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 47 const char *usbcore_name = "usbcore"; 48 49 static int nousb; /* Disable USB when built into kernel image */ 50 51 /* Workqueue for autosuspend and for remote wakeup of root hubs */ 52 struct workqueue_struct *ksuspend_usb_wq; 53 54 #ifdef CONFIG_USB_SUSPEND 55 static int usb_autosuspend_delay = 2; /* Default delay value, 56 * in seconds */ 57 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644); 58 MODULE_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 */ 84 struct 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 EXPORT_SYMBOL_GPL(usb_ifnum_to_if); 100 101 /** 102 * usb_altnum_to_altsetting - get the altsetting structure with a given 103 * alternate setting number. 104 * @intf: the interface containing the altsetting in question 105 * @altnum: the desired alternate setting number 106 * 107 * This searches the altsetting array of the specified interface for 108 * an entry with the correct bAlternateSetting value and returns a pointer 109 * to that entry, or null. 110 * 111 * Note that altsettings need not be stored sequentially by number, so 112 * it would be incorrect to assume that the first altsetting entry in 113 * the array corresponds to altsetting zero. This routine helps device 114 * drivers avoid such mistakes. 115 * 116 * Don't call this function unless you are bound to the intf interface 117 * or you have locked the device! 118 */ 119 struct usb_host_interface *usb_altnum_to_altsetting( 120 const struct usb_interface *intf, 121 unsigned int altnum) 122 { 123 int i; 124 125 for (i = 0; i < intf->num_altsetting; i++) { 126 if (intf->altsetting[i].desc.bAlternateSetting == altnum) 127 return &intf->altsetting[i]; 128 } 129 return NULL; 130 } 131 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting); 132 133 struct find_interface_arg { 134 int minor; 135 struct usb_interface *interface; 136 }; 137 138 static int __find_interface(struct device *dev, void *data) 139 { 140 struct find_interface_arg *arg = data; 141 struct usb_interface *intf; 142 143 /* can't look at usb devices, only interfaces */ 144 if (is_usb_device(dev)) 145 return 0; 146 147 intf = to_usb_interface(dev); 148 if (intf->minor != -1 && intf->minor == arg->minor) { 149 arg->interface = intf; 150 return 1; 151 } 152 return 0; 153 } 154 155 /** 156 * usb_find_interface - find usb_interface pointer for driver and device 157 * @drv: the driver whose current configuration is considered 158 * @minor: the minor number of the desired device 159 * 160 * This walks the driver device list and returns a pointer to the interface 161 * with the matching minor. Note, this only works for devices that share the 162 * USB major number. 163 */ 164 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor) 165 { 166 struct find_interface_arg argb; 167 int retval; 168 169 argb.minor = minor; 170 argb.interface = NULL; 171 /* eat the error, it will be in argb.interface */ 172 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb, 173 __find_interface); 174 return argb.interface; 175 } 176 EXPORT_SYMBOL_GPL(usb_find_interface); 177 178 /** 179 * usb_release_dev - free a usb device structure when all users of it are finished. 180 * @dev: device that's been disconnected 181 * 182 * Will be called only by the device core when all users of this usb device are 183 * done. 184 */ 185 static void usb_release_dev(struct device *dev) 186 { 187 struct usb_device *udev; 188 189 udev = to_usb_device(dev); 190 191 usb_destroy_configuration(udev); 192 usb_put_hcd(bus_to_hcd(udev->bus)); 193 kfree(udev->product); 194 kfree(udev->manufacturer); 195 kfree(udev->serial); 196 kfree(udev); 197 } 198 199 #ifdef CONFIG_HOTPLUG 200 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 201 { 202 struct usb_device *usb_dev; 203 204 usb_dev = to_usb_device(dev); 205 206 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum)) 207 return -ENOMEM; 208 209 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum)) 210 return -ENOMEM; 211 212 return 0; 213 } 214 215 #else 216 217 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 218 { 219 return -ENODEV; 220 } 221 #endif /* CONFIG_HOTPLUG */ 222 223 struct device_type usb_device_type = { 224 .name = "usb_device", 225 .release = usb_release_dev, 226 .uevent = usb_dev_uevent, 227 }; 228 229 #ifdef CONFIG_PM 230 231 static int ksuspend_usb_init(void) 232 { 233 /* This workqueue is supposed to be both freezable and 234 * singlethreaded. Its job doesn't justify running on more 235 * than one CPU. 236 */ 237 ksuspend_usb_wq = create_singlethread_workqueue("ksuspend_usbd"); 238 if (!ksuspend_usb_wq) 239 return -ENOMEM; 240 return 0; 241 } 242 243 static void ksuspend_usb_cleanup(void) 244 { 245 destroy_workqueue(ksuspend_usb_wq); 246 } 247 248 #else 249 250 #define ksuspend_usb_init() 0 251 #define ksuspend_usb_cleanup() do {} while (0) 252 253 #endif /* CONFIG_PM */ 254 255 256 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */ 257 static unsigned usb_bus_is_wusb(struct usb_bus *bus) 258 { 259 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self); 260 return hcd->wireless; 261 } 262 263 264 /** 265 * usb_alloc_dev - usb device constructor (usbcore-internal) 266 * @parent: hub to which device is connected; null to allocate a root hub 267 * @bus: bus used to access the device 268 * @port1: one-based index of port; ignored for root hubs 269 * Context: !in_interrupt() 270 * 271 * Only hub drivers (including virtual root hub drivers for host 272 * controllers) should ever call this. 273 * 274 * This call may not be used in a non-sleeping context. 275 */ 276 struct usb_device *usb_alloc_dev(struct usb_device *parent, 277 struct usb_bus *bus, unsigned port1) 278 { 279 struct usb_device *dev; 280 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self); 281 unsigned root_hub = 0; 282 283 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 284 if (!dev) 285 return NULL; 286 287 if (!usb_get_hcd(bus_to_hcd(bus))) { 288 kfree(dev); 289 return NULL; 290 } 291 292 device_initialize(&dev->dev); 293 dev->dev.bus = &usb_bus_type; 294 dev->dev.type = &usb_device_type; 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 */ 370 struct usb_device *usb_get_dev(struct usb_device *dev) 371 { 372 if (dev) 373 get_device(&dev->dev); 374 return dev; 375 } 376 EXPORT_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 */ 385 void usb_put_dev(struct usb_device *dev) 386 { 387 if (dev) 388 put_device(&dev->dev); 389 } 390 EXPORT_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 */ 405 struct usb_interface *usb_get_intf(struct usb_interface *intf) 406 { 407 if (intf) 408 get_device(&intf->dev); 409 return intf; 410 } 411 EXPORT_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 */ 421 void usb_put_intf(struct usb_interface *intf) 422 { 423 if (intf) 424 put_device(&intf->dev); 425 } 426 EXPORT_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 446 * usb device structure 447 * @udev: device that's being locked 448 * @iface: interface bound to the driver making the request (optional) 449 * 450 * Attempts to acquire the device lock, but fails if the device is 451 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface 452 * is neither BINDING nor BOUND. Rather than sleeping to wait for the 453 * lock, the routine polls repeatedly. This is to prevent deadlock with 454 * disconnect; in some drivers (such as usb-storage) the disconnect() 455 * or suspend() method will block waiting for a device reset to complete. 456 * 457 * Returns a negative error code for failure, otherwise 1 or 0 to indicate 458 * that the device will or will not have to be unlocked. (0 can be 459 * returned when an interface is given and is BINDING, because in that 460 * case the driver already owns the device lock.) 461 */ 462 int usb_lock_device_for_reset(struct usb_device *udev, 463 const struct usb_interface *iface) 464 { 465 unsigned long jiffies_expire = jiffies + HZ; 466 467 if (udev->state == USB_STATE_NOTATTACHED) 468 return -ENODEV; 469 if (udev->state == USB_STATE_SUSPENDED) 470 return -EHOSTUNREACH; 471 if (iface) { 472 switch (iface->condition) { 473 case USB_INTERFACE_BINDING: 474 return 0; 475 case USB_INTERFACE_BOUND: 476 break; 477 default: 478 return -EINTR; 479 } 480 } 481 482 while (usb_trylock_device(udev) != 0) { 483 484 /* If we can't acquire the lock after waiting one second, 485 * we're probably deadlocked */ 486 if (time_after(jiffies, jiffies_expire)) 487 return -EBUSY; 488 489 msleep(15); 490 if (udev->state == USB_STATE_NOTATTACHED) 491 return -ENODEV; 492 if (udev->state == USB_STATE_SUSPENDED) 493 return -EHOSTUNREACH; 494 if (iface && iface->condition != USB_INTERFACE_BOUND) 495 return -EINTR; 496 } 497 return 1; 498 } 499 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset); 500 501 static struct usb_device *match_device(struct usb_device *dev, 502 u16 vendor_id, u16 product_id) 503 { 504 struct usb_device *ret_dev = NULL; 505 int child; 506 507 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n", 508 le16_to_cpu(dev->descriptor.idVendor), 509 le16_to_cpu(dev->descriptor.idProduct)); 510 511 /* see if this device matches */ 512 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) && 513 (product_id == le16_to_cpu(dev->descriptor.idProduct))) { 514 dev_dbg(&dev->dev, "matched this device!\n"); 515 ret_dev = usb_get_dev(dev); 516 goto exit; 517 } 518 519 /* look through all of the children of this device */ 520 for (child = 0; child < dev->maxchild; ++child) { 521 if (dev->children[child]) { 522 usb_lock_device(dev->children[child]); 523 ret_dev = match_device(dev->children[child], 524 vendor_id, product_id); 525 usb_unlock_device(dev->children[child]); 526 if (ret_dev) 527 goto exit; 528 } 529 } 530 exit: 531 return ret_dev; 532 } 533 534 /** 535 * usb_find_device - find a specific usb device in the system 536 * @vendor_id: the vendor id of the device to find 537 * @product_id: the product id of the device to find 538 * 539 * Returns a pointer to a struct usb_device if such a specified usb 540 * device is present in the system currently. The usage count of the 541 * device will be incremented if a device is found. Make sure to call 542 * usb_put_dev() when the caller is finished with the device. 543 * 544 * If a device with the specified vendor and product id is not found, 545 * NULL is returned. 546 */ 547 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id) 548 { 549 struct list_head *buslist; 550 struct usb_bus *bus; 551 struct usb_device *dev = NULL; 552 553 mutex_lock(&usb_bus_list_lock); 554 for (buslist = usb_bus_list.next; 555 buslist != &usb_bus_list; 556 buslist = buslist->next) { 557 bus = container_of(buslist, struct usb_bus, bus_list); 558 if (!bus->root_hub) 559 continue; 560 usb_lock_device(bus->root_hub); 561 dev = match_device(bus->root_hub, vendor_id, product_id); 562 usb_unlock_device(bus->root_hub); 563 if (dev) 564 goto exit; 565 } 566 exit: 567 mutex_unlock(&usb_bus_list_lock); 568 return dev; 569 } 570 571 /** 572 * usb_get_current_frame_number - return current bus frame number 573 * @dev: the device whose bus is being queried 574 * 575 * Returns the current frame number for the USB host controller 576 * used with the given USB device. This can be used when scheduling 577 * isochronous requests. 578 * 579 * Note that different kinds of host controller have different 580 * "scheduling horizons". While one type might support scheduling only 581 * 32 frames into the future, others could support scheduling up to 582 * 1024 frames into the future. 583 */ 584 int usb_get_current_frame_number(struct usb_device *dev) 585 { 586 return usb_hcd_get_frame_number(dev); 587 } 588 EXPORT_SYMBOL_GPL(usb_get_current_frame_number); 589 590 /*-------------------------------------------------------------------*/ 591 /* 592 * __usb_get_extra_descriptor() finds a descriptor of specific type in the 593 * extra field of the interface and endpoint descriptor structs. 594 */ 595 596 int __usb_get_extra_descriptor(char *buffer, unsigned size, 597 unsigned char type, void **ptr) 598 { 599 struct usb_descriptor_header *header; 600 601 while (size >= sizeof(struct usb_descriptor_header)) { 602 header = (struct usb_descriptor_header *)buffer; 603 604 if (header->bLength < 2) { 605 printk(KERN_ERR 606 "%s: bogus descriptor, type %d length %d\n", 607 usbcore_name, 608 header->bDescriptorType, 609 header->bLength); 610 return -1; 611 } 612 613 if (header->bDescriptorType == type) { 614 *ptr = header; 615 return 0; 616 } 617 618 buffer += header->bLength; 619 size -= header->bLength; 620 } 621 return -1; 622 } 623 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor); 624 625 /** 626 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP 627 * @dev: device the buffer will be used with 628 * @size: requested buffer size 629 * @mem_flags: affect whether allocation may block 630 * @dma: used to return DMA address of buffer 631 * 632 * Return value is either null (indicating no buffer could be allocated), or 633 * the cpu-space pointer to a buffer that may be used to perform DMA to the 634 * specified device. Such cpu-space buffers are returned along with the DMA 635 * address (through the pointer provided). 636 * 637 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags 638 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU 639 * hardware during URB completion/resubmit. The implementation varies between 640 * platforms, depending on details of how DMA will work to this device. 641 * Using these buffers also eliminates cacheline sharing problems on 642 * architectures where CPU caches are not DMA-coherent. On systems without 643 * bus-snooping caches, these buffers are uncached. 644 * 645 * When the buffer is no longer used, free it with usb_buffer_free(). 646 */ 647 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags, 648 dma_addr_t *dma) 649 { 650 if (!dev || !dev->bus) 651 return NULL; 652 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma); 653 } 654 EXPORT_SYMBOL_GPL(usb_buffer_alloc); 655 656 /** 657 * usb_buffer_free - free memory allocated with usb_buffer_alloc() 658 * @dev: device the buffer was used with 659 * @size: requested buffer size 660 * @addr: CPU address of buffer 661 * @dma: DMA address of buffer 662 * 663 * This reclaims an I/O buffer, letting it be reused. The memory must have 664 * been allocated using usb_buffer_alloc(), and the parameters must match 665 * those provided in that allocation request. 666 */ 667 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr, 668 dma_addr_t dma) 669 { 670 if (!dev || !dev->bus) 671 return; 672 if (!addr) 673 return; 674 hcd_buffer_free(dev->bus, size, addr, dma); 675 } 676 EXPORT_SYMBOL_GPL(usb_buffer_free); 677 678 /** 679 * usb_buffer_map - create DMA mapping(s) for an urb 680 * @urb: urb whose transfer_buffer/setup_packet will be mapped 681 * 682 * Return value is either null (indicating no buffer could be mapped), or 683 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are 684 * added to urb->transfer_flags if the operation succeeds. If the device 685 * is connected to this system through a non-DMA controller, this operation 686 * always succeeds. 687 * 688 * This call would normally be used for an urb which is reused, perhaps 689 * as the target of a large periodic transfer, with usb_buffer_dmasync() 690 * calls to synchronize memory and dma state. 691 * 692 * Reverse the effect of this call with usb_buffer_unmap(). 693 */ 694 #if 0 695 struct urb *usb_buffer_map(struct urb *urb) 696 { 697 struct usb_bus *bus; 698 struct device *controller; 699 700 if (!urb 701 || !urb->dev 702 || !(bus = urb->dev->bus) 703 || !(controller = bus->controller)) 704 return NULL; 705 706 if (controller->dma_mask) { 707 urb->transfer_dma = dma_map_single(controller, 708 urb->transfer_buffer, urb->transfer_buffer_length, 709 usb_pipein(urb->pipe) 710 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 711 if (usb_pipecontrol(urb->pipe)) 712 urb->setup_dma = dma_map_single(controller, 713 urb->setup_packet, 714 sizeof(struct usb_ctrlrequest), 715 DMA_TO_DEVICE); 716 /* FIXME generic api broken like pci, can't report errors */ 717 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */ 718 } else 719 urb->transfer_dma = ~0; 720 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP 721 | URB_NO_SETUP_DMA_MAP); 722 return urb; 723 } 724 EXPORT_SYMBOL_GPL(usb_buffer_map); 725 #endif /* 0 */ 726 727 /* XXX DISABLED, no users currently. If you wish to re-enable this 728 * XXX please determine whether the sync is to transfer ownership of 729 * XXX the buffer from device to cpu or vice verse, and thusly use the 730 * XXX appropriate _for_{cpu,device}() method. -DaveM 731 */ 732 #if 0 733 734 /** 735 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s) 736 * @urb: urb whose transfer_buffer/setup_packet will be synchronized 737 */ 738 void usb_buffer_dmasync(struct urb *urb) 739 { 740 struct usb_bus *bus; 741 struct device *controller; 742 743 if (!urb 744 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 745 || !urb->dev 746 || !(bus = urb->dev->bus) 747 || !(controller = bus->controller)) 748 return; 749 750 if (controller->dma_mask) { 751 dma_sync_single(controller, 752 urb->transfer_dma, urb->transfer_buffer_length, 753 usb_pipein(urb->pipe) 754 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 755 if (usb_pipecontrol(urb->pipe)) 756 dma_sync_single(controller, 757 urb->setup_dma, 758 sizeof(struct usb_ctrlrequest), 759 DMA_TO_DEVICE); 760 } 761 } 762 EXPORT_SYMBOL_GPL(usb_buffer_dmasync); 763 #endif 764 765 /** 766 * usb_buffer_unmap - free DMA mapping(s) for an urb 767 * @urb: urb whose transfer_buffer will be unmapped 768 * 769 * Reverses the effect of usb_buffer_map(). 770 */ 771 #if 0 772 void usb_buffer_unmap(struct urb *urb) 773 { 774 struct usb_bus *bus; 775 struct device *controller; 776 777 if (!urb 778 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) 779 || !urb->dev 780 || !(bus = urb->dev->bus) 781 || !(controller = bus->controller)) 782 return; 783 784 if (controller->dma_mask) { 785 dma_unmap_single(controller, 786 urb->transfer_dma, urb->transfer_buffer_length, 787 usb_pipein(urb->pipe) 788 ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 789 if (usb_pipecontrol(urb->pipe)) 790 dma_unmap_single(controller, 791 urb->setup_dma, 792 sizeof(struct usb_ctrlrequest), 793 DMA_TO_DEVICE); 794 } 795 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP 796 | URB_NO_SETUP_DMA_MAP); 797 } 798 EXPORT_SYMBOL_GPL(usb_buffer_unmap); 799 #endif /* 0 */ 800 801 /** 802 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint 803 * @dev: device to which the scatterlist will be mapped 804 * @is_in: mapping transfer direction 805 * @sg: the scatterlist to map 806 * @nents: the number of entries in the scatterlist 807 * 808 * Return value is either < 0 (indicating no buffers could be mapped), or 809 * the number of DMA mapping array entries in the scatterlist. 810 * 811 * The caller is responsible for placing the resulting DMA addresses from 812 * the scatterlist into URB transfer buffer pointers, and for setting the 813 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs. 814 * 815 * Top I/O rates come from queuing URBs, instead of waiting for each one 816 * to complete before starting the next I/O. This is particularly easy 817 * to do with scatterlists. Just allocate and submit one URB for each DMA 818 * mapping entry returned, stopping on the first error or when all succeed. 819 * Better yet, use the usb_sg_*() calls, which do that (and more) for you. 820 * 821 * This call would normally be used when translating scatterlist requests, 822 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it 823 * may be able to coalesce mappings for improved I/O efficiency. 824 * 825 * Reverse the effect of this call with usb_buffer_unmap_sg(). 826 */ 827 int usb_buffer_map_sg(const struct usb_device *dev, int is_in, 828 struct scatterlist *sg, int nents) 829 { 830 struct usb_bus *bus; 831 struct device *controller; 832 833 if (!dev 834 || !(bus = dev->bus) 835 || !(controller = bus->controller) 836 || !controller->dma_mask) 837 return -1; 838 839 /* FIXME generic api broken like pci, can't report errors */ 840 return dma_map_sg(controller, sg, nents, 841 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 842 } 843 EXPORT_SYMBOL_GPL(usb_buffer_map_sg); 844 845 /* XXX DISABLED, no users currently. If you wish to re-enable this 846 * XXX please determine whether the sync is to transfer ownership of 847 * XXX the buffer from device to cpu or vice verse, and thusly use the 848 * XXX appropriate _for_{cpu,device}() method. -DaveM 849 */ 850 #if 0 851 852 /** 853 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s) 854 * @dev: device to which the scatterlist will be mapped 855 * @is_in: mapping transfer direction 856 * @sg: the scatterlist to synchronize 857 * @n_hw_ents: the positive return value from usb_buffer_map_sg 858 * 859 * Use this when you are re-using a scatterlist's data buffers for 860 * another USB request. 861 */ 862 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, 863 struct scatterlist *sg, int n_hw_ents) 864 { 865 struct usb_bus *bus; 866 struct device *controller; 867 868 if (!dev 869 || !(bus = dev->bus) 870 || !(controller = bus->controller) 871 || !controller->dma_mask) 872 return; 873 874 dma_sync_sg(controller, sg, n_hw_ents, 875 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 876 } 877 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); 878 #endif 879 880 /** 881 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist 882 * @dev: device to which the scatterlist will be mapped 883 * @is_in: mapping transfer direction 884 * @sg: the scatterlist to unmap 885 * @n_hw_ents: the positive return value from usb_buffer_map_sg 886 * 887 * Reverses the effect of usb_buffer_map_sg(). 888 */ 889 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, 890 struct scatterlist *sg, int n_hw_ents) 891 { 892 struct usb_bus *bus; 893 struct device *controller; 894 895 if (!dev 896 || !(bus = dev->bus) 897 || !(controller = bus->controller) 898 || !controller->dma_mask) 899 return; 900 901 dma_unmap_sg(controller, sg, n_hw_ents, 902 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 903 } 904 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); 905 906 /* format to disable USB on kernel command line is: nousb */ 907 __module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444); 908 909 /* 910 * for external read access to <nousb> 911 */ 912 int usb_disabled(void) 913 { 914 return nousb; 915 } 916 EXPORT_SYMBOL_GPL(usb_disabled); 917 918 /* 919 * Init 920 */ 921 static int __init usb_init(void) 922 { 923 int retval; 924 if (nousb) { 925 pr_info("%s: USB support disabled\n", usbcore_name); 926 return 0; 927 } 928 929 retval = ksuspend_usb_init(); 930 if (retval) 931 goto out; 932 retval = bus_register(&usb_bus_type); 933 if (retval) 934 goto bus_register_failed; 935 retval = usb_host_init(); 936 if (retval) 937 goto host_init_failed; 938 retval = usb_major_init(); 939 if (retval) 940 goto major_init_failed; 941 retval = usb_register(&usbfs_driver); 942 if (retval) 943 goto driver_register_failed; 944 retval = usb_devio_init(); 945 if (retval) 946 goto usb_devio_init_failed; 947 retval = usbfs_init(); 948 if (retval) 949 goto fs_init_failed; 950 retval = usb_hub_init(); 951 if (retval) 952 goto hub_init_failed; 953 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE); 954 if (!retval) 955 goto out; 956 957 usb_hub_cleanup(); 958 hub_init_failed: 959 usbfs_cleanup(); 960 fs_init_failed: 961 usb_devio_cleanup(); 962 usb_devio_init_failed: 963 usb_deregister(&usbfs_driver); 964 driver_register_failed: 965 usb_major_cleanup(); 966 major_init_failed: 967 usb_host_cleanup(); 968 host_init_failed: 969 bus_unregister(&usb_bus_type); 970 bus_register_failed: 971 ksuspend_usb_cleanup(); 972 out: 973 return retval; 974 } 975 976 /* 977 * Cleanup 978 */ 979 static void __exit usb_exit(void) 980 { 981 /* This will matter if shutdown/reboot does exitcalls. */ 982 if (nousb) 983 return; 984 985 usb_deregister_device_driver(&usb_generic_driver); 986 usb_major_cleanup(); 987 usbfs_cleanup(); 988 usb_deregister(&usbfs_driver); 989 usb_devio_cleanup(); 990 usb_hub_cleanup(); 991 usb_host_cleanup(); 992 bus_unregister(&usb_bus_type); 993 ksuspend_usb_cleanup(); 994 } 995 996 subsys_initcall(usb_init); 997 module_exit(usb_exit); 998 MODULE_LICENSE("GPL"); 999