ioctl,
 694         .llseek = noop_llseek,
 695 };
 696
 697 int __init nvdimm_bus_init(void)
 698 {
 699         int rc;
 700
 701         rc = bus_register(&nvdimm_bus_type);
 702         if (rc)
 703                 return rc;
 704
 705         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 706         if (rc < 0)
 707                 goto err_bus_chrdev;
 708         nvdimm_bus_major = rc;
 709
 710         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 711         if (rc < 0)
 712                 goto err_dimm_chrdev;
 713         nvdimm_major = rc;
 714
 715         nd_class = class_create(THIS_MODULE, "nd");
 716         if (IS_ERR(nd_class)) {
 717                 rc = PTR_ERR(nd_class);
 718                 goto err_class;
 719         }
 720
 721         return 0;
 722
 723  err_class:
 724         unregister_chrdev(nvdimm_major, "dimmctl");
 725  err_dimm_chrdev:
 726         unregister_chrdev(nvdimm_bus_major, "ndctl");
 727  err_bus_chrdev:
 728         bus_unregister(&nvdimm_bus_type);
 729
 730         return rc;
 731 }
 732
 733 void nvdimm_bus_exit(void)
 734 {
 735         class_destroy(nd_class);
 736         unregister_chrdev(nvdimm_bus_major, "ndctl");
 737         unregister_chrdev(nvdimm_major, "dimmctl");
 738         bus_unregister(&nvdimm_bus_type);
 739 }