drivers/misc/enclosure.c

   1 /*
   2  * Enclosure Services
   3  *
   4  * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
   5  *
   6 **-----------------------------------------------------------------------------
   7 **
   8 **  This program is free software; you can redistribute it and/or
   9 **  modify it under the terms of the GNU General Public License
  10 **  version 2 as published by the Free Software Foundation.
  11 **
  12 **  This program is distributed in the hope that it will be useful,
  13 **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 **  GNU General Public License for more details.
  16 **
  17 **  You should have received a copy of the GNU General Public License
  18 **  along with this program; if not, write to the Free Software
  19 **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 **
  21 **-----------------------------------------------------------------------------
  22 */
  23 #include <linux/device.h>
  24 #include <linux/enclosure.h>
  25 #include <linux/err.h>
  26 #include <linux/list.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/mutex.h>
  30
  31 static LIST_HEAD(container_list);
  32 static DEFINE_MUTEX(container_list_lock);
  33 static struct class enclosure_class;
  34
  35 /**
  36  * enclosure_find - find an enclosure given a parent device
  37  * @dev:        the parent to match against
  38  * @start:      Optional enclosure device to start from (NULL if none)
  39  *
  40  * Looks through the list of registered enclosures to find all those
  41  * with @dev as a parent.  Returns NULL if no enclosure is
  42  * found. @start can be used as a starting point to obtain multiple
  43  * enclosures per parent (should begin with NULL and then be set to
  44  * each returned enclosure device). Obtains a reference to the
  45  * enclosure class device which must be released with device_put().
  46  * If @start is not NULL, a reference must be taken on it which is
  47  * released before returning (this allows a loop through all
  48  * enclosures to exit with only the reference on the enclosure of
  49  * interest held).  Note that the @dev may correspond to the actual
  50  * device housing the enclosure, in which case no iteration via @start
  51  * is required.
  52  */
  53 struct enclosure_device *enclosure_find(struct device *dev,
  54                                         struct enclosure_device *start)
  55 {
  56         struct enclosure_device *edev;
  57
  58         mutex_lock(&container_list_lock);
  59         edev = list_prepare_entry(start, &container_list, node);
  60         if (start)
  61                 put_device(&start->edev);
  62
  63         list_for_each_entry_continue(edev, &container_list, node) {
  64                 struct device *parent = edev->edev.parent;
  65                 /* parent might not be immediate, so iterate up to
  66                  * the root of the tree if necessary */
  67                 while (parent) {
  68                         if (parent == dev) {
  69                                 get_device(&edev->edev);
  70                                 mutex_unlock(&container_list_lock);
  71                                 return edev;
  72                         }
  73                         parent = parent->parent;
  74                 }
  75         }
  76         mutex_unlock(&container_list_lock);
  77
  78         return NULL;
  79 }
  80 EXPORT_SYMBOL_GPL(enclosure_find);
  81
  82 /**
  83  * enclosure_for_each_device - calls a function for each enclosure
  84  * @fn:         the function to call
  85  * @data:       the data to pass to each call
  86  *
  87  * Loops over all the enclosures calling the function.
  88  *
  89  * Note, this function uses a mutex which will be held across calls to
  90  * @fn, so it must have non atomic context, and @fn may (although it
  91  * should not) sleep or otherwise cause the mutex to be held for
  92  * indefinite periods
  93  */
  94 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
  95                               void *data)
  96 {
  97         int error = 0;
  98         struct enclosure_device *edev;
  99
 100         mutex_lock(&container_list_lock);
 101         list_for_each_entry(edev, &container_list, node) {
 102                 error = fn(edev, data);
 103                 if (error)
 104                         break;
 105         }
 106         mutex_unlock(&container_list_lock);
 107
 108         return error;
 109 }
 110 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
 111
 112 /**
 113  * enclosure_register - register device as an enclosure
 114  *
 115  * @dev:        device containing the enclosure
 116  * @components: number of components in the enclosure
 117  *
 118  * This sets up the device for being an enclosure.  Note that @dev does
 119  * not have to be a dedicated enclosure device.  It may be some other type
 120  * of device that additionally responds to enclosure services
 121  */
 122 struct enclosure_device *
 123 enclosure_register(struct device *dev, const char *name, int components,
 124                    struct enclosure_component_callbacks *cb)
 125 {
 126         struct enclosure_device *edev =
 127                 kzalloc(sizeof(struct enclosure_device) +
 128                         sizeof(struct enclosure_component)*components,
 129                         GFP_KERNEL);
 130         int err, i;
 131
 132         BUG_ON(!cb);
 133
 134         if (!edev)
 135                 return ERR_PTR(-ENOMEM);
 136
 137         edev->components = components;
 138
 139         edev->edev.class = &enclosure_class;
 140         edev->edev.parent = get_device(dev);
 141         edev->cb = cb;
 142         dev_set_name(&edev->edev, "%s", name);
 143         err = device_register(&edev->edev);
 144         if (err)
 145                 goto err;
 146
 147         for (i = 0; i < components; i++)
 148                 edev->component[i].number = -1;
 149
 150         mutex_lock(&container_list_lock);
 151         list_add_tail(&edev->node, &container_list);
 152         mutex_unlock(&container_list_lock);
 153
 154         return edev;
 155
 156  err:
 157         put_device(edev->edev.parent);
 158         kfree(edev);
 159         return ERR_PTR(err);
 160 }
 161 EXPORT_SYMBOL_GPL(enclosure_register);
 162
 163 static struct enclosure_component_callbacks enclosure_null_callbacks;
 164
 165 /**
 166  * enclosure_unregister - remove an enclosure
 167  *
 168  * @edev:       the registered enclosure to remove;
 169  */
 170 void enclosure_unregister(struct enclosure_device *edev)
 171 {
 172         int i;
 173
 174         mutex_lock(&container_list_lock);
 175         list_del(&edev->node);
 176         mutex_unlock(&container_list_lock);
 177
 178         for (i = 0; i < edev->components; i++)
 179                 if (edev->component[i].number != -1)
 180                         device_unregister(&edev->component[i].cdev);
 181
 182         /* prevent any callbacks into service user */
 183         edev->cb = &enclosure_null_callbacks;
 184         device_unregister(&edev->edev);
 185 }
 186 EXPORT_SYMBOL_GPL(enclosure_unregister);
 187
 188 #define ENCLOSURE_NAME_SIZE     64
 189
 190 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
 191 {
 192         strcpy(name, "enclosure_device:");
 193         strcat(name, dev_name(&cdev->cdev));
 194 }
 195
 196 static void enclosure_remove_links(struct enclosure_component *cdev)
 197 {
 198         char name[ENCLOSURE_NAME_SIZE];
 199
 200         enclosure_link_name(cdev, name);
 201         sysfs_remove_link(&cdev->dev->kobj, name);
 202         sysfs_remove_link(&cdev->cdev.kobj, "device");
 203 }
 204
 205 static int enclosure_add_links(struct enclosure_component *cdev)
 206 {
 207         int error;
 208         char name[ENCLOSURE_NAME_SIZE];
 209
 210         error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
 211         if (error)
 212                 return error;
 213
 214         enclosure_link_name(cdev, name);
 215         error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
 216         if (error)
 217                 sysfs_remove_link(&cdev->cdev.kobj, "device");
 218
 219         return error;
 220 }
 221
 222 static void enclosure_release(struct device *cdev)
 223 {
 224         struct enclosure_device *edev = to_enclosure_device(cdev);
 225
 226         put_device(cdev->parent);
 227         kfree(edev);
 228 }
 229
 230 static void enclosure_component_release(struct device *dev)
 231 {
 232         struct enclosure_component *cdev = to_enclosure_component(dev);
 233
 234         if (cdev->dev) {
 235                 enclosure_remove_links(cdev);
 236                 put_device(cdev->dev);
 237         }
 238         put_device(dev->parent);
 239 }
 240
 241 static struct attribute_group *enclosure_groups[];
 242
 243 /**
 244  * enclosure_component_register - add a particular component to an enclosure
 245  * @edev:       the enclosure to add the component
 246  * @num:        the device number
 247  * @type:       the type of component being added
 248  * @name:       an optional name to appear in sysfs (leave NULL if none)
 249  *
 250  * Registers the component.  The name is optional for enclosures that
 251  * give their components a unique name.  If not, leave the field NULL
 252  * and a name will be assigned.
 253  *
 254  * Returns a pointer to the enclosure component or an error.
 255  */
 256 struct enclosure_component *
 257 enclosure_component_register(struct enclosure_device *edev,
 258                              unsigned int number,
 259                              enum enclosure_component_type type,
 260                              const char *name)
 261 {
 262         struct enclosure_component *ecomp;
 263         struct device *cdev;
 264         int err;
 265
 266         if (number >= edev->components)
 267                 return ERR_PTR(-EINVAL);
 268
 269         ecomp = &edev->component[number];
 270
 271         if (ecomp->number != -1)
 272                 return ERR_PTR(-EINVAL);
 273
 274         ecomp->type = type;
 275         ecomp->number = number;
 276         cdev = &ecomp->cdev;
 277         cdev->parent = get_device(&edev->edev);
 278         if (name && name[0])
 279                 dev_set_name(cdev, "%s", name);
 280         else
 281                 dev_set_name(cdev, "%u", number);
 282
 283         cdev->release = enclosure_component_release;
 284         cdev->groups = enclosure_groups;
 285
 286         err = device_register(cdev);
 287         if (err)
 288                 ERR_PTR(err);
 289
 290         return ecomp;
 291 }
 292 EXPORT_SYMBOL_GPL(enclosure_component_register);
 293
 294 /**
 295  * enclosure_add_device - add a device as being part of an enclosure
 296  * @edev:       the enclosure device being added to.
 297  * @num:        the number of the component
 298  * @dev:        the device being added
 299  *
 300  * Declares a real device to reside in slot (or identifier) @num of an
 301  * enclosure.  This will cause the relevant sysfs links to appear.
 302  * This function may also be used to change a device associated with
 303  * an enclosure without having to call enclosure_remove_device() in
 304  * between.
 305  *
 306  * Returns zero on success or an error.
 307  */
 308 int enclosure_add_device(struct enclosure_device *edev, int component,
 309                          struct device *dev)
 310 {
 311         struct enclosure_component *cdev;
 312
 313         if (!edev || component >= edev->components)
 314                 return -EINVAL;
 315
 316         cdev = &edev->component[component];
 317
 318         if (cdev->dev == dev)
 319                 return -EEXIST;
 320
 321         if (cdev->dev)
 322                 enclosure_remove_links(cdev);
 323
 324         put_device(cdev->dev);
 325         cdev->dev = get_device(dev);
 326         return enclosure_add_links(cdev);
 327 }
 328 EXPORT_SYMBOL_GPL(enclosure_add_device);
 329
 330 /**
 331  * enclosure_remove_device - remove a device from an enclosure
 332  * @edev:       the enclosure device
 333  * @num:        the number of the component to remove
 334  *
 335  * Returns zero on success or an error.
 336  *
 337  */
 338 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
 339 {
 340         struct enclosure_component *cdev;
 341         int i;
 342
 343         if (!edev || !dev)
 344                 return -EINVAL;
 345
 346         for (i = 0; i < edev->components; i++) {
 347                 cdev = &edev->component[i];
 348                 if (cdev->dev == dev) {
 349                         enclosure_remove_links(cdev);
 350                         device_del(&cdev->cdev);
 351                         put_device(dev);
 352                         cdev->dev = NULL;
 353                         return device_add(&cdev->cdev);
 354                 }
 355         }
 356         return -ENODEV;
 357 }
 358 EXPORT_SYMBOL_GPL(enclosure_remove_device);
 359
 360 /*
 361  * sysfs pieces below
 362  */
 363
 364 static ssize_t enclosure_show_components(struct device *cdev,
 365                                          struct device_attribute *attr,
 366                                          char *buf)
 367 {
 368         struct enclosure_device *edev = to_enclosure_device(cdev);
 369
 370         return snprintf(buf, 40, "%d\n", edev->components);
 371 }
 372
 373 static struct device_attribute enclosure_attrs[] = {
 374         __ATTR(components, S_IRUGO, enclosure_show_components, NULL),
 375         __ATTR_NULL
 376 };
 377
 378 static struct class enclosure_class = {
 379         .name                   = "enclosure",
 380         .owner                  = THIS_MODULE,
 381         .dev_release            = enclosure_release,
 382         .dev_attrs              = enclosure_attrs,
 383 };
 384
 385 static const char *const enclosure_status [] = {
 386         [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
 387         [ENCLOSURE_STATUS_OK] = "OK",
 388         [ENCLOSURE_STATUS_CRITICAL] = "critical",
 389         [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
 390         [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
 391         [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
 392         [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
 393         [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
 394 };
 395
 396 static const char *const enclosure_type [] = {
 397         [ENCLOSURE_COMPONENT_DEVICE] = "device",
 398         [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
 399 };
 400
 401 static ssize_t get_component_fault(struct device *cdev,
 402                                    struct device_attribute *attr, char *buf)
 403 {
 404         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 405         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 406
 407         if (edev->cb->get_fault)
 408                 edev->cb->get_fault(edev, ecomp);
 409         return snprintf(buf, 40, "%d\n", ecomp->fault);
 410 }
 411
 412 static ssize_t set_component_fault(struct device *cdev,
 413                                    struct device_attribute *attr,
 414                                    const char *buf, size_t count)
 415 {
 416         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 417         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 418         int val = simple_strtoul(buf, NULL, 0);
 419
 420         if (edev->cb->set_fault)
 421                 edev->cb->set_fault(edev, ecomp, val);
 422         return count;
 423 }
 424
 425 static ssize_t get_component_status(struct device *cdev,
 426                                     struct device_attribute *attr,char *buf)
 427 {
 428         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 429         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 430
 431         if (edev->cb->get_status)
 432                 edev->cb->get_status(edev, ecomp);
 433         return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
 434 }
 435
 436 static ssize_t set_component_status(struct device *cdev,
 437                                     struct device_attribute *attr,
 438                                     const char *buf, size_t count)
 439 {
 440         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 441         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 442         int i;
 443
 444         for (i = 0; enclosure_status[i]; i++) {
 445                 if (strncmp(buf, enclosure_status[i],
 446                             strlen(enclosure_status[i])) == 0 &&
 447                     (buf[strlen(enclosure_status[i])] == '\n' ||
 448                      buf[strlen(enclosure_status[i])] == '\0'))
 449                         break;
 450         }
 451
 452         if (enclosure_status[i] && edev->cb->set_status) {
 453                 edev->cb->set_status(edev, ecomp, i);
 454                 return count;
 455         } else
 456                 return -EINVAL;
 457 }
 458
 459 static ssize_t get_component_active(struct device *cdev,
 460                                     struct device_attribute *attr, char *buf)
 461 {
 462         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 463         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 464
 465         if (edev->cb->get_active)
 466                 edev->cb->get_active(edev, ecomp);
 467         return snprintf(buf, 40, "%d\n", ecomp->active);
 468 }
 469
 470 static ssize_t set_component_active(struct device *cdev,
 471                                     struct device_attribute *attr,
 472                                     const char *buf, size_t count)
 473 {
 474         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 475         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 476         int val = simple_strtoul(buf, NULL, 0);
 477
 478         if (edev->cb->set_active)
 479                 edev->cb->set_active(edev, ecomp, val);
 480         return count;
 481 }
 482
 483 static ssize_t get_component_locate(struct device *cdev,
 484                                     struct device_attribute *attr, char *buf)
 485 {
 486         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 487         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 488
 489         if (edev->cb->get_locate)
 490                 edev->cb->get_locate(edev, ecomp);
 491         return snprintf(buf, 40, "%d\n", ecomp->locate);
 492 }
 493
 494 static ssize_t set_component_locate(struct device *cdev,
 495                                     struct device_attribute *attr,
 496                                     const char *buf, size_t count)
 497 {
 498         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 499         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 500         int val = simple_strtoul(buf, NULL, 0);
 501
 502         if (edev->cb->set_locate)
 503                 edev->cb->set_locate(edev, ecomp, val);
 504         return count;
 505 }
 506
 507 static ssize_t get_component_type(struct device *cdev,
 508                                   struct device_attribute *attr, char *buf)
 509 {
 510         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 511
 512         return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
 513 }
 514
 515
 516 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
 517                     set_component_fault);
 518 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
 519                    set_component_status);
 520 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
 521                    set_component_active);
 522 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
 523                    set_component_locate);
 524 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
 525
 526 static struct attribute *enclosure_component_attrs[] = {
 527         &dev_attr_fault.attr,
 528         &dev_attr_status.attr,
 529         &dev_attr_active.attr,
 530         &dev_attr_locate.attr,
 531         &dev_attr_type.attr,
 532         NULL
 533 };
 534
 535 static struct attribute_group enclosure_group = {
 536         .attrs = enclosure_component_attrs,
 537 };
 538
 539 static struct attribute_group *enclosure_groups[] = {
 540         &enclosure_group,
 541         NULL
 542 };
 543
 544 static int __init enclosure_init(void)
 545 {
 546         int err;
 547
 548         err = class_register(&enclosure_class);
 549         if (err)
 550                 return err;
 551
 552         return 0;
 553 }
 554
 555 static void __exit enclosure_exit(void)
 556 {
 557         class_unregister(&enclosure_class);
 558 }
 559
 560 module_init(enclosure_init);
 561 module_exit(enclosure_exit);
 562
 563 MODULE_AUTHOR("James Bottomley");
 564 MODULE_DESCRIPTION("Enclosure Services");
 565 MODULE_LICENSE("GPL v2");