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         int disk_ro = get_disk_ro(disk);
 241
 242         /*
 243          * Upgrade to read-only if the region is read-only preserve as
 244          * read-only if the disk is already read-only.
 245          */
 246         if (disk_ro || nd_region->ro == disk_ro)
 247                 return 0;
 248
 249         dev_info(dev, "%s read-only, marking %s read-only\n",
 250                         dev_name(&nd_region->dev), disk->disk_name);
 251         set_disk_ro(disk, 1);
 252
 253         return 0;
 254
 255 }
 256 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 257
 258 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 259                 char *buf)
 260 {
 261         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 262                         to_nd_device_type(dev));
 263 }
 264 static DEVICE_ATTR_RO(modalias);
 265
 266 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 267                 char *buf)
 268 {
 269         return sprintf(buf, "%s\n", dev->type->name);
 270 }
 271 static DEVICE_ATTR_RO(devtype);
 272
 273 static struct attribute *nd_device_attributes[] = {
 274         &dev_attr_modalias.attr,
 275         &dev_attr_devtype.attr,
 276         NULL,
 277 };
 278
 279 /**
 280  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 281  */
 282 struct attribute_group nd_device_attribute_group = {
 283         .attrs = nd_device_attributes,
 284 };
 285 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 286
 287 static ssize_t numa_node_show(struct device *dev,
 288                 struct device_attribute *attr, char *buf)
 289 {
 290         return sprintf(buf, "%d\n", dev_to_node(dev));
 291 }
 292 static DEVICE_ATTR_RO(numa_node);
 293
 294 static struct attribute *nd_numa_attributes[] = {
 295         &dev_attr_numa_node.attr,
 296         NULL,
 297 };
 298
 299 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 300                 int n)
 301 {
 302         if (!IS_ENABLED(CONFIG_NUMA))
 303                 return 0;
 304
 305         return a->mode;
 306 }
 307
 308 /**
 309  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 310  */
 311 struct attribute_group nd_numa_attribute_group = {
 312         .attrs = nd_numa_attributes,
 313         .is_visible = nd_numa_attr_visible,
 314 };
 315 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 316
 317 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 318 {
 319         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 320         struct device *dev;
 321
 322         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 323                         "ndctl%d", nvdimm_bus->id);
 324
 325         if (IS_ERR(dev)) {
 326                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 327                                 nvdimm_bus->id, PTR_ERR(dev));
 328                 return PTR_ERR(dev);
 329         }
 330         return 0;
 331 }
 332
 333 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 334 {
 335         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 336 }
 337
 338 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 339         [ND_CMD_IMPLEMENTED] = { },
 340         [ND_CMD_SMART] = {
 341                 .out_num = 2,
 342                 .out_sizes = { 4, 128, },
 343         },
 344         [ND_CMD_SMART_THRESHOLD] = {
 345                 .out_num = 2,
 346                 .out_sizes = { 4, 8, },
 347         },
 348         [ND_CMD_DIMM_FLAGS] = {
 349                 .out_num = 2,
 350                 .out_sizes = { 4, 4 },
 351         },
 352         [ND_CMD_GET_CONFIG_SIZE] = {
 353                 .out_num = 3,
 354                 .out_sizes = { 4, 4, 4, },
 355         },
 356         [ND_CMD_GET_CONFIG_DATA] = {
 357                 .in_num = 2,
 358                 .in_sizes = { 4, 4, },
 359                 .out_num = 2,
 360                 .out_sizes = { 4, UINT_MAX, },
 361         },
 362         [ND_CMD_SET_CONFIG_DATA] = {
 363                 .in_num = 3,
 364                 .in_sizes = { 4, 4, UINT_MAX, },
 365                 .out_num = 1,
 366                 .out_sizes = { 4, },
 367         },
 368         [ND_CMD_VENDOR] = {
 369                 .in_num = 3,
 370                 .in_sizes = { 4, 4, UINT_MAX, },
 371                 .out_num = 3,
 372                 .out_sizes = { 4, 4, UINT_MAX, },
 373         },
 374 };
 375
 376 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 377 {
 378         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 379                 return &__nd_cmd_dimm_descs[cmd];
 380         return NULL;
 381 }
 382 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 383
 384 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 385         [ND_CMD_IMPLEMENTED] = { },
 386         [ND_CMD_ARS_CAP] = {
 387                 .in_num = 2,
 388                 .in_sizes = { 8, 8, },
 389                 .out_num = 2,
 390                 .out_sizes = { 4, 4, },
 391         },
 392         [ND_CMD_ARS_START] = {
 393                 .in_num = 4,
 394                 .in_sizes = { 8, 8, 2, 6, },
 395                 .out_num = 1,
 396                 .out_sizes = { 4, },
 397         },
 398         [ND_CMD_ARS_STATUS] = {
 399                 .out_num = 2,
 400                 .out_sizes = { 4, UINT_MAX, },
 401         },
 402 };
 403
 404 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 405 {
 406         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 407                 return &__nd_cmd_bus_descs[cmd];
 408         return NULL;
 409 }
 410 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 411
 412 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 413                 const struct nd_cmd_desc *desc, int idx, void *buf)
 414 {
 415         if (idx >= desc->in_num)
 416                 return UINT_MAX;
 417
 418         if (desc->in_sizes[idx] < UINT_MAX)
 419                 return desc->in_sizes[idx];
 420
 421         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 422                 struct nd_cmd_set_config_hdr *hdr = buf;
 423
 424                 return hdr->in_length;
 425         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 426                 struct nd_cmd_vendor_hdr *hdr = buf;
 427
 428                 return hdr->in_length;
 429         }
 430
 431         return UINT_MAX;
 432 }
 433 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 434
 435 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 436                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 437                 const u32 *out_field)
 438 {
 439         if (idx >= desc->out_num)
 440                 return UINT_MAX;
 441
 442         if (desc->out_sizes[idx] < UINT_MAX)
 443                 return desc->out_sizes[idx];
 444
 445         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 446                 return in_field[1];
 447         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 448                 return out_field[1];
 449         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
 450                 return ND_CMD_ARS_STATUS_MAX;
 451
 452         return UINT_MAX;
 453 }
 454 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 455
 456 void wait_nvdimm_bus_probe_idle(struct device *dev)
 457 {
 458         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 459
 460         do {
 461                 if (nvdimm_bus->probe_active == 0)
 462                         break;
 463                 nvdimm_bus_unlock(&nvdimm_bus->dev);
 464                 wait_event(nvdimm_bus->probe_wait,
 465                                 nvdimm_bus->probe_active == 0);
 466                 nvdimm_bus_lock(&nvdimm_bus->dev);
 467         } while (true);
 468 }
 469
 470 /* set_config requires an idle interleave set */
 471 static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
 472 {
 473         struct nvdimm_bus *nvdimm_bus;
 474
 475         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 476                 return 0;
 477
 478         nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
 479         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 480
 481         if (atomic_read(&nvdimm->busy))
 482                 return -EBUSY;
 483         return 0;
 484 }
 485
 486 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 487                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 488 {
 489         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 490         size_t buf_len = 0, in_len = 0, out_len = 0;
 491         static char out_env[ND_CMD_MAX_ENVELOPE];
 492         static char in_env[ND_CMD_MAX_ENVELOPE];
 493         const struct nd_cmd_desc *desc = NULL;
 494         unsigned int cmd = _IOC_NR(ioctl_cmd);
 495         void __user *p = (void __user *) arg;
 496         struct device *dev = &nvdimm_bus->dev;
 497         const char *cmd_name, *dimm_name;
 498         unsigned long dsm_mask;
 499         void *buf;
 500         int rc, i;
 501
 502         if (nvdimm) {
 503                 desc = nd_cmd_dimm_desc(cmd);
 504                 cmd_name = nvdimm_cmd_name(cmd);
 505                 dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 506                 dimm_name = dev_name(&nvdimm->dev);
 507         } else {
 508                 desc = nd_cmd_bus_desc(cmd);
 509                 cmd_name = nvdimm_bus_cmd_name(cmd);
 510                 dsm_mask = nd_desc->dsm_mask;
 511                 dimm_name = "bus";
 512         }
 513
 514         if (!desc || (desc->out_num + desc->in_num == 0) ||
 515                         !test_bit(cmd, &dsm_mask))
 516                 return -ENOTTY;
 517
 518         /* fail write commands (when read-only) */
 519         if (read_only)
 520                 switch (cmd) {
 521                 case ND_CMD_VENDOR:
 522                 case ND_CMD_SET_CONFIG_DATA:
 523                 case ND_CMD_ARS_START:
 524                         dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 525                                         nvdimm ? nvdimm_cmd_name(cmd)
 526                                         : nvdimm_bus_cmd_name(cmd));
 527                         return -EPERM;
 528                 default:
 529                         break;
 530                 }
 531
 532         /* process an input envelope */
 533         for (i = 0; i < desc->in_num; i++) {
 534                 u32 in_size, copy;
 535
 536                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 537                 if (in_size == UINT_MAX) {
 538                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 539                                         __func__, dimm_name, cmd_name, i);
 540                         return -ENXIO;
 541                 }
 542                 if (in_len < sizeof(in_env))
 543                         copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 544                 else
 545                         copy = 0;
 546                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 547                         return -EFAULT;
 548                 in_len += in_size;
 549         }
 550
 551         /* process an output envelope */
 552         for (i = 0; i < desc->out_num; i++) {
 553                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 554                                 (u32 *) in_env, (u32 *) out_env);
 555                 u32 copy;
 556
 557                 if (out_size == UINT_MAX) {
 558                         dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 559                                         __func__, dimm_name, cmd_name, i);
 560                         return -EFAULT;
 561                 }
 562                 if (out_len < sizeof(out_env))
 563                         copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 564                 else
 565                         copy = 0;
 566                 if (copy && copy_from_user(&out_env[out_len],
 567                                         p + in_len + out_len, copy))
 568                         return -EFAULT;
 569                 out_len += out_size;
 570         }
 571
 572         buf_len = out_len + in_len;
 573         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 574                 dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 575                                 dimm_name, cmd_name, buf_len,
 576                                 ND_IOCTL_MAX_BUFLEN);
 577                 return -EINVAL;
 578         }
 579
 580         buf = vmalloc(buf_len);
 581         if (!buf)
 582                 return -ENOMEM;
 583
 584         if (copy_from_user(buf, p, buf_len)) {
 585                 rc = -EFAULT;
 586                 goto out;
 587         }
 588
 589         nvdimm_bus_lock(&nvdimm_bus->dev);
 590         rc = nd_cmd_clear_to_send(nvdimm, cmd);
 591         if (rc)
 592                 goto out_unlock;
 593
 594         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
 595         if (rc < 0)
 596                 goto out_unlock;
 597         nvdimm_bus_unlock(&nvdimm_bus->dev);
 598
 599         if (copy_to_user(p, buf, buf_len))
 600                 rc = -EFAULT;
 601
 602         vfree(buf);
 603         return rc;
 604
 605  out_unlock:
 606         nvdimm_bus_unlock(&nvdimm_bus->dev);
 607  out:
 608         vfree(buf);
 609         return rc;
 610 }
 611
 612 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 613 {
 614         long id = (long) file->private_data;
 615         int rc = -ENXIO, read_only;
 616         struct nvdimm_bus *nvdimm_bus;
 617
 618         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 619         mutex_lock(&nvdimm_bus_list_mutex);
 620         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 621                 if (nvdimm_bus->id == id) {
 622                         rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
 623                         break;
 624                 }
 625         }
 626         mutex_unlock(&nvdimm_bus_list_mutex);
 627
 628         return rc;
 629 }
 630
 631 static int match_dimm(struct device *dev, void *data)
 632 {
 633         long id = (long) data;
 634
 635         if (is_nvdimm(dev)) {
 636                 struct nvdimm *nvdimm = to_nvdimm(dev);
 637
 638                 return nvdimm->id == id;
 639         }
 640
 641         return 0;
 642 }
 643
 644 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 645 {
 646         int rc = -ENXIO, read_only;
 647         struct nvdimm_bus *nvdimm_bus;
 648
 649         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 650         mutex_lock(&nvdimm_bus_list_mutex);
 651         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 652                 struct device *dev = device_find_child(&nvdimm_bus->dev,
 653                                 file->private_data, match_dimm);
 654                 struct nvdimm *nvdimm;
 655
 656                 if (!dev)
 657                         continue;
 658
 659                 nvdimm = to_nvdimm(dev);
 660                 rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
 661                 put_device(dev);
 662                 break;
 663         }
 664         mutex_unlock(&nvdimm_bus_list_mutex);
 665
 666         return rc;
 667 }
 668
 669 static int nd_open(struct inode *inode, struct file *file)
 670 {
 671         long minor = iminor(inode);
 672
 673         file->private_data = (void *) minor;
 674         return 0;
 675 }
 676
 677 static const struct file_operations nvdimm_bus_fops = {
 678         .owner = THIS_MODULE,
 679         .open = nd_open,
 680         .unlocked_ioctl = nd_ioctl,
 681         .compat_ioctl = nd_ioctl,
 682         .llseek = noop_llseek,
 683 };
 684
 685 static const struct file_operations nvdimm_fops = {
 686         .owner = THIS_MODULE,
 687         .open = nd_open,
 688         .unlocked_ioctl = nvdimm_ioctl,
 689         .compat_ioctl = nvdimm_ioctl,
 690         .llseek = noop_llseek,
 691 };
 692
 693 int __init nvdimm_bus_init(void)
 694 {
 695         int rc;
 696
 697         rc = bus_register(&nvdimm_bus_type);
 698         if (rc)
 699                 return rc;
 700
 701         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 702         if (rc < 0)
 703                 goto err_bus_chrdev;
 704         nvdimm_bus_major = rc;
 705
 706         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 707         if (rc < 0)
 708                 goto err_dimm_chrdev;
 709         nvdimm_major = rc;
 710
 711         nd_class = class_create(THIS_MODULE, "nd");
 712         if (IS_ERR(nd_class)) {
 713                 rc = PTR_ERR(nd_class);
 714                 goto err_class;
 715         }
 716
 717         return 0;
 718
 719  err_class:
 720         unregister_chrdev(nvdimm_major, "dimmctl");
 721  err_dimm_chrdev:
 722         unregister_chrdev(nvdimm_bus_major, "ndctl");
 723  err_bus_chrdev:
 724         bus_unregister(&nvdimm_bus_type);
 725
 726         return rc;
 727 }
 728
 729 void nvdimm_bus_exit(void)
 730 {
 731         class_destroy(nd_class);
 732         unregister_chrdev(nvdimm_bus_major, "ndctl");
 733         unregister_chrdev(nvdimm_major, "dimmctl");
 734         bus_unregister(&nvdimm_bus_type);
 735 }