usb.c revision bdd016ba64d909329cb4bacacc8443901c00e112
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 <asm/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} 99 100/** 101 * usb_altnum_to_altsetting - get the altsetting structure with a given 102 * 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(const struct usb_interface *intf, 119 unsigned int altnum) 120{ 121 int i; 122 123 for (i = 0; i < intf->num_altsetting; i++) { 124 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 125 return &intf->altsetting[i]; 126 } 127 return NULL; 128} 129 130struct find_interface_arg { 131 int minor; 132 struct usb_interface *interface; 133}; 134 135static int __find_interface(struct device * dev, void * data) 136{ 137 struct find_interface_arg *arg = data; 138 struct usb_interface *intf; 139 140 /* can't look at usb devices, only interfaces */ 141 if (is_usb_device(dev)) 142 return 0; 143 144 intf = to_usb_interface(dev); 145 if (intf->minor != -1 && intf->minor == arg->minor) { 146 arg->interface = intf; 147 return 1; 148 } 149 return 0; 150} 151 152/** 153 * usb_find_interface - find usb_interface pointer for driver and device 154 * @drv: the driver whose current configuration is considered 155 * @minor: the minor number of the desired device 156 * 157 * This walks the driver device list and returns a pointer to the interface 158 * with the matching minor. Note, this only works for devices that share the 159 * USB major number. 160 */ 161struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 162{ 163 struct find_interface_arg argb; 164 int retval; 165 166 argb.minor = minor; 167 argb.interface = NULL; 168 /* eat the error, it will be in argb.interface */ 169 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb, 170 __find_interface); 171 return argb.interface; 172} 173 174/** 175 * usb_release_dev - free a usb device structure when all users of it are finished. 176 * @dev: device that's been disconnected 177 * 178 * Will be called only by the device core when all users of this usb device are 179 * done. 180 */ 181static void usb_release_dev(struct device *dev) 182{ 183 struct usb_device *udev; 184 185 udev = to_usb_device(dev); 186 187 usb_destroy_configuration(udev); 188 usb_put_hcd(bus_to_hcd(udev->bus)); 189 kfree(udev->product); 190 kfree(udev->manufacturer); 191 kfree(udev->serial); 192 kfree(udev); 193} 194 195struct device_type usb_device_type = { 196 .name = "usb_device", 197 .release = usb_release_dev, 198}; 199 200#ifdef CONFIG_PM 201 202static int ksuspend_usb_init(void) 203{ 204 /* This workqueue is supposed to be both freezable and 205 * singlethreaded. Its job doesn't justify running on more 206 * than one CPU. 207 */ 208 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd"); 209 if (!ksuspend_usb_wq) 210 return -ENOMEM; 211 return 0; 212} 213 214static void ksuspend_usb_cleanup(void) 215{ 216 destroy_workqueue(ksuspend_usb_wq); 217} 218 219#else 220 221#define ksuspend_usb_init() 0 222#define ksuspend_usb_cleanup() do {} while (0) 223 224#endif /* CONFIG_PM */ 225 226/** 227 * usb_alloc_dev - usb device constructor (usbcore-internal) 228 * @parent: hub to which device is connected; null to allocate a root hub 229 * @bus: bus used to access the device 230 * @port1: one-based index of port; ignored for root hubs 231 * Context: !in_interrupt() 232 * 233 * Only hub drivers (including virtual root hub drivers for host 234 * controllers) should ever call this. 235 * 236 * This call may not be used in a non-sleeping context. 237 */ 238struct usb_device * 239usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 240{ 241 struct usb_device *dev; 242 243 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 244 if (!dev) 245 return NULL; 246 247 if (!usb_get_hcd(bus_to_hcd(bus))) { 248 kfree(dev); 249 return NULL; 250 } 251 252 device_initialize(&dev->dev); 253 dev->dev.bus = &usb_bus_type; 254 dev->dev.type = &usb_device_type; 255 dev->dev.dma_mask = bus->controller->dma_mask; 256 set_dev_node(&dev->dev, dev_to_node(bus->controller)); 257 dev->state = USB_STATE_ATTACHED; 258 259 INIT_LIST_HEAD(&dev->ep0.urb_list); 260 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; 261 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; 262 /* ep0 maxpacket comes later, from device descriptor */ 263 usb_enable_endpoint(dev, &dev->ep0); 264 265 /* Save readable and stable topology id, distinguishing devices 266 * by location for diagnostics, tools, driver model, etc. The 267 * string is a path along hub ports, from the root. Each device's 268 * dev->devpath will be stable until USB is re-cabled, and hubs 269 * are often labeled with these port numbers. The bus_id isn't 270 * as stable: bus->busnum changes easily from modprobe order, 271 * cardbus or pci hotplugging, and so on. 272 */ 273 if (unlikely(!parent)) { 274 dev->devpath[0] = '0'; 275 276 dev->dev.parent = bus->controller; 277 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum); 278 } else { 279 /* match any labeling on the hubs; it's one-based */ 280 if (parent->devpath[0] == '0') 281 snprintf(dev->devpath, sizeof dev->devpath, 282 "%d", port1); 283 else 284 snprintf(dev->devpath, sizeof dev->devpath, 285 "%s.%d", parent->devpath, port1); 286 287 dev->dev.parent = &parent->dev; 288 sprintf(&dev->dev.bus_id[0], "%d-%s", 289 bus->busnum, dev->devpath); 290 291 /* hub driver sets up TT records */ 292 } 293 294 dev->portnum = port1; 295 dev->bus = bus; 296 dev->parent = parent; 297 INIT_LIST_HEAD(&dev->filelist); 298 299#ifdef CONFIG_PM 300 mutex_init(&dev->pm_mutex); 301 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work); 302 dev->autosuspend_delay = usb_autosuspend_delay * HZ; 303#endif 304 return dev; 305} 306 307/** 308 * usb_get_dev - increments the reference count of the usb device structure 309 * @dev: the device being referenced 310 * 311 * Each live reference to a device should be refcounted. 312 * 313 * Drivers for USB interfaces should normally record such references in 314 * their probe() methods, when they bind to an interface, and release 315 * them by calling usb_put_dev(), in their disconnect() methods. 316 * 317 * A pointer to the device with the incremented reference counter is returned. 318 */ 319struct usb_device *usb_get_dev(struct usb_device *dev) 320{ 321 if (dev) 322 get_device(&dev->dev); 323 return dev; 324} 325 326/** 327 * usb_put_dev - release a use of the usb device structure 328 * @dev: device that's been disconnected 329 * 330 * Must be called when a user of a device is finished with it. When the last 331 * user of the device calls this function, the memory of the device is freed. 332 */ 333void usb_put_dev(struct usb_device *dev) 334{ 335 if (dev) 336 put_device(&dev->dev); 337} 338 339/** 340 * usb_get_intf - increments the reference count of the usb interface structure 341 * @intf: the interface being referenced 342 * 343 * Each live reference to a interface must be refcounted. 344 * 345 * Drivers for USB interfaces should normally record such references in 346 * their probe() methods, when they bind to an interface, and release 347 * them by calling usb_put_intf(), in their disconnect() methods. 348 * 349 * A pointer to the interface with the incremented reference counter is 350 * returned. 351 */ 352struct usb_interface *usb_get_intf(struct usb_interface *intf) 353{ 354 if (intf) 355 get_device(&intf->dev); 356 return intf; 357} 358 359/** 360 * usb_put_intf - release a use of the usb interface structure 361 * @intf: interface that's been decremented 362 * 363 * Must be called when a user of an interface is finished with it. When the 364 * last user of the interface calls this function, the memory of the interface 365 * is freed. 366 */ 367void usb_put_intf(struct usb_interface *intf) 368{ 369 if (intf) 370 put_device(&intf->dev); 371} 372 373 374/* USB device locking 375 * 376 * USB devices and interfaces are locked using the semaphore in their 377 * embedded struct device. The hub driver guarantees that whenever a 378 * device is connected or disconnected, drivers are called with the 379 * USB device locked as well as their particular interface. 380 * 381 * Complications arise when several devices are to be locked at the same 382 * time. Only hub-aware drivers that are part of usbcore ever have to 383 * do this; nobody else needs to worry about it. The rule for locking 384 * is simple: 385 * 386 * When locking both a device and its parent, always lock the 387 * the parent first. 388 */ 389 390/** 391 * usb_lock_device_for_reset - cautiously acquire the lock for a 392 * usb device structure 393 * @udev: device that's being locked 394 * @iface: interface bound to the driver making the request (optional) 395 * 396 * Attempts to acquire the device lock, but fails if the device is 397 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 398 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 399 * lock, the routine polls repeatedly. This is to prevent deadlock with 400 * disconnect; in some drivers (such as usb-storage) the disconnect() 401 * or suspend() method will block waiting for a device reset to complete. 402 * 403 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 404 * that the device will or will not have to be unlocked. (0 can be 405 * returned when an interface is given and is BINDING, because in that 406 * case the driver already owns the device lock.) 407 */ 408int usb_lock_device_for_reset(struct usb_device *udev, 409 const struct usb_interface *iface) 410{ 411 unsigned long jiffies_expire = jiffies + HZ; 412 413 if (udev->state == USB_STATE_NOTATTACHED) 414 return -ENODEV; 415 if (udev->state == USB_STATE_SUSPENDED) 416 return -EHOSTUNREACH; 417 if (iface) { 418 switch (iface->condition) { 419 case USB_INTERFACE_BINDING: 420 return 0; 421 case USB_INTERFACE_BOUND: 422 break; 423 default: 424 return -EINTR; 425 } 426 } 427 428 while (usb_trylock_device(udev) != 0) { 429 430 /* If we can't acquire the lock after waiting one second, 431 * we're probably deadlocked */ 432 if (time_after(jiffies, jiffies_expire)) 433 return -EBUSY; 434 435 msleep(15); 436 if (udev->state == USB_STATE_NOTATTACHED) 437 return -ENODEV; 438 if (udev->state == USB_STATE_SUSPENDED) 439 return -EHOSTUNREACH; 440 if (iface && iface->condition != USB_INTERFACE_BOUND) 441 return -EINTR; 442 } 443 return 1; 444} 445 446 447static struct usb_device *match_device(struct usb_device *dev, 448 u16 vendor_id, u16 product_id) 449{ 450 struct usb_device *ret_dev = NULL; 451 int child; 452 453 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 454 le16_to_cpu(dev->descriptor.idVendor), 455 le16_to_cpu(dev->descriptor.idProduct)); 456 457 /* see if this device matches */ 458 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 459 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 460 dev_dbg(&dev->dev, "matched this device!\n"); 461 ret_dev = usb_get_dev(dev); 462 goto exit; 463 } 464 465 /* look through all of the children of this device */ 466 for (child = 0; child < dev->maxchild; ++child) { 467 if (dev->children[child]) { 468 usb_lock_device(dev->children[child]); 469 ret_dev = match_device(dev->children[child], 470 vendor_id, product_id); 471 usb_unlock_device(dev->children[child]); 472 if (ret_dev) 473 goto exit; 474 } 475 } 476exit: 477 return ret_dev; 478} 479 480/** 481 * usb_find_device - find a specific usb device in the system 482 * @vendor_id: the vendor id of the device to find 483 * @product_id: the product id of the device to find 484 * 485 * Returns a pointer to a struct usb_device if such a specified usb 486 * device is present in the system currently. The usage count of the 487 * device will be incremented if a device is found. Make sure to call 488 * usb_put_dev() when the caller is finished with the device. 489 * 490 * If a device with the specified vendor and product id is not found, 491 * NULL is returned. 492 */ 493struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 494{ 495 struct list_head *buslist; 496 struct usb_bus *bus; 497 struct usb_device *dev = NULL; 498 499 mutex_lock(&usb_bus_list_lock); 500 for (buslist = usb_bus_list.next; 501 buslist != &usb_bus_list; 502 buslist = buslist->next) { 503 bus = container_of(buslist, struct usb_bus, bus_list); 504 if (!bus->root_hub) 505 continue; 506 usb_lock_device(bus->root_hub); 507 dev = match_device(bus->root_hub, vendor_id, product_id); 508 usb_unlock_device(bus->root_hub); 509 if (dev) 510 goto exit; 511 } 512exit: 513 mutex_unlock(&usb_bus_list_lock); 514 return dev; 515} 516 517/** 518 * usb_get_current_frame_number - return current bus frame number 519 * @dev: the device whose bus is being queried 520 * 521 * Returns the current frame number for the USB host controller 522 * used with the given USB device. This can be used when scheduling 523 * isochronous requests. 524 * 525 * Note that different kinds of host controller have different 526 * "scheduling horizons". While one type might support scheduling only 527 * 32 frames into the future, others could support scheduling up to 528 * 1024 frames into the future. 529 */ 530int usb_get_current_frame_number(struct usb_device *dev) 531{ 532 return usb_hcd_get_frame_number(dev); 533} 534 535/*-------------------------------------------------------------------*/ 536/* 537 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 538 * extra field of the interface and endpoint descriptor structs. 539 */ 540 541int __usb_get_extra_descriptor(char *buffer, unsigned size, 542 unsigned char type, void **ptr) 543{ 544 struct usb_descriptor_header *header; 545 546 while (size >= sizeof(struct usb_descriptor_header)) { 547 header = (struct usb_descriptor_header *)buffer; 548 549 if (header->bLength < 2) { 550 printk(KERN_ERR 551 "%s: bogus descriptor, type %d length %d\n", 552 usbcore_name, 553 header->bDescriptorType, 554 header->bLength); 555 return -1; 556 } 557 558 if (header->bDescriptorType == type) { 559 *ptr = header; 560 return 0; 561 } 562 563 buffer += header->bLength; 564 size -= header->bLength; 565 } 566 return -1; 567} 568 569/** 570 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 571 * @dev: device the buffer will be used with 572 * @size: requested buffer size 573 * @mem_flags: affect whether allocation may block 574 * @dma: used to return DMA address of buffer 575 * 576 * Return value is either null (indicating no buffer could be allocated), or 577 * the cpu-space pointer to a buffer that may be used to perform DMA to the 578 * specified device. Such cpu-space buffers are returned along with the DMA 579 * address (through the pointer provided). 580 * 581 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 582 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 583 * hardware during URB completion/resubmit. The implementation varies between 584 * platforms, depending on details of how DMA will work to this device. 585 * Using these buffers also eliminates cacheline sharing problems on 586 * architectures where CPU caches are not DMA-coherent. On systems without 587 * bus-snooping caches, these buffers are uncached. 588 * 589 * When the buffer is no longer used, free it with usb_buffer_free(). 590 */ 591void *usb_buffer_alloc( 592 struct usb_device *dev, 593 size_t size, 594 gfp_t mem_flags, 595 dma_addr_t *dma 596) 597{ 598 if (!dev || !dev->bus) 599 return NULL; 600 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 601} 602 603/** 604 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 605 * @dev: device the buffer was used with 606 * @size: requested buffer size 607 * @addr: CPU address of buffer 608 * @dma: DMA address of buffer 609 * 610 * This reclaims an I/O buffer, letting it be reused. The memory must have 611 * been allocated using usb_buffer_alloc(), and the parameters must match 612 * those provided in that allocation request. 613 */ 614void usb_buffer_free( 615 struct usb_device *dev, 616 size_t size, 617 void *addr, 618 dma_addr_t dma 619) 620{ 621 if (!dev || !dev->bus) 622 return; 623 if (!addr) 624 return; 625 hcd_buffer_free(dev->bus, size, addr, dma); 626} 627 628/** 629 * usb_buffer_map - create DMA mapping(s) for an urb 630 * @urb: urb whose transfer_buffer/setup_packet will be mapped 631 * 632 * Return value is either null (indicating no buffer could be mapped), or 633 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 634 * added to urb->transfer_flags if the operation succeeds. If the device 635 * is connected to this system through a non-DMA controller, this operation 636 * always succeeds. 637 * 638 * This call would normally be used for an urb which is reused, perhaps 639 * as the target of a large periodic transfer, with usb_buffer_dmasync() 640 * calls to synchronize memory and dma state. 641 * 642 * Reverse the effect of this call with usb_buffer_unmap(). 643 */ 644#if 0 645struct urb *usb_buffer_map(struct urb *urb) 646{ 647 struct usb_bus *bus; 648 struct device *controller; 649 650 if (!urb 651 || !urb->dev 652 || !(bus = urb->dev->bus) 653 || !(controller = bus->controller)) 654 return NULL; 655 656 if (controller->dma_mask) { 657 urb->transfer_dma = dma_map_single(controller, 658 urb->transfer_buffer, urb->transfer_buffer_length, 659 usb_pipein(urb->pipe) 660 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 661 if (usb_pipecontrol(urb->pipe)) 662 urb->setup_dma = dma_map_single(controller, 663 urb->setup_packet, 664 sizeof(struct usb_ctrlrequest), 665 DMA_TO_DEVICE); 666 // FIXME generic api broken like pci, can't report errors 667 // if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; 668 } else 669 urb->transfer_dma = ~0; 670 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 671 | URB_NO_SETUP_DMA_MAP); 672 return urb; 673} 674#endif /* 0 */ 675 676/* XXX DISABLED, no users currently. If you wish to re-enable this 677 * XXX please determine whether the sync is to transfer ownership of 678 * XXX the buffer from device to cpu or vice verse, and thusly use the 679 * XXX appropriate _for_{cpu,device}() method. -DaveM 680 */ 681#if 0 682 683/** 684 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 685 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 686 */ 687void usb_buffer_dmasync(struct urb *urb) 688{ 689 struct usb_bus *bus; 690 struct device *controller; 691 692 if (!urb 693 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 694 || !urb->dev 695 || !(bus = urb->dev->bus) 696 || !(controller = bus->controller)) 697 return; 698 699 if (controller->dma_mask) { 700 dma_sync_single(controller, 701 urb->transfer_dma, urb->transfer_buffer_length, 702 usb_pipein(urb->pipe) 703 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 704 if (usb_pipecontrol(urb->pipe)) 705 dma_sync_single(controller, 706 urb->setup_dma, 707 sizeof(struct usb_ctrlrequest), 708 DMA_TO_DEVICE); 709 } 710} 711#endif 712 713/** 714 * usb_buffer_unmap - free DMA mapping(s) for an urb 715 * @urb: urb whose transfer_buffer will be unmapped 716 * 717 * Reverses the effect of usb_buffer_map(). 718 */ 719#if 0 720void usb_buffer_unmap(struct urb *urb) 721{ 722 struct usb_bus *bus; 723 struct device *controller; 724 725 if (!urb 726 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 727 || !urb->dev 728 || !(bus = urb->dev->bus) 729 || !(controller = bus->controller)) 730 return; 731 732 if (controller->dma_mask) { 733 dma_unmap_single(controller, 734 urb->transfer_dma, urb->transfer_buffer_length, 735 usb_pipein(urb->pipe) 736 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 737 if (usb_pipecontrol(urb->pipe)) 738 dma_unmap_single(controller, 739 urb->setup_dma, 740 sizeof(struct usb_ctrlrequest), 741 DMA_TO_DEVICE); 742 } 743 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 744 | URB_NO_SETUP_DMA_MAP); 745} 746#endif /* 0 */ 747 748/** 749 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 750 * @dev: device to which the scatterlist will be mapped 751 * @pipe: endpoint defining the mapping direction 752 * @sg: the scatterlist to map 753 * @nents: the number of entries in the scatterlist 754 * 755 * Return value is either < 0 (indicating no buffers could be mapped), or 756 * the number of DMA mapping array entries in the scatterlist. 757 * 758 * The caller is responsible for placing the resulting DMA addresses from 759 * the scatterlist into URB transfer buffer pointers, and for setting the 760 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 761 * 762 * Top I/O rates come from queuing URBs, instead of waiting for each one 763 * to complete before starting the next I/O. This is particularly easy 764 * to do with scatterlists. Just allocate and submit one URB for each DMA 765 * mapping entry returned, stopping on the first error or when all succeed. 766 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 767 * 768 * This call would normally be used when translating scatterlist requests, 769 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 770 * may be able to coalesce mappings for improved I/O efficiency. 771 * 772 * Reverse the effect of this call with usb_buffer_unmap_sg(). 773 */ 774int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe, 775 struct scatterlist *sg, int nents) 776{ 777 struct usb_bus *bus; 778 struct device *controller; 779 780 if (!dev 781 || usb_pipecontrol(pipe) 782 || !(bus = dev->bus) 783 || !(controller = bus->controller) 784 || !controller->dma_mask) 785 return -1; 786 787 // FIXME generic api broken like pci, can't report errors 788 return dma_map_sg(controller, sg, nents, 789 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 790} 791 792/* XXX DISABLED, no users currently. If you wish to re-enable this 793 * XXX please determine whether the sync is to transfer ownership of 794 * XXX the buffer from device to cpu or vice verse, and thusly use the 795 * XXX appropriate _for_{cpu,device}() method. -DaveM 796 */ 797#if 0 798 799/** 800 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 801 * @dev: device to which the scatterlist will be mapped 802 * @pipe: endpoint defining the mapping direction 803 * @sg: the scatterlist to synchronize 804 * @n_hw_ents: the positive return value from usb_buffer_map_sg 805 * 806 * Use this when you are re-using a scatterlist's data buffers for 807 * another USB request. 808 */ 809void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe, 810 struct scatterlist *sg, int n_hw_ents) 811{ 812 struct usb_bus *bus; 813 struct device *controller; 814 815 if (!dev 816 || !(bus = dev->bus) 817 || !(controller = bus->controller) 818 || !controller->dma_mask) 819 return; 820 821 dma_sync_sg(controller, sg, n_hw_ents, 822 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 823} 824#endif 825 826/** 827 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 828 * @dev: device to which the scatterlist will be mapped 829 * @pipe: endpoint defining the mapping direction 830 * @sg: the scatterlist to unmap 831 * @n_hw_ents: the positive return value from usb_buffer_map_sg 832 * 833 * Reverses the effect of usb_buffer_map_sg(). 834 */ 835void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe, 836 struct scatterlist *sg, int n_hw_ents) 837{ 838 struct usb_bus *bus; 839 struct device *controller; 840 841 if (!dev 842 || !(bus = dev->bus) 843 || !(controller = bus->controller) 844 || !controller->dma_mask) 845 return; 846 847 dma_unmap_sg(controller, sg, n_hw_ents, 848 usb_pipein(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 849} 850 851/* format to disable USB on kernel command line is: nousb */ 852__module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 853 854/* 855 * for external read access to <nousb> 856 */ 857int usb_disabled(void) 858{ 859 return nousb; 860} 861 862/* 863 * Init 864 */ 865static int __init usb_init(void) 866{ 867 int retval; 868 if (nousb) { 869 pr_info("%s: USB support disabled\n", usbcore_name); 870 return 0; 871 } 872 873 retval = ksuspend_usb_init(); 874 if (retval) 875 goto out; 876 retval = bus_register(&usb_bus_type); 877 if (retval) 878 goto bus_register_failed; 879 retval = usb_host_init(); 880 if (retval) 881 goto host_init_failed; 882 retval = usb_major_init(); 883 if (retval) 884 goto major_init_failed; 885 retval = usb_register(&usbfs_driver); 886 if (retval) 887 goto driver_register_failed; 888 retval = usb_devio_init(); 889 if (retval) 890 goto usb_devio_init_failed; 891 retval = usbfs_init(); 892 if (retval) 893 goto fs_init_failed; 894 retval = usb_hub_init(); 895 if (retval) 896 goto hub_init_failed; 897 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 898 if (!retval) 899 goto out; 900 901 usb_hub_cleanup(); 902hub_init_failed: 903 usbfs_cleanup(); 904fs_init_failed: 905 usb_devio_cleanup(); 906usb_devio_init_failed: 907 usb_deregister(&usbfs_driver); 908driver_register_failed: 909 usb_major_cleanup(); 910major_init_failed: 911 usb_host_cleanup(); 912host_init_failed: 913 bus_unregister(&usb_bus_type); 914bus_register_failed: 915 ksuspend_usb_cleanup(); 916out: 917 return retval; 918} 919 920/* 921 * Cleanup 922 */ 923static void __exit usb_exit(void) 924{ 925 /* This will matter if shutdown/reboot does exitcalls. */ 926 if (nousb) 927 return; 928 929 usb_deregister_device_driver(&usb_generic_driver); 930 usb_major_cleanup(); 931 usbfs_cleanup(); 932 usb_deregister(&usbfs_driver); 933 usb_devio_cleanup(); 934 usb_hub_cleanup(); 935 usb_host_cleanup(); 936 bus_unregister(&usb_bus_type); 937 ksuspend_usb_cleanup(); 938} 939 940subsys_initcall(usb_init); 941module_exit(usb_exit); 942 943/* 944 * USB may be built into the kernel or be built as modules. 945 * These symbols are exported for device (or host controller) 946 * driver modules to use. 947 */ 948 949EXPORT_SYMBOL(usb_disabled); 950 951EXPORT_SYMBOL_GPL(usb_get_intf); 952EXPORT_SYMBOL_GPL(usb_put_intf); 953 954EXPORT_SYMBOL(usb_put_dev); 955EXPORT_SYMBOL(usb_get_dev); 956EXPORT_SYMBOL(usb_hub_tt_clear_buffer); 957 958EXPORT_SYMBOL(usb_lock_device_for_reset); 959 960EXPORT_SYMBOL(usb_find_interface); 961EXPORT_SYMBOL(usb_ifnum_to_if); 962EXPORT_SYMBOL(usb_altnum_to_altsetting); 963 964EXPORT_SYMBOL(__usb_get_extra_descriptor); 965 966EXPORT_SYMBOL(usb_find_device); 967EXPORT_SYMBOL(usb_get_current_frame_number); 968 969EXPORT_SYMBOL(usb_buffer_alloc); 970EXPORT_SYMBOL(usb_buffer_free); 971 972#if 0 973EXPORT_SYMBOL(usb_buffer_map); 974EXPORT_SYMBOL(usb_buffer_dmasync); 975EXPORT_SYMBOL(usb_buffer_unmap); 976#endif 977 978EXPORT_SYMBOL(usb_buffer_map_sg); 979#if 0 980EXPORT_SYMBOL(usb_buffer_dmasync_sg); 981#endif 982EXPORT_SYMBOL(usb_buffer_unmap_sg); 983 984MODULE_LICENSE("GPL"); 985