usb.c 28 KB

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