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 #include <linux/debugfs.h>
38
39 #include <asm/io.h>
40 #include <linux/scatterlist.h>
41 #include <linux/mm.h>
42 #include <linux/dma-mapping.h>
43
44 #include "hcd.h"
45 #include "usb.h"
46
47
48 const char *usbcore_name = "usbcore";
49
50 static int nousb; /* Disable USB when built into kernel image */
51
52 /* Workqueue for autosuspend and for remote wakeup of root hubs */
53 struct workqueue_struct *ksuspend_usb_wq;
54
55 #ifdef CONFIG_USB_SUSPEND
56 static int usb_autosuspend_delay = 2; /* Default delay value,
57 * in seconds */
58 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
59 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
60
61 #else
62 #define usb_autosuspend_delay 0
63 #endif
64
65
66 /**
67 * usb_ifnum_to_if - get the interface object with a given interface number
68 * @dev: the device whose current configuration is considered
69 * @ifnum: the desired interface
70 *
71 * This walks the device descriptor for the currently active configuration
72 * and returns a pointer to the interface with that particular interface
73 * number, or null.
74 *
75 * Note that configuration descriptors are not required to assign interface
76 * numbers sequentially, so that it would be incorrect to assume that
77 * the first interface in that descriptor corresponds to interface zero.
78 * This routine helps device drivers avoid such mistakes.
79 * However, you should make sure that you do the right thing with any
80 * alternate settings available for this interfaces.
81 *
82 * Don't call this function unless you are bound to one of the interfaces
83 * on this device or you have locked the device!
84 */
85 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
86 unsigned ifnum)
87 {
88 struct usb_host_config *config = dev->actconfig;
89 int i;
90
91 if (!config)
92 return NULL;
93 for (i = 0; i < config->desc.bNumInterfaces; i++)
94 if (config->interface[i]->altsetting[0]
95 .desc.bInterfaceNumber == ifnum)
96 return config->interface[i];
97
98 return NULL;
99 }
100 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
101
102 /**
103 * usb_altnum_to_altsetting - get the altsetting structure with a given 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 device_driver *drv;
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 if (!is_usb_interface(dev))
144 return 0;
145
146 if (dev->driver != arg->drv)
147 return 0;
148 intf = to_usb_interface(dev);
149 return intf->minor == arg->minor;
150 }
151
152 /**
153 * usb_find_interface - find usb_interface pointer for driver and device
154 * @drv: the driver whose current configuration is considered
155 * @minor: the minor number of the desired device
156 *
157 * This walks the bus device list and returns a pointer to the interface
158 * with the matching minor and driver. Note, this only works for devices
159 * that share the USB major number.
160 */
161 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
162 {
163 struct find_interface_arg argb;
164 struct device *dev;
165
166 argb.minor = minor;
167 argb.drv = &drv->drvwrap.driver;
168
169 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
170
171 /* Drop reference count from bus_find_device */
172 put_device(dev);
173
174 return dev ? to_usb_interface(dev) : NULL;
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 struct usb_hcd *hcd;
189
190 udev = to_usb_device(dev);
191 hcd = bus_to_hcd(udev->bus);
192
193 usb_destroy_configuration(udev);
194 /* Root hubs aren't real devices, so don't free HCD resources */
195 if (hcd->driver->free_dev && udev->parent)
196 hcd->driver->free_dev(hcd, udev);
197 usb_put_hcd(hcd);
198 kfree(udev->product);
199 kfree(udev->manufacturer);
200 kfree(udev->serial);
201 kfree(udev);
202 }
203
204 #ifdef CONFIG_HOTPLUG
205 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
206 {
207 struct usb_device *usb_dev;
208
209 usb_dev = to_usb_device(dev);
210
211 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
212 return -ENOMEM;
213
214 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
215 return -ENOMEM;
216
217 return 0;
218 }
219
220 #else
221
222 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
223 {
224 return -ENODEV;
225 }
226 #endif /* CONFIG_HOTPLUG */
227
228 #ifdef CONFIG_PM
229
230 static int ksuspend_usb_init(void)
231 {
232 /* This workqueue is supposed to be both freezable and
233 * singlethreaded. Its job doesn't justify running on more
234 * than one CPU.
235 */
236 ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
237 if (!ksuspend_usb_wq)
238 return -ENOMEM;
239 return 0;
240 }
241
242 static void ksuspend_usb_cleanup(void)
243 {
244 destroy_workqueue(ksuspend_usb_wq);
245 }
246
247 /* USB device Power-Management thunks.
248 * There's no need to distinguish here between quiescing a USB device
249 * and powering it down; the generic_suspend() routine takes care of
250 * it by skipping the usb_port_suspend() call for a quiesce. And for
251 * USB interfaces there's no difference at all.
252 */
253
254 static int usb_dev_prepare(struct device *dev)
255 {
256 return 0; /* Implement eventually? */
257 }
258
259 static void usb_dev_complete(struct device *dev)
260 {
261 /* Currently used only for rebinding interfaces */
262 usb_resume(dev, PMSG_RESUME); /* Message event is meaningless */
263 }
264
265 static int usb_dev_suspend(struct device *dev)
266 {
267 return usb_suspend(dev, PMSG_SUSPEND);
268 }
269
270 static int usb_dev_resume(struct device *dev)
271 {
272 return usb_resume(dev, PMSG_RESUME);
273 }
274
275 static int usb_dev_freeze(struct device *dev)
276 {
277 return usb_suspend(dev, PMSG_FREEZE);
278 }
279
280 static int usb_dev_thaw(struct device *dev)
281 {
282 return usb_resume(dev, PMSG_THAW);
283 }
284
285 static int usb_dev_poweroff(struct device *dev)
286 {
287 return usb_suspend(dev, PMSG_HIBERNATE);
288 }
289
290 static int usb_dev_restore(struct device *dev)
291 {
292 return usb_resume(dev, PMSG_RESTORE);
293 }
294
295 static struct dev_pm_ops usb_device_pm_ops = {
296 .prepare = usb_dev_prepare,
297 .complete = usb_dev_complete,
298 .suspend = usb_dev_suspend,
299 .resume = usb_dev_resume,
300 .freeze = usb_dev_freeze,
301 .thaw = usb_dev_thaw,
302 .poweroff = usb_dev_poweroff,
303 .restore = usb_dev_restore,
304 };
305
306 #else
307
308 #define ksuspend_usb_init() 0
309 #define ksuspend_usb_cleanup() do {} while (0)
310 #define usb_device_pm_ops (*(struct dev_pm_ops *)0)
311
312 #endif /* CONFIG_PM */
313
314
315 static char *usb_nodename(struct device *dev)
316 {
317 struct usb_device *usb_dev;
318
319 usb_dev = to_usb_device(dev);
320 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
321 usb_dev->bus->busnum, usb_dev->devnum);
322 }
323
324 struct device_type usb_device_type = {
325 .name = "usb_device",
326 .release = usb_release_dev,
327 .uevent = usb_dev_uevent,
328 .nodename = usb_nodename,
329 .pm = &usb_device_pm_ops,
330 };
331
332
333 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
334 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
335 {
336 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
337 return hcd->wireless;
338 }
339
340
341 /**
342 * usb_alloc_dev - usb device constructor (usbcore-internal)
343 * @parent: hub to which device is connected; null to allocate a root hub
344 * @bus: bus used to access the device
345 * @port1: one-based index of port; ignored for root hubs
346 * Context: !in_interrupt()
347 *
348 * Only hub drivers (including virtual root hub drivers for host
349 * controllers) should ever call this.
350 *
351 * This call may not be used in a non-sleeping context.
352 */
353 struct usb_device *usb_alloc_dev(struct usb_device *parent,
354 struct usb_bus *bus, unsigned port1)
355 {
356 struct usb_device *dev;
357 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
358 unsigned root_hub = 0;
359
360 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
361 if (!dev)
362 return NULL;
363
364 if (!usb_get_hcd(bus_to_hcd(bus))) {
365 kfree(dev);
366 return NULL;
367 }
368 /* Root hubs aren't true devices, so don't allocate HCD resources */
369 if (usb_hcd->driver->alloc_dev && parent &&
370 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
371 usb_put_hcd(bus_to_hcd(bus));
372 kfree(dev);
373 return NULL;
374 }
375
376 device_initialize(&dev->dev);
377 dev->dev.bus = &usb_bus_type;
378 dev->dev.type = &usb_device_type;
379 dev->dev.groups = usb_device_groups;
380 dev->dev.dma_mask = bus->controller->dma_mask;
381 set_dev_node(&dev->dev, dev_to_node(bus->controller));
382 dev->state = USB_STATE_ATTACHED;
383 atomic_set(&dev->urbnum, 0);
384
385 INIT_LIST_HEAD(&dev->ep0.urb_list);
386 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
387 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
388 /* ep0 maxpacket comes later, from device descriptor */
389 usb_enable_endpoint(dev, &dev->ep0, false);
390 dev->can_submit = 1;
391
392 /* Save readable and stable topology id, distinguishing devices
393 * by location for diagnostics, tools, driver model, etc. The
394 * string is a path along hub ports, from the root. Each device's
395 * dev->devpath will be stable until USB is re-cabled, and hubs
396 * are often labeled with these port numbers. The name isn't
397 * as stable: bus->busnum changes easily from modprobe order,
398 * cardbus or pci hotplugging, and so on.
399 */
400 if (unlikely(!parent)) {
401 dev->devpath[0] = '';
402 dev->route = 0;
403
404 dev->dev.parent = bus->controller;
405 dev_set_name(&dev->dev, "usb%d", bus->busnum);
406 root_hub = 1;
407 } else {
408 /* match any labeling on the hubs; it's one-based */
409 if (parent->devpath[0] == '') {
410 snprintf(dev->devpath, sizeof dev->devpath,
411 "%d", port1);
412 /* Root ports are not counted in route string */
413 dev->route = 0;
414 } else {
415 snprintf(dev->devpath, sizeof dev->devpath,
416 "%s.%d", parent->devpath, port1);
417 dev->route = parent->route +
418 (port1 << ((parent->level - 1)*4));
419 }
420
421 dev->dev.parent = &parent->dev;
422 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
423
424 /* hub driver sets up TT records */
425 }
426
427 dev->portnum = port1;
428 dev->bus = bus;
429 dev->parent = parent;
430 INIT_LIST_HEAD(&dev->filelist);
431
432 #ifdef CONFIG_PM
433 mutex_init(&dev->pm_mutex);
434 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
435 INIT_WORK(&dev->autoresume, usb_autoresume_work);
436 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
437 dev->connect_time = jiffies;
438 dev->active_duration = -jiffies;
439 #endif
440 if (root_hub) /* Root hub always ok [and always wired] */
441 dev->authorized = 1;
442 else {
443 dev->authorized = usb_hcd->authorized_default;
444 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0;
445 }
446 return dev;
447 }
448
449 /**
450 * usb_get_dev - increments the reference count of the usb device structure
451 * @dev: the device being referenced
452 *
453 * Each live reference to a device should be refcounted.
454 *
455 * Drivers for USB interfaces should normally record such references in
456 * their probe() methods, when they bind to an interface, and release
457 * them by calling usb_put_dev(), in their disconnect() methods.
458 *
459 * A pointer to the device with the incremented reference counter is returned.
460 */
461 struct usb_device *usb_get_dev(struct usb_device *dev)
462 {
463 if (dev)
464 get_device(&dev->dev);
465 return dev;
466 }
467 EXPORT_SYMBOL_GPL(usb_get_dev);
468
469 /**
470 * usb_put_dev - release a use of the usb device structure
471 * @dev: device that's been disconnected
472 *
473 * Must be called when a user of a device is finished with it. When the last
474 * user of the device calls this function, the memory of the device is freed.
475 */
476 void usb_put_dev(struct usb_device *dev)
477 {
478 if (dev)
479 put_device(&dev->dev);
480 }
481 EXPORT_SYMBOL_GPL(usb_put_dev);
482
483 /**
484 * usb_get_intf - increments the reference count of the usb interface structure
485 * @intf: the interface being referenced
486 *
487 * Each live reference to a interface must be refcounted.
488 *
489 * Drivers for USB interfaces should normally record such references in
490 * their probe() methods, when they bind to an interface, and release
491 * them by calling usb_put_intf(), in their disconnect() methods.
492 *
493 * A pointer to the interface with the incremented reference counter is
494 * returned.
495 */
496 struct usb_interface *usb_get_intf(struct usb_interface *intf)
497 {
498 if (intf)
499 get_device(&intf->dev);
500 return intf;
501 }
502 EXPORT_SYMBOL_GPL(usb_get_intf);
503
504 /**
505 * usb_put_intf - release a use of the usb interface structure
506 * @intf: interface that's been decremented
507 *
508 * Must be called when a user of an interface is finished with it. When the
509 * last user of the interface calls this function, the memory of the interface
510 * is freed.
511 */
512 void usb_put_intf(struct usb_interface *intf)
513 {
514 if (intf)
515 put_device(&intf->dev);
516 }
517 EXPORT_SYMBOL_GPL(usb_put_intf);
518
519 /* USB device locking
520 *
521 * USB devices and interfaces are locked using the semaphore in their
522 * embedded struct device. The hub driver guarantees that whenever a
523 * device is connected or disconnected, drivers are called with the
524 * USB device locked as well as their particular interface.
525 *
526 * Complications arise when several devices are to be locked at the same
527 * time. Only hub-aware drivers that are part of usbcore ever have to
528 * do this; nobody else needs to worry about it. The rule for locking
529 * is simple:
530 *
531 * When locking both a device and its parent, always lock the
532 * the parent first.
533 */
534
535 /**
536 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
537 * @udev: device that's being locked
538 * @iface: interface bound to the driver making the request (optional)
539 *
540 * Attempts to acquire the device lock, but fails if the device is
541 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
542 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
543 * lock, the routine polls repeatedly. This is to prevent deadlock with
544 * disconnect; in some drivers (such as usb-storage) the disconnect()
545 * or suspend() method will block waiting for a device reset to complete.
546 *
547 * Returns a negative error code for failure, otherwise 0.
548 */
549 int usb_lock_device_for_reset(struct usb_device *udev,
550 const struct usb_interface *iface)
551 {
552 unsigned long jiffies_expire = jiffies + HZ;
553
554 if (udev->state == USB_STATE_NOTATTACHED)
555 return -ENODEV;
556 if (udev->state == USB_STATE_SUSPENDED)
557 return -EHOSTUNREACH;
558 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
559 iface->condition == USB_INTERFACE_UNBOUND))
560 return -EINTR;
561
562 while (usb_trylock_device(udev) != 0) {
563
564 /* If we can't acquire the lock after waiting one second,
565 * we're probably deadlocked */
566 if (time_after(jiffies, jiffies_expire))
567 return -EBUSY;
568
569 msleep(15);
570 if (udev->state == USB_STATE_NOTATTACHED)
571 return -ENODEV;
572 if (udev->state == USB_STATE_SUSPENDED)
573 return -EHOSTUNREACH;
574 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
575 iface->condition == USB_INTERFACE_UNBOUND))
576 return -EINTR;
577 }
578 return 0;
579 }
580 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
581
582 static struct usb_device *match_device(struct usb_device *dev,
583 u16 vendor_id, u16 product_id)
584 {
585 struct usb_device *ret_dev = NULL;
586 int child;
587
588 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
589 le16_to_cpu(dev->descriptor.idVendor),
590 le16_to_cpu(dev->descriptor.idProduct));
591
592 /* see if this device matches */
593 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
594 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
595 dev_dbg(&dev->dev, "matched this device!\n");
596 ret_dev = usb_get_dev(dev);
597 goto exit;
598 }
599
600 /* look through all of the children of this device */
601 for (child = 0; child < dev->maxchild; ++child) {
602 if (dev->children[child]) {
603 usb_lock_device(dev->children[child]);
604 ret_dev = match_device(dev->children[child],
605 vendor_id, product_id);
606 usb_unlock_device(dev->children[child]);
607 if (ret_dev)
608 goto exit;
609 }
610 }
611 exit:
612 return ret_dev;
613 }
614
615 /**
616 * usb_find_device - find a specific usb device in the system
617 * @vendor_id: the vendor id of the device to find
618 * @product_id: the product id of the device to find
619 *
620 * Returns a pointer to a struct usb_device if such a specified usb
621 * device is present in the system currently. The usage count of the
622 * device will be incremented if a device is found. Make sure to call
623 * usb_put_dev() when the caller is finished with the device.
624 *
625 * If a device with the specified vendor and product id is not found,
626 * NULL is returned.
627 */
628 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
629 {
630 struct list_head *buslist;
631 struct usb_bus *bus;
632 struct usb_device *dev = NULL;
633
634 mutex_lock(&usb_bus_list_lock);
635 for (buslist = usb_bus_list.next;
636 buslist != &usb_bus_list;
637 buslist = buslist->next) {
638 bus = container_of(buslist, struct usb_bus, bus_list);
639 if (!bus->root_hub)
640 continue;
641 usb_lock_device(bus->root_hub);
642 dev = match_device(bus->root_hub, vendor_id, product_id);
643 usb_unlock_device(bus->root_hub);
644 if (dev)
645 goto exit;
646 }
647 exit:
648 mutex_unlock(&usb_bus_list_lock);
649 return dev;
650 }
651
652 /**
653 * usb_get_current_frame_number - return current bus frame number
654 * @dev: the device whose bus is being queried
655 *
656 * Returns the current frame number for the USB host controller
657 * used with the given USB device. This can be used when scheduling
658 * isochronous requests.
659 *
660 * Note that different kinds of host controller have different
661 * "scheduling horizons". While one type might support scheduling only
662 * 32 frames into the future, others could support scheduling up to
663 * 1024 frames into the future.
664 */
665 int usb_get_current_frame_number(struct usb_device *dev)
666 {
667 return usb_hcd_get_frame_number(dev);
668 }
669 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
670
671 /*-------------------------------------------------------------------*/
672 /*
673 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
674 * extra field of the interface and endpoint descriptor structs.
675 */
676
677 int __usb_get_extra_descriptor(char *buffer, unsigned size,
678 unsigned char type, void **ptr)
679 {
680 struct usb_descriptor_header *header;
681
682 while (size >= sizeof(struct usb_descriptor_header)) {
683 header = (struct usb_descriptor_header *)buffer;
684
685 if (header->bLength < 2) {
686 printk(KERN_ERR
687 "%s: bogus descriptor, type %d length %d\n",
688 usbcore_name,
689 header->bDescriptorType,
690 header->bLength);
691 return -1;
692 }
693
694 if (header->bDescriptorType == type) {
695 *ptr = header;
696 return 0;
697 }
698
699 buffer += header->bLength;
700 size -= header->bLength;
701 }
702 return -1;
703 }
704 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
705
706 /**
707 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
708 * @dev: device the buffer will be used with
709 * @size: requested buffer size
710 * @mem_flags: affect whether allocation may block
711 * @dma: used to return DMA address of buffer
712 *
713 * Return value is either null (indicating no buffer could be allocated), or
714 * the cpu-space pointer to a buffer that may be used to perform DMA to the
715 * specified device. Such cpu-space buffers are returned along with the DMA
716 * address (through the pointer provided).
717 *
718 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
719 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
720 * hardware during URB completion/resubmit. The implementation varies between
721 * platforms, depending on details of how DMA will work to this device.
722 * Using these buffers also eliminates cacheline sharing problems on
723 * architectures where CPU caches are not DMA-coherent. On systems without
724 * bus-snooping caches, these buffers are uncached.
725 *
726 * When the buffer is no longer used, free it with usb_buffer_free().
727 */
728 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
729 dma_addr_t *dma)
730 {
731 if (!dev || !dev->bus)
732 return NULL;
733 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
734 }
735 EXPORT_SYMBOL_GPL(usb_buffer_alloc);
736
737 /**
738 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
739 * @dev: device the buffer was used with
740 * @size: requested buffer size
741 * @addr: CPU address of buffer
742 * @dma: DMA address of buffer
743 *
744 * This reclaims an I/O buffer, letting it be reused. The memory must have
745 * been allocated using usb_buffer_alloc(), and the parameters must match
746 * those provided in that allocation request.
747 */
748 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
749 dma_addr_t dma)
750 {
751 if (!dev || !dev->bus)
752 return;
753 if (!addr)
754 return;
755 hcd_buffer_free(dev->bus, size, addr, dma);
756 }
757 EXPORT_SYMBOL_GPL(usb_buffer_free);
758
759 /**
760 * usb_buffer_map - create DMA mapping(s) for an urb
761 * @urb: urb whose transfer_buffer/setup_packet will be mapped
762 *
763 * Return value is either null (indicating no buffer could be mapped), or
764 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
765 * added to urb->transfer_flags if the operation succeeds. If the device
766 * is connected to this system through a non-DMA controller, this operation
767 * always succeeds.
768 *
769 * This call would normally be used for an urb which is reused, perhaps
770 * as the target of a large periodic transfer, with usb_buffer_dmasync()
771 * calls to synchronize memory and dma state.
772 *
773 * Reverse the effect of this call with usb_buffer_unmap().
774 */
775 #if 0
776 struct urb *usb_buffer_map(struct urb *urb)
777 {
778 struct usb_bus *bus;
779 struct device *controller;
780
781 if (!urb
782 || !urb->dev
783 || !(bus = urb->dev->bus)
784 || !(controller = bus->controller))
785 return NULL;
786
787 if (controller->dma_mask) {
788 urb->transfer_dma = dma_map_single(controller,
789 urb->transfer_buffer, urb->transfer_buffer_length,
790 usb_pipein(urb->pipe)
791 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
792 if (usb_pipecontrol(urb->pipe))
793 urb->setup_dma = dma_map_single(controller,
794 urb->setup_packet,
795 sizeof(struct usb_ctrlrequest),
796 DMA_TO_DEVICE);
797 /* FIXME generic api broken like pci, can't report errors */
798 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
799 } else
800 urb->transfer_dma = ~0;
801 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
802 | URB_NO_SETUP_DMA_MAP);
803 return urb;
804 }
805 EXPORT_SYMBOL_GPL(usb_buffer_map);
806 #endif /* 0 */
807
808 /* XXX DISABLED, no users currently. If you wish to re-enable this
809 * XXX please determine whether the sync is to transfer ownership of
810 * XXX the buffer from device to cpu or vice verse, and thusly use the
811 * XXX appropriate _for_{cpu,device}() method. -DaveM
812 */
813 #if 0
814
815 /**
816 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
817 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
818 */
819 void usb_buffer_dmasync(struct urb *urb)
820 {
821 struct usb_bus *bus;
822 struct device *controller;
823
824 if (!urb
825 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
826 || !urb->dev
827 || !(bus = urb->dev->bus)
828 || !(controller = bus->controller))
829 return;
830
831 if (controller->dma_mask) {
832 dma_sync_single_for_cpu(controller,
833 urb->transfer_dma, urb->transfer_buffer_length,
834 usb_pipein(urb->pipe)
835 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
836 if (usb_pipecontrol(urb->pipe))
837 dma_sync_single_for_cpu(controller,
838 urb->setup_dma,
839 sizeof(struct usb_ctrlrequest),
840 DMA_TO_DEVICE);
841 }
842 }
843 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
844 #endif
845
846 /**
847 * usb_buffer_unmap - free DMA mapping(s) for an urb
848 * @urb: urb whose transfer_buffer will be unmapped
849 *
850 * Reverses the effect of usb_buffer_map().
851 */
852 #if 0
853 void usb_buffer_unmap(struct urb *urb)
854 {
855 struct usb_bus *bus;
856 struct device *controller;
857
858 if (!urb
859 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
860 || !urb->dev
861 || !(bus = urb->dev->bus)
862 || !(controller = bus->controller))
863 return;
864
865 if (controller->dma_mask) {
866 dma_unmap_single(controller,
867 urb->transfer_dma, urb->transfer_buffer_length,
868 usb_pipein(urb->pipe)
869 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
870 if (usb_pipecontrol(urb->pipe))
871 dma_unmap_single(controller,
872 urb->setup_dma,
873 sizeof(struct usb_ctrlrequest),
874 DMA_TO_DEVICE);
875 }
876 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
877 | URB_NO_SETUP_DMA_MAP);
878 }
879 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
880 #endif /* 0 */
881
882 /**
883 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
884 * @dev: device to which the scatterlist will be mapped
885 * @is_in: mapping transfer direction
886 * @sg: the scatterlist to map
887 * @nents: the number of entries in the scatterlist
888 *
889 * Return value is either < 0 (indicating no buffers could be mapped), or
890 * the number of DMA mapping array entries in the scatterlist.
891 *
892 * The caller is responsible for placing the resulting DMA addresses from
893 * the scatterlist into URB transfer buffer pointers, and for setting the
894 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
895 *
896 * Top I/O rates come from queuing URBs, instead of waiting for each one
897 * to complete before starting the next I/O. This is particularly easy
898 * to do with scatterlists. Just allocate and submit one URB for each DMA
899 * mapping entry returned, stopping on the first error or when all succeed.
900 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
901 *
902 * This call would normally be used when translating scatterlist requests,
903 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
904 * may be able to coalesce mappings for improved I/O efficiency.
905 *
906 * Reverse the effect of this call with usb_buffer_unmap_sg().
907 */
908 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
909 struct scatterlist *sg, int nents)
910 {
911 struct usb_bus *bus;
912 struct device *controller;
913
914 if (!dev
915 || !(bus = dev->bus)
916 || !(controller = bus->controller)
917 || !controller->dma_mask)
918 return -1;
919
920 /* FIXME generic api broken like pci, can't report errors */
921 return dma_map_sg(controller, sg, nents,
922 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
923 }
924 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
925
926 /* XXX DISABLED, no users currently. If you wish to re-enable this
927 * XXX please determine whether the sync is to transfer ownership of
928 * XXX the buffer from device to cpu or vice verse, and thusly use the
929 * XXX appropriate _for_{cpu,device}() method. -DaveM
930 */
931 #if 0
932
933 /**
934 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
935 * @dev: device to which the scatterlist will be mapped
936 * @is_in: mapping transfer direction
937 * @sg: the scatterlist to synchronize
938 * @n_hw_ents: the positive return value from usb_buffer_map_sg
939 *
940 * Use this when you are re-using a scatterlist's data buffers for
941 * another USB request.
942 */
943 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
944 struct scatterlist *sg, int n_hw_ents)
945 {
946 struct usb_bus *bus;
947 struct device *controller;
948
949 if (!dev
950 || !(bus = dev->bus)
951 || !(controller = bus->controller)
952 || !controller->dma_mask)
953 return;
954
955 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
956 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
957 }
958 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
959 #endif
960
961 /**
962 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
963 * @dev: device to which the scatterlist will be mapped
964 * @is_in: mapping transfer direction
965 * @sg: the scatterlist to unmap
966 * @n_hw_ents: the positive return value from usb_buffer_map_sg
967 *
968 * Reverses the effect of usb_buffer_map_sg().
969 */
970 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
971 struct scatterlist *sg, int n_hw_ents)
972 {
973 struct usb_bus *bus;
974 struct device *controller;
975
976 if (!dev
977 || !(bus = dev->bus)
978 || !(controller = bus->controller)
979 || !controller->dma_mask)
980 return;
981
982 dma_unmap_sg(controller, sg, n_hw_ents,
983 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
984 }
985 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
986
987 /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */
988 #ifdef MODULE
989 module_param(nousb, bool, 0444);
990 #else
991 core_param(nousb, nousb, bool, 0444);
992 #endif
993
994 /*
995 * for external read access to <nousb>
996 */
997 int usb_disabled(void)
998 {
999 return nousb;
1000 }
1001 EXPORT_SYMBOL_GPL(usb_disabled);
1002
1003 /*
1004 * Notifications of device and interface registration
1005 */
1006 static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1007 void *data)
1008 {
1009 struct device *dev = data;
1010
1011 switch (action) {
1012 case BUS_NOTIFY_ADD_DEVICE:
1013 if (dev->type == &usb_device_type)
1014 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1015 else if (dev->type == &usb_if_device_type)
1016 (void) usb_create_sysfs_intf_files(
1017 to_usb_interface(dev));
1018 break;
1019
1020 case BUS_NOTIFY_DEL_DEVICE:
1021 if (dev->type == &usb_device_type)
1022 usb_remove_sysfs_dev_files(to_usb_device(dev));
1023 else if (dev->type == &usb_if_device_type)
1024 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1025 break;
1026 }
1027 return 0;
1028 }
1029
1030 static struct notifier_block usb_bus_nb = {
1031 .notifier_call = usb_bus_notify,
1032 };
1033
1034 struct dentry *usb_debug_root;
1035 EXPORT_SYMBOL_GPL(usb_debug_root);
1036
1037 struct dentry *usb_debug_devices;
1038
1039 static int usb_debugfs_init(void)
1040 {
1041 usb_debug_root = debugfs_create_dir("usb", NULL);
1042 if (!usb_debug_root)
1043 return -ENOENT;
1044
1045 usb_debug_devices = debugfs_create_file("devices", 0444,
1046 usb_debug_root, NULL,
1047 &usbfs_devices_fops);
1048 if (!usb_debug_devices) {
1049 debugfs_remove(usb_debug_root);
1050 usb_debug_root = NULL;
1051 return -ENOENT;
1052 }
1053
1054 return 0;
1055 }
1056
1057 static void usb_debugfs_cleanup(void)
1058 {
1059 debugfs_remove(usb_debug_devices);
1060 debugfs_remove(usb_debug_root);
1061 }
1062
1063 /*
1064 * Init
1065 */
1066 static int __init usb_init(void)
1067 {
1068 int retval;
1069 if (nousb) {
1070 pr_info("%s: USB support disabled\n", usbcore_name);
1071 return 0;
1072 }
1073
1074 retval = usb_debugfs_init();
1075 if (retval)
1076 goto out;
1077
1078 retval = ksuspend_usb_init();
1079 if (retval)
1080 goto out;
1081 retval = bus_register(&usb_bus_type);
1082 if (retval)
1083 goto bus_register_failed;
1084 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1085 if (retval)
1086 goto bus_notifier_failed;
1087 retval = usb_major_init();
1088 if (retval)
1089 goto major_init_failed;
1090 retval = usb_register(&usbfs_driver);
1091 if (retval)
1092 goto driver_register_failed;
1093 retval = usb_devio_init();
1094 if (retval)
1095 goto usb_devio_init_failed;
1096 retval = usbfs_init();
1097 if (retval)
1098 goto fs_init_failed;
1099 retval = usb_hub_init();
1100 if (retval)
1101 goto hub_init_failed;
1102 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1103 if (!retval)
1104 goto out;
1105
1106 usb_hub_cleanup();
1107 hub_init_failed:
1108 usbfs_cleanup();
1109 fs_init_failed:
1110 usb_devio_cleanup();
1111 usb_devio_init_failed:
1112 usb_deregister(&usbfs_driver);
1113 driver_register_failed:
1114 usb_major_cleanup();
1115 major_init_failed:
1116 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1117 bus_notifier_failed:
1118 bus_unregister(&usb_bus_type);
1119 bus_register_failed:
1120 ksuspend_usb_cleanup();
1121 out:
1122 return retval;
1123 }
1124
1125 /*
1126 * Cleanup
1127 */
1128 static void __exit usb_exit(void)
1129 {
1130 /* This will matter if shutdown/reboot does exitcalls. */
1131 if (nousb)
1132 return;
1133
1134 usb_deregister_device_driver(&usb_generic_driver);
1135 usb_major_cleanup();
1136 usbfs_cleanup();
1137 usb_deregister(&usbfs_driver);
1138 usb_devio_cleanup();
1139 usb_hub_cleanup();
1140 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1141 bus_unregister(&usb_bus_type);
1142 ksuspend_usb_cleanup();
1143 usb_debugfs_cleanup();
1144 }
1145
1146 subsys_initcall(usb_init);
1147 module_exit(usb_exit);
1148 MODULE_LICENSE("GPL");
1149
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