usb.c revision 2e5f10e4f0a9649186d8a8c793822b2e0dae8373
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/mutex.h> 36#include <linux/workqueue.h> 37 38#include <asm/io.h> 39#include <linux/scatterlist.h> 40#include <linux/mm.h> 41#include <linux/dma-mapping.h> 42 43#include "hcd.h" 44#include "usb.h" 45 46 47const char *usbcore_name = "usbcore"; 48 49static int nousb; /* Disable USB when built into kernel image */ 50 51/* Workqueue for autosuspend and for remote wakeup of root hubs */ 52struct workqueue_struct *ksuspend_usb_wq; 53 54#ifdef CONFIG_USB_SUSPEND 55static int usb_autosuspend_delay = 2; /* Default delay value, 56 * in seconds */ 57module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); 58MODULE_PARM_DESC(autosuspend, "default autosuspend delay"); 59 60#else 61#define usb_autosuspend_delay 0 62#endif 63 64 65/** 66 * usb_ifnum_to_if - get the interface object with a given interface number 67 * @dev: the device whose current configuration is considered 68 * @ifnum: the desired interface 69 * 70 * This walks the device descriptor for the currently active configuration 71 * and returns a pointer to the interface with that particular interface 72 * number, or null. 73 * 74 * Note that configuration descriptors are not required to assign interface 75 * numbers sequentially, so that it would be incorrect to assume that 76 * the first interface in that descriptor corresponds to interface zero. 77 * This routine helps device drivers avoid such mistakes. 78 * However, you should make sure that you do the right thing with any 79 * alternate settings available for this interfaces. 80 * 81 * Don't call this function unless you are bound to one of the interfaces 82 * on this device or you have locked the device! 83 */ 84struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev, 85 unsigned ifnum) 86{ 87 struct usb_host_config *config = dev->actconfig; 88 int i; 89 90 if (!config) 91 return NULL; 92 for (i = 0; i < config->desc.bNumInterfaces; i++) 93 if (config->interface[i]->altsetting[0] 94 .desc.bInterfaceNumber == ifnum) 95 return config->interface[i]; 96 97 return NULL; 98} 99EXPORT_SYMBOL_GPL(usb_ifnum_to_if); 100 101/** 102 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number. 103 * @intf: the interface containing the altsetting in question 104 * @altnum: the desired alternate setting number 105 * 106 * This searches the altsetting array of the specified interface for 107 * an entry with the correct bAlternateSetting value and returns a pointer 108 * to that entry, or null. 109 * 110 * Note that altsettings need not be stored sequentially by number, so 111 * it would be incorrect to assume that the first altsetting entry in 112 * the array corresponds to altsetting zero. This routine helps device 113 * drivers avoid such mistakes. 114 * 115 * Don't call this function unless you are bound to the intf interface 116 * or you have locked the device! 117 */ 118struct usb_host_interface *usb_altnum_to_altsetting( 119 const struct usb_interface *intf, 120 unsigned int altnum) 121{ 122 int i; 123 124 for (i = 0; i < intf->num_altsetting; i++) { 125 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 126 return &intf->altsetting[i]; 127 } 128 return NULL; 129} 130EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); 131 132struct find_interface_arg { 133 int minor; 134 struct usb_interface *interface; 135}; 136 137static int __find_interface(struct device *dev, void *data) 138{ 139 struct find_interface_arg *arg = data; 140 struct usb_interface *intf; 141 142 /* can't look at usb devices, only interfaces */ 143 if (is_usb_device(dev)) 144 return 0; 145 146 intf = to_usb_interface(dev); 147 if (intf->minor != -1 && intf->minor == arg->minor) { 148 arg->interface = intf; 149 return 1; 150 } 151 return 0; 152} 153 154/** 155 * usb_find_interface - find usb_interface pointer for driver and device 156 * @drv: the driver whose current configuration is considered 157 * @minor: the minor number of the desired device 158 * 159 * This walks the driver device list and returns a pointer to the interface 160 * with the matching minor. Note, this only works for devices that share the 161 * USB major number. 162 */ 163struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 164{ 165 struct find_interface_arg argb; 166 int retval; 167 168 argb.minor = minor; 169 argb.interface = NULL; 170 /* eat the error, it will be in argb.interface */ 171 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb, 172 __find_interface); 173 return argb.interface; 174} 175EXPORT_SYMBOL_GPL(usb_find_interface); 176 177/** 178 * usb_release_dev - free a usb device structure when all users of it are finished. 179 * @dev: device that's been disconnected 180 * 181 * Will be called only by the device core when all users of this usb device are 182 * done. 183 */ 184static void usb_release_dev(struct device *dev) 185{ 186 struct usb_device *udev; 187 188 udev = to_usb_device(dev); 189 190 usb_destroy_configuration(udev); 191 usb_put_hcd(bus_to_hcd(udev->bus)); 192 kfree(udev->product); 193 kfree(udev->manufacturer); 194 kfree(udev->serial); 195 kfree(udev); 196} 197 198#ifdef CONFIG_HOTPLUG 199static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 200{ 201 struct usb_device *usb_dev; 202 203 usb_dev = to_usb_device(dev); 204 205 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) 206 return -ENOMEM; 207 208 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) 209 return -ENOMEM; 210 211 return 0; 212} 213 214#else 215 216static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 217{ 218 return -ENODEV; 219} 220#endif /* CONFIG_HOTPLUG */ 221 222struct device_type usb_device_type = { 223 .name = "usb_device", 224 .release = usb_release_dev, 225 .uevent = usb_dev_uevent, 226}; 227 228#ifdef CONFIG_PM 229 230static int ksuspend_usb_init(void) 231{ 232 /* This workqueue is supposed to be both freezable and 233 * singlethreaded. Its job doesn't justify running on more 234 * than one CPU. 235 */ 236 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd"); 237 if (!ksuspend_usb_wq) 238 return -ENOMEM; 239 return 0; 240} 241 242static void ksuspend_usb_cleanup(void) 243{ 244 destroy_workqueue(ksuspend_usb_wq); 245} 246 247#else 248 249#define ksuspend_usb_init() 0 250#define ksuspend_usb_cleanup() do {} while (0) 251 252#endif /* CONFIG_PM */ 253 254 255/* Returns 1 if @usb_bus is WUSB, 0 otherwise */ 256static unsigned usb_bus_is_wusb(struct usb_bus *bus) 257{ 258 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self); 259 return hcd->wireless; 260} 261 262 263/** 264 * usb_alloc_dev - usb device constructor (usbcore-internal) 265 * @parent: hub to which device is connected; null to allocate a root hub 266 * @bus: bus used to access the device 267 * @port1: one-based index of port; ignored for root hubs 268 * Context: !in_interrupt() 269 * 270 * Only hub drivers (including virtual root hub drivers for host 271 * controllers) should ever call this. 272 * 273 * This call may not be used in a non-sleeping context. 274 */ 275struct usb_device *usb_alloc_dev(struct usb_device *parent, 276 struct usb_bus *bus, unsigned port1) 277{ 278 struct usb_device *dev; 279 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self); 280 unsigned root_hub = 0; 281 282 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 283 if (!dev) 284 return NULL; 285 286 if (!usb_get_hcd(bus_to_hcd(bus))) { 287 kfree(dev); 288 return NULL; 289 } 290 291 device_initialize(&dev->dev); 292 dev->dev.bus = &usb_bus_type; 293 dev->dev.type = &usb_device_type; 294 dev->dev.groups = usb_device_groups; 295 dev->dev.dma_mask = bus->controller->dma_mask; 296 set_dev_node(&dev->dev, dev_to_node(bus->controller)); 297 dev->state = USB_STATE_ATTACHED; 298 atomic_set(&dev->urbnum, 0); 299 300 INIT_LIST_HEAD(&dev->ep0.urb_list); 301 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 302 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 303 /* ep0 maxpacket comes later, from device descriptor */ 304 usb_enable_endpoint(dev, &dev->ep0); 305 dev->can_submit = 1; 306 307 /* Save readable and stable topology id, distinguishing devices 308 * by location for diagnostics, tools, driver model, etc. The 309 * string is a path along hub ports, from the root. Each device's 310 * dev->devpath will be stable until USB is re-cabled, and hubs 311 * are often labeled with these port numbers. The bus_id isn't 312 * as stable: bus->busnum changes easily from modprobe order, 313 * cardbus or pci hotplugging, and so on. 314 */ 315 if (unlikely(!parent)) { 316 dev->devpath[0] = '0'; 317 318 dev->dev.parent = bus->controller; 319 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum); 320 root_hub = 1; 321 } else { 322 /* match any labeling on the hubs; it's one-based */ 323 if (parent->devpath[0] == '0') 324 snprintf(dev->devpath, sizeof dev->devpath, 325 "%d", port1); 326 else 327 snprintf(dev->devpath, sizeof dev->devpath, 328 "%s.%d", parent->devpath, port1); 329 330 dev->dev.parent = &parent->dev; 331 sprintf(&dev->dev.bus_id[0], "%d-%s", 332 bus->busnum, dev->devpath); 333 334 /* hub driver sets up TT records */ 335 } 336 337 dev->portnum = port1; 338 dev->bus = bus; 339 dev->parent = parent; 340 INIT_LIST_HEAD(&dev->filelist); 341 342#ifdef CONFIG_PM 343 mutex_init(&dev->pm_mutex); 344 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work); 345 dev->autosuspend_delay = usb_autosuspend_delay * HZ; 346 dev->connect_time = jiffies; 347 dev->active_duration = -jiffies; 348#endif 349 if (root_hub) /* Root hub always ok [and always wired] */ 350 dev->authorized = 1; 351 else { 352 dev->authorized = usb_hcd->authorized_default; 353 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0; 354 } 355 return dev; 356} 357 358/** 359 * usb_get_dev - increments the reference count of the usb device structure 360 * @dev: the device being referenced 361 * 362 * Each live reference to a device should be refcounted. 363 * 364 * Drivers for USB interfaces should normally record such references in 365 * their probe() methods, when they bind to an interface, and release 366 * them by calling usb_put_dev(), in their disconnect() methods. 367 * 368 * A pointer to the device with the incremented reference counter is returned. 369 */ 370struct usb_device *usb_get_dev(struct usb_device *dev) 371{ 372 if (dev) 373 get_device(&dev->dev); 374 return dev; 375} 376EXPORT_SYMBOL_GPL(usb_get_dev); 377 378/** 379 * usb_put_dev - release a use of the usb device structure 380 * @dev: device that's been disconnected 381 * 382 * Must be called when a user of a device is finished with it. When the last 383 * user of the device calls this function, the memory of the device is freed. 384 */ 385void usb_put_dev(struct usb_device *dev) 386{ 387 if (dev) 388 put_device(&dev->dev); 389} 390EXPORT_SYMBOL_GPL(usb_put_dev); 391 392/** 393 * usb_get_intf - increments the reference count of the usb interface structure 394 * @intf: the interface being referenced 395 * 396 * Each live reference to a interface must be refcounted. 397 * 398 * Drivers for USB interfaces should normally record such references in 399 * their probe() methods, when they bind to an interface, and release 400 * them by calling usb_put_intf(), in their disconnect() methods. 401 * 402 * A pointer to the interface with the incremented reference counter is 403 * returned. 404 */ 405struct usb_interface *usb_get_intf(struct usb_interface *intf) 406{ 407 if (intf) 408 get_device(&intf->dev); 409 return intf; 410} 411EXPORT_SYMBOL_GPL(usb_get_intf); 412 413/** 414 * usb_put_intf - release a use of the usb interface structure 415 * @intf: interface that's been decremented 416 * 417 * Must be called when a user of an interface is finished with it. When the 418 * last user of the interface calls this function, the memory of the interface 419 * is freed. 420 */ 421void usb_put_intf(struct usb_interface *intf) 422{ 423 if (intf) 424 put_device(&intf->dev); 425} 426EXPORT_SYMBOL_GPL(usb_put_intf); 427 428/* USB device locking 429 * 430 * USB devices and interfaces are locked using the semaphore in their 431 * embedded struct device. The hub driver guarantees that whenever a 432 * device is connected or disconnected, drivers are called with the 433 * USB device locked as well as their particular interface. 434 * 435 * Complications arise when several devices are to be locked at the same 436 * time. Only hub-aware drivers that are part of usbcore ever have to 437 * do this; nobody else needs to worry about it. The rule for locking 438 * is simple: 439 * 440 * When locking both a device and its parent, always lock the 441 * the parent first. 442 */ 443 444/** 445 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure 446 * @udev: device that's being locked 447 * @iface: interface bound to the driver making the request (optional) 448 * 449 * Attempts to acquire the device lock, but fails if the device is 450 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 451 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 452 * lock, the routine polls repeatedly. This is to prevent deadlock with 453 * disconnect; in some drivers (such as usb-storage) the disconnect() 454 * or suspend() method will block waiting for a device reset to complete. 455 * 456 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 457 * that the device will or will not have to be unlocked. (0 can be 458 * returned when an interface is given and is BINDING, because in that 459 * case the driver already owns the device lock.) 460 */ 461int usb_lock_device_for_reset(struct usb_device *udev, 462 const struct usb_interface *iface) 463{ 464 unsigned long jiffies_expire = jiffies + HZ; 465 466 if (udev->state == USB_STATE_NOTATTACHED) 467 return -ENODEV; 468 if (udev->state == USB_STATE_SUSPENDED) 469 return -EHOSTUNREACH; 470 if (iface) { 471 switch (iface->condition) { 472 case USB_INTERFACE_BINDING: 473 return 0; 474 case USB_INTERFACE_BOUND: 475 break; 476 default: 477 return -EINTR; 478 } 479 } 480 481 while (usb_trylock_device(udev) != 0) { 482 483 /* If we can't acquire the lock after waiting one second, 484 * we're probably deadlocked */ 485 if (time_after(jiffies, jiffies_expire)) 486 return -EBUSY; 487 488 msleep(15); 489 if (udev->state == USB_STATE_NOTATTACHED) 490 return -ENODEV; 491 if (udev->state == USB_STATE_SUSPENDED) 492 return -EHOSTUNREACH; 493 if (iface && iface->condition != USB_INTERFACE_BOUND) 494 return -EINTR; 495 } 496 return 1; 497} 498EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); 499 500static struct usb_device *match_device(struct usb_device *dev, 501 u16 vendor_id, u16 product_id) 502{ 503 struct usb_device *ret_dev = NULL; 504 int child; 505 506 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 507 le16_to_cpu(dev->descriptor.idVendor), 508 le16_to_cpu(dev->descriptor.idProduct)); 509 510 /* see if this device matches */ 511 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 512 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 513 dev_dbg(&dev->dev, "matched this device!\n"); 514 ret_dev = usb_get_dev(dev); 515 goto exit; 516 } 517 518 /* look through all of the children of this device */ 519 for (child = 0; child < dev->maxchild; ++child) { 520 if (dev->children[child]) { 521 usb_lock_device(dev->children[child]); 522 ret_dev = match_device(dev->children[child], 523 vendor_id, product_id); 524 usb_unlock_device(dev->children[child]); 525 if (ret_dev) 526 goto exit; 527 } 528 } 529exit: 530 return ret_dev; 531} 532 533/** 534 * usb_find_device - find a specific usb device in the system 535 * @vendor_id: the vendor id of the device to find 536 * @product_id: the product id of the device to find 537 * 538 * Returns a pointer to a struct usb_device if such a specified usb 539 * device is present in the system currently. The usage count of the 540 * device will be incremented if a device is found. Make sure to call 541 * usb_put_dev() when the caller is finished with the device. 542 * 543 * If a device with the specified vendor and product id is not found, 544 * NULL is returned. 545 */ 546struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 547{ 548 struct list_head *buslist; 549 struct usb_bus *bus; 550 struct usb_device *dev = NULL; 551 552 mutex_lock(&usb_bus_list_lock); 553 for (buslist = usb_bus_list.next; 554 buslist != &usb_bus_list; 555 buslist = buslist->next) { 556 bus = container_of(buslist, struct usb_bus, bus_list); 557 if (!bus->root_hub) 558 continue; 559 usb_lock_device(bus->root_hub); 560 dev = match_device(bus->root_hub, vendor_id, product_id); 561 usb_unlock_device(bus->root_hub); 562 if (dev) 563 goto exit; 564 } 565exit: 566 mutex_unlock(&usb_bus_list_lock); 567 return dev; 568} 569 570/** 571 * usb_get_current_frame_number - return current bus frame number 572 * @dev: the device whose bus is being queried 573 * 574 * Returns the current frame number for the USB host controller 575 * used with the given USB device. This can be used when scheduling 576 * isochronous requests. 577 * 578 * Note that different kinds of host controller have different 579 * "scheduling horizons". While one type might support scheduling only 580 * 32 frames into the future, others could support scheduling up to 581 * 1024 frames into the future. 582 */ 583int usb_get_current_frame_number(struct usb_device *dev) 584{ 585 return usb_hcd_get_frame_number(dev); 586} 587EXPORT_SYMBOL_GPL(usb_get_current_frame_number); 588 589/*-------------------------------------------------------------------*/ 590/* 591 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 592 * extra field of the interface and endpoint descriptor structs. 593 */ 594 595int __usb_get_extra_descriptor(char *buffer, unsigned size, 596 unsigned char type, void **ptr) 597{ 598 struct usb_descriptor_header *header; 599 600 while (size >= sizeof(struct usb_descriptor_header)) { 601 header = (struct usb_descriptor_header *)buffer; 602 603 if (header->bLength < 2) { 604 printk(KERN_ERR 605 "%s: bogus descriptor, type %d length %d\n", 606 usbcore_name, 607 header->bDescriptorType, 608 header->bLength); 609 return -1; 610 } 611 612 if (header->bDescriptorType == type) { 613 *ptr = header; 614 return 0; 615 } 616 617 buffer += header->bLength; 618 size -= header->bLength; 619 } 620 return -1; 621} 622EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); 623 624/** 625 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 626 * @dev: device the buffer will be used with 627 * @size: requested buffer size 628 * @mem_flags: affect whether allocation may block 629 * @dma: used to return DMA address of buffer 630 * 631 * Return value is either null (indicating no buffer could be allocated), or 632 * the cpu-space pointer to a buffer that may be used to perform DMA to the 633 * specified device. Such cpu-space buffers are returned along with the DMA 634 * address (through the pointer provided). 635 * 636 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 637 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 638 * hardware during URB completion/resubmit. The implementation varies between 639 * platforms, depending on details of how DMA will work to this device. 640 * Using these buffers also eliminates cacheline sharing problems on 641 * architectures where CPU caches are not DMA-coherent. On systems without 642 * bus-snooping caches, these buffers are uncached. 643 * 644 * When the buffer is no longer used, free it with usb_buffer_free(). 645 */ 646void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags, 647 dma_addr_t *dma) 648{ 649 if (!dev || !dev->bus) 650 return NULL; 651 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 652} 653EXPORT_SYMBOL_GPL(usb_buffer_alloc); 654 655/** 656 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 657 * @dev: device the buffer was used with 658 * @size: requested buffer size 659 * @addr: CPU address of buffer 660 * @dma: DMA address of buffer 661 * 662 * This reclaims an I/O buffer, letting it be reused. The memory must have 663 * been allocated using usb_buffer_alloc(), and the parameters must match 664 * those provided in that allocation request. 665 */ 666void usb_buffer_free(struct usb_device *dev, size_t size, void *addr, 667 dma_addr_t dma) 668{ 669 if (!dev || !dev->bus) 670 return; 671 if (!addr) 672 return; 673 hcd_buffer_free(dev->bus, size, addr, dma); 674} 675EXPORT_SYMBOL_GPL(usb_buffer_free); 676 677/** 678 * usb_buffer_map - create DMA mapping(s) for an urb 679 * @urb: urb whose transfer_buffer/setup_packet will be mapped 680 * 681 * Return value is either null (indicating no buffer could be mapped), or 682 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 683 * added to urb->transfer_flags if the operation succeeds. If the device 684 * is connected to this system through a non-DMA controller, this operation 685 * always succeeds. 686 * 687 * This call would normally be used for an urb which is reused, perhaps 688 * as the target of a large periodic transfer, with usb_buffer_dmasync() 689 * calls to synchronize memory and dma state. 690 * 691 * Reverse the effect of this call with usb_buffer_unmap(). 692 */ 693#if 0 694struct urb *usb_buffer_map(struct urb *urb) 695{ 696 struct usb_bus *bus; 697 struct device *controller; 698 699 if (!urb 700 || !urb->dev 701 || !(bus = urb->dev->bus) 702 || !(controller = bus->controller)) 703 return NULL; 704 705 if (controller->dma_mask) { 706 urb->transfer_dma = dma_map_single(controller, 707 urb->transfer_buffer, urb->transfer_buffer_length, 708 usb_pipein(urb->pipe) 709 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 710 if (usb_pipecontrol(urb->pipe)) 711 urb->setup_dma = dma_map_single(controller, 712 urb->setup_packet, 713 sizeof(struct usb_ctrlrequest), 714 DMA_TO_DEVICE); 715 /* FIXME generic api broken like pci, can't report errors */ 716 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */ 717 } else 718 urb->transfer_dma = ~0; 719 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 720 | URB_NO_SETUP_DMA_MAP); 721 return urb; 722} 723EXPORT_SYMBOL_GPL(usb_buffer_map); 724#endif /* 0 */ 725 726/* XXX DISABLED, no users currently. If you wish to re-enable this 727 * XXX please determine whether the sync is to transfer ownership of 728 * XXX the buffer from device to cpu or vice verse, and thusly use the 729 * XXX appropriate _for_{cpu,device}() method. -DaveM 730 */ 731#if 0 732 733/** 734 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 735 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 736 */ 737void usb_buffer_dmasync(struct urb *urb) 738{ 739 struct usb_bus *bus; 740 struct device *controller; 741 742 if (!urb 743 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 744 || !urb->dev 745 || !(bus = urb->dev->bus) 746 || !(controller = bus->controller)) 747 return; 748 749 if (controller->dma_mask) { 750 dma_sync_single(controller, 751 urb->transfer_dma, urb->transfer_buffer_length, 752 usb_pipein(urb->pipe) 753 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 754 if (usb_pipecontrol(urb->pipe)) 755 dma_sync_single(controller, 756 urb->setup_dma, 757 sizeof(struct usb_ctrlrequest), 758 DMA_TO_DEVICE); 759 } 760} 761EXPORT_SYMBOL_GPL(usb_buffer_dmasync); 762#endif 763 764/** 765 * usb_buffer_unmap - free DMA mapping(s) for an urb 766 * @urb: urb whose transfer_buffer will be unmapped 767 * 768 * Reverses the effect of usb_buffer_map(). 769 */ 770#if 0 771void usb_buffer_unmap(struct urb *urb) 772{ 773 struct usb_bus *bus; 774 struct device *controller; 775 776 if (!urb 777 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 778 || !urb->dev 779 || !(bus = urb->dev->bus) 780 || !(controller = bus->controller)) 781 return; 782 783 if (controller->dma_mask) { 784 dma_unmap_single(controller, 785 urb->transfer_dma, urb->transfer_buffer_length, 786 usb_pipein(urb->pipe) 787 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 788 if (usb_pipecontrol(urb->pipe)) 789 dma_unmap_single(controller, 790 urb->setup_dma, 791 sizeof(struct usb_ctrlrequest), 792 DMA_TO_DEVICE); 793 } 794 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 795 | URB_NO_SETUP_DMA_MAP); 796} 797EXPORT_SYMBOL_GPL(usb_buffer_unmap); 798#endif /* 0 */ 799 800/** 801 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 802 * @dev: device to which the scatterlist will be mapped 803 * @is_in: mapping transfer direction 804 * @sg: the scatterlist to map 805 * @nents: the number of entries in the scatterlist 806 * 807 * Return value is either < 0 (indicating no buffers could be mapped), or 808 * the number of DMA mapping array entries in the scatterlist. 809 * 810 * The caller is responsible for placing the resulting DMA addresses from 811 * the scatterlist into URB transfer buffer pointers, and for setting the 812 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 813 * 814 * Top I/O rates come from queuing URBs, instead of waiting for each one 815 * to complete before starting the next I/O. This is particularly easy 816 * to do with scatterlists. Just allocate and submit one URB for each DMA 817 * mapping entry returned, stopping on the first error or when all succeed. 818 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 819 * 820 * This call would normally be used when translating scatterlist requests, 821 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 822 * may be able to coalesce mappings for improved I/O efficiency. 823 * 824 * Reverse the effect of this call with usb_buffer_unmap_sg(). 825 */ 826int usb_buffer_map_sg(const struct usb_device *dev, int is_in, 827 struct scatterlist *sg, int nents) 828{ 829 struct usb_bus *bus; 830 struct device *controller; 831 832 if (!dev 833 || !(bus = dev->bus) 834 || !(controller = bus->controller) 835 || !controller->dma_mask) 836 return -1; 837 838 /* FIXME generic api broken like pci, can't report errors */ 839 return dma_map_sg(controller, sg, nents, 840 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 841} 842EXPORT_SYMBOL_GPL(usb_buffer_map_sg); 843 844/* XXX DISABLED, no users currently. If you wish to re-enable this 845 * XXX please determine whether the sync is to transfer ownership of 846 * XXX the buffer from device to cpu or vice verse, and thusly use the 847 * XXX appropriate _for_{cpu,device}() method. -DaveM 848 */ 849#if 0 850 851/** 852 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 853 * @dev: device to which the scatterlist will be mapped 854 * @is_in: mapping transfer direction 855 * @sg: the scatterlist to synchronize 856 * @n_hw_ents: the positive return value from usb_buffer_map_sg 857 * 858 * Use this when you are re-using a scatterlist's data buffers for 859 * another USB request. 860 */ 861void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, 862 struct scatterlist *sg, int n_hw_ents) 863{ 864 struct usb_bus *bus; 865 struct device *controller; 866 867 if (!dev 868 || !(bus = dev->bus) 869 || !(controller = bus->controller) 870 || !controller->dma_mask) 871 return; 872 873 dma_sync_sg(controller, sg, n_hw_ents, 874 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 875} 876EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); 877#endif 878 879/** 880 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 881 * @dev: device to which the scatterlist will be mapped 882 * @is_in: mapping transfer direction 883 * @sg: the scatterlist to unmap 884 * @n_hw_ents: the positive return value from usb_buffer_map_sg 885 * 886 * Reverses the effect of usb_buffer_map_sg(). 887 */ 888void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, 889 struct scatterlist *sg, int n_hw_ents) 890{ 891 struct usb_bus *bus; 892 struct device *controller; 893 894 if (!dev 895 || !(bus = dev->bus) 896 || !(controller = bus->controller) 897 || !controller->dma_mask) 898 return; 899 900 dma_unmap_sg(controller, sg, n_hw_ents, 901 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 902} 903EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); 904 905/* format to disable USB on kernel command line is: nousb */ 906__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 907 908/* 909 * for external read access to <nousb> 910 */ 911int usb_disabled(void) 912{ 913 return nousb; 914} 915EXPORT_SYMBOL_GPL(usb_disabled); 916 917/* 918 * Init 919 */ 920static int __init usb_init(void) 921{ 922 int retval; 923 if (nousb) { 924 pr_info("%s: USB support disabled\n", usbcore_name); 925 return 0; 926 } 927 928 retval = ksuspend_usb_init(); 929 if (retval) 930 goto out; 931 retval = bus_register(&usb_bus_type); 932 if (retval) 933 goto bus_register_failed; 934 retval = usb_host_init(); 935 if (retval) 936 goto host_init_failed; 937 retval = usb_major_init(); 938 if (retval) 939 goto major_init_failed; 940 retval = usb_register(&usbfs_driver); 941 if (retval) 942 goto driver_register_failed; 943 retval = usb_devio_init(); 944 if (retval) 945 goto usb_devio_init_failed; 946 retval = usbfs_init(); 947 if (retval) 948 goto fs_init_failed; 949 retval = usb_hub_init(); 950 if (retval) 951 goto hub_init_failed; 952 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 953 if (!retval) 954 goto out; 955 956 usb_hub_cleanup(); 957hub_init_failed: 958 usbfs_cleanup(); 959fs_init_failed: 960 usb_devio_cleanup(); 961usb_devio_init_failed: 962 usb_deregister(&usbfs_driver); 963driver_register_failed: 964 usb_major_cleanup(); 965major_init_failed: 966 usb_host_cleanup(); 967host_init_failed: 968 bus_unregister(&usb_bus_type); 969bus_register_failed: 970 ksuspend_usb_cleanup(); 971out: 972 return retval; 973} 974 975/* 976 * Cleanup 977 */ 978static void __exit usb_exit(void) 979{ 980 /* This will matter if shutdown/reboot does exitcalls. */ 981 if (nousb) 982 return; 983 984 usb_deregister_device_driver(&usb_generic_driver); 985 usb_major_cleanup(); 986 usbfs_cleanup(); 987 usb_deregister(&usbfs_driver); 988 usb_devio_cleanup(); 989 usb_hub_cleanup(); 990 usb_host_cleanup(); 991 bus_unregister(&usb_bus_type); 992 ksuspend_usb_cleanup(); 993} 994 995subsys_initcall(usb_init); 996module_exit(usb_exit); 997MODULE_LICENSE("GPL"); 998