xref: /linux/drivers/usb/core/hcd.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*
2  * (C) Copyright Linus Torvalds 1999
3  * (C) Copyright Johannes Erdfelt 1999-2001
4  * (C) Copyright Andreas Gal 1999
5  * (C) Copyright Gregory P. Smith 1999
6  * (C) Copyright Deti Fliegl 1999
7  * (C) Copyright Randy Dunlap 2000
8  * (C) Copyright David Brownell 2000-2002
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the
12  * Free Software Foundation; either version 2 of the License, or (at your
13  * option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  * for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software Foundation,
22  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  */
24 
25 #include <linux/bcd.h>
26 #include <linux/module.h>
27 #include <linux/version.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/completion.h>
31 #include <linux/utsname.h>
32 #include <linux/mm.h>
33 #include <asm/io.h>
34 #include <linux/device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/mutex.h>
37 #include <asm/irq.h>
38 #include <asm/byteorder.h>
39 #include <asm/unaligned.h>
40 #include <linux/platform_device.h>
41 #include <linux/workqueue.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/types.h>
44 
45 #include <linux/phy/phy.h>
46 #include <linux/usb.h>
47 #include <linux/usb/hcd.h>
48 #include <linux/usb/phy.h>
49 
50 #include "usb.h"
51 
52 
53 /*-------------------------------------------------------------------------*/
54 
55 /*
56  * USB Host Controller Driver framework
57  *
58  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
59  * HCD-specific behaviors/bugs.
60  *
61  * This does error checks, tracks devices and urbs, and delegates to a
62  * "hc_driver" only for code (and data) that really needs to know about
63  * hardware differences.  That includes root hub registers, i/o queues,
64  * and so on ... but as little else as possible.
65  *
66  * Shared code includes most of the "root hub" code (these are emulated,
67  * though each HC's hardware works differently) and PCI glue, plus request
68  * tracking overhead.  The HCD code should only block on spinlocks or on
69  * hardware handshaking; blocking on software events (such as other kernel
70  * threads releasing resources, or completing actions) is all generic.
71  *
72  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
73  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
74  * only by the hub driver ... and that neither should be seen or used by
75  * usb client device drivers.
76  *
77  * Contributors of ideas or unattributed patches include: David Brownell,
78  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
79  *
80  * HISTORY:
81  * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
82  *		associated cleanup.  "usb_hcd" still != "usb_bus".
83  * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
84  */
85 
86 /*-------------------------------------------------------------------------*/
87 
88 /* Keep track of which host controller drivers are loaded */
89 unsigned long usb_hcds_loaded;
90 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
91 
92 /* host controllers we manage */
93 LIST_HEAD (usb_bus_list);
94 EXPORT_SYMBOL_GPL (usb_bus_list);
95 
96 /* used when allocating bus numbers */
97 #define USB_MAXBUS		64
98 static DECLARE_BITMAP(busmap, USB_MAXBUS);
99 
100 /* used when updating list of hcds */
101 DEFINE_MUTEX(usb_bus_list_lock);	/* exported only for usbfs */
102 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
103 
104 /* used for controlling access to virtual root hubs */
105 static DEFINE_SPINLOCK(hcd_root_hub_lock);
106 
107 /* used when updating an endpoint's URB list */
108 static DEFINE_SPINLOCK(hcd_urb_list_lock);
109 
110 /* used to protect against unlinking URBs after the device is gone */
111 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
112 
113 /* wait queue for synchronous unlinks */
114 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
115 
116 static inline int is_root_hub(struct usb_device *udev)
117 {
118 	return (udev->parent == NULL);
119 }
120 
121 /*-------------------------------------------------------------------------*/
122 
123 /*
124  * Sharable chunks of root hub code.
125  */
126 
127 /*-------------------------------------------------------------------------*/
128 #define KERNEL_REL	bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
129 #define KERNEL_VER	bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
130 
131 /* usb 3.0 root hub device descriptor */
132 static const u8 usb3_rh_dev_descriptor[18] = {
133 	0x12,       /*  __u8  bLength; */
134 	0x01,       /*  __u8  bDescriptorType; Device */
135 	0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
136 
137 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
138 	0x00,	    /*  __u8  bDeviceSubClass; */
139 	0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
140 	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
141 
142 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
143 	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
144 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
145 
146 	0x03,       /*  __u8  iManufacturer; */
147 	0x02,       /*  __u8  iProduct; */
148 	0x01,       /*  __u8  iSerialNumber; */
149 	0x01        /*  __u8  bNumConfigurations; */
150 };
151 
152 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
153 static const u8 usb25_rh_dev_descriptor[18] = {
154 	0x12,       /*  __u8  bLength; */
155 	0x01,       /*  __u8  bDescriptorType; Device */
156 	0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
157 
158 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
159 	0x00,	    /*  __u8  bDeviceSubClass; */
160 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
161 	0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
162 
163 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
164 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
165 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
166 
167 	0x03,       /*  __u8  iManufacturer; */
168 	0x02,       /*  __u8  iProduct; */
169 	0x01,       /*  __u8  iSerialNumber; */
170 	0x01        /*  __u8  bNumConfigurations; */
171 };
172 
173 /* usb 2.0 root hub device descriptor */
174 static const u8 usb2_rh_dev_descriptor[18] = {
175 	0x12,       /*  __u8  bLength; */
176 	0x01,       /*  __u8  bDescriptorType; Device */
177 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
178 
179 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
180 	0x00,	    /*  __u8  bDeviceSubClass; */
181 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
182 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
183 
184 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
185 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
186 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
187 
188 	0x03,       /*  __u8  iManufacturer; */
189 	0x02,       /*  __u8  iProduct; */
190 	0x01,       /*  __u8  iSerialNumber; */
191 	0x01        /*  __u8  bNumConfigurations; */
192 };
193 
194 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
195 
196 /* usb 1.1 root hub device descriptor */
197 static const u8 usb11_rh_dev_descriptor[18] = {
198 	0x12,       /*  __u8  bLength; */
199 	0x01,       /*  __u8  bDescriptorType; Device */
200 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
201 
202 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
203 	0x00,	    /*  __u8  bDeviceSubClass; */
204 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
205 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
206 
207 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
208 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
209 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
210 
211 	0x03,       /*  __u8  iManufacturer; */
212 	0x02,       /*  __u8  iProduct; */
213 	0x01,       /*  __u8  iSerialNumber; */
214 	0x01        /*  __u8  bNumConfigurations; */
215 };
216 
217 
218 /*-------------------------------------------------------------------------*/
219 
220 /* Configuration descriptors for our root hubs */
221 
222 static const u8 fs_rh_config_descriptor[] = {
223 
224 	/* one configuration */
225 	0x09,       /*  __u8  bLength; */
226 	0x02,       /*  __u8  bDescriptorType; Configuration */
227 	0x19, 0x00, /*  __le16 wTotalLength; */
228 	0x01,       /*  __u8  bNumInterfaces; (1) */
229 	0x01,       /*  __u8  bConfigurationValue; */
230 	0x00,       /*  __u8  iConfiguration; */
231 	0xc0,       /*  __u8  bmAttributes;
232 				 Bit 7: must be set,
233 				     6: Self-powered,
234 				     5: Remote wakeup,
235 				     4..0: resvd */
236 	0x00,       /*  __u8  MaxPower; */
237 
238 	/* USB 1.1:
239 	 * USB 2.0, single TT organization (mandatory):
240 	 *	one interface, protocol 0
241 	 *
242 	 * USB 2.0, multiple TT organization (optional):
243 	 *	two interfaces, protocols 1 (like single TT)
244 	 *	and 2 (multiple TT mode) ... config is
245 	 *	sometimes settable
246 	 *	NOT IMPLEMENTED
247 	 */
248 
249 	/* one interface */
250 	0x09,       /*  __u8  if_bLength; */
251 	0x04,       /*  __u8  if_bDescriptorType; Interface */
252 	0x00,       /*  __u8  if_bInterfaceNumber; */
253 	0x00,       /*  __u8  if_bAlternateSetting; */
254 	0x01,       /*  __u8  if_bNumEndpoints; */
255 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
256 	0x00,       /*  __u8  if_bInterfaceSubClass; */
257 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
258 	0x00,       /*  __u8  if_iInterface; */
259 
260 	/* one endpoint (status change endpoint) */
261 	0x07,       /*  __u8  ep_bLength; */
262 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
263 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
264 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
265 	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
266 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
267 };
268 
269 static const u8 hs_rh_config_descriptor[] = {
270 
271 	/* one configuration */
272 	0x09,       /*  __u8  bLength; */
273 	0x02,       /*  __u8  bDescriptorType; Configuration */
274 	0x19, 0x00, /*  __le16 wTotalLength; */
275 	0x01,       /*  __u8  bNumInterfaces; (1) */
276 	0x01,       /*  __u8  bConfigurationValue; */
277 	0x00,       /*  __u8  iConfiguration; */
278 	0xc0,       /*  __u8  bmAttributes;
279 				 Bit 7: must be set,
280 				     6: Self-powered,
281 				     5: Remote wakeup,
282 				     4..0: resvd */
283 	0x00,       /*  __u8  MaxPower; */
284 
285 	/* USB 1.1:
286 	 * USB 2.0, single TT organization (mandatory):
287 	 *	one interface, protocol 0
288 	 *
289 	 * USB 2.0, multiple TT organization (optional):
290 	 *	two interfaces, protocols 1 (like single TT)
291 	 *	and 2 (multiple TT mode) ... config is
292 	 *	sometimes settable
293 	 *	NOT IMPLEMENTED
294 	 */
295 
296 	/* one interface */
297 	0x09,       /*  __u8  if_bLength; */
298 	0x04,       /*  __u8  if_bDescriptorType; Interface */
299 	0x00,       /*  __u8  if_bInterfaceNumber; */
300 	0x00,       /*  __u8  if_bAlternateSetting; */
301 	0x01,       /*  __u8  if_bNumEndpoints; */
302 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
303 	0x00,       /*  __u8  if_bInterfaceSubClass; */
304 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
305 	0x00,       /*  __u8  if_iInterface; */
306 
307 	/* one endpoint (status change endpoint) */
308 	0x07,       /*  __u8  ep_bLength; */
309 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
310 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
311 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
312 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
313 		     * see hub.c:hub_configure() for details. */
314 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
315 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
316 };
317 
318 static const u8 ss_rh_config_descriptor[] = {
319 	/* one configuration */
320 	0x09,       /*  __u8  bLength; */
321 	0x02,       /*  __u8  bDescriptorType; Configuration */
322 	0x1f, 0x00, /*  __le16 wTotalLength; */
323 	0x01,       /*  __u8  bNumInterfaces; (1) */
324 	0x01,       /*  __u8  bConfigurationValue; */
325 	0x00,       /*  __u8  iConfiguration; */
326 	0xc0,       /*  __u8  bmAttributes;
327 				 Bit 7: must be set,
328 				     6: Self-powered,
329 				     5: Remote wakeup,
330 				     4..0: resvd */
331 	0x00,       /*  __u8  MaxPower; */
332 
333 	/* one interface */
334 	0x09,       /*  __u8  if_bLength; */
335 	0x04,       /*  __u8  if_bDescriptorType; Interface */
336 	0x00,       /*  __u8  if_bInterfaceNumber; */
337 	0x00,       /*  __u8  if_bAlternateSetting; */
338 	0x01,       /*  __u8  if_bNumEndpoints; */
339 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
340 	0x00,       /*  __u8  if_bInterfaceSubClass; */
341 	0x00,       /*  __u8  if_bInterfaceProtocol; */
342 	0x00,       /*  __u8  if_iInterface; */
343 
344 	/* one endpoint (status change endpoint) */
345 	0x07,       /*  __u8  ep_bLength; */
346 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
347 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
348 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
349 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
350 		     * see hub.c:hub_configure() for details. */
351 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
352 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
353 
354 	/* one SuperSpeed endpoint companion descriptor */
355 	0x06,        /* __u8 ss_bLength */
356 	0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
357 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
358 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
359 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
360 };
361 
362 /* authorized_default behaviour:
363  * -1 is authorized for all devices except wireless (old behaviour)
364  * 0 is unauthorized for all devices
365  * 1 is authorized for all devices
366  */
367 static int authorized_default = -1;
368 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
369 MODULE_PARM_DESC(authorized_default,
370 		"Default USB device authorization: 0 is not authorized, 1 is "
371 		"authorized, -1 is authorized except for wireless USB (default, "
372 		"old behaviour");
373 /*-------------------------------------------------------------------------*/
374 
375 /**
376  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
377  * @s: Null-terminated ASCII (actually ISO-8859-1) string
378  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
379  * @len: Length (in bytes; may be odd) of descriptor buffer.
380  *
381  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
382  * whichever is less.
383  *
384  * Note:
385  * USB String descriptors can contain at most 126 characters; input
386  * strings longer than that are truncated.
387  */
388 static unsigned
389 ascii2desc(char const *s, u8 *buf, unsigned len)
390 {
391 	unsigned n, t = 2 + 2*strlen(s);
392 
393 	if (t > 254)
394 		t = 254;	/* Longest possible UTF string descriptor */
395 	if (len > t)
396 		len = t;
397 
398 	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
399 
400 	n = len;
401 	while (n--) {
402 		*buf++ = t;
403 		if (!n--)
404 			break;
405 		*buf++ = t >> 8;
406 		t = (unsigned char)*s++;
407 	}
408 	return len;
409 }
410 
411 /**
412  * rh_string() - provides string descriptors for root hub
413  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
414  * @hcd: the host controller for this root hub
415  * @data: buffer for output packet
416  * @len: length of the provided buffer
417  *
418  * Produces either a manufacturer, product or serial number string for the
419  * virtual root hub device.
420  *
421  * Return: The number of bytes filled in: the length of the descriptor or
422  * of the provided buffer, whichever is less.
423  */
424 static unsigned
425 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
426 {
427 	char buf[100];
428 	char const *s;
429 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
430 
431 	/* language ids */
432 	switch (id) {
433 	case 0:
434 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
435 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
436 		if (len > 4)
437 			len = 4;
438 		memcpy(data, langids, len);
439 		return len;
440 	case 1:
441 		/* Serial number */
442 		s = hcd->self.bus_name;
443 		break;
444 	case 2:
445 		/* Product name */
446 		s = hcd->product_desc;
447 		break;
448 	case 3:
449 		/* Manufacturer */
450 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
451 			init_utsname()->release, hcd->driver->description);
452 		s = buf;
453 		break;
454 	default:
455 		/* Can't happen; caller guarantees it */
456 		return 0;
457 	}
458 
459 	return ascii2desc(s, data, len);
460 }
461 
462 
463 /* Root hub control transfers execute synchronously */
464 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
465 {
466 	struct usb_ctrlrequest *cmd;
467 	u16		typeReq, wValue, wIndex, wLength;
468 	u8		*ubuf = urb->transfer_buffer;
469 	unsigned	len = 0;
470 	int		status;
471 	u8		patch_wakeup = 0;
472 	u8		patch_protocol = 0;
473 	u16		tbuf_size;
474 	u8		*tbuf = NULL;
475 	const u8	*bufp;
476 
477 	might_sleep();
478 
479 	spin_lock_irq(&hcd_root_hub_lock);
480 	status = usb_hcd_link_urb_to_ep(hcd, urb);
481 	spin_unlock_irq(&hcd_root_hub_lock);
482 	if (status)
483 		return status;
484 	urb->hcpriv = hcd;	/* Indicate it's queued */
485 
486 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
487 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
488 	wValue   = le16_to_cpu (cmd->wValue);
489 	wIndex   = le16_to_cpu (cmd->wIndex);
490 	wLength  = le16_to_cpu (cmd->wLength);
491 
492 	if (wLength > urb->transfer_buffer_length)
493 		goto error;
494 
495 	/*
496 	 * tbuf should be at least as big as the
497 	 * USB hub descriptor.
498 	 */
499 	tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
500 	tbuf = kzalloc(tbuf_size, GFP_KERNEL);
501 	if (!tbuf)
502 		return -ENOMEM;
503 
504 	bufp = tbuf;
505 
506 
507 	urb->actual_length = 0;
508 	switch (typeReq) {
509 
510 	/* DEVICE REQUESTS */
511 
512 	/* The root hub's remote wakeup enable bit is implemented using
513 	 * driver model wakeup flags.  If this system supports wakeup
514 	 * through USB, userspace may change the default "allow wakeup"
515 	 * policy through sysfs or these calls.
516 	 *
517 	 * Most root hubs support wakeup from downstream devices, for
518 	 * runtime power management (disabling USB clocks and reducing
519 	 * VBUS power usage).  However, not all of them do so; silicon,
520 	 * board, and BIOS bugs here are not uncommon, so these can't
521 	 * be treated quite like external hubs.
522 	 *
523 	 * Likewise, not all root hubs will pass wakeup events upstream,
524 	 * to wake up the whole system.  So don't assume root hub and
525 	 * controller capabilities are identical.
526 	 */
527 
528 	case DeviceRequest | USB_REQ_GET_STATUS:
529 		tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
530 					<< USB_DEVICE_REMOTE_WAKEUP)
531 				| (1 << USB_DEVICE_SELF_POWERED);
532 		tbuf[1] = 0;
533 		len = 2;
534 		break;
535 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
536 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
537 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
538 		else
539 			goto error;
540 		break;
541 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
542 		if (device_can_wakeup(&hcd->self.root_hub->dev)
543 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
544 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
545 		else
546 			goto error;
547 		break;
548 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
549 		tbuf[0] = 1;
550 		len = 1;
551 			/* FALLTHROUGH */
552 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
553 		break;
554 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
555 		switch (wValue & 0xff00) {
556 		case USB_DT_DEVICE << 8:
557 			switch (hcd->speed) {
558 			case HCD_USB3:
559 				bufp = usb3_rh_dev_descriptor;
560 				break;
561 			case HCD_USB25:
562 				bufp = usb25_rh_dev_descriptor;
563 				break;
564 			case HCD_USB2:
565 				bufp = usb2_rh_dev_descriptor;
566 				break;
567 			case HCD_USB11:
568 				bufp = usb11_rh_dev_descriptor;
569 				break;
570 			default:
571 				goto error;
572 			}
573 			len = 18;
574 			if (hcd->has_tt)
575 				patch_protocol = 1;
576 			break;
577 		case USB_DT_CONFIG << 8:
578 			switch (hcd->speed) {
579 			case HCD_USB3:
580 				bufp = ss_rh_config_descriptor;
581 				len = sizeof ss_rh_config_descriptor;
582 				break;
583 			case HCD_USB25:
584 			case HCD_USB2:
585 				bufp = hs_rh_config_descriptor;
586 				len = sizeof hs_rh_config_descriptor;
587 				break;
588 			case HCD_USB11:
589 				bufp = fs_rh_config_descriptor;
590 				len = sizeof fs_rh_config_descriptor;
591 				break;
592 			default:
593 				goto error;
594 			}
595 			if (device_can_wakeup(&hcd->self.root_hub->dev))
596 				patch_wakeup = 1;
597 			break;
598 		case USB_DT_STRING << 8:
599 			if ((wValue & 0xff) < 4)
600 				urb->actual_length = rh_string(wValue & 0xff,
601 						hcd, ubuf, wLength);
602 			else /* unsupported IDs --> "protocol stall" */
603 				goto error;
604 			break;
605 		case USB_DT_BOS << 8:
606 			goto nongeneric;
607 		default:
608 			goto error;
609 		}
610 		break;
611 	case DeviceRequest | USB_REQ_GET_INTERFACE:
612 		tbuf[0] = 0;
613 		len = 1;
614 			/* FALLTHROUGH */
615 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
616 		break;
617 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
618 		/* wValue == urb->dev->devaddr */
619 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
620 			wValue);
621 		break;
622 
623 	/* INTERFACE REQUESTS (no defined feature/status flags) */
624 
625 	/* ENDPOINT REQUESTS */
626 
627 	case EndpointRequest | USB_REQ_GET_STATUS:
628 		/* ENDPOINT_HALT flag */
629 		tbuf[0] = 0;
630 		tbuf[1] = 0;
631 		len = 2;
632 			/* FALLTHROUGH */
633 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
634 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
635 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
636 		break;
637 
638 	/* CLASS REQUESTS (and errors) */
639 
640 	default:
641 nongeneric:
642 		/* non-generic request */
643 		switch (typeReq) {
644 		case GetHubStatus:
645 		case GetPortStatus:
646 			len = 4;
647 			break;
648 		case GetHubDescriptor:
649 			len = sizeof (struct usb_hub_descriptor);
650 			break;
651 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
652 			/* len is returned by hub_control */
653 			break;
654 		}
655 		status = hcd->driver->hub_control (hcd,
656 			typeReq, wValue, wIndex,
657 			tbuf, wLength);
658 
659 		if (typeReq == GetHubDescriptor)
660 			usb_hub_adjust_deviceremovable(hcd->self.root_hub,
661 				(struct usb_hub_descriptor *)tbuf);
662 		break;
663 error:
664 		/* "protocol stall" on error */
665 		status = -EPIPE;
666 	}
667 
668 	if (status < 0) {
669 		len = 0;
670 		if (status != -EPIPE) {
671 			dev_dbg (hcd->self.controller,
672 				"CTRL: TypeReq=0x%x val=0x%x "
673 				"idx=0x%x len=%d ==> %d\n",
674 				typeReq, wValue, wIndex,
675 				wLength, status);
676 		}
677 	} else if (status > 0) {
678 		/* hub_control may return the length of data copied. */
679 		len = status;
680 		status = 0;
681 	}
682 	if (len) {
683 		if (urb->transfer_buffer_length < len)
684 			len = urb->transfer_buffer_length;
685 		urb->actual_length = len;
686 		/* always USB_DIR_IN, toward host */
687 		memcpy (ubuf, bufp, len);
688 
689 		/* report whether RH hardware supports remote wakeup */
690 		if (patch_wakeup &&
691 				len > offsetof (struct usb_config_descriptor,
692 						bmAttributes))
693 			((struct usb_config_descriptor *)ubuf)->bmAttributes
694 				|= USB_CONFIG_ATT_WAKEUP;
695 
696 		/* report whether RH hardware has an integrated TT */
697 		if (patch_protocol &&
698 				len > offsetof(struct usb_device_descriptor,
699 						bDeviceProtocol))
700 			((struct usb_device_descriptor *) ubuf)->
701 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
702 	}
703 
704 	kfree(tbuf);
705 
706 	/* any errors get returned through the urb completion */
707 	spin_lock_irq(&hcd_root_hub_lock);
708 	usb_hcd_unlink_urb_from_ep(hcd, urb);
709 	usb_hcd_giveback_urb(hcd, urb, status);
710 	spin_unlock_irq(&hcd_root_hub_lock);
711 	return 0;
712 }
713 
714 /*-------------------------------------------------------------------------*/
715 
716 /*
717  * Root Hub interrupt transfers are polled using a timer if the
718  * driver requests it; otherwise the driver is responsible for
719  * calling usb_hcd_poll_rh_status() when an event occurs.
720  *
721  * Completions are called in_interrupt(), but they may or may not
722  * be in_irq().
723  */
724 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
725 {
726 	struct urb	*urb;
727 	int		length;
728 	unsigned long	flags;
729 	char		buffer[6];	/* Any root hubs with > 31 ports? */
730 
731 	if (unlikely(!hcd->rh_pollable))
732 		return;
733 	if (!hcd->uses_new_polling && !hcd->status_urb)
734 		return;
735 
736 	length = hcd->driver->hub_status_data(hcd, buffer);
737 	if (length > 0) {
738 
739 		/* try to complete the status urb */
740 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
741 		urb = hcd->status_urb;
742 		if (urb) {
743 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
744 			hcd->status_urb = NULL;
745 			urb->actual_length = length;
746 			memcpy(urb->transfer_buffer, buffer, length);
747 
748 			usb_hcd_unlink_urb_from_ep(hcd, urb);
749 			usb_hcd_giveback_urb(hcd, urb, 0);
750 		} else {
751 			length = 0;
752 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
753 		}
754 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
755 	}
756 
757 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
758 	 * exceed that limit if HZ is 100. The math is more clunky than
759 	 * maybe expected, this is to make sure that all timers for USB devices
760 	 * fire at the same time to give the CPU a break in between */
761 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
762 			(length == 0 && hcd->status_urb != NULL))
763 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
764 }
765 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
766 
767 /* timer callback */
768 static void rh_timer_func (unsigned long _hcd)
769 {
770 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
771 }
772 
773 /*-------------------------------------------------------------------------*/
774 
775 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
776 {
777 	int		retval;
778 	unsigned long	flags;
779 	unsigned	len = 1 + (urb->dev->maxchild / 8);
780 
781 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
782 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
783 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
784 		retval = -EINVAL;
785 		goto done;
786 	}
787 
788 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
789 	if (retval)
790 		goto done;
791 
792 	hcd->status_urb = urb;
793 	urb->hcpriv = hcd;	/* indicate it's queued */
794 	if (!hcd->uses_new_polling)
795 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
796 
797 	/* If a status change has already occurred, report it ASAP */
798 	else if (HCD_POLL_PENDING(hcd))
799 		mod_timer(&hcd->rh_timer, jiffies);
800 	retval = 0;
801  done:
802 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
803 	return retval;
804 }
805 
806 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
807 {
808 	if (usb_endpoint_xfer_int(&urb->ep->desc))
809 		return rh_queue_status (hcd, urb);
810 	if (usb_endpoint_xfer_control(&urb->ep->desc))
811 		return rh_call_control (hcd, urb);
812 	return -EINVAL;
813 }
814 
815 /*-------------------------------------------------------------------------*/
816 
817 /* Unlinks of root-hub control URBs are legal, but they don't do anything
818  * since these URBs always execute synchronously.
819  */
820 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
821 {
822 	unsigned long	flags;
823 	int		rc;
824 
825 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
826 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
827 	if (rc)
828 		goto done;
829 
830 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
831 		;	/* Do nothing */
832 
833 	} else {				/* Status URB */
834 		if (!hcd->uses_new_polling)
835 			del_timer (&hcd->rh_timer);
836 		if (urb == hcd->status_urb) {
837 			hcd->status_urb = NULL;
838 			usb_hcd_unlink_urb_from_ep(hcd, urb);
839 			usb_hcd_giveback_urb(hcd, urb, status);
840 		}
841 	}
842  done:
843 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
844 	return rc;
845 }
846 
847 
848 
849 /*
850  * Show & store the current value of authorized_default
851  */
852 static ssize_t authorized_default_show(struct device *dev,
853 				       struct device_attribute *attr, char *buf)
854 {
855 	struct usb_device *rh_usb_dev = to_usb_device(dev);
856 	struct usb_bus *usb_bus = rh_usb_dev->bus;
857 	struct usb_hcd *usb_hcd;
858 
859 	usb_hcd = bus_to_hcd(usb_bus);
860 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
861 }
862 
863 static ssize_t authorized_default_store(struct device *dev,
864 					struct device_attribute *attr,
865 					const char *buf, size_t size)
866 {
867 	ssize_t result;
868 	unsigned val;
869 	struct usb_device *rh_usb_dev = to_usb_device(dev);
870 	struct usb_bus *usb_bus = rh_usb_dev->bus;
871 	struct usb_hcd *usb_hcd;
872 
873 	usb_hcd = bus_to_hcd(usb_bus);
874 	result = sscanf(buf, "%u\n", &val);
875 	if (result == 1) {
876 		usb_hcd->authorized_default = val ? 1 : 0;
877 		result = size;
878 	} else {
879 		result = -EINVAL;
880 	}
881 	return result;
882 }
883 static DEVICE_ATTR_RW(authorized_default);
884 
885 /* Group all the USB bus attributes */
886 static struct attribute *usb_bus_attrs[] = {
887 		&dev_attr_authorized_default.attr,
888 		NULL,
889 };
890 
891 static struct attribute_group usb_bus_attr_group = {
892 	.name = NULL,	/* we want them in the same directory */
893 	.attrs = usb_bus_attrs,
894 };
895 
896 
897 
898 /*-------------------------------------------------------------------------*/
899 
900 /**
901  * usb_bus_init - shared initialization code
902  * @bus: the bus structure being initialized
903  *
904  * This code is used to initialize a usb_bus structure, memory for which is
905  * separately managed.
906  */
907 static void usb_bus_init (struct usb_bus *bus)
908 {
909 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
910 
911 	bus->devnum_next = 1;
912 
913 	bus->root_hub = NULL;
914 	bus->busnum = -1;
915 	bus->bandwidth_allocated = 0;
916 	bus->bandwidth_int_reqs  = 0;
917 	bus->bandwidth_isoc_reqs = 0;
918 	mutex_init(&bus->usb_address0_mutex);
919 
920 	INIT_LIST_HEAD (&bus->bus_list);
921 }
922 
923 /*-------------------------------------------------------------------------*/
924 
925 /**
926  * usb_register_bus - registers the USB host controller with the usb core
927  * @bus: pointer to the bus to register
928  * Context: !in_interrupt()
929  *
930  * Assigns a bus number, and links the controller into usbcore data
931  * structures so that it can be seen by scanning the bus list.
932  *
933  * Return: 0 if successful. A negative error code otherwise.
934  */
935 static int usb_register_bus(struct usb_bus *bus)
936 {
937 	int result = -E2BIG;
938 	int busnum;
939 
940 	mutex_lock(&usb_bus_list_lock);
941 	busnum = find_next_zero_bit(busmap, USB_MAXBUS, 1);
942 	if (busnum >= USB_MAXBUS) {
943 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
944 		goto error_find_busnum;
945 	}
946 	set_bit(busnum, busmap);
947 	bus->busnum = busnum;
948 
949 	/* Add it to the local list of buses */
950 	list_add (&bus->bus_list, &usb_bus_list);
951 	mutex_unlock(&usb_bus_list_lock);
952 
953 	usb_notify_add_bus(bus);
954 
955 	dev_info (bus->controller, "new USB bus registered, assigned bus "
956 		  "number %d\n", bus->busnum);
957 	return 0;
958 
959 error_find_busnum:
960 	mutex_unlock(&usb_bus_list_lock);
961 	return result;
962 }
963 
964 /**
965  * usb_deregister_bus - deregisters the USB host controller
966  * @bus: pointer to the bus to deregister
967  * Context: !in_interrupt()
968  *
969  * Recycles the bus number, and unlinks the controller from usbcore data
970  * structures so that it won't be seen by scanning the bus list.
971  */
972 static void usb_deregister_bus (struct usb_bus *bus)
973 {
974 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
975 
976 	/*
977 	 * NOTE: make sure that all the devices are removed by the
978 	 * controller code, as well as having it call this when cleaning
979 	 * itself up
980 	 */
981 	mutex_lock(&usb_bus_list_lock);
982 	list_del (&bus->bus_list);
983 	mutex_unlock(&usb_bus_list_lock);
984 
985 	usb_notify_remove_bus(bus);
986 
987 	clear_bit(bus->busnum, busmap);
988 }
989 
990 /**
991  * register_root_hub - called by usb_add_hcd() to register a root hub
992  * @hcd: host controller for this root hub
993  *
994  * This function registers the root hub with the USB subsystem.  It sets up
995  * the device properly in the device tree and then calls usb_new_device()
996  * to register the usb device.  It also assigns the root hub's USB address
997  * (always 1).
998  *
999  * Return: 0 if successful. A negative error code otherwise.
1000  */
1001 static int register_root_hub(struct usb_hcd *hcd)
1002 {
1003 	struct device *parent_dev = hcd->self.controller;
1004 	struct usb_device *usb_dev = hcd->self.root_hub;
1005 	const int devnum = 1;
1006 	int retval;
1007 
1008 	usb_dev->devnum = devnum;
1009 	usb_dev->bus->devnum_next = devnum + 1;
1010 	memset (&usb_dev->bus->devmap.devicemap, 0,
1011 			sizeof usb_dev->bus->devmap.devicemap);
1012 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1013 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1014 
1015 	mutex_lock(&usb_bus_list_lock);
1016 
1017 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1018 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1019 	if (retval != sizeof usb_dev->descriptor) {
1020 		mutex_unlock(&usb_bus_list_lock);
1021 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1022 				dev_name(&usb_dev->dev), retval);
1023 		return (retval < 0) ? retval : -EMSGSIZE;
1024 	}
1025 	if (usb_dev->speed == USB_SPEED_SUPER) {
1026 		retval = usb_get_bos_descriptor(usb_dev);
1027 		if (retval < 0) {
1028 			mutex_unlock(&usb_bus_list_lock);
1029 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1030 					dev_name(&usb_dev->dev), retval);
1031 			return retval;
1032 		}
1033 	}
1034 
1035 	retval = usb_new_device (usb_dev);
1036 	if (retval) {
1037 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1038 				dev_name(&usb_dev->dev), retval);
1039 	} else {
1040 		spin_lock_irq (&hcd_root_hub_lock);
1041 		hcd->rh_registered = 1;
1042 		spin_unlock_irq (&hcd_root_hub_lock);
1043 
1044 		/* Did the HC die before the root hub was registered? */
1045 		if (HCD_DEAD(hcd))
1046 			usb_hc_died (hcd);	/* This time clean up */
1047 	}
1048 	mutex_unlock(&usb_bus_list_lock);
1049 
1050 	return retval;
1051 }
1052 
1053 /*
1054  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1055  * @bus: the bus which the root hub belongs to
1056  * @portnum: the port which is being resumed
1057  *
1058  * HCDs should call this function when they know that a resume signal is
1059  * being sent to a root-hub port.  The root hub will be prevented from
1060  * going into autosuspend until usb_hcd_end_port_resume() is called.
1061  *
1062  * The bus's private lock must be held by the caller.
1063  */
1064 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1065 {
1066 	unsigned bit = 1 << portnum;
1067 
1068 	if (!(bus->resuming_ports & bit)) {
1069 		bus->resuming_ports |= bit;
1070 		pm_runtime_get_noresume(&bus->root_hub->dev);
1071 	}
1072 }
1073 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1074 
1075 /*
1076  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1077  * @bus: the bus which the root hub belongs to
1078  * @portnum: the port which is being resumed
1079  *
1080  * HCDs should call this function when they know that a resume signal has
1081  * stopped being sent to a root-hub port.  The root hub will be allowed to
1082  * autosuspend again.
1083  *
1084  * The bus's private lock must be held by the caller.
1085  */
1086 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1087 {
1088 	unsigned bit = 1 << portnum;
1089 
1090 	if (bus->resuming_ports & bit) {
1091 		bus->resuming_ports &= ~bit;
1092 		pm_runtime_put_noidle(&bus->root_hub->dev);
1093 	}
1094 }
1095 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1096 
1097 /*-------------------------------------------------------------------------*/
1098 
1099 /**
1100  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1101  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1102  * @is_input: true iff the transaction sends data to the host
1103  * @isoc: true for isochronous transactions, false for interrupt ones
1104  * @bytecount: how many bytes in the transaction.
1105  *
1106  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1107  *
1108  * Note:
1109  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1110  * scheduled in software, this function is only used for such scheduling.
1111  */
1112 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1113 {
1114 	unsigned long	tmp;
1115 
1116 	switch (speed) {
1117 	case USB_SPEED_LOW: 	/* INTR only */
1118 		if (is_input) {
1119 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1120 			return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1121 		} else {
1122 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1123 			return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1124 		}
1125 	case USB_SPEED_FULL:	/* ISOC or INTR */
1126 		if (isoc) {
1127 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1128 			return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1129 		} else {
1130 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1131 			return 9107L + BW_HOST_DELAY + tmp;
1132 		}
1133 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1134 		/* FIXME adjust for input vs output */
1135 		if (isoc)
1136 			tmp = HS_NSECS_ISO (bytecount);
1137 		else
1138 			tmp = HS_NSECS (bytecount);
1139 		return tmp;
1140 	default:
1141 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1142 		return -1;
1143 	}
1144 }
1145 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1146 
1147 
1148 /*-------------------------------------------------------------------------*/
1149 
1150 /*
1151  * Generic HC operations.
1152  */
1153 
1154 /*-------------------------------------------------------------------------*/
1155 
1156 /**
1157  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1158  * @hcd: host controller to which @urb was submitted
1159  * @urb: URB being submitted
1160  *
1161  * Host controller drivers should call this routine in their enqueue()
1162  * method.  The HCD's private spinlock must be held and interrupts must
1163  * be disabled.  The actions carried out here are required for URB
1164  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1165  *
1166  * Return: 0 for no error, otherwise a negative error code (in which case
1167  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1168  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1169  * the private spinlock and returning.
1170  */
1171 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1172 {
1173 	int		rc = 0;
1174 
1175 	spin_lock(&hcd_urb_list_lock);
1176 
1177 	/* Check that the URB isn't being killed */
1178 	if (unlikely(atomic_read(&urb->reject))) {
1179 		rc = -EPERM;
1180 		goto done;
1181 	}
1182 
1183 	if (unlikely(!urb->ep->enabled)) {
1184 		rc = -ENOENT;
1185 		goto done;
1186 	}
1187 
1188 	if (unlikely(!urb->dev->can_submit)) {
1189 		rc = -EHOSTUNREACH;
1190 		goto done;
1191 	}
1192 
1193 	/*
1194 	 * Check the host controller's state and add the URB to the
1195 	 * endpoint's queue.
1196 	 */
1197 	if (HCD_RH_RUNNING(hcd)) {
1198 		urb->unlinked = 0;
1199 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1200 	} else {
1201 		rc = -ESHUTDOWN;
1202 		goto done;
1203 	}
1204  done:
1205 	spin_unlock(&hcd_urb_list_lock);
1206 	return rc;
1207 }
1208 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1209 
1210 /**
1211  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1212  * @hcd: host controller to which @urb was submitted
1213  * @urb: URB being checked for unlinkability
1214  * @status: error code to store in @urb if the unlink succeeds
1215  *
1216  * Host controller drivers should call this routine in their dequeue()
1217  * method.  The HCD's private spinlock must be held and interrupts must
1218  * be disabled.  The actions carried out here are required for making
1219  * sure than an unlink is valid.
1220  *
1221  * Return: 0 for no error, otherwise a negative error code (in which case
1222  * the dequeue() method must fail).  The possible error codes are:
1223  *
1224  *	-EIDRM: @urb was not submitted or has already completed.
1225  *		The completion function may not have been called yet.
1226  *
1227  *	-EBUSY: @urb has already been unlinked.
1228  */
1229 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1230 		int status)
1231 {
1232 	struct list_head	*tmp;
1233 
1234 	/* insist the urb is still queued */
1235 	list_for_each(tmp, &urb->ep->urb_list) {
1236 		if (tmp == &urb->urb_list)
1237 			break;
1238 	}
1239 	if (tmp != &urb->urb_list)
1240 		return -EIDRM;
1241 
1242 	/* Any status except -EINPROGRESS means something already started to
1243 	 * unlink this URB from the hardware.  So there's no more work to do.
1244 	 */
1245 	if (urb->unlinked)
1246 		return -EBUSY;
1247 	urb->unlinked = status;
1248 	return 0;
1249 }
1250 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1251 
1252 /**
1253  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1254  * @hcd: host controller to which @urb was submitted
1255  * @urb: URB being unlinked
1256  *
1257  * Host controller drivers should call this routine before calling
1258  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1259  * interrupts must be disabled.  The actions carried out here are required
1260  * for URB completion.
1261  */
1262 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1263 {
1264 	/* clear all state linking urb to this dev (and hcd) */
1265 	spin_lock(&hcd_urb_list_lock);
1266 	list_del_init(&urb->urb_list);
1267 	spin_unlock(&hcd_urb_list_lock);
1268 }
1269 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1270 
1271 /*
1272  * Some usb host controllers can only perform dma using a small SRAM area.
1273  * The usb core itself is however optimized for host controllers that can dma
1274  * using regular system memory - like pci devices doing bus mastering.
1275  *
1276  * To support host controllers with limited dma capabilities we provide dma
1277  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1278  * For this to work properly the host controller code must first use the
1279  * function dma_declare_coherent_memory() to point out which memory area
1280  * that should be used for dma allocations.
1281  *
1282  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1283  * dma using dma_alloc_coherent() which in turn allocates from the memory
1284  * area pointed out with dma_declare_coherent_memory().
1285  *
1286  * So, to summarize...
1287  *
1288  * - We need "local" memory, canonical example being
1289  *   a small SRAM on a discrete controller being the
1290  *   only memory that the controller can read ...
1291  *   (a) "normal" kernel memory is no good, and
1292  *   (b) there's not enough to share
1293  *
1294  * - The only *portable* hook for such stuff in the
1295  *   DMA framework is dma_declare_coherent_memory()
1296  *
1297  * - So we use that, even though the primary requirement
1298  *   is that the memory be "local" (hence addressable
1299  *   by that device), not "coherent".
1300  *
1301  */
1302 
1303 static int hcd_alloc_coherent(struct usb_bus *bus,
1304 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1305 			      void **vaddr_handle, size_t size,
1306 			      enum dma_data_direction dir)
1307 {
1308 	unsigned char *vaddr;
1309 
1310 	if (*vaddr_handle == NULL) {
1311 		WARN_ON_ONCE(1);
1312 		return -EFAULT;
1313 	}
1314 
1315 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1316 				 mem_flags, dma_handle);
1317 	if (!vaddr)
1318 		return -ENOMEM;
1319 
1320 	/*
1321 	 * Store the virtual address of the buffer at the end
1322 	 * of the allocated dma buffer. The size of the buffer
1323 	 * may be uneven so use unaligned functions instead
1324 	 * of just rounding up. It makes sense to optimize for
1325 	 * memory footprint over access speed since the amount
1326 	 * of memory available for dma may be limited.
1327 	 */
1328 	put_unaligned((unsigned long)*vaddr_handle,
1329 		      (unsigned long *)(vaddr + size));
1330 
1331 	if (dir == DMA_TO_DEVICE)
1332 		memcpy(vaddr, *vaddr_handle, size);
1333 
1334 	*vaddr_handle = vaddr;
1335 	return 0;
1336 }
1337 
1338 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1339 			      void **vaddr_handle, size_t size,
1340 			      enum dma_data_direction dir)
1341 {
1342 	unsigned char *vaddr = *vaddr_handle;
1343 
1344 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1345 
1346 	if (dir == DMA_FROM_DEVICE)
1347 		memcpy(vaddr, *vaddr_handle, size);
1348 
1349 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1350 
1351 	*vaddr_handle = vaddr;
1352 	*dma_handle = 0;
1353 }
1354 
1355 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1356 {
1357 	if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1358 		dma_unmap_single(hcd->self.controller,
1359 				urb->setup_dma,
1360 				sizeof(struct usb_ctrlrequest),
1361 				DMA_TO_DEVICE);
1362 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1363 		hcd_free_coherent(urb->dev->bus,
1364 				&urb->setup_dma,
1365 				(void **) &urb->setup_packet,
1366 				sizeof(struct usb_ctrlrequest),
1367 				DMA_TO_DEVICE);
1368 
1369 	/* Make it safe to call this routine more than once */
1370 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1371 }
1372 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1373 
1374 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1375 {
1376 	if (hcd->driver->unmap_urb_for_dma)
1377 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1378 	else
1379 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1380 }
1381 
1382 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1383 {
1384 	enum dma_data_direction dir;
1385 
1386 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1387 
1388 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1389 	if (urb->transfer_flags & URB_DMA_MAP_SG)
1390 		dma_unmap_sg(hcd->self.controller,
1391 				urb->sg,
1392 				urb->num_sgs,
1393 				dir);
1394 	else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1395 		dma_unmap_page(hcd->self.controller,
1396 				urb->transfer_dma,
1397 				urb->transfer_buffer_length,
1398 				dir);
1399 	else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1400 		dma_unmap_single(hcd->self.controller,
1401 				urb->transfer_dma,
1402 				urb->transfer_buffer_length,
1403 				dir);
1404 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1405 		hcd_free_coherent(urb->dev->bus,
1406 				&urb->transfer_dma,
1407 				&urb->transfer_buffer,
1408 				urb->transfer_buffer_length,
1409 				dir);
1410 
1411 	/* Make it safe to call this routine more than once */
1412 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1413 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1414 }
1415 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1416 
1417 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1418 			   gfp_t mem_flags)
1419 {
1420 	if (hcd->driver->map_urb_for_dma)
1421 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1422 	else
1423 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1424 }
1425 
1426 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1427 			    gfp_t mem_flags)
1428 {
1429 	enum dma_data_direction dir;
1430 	int ret = 0;
1431 
1432 	/* Map the URB's buffers for DMA access.
1433 	 * Lower level HCD code should use *_dma exclusively,
1434 	 * unless it uses pio or talks to another transport,
1435 	 * or uses the provided scatter gather list for bulk.
1436 	 */
1437 
1438 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1439 		if (hcd->self.uses_pio_for_control)
1440 			return ret;
1441 		if (hcd->self.uses_dma) {
1442 			urb->setup_dma = dma_map_single(
1443 					hcd->self.controller,
1444 					urb->setup_packet,
1445 					sizeof(struct usb_ctrlrequest),
1446 					DMA_TO_DEVICE);
1447 			if (dma_mapping_error(hcd->self.controller,
1448 						urb->setup_dma))
1449 				return -EAGAIN;
1450 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1451 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1452 			ret = hcd_alloc_coherent(
1453 					urb->dev->bus, mem_flags,
1454 					&urb->setup_dma,
1455 					(void **)&urb->setup_packet,
1456 					sizeof(struct usb_ctrlrequest),
1457 					DMA_TO_DEVICE);
1458 			if (ret)
1459 				return ret;
1460 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1461 		}
1462 	}
1463 
1464 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1465 	if (urb->transfer_buffer_length != 0
1466 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1467 		if (hcd->self.uses_dma) {
1468 			if (urb->num_sgs) {
1469 				int n;
1470 
1471 				/* We don't support sg for isoc transfers ! */
1472 				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1473 					WARN_ON(1);
1474 					return -EINVAL;
1475 				}
1476 
1477 				n = dma_map_sg(
1478 						hcd->self.controller,
1479 						urb->sg,
1480 						urb->num_sgs,
1481 						dir);
1482 				if (n <= 0)
1483 					ret = -EAGAIN;
1484 				else
1485 					urb->transfer_flags |= URB_DMA_MAP_SG;
1486 				urb->num_mapped_sgs = n;
1487 				if (n != urb->num_sgs)
1488 					urb->transfer_flags |=
1489 							URB_DMA_SG_COMBINED;
1490 			} else if (urb->sg) {
1491 				struct scatterlist *sg = urb->sg;
1492 				urb->transfer_dma = dma_map_page(
1493 						hcd->self.controller,
1494 						sg_page(sg),
1495 						sg->offset,
1496 						urb->transfer_buffer_length,
1497 						dir);
1498 				if (dma_mapping_error(hcd->self.controller,
1499 						urb->transfer_dma))
1500 					ret = -EAGAIN;
1501 				else
1502 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1503 			} else if (is_vmalloc_addr(urb->transfer_buffer)) {
1504 				WARN_ONCE(1, "transfer buffer not dma capable\n");
1505 				ret = -EAGAIN;
1506 			} else {
1507 				urb->transfer_dma = dma_map_single(
1508 						hcd->self.controller,
1509 						urb->transfer_buffer,
1510 						urb->transfer_buffer_length,
1511 						dir);
1512 				if (dma_mapping_error(hcd->self.controller,
1513 						urb->transfer_dma))
1514 					ret = -EAGAIN;
1515 				else
1516 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1517 			}
1518 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1519 			ret = hcd_alloc_coherent(
1520 					urb->dev->bus, mem_flags,
1521 					&urb->transfer_dma,
1522 					&urb->transfer_buffer,
1523 					urb->transfer_buffer_length,
1524 					dir);
1525 			if (ret == 0)
1526 				urb->transfer_flags |= URB_MAP_LOCAL;
1527 		}
1528 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1529 				URB_SETUP_MAP_LOCAL)))
1530 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1531 	}
1532 	return ret;
1533 }
1534 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1535 
1536 /*-------------------------------------------------------------------------*/
1537 
1538 /* may be called in any context with a valid urb->dev usecount
1539  * caller surrenders "ownership" of urb
1540  * expects usb_submit_urb() to have sanity checked and conditioned all
1541  * inputs in the urb
1542  */
1543 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1544 {
1545 	int			status;
1546 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1547 
1548 	/* increment urb's reference count as part of giving it to the HCD
1549 	 * (which will control it).  HCD guarantees that it either returns
1550 	 * an error or calls giveback(), but not both.
1551 	 */
1552 	usb_get_urb(urb);
1553 	atomic_inc(&urb->use_count);
1554 	atomic_inc(&urb->dev->urbnum);
1555 	usbmon_urb_submit(&hcd->self, urb);
1556 
1557 	/* NOTE requirements on root-hub callers (usbfs and the hub
1558 	 * driver, for now):  URBs' urb->transfer_buffer must be
1559 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1560 	 * they could clobber root hub response data.  Also, control
1561 	 * URBs must be submitted in process context with interrupts
1562 	 * enabled.
1563 	 */
1564 
1565 	if (is_root_hub(urb->dev)) {
1566 		status = rh_urb_enqueue(hcd, urb);
1567 	} else {
1568 		status = map_urb_for_dma(hcd, urb, mem_flags);
1569 		if (likely(status == 0)) {
1570 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1571 			if (unlikely(status))
1572 				unmap_urb_for_dma(hcd, urb);
1573 		}
1574 	}
1575 
1576 	if (unlikely(status)) {
1577 		usbmon_urb_submit_error(&hcd->self, urb, status);
1578 		urb->hcpriv = NULL;
1579 		INIT_LIST_HEAD(&urb->urb_list);
1580 		atomic_dec(&urb->use_count);
1581 		atomic_dec(&urb->dev->urbnum);
1582 		if (atomic_read(&urb->reject))
1583 			wake_up(&usb_kill_urb_queue);
1584 		usb_put_urb(urb);
1585 	}
1586 	return status;
1587 }
1588 
1589 /*-------------------------------------------------------------------------*/
1590 
1591 /* this makes the hcd giveback() the urb more quickly, by kicking it
1592  * off hardware queues (which may take a while) and returning it as
1593  * soon as practical.  we've already set up the urb's return status,
1594  * but we can't know if the callback completed already.
1595  */
1596 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1597 {
1598 	int		value;
1599 
1600 	if (is_root_hub(urb->dev))
1601 		value = usb_rh_urb_dequeue(hcd, urb, status);
1602 	else {
1603 
1604 		/* The only reason an HCD might fail this call is if
1605 		 * it has not yet fully queued the urb to begin with.
1606 		 * Such failures should be harmless. */
1607 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1608 	}
1609 	return value;
1610 }
1611 
1612 /*
1613  * called in any context
1614  *
1615  * caller guarantees urb won't be recycled till both unlink()
1616  * and the urb's completion function return
1617  */
1618 int usb_hcd_unlink_urb (struct urb *urb, int status)
1619 {
1620 	struct usb_hcd		*hcd;
1621 	int			retval = -EIDRM;
1622 	unsigned long		flags;
1623 
1624 	/* Prevent the device and bus from going away while
1625 	 * the unlink is carried out.  If they are already gone
1626 	 * then urb->use_count must be 0, since disconnected
1627 	 * devices can't have any active URBs.
1628 	 */
1629 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1630 	if (atomic_read(&urb->use_count) > 0) {
1631 		retval = 0;
1632 		usb_get_dev(urb->dev);
1633 	}
1634 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1635 	if (retval == 0) {
1636 		hcd = bus_to_hcd(urb->dev->bus);
1637 		retval = unlink1(hcd, urb, status);
1638 		usb_put_dev(urb->dev);
1639 	}
1640 
1641 	if (retval == 0)
1642 		retval = -EINPROGRESS;
1643 	else if (retval != -EIDRM && retval != -EBUSY)
1644 		dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1645 				urb, retval);
1646 	return retval;
1647 }
1648 
1649 /*-------------------------------------------------------------------------*/
1650 
1651 static void __usb_hcd_giveback_urb(struct urb *urb)
1652 {
1653 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1654 	struct usb_anchor *anchor = urb->anchor;
1655 	int status = urb->unlinked;
1656 	unsigned long flags;
1657 
1658 	urb->hcpriv = NULL;
1659 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1660 	    urb->actual_length < urb->transfer_buffer_length &&
1661 	    !status))
1662 		status = -EREMOTEIO;
1663 
1664 	unmap_urb_for_dma(hcd, urb);
1665 	usbmon_urb_complete(&hcd->self, urb, status);
1666 	usb_anchor_suspend_wakeups(anchor);
1667 	usb_unanchor_urb(urb);
1668 	if (likely(status == 0))
1669 		usb_led_activity(USB_LED_EVENT_HOST);
1670 
1671 	/* pass ownership to the completion handler */
1672 	urb->status = status;
1673 
1674 	/*
1675 	 * We disable local IRQs here avoid possible deadlock because
1676 	 * drivers may call spin_lock() to hold lock which might be
1677 	 * acquired in one hard interrupt handler.
1678 	 *
1679 	 * The local_irq_save()/local_irq_restore() around complete()
1680 	 * will be removed if current USB drivers have been cleaned up
1681 	 * and no one may trigger the above deadlock situation when
1682 	 * running complete() in tasklet.
1683 	 */
1684 	local_irq_save(flags);
1685 	urb->complete(urb);
1686 	local_irq_restore(flags);
1687 
1688 	usb_anchor_resume_wakeups(anchor);
1689 	atomic_dec(&urb->use_count);
1690 	if (unlikely(atomic_read(&urb->reject)))
1691 		wake_up(&usb_kill_urb_queue);
1692 	usb_put_urb(urb);
1693 }
1694 
1695 static void usb_giveback_urb_bh(unsigned long param)
1696 {
1697 	struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1698 	struct list_head local_list;
1699 
1700 	spin_lock_irq(&bh->lock);
1701 	bh->running = true;
1702  restart:
1703 	list_replace_init(&bh->head, &local_list);
1704 	spin_unlock_irq(&bh->lock);
1705 
1706 	while (!list_empty(&local_list)) {
1707 		struct urb *urb;
1708 
1709 		urb = list_entry(local_list.next, struct urb, urb_list);
1710 		list_del_init(&urb->urb_list);
1711 		bh->completing_ep = urb->ep;
1712 		__usb_hcd_giveback_urb(urb);
1713 		bh->completing_ep = NULL;
1714 	}
1715 
1716 	/* check if there are new URBs to giveback */
1717 	spin_lock_irq(&bh->lock);
1718 	if (!list_empty(&bh->head))
1719 		goto restart;
1720 	bh->running = false;
1721 	spin_unlock_irq(&bh->lock);
1722 }
1723 
1724 /**
1725  * usb_hcd_giveback_urb - return URB from HCD to device driver
1726  * @hcd: host controller returning the URB
1727  * @urb: urb being returned to the USB device driver.
1728  * @status: completion status code for the URB.
1729  * Context: in_interrupt()
1730  *
1731  * This hands the URB from HCD to its USB device driver, using its
1732  * completion function.  The HCD has freed all per-urb resources
1733  * (and is done using urb->hcpriv).  It also released all HCD locks;
1734  * the device driver won't cause problems if it frees, modifies,
1735  * or resubmits this URB.
1736  *
1737  * If @urb was unlinked, the value of @status will be overridden by
1738  * @urb->unlinked.  Erroneous short transfers are detected in case
1739  * the HCD hasn't checked for them.
1740  */
1741 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1742 {
1743 	struct giveback_urb_bh *bh;
1744 	bool running, high_prio_bh;
1745 
1746 	/* pass status to tasklet via unlinked */
1747 	if (likely(!urb->unlinked))
1748 		urb->unlinked = status;
1749 
1750 	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1751 		__usb_hcd_giveback_urb(urb);
1752 		return;
1753 	}
1754 
1755 	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1756 		bh = &hcd->high_prio_bh;
1757 		high_prio_bh = true;
1758 	} else {
1759 		bh = &hcd->low_prio_bh;
1760 		high_prio_bh = false;
1761 	}
1762 
1763 	spin_lock(&bh->lock);
1764 	list_add_tail(&urb->urb_list, &bh->head);
1765 	running = bh->running;
1766 	spin_unlock(&bh->lock);
1767 
1768 	if (running)
1769 		;
1770 	else if (high_prio_bh)
1771 		tasklet_hi_schedule(&bh->bh);
1772 	else
1773 		tasklet_schedule(&bh->bh);
1774 }
1775 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1776 
1777 /*-------------------------------------------------------------------------*/
1778 
1779 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1780  * queue to drain completely.  The caller must first insure that no more
1781  * URBs can be submitted for this endpoint.
1782  */
1783 void usb_hcd_flush_endpoint(struct usb_device *udev,
1784 		struct usb_host_endpoint *ep)
1785 {
1786 	struct usb_hcd		*hcd;
1787 	struct urb		*urb;
1788 
1789 	if (!ep)
1790 		return;
1791 	might_sleep();
1792 	hcd = bus_to_hcd(udev->bus);
1793 
1794 	/* No more submits can occur */
1795 	spin_lock_irq(&hcd_urb_list_lock);
1796 rescan:
1797 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1798 		int	is_in;
1799 
1800 		if (urb->unlinked)
1801 			continue;
1802 		usb_get_urb (urb);
1803 		is_in = usb_urb_dir_in(urb);
1804 		spin_unlock(&hcd_urb_list_lock);
1805 
1806 		/* kick hcd */
1807 		unlink1(hcd, urb, -ESHUTDOWN);
1808 		dev_dbg (hcd->self.controller,
1809 			"shutdown urb %p ep%d%s%s\n",
1810 			urb, usb_endpoint_num(&ep->desc),
1811 			is_in ? "in" : "out",
1812 			({	char *s;
1813 
1814 				 switch (usb_endpoint_type(&ep->desc)) {
1815 				 case USB_ENDPOINT_XFER_CONTROL:
1816 					s = ""; break;
1817 				 case USB_ENDPOINT_XFER_BULK:
1818 					s = "-bulk"; break;
1819 				 case USB_ENDPOINT_XFER_INT:
1820 					s = "-intr"; break;
1821 				 default:
1822 					s = "-iso"; break;
1823 				};
1824 				s;
1825 			}));
1826 		usb_put_urb (urb);
1827 
1828 		/* list contents may have changed */
1829 		spin_lock(&hcd_urb_list_lock);
1830 		goto rescan;
1831 	}
1832 	spin_unlock_irq(&hcd_urb_list_lock);
1833 
1834 	/* Wait until the endpoint queue is completely empty */
1835 	while (!list_empty (&ep->urb_list)) {
1836 		spin_lock_irq(&hcd_urb_list_lock);
1837 
1838 		/* The list may have changed while we acquired the spinlock */
1839 		urb = NULL;
1840 		if (!list_empty (&ep->urb_list)) {
1841 			urb = list_entry (ep->urb_list.prev, struct urb,
1842 					urb_list);
1843 			usb_get_urb (urb);
1844 		}
1845 		spin_unlock_irq(&hcd_urb_list_lock);
1846 
1847 		if (urb) {
1848 			usb_kill_urb (urb);
1849 			usb_put_urb (urb);
1850 		}
1851 	}
1852 }
1853 
1854 /**
1855  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1856  *				the bus bandwidth
1857  * @udev: target &usb_device
1858  * @new_config: new configuration to install
1859  * @cur_alt: the current alternate interface setting
1860  * @new_alt: alternate interface setting that is being installed
1861  *
1862  * To change configurations, pass in the new configuration in new_config,
1863  * and pass NULL for cur_alt and new_alt.
1864  *
1865  * To reset a device's configuration (put the device in the ADDRESSED state),
1866  * pass in NULL for new_config, cur_alt, and new_alt.
1867  *
1868  * To change alternate interface settings, pass in NULL for new_config,
1869  * pass in the current alternate interface setting in cur_alt,
1870  * and pass in the new alternate interface setting in new_alt.
1871  *
1872  * Return: An error if the requested bandwidth change exceeds the
1873  * bus bandwidth or host controller internal resources.
1874  */
1875 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1876 		struct usb_host_config *new_config,
1877 		struct usb_host_interface *cur_alt,
1878 		struct usb_host_interface *new_alt)
1879 {
1880 	int num_intfs, i, j;
1881 	struct usb_host_interface *alt = NULL;
1882 	int ret = 0;
1883 	struct usb_hcd *hcd;
1884 	struct usb_host_endpoint *ep;
1885 
1886 	hcd = bus_to_hcd(udev->bus);
1887 	if (!hcd->driver->check_bandwidth)
1888 		return 0;
1889 
1890 	/* Configuration is being removed - set configuration 0 */
1891 	if (!new_config && !cur_alt) {
1892 		for (i = 1; i < 16; ++i) {
1893 			ep = udev->ep_out[i];
1894 			if (ep)
1895 				hcd->driver->drop_endpoint(hcd, udev, ep);
1896 			ep = udev->ep_in[i];
1897 			if (ep)
1898 				hcd->driver->drop_endpoint(hcd, udev, ep);
1899 		}
1900 		hcd->driver->check_bandwidth(hcd, udev);
1901 		return 0;
1902 	}
1903 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1904 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1905 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1906 	 * ok to exclude it.
1907 	 */
1908 	if (new_config) {
1909 		num_intfs = new_config->desc.bNumInterfaces;
1910 		/* Remove endpoints (except endpoint 0, which is always on the
1911 		 * schedule) from the old config from the schedule
1912 		 */
1913 		for (i = 1; i < 16; ++i) {
1914 			ep = udev->ep_out[i];
1915 			if (ep) {
1916 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1917 				if (ret < 0)
1918 					goto reset;
1919 			}
1920 			ep = udev->ep_in[i];
1921 			if (ep) {
1922 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1923 				if (ret < 0)
1924 					goto reset;
1925 			}
1926 		}
1927 		for (i = 0; i < num_intfs; ++i) {
1928 			struct usb_host_interface *first_alt;
1929 			int iface_num;
1930 
1931 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1932 			iface_num = first_alt->desc.bInterfaceNumber;
1933 			/* Set up endpoints for alternate interface setting 0 */
1934 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1935 			if (!alt)
1936 				/* No alt setting 0? Pick the first setting. */
1937 				alt = first_alt;
1938 
1939 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1940 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1941 				if (ret < 0)
1942 					goto reset;
1943 			}
1944 		}
1945 	}
1946 	if (cur_alt && new_alt) {
1947 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1948 				cur_alt->desc.bInterfaceNumber);
1949 
1950 		if (!iface)
1951 			return -EINVAL;
1952 		if (iface->resetting_device) {
1953 			/*
1954 			 * The USB core just reset the device, so the xHCI host
1955 			 * and the device will think alt setting 0 is installed.
1956 			 * However, the USB core will pass in the alternate
1957 			 * setting installed before the reset as cur_alt.  Dig
1958 			 * out the alternate setting 0 structure, or the first
1959 			 * alternate setting if a broken device doesn't have alt
1960 			 * setting 0.
1961 			 */
1962 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1963 			if (!cur_alt)
1964 				cur_alt = &iface->altsetting[0];
1965 		}
1966 
1967 		/* Drop all the endpoints in the current alt setting */
1968 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1969 			ret = hcd->driver->drop_endpoint(hcd, udev,
1970 					&cur_alt->endpoint[i]);
1971 			if (ret < 0)
1972 				goto reset;
1973 		}
1974 		/* Add all the endpoints in the new alt setting */
1975 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1976 			ret = hcd->driver->add_endpoint(hcd, udev,
1977 					&new_alt->endpoint[i]);
1978 			if (ret < 0)
1979 				goto reset;
1980 		}
1981 	}
1982 	ret = hcd->driver->check_bandwidth(hcd, udev);
1983 reset:
1984 	if (ret < 0)
1985 		hcd->driver->reset_bandwidth(hcd, udev);
1986 	return ret;
1987 }
1988 
1989 /* Disables the endpoint: synchronizes with the hcd to make sure all
1990  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1991  * have been called previously.  Use for set_configuration, set_interface,
1992  * driver removal, physical disconnect.
1993  *
1994  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1995  * type, maxpacket size, toggle, halt status, and scheduling.
1996  */
1997 void usb_hcd_disable_endpoint(struct usb_device *udev,
1998 		struct usb_host_endpoint *ep)
1999 {
2000 	struct usb_hcd		*hcd;
2001 
2002 	might_sleep();
2003 	hcd = bus_to_hcd(udev->bus);
2004 	if (hcd->driver->endpoint_disable)
2005 		hcd->driver->endpoint_disable(hcd, ep);
2006 }
2007 
2008 /**
2009  * usb_hcd_reset_endpoint - reset host endpoint state
2010  * @udev: USB device.
2011  * @ep:   the endpoint to reset.
2012  *
2013  * Resets any host endpoint state such as the toggle bit, sequence
2014  * number and current window.
2015  */
2016 void usb_hcd_reset_endpoint(struct usb_device *udev,
2017 			    struct usb_host_endpoint *ep)
2018 {
2019 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2020 
2021 	if (hcd->driver->endpoint_reset)
2022 		hcd->driver->endpoint_reset(hcd, ep);
2023 	else {
2024 		int epnum = usb_endpoint_num(&ep->desc);
2025 		int is_out = usb_endpoint_dir_out(&ep->desc);
2026 		int is_control = usb_endpoint_xfer_control(&ep->desc);
2027 
2028 		usb_settoggle(udev, epnum, is_out, 0);
2029 		if (is_control)
2030 			usb_settoggle(udev, epnum, !is_out, 0);
2031 	}
2032 }
2033 
2034 /**
2035  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2036  * @interface:		alternate setting that includes all endpoints.
2037  * @eps:		array of endpoints that need streams.
2038  * @num_eps:		number of endpoints in the array.
2039  * @num_streams:	number of streams to allocate.
2040  * @mem_flags:		flags hcd should use to allocate memory.
2041  *
2042  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2043  * Drivers may queue multiple transfers to different stream IDs, which may
2044  * complete in a different order than they were queued.
2045  *
2046  * Return: On success, the number of allocated streams. On failure, a negative
2047  * error code.
2048  */
2049 int usb_alloc_streams(struct usb_interface *interface,
2050 		struct usb_host_endpoint **eps, unsigned int num_eps,
2051 		unsigned int num_streams, gfp_t mem_flags)
2052 {
2053 	struct usb_hcd *hcd;
2054 	struct usb_device *dev;
2055 	int i, ret;
2056 
2057 	dev = interface_to_usbdev(interface);
2058 	hcd = bus_to_hcd(dev->bus);
2059 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2060 		return -EINVAL;
2061 	if (dev->speed != USB_SPEED_SUPER)
2062 		return -EINVAL;
2063 	if (dev->state < USB_STATE_CONFIGURED)
2064 		return -ENODEV;
2065 
2066 	for (i = 0; i < num_eps; i++) {
2067 		/* Streams only apply to bulk endpoints. */
2068 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2069 			return -EINVAL;
2070 		/* Re-alloc is not allowed */
2071 		if (eps[i]->streams)
2072 			return -EINVAL;
2073 	}
2074 
2075 	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2076 			num_streams, mem_flags);
2077 	if (ret < 0)
2078 		return ret;
2079 
2080 	for (i = 0; i < num_eps; i++)
2081 		eps[i]->streams = ret;
2082 
2083 	return ret;
2084 }
2085 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2086 
2087 /**
2088  * usb_free_streams - free bulk endpoint stream IDs.
2089  * @interface:	alternate setting that includes all endpoints.
2090  * @eps:	array of endpoints to remove streams from.
2091  * @num_eps:	number of endpoints in the array.
2092  * @mem_flags:	flags hcd should use to allocate memory.
2093  *
2094  * Reverts a group of bulk endpoints back to not using stream IDs.
2095  * Can fail if we are given bad arguments, or HCD is broken.
2096  *
2097  * Return: 0 on success. On failure, a negative error code.
2098  */
2099 int usb_free_streams(struct usb_interface *interface,
2100 		struct usb_host_endpoint **eps, unsigned int num_eps,
2101 		gfp_t mem_flags)
2102 {
2103 	struct usb_hcd *hcd;
2104 	struct usb_device *dev;
2105 	int i, ret;
2106 
2107 	dev = interface_to_usbdev(interface);
2108 	hcd = bus_to_hcd(dev->bus);
2109 	if (dev->speed != USB_SPEED_SUPER)
2110 		return -EINVAL;
2111 
2112 	/* Double-free is not allowed */
2113 	for (i = 0; i < num_eps; i++)
2114 		if (!eps[i] || !eps[i]->streams)
2115 			return -EINVAL;
2116 
2117 	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2118 	if (ret < 0)
2119 		return ret;
2120 
2121 	for (i = 0; i < num_eps; i++)
2122 		eps[i]->streams = 0;
2123 
2124 	return ret;
2125 }
2126 EXPORT_SYMBOL_GPL(usb_free_streams);
2127 
2128 /* Protect against drivers that try to unlink URBs after the device
2129  * is gone, by waiting until all unlinks for @udev are finished.
2130  * Since we don't currently track URBs by device, simply wait until
2131  * nothing is running in the locked region of usb_hcd_unlink_urb().
2132  */
2133 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2134 {
2135 	spin_lock_irq(&hcd_urb_unlink_lock);
2136 	spin_unlock_irq(&hcd_urb_unlink_lock);
2137 }
2138 
2139 /*-------------------------------------------------------------------------*/
2140 
2141 /* called in any context */
2142 int usb_hcd_get_frame_number (struct usb_device *udev)
2143 {
2144 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2145 
2146 	if (!HCD_RH_RUNNING(hcd))
2147 		return -ESHUTDOWN;
2148 	return hcd->driver->get_frame_number (hcd);
2149 }
2150 
2151 /*-------------------------------------------------------------------------*/
2152 
2153 #ifdef	CONFIG_PM
2154 
2155 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2156 {
2157 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2158 	int		status;
2159 	int		old_state = hcd->state;
2160 
2161 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2162 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2163 			rhdev->do_remote_wakeup);
2164 	if (HCD_DEAD(hcd)) {
2165 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2166 		return 0;
2167 	}
2168 
2169 	if (!hcd->driver->bus_suspend) {
2170 		status = -ENOENT;
2171 	} else {
2172 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2173 		hcd->state = HC_STATE_QUIESCING;
2174 		status = hcd->driver->bus_suspend(hcd);
2175 	}
2176 	if (status == 0) {
2177 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2178 		hcd->state = HC_STATE_SUSPENDED;
2179 
2180 		/* Did we race with a root-hub wakeup event? */
2181 		if (rhdev->do_remote_wakeup) {
2182 			char	buffer[6];
2183 
2184 			status = hcd->driver->hub_status_data(hcd, buffer);
2185 			if (status != 0) {
2186 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2187 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2188 				status = -EBUSY;
2189 			}
2190 		}
2191 	} else {
2192 		spin_lock_irq(&hcd_root_hub_lock);
2193 		if (!HCD_DEAD(hcd)) {
2194 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2195 			hcd->state = old_state;
2196 		}
2197 		spin_unlock_irq(&hcd_root_hub_lock);
2198 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2199 				"suspend", status);
2200 	}
2201 	return status;
2202 }
2203 
2204 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2205 {
2206 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2207 	int		status;
2208 	int		old_state = hcd->state;
2209 
2210 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2211 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2212 	if (HCD_DEAD(hcd)) {
2213 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2214 		return 0;
2215 	}
2216 	if (!hcd->driver->bus_resume)
2217 		return -ENOENT;
2218 	if (HCD_RH_RUNNING(hcd))
2219 		return 0;
2220 
2221 	hcd->state = HC_STATE_RESUMING;
2222 	status = hcd->driver->bus_resume(hcd);
2223 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2224 	if (status == 0) {
2225 		struct usb_device *udev;
2226 		int port1;
2227 
2228 		spin_lock_irq(&hcd_root_hub_lock);
2229 		if (!HCD_DEAD(hcd)) {
2230 			usb_set_device_state(rhdev, rhdev->actconfig
2231 					? USB_STATE_CONFIGURED
2232 					: USB_STATE_ADDRESS);
2233 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2234 			hcd->state = HC_STATE_RUNNING;
2235 		}
2236 		spin_unlock_irq(&hcd_root_hub_lock);
2237 
2238 		/*
2239 		 * Check whether any of the enabled ports on the root hub are
2240 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2241 		 * (this is what the USB-2 spec calls a "global resume").
2242 		 * Otherwise we can skip the delay.
2243 		 */
2244 		usb_hub_for_each_child(rhdev, port1, udev) {
2245 			if (udev->state != USB_STATE_NOTATTACHED &&
2246 					!udev->port_is_suspended) {
2247 				usleep_range(10000, 11000);	/* TRSMRCY */
2248 				break;
2249 			}
2250 		}
2251 	} else {
2252 		hcd->state = old_state;
2253 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2254 				"resume", status);
2255 		if (status != -ESHUTDOWN)
2256 			usb_hc_died(hcd);
2257 	}
2258 	return status;
2259 }
2260 
2261 /* Workqueue routine for root-hub remote wakeup */
2262 static void hcd_resume_work(struct work_struct *work)
2263 {
2264 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2265 	struct usb_device *udev = hcd->self.root_hub;
2266 
2267 	usb_remote_wakeup(udev);
2268 }
2269 
2270 /**
2271  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2272  * @hcd: host controller for this root hub
2273  *
2274  * The USB host controller calls this function when its root hub is
2275  * suspended (with the remote wakeup feature enabled) and a remote
2276  * wakeup request is received.  The routine submits a workqueue request
2277  * to resume the root hub (that is, manage its downstream ports again).
2278  */
2279 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2280 {
2281 	unsigned long flags;
2282 
2283 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2284 	if (hcd->rh_registered) {
2285 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2286 		queue_work(pm_wq, &hcd->wakeup_work);
2287 	}
2288 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2289 }
2290 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2291 
2292 #endif	/* CONFIG_PM */
2293 
2294 /*-------------------------------------------------------------------------*/
2295 
2296 #ifdef	CONFIG_USB_OTG
2297 
2298 /**
2299  * usb_bus_start_enum - start immediate enumeration (for OTG)
2300  * @bus: the bus (must use hcd framework)
2301  * @port_num: 1-based number of port; usually bus->otg_port
2302  * Context: in_interrupt()
2303  *
2304  * Starts enumeration, with an immediate reset followed later by
2305  * hub_wq identifying and possibly configuring the device.
2306  * This is needed by OTG controller drivers, where it helps meet
2307  * HNP protocol timing requirements for starting a port reset.
2308  *
2309  * Return: 0 if successful.
2310  */
2311 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2312 {
2313 	struct usb_hcd		*hcd;
2314 	int			status = -EOPNOTSUPP;
2315 
2316 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2317 	 * boards with root hubs hooked up to internal devices (instead of
2318 	 * just the OTG port) may need more attention to resetting...
2319 	 */
2320 	hcd = container_of (bus, struct usb_hcd, self);
2321 	if (port_num && hcd->driver->start_port_reset)
2322 		status = hcd->driver->start_port_reset(hcd, port_num);
2323 
2324 	/* allocate hub_wq shortly after (first) root port reset finishes;
2325 	 * it may issue others, until at least 50 msecs have passed.
2326 	 */
2327 	if (status == 0)
2328 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2329 	return status;
2330 }
2331 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2332 
2333 #endif
2334 
2335 /*-------------------------------------------------------------------------*/
2336 
2337 /**
2338  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2339  * @irq: the IRQ being raised
2340  * @__hcd: pointer to the HCD whose IRQ is being signaled
2341  *
2342  * If the controller isn't HALTed, calls the driver's irq handler.
2343  * Checks whether the controller is now dead.
2344  *
2345  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2346  */
2347 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2348 {
2349 	struct usb_hcd		*hcd = __hcd;
2350 	irqreturn_t		rc;
2351 
2352 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2353 		rc = IRQ_NONE;
2354 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2355 		rc = IRQ_NONE;
2356 	else
2357 		rc = IRQ_HANDLED;
2358 
2359 	return rc;
2360 }
2361 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2362 
2363 /*-------------------------------------------------------------------------*/
2364 
2365 /**
2366  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2367  * @hcd: pointer to the HCD representing the controller
2368  *
2369  * This is called by bus glue to report a USB host controller that died
2370  * while operations may still have been pending.  It's called automatically
2371  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2372  *
2373  * Only call this function with the primary HCD.
2374  */
2375 void usb_hc_died (struct usb_hcd *hcd)
2376 {
2377 	unsigned long flags;
2378 
2379 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2380 
2381 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2382 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2383 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2384 	if (hcd->rh_registered) {
2385 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2386 
2387 		/* make hub_wq clean up old urbs and devices */
2388 		usb_set_device_state (hcd->self.root_hub,
2389 				USB_STATE_NOTATTACHED);
2390 		usb_kick_hub_wq(hcd->self.root_hub);
2391 	}
2392 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2393 		hcd = hcd->shared_hcd;
2394 		if (hcd->rh_registered) {
2395 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2396 
2397 			/* make hub_wq clean up old urbs and devices */
2398 			usb_set_device_state(hcd->self.root_hub,
2399 					USB_STATE_NOTATTACHED);
2400 			usb_kick_hub_wq(hcd->self.root_hub);
2401 		}
2402 	}
2403 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2404 	/* Make sure that the other roothub is also deallocated. */
2405 }
2406 EXPORT_SYMBOL_GPL (usb_hc_died);
2407 
2408 /*-------------------------------------------------------------------------*/
2409 
2410 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2411 {
2412 
2413 	spin_lock_init(&bh->lock);
2414 	INIT_LIST_HEAD(&bh->head);
2415 	tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2416 }
2417 
2418 /**
2419  * usb_create_shared_hcd - create and initialize an HCD structure
2420  * @driver: HC driver that will use this hcd
2421  * @dev: device for this HC, stored in hcd->self.controller
2422  * @bus_name: value to store in hcd->self.bus_name
2423  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2424  *              PCI device.  Only allocate certain resources for the primary HCD
2425  * Context: !in_interrupt()
2426  *
2427  * Allocate a struct usb_hcd, with extra space at the end for the
2428  * HC driver's private data.  Initialize the generic members of the
2429  * hcd structure.
2430  *
2431  * Return: On success, a pointer to the created and initialized HCD structure.
2432  * On failure (e.g. if memory is unavailable), %NULL.
2433  */
2434 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2435 		struct device *dev, const char *bus_name,
2436 		struct usb_hcd *primary_hcd)
2437 {
2438 	struct usb_hcd *hcd;
2439 
2440 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2441 	if (!hcd) {
2442 		dev_dbg (dev, "hcd alloc failed\n");
2443 		return NULL;
2444 	}
2445 	if (primary_hcd == NULL) {
2446 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2447 				GFP_KERNEL);
2448 		if (!hcd->bandwidth_mutex) {
2449 			kfree(hcd);
2450 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2451 			return NULL;
2452 		}
2453 		mutex_init(hcd->bandwidth_mutex);
2454 		dev_set_drvdata(dev, hcd);
2455 	} else {
2456 		mutex_lock(&usb_port_peer_mutex);
2457 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2458 		hcd->primary_hcd = primary_hcd;
2459 		primary_hcd->primary_hcd = primary_hcd;
2460 		hcd->shared_hcd = primary_hcd;
2461 		primary_hcd->shared_hcd = hcd;
2462 		mutex_unlock(&usb_port_peer_mutex);
2463 	}
2464 
2465 	kref_init(&hcd->kref);
2466 
2467 	usb_bus_init(&hcd->self);
2468 	hcd->self.controller = dev;
2469 	hcd->self.bus_name = bus_name;
2470 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2471 
2472 	init_timer(&hcd->rh_timer);
2473 	hcd->rh_timer.function = rh_timer_func;
2474 	hcd->rh_timer.data = (unsigned long) hcd;
2475 #ifdef CONFIG_PM
2476 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2477 #endif
2478 
2479 	hcd->driver = driver;
2480 	hcd->speed = driver->flags & HCD_MASK;
2481 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2482 			"USB Host Controller";
2483 	return hcd;
2484 }
2485 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2486 
2487 /**
2488  * usb_create_hcd - create and initialize an HCD structure
2489  * @driver: HC driver that will use this hcd
2490  * @dev: device for this HC, stored in hcd->self.controller
2491  * @bus_name: value to store in hcd->self.bus_name
2492  * Context: !in_interrupt()
2493  *
2494  * Allocate a struct usb_hcd, with extra space at the end for the
2495  * HC driver's private data.  Initialize the generic members of the
2496  * hcd structure.
2497  *
2498  * Return: On success, a pointer to the created and initialized HCD
2499  * structure. On failure (e.g. if memory is unavailable), %NULL.
2500  */
2501 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2502 		struct device *dev, const char *bus_name)
2503 {
2504 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2505 }
2506 EXPORT_SYMBOL_GPL(usb_create_hcd);
2507 
2508 /*
2509  * Roothubs that share one PCI device must also share the bandwidth mutex.
2510  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2511  * deallocated.
2512  *
2513  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2514  * freed.  When hcd_release() is called for either hcd in a peer set
2515  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers to
2516  * block new peering attempts
2517  */
2518 static void hcd_release(struct kref *kref)
2519 {
2520 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2521 
2522 	mutex_lock(&usb_port_peer_mutex);
2523 	if (usb_hcd_is_primary_hcd(hcd))
2524 		kfree(hcd->bandwidth_mutex);
2525 	if (hcd->shared_hcd) {
2526 		struct usb_hcd *peer = hcd->shared_hcd;
2527 
2528 		peer->shared_hcd = NULL;
2529 		if (peer->primary_hcd == hcd)
2530 			peer->primary_hcd = NULL;
2531 	}
2532 	mutex_unlock(&usb_port_peer_mutex);
2533 	kfree(hcd);
2534 }
2535 
2536 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2537 {
2538 	if (hcd)
2539 		kref_get (&hcd->kref);
2540 	return hcd;
2541 }
2542 EXPORT_SYMBOL_GPL(usb_get_hcd);
2543 
2544 void usb_put_hcd (struct usb_hcd *hcd)
2545 {
2546 	if (hcd)
2547 		kref_put (&hcd->kref, hcd_release);
2548 }
2549 EXPORT_SYMBOL_GPL(usb_put_hcd);
2550 
2551 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2552 {
2553 	if (!hcd->primary_hcd)
2554 		return 1;
2555 	return hcd == hcd->primary_hcd;
2556 }
2557 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2558 
2559 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2560 {
2561 	if (!hcd->driver->find_raw_port_number)
2562 		return port1;
2563 
2564 	return hcd->driver->find_raw_port_number(hcd, port1);
2565 }
2566 
2567 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2568 		unsigned int irqnum, unsigned long irqflags)
2569 {
2570 	int retval;
2571 
2572 	if (hcd->driver->irq) {
2573 
2574 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2575 				hcd->driver->description, hcd->self.busnum);
2576 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2577 				hcd->irq_descr, hcd);
2578 		if (retval != 0) {
2579 			dev_err(hcd->self.controller,
2580 					"request interrupt %d failed\n",
2581 					irqnum);
2582 			return retval;
2583 		}
2584 		hcd->irq = irqnum;
2585 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2586 				(hcd->driver->flags & HCD_MEMORY) ?
2587 					"io mem" : "io base",
2588 					(unsigned long long)hcd->rsrc_start);
2589 	} else {
2590 		hcd->irq = 0;
2591 		if (hcd->rsrc_start)
2592 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2593 					(hcd->driver->flags & HCD_MEMORY) ?
2594 					"io mem" : "io base",
2595 					(unsigned long long)hcd->rsrc_start);
2596 	}
2597 	return 0;
2598 }
2599 
2600 /*
2601  * Before we free this root hub, flush in-flight peering attempts
2602  * and disable peer lookups
2603  */
2604 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2605 {
2606 	struct usb_device *rhdev;
2607 
2608 	mutex_lock(&usb_port_peer_mutex);
2609 	rhdev = hcd->self.root_hub;
2610 	hcd->self.root_hub = NULL;
2611 	mutex_unlock(&usb_port_peer_mutex);
2612 	usb_put_dev(rhdev);
2613 }
2614 
2615 /**
2616  * usb_add_hcd - finish generic HCD structure initialization and register
2617  * @hcd: the usb_hcd structure to initialize
2618  * @irqnum: Interrupt line to allocate
2619  * @irqflags: Interrupt type flags
2620  *
2621  * Finish the remaining parts of generic HCD initialization: allocate the
2622  * buffers of consistent memory, register the bus, request the IRQ line,
2623  * and call the driver's reset() and start() routines.
2624  */
2625 int usb_add_hcd(struct usb_hcd *hcd,
2626 		unsigned int irqnum, unsigned long irqflags)
2627 {
2628 	int retval;
2629 	struct usb_device *rhdev;
2630 
2631 	if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) {
2632 		struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0);
2633 
2634 		if (IS_ERR(phy)) {
2635 			retval = PTR_ERR(phy);
2636 			if (retval == -EPROBE_DEFER)
2637 				return retval;
2638 		} else {
2639 			retval = usb_phy_init(phy);
2640 			if (retval) {
2641 				usb_put_phy(phy);
2642 				return retval;
2643 			}
2644 			hcd->usb_phy = phy;
2645 			hcd->remove_phy = 1;
2646 		}
2647 	}
2648 
2649 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) {
2650 		struct phy *phy = phy_get(hcd->self.controller, "usb");
2651 
2652 		if (IS_ERR(phy)) {
2653 			retval = PTR_ERR(phy);
2654 			if (retval == -EPROBE_DEFER)
2655 				goto err_phy;
2656 		} else {
2657 			retval = phy_init(phy);
2658 			if (retval) {
2659 				phy_put(phy);
2660 				goto err_phy;
2661 			}
2662 			retval = phy_power_on(phy);
2663 			if (retval) {
2664 				phy_exit(phy);
2665 				phy_put(phy);
2666 				goto err_phy;
2667 			}
2668 			hcd->phy = phy;
2669 			hcd->remove_phy = 1;
2670 		}
2671 	}
2672 
2673 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2674 
2675 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2676 	if (authorized_default < 0 || authorized_default > 1)
2677 		hcd->authorized_default = hcd->wireless ? 0 : 1;
2678 	else
2679 		hcd->authorized_default = authorized_default;
2680 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2681 
2682 	/* HC is in reset state, but accessible.  Now do the one-time init,
2683 	 * bottom up so that hcds can customize the root hubs before hub_wq
2684 	 * starts talking to them.  (Note, bus id is assigned early too.)
2685 	 */
2686 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2687 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2688 		goto err_create_buf;
2689 	}
2690 
2691 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2692 		goto err_register_bus;
2693 
2694 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2695 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2696 		retval = -ENOMEM;
2697 		goto err_allocate_root_hub;
2698 	}
2699 	mutex_lock(&usb_port_peer_mutex);
2700 	hcd->self.root_hub = rhdev;
2701 	mutex_unlock(&usb_port_peer_mutex);
2702 
2703 	switch (hcd->speed) {
2704 	case HCD_USB11:
2705 		rhdev->speed = USB_SPEED_FULL;
2706 		break;
2707 	case HCD_USB2:
2708 		rhdev->speed = USB_SPEED_HIGH;
2709 		break;
2710 	case HCD_USB25:
2711 		rhdev->speed = USB_SPEED_WIRELESS;
2712 		break;
2713 	case HCD_USB3:
2714 		rhdev->speed = USB_SPEED_SUPER;
2715 		break;
2716 	default:
2717 		retval = -EINVAL;
2718 		goto err_set_rh_speed;
2719 	}
2720 
2721 	/* wakeup flag init defaults to "everything works" for root hubs,
2722 	 * but drivers can override it in reset() if needed, along with
2723 	 * recording the overall controller's system wakeup capability.
2724 	 */
2725 	device_set_wakeup_capable(&rhdev->dev, 1);
2726 
2727 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2728 	 * registered.  But since the controller can die at any time,
2729 	 * let's initialize the flag before touching the hardware.
2730 	 */
2731 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2732 
2733 	/* "reset" is misnamed; its role is now one-time init. the controller
2734 	 * should already have been reset (and boot firmware kicked off etc).
2735 	 */
2736 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2737 		dev_err(hcd->self.controller, "can't setup: %d\n", retval);
2738 		goto err_hcd_driver_setup;
2739 	}
2740 	hcd->rh_pollable = 1;
2741 
2742 	/* NOTE: root hub and controller capabilities may not be the same */
2743 	if (device_can_wakeup(hcd->self.controller)
2744 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2745 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2746 
2747 	/* initialize tasklets */
2748 	init_giveback_urb_bh(&hcd->high_prio_bh);
2749 	init_giveback_urb_bh(&hcd->low_prio_bh);
2750 
2751 	/* enable irqs just before we start the controller,
2752 	 * if the BIOS provides legacy PCI irqs.
2753 	 */
2754 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2755 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2756 		if (retval)
2757 			goto err_request_irq;
2758 	}
2759 
2760 	hcd->state = HC_STATE_RUNNING;
2761 	retval = hcd->driver->start(hcd);
2762 	if (retval < 0) {
2763 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2764 		goto err_hcd_driver_start;
2765 	}
2766 
2767 	/* starting here, usbcore will pay attention to this root hub */
2768 	if ((retval = register_root_hub(hcd)) != 0)
2769 		goto err_register_root_hub;
2770 
2771 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2772 	if (retval < 0) {
2773 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2774 		       retval);
2775 		goto error_create_attr_group;
2776 	}
2777 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2778 		usb_hcd_poll_rh_status(hcd);
2779 
2780 	return retval;
2781 
2782 error_create_attr_group:
2783 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2784 	if (HC_IS_RUNNING(hcd->state))
2785 		hcd->state = HC_STATE_QUIESCING;
2786 	spin_lock_irq(&hcd_root_hub_lock);
2787 	hcd->rh_registered = 0;
2788 	spin_unlock_irq(&hcd_root_hub_lock);
2789 
2790 #ifdef CONFIG_PM
2791 	cancel_work_sync(&hcd->wakeup_work);
2792 #endif
2793 	mutex_lock(&usb_bus_list_lock);
2794 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2795 	mutex_unlock(&usb_bus_list_lock);
2796 err_register_root_hub:
2797 	hcd->rh_pollable = 0;
2798 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2799 	del_timer_sync(&hcd->rh_timer);
2800 	hcd->driver->stop(hcd);
2801 	hcd->state = HC_STATE_HALT;
2802 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2803 	del_timer_sync(&hcd->rh_timer);
2804 err_hcd_driver_start:
2805 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2806 		free_irq(irqnum, hcd);
2807 err_request_irq:
2808 err_hcd_driver_setup:
2809 err_set_rh_speed:
2810 	usb_put_invalidate_rhdev(hcd);
2811 err_allocate_root_hub:
2812 	usb_deregister_bus(&hcd->self);
2813 err_register_bus:
2814 	hcd_buffer_destroy(hcd);
2815 err_create_buf:
2816 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2817 		phy_power_off(hcd->phy);
2818 		phy_exit(hcd->phy);
2819 		phy_put(hcd->phy);
2820 		hcd->phy = NULL;
2821 	}
2822 err_phy:
2823 	if (hcd->remove_phy && hcd->usb_phy) {
2824 		usb_phy_shutdown(hcd->usb_phy);
2825 		usb_put_phy(hcd->usb_phy);
2826 		hcd->usb_phy = NULL;
2827 	}
2828 	return retval;
2829 }
2830 EXPORT_SYMBOL_GPL(usb_add_hcd);
2831 
2832 /**
2833  * usb_remove_hcd - shutdown processing for generic HCDs
2834  * @hcd: the usb_hcd structure to remove
2835  * Context: !in_interrupt()
2836  *
2837  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2838  * invoking the HCD's stop() method.
2839  */
2840 void usb_remove_hcd(struct usb_hcd *hcd)
2841 {
2842 	struct usb_device *rhdev = hcd->self.root_hub;
2843 
2844 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2845 
2846 	usb_get_dev(rhdev);
2847 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2848 
2849 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2850 	if (HC_IS_RUNNING (hcd->state))
2851 		hcd->state = HC_STATE_QUIESCING;
2852 
2853 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2854 	spin_lock_irq (&hcd_root_hub_lock);
2855 	hcd->rh_registered = 0;
2856 	spin_unlock_irq (&hcd_root_hub_lock);
2857 
2858 #ifdef CONFIG_PM
2859 	cancel_work_sync(&hcd->wakeup_work);
2860 #endif
2861 
2862 	mutex_lock(&usb_bus_list_lock);
2863 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2864 	mutex_unlock(&usb_bus_list_lock);
2865 
2866 	/*
2867 	 * tasklet_kill() isn't needed here because:
2868 	 * - driver's disconnect() called from usb_disconnect() should
2869 	 *   make sure its URBs are completed during the disconnect()
2870 	 *   callback
2871 	 *
2872 	 * - it is too late to run complete() here since driver may have
2873 	 *   been removed already now
2874 	 */
2875 
2876 	/* Prevent any more root-hub status calls from the timer.
2877 	 * The HCD might still restart the timer (if a port status change
2878 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2879 	 * the hub_status_data() callback.
2880 	 */
2881 	hcd->rh_pollable = 0;
2882 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2883 	del_timer_sync(&hcd->rh_timer);
2884 
2885 	hcd->driver->stop(hcd);
2886 	hcd->state = HC_STATE_HALT;
2887 
2888 	/* In case the HCD restarted the timer, stop it again. */
2889 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2890 	del_timer_sync(&hcd->rh_timer);
2891 
2892 	if (usb_hcd_is_primary_hcd(hcd)) {
2893 		if (hcd->irq > 0)
2894 			free_irq(hcd->irq, hcd);
2895 	}
2896 
2897 	usb_deregister_bus(&hcd->self);
2898 	hcd_buffer_destroy(hcd);
2899 
2900 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2901 		phy_power_off(hcd->phy);
2902 		phy_exit(hcd->phy);
2903 		phy_put(hcd->phy);
2904 		hcd->phy = NULL;
2905 	}
2906 	if (hcd->remove_phy && hcd->usb_phy) {
2907 		usb_phy_shutdown(hcd->usb_phy);
2908 		usb_put_phy(hcd->usb_phy);
2909 		hcd->usb_phy = NULL;
2910 	}
2911 
2912 	usb_put_invalidate_rhdev(hcd);
2913 }
2914 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2915 
2916 void
2917 usb_hcd_platform_shutdown(struct platform_device *dev)
2918 {
2919 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2920 
2921 	if (hcd->driver->shutdown)
2922 		hcd->driver->shutdown(hcd);
2923 }
2924 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2925 
2926 /*-------------------------------------------------------------------------*/
2927 
2928 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2929 
2930 struct usb_mon_operations *mon_ops;
2931 
2932 /*
2933  * The registration is unlocked.
2934  * We do it this way because we do not want to lock in hot paths.
2935  *
2936  * Notice that the code is minimally error-proof. Because usbmon needs
2937  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2938  */
2939 
2940 int usb_mon_register (struct usb_mon_operations *ops)
2941 {
2942 
2943 	if (mon_ops)
2944 		return -EBUSY;
2945 
2946 	mon_ops = ops;
2947 	mb();
2948 	return 0;
2949 }
2950 EXPORT_SYMBOL_GPL (usb_mon_register);
2951 
2952 void usb_mon_deregister (void)
2953 {
2954 
2955 	if (mon_ops == NULL) {
2956 		printk(KERN_ERR "USB: monitor was not registered\n");
2957 		return;
2958 	}
2959 	mon_ops = NULL;
2960 	mb();
2961 }
2962 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2963 
2964 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2965