1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Enclosure Services 4 * 5 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com> 6 * 7 **----------------------------------------------------------------------------- 8 ** 9 ** 10 **----------------------------------------------------------------------------- 11 */ 12 #include <linux/device.h> 13 #include <linux/enclosure.h> 14 #include <linux/err.h> 15 #include <linux/list.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/mutex.h> 19 #include <linux/slab.h> 20 21 static LIST_HEAD(container_list); 22 static DEFINE_MUTEX(container_list_lock); 23 static struct class enclosure_class; 24 25 /** 26 * enclosure_find - find an enclosure given a parent device 27 * @dev: the parent to match against 28 * @start: Optional enclosure device to start from (NULL if none) 29 * 30 * Looks through the list of registered enclosures to find all those 31 * with @dev as a parent. Returns NULL if no enclosure is 32 * found. @start can be used as a starting point to obtain multiple 33 * enclosures per parent (should begin with NULL and then be set to 34 * each returned enclosure device). Obtains a reference to the 35 * enclosure class device which must be released with put_device(). 36 * If @start is not NULL, a reference must be taken on it which is 37 * released before returning (this allows a loop through all 38 * enclosures to exit with only the reference on the enclosure of 39 * interest held). Note that the @dev may correspond to the actual 40 * device housing the enclosure, in which case no iteration via @start 41 * is required. 42 */ 43 struct enclosure_device *enclosure_find(struct device *dev, 44 struct enclosure_device *start) 45 { 46 struct enclosure_device *edev; 47 48 mutex_lock(&container_list_lock); 49 edev = list_prepare_entry(start, &container_list, node); 50 if (start) 51 put_device(&start->edev); 52 53 list_for_each_entry_continue(edev, &container_list, node) { 54 struct device *parent = edev->edev.parent; 55 /* parent might not be immediate, so iterate up to 56 * the root of the tree if necessary */ 57 while (parent) { 58 if (parent == dev) { 59 get_device(&edev->edev); 60 mutex_unlock(&container_list_lock); 61 return edev; 62 } 63 parent = parent->parent; 64 } 65 } 66 mutex_unlock(&container_list_lock); 67 68 return NULL; 69 } 70 EXPORT_SYMBOL_GPL(enclosure_find); 71 72 /** 73 * enclosure_for_each_device - calls a function for each enclosure 74 * @fn: the function to call 75 * @data: the data to pass to each call 76 * 77 * Loops over all the enclosures calling the function. 78 * 79 * Note, this function uses a mutex which will be held across calls to 80 * @fn, so it must have non atomic context, and @fn may (although it 81 * should not) sleep or otherwise cause the mutex to be held for 82 * indefinite periods 83 */ 84 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *), 85 void *data) 86 { 87 int error = 0; 88 struct enclosure_device *edev; 89 90 mutex_lock(&container_list_lock); 91 list_for_each_entry(edev, &container_list, node) { 92 error = fn(edev, data); 93 if (error) 94 break; 95 } 96 mutex_unlock(&container_list_lock); 97 98 return error; 99 } 100 EXPORT_SYMBOL_GPL(enclosure_for_each_device); 101 102 /** 103 * enclosure_register - register device as an enclosure 104 * 105 * @dev: device containing the enclosure 106 * @name: chosen device name 107 * @components: number of components in the enclosure 108 * @cb: platform call-backs 109 * 110 * This sets up the device for being an enclosure. Note that @dev does 111 * not have to be a dedicated enclosure device. It may be some other type 112 * of device that additionally responds to enclosure services 113 */ 114 struct enclosure_device * 115 enclosure_register(struct device *dev, const char *name, int components, 116 struct enclosure_component_callbacks *cb) 117 { 118 struct enclosure_device *edev = 119 kzalloc(struct_size(edev, component, components), GFP_KERNEL); 120 int err, i; 121 122 BUG_ON(!cb); 123 124 if (!edev) 125 return ERR_PTR(-ENOMEM); 126 127 edev->components = components; 128 129 edev->edev.class = &enclosure_class; 130 edev->edev.parent = get_device(dev); 131 edev->cb = cb; 132 dev_set_name(&edev->edev, "%s", name); 133 err = device_register(&edev->edev); 134 if (err) 135 goto err; 136 137 for (i = 0; i < components; i++) { 138 edev->component[i].number = -1; 139 edev->component[i].slot = -1; 140 edev->component[i].power_status = -1; 141 } 142 143 mutex_lock(&container_list_lock); 144 list_add_tail(&edev->node, &container_list); 145 mutex_unlock(&container_list_lock); 146 147 return edev; 148 149 err: 150 put_device(edev->edev.parent); 151 kfree(edev); 152 return ERR_PTR(err); 153 } 154 EXPORT_SYMBOL_GPL(enclosure_register); 155 156 static struct enclosure_component_callbacks enclosure_null_callbacks; 157 158 /** 159 * enclosure_unregister - remove an enclosure 160 * 161 * @edev: the registered enclosure to remove; 162 */ 163 void enclosure_unregister(struct enclosure_device *edev) 164 { 165 int i; 166 167 mutex_lock(&container_list_lock); 168 list_del(&edev->node); 169 mutex_unlock(&container_list_lock); 170 171 for (i = 0; i < edev->components; i++) 172 if (edev->component[i].number != -1) 173 device_unregister(&edev->component[i].cdev); 174 175 /* prevent any callbacks into service user */ 176 edev->cb = &enclosure_null_callbacks; 177 device_unregister(&edev->edev); 178 } 179 EXPORT_SYMBOL_GPL(enclosure_unregister); 180 181 #define ENCLOSURE_NAME_SIZE 64 182 #define COMPONENT_NAME_SIZE 64 183 184 static void enclosure_link_name(struct enclosure_component *cdev, char *name) 185 { 186 strcpy(name, "enclosure_device:"); 187 strcat(name, dev_name(&cdev->cdev)); 188 } 189 190 static void enclosure_remove_links(struct enclosure_component *cdev) 191 { 192 char name[ENCLOSURE_NAME_SIZE]; 193 194 enclosure_link_name(cdev, name); 195 196 /* 197 * In odd circumstances, like multipath devices, something else may 198 * already have removed the links, so check for this condition first. 199 */ 200 if (cdev->dev->kobj.sd) 201 sysfs_remove_link(&cdev->dev->kobj, name); 202 203 if (cdev->cdev.kobj.sd) 204 sysfs_remove_link(&cdev->cdev.kobj, "device"); 205 } 206 207 static int enclosure_add_links(struct enclosure_component *cdev) 208 { 209 int error; 210 char name[ENCLOSURE_NAME_SIZE]; 211 212 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device"); 213 if (error) 214 return error; 215 216 enclosure_link_name(cdev, name); 217 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name); 218 if (error) 219 sysfs_remove_link(&cdev->cdev.kobj, "device"); 220 221 return error; 222 } 223 224 static void enclosure_release(struct device *cdev) 225 { 226 struct enclosure_device *edev = to_enclosure_device(cdev); 227 228 put_device(cdev->parent); 229 kfree(edev); 230 } 231 232 static void enclosure_component_release(struct device *dev) 233 { 234 struct enclosure_component *cdev = to_enclosure_component(dev); 235 236 if (cdev->dev) { 237 enclosure_remove_links(cdev); 238 put_device(cdev->dev); 239 } 240 put_device(dev->parent); 241 } 242 243 static struct enclosure_component * 244 enclosure_component_find_by_name(struct enclosure_device *edev, 245 const char *name) 246 { 247 int i; 248 const char *cname; 249 struct enclosure_component *ecomp; 250 251 if (!edev || !name || !name[0]) 252 return NULL; 253 254 for (i = 0; i < edev->components; i++) { 255 ecomp = &edev->component[i]; 256 cname = dev_name(&ecomp->cdev); 257 if (ecomp->number != -1 && 258 cname && cname[0] && 259 !strcmp(cname, name)) 260 return ecomp; 261 } 262 263 return NULL; 264 } 265 266 static const struct attribute_group *enclosure_component_groups[]; 267 268 /** 269 * enclosure_component_alloc - prepare a new enclosure component 270 * @edev: the enclosure to add the component 271 * @number: the device number 272 * @type: the type of component being added 273 * @name: an optional name to appear in sysfs (leave NULL if none) 274 * 275 * The name is optional for enclosures that give their components a unique 276 * name. If not, leave the field NULL and a name will be assigned. 277 * 278 * Returns a pointer to the enclosure component or an error. 279 */ 280 struct enclosure_component * 281 enclosure_component_alloc(struct enclosure_device *edev, 282 unsigned int number, 283 enum enclosure_component_type type, 284 const char *name) 285 { 286 struct enclosure_component *ecomp; 287 struct device *cdev; 288 int i; 289 char newname[COMPONENT_NAME_SIZE]; 290 291 if (number >= edev->components) 292 return ERR_PTR(-EINVAL); 293 294 ecomp = &edev->component[number]; 295 296 if (ecomp->number != -1) 297 return ERR_PTR(-EINVAL); 298 299 ecomp->type = type; 300 ecomp->number = number; 301 cdev = &ecomp->cdev; 302 cdev->parent = get_device(&edev->edev); 303 304 if (name && name[0]) { 305 /* Some hardware (e.g. enclosure in RX300 S6) has components 306 * with non unique names. Registering duplicates in sysfs 307 * will lead to warnings during bootup. So make the names 308 * unique by appending consecutive numbers -1, -2, ... */ 309 i = 1; 310 snprintf(newname, COMPONENT_NAME_SIZE, 311 "%s", name); 312 while (enclosure_component_find_by_name(edev, newname)) 313 snprintf(newname, COMPONENT_NAME_SIZE, 314 "%s-%i", name, i++); 315 dev_set_name(cdev, "%s", newname); 316 } else 317 dev_set_name(cdev, "%u", number); 318 319 cdev->release = enclosure_component_release; 320 cdev->groups = enclosure_component_groups; 321 322 return ecomp; 323 } 324 EXPORT_SYMBOL_GPL(enclosure_component_alloc); 325 326 /** 327 * enclosure_component_register - publishes an initialized enclosure component 328 * @ecomp: component to add 329 * 330 * Returns 0 on successful registration, releases the component otherwise 331 */ 332 int enclosure_component_register(struct enclosure_component *ecomp) 333 { 334 struct device *cdev; 335 int err; 336 337 cdev = &ecomp->cdev; 338 err = device_register(cdev); 339 if (err) { 340 ecomp->number = -1; 341 put_device(cdev); 342 return err; 343 } 344 345 return 0; 346 } 347 EXPORT_SYMBOL_GPL(enclosure_component_register); 348 349 /** 350 * enclosure_add_device - add a device as being part of an enclosure 351 * @edev: the enclosure device being added to. 352 * @component: the number of the component 353 * @dev: the device being added 354 * 355 * Declares a real device to reside in slot (or identifier) @num of an 356 * enclosure. This will cause the relevant sysfs links to appear. 357 * This function may also be used to change a device associated with 358 * an enclosure without having to call enclosure_remove_device() in 359 * between. 360 * 361 * Returns zero on success or an error. 362 */ 363 int enclosure_add_device(struct enclosure_device *edev, int component, 364 struct device *dev) 365 { 366 struct enclosure_component *cdev; 367 int err; 368 369 if (!edev || component >= edev->components) 370 return -EINVAL; 371 372 cdev = &edev->component[component]; 373 374 if (cdev->dev == dev) 375 return -EEXIST; 376 377 if (cdev->dev) { 378 enclosure_remove_links(cdev); 379 put_device(cdev->dev); 380 } 381 cdev->dev = get_device(dev); 382 err = enclosure_add_links(cdev); 383 if (err) { 384 put_device(cdev->dev); 385 cdev->dev = NULL; 386 } 387 return err; 388 } 389 EXPORT_SYMBOL_GPL(enclosure_add_device); 390 391 /** 392 * enclosure_remove_device - remove a device from an enclosure 393 * @edev: the enclosure device 394 * @dev: device to remove/put 395 * 396 * Returns zero on success or an error. 397 * 398 */ 399 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev) 400 { 401 struct enclosure_component *cdev; 402 int i; 403 404 if (!edev || !dev) 405 return -EINVAL; 406 407 for (i = 0; i < edev->components; i++) { 408 cdev = &edev->component[i]; 409 if (cdev->dev == dev) { 410 enclosure_remove_links(cdev); 411 put_device(dev); 412 cdev->dev = NULL; 413 return 0; 414 } 415 } 416 return -ENODEV; 417 } 418 EXPORT_SYMBOL_GPL(enclosure_remove_device); 419 420 /* 421 * sysfs pieces below 422 */ 423 424 static ssize_t components_show(struct device *cdev, 425 struct device_attribute *attr, char *buf) 426 { 427 struct enclosure_device *edev = to_enclosure_device(cdev); 428 429 return sysfs_emit(buf, "%d\n", edev->components); 430 } 431 static DEVICE_ATTR_RO(components); 432 433 static ssize_t id_show(struct device *cdev, 434 struct device_attribute *attr, 435 char *buf) 436 { 437 struct enclosure_device *edev = to_enclosure_device(cdev); 438 439 if (edev->cb->show_id) 440 return edev->cb->show_id(edev, buf); 441 return -EINVAL; 442 } 443 static DEVICE_ATTR_RO(id); 444 445 static struct attribute *enclosure_class_attrs[] = { 446 &dev_attr_components.attr, 447 &dev_attr_id.attr, 448 NULL, 449 }; 450 ATTRIBUTE_GROUPS(enclosure_class); 451 452 static struct class enclosure_class = { 453 .name = "enclosure", 454 .dev_release = enclosure_release, 455 .dev_groups = enclosure_class_groups, 456 }; 457 458 static const char *const enclosure_status[] = { 459 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported", 460 [ENCLOSURE_STATUS_OK] = "OK", 461 [ENCLOSURE_STATUS_CRITICAL] = "critical", 462 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical", 463 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable", 464 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed", 465 [ENCLOSURE_STATUS_UNKNOWN] = "unknown", 466 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable", 467 [ENCLOSURE_STATUS_MAX] = NULL, 468 }; 469 470 static const char *const enclosure_type[] = { 471 [ENCLOSURE_COMPONENT_DEVICE] = "device", 472 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device", 473 }; 474 475 static ssize_t get_component_fault(struct device *cdev, 476 struct device_attribute *attr, char *buf) 477 { 478 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 479 struct enclosure_component *ecomp = to_enclosure_component(cdev); 480 481 if (edev->cb->get_fault) 482 edev->cb->get_fault(edev, ecomp); 483 return sysfs_emit(buf, "%d\n", ecomp->fault); 484 } 485 486 static ssize_t set_component_fault(struct device *cdev, 487 struct device_attribute *attr, 488 const char *buf, size_t count) 489 { 490 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 491 struct enclosure_component *ecomp = to_enclosure_component(cdev); 492 int val = simple_strtoul(buf, NULL, 0); 493 494 if (edev->cb->set_fault) 495 edev->cb->set_fault(edev, ecomp, val); 496 return count; 497 } 498 499 static ssize_t get_component_status(struct device *cdev, 500 struct device_attribute *attr,char *buf) 501 { 502 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 503 struct enclosure_component *ecomp = to_enclosure_component(cdev); 504 505 if (edev->cb->get_status) 506 edev->cb->get_status(edev, ecomp); 507 return sysfs_emit(buf, "%s\n", enclosure_status[ecomp->status]); 508 } 509 510 static ssize_t set_component_status(struct device *cdev, 511 struct device_attribute *attr, 512 const char *buf, size_t count) 513 { 514 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 515 struct enclosure_component *ecomp = to_enclosure_component(cdev); 516 int i; 517 518 for (i = 0; enclosure_status[i]; i++) { 519 if (strncmp(buf, enclosure_status[i], 520 strlen(enclosure_status[i])) == 0 && 521 (buf[strlen(enclosure_status[i])] == '\n' || 522 buf[strlen(enclosure_status[i])] == '\0')) 523 break; 524 } 525 526 if (enclosure_status[i] && edev->cb->set_status) { 527 edev->cb->set_status(edev, ecomp, i); 528 return count; 529 } else 530 return -EINVAL; 531 } 532 533 static ssize_t get_component_active(struct device *cdev, 534 struct device_attribute *attr, char *buf) 535 { 536 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 537 struct enclosure_component *ecomp = to_enclosure_component(cdev); 538 539 if (edev->cb->get_active) 540 edev->cb->get_active(edev, ecomp); 541 return sysfs_emit(buf, "%d\n", ecomp->active); 542 } 543 544 static ssize_t set_component_active(struct device *cdev, 545 struct device_attribute *attr, 546 const char *buf, size_t count) 547 { 548 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 549 struct enclosure_component *ecomp = to_enclosure_component(cdev); 550 int val = simple_strtoul(buf, NULL, 0); 551 552 if (edev->cb->set_active) 553 edev->cb->set_active(edev, ecomp, val); 554 return count; 555 } 556 557 static ssize_t get_component_locate(struct device *cdev, 558 struct device_attribute *attr, char *buf) 559 { 560 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 561 struct enclosure_component *ecomp = to_enclosure_component(cdev); 562 563 if (edev->cb->get_locate) 564 edev->cb->get_locate(edev, ecomp); 565 return sysfs_emit(buf, "%d\n", ecomp->locate); 566 } 567 568 static ssize_t set_component_locate(struct device *cdev, 569 struct device_attribute *attr, 570 const char *buf, size_t count) 571 { 572 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 573 struct enclosure_component *ecomp = to_enclosure_component(cdev); 574 int val = simple_strtoul(buf, NULL, 0); 575 576 if (edev->cb->set_locate) 577 edev->cb->set_locate(edev, ecomp, val); 578 return count; 579 } 580 581 static ssize_t get_component_power_status(struct device *cdev, 582 struct device_attribute *attr, 583 char *buf) 584 { 585 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 586 struct enclosure_component *ecomp = to_enclosure_component(cdev); 587 588 if (edev->cb->get_power_status) 589 edev->cb->get_power_status(edev, ecomp); 590 591 /* If still uninitialized, the callback failed or does not exist. */ 592 if (ecomp->power_status == -1) 593 return (edev->cb->get_power_status) ? -EIO : -ENOTTY; 594 595 return sysfs_emit(buf, "%s\n", ecomp->power_status ? "on" : "off"); 596 } 597 598 static ssize_t set_component_power_status(struct device *cdev, 599 struct device_attribute *attr, 600 const char *buf, size_t count) 601 { 602 struct enclosure_device *edev = to_enclosure_device(cdev->parent); 603 struct enclosure_component *ecomp = to_enclosure_component(cdev); 604 int val; 605 606 if (strncmp(buf, "on", 2) == 0 && 607 (buf[2] == '\n' || buf[2] == '\0')) 608 val = 1; 609 else if (strncmp(buf, "off", 3) == 0 && 610 (buf[3] == '\n' || buf[3] == '\0')) 611 val = 0; 612 else 613 return -EINVAL; 614 615 if (edev->cb->set_power_status) 616 edev->cb->set_power_status(edev, ecomp, val); 617 return count; 618 } 619 620 static ssize_t get_component_type(struct device *cdev, 621 struct device_attribute *attr, char *buf) 622 { 623 struct enclosure_component *ecomp = to_enclosure_component(cdev); 624 625 return sysfs_emit(buf, "%s\n", enclosure_type[ecomp->type]); 626 } 627 628 static ssize_t get_component_slot(struct device *cdev, 629 struct device_attribute *attr, char *buf) 630 { 631 struct enclosure_component *ecomp = to_enclosure_component(cdev); 632 int slot; 633 634 /* if the enclosure does not override then use 'number' as a stand-in */ 635 if (ecomp->slot >= 0) 636 slot = ecomp->slot; 637 else 638 slot = ecomp->number; 639 640 return sysfs_emit(buf, "%d\n", slot); 641 } 642 643 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault, 644 set_component_fault); 645 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status, 646 set_component_status); 647 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active, 648 set_component_active); 649 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate, 650 set_component_locate); 651 static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status, 652 set_component_power_status); 653 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL); 654 static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL); 655 656 static struct attribute *enclosure_component_attrs[] = { 657 &dev_attr_fault.attr, 658 &dev_attr_status.attr, 659 &dev_attr_active.attr, 660 &dev_attr_locate.attr, 661 &dev_attr_power_status.attr, 662 &dev_attr_type.attr, 663 &dev_attr_slot.attr, 664 NULL 665 }; 666 ATTRIBUTE_GROUPS(enclosure_component); 667 668 static int __init enclosure_init(void) 669 { 670 return class_register(&enclosure_class); 671 } 672 673 static void __exit enclosure_exit(void) 674 { 675 class_unregister(&enclosure_class); 676 } 677 678 module_init(enclosure_init); 679 module_exit(enclosure_exit); 680 681 MODULE_AUTHOR("James Bottomley"); 682 MODULE_DESCRIPTION("Enclosure Services"); 683 MODULE_LICENSE("GPL v2"); 684