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 #include <linux/slab.h>
  31
  32 static LIST_HEAD(container_list);
  33 static DEFINE_MUTEX(container_list_lock);
  34 static struct class enclosure_class;
  35
  36 /**
  37  * enclosure_find - find an enclosure given a parent device
  38  * @dev:        the parent to match against
  39  * @start:      Optional enclosure device to start from (NULL if none)
  40  *
  41  * Looks through the list of registered enclosures to find all those
  42  * with @dev as a parent.  Returns NULL if no enclosure is
  43  * found. @start can be used as a starting point to obtain multiple
  44  * enclosures per parent (should begin with NULL and then be set to
  45  * each returned enclosure device). Obtains a reference to the
  46  * enclosure class device which must be released with device_put().
  47  * If @start is not NULL, a reference must be taken on it which is
  48  * released before returning (this allows a loop through all
  49  * enclosures to exit with only the reference on the enclosure of
  50  * interest held).  Note that the @dev may correspond to the actual
  51  * device housing the enclosure, in which case no iteration via @start
  52  * is required.
  53  */
  54 struct enclosure_device *enclosure_find(struct device *dev,
  55                                         struct enclosure_device *start)
  56 {
  57         struct enclosure_device *edev;
  58
  59         mutex_lock(&container_list_lock);
  60         edev = list_prepare_entry(start, &container_list, node);
  61         if (start)
  62                 put_device(&start->edev);
  63
  64         list_for_each_entry_continue(edev, &container_list, node) {
  65                 struct device *parent = edev->edev.parent;
  66                 /* parent might not be immediate, so iterate up to
  67                  * the root of the tree if necessary */
  68                 while (parent) {
  69                         if (parent == dev) {
  70                                 get_device(&edev->edev);
  71                                 mutex_unlock(&container_list_lock);
  72                                 return edev;
  73                         }
  74                         parent = parent->parent;
  75                 }
  76         }
  77         mutex_unlock(&container_list_lock);
  78
  79         return NULL;
  80 }
  81 EXPORT_SYMBOL_GPL(enclosure_find);
  82
  83 /**
  84  * enclosure_for_each_device - calls a function for each enclosure
  85  * @fn:         the function to call
  86  * @data:       the data to pass to each call
  87  *
  88  * Loops over all the enclosures calling the function.
  89  *
  90  * Note, this function uses a mutex which will be held across calls to
  91  * @fn, so it must have non atomic context, and @fn may (although it
  92  * should not) sleep or otherwise cause the mutex to be held for
  93  * indefinite periods
  94  */
  95 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
  96                               void *data)
  97 {
  98         int error = 0;
  99         struct enclosure_device *edev;
 100
 101         mutex_lock(&container_list_lock);
 102         list_for_each_entry(edev, &container_list, node) {
 103                 error = fn(edev, data);
 104                 if (error)
 105                         break;
 106         }
 107         mutex_unlock(&container_list_lock);
 108
 109         return error;
 110 }
 111 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
 112
 113 /**
 114  * enclosure_register - register device as an enclosure
 115  *
 116  * @dev:        device containing the enclosure
 117  * @components: number of components in the enclosure
 118  *
 119  * This sets up the device for being an enclosure.  Note that @dev does
 120  * not have to be a dedicated enclosure device.  It may be some other type
 121  * of device that additionally responds to enclosure services
 122  */
 123 struct enclosure_device *
 124 enclosure_register(struct device *dev, const char *name, int components,
 125                    struct enclosure_component_callbacks *cb)
 126 {
 127         struct enclosure_device *edev =
 128                 kzalloc(sizeof(struct enclosure_device) +
 129                         sizeof(struct enclosure_component)*components,
 130                         GFP_KERNEL);
 131         int err, i;
 132
 133         BUG_ON(!cb);
 134
 135         if (!edev)
 136                 return ERR_PTR(-ENOMEM);
 137
 138         edev->components = components;
 139
 140         edev->edev.class = &enclosure_class;
 141         edev->edev.parent = get_device(dev);
 142         edev->cb = cb;
 143         dev_set_name(&edev->edev, "%s", name);
 144         err = device_register(&edev->edev);
 145         if (err)
 146                 goto err;
 147
 148         for (i = 0; i < components; i++)
 149                 edev->component[i].number = -1;
 150
 151         mutex_lock(&container_list_lock);
 152         list_add_tail(&edev->node, &container_list);
 153         mutex_unlock(&container_list_lock);
 154
 155         return edev;
 156
 157  err:
 158         put_device(edev->edev.parent);
 159         kfree(edev);
 160         return ERR_PTR(err);
 161 }
 162 EXPORT_SYMBOL_GPL(enclosure_register);
 163
 164 static struct enclosure_component_callbacks enclosure_null_callbacks;
 165
 166 /**
 167  * enclosure_unregister - remove an enclosure
 168  *
 169  * @edev:       the registered enclosure to remove;
 170  */
 171 void enclosure_unregister(struct enclosure_device *edev)
 172 {
 173         int i;
 174
 175         mutex_lock(&container_list_lock);
 176         list_del(&edev->node);
 177         mutex_unlock(&container_list_lock);
 178
 179         for (i = 0; i < edev->components; i++)
 180                 if (edev->component[i].number != -1)
 181                         device_unregister(&edev->component[i].cdev);
 182
 183         /* prevent any callbacks into service user */
 184         edev->cb = &enclosure_null_callbacks;
 185         device_unregister(&edev->edev);
 186 }
 187 EXPORT_SYMBOL_GPL(enclosure_unregister);
 188
 189 #define ENCLOSURE_NAME_SIZE     64
 190 #define COMPONENT_NAME_SIZE     64
 191
 192 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
 193 {
 194         strcpy(name, "enclosure_device:");
 195         strcat(name, dev_name(&cdev->cdev));
 196 }
 197
 198 static void enclosure_remove_links(struct enclosure_component *cdev)
 199 {
 200         char name[ENCLOSURE_NAME_SIZE];
 201
 202         /*
 203          * In odd circumstances, like multipath devices, something else may
 204          * already have removed the links, so check for this condition first.
 205          */
 206         if (!cdev->dev->kobj.sd)
 207                 return;
 208
 209         enclosure_link_name(cdev, name);
 210         sysfs_remove_link(&cdev->dev->kobj, name);
 211         sysfs_remove_link(&cdev->cdev.kobj, "device");
 212 }
 213
 214 static int enclosure_add_links(struct enclosure_component *cdev)
 215 {
 216         int error;
 217         char name[ENCLOSURE_NAME_SIZE];
 218
 219         error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
 220         if (error)
 221                 return error;
 222
 223         enclosure_link_name(cdev, name);
 224         error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
 225         if (error)
 226                 sysfs_remove_link(&cdev->cdev.kobj, "device");
 227
 228         return error;
 229 }
 230
 231 static void enclosure_release(struct device *cdev)
 232 {
 233         struct enclosure_device *edev = to_enclosure_device(cdev);
 234
 235         put_device(cdev->parent);
 236         kfree(edev);
 237 }
 238
 239 static void enclosure_component_release(struct device *dev)
 240 {
 241         struct enclosure_component *cdev = to_enclosure_component(dev);
 242
 243         if (cdev->dev) {
 244                 enclosure_remove_links(cdev);
 245                 put_device(cdev->dev);
 246         }
 247         put_device(dev->parent);
 248 }
 249
 250 static struct enclosure_component *
 251 enclosure_component_find_by_name(struct enclosure_device *edev,
 252                                 const char *name)
 253 {
 254         int i;
 255         const char *cname;
 256         struct enclosure_component *ecomp;
 257
 258         if (!edev || !name || !name[0])
 259                 return NULL;
 260
 261         for (i = 0; i < edev->components; i++) {
 262                 ecomp = &edev->component[i];
 263                 cname = dev_name(&ecomp->cdev);
 264                 if (ecomp->number != -1 &&
 265                     cname && cname[0] &&
 266                     !strcmp(cname, name))
 267                         return ecomp;
 268         }
 269
 270         return NULL;
 271 }
 272
 273 static const struct attribute_group *enclosure_component_groups[];
 274
 275 /**
 276  * enclosure_component_register - add a particular component to an enclosure
 277  * @edev:       the enclosure to add the component
 278  * @num:        the device number
 279  * @type:       the type of component being added
 280  * @name:       an optional name to appear in sysfs (leave NULL if none)
 281  *
 282  * Registers the component.  The name is optional for enclosures that
 283  * give their components a unique name.  If not, leave the field NULL
 284  * and a name will be assigned.
 285  *
 286  * Returns a pointer to the enclosure component or an error.
 287  */
 288 struct enclosure_component *
 289 enclosure_component_register(struct enclosure_device *edev,
 290                              unsigned int number,
 291                              enum enclosure_component_type type,
 292                              const char *name)
 293 {
 294         struct enclosure_component *ecomp;
 295         struct device *cdev;
 296         int err, i;
 297         char newname[COMPONENT_NAME_SIZE];
 298
 299         if (number >= edev->components)
 300                 return ERR_PTR(-EINVAL);
 301
 302         ecomp = &edev->component[number];
 303
 304         if (ecomp->number != -1)
 305                 return ERR_PTR(-EINVAL);
 306
 307         ecomp->type = type;
 308         ecomp->number = number;
 309         cdev = &ecomp->cdev;
 310         cdev->parent = get_device(&edev->edev);
 311
 312         if (name && name[0]) {
 313                 /* Some hardware (e.g. enclosure in RX300 S6) has components
 314                  * with non unique names. Registering duplicates in sysfs
 315                  * will lead to warnings during bootup. So make the names
 316                  * unique by appending consecutive numbers -1, -2, ... */
 317                 i = 1;
 318                 snprintf(newname, COMPONENT_NAME_SIZE,
 319                          "%s", name);
 320                 while (enclosure_component_find_by_name(edev, newname))
 321                         snprintf(newname, COMPONENT_NAME_SIZE,
 322                                  "%s-%i", name, i++);
 323                 dev_set_name(cdev, "%s", newname);
 324         } else
 325                 dev_set_name(cdev, "%u", number);
 326
 327         cdev->release = enclosure_component_release;
 328         cdev->groups = enclosure_component_groups;
 329
 330         err = device_register(cdev);
 331         if (err) {
 332                 ecomp->number = -1;
 333                 put_device(cdev);
 334                 return ERR_PTR(err);
 335         }
 336
 337         return ecomp;
 338 }
 339 EXPORT_SYMBOL_GPL(enclosure_component_register);
 340
 341 /**
 342  * enclosure_add_device - add a device as being part of an enclosure
 343  * @edev:       the enclosure device being added to.
 344  * @num:        the number of the component
 345  * @dev:        the device being added
 346  *
 347  * Declares a real device to reside in slot (or identifier) @num of an
 348  * enclosure.  This will cause the relevant sysfs links to appear.
 349  * This function may also be used to change a device associated with
 350  * an enclosure without having to call enclosure_remove_device() in
 351  * between.
 352  *
 353  * Returns zero on success or an error.
 354  */
 355 int enclosure_add_device(struct enclosure_device *edev, int component,
 356                          struct device *dev)
 357 {
 358         struct enclosure_component *cdev;
 359
 360         if (!edev || component >= edev->components)
 361                 return -EINVAL;
 362
 363         cdev = &edev->component[component];
 364
 365         if (cdev->dev == dev)
 366                 return -EEXIST;
 367
 368         if (cdev->dev)
 369                 enclosure_remove_links(cdev);
 370
 371         put_device(cdev->dev);
 372         cdev->dev = get_device(dev);
 373         return enclosure_add_links(cdev);
 374 }
 375 EXPORT_SYMBOL_GPL(enclosure_add_device);
 376
 377 /**
 378  * enclosure_remove_device - remove a device from an enclosure
 379  * @edev:       the enclosure device
 380  * @num:        the number of the component to remove
 381  *
 382  * Returns zero on success or an error.
 383  *
 384  */
 385 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
 386 {
 387         struct enclosure_component *cdev;
 388         int i;
 389
 390         if (!edev || !dev)
 391                 return -EINVAL;
 392
 393         for (i = 0; i < edev->components; i++) {
 394                 cdev = &edev->component[i];
 395                 if (cdev->dev == dev) {
 396                         enclosure_remove_links(cdev);
 397                         device_del(&cdev->cdev);
 398                         put_device(dev);
 399                         cdev->dev = NULL;
 400                         return device_add(&cdev->cdev);
 401                 }
 402         }
 403         return -ENODEV;
 404 }
 405 EXPORT_SYMBOL_GPL(enclosure_remove_device);
 406
 407 /*
 408  * sysfs pieces below
 409  */
 410
 411 static ssize_t components_show(struct device *cdev,
 412                                struct device_attribute *attr, char *buf)
 413 {
 414         struct enclosure_device *edev = to_enclosure_device(cdev);
 415
 416         return snprintf(buf, 40, "%d\n", edev->components);
 417 }
 418 static DEVICE_ATTR_RO(components);
 419
 420 static struct attribute *enclosure_class_attrs[] = {
 421         &dev_attr_components.attr,
 422         NULL,
 423 };
 424 ATTRIBUTE_GROUPS(enclosure_class);
 425
 426 static struct class enclosure_class = {
 427         .name                   = "enclosure",
 428         .owner                  = THIS_MODULE,
 429         .dev_release            = enclosure_release,
 430         .dev_groups             = enclosure_class_groups,
 431 };
 432
 433 static const char *const enclosure_status [] = {
 434         [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
 435         [ENCLOSURE_STATUS_OK] = "OK",
 436         [ENCLOSURE_STATUS_CRITICAL] = "critical",
 437         [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
 438         [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
 439         [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
 440         [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
 441         [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
 442         [ENCLOSURE_STATUS_MAX] = NULL,
 443 };
 444
 445 static const char *const enclosure_type [] = {
 446         [ENCLOSURE_COMPONENT_DEVICE] = "device",
 447         [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
 448 };
 449
 450 static ssize_t get_component_fault(struct device *cdev,
 451                                    struct device_attribute *attr, char *buf)
 452 {
 453         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 454         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 455
 456         if (edev->cb->get_fault)
 457                 edev->cb->get_fault(edev, ecomp);
 458         return snprintf(buf, 40, "%d\n", ecomp->fault);
 459 }
 460
 461 static ssize_t set_component_fault(struct device *cdev,
 462                                    struct device_attribute *attr,
 463                                    const char *buf, size_t count)
 464 {
 465         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 466         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 467         int val = simple_strtoul(buf, NULL, 0);
 468
 469         if (edev->cb->set_fault)
 470                 edev->cb->set_fault(edev, ecomp, val);
 471         return count;
 472 }
 473
 474 static ssize_t get_component_status(struct device *cdev,
 475                                     struct device_attribute *attr,char *buf)
 476 {
 477         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 478         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 479
 480         if (edev->cb->get_status)
 481                 edev->cb->get_status(edev, ecomp);
 482         return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
 483 }
 484
 485 static ssize_t set_component_status(struct device *cdev,
 486                                     struct device_attribute *attr,
 487                                     const char *buf, size_t count)
 488 {
 489         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 490         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 491         int i;
 492
 493         for (i = 0; enclosure_status[i]; i++) {
 494                 if (strncmp(buf, enclosure_status[i],
 495                             strlen(enclosure_status[i])) == 0 &&
 496                     (buf[strlen(enclosure_status[i])] == '\n' ||
 497                      buf[strlen(enclosure_status[i])] == '\0'))
 498                         break;
 499         }
 500
 501         if (enclosure_status[i] && edev->cb->set_status) {
 502                 edev->cb->set_status(edev, ecomp, i);
 503                 return count;
 504         } else
 505                 return -EINVAL;
 506 }
 507
 508 static ssize_t get_component_active(struct device *cdev,
 509                                     struct device_attribute *attr, char *buf)
 510 {
 511         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 512         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 513
 514         if (edev->cb->get_active)
 515                 edev->cb->get_active(edev, ecomp);
 516         return snprintf(buf, 40, "%d\n", ecomp->active);
 517 }
 518
 519 static ssize_t set_component_active(struct device *cdev,
 520                                     struct device_attribute *attr,
 521                                     const char *buf, size_t count)
 522 {
 523         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 524         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 525         int val = simple_strtoul(buf, NULL, 0);
 526
 527         if (edev->cb->set_active)
 528                 edev->cb->set_active(edev, ecomp, val);
 529         return count;
 530 }
 531
 532 static ssize_t get_component_locate(struct device *cdev,
 533                                     struct device_attribute *attr, char *buf)
 534 {
 535         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 536         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 537
 538         if (edev->cb->get_locate)
 539                 edev->cb->get_locate(edev, ecomp);
 540         return snprintf(buf, 40, "%d\n", ecomp->locate);
 541 }
 542
 543 static ssize_t set_component_locate(struct device *cdev,
 544                                     struct device_attribute *attr,
 545                                     const char *buf, size_t count)
 546 {
 547         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 548         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 549         int val = simple_strtoul(buf, NULL, 0);
 550
 551         if (edev->cb->set_locate)
 552                 edev->cb->set_locate(edev, ecomp, val);
 553         return count;
 554 }
 555
 556 static ssize_t get_component_type(struct device *cdev,
 557                                   struct device_attribute *attr, char *buf)
 558 {
 559         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 560
 561         return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
 562 }
 563
 564
 565 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
 566                     set_component_fault);
 567 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
 568                    set_component_status);
 569 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
 570                    set_component_active);
 571 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
 572                    set_component_locate);
 573 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
 574
 575 static struct attribute *enclosure_component_attrs[] = {
 576         &dev_attr_fault.attr,
 577         &dev_attr_status.attr,
 578         &dev_attr_active.attr,
 579         &dev_attr_locate.attr,
 580         &dev_attr_type.attr,
 581         NULL
 582 };
 583 ATTRIBUTE_GROUPS(enclosure_component);
 584
 585 static int __init enclosure_init(void)
 586 {
 587         int err;
 588
 589         err = class_register(&enclosure_class);
 590         if (err)
 591                 return err;
 592
 593         return 0;
 594 }
 595
 596 static void __exit enclosure_exit(void)
 597 {
 598         class_unregister(&enclosure_class);
 599 }
 600
 601 module_init(enclosure_init);
 602 module_exit(enclosure_exit);
 603
 604 MODULE_AUTHOR("James Bottomley");
 605 MODULE_DESCRIPTION("Enclosure Services");
 606 MODULE_LICENSE("GPL v2");