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 }
 162
 163 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 164 {
 165         struct device *dev = d;
 166
 167         /* flush bus operations before delete */
 168         nvdimm_bus_lock(dev);
 169         nvdimm_bus_unlock(dev);
 170
 171         device_unregister(dev);
 172         put_device(dev);
 173 }
 174
 175 void __nd_device_register(struct device *dev)
 176 {
 177         dev->bus = &nvdimm_bus_type;
 178         get_device(dev);
 179         async_schedule_domain(nd_async_device_register, dev,
 180                         &nd_async_domain);
 181 }
 182
 183 void nd_device_register(struct device *dev)
 184 {
 185         device_initialize(dev);
 186         __nd_device_register(dev);
 187 }
 188 EXPORT_SYMBOL(nd_device_register);
 189
 190 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 191 {
 192         switch (mode) {
 193         case ND_ASYNC:
 194                 get_device(dev);
 195                 async_schedule_domain(nd_async_device_unregister, dev,
 196                                 &nd_async_domain);
 197                 break;
 198         case ND_SYNC:
 199                 nd_synchronize();
 200                 device_unregister(dev);
 201                 break;
 202         }
 203 }
 204 EXPORT_SYMBOL(nd_device_unregister);
 205
 206 /**
 207  * __nd_driver_register() - register a region or a namespace driver
 208  * @nd_drv: driver to register
 209  * @owner: automatically set by nd_driver_register() macro
 210  * @mod_name: automatically set by nd_driver_register() macro
 211  */
 212 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 213                 const char *mod_name)
 214 {
 215         struct device_driver *drv = &nd_drv->drv;
 216
 217         if (!nd_drv->type) {
 218                 pr_debug("driver type bitmask not set (%pf)\n",
 219                                 __builtin_return_address(0));
 220                 return -EINVAL;
 221         }
 222
 223         if (!nd_drv->probe || !nd_drv->remove) {
 224                 pr_debug("->probe() and ->remove() must be specified\n");
 225                 return -EINVAL;
 226         }
 227
 228         drv->bus = &nvdimm_bus_type;
 229         drv->owner = owner;
 230         drv->mod_name = mod_name;
 231
 232         return driver_register(drv);
 233 }
 234 EXPORT_SYMBOL(__nd_driver_register);
 235
 236 int nvdimm_revalidate_disk(struct gendisk *disk)
 237 {
 238         struct device *dev = disk->driverfs_dev;
 239         struct nd_region *nd_region = to_nd_region(dev->parent);
 240         const char *pol = nd_region->ro ? "only" : "write";
 241
 242         if (nd_region->ro == get_disk_ro(disk))
 243                 return 0;
 244
 245         dev_info(dev, "%s read-%s, marking %s read-%s\n",
 246                         dev_name(&nd_region->dev), pol, disk->disk_name, pol);
 247         set_disk_ro(disk, nd_region->ro);
 248
 249         return 0;
 250
 251 }
 252 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 253
 254 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 255                 char *buf)
 256 {
 257         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 258                         to_nd_device_type(dev));
 259 }
 260 static DEVICE_ATTR_RO(modalias);
 261
 262 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 263                 char *buf)
 264 {
 265         return sprintf(buf, "%s\n", dev->type->name);
 266 }
 267 static DEVICE_ATTR_RO(devtype);
 268
 269 static struct attribute *nd_device_attributes[] = {
 270         &dev_attr_modalias.attr,
 271         &dev_attr_devtype.attr,
 272         NULL,
 273 };
 274
 275 /**
 276  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 277  */
 278 struct attribute_group nd_device_attribute_group = {
 279         .attrs = nd_device_attributes,
 280 };
 281 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 282
 283 static ssize_t numa_node_show(struct device *dev,
 284                 struct device_attribute *attr, char *buf)
 285 {
 286         return sprintf(buf, "%d\n", dev_to_node(dev));
 287 }
 288 static DEVICE_ATTR_RO(numa_node);
 289
 290 static struct attribute *nd_numa_attributes[] = {
 291         &dev_attr_numa_node.attr,
 292         NULL,
 293 };
 294
 295 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 296                 int n)
 297 {
 298         if (!IS_ENABLED(CONFIG_NUMA))
 299                 return 0;
 300
 301         return a->mode;
 302 }
 303
 304 /**
 305  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 306  */
 307 struct attribute_group nd_numa_attribute_group = {
 308         .attrs = nd_numa_attributes,
 309         .is_visible = nd_numa_attr_visible,
 310 };
 311 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 312
 313 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 314 {
 315         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 316         struct device *dev;
 317
 318         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 319                         "ndctl%d", nvdimm_bus->id);
 320
 321         if (IS_ERR(dev)) {
 322                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 323                                 nvdimm_bus->id, PTR_ERR(dev));
 324                 return PTR_ERR(dev);
 325         }
 326         return 0;
 327 }
 328
 329 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 330 {
 331         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 332 }
 333
 334 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 335         [ND_CMD_IMPLEMENTED] = { },
 336         [ND_CMD_SMART] = {
 337                 .out_num = 2,
 338                 .out_sizes = { 4, 8, },
 339         },
 340         [ND_CMD_SMART_THRESHOLD] = {
 341                 .out_num = 2,
 342                 .out_sizes = { 4, 8, },
 343         },
 344         [ND_CMD_DIMM_FLAGS] = {
 345                 .out_num = 2,
 346                 .out_sizes = { 4, 4 },
 347         },
 348         [ND_CMD_GET_CONFIG_SIZE] = {
 349                 .out_num = 3,
 350                 .out_sizes = { 4, 4, 4, },
 351         },
 352         [ND_CMD_GET_CONFIG_DATA] = {
 353                 .in_num = 2,
 354                 .in_sizes = { 4, 4, },
 355                 .out_num = 2,
 356                 .out_sizes = { 4, UINT_MAX, },
 357         },
 358         [ND_CMD_SET_CONFIG_DATA] = {
 359                 .in_num = 3,
 360                 .in_sizes = { 4, 4, UINT_MAX, },
 361                 .out_num = 1,
 362                 .out_sizes = { 4, },
 363         },
 364         [ND_CMD_VENDOR] = {
 365                 .in_num = 3,
 366                 .in_sizes = { 4, 4, UINT_MAX, },
 367                 .out_num = 3,
 368                 .out_sizes = { 4, 4, UINT_MAX, },
 369         },
 370 };
 371
 372 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 373 {
 374         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 375                 return &__nd_cmd_dimm_descs[cmd];
 376         return NULL;
 377 }
 378 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 379
 380 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 381         [ND_CMD_IMPLEMENTED] = { },
 382         [ND_CMD_ARS_CAP] = {
 383                 .in_num = 2,
 384                 .in_sizes = { 8, 8, },
 385                 .out_num = 2,
 386                 .out_sizes = { 4, 4, },
 387         },
 388         [ND_CMD_ARS_START] = {
 389                 .in_num = 4,
 390                 .in_sizes = { 8, 8, 2, 6, },
 391                 .out_num = 1,
 392                 .out_sizes = { 4, },
 393         },
 394         [ND_CMD_ARS_STATUS] = {
 395                 .out_num = 2,
 396                 .out_sizes = { 4, UINT_MAX, },
 397         },
 398 };
 399
 400 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 401 {
 402         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 403                 return &__nd_cmd_bus_descs[cmd];
 404         return NULL;
 405 }
 406 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 407
 408 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 409                 const struct nd_cmd_desc *desc, int idx, void *buf)
 410 {
 411         if (idx >= desc->in_num)
 412                 return UINT_MAX;
 413
 414         if (desc->in_sizes[idx] < UINT_MAX)
 415                 return desc->in_sizes[idx];
 416
 417         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 418                 struct nd_cmd_set_config_hdr *hdr = buf;
 419
 420                 return hdr->in_length;
 421         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 422                 struct nd_cmd_vendor_hdr *hdr = buf;
 423
 424                 return hdr->in_length;
 425         }
 426
 427         return UINT_MAX;
 428 }
 429 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 430
 431 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 432                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 433                 const u32 *out_field)
 434 {
 435         if (idx >= desc->out_num)
 436                 return UINT_MAX;
 437
 438         if (desc->out_sizes[idx] < UINT_MAX)
 439                 return desc->out_sizes[idx];
 440
 441         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 442                 return in_field[1];
 443         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 444                 return out_field[1];
 445         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
 446                 return ND_CMD_ARS_STATUS_MAX;
 447
 448         return UINT_MAX;
 449 }
 450 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 451
 452 void wait_nvdimm_bus_probe_idle(struct device *dev)
 453 {
 454         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 455
 456         do {
 457                 if (nvdimm_bus->probe_active == 0)
 458                         break;
 459                 nvdimm_bus_unlock(&nvdimm_bus->dev);
 460                 wait_event(nvdimm_bus->probe_wait,
 461                                 nvdimm_bus->probe_active == 0);
 462                 nvdimm_bus_lock(&nvdimm_bus->dev);
 463         } while (true);
 464 }
 465
 466 /* set_config requires an idle interleave set */
 467 static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
 468 {
 469         struct nvdimm_bus *nvdimm_bus;
 470
 471         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 472                 return 0;
 473
 474         nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
 475         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 476
 477         if (atomic_read(&nvdimm->busy))
 478                 return -EBUSY;
 479         return 0;
 480 }
 481
 482 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 483                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 484 {
 485         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 486         size_t buf_len = 0, in_len = 0, out_len = 0;
 487         static char out_env[ND_CMD_MAX_ENVELOPE];
 488         static char in_env[ND_CMD_MAX_ENVELOPE];
 489         const struct nd_cmd_desc *desc = NULL;
 490         unsigned int cmd = _IOC_NR(ioctl_cmd);
 491         void __user *p = (void __user *) arg;
 492         struct device *dev = &nvdimm_bus->dev;
 493         const char *cmd_name, *dimm_name;
 494         unsigned long dsm_mask;
 495         void *buf;
 496         int rc, i;
 497
 498         if (nvdimm) {
 499                 desc = nd_cmd_dimm_desc(cmd);
 500                 cmd_name = nvdimm_cmd_name(cmd);
 501                 dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 502                 dimm_name = dev_name(&nvdimm->dev);
 503         } else {
 504                 desc = nd_cmd_bus_desc(cmd);
 505                 cmd_name = nvdimm_bus_cmd_name(cmd);
 506                 dsm_mask = nd_desc->dsm_mask;
 507                 dimm_name = "bus";
 508         }
 509
 510         if (!desc || (desc->out_num + desc->in_num == 0) ||
 511                         !test_bit(cmd, &dsm_mask))
 512                 return -ENOTTY;
 513
 514         /* fail write commands (when read-only) */
 515         if (read_only)
 516                 switch (ioctl_cmd) {
 517                 case ND_IOCTL_VENDOR:
 518                 case ND_IOCTL_SET_CONFIG_DATA:
 519                 case ND_IOCTL_ARS_START:
 520                         dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 521                                         nvdimm ? nvdimm_cmd_name(cmd)
 522                                         : nvdimm_bus_cmd_name(cmd));
 523                         return -EPERM;
 524                 default:
 525                         break;
 526                 }
 527
 528         /* process an input envelope */
 529         for (i = 0; i < desc->in_num; i++) {
 530                 u32 in_size, copy;
 531
 532                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 533                 if (in_size == UINT_MAX) {
 534                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 535                                         __func__, dimm_name, cmd_name, i);
 536                         return -ENXIO;
 537                 }
 538                 if (in_len < sizeof(in_env))
 539                         copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 540                 else
 541                         copy = 0;
 542                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 543                         return -EFAULT;
 544                 in_len += in_size;
 545         }
 546
 547         /* process an output envelope */
 548         for (i = 0; i < desc->out_num; i++) {
 549                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 550                                 (u32 *) in_env, (u32 *) out_env);
 551                 u32 copy;
 552
 553                 if (out_size == UINT_MAX) {
 554                         dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 555                                         __func__, dimm_name, cmd_name, i);
 556                         return -EFAULT;
 557                 }
 558                 if (out_len < sizeof(out_env))
 559                         copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 560                 else
 561                         copy = 0;
 562                 if (copy && copy_from_user(&out_env[out_len],
 563                                         p + in_len + out_len, copy))
 564                         return -EFAULT;
 565                 out_len += out_size;
 566         }
 567
 568         buf_len = out_len + in_len;
 569         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 570                 dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 571                                 dimm_name, cmd_name, buf_len,
 572                                 ND_IOCTL_MAX_BUFLEN);
 573                 return -EINVAL;
 574         }
 575
 576         buf = vmalloc(buf_len);
 577         if (!buf)
 578                 return -ENOMEM;
 579
 580         if (copy_from_user(buf, p, buf_len)) {
 581                 rc = -EFAULT;
 582                 goto out;
 583         }
 584
 585         nvdimm_bus_lock(&nvdimm_bus->dev);
 586         rc = nd_cmd_clear_to_send(nvdimm, cmd);
 587         if (rc)
 588                 goto out_unlock;
 589
 590         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
 591         if (rc < 0)
 592                 goto out_unlock;
 593         if (copy_to_user(p, buf, buf_len))
 594                 rc = -EFAULT;
 595  out_unlock:
 596         nvdimm_bus_unlock(&nvdimm_bus->dev);
 597  out:
 598         vfree(buf);
 599         return rc;
 600 }
 601
 602 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 603 {
 604         long id = (long) file->private_data;
 605         int rc = -ENXIO, read_only;
 606         struct nvdimm_bus *nvdimm_bus;
 607
 608         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 609         mutex_lock(&nvdimm_bus_list_mutex);
 610         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 611                 if (nvdimm_bus->id == id) {
 612                         rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
 613                         break;
 614                 }
 615         }
 616         mutex_unlock(&nvdimm_bus_list_mutex);
 617
 618         return rc;
 619 }
 620
 621 static int match_dimm(struct device *dev, void *data)
 622 {
 623         long id = (long) data;
 624
 625         if (is_nvdimm(dev)) {
 626                 struct nvdimm *nvdimm = to_nvdimm(dev);
 627
 628                 return nvdimm->id == id;
 629         }
 630
 631         return 0;
 632 }
 633
 634 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 635 {
 636         int rc = -ENXIO, read_only;
 637         struct nvdimm_bus *nvdimm_bus;
 638
 639         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 640         mutex_lock(&nvdimm_bus_list_mutex);
 641         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 642                 struct device *dev = device_find_child(&nvdimm_bus->dev,
 643                                 file->private_data, match_dimm);
 644                 struct nvdimm *nvdimm;
 645
 646                 if (!dev)
 647                         continue;
 648
 649                 nvdimm = to_nvdimm(dev);
 650                 rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
 651                 put_device(dev);
 652                 break;
 653         }
 654         mutex_unlock(&nvdimm_bus_list_mutex);
 655
 656         return rc;
 657 }
 658
 659 static int nd_open(struct inode *inode, struct file *file)
 660 {
 661         long minor = iminor(inode);
 662
 663         file->private_data = (void *) minor;
 664         return 0;
 665 }
 666
 667 static const struct file_operations nvdimm_bus_fops = {
 668         .owner = THIS_MODULE,
 669         .open = nd_open,
 670         .unlocked_ioctl = nd_ioctl,
 671         .compat_ioctl = nd_ioctl,
 672         .llseek = noop_llseek,
 673 };
 674
 675 static const struct file_operations nvdimm_fops = {
 676         .owner = THIS_MODULE,
 677         .open = nd_open,
 678         .unlocked_ioctl = nvdimm_ioctl,
 679         .compat_ioctl = nvdimm_ioctl,
 680         .llseek = noop_llseek,
 681 };
 682
 683 int __init nvdimm_bus_init(void)
 684 {
 685         int rc;
 686
 687         rc = bus_register(&nvdimm_bus_type);
 688         if (rc)
 689                 return rc;
 690
 691         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 692         if (rc < 0)
 693                 goto err_bus_chrdev;
 694         nvdimm_bus_major = rc;
 695
 696         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 697         if (rc < 0)
 698                 goto err_dimm_chrdev;
 699         nvdimm_major = rc;
 700
 701         nd_class = class_create(THIS_MODULE, "nd");
 702         if (IS_ERR(nd_class)) {
 703                 rc = PTR_ERR(nd_class);
 704                 goto err_class;
 705         }
 706
 707         return 0;
 708
 709  err_class:
 710         unregister_chrdev(nvdimm_major, "dimmctl");
 711  err_dimm_chrdev:
 712         unregister_chrdev(nvdimm_bus_major, "ndctl");
 713  err_bus_chrdev:
 714         bus_unregister(&nvdimm_bus_type);
 715
 716         return rc;
 717 }
 718
 719 void nvdimm_bus_exit(void)
 720 {
 721         class_destroy(nd_class);
 722         unregister_chrdev(nvdimm_bus_major, "ndctl");
 723         unregister_chrdev(nvdimm_major, "dimmctl");
 724         bus_unregister(&nvdimm_bus_type);
 725 }