1 /* 2 * drivers/base/core.c - core driver model code (device registration, etc) 3 * 4 * Copyright (c) 2002-3 Patrick Mochel 5 * Copyright (c) 2002-3 Open Source Development Labs 6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de> 7 * Copyright (c) 2006 Novell, Inc. 8 * 9 * This file is released under the GPLv2 10 * 11 */ 12 13 #include <linux/device.h> 14 #include <linux/err.h> 15 #include <linux/init.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/string.h> 19 #include <linux/kdev_t.h> 20 #include <linux/notifier.h> 21 #include <linux/genhd.h> 22 #include <linux/kallsyms.h> 23 #include <linux/semaphore.h> 24 25 #include "base.h" 26 #include "power/power.h" 27 28 int (*platform_notify)(struct device *dev) = NULL; 29 int (*platform_notify_remove)(struct device *dev) = NULL; 30 31 #ifdef CONFIG_BLOCK 32 static inline int device_is_not_partition(struct device *dev) 33 { 34 return !(dev->type == &part_type); 35 } 36 #else 37 static inline int device_is_not_partition(struct device *dev) 38 { 39 return 1; 40 } 41 #endif 42 43 /** 44 * dev_driver_string - Return a device's driver name, if at all possible 45 * @dev: struct device to get the name of 46 * 47 * Will return the device's driver's name if it is bound to a device. If 48 * the device is not bound to a device, it will return the name of the bus 49 * it is attached to. If it is not attached to a bus either, an empty 50 * string will be returned. 51 */ 52 const char *dev_driver_string(struct device *dev) 53 { 54 return dev->driver ? dev->driver->name : 55 (dev->bus ? dev->bus->name : 56 (dev->class ? dev->class->name : "")); 57 } 58 EXPORT_SYMBOL(dev_driver_string); 59 60 #define to_dev(obj) container_of(obj, struct device, kobj) 61 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) 62 63 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, 64 char *buf) 65 { 66 struct device_attribute *dev_attr = to_dev_attr(attr); 67 struct device *dev = to_dev(kobj); 68 ssize_t ret = -EIO; 69 70 if (dev_attr->show) 71 ret = dev_attr->show(dev, dev_attr, buf); 72 if (ret >= (ssize_t)PAGE_SIZE) { 73 print_symbol("dev_attr_show: %s returned bad count\n", 74 (unsigned long)dev_attr->show); 75 } 76 return ret; 77 } 78 79 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr, 80 const char *buf, size_t count) 81 { 82 struct device_attribute *dev_attr = to_dev_attr(attr); 83 struct device *dev = to_dev(kobj); 84 ssize_t ret = -EIO; 85 86 if (dev_attr->store) 87 ret = dev_attr->store(dev, dev_attr, buf, count); 88 return ret; 89 } 90 91 static struct sysfs_ops dev_sysfs_ops = { 92 .show = dev_attr_show, 93 .store = dev_attr_store, 94 }; 95 96 97 /** 98 * device_release - free device structure. 99 * @kobj: device's kobject. 100 * 101 * This is called once the reference count for the object 102 * reaches 0. We forward the call to the device's release 103 * method, which should handle actually freeing the structure. 104 */ 105 static void device_release(struct kobject *kobj) 106 { 107 struct device *dev = to_dev(kobj); 108 109 if (dev->release) 110 dev->release(dev); 111 else if (dev->type && dev->type->release) 112 dev->type->release(dev); 113 else if (dev->class && dev->class->dev_release) 114 dev->class->dev_release(dev); 115 else { 116 printk(KERN_ERR "Device '%s' does not have a release() " 117 "function, it is broken and must be fixed.\n", 118 dev->bus_id); 119 WARN_ON(1); 120 } 121 } 122 123 static struct kobj_type device_ktype = { 124 .release = device_release, 125 .sysfs_ops = &dev_sysfs_ops, 126 }; 127 128 129 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) 130 { 131 struct kobj_type *ktype = get_ktype(kobj); 132 133 if (ktype == &device_ktype) { 134 struct device *dev = to_dev(kobj); 135 if (dev->uevent_suppress) 136 return 0; 137 if (dev->bus) 138 return 1; 139 if (dev->class) 140 return 1; 141 } 142 return 0; 143 } 144 145 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) 146 { 147 struct device *dev = to_dev(kobj); 148 149 if (dev->bus) 150 return dev->bus->name; 151 if (dev->class) 152 return dev->class->name; 153 return NULL; 154 } 155 156 static int dev_uevent(struct kset *kset, struct kobject *kobj, 157 struct kobj_uevent_env *env) 158 { 159 struct device *dev = to_dev(kobj); 160 int retval = 0; 161 162 /* add the major/minor if present */ 163 if (MAJOR(dev->devt)) { 164 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt)); 165 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt)); 166 } 167 168 if (dev->type && dev->type->name) 169 add_uevent_var(env, "DEVTYPE=%s", dev->type->name); 170 171 if (dev->driver) 172 add_uevent_var(env, "DRIVER=%s", dev->driver->name); 173 174 #ifdef CONFIG_SYSFS_DEPRECATED 175 if (dev->class) { 176 struct device *parent = dev->parent; 177 178 /* find first bus device in parent chain */ 179 while (parent && !parent->bus) 180 parent = parent->parent; 181 if (parent && parent->bus) { 182 const char *path; 183 184 path = kobject_get_path(&parent->kobj, GFP_KERNEL); 185 if (path) { 186 add_uevent_var(env, "PHYSDEVPATH=%s", path); 187 kfree(path); 188 } 189 190 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name); 191 192 if (parent->driver) 193 add_uevent_var(env, "PHYSDEVDRIVER=%s", 194 parent->driver->name); 195 } 196 } else if (dev->bus) { 197 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name); 198 199 if (dev->driver) 200 add_uevent_var(env, "PHYSDEVDRIVER=%s", 201 dev->driver->name); 202 } 203 #endif 204 205 /* have the bus specific function add its stuff */ 206 if (dev->bus && dev->bus->uevent) { 207 retval = dev->bus->uevent(dev, env); 208 if (retval) 209 pr_debug("device: '%s': %s: bus uevent() returned %d\n", 210 dev->bus_id, __func__, retval); 211 } 212 213 /* have the class specific function add its stuff */ 214 if (dev->class && dev->class->dev_uevent) { 215 retval = dev->class->dev_uevent(dev, env); 216 if (retval) 217 pr_debug("device: '%s': %s: class uevent() " 218 "returned %d\n", dev->bus_id, 219 __func__, retval); 220 } 221 222 /* have the device type specific fuction add its stuff */ 223 if (dev->type && dev->type->uevent) { 224 retval = dev->type->uevent(dev, env); 225 if (retval) 226 pr_debug("device: '%s': %s: dev_type uevent() " 227 "returned %d\n", dev->bus_id, 228 __func__, retval); 229 } 230 231 return retval; 232 } 233 234 static struct kset_uevent_ops device_uevent_ops = { 235 .filter = dev_uevent_filter, 236 .name = dev_uevent_name, 237 .uevent = dev_uevent, 238 }; 239 240 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr, 241 char *buf) 242 { 243 struct kobject *top_kobj; 244 struct kset *kset; 245 struct kobj_uevent_env *env = NULL; 246 int i; 247 size_t count = 0; 248 int retval; 249 250 /* search the kset, the device belongs to */ 251 top_kobj = &dev->kobj; 252 while (!top_kobj->kset && top_kobj->parent) 253 top_kobj = top_kobj->parent; 254 if (!top_kobj->kset) 255 goto out; 256 257 kset = top_kobj->kset; 258 if (!kset->uevent_ops || !kset->uevent_ops->uevent) 259 goto out; 260 261 /* respect filter */ 262 if (kset->uevent_ops && kset->uevent_ops->filter) 263 if (!kset->uevent_ops->filter(kset, &dev->kobj)) 264 goto out; 265 266 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); 267 if (!env) 268 return -ENOMEM; 269 270 /* let the kset specific function add its keys */ 271 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env); 272 if (retval) 273 goto out; 274 275 /* copy keys to file */ 276 for (i = 0; i < env->envp_idx; i++) 277 count += sprintf(&buf[count], "%s\n", env->envp[i]); 278 out: 279 kfree(env); 280 return count; 281 } 282 283 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, 284 const char *buf, size_t count) 285 { 286 enum kobject_action action; 287 288 if (kobject_action_type(buf, count, &action) == 0) { 289 kobject_uevent(&dev->kobj, action); 290 goto out; 291 } 292 293 dev_err(dev, "uevent: unsupported action-string; this will " 294 "be ignored in a future kernel version\n"); 295 kobject_uevent(&dev->kobj, KOBJ_ADD); 296 out: 297 return count; 298 } 299 300 static struct device_attribute uevent_attr = 301 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent); 302 303 static int device_add_attributes(struct device *dev, 304 struct device_attribute *attrs) 305 { 306 int error = 0; 307 int i; 308 309 if (attrs) { 310 for (i = 0; attr_name(attrs[i]); i++) { 311 error = device_create_file(dev, &attrs[i]); 312 if (error) 313 break; 314 } 315 if (error) 316 while (--i >= 0) 317 device_remove_file(dev, &attrs[i]); 318 } 319 return error; 320 } 321 322 static void device_remove_attributes(struct device *dev, 323 struct device_attribute *attrs) 324 { 325 int i; 326 327 if (attrs) 328 for (i = 0; attr_name(attrs[i]); i++) 329 device_remove_file(dev, &attrs[i]); 330 } 331 332 static int device_add_groups(struct device *dev, 333 struct attribute_group **groups) 334 { 335 int error = 0; 336 int i; 337 338 if (groups) { 339 for (i = 0; groups[i]; i++) { 340 error = sysfs_create_group(&dev->kobj, groups[i]); 341 if (error) { 342 while (--i >= 0) 343 sysfs_remove_group(&dev->kobj, 344 groups[i]); 345 break; 346 } 347 } 348 } 349 return error; 350 } 351 352 static void device_remove_groups(struct device *dev, 353 struct attribute_group **groups) 354 { 355 int i; 356 357 if (groups) 358 for (i = 0; groups[i]; i++) 359 sysfs_remove_group(&dev->kobj, groups[i]); 360 } 361 362 static int device_add_attrs(struct device *dev) 363 { 364 struct class *class = dev->class; 365 struct device_type *type = dev->type; 366 int error; 367 368 if (class) { 369 error = device_add_attributes(dev, class->dev_attrs); 370 if (error) 371 return error; 372 } 373 374 if (type) { 375 error = device_add_groups(dev, type->groups); 376 if (error) 377 goto err_remove_class_attrs; 378 } 379 380 error = device_add_groups(dev, dev->groups); 381 if (error) 382 goto err_remove_type_groups; 383 384 return 0; 385 386 err_remove_type_groups: 387 if (type) 388 device_remove_groups(dev, type->groups); 389 err_remove_class_attrs: 390 if (class) 391 device_remove_attributes(dev, class->dev_attrs); 392 393 return error; 394 } 395 396 static void device_remove_attrs(struct device *dev) 397 { 398 struct class *class = dev->class; 399 struct device_type *type = dev->type; 400 401 device_remove_groups(dev, dev->groups); 402 403 if (type) 404 device_remove_groups(dev, type->groups); 405 406 if (class) 407 device_remove_attributes(dev, class->dev_attrs); 408 } 409 410 411 static ssize_t show_dev(struct device *dev, struct device_attribute *attr, 412 char *buf) 413 { 414 return print_dev_t(buf, dev->devt); 415 } 416 417 static struct device_attribute devt_attr = 418 __ATTR(dev, S_IRUGO, show_dev, NULL); 419 420 /* kset to create /sys/devices/ */ 421 struct kset *devices_kset; 422 423 /** 424 * device_create_file - create sysfs attribute file for device. 425 * @dev: device. 426 * @attr: device attribute descriptor. 427 */ 428 int device_create_file(struct device *dev, struct device_attribute *attr) 429 { 430 int error = 0; 431 if (dev) 432 error = sysfs_create_file(&dev->kobj, &attr->attr); 433 return error; 434 } 435 436 /** 437 * device_remove_file - remove sysfs attribute file. 438 * @dev: device. 439 * @attr: device attribute descriptor. 440 */ 441 void device_remove_file(struct device *dev, struct device_attribute *attr) 442 { 443 if (dev) 444 sysfs_remove_file(&dev->kobj, &attr->attr); 445 } 446 447 /** 448 * device_create_bin_file - create sysfs binary attribute file for device. 449 * @dev: device. 450 * @attr: device binary attribute descriptor. 451 */ 452 int device_create_bin_file(struct device *dev, struct bin_attribute *attr) 453 { 454 int error = -EINVAL; 455 if (dev) 456 error = sysfs_create_bin_file(&dev->kobj, attr); 457 return error; 458 } 459 EXPORT_SYMBOL_GPL(device_create_bin_file); 460 461 /** 462 * device_remove_bin_file - remove sysfs binary attribute file 463 * @dev: device. 464 * @attr: device binary attribute descriptor. 465 */ 466 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr) 467 { 468 if (dev) 469 sysfs_remove_bin_file(&dev->kobj, attr); 470 } 471 EXPORT_SYMBOL_GPL(device_remove_bin_file); 472 473 /** 474 * device_schedule_callback_owner - helper to schedule a callback for a device 475 * @dev: device. 476 * @func: callback function to invoke later. 477 * @owner: module owning the callback routine 478 * 479 * Attribute methods must not unregister themselves or their parent device 480 * (which would amount to the same thing). Attempts to do so will deadlock, 481 * since unregistration is mutually exclusive with driver callbacks. 482 * 483 * Instead methods can call this routine, which will attempt to allocate 484 * and schedule a workqueue request to call back @func with @dev as its 485 * argument in the workqueue's process context. @dev will be pinned until 486 * @func returns. 487 * 488 * This routine is usually called via the inline device_schedule_callback(), 489 * which automatically sets @owner to THIS_MODULE. 490 * 491 * Returns 0 if the request was submitted, -ENOMEM if storage could not 492 * be allocated, -ENODEV if a reference to @owner isn't available. 493 * 494 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an 495 * underlying sysfs routine (since it is intended for use by attribute 496 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS. 497 */ 498 int device_schedule_callback_owner(struct device *dev, 499 void (*func)(struct device *), struct module *owner) 500 { 501 return sysfs_schedule_callback(&dev->kobj, 502 (void (*)(void *)) func, dev, owner); 503 } 504 EXPORT_SYMBOL_GPL(device_schedule_callback_owner); 505 506 static void klist_children_get(struct klist_node *n) 507 { 508 struct device *dev = container_of(n, struct device, knode_parent); 509 510 get_device(dev); 511 } 512 513 static void klist_children_put(struct klist_node *n) 514 { 515 struct device *dev = container_of(n, struct device, knode_parent); 516 517 put_device(dev); 518 } 519 520 /** 521 * device_initialize - init device structure. 522 * @dev: device. 523 * 524 * This prepares the device for use by other layers, 525 * including adding it to the device hierarchy. 526 * It is the first half of device_register(), if called by 527 * that, though it can also be called separately, so one 528 * may use @dev's fields (e.g. the refcount). 529 */ 530 void device_initialize(struct device *dev) 531 { 532 dev->kobj.kset = devices_kset; 533 kobject_init(&dev->kobj, &device_ktype); 534 klist_init(&dev->klist_children, klist_children_get, 535 klist_children_put); 536 INIT_LIST_HEAD(&dev->dma_pools); 537 INIT_LIST_HEAD(&dev->node); 538 init_MUTEX(&dev->sem); 539 spin_lock_init(&dev->devres_lock); 540 INIT_LIST_HEAD(&dev->devres_head); 541 device_init_wakeup(dev, 0); 542 set_dev_node(dev, -1); 543 } 544 545 #ifdef CONFIG_SYSFS_DEPRECATED 546 static struct kobject *get_device_parent(struct device *dev, 547 struct device *parent) 548 { 549 /* class devices without a parent live in /sys/class/<classname>/ */ 550 if (dev->class && (!parent || parent->class != dev->class)) 551 return &dev->class->subsys.kobj; 552 /* all other devices keep their parent */ 553 else if (parent) 554 return &parent->kobj; 555 556 return NULL; 557 } 558 559 static inline void cleanup_device_parent(struct device *dev) {} 560 static inline void cleanup_glue_dir(struct device *dev, 561 struct kobject *glue_dir) {} 562 #else 563 static struct kobject *virtual_device_parent(struct device *dev) 564 { 565 static struct kobject *virtual_dir = NULL; 566 567 if (!virtual_dir) 568 virtual_dir = kobject_create_and_add("virtual", 569 &devices_kset->kobj); 570 571 return virtual_dir; 572 } 573 574 static struct kobject *get_device_parent(struct device *dev, 575 struct device *parent) 576 { 577 int retval; 578 579 if (dev->class) { 580 struct kobject *kobj = NULL; 581 struct kobject *parent_kobj; 582 struct kobject *k; 583 584 /* 585 * If we have no parent, we live in "virtual". 586 * Class-devices with a non class-device as parent, live 587 * in a "glue" directory to prevent namespace collisions. 588 */ 589 if (parent == NULL) 590 parent_kobj = virtual_device_parent(dev); 591 else if (parent->class) 592 return &parent->kobj; 593 else 594 parent_kobj = &parent->kobj; 595 596 /* find our class-directory at the parent and reference it */ 597 spin_lock(&dev->class->class_dirs.list_lock); 598 list_for_each_entry(k, &dev->class->class_dirs.list, entry) 599 if (k->parent == parent_kobj) { 600 kobj = kobject_get(k); 601 break; 602 } 603 spin_unlock(&dev->class->class_dirs.list_lock); 604 if (kobj) 605 return kobj; 606 607 /* or create a new class-directory at the parent device */ 608 k = kobject_create(); 609 if (!k) 610 return NULL; 611 k->kset = &dev->class->class_dirs; 612 retval = kobject_add(k, parent_kobj, "%s", dev->class->name); 613 if (retval < 0) { 614 kobject_put(k); 615 return NULL; 616 } 617 /* do not emit an uevent for this simple "glue" directory */ 618 return k; 619 } 620 621 if (parent) 622 return &parent->kobj; 623 return NULL; 624 } 625 626 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir) 627 { 628 /* see if we live in a "glue" directory */ 629 if (!glue_dir || !dev->class || 630 glue_dir->kset != &dev->class->class_dirs) 631 return; 632 633 kobject_put(glue_dir); 634 } 635 636 static void cleanup_device_parent(struct device *dev) 637 { 638 cleanup_glue_dir(dev, dev->kobj.parent); 639 } 640 #endif 641 642 static void setup_parent(struct device *dev, struct device *parent) 643 { 644 struct kobject *kobj; 645 kobj = get_device_parent(dev, parent); 646 if (kobj) 647 dev->kobj.parent = kobj; 648 } 649 650 static int device_add_class_symlinks(struct device *dev) 651 { 652 int error; 653 654 if (!dev->class) 655 return 0; 656 657 error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj, 658 "subsystem"); 659 if (error) 660 goto out; 661 662 #ifdef CONFIG_SYSFS_DEPRECATED 663 /* stacked class devices need a symlink in the class directory */ 664 if (dev->kobj.parent != &dev->class->subsys.kobj && 665 device_is_not_partition(dev)) { 666 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj, 667 dev->bus_id); 668 if (error) 669 goto out_subsys; 670 } 671 672 if (dev->parent && device_is_not_partition(dev)) { 673 struct device *parent = dev->parent; 674 char *class_name; 675 676 /* 677 * stacked class devices have the 'device' link 678 * pointing to the bus device instead of the parent 679 */ 680 while (parent->class && !parent->bus && parent->parent) 681 parent = parent->parent; 682 683 error = sysfs_create_link(&dev->kobj, 684 &parent->kobj, 685 "device"); 686 if (error) 687 goto out_busid; 688 689 class_name = make_class_name(dev->class->name, 690 &dev->kobj); 691 if (class_name) 692 error = sysfs_create_link(&dev->parent->kobj, 693 &dev->kobj, class_name); 694 kfree(class_name); 695 if (error) 696 goto out_device; 697 } 698 return 0; 699 700 out_device: 701 if (dev->parent && device_is_not_partition(dev)) 702 sysfs_remove_link(&dev->kobj, "device"); 703 out_busid: 704 if (dev->kobj.parent != &dev->class->subsys.kobj && 705 device_is_not_partition(dev)) 706 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id); 707 #else 708 /* link in the class directory pointing to the device */ 709 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj, 710 dev->bus_id); 711 if (error) 712 goto out_subsys; 713 714 if (dev->parent && device_is_not_partition(dev)) { 715 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj, 716 "device"); 717 if (error) 718 goto out_busid; 719 } 720 return 0; 721 722 out_busid: 723 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id); 724 #endif 725 726 out_subsys: 727 sysfs_remove_link(&dev->kobj, "subsystem"); 728 out: 729 return error; 730 } 731 732 static void device_remove_class_symlinks(struct device *dev) 733 { 734 if (!dev->class) 735 return; 736 737 #ifdef CONFIG_SYSFS_DEPRECATED 738 if (dev->parent && device_is_not_partition(dev)) { 739 char *class_name; 740 741 class_name = make_class_name(dev->class->name, &dev->kobj); 742 if (class_name) { 743 sysfs_remove_link(&dev->parent->kobj, class_name); 744 kfree(class_name); 745 } 746 sysfs_remove_link(&dev->kobj, "device"); 747 } 748 749 if (dev->kobj.parent != &dev->class->subsys.kobj && 750 device_is_not_partition(dev)) 751 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id); 752 #else 753 if (dev->parent && device_is_not_partition(dev)) 754 sysfs_remove_link(&dev->kobj, "device"); 755 756 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id); 757 #endif 758 759 sysfs_remove_link(&dev->kobj, "subsystem"); 760 } 761 762 /** 763 * dev_set_name - set a device name 764 * @dev: device 765 */ 766 int dev_set_name(struct device *dev, const char *fmt, ...) 767 { 768 va_list vargs; 769 770 va_start(vargs, fmt); 771 vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs); 772 va_end(vargs); 773 return 0; 774 } 775 EXPORT_SYMBOL_GPL(dev_set_name); 776 777 /** 778 * device_add - add device to device hierarchy. 779 * @dev: device. 780 * 781 * This is part 2 of device_register(), though may be called 782 * separately _iff_ device_initialize() has been called separately. 783 * 784 * This adds it to the kobject hierarchy via kobject_add(), adds it 785 * to the global and sibling lists for the device, then 786 * adds it to the other relevant subsystems of the driver model. 787 */ 788 int device_add(struct device *dev) 789 { 790 struct device *parent = NULL; 791 struct class_interface *class_intf; 792 int error; 793 794 dev = get_device(dev); 795 if (!dev || !strlen(dev->bus_id)) { 796 error = -EINVAL; 797 goto Done; 798 } 799 800 pr_debug("device: '%s': %s\n", dev->bus_id, __func__); 801 802 parent = get_device(dev->parent); 803 setup_parent(dev, parent); 804 805 /* use parent numa_node */ 806 if (parent) 807 set_dev_node(dev, dev_to_node(parent)); 808 809 /* first, register with generic layer. */ 810 error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id); 811 if (error) 812 goto Error; 813 814 /* notify platform of device entry */ 815 if (platform_notify) 816 platform_notify(dev); 817 818 /* notify clients of device entry (new way) */ 819 if (dev->bus) 820 blocking_notifier_call_chain(&dev->bus->p->bus_notifier, 821 BUS_NOTIFY_ADD_DEVICE, dev); 822 823 error = device_create_file(dev, &uevent_attr); 824 if (error) 825 goto attrError; 826 827 if (MAJOR(dev->devt)) { 828 error = device_create_file(dev, &devt_attr); 829 if (error) 830 goto ueventattrError; 831 } 832 833 error = device_add_class_symlinks(dev); 834 if (error) 835 goto SymlinkError; 836 error = device_add_attrs(dev); 837 if (error) 838 goto AttrsError; 839 error = bus_add_device(dev); 840 if (error) 841 goto BusError; 842 error = device_pm_add(dev); 843 if (error) 844 goto PMError; 845 kobject_uevent(&dev->kobj, KOBJ_ADD); 846 bus_attach_device(dev); 847 if (parent) 848 klist_add_tail(&dev->knode_parent, &parent->klist_children); 849 850 if (dev->class) { 851 down(&dev->class->sem); 852 /* tie the class to the device */ 853 list_add_tail(&dev->node, &dev->class->devices); 854 855 /* notify any interfaces that the device is here */ 856 list_for_each_entry(class_intf, &dev->class->interfaces, node) 857 if (class_intf->add_dev) 858 class_intf->add_dev(dev, class_intf); 859 up(&dev->class->sem); 860 } 861 Done: 862 put_device(dev); 863 return error; 864 PMError: 865 bus_remove_device(dev); 866 BusError: 867 if (dev->bus) 868 blocking_notifier_call_chain(&dev->bus->p->bus_notifier, 869 BUS_NOTIFY_DEL_DEVICE, dev); 870 device_remove_attrs(dev); 871 AttrsError: 872 device_remove_class_symlinks(dev); 873 SymlinkError: 874 if (MAJOR(dev->devt)) 875 device_remove_file(dev, &devt_attr); 876 ueventattrError: 877 device_remove_file(dev, &uevent_attr); 878 attrError: 879 kobject_uevent(&dev->kobj, KOBJ_REMOVE); 880 kobject_del(&dev->kobj); 881 Error: 882 cleanup_device_parent(dev); 883 if (parent) 884 put_device(parent); 885 goto Done; 886 } 887 888 /** 889 * device_register - register a device with the system. 890 * @dev: pointer to the device structure 891 * 892 * This happens in two clean steps - initialize the device 893 * and add it to the system. The two steps can be called 894 * separately, but this is the easiest and most common. 895 * I.e. you should only call the two helpers separately if 896 * have a clearly defined need to use and refcount the device 897 * before it is added to the hierarchy. 898 */ 899 int device_register(struct device *dev) 900 { 901 device_initialize(dev); 902 return device_add(dev); 903 } 904 905 /** 906 * get_device - increment reference count for device. 907 * @dev: device. 908 * 909 * This simply forwards the call to kobject_get(), though 910 * we do take care to provide for the case that we get a NULL 911 * pointer passed in. 912 */ 913 struct device *get_device(struct device *dev) 914 { 915 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL; 916 } 917 918 /** 919 * put_device - decrement reference count. 920 * @dev: device in question. 921 */ 922 void put_device(struct device *dev) 923 { 924 /* might_sleep(); */ 925 if (dev) 926 kobject_put(&dev->kobj); 927 } 928 929 /** 930 * device_del - delete device from system. 931 * @dev: device. 932 * 933 * This is the first part of the device unregistration 934 * sequence. This removes the device from the lists we control 935 * from here, has it removed from the other driver model 936 * subsystems it was added to in device_add(), and removes it 937 * from the kobject hierarchy. 938 * 939 * NOTE: this should be called manually _iff_ device_add() was 940 * also called manually. 941 */ 942 void device_del(struct device *dev) 943 { 944 struct device *parent = dev->parent; 945 struct class_interface *class_intf; 946 947 device_pm_remove(dev); 948 if (parent) 949 klist_del(&dev->knode_parent); 950 if (MAJOR(dev->devt)) 951 device_remove_file(dev, &devt_attr); 952 if (dev->class) { 953 device_remove_class_symlinks(dev); 954 955 down(&dev->class->sem); 956 /* notify any interfaces that the device is now gone */ 957 list_for_each_entry(class_intf, &dev->class->interfaces, node) 958 if (class_intf->remove_dev) 959 class_intf->remove_dev(dev, class_intf); 960 /* remove the device from the class list */ 961 list_del_init(&dev->node); 962 up(&dev->class->sem); 963 } 964 device_remove_file(dev, &uevent_attr); 965 device_remove_attrs(dev); 966 bus_remove_device(dev); 967 968 /* 969 * Some platform devices are driven without driver attached 970 * and managed resources may have been acquired. Make sure 971 * all resources are released. 972 */ 973 devres_release_all(dev); 974 975 /* Notify the platform of the removal, in case they 976 * need to do anything... 977 */ 978 if (platform_notify_remove) 979 platform_notify_remove(dev); 980 if (dev->bus) 981 blocking_notifier_call_chain(&dev->bus->p->bus_notifier, 982 BUS_NOTIFY_DEL_DEVICE, dev); 983 kobject_uevent(&dev->kobj, KOBJ_REMOVE); 984 cleanup_device_parent(dev); 985 kobject_del(&dev->kobj); 986 put_device(parent); 987 } 988 989 /** 990 * device_unregister - unregister device from system. 991 * @dev: device going away. 992 * 993 * We do this in two parts, like we do device_register(). First, 994 * we remove it from all the subsystems with device_del(), then 995 * we decrement the reference count via put_device(). If that 996 * is the final reference count, the device will be cleaned up 997 * via device_release() above. Otherwise, the structure will 998 * stick around until the final reference to the device is dropped. 999 */ 1000 void device_unregister(struct device *dev) 1001 { 1002 pr_debug("device: '%s': %s\n", dev->bus_id, __func__); 1003 device_del(dev); 1004 put_device(dev); 1005 } 1006 1007 static struct device *next_device(struct klist_iter *i) 1008 { 1009 struct klist_node *n = klist_next(i); 1010 return n ? container_of(n, struct device, knode_parent) : NULL; 1011 } 1012 1013 /** 1014 * device_for_each_child - device child iterator. 1015 * @parent: parent struct device. 1016 * @data: data for the callback. 1017 * @fn: function to be called for each device. 1018 * 1019 * Iterate over @parent's child devices, and call @fn for each, 1020 * passing it @data. 1021 * 1022 * We check the return of @fn each time. If it returns anything 1023 * other than 0, we break out and return that value. 1024 */ 1025 int device_for_each_child(struct device *parent, void *data, 1026 int (*fn)(struct device *dev, void *data)) 1027 { 1028 struct klist_iter i; 1029 struct device *child; 1030 int error = 0; 1031 1032 klist_iter_init(&parent->klist_children, &i); 1033 while ((child = next_device(&i)) && !error) 1034 error = fn(child, data); 1035 klist_iter_exit(&i); 1036 return error; 1037 } 1038 1039 /** 1040 * device_find_child - device iterator for locating a particular device. 1041 * @parent: parent struct device 1042 * @data: Data to pass to match function 1043 * @match: Callback function to check device 1044 * 1045 * This is similar to the device_for_each_child() function above, but it 1046 * returns a reference to a device that is 'found' for later use, as 1047 * determined by the @match callback. 1048 * 1049 * The callback should return 0 if the device doesn't match and non-zero 1050 * if it does. If the callback returns non-zero and a reference to the 1051 * current device can be obtained, this function will return to the caller 1052 * and not iterate over any more devices. 1053 */ 1054 struct device *device_find_child(struct device *parent, void *data, 1055 int (*match)(struct device *dev, void *data)) 1056 { 1057 struct klist_iter i; 1058 struct device *child; 1059 1060 if (!parent) 1061 return NULL; 1062 1063 klist_iter_init(&parent->klist_children, &i); 1064 while ((child = next_device(&i))) 1065 if (match(child, data) && get_device(child)) 1066 break; 1067 klist_iter_exit(&i); 1068 return child; 1069 } 1070 1071 int __init devices_init(void) 1072 { 1073 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); 1074 if (!devices_kset) 1075 return -ENOMEM; 1076 return 0; 1077 } 1078 1079 EXPORT_SYMBOL_GPL(device_for_each_child); 1080 EXPORT_SYMBOL_GPL(device_find_child); 1081 1082 EXPORT_SYMBOL_GPL(device_initialize); 1083 EXPORT_SYMBOL_GPL(device_add); 1084 EXPORT_SYMBOL_GPL(device_register); 1085 1086 EXPORT_SYMBOL_GPL(device_del); 1087 EXPORT_SYMBOL_GPL(device_unregister); 1088 EXPORT_SYMBOL_GPL(get_device); 1089 EXPORT_SYMBOL_GPL(put_device); 1090 1091 EXPORT_SYMBOL_GPL(device_create_file); 1092 EXPORT_SYMBOL_GPL(device_remove_file); 1093 1094 1095 static void device_create_release(struct device *dev) 1096 { 1097 pr_debug("device: '%s': %s\n", dev->bus_id, __func__); 1098 kfree(dev); 1099 } 1100 1101 /** 1102 * device_create_vargs - creates a device and registers it with sysfs 1103 * @class: pointer to the struct class that this device should be registered to 1104 * @parent: pointer to the parent struct device of this new device, if any 1105 * @devt: the dev_t for the char device to be added 1106 * @drvdata: the data to be added to the device for callbacks 1107 * @fmt: string for the device's name 1108 * @args: va_list for the device's name 1109 * 1110 * This function can be used by char device classes. A struct device 1111 * will be created in sysfs, registered to the specified class. 1112 * 1113 * A "dev" file will be created, showing the dev_t for the device, if 1114 * the dev_t is not 0,0. 1115 * If a pointer to a parent struct device is passed in, the newly created 1116 * struct device will be a child of that device in sysfs. 1117 * The pointer to the struct device will be returned from the call. 1118 * Any further sysfs files that might be required can be created using this 1119 * pointer. 1120 * 1121 * Note: the struct class passed to this function must have previously 1122 * been created with a call to class_create(). 1123 */ 1124 struct device *device_create_vargs(struct class *class, struct device *parent, 1125 dev_t devt, void *drvdata, const char *fmt, 1126 va_list args) 1127 { 1128 struct device *dev = NULL; 1129 int retval = -ENODEV; 1130 1131 if (class == NULL || IS_ERR(class)) 1132 goto error; 1133 1134 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 1135 if (!dev) { 1136 retval = -ENOMEM; 1137 goto error; 1138 } 1139 1140 dev->devt = devt; 1141 dev->class = class; 1142 dev->parent = parent; 1143 dev->release = device_create_release; 1144 dev_set_drvdata(dev, drvdata); 1145 1146 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args); 1147 retval = device_register(dev); 1148 if (retval) 1149 goto error; 1150 1151 return dev; 1152 1153 error: 1154 kfree(dev); 1155 return ERR_PTR(retval); 1156 } 1157 EXPORT_SYMBOL_GPL(device_create_vargs); 1158 1159 /** 1160 * device_create_drvdata - creates a device and registers it with sysfs 1161 * @class: pointer to the struct class that this device should be registered to 1162 * @parent: pointer to the parent struct device of this new device, if any 1163 * @devt: the dev_t for the char device to be added 1164 * @drvdata: the data to be added to the device for callbacks 1165 * @fmt: string for the device's name 1166 * 1167 * This function can be used by char device classes. A struct device 1168 * will be created in sysfs, registered to the specified class. 1169 * 1170 * A "dev" file will be created, showing the dev_t for the device, if 1171 * the dev_t is not 0,0. 1172 * If a pointer to a parent struct device is passed in, the newly created 1173 * struct device will be a child of that device in sysfs. 1174 * The pointer to the struct device will be returned from the call. 1175 * Any further sysfs files that might be required can be created using this 1176 * pointer. 1177 * 1178 * Note: the struct class passed to this function must have previously 1179 * been created with a call to class_create(). 1180 */ 1181 struct device *device_create_drvdata(struct class *class, 1182 struct device *parent, 1183 dev_t devt, 1184 void *drvdata, 1185 const char *fmt, ...) 1186 { 1187 va_list vargs; 1188 struct device *dev; 1189 1190 va_start(vargs, fmt); 1191 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs); 1192 va_end(vargs); 1193 return dev; 1194 } 1195 EXPORT_SYMBOL_GPL(device_create_drvdata); 1196 1197 /** 1198 * device_create - creates a device and registers it with sysfs 1199 * @class: pointer to the struct class that this device should be registered to 1200 * @parent: pointer to the parent struct device of this new device, if any 1201 * @devt: the dev_t for the char device to be added 1202 * @fmt: string for the device's name 1203 * 1204 * This function can be used by char device classes. A struct device 1205 * will be created in sysfs, registered to the specified class. 1206 * 1207 * A "dev" file will be created, showing the dev_t for the device, if 1208 * the dev_t is not 0,0. 1209 * If a pointer to a parent struct device is passed in, the newly created 1210 * struct device will be a child of that device in sysfs. 1211 * The pointer to the struct device will be returned from the call. 1212 * Any further sysfs files that might be required can be created using this 1213 * pointer. 1214 * 1215 * Note: the struct class passed to this function must have previously 1216 * been created with a call to class_create(). 1217 */ 1218 struct device *device_create(struct class *class, struct device *parent, 1219 dev_t devt, const char *fmt, ...) 1220 { 1221 va_list vargs; 1222 struct device *dev; 1223 1224 va_start(vargs, fmt); 1225 dev = device_create_vargs(class, parent, devt, NULL, fmt, vargs); 1226 va_end(vargs); 1227 return dev; 1228 } 1229 EXPORT_SYMBOL_GPL(device_create); 1230 1231 static int __match_devt(struct device *dev, void *data) 1232 { 1233 dev_t *devt = data; 1234 1235 return dev->devt == *devt; 1236 } 1237 1238 /** 1239 * device_destroy - removes a device that was created with device_create() 1240 * @class: pointer to the struct class that this device was registered with 1241 * @devt: the dev_t of the device that was previously registered 1242 * 1243 * This call unregisters and cleans up a device that was created with a 1244 * call to device_create(). 1245 */ 1246 void device_destroy(struct class *class, dev_t devt) 1247 { 1248 struct device *dev; 1249 1250 dev = class_find_device(class, &devt, __match_devt); 1251 if (dev) { 1252 put_device(dev); 1253 device_unregister(dev); 1254 } 1255 } 1256 EXPORT_SYMBOL_GPL(device_destroy); 1257 1258 /** 1259 * device_rename - renames a device 1260 * @dev: the pointer to the struct device to be renamed 1261 * @new_name: the new name of the device 1262 */ 1263 int device_rename(struct device *dev, char *new_name) 1264 { 1265 char *old_class_name = NULL; 1266 char *new_class_name = NULL; 1267 char *old_device_name = NULL; 1268 int error; 1269 1270 dev = get_device(dev); 1271 if (!dev) 1272 return -EINVAL; 1273 1274 pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id, 1275 __func__, new_name); 1276 1277 #ifdef CONFIG_SYSFS_DEPRECATED 1278 if ((dev->class) && (dev->parent)) 1279 old_class_name = make_class_name(dev->class->name, &dev->kobj); 1280 #endif 1281 1282 old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL); 1283 if (!old_device_name) { 1284 error = -ENOMEM; 1285 goto out; 1286 } 1287 strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE); 1288 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE); 1289 1290 error = kobject_rename(&dev->kobj, new_name); 1291 if (error) { 1292 strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE); 1293 goto out; 1294 } 1295 1296 #ifdef CONFIG_SYSFS_DEPRECATED 1297 if (old_class_name) { 1298 new_class_name = make_class_name(dev->class->name, &dev->kobj); 1299 if (new_class_name) { 1300 error = sysfs_create_link(&dev->parent->kobj, 1301 &dev->kobj, new_class_name); 1302 if (error) 1303 goto out; 1304 sysfs_remove_link(&dev->parent->kobj, old_class_name); 1305 } 1306 } 1307 #else 1308 if (dev->class) { 1309 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj, 1310 dev->bus_id); 1311 if (error) 1312 goto out; 1313 sysfs_remove_link(&dev->class->subsys.kobj, old_device_name); 1314 } 1315 #endif 1316 1317 out: 1318 put_device(dev); 1319 1320 kfree(new_class_name); 1321 kfree(old_class_name); 1322 kfree(old_device_name); 1323 1324 return error; 1325 } 1326 EXPORT_SYMBOL_GPL(device_rename); 1327 1328 static int device_move_class_links(struct device *dev, 1329 struct device *old_parent, 1330 struct device *new_parent) 1331 { 1332 int error = 0; 1333 #ifdef CONFIG_SYSFS_DEPRECATED 1334 char *class_name; 1335 1336 class_name = make_class_name(dev->class->name, &dev->kobj); 1337 if (!class_name) { 1338 error = -ENOMEM; 1339 goto out; 1340 } 1341 if (old_parent) { 1342 sysfs_remove_link(&dev->kobj, "device"); 1343 sysfs_remove_link(&old_parent->kobj, class_name); 1344 } 1345 if (new_parent) { 1346 error = sysfs_create_link(&dev->kobj, &new_parent->kobj, 1347 "device"); 1348 if (error) 1349 goto out; 1350 error = sysfs_create_link(&new_parent->kobj, &dev->kobj, 1351 class_name); 1352 if (error) 1353 sysfs_remove_link(&dev->kobj, "device"); 1354 } else 1355 error = 0; 1356 out: 1357 kfree(class_name); 1358 return error; 1359 #else 1360 if (old_parent) 1361 sysfs_remove_link(&dev->kobj, "device"); 1362 if (new_parent) 1363 error = sysfs_create_link(&dev->kobj, &new_parent->kobj, 1364 "device"); 1365 return error; 1366 #endif 1367 } 1368 1369 /** 1370 * device_move - moves a device to a new parent 1371 * @dev: the pointer to the struct device to be moved 1372 * @new_parent: the new parent of the device (can by NULL) 1373 */ 1374 int device_move(struct device *dev, struct device *new_parent) 1375 { 1376 int error; 1377 struct device *old_parent; 1378 struct kobject *new_parent_kobj; 1379 1380 dev = get_device(dev); 1381 if (!dev) 1382 return -EINVAL; 1383 1384 new_parent = get_device(new_parent); 1385 new_parent_kobj = get_device_parent(dev, new_parent); 1386 1387 pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id, 1388 __func__, new_parent ? new_parent->bus_id : "<NULL>"); 1389 error = kobject_move(&dev->kobj, new_parent_kobj); 1390 if (error) { 1391 cleanup_glue_dir(dev, new_parent_kobj); 1392 put_device(new_parent); 1393 goto out; 1394 } 1395 old_parent = dev->parent; 1396 dev->parent = new_parent; 1397 if (old_parent) 1398 klist_remove(&dev->knode_parent); 1399 if (new_parent) { 1400 klist_add_tail(&dev->knode_parent, &new_parent->klist_children); 1401 set_dev_node(dev, dev_to_node(new_parent)); 1402 } 1403 1404 if (!dev->class) 1405 goto out_put; 1406 error = device_move_class_links(dev, old_parent, new_parent); 1407 if (error) { 1408 /* We ignore errors on cleanup since we're hosed anyway... */ 1409 device_move_class_links(dev, new_parent, old_parent); 1410 if (!kobject_move(&dev->kobj, &old_parent->kobj)) { 1411 if (new_parent) 1412 klist_remove(&dev->knode_parent); 1413 dev->parent = old_parent; 1414 if (old_parent) { 1415 klist_add_tail(&dev->knode_parent, 1416 &old_parent->klist_children); 1417 set_dev_node(dev, dev_to_node(old_parent)); 1418 } 1419 } 1420 cleanup_glue_dir(dev, new_parent_kobj); 1421 put_device(new_parent); 1422 goto out; 1423 } 1424 out_put: 1425 put_device(old_parent); 1426 out: 1427 put_device(dev); 1428 return error; 1429 } 1430 EXPORT_SYMBOL_GPL(device_move); 1431 1432 /** 1433 * device_shutdown - call ->shutdown() on each device to shutdown. 1434 */ 1435 void device_shutdown(void) 1436 { 1437 struct device *dev, *devn; 1438 1439 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list, 1440 kobj.entry) { 1441 if (dev->bus && dev->bus->shutdown) { 1442 dev_dbg(dev, "shutdown\n"); 1443 dev->bus->shutdown(dev); 1444 } else if (dev->driver && dev->driver->shutdown) { 1445 dev_dbg(dev, "shutdown\n"); 1446 dev->driver->shutdown(dev); 1447 } 1448 } 1449 } 1450