1 /* 2 * drivers/usb/core/usb.c 3 * 4 * (C) Copyright Linus Torvalds 1999 5 * (C) Copyright Johannes Erdfelt 1999-2001 6 * (C) Copyright Andreas Gal 1999 7 * (C) Copyright Gregory P. Smith 1999 8 * (C) Copyright Deti Fliegl 1999 (new USB architecture) 9 * (C) Copyright Randy Dunlap 2000 10 * (C) Copyright David Brownell 2000-2004 11 * (C) Copyright Yggdrasil Computing, Inc. 2000 12 * (usb_device_id matching changes by Adam J. Richter) 13 * (C) Copyright Greg Kroah-Hartman 2002-2003 14 * 15 * NOTE! This is not actually a driver at all, rather this is 16 * just a collection of helper routines that implement the 17 * generic USB things that the real drivers can use.. 18 * 19 * Think of this as a "USB library" rather than anything else. 20 * It should be considered a slave, with no callbacks. Callbacks 21 * are evil. 22 */ 23 24 #include <linux/module.h> 25 #include <linux/moduleparam.h> 26 #include <linux/string.h> 27 #include <linux/bitops.h> 28 #include <linux/slab.h> 29 #include <linux/interrupt.h> /* for in_interrupt() */ 30 #include <linux/kmod.h> 31 #include <linux/init.h> 32 #include <linux/spinlock.h> 33 #include <linux/errno.h> 34 #include <linux/usb.h> 35 #include <linux/usb/hcd.h> 36 #include <linux/mutex.h> 37 #include <linux/workqueue.h> 38 #include <linux/debugfs.h> 39 #include <linux/usb/of.h> 40 41 #include <asm/io.h> 42 #include <linux/scatterlist.h> 43 #include <linux/mm.h> 44 #include <linux/dma-mapping.h> 45 46 #include "usb.h" 47 48 49 const char *usbcore_name = "usbcore"; 50 51 static bool nousb; /* Disable USB when built into kernel image */ 52 53 module_param(nousb, bool, 0444); 54 55 /* 56 * for external read access to <nousb> 57 */ 58 int usb_disabled(void) 59 { 60 return nousb; 61 } 62 EXPORT_SYMBOL_GPL(usb_disabled); 63 64 #ifdef CONFIG_PM 65 static int usb_autosuspend_delay = 2; /* Default delay value, 66 * in seconds */ 67 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); 68 MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); 69 70 #else 71 #define usb_autosuspend_delay 0 72 #endif 73 74 75 /** 76 * usb_find_alt_setting() - Given a configuration, find the alternate setting 77 * for the given interface. 78 * @config: the configuration to search (not necessarily the current config). 79 * @iface_num: interface number to search in 80 * @alt_num: alternate interface setting number to search for. 81 * 82 * Search the configuration's interface cache for the given alt setting. 83 * 84 * Return: The alternate setting, if found. %NULL otherwise. 85 */ 86 struct usb_host_interface *usb_find_alt_setting( 87 struct usb_host_config *config, 88 unsigned int iface_num, 89 unsigned int alt_num) 90 { 91 struct usb_interface_cache *intf_cache = NULL; 92 int i; 93 94 for (i = 0; i < config->desc.bNumInterfaces; i++) { 95 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber 96 == iface_num) { 97 intf_cache = config->intf_cache[i]; 98 break; 99 } 100 } 101 if (!intf_cache) 102 return NULL; 103 for (i = 0; i < intf_cache->num_altsetting; i++) 104 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num) 105 return &intf_cache->altsetting[i]; 106 107 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, " 108 "config %u\n", alt_num, iface_num, 109 config->desc.bConfigurationValue); 110 return NULL; 111 } 112 EXPORT_SYMBOL_GPL(usb_find_alt_setting); 113 114 /** 115 * usb_ifnum_to_if - get the interface object with a given interface number 116 * @dev: the device whose current configuration is considered 117 * @ifnum: the desired interface 118 * 119 * This walks the device descriptor for the currently active configuration 120 * to find the interface object with the particular interface number. 121 * 122 * Note that configuration descriptors are not required to assign interface 123 * numbers sequentially, so that it would be incorrect to assume that 124 * the first interface in that descriptor corresponds to interface zero. 125 * This routine helps device drivers avoid such mistakes. 126 * However, you should make sure that you do the right thing with any 127 * alternate settings available for this interfaces. 128 * 129 * Don't call this function unless you are bound to one of the interfaces 130 * on this device or you have locked the device! 131 * 132 * Return: A pointer to the interface that has @ifnum as interface number, 133 * if found. %NULL otherwise. 134 */ 135 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, 136 unsigned ifnum) 137 { 138 struct usb_host_config *config = dev->actconfig; 139 int i; 140 141 if (!config) 142 return NULL; 143 for (i = 0; i < config->desc.bNumInterfaces; i++) 144 if (config->interface[i]->altsetting[0] 145 .desc.bInterfaceNumber == ifnum) 146 return config->interface[i]; 147 148 return NULL; 149 } 150 EXPORT_SYMBOL_GPL(usb_ifnum_to_if); 151 152 /** 153 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number. 154 * @intf: the interface containing the altsetting in question 155 * @altnum: the desired alternate setting number 156 * 157 * This searches the altsetting array of the specified interface for 158 * an entry with the correct bAlternateSetting value. 159 * 160 * Note that altsettings need not be stored sequentially by number, so 161 * it would be incorrect to assume that the first altsetting entry in 162 * the array corresponds to altsetting zero. This routine helps device 163 * drivers avoid such mistakes. 164 * 165 * Don't call this function unless you are bound to the intf interface 166 * or you have locked the device! 167 * 168 * Return: A pointer to the entry of the altsetting array of @intf that 169 * has @altnum as the alternate setting number. %NULL if not found. 170 */ 171 struct usb_host_interface *usb_altnum_to_altsetting( 172 const struct usb_interface *intf, 173 unsigned int altnum) 174 { 175 int i; 176 177 for (i = 0; i < intf->num_altsetting; i++) { 178 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 179 return &intf->altsetting[i]; 180 } 181 return NULL; 182 } 183 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); 184 185 struct find_interface_arg { 186 int minor; 187 struct device_driver *drv; 188 }; 189 190 static int __find_interface(struct device *dev, void *data) 191 { 192 struct find_interface_arg *arg = data; 193 struct usb_interface *intf; 194 195 if (!is_usb_interface(dev)) 196 return 0; 197 198 if (dev->driver != arg->drv) 199 return 0; 200 intf = to_usb_interface(dev); 201 return intf->minor == arg->minor; 202 } 203 204 /** 205 * usb_find_interface - find usb_interface pointer for driver and device 206 * @drv: the driver whose current configuration is considered 207 * @minor: the minor number of the desired device 208 * 209 * This walks the bus device list and returns a pointer to the interface 210 * with the matching minor and driver. Note, this only works for devices 211 * that share the USB major number. 212 * 213 * Return: A pointer to the interface with the matching major and @minor. 214 */ 215 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 216 { 217 struct find_interface_arg argb; 218 struct device *dev; 219 220 argb.minor = minor; 221 argb.drv = &drv->drvwrap.driver; 222 223 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface); 224 225 /* Drop reference count from bus_find_device */ 226 put_device(dev); 227 228 return dev ? to_usb_interface(dev) : NULL; 229 } 230 EXPORT_SYMBOL_GPL(usb_find_interface); 231 232 struct each_dev_arg { 233 void *data; 234 int (*fn)(struct usb_device *, void *); 235 }; 236 237 static int __each_dev(struct device *dev, void *data) 238 { 239 struct each_dev_arg *arg = (struct each_dev_arg *)data; 240 241 /* There are struct usb_interface on the same bus, filter them out */ 242 if (!is_usb_device(dev)) 243 return 0; 244 245 return arg->fn(to_usb_device(dev), arg->data); 246 } 247 248 /** 249 * usb_for_each_dev - iterate over all USB devices in the system 250 * @data: data pointer that will be handed to the callback function 251 * @fn: callback function to be called for each USB device 252 * 253 * Iterate over all USB devices and call @fn for each, passing it @data. If it 254 * returns anything other than 0, we break the iteration prematurely and return 255 * that value. 256 */ 257 int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *)) 258 { 259 struct each_dev_arg arg = {data, fn}; 260 261 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev); 262 } 263 EXPORT_SYMBOL_GPL(usb_for_each_dev); 264 265 /** 266 * usb_release_dev - free a usb device structure when all users of it are finished. 267 * @dev: device that's been disconnected 268 * 269 * Will be called only by the device core when all users of this usb device are 270 * done. 271 */ 272 static void usb_release_dev(struct device *dev) 273 { 274 struct usb_device *udev; 275 struct usb_hcd *hcd; 276 277 udev = to_usb_device(dev); 278 hcd = bus_to_hcd(udev->bus); 279 280 usb_destroy_configuration(udev); 281 usb_release_bos_descriptor(udev); 282 usb_put_hcd(hcd); 283 kfree(udev->product); 284 kfree(udev->manufacturer); 285 kfree(udev->serial); 286 kfree(udev); 287 } 288 289 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 290 { 291 struct usb_device *usb_dev; 292 293 usb_dev = to_usb_device(dev); 294 295 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) 296 return -ENOMEM; 297 298 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) 299 return -ENOMEM; 300 301 return 0; 302 } 303 304 #ifdef CONFIG_PM 305 306 /* USB device Power-Management thunks. 307 * There's no need to distinguish here between quiescing a USB device 308 * and powering it down; the generic_suspend() routine takes care of 309 * it by skipping the usb_port_suspend() call for a quiesce. And for 310 * USB interfaces there's no difference at all. 311 */ 312 313 static int usb_dev_prepare(struct device *dev) 314 { 315 struct usb_device *udev = to_usb_device(dev); 316 317 /* Return 0 if the current wakeup setting is wrong, otherwise 1 */ 318 if (udev->do_remote_wakeup != device_may_wakeup(dev)) 319 return 0; 320 321 return 1; 322 } 323 324 static void usb_dev_complete(struct device *dev) 325 { 326 /* Currently used only for rebinding interfaces */ 327 usb_resume_complete(dev); 328 } 329 330 static int usb_dev_suspend(struct device *dev) 331 { 332 return usb_suspend(dev, PMSG_SUSPEND); 333 } 334 335 static int usb_dev_resume(struct device *dev) 336 { 337 return usb_resume(dev, PMSG_RESUME); 338 } 339 340 static int usb_dev_freeze(struct device *dev) 341 { 342 return usb_suspend(dev, PMSG_FREEZE); 343 } 344 345 static int usb_dev_thaw(struct device *dev) 346 { 347 return usb_resume(dev, PMSG_THAW); 348 } 349 350 static int usb_dev_poweroff(struct device *dev) 351 { 352 return usb_suspend(dev, PMSG_HIBERNATE); 353 } 354 355 static int usb_dev_restore(struct device *dev) 356 { 357 return usb_resume(dev, PMSG_RESTORE); 358 } 359 360 static const struct dev_pm_ops usb_device_pm_ops = { 361 .prepare = usb_dev_prepare, 362 .complete = usb_dev_complete, 363 .suspend = usb_dev_suspend, 364 .resume = usb_dev_resume, 365 .freeze = usb_dev_freeze, 366 .thaw = usb_dev_thaw, 367 .poweroff = usb_dev_poweroff, 368 .restore = usb_dev_restore, 369 .runtime_suspend = usb_runtime_suspend, 370 .runtime_resume = usb_runtime_resume, 371 .runtime_idle = usb_runtime_idle, 372 }; 373 374 #endif /* CONFIG_PM */ 375 376 377 static char *usb_devnode(struct device *dev, 378 umode_t *mode, kuid_t *uid, kgid_t *gid) 379 { 380 struct usb_device *usb_dev; 381 382 usb_dev = to_usb_device(dev); 383 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d", 384 usb_dev->bus->busnum, usb_dev->devnum); 385 } 386 387 struct device_type usb_device_type = { 388 .name = "usb_device", 389 .release = usb_release_dev, 390 .uevent = usb_dev_uevent, 391 .devnode = usb_devnode, 392 #ifdef CONFIG_PM 393 .pm = &usb_device_pm_ops, 394 #endif 395 }; 396 397 398 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */ 399 static unsigned usb_bus_is_wusb(struct usb_bus *bus) 400 { 401 struct usb_hcd *hcd = bus_to_hcd(bus); 402 return hcd->wireless; 403 } 404 405 406 /** 407 * usb_alloc_dev - usb device constructor (usbcore-internal) 408 * @parent: hub to which device is connected; null to allocate a root hub 409 * @bus: bus used to access the device 410 * @port1: one-based index of port; ignored for root hubs 411 * Context: !in_interrupt() 412 * 413 * Only hub drivers (including virtual root hub drivers for host 414 * controllers) should ever call this. 415 * 416 * This call may not be used in a non-sleeping context. 417 * 418 * Return: On success, a pointer to the allocated usb device. %NULL on 419 * failure. 420 */ 421 struct usb_device *usb_alloc_dev(struct usb_device *parent, 422 struct usb_bus *bus, unsigned port1) 423 { 424 struct usb_device *dev; 425 struct usb_hcd *usb_hcd = bus_to_hcd(bus); 426 unsigned root_hub = 0; 427 unsigned raw_port = port1; 428 429 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 430 if (!dev) 431 return NULL; 432 433 if (!usb_get_hcd(usb_hcd)) { 434 kfree(dev); 435 return NULL; 436 } 437 /* Root hubs aren't true devices, so don't allocate HCD resources */ 438 if (usb_hcd->driver->alloc_dev && parent && 439 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) { 440 usb_put_hcd(bus_to_hcd(bus)); 441 kfree(dev); 442 return NULL; 443 } 444 445 device_initialize(&dev->dev); 446 dev->dev.bus = &usb_bus_type; 447 dev->dev.type = &usb_device_type; 448 dev->dev.groups = usb_device_groups; 449 dev->dev.dma_mask = bus->controller->dma_mask; 450 set_dev_node(&dev->dev, dev_to_node(bus->controller)); 451 dev->state = USB_STATE_ATTACHED; 452 dev->lpm_disable_count = 1; 453 atomic_set(&dev->urbnum, 0); 454 455 INIT_LIST_HEAD(&dev->ep0.urb_list); 456 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 457 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 458 /* ep0 maxpacket comes later, from device descriptor */ 459 usb_enable_endpoint(dev, &dev->ep0, false); 460 dev->can_submit = 1; 461 462 /* Save readable and stable topology id, distinguishing devices 463 * by location for diagnostics, tools, driver model, etc. The 464 * string is a path along hub ports, from the root. Each device's 465 * dev->devpath will be stable until USB is re-cabled, and hubs 466 * are often labeled with these port numbers. The name isn't 467 * as stable: bus->busnum changes easily from modprobe order, 468 * cardbus or pci hotplugging, and so on. 469 */ 470 if (unlikely(!parent)) { 471 dev->devpath[0] = '0'; 472 dev->route = 0; 473 474 dev->dev.parent = bus->controller; 475 dev->dev.of_node = bus->controller->of_node; 476 dev_set_name(&dev->dev, "usb%d", bus->busnum); 477 root_hub = 1; 478 } else { 479 /* match any labeling on the hubs; it's one-based */ 480 if (parent->devpath[0] == '0') { 481 snprintf(dev->devpath, sizeof dev->devpath, 482 "%d", port1); 483 /* Root ports are not counted in route string */ 484 dev->route = 0; 485 } else { 486 snprintf(dev->devpath, sizeof dev->devpath, 487 "%s.%d", parent->devpath, port1); 488 /* Route string assumes hubs have less than 16 ports */ 489 if (port1 < 15) 490 dev->route = parent->route + 491 (port1 << ((parent->level - 1)*4)); 492 else 493 dev->route = parent->route + 494 (15 << ((parent->level - 1)*4)); 495 } 496 497 dev->dev.parent = &parent->dev; 498 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath); 499 500 if (!parent->parent) { 501 /* device under root hub's port */ 502 raw_port = usb_hcd_find_raw_port_number(usb_hcd, 503 port1); 504 } 505 dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node, 506 raw_port); 507 508 /* hub driver sets up TT records */ 509 } 510 511 dev->portnum = port1; 512 dev->bus = bus; 513 dev->parent = parent; 514 INIT_LIST_HEAD(&dev->filelist); 515 516 #ifdef CONFIG_PM 517 pm_runtime_set_autosuspend_delay(&dev->dev, 518 usb_autosuspend_delay * 1000); 519 dev->connect_time = jiffies; 520 dev->active_duration = -jiffies; 521 #endif 522 if (root_hub) /* Root hub always ok [and always wired] */ 523 dev->authorized = 1; 524 else { 525 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd); 526 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0; 527 } 528 return dev; 529 } 530 EXPORT_SYMBOL_GPL(usb_alloc_dev); 531 532 /** 533 * usb_get_dev - increments the reference count of the usb device structure 534 * @dev: the device being referenced 535 * 536 * Each live reference to a device should be refcounted. 537 * 538 * Drivers for USB interfaces should normally record such references in 539 * their probe() methods, when they bind to an interface, and release 540 * them by calling usb_put_dev(), in their disconnect() methods. 541 * 542 * Return: A pointer to the device with the incremented reference counter. 543 */ 544 struct usb_device *usb_get_dev(struct usb_device *dev) 545 { 546 if (dev) 547 get_device(&dev->dev); 548 return dev; 549 } 550 EXPORT_SYMBOL_GPL(usb_get_dev); 551 552 /** 553 * usb_put_dev - release a use of the usb device structure 554 * @dev: device that's been disconnected 555 * 556 * Must be called when a user of a device is finished with it. When the last 557 * user of the device calls this function, the memory of the device is freed. 558 */ 559 void usb_put_dev(struct usb_device *dev) 560 { 561 if (dev) 562 put_device(&dev->dev); 563 } 564 EXPORT_SYMBOL_GPL(usb_put_dev); 565 566 /** 567 * usb_get_intf - increments the reference count of the usb interface structure 568 * @intf: the interface being referenced 569 * 570 * Each live reference to a interface must be refcounted. 571 * 572 * Drivers for USB interfaces should normally record such references in 573 * their probe() methods, when they bind to an interface, and release 574 * them by calling usb_put_intf(), in their disconnect() methods. 575 * 576 * Return: A pointer to the interface with the incremented reference counter. 577 */ 578 struct usb_interface *usb_get_intf(struct usb_interface *intf) 579 { 580 if (intf) 581 get_device(&intf->dev); 582 return intf; 583 } 584 EXPORT_SYMBOL_GPL(usb_get_intf); 585 586 /** 587 * usb_put_intf - release a use of the usb interface structure 588 * @intf: interface that's been decremented 589 * 590 * Must be called when a user of an interface is finished with it. When the 591 * last user of the interface calls this function, the memory of the interface 592 * is freed. 593 */ 594 void usb_put_intf(struct usb_interface *intf) 595 { 596 if (intf) 597 put_device(&intf->dev); 598 } 599 EXPORT_SYMBOL_GPL(usb_put_intf); 600 601 /* USB device locking 602 * 603 * USB devices and interfaces are locked using the semaphore in their 604 * embedded struct device. The hub driver guarantees that whenever a 605 * device is connected or disconnected, drivers are called with the 606 * USB device locked as well as their particular interface. 607 * 608 * Complications arise when several devices are to be locked at the same 609 * time. Only hub-aware drivers that are part of usbcore ever have to 610 * do this; nobody else needs to worry about it. The rule for locking 611 * is simple: 612 * 613 * When locking both a device and its parent, always lock the 614 * the parent first. 615 */ 616 617 /** 618 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure 619 * @udev: device that's being locked 620 * @iface: interface bound to the driver making the request (optional) 621 * 622 * Attempts to acquire the device lock, but fails if the device is 623 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 624 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 625 * lock, the routine polls repeatedly. This is to prevent deadlock with 626 * disconnect; in some drivers (such as usb-storage) the disconnect() 627 * or suspend() method will block waiting for a device reset to complete. 628 * 629 * Return: A negative error code for failure, otherwise 0. 630 */ 631 int usb_lock_device_for_reset(struct usb_device *udev, 632 const struct usb_interface *iface) 633 { 634 unsigned long jiffies_expire = jiffies + HZ; 635 636 if (udev->state == USB_STATE_NOTATTACHED) 637 return -ENODEV; 638 if (udev->state == USB_STATE_SUSPENDED) 639 return -EHOSTUNREACH; 640 if (iface && (iface->condition == USB_INTERFACE_UNBINDING || 641 iface->condition == USB_INTERFACE_UNBOUND)) 642 return -EINTR; 643 644 while (!usb_trylock_device(udev)) { 645 646 /* If we can't acquire the lock after waiting one second, 647 * we're probably deadlocked */ 648 if (time_after(jiffies, jiffies_expire)) 649 return -EBUSY; 650 651 msleep(15); 652 if (udev->state == USB_STATE_NOTATTACHED) 653 return -ENODEV; 654 if (udev->state == USB_STATE_SUSPENDED) 655 return -EHOSTUNREACH; 656 if (iface && (iface->condition == USB_INTERFACE_UNBINDING || 657 iface->condition == USB_INTERFACE_UNBOUND)) 658 return -EINTR; 659 } 660 return 0; 661 } 662 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); 663 664 /** 665 * usb_get_current_frame_number - return current bus frame number 666 * @dev: the device whose bus is being queried 667 * 668 * Return: The current frame number for the USB host controller used 669 * with the given USB device. This can be used when scheduling 670 * isochronous requests. 671 * 672 * Note: Different kinds of host controller have different "scheduling 673 * horizons". While one type might support scheduling only 32 frames 674 * into the future, others could support scheduling up to 1024 frames 675 * into the future. 676 * 677 */ 678 int usb_get_current_frame_number(struct usb_device *dev) 679 { 680 return usb_hcd_get_frame_number(dev); 681 } 682 EXPORT_SYMBOL_GPL(usb_get_current_frame_number); 683 684 /*-------------------------------------------------------------------*/ 685 /* 686 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 687 * extra field of the interface and endpoint descriptor structs. 688 */ 689 690 int __usb_get_extra_descriptor(char *buffer, unsigned size, 691 unsigned char type, void **ptr) 692 { 693 struct usb_descriptor_header *header; 694 695 while (size >= sizeof(struct usb_descriptor_header)) { 696 header = (struct usb_descriptor_header *)buffer; 697 698 if (header->bLength < 2) { 699 printk(KERN_ERR 700 "%s: bogus descriptor, type %d length %d\n", 701 usbcore_name, 702 header->bDescriptorType, 703 header->bLength); 704 return -1; 705 } 706 707 if (header->bDescriptorType == type) { 708 *ptr = header; 709 return 0; 710 } 711 712 buffer += header->bLength; 713 size -= header->bLength; 714 } 715 return -1; 716 } 717 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); 718 719 /** 720 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 721 * @dev: device the buffer will be used with 722 * @size: requested buffer size 723 * @mem_flags: affect whether allocation may block 724 * @dma: used to return DMA address of buffer 725 * 726 * Return: Either null (indicating no buffer could be allocated), or the 727 * cpu-space pointer to a buffer that may be used to perform DMA to the 728 * specified device. Such cpu-space buffers are returned along with the DMA 729 * address (through the pointer provided). 730 * 731 * Note: 732 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 733 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 734 * hardware during URB completion/resubmit. The implementation varies between 735 * platforms, depending on details of how DMA will work to this device. 736 * Using these buffers also eliminates cacheline sharing problems on 737 * architectures where CPU caches are not DMA-coherent. On systems without 738 * bus-snooping caches, these buffers are uncached. 739 * 740 * When the buffer is no longer used, free it with usb_free_coherent(). 741 */ 742 void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags, 743 dma_addr_t *dma) 744 { 745 if (!dev || !dev->bus) 746 return NULL; 747 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 748 } 749 EXPORT_SYMBOL_GPL(usb_alloc_coherent); 750 751 /** 752 * usb_free_coherent - free memory allocated with usb_alloc_coherent() 753 * @dev: device the buffer was used with 754 * @size: requested buffer size 755 * @addr: CPU address of buffer 756 * @dma: DMA address of buffer 757 * 758 * This reclaims an I/O buffer, letting it be reused. The memory must have 759 * been allocated using usb_alloc_coherent(), and the parameters must match 760 * those provided in that allocation request. 761 */ 762 void usb_free_coherent(struct usb_device *dev, size_t size, void *addr, 763 dma_addr_t dma) 764 { 765 if (!dev || !dev->bus) 766 return; 767 if (!addr) 768 return; 769 hcd_buffer_free(dev->bus, size, addr, dma); 770 } 771 EXPORT_SYMBOL_GPL(usb_free_coherent); 772 773 /** 774 * usb_buffer_map - create DMA mapping(s) for an urb 775 * @urb: urb whose transfer_buffer/setup_packet will be mapped 776 * 777 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation 778 * succeeds. If the device is connected to this system through a non-DMA 779 * controller, this operation always succeeds. 780 * 781 * This call would normally be used for an urb which is reused, perhaps 782 * as the target of a large periodic transfer, with usb_buffer_dmasync() 783 * calls to synchronize memory and dma state. 784 * 785 * Reverse the effect of this call with usb_buffer_unmap(). 786 * 787 * Return: Either %NULL (indicating no buffer could be mapped), or @urb. 788 * 789 */ 790 #if 0 791 struct urb *usb_buffer_map(struct urb *urb) 792 { 793 struct usb_bus *bus; 794 struct device *controller; 795 796 if (!urb 797 || !urb->dev 798 || !(bus = urb->dev->bus) 799 || !(controller = bus->controller)) 800 return NULL; 801 802 if (controller->dma_mask) { 803 urb->transfer_dma = dma_map_single(controller, 804 urb->transfer_buffer, urb->transfer_buffer_length, 805 usb_pipein(urb->pipe) 806 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 807 /* FIXME generic api broken like pci, can't report errors */ 808 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */ 809 } else 810 urb->transfer_dma = ~0; 811 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 812 return urb; 813 } 814 EXPORT_SYMBOL_GPL(usb_buffer_map); 815 #endif /* 0 */ 816 817 /* XXX DISABLED, no users currently. If you wish to re-enable this 818 * XXX please determine whether the sync is to transfer ownership of 819 * XXX the buffer from device to cpu or vice verse, and thusly use the 820 * XXX appropriate _for_{cpu,device}() method. -DaveM 821 */ 822 #if 0 823 824 /** 825 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 826 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 827 */ 828 void usb_buffer_dmasync(struct urb *urb) 829 { 830 struct usb_bus *bus; 831 struct device *controller; 832 833 if (!urb 834 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 835 || !urb->dev 836 || !(bus = urb->dev->bus) 837 || !(controller = bus->controller)) 838 return; 839 840 if (controller->dma_mask) { 841 dma_sync_single_for_cpu(controller, 842 urb->transfer_dma, urb->transfer_buffer_length, 843 usb_pipein(urb->pipe) 844 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 845 if (usb_pipecontrol(urb->pipe)) 846 dma_sync_single_for_cpu(controller, 847 urb->setup_dma, 848 sizeof(struct usb_ctrlrequest), 849 DMA_TO_DEVICE); 850 } 851 } 852 EXPORT_SYMBOL_GPL(usb_buffer_dmasync); 853 #endif 854 855 /** 856 * usb_buffer_unmap - free DMA mapping(s) for an urb 857 * @urb: urb whose transfer_buffer will be unmapped 858 * 859 * Reverses the effect of usb_buffer_map(). 860 */ 861 #if 0 862 void usb_buffer_unmap(struct urb *urb) 863 { 864 struct usb_bus *bus; 865 struct device *controller; 866 867 if (!urb 868 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 869 || !urb->dev 870 || !(bus = urb->dev->bus) 871 || !(controller = bus->controller)) 872 return; 873 874 if (controller->dma_mask) { 875 dma_unmap_single(controller, 876 urb->transfer_dma, urb->transfer_buffer_length, 877 usb_pipein(urb->pipe) 878 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 879 } 880 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP; 881 } 882 EXPORT_SYMBOL_GPL(usb_buffer_unmap); 883 #endif /* 0 */ 884 885 #if 0 886 /** 887 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 888 * @dev: device to which the scatterlist will be mapped 889 * @is_in: mapping transfer direction 890 * @sg: the scatterlist to map 891 * @nents: the number of entries in the scatterlist 892 * 893 * Return: Either < 0 (indicating no buffers could be mapped), or the 894 * number of DMA mapping array entries in the scatterlist. 895 * 896 * Note: 897 * The caller is responsible for placing the resulting DMA addresses from 898 * the scatterlist into URB transfer buffer pointers, and for setting the 899 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 900 * 901 * Top I/O rates come from queuing URBs, instead of waiting for each one 902 * to complete before starting the next I/O. This is particularly easy 903 * to do with scatterlists. Just allocate and submit one URB for each DMA 904 * mapping entry returned, stopping on the first error or when all succeed. 905 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 906 * 907 * This call would normally be used when translating scatterlist requests, 908 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 909 * may be able to coalesce mappings for improved I/O efficiency. 910 * 911 * Reverse the effect of this call with usb_buffer_unmap_sg(). 912 */ 913 int usb_buffer_map_sg(const struct usb_device *dev, int is_in, 914 struct scatterlist *sg, int nents) 915 { 916 struct usb_bus *bus; 917 struct device *controller; 918 919 if (!dev 920 || !(bus = dev->bus) 921 || !(controller = bus->controller) 922 || !controller->dma_mask) 923 return -EINVAL; 924 925 /* FIXME generic api broken like pci, can't report errors */ 926 return dma_map_sg(controller, sg, nents, 927 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM; 928 } 929 EXPORT_SYMBOL_GPL(usb_buffer_map_sg); 930 #endif 931 932 /* XXX DISABLED, no users currently. If you wish to re-enable this 933 * XXX please determine whether the sync is to transfer ownership of 934 * XXX the buffer from device to cpu or vice verse, and thusly use the 935 * XXX appropriate _for_{cpu,device}() method. -DaveM 936 */ 937 #if 0 938 939 /** 940 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 941 * @dev: device to which the scatterlist will be mapped 942 * @is_in: mapping transfer direction 943 * @sg: the scatterlist to synchronize 944 * @n_hw_ents: the positive return value from usb_buffer_map_sg 945 * 946 * Use this when you are re-using a scatterlist's data buffers for 947 * another USB request. 948 */ 949 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, 950 struct scatterlist *sg, int n_hw_ents) 951 { 952 struct usb_bus *bus; 953 struct device *controller; 954 955 if (!dev 956 || !(bus = dev->bus) 957 || !(controller = bus->controller) 958 || !controller->dma_mask) 959 return; 960 961 dma_sync_sg_for_cpu(controller, sg, n_hw_ents, 962 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 963 } 964 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); 965 #endif 966 967 #if 0 968 /** 969 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 970 * @dev: device to which the scatterlist will be mapped 971 * @is_in: mapping transfer direction 972 * @sg: the scatterlist to unmap 973 * @n_hw_ents: the positive return value from usb_buffer_map_sg 974 * 975 * Reverses the effect of usb_buffer_map_sg(). 976 */ 977 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, 978 struct scatterlist *sg, int n_hw_ents) 979 { 980 struct usb_bus *bus; 981 struct device *controller; 982 983 if (!dev 984 || !(bus = dev->bus) 985 || !(controller = bus->controller) 986 || !controller->dma_mask) 987 return; 988 989 dma_unmap_sg(controller, sg, n_hw_ents, 990 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 991 } 992 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); 993 #endif 994 995 /* 996 * Notifications of device and interface registration 997 */ 998 static int usb_bus_notify(struct notifier_block *nb, unsigned long action, 999 void *data) 1000 { 1001 struct device *dev = data; 1002 1003 switch (action) { 1004 case BUS_NOTIFY_ADD_DEVICE: 1005 if (dev->type == &usb_device_type) 1006 (void) usb_create_sysfs_dev_files(to_usb_device(dev)); 1007 else if (dev->type == &usb_if_device_type) 1008 usb_create_sysfs_intf_files(to_usb_interface(dev)); 1009 break; 1010 1011 case BUS_NOTIFY_DEL_DEVICE: 1012 if (dev->type == &usb_device_type) 1013 usb_remove_sysfs_dev_files(to_usb_device(dev)); 1014 else if (dev->type == &usb_if_device_type) 1015 usb_remove_sysfs_intf_files(to_usb_interface(dev)); 1016 break; 1017 } 1018 return 0; 1019 } 1020 1021 static struct notifier_block usb_bus_nb = { 1022 .notifier_call = usb_bus_notify, 1023 }; 1024 1025 struct dentry *usb_debug_root; 1026 EXPORT_SYMBOL_GPL(usb_debug_root); 1027 1028 static struct dentry *usb_debug_devices; 1029 1030 static int usb_debugfs_init(void) 1031 { 1032 usb_debug_root = debugfs_create_dir("usb", NULL); 1033 if (!usb_debug_root) 1034 return -ENOENT; 1035 1036 usb_debug_devices = debugfs_create_file("devices", 0444, 1037 usb_debug_root, NULL, 1038 &usbfs_devices_fops); 1039 if (!usb_debug_devices) { 1040 debugfs_remove(usb_debug_root); 1041 usb_debug_root = NULL; 1042 return -ENOENT; 1043 } 1044 1045 return 0; 1046 } 1047 1048 static void usb_debugfs_cleanup(void) 1049 { 1050 debugfs_remove(usb_debug_devices); 1051 debugfs_remove(usb_debug_root); 1052 } 1053 1054 /* 1055 * Init 1056 */ 1057 static int __init usb_init(void) 1058 { 1059 int retval; 1060 if (usb_disabled()) { 1061 pr_info("%s: USB support disabled\n", usbcore_name); 1062 return 0; 1063 } 1064 usb_init_pool_max(); 1065 1066 retval = usb_debugfs_init(); 1067 if (retval) 1068 goto out; 1069 1070 usb_acpi_register(); 1071 retval = bus_register(&usb_bus_type); 1072 if (retval) 1073 goto bus_register_failed; 1074 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb); 1075 if (retval) 1076 goto bus_notifier_failed; 1077 retval = usb_major_init(); 1078 if (retval) 1079 goto major_init_failed; 1080 retval = usb_register(&usbfs_driver); 1081 if (retval) 1082 goto driver_register_failed; 1083 retval = usb_devio_init(); 1084 if (retval) 1085 goto usb_devio_init_failed; 1086 retval = usb_hub_init(); 1087 if (retval) 1088 goto hub_init_failed; 1089 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 1090 if (!retval) 1091 goto out; 1092 1093 usb_hub_cleanup(); 1094 hub_init_failed: 1095 usb_devio_cleanup(); 1096 usb_devio_init_failed: 1097 usb_deregister(&usbfs_driver); 1098 driver_register_failed: 1099 usb_major_cleanup(); 1100 major_init_failed: 1101 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); 1102 bus_notifier_failed: 1103 bus_unregister(&usb_bus_type); 1104 bus_register_failed: 1105 usb_acpi_unregister(); 1106 usb_debugfs_cleanup(); 1107 out: 1108 return retval; 1109 } 1110 1111 /* 1112 * Cleanup 1113 */ 1114 static void __exit usb_exit(void) 1115 { 1116 /* This will matter if shutdown/reboot does exitcalls. */ 1117 if (usb_disabled()) 1118 return; 1119 1120 usb_deregister_device_driver(&usb_generic_driver); 1121 usb_major_cleanup(); 1122 usb_deregister(&usbfs_driver); 1123 usb_devio_cleanup(); 1124 usb_hub_cleanup(); 1125 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb); 1126 bus_unregister(&usb_bus_type); 1127 usb_acpi_unregister(); 1128 usb_debugfs_cleanup(); 1129 idr_destroy(&usb_bus_idr); 1130 } 1131 1132 subsys_initcall(usb_init); 1133 module_exit(usb_exit); 1134 MODULE_LICENSE("GPL"); 1135