xref: /openbmc/linux/drivers/usb/core/hcd.c (revision 9cdb81c7)
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/module.h>
26 #include <linux/version.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/completion.h>
30 #include <linux/utsname.h>
31 #include <linux/mm.h>
32 #include <asm/io.h>
33 #include <linux/device.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/mutex.h>
36 #include <asm/irq.h>
37 #include <asm/byteorder.h>
38 #include <asm/unaligned.h>
39 #include <linux/platform_device.h>
40 #include <linux/workqueue.h>
41 
42 #include <linux/usb.h>
43 #include <linux/usb/hcd.h>
44 
45 #include "usb.h"
46 
47 
48 /*-------------------------------------------------------------------------*/
49 
50 /*
51  * USB Host Controller Driver framework
52  *
53  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
54  * HCD-specific behaviors/bugs.
55  *
56  * This does error checks, tracks devices and urbs, and delegates to a
57  * "hc_driver" only for code (and data) that really needs to know about
58  * hardware differences.  That includes root hub registers, i/o queues,
59  * and so on ... but as little else as possible.
60  *
61  * Shared code includes most of the "root hub" code (these are emulated,
62  * though each HC's hardware works differently) and PCI glue, plus request
63  * tracking overhead.  The HCD code should only block on spinlocks or on
64  * hardware handshaking; blocking on software events (such as other kernel
65  * threads releasing resources, or completing actions) is all generic.
66  *
67  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
68  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
69  * only by the hub driver ... and that neither should be seen or used by
70  * usb client device drivers.
71  *
72  * Contributors of ideas or unattributed patches include: David Brownell,
73  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
74  *
75  * HISTORY:
76  * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
77  *		associated cleanup.  "usb_hcd" still != "usb_bus".
78  * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
79  */
80 
81 /*-------------------------------------------------------------------------*/
82 
83 /* Keep track of which host controller drivers are loaded */
84 unsigned long usb_hcds_loaded;
85 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
86 
87 /* host controllers we manage */
88 LIST_HEAD (usb_bus_list);
89 EXPORT_SYMBOL_GPL (usb_bus_list);
90 
91 /* used when allocating bus numbers */
92 #define USB_MAXBUS		64
93 struct usb_busmap {
94 	unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
95 };
96 static struct usb_busmap busmap;
97 
98 /* used when updating list of hcds */
99 DEFINE_MUTEX(usb_bus_list_lock);	/* exported only for usbfs */
100 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
101 
102 /* used for controlling access to virtual root hubs */
103 static DEFINE_SPINLOCK(hcd_root_hub_lock);
104 
105 /* used when updating an endpoint's URB list */
106 static DEFINE_SPINLOCK(hcd_urb_list_lock);
107 
108 /* used to protect against unlinking URBs after the device is gone */
109 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
110 
111 /* wait queue for synchronous unlinks */
112 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
113 
114 static inline int is_root_hub(struct usb_device *udev)
115 {
116 	return (udev->parent == NULL);
117 }
118 
119 /*-------------------------------------------------------------------------*/
120 
121 /*
122  * Sharable chunks of root hub code.
123  */
124 
125 /*-------------------------------------------------------------------------*/
126 
127 #define KERNEL_REL	((LINUX_VERSION_CODE >> 16) & 0x0ff)
128 #define KERNEL_VER	((LINUX_VERSION_CODE >> 8) & 0x0ff)
129 
130 /* usb 3.0 root hub device descriptor */
131 static const u8 usb3_rh_dev_descriptor[18] = {
132 	0x12,       /*  __u8  bLength; */
133 	0x01,       /*  __u8  bDescriptorType; Device */
134 	0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
135 
136 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
137 	0x00,	    /*  __u8  bDeviceSubClass; */
138 	0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
139 	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
140 
141 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation */
142 	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
143 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
144 
145 	0x03,       /*  __u8  iManufacturer; */
146 	0x02,       /*  __u8  iProduct; */
147 	0x01,       /*  __u8  iSerialNumber; */
148 	0x01        /*  __u8  bNumConfigurations; */
149 };
150 
151 /* usb 2.0 root hub device descriptor */
152 static const u8 usb2_rh_dev_descriptor [18] = {
153 	0x12,       /*  __u8  bLength; */
154 	0x01,       /*  __u8  bDescriptorType; Device */
155 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
156 
157 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
158 	0x00,	    /*  __u8  bDeviceSubClass; */
159 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
160 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
161 
162 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation */
163 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
164 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
165 
166 	0x03,       /*  __u8  iManufacturer; */
167 	0x02,       /*  __u8  iProduct; */
168 	0x01,       /*  __u8  iSerialNumber; */
169 	0x01        /*  __u8  bNumConfigurations; */
170 };
171 
172 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
173 
174 /* usb 1.1 root hub device descriptor */
175 static const u8 usb11_rh_dev_descriptor [18] = {
176 	0x12,       /*  __u8  bLength; */
177 	0x01,       /*  __u8  bDescriptorType; Device */
178 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
179 
180 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
181 	0x00,	    /*  __u8  bDeviceSubClass; */
182 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
183 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
184 
185 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation */
186 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
187 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
188 
189 	0x03,       /*  __u8  iManufacturer; */
190 	0x02,       /*  __u8  iProduct; */
191 	0x01,       /*  __u8  iSerialNumber; */
192 	0x01        /*  __u8  bNumConfigurations; */
193 };
194 
195 
196 /*-------------------------------------------------------------------------*/
197 
198 /* Configuration descriptors for our root hubs */
199 
200 static const u8 fs_rh_config_descriptor [] = {
201 
202 	/* one configuration */
203 	0x09,       /*  __u8  bLength; */
204 	0x02,       /*  __u8  bDescriptorType; Configuration */
205 	0x19, 0x00, /*  __le16 wTotalLength; */
206 	0x01,       /*  __u8  bNumInterfaces; (1) */
207 	0x01,       /*  __u8  bConfigurationValue; */
208 	0x00,       /*  __u8  iConfiguration; */
209 	0xc0,       /*  __u8  bmAttributes;
210 				 Bit 7: must be set,
211 				     6: Self-powered,
212 				     5: Remote wakeup,
213 				     4..0: resvd */
214 	0x00,       /*  __u8  MaxPower; */
215 
216 	/* USB 1.1:
217 	 * USB 2.0, single TT organization (mandatory):
218 	 *	one interface, protocol 0
219 	 *
220 	 * USB 2.0, multiple TT organization (optional):
221 	 *	two interfaces, protocols 1 (like single TT)
222 	 *	and 2 (multiple TT mode) ... config is
223 	 *	sometimes settable
224 	 *	NOT IMPLEMENTED
225 	 */
226 
227 	/* one interface */
228 	0x09,       /*  __u8  if_bLength; */
229 	0x04,       /*  __u8  if_bDescriptorType; Interface */
230 	0x00,       /*  __u8  if_bInterfaceNumber; */
231 	0x00,       /*  __u8  if_bAlternateSetting; */
232 	0x01,       /*  __u8  if_bNumEndpoints; */
233 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
234 	0x00,       /*  __u8  if_bInterfaceSubClass; */
235 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
236 	0x00,       /*  __u8  if_iInterface; */
237 
238 	/* one endpoint (status change endpoint) */
239 	0x07,       /*  __u8  ep_bLength; */
240 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
241 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
242  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
243  	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
244 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
245 };
246 
247 static const u8 hs_rh_config_descriptor [] = {
248 
249 	/* one configuration */
250 	0x09,       /*  __u8  bLength; */
251 	0x02,       /*  __u8  bDescriptorType; Configuration */
252 	0x19, 0x00, /*  __le16 wTotalLength; */
253 	0x01,       /*  __u8  bNumInterfaces; (1) */
254 	0x01,       /*  __u8  bConfigurationValue; */
255 	0x00,       /*  __u8  iConfiguration; */
256 	0xc0,       /*  __u8  bmAttributes;
257 				 Bit 7: must be set,
258 				     6: Self-powered,
259 				     5: Remote wakeup,
260 				     4..0: resvd */
261 	0x00,       /*  __u8  MaxPower; */
262 
263 	/* USB 1.1:
264 	 * USB 2.0, single TT organization (mandatory):
265 	 *	one interface, protocol 0
266 	 *
267 	 * USB 2.0, multiple TT organization (optional):
268 	 *	two interfaces, protocols 1 (like single TT)
269 	 *	and 2 (multiple TT mode) ... config is
270 	 *	sometimes settable
271 	 *	NOT IMPLEMENTED
272 	 */
273 
274 	/* one interface */
275 	0x09,       /*  __u8  if_bLength; */
276 	0x04,       /*  __u8  if_bDescriptorType; Interface */
277 	0x00,       /*  __u8  if_bInterfaceNumber; */
278 	0x00,       /*  __u8  if_bAlternateSetting; */
279 	0x01,       /*  __u8  if_bNumEndpoints; */
280 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
281 	0x00,       /*  __u8  if_bInterfaceSubClass; */
282 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
283 	0x00,       /*  __u8  if_iInterface; */
284 
285 	/* one endpoint (status change endpoint) */
286 	0x07,       /*  __u8  ep_bLength; */
287 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
288 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
289  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
290 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
291 		     * see hub.c:hub_configure() for details. */
292 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
293 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
294 };
295 
296 static const u8 ss_rh_config_descriptor[] = {
297 	/* one configuration */
298 	0x09,       /*  __u8  bLength; */
299 	0x02,       /*  __u8  bDescriptorType; Configuration */
300 	0x1f, 0x00, /*  __le16 wTotalLength; */
301 	0x01,       /*  __u8  bNumInterfaces; (1) */
302 	0x01,       /*  __u8  bConfigurationValue; */
303 	0x00,       /*  __u8  iConfiguration; */
304 	0xc0,       /*  __u8  bmAttributes;
305 				 Bit 7: must be set,
306 				     6: Self-powered,
307 				     5: Remote wakeup,
308 				     4..0: resvd */
309 	0x00,       /*  __u8  MaxPower; */
310 
311 	/* one interface */
312 	0x09,       /*  __u8  if_bLength; */
313 	0x04,       /*  __u8  if_bDescriptorType; Interface */
314 	0x00,       /*  __u8  if_bInterfaceNumber; */
315 	0x00,       /*  __u8  if_bAlternateSetting; */
316 	0x01,       /*  __u8  if_bNumEndpoints; */
317 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
318 	0x00,       /*  __u8  if_bInterfaceSubClass; */
319 	0x00,       /*  __u8  if_bInterfaceProtocol; */
320 	0x00,       /*  __u8  if_iInterface; */
321 
322 	/* one endpoint (status change endpoint) */
323 	0x07,       /*  __u8  ep_bLength; */
324 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
325 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
326 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
327 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
328 		     * see hub.c:hub_configure() for details. */
329 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
330 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
331 
332 	/* one SuperSpeed endpoint companion descriptor */
333 	0x06,        /* __u8 ss_bLength */
334 	0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
335 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
336 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
337 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
338 };
339 
340 /* authorized_default behaviour:
341  * -1 is authorized for all devices except wireless (old behaviour)
342  * 0 is unauthorized for all devices
343  * 1 is authorized for all devices
344  */
345 static int authorized_default = -1;
346 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
347 MODULE_PARM_DESC(authorized_default,
348 		"Default USB device authorization: 0 is not authorized, 1 is "
349 		"authorized, -1 is authorized except for wireless USB (default, "
350 		"old behaviour");
351 /*-------------------------------------------------------------------------*/
352 
353 /**
354  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
355  * @s: Null-terminated ASCII (actually ISO-8859-1) string
356  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
357  * @len: Length (in bytes; may be odd) of descriptor buffer.
358  *
359  * The return value is the number of bytes filled in: 2 + 2*strlen(s) or
360  * buflen, whichever is less.
361  *
362  * USB String descriptors can contain at most 126 characters; input
363  * strings longer than that are truncated.
364  */
365 static unsigned
366 ascii2desc(char const *s, u8 *buf, unsigned len)
367 {
368 	unsigned n, t = 2 + 2*strlen(s);
369 
370 	if (t > 254)
371 		t = 254;	/* Longest possible UTF string descriptor */
372 	if (len > t)
373 		len = t;
374 
375 	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
376 
377 	n = len;
378 	while (n--) {
379 		*buf++ = t;
380 		if (!n--)
381 			break;
382 		*buf++ = t >> 8;
383 		t = (unsigned char)*s++;
384 	}
385 	return len;
386 }
387 
388 /**
389  * rh_string() - provides string descriptors for root hub
390  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
391  * @hcd: the host controller for this root hub
392  * @data: buffer for output packet
393  * @len: length of the provided buffer
394  *
395  * Produces either a manufacturer, product or serial number string for the
396  * virtual root hub device.
397  * Returns the number of bytes filled in: the length of the descriptor or
398  * of the provided buffer, whichever is less.
399  */
400 static unsigned
401 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
402 {
403 	char buf[100];
404 	char const *s;
405 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
406 
407 	// language ids
408 	switch (id) {
409 	case 0:
410 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
411 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
412 		if (len > 4)
413 			len = 4;
414 		memcpy(data, langids, len);
415 		return len;
416 	case 1:
417 		/* Serial number */
418 		s = hcd->self.bus_name;
419 		break;
420 	case 2:
421 		/* Product name */
422 		s = hcd->product_desc;
423 		break;
424 	case 3:
425 		/* Manufacturer */
426 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
427 			init_utsname()->release, hcd->driver->description);
428 		s = buf;
429 		break;
430 	default:
431 		/* Can't happen; caller guarantees it */
432 		return 0;
433 	}
434 
435 	return ascii2desc(s, data, len);
436 }
437 
438 
439 /* Root hub control transfers execute synchronously */
440 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
441 {
442 	struct usb_ctrlrequest *cmd;
443  	u16		typeReq, wValue, wIndex, wLength;
444 	u8		*ubuf = urb->transfer_buffer;
445 	/*
446 	 * tbuf should be as big as the BOS descriptor and
447 	 * the USB hub descriptor.
448 	 */
449 	u8		tbuf[USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE]
450 		__attribute__((aligned(4)));
451 	const u8	*bufp = tbuf;
452 	unsigned	len = 0;
453 	int		status;
454 	u8		patch_wakeup = 0;
455 	u8		patch_protocol = 0;
456 
457 	might_sleep();
458 
459 	spin_lock_irq(&hcd_root_hub_lock);
460 	status = usb_hcd_link_urb_to_ep(hcd, urb);
461 	spin_unlock_irq(&hcd_root_hub_lock);
462 	if (status)
463 		return status;
464 	urb->hcpriv = hcd;	/* Indicate it's queued */
465 
466 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
467 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
468 	wValue   = le16_to_cpu (cmd->wValue);
469 	wIndex   = le16_to_cpu (cmd->wIndex);
470 	wLength  = le16_to_cpu (cmd->wLength);
471 
472 	if (wLength > urb->transfer_buffer_length)
473 		goto error;
474 
475 	urb->actual_length = 0;
476 	switch (typeReq) {
477 
478 	/* DEVICE REQUESTS */
479 
480 	/* The root hub's remote wakeup enable bit is implemented using
481 	 * driver model wakeup flags.  If this system supports wakeup
482 	 * through USB, userspace may change the default "allow wakeup"
483 	 * policy through sysfs or these calls.
484 	 *
485 	 * Most root hubs support wakeup from downstream devices, for
486 	 * runtime power management (disabling USB clocks and reducing
487 	 * VBUS power usage).  However, not all of them do so; silicon,
488 	 * board, and BIOS bugs here are not uncommon, so these can't
489 	 * be treated quite like external hubs.
490 	 *
491 	 * Likewise, not all root hubs will pass wakeup events upstream,
492 	 * to wake up the whole system.  So don't assume root hub and
493 	 * controller capabilities are identical.
494 	 */
495 
496 	case DeviceRequest | USB_REQ_GET_STATUS:
497 		tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
498 					<< USB_DEVICE_REMOTE_WAKEUP)
499 				| (1 << USB_DEVICE_SELF_POWERED);
500 		tbuf [1] = 0;
501 		len = 2;
502 		break;
503 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
504 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
505 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
506 		else
507 			goto error;
508 		break;
509 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
510 		if (device_can_wakeup(&hcd->self.root_hub->dev)
511 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
512 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
513 		else
514 			goto error;
515 		break;
516 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
517 		tbuf [0] = 1;
518 		len = 1;
519 			/* FALLTHROUGH */
520 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
521 		break;
522 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
523 		switch (wValue & 0xff00) {
524 		case USB_DT_DEVICE << 8:
525 			switch (hcd->speed) {
526 			case HCD_USB3:
527 				bufp = usb3_rh_dev_descriptor;
528 				break;
529 			case HCD_USB2:
530 				bufp = usb2_rh_dev_descriptor;
531 				break;
532 			case HCD_USB11:
533 				bufp = usb11_rh_dev_descriptor;
534 				break;
535 			default:
536 				goto error;
537 			}
538 			len = 18;
539 			if (hcd->has_tt)
540 				patch_protocol = 1;
541 			break;
542 		case USB_DT_CONFIG << 8:
543 			switch (hcd->speed) {
544 			case HCD_USB3:
545 				bufp = ss_rh_config_descriptor;
546 				len = sizeof ss_rh_config_descriptor;
547 				break;
548 			case HCD_USB2:
549 				bufp = hs_rh_config_descriptor;
550 				len = sizeof hs_rh_config_descriptor;
551 				break;
552 			case HCD_USB11:
553 				bufp = fs_rh_config_descriptor;
554 				len = sizeof fs_rh_config_descriptor;
555 				break;
556 			default:
557 				goto error;
558 			}
559 			if (device_can_wakeup(&hcd->self.root_hub->dev))
560 				patch_wakeup = 1;
561 			break;
562 		case USB_DT_STRING << 8:
563 			if ((wValue & 0xff) < 4)
564 				urb->actual_length = rh_string(wValue & 0xff,
565 						hcd, ubuf, wLength);
566 			else /* unsupported IDs --> "protocol stall" */
567 				goto error;
568 			break;
569 		case USB_DT_BOS << 8:
570 			goto nongeneric;
571 		default:
572 			goto error;
573 		}
574 		break;
575 	case DeviceRequest | USB_REQ_GET_INTERFACE:
576 		tbuf [0] = 0;
577 		len = 1;
578 			/* FALLTHROUGH */
579 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
580 		break;
581 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
582 		// wValue == urb->dev->devaddr
583 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
584 			wValue);
585 		break;
586 
587 	/* INTERFACE REQUESTS (no defined feature/status flags) */
588 
589 	/* ENDPOINT REQUESTS */
590 
591 	case EndpointRequest | USB_REQ_GET_STATUS:
592 		// ENDPOINT_HALT flag
593 		tbuf [0] = 0;
594 		tbuf [1] = 0;
595 		len = 2;
596 			/* FALLTHROUGH */
597 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
598 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
599 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
600 		break;
601 
602 	/* CLASS REQUESTS (and errors) */
603 
604 	default:
605 nongeneric:
606 		/* non-generic request */
607 		switch (typeReq) {
608 		case GetHubStatus:
609 		case GetPortStatus:
610 			len = 4;
611 			break;
612 		case GetHubDescriptor:
613 			len = sizeof (struct usb_hub_descriptor);
614 			break;
615 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
616 			/* len is returned by hub_control */
617 			break;
618 		}
619 		status = hcd->driver->hub_control (hcd,
620 			typeReq, wValue, wIndex,
621 			tbuf, wLength);
622 		break;
623 error:
624 		/* "protocol stall" on error */
625 		status = -EPIPE;
626 	}
627 
628 	if (status < 0) {
629 		len = 0;
630 		if (status != -EPIPE) {
631 			dev_dbg (hcd->self.controller,
632 				"CTRL: TypeReq=0x%x val=0x%x "
633 				"idx=0x%x len=%d ==> %d\n",
634 				typeReq, wValue, wIndex,
635 				wLength, status);
636 		}
637 	} else if (status > 0) {
638 		/* hub_control may return the length of data copied. */
639 		len = status;
640 		status = 0;
641 	}
642 	if (len) {
643 		if (urb->transfer_buffer_length < len)
644 			len = urb->transfer_buffer_length;
645 		urb->actual_length = len;
646 		// always USB_DIR_IN, toward host
647 		memcpy (ubuf, bufp, len);
648 
649 		/* report whether RH hardware supports remote wakeup */
650 		if (patch_wakeup &&
651 				len > offsetof (struct usb_config_descriptor,
652 						bmAttributes))
653 			((struct usb_config_descriptor *)ubuf)->bmAttributes
654 				|= USB_CONFIG_ATT_WAKEUP;
655 
656 		/* report whether RH hardware has an integrated TT */
657 		if (patch_protocol &&
658 				len > offsetof(struct usb_device_descriptor,
659 						bDeviceProtocol))
660 			((struct usb_device_descriptor *) ubuf)->
661 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
662 	}
663 
664 	/* any errors get returned through the urb completion */
665 	spin_lock_irq(&hcd_root_hub_lock);
666 	usb_hcd_unlink_urb_from_ep(hcd, urb);
667 
668 	/* This peculiar use of spinlocks echoes what real HC drivers do.
669 	 * Avoiding calls to local_irq_disable/enable makes the code
670 	 * RT-friendly.
671 	 */
672 	spin_unlock(&hcd_root_hub_lock);
673 	usb_hcd_giveback_urb(hcd, urb, status);
674 	spin_lock(&hcd_root_hub_lock);
675 
676 	spin_unlock_irq(&hcd_root_hub_lock);
677 	return 0;
678 }
679 
680 /*-------------------------------------------------------------------------*/
681 
682 /*
683  * Root Hub interrupt transfers are polled using a timer if the
684  * driver requests it; otherwise the driver is responsible for
685  * calling usb_hcd_poll_rh_status() when an event occurs.
686  *
687  * Completions are called in_interrupt(), but they may or may not
688  * be in_irq().
689  */
690 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
691 {
692 	struct urb	*urb;
693 	int		length;
694 	unsigned long	flags;
695 	char		buffer[6];	/* Any root hubs with > 31 ports? */
696 
697 	if (unlikely(!hcd->rh_pollable))
698 		return;
699 	if (!hcd->uses_new_polling && !hcd->status_urb)
700 		return;
701 
702 	length = hcd->driver->hub_status_data(hcd, buffer);
703 	if (length > 0) {
704 
705 		/* try to complete the status urb */
706 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
707 		urb = hcd->status_urb;
708 		if (urb) {
709 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
710 			hcd->status_urb = NULL;
711 			urb->actual_length = length;
712 			memcpy(urb->transfer_buffer, buffer, length);
713 
714 			usb_hcd_unlink_urb_from_ep(hcd, urb);
715 			spin_unlock(&hcd_root_hub_lock);
716 			usb_hcd_giveback_urb(hcd, urb, 0);
717 			spin_lock(&hcd_root_hub_lock);
718 		} else {
719 			length = 0;
720 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
721 		}
722 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
723 	}
724 
725 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
726 	 * exceed that limit if HZ is 100. The math is more clunky than
727 	 * maybe expected, this is to make sure that all timers for USB devices
728 	 * fire at the same time to give the CPU a break in between */
729 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
730 			(length == 0 && hcd->status_urb != NULL))
731 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
732 }
733 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
734 
735 /* timer callback */
736 static void rh_timer_func (unsigned long _hcd)
737 {
738 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
739 }
740 
741 /*-------------------------------------------------------------------------*/
742 
743 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
744 {
745 	int		retval;
746 	unsigned long	flags;
747 	unsigned	len = 1 + (urb->dev->maxchild / 8);
748 
749 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
750 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
751 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
752 		retval = -EINVAL;
753 		goto done;
754 	}
755 
756 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
757 	if (retval)
758 		goto done;
759 
760 	hcd->status_urb = urb;
761 	urb->hcpriv = hcd;	/* indicate it's queued */
762 	if (!hcd->uses_new_polling)
763 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
764 
765 	/* If a status change has already occurred, report it ASAP */
766 	else if (HCD_POLL_PENDING(hcd))
767 		mod_timer(&hcd->rh_timer, jiffies);
768 	retval = 0;
769  done:
770 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
771 	return retval;
772 }
773 
774 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
775 {
776 	if (usb_endpoint_xfer_int(&urb->ep->desc))
777 		return rh_queue_status (hcd, urb);
778 	if (usb_endpoint_xfer_control(&urb->ep->desc))
779 		return rh_call_control (hcd, urb);
780 	return -EINVAL;
781 }
782 
783 /*-------------------------------------------------------------------------*/
784 
785 /* Unlinks of root-hub control URBs are legal, but they don't do anything
786  * since these URBs always execute synchronously.
787  */
788 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
789 {
790 	unsigned long	flags;
791 	int		rc;
792 
793 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
794 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
795 	if (rc)
796 		goto done;
797 
798 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
799 		;	/* Do nothing */
800 
801 	} else {				/* Status URB */
802 		if (!hcd->uses_new_polling)
803 			del_timer (&hcd->rh_timer);
804 		if (urb == hcd->status_urb) {
805 			hcd->status_urb = NULL;
806 			usb_hcd_unlink_urb_from_ep(hcd, urb);
807 
808 			spin_unlock(&hcd_root_hub_lock);
809 			usb_hcd_giveback_urb(hcd, urb, status);
810 			spin_lock(&hcd_root_hub_lock);
811 		}
812 	}
813  done:
814 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
815 	return rc;
816 }
817 
818 
819 
820 /*
821  * Show & store the current value of authorized_default
822  */
823 static ssize_t usb_host_authorized_default_show(struct device *dev,
824 						struct device_attribute *attr,
825 						char *buf)
826 {
827 	struct usb_device *rh_usb_dev = to_usb_device(dev);
828 	struct usb_bus *usb_bus = rh_usb_dev->bus;
829 	struct usb_hcd *usb_hcd;
830 
831 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
832 		return -ENODEV;
833 	usb_hcd = bus_to_hcd(usb_bus);
834 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
835 }
836 
837 static ssize_t usb_host_authorized_default_store(struct device *dev,
838 						 struct device_attribute *attr,
839 						 const char *buf, size_t size)
840 {
841 	ssize_t result;
842 	unsigned val;
843 	struct usb_device *rh_usb_dev = to_usb_device(dev);
844 	struct usb_bus *usb_bus = rh_usb_dev->bus;
845 	struct usb_hcd *usb_hcd;
846 
847 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
848 		return -ENODEV;
849 	usb_hcd = bus_to_hcd(usb_bus);
850 	result = sscanf(buf, "%u\n", &val);
851 	if (result == 1) {
852 		usb_hcd->authorized_default = val? 1 : 0;
853 		result = size;
854 	}
855 	else
856 		result = -EINVAL;
857 	return result;
858 }
859 
860 static DEVICE_ATTR(authorized_default, 0644,
861 	    usb_host_authorized_default_show,
862 	    usb_host_authorized_default_store);
863 
864 
865 /* Group all the USB bus attributes */
866 static struct attribute *usb_bus_attrs[] = {
867 		&dev_attr_authorized_default.attr,
868 		NULL,
869 };
870 
871 static struct attribute_group usb_bus_attr_group = {
872 	.name = NULL,	/* we want them in the same directory */
873 	.attrs = usb_bus_attrs,
874 };
875 
876 
877 
878 /*-------------------------------------------------------------------------*/
879 
880 /**
881  * usb_bus_init - shared initialization code
882  * @bus: the bus structure being initialized
883  *
884  * This code is used to initialize a usb_bus structure, memory for which is
885  * separately managed.
886  */
887 static void usb_bus_init (struct usb_bus *bus)
888 {
889 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
890 
891 	bus->devnum_next = 1;
892 
893 	bus->root_hub = NULL;
894 	bus->busnum = -1;
895 	bus->bandwidth_allocated = 0;
896 	bus->bandwidth_int_reqs  = 0;
897 	bus->bandwidth_isoc_reqs = 0;
898 
899 	INIT_LIST_HEAD (&bus->bus_list);
900 }
901 
902 /*-------------------------------------------------------------------------*/
903 
904 /**
905  * usb_register_bus - registers the USB host controller with the usb core
906  * @bus: pointer to the bus to register
907  * Context: !in_interrupt()
908  *
909  * Assigns a bus number, and links the controller into usbcore data
910  * structures so that it can be seen by scanning the bus list.
911  */
912 static int usb_register_bus(struct usb_bus *bus)
913 {
914 	int result = -E2BIG;
915 	int busnum;
916 
917 	mutex_lock(&usb_bus_list_lock);
918 	busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
919 	if (busnum >= USB_MAXBUS) {
920 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
921 		goto error_find_busnum;
922 	}
923 	set_bit (busnum, busmap.busmap);
924 	bus->busnum = busnum;
925 
926 	/* Add it to the local list of buses */
927 	list_add (&bus->bus_list, &usb_bus_list);
928 	mutex_unlock(&usb_bus_list_lock);
929 
930 	usb_notify_add_bus(bus);
931 
932 	dev_info (bus->controller, "new USB bus registered, assigned bus "
933 		  "number %d\n", bus->busnum);
934 	return 0;
935 
936 error_find_busnum:
937 	mutex_unlock(&usb_bus_list_lock);
938 	return result;
939 }
940 
941 /**
942  * usb_deregister_bus - deregisters the USB host controller
943  * @bus: pointer to the bus to deregister
944  * Context: !in_interrupt()
945  *
946  * Recycles the bus number, and unlinks the controller from usbcore data
947  * structures so that it won't be seen by scanning the bus list.
948  */
949 static void usb_deregister_bus (struct usb_bus *bus)
950 {
951 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
952 
953 	/*
954 	 * NOTE: make sure that all the devices are removed by the
955 	 * controller code, as well as having it call this when cleaning
956 	 * itself up
957 	 */
958 	mutex_lock(&usb_bus_list_lock);
959 	list_del (&bus->bus_list);
960 	mutex_unlock(&usb_bus_list_lock);
961 
962 	usb_notify_remove_bus(bus);
963 
964 	clear_bit (bus->busnum, busmap.busmap);
965 }
966 
967 /**
968  * register_root_hub - called by usb_add_hcd() to register a root hub
969  * @hcd: host controller for this root hub
970  *
971  * This function registers the root hub with the USB subsystem.  It sets up
972  * the device properly in the device tree and then calls usb_new_device()
973  * to register the usb device.  It also assigns the root hub's USB address
974  * (always 1).
975  */
976 static int register_root_hub(struct usb_hcd *hcd)
977 {
978 	struct device *parent_dev = hcd->self.controller;
979 	struct usb_device *usb_dev = hcd->self.root_hub;
980 	const int devnum = 1;
981 	int retval;
982 
983 	usb_dev->devnum = devnum;
984 	usb_dev->bus->devnum_next = devnum + 1;
985 	memset (&usb_dev->bus->devmap.devicemap, 0,
986 			sizeof usb_dev->bus->devmap.devicemap);
987 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
988 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
989 
990 	mutex_lock(&usb_bus_list_lock);
991 
992 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
993 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
994 	if (retval != sizeof usb_dev->descriptor) {
995 		mutex_unlock(&usb_bus_list_lock);
996 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
997 				dev_name(&usb_dev->dev), retval);
998 		return (retval < 0) ? retval : -EMSGSIZE;
999 	}
1000 
1001 	retval = usb_new_device (usb_dev);
1002 	if (retval) {
1003 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1004 				dev_name(&usb_dev->dev), retval);
1005 	}
1006 	mutex_unlock(&usb_bus_list_lock);
1007 
1008 	if (retval == 0) {
1009 		spin_lock_irq (&hcd_root_hub_lock);
1010 		hcd->rh_registered = 1;
1011 		spin_unlock_irq (&hcd_root_hub_lock);
1012 
1013 		/* Did the HC die before the root hub was registered? */
1014 		if (HCD_DEAD(hcd))
1015 			usb_hc_died (hcd);	/* This time clean up */
1016 	}
1017 
1018 	return retval;
1019 }
1020 
1021 
1022 /*-------------------------------------------------------------------------*/
1023 
1024 /**
1025  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1026  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1027  * @is_input: true iff the transaction sends data to the host
1028  * @isoc: true for isochronous transactions, false for interrupt ones
1029  * @bytecount: how many bytes in the transaction.
1030  *
1031  * Returns approximate bus time in nanoseconds for a periodic transaction.
1032  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1033  * scheduled in software, this function is only used for such scheduling.
1034  */
1035 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1036 {
1037 	unsigned long	tmp;
1038 
1039 	switch (speed) {
1040 	case USB_SPEED_LOW: 	/* INTR only */
1041 		if (is_input) {
1042 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1043 			return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1044 		} else {
1045 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1046 			return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1047 		}
1048 	case USB_SPEED_FULL:	/* ISOC or INTR */
1049 		if (isoc) {
1050 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1051 			return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
1052 		} else {
1053 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1054 			return (9107L + BW_HOST_DELAY + tmp);
1055 		}
1056 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1057 		// FIXME adjust for input vs output
1058 		if (isoc)
1059 			tmp = HS_NSECS_ISO (bytecount);
1060 		else
1061 			tmp = HS_NSECS (bytecount);
1062 		return tmp;
1063 	default:
1064 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1065 		return -1;
1066 	}
1067 }
1068 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1069 
1070 
1071 /*-------------------------------------------------------------------------*/
1072 
1073 /*
1074  * Generic HC operations.
1075  */
1076 
1077 /*-------------------------------------------------------------------------*/
1078 
1079 /**
1080  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1081  * @hcd: host controller to which @urb was submitted
1082  * @urb: URB being submitted
1083  *
1084  * Host controller drivers should call this routine in their enqueue()
1085  * method.  The HCD's private spinlock must be held and interrupts must
1086  * be disabled.  The actions carried out here are required for URB
1087  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1088  *
1089  * Returns 0 for no error, otherwise a negative error code (in which case
1090  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1091  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1092  * the private spinlock and returning.
1093  */
1094 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1095 {
1096 	int		rc = 0;
1097 
1098 	spin_lock(&hcd_urb_list_lock);
1099 
1100 	/* Check that the URB isn't being killed */
1101 	if (unlikely(atomic_read(&urb->reject))) {
1102 		rc = -EPERM;
1103 		goto done;
1104 	}
1105 
1106 	if (unlikely(!urb->ep->enabled)) {
1107 		rc = -ENOENT;
1108 		goto done;
1109 	}
1110 
1111 	if (unlikely(!urb->dev->can_submit)) {
1112 		rc = -EHOSTUNREACH;
1113 		goto done;
1114 	}
1115 
1116 	/*
1117 	 * Check the host controller's state and add the URB to the
1118 	 * endpoint's queue.
1119 	 */
1120 	if (HCD_RH_RUNNING(hcd)) {
1121 		urb->unlinked = 0;
1122 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1123 	} else {
1124 		rc = -ESHUTDOWN;
1125 		goto done;
1126 	}
1127  done:
1128 	spin_unlock(&hcd_urb_list_lock);
1129 	return rc;
1130 }
1131 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1132 
1133 /**
1134  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1135  * @hcd: host controller to which @urb was submitted
1136  * @urb: URB being checked for unlinkability
1137  * @status: error code to store in @urb if the unlink succeeds
1138  *
1139  * Host controller drivers should call this routine in their dequeue()
1140  * method.  The HCD's private spinlock must be held and interrupts must
1141  * be disabled.  The actions carried out here are required for making
1142  * sure than an unlink is valid.
1143  *
1144  * Returns 0 for no error, otherwise a negative error code (in which case
1145  * the dequeue() method must fail).  The possible error codes are:
1146  *
1147  *	-EIDRM: @urb was not submitted or has already completed.
1148  *		The completion function may not have been called yet.
1149  *
1150  *	-EBUSY: @urb has already been unlinked.
1151  */
1152 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1153 		int status)
1154 {
1155 	struct list_head	*tmp;
1156 
1157 	/* insist the urb is still queued */
1158 	list_for_each(tmp, &urb->ep->urb_list) {
1159 		if (tmp == &urb->urb_list)
1160 			break;
1161 	}
1162 	if (tmp != &urb->urb_list)
1163 		return -EIDRM;
1164 
1165 	/* Any status except -EINPROGRESS means something already started to
1166 	 * unlink this URB from the hardware.  So there's no more work to do.
1167 	 */
1168 	if (urb->unlinked)
1169 		return -EBUSY;
1170 	urb->unlinked = status;
1171 	return 0;
1172 }
1173 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1174 
1175 /**
1176  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1177  * @hcd: host controller to which @urb was submitted
1178  * @urb: URB being unlinked
1179  *
1180  * Host controller drivers should call this routine before calling
1181  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1182  * interrupts must be disabled.  The actions carried out here are required
1183  * for URB completion.
1184  */
1185 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1186 {
1187 	/* clear all state linking urb to this dev (and hcd) */
1188 	spin_lock(&hcd_urb_list_lock);
1189 	list_del_init(&urb->urb_list);
1190 	spin_unlock(&hcd_urb_list_lock);
1191 }
1192 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1193 
1194 /*
1195  * Some usb host controllers can only perform dma using a small SRAM area.
1196  * The usb core itself is however optimized for host controllers that can dma
1197  * using regular system memory - like pci devices doing bus mastering.
1198  *
1199  * To support host controllers with limited dma capabilites we provide dma
1200  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1201  * For this to work properly the host controller code must first use the
1202  * function dma_declare_coherent_memory() to point out which memory area
1203  * that should be used for dma allocations.
1204  *
1205  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1206  * dma using dma_alloc_coherent() which in turn allocates from the memory
1207  * area pointed out with dma_declare_coherent_memory().
1208  *
1209  * So, to summarize...
1210  *
1211  * - We need "local" memory, canonical example being
1212  *   a small SRAM on a discrete controller being the
1213  *   only memory that the controller can read ...
1214  *   (a) "normal" kernel memory is no good, and
1215  *   (b) there's not enough to share
1216  *
1217  * - The only *portable* hook for such stuff in the
1218  *   DMA framework is dma_declare_coherent_memory()
1219  *
1220  * - So we use that, even though the primary requirement
1221  *   is that the memory be "local" (hence addressible
1222  *   by that device), not "coherent".
1223  *
1224  */
1225 
1226 static int hcd_alloc_coherent(struct usb_bus *bus,
1227 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1228 			      void **vaddr_handle, size_t size,
1229 			      enum dma_data_direction dir)
1230 {
1231 	unsigned char *vaddr;
1232 
1233 	if (*vaddr_handle == NULL) {
1234 		WARN_ON_ONCE(1);
1235 		return -EFAULT;
1236 	}
1237 
1238 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1239 				 mem_flags, dma_handle);
1240 	if (!vaddr)
1241 		return -ENOMEM;
1242 
1243 	/*
1244 	 * Store the virtual address of the buffer at the end
1245 	 * of the allocated dma buffer. The size of the buffer
1246 	 * may be uneven so use unaligned functions instead
1247 	 * of just rounding up. It makes sense to optimize for
1248 	 * memory footprint over access speed since the amount
1249 	 * of memory available for dma may be limited.
1250 	 */
1251 	put_unaligned((unsigned long)*vaddr_handle,
1252 		      (unsigned long *)(vaddr + size));
1253 
1254 	if (dir == DMA_TO_DEVICE)
1255 		memcpy(vaddr, *vaddr_handle, size);
1256 
1257 	*vaddr_handle = vaddr;
1258 	return 0;
1259 }
1260 
1261 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1262 			      void **vaddr_handle, size_t size,
1263 			      enum dma_data_direction dir)
1264 {
1265 	unsigned char *vaddr = *vaddr_handle;
1266 
1267 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1268 
1269 	if (dir == DMA_FROM_DEVICE)
1270 		memcpy(vaddr, *vaddr_handle, size);
1271 
1272 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1273 
1274 	*vaddr_handle = vaddr;
1275 	*dma_handle = 0;
1276 }
1277 
1278 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1279 {
1280 	if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1281 		dma_unmap_single(hcd->self.controller,
1282 				urb->setup_dma,
1283 				sizeof(struct usb_ctrlrequest),
1284 				DMA_TO_DEVICE);
1285 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1286 		hcd_free_coherent(urb->dev->bus,
1287 				&urb->setup_dma,
1288 				(void **) &urb->setup_packet,
1289 				sizeof(struct usb_ctrlrequest),
1290 				DMA_TO_DEVICE);
1291 
1292 	/* Make it safe to call this routine more than once */
1293 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1294 }
1295 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1296 
1297 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1298 {
1299 	if (hcd->driver->unmap_urb_for_dma)
1300 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1301 	else
1302 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1303 }
1304 
1305 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1306 {
1307 	enum dma_data_direction dir;
1308 
1309 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1310 
1311 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1312 	if (urb->transfer_flags & URB_DMA_MAP_SG)
1313 		dma_unmap_sg(hcd->self.controller,
1314 				urb->sg,
1315 				urb->num_sgs,
1316 				dir);
1317 	else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1318 		dma_unmap_page(hcd->self.controller,
1319 				urb->transfer_dma,
1320 				urb->transfer_buffer_length,
1321 				dir);
1322 	else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1323 		dma_unmap_single(hcd->self.controller,
1324 				urb->transfer_dma,
1325 				urb->transfer_buffer_length,
1326 				dir);
1327 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1328 		hcd_free_coherent(urb->dev->bus,
1329 				&urb->transfer_dma,
1330 				&urb->transfer_buffer,
1331 				urb->transfer_buffer_length,
1332 				dir);
1333 
1334 	/* Make it safe to call this routine more than once */
1335 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1336 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1337 }
1338 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1339 
1340 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1341 			   gfp_t mem_flags)
1342 {
1343 	if (hcd->driver->map_urb_for_dma)
1344 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1345 	else
1346 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1347 }
1348 
1349 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1350 			    gfp_t mem_flags)
1351 {
1352 	enum dma_data_direction dir;
1353 	int ret = 0;
1354 
1355 	/* Map the URB's buffers for DMA access.
1356 	 * Lower level HCD code should use *_dma exclusively,
1357 	 * unless it uses pio or talks to another transport,
1358 	 * or uses the provided scatter gather list for bulk.
1359 	 */
1360 
1361 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1362 		if (hcd->self.uses_pio_for_control)
1363 			return ret;
1364 		if (hcd->self.uses_dma) {
1365 			urb->setup_dma = dma_map_single(
1366 					hcd->self.controller,
1367 					urb->setup_packet,
1368 					sizeof(struct usb_ctrlrequest),
1369 					DMA_TO_DEVICE);
1370 			if (dma_mapping_error(hcd->self.controller,
1371 						urb->setup_dma))
1372 				return -EAGAIN;
1373 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1374 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1375 			ret = hcd_alloc_coherent(
1376 					urb->dev->bus, mem_flags,
1377 					&urb->setup_dma,
1378 					(void **)&urb->setup_packet,
1379 					sizeof(struct usb_ctrlrequest),
1380 					DMA_TO_DEVICE);
1381 			if (ret)
1382 				return ret;
1383 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1384 		}
1385 	}
1386 
1387 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1388 	if (urb->transfer_buffer_length != 0
1389 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1390 		if (hcd->self.uses_dma) {
1391 			if (urb->num_sgs) {
1392 				int n = dma_map_sg(
1393 						hcd->self.controller,
1394 						urb->sg,
1395 						urb->num_sgs,
1396 						dir);
1397 				if (n <= 0)
1398 					ret = -EAGAIN;
1399 				else
1400 					urb->transfer_flags |= URB_DMA_MAP_SG;
1401 				urb->num_mapped_sgs = n;
1402 				if (n != urb->num_sgs)
1403 					urb->transfer_flags |=
1404 							URB_DMA_SG_COMBINED;
1405 			} else if (urb->sg) {
1406 				struct scatterlist *sg = urb->sg;
1407 				urb->transfer_dma = dma_map_page(
1408 						hcd->self.controller,
1409 						sg_page(sg),
1410 						sg->offset,
1411 						urb->transfer_buffer_length,
1412 						dir);
1413 				if (dma_mapping_error(hcd->self.controller,
1414 						urb->transfer_dma))
1415 					ret = -EAGAIN;
1416 				else
1417 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1418 			} else {
1419 				urb->transfer_dma = dma_map_single(
1420 						hcd->self.controller,
1421 						urb->transfer_buffer,
1422 						urb->transfer_buffer_length,
1423 						dir);
1424 				if (dma_mapping_error(hcd->self.controller,
1425 						urb->transfer_dma))
1426 					ret = -EAGAIN;
1427 				else
1428 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1429 			}
1430 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1431 			ret = hcd_alloc_coherent(
1432 					urb->dev->bus, mem_flags,
1433 					&urb->transfer_dma,
1434 					&urb->transfer_buffer,
1435 					urb->transfer_buffer_length,
1436 					dir);
1437 			if (ret == 0)
1438 				urb->transfer_flags |= URB_MAP_LOCAL;
1439 		}
1440 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1441 				URB_SETUP_MAP_LOCAL)))
1442 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1443 	}
1444 	return ret;
1445 }
1446 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1447 
1448 /*-------------------------------------------------------------------------*/
1449 
1450 /* may be called in any context with a valid urb->dev usecount
1451  * caller surrenders "ownership" of urb
1452  * expects usb_submit_urb() to have sanity checked and conditioned all
1453  * inputs in the urb
1454  */
1455 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1456 {
1457 	int			status;
1458 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1459 
1460 	/* increment urb's reference count as part of giving it to the HCD
1461 	 * (which will control it).  HCD guarantees that it either returns
1462 	 * an error or calls giveback(), but not both.
1463 	 */
1464 	usb_get_urb(urb);
1465 	atomic_inc(&urb->use_count);
1466 	atomic_inc(&urb->dev->urbnum);
1467 	usbmon_urb_submit(&hcd->self, urb);
1468 
1469 	/* NOTE requirements on root-hub callers (usbfs and the hub
1470 	 * driver, for now):  URBs' urb->transfer_buffer must be
1471 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1472 	 * they could clobber root hub response data.  Also, control
1473 	 * URBs must be submitted in process context with interrupts
1474 	 * enabled.
1475 	 */
1476 
1477 	if (is_root_hub(urb->dev)) {
1478 		status = rh_urb_enqueue(hcd, urb);
1479 	} else {
1480 		status = map_urb_for_dma(hcd, urb, mem_flags);
1481 		if (likely(status == 0)) {
1482 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1483 			if (unlikely(status))
1484 				unmap_urb_for_dma(hcd, urb);
1485 		}
1486 	}
1487 
1488 	if (unlikely(status)) {
1489 		usbmon_urb_submit_error(&hcd->self, urb, status);
1490 		urb->hcpriv = NULL;
1491 		INIT_LIST_HEAD(&urb->urb_list);
1492 		atomic_dec(&urb->use_count);
1493 		atomic_dec(&urb->dev->urbnum);
1494 		if (atomic_read(&urb->reject))
1495 			wake_up(&usb_kill_urb_queue);
1496 		usb_put_urb(urb);
1497 	}
1498 	return status;
1499 }
1500 
1501 /*-------------------------------------------------------------------------*/
1502 
1503 /* this makes the hcd giveback() the urb more quickly, by kicking it
1504  * off hardware queues (which may take a while) and returning it as
1505  * soon as practical.  we've already set up the urb's return status,
1506  * but we can't know if the callback completed already.
1507  */
1508 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1509 {
1510 	int		value;
1511 
1512 	if (is_root_hub(urb->dev))
1513 		value = usb_rh_urb_dequeue(hcd, urb, status);
1514 	else {
1515 
1516 		/* The only reason an HCD might fail this call is if
1517 		 * it has not yet fully queued the urb to begin with.
1518 		 * Such failures should be harmless. */
1519 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1520 	}
1521 	return value;
1522 }
1523 
1524 /*
1525  * called in any context
1526  *
1527  * caller guarantees urb won't be recycled till both unlink()
1528  * and the urb's completion function return
1529  */
1530 int usb_hcd_unlink_urb (struct urb *urb, int status)
1531 {
1532 	struct usb_hcd		*hcd;
1533 	int			retval = -EIDRM;
1534 	unsigned long		flags;
1535 
1536 	/* Prevent the device and bus from going away while
1537 	 * the unlink is carried out.  If they are already gone
1538 	 * then urb->use_count must be 0, since disconnected
1539 	 * devices can't have any active URBs.
1540 	 */
1541 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1542 	if (atomic_read(&urb->use_count) > 0) {
1543 		retval = 0;
1544 		usb_get_dev(urb->dev);
1545 	}
1546 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1547 	if (retval == 0) {
1548 		hcd = bus_to_hcd(urb->dev->bus);
1549 		retval = unlink1(hcd, urb, status);
1550 		usb_put_dev(urb->dev);
1551 	}
1552 
1553 	if (retval == 0)
1554 		retval = -EINPROGRESS;
1555 	else if (retval != -EIDRM && retval != -EBUSY)
1556 		dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1557 				urb, retval);
1558 	return retval;
1559 }
1560 
1561 /*-------------------------------------------------------------------------*/
1562 
1563 /**
1564  * usb_hcd_giveback_urb - return URB from HCD to device driver
1565  * @hcd: host controller returning the URB
1566  * @urb: urb being returned to the USB device driver.
1567  * @status: completion status code for the URB.
1568  * Context: in_interrupt()
1569  *
1570  * This hands the URB from HCD to its USB device driver, using its
1571  * completion function.  The HCD has freed all per-urb resources
1572  * (and is done using urb->hcpriv).  It also released all HCD locks;
1573  * the device driver won't cause problems if it frees, modifies,
1574  * or resubmits this URB.
1575  *
1576  * If @urb was unlinked, the value of @status will be overridden by
1577  * @urb->unlinked.  Erroneous short transfers are detected in case
1578  * the HCD hasn't checked for them.
1579  */
1580 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1581 {
1582 	urb->hcpriv = NULL;
1583 	if (unlikely(urb->unlinked))
1584 		status = urb->unlinked;
1585 	else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1586 			urb->actual_length < urb->transfer_buffer_length &&
1587 			!status))
1588 		status = -EREMOTEIO;
1589 
1590 	unmap_urb_for_dma(hcd, urb);
1591 	usbmon_urb_complete(&hcd->self, urb, status);
1592 	usb_unanchor_urb(urb);
1593 
1594 	/* pass ownership to the completion handler */
1595 	urb->status = status;
1596 	urb->complete (urb);
1597 	atomic_dec (&urb->use_count);
1598 	if (unlikely(atomic_read(&urb->reject)))
1599 		wake_up (&usb_kill_urb_queue);
1600 	usb_put_urb (urb);
1601 }
1602 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1603 
1604 /*-------------------------------------------------------------------------*/
1605 
1606 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1607  * queue to drain completely.  The caller must first insure that no more
1608  * URBs can be submitted for this endpoint.
1609  */
1610 void usb_hcd_flush_endpoint(struct usb_device *udev,
1611 		struct usb_host_endpoint *ep)
1612 {
1613 	struct usb_hcd		*hcd;
1614 	struct urb		*urb;
1615 
1616 	if (!ep)
1617 		return;
1618 	might_sleep();
1619 	hcd = bus_to_hcd(udev->bus);
1620 
1621 	/* No more submits can occur */
1622 	spin_lock_irq(&hcd_urb_list_lock);
1623 rescan:
1624 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1625 		int	is_in;
1626 
1627 		if (urb->unlinked)
1628 			continue;
1629 		usb_get_urb (urb);
1630 		is_in = usb_urb_dir_in(urb);
1631 		spin_unlock(&hcd_urb_list_lock);
1632 
1633 		/* kick hcd */
1634 		unlink1(hcd, urb, -ESHUTDOWN);
1635 		dev_dbg (hcd->self.controller,
1636 			"shutdown urb %p ep%d%s%s\n",
1637 			urb, usb_endpoint_num(&ep->desc),
1638 			is_in ? "in" : "out",
1639 			({	char *s;
1640 
1641 				 switch (usb_endpoint_type(&ep->desc)) {
1642 				 case USB_ENDPOINT_XFER_CONTROL:
1643 					s = ""; break;
1644 				 case USB_ENDPOINT_XFER_BULK:
1645 					s = "-bulk"; break;
1646 				 case USB_ENDPOINT_XFER_INT:
1647 					s = "-intr"; break;
1648 				 default:
1649 			 		s = "-iso"; break;
1650 				};
1651 				s;
1652 			}));
1653 		usb_put_urb (urb);
1654 
1655 		/* list contents may have changed */
1656 		spin_lock(&hcd_urb_list_lock);
1657 		goto rescan;
1658 	}
1659 	spin_unlock_irq(&hcd_urb_list_lock);
1660 
1661 	/* Wait until the endpoint queue is completely empty */
1662 	while (!list_empty (&ep->urb_list)) {
1663 		spin_lock_irq(&hcd_urb_list_lock);
1664 
1665 		/* The list may have changed while we acquired the spinlock */
1666 		urb = NULL;
1667 		if (!list_empty (&ep->urb_list)) {
1668 			urb = list_entry (ep->urb_list.prev, struct urb,
1669 					urb_list);
1670 			usb_get_urb (urb);
1671 		}
1672 		spin_unlock_irq(&hcd_urb_list_lock);
1673 
1674 		if (urb) {
1675 			usb_kill_urb (urb);
1676 			usb_put_urb (urb);
1677 		}
1678 	}
1679 }
1680 
1681 /**
1682  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1683  *				the bus bandwidth
1684  * @udev: target &usb_device
1685  * @new_config: new configuration to install
1686  * @cur_alt: the current alternate interface setting
1687  * @new_alt: alternate interface setting that is being installed
1688  *
1689  * To change configurations, pass in the new configuration in new_config,
1690  * and pass NULL for cur_alt and new_alt.
1691  *
1692  * To reset a device's configuration (put the device in the ADDRESSED state),
1693  * pass in NULL for new_config, cur_alt, and new_alt.
1694  *
1695  * To change alternate interface settings, pass in NULL for new_config,
1696  * pass in the current alternate interface setting in cur_alt,
1697  * and pass in the new alternate interface setting in new_alt.
1698  *
1699  * Returns an error if the requested bandwidth change exceeds the
1700  * bus bandwidth or host controller internal resources.
1701  */
1702 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1703 		struct usb_host_config *new_config,
1704 		struct usb_host_interface *cur_alt,
1705 		struct usb_host_interface *new_alt)
1706 {
1707 	int num_intfs, i, j;
1708 	struct usb_host_interface *alt = NULL;
1709 	int ret = 0;
1710 	struct usb_hcd *hcd;
1711 	struct usb_host_endpoint *ep;
1712 
1713 	hcd = bus_to_hcd(udev->bus);
1714 	if (!hcd->driver->check_bandwidth)
1715 		return 0;
1716 
1717 	/* Configuration is being removed - set configuration 0 */
1718 	if (!new_config && !cur_alt) {
1719 		for (i = 1; i < 16; ++i) {
1720 			ep = udev->ep_out[i];
1721 			if (ep)
1722 				hcd->driver->drop_endpoint(hcd, udev, ep);
1723 			ep = udev->ep_in[i];
1724 			if (ep)
1725 				hcd->driver->drop_endpoint(hcd, udev, ep);
1726 		}
1727 		hcd->driver->check_bandwidth(hcd, udev);
1728 		return 0;
1729 	}
1730 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1731 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1732 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1733 	 * ok to exclude it.
1734 	 */
1735 	if (new_config) {
1736 		num_intfs = new_config->desc.bNumInterfaces;
1737 		/* Remove endpoints (except endpoint 0, which is always on the
1738 		 * schedule) from the old config from the schedule
1739 		 */
1740 		for (i = 1; i < 16; ++i) {
1741 			ep = udev->ep_out[i];
1742 			if (ep) {
1743 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1744 				if (ret < 0)
1745 					goto reset;
1746 			}
1747 			ep = udev->ep_in[i];
1748 			if (ep) {
1749 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1750 				if (ret < 0)
1751 					goto reset;
1752 			}
1753 		}
1754 		for (i = 0; i < num_intfs; ++i) {
1755 			struct usb_host_interface *first_alt;
1756 			int iface_num;
1757 
1758 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1759 			iface_num = first_alt->desc.bInterfaceNumber;
1760 			/* Set up endpoints for alternate interface setting 0 */
1761 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1762 			if (!alt)
1763 				/* No alt setting 0? Pick the first setting. */
1764 				alt = first_alt;
1765 
1766 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1767 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1768 				if (ret < 0)
1769 					goto reset;
1770 			}
1771 		}
1772 	}
1773 	if (cur_alt && new_alt) {
1774 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1775 				cur_alt->desc.bInterfaceNumber);
1776 
1777 		if (!iface)
1778 			return -EINVAL;
1779 		if (iface->resetting_device) {
1780 			/*
1781 			 * The USB core just reset the device, so the xHCI host
1782 			 * and the device will think alt setting 0 is installed.
1783 			 * However, the USB core will pass in the alternate
1784 			 * setting installed before the reset as cur_alt.  Dig
1785 			 * out the alternate setting 0 structure, or the first
1786 			 * alternate setting if a broken device doesn't have alt
1787 			 * setting 0.
1788 			 */
1789 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1790 			if (!cur_alt)
1791 				cur_alt = &iface->altsetting[0];
1792 		}
1793 
1794 		/* Drop all the endpoints in the current alt setting */
1795 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1796 			ret = hcd->driver->drop_endpoint(hcd, udev,
1797 					&cur_alt->endpoint[i]);
1798 			if (ret < 0)
1799 				goto reset;
1800 		}
1801 		/* Add all the endpoints in the new alt setting */
1802 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1803 			ret = hcd->driver->add_endpoint(hcd, udev,
1804 					&new_alt->endpoint[i]);
1805 			if (ret < 0)
1806 				goto reset;
1807 		}
1808 	}
1809 	ret = hcd->driver->check_bandwidth(hcd, udev);
1810 reset:
1811 	if (ret < 0)
1812 		hcd->driver->reset_bandwidth(hcd, udev);
1813 	return ret;
1814 }
1815 
1816 /* Disables the endpoint: synchronizes with the hcd to make sure all
1817  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1818  * have been called previously.  Use for set_configuration, set_interface,
1819  * driver removal, physical disconnect.
1820  *
1821  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1822  * type, maxpacket size, toggle, halt status, and scheduling.
1823  */
1824 void usb_hcd_disable_endpoint(struct usb_device *udev,
1825 		struct usb_host_endpoint *ep)
1826 {
1827 	struct usb_hcd		*hcd;
1828 
1829 	might_sleep();
1830 	hcd = bus_to_hcd(udev->bus);
1831 	if (hcd->driver->endpoint_disable)
1832 		hcd->driver->endpoint_disable(hcd, ep);
1833 }
1834 
1835 /**
1836  * usb_hcd_reset_endpoint - reset host endpoint state
1837  * @udev: USB device.
1838  * @ep:   the endpoint to reset.
1839  *
1840  * Resets any host endpoint state such as the toggle bit, sequence
1841  * number and current window.
1842  */
1843 void usb_hcd_reset_endpoint(struct usb_device *udev,
1844 			    struct usb_host_endpoint *ep)
1845 {
1846 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1847 
1848 	if (hcd->driver->endpoint_reset)
1849 		hcd->driver->endpoint_reset(hcd, ep);
1850 	else {
1851 		int epnum = usb_endpoint_num(&ep->desc);
1852 		int is_out = usb_endpoint_dir_out(&ep->desc);
1853 		int is_control = usb_endpoint_xfer_control(&ep->desc);
1854 
1855 		usb_settoggle(udev, epnum, is_out, 0);
1856 		if (is_control)
1857 			usb_settoggle(udev, epnum, !is_out, 0);
1858 	}
1859 }
1860 
1861 /**
1862  * usb_alloc_streams - allocate bulk endpoint stream IDs.
1863  * @interface:		alternate setting that includes all endpoints.
1864  * @eps:		array of endpoints that need streams.
1865  * @num_eps:		number of endpoints in the array.
1866  * @num_streams:	number of streams to allocate.
1867  * @mem_flags:		flags hcd should use to allocate memory.
1868  *
1869  * Sets up a group of bulk endpoints to have num_streams stream IDs available.
1870  * Drivers may queue multiple transfers to different stream IDs, which may
1871  * complete in a different order than they were queued.
1872  */
1873 int usb_alloc_streams(struct usb_interface *interface,
1874 		struct usb_host_endpoint **eps, unsigned int num_eps,
1875 		unsigned int num_streams, gfp_t mem_flags)
1876 {
1877 	struct usb_hcd *hcd;
1878 	struct usb_device *dev;
1879 	int i;
1880 
1881 	dev = interface_to_usbdev(interface);
1882 	hcd = bus_to_hcd(dev->bus);
1883 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
1884 		return -EINVAL;
1885 	if (dev->speed != USB_SPEED_SUPER)
1886 		return -EINVAL;
1887 
1888 	/* Streams only apply to bulk endpoints. */
1889 	for (i = 0; i < num_eps; i++)
1890 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
1891 			return -EINVAL;
1892 
1893 	return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
1894 			num_streams, mem_flags);
1895 }
1896 EXPORT_SYMBOL_GPL(usb_alloc_streams);
1897 
1898 /**
1899  * usb_free_streams - free bulk endpoint stream IDs.
1900  * @interface:	alternate setting that includes all endpoints.
1901  * @eps:	array of endpoints to remove streams from.
1902  * @num_eps:	number of endpoints in the array.
1903  * @mem_flags:	flags hcd should use to allocate memory.
1904  *
1905  * Reverts a group of bulk endpoints back to not using stream IDs.
1906  * Can fail if we are given bad arguments, or HCD is broken.
1907  */
1908 void usb_free_streams(struct usb_interface *interface,
1909 		struct usb_host_endpoint **eps, unsigned int num_eps,
1910 		gfp_t mem_flags)
1911 {
1912 	struct usb_hcd *hcd;
1913 	struct usb_device *dev;
1914 	int i;
1915 
1916 	dev = interface_to_usbdev(interface);
1917 	hcd = bus_to_hcd(dev->bus);
1918 	if (dev->speed != USB_SPEED_SUPER)
1919 		return;
1920 
1921 	/* Streams only apply to bulk endpoints. */
1922 	for (i = 0; i < num_eps; i++)
1923 		if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
1924 			return;
1925 
1926 	hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
1927 }
1928 EXPORT_SYMBOL_GPL(usb_free_streams);
1929 
1930 /* Protect against drivers that try to unlink URBs after the device
1931  * is gone, by waiting until all unlinks for @udev are finished.
1932  * Since we don't currently track URBs by device, simply wait until
1933  * nothing is running in the locked region of usb_hcd_unlink_urb().
1934  */
1935 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
1936 {
1937 	spin_lock_irq(&hcd_urb_unlink_lock);
1938 	spin_unlock_irq(&hcd_urb_unlink_lock);
1939 }
1940 
1941 /*-------------------------------------------------------------------------*/
1942 
1943 /* called in any context */
1944 int usb_hcd_get_frame_number (struct usb_device *udev)
1945 {
1946 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
1947 
1948 	if (!HCD_RH_RUNNING(hcd))
1949 		return -ESHUTDOWN;
1950 	return hcd->driver->get_frame_number (hcd);
1951 }
1952 
1953 /*-------------------------------------------------------------------------*/
1954 
1955 #ifdef	CONFIG_PM
1956 
1957 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
1958 {
1959 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
1960 	int		status;
1961 	int		old_state = hcd->state;
1962 
1963 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
1964 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
1965 			rhdev->do_remote_wakeup);
1966 	if (HCD_DEAD(hcd)) {
1967 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
1968 		return 0;
1969 	}
1970 
1971 	if (!hcd->driver->bus_suspend) {
1972 		status = -ENOENT;
1973 	} else {
1974 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1975 		hcd->state = HC_STATE_QUIESCING;
1976 		status = hcd->driver->bus_suspend(hcd);
1977 	}
1978 	if (status == 0) {
1979 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
1980 		hcd->state = HC_STATE_SUSPENDED;
1981 	} else {
1982 		spin_lock_irq(&hcd_root_hub_lock);
1983 		if (!HCD_DEAD(hcd)) {
1984 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1985 			hcd->state = old_state;
1986 		}
1987 		spin_unlock_irq(&hcd_root_hub_lock);
1988 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
1989 				"suspend", status);
1990 	}
1991 	return status;
1992 }
1993 
1994 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
1995 {
1996 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
1997 	int		status;
1998 	int		old_state = hcd->state;
1999 
2000 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2001 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2002 	if (HCD_DEAD(hcd)) {
2003 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2004 		return 0;
2005 	}
2006 	if (!hcd->driver->bus_resume)
2007 		return -ENOENT;
2008 	if (HCD_RH_RUNNING(hcd))
2009 		return 0;
2010 
2011 	hcd->state = HC_STATE_RESUMING;
2012 	status = hcd->driver->bus_resume(hcd);
2013 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2014 	if (status == 0) {
2015 		/* TRSMRCY = 10 msec */
2016 		msleep(10);
2017 		spin_lock_irq(&hcd_root_hub_lock);
2018 		if (!HCD_DEAD(hcd)) {
2019 			usb_set_device_state(rhdev, rhdev->actconfig
2020 					? USB_STATE_CONFIGURED
2021 					: USB_STATE_ADDRESS);
2022 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2023 			hcd->state = HC_STATE_RUNNING;
2024 		}
2025 		spin_unlock_irq(&hcd_root_hub_lock);
2026 	} else {
2027 		hcd->state = old_state;
2028 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2029 				"resume", status);
2030 		if (status != -ESHUTDOWN)
2031 			usb_hc_died(hcd);
2032 	}
2033 	return status;
2034 }
2035 
2036 #endif	/* CONFIG_PM */
2037 
2038 #ifdef	CONFIG_USB_SUSPEND
2039 
2040 /* Workqueue routine for root-hub remote wakeup */
2041 static void hcd_resume_work(struct work_struct *work)
2042 {
2043 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2044 	struct usb_device *udev = hcd->self.root_hub;
2045 
2046 	usb_lock_device(udev);
2047 	usb_remote_wakeup(udev);
2048 	usb_unlock_device(udev);
2049 }
2050 
2051 /**
2052  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2053  * @hcd: host controller for this root hub
2054  *
2055  * The USB host controller calls this function when its root hub is
2056  * suspended (with the remote wakeup feature enabled) and a remote
2057  * wakeup request is received.  The routine submits a workqueue request
2058  * to resume the root hub (that is, manage its downstream ports again).
2059  */
2060 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2061 {
2062 	unsigned long flags;
2063 
2064 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2065 	if (hcd->rh_registered) {
2066 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2067 		queue_work(pm_wq, &hcd->wakeup_work);
2068 	}
2069 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2070 }
2071 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2072 
2073 #endif	/* CONFIG_USB_SUSPEND */
2074 
2075 /*-------------------------------------------------------------------------*/
2076 
2077 #ifdef	CONFIG_USB_OTG
2078 
2079 /**
2080  * usb_bus_start_enum - start immediate enumeration (for OTG)
2081  * @bus: the bus (must use hcd framework)
2082  * @port_num: 1-based number of port; usually bus->otg_port
2083  * Context: in_interrupt()
2084  *
2085  * Starts enumeration, with an immediate reset followed later by
2086  * khubd identifying and possibly configuring the device.
2087  * This is needed by OTG controller drivers, where it helps meet
2088  * HNP protocol timing requirements for starting a port reset.
2089  */
2090 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2091 {
2092 	struct usb_hcd		*hcd;
2093 	int			status = -EOPNOTSUPP;
2094 
2095 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2096 	 * boards with root hubs hooked up to internal devices (instead of
2097 	 * just the OTG port) may need more attention to resetting...
2098 	 */
2099 	hcd = container_of (bus, struct usb_hcd, self);
2100 	if (port_num && hcd->driver->start_port_reset)
2101 		status = hcd->driver->start_port_reset(hcd, port_num);
2102 
2103 	/* run khubd shortly after (first) root port reset finishes;
2104 	 * it may issue others, until at least 50 msecs have passed.
2105 	 */
2106 	if (status == 0)
2107 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2108 	return status;
2109 }
2110 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2111 
2112 #endif
2113 
2114 /*-------------------------------------------------------------------------*/
2115 
2116 /**
2117  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2118  * @irq: the IRQ being raised
2119  * @__hcd: pointer to the HCD whose IRQ is being signaled
2120  *
2121  * If the controller isn't HALTed, calls the driver's irq handler.
2122  * Checks whether the controller is now dead.
2123  */
2124 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2125 {
2126 	struct usb_hcd		*hcd = __hcd;
2127 	unsigned long		flags;
2128 	irqreturn_t		rc;
2129 
2130 	/* IRQF_DISABLED doesn't work correctly with shared IRQs
2131 	 * when the first handler doesn't use it.  So let's just
2132 	 * assume it's never used.
2133 	 */
2134 	local_irq_save(flags);
2135 
2136 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2137 		rc = IRQ_NONE;
2138 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2139 		rc = IRQ_NONE;
2140 	else
2141 		rc = IRQ_HANDLED;
2142 
2143 	local_irq_restore(flags);
2144 	return rc;
2145 }
2146 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2147 
2148 /*-------------------------------------------------------------------------*/
2149 
2150 /**
2151  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2152  * @hcd: pointer to the HCD representing the controller
2153  *
2154  * This is called by bus glue to report a USB host controller that died
2155  * while operations may still have been pending.  It's called automatically
2156  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2157  *
2158  * Only call this function with the primary HCD.
2159  */
2160 void usb_hc_died (struct usb_hcd *hcd)
2161 {
2162 	unsigned long flags;
2163 
2164 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2165 
2166 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2167 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2168 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2169 	if (hcd->rh_registered) {
2170 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2171 
2172 		/* make khubd clean up old urbs and devices */
2173 		usb_set_device_state (hcd->self.root_hub,
2174 				USB_STATE_NOTATTACHED);
2175 		usb_kick_khubd (hcd->self.root_hub);
2176 	}
2177 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2178 		hcd = hcd->shared_hcd;
2179 		if (hcd->rh_registered) {
2180 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2181 
2182 			/* make khubd clean up old urbs and devices */
2183 			usb_set_device_state(hcd->self.root_hub,
2184 					USB_STATE_NOTATTACHED);
2185 			usb_kick_khubd(hcd->self.root_hub);
2186 		}
2187 	}
2188 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2189 	/* Make sure that the other roothub is also deallocated. */
2190 }
2191 EXPORT_SYMBOL_GPL (usb_hc_died);
2192 
2193 /*-------------------------------------------------------------------------*/
2194 
2195 /**
2196  * usb_create_shared_hcd - create and initialize an HCD structure
2197  * @driver: HC driver that will use this hcd
2198  * @dev: device for this HC, stored in hcd->self.controller
2199  * @bus_name: value to store in hcd->self.bus_name
2200  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2201  *              PCI device.  Only allocate certain resources for the primary HCD
2202  * Context: !in_interrupt()
2203  *
2204  * Allocate a struct usb_hcd, with extra space at the end for the
2205  * HC driver's private data.  Initialize the generic members of the
2206  * hcd structure.
2207  *
2208  * If memory is unavailable, returns NULL.
2209  */
2210 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2211 		struct device *dev, const char *bus_name,
2212 		struct usb_hcd *primary_hcd)
2213 {
2214 	struct usb_hcd *hcd;
2215 
2216 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2217 	if (!hcd) {
2218 		dev_dbg (dev, "hcd alloc failed\n");
2219 		return NULL;
2220 	}
2221 	if (primary_hcd == NULL) {
2222 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2223 				GFP_KERNEL);
2224 		if (!hcd->bandwidth_mutex) {
2225 			kfree(hcd);
2226 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2227 			return NULL;
2228 		}
2229 		mutex_init(hcd->bandwidth_mutex);
2230 		dev_set_drvdata(dev, hcd);
2231 	} else {
2232 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2233 		hcd->primary_hcd = primary_hcd;
2234 		primary_hcd->primary_hcd = primary_hcd;
2235 		hcd->shared_hcd = primary_hcd;
2236 		primary_hcd->shared_hcd = hcd;
2237 	}
2238 
2239 	kref_init(&hcd->kref);
2240 
2241 	usb_bus_init(&hcd->self);
2242 	hcd->self.controller = dev;
2243 	hcd->self.bus_name = bus_name;
2244 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2245 
2246 	init_timer(&hcd->rh_timer);
2247 	hcd->rh_timer.function = rh_timer_func;
2248 	hcd->rh_timer.data = (unsigned long) hcd;
2249 #ifdef CONFIG_USB_SUSPEND
2250 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2251 #endif
2252 
2253 	hcd->driver = driver;
2254 	hcd->speed = driver->flags & HCD_MASK;
2255 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2256 			"USB Host Controller";
2257 	return hcd;
2258 }
2259 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2260 
2261 /**
2262  * usb_create_hcd - create and initialize an HCD structure
2263  * @driver: HC driver that will use this hcd
2264  * @dev: device for this HC, stored in hcd->self.controller
2265  * @bus_name: value to store in hcd->self.bus_name
2266  * Context: !in_interrupt()
2267  *
2268  * Allocate a struct usb_hcd, with extra space at the end for the
2269  * HC driver's private data.  Initialize the generic members of the
2270  * hcd structure.
2271  *
2272  * If memory is unavailable, returns NULL.
2273  */
2274 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2275 		struct device *dev, const char *bus_name)
2276 {
2277 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2278 }
2279 EXPORT_SYMBOL_GPL(usb_create_hcd);
2280 
2281 /*
2282  * Roothubs that share one PCI device must also share the bandwidth mutex.
2283  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2284  * deallocated.
2285  *
2286  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2287  * freed.  When hcd_release() is called for the non-primary HCD, set the
2288  * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2289  * freed shortly).
2290  */
2291 static void hcd_release (struct kref *kref)
2292 {
2293 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2294 
2295 	if (usb_hcd_is_primary_hcd(hcd))
2296 		kfree(hcd->bandwidth_mutex);
2297 	else
2298 		hcd->shared_hcd->shared_hcd = NULL;
2299 	kfree(hcd);
2300 }
2301 
2302 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2303 {
2304 	if (hcd)
2305 		kref_get (&hcd->kref);
2306 	return hcd;
2307 }
2308 EXPORT_SYMBOL_GPL(usb_get_hcd);
2309 
2310 void usb_put_hcd (struct usb_hcd *hcd)
2311 {
2312 	if (hcd)
2313 		kref_put (&hcd->kref, hcd_release);
2314 }
2315 EXPORT_SYMBOL_GPL(usb_put_hcd);
2316 
2317 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2318 {
2319 	if (!hcd->primary_hcd)
2320 		return 1;
2321 	return hcd == hcd->primary_hcd;
2322 }
2323 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2324 
2325 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2326 		unsigned int irqnum, unsigned long irqflags)
2327 {
2328 	int retval;
2329 
2330 	if (hcd->driver->irq) {
2331 
2332 		/* IRQF_DISABLED doesn't work as advertised when used together
2333 		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
2334 		 * interrupts we can remove it here.
2335 		 */
2336 		if (irqflags & IRQF_SHARED)
2337 			irqflags &= ~IRQF_DISABLED;
2338 
2339 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2340 				hcd->driver->description, hcd->self.busnum);
2341 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2342 				hcd->irq_descr, hcd);
2343 		if (retval != 0) {
2344 			dev_err(hcd->self.controller,
2345 					"request interrupt %d failed\n",
2346 					irqnum);
2347 			return retval;
2348 		}
2349 		hcd->irq = irqnum;
2350 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2351 				(hcd->driver->flags & HCD_MEMORY) ?
2352 					"io mem" : "io base",
2353 					(unsigned long long)hcd->rsrc_start);
2354 	} else {
2355 		hcd->irq = 0;
2356 		if (hcd->rsrc_start)
2357 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2358 					(hcd->driver->flags & HCD_MEMORY) ?
2359 					"io mem" : "io base",
2360 					(unsigned long long)hcd->rsrc_start);
2361 	}
2362 	return 0;
2363 }
2364 
2365 /**
2366  * usb_add_hcd - finish generic HCD structure initialization and register
2367  * @hcd: the usb_hcd structure to initialize
2368  * @irqnum: Interrupt line to allocate
2369  * @irqflags: Interrupt type flags
2370  *
2371  * Finish the remaining parts of generic HCD initialization: allocate the
2372  * buffers of consistent memory, register the bus, request the IRQ line,
2373  * and call the driver's reset() and start() routines.
2374  */
2375 int usb_add_hcd(struct usb_hcd *hcd,
2376 		unsigned int irqnum, unsigned long irqflags)
2377 {
2378 	int retval;
2379 	struct usb_device *rhdev;
2380 
2381 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2382 
2383 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2384 	if (authorized_default < 0 || authorized_default > 1)
2385 		hcd->authorized_default = hcd->wireless? 0 : 1;
2386 	else
2387 		hcd->authorized_default = authorized_default;
2388 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2389 
2390 	/* HC is in reset state, but accessible.  Now do the one-time init,
2391 	 * bottom up so that hcds can customize the root hubs before khubd
2392 	 * starts talking to them.  (Note, bus id is assigned early too.)
2393 	 */
2394 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2395 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2396 		return retval;
2397 	}
2398 
2399 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2400 		goto err_register_bus;
2401 
2402 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2403 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2404 		retval = -ENOMEM;
2405 		goto err_allocate_root_hub;
2406 	}
2407 	hcd->self.root_hub = rhdev;
2408 
2409 	switch (hcd->speed) {
2410 	case HCD_USB11:
2411 		rhdev->speed = USB_SPEED_FULL;
2412 		break;
2413 	case HCD_USB2:
2414 		rhdev->speed = USB_SPEED_HIGH;
2415 		break;
2416 	case HCD_USB3:
2417 		rhdev->speed = USB_SPEED_SUPER;
2418 		break;
2419 	default:
2420 		retval = -EINVAL;
2421 		goto err_set_rh_speed;
2422 	}
2423 
2424 	/* wakeup flag init defaults to "everything works" for root hubs,
2425 	 * but drivers can override it in reset() if needed, along with
2426 	 * recording the overall controller's system wakeup capability.
2427 	 */
2428 	device_set_wakeup_capable(&rhdev->dev, 1);
2429 
2430 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2431 	 * registered.  But since the controller can die at any time,
2432 	 * let's initialize the flag before touching the hardware.
2433 	 */
2434 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2435 
2436 	/* "reset" is misnamed; its role is now one-time init. the controller
2437 	 * should already have been reset (and boot firmware kicked off etc).
2438 	 */
2439 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2440 		dev_err(hcd->self.controller, "can't setup\n");
2441 		goto err_hcd_driver_setup;
2442 	}
2443 	hcd->rh_pollable = 1;
2444 
2445 	/* NOTE: root hub and controller capabilities may not be the same */
2446 	if (device_can_wakeup(hcd->self.controller)
2447 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2448 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2449 
2450 	/* enable irqs just before we start the controller,
2451 	 * if the BIOS provides legacy PCI irqs.
2452 	 */
2453 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2454 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2455 		if (retval)
2456 			goto err_request_irq;
2457 	}
2458 
2459 	hcd->state = HC_STATE_RUNNING;
2460 	retval = hcd->driver->start(hcd);
2461 	if (retval < 0) {
2462 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2463 		goto err_hcd_driver_start;
2464 	}
2465 
2466 	/* starting here, usbcore will pay attention to this root hub */
2467 	rhdev->bus_mA = min(500u, hcd->power_budget);
2468 	if ((retval = register_root_hub(hcd)) != 0)
2469 		goto err_register_root_hub;
2470 
2471 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2472 	if (retval < 0) {
2473 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2474 		       retval);
2475 		goto error_create_attr_group;
2476 	}
2477 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2478 		usb_hcd_poll_rh_status(hcd);
2479 
2480 	/*
2481 	 * Host controllers don't generate their own wakeup requests;
2482 	 * they only forward requests from the root hub.  Therefore
2483 	 * controllers should always be enabled for remote wakeup.
2484 	 */
2485 	device_wakeup_enable(hcd->self.controller);
2486 	return retval;
2487 
2488 error_create_attr_group:
2489 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2490 	if (HC_IS_RUNNING(hcd->state))
2491 		hcd->state = HC_STATE_QUIESCING;
2492 	spin_lock_irq(&hcd_root_hub_lock);
2493 	hcd->rh_registered = 0;
2494 	spin_unlock_irq(&hcd_root_hub_lock);
2495 
2496 #ifdef CONFIG_USB_SUSPEND
2497 	cancel_work_sync(&hcd->wakeup_work);
2498 #endif
2499 	mutex_lock(&usb_bus_list_lock);
2500 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2501 	mutex_unlock(&usb_bus_list_lock);
2502 err_register_root_hub:
2503 	hcd->rh_pollable = 0;
2504 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2505 	del_timer_sync(&hcd->rh_timer);
2506 	hcd->driver->stop(hcd);
2507 	hcd->state = HC_STATE_HALT;
2508 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2509 	del_timer_sync(&hcd->rh_timer);
2510 err_hcd_driver_start:
2511 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2512 		free_irq(irqnum, hcd);
2513 err_request_irq:
2514 err_hcd_driver_setup:
2515 err_set_rh_speed:
2516 	usb_put_dev(hcd->self.root_hub);
2517 err_allocate_root_hub:
2518 	usb_deregister_bus(&hcd->self);
2519 err_register_bus:
2520 	hcd_buffer_destroy(hcd);
2521 	return retval;
2522 }
2523 EXPORT_SYMBOL_GPL(usb_add_hcd);
2524 
2525 /**
2526  * usb_remove_hcd - shutdown processing for generic HCDs
2527  * @hcd: the usb_hcd structure to remove
2528  * Context: !in_interrupt()
2529  *
2530  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2531  * invoking the HCD's stop() method.
2532  */
2533 void usb_remove_hcd(struct usb_hcd *hcd)
2534 {
2535 	struct usb_device *rhdev = hcd->self.root_hub;
2536 
2537 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2538 
2539 	usb_get_dev(rhdev);
2540 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2541 
2542 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2543 	if (HC_IS_RUNNING (hcd->state))
2544 		hcd->state = HC_STATE_QUIESCING;
2545 
2546 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2547 	spin_lock_irq (&hcd_root_hub_lock);
2548 	hcd->rh_registered = 0;
2549 	spin_unlock_irq (&hcd_root_hub_lock);
2550 
2551 #ifdef CONFIG_USB_SUSPEND
2552 	cancel_work_sync(&hcd->wakeup_work);
2553 #endif
2554 
2555 	mutex_lock(&usb_bus_list_lock);
2556 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2557 	mutex_unlock(&usb_bus_list_lock);
2558 
2559 	/* Prevent any more root-hub status calls from the timer.
2560 	 * The HCD might still restart the timer (if a port status change
2561 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2562 	 * the hub_status_data() callback.
2563 	 */
2564 	hcd->rh_pollable = 0;
2565 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2566 	del_timer_sync(&hcd->rh_timer);
2567 
2568 	hcd->driver->stop(hcd);
2569 	hcd->state = HC_STATE_HALT;
2570 
2571 	/* In case the HCD restarted the timer, stop it again. */
2572 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2573 	del_timer_sync(&hcd->rh_timer);
2574 
2575 	if (usb_hcd_is_primary_hcd(hcd)) {
2576 		if (hcd->irq > 0)
2577 			free_irq(hcd->irq, hcd);
2578 	}
2579 
2580 	usb_put_dev(hcd->self.root_hub);
2581 	usb_deregister_bus(&hcd->self);
2582 	hcd_buffer_destroy(hcd);
2583 }
2584 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2585 
2586 void
2587 usb_hcd_platform_shutdown(struct platform_device* dev)
2588 {
2589 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2590 
2591 	if (hcd->driver->shutdown)
2592 		hcd->driver->shutdown(hcd);
2593 }
2594 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2595 
2596 /*-------------------------------------------------------------------------*/
2597 
2598 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2599 
2600 struct usb_mon_operations *mon_ops;
2601 
2602 /*
2603  * The registration is unlocked.
2604  * We do it this way because we do not want to lock in hot paths.
2605  *
2606  * Notice that the code is minimally error-proof. Because usbmon needs
2607  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2608  */
2609 
2610 int usb_mon_register (struct usb_mon_operations *ops)
2611 {
2612 
2613 	if (mon_ops)
2614 		return -EBUSY;
2615 
2616 	mon_ops = ops;
2617 	mb();
2618 	return 0;
2619 }
2620 EXPORT_SYMBOL_GPL (usb_mon_register);
2621 
2622 void usb_mon_deregister (void)
2623 {
2624 
2625 	if (mon_ops == NULL) {
2626 		printk(KERN_ERR "USB: monitor was not registered\n");
2627 		return;
2628 	}
2629 	mon_ops = NULL;
2630 	mb();
2631 }
2632 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2633 
2634 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2635