1 /*
2 * drivers/usb/core/usb.c
3 *
4 * (C) Copyright Linus Torvalds 1999
5 * (C) Copyright Johannes Erdfelt 1999-2001
6 * (C) Copyright Andreas Gal 1999
7 * (C) Copyright Gregory P. Smith 1999
8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9 * (C) Copyright Randy Dunlap 2000
10 * (C) Copyright David Brownell 2000-2004
11 * (C) Copyright Yggdrasil Computing, Inc. 2000
12 * (usb_device_id matching changes by Adam J. Richter)
13 * (C) Copyright Greg Kroah-Hartman 2002-2003
14 *
15 * NOTE! This is not actually a driver at all, rather this is
16 * just a collection of helper routines that implement the
17 * generic USB things that the real drivers can use..
18 *
19 * Think of this as a "USB library" rather than anything else.
20 * It should be considered a slave, with no callbacks. Callbacks
21 * are evil.
22 */
23
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/string.h>
27 #include <linux/bitops.h>
28 #include <linux/slab.h>
29 #include <linux/interrupt.h> /* for in_interrupt() */
30 #include <linux/kmod.h>
31 #include <linux/init.h>
32 #include <linux/spinlock.h>
33 #include <linux/errno.h>
34 #include <linux/usb.h>
35 #include <linux/mutex.h>
36 #include <linux/workqueue.h>
37
38 #include <asm/io.h>
39 #include <linux/scatterlist.h>
40 #include <linux/mm.h>
41 #include <linux/dma-mapping.h>
42
43 #include "hcd.h"
44 #include "usb.h"
45
46
47 const char *usbcore_name = "usbcore";
48
49 static int nousb; /* Disable USB when built into kernel image */
50
51 /* Workqueue for autosuspend and for remote wakeup of root hubs */
52 struct workqueue_struct *ksuspend_usb_wq;
53
54 #ifdef CONFIG_USB_SUSPEND
55 static int usb_autosuspend_delay = 2; /* Default delay value,
56 * in seconds */
57 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
58 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
59
60 #else
61 #define usb_autosuspend_delay 0
62 #endif
63
64
65 /**
66 * usb_ifnum_to_if - get the interface object with a given interface number
67 * @dev: the device whose current configuration is considered
68 * @ifnum: the desired interface
69 *
70 * This walks the device descriptor for the currently active configuration
71 * and returns a pointer to the interface with that particular interface
72 * number, or null.
73 *
74 * Note that configuration descriptors are not required to assign interface
75 * numbers sequentially, so that it would be incorrect to assume that
76 * the first interface in that descriptor corresponds to interface zero.
77 * This routine helps device drivers avoid such mistakes.
78 * However, you should make sure that you do the right thing with any
79 * alternate settings available for this interfaces.
80 *
81 * Don't call this function unless you are bound to one of the interfaces
82 * on this device or you have locked the device!
83 */
84 struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
85 unsigned ifnum)
86 {
87 struct usb_host_config *config = dev->actconfig;
88 int i;
89
90 if (!config)
91 return NULL;
92 for (i = 0; i < config->desc.bNumInterfaces; i++)
93 if (config->interface[i]->altsetting[0]
94 .desc.bInterfaceNumber == ifnum)
95 return config->interface[i];
96
97 return NULL;
98 }
99 EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
100
101 /**
102 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
103 * @intf: the interface containing the altsetting in question
104 * @altnum: the desired alternate setting number
105 *
106 * This searches the altsetting array of the specified interface for
107 * an entry with the correct bAlternateSetting value and returns a pointer
108 * to that entry, or null.
109 *
110 * Note that altsettings need not be stored sequentially by number, so
111 * it would be incorrect to assume that the first altsetting entry in
112 * the array corresponds to altsetting zero. This routine helps device
113 * drivers avoid such mistakes.
114 *
115 * Don't call this function unless you are bound to the intf interface
116 * or you have locked the device!
117 */
118 struct usb_host_interface *usb_altnum_to_altsetting(
119 const struct usb_interface *intf,
120 unsigned int altnum)
121 {
122 int i;
123
124 for (i = 0; i < intf->num_altsetting; i++) {
125 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
126 return &intf->altsetting[i];
127 }
128 return NULL;
129 }
130 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
131
132 struct find_interface_arg {
133 int minor;
134 struct usb_interface *interface;
135 };
136
137 static int __find_interface(struct device *dev, void *data)
138 {
139 struct find_interface_arg *arg = data;
140 struct usb_interface *intf;
141
142 /* can't look at usb devices, only interfaces */
143 if (is_usb_device(dev))
144 return 0;
145
146 intf = to_usb_interface(dev);
147 if (intf->minor != -1 && intf->minor == arg->minor) {
148 arg->interface = intf;
149 return 1;
150 }
151 return 0;
152 }
153
154 /**
155 * usb_find_interface - find usb_interface pointer for driver and device
156 * @drv: the driver whose current configuration is considered
157 * @minor: the minor number of the desired device
158 *
159 * This walks the driver device list and returns a pointer to the interface
160 * with the matching minor. Note, this only works for devices that share the
161 * USB major number.
162 */
163 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
164 {
165 struct find_interface_arg argb;
166 int retval;
167
168 argb.minor = minor;
169 argb.interface = NULL;
170 /* eat the error, it will be in argb.interface */
171 retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
172 __find_interface);
173 return argb.interface;
174 }
175 EXPORT_SYMBOL_GPL(usb_find_interface);
176
177 /**
178 * usb_release_dev - free a usb device structure when all users of it are finished.
179 * @dev: device that's been disconnected
180 *
181 * Will be called only by the device core when all users of this usb device are
182 * done.
183 */
184 static void usb_release_dev(struct device *dev)
185 {
186 struct usb_device *udev;
187
188 udev = to_usb_device(dev);
189
190 usb_destroy_configuration(udev);
191 usb_put_hcd(bus_to_hcd(udev->bus));
192 kfree(udev->product);
193 kfree(udev->manufacturer);
194 kfree(udev->serial);
195 kfree(udev);
196 }
197
198 #ifdef CONFIG_HOTPLUG
199 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
200 {
201 struct usb_device *usb_dev;
202
203 usb_dev = to_usb_device(dev);
204
205 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
206 return -ENOMEM;
207
208 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
209 return -ENOMEM;
210
211 return 0;
212 }
213
214 #else
215
216 static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
217 {
218 return -ENODEV;
219 }
220 #endif /* CONFIG_HOTPLUG */
221
222 struct device_type usb_device_type = {
223 .name = "usb_device",
224 .release = usb_release_dev,
225 .uevent = usb_dev_uevent,
226 };
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 #else
248
249 #define ksuspend_usb_init() 0
250 #define ksuspend_usb_cleanup() do {} while (0)
251
252 #endif /* CONFIG_PM */
253
254
255 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
256 static unsigned usb_bus_is_wusb(struct usb_bus *bus)
257 {
258 struct usb_hcd *hcd = container_of(bus, struct usb_hcd, self);
259 return hcd->wireless;
260 }
261
262
263 /**
264 * usb_alloc_dev - usb device constructor (usbcore-internal)
265 * @parent: hub to which device is connected; null to allocate a root hub
266 * @bus: bus used to access the device
267 * @port1: one-based index of port; ignored for root hubs
268 * Context: !in_interrupt()
269 *
270 * Only hub drivers (including virtual root hub drivers for host
271 * controllers) should ever call this.
272 *
273 * This call may not be used in a non-sleeping context.
274 */
275 struct usb_device *usb_alloc_dev(struct usb_device *parent,
276 struct usb_bus *bus, unsigned port1)
277 {
278 struct usb_device *dev;
279 struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
280 unsigned root_hub = 0;
281
282 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
283 if (!dev)
284 return NULL;
285
286 if (!usb_get_hcd(bus_to_hcd(bus))) {
287 kfree(dev);
288 return NULL;
289 }
290
291 device_initialize(&dev->dev);
292 dev->dev.bus = &usb_bus_type;
293 dev->dev.type = &usb_device_type;
294 dev->dev.dma_mask = bus->controller->dma_mask;
295 set_dev_node(&dev->dev, dev_to_node(bus->controller));
296 dev->state = USB_STATE_ATTACHED;
297 atomic_set(&dev->urbnum, 0);
298
299 INIT_LIST_HEAD(&dev->ep0.urb_list);
300 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
301 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
302 /* ep0 maxpacket comes later, from device descriptor */
303 usb_enable_endpoint(dev, &dev->ep0);
304 dev->can_submit = 1;
305
306 /* Save readable and stable topology id, distinguishing devices
307 * by location for diagnostics, tools, driver model, etc. The
308 * string is a path along hub ports, from the root. Each device's
309 * dev->devpath will be stable until USB is re-cabled, and hubs
310 * are often labeled with these port numbers. The bus_id isn't
311 * as stable: bus->busnum changes easily from modprobe order,
312 * cardbus or pci hotplugging, and so on.
313 */
314 if (unlikely(!parent)) {
315 dev->devpath[0] = '';
316
317 dev->dev.parent = bus->controller;
318 sprintf(&dev->dev.bus_id[0], "usb%d", bus->busnum);
319 root_hub = 1;
320 } else {
321 /* match any labeling on the hubs; it's one-based */
322 if (parent->devpath[0] == '')
323 snprintf(dev->devpath, sizeof dev->devpath,
324 "%d", port1);
325 else
326 snprintf(dev->devpath, sizeof dev->devpath,
327 "%s.%d", parent->devpath, port1);
328
329 dev->dev.parent = &parent->dev;
330 sprintf(&dev->dev.bus_id[0], "%d-%s",
331 bus->busnum, dev->devpath);
332
333 /* hub driver sets up TT records */
334 }
335
336 dev->portnum = port1;
337 dev->bus = bus;
338 dev->parent = parent;
339 INIT_LIST_HEAD(&dev->filelist);
340
341 #ifdef CONFIG_PM
342 mutex_init(&dev->pm_mutex);
343 INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
344 dev->autosuspend_delay = usb_autosuspend_delay * HZ;
345 dev->connect_time = jiffies;
346 dev->active_duration = -jiffies;
347 #endif
348 if (root_hub) /* Root hub always ok [and always wired] */
349 dev->authorized = 1;
350 else {
351 dev->authorized = usb_hcd->authorized_default;
352 dev->wusb = usb_bus_is_wusb(bus)? 1 : 0;
353 }
354 return dev;
355 }
356
357 /**
358 * usb_get_dev - increments the reference count of the usb device structure
359 * @dev: the device being referenced
360 *
361 * Each live reference to a device should be refcounted.
362 *
363 * Drivers for USB interfaces should normally record such references in
364 * their probe() methods, when they bind to an interface, and release
365 * them by calling usb_put_dev(), in their disconnect() methods.
366 *
367 * A pointer to the device with the incremented reference counter is returned.
368 */
369 struct usb_device *usb_get_dev(struct usb_device *dev)
370 {
371 if (dev)
372 get_device(&dev->dev);
373 return dev;
374 }
375 EXPORT_SYMBOL_GPL(usb_get_dev);
376
377 /**
378 * usb_put_dev - release a use of the usb device structure
379 * @dev: device that's been disconnected
380 *
381 * Must be called when a user of a device is finished with it. When the last
382 * user of the device calls this function, the memory of the device is freed.
383 */
384 void usb_put_dev(struct usb_device *dev)
385 {
386 if (dev)
387 put_device(&dev->dev);
388 }
389 EXPORT_SYMBOL_GPL(usb_put_dev);
390
391 /**
392 * usb_get_intf - increments the reference count of the usb interface structure
393 * @intf: the interface being referenced
394 *
395 * Each live reference to a interface must be refcounted.
396 *
397 * Drivers for USB interfaces should normally record such references in
398 * their probe() methods, when they bind to an interface, and release
399 * them by calling usb_put_intf(), in their disconnect() methods.
400 *
401 * A pointer to the interface with the incremented reference counter is
402 * returned.
403 */
404 struct usb_interface *usb_get_intf(struct usb_interface *intf)
405 {
406 if (intf)
407 get_device(&intf->dev);
408 return intf;
409 }
410 EXPORT_SYMBOL_GPL(usb_get_intf);
411
412 /**
413 * usb_put_intf - release a use of the usb interface structure
414 * @intf: interface that's been decremented
415 *
416 * Must be called when a user of an interface is finished with it. When the
417 * last user of the interface calls this function, the memory of the interface
418 * is freed.
419 */
420 void usb_put_intf(struct usb_interface *intf)
421 {
422 if (intf)
423 put_device(&intf->dev);
424 }
425 EXPORT_SYMBOL_GPL(usb_put_intf);
426
427 /* USB device locking
428 *
429 * USB devices and interfaces are locked using the semaphore in their
430 * embedded struct device. The hub driver guarantees that whenever a
431 * device is connected or disconnected, drivers are called with the
432 * USB device locked as well as their particular interface.
433 *
434 * Complications arise when several devices are to be locked at the same
435 * time. Only hub-aware drivers that are part of usbcore ever have to
436 * do this; nobody else needs to worry about it. The rule for locking
437 * is simple:
438 *
439 * When locking both a device and its parent, always lock the
440 * the parent first.
441 */
442
443 /**
444 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
445 * @udev: device that's being locked
446 * @iface: interface bound to the driver making the request (optional)
447 *
448 * Attempts to acquire the device lock, but fails if the device is
449 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
450 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
451 * lock, the routine polls repeatedly. This is to prevent deadlock with
452 * disconnect; in some drivers (such as usb-storage) the disconnect()
453 * or suspend() method will block waiting for a device reset to complete.
454 *
455 * Returns a negative error code for failure, otherwise 1 or 0 to indicate
456 * that the device will or will not have to be unlocked. (0 can be
457 * returned when an interface is given and is BINDING, because in that
458 * case the driver already owns the device lock.)
459 */
460 int usb_lock_device_for_reset(struct usb_device *udev,
461 const struct usb_interface *iface)
462 {
463 unsigned long jiffies_expire = jiffies + HZ;
464
465 if (udev->state == USB_STATE_NOTATTACHED)
466 return -ENODEV;
467 if (udev->state == USB_STATE_SUSPENDED)
468 return -EHOSTUNREACH;
469 if (iface) {
470 switch (iface->condition) {
471 case USB_INTERFACE_BINDING:
472 return 0;
473 case USB_INTERFACE_BOUND:
474 break;
475 default:
476 return -EINTR;
477 }
478 }
479
480 while (usb_trylock_device(udev) != 0) {
481
482 /* If we can't acquire the lock after waiting one second,
483 * we're probably deadlocked */
484 if (time_after(jiffies, jiffies_expire))
485 return -EBUSY;
486
487 msleep(15);
488 if (udev->state == USB_STATE_NOTATTACHED)
489 return -ENODEV;
490 if (udev->state == USB_STATE_SUSPENDED)
491 return -EHOSTUNREACH;
492 if (iface && iface->condition != USB_INTERFACE_BOUND)
493 return -EINTR;
494 }
495 return 1;
496 }
497 EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
498
499 static struct usb_device *match_device(struct usb_device *dev,
500 u16 vendor_id, u16 product_id)
501 {
502 struct usb_device *ret_dev = NULL;
503 int child;
504
505 dev_dbg(&dev->dev, "check for vendor %04x, product %04x ...\n",
506 le16_to_cpu(dev->descriptor.idVendor),
507 le16_to_cpu(dev->descriptor.idProduct));
508
509 /* see if this device matches */
510 if ((vendor_id == le16_to_cpu(dev->descriptor.idVendor)) &&
511 (product_id == le16_to_cpu(dev->descriptor.idProduct))) {
512 dev_dbg(&dev->dev, "matched this device!\n");
513 ret_dev = usb_get_dev(dev);
514 goto exit;
515 }
516
517 /* look through all of the children of this device */
518 for (child = 0; child < dev->maxchild; ++child) {
519 if (dev->children[child]) {
520 usb_lock_device(dev->children[child]);
521 ret_dev = match_device(dev->children[child],
522 vendor_id, product_id);
523 usb_unlock_device(dev->children[child]);
524 if (ret_dev)
525 goto exit;
526 }
527 }
528 exit:
529 return ret_dev;
530 }
531
532 /**
533 * usb_find_device - find a specific usb device in the system
534 * @vendor_id: the vendor id of the device to find
535 * @product_id: the product id of the device to find
536 *
537 * Returns a pointer to a struct usb_device if such a specified usb
538 * device is present in the system currently. The usage count of the
539 * device will be incremented if a device is found. Make sure to call
540 * usb_put_dev() when the caller is finished with the device.
541 *
542 * If a device with the specified vendor and product id is not found,
543 * NULL is returned.
544 */
545 struct usb_device *usb_find_device(u16 vendor_id, u16 product_id)
546 {
547 struct list_head *buslist;
548 struct usb_bus *bus;
549 struct usb_device *dev = NULL;
550
551 mutex_lock(&usb_bus_list_lock);
552 for (buslist = usb_bus_list.next;
553 buslist != &usb_bus_list;
554 buslist = buslist->next) {
555 bus = container_of(buslist, struct usb_bus, bus_list);
556 if (!bus->root_hub)
557 continue;
558 usb_lock_device(bus->root_hub);
559 dev = match_device(bus->root_hub, vendor_id, product_id);
560 usb_unlock_device(bus->root_hub);
561 if (dev)
562 goto exit;
563 }
564 exit:
565 mutex_unlock(&usb_bus_list_lock);
566 return dev;
567 }
568
569 /**
570 * usb_get_current_frame_number - return current bus frame number
571 * @dev: the device whose bus is being queried
572 *
573 * Returns the current frame number for the USB host controller
574 * used with the given USB device. This can be used when scheduling
575 * isochronous requests.
576 *
577 * Note that different kinds of host controller have different
578 * "scheduling horizons". While one type might support scheduling only
579 * 32 frames into the future, others could support scheduling up to
580 * 1024 frames into the future.
581 */
582 int usb_get_current_frame_number(struct usb_device *dev)
583 {
584 return usb_hcd_get_frame_number(dev);
585 }
586 EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
587
588 /*-------------------------------------------------------------------*/
589 /*
590 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
591 * extra field of the interface and endpoint descriptor structs.
592 */
593
594 int __usb_get_extra_descriptor(char *buffer, unsigned size,
595 unsigned char type, void **ptr)
596 {
597 struct usb_descriptor_header *header;
598
599 while (size >= sizeof(struct usb_descriptor_header)) {
600 header = (struct usb_descriptor_header *)buffer;
601
602 if (header->bLength < 2) {
603 printk(KERN_ERR
604 "%s: bogus descriptor, type %d length %d\n",
605 usbcore_name,
606 header->bDescriptorType,
607 header->bLength);
608 return -1;
609 }
610
611 if (header->bDescriptorType == type) {
612 *ptr = header;
613 return 0;
614 }
615
616 buffer += header->bLength;
617 size -= header->bLength;
618 }
619 return -1;
620 }
621 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
622
623 /**
624 * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
625 * @dev: device the buffer will be used with
626 * @size: requested buffer size
627 * @mem_flags: affect whether allocation may block
628 * @dma: used to return DMA address of buffer
629 *
630 * Return value is either null (indicating no buffer could be allocated), or
631 * the cpu-space pointer to a buffer that may be used to perform DMA to the
632 * specified device. Such cpu-space buffers are returned along with the DMA
633 * address (through the pointer provided).
634 *
635 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
636 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
637 * hardware during URB completion/resubmit. The implementation varies between
638 * platforms, depending on details of how DMA will work to this device.
639 * Using these buffers also eliminates cacheline sharing problems on
640 * architectures where CPU caches are not DMA-coherent. On systems without
641 * bus-snooping caches, these buffers are uncached.
642 *
643 * When the buffer is no longer used, free it with usb_buffer_free().
644 */
645 void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
646 dma_addr_t *dma)
647 {
648 if (!dev || !dev->bus)
649 return NULL;
650 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
651 }
652 EXPORT_SYMBOL_GPL(usb_buffer_alloc);
653
654 /**
655 * usb_buffer_free - free memory allocated with usb_buffer_alloc()
656 * @dev: device the buffer was used with
657 * @size: requested buffer size
658 * @addr: CPU address of buffer
659 * @dma: DMA address of buffer
660 *
661 * This reclaims an I/O buffer, letting it be reused. The memory must have
662 * been allocated using usb_buffer_alloc(), and the parameters must match
663 * those provided in that allocation request.
664 */
665 void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
666 dma_addr_t dma)
667 {
668 if (!dev || !dev->bus)
669 return;
670 if (!addr)
671 return;
672 hcd_buffer_free(dev->bus, size, addr, dma);
673 }
674 EXPORT_SYMBOL_GPL(usb_buffer_free);
675
676 /**
677 * usb_buffer_map - create DMA mapping(s) for an urb
678 * @urb: urb whose transfer_buffer/setup_packet will be mapped
679 *
680 * Return value is either null (indicating no buffer could be mapped), or
681 * the parameter. URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
682 * added to urb->transfer_flags if the operation succeeds. If the device
683 * is connected to this system through a non-DMA controller, this operation
684 * always succeeds.
685 *
686 * This call would normally be used for an urb which is reused, perhaps
687 * as the target of a large periodic transfer, with usb_buffer_dmasync()
688 * calls to synchronize memory and dma state.
689 *
690 * Reverse the effect of this call with usb_buffer_unmap().
691 */
692 #if 0
693 struct urb *usb_buffer_map(struct urb *urb)
694 {
695 struct usb_bus *bus;
696 struct device *controller;
697
698 if (!urb
699 || !urb->dev
700 || !(bus = urb->dev->bus)
701 || !(controller = bus->controller))
702 return NULL;
703
704 if (controller->dma_mask) {
705 urb->transfer_dma = dma_map_single(controller,
706 urb->transfer_buffer, urb->transfer_buffer_length,
707 usb_pipein(urb->pipe)
708 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
709 if (usb_pipecontrol(urb->pipe))
710 urb->setup_dma = dma_map_single(controller,
711 urb->setup_packet,
712 sizeof(struct usb_ctrlrequest),
713 DMA_TO_DEVICE);
714 /* FIXME generic api broken like pci, can't report errors */
715 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
716 } else
717 urb->transfer_dma = ~0;
718 urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
719 | URB_NO_SETUP_DMA_MAP);
720 return urb;
721 }
722 EXPORT_SYMBOL_GPL(usb_buffer_map);
723 #endif /* 0 */
724
725 /* XXX DISABLED, no users currently. If you wish to re-enable this
726 * XXX please determine whether the sync is to transfer ownership of
727 * XXX the buffer from device to cpu or vice verse, and thusly use the
728 * XXX appropriate _for_{cpu,device}() method. -DaveM
729 */
730 #if 0
731
732 /**
733 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
734 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
735 */
736 void usb_buffer_dmasync(struct urb *urb)
737 {
738 struct usb_bus *bus;
739 struct device *controller;
740
741 if (!urb
742 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
743 || !urb->dev
744 || !(bus = urb->dev->bus)
745 || !(controller = bus->controller))
746 return;
747
748 if (controller->dma_mask) {
749 dma_sync_single(controller,
750 urb->transfer_dma, urb->transfer_buffer_length,
751 usb_pipein(urb->pipe)
752 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
753 if (usb_pipecontrol(urb->pipe))
754 dma_sync_single(controller,
755 urb->setup_dma,
756 sizeof(struct usb_ctrlrequest),
757 DMA_TO_DEVICE);
758 }
759 }
760 EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
761 #endif
762
763 /**
764 * usb_buffer_unmap - free DMA mapping(s) for an urb
765 * @urb: urb whose transfer_buffer will be unmapped
766 *
767 * Reverses the effect of usb_buffer_map().
768 */
769 #if 0
770 void usb_buffer_unmap(struct urb *urb)
771 {
772 struct usb_bus *bus;
773 struct device *controller;
774
775 if (!urb
776 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
777 || !urb->dev
778 || !(bus = urb->dev->bus)
779 || !(controller = bus->controller))
780 return;
781
782 if (controller->dma_mask) {
783 dma_unmap_single(controller,
784 urb->transfer_dma, urb->transfer_buffer_length,
785 usb_pipein(urb->pipe)
786 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
787 if (usb_pipecontrol(urb->pipe))
788 dma_unmap_single(controller,
789 urb->setup_dma,
790 sizeof(struct usb_ctrlrequest),
791 DMA_TO_DEVICE);
792 }
793 urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
794 | URB_NO_SETUP_DMA_MAP);
795 }
796 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
797 #endif /* 0 */
798
799 /**
800 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
801 * @dev: device to which the scatterlist will be mapped
802 * @is_in: mapping transfer direction
803 * @sg: the scatterlist to map
804 * @nents: the number of entries in the scatterlist
805 *
806 * Return value is either < 0 (indicating no buffers could be mapped), or
807 * the number of DMA mapping array entries in the scatterlist.
808 *
809 * The caller is responsible for placing the resulting DMA addresses from
810 * the scatterlist into URB transfer buffer pointers, and for setting the
811 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
812 *
813 * Top I/O rates come from queuing URBs, instead of waiting for each one
814 * to complete before starting the next I/O. This is particularly easy
815 * to do with scatterlists. Just allocate and submit one URB for each DMA
816 * mapping entry returned, stopping on the first error or when all succeed.
817 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
818 *
819 * This call would normally be used when translating scatterlist requests,
820 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
821 * may be able to coalesce mappings for improved I/O efficiency.
822 *
823 * Reverse the effect of this call with usb_buffer_unmap_sg().
824 */
825 int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
826 struct scatterlist *sg, int nents)
827 {
828 struct usb_bus *bus;
829 struct device *controller;
830
831 if (!dev
832 || !(bus = dev->bus)
833 || !(controller = bus->controller)
834 || !controller->dma_mask)
835 return -1;
836
837 /* FIXME generic api broken like pci, can't report errors */
838 return dma_map_sg(controller, sg, nents,
839 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
840 }
841 EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
842
843 /* XXX DISABLED, no users currently. If you wish to re-enable this
844 * XXX please determine whether the sync is to transfer ownership of
845 * XXX the buffer from device to cpu or vice verse, and thusly use the
846 * XXX appropriate _for_{cpu,device}() method. -DaveM
847 */
848 #if 0
849
850 /**
851 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
852 * @dev: device to which the scatterlist will be mapped
853 * @is_in: mapping transfer direction
854 * @sg: the scatterlist to synchronize
855 * @n_hw_ents: the positive return value from usb_buffer_map_sg
856 *
857 * Use this when you are re-using a scatterlist's data buffers for
858 * another USB request.
859 */
860 void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
861 struct scatterlist *sg, int n_hw_ents)
862 {
863 struct usb_bus *bus;
864 struct device *controller;
865
866 if (!dev
867 || !(bus = dev->bus)
868 || !(controller = bus->controller)
869 || !controller->dma_mask)
870 return;
871
872 dma_sync_sg(controller, sg, n_hw_ents,
873 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
874 }
875 EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
876 #endif
877
878 /**
879 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
880 * @dev: device to which the scatterlist will be mapped
881 * @is_in: mapping transfer direction
882 * @sg: the scatterlist to unmap
883 * @n_hw_ents: the positive return value from usb_buffer_map_sg
884 *
885 * Reverses the effect of usb_buffer_map_sg().
886 */
887 void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
888 struct scatterlist *sg, int n_hw_ents)
889 {
890 struct usb_bus *bus;
891 struct device *controller;
892
893 if (!dev
894 || !(bus = dev->bus)
895 || !(controller = bus->controller)
896 || !controller->dma_mask)
897 return;
898
899 dma_unmap_sg(controller, sg, n_hw_ents,
900 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
901 }
902 EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
903
904 /* format to disable USB on kernel command line is: nousb */
905 __module_param_call("", nousb, param_set_bool, param_get_bool, &nousb, 0444);
906
907 /*
908 * for external read access to <nousb>
909 */
910 int usb_disabled(void)
911 {
912 return nousb;
913 }
914 EXPORT_SYMBOL_GPL(usb_disabled);
915
916 /*
917 * Init
918 */
919 static int __init usb_init(void)
920 {
921 int retval;
922 if (nousb) {
923 pr_info("%s: USB support disabled\n", usbcore_name);
924 return 0;
925 }
926
927 retval = ksuspend_usb_init();
928 if (retval)
929 goto out;
930 retval = bus_register(&usb_bus_type);
931 if (retval)
932 goto bus_register_failed;
933 retval = usb_host_init();
934 if (retval)
935 goto host_init_failed;
936 retval = usb_major_init();
937 if (retval)
938 goto major_init_failed;
939 retval = usb_register(&usbfs_driver);
940 if (retval)
941 goto driver_register_failed;
942 retval = usb_devio_init();
943 if (retval)
944 goto usb_devio_init_failed;
945 retval = usbfs_init();
946 if (retval)
947 goto fs_init_failed;
948 retval = usb_hub_init();
949 if (retval)
950 goto hub_init_failed;
951 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
952 if (!retval)
953 goto out;
954
955 usb_hub_cleanup();
956 hub_init_failed:
957 usbfs_cleanup();
958 fs_init_failed:
959 usb_devio_cleanup();
960 usb_devio_init_failed:
961 usb_deregister(&usbfs_driver);
962 driver_register_failed:
963 usb_major_cleanup();
964 major_init_failed:
965 usb_host_cleanup();
966 host_init_failed:
967 bus_unregister(&usb_bus_type);
968 bus_register_failed:
969 ksuspend_usb_cleanup();
970 out:
971 return retval;
972 }
973
974 /*
975 * Cleanup
976 */
977 static void __exit usb_exit(void)
978 {
979 /* This will matter if shutdown/reboot does exitcalls. */
980 if (nousb)
981 return;
982
983 usb_deregister_device_driver(&usb_generic_driver);
984 usb_major_cleanup();
985 usbfs_cleanup();
986 usb_deregister(&usbfs_driver);
987 usb_devio_cleanup();
988 usb_hub_cleanup();
989 usb_host_cleanup();
990 bus_unregister(&usb_bus_type);
991 ksuspend_usb_cleanup();
992 }
993
994 subsys_initcall(usb_init);
995 module_exit(usb_exit);
996 MODULE_LICENSE("GPL");
997
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