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 void nd_device_notify(struct device *dev, enum nvdimm_event event)
 137 {
 138         device_lock(dev);
 139         if (dev->driver) {
 140                 struct nd_device_driver *nd_drv;
 141
 142                 nd_drv = to_nd_device_driver(dev->driver);
 143                 if (nd_drv->notify)
 144                         nd_drv->notify(dev, event);
 145         }
 146         device_unlock(dev);
 147 }
 148 EXPORT_SYMBOL(nd_device_notify);
 149
 150 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
 151 {
 152         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 153
 154         if (!nvdimm_bus)
 155                 return;
 156
 157         /* caller is responsible for holding a reference on the device */
 158         nd_device_notify(&nd_region->dev, event);
 159 }
 160 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
 161
 162 static struct bus_type nvdimm_bus_type = {
 163         .name = "nd",
 164         .uevent = nvdimm_bus_uevent,
 165         .match = nvdimm_bus_match,
 166         .probe = nvdimm_bus_probe,
 167         .remove = nvdimm_bus_remove,
 168 };
 169
 170 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 171
 172 void nd_synchronize(void)
 173 {
 174         async_synchronize_full_domain(&nd_async_domain);
 175 }
 176 EXPORT_SYMBOL_GPL(nd_synchronize);
 177
 178 static void nd_async_device_register(void *d, async_cookie_t cookie)
 179 {
 180         struct device *dev = d;
 181
 182         if (device_add(dev) != 0) {
 183                 dev_err(dev, "%s: failed\n", __func__);
 184                 put_device(dev);
 185         }
 186         put_device(dev);
 187 }
 188
 189 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 190 {
 191         struct device *dev = d;
 192
 193         /* flush bus operations before delete */
 194         nvdimm_bus_lock(dev);
 195         nvdimm_bus_unlock(dev);
 196
 197         device_unregister(dev);
 198         put_device(dev);
 199 }
 200
 201 void __nd_device_register(struct device *dev)
 202 {
 203         dev->bus = &nvdimm_bus_type;
 204         get_device(dev);
 205         async_schedule_domain(nd_async_device_register, dev,
 206                         &nd_async_domain);
 207 }
 208
 209 void nd_device_register(struct device *dev)
 210 {
 211         device_initialize(dev);
 212         __nd_device_register(dev);
 213 }
 214 EXPORT_SYMBOL(nd_device_register);
 215
 216 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 217 {
 218         switch (mode) {
 219         case ND_ASYNC:
 220                 get_device(dev);
 221                 async_schedule_domain(nd_async_device_unregister, dev,
 222                                 &nd_async_domain);
 223                 break;
 224         case ND_SYNC:
 225                 nd_synchronize();
 226                 device_unregister(dev);
 227                 break;
 228         }
 229 }
 230 EXPORT_SYMBOL(nd_device_unregister);
 231
 232 /**
 233  * __nd_driver_register() - register a region or a namespace driver
 234  * @nd_drv: driver to register
 235  * @owner: automatically set by nd_driver_register() macro
 236  * @mod_name: automatically set by nd_driver_register() macro
 237  */
 238 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 239                 const char *mod_name)
 240 {
 241         struct device_driver *drv = &nd_drv->drv;
 242
 243         if (!nd_drv->type) {
 244                 pr_debug("driver type bitmask not set (%pf)\n",
 245                                 __builtin_return_address(0));
 246                 return -EINVAL;
 247         }
 248
 249         if (!nd_drv->probe || !nd_drv->remove) {
 250                 pr_debug("->probe() and ->remove() must be specified\n");
 251                 return -EINVAL;
 252         }
 253
 254         drv->bus = &nvdimm_bus_type;
 255         drv->owner = owner;
 256         drv->mod_name = mod_name;
 257
 258         return driver_register(drv);
 259 }
 260 EXPORT_SYMBOL(__nd_driver_register);
 261
 262 int nvdimm_revalidate_disk(struct gendisk *disk)
 263 {
 264         struct device *dev = disk->driverfs_dev;
 265         struct nd_region *nd_region = to_nd_region(dev->parent);
 266         const char *pol = nd_region->ro ? "only" : "write";
 267
 268         if (nd_region->ro == get_disk_ro(disk))
 269                 return 0;
 270
 271         dev_info(dev, "%s read-%s, marking %s read-%s\n",
 272                         dev_name(&nd_region->dev), pol, disk->disk_name, pol);
 273         set_disk_ro(disk, nd_region->ro);
 274
 275         return 0;
 276
 277 }
 278 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 279
 280 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 281                 char *buf)
 282 {
 283         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 284                         to_nd_device_type(dev));
 285 }
 286 static DEVICE_ATTR_RO(modalias);
 287
 288 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 289                 char *buf)
 290 {
 291         return sprintf(buf, "%s\n", dev->type->name);
 292 }
 293 static DEVICE_ATTR_RO(devtype);
 294
 295 static struct attribute *nd_device_attributes[] = {
 296         &dev_attr_modalias.attr,
 297         &dev_attr_devtype.attr,
 298         NULL,
 299 };
 300
 301 /**
 302  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 303  */
 304 struct attribute_group nd_device_attribute_group = {
 305         .attrs = nd_device_attributes,
 306 };
 307 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 308
 309 static ssize_t numa_node_show(struct device *dev,
 310                 struct device_attribute *attr, char *buf)
 311 {
 312         return sprintf(buf, "%d\n", dev_to_node(dev));
 313 }
 314 static DEVICE_ATTR_RO(numa_node);
 315
 316 static struct attribute *nd_numa_attributes[] = {
 317         &dev_attr_numa_node.attr,
 318         NULL,
 319 };
 320
 321 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 322                 int n)
 323 {
 324         if (!IS_ENABLED(CONFIG_NUMA))
 325                 return 0;
 326
 327         return a->mode;
 328 }
 329
 330 /**
 331  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 332  */
 333 struct attribute_group nd_numa_attribute_group = {
 334         .attrs = nd_numa_attributes,
 335         .is_visible = nd_numa_attr_visible,
 336 };
 337 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 338
 339 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 340 {
 341         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 342         struct device *dev;
 343
 344         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 345                         "ndctl%d", nvdimm_bus->id);
 346
 347         if (IS_ERR(dev)) {
 348                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 349                                 nvdimm_bus->id, PTR_ERR(dev));
 350                 return PTR_ERR(dev);
 351         }
 352         return 0;
 353 }
 354
 355 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 356 {
 357         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 358 }
 359
 360 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 361         [ND_CMD_IMPLEMENTED] = { },
 362         [ND_CMD_SMART] = {
 363                 .out_num = 2,
 364                 .out_sizes = { 4, 8, },
 365         },
 366         [ND_CMD_SMART_THRESHOLD] = {
 367                 .out_num = 2,
 368                 .out_sizes = { 4, 8, },
 369         },
 370         [ND_CMD_DIMM_FLAGS] = {
 371                 .out_num = 2,
 372                 .out_sizes = { 4, 4 },
 373         },
 374         [ND_CMD_GET_CONFIG_SIZE] = {
 375                 .out_num = 3,
 376                 .out_sizes = { 4, 4, 4, },
 377         },
 378         [ND_CMD_GET_CONFIG_DATA] = {
 379                 .in_num = 2,
 380                 .in_sizes = { 4, 4, },
 381                 .out_num = 2,
 382                 .out_sizes = { 4, UINT_MAX, },
 383         },
 384         [ND_CMD_SET_CONFIG_DATA] = {
 385                 .in_num = 3,
 386                 .in_sizes = { 4, 4, UINT_MAX, },
 387                 .out_num = 1,
 388                 .out_sizes = { 4, },
 389         },
 390         [ND_CMD_VENDOR] = {
 391                 .in_num = 3,
 392                 .in_sizes = { 4, 4, UINT_MAX, },
 393                 .out_num = 3,
 394                 .out_sizes = { 4, 4, UINT_MAX, },
 395         },
 396 };
 397
 398 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 399 {
 400         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 401                 return &__nd_cmd_dimm_descs[cmd];
 402         return NULL;
 403 }
 404 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 405
 406 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 407         [ND_CMD_IMPLEMENTED] = { },
 408         [ND_CMD_ARS_CAP] = {
 409                 .in_num = 2,
 410                 .in_sizes = { 8, 8, },
 411                 .out_num = 4,
 412                 .out_sizes = { 4, 4, 4, 4, },
 413         },
 414         [ND_CMD_ARS_START] = {
 415                 .in_num = 5,
 416                 .in_sizes = { 8, 8, 2, 1, 5, },
 417                 .out_num = 2,
 418                 .out_sizes = { 4, 4, },
 419         },
 420         [ND_CMD_ARS_STATUS] = {
 421                 .out_num = 3,
 422                 .out_sizes = { 4, 4, UINT_MAX, },
 423         },
 424 };
 425
 426 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 427 {
 428         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 429                 return &__nd_cmd_bus_descs[cmd];
 430         return NULL;
 431 }
 432 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 433
 434 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 435                 const struct nd_cmd_desc *desc, int idx, void *buf)
 436 {
 437         if (idx >= desc->in_num)
 438                 return UINT_MAX;
 439
 440         if (desc->in_sizes[idx] < UINT_MAX)
 441                 return desc->in_sizes[idx];
 442
 443         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 444                 struct nd_cmd_set_config_hdr *hdr = buf;
 445
 446                 return hdr->in_length;
 447         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 448                 struct nd_cmd_vendor_hdr *hdr = buf;
 449
 450                 return hdr->in_length;
 451         }
 452
 453         return UINT_MAX;
 454 }
 455 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 456
 457 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 458                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 459                 const u32 *out_field)
 460 {
 461         if (idx >= desc->out_num)
 462                 return UINT_MAX;
 463
 464         if (desc->out_sizes[idx] < UINT_MAX)
 465                 return desc->out_sizes[idx];
 466
 467         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 468                 return in_field[1];
 469         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 470                 return out_field[1];
 471         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2)
 472                 return out_field[1] - 8;
 473
 474         return UINT_MAX;
 475 }
 476 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 477
 478 void wait_nvdimm_bus_probe_idle(struct device *dev)
 479 {
 480         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 481
 482         do {
 483                 if (nvdimm_bus->probe_active == 0)
 484                         break;
 485                 nvdimm_bus_unlock(&nvdimm_bus->dev);
 486                 wait_event(nvdimm_bus->probe_wait,
 487                                 nvdimm_bus->probe_active == 0);
 488                 nvdimm_bus_lock(&nvdimm_bus->dev);
 489         } while (true);
 490 }
 491
 492 /* set_config requires an idle interleave set */
 493 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
 494                 struct nvdimm *nvdimm, unsigned int cmd)
 495 {
 496         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 497
 498         /* ask the bus provider if it would like to block this request */
 499         if (nd_desc->clear_to_send) {
 500                 int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd);
 501
 502                 if (rc)
 503                         return rc;
 504         }
 505
 506         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 507                 return 0;
 508
 509         /* prevent label manipulation while the kernel owns label updates */
 510         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 511         if (atomic_read(&nvdimm->busy))
 512                 return -EBUSY;
 513         return 0;
 514 }
 515
 516 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 517                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 518 {
 519         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 520         size_t buf_len = 0, in_len = 0, out_len = 0;
 521         static char out_env[ND_CMD_MAX_ENVELOPE];
 522         static char in_env[ND_CMD_MAX_ENVELOPE];
 523         const struct nd_cmd_desc *desc = NULL;
 524         unsigned int cmd = _IOC_NR(ioctl_cmd);
 525         void __user *p = (void __user *) arg;
 526         struct device *dev = &nvdimm_bus->dev;
 527         const char *cmd_name, *dimm_name;
 528         unsigned long dsm_mask;
 529         void *buf;
 530         int rc, i;
 531
 532         if (nvdimm) {
 533                 desc = nd_cmd_dimm_desc(cmd);
 534                 cmd_name = nvdimm_cmd_name(cmd);
 535                 dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 536                 dimm_name = dev_name(&nvdimm->dev);
 537         } else {
 538                 desc = nd_cmd_bus_desc(cmd);
 539                 cmd_name = nvdimm_bus_cmd_name(cmd);
 540                 dsm_mask = nd_desc->dsm_mask;
 541                 dimm_name = "bus";
 542         }
 543
 544         if (!desc || (desc->out_num + desc->in_num == 0) ||
 545                         !test_bit(cmd, &dsm_mask))
 546                 return -ENOTTY;
 547
 548         /* fail write commands (when read-only) */
 549         if (read_only)
 550                 switch (ioctl_cmd) {
 551                 case ND_IOCTL_VENDOR:
 552                 case ND_IOCTL_SET_CONFIG_DATA:
 553                 case ND_IOCTL_ARS_START:
 554                         dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 555                                         nvdimm ? nvdimm_cmd_name(cmd)
 556                                         : nvdimm_bus_cmd_name(cmd));
 557                         return -EPERM;
 558                 default:
 559                         break;
 560                 }
 561
 562         /* process an input envelope */
 563         for (i = 0; i < desc->in_num; i++) {
 564                 u32 in_size, copy;
 565
 566                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 567                 if (in_size == UINT_MAX) {
 568                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 569                                         __func__, dimm_name, cmd_name, i);
 570                         return -ENXIO;
 571                 }
 572                 if (in_len < sizeof(in_env))
 573                         copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 574                 else
 575                         copy = 0;
 576                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 577                         return -EFAULT;
 578                 in_len += in_size;
 579         }
 580
 581         /* process an output envelope */
 582         for (i = 0; i < desc->out_num; i++) {
 583                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 584                                 (u32 *) in_env, (u32 *) out_env);
 585                 u32 copy;
 586
 587                 if (out_size == UINT_MAX) {
 588                         dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 589                                         __func__, dimm_name, cmd_name, i);
 590                         return -EFAULT;
 591                 }
 592                 if (out_len < sizeof(out_env))
 593                         copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 594                 else
 595                         copy = 0;
 596                 if (copy && copy_from_user(&out_env[out_len],
 597                                         p + in_len + out_len, copy))
 598                         return -EFAULT;
 599                 out_len += out_size;
 600         }
 601
 602         buf_len = out_len + in_len;
 603         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 604                 dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 605                                 dimm_name, cmd_name, buf_len,
 606                                 ND_IOCTL_MAX_BUFLEN);
 607                 return -EINVAL;
 608         }
 609
 610         buf = vmalloc(buf_len);
 611         if (!buf)
 612                 return -ENOMEM;
 613
 614         if (copy_from_user(buf, p, buf_len)) {
 615                 rc = -EFAULT;
 616                 goto out;
 617         }
 618
 619         nvdimm_bus_lock(&nvdimm_bus->dev);
 620         rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, cmd);
 621         if (rc)
 622                 goto out_unlock;
 623
 624         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, NULL);
 625         if (rc < 0)
 626                 goto out_unlock;
 627         if (copy_to_user(p, buf, buf_len))
 628                 rc = -EFAULT;
 629  out_unlock:
 630         nvdimm_bus_unlock(&nvdimm_bus->dev);
 631  out:
 632         vfree(buf);
 633         return rc;
 634 }
 635
 636 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 637 {
 638         long id = (long) file->private_data;
 639         int rc = -ENXIO, ro;
 640         struct nvdimm_bus *nvdimm_bus;
 641
 642         ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
 643         mutex_lock(&nvdimm_bus_list_mutex);
 644         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 645                 if (nvdimm_bus->id == id) {
 646                         rc = __nd_ioctl(nvdimm_bus, NULL, ro, cmd, arg);
 647                         break;
 648                 }
 649         }
 650         mutex_unlock(&nvdimm_bus_list_mutex);
 651
 652         return rc;
 653 }
 654
 655 static int match_dimm(struct device *dev, void *data)
 656 {
 657         long id = (long) data;
 658
 659         if (is_nvdimm(dev)) {
 660                 struct nvdimm *nvdimm = to_nvdimm(dev);
 661
 662                 return nvdimm->id == id;
 663         }
 664
 665         return 0;
 666 }
 667
 668 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 669 {
 670         int rc = -ENXIO, ro;
 671         struct nvdimm_bus *nvdimm_bus;
 672
 673         ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
 674         mutex_lock(&nvdimm_bus_list_mutex);
 675         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 676                 struct device *dev = device_find_child(&nvdimm_bus->dev,
 677                                 file->private_data, match_dimm);
 678                 struct nvdimm *nvdimm;
 679
 680                 if (!dev)
 681                         continue;
 682
 683                 nvdimm = to_nvdimm(dev);
 684                 rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
 685                 put_device(dev);
 686                 break;
 687         }
 688         mutex_unlock(&nvdimm_bus_list_mutex);
 689
 690         return rc;
 691 }
 692
 693 static int nd_open(struct inode *inode, struct file *file)
 694 {
 695         long minor = iminor(inode);
 696
 697         file->private_data = (void *) minor;
 698         return 0;
 699 }
 700
 701 static const struct file_operations nvdimm_bus_fops = {
 702         .owner = THIS_MODULE,
 703         .open = nd_open,
 704         .unlocked_ioctl = nd_ioctl,
 705         .compat_ioctl = nd_ioctl,
 706         .llseek = noop_llseek,
 707 };
 708
 709 static const struct file_operations nvdimm_fops = {
 710         .owner = THIS_MODULE,
 711         .open = nd_open,
 712         .unlocked_ioctl = nvdimm_ioctl,
 713         .compat_ioctl = nvdimm_ioctl,
 714         .llseek = noop_llseek,
 715 };
 716
 717 int __init nvdimm_bus_init(void)
 718 {
 719         int rc;
 720
 721         rc = bus_register(&nvdimm_bus_type);
 722         if (rc)
 723                 return rc;
 724
 725         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 726         if (rc < 0)
 727                 goto err_bus_chrdev;
 728         nvdimm_bus_major = rc;
 729
 730         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 731         if (rc < 0)
 732                 goto err_dimm_chrdev;
 733         nvdimm_major = rc;
 734
 735         nd_class = class_create(THIS_MODULE, "nd");
 736         if (IS_ERR(nd_class)) {
 737                 rc = PTR_ERR(nd_class);
 738                 goto err_class;
 739         }
 740
 741         return 0;
 742
 743  err_class:
 744         unregister_chrdev(nvdimm_major, "dimmctl");
 745  err_dimm_chrdev:
 746         unregister_chrdev(nvdimm_bus_major, "ndctl");
 747  err_bus_chrdev:
 748         bus_unregister(&nvdimm_bus_type);
 749
 750         return rc;
 751 }
 752
 753 void nvdimm_bus_exit(void)
 754 {
 755         class_destroy(nd_class);
 756         unregister_chrdev(nvdimm_bus_major, "ndctl");
 757         unregister_chrdev(nvdimm_major, "dimmctl");
 758         bus_unregister(&nvdimm_bus_type);
 759 }