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