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 
49 const char *usbcore_name = "usbcore";
50 
51 static bool nousb;	/* Disable USB when built into kernel image */
52 
53 module_param(nousb, bool, 0444);
54 
55 /*
56  * for external read access to <nousb>
57  */
usb_disabled(void)58 int usb_disabled(void)
59 {
60 	return nousb;
61 }
62 EXPORT_SYMBOL_GPL(usb_disabled);
63 
64 #ifdef	CONFIG_PM
65 /* Default delay value, in seconds */
66 static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
67 module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
68 MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
69 
70 #else
71 #define usb_autosuspend_delay		0
72 #endif
73 
match_endpoint(struct usb_endpoint_descriptor * epd,struct usb_endpoint_descriptor ** bulk_in,struct usb_endpoint_descriptor ** bulk_out,struct usb_endpoint_descriptor ** int_in,struct usb_endpoint_descriptor ** int_out)74 static 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  */
usb_find_common_endpoints(struct usb_host_interface * alt,struct usb_endpoint_descriptor ** bulk_in,struct usb_endpoint_descriptor ** bulk_out,struct usb_endpoint_descriptor ** int_in,struct usb_endpoint_descriptor ** int_out)134 int 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 }
161 EXPORT_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  */
usb_find_common_endpoints_reverse(struct usb_host_interface * alt,struct usb_endpoint_descriptor ** bulk_in,struct usb_endpoint_descriptor ** bulk_out,struct usb_endpoint_descriptor ** int_in,struct usb_endpoint_descriptor ** int_out)180 int 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 }
207 EXPORT_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  */
usb_find_alt_setting(struct usb_host_config * config,unsigned int iface_num,unsigned int alt_num)220 struct 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 }
248 EXPORT_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  */
usb_ifnum_to_if(const struct usb_device * dev,unsigned ifnum)271 struct 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 }
286 EXPORT_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  */
usb_altnum_to_altsetting(const struct usb_interface * intf,unsigned int altnum)307 struct 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 }
319 EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
320 
321 struct find_interface_arg {
322 	int minor;
323 	struct device_driver *drv;
324 };
325 
__find_interface(struct device * dev,const void * data)326 static 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  */
usb_find_interface(struct usb_driver * drv,int minor)351 struct 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 }
366 EXPORT_SYMBOL_GPL(usb_find_interface);
367 
368 struct each_dev_arg {
369 	void *data;
370 	int (*fn)(struct usb_device *, void *);
371 };
372 
__each_dev(struct device * dev,void * data)373 static 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  */
usb_for_each_dev(void * data,int (* fn)(struct usb_device *,void *))393 int 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 }
399 EXPORT_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  */
usb_release_dev(struct device * dev)408 static 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 
usb_dev_uevent(struct device * dev,struct kobj_uevent_env * env)426 static 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 
usb_dev_prepare(struct device * dev)450 static int usb_dev_prepare(struct device *dev)
451 {
452 	return 0;		/* Implement eventually? */
453 }
454 
usb_dev_complete(struct device * dev)455 static void usb_dev_complete(struct device *dev)
456 {
457 	/* Currently used only for rebinding interfaces */
458 	usb_resume_complete(dev);
459 }
460 
usb_dev_suspend(struct device * dev)461 static int usb_dev_suspend(struct device *dev)
462 {
463 	return usb_suspend(dev, PMSG_SUSPEND);
464 }
465 
usb_dev_resume(struct device * dev)466 static int usb_dev_resume(struct device *dev)
467 {
468 	return usb_resume(dev, PMSG_RESUME);
469 }
470 
usb_dev_freeze(struct device * dev)471 static int usb_dev_freeze(struct device *dev)
472 {
473 	return usb_suspend(dev, PMSG_FREEZE);
474 }
475 
usb_dev_thaw(struct device * dev)476 static int usb_dev_thaw(struct device *dev)
477 {
478 	return usb_resume(dev, PMSG_THAW);
479 }
480 
usb_dev_poweroff(struct device * dev)481 static int usb_dev_poweroff(struct device *dev)
482 {
483 	return usb_suspend(dev, PMSG_HIBERNATE);
484 }
485 
usb_dev_restore(struct device * dev)486 static int usb_dev_restore(struct device *dev)
487 {
488 	return usb_resume(dev, PMSG_RESTORE);
489 }
490 
491 static 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 
usb_devnode(struct device * dev,umode_t * mode,kuid_t * uid,kgid_t * gid)508 static 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 
518 struct 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 */
usb_bus_is_wusb(struct usb_bus * bus)530 static 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 
usb_dev_authorized(struct usb_device * dev,struct usb_hcd * hcd)536 static 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  */
usb_alloc_dev(struct usb_device * parent,struct usb_bus * bus,unsigned port1)574 struct 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 }
680 EXPORT_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  */
usb_get_dev(struct usb_device * dev)698 struct usb_device *usb_get_dev(struct usb_device *dev)
699 {
700 	if (dev)
701 		get_device(&dev->dev);
702 	return dev;
703 }
704 EXPORT_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  */
usb_put_dev(struct usb_device * dev)713 void usb_put_dev(struct usb_device *dev)
714 {
715 	if (dev)
716 		put_device(&dev->dev);
717 }
718 EXPORT_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  */
usb_get_intf(struct usb_interface * intf)736 struct usb_interface *usb_get_intf(struct usb_interface *intf)
737 {
738 	if (intf)
739 		get_device(&intf->dev);
740 	return intf;
741 }
742 EXPORT_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  */
usb_put_intf(struct usb_interface * intf)752 void usb_put_intf(struct usb_interface *intf)
753 {
754 	if (intf)
755 		put_device(&intf->dev);
756 }
757 EXPORT_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  */
usb_intf_get_dma_device(struct usb_interface * intf)773 struct 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 }
789 EXPORT_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  *	the 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  */
usb_lock_device_for_reset(struct usb_device * udev,const struct usb_interface * iface)821 int 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 }
852 EXPORT_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  */
usb_get_current_frame_number(struct usb_device * dev)868 int usb_get_current_frame_number(struct usb_device *dev)
869 {
870 	return usb_hcd_get_frame_number(dev);
871 }
872 EXPORT_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 
__usb_get_extra_descriptor(char * buffer,unsigned size,unsigned char type,void ** ptr,size_t minsize)880 int __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 }
907 EXPORT_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  */
usb_alloc_coherent(struct usb_device * dev,size_t size,gfp_t mem_flags,dma_addr_t * dma)932 void *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 }
939 EXPORT_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  */
usb_free_coherent(struct usb_device * dev,size_t size,void * addr,dma_addr_t dma)952 void 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 }
961 EXPORT_SYMBOL_GPL(usb_free_coherent);
962 
963 /*
964  * Notifications of device and interface registration
965  */
usb_bus_notify(struct notifier_block * nb,unsigned long action,void * data)966 static 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 
989 static struct notifier_block usb_bus_nb = {
990 	.notifier_call = usb_bus_notify,
991 };
992 
usb_debugfs_init(void)993 static void usb_debugfs_init(void)
994 {
995 	debugfs_create_file("devices", 0444, usb_debug_root, NULL,
996 			    &usbfs_devices_fops);
997 }
998 
usb_debugfs_cleanup(void)999 static void usb_debugfs_cleanup(void)
1000 {
1001 	debugfs_remove(debugfs_lookup("devices", usb_debug_root));
1002 }
1003 
1004 /*
1005  * Init
1006  */
usb_init(void)1007 static 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();
1042 hub_init_failed:
1043 	usb_devio_cleanup();
1044 usb_devio_init_failed:
1045 	usb_deregister(&usbfs_driver);
1046 driver_register_failed:
1047 	usb_major_cleanup();
1048 major_init_failed:
1049 	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1050 bus_notifier_failed:
1051 	bus_unregister(&usb_bus_type);
1052 bus_register_failed:
1053 	usb_acpi_unregister();
1054 	usb_debugfs_cleanup();
1055 out:
1056 	return retval;
1057 }
1058 
1059 /*
1060  * Cleanup
1061  */
usb_exit(void)1062 static 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 
1081 subsys_initcall(usb_init);
1082 module_exit(usb_exit);
1083 MODULE_LICENSE("GPL");
1084