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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/usb/core/usb.c
4 *
5 * (C) Copyright Linus Torvalds 1999
6 * (C) Copyright Johannes Erdfelt 1999-2001
7 * (C) Copyright Andreas Gal 1999
8 * (C) Copyright Gregory P. Smith 1999
9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10 * (C) Copyright Randy Dunlap 2000
11 * (C) Copyright David Brownell 2000-2004
12 * (C) Copyright Yggdrasil Computing, Inc. 2000
13 * (usb_device_id matching changes by Adam J. Richter)
14 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 *
16 * Released under the GPLv2 only.
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else,
23 * with no callbacks. Callbacks are evil.
24 */
25
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/string.h>
29#include <linux/bitops.h>
30#include <linux/slab.h>
31#include <linux/kmod.h>
32#include <linux/init.h>
33#include <linux/spinlock.h>
34#include <linux/errno.h>
35#include <linux/usb.h>
36#include <linux/usb/hcd.h>
37#include <linux/mutex.h>
38#include <linux/workqueue.h>
39#include <linux/debugfs.h>
40#include <linux/usb/of.h>
41
42#include <asm/io.h>
43#include <linux/scatterlist.h>
44#include <linux/mm.h>
45#include <linux/dma-mapping.h>
46
47#include "hub.h"
48
49const char *usbcore_name = "usbcore";
50
51static bool nousb; /* Disable USB when built into kernel image */
52
53module_param(nousb, bool, 0444);
54
55/*
56 * for external read access to <nousb>
57 */
58int usb_disabled(void)
59{
60 return nousb;
61}
62EXPORT_SYMBOL_GPL(usb_disabled);
63
64#ifdef CONFIG_PM
65/* Default delay value, in seconds */
66static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
67module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
69
70#else
71#define usb_autosuspend_delay 0
72#endif
73
74static bool match_endpoint(struct usb_endpoint_descriptor *epd,
75 struct usb_endpoint_descriptor **bulk_in,
76 struct usb_endpoint_descriptor **bulk_out,
77 struct usb_endpoint_descriptor **int_in,
78 struct usb_endpoint_descriptor **int_out)
79{
80 switch (usb_endpoint_type(epd)) {
81 case USB_ENDPOINT_XFER_BULK:
82 if (usb_endpoint_dir_in(epd)) {
83 if (bulk_in && !*bulk_in) {
84 *bulk_in = epd;
85 break;
86 }
87 } else {
88 if (bulk_out && !*bulk_out) {
89 *bulk_out = epd;
90 break;
91 }
92 }
93
94 return false;
95 case USB_ENDPOINT_XFER_INT:
96 if (usb_endpoint_dir_in(epd)) {
97 if (int_in && !*int_in) {
98 *int_in = epd;
99 break;
100 }
101 } else {
102 if (int_out && !*int_out) {
103 *int_out = epd;
104 break;
105 }
106 }
107
108 return false;
109 default:
110 return false;
111 }
112
113 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
114 (!int_in || *int_in) && (!int_out || *int_out);
115}
116
117/**
118 * usb_find_common_endpoints() -- look up common endpoint descriptors
119 * @alt: alternate setting to search
120 * @bulk_in: pointer to descriptor pointer, or NULL
121 * @bulk_out: pointer to descriptor pointer, or NULL
122 * @int_in: pointer to descriptor pointer, or NULL
123 * @int_out: pointer to descriptor pointer, or NULL
124 *
125 * Search the alternate setting's endpoint descriptors for the first bulk-in,
126 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
127 * provided pointers (unless they are NULL).
128 *
129 * If a requested endpoint is not found, the corresponding pointer is set to
130 * NULL.
131 *
132 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
133 */
134int usb_find_common_endpoints(struct usb_host_interface *alt,
135 struct usb_endpoint_descriptor **bulk_in,
136 struct usb_endpoint_descriptor **bulk_out,
137 struct usb_endpoint_descriptor **int_in,
138 struct usb_endpoint_descriptor **int_out)
139{
140 struct usb_endpoint_descriptor *epd;
141 int i;
142
143 if (bulk_in)
144 *bulk_in = NULL;
145 if (bulk_out)
146 *bulk_out = NULL;
147 if (int_in)
148 *int_in = NULL;
149 if (int_out)
150 *int_out = NULL;
151
152 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
153 epd = &alt->endpoint[i].desc;
154
155 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
156 return 0;
157 }
158
159 return -ENXIO;
160}
161EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
162
163/**
164 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
165 * @alt: alternate setting to search
166 * @bulk_in: pointer to descriptor pointer, or NULL
167 * @bulk_out: pointer to descriptor pointer, or NULL
168 * @int_in: pointer to descriptor pointer, or NULL
169 * @int_out: pointer to descriptor pointer, or NULL
170 *
171 * Search the alternate setting's endpoint descriptors for the last bulk-in,
172 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
173 * provided pointers (unless they are NULL).
174 *
175 * If a requested endpoint is not found, the corresponding pointer is set to
176 * NULL.
177 *
178 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
179 */
180int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
181 struct usb_endpoint_descriptor **bulk_in,
182 struct usb_endpoint_descriptor **bulk_out,
183 struct usb_endpoint_descriptor **int_in,
184 struct usb_endpoint_descriptor **int_out)
185{
186 struct usb_endpoint_descriptor *epd;
187 int i;
188
189 if (bulk_in)
190 *bulk_in = NULL;
191 if (bulk_out)
192 *bulk_out = NULL;
193 if (int_in)
194 *int_in = NULL;
195 if (int_out)
196 *int_out = NULL;
197
198 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
199 epd = &alt->endpoint[i].desc;
200
201 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
202 return 0;
203 }
204
205 return -ENXIO;
206}
207EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
208
209/**
210 * usb_find_alt_setting() - Given a configuration, find the alternate setting
211 * for the given interface.
212 * @config: the configuration to search (not necessarily the current config).
213 * @iface_num: interface number to search in
214 * @alt_num: alternate interface setting number to search for.
215 *
216 * Search the configuration's interface cache for the given alt setting.
217 *
218 * Return: The alternate setting, if found. %NULL otherwise.
219 */
220struct usb_host_interface *usb_find_alt_setting(
221 struct usb_host_config *config,
222 unsigned int iface_num,
223 unsigned int alt_num)
224{
225 struct usb_interface_cache *intf_cache = NULL;
226 int i;
227
228 if (!config)
229 return NULL;
230 for (i = 0; i < config->desc.bNumInterfaces; i++) {
231 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
232 == iface_num) {
233 intf_cache = config->intf_cache[i];
234 break;
235 }
236 }
237 if (!intf_cache)
238 return NULL;
239 for (i = 0; i < intf_cache->num_altsetting; i++)
240 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
241 return &intf_cache->altsetting[i];
242
243 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
244 "config %u\n", alt_num, iface_num,
245 config->desc.bConfigurationValue);
246 return NULL;
247}
248EXPORT_SYMBOL_GPL(usb_find_alt_setting);
249
250/**
251 * usb_ifnum_to_if - get the interface object with a given interface number
252 * @dev: the device whose current configuration is considered
253 * @ifnum: the desired interface
254 *
255 * This walks the device descriptor for the currently active configuration
256 * to find the interface object with the particular interface number.
257 *
258 * Note that configuration descriptors are not required to assign interface
259 * numbers sequentially, so that it would be incorrect to assume that
260 * the first interface in that descriptor corresponds to interface zero.
261 * This routine helps device drivers avoid such mistakes.
262 * However, you should make sure that you do the right thing with any
263 * alternate settings available for this interfaces.
264 *
265 * Don't call this function unless you are bound to one of the interfaces
266 * on this device or you have locked the device!
267 *
268 * Return: A pointer to the interface that has @ifnum as interface number,
269 * if found. %NULL otherwise.
270 */
271struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
272 unsigned ifnum)
273{
274 struct usb_host_config *config = dev->actconfig;
275 int i;
276
277 if (!config)
278 return NULL;
279 for (i = 0; i < config->desc.bNumInterfaces; i++)
280 if (config->interface[i]->altsetting[0]
281 .desc.bInterfaceNumber == ifnum)
282 return config->interface[i];
283
284 return NULL;
285}
286EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
287
288/**
289 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
290 * @intf: the interface containing the altsetting in question
291 * @altnum: the desired alternate setting number
292 *
293 * This searches the altsetting array of the specified interface for
294 * an entry with the correct bAlternateSetting value.
295 *
296 * Note that altsettings need not be stored sequentially by number, so
297 * it would be incorrect to assume that the first altsetting entry in
298 * the array corresponds to altsetting zero. This routine helps device
299 * drivers avoid such mistakes.
300 *
301 * Don't call this function unless you are bound to the intf interface
302 * or you have locked the device!
303 *
304 * Return: A pointer to the entry of the altsetting array of @intf that
305 * has @altnum as the alternate setting number. %NULL if not found.
306 */
307struct usb_host_interface *usb_altnum_to_altsetting(
308 const struct usb_interface *intf,
309 unsigned int altnum)
310{
311 int i;
312
313 for (i = 0; i < intf->num_altsetting; i++) {
314 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
315 return &intf->altsetting[i];
316 }
317 return NULL;
318}
319EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
320
321struct find_interface_arg {
322 int minor;
323 struct device_driver *drv;
324};
325
326static int __find_interface(struct device *dev, const void *data)
327{
328 const struct find_interface_arg *arg = data;
329 struct usb_interface *intf;
330
331 if (!is_usb_interface(dev))
332 return 0;
333
334 if (dev->driver != arg->drv)
335 return 0;
336 intf = to_usb_interface(dev);
337 return intf->minor == arg->minor;
338}
339
340/**
341 * usb_find_interface - find usb_interface pointer for driver and device
342 * @drv: the driver whose current configuration is considered
343 * @minor: the minor number of the desired device
344 *
345 * This walks the bus device list and returns a pointer to the interface
346 * with the matching minor and driver. Note, this only works for devices
347 * that share the USB major number.
348 *
349 * Return: A pointer to the interface with the matching major and @minor.
350 */
351struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
352{
353 struct find_interface_arg argb;
354 struct device *dev;
355
356 argb.minor = minor;
357 argb.drv = &drv->drvwrap.driver;
358
359 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
360
361 /* Drop reference count from bus_find_device */
362 put_device(dev);
363
364 return dev ? to_usb_interface(dev) : NULL;
365}
366EXPORT_SYMBOL_GPL(usb_find_interface);
367
368struct each_dev_arg {
369 void *data;
370 int (*fn)(struct usb_device *, void *);
371};
372
373static int __each_dev(struct device *dev, void *data)
374{
375 struct each_dev_arg *arg = (struct each_dev_arg *)data;
376
377 /* There are struct usb_interface on the same bus, filter them out */
378 if (!is_usb_device(dev))
379 return 0;
380
381 return arg->fn(to_usb_device(dev), arg->data);
382}
383
384/**
385 * usb_for_each_dev - iterate over all USB devices in the system
386 * @data: data pointer that will be handed to the callback function
387 * @fn: callback function to be called for each USB device
388 *
389 * Iterate over all USB devices and call @fn for each, passing it @data. If it
390 * returns anything other than 0, we break the iteration prematurely and return
391 * that value.
392 */
393int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
394{
395 struct each_dev_arg arg = {data, fn};
396
397 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
398}
399EXPORT_SYMBOL_GPL(usb_for_each_dev);
400
401/**
402 * usb_release_dev - free a usb device structure when all users of it are finished.
403 * @dev: device that's been disconnected
404 *
405 * Will be called only by the device core when all users of this usb device are
406 * done.
407 */
408static void usb_release_dev(struct device *dev)
409{
410 struct usb_device *udev;
411 struct usb_hcd *hcd;
412
413 udev = to_usb_device(dev);
414 hcd = bus_to_hcd(udev->bus);
415
416 usb_destroy_configuration(udev);
417 usb_release_bos_descriptor(udev);
418 of_node_put(dev->of_node);
419 usb_put_hcd(hcd);
420 kfree(udev->product);
421 kfree(udev->manufacturer);
422 kfree(udev->serial);
423 kfree(udev);
424}
425
426static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
427{
428 struct usb_device *usb_dev;
429
430 usb_dev = to_usb_device(dev);
431
432 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
433 return -ENOMEM;
434
435 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
436 return -ENOMEM;
437
438 return 0;
439}
440
441#ifdef CONFIG_PM
442
443/* USB device Power-Management thunks.
444 * There's no need to distinguish here between quiescing a USB device
445 * and powering it down; the generic_suspend() routine takes care of
446 * it by skipping the usb_port_suspend() call for a quiesce. And for
447 * USB interfaces there's no difference at all.
448 */
449
450static int usb_dev_prepare(struct device *dev)
451{
452 return 0; /* Implement eventually? */
453}
454
455static void usb_dev_complete(struct device *dev)
456{
457 /* Currently used only for rebinding interfaces */
458 usb_resume_complete(dev);
459}
460
461static int usb_dev_suspend(struct device *dev)
462{
463 return usb_suspend(dev, PMSG_SUSPEND);
464}
465
466static int usb_dev_resume(struct device *dev)
467{
468 return usb_resume(dev, PMSG_RESUME);
469}
470
471static int usb_dev_freeze(struct device *dev)
472{
473 return usb_suspend(dev, PMSG_FREEZE);
474}
475
476static int usb_dev_thaw(struct device *dev)
477{
478 return usb_resume(dev, PMSG_THAW);
479}
480
481static int usb_dev_poweroff(struct device *dev)
482{
483 return usb_suspend(dev, PMSG_HIBERNATE);
484}
485
486static int usb_dev_restore(struct device *dev)
487{
488 return usb_resume(dev, PMSG_RESTORE);
489}
490
491static const struct dev_pm_ops usb_device_pm_ops = {
492 .prepare = usb_dev_prepare,
493 .complete = usb_dev_complete,
494 .suspend = usb_dev_suspend,
495 .resume = usb_dev_resume,
496 .freeze = usb_dev_freeze,
497 .thaw = usb_dev_thaw,
498 .poweroff = usb_dev_poweroff,
499 .restore = usb_dev_restore,
500 .runtime_suspend = usb_runtime_suspend,
501 .runtime_resume = usb_runtime_resume,
502 .runtime_idle = usb_runtime_idle,
503};
504
505#endif /* CONFIG_PM */
506
507
508static char *usb_devnode(struct device *dev,
509 umode_t *mode, kuid_t *uid, kgid_t *gid)
510{
511 struct usb_device *usb_dev;
512
513 usb_dev = to_usb_device(dev);
514 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
515 usb_dev->bus->busnum, usb_dev->devnum);
516}
517
518struct device_type usb_device_type = {
519 .name = "usb_device",
520 .release = usb_release_dev,
521 .uevent = usb_dev_uevent,
522 .devnode = usb_devnode,
523#ifdef CONFIG_PM
524 .pm = &usb_device_pm_ops,
525#endif
526};
527
528
529/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
530static unsigned usb_bus_is_wusb(struct usb_bus *bus)
531{
532 struct usb_hcd *hcd = bus_to_hcd(bus);
533 return hcd->wireless;
534}
535
536static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
537{
538 struct usb_hub *hub;
539
540 if (!dev->parent)
541 return true; /* Root hub always ok [and always wired] */
542
543 switch (hcd->dev_policy) {
544 case USB_DEVICE_AUTHORIZE_NONE:
545 default:
546 return false;
547
548 case USB_DEVICE_AUTHORIZE_ALL:
549 return true;
550
551 case USB_DEVICE_AUTHORIZE_INTERNAL:
552 hub = usb_hub_to_struct_hub(dev->parent);
553 return hub->ports[dev->portnum - 1]->connect_type ==
554 USB_PORT_CONNECT_TYPE_HARD_WIRED;
555 }
556}
557
558/**
559 * usb_alloc_dev - usb device constructor (usbcore-internal)
560 * @parent: hub to which device is connected; null to allocate a root hub
561 * @bus: bus used to access the device
562 * @port1: one-based index of port; ignored for root hubs
563 *
564 * Context: task context, might sleep.
565 *
566 * Only hub drivers (including virtual root hub drivers for host
567 * controllers) should ever call this.
568 *
569 * This call may not be used in a non-sleeping context.
570 *
571 * Return: On success, a pointer to the allocated usb device. %NULL on
572 * failure.
573 */
574struct usb_device *usb_alloc_dev(struct usb_device *parent,
575 struct usb_bus *bus, unsigned port1)
576{
577 struct usb_device *dev;
578 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
579 unsigned root_hub = 0;
580 unsigned raw_port = port1;
581
582 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
583 if (!dev)
584 return NULL;
585
586 if (!usb_get_hcd(usb_hcd)) {
587 kfree(dev);
588 return NULL;
589 }
590 /* Root hubs aren't true devices, so don't allocate HCD resources */
591 if (usb_hcd->driver->alloc_dev && parent &&
592 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
593 usb_put_hcd(bus_to_hcd(bus));
594 kfree(dev);
595 return NULL;
596 }
597
598 device_initialize(&dev->dev);
599 dev->dev.bus = &usb_bus_type;
600 dev->dev.type = &usb_device_type;
601 dev->dev.groups = usb_device_groups;
602 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
603 dev->state = USB_STATE_ATTACHED;
604 dev->lpm_disable_count = 1;
605 atomic_set(&dev->urbnum, 0);
606
607 INIT_LIST_HEAD(&dev->ep0.urb_list);
608 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
609 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
610 /* ep0 maxpacket comes later, from device descriptor */
611 usb_enable_endpoint(dev, &dev->ep0, false);
612 dev->can_submit = 1;
613
614 /* Save readable and stable topology id, distinguishing devices
615 * by location for diagnostics, tools, driver model, etc. The
616 * string is a path along hub ports, from the root. Each device's
617 * dev->devpath will be stable until USB is re-cabled, and hubs
618 * are often labeled with these port numbers. The name isn't
619 * as stable: bus->busnum changes easily from modprobe order,
620 * cardbus or pci hotplugging, and so on.
621 */
622 if (unlikely(!parent)) {
623 dev->devpath[0] = '0';
624 dev->route = 0;
625
626 dev->dev.parent = bus->controller;
627 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
628 dev_set_name(&dev->dev, "usb%d", bus->busnum);
629 root_hub = 1;
630 } else {
631 /* match any labeling on the hubs; it's one-based */
632 if (parent->devpath[0] == '0') {
633 snprintf(dev->devpath, sizeof dev->devpath,
634 "%d", port1);
635 /* Root ports are not counted in route string */
636 dev->route = 0;
637 } else {
638 snprintf(dev->devpath, sizeof dev->devpath,
639 "%s.%d", parent->devpath, port1);
640 /* Route string assumes hubs have less than 16 ports */
641 if (port1 < 15)
642 dev->route = parent->route +
643 (port1 << ((parent->level - 1)*4));
644 else
645 dev->route = parent->route +
646 (15 << ((parent->level - 1)*4));
647 }
648
649 dev->dev.parent = &parent->dev;
650 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
651
652 if (!parent->parent) {
653 /* device under root hub's port */
654 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
655 port1);
656 }
657 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
658
659 /* hub driver sets up TT records */
660 }
661
662 dev->portnum = port1;
663 dev->bus = bus;
664 dev->parent = parent;
665 INIT_LIST_HEAD(&dev->filelist);
666
667#ifdef CONFIG_PM
668 pm_runtime_set_autosuspend_delay(&dev->dev,
669 usb_autosuspend_delay * 1000);
670 dev->connect_time = jiffies;
671 dev->active_duration = -jiffies;
672#endif
673
674 dev->authorized = usb_dev_authorized(dev, usb_hcd);
675 if (!root_hub)
676 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
677
678 return dev;
679}
680EXPORT_SYMBOL_GPL(usb_alloc_dev);
681
682/**
683 * usb_get_dev - increments the reference count of the usb device structure
684 * @dev: the device being referenced
685 *
686 * Each live reference to a device should be refcounted.
687 *
688 * Drivers for USB interfaces should normally record such references in
689 * their probe() methods, when they bind to an interface, and release
690 * them by calling usb_put_dev(), in their disconnect() methods.
691 * However, if a driver does not access the usb_device structure after
692 * its disconnect() method returns then refcounting is not necessary,
693 * because the USB core guarantees that a usb_device will not be
694 * deallocated until after all of its interface drivers have been unbound.
695 *
696 * Return: A pointer to the device with the incremented reference counter.
697 */
698struct usb_device *usb_get_dev(struct usb_device *dev)
699{
700 if (dev)
701 get_device(&dev->dev);
702 return dev;
703}
704EXPORT_SYMBOL_GPL(usb_get_dev);
705
706/**
707 * usb_put_dev - release a use of the usb device structure
708 * @dev: device that's been disconnected
709 *
710 * Must be called when a user of a device is finished with it. When the last
711 * user of the device calls this function, the memory of the device is freed.
712 */
713void usb_put_dev(struct usb_device *dev)
714{
715 if (dev)
716 put_device(&dev->dev);
717}
718EXPORT_SYMBOL_GPL(usb_put_dev);
719
720/**
721 * usb_get_intf - increments the reference count of the usb interface structure
722 * @intf: the interface being referenced
723 *
724 * Each live reference to a interface must be refcounted.
725 *
726 * Drivers for USB interfaces should normally record such references in
727 * their probe() methods, when they bind to an interface, and release
728 * them by calling usb_put_intf(), in their disconnect() methods.
729 * However, if a driver does not access the usb_interface structure after
730 * its disconnect() method returns then refcounting is not necessary,
731 * because the USB core guarantees that a usb_interface will not be
732 * deallocated until after its driver has been unbound.
733 *
734 * Return: A pointer to the interface with the incremented reference counter.
735 */
736struct usb_interface *usb_get_intf(struct usb_interface *intf)
737{
738 if (intf)
739 get_device(&intf->dev);
740 return intf;
741}
742EXPORT_SYMBOL_GPL(usb_get_intf);
743
744/**
745 * usb_put_intf - release a use of the usb interface structure
746 * @intf: interface that's been decremented
747 *
748 * Must be called when a user of an interface is finished with it. When the
749 * last user of the interface calls this function, the memory of the interface
750 * is freed.
751 */
752void usb_put_intf(struct usb_interface *intf)
753{
754 if (intf)
755 put_device(&intf->dev);
756}
757EXPORT_SYMBOL_GPL(usb_put_intf);
758
759/**
760 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
761 * @intf: the usb interface
762 *
763 * While a USB device cannot perform DMA operations by itself, many USB
764 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
765 * for the given USB interface, if any. The returned device structure must be
766 * released with put_device().
767 *
768 * See also usb_get_dma_device().
769 *
770 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
771 * exists.
772 */
773struct device *usb_intf_get_dma_device(struct usb_interface *intf)
774{
775 struct usb_device *udev = interface_to_usbdev(intf);
776 struct device *dmadev;
777
778 if (!udev->bus)
779 return NULL;
780
781 dmadev = get_device(udev->bus->sysdev);
782 if (!dmadev || !dmadev->dma_mask) {
783 put_device(dmadev);
784 return NULL;
785 }
786
787 return dmadev;
788}
789EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
790
791/* USB device locking
792 *
793 * USB devices and interfaces are locked using the semaphore in their
794 * embedded struct device. The hub driver guarantees that whenever a
795 * device is connected or disconnected, drivers are called with the
796 * USB device locked as well as their particular interface.
797 *
798 * Complications arise when several devices are to be locked at the same
799 * time. Only hub-aware drivers that are part of usbcore ever have to
800 * do this; nobody else needs to worry about it. The rule for locking
801 * is simple:
802 *
803 * When locking both a device and its parent, always lock the
804 * parent first.
805 */
806
807/**
808 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
809 * @udev: device that's being locked
810 * @iface: interface bound to the driver making the request (optional)
811 *
812 * Attempts to acquire the device lock, but fails if the device is
813 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
814 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
815 * lock, the routine polls repeatedly. This is to prevent deadlock with
816 * disconnect; in some drivers (such as usb-storage) the disconnect()
817 * or suspend() method will block waiting for a device reset to complete.
818 *
819 * Return: A negative error code for failure, otherwise 0.
820 */
821int usb_lock_device_for_reset(struct usb_device *udev,
822 const struct usb_interface *iface)
823{
824 unsigned long jiffies_expire = jiffies + HZ;
825
826 if (udev->state == USB_STATE_NOTATTACHED)
827 return -ENODEV;
828 if (udev->state == USB_STATE_SUSPENDED)
829 return -EHOSTUNREACH;
830 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
831 iface->condition == USB_INTERFACE_UNBOUND))
832 return -EINTR;
833
834 while (!usb_trylock_device(udev)) {
835
836 /* If we can't acquire the lock after waiting one second,
837 * we're probably deadlocked */
838 if (time_after(jiffies, jiffies_expire))
839 return -EBUSY;
840
841 msleep(15);
842 if (udev->state == USB_STATE_NOTATTACHED)
843 return -ENODEV;
844 if (udev->state == USB_STATE_SUSPENDED)
845 return -EHOSTUNREACH;
846 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
847 iface->condition == USB_INTERFACE_UNBOUND))
848 return -EINTR;
849 }
850 return 0;
851}
852EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
853
854/**
855 * usb_get_current_frame_number - return current bus frame number
856 * @dev: the device whose bus is being queried
857 *
858 * Return: The current frame number for the USB host controller used
859 * with the given USB device. This can be used when scheduling
860 * isochronous requests.
861 *
862 * Note: Different kinds of host controller have different "scheduling
863 * horizons". While one type might support scheduling only 32 frames
864 * into the future, others could support scheduling up to 1024 frames
865 * into the future.
866 *
867 */
868int usb_get_current_frame_number(struct usb_device *dev)
869{
870 return usb_hcd_get_frame_number(dev);
871}
872EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
873
874/*-------------------------------------------------------------------*/
875/*
876 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
877 * extra field of the interface and endpoint descriptor structs.
878 */
879
880int __usb_get_extra_descriptor(char *buffer, unsigned size,
881 unsigned char type, void **ptr, size_t minsize)
882{
883 struct usb_descriptor_header *header;
884
885 while (size >= sizeof(struct usb_descriptor_header)) {
886 header = (struct usb_descriptor_header *)buffer;
887
888 if (header->bLength < 2 || header->bLength > size) {
889 printk(KERN_ERR
890 "%s: bogus descriptor, type %d length %d\n",
891 usbcore_name,
892 header->bDescriptorType,
893 header->bLength);
894 return -1;
895 }
896
897 if (header->bDescriptorType == type && header->bLength >= minsize) {
898 *ptr = header;
899 return 0;
900 }
901
902 buffer += header->bLength;
903 size -= header->bLength;
904 }
905 return -1;
906}
907EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
908
909/**
910 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
911 * @dev: device the buffer will be used with
912 * @size: requested buffer size
913 * @mem_flags: affect whether allocation may block
914 * @dma: used to return DMA address of buffer
915 *
916 * Return: Either null (indicating no buffer could be allocated), or the
917 * cpu-space pointer to a buffer that may be used to perform DMA to the
918 * specified device. Such cpu-space buffers are returned along with the DMA
919 * address (through the pointer provided).
920 *
921 * Note:
922 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
923 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
924 * hardware during URB completion/resubmit. The implementation varies between
925 * platforms, depending on details of how DMA will work to this device.
926 * Using these buffers also eliminates cacheline sharing problems on
927 * architectures where CPU caches are not DMA-coherent. On systems without
928 * bus-snooping caches, these buffers are uncached.
929 *
930 * When the buffer is no longer used, free it with usb_free_coherent().
931 */
932void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
933 dma_addr_t *dma)
934{
935 if (!dev || !dev->bus)
936 return NULL;
937 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
938}
939EXPORT_SYMBOL_GPL(usb_alloc_coherent);
940
941/**
942 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
943 * @dev: device the buffer was used with
944 * @size: requested buffer size
945 * @addr: CPU address of buffer
946 * @dma: DMA address of buffer
947 *
948 * This reclaims an I/O buffer, letting it be reused. The memory must have
949 * been allocated using usb_alloc_coherent(), and the parameters must match
950 * those provided in that allocation request.
951 */
952void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
953 dma_addr_t dma)
954{
955 if (!dev || !dev->bus)
956 return;
957 if (!addr)
958 return;
959 hcd_buffer_free(dev->bus, size, addr, dma);
960}
961EXPORT_SYMBOL_GPL(usb_free_coherent);
962
963/*
964 * Notifications of device and interface registration
965 */
966static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
967 void *data)
968{
969 struct device *dev = data;
970
971 switch (action) {
972 case BUS_NOTIFY_ADD_DEVICE:
973 if (dev->type == &usb_device_type)
974 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
975 else if (dev->type == &usb_if_device_type)
976 usb_create_sysfs_intf_files(to_usb_interface(dev));
977 break;
978
979 case BUS_NOTIFY_DEL_DEVICE:
980 if (dev->type == &usb_device_type)
981 usb_remove_sysfs_dev_files(to_usb_device(dev));
982 else if (dev->type == &usb_if_device_type)
983 usb_remove_sysfs_intf_files(to_usb_interface(dev));
984 break;
985 }
986 return 0;
987}
988
989static struct notifier_block usb_bus_nb = {
990 .notifier_call = usb_bus_notify,
991};
992
993static void usb_debugfs_init(void)
994{
995 debugfs_create_file("devices", 0444, usb_debug_root, NULL,
996 &usbfs_devices_fops);
997}
998
999static void usb_debugfs_cleanup(void)
1000{
1001 debugfs_remove(debugfs_lookup("devices", usb_debug_root));
1002}
1003
1004/*
1005 * Init
1006 */
1007static int __init usb_init(void)
1008{
1009 int retval;
1010 if (usb_disabled()) {
1011 pr_info("%s: USB support disabled\n", usbcore_name);
1012 return 0;
1013 }
1014 usb_init_pool_max();
1015
1016 usb_debugfs_init();
1017
1018 usb_acpi_register();
1019 retval = bus_register(&usb_bus_type);
1020 if (retval)
1021 goto bus_register_failed;
1022 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1023 if (retval)
1024 goto bus_notifier_failed;
1025 retval = usb_major_init();
1026 if (retval)
1027 goto major_init_failed;
1028 retval = usb_register(&usbfs_driver);
1029 if (retval)
1030 goto driver_register_failed;
1031 retval = usb_devio_init();
1032 if (retval)
1033 goto usb_devio_init_failed;
1034 retval = usb_hub_init();
1035 if (retval)
1036 goto hub_init_failed;
1037 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1038 if (!retval)
1039 goto out;
1040
1041 usb_hub_cleanup();
1042hub_init_failed:
1043 usb_devio_cleanup();
1044usb_devio_init_failed:
1045 usb_deregister(&usbfs_driver);
1046driver_register_failed:
1047 usb_major_cleanup();
1048major_init_failed:
1049 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1050bus_notifier_failed:
1051 bus_unregister(&usb_bus_type);
1052bus_register_failed:
1053 usb_acpi_unregister();
1054 usb_debugfs_cleanup();
1055out:
1056 return retval;
1057}
1058
1059/*
1060 * Cleanup
1061 */
1062static void __exit usb_exit(void)
1063{
1064 /* This will matter if shutdown/reboot does exitcalls. */
1065 if (usb_disabled())
1066 return;
1067
1068 usb_release_quirk_list();
1069 usb_deregister_device_driver(&usb_generic_driver);
1070 usb_major_cleanup();
1071 usb_deregister(&usbfs_driver);
1072 usb_devio_cleanup();
1073 usb_hub_cleanup();
1074 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1075 bus_unregister(&usb_bus_type);
1076 usb_acpi_unregister();
1077 usb_debugfs_cleanup();
1078 idr_destroy(&usb_bus_idr);
1079}
1080
1081subsys_initcall(usb_init);
1082module_exit(usb_exit);
1083MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/usb/core/usb.c
4 *
5 * (C) Copyright Linus Torvalds 1999
6 * (C) Copyright Johannes Erdfelt 1999-2001
7 * (C) Copyright Andreas Gal 1999
8 * (C) Copyright Gregory P. Smith 1999
9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10 * (C) Copyright Randy Dunlap 2000
11 * (C) Copyright David Brownell 2000-2004
12 * (C) Copyright Yggdrasil Computing, Inc. 2000
13 * (usb_device_id matching changes by Adam J. Richter)
14 * (C) Copyright Greg Kroah-Hartman 2002-2003
15 *
16 * Released under the GPLv2 only.
17 *
18 * NOTE! This is not actually a driver at all, rather this is
19 * just a collection of helper routines that implement the
20 * generic USB things that the real drivers can use..
21 *
22 * Think of this as a "USB library" rather than anything else.
23 * It should be considered a slave, with no callbacks. Callbacks
24 * are evil.
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/string.h>
30#include <linux/bitops.h>
31#include <linux/slab.h>
32#include <linux/interrupt.h> /* for in_interrupt() */
33#include <linux/kmod.h>
34#include <linux/init.h>
35#include <linux/spinlock.h>
36#include <linux/errno.h>
37#include <linux/usb.h>
38#include <linux/usb/hcd.h>
39#include <linux/mutex.h>
40#include <linux/workqueue.h>
41#include <linux/debugfs.h>
42#include <linux/usb/of.h>
43
44#include <asm/io.h>
45#include <linux/scatterlist.h>
46#include <linux/mm.h>
47#include <linux/dma-mapping.h>
48
49#include "usb.h"
50
51
52const char *usbcore_name = "usbcore";
53
54static bool nousb; /* Disable USB when built into kernel image */
55
56module_param(nousb, bool, 0444);
57
58/*
59 * for external read access to <nousb>
60 */
61int usb_disabled(void)
62{
63 return nousb;
64}
65EXPORT_SYMBOL_GPL(usb_disabled);
66
67#ifdef CONFIG_PM
68static int usb_autosuspend_delay = 2; /* Default delay value,
69 * in seconds */
70module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
71MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
72
73#else
74#define usb_autosuspend_delay 0
75#endif
76
77static bool match_endpoint(struct usb_endpoint_descriptor *epd,
78 struct usb_endpoint_descriptor **bulk_in,
79 struct usb_endpoint_descriptor **bulk_out,
80 struct usb_endpoint_descriptor **int_in,
81 struct usb_endpoint_descriptor **int_out)
82{
83 switch (usb_endpoint_type(epd)) {
84 case USB_ENDPOINT_XFER_BULK:
85 if (usb_endpoint_dir_in(epd)) {
86 if (bulk_in && !*bulk_in) {
87 *bulk_in = epd;
88 break;
89 }
90 } else {
91 if (bulk_out && !*bulk_out) {
92 *bulk_out = epd;
93 break;
94 }
95 }
96
97 return false;
98 case USB_ENDPOINT_XFER_INT:
99 if (usb_endpoint_dir_in(epd)) {
100 if (int_in && !*int_in) {
101 *int_in = epd;
102 break;
103 }
104 } else {
105 if (int_out && !*int_out) {
106 *int_out = epd;
107 break;
108 }
109 }
110
111 return false;
112 default:
113 return false;
114 }
115
116 return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
117 (!int_in || *int_in) && (!int_out || *int_out);
118}
119
120/**
121 * usb_find_common_endpoints() -- look up common endpoint descriptors
122 * @alt: alternate setting to search
123 * @bulk_in: pointer to descriptor pointer, or NULL
124 * @bulk_out: pointer to descriptor pointer, or NULL
125 * @int_in: pointer to descriptor pointer, or NULL
126 * @int_out: pointer to descriptor pointer, or NULL
127 *
128 * Search the alternate setting's endpoint descriptors for the first bulk-in,
129 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
130 * provided pointers (unless they are NULL).
131 *
132 * If a requested endpoint is not found, the corresponding pointer is set to
133 * NULL.
134 *
135 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
136 */
137int usb_find_common_endpoints(struct usb_host_interface *alt,
138 struct usb_endpoint_descriptor **bulk_in,
139 struct usb_endpoint_descriptor **bulk_out,
140 struct usb_endpoint_descriptor **int_in,
141 struct usb_endpoint_descriptor **int_out)
142{
143 struct usb_endpoint_descriptor *epd;
144 int i;
145
146 if (bulk_in)
147 *bulk_in = NULL;
148 if (bulk_out)
149 *bulk_out = NULL;
150 if (int_in)
151 *int_in = NULL;
152 if (int_out)
153 *int_out = NULL;
154
155 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
156 epd = &alt->endpoint[i].desc;
157
158 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
159 return 0;
160 }
161
162 return -ENXIO;
163}
164EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
165
166/**
167 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
168 * @alt: alternate setting to search
169 * @bulk_in: pointer to descriptor pointer, or NULL
170 * @bulk_out: pointer to descriptor pointer, or NULL
171 * @int_in: pointer to descriptor pointer, or NULL
172 * @int_out: pointer to descriptor pointer, or NULL
173 *
174 * Search the alternate setting's endpoint descriptors for the last bulk-in,
175 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
176 * provided pointers (unless they are NULL).
177 *
178 * If a requested endpoint is not found, the corresponding pointer is set to
179 * NULL.
180 *
181 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
182 */
183int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
184 struct usb_endpoint_descriptor **bulk_in,
185 struct usb_endpoint_descriptor **bulk_out,
186 struct usb_endpoint_descriptor **int_in,
187 struct usb_endpoint_descriptor **int_out)
188{
189 struct usb_endpoint_descriptor *epd;
190 int i;
191
192 if (bulk_in)
193 *bulk_in = NULL;
194 if (bulk_out)
195 *bulk_out = NULL;
196 if (int_in)
197 *int_in = NULL;
198 if (int_out)
199 *int_out = NULL;
200
201 for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
202 epd = &alt->endpoint[i].desc;
203
204 if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
205 return 0;
206 }
207
208 return -ENXIO;
209}
210EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
211
212/**
213 * usb_find_alt_setting() - Given a configuration, find the alternate setting
214 * for the given interface.
215 * @config: the configuration to search (not necessarily the current config).
216 * @iface_num: interface number to search in
217 * @alt_num: alternate interface setting number to search for.
218 *
219 * Search the configuration's interface cache for the given alt setting.
220 *
221 * Return: The alternate setting, if found. %NULL otherwise.
222 */
223struct usb_host_interface *usb_find_alt_setting(
224 struct usb_host_config *config,
225 unsigned int iface_num,
226 unsigned int alt_num)
227{
228 struct usb_interface_cache *intf_cache = NULL;
229 int i;
230
231 for (i = 0; i < config->desc.bNumInterfaces; i++) {
232 if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
233 == iface_num) {
234 intf_cache = config->intf_cache[i];
235 break;
236 }
237 }
238 if (!intf_cache)
239 return NULL;
240 for (i = 0; i < intf_cache->num_altsetting; i++)
241 if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
242 return &intf_cache->altsetting[i];
243
244 printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
245 "config %u\n", alt_num, iface_num,
246 config->desc.bConfigurationValue);
247 return NULL;
248}
249EXPORT_SYMBOL_GPL(usb_find_alt_setting);
250
251/**
252 * usb_ifnum_to_if - get the interface object with a given interface number
253 * @dev: the device whose current configuration is considered
254 * @ifnum: the desired interface
255 *
256 * This walks the device descriptor for the currently active configuration
257 * to find the interface object with the particular interface number.
258 *
259 * Note that configuration descriptors are not required to assign interface
260 * numbers sequentially, so that it would be incorrect to assume that
261 * the first interface in that descriptor corresponds to interface zero.
262 * This routine helps device drivers avoid such mistakes.
263 * However, you should make sure that you do the right thing with any
264 * alternate settings available for this interfaces.
265 *
266 * Don't call this function unless you are bound to one of the interfaces
267 * on this device or you have locked the device!
268 *
269 * Return: A pointer to the interface that has @ifnum as interface number,
270 * if found. %NULL otherwise.
271 */
272struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
273 unsigned ifnum)
274{
275 struct usb_host_config *config = dev->actconfig;
276 int i;
277
278 if (!config)
279 return NULL;
280 for (i = 0; i < config->desc.bNumInterfaces; i++)
281 if (config->interface[i]->altsetting[0]
282 .desc.bInterfaceNumber == ifnum)
283 return config->interface[i];
284
285 return NULL;
286}
287EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
288
289/**
290 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
291 * @intf: the interface containing the altsetting in question
292 * @altnum: the desired alternate setting number
293 *
294 * This searches the altsetting array of the specified interface for
295 * an entry with the correct bAlternateSetting value.
296 *
297 * Note that altsettings need not be stored sequentially by number, so
298 * it would be incorrect to assume that the first altsetting entry in
299 * the array corresponds to altsetting zero. This routine helps device
300 * drivers avoid such mistakes.
301 *
302 * Don't call this function unless you are bound to the intf interface
303 * or you have locked the device!
304 *
305 * Return: A pointer to the entry of the altsetting array of @intf that
306 * has @altnum as the alternate setting number. %NULL if not found.
307 */
308struct usb_host_interface *usb_altnum_to_altsetting(
309 const struct usb_interface *intf,
310 unsigned int altnum)
311{
312 int i;
313
314 for (i = 0; i < intf->num_altsetting; i++) {
315 if (intf->altsetting[i].desc.bAlternateSetting == altnum)
316 return &intf->altsetting[i];
317 }
318 return NULL;
319}
320EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
321
322struct find_interface_arg {
323 int minor;
324 struct device_driver *drv;
325};
326
327static int __find_interface(struct device *dev, void *data)
328{
329 struct find_interface_arg *arg = data;
330 struct usb_interface *intf;
331
332 if (!is_usb_interface(dev))
333 return 0;
334
335 if (dev->driver != arg->drv)
336 return 0;
337 intf = to_usb_interface(dev);
338 return intf->minor == arg->minor;
339}
340
341/**
342 * usb_find_interface - find usb_interface pointer for driver and device
343 * @drv: the driver whose current configuration is considered
344 * @minor: the minor number of the desired device
345 *
346 * This walks the bus device list and returns a pointer to the interface
347 * with the matching minor and driver. Note, this only works for devices
348 * that share the USB major number.
349 *
350 * Return: A pointer to the interface with the matching major and @minor.
351 */
352struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
353{
354 struct find_interface_arg argb;
355 struct device *dev;
356
357 argb.minor = minor;
358 argb.drv = &drv->drvwrap.driver;
359
360 dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
361
362 /* Drop reference count from bus_find_device */
363 put_device(dev);
364
365 return dev ? to_usb_interface(dev) : NULL;
366}
367EXPORT_SYMBOL_GPL(usb_find_interface);
368
369struct each_dev_arg {
370 void *data;
371 int (*fn)(struct usb_device *, void *);
372};
373
374static int __each_dev(struct device *dev, void *data)
375{
376 struct each_dev_arg *arg = (struct each_dev_arg *)data;
377
378 /* There are struct usb_interface on the same bus, filter them out */
379 if (!is_usb_device(dev))
380 return 0;
381
382 return arg->fn(to_usb_device(dev), arg->data);
383}
384
385/**
386 * usb_for_each_dev - iterate over all USB devices in the system
387 * @data: data pointer that will be handed to the callback function
388 * @fn: callback function to be called for each USB device
389 *
390 * Iterate over all USB devices and call @fn for each, passing it @data. If it
391 * returns anything other than 0, we break the iteration prematurely and return
392 * that value.
393 */
394int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
395{
396 struct each_dev_arg arg = {data, fn};
397
398 return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
399}
400EXPORT_SYMBOL_GPL(usb_for_each_dev);
401
402/**
403 * usb_release_dev - free a usb device structure when all users of it are finished.
404 * @dev: device that's been disconnected
405 *
406 * Will be called only by the device core when all users of this usb device are
407 * done.
408 */
409static void usb_release_dev(struct device *dev)
410{
411 struct usb_device *udev;
412 struct usb_hcd *hcd;
413
414 udev = to_usb_device(dev);
415 hcd = bus_to_hcd(udev->bus);
416
417 usb_destroy_configuration(udev);
418 usb_release_bos_descriptor(udev);
419 of_node_put(dev->of_node);
420 usb_put_hcd(hcd);
421 kfree(udev->product);
422 kfree(udev->manufacturer);
423 kfree(udev->serial);
424 kfree(udev);
425}
426
427static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
428{
429 struct usb_device *usb_dev;
430
431 usb_dev = to_usb_device(dev);
432
433 if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
434 return -ENOMEM;
435
436 if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
437 return -ENOMEM;
438
439 return 0;
440}
441
442#ifdef CONFIG_PM
443
444/* USB device Power-Management thunks.
445 * There's no need to distinguish here between quiescing a USB device
446 * and powering it down; the generic_suspend() routine takes care of
447 * it by skipping the usb_port_suspend() call for a quiesce. And for
448 * USB interfaces there's no difference at all.
449 */
450
451static int usb_dev_prepare(struct device *dev)
452{
453 return 0; /* Implement eventually? */
454}
455
456static void usb_dev_complete(struct device *dev)
457{
458 /* Currently used only for rebinding interfaces */
459 usb_resume_complete(dev);
460}
461
462static int usb_dev_suspend(struct device *dev)
463{
464 return usb_suspend(dev, PMSG_SUSPEND);
465}
466
467static int usb_dev_resume(struct device *dev)
468{
469 return usb_resume(dev, PMSG_RESUME);
470}
471
472static int usb_dev_freeze(struct device *dev)
473{
474 return usb_suspend(dev, PMSG_FREEZE);
475}
476
477static int usb_dev_thaw(struct device *dev)
478{
479 return usb_resume(dev, PMSG_THAW);
480}
481
482static int usb_dev_poweroff(struct device *dev)
483{
484 return usb_suspend(dev, PMSG_HIBERNATE);
485}
486
487static int usb_dev_restore(struct device *dev)
488{
489 return usb_resume(dev, PMSG_RESTORE);
490}
491
492static const struct dev_pm_ops usb_device_pm_ops = {
493 .prepare = usb_dev_prepare,
494 .complete = usb_dev_complete,
495 .suspend = usb_dev_suspend,
496 .resume = usb_dev_resume,
497 .freeze = usb_dev_freeze,
498 .thaw = usb_dev_thaw,
499 .poweroff = usb_dev_poweroff,
500 .restore = usb_dev_restore,
501 .runtime_suspend = usb_runtime_suspend,
502 .runtime_resume = usb_runtime_resume,
503 .runtime_idle = usb_runtime_idle,
504};
505
506#endif /* CONFIG_PM */
507
508
509static char *usb_devnode(struct device *dev,
510 umode_t *mode, kuid_t *uid, kgid_t *gid)
511{
512 struct usb_device *usb_dev;
513
514 usb_dev = to_usb_device(dev);
515 return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
516 usb_dev->bus->busnum, usb_dev->devnum);
517}
518
519struct device_type usb_device_type = {
520 .name = "usb_device",
521 .release = usb_release_dev,
522 .uevent = usb_dev_uevent,
523 .devnode = usb_devnode,
524#ifdef CONFIG_PM
525 .pm = &usb_device_pm_ops,
526#endif
527};
528
529
530/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
531static unsigned usb_bus_is_wusb(struct usb_bus *bus)
532{
533 struct usb_hcd *hcd = bus_to_hcd(bus);
534 return hcd->wireless;
535}
536
537
538/**
539 * usb_alloc_dev - usb device constructor (usbcore-internal)
540 * @parent: hub to which device is connected; null to allocate a root hub
541 * @bus: bus used to access the device
542 * @port1: one-based index of port; ignored for root hubs
543 * Context: !in_interrupt()
544 *
545 * Only hub drivers (including virtual root hub drivers for host
546 * controllers) should ever call this.
547 *
548 * This call may not be used in a non-sleeping context.
549 *
550 * Return: On success, a pointer to the allocated usb device. %NULL on
551 * failure.
552 */
553struct usb_device *usb_alloc_dev(struct usb_device *parent,
554 struct usb_bus *bus, unsigned port1)
555{
556 struct usb_device *dev;
557 struct usb_hcd *usb_hcd = bus_to_hcd(bus);
558 unsigned root_hub = 0;
559 unsigned raw_port = port1;
560
561 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
562 if (!dev)
563 return NULL;
564
565 if (!usb_get_hcd(usb_hcd)) {
566 kfree(dev);
567 return NULL;
568 }
569 /* Root hubs aren't true devices, so don't allocate HCD resources */
570 if (usb_hcd->driver->alloc_dev && parent &&
571 !usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
572 usb_put_hcd(bus_to_hcd(bus));
573 kfree(dev);
574 return NULL;
575 }
576
577 device_initialize(&dev->dev);
578 dev->dev.bus = &usb_bus_type;
579 dev->dev.type = &usb_device_type;
580 dev->dev.groups = usb_device_groups;
581 /*
582 * Fake a dma_mask/offset for the USB device:
583 * We cannot really use the dma-mapping API (dma_alloc_* and
584 * dma_map_*) for USB devices but instead need to use
585 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
586 * manually look into the mask/offset pair to determine whether
587 * they need bounce buffers.
588 * Note: calling dma_set_mask() on a USB device would set the
589 * mask for the entire HCD, so don't do that.
590 */
591 dev->dev.dma_mask = bus->sysdev->dma_mask;
592 dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset;
593 set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
594 dev->state = USB_STATE_ATTACHED;
595 dev->lpm_disable_count = 1;
596 atomic_set(&dev->urbnum, 0);
597
598 INIT_LIST_HEAD(&dev->ep0.urb_list);
599 dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
600 dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
601 /* ep0 maxpacket comes later, from device descriptor */
602 usb_enable_endpoint(dev, &dev->ep0, false);
603 dev->can_submit = 1;
604
605 /* Save readable and stable topology id, distinguishing devices
606 * by location for diagnostics, tools, driver model, etc. The
607 * string is a path along hub ports, from the root. Each device's
608 * dev->devpath will be stable until USB is re-cabled, and hubs
609 * are often labeled with these port numbers. The name isn't
610 * as stable: bus->busnum changes easily from modprobe order,
611 * cardbus or pci hotplugging, and so on.
612 */
613 if (unlikely(!parent)) {
614 dev->devpath[0] = '0';
615 dev->route = 0;
616
617 dev->dev.parent = bus->controller;
618 device_set_of_node_from_dev(&dev->dev, bus->sysdev);
619 dev_set_name(&dev->dev, "usb%d", bus->busnum);
620 root_hub = 1;
621 } else {
622 /* match any labeling on the hubs; it's one-based */
623 if (parent->devpath[0] == '0') {
624 snprintf(dev->devpath, sizeof dev->devpath,
625 "%d", port1);
626 /* Root ports are not counted in route string */
627 dev->route = 0;
628 } else {
629 snprintf(dev->devpath, sizeof dev->devpath,
630 "%s.%d", parent->devpath, port1);
631 /* Route string assumes hubs have less than 16 ports */
632 if (port1 < 15)
633 dev->route = parent->route +
634 (port1 << ((parent->level - 1)*4));
635 else
636 dev->route = parent->route +
637 (15 << ((parent->level - 1)*4));
638 }
639
640 dev->dev.parent = &parent->dev;
641 dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
642
643 if (!parent->parent) {
644 /* device under root hub's port */
645 raw_port = usb_hcd_find_raw_port_number(usb_hcd,
646 port1);
647 }
648 dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
649
650 /* hub driver sets up TT records */
651 }
652
653 dev->portnum = port1;
654 dev->bus = bus;
655 dev->parent = parent;
656 INIT_LIST_HEAD(&dev->filelist);
657
658#ifdef CONFIG_PM
659 pm_runtime_set_autosuspend_delay(&dev->dev,
660 usb_autosuspend_delay * 1000);
661 dev->connect_time = jiffies;
662 dev->active_duration = -jiffies;
663#endif
664 if (root_hub) /* Root hub always ok [and always wired] */
665 dev->authorized = 1;
666 else {
667 dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
668 dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
669 }
670 return dev;
671}
672EXPORT_SYMBOL_GPL(usb_alloc_dev);
673
674/**
675 * usb_get_dev - increments the reference count of the usb device structure
676 * @dev: the device being referenced
677 *
678 * Each live reference to a device should be refcounted.
679 *
680 * Drivers for USB interfaces should normally record such references in
681 * their probe() methods, when they bind to an interface, and release
682 * them by calling usb_put_dev(), in their disconnect() methods.
683 *
684 * Return: A pointer to the device with the incremented reference counter.
685 */
686struct usb_device *usb_get_dev(struct usb_device *dev)
687{
688 if (dev)
689 get_device(&dev->dev);
690 return dev;
691}
692EXPORT_SYMBOL_GPL(usb_get_dev);
693
694/**
695 * usb_put_dev - release a use of the usb device structure
696 * @dev: device that's been disconnected
697 *
698 * Must be called when a user of a device is finished with it. When the last
699 * user of the device calls this function, the memory of the device is freed.
700 */
701void usb_put_dev(struct usb_device *dev)
702{
703 if (dev)
704 put_device(&dev->dev);
705}
706EXPORT_SYMBOL_GPL(usb_put_dev);
707
708/**
709 * usb_get_intf - increments the reference count of the usb interface structure
710 * @intf: the interface being referenced
711 *
712 * Each live reference to a interface must be refcounted.
713 *
714 * Drivers for USB interfaces should normally record such references in
715 * their probe() methods, when they bind to an interface, and release
716 * them by calling usb_put_intf(), in their disconnect() methods.
717 *
718 * Return: A pointer to the interface with the incremented reference counter.
719 */
720struct usb_interface *usb_get_intf(struct usb_interface *intf)
721{
722 if (intf)
723 get_device(&intf->dev);
724 return intf;
725}
726EXPORT_SYMBOL_GPL(usb_get_intf);
727
728/**
729 * usb_put_intf - release a use of the usb interface structure
730 * @intf: interface that's been decremented
731 *
732 * Must be called when a user of an interface is finished with it. When the
733 * last user of the interface calls this function, the memory of the interface
734 * is freed.
735 */
736void usb_put_intf(struct usb_interface *intf)
737{
738 if (intf)
739 put_device(&intf->dev);
740}
741EXPORT_SYMBOL_GPL(usb_put_intf);
742
743/* USB device locking
744 *
745 * USB devices and interfaces are locked using the semaphore in their
746 * embedded struct device. The hub driver guarantees that whenever a
747 * device is connected or disconnected, drivers are called with the
748 * USB device locked as well as their particular interface.
749 *
750 * Complications arise when several devices are to be locked at the same
751 * time. Only hub-aware drivers that are part of usbcore ever have to
752 * do this; nobody else needs to worry about it. The rule for locking
753 * is simple:
754 *
755 * When locking both a device and its parent, always lock the
756 * the parent first.
757 */
758
759/**
760 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
761 * @udev: device that's being locked
762 * @iface: interface bound to the driver making the request (optional)
763 *
764 * Attempts to acquire the device lock, but fails if the device is
765 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
766 * is neither BINDING nor BOUND. Rather than sleeping to wait for the
767 * lock, the routine polls repeatedly. This is to prevent deadlock with
768 * disconnect; in some drivers (such as usb-storage) the disconnect()
769 * or suspend() method will block waiting for a device reset to complete.
770 *
771 * Return: A negative error code for failure, otherwise 0.
772 */
773int usb_lock_device_for_reset(struct usb_device *udev,
774 const struct usb_interface *iface)
775{
776 unsigned long jiffies_expire = jiffies + HZ;
777
778 if (udev->state == USB_STATE_NOTATTACHED)
779 return -ENODEV;
780 if (udev->state == USB_STATE_SUSPENDED)
781 return -EHOSTUNREACH;
782 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
783 iface->condition == USB_INTERFACE_UNBOUND))
784 return -EINTR;
785
786 while (!usb_trylock_device(udev)) {
787
788 /* If we can't acquire the lock after waiting one second,
789 * we're probably deadlocked */
790 if (time_after(jiffies, jiffies_expire))
791 return -EBUSY;
792
793 msleep(15);
794 if (udev->state == USB_STATE_NOTATTACHED)
795 return -ENODEV;
796 if (udev->state == USB_STATE_SUSPENDED)
797 return -EHOSTUNREACH;
798 if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
799 iface->condition == USB_INTERFACE_UNBOUND))
800 return -EINTR;
801 }
802 return 0;
803}
804EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
805
806/**
807 * usb_get_current_frame_number - return current bus frame number
808 * @dev: the device whose bus is being queried
809 *
810 * Return: The current frame number for the USB host controller used
811 * with the given USB device. This can be used when scheduling
812 * isochronous requests.
813 *
814 * Note: Different kinds of host controller have different "scheduling
815 * horizons". While one type might support scheduling only 32 frames
816 * into the future, others could support scheduling up to 1024 frames
817 * into the future.
818 *
819 */
820int usb_get_current_frame_number(struct usb_device *dev)
821{
822 return usb_hcd_get_frame_number(dev);
823}
824EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
825
826/*-------------------------------------------------------------------*/
827/*
828 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
829 * extra field of the interface and endpoint descriptor structs.
830 */
831
832int __usb_get_extra_descriptor(char *buffer, unsigned size,
833 unsigned char type, void **ptr)
834{
835 struct usb_descriptor_header *header;
836
837 while (size >= sizeof(struct usb_descriptor_header)) {
838 header = (struct usb_descriptor_header *)buffer;
839
840 if (header->bLength < 2) {
841 printk(KERN_ERR
842 "%s: bogus descriptor, type %d length %d\n",
843 usbcore_name,
844 header->bDescriptorType,
845 header->bLength);
846 return -1;
847 }
848
849 if (header->bDescriptorType == type) {
850 *ptr = header;
851 return 0;
852 }
853
854 buffer += header->bLength;
855 size -= header->bLength;
856 }
857 return -1;
858}
859EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
860
861/**
862 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
863 * @dev: device the buffer will be used with
864 * @size: requested buffer size
865 * @mem_flags: affect whether allocation may block
866 * @dma: used to return DMA address of buffer
867 *
868 * Return: Either null (indicating no buffer could be allocated), or the
869 * cpu-space pointer to a buffer that may be used to perform DMA to the
870 * specified device. Such cpu-space buffers are returned along with the DMA
871 * address (through the pointer provided).
872 *
873 * Note:
874 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
875 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
876 * hardware during URB completion/resubmit. The implementation varies between
877 * platforms, depending on details of how DMA will work to this device.
878 * Using these buffers also eliminates cacheline sharing problems on
879 * architectures where CPU caches are not DMA-coherent. On systems without
880 * bus-snooping caches, these buffers are uncached.
881 *
882 * When the buffer is no longer used, free it with usb_free_coherent().
883 */
884void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
885 dma_addr_t *dma)
886{
887 if (!dev || !dev->bus)
888 return NULL;
889 return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
890}
891EXPORT_SYMBOL_GPL(usb_alloc_coherent);
892
893/**
894 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
895 * @dev: device the buffer was used with
896 * @size: requested buffer size
897 * @addr: CPU address of buffer
898 * @dma: DMA address of buffer
899 *
900 * This reclaims an I/O buffer, letting it be reused. The memory must have
901 * been allocated using usb_alloc_coherent(), and the parameters must match
902 * those provided in that allocation request.
903 */
904void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
905 dma_addr_t dma)
906{
907 if (!dev || !dev->bus)
908 return;
909 if (!addr)
910 return;
911 hcd_buffer_free(dev->bus, size, addr, dma);
912}
913EXPORT_SYMBOL_GPL(usb_free_coherent);
914
915/**
916 * usb_buffer_map - create DMA mapping(s) for an urb
917 * @urb: urb whose transfer_buffer/setup_packet will be mapped
918 *
919 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
920 * succeeds. If the device is connected to this system through a non-DMA
921 * controller, this operation always succeeds.
922 *
923 * This call would normally be used for an urb which is reused, perhaps
924 * as the target of a large periodic transfer, with usb_buffer_dmasync()
925 * calls to synchronize memory and dma state.
926 *
927 * Reverse the effect of this call with usb_buffer_unmap().
928 *
929 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
930 *
931 */
932#if 0
933struct urb *usb_buffer_map(struct urb *urb)
934{
935 struct usb_bus *bus;
936 struct device *controller;
937
938 if (!urb
939 || !urb->dev
940 || !(bus = urb->dev->bus)
941 || !(controller = bus->sysdev))
942 return NULL;
943
944 if (controller->dma_mask) {
945 urb->transfer_dma = dma_map_single(controller,
946 urb->transfer_buffer, urb->transfer_buffer_length,
947 usb_pipein(urb->pipe)
948 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
949 /* FIXME generic api broken like pci, can't report errors */
950 /* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
951 } else
952 urb->transfer_dma = ~0;
953 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
954 return urb;
955}
956EXPORT_SYMBOL_GPL(usb_buffer_map);
957#endif /* 0 */
958
959/* XXX DISABLED, no users currently. If you wish to re-enable this
960 * XXX please determine whether the sync is to transfer ownership of
961 * XXX the buffer from device to cpu or vice verse, and thusly use the
962 * XXX appropriate _for_{cpu,device}() method. -DaveM
963 */
964#if 0
965
966/**
967 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
968 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
969 */
970void usb_buffer_dmasync(struct urb *urb)
971{
972 struct usb_bus *bus;
973 struct device *controller;
974
975 if (!urb
976 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
977 || !urb->dev
978 || !(bus = urb->dev->bus)
979 || !(controller = bus->sysdev))
980 return;
981
982 if (controller->dma_mask) {
983 dma_sync_single_for_cpu(controller,
984 urb->transfer_dma, urb->transfer_buffer_length,
985 usb_pipein(urb->pipe)
986 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
987 if (usb_pipecontrol(urb->pipe))
988 dma_sync_single_for_cpu(controller,
989 urb->setup_dma,
990 sizeof(struct usb_ctrlrequest),
991 DMA_TO_DEVICE);
992 }
993}
994EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
995#endif
996
997/**
998 * usb_buffer_unmap - free DMA mapping(s) for an urb
999 * @urb: urb whose transfer_buffer will be unmapped
1000 *
1001 * Reverses the effect of usb_buffer_map().
1002 */
1003#if 0
1004void usb_buffer_unmap(struct urb *urb)
1005{
1006 struct usb_bus *bus;
1007 struct device *controller;
1008
1009 if (!urb
1010 || !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
1011 || !urb->dev
1012 || !(bus = urb->dev->bus)
1013 || !(controller = bus->sysdev))
1014 return;
1015
1016 if (controller->dma_mask) {
1017 dma_unmap_single(controller,
1018 urb->transfer_dma, urb->transfer_buffer_length,
1019 usb_pipein(urb->pipe)
1020 ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1021 }
1022 urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
1023}
1024EXPORT_SYMBOL_GPL(usb_buffer_unmap);
1025#endif /* 0 */
1026
1027#if 0
1028/**
1029 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
1030 * @dev: device to which the scatterlist will be mapped
1031 * @is_in: mapping transfer direction
1032 * @sg: the scatterlist to map
1033 * @nents: the number of entries in the scatterlist
1034 *
1035 * Return: Either < 0 (indicating no buffers could be mapped), or the
1036 * number of DMA mapping array entries in the scatterlist.
1037 *
1038 * Note:
1039 * The caller is responsible for placing the resulting DMA addresses from
1040 * the scatterlist into URB transfer buffer pointers, and for setting the
1041 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
1042 *
1043 * Top I/O rates come from queuing URBs, instead of waiting for each one
1044 * to complete before starting the next I/O. This is particularly easy
1045 * to do with scatterlists. Just allocate and submit one URB for each DMA
1046 * mapping entry returned, stopping on the first error or when all succeed.
1047 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
1048 *
1049 * This call would normally be used when translating scatterlist requests,
1050 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
1051 * may be able to coalesce mappings for improved I/O efficiency.
1052 *
1053 * Reverse the effect of this call with usb_buffer_unmap_sg().
1054 */
1055int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
1056 struct scatterlist *sg, int nents)
1057{
1058 struct usb_bus *bus;
1059 struct device *controller;
1060
1061 if (!dev
1062 || !(bus = dev->bus)
1063 || !(controller = bus->sysdev)
1064 || !controller->dma_mask)
1065 return -EINVAL;
1066
1067 /* FIXME generic api broken like pci, can't report errors */
1068 return dma_map_sg(controller, sg, nents,
1069 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
1070}
1071EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
1072#endif
1073
1074/* XXX DISABLED, no users currently. If you wish to re-enable this
1075 * XXX please determine whether the sync is to transfer ownership of
1076 * XXX the buffer from device to cpu or vice verse, and thusly use the
1077 * XXX appropriate _for_{cpu,device}() method. -DaveM
1078 */
1079#if 0
1080
1081/**
1082 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
1083 * @dev: device to which the scatterlist will be mapped
1084 * @is_in: mapping transfer direction
1085 * @sg: the scatterlist to synchronize
1086 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1087 *
1088 * Use this when you are re-using a scatterlist's data buffers for
1089 * another USB request.
1090 */
1091void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
1092 struct scatterlist *sg, int n_hw_ents)
1093{
1094 struct usb_bus *bus;
1095 struct device *controller;
1096
1097 if (!dev
1098 || !(bus = dev->bus)
1099 || !(controller = bus->sysdev)
1100 || !controller->dma_mask)
1101 return;
1102
1103 dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
1104 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1105}
1106EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
1107#endif
1108
1109#if 0
1110/**
1111 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
1112 * @dev: device to which the scatterlist will be mapped
1113 * @is_in: mapping transfer direction
1114 * @sg: the scatterlist to unmap
1115 * @n_hw_ents: the positive return value from usb_buffer_map_sg
1116 *
1117 * Reverses the effect of usb_buffer_map_sg().
1118 */
1119void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
1120 struct scatterlist *sg, int n_hw_ents)
1121{
1122 struct usb_bus *bus;
1123 struct device *controller;
1124
1125 if (!dev
1126 || !(bus = dev->bus)
1127 || !(controller = bus->sysdev)
1128 || !controller->dma_mask)
1129 return;
1130
1131 dma_unmap_sg(controller, sg, n_hw_ents,
1132 is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1133}
1134EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1135#endif
1136
1137/*
1138 * Notifications of device and interface registration
1139 */
1140static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1141 void *data)
1142{
1143 struct device *dev = data;
1144
1145 switch (action) {
1146 case BUS_NOTIFY_ADD_DEVICE:
1147 if (dev->type == &usb_device_type)
1148 (void) usb_create_sysfs_dev_files(to_usb_device(dev));
1149 else if (dev->type == &usb_if_device_type)
1150 usb_create_sysfs_intf_files(to_usb_interface(dev));
1151 break;
1152
1153 case BUS_NOTIFY_DEL_DEVICE:
1154 if (dev->type == &usb_device_type)
1155 usb_remove_sysfs_dev_files(to_usb_device(dev));
1156 else if (dev->type == &usb_if_device_type)
1157 usb_remove_sysfs_intf_files(to_usb_interface(dev));
1158 break;
1159 }
1160 return 0;
1161}
1162
1163static struct notifier_block usb_bus_nb = {
1164 .notifier_call = usb_bus_notify,
1165};
1166
1167struct dentry *usb_debug_root;
1168EXPORT_SYMBOL_GPL(usb_debug_root);
1169
1170static struct dentry *usb_debug_devices;
1171
1172static int usb_debugfs_init(void)
1173{
1174 usb_debug_root = debugfs_create_dir("usb", NULL);
1175 if (!usb_debug_root)
1176 return -ENOENT;
1177
1178 usb_debug_devices = debugfs_create_file("devices", 0444,
1179 usb_debug_root, NULL,
1180 &usbfs_devices_fops);
1181 if (!usb_debug_devices) {
1182 debugfs_remove(usb_debug_root);
1183 usb_debug_root = NULL;
1184 return -ENOENT;
1185 }
1186
1187 return 0;
1188}
1189
1190static void usb_debugfs_cleanup(void)
1191{
1192 debugfs_remove(usb_debug_devices);
1193 debugfs_remove(usb_debug_root);
1194}
1195
1196/*
1197 * Init
1198 */
1199static int __init usb_init(void)
1200{
1201 int retval;
1202 if (usb_disabled()) {
1203 pr_info("%s: USB support disabled\n", usbcore_name);
1204 return 0;
1205 }
1206 usb_init_pool_max();
1207
1208 retval = usb_debugfs_init();
1209 if (retval)
1210 goto out;
1211
1212 usb_acpi_register();
1213 retval = bus_register(&usb_bus_type);
1214 if (retval)
1215 goto bus_register_failed;
1216 retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1217 if (retval)
1218 goto bus_notifier_failed;
1219 retval = usb_major_init();
1220 if (retval)
1221 goto major_init_failed;
1222 retval = usb_register(&usbfs_driver);
1223 if (retval)
1224 goto driver_register_failed;
1225 retval = usb_devio_init();
1226 if (retval)
1227 goto usb_devio_init_failed;
1228 retval = usb_hub_init();
1229 if (retval)
1230 goto hub_init_failed;
1231 retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1232 if (!retval)
1233 goto out;
1234
1235 usb_hub_cleanup();
1236hub_init_failed:
1237 usb_devio_cleanup();
1238usb_devio_init_failed:
1239 usb_deregister(&usbfs_driver);
1240driver_register_failed:
1241 usb_major_cleanup();
1242major_init_failed:
1243 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1244bus_notifier_failed:
1245 bus_unregister(&usb_bus_type);
1246bus_register_failed:
1247 usb_acpi_unregister();
1248 usb_debugfs_cleanup();
1249out:
1250 return retval;
1251}
1252
1253/*
1254 * Cleanup
1255 */
1256static void __exit usb_exit(void)
1257{
1258 /* This will matter if shutdown/reboot does exitcalls. */
1259 if (usb_disabled())
1260 return;
1261
1262 usb_release_quirk_list();
1263 usb_deregister_device_driver(&usb_generic_driver);
1264 usb_major_cleanup();
1265 usb_deregister(&usbfs_driver);
1266 usb_devio_cleanup();
1267 usb_hub_cleanup();
1268 bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1269 bus_unregister(&usb_bus_type);
1270 usb_acpi_unregister();
1271 usb_debugfs_cleanup();
1272 idr_destroy(&usb_bus_idr);
1273}
1274
1275subsys_initcall(usb_init);
1276module_exit(usb_exit);
1277MODULE_LICENSE("GPL");