xref: /openbmc/linux/drivers/usb/core/hcd.c (revision 861e10be)
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 
44 #include <linux/usb.h>
45 #include <linux/usb/hcd.h>
46 
47 #include "usb.h"
48 
49 
50 /*-------------------------------------------------------------------------*/
51 
52 /*
53  * USB Host Controller Driver framework
54  *
55  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
56  * HCD-specific behaviors/bugs.
57  *
58  * This does error checks, tracks devices and urbs, and delegates to a
59  * "hc_driver" only for code (and data) that really needs to know about
60  * hardware differences.  That includes root hub registers, i/o queues,
61  * and so on ... but as little else as possible.
62  *
63  * Shared code includes most of the "root hub" code (these are emulated,
64  * though each HC's hardware works differently) and PCI glue, plus request
65  * tracking overhead.  The HCD code should only block on spinlocks or on
66  * hardware handshaking; blocking on software events (such as other kernel
67  * threads releasing resources, or completing actions) is all generic.
68  *
69  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
70  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
71  * only by the hub driver ... and that neither should be seen or used by
72  * usb client device drivers.
73  *
74  * Contributors of ideas or unattributed patches include: David Brownell,
75  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
76  *
77  * HISTORY:
78  * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
79  *		associated cleanup.  "usb_hcd" still != "usb_bus".
80  * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
81  */
82 
83 /*-------------------------------------------------------------------------*/
84 
85 /* Keep track of which host controller drivers are loaded */
86 unsigned long usb_hcds_loaded;
87 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
88 
89 /* host controllers we manage */
90 LIST_HEAD (usb_bus_list);
91 EXPORT_SYMBOL_GPL (usb_bus_list);
92 
93 /* used when allocating bus numbers */
94 #define USB_MAXBUS		64
95 struct usb_busmap {
96 	unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
97 };
98 static struct usb_busmap busmap;
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 2.0 root hub device descriptor */
153 static const u8 usb2_rh_dev_descriptor [18] = {
154 	0x12,       /*  __u8  bLength; */
155 	0x01,       /*  __u8  bDescriptorType; Device */
156 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
157 
158 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
159 	0x00,	    /*  __u8  bDeviceSubClass; */
160 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
161 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
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 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
174 
175 /* usb 1.1 root hub device descriptor */
176 static const u8 usb11_rh_dev_descriptor [18] = {
177 	0x12,       /*  __u8  bLength; */
178 	0x01,       /*  __u8  bDescriptorType; Device */
179 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
180 
181 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
182 	0x00,	    /*  __u8  bDeviceSubClass; */
183 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
184 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
185 
186 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
187 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
188 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
189 
190 	0x03,       /*  __u8  iManufacturer; */
191 	0x02,       /*  __u8  iProduct; */
192 	0x01,       /*  __u8  iSerialNumber; */
193 	0x01        /*  __u8  bNumConfigurations; */
194 };
195 
196 
197 /*-------------------------------------------------------------------------*/
198 
199 /* Configuration descriptors for our root hubs */
200 
201 static const u8 fs_rh_config_descriptor [] = {
202 
203 	/* one configuration */
204 	0x09,       /*  __u8  bLength; */
205 	0x02,       /*  __u8  bDescriptorType; Configuration */
206 	0x19, 0x00, /*  __le16 wTotalLength; */
207 	0x01,       /*  __u8  bNumInterfaces; (1) */
208 	0x01,       /*  __u8  bConfigurationValue; */
209 	0x00,       /*  __u8  iConfiguration; */
210 	0xc0,       /*  __u8  bmAttributes;
211 				 Bit 7: must be set,
212 				     6: Self-powered,
213 				     5: Remote wakeup,
214 				     4..0: resvd */
215 	0x00,       /*  __u8  MaxPower; */
216 
217 	/* USB 1.1:
218 	 * USB 2.0, single TT organization (mandatory):
219 	 *	one interface, protocol 0
220 	 *
221 	 * USB 2.0, multiple TT organization (optional):
222 	 *	two interfaces, protocols 1 (like single TT)
223 	 *	and 2 (multiple TT mode) ... config is
224 	 *	sometimes settable
225 	 *	NOT IMPLEMENTED
226 	 */
227 
228 	/* one interface */
229 	0x09,       /*  __u8  if_bLength; */
230 	0x04,       /*  __u8  if_bDescriptorType; Interface */
231 	0x00,       /*  __u8  if_bInterfaceNumber; */
232 	0x00,       /*  __u8  if_bAlternateSetting; */
233 	0x01,       /*  __u8  if_bNumEndpoints; */
234 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
235 	0x00,       /*  __u8  if_bInterfaceSubClass; */
236 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
237 	0x00,       /*  __u8  if_iInterface; */
238 
239 	/* one endpoint (status change endpoint) */
240 	0x07,       /*  __u8  ep_bLength; */
241 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
242 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
243  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
244  	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
245 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
246 };
247 
248 static const u8 hs_rh_config_descriptor [] = {
249 
250 	/* one configuration */
251 	0x09,       /*  __u8  bLength; */
252 	0x02,       /*  __u8  bDescriptorType; Configuration */
253 	0x19, 0x00, /*  __le16 wTotalLength; */
254 	0x01,       /*  __u8  bNumInterfaces; (1) */
255 	0x01,       /*  __u8  bConfigurationValue; */
256 	0x00,       /*  __u8  iConfiguration; */
257 	0xc0,       /*  __u8  bmAttributes;
258 				 Bit 7: must be set,
259 				     6: Self-powered,
260 				     5: Remote wakeup,
261 				     4..0: resvd */
262 	0x00,       /*  __u8  MaxPower; */
263 
264 	/* USB 1.1:
265 	 * USB 2.0, single TT organization (mandatory):
266 	 *	one interface, protocol 0
267 	 *
268 	 * USB 2.0, multiple TT organization (optional):
269 	 *	two interfaces, protocols 1 (like single TT)
270 	 *	and 2 (multiple TT mode) ... config is
271 	 *	sometimes settable
272 	 *	NOT IMPLEMENTED
273 	 */
274 
275 	/* one interface */
276 	0x09,       /*  __u8  if_bLength; */
277 	0x04,       /*  __u8  if_bDescriptorType; Interface */
278 	0x00,       /*  __u8  if_bInterfaceNumber; */
279 	0x00,       /*  __u8  if_bAlternateSetting; */
280 	0x01,       /*  __u8  if_bNumEndpoints; */
281 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
282 	0x00,       /*  __u8  if_bInterfaceSubClass; */
283 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
284 	0x00,       /*  __u8  if_iInterface; */
285 
286 	/* one endpoint (status change endpoint) */
287 	0x07,       /*  __u8  ep_bLength; */
288 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
289 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
290  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
291 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
292 		     * see hub.c:hub_configure() for details. */
293 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
294 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
295 };
296 
297 static const u8 ss_rh_config_descriptor[] = {
298 	/* one configuration */
299 	0x09,       /*  __u8  bLength; */
300 	0x02,       /*  __u8  bDescriptorType; Configuration */
301 	0x1f, 0x00, /*  __le16 wTotalLength; */
302 	0x01,       /*  __u8  bNumInterfaces; (1) */
303 	0x01,       /*  __u8  bConfigurationValue; */
304 	0x00,       /*  __u8  iConfiguration; */
305 	0xc0,       /*  __u8  bmAttributes;
306 				 Bit 7: must be set,
307 				     6: Self-powered,
308 				     5: Remote wakeup,
309 				     4..0: resvd */
310 	0x00,       /*  __u8  MaxPower; */
311 
312 	/* one interface */
313 	0x09,       /*  __u8  if_bLength; */
314 	0x04,       /*  __u8  if_bDescriptorType; Interface */
315 	0x00,       /*  __u8  if_bInterfaceNumber; */
316 	0x00,       /*  __u8  if_bAlternateSetting; */
317 	0x01,       /*  __u8  if_bNumEndpoints; */
318 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
319 	0x00,       /*  __u8  if_bInterfaceSubClass; */
320 	0x00,       /*  __u8  if_bInterfaceProtocol; */
321 	0x00,       /*  __u8  if_iInterface; */
322 
323 	/* one endpoint (status change endpoint) */
324 	0x07,       /*  __u8  ep_bLength; */
325 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
326 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
327 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
328 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
329 		     * see hub.c:hub_configure() for details. */
330 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
331 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
332 
333 	/* one SuperSpeed endpoint companion descriptor */
334 	0x06,        /* __u8 ss_bLength */
335 	0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
336 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
337 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
338 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
339 };
340 
341 /* authorized_default behaviour:
342  * -1 is authorized for all devices except wireless (old behaviour)
343  * 0 is unauthorized for all devices
344  * 1 is authorized for all devices
345  */
346 static int authorized_default = -1;
347 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
348 MODULE_PARM_DESC(authorized_default,
349 		"Default USB device authorization: 0 is not authorized, 1 is "
350 		"authorized, -1 is authorized except for wireless USB (default, "
351 		"old behaviour");
352 /*-------------------------------------------------------------------------*/
353 
354 /**
355  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
356  * @s: Null-terminated ASCII (actually ISO-8859-1) string
357  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
358  * @len: Length (in bytes; may be odd) of descriptor buffer.
359  *
360  * The return value is the number of bytes filled in: 2 + 2*strlen(s) or
361  * buflen, whichever is less.
362  *
363  * USB String descriptors can contain at most 126 characters; input
364  * strings longer than that are truncated.
365  */
366 static unsigned
367 ascii2desc(char const *s, u8 *buf, unsigned len)
368 {
369 	unsigned n, t = 2 + 2*strlen(s);
370 
371 	if (t > 254)
372 		t = 254;	/* Longest possible UTF string descriptor */
373 	if (len > t)
374 		len = t;
375 
376 	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
377 
378 	n = len;
379 	while (n--) {
380 		*buf++ = t;
381 		if (!n--)
382 			break;
383 		*buf++ = t >> 8;
384 		t = (unsigned char)*s++;
385 	}
386 	return len;
387 }
388 
389 /**
390  * rh_string() - provides string descriptors for root hub
391  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
392  * @hcd: the host controller for this root hub
393  * @data: buffer for output packet
394  * @len: length of the provided buffer
395  *
396  * Produces either a manufacturer, product or serial number string for the
397  * virtual root hub device.
398  * Returns the number of bytes filled in: the length of the descriptor or
399  * of the provided buffer, whichever is less.
400  */
401 static unsigned
402 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
403 {
404 	char buf[100];
405 	char const *s;
406 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
407 
408 	// language ids
409 	switch (id) {
410 	case 0:
411 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
412 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
413 		if (len > 4)
414 			len = 4;
415 		memcpy(data, langids, len);
416 		return len;
417 	case 1:
418 		/* Serial number */
419 		s = hcd->self.bus_name;
420 		break;
421 	case 2:
422 		/* Product name */
423 		s = hcd->product_desc;
424 		break;
425 	case 3:
426 		/* Manufacturer */
427 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
428 			init_utsname()->release, hcd->driver->description);
429 		s = buf;
430 		break;
431 	default:
432 		/* Can't happen; caller guarantees it */
433 		return 0;
434 	}
435 
436 	return ascii2desc(s, data, len);
437 }
438 
439 
440 /* Root hub control transfers execute synchronously */
441 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
442 {
443 	struct usb_ctrlrequest *cmd;
444  	u16		typeReq, wValue, wIndex, wLength;
445 	u8		*ubuf = urb->transfer_buffer;
446 	/*
447 	 * tbuf should be as big as the BOS descriptor and
448 	 * the USB hub descriptor.
449 	 */
450 	u8		tbuf[USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE]
451 		__attribute__((aligned(4)));
452 	const u8	*bufp = tbuf;
453 	unsigned	len = 0;
454 	int		status;
455 	u8		patch_wakeup = 0;
456 	u8		patch_protocol = 0;
457 
458 	might_sleep();
459 
460 	spin_lock_irq(&hcd_root_hub_lock);
461 	status = usb_hcd_link_urb_to_ep(hcd, urb);
462 	spin_unlock_irq(&hcd_root_hub_lock);
463 	if (status)
464 		return status;
465 	urb->hcpriv = hcd;	/* Indicate it's queued */
466 
467 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
468 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
469 	wValue   = le16_to_cpu (cmd->wValue);
470 	wIndex   = le16_to_cpu (cmd->wIndex);
471 	wLength  = le16_to_cpu (cmd->wLength);
472 
473 	if (wLength > urb->transfer_buffer_length)
474 		goto error;
475 
476 	urb->actual_length = 0;
477 	switch (typeReq) {
478 
479 	/* DEVICE REQUESTS */
480 
481 	/* The root hub's remote wakeup enable bit is implemented using
482 	 * driver model wakeup flags.  If this system supports wakeup
483 	 * through USB, userspace may change the default "allow wakeup"
484 	 * policy through sysfs or these calls.
485 	 *
486 	 * Most root hubs support wakeup from downstream devices, for
487 	 * runtime power management (disabling USB clocks and reducing
488 	 * VBUS power usage).  However, not all of them do so; silicon,
489 	 * board, and BIOS bugs here are not uncommon, so these can't
490 	 * be treated quite like external hubs.
491 	 *
492 	 * Likewise, not all root hubs will pass wakeup events upstream,
493 	 * to wake up the whole system.  So don't assume root hub and
494 	 * controller capabilities are identical.
495 	 */
496 
497 	case DeviceRequest | USB_REQ_GET_STATUS:
498 		tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
499 					<< USB_DEVICE_REMOTE_WAKEUP)
500 				| (1 << USB_DEVICE_SELF_POWERED);
501 		tbuf [1] = 0;
502 		len = 2;
503 		break;
504 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
505 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
506 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
507 		else
508 			goto error;
509 		break;
510 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
511 		if (device_can_wakeup(&hcd->self.root_hub->dev)
512 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
513 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
514 		else
515 			goto error;
516 		break;
517 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
518 		tbuf [0] = 1;
519 		len = 1;
520 			/* FALLTHROUGH */
521 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
522 		break;
523 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
524 		switch (wValue & 0xff00) {
525 		case USB_DT_DEVICE << 8:
526 			switch (hcd->speed) {
527 			case HCD_USB3:
528 				bufp = usb3_rh_dev_descriptor;
529 				break;
530 			case HCD_USB2:
531 				bufp = usb2_rh_dev_descriptor;
532 				break;
533 			case HCD_USB11:
534 				bufp = usb11_rh_dev_descriptor;
535 				break;
536 			default:
537 				goto error;
538 			}
539 			len = 18;
540 			if (hcd->has_tt)
541 				patch_protocol = 1;
542 			break;
543 		case USB_DT_CONFIG << 8:
544 			switch (hcd->speed) {
545 			case HCD_USB3:
546 				bufp = ss_rh_config_descriptor;
547 				len = sizeof ss_rh_config_descriptor;
548 				break;
549 			case HCD_USB2:
550 				bufp = hs_rh_config_descriptor;
551 				len = sizeof hs_rh_config_descriptor;
552 				break;
553 			case HCD_USB11:
554 				bufp = fs_rh_config_descriptor;
555 				len = sizeof fs_rh_config_descriptor;
556 				break;
557 			default:
558 				goto error;
559 			}
560 			if (device_can_wakeup(&hcd->self.root_hub->dev))
561 				patch_wakeup = 1;
562 			break;
563 		case USB_DT_STRING << 8:
564 			if ((wValue & 0xff) < 4)
565 				urb->actual_length = rh_string(wValue & 0xff,
566 						hcd, ubuf, wLength);
567 			else /* unsupported IDs --> "protocol stall" */
568 				goto error;
569 			break;
570 		case USB_DT_BOS << 8:
571 			goto nongeneric;
572 		default:
573 			goto error;
574 		}
575 		break;
576 	case DeviceRequest | USB_REQ_GET_INTERFACE:
577 		tbuf [0] = 0;
578 		len = 1;
579 			/* FALLTHROUGH */
580 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
581 		break;
582 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
583 		// wValue == urb->dev->devaddr
584 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
585 			wValue);
586 		break;
587 
588 	/* INTERFACE REQUESTS (no defined feature/status flags) */
589 
590 	/* ENDPOINT REQUESTS */
591 
592 	case EndpointRequest | USB_REQ_GET_STATUS:
593 		// ENDPOINT_HALT flag
594 		tbuf [0] = 0;
595 		tbuf [1] = 0;
596 		len = 2;
597 			/* FALLTHROUGH */
598 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
599 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
600 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
601 		break;
602 
603 	/* CLASS REQUESTS (and errors) */
604 
605 	default:
606 nongeneric:
607 		/* non-generic request */
608 		switch (typeReq) {
609 		case GetHubStatus:
610 		case GetPortStatus:
611 			len = 4;
612 			break;
613 		case GetHubDescriptor:
614 			len = sizeof (struct usb_hub_descriptor);
615 			break;
616 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
617 			/* len is returned by hub_control */
618 			break;
619 		}
620 		status = hcd->driver->hub_control (hcd,
621 			typeReq, wValue, wIndex,
622 			tbuf, wLength);
623 		break;
624 error:
625 		/* "protocol stall" on error */
626 		status = -EPIPE;
627 	}
628 
629 	if (status < 0) {
630 		len = 0;
631 		if (status != -EPIPE) {
632 			dev_dbg (hcd->self.controller,
633 				"CTRL: TypeReq=0x%x val=0x%x "
634 				"idx=0x%x len=%d ==> %d\n",
635 				typeReq, wValue, wIndex,
636 				wLength, status);
637 		}
638 	} else if (status > 0) {
639 		/* hub_control may return the length of data copied. */
640 		len = status;
641 		status = 0;
642 	}
643 	if (len) {
644 		if (urb->transfer_buffer_length < len)
645 			len = urb->transfer_buffer_length;
646 		urb->actual_length = len;
647 		// always USB_DIR_IN, toward host
648 		memcpy (ubuf, bufp, len);
649 
650 		/* report whether RH hardware supports remote wakeup */
651 		if (patch_wakeup &&
652 				len > offsetof (struct usb_config_descriptor,
653 						bmAttributes))
654 			((struct usb_config_descriptor *)ubuf)->bmAttributes
655 				|= USB_CONFIG_ATT_WAKEUP;
656 
657 		/* report whether RH hardware has an integrated TT */
658 		if (patch_protocol &&
659 				len > offsetof(struct usb_device_descriptor,
660 						bDeviceProtocol))
661 			((struct usb_device_descriptor *) ubuf)->
662 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
663 	}
664 
665 	/* any errors get returned through the urb completion */
666 	spin_lock_irq(&hcd_root_hub_lock);
667 	usb_hcd_unlink_urb_from_ep(hcd, urb);
668 
669 	/* This peculiar use of spinlocks echoes what real HC drivers do.
670 	 * Avoiding calls to local_irq_disable/enable makes the code
671 	 * RT-friendly.
672 	 */
673 	spin_unlock(&hcd_root_hub_lock);
674 	usb_hcd_giveback_urb(hcd, urb, status);
675 	spin_lock(&hcd_root_hub_lock);
676 
677 	spin_unlock_irq(&hcd_root_hub_lock);
678 	return 0;
679 }
680 
681 /*-------------------------------------------------------------------------*/
682 
683 /*
684  * Root Hub interrupt transfers are polled using a timer if the
685  * driver requests it; otherwise the driver is responsible for
686  * calling usb_hcd_poll_rh_status() when an event occurs.
687  *
688  * Completions are called in_interrupt(), but they may or may not
689  * be in_irq().
690  */
691 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
692 {
693 	struct urb	*urb;
694 	int		length;
695 	unsigned long	flags;
696 	char		buffer[6];	/* Any root hubs with > 31 ports? */
697 
698 	if (unlikely(!hcd->rh_pollable))
699 		return;
700 	if (!hcd->uses_new_polling && !hcd->status_urb)
701 		return;
702 
703 	length = hcd->driver->hub_status_data(hcd, buffer);
704 	if (length > 0) {
705 
706 		/* try to complete the status urb */
707 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
708 		urb = hcd->status_urb;
709 		if (urb) {
710 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
711 			hcd->status_urb = NULL;
712 			urb->actual_length = length;
713 			memcpy(urb->transfer_buffer, buffer, length);
714 
715 			usb_hcd_unlink_urb_from_ep(hcd, urb);
716 			spin_unlock(&hcd_root_hub_lock);
717 			usb_hcd_giveback_urb(hcd, urb, 0);
718 			spin_lock(&hcd_root_hub_lock);
719 		} else {
720 			length = 0;
721 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
722 		}
723 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
724 	}
725 
726 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
727 	 * exceed that limit if HZ is 100. The math is more clunky than
728 	 * maybe expected, this is to make sure that all timers for USB devices
729 	 * fire at the same time to give the CPU a break in between */
730 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
731 			(length == 0 && hcd->status_urb != NULL))
732 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
733 }
734 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
735 
736 /* timer callback */
737 static void rh_timer_func (unsigned long _hcd)
738 {
739 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
740 }
741 
742 /*-------------------------------------------------------------------------*/
743 
744 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
745 {
746 	int		retval;
747 	unsigned long	flags;
748 	unsigned	len = 1 + (urb->dev->maxchild / 8);
749 
750 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
751 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
752 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
753 		retval = -EINVAL;
754 		goto done;
755 	}
756 
757 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
758 	if (retval)
759 		goto done;
760 
761 	hcd->status_urb = urb;
762 	urb->hcpriv = hcd;	/* indicate it's queued */
763 	if (!hcd->uses_new_polling)
764 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
765 
766 	/* If a status change has already occurred, report it ASAP */
767 	else if (HCD_POLL_PENDING(hcd))
768 		mod_timer(&hcd->rh_timer, jiffies);
769 	retval = 0;
770  done:
771 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
772 	return retval;
773 }
774 
775 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
776 {
777 	if (usb_endpoint_xfer_int(&urb->ep->desc))
778 		return rh_queue_status (hcd, urb);
779 	if (usb_endpoint_xfer_control(&urb->ep->desc))
780 		return rh_call_control (hcd, urb);
781 	return -EINVAL;
782 }
783 
784 /*-------------------------------------------------------------------------*/
785 
786 /* Unlinks of root-hub control URBs are legal, but they don't do anything
787  * since these URBs always execute synchronously.
788  */
789 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
790 {
791 	unsigned long	flags;
792 	int		rc;
793 
794 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
795 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
796 	if (rc)
797 		goto done;
798 
799 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
800 		;	/* Do nothing */
801 
802 	} else {				/* Status URB */
803 		if (!hcd->uses_new_polling)
804 			del_timer (&hcd->rh_timer);
805 		if (urb == hcd->status_urb) {
806 			hcd->status_urb = NULL;
807 			usb_hcd_unlink_urb_from_ep(hcd, urb);
808 
809 			spin_unlock(&hcd_root_hub_lock);
810 			usb_hcd_giveback_urb(hcd, urb, status);
811 			spin_lock(&hcd_root_hub_lock);
812 		}
813 	}
814  done:
815 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
816 	return rc;
817 }
818 
819 
820 
821 /*
822  * Show & store the current value of authorized_default
823  */
824 static ssize_t usb_host_authorized_default_show(struct device *dev,
825 						struct device_attribute *attr,
826 						char *buf)
827 {
828 	struct usb_device *rh_usb_dev = to_usb_device(dev);
829 	struct usb_bus *usb_bus = rh_usb_dev->bus;
830 	struct usb_hcd *usb_hcd;
831 
832 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
833 		return -ENODEV;
834 	usb_hcd = bus_to_hcd(usb_bus);
835 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
836 }
837 
838 static ssize_t usb_host_authorized_default_store(struct device *dev,
839 						 struct device_attribute *attr,
840 						 const char *buf, size_t size)
841 {
842 	ssize_t result;
843 	unsigned val;
844 	struct usb_device *rh_usb_dev = to_usb_device(dev);
845 	struct usb_bus *usb_bus = rh_usb_dev->bus;
846 	struct usb_hcd *usb_hcd;
847 
848 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
849 		return -ENODEV;
850 	usb_hcd = bus_to_hcd(usb_bus);
851 	result = sscanf(buf, "%u\n", &val);
852 	if (result == 1) {
853 		usb_hcd->authorized_default = val? 1 : 0;
854 		result = size;
855 	}
856 	else
857 		result = -EINVAL;
858 	return result;
859 }
860 
861 static DEVICE_ATTR(authorized_default, 0644,
862 	    usb_host_authorized_default_show,
863 	    usb_host_authorized_default_store);
864 
865 
866 /* Group all the USB bus attributes */
867 static struct attribute *usb_bus_attrs[] = {
868 		&dev_attr_authorized_default.attr,
869 		NULL,
870 };
871 
872 static struct attribute_group usb_bus_attr_group = {
873 	.name = NULL,	/* we want them in the same directory */
874 	.attrs = usb_bus_attrs,
875 };
876 
877 
878 
879 /*-------------------------------------------------------------------------*/
880 
881 /**
882  * usb_bus_init - shared initialization code
883  * @bus: the bus structure being initialized
884  *
885  * This code is used to initialize a usb_bus structure, memory for which is
886  * separately managed.
887  */
888 static void usb_bus_init (struct usb_bus *bus)
889 {
890 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
891 
892 	bus->devnum_next = 1;
893 
894 	bus->root_hub = NULL;
895 	bus->busnum = -1;
896 	bus->bandwidth_allocated = 0;
897 	bus->bandwidth_int_reqs  = 0;
898 	bus->bandwidth_isoc_reqs = 0;
899 
900 	INIT_LIST_HEAD (&bus->bus_list);
901 }
902 
903 /*-------------------------------------------------------------------------*/
904 
905 /**
906  * usb_register_bus - registers the USB host controller with the usb core
907  * @bus: pointer to the bus to register
908  * Context: !in_interrupt()
909  *
910  * Assigns a bus number, and links the controller into usbcore data
911  * structures so that it can be seen by scanning the bus list.
912  */
913 static int usb_register_bus(struct usb_bus *bus)
914 {
915 	int result = -E2BIG;
916 	int busnum;
917 
918 	mutex_lock(&usb_bus_list_lock);
919 	busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
920 	if (busnum >= USB_MAXBUS) {
921 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
922 		goto error_find_busnum;
923 	}
924 	set_bit (busnum, busmap.busmap);
925 	bus->busnum = busnum;
926 
927 	/* Add it to the local list of buses */
928 	list_add (&bus->bus_list, &usb_bus_list);
929 	mutex_unlock(&usb_bus_list_lock);
930 
931 	usb_notify_add_bus(bus);
932 
933 	dev_info (bus->controller, "new USB bus registered, assigned bus "
934 		  "number %d\n", bus->busnum);
935 	return 0;
936 
937 error_find_busnum:
938 	mutex_unlock(&usb_bus_list_lock);
939 	return result;
940 }
941 
942 /**
943  * usb_deregister_bus - deregisters the USB host controller
944  * @bus: pointer to the bus to deregister
945  * Context: !in_interrupt()
946  *
947  * Recycles the bus number, and unlinks the controller from usbcore data
948  * structures so that it won't be seen by scanning the bus list.
949  */
950 static void usb_deregister_bus (struct usb_bus *bus)
951 {
952 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
953 
954 	/*
955 	 * NOTE: make sure that all the devices are removed by the
956 	 * controller code, as well as having it call this when cleaning
957 	 * itself up
958 	 */
959 	mutex_lock(&usb_bus_list_lock);
960 	list_del (&bus->bus_list);
961 	mutex_unlock(&usb_bus_list_lock);
962 
963 	usb_notify_remove_bus(bus);
964 
965 	clear_bit (bus->busnum, busmap.busmap);
966 }
967 
968 /**
969  * register_root_hub - called by usb_add_hcd() to register a root hub
970  * @hcd: host controller for this root hub
971  *
972  * This function registers the root hub with the USB subsystem.  It sets up
973  * the device properly in the device tree and then calls usb_new_device()
974  * to register the usb device.  It also assigns the root hub's USB address
975  * (always 1).
976  */
977 static int register_root_hub(struct usb_hcd *hcd)
978 {
979 	struct device *parent_dev = hcd->self.controller;
980 	struct usb_device *usb_dev = hcd->self.root_hub;
981 	const int devnum = 1;
982 	int retval;
983 
984 	usb_dev->devnum = devnum;
985 	usb_dev->bus->devnum_next = devnum + 1;
986 	memset (&usb_dev->bus->devmap.devicemap, 0,
987 			sizeof usb_dev->bus->devmap.devicemap);
988 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
989 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
990 
991 	mutex_lock(&usb_bus_list_lock);
992 
993 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
994 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
995 	if (retval != sizeof usb_dev->descriptor) {
996 		mutex_unlock(&usb_bus_list_lock);
997 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
998 				dev_name(&usb_dev->dev), retval);
999 		return (retval < 0) ? retval : -EMSGSIZE;
1000 	}
1001 	if (usb_dev->speed == USB_SPEED_SUPER) {
1002 		retval = usb_get_bos_descriptor(usb_dev);
1003 		if (retval < 0) {
1004 			mutex_unlock(&usb_bus_list_lock);
1005 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1006 					dev_name(&usb_dev->dev), retval);
1007 			return retval;
1008 		}
1009 	}
1010 
1011 	retval = usb_new_device (usb_dev);
1012 	if (retval) {
1013 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1014 				dev_name(&usb_dev->dev), retval);
1015 	} else {
1016 		spin_lock_irq (&hcd_root_hub_lock);
1017 		hcd->rh_registered = 1;
1018 		spin_unlock_irq (&hcd_root_hub_lock);
1019 
1020 		/* Did the HC die before the root hub was registered? */
1021 		if (HCD_DEAD(hcd))
1022 			usb_hc_died (hcd);	/* This time clean up */
1023 	}
1024 	mutex_unlock(&usb_bus_list_lock);
1025 
1026 	return retval;
1027 }
1028 
1029 /*
1030  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1031  * @bus: the bus which the root hub belongs to
1032  * @portnum: the port which is being resumed
1033  *
1034  * HCDs should call this function when they know that a resume signal is
1035  * being sent to a root-hub port.  The root hub will be prevented from
1036  * going into autosuspend until usb_hcd_end_port_resume() is called.
1037  *
1038  * The bus's private lock must be held by the caller.
1039  */
1040 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1041 {
1042 	unsigned bit = 1 << portnum;
1043 
1044 	if (!(bus->resuming_ports & bit)) {
1045 		bus->resuming_ports |= bit;
1046 		pm_runtime_get_noresume(&bus->root_hub->dev);
1047 	}
1048 }
1049 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1050 
1051 /*
1052  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1053  * @bus: the bus which the root hub belongs to
1054  * @portnum: the port which is being resumed
1055  *
1056  * HCDs should call this function when they know that a resume signal has
1057  * stopped being sent to a root-hub port.  The root hub will be allowed to
1058  * autosuspend again.
1059  *
1060  * The bus's private lock must be held by the caller.
1061  */
1062 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1063 {
1064 	unsigned bit = 1 << portnum;
1065 
1066 	if (bus->resuming_ports & bit) {
1067 		bus->resuming_ports &= ~bit;
1068 		pm_runtime_put_noidle(&bus->root_hub->dev);
1069 	}
1070 }
1071 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1072 
1073 /*-------------------------------------------------------------------------*/
1074 
1075 /**
1076  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1077  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1078  * @is_input: true iff the transaction sends data to the host
1079  * @isoc: true for isochronous transactions, false for interrupt ones
1080  * @bytecount: how many bytes in the transaction.
1081  *
1082  * Returns approximate bus time in nanoseconds for a periodic transaction.
1083  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1084  * scheduled in software, this function is only used for such scheduling.
1085  */
1086 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1087 {
1088 	unsigned long	tmp;
1089 
1090 	switch (speed) {
1091 	case USB_SPEED_LOW: 	/* INTR only */
1092 		if (is_input) {
1093 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1094 			return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1095 		} else {
1096 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1097 			return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1098 		}
1099 	case USB_SPEED_FULL:	/* ISOC or INTR */
1100 		if (isoc) {
1101 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1102 			return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
1103 		} else {
1104 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1105 			return (9107L + BW_HOST_DELAY + tmp);
1106 		}
1107 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1108 		// FIXME adjust for input vs output
1109 		if (isoc)
1110 			tmp = HS_NSECS_ISO (bytecount);
1111 		else
1112 			tmp = HS_NSECS (bytecount);
1113 		return tmp;
1114 	default:
1115 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1116 		return -1;
1117 	}
1118 }
1119 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1120 
1121 
1122 /*-------------------------------------------------------------------------*/
1123 
1124 /*
1125  * Generic HC operations.
1126  */
1127 
1128 /*-------------------------------------------------------------------------*/
1129 
1130 /**
1131  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1132  * @hcd: host controller to which @urb was submitted
1133  * @urb: URB being submitted
1134  *
1135  * Host controller drivers should call this routine in their enqueue()
1136  * method.  The HCD's private spinlock must be held and interrupts must
1137  * be disabled.  The actions carried out here are required for URB
1138  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1139  *
1140  * Returns 0 for no error, otherwise a negative error code (in which case
1141  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1142  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1143  * the private spinlock and returning.
1144  */
1145 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1146 {
1147 	int		rc = 0;
1148 
1149 	spin_lock(&hcd_urb_list_lock);
1150 
1151 	/* Check that the URB isn't being killed */
1152 	if (unlikely(atomic_read(&urb->reject))) {
1153 		rc = -EPERM;
1154 		goto done;
1155 	}
1156 
1157 	if (unlikely(!urb->ep->enabled)) {
1158 		rc = -ENOENT;
1159 		goto done;
1160 	}
1161 
1162 	if (unlikely(!urb->dev->can_submit)) {
1163 		rc = -EHOSTUNREACH;
1164 		goto done;
1165 	}
1166 
1167 	/*
1168 	 * Check the host controller's state and add the URB to the
1169 	 * endpoint's queue.
1170 	 */
1171 	if (HCD_RH_RUNNING(hcd)) {
1172 		urb->unlinked = 0;
1173 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1174 	} else {
1175 		rc = -ESHUTDOWN;
1176 		goto done;
1177 	}
1178  done:
1179 	spin_unlock(&hcd_urb_list_lock);
1180 	return rc;
1181 }
1182 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1183 
1184 /**
1185  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1186  * @hcd: host controller to which @urb was submitted
1187  * @urb: URB being checked for unlinkability
1188  * @status: error code to store in @urb if the unlink succeeds
1189  *
1190  * Host controller drivers should call this routine in their dequeue()
1191  * method.  The HCD's private spinlock must be held and interrupts must
1192  * be disabled.  The actions carried out here are required for making
1193  * sure than an unlink is valid.
1194  *
1195  * Returns 0 for no error, otherwise a negative error code (in which case
1196  * the dequeue() method must fail).  The possible error codes are:
1197  *
1198  *	-EIDRM: @urb was not submitted or has already completed.
1199  *		The completion function may not have been called yet.
1200  *
1201  *	-EBUSY: @urb has already been unlinked.
1202  */
1203 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1204 		int status)
1205 {
1206 	struct list_head	*tmp;
1207 
1208 	/* insist the urb is still queued */
1209 	list_for_each(tmp, &urb->ep->urb_list) {
1210 		if (tmp == &urb->urb_list)
1211 			break;
1212 	}
1213 	if (tmp != &urb->urb_list)
1214 		return -EIDRM;
1215 
1216 	/* Any status except -EINPROGRESS means something already started to
1217 	 * unlink this URB from the hardware.  So there's no more work to do.
1218 	 */
1219 	if (urb->unlinked)
1220 		return -EBUSY;
1221 	urb->unlinked = status;
1222 	return 0;
1223 }
1224 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1225 
1226 /**
1227  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1228  * @hcd: host controller to which @urb was submitted
1229  * @urb: URB being unlinked
1230  *
1231  * Host controller drivers should call this routine before calling
1232  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1233  * interrupts must be disabled.  The actions carried out here are required
1234  * for URB completion.
1235  */
1236 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1237 {
1238 	/* clear all state linking urb to this dev (and hcd) */
1239 	spin_lock(&hcd_urb_list_lock);
1240 	list_del_init(&urb->urb_list);
1241 	spin_unlock(&hcd_urb_list_lock);
1242 }
1243 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1244 
1245 /*
1246  * Some usb host controllers can only perform dma using a small SRAM area.
1247  * The usb core itself is however optimized for host controllers that can dma
1248  * using regular system memory - like pci devices doing bus mastering.
1249  *
1250  * To support host controllers with limited dma capabilites we provide dma
1251  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1252  * For this to work properly the host controller code must first use the
1253  * function dma_declare_coherent_memory() to point out which memory area
1254  * that should be used for dma allocations.
1255  *
1256  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1257  * dma using dma_alloc_coherent() which in turn allocates from the memory
1258  * area pointed out with dma_declare_coherent_memory().
1259  *
1260  * So, to summarize...
1261  *
1262  * - We need "local" memory, canonical example being
1263  *   a small SRAM on a discrete controller being the
1264  *   only memory that the controller can read ...
1265  *   (a) "normal" kernel memory is no good, and
1266  *   (b) there's not enough to share
1267  *
1268  * - The only *portable* hook for such stuff in the
1269  *   DMA framework is dma_declare_coherent_memory()
1270  *
1271  * - So we use that, even though the primary requirement
1272  *   is that the memory be "local" (hence addressible
1273  *   by that device), not "coherent".
1274  *
1275  */
1276 
1277 static int hcd_alloc_coherent(struct usb_bus *bus,
1278 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1279 			      void **vaddr_handle, size_t size,
1280 			      enum dma_data_direction dir)
1281 {
1282 	unsigned char *vaddr;
1283 
1284 	if (*vaddr_handle == NULL) {
1285 		WARN_ON_ONCE(1);
1286 		return -EFAULT;
1287 	}
1288 
1289 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1290 				 mem_flags, dma_handle);
1291 	if (!vaddr)
1292 		return -ENOMEM;
1293 
1294 	/*
1295 	 * Store the virtual address of the buffer at the end
1296 	 * of the allocated dma buffer. The size of the buffer
1297 	 * may be uneven so use unaligned functions instead
1298 	 * of just rounding up. It makes sense to optimize for
1299 	 * memory footprint over access speed since the amount
1300 	 * of memory available for dma may be limited.
1301 	 */
1302 	put_unaligned((unsigned long)*vaddr_handle,
1303 		      (unsigned long *)(vaddr + size));
1304 
1305 	if (dir == DMA_TO_DEVICE)
1306 		memcpy(vaddr, *vaddr_handle, size);
1307 
1308 	*vaddr_handle = vaddr;
1309 	return 0;
1310 }
1311 
1312 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1313 			      void **vaddr_handle, size_t size,
1314 			      enum dma_data_direction dir)
1315 {
1316 	unsigned char *vaddr = *vaddr_handle;
1317 
1318 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1319 
1320 	if (dir == DMA_FROM_DEVICE)
1321 		memcpy(vaddr, *vaddr_handle, size);
1322 
1323 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1324 
1325 	*vaddr_handle = vaddr;
1326 	*dma_handle = 0;
1327 }
1328 
1329 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1330 {
1331 	if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1332 		dma_unmap_single(hcd->self.controller,
1333 				urb->setup_dma,
1334 				sizeof(struct usb_ctrlrequest),
1335 				DMA_TO_DEVICE);
1336 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1337 		hcd_free_coherent(urb->dev->bus,
1338 				&urb->setup_dma,
1339 				(void **) &urb->setup_packet,
1340 				sizeof(struct usb_ctrlrequest),
1341 				DMA_TO_DEVICE);
1342 
1343 	/* Make it safe to call this routine more than once */
1344 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1345 }
1346 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1347 
1348 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1349 {
1350 	if (hcd->driver->unmap_urb_for_dma)
1351 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1352 	else
1353 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1354 }
1355 
1356 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1357 {
1358 	enum dma_data_direction dir;
1359 
1360 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1361 
1362 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1363 	if (urb->transfer_flags & URB_DMA_MAP_SG)
1364 		dma_unmap_sg(hcd->self.controller,
1365 				urb->sg,
1366 				urb->num_sgs,
1367 				dir);
1368 	else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1369 		dma_unmap_page(hcd->self.controller,
1370 				urb->transfer_dma,
1371 				urb->transfer_buffer_length,
1372 				dir);
1373 	else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1374 		dma_unmap_single(hcd->self.controller,
1375 				urb->transfer_dma,
1376 				urb->transfer_buffer_length,
1377 				dir);
1378 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1379 		hcd_free_coherent(urb->dev->bus,
1380 				&urb->transfer_dma,
1381 				&urb->transfer_buffer,
1382 				urb->transfer_buffer_length,
1383 				dir);
1384 
1385 	/* Make it safe to call this routine more than once */
1386 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1387 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1388 }
1389 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1390 
1391 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1392 			   gfp_t mem_flags)
1393 {
1394 	if (hcd->driver->map_urb_for_dma)
1395 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1396 	else
1397 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1398 }
1399 
1400 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1401 			    gfp_t mem_flags)
1402 {
1403 	enum dma_data_direction dir;
1404 	int ret = 0;
1405 
1406 	/* Map the URB's buffers for DMA access.
1407 	 * Lower level HCD code should use *_dma exclusively,
1408 	 * unless it uses pio or talks to another transport,
1409 	 * or uses the provided scatter gather list for bulk.
1410 	 */
1411 
1412 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1413 		if (hcd->self.uses_pio_for_control)
1414 			return ret;
1415 		if (hcd->self.uses_dma) {
1416 			urb->setup_dma = dma_map_single(
1417 					hcd->self.controller,
1418 					urb->setup_packet,
1419 					sizeof(struct usb_ctrlrequest),
1420 					DMA_TO_DEVICE);
1421 			if (dma_mapping_error(hcd->self.controller,
1422 						urb->setup_dma))
1423 				return -EAGAIN;
1424 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1425 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1426 			ret = hcd_alloc_coherent(
1427 					urb->dev->bus, mem_flags,
1428 					&urb->setup_dma,
1429 					(void **)&urb->setup_packet,
1430 					sizeof(struct usb_ctrlrequest),
1431 					DMA_TO_DEVICE);
1432 			if (ret)
1433 				return ret;
1434 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1435 		}
1436 	}
1437 
1438 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1439 	if (urb->transfer_buffer_length != 0
1440 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1441 		if (hcd->self.uses_dma) {
1442 			if (urb->num_sgs) {
1443 				int n;
1444 
1445 				/* We don't support sg for isoc transfers ! */
1446 				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1447 					WARN_ON(1);
1448 					return -EINVAL;
1449 				}
1450 
1451 				n = dma_map_sg(
1452 						hcd->self.controller,
1453 						urb->sg,
1454 						urb->num_sgs,
1455 						dir);
1456 				if (n <= 0)
1457 					ret = -EAGAIN;
1458 				else
1459 					urb->transfer_flags |= URB_DMA_MAP_SG;
1460 				urb->num_mapped_sgs = n;
1461 				if (n != urb->num_sgs)
1462 					urb->transfer_flags |=
1463 							URB_DMA_SG_COMBINED;
1464 			} else if (urb->sg) {
1465 				struct scatterlist *sg = urb->sg;
1466 				urb->transfer_dma = dma_map_page(
1467 						hcd->self.controller,
1468 						sg_page(sg),
1469 						sg->offset,
1470 						urb->transfer_buffer_length,
1471 						dir);
1472 				if (dma_mapping_error(hcd->self.controller,
1473 						urb->transfer_dma))
1474 					ret = -EAGAIN;
1475 				else
1476 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1477 			} else {
1478 				urb->transfer_dma = dma_map_single(
1479 						hcd->self.controller,
1480 						urb->transfer_buffer,
1481 						urb->transfer_buffer_length,
1482 						dir);
1483 				if (dma_mapping_error(hcd->self.controller,
1484 						urb->transfer_dma))
1485 					ret = -EAGAIN;
1486 				else
1487 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1488 			}
1489 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1490 			ret = hcd_alloc_coherent(
1491 					urb->dev->bus, mem_flags,
1492 					&urb->transfer_dma,
1493 					&urb->transfer_buffer,
1494 					urb->transfer_buffer_length,
1495 					dir);
1496 			if (ret == 0)
1497 				urb->transfer_flags |= URB_MAP_LOCAL;
1498 		}
1499 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1500 				URB_SETUP_MAP_LOCAL)))
1501 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1502 	}
1503 	return ret;
1504 }
1505 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1506 
1507 /*-------------------------------------------------------------------------*/
1508 
1509 /* may be called in any context with a valid urb->dev usecount
1510  * caller surrenders "ownership" of urb
1511  * expects usb_submit_urb() to have sanity checked and conditioned all
1512  * inputs in the urb
1513  */
1514 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1515 {
1516 	int			status;
1517 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1518 
1519 	/* increment urb's reference count as part of giving it to the HCD
1520 	 * (which will control it).  HCD guarantees that it either returns
1521 	 * an error or calls giveback(), but not both.
1522 	 */
1523 	usb_get_urb(urb);
1524 	atomic_inc(&urb->use_count);
1525 	atomic_inc(&urb->dev->urbnum);
1526 	usbmon_urb_submit(&hcd->self, urb);
1527 
1528 	/* NOTE requirements on root-hub callers (usbfs and the hub
1529 	 * driver, for now):  URBs' urb->transfer_buffer must be
1530 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1531 	 * they could clobber root hub response data.  Also, control
1532 	 * URBs must be submitted in process context with interrupts
1533 	 * enabled.
1534 	 */
1535 
1536 	if (is_root_hub(urb->dev)) {
1537 		status = rh_urb_enqueue(hcd, urb);
1538 	} else {
1539 		status = map_urb_for_dma(hcd, urb, mem_flags);
1540 		if (likely(status == 0)) {
1541 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1542 			if (unlikely(status))
1543 				unmap_urb_for_dma(hcd, urb);
1544 		}
1545 	}
1546 
1547 	if (unlikely(status)) {
1548 		usbmon_urb_submit_error(&hcd->self, urb, status);
1549 		urb->hcpriv = NULL;
1550 		INIT_LIST_HEAD(&urb->urb_list);
1551 		atomic_dec(&urb->use_count);
1552 		atomic_dec(&urb->dev->urbnum);
1553 		if (atomic_read(&urb->reject))
1554 			wake_up(&usb_kill_urb_queue);
1555 		usb_put_urb(urb);
1556 	}
1557 	return status;
1558 }
1559 
1560 /*-------------------------------------------------------------------------*/
1561 
1562 /* this makes the hcd giveback() the urb more quickly, by kicking it
1563  * off hardware queues (which may take a while) and returning it as
1564  * soon as practical.  we've already set up the urb's return status,
1565  * but we can't know if the callback completed already.
1566  */
1567 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1568 {
1569 	int		value;
1570 
1571 	if (is_root_hub(urb->dev))
1572 		value = usb_rh_urb_dequeue(hcd, urb, status);
1573 	else {
1574 
1575 		/* The only reason an HCD might fail this call is if
1576 		 * it has not yet fully queued the urb to begin with.
1577 		 * Such failures should be harmless. */
1578 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1579 	}
1580 	return value;
1581 }
1582 
1583 /*
1584  * called in any context
1585  *
1586  * caller guarantees urb won't be recycled till both unlink()
1587  * and the urb's completion function return
1588  */
1589 int usb_hcd_unlink_urb (struct urb *urb, int status)
1590 {
1591 	struct usb_hcd		*hcd;
1592 	int			retval = -EIDRM;
1593 	unsigned long		flags;
1594 
1595 	/* Prevent the device and bus from going away while
1596 	 * the unlink is carried out.  If they are already gone
1597 	 * then urb->use_count must be 0, since disconnected
1598 	 * devices can't have any active URBs.
1599 	 */
1600 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1601 	if (atomic_read(&urb->use_count) > 0) {
1602 		retval = 0;
1603 		usb_get_dev(urb->dev);
1604 	}
1605 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1606 	if (retval == 0) {
1607 		hcd = bus_to_hcd(urb->dev->bus);
1608 		retval = unlink1(hcd, urb, status);
1609 		usb_put_dev(urb->dev);
1610 	}
1611 
1612 	if (retval == 0)
1613 		retval = -EINPROGRESS;
1614 	else if (retval != -EIDRM && retval != -EBUSY)
1615 		dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1616 				urb, retval);
1617 	return retval;
1618 }
1619 
1620 /*-------------------------------------------------------------------------*/
1621 
1622 /**
1623  * usb_hcd_giveback_urb - return URB from HCD to device driver
1624  * @hcd: host controller returning the URB
1625  * @urb: urb being returned to the USB device driver.
1626  * @status: completion status code for the URB.
1627  * Context: in_interrupt()
1628  *
1629  * This hands the URB from HCD to its USB device driver, using its
1630  * completion function.  The HCD has freed all per-urb resources
1631  * (and is done using urb->hcpriv).  It also released all HCD locks;
1632  * the device driver won't cause problems if it frees, modifies,
1633  * or resubmits this URB.
1634  *
1635  * If @urb was unlinked, the value of @status will be overridden by
1636  * @urb->unlinked.  Erroneous short transfers are detected in case
1637  * the HCD hasn't checked for them.
1638  */
1639 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1640 {
1641 	urb->hcpriv = NULL;
1642 	if (unlikely(urb->unlinked))
1643 		status = urb->unlinked;
1644 	else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1645 			urb->actual_length < urb->transfer_buffer_length &&
1646 			!status))
1647 		status = -EREMOTEIO;
1648 
1649 	unmap_urb_for_dma(hcd, urb);
1650 	usbmon_urb_complete(&hcd->self, urb, status);
1651 	usb_unanchor_urb(urb);
1652 
1653 	/* pass ownership to the completion handler */
1654 	urb->status = status;
1655 	urb->complete (urb);
1656 	atomic_dec (&urb->use_count);
1657 	if (unlikely(atomic_read(&urb->reject)))
1658 		wake_up (&usb_kill_urb_queue);
1659 	usb_put_urb (urb);
1660 }
1661 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1662 
1663 /*-------------------------------------------------------------------------*/
1664 
1665 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1666  * queue to drain completely.  The caller must first insure that no more
1667  * URBs can be submitted for this endpoint.
1668  */
1669 void usb_hcd_flush_endpoint(struct usb_device *udev,
1670 		struct usb_host_endpoint *ep)
1671 {
1672 	struct usb_hcd		*hcd;
1673 	struct urb		*urb;
1674 
1675 	if (!ep)
1676 		return;
1677 	might_sleep();
1678 	hcd = bus_to_hcd(udev->bus);
1679 
1680 	/* No more submits can occur */
1681 	spin_lock_irq(&hcd_urb_list_lock);
1682 rescan:
1683 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1684 		int	is_in;
1685 
1686 		if (urb->unlinked)
1687 			continue;
1688 		usb_get_urb (urb);
1689 		is_in = usb_urb_dir_in(urb);
1690 		spin_unlock(&hcd_urb_list_lock);
1691 
1692 		/* kick hcd */
1693 		unlink1(hcd, urb, -ESHUTDOWN);
1694 		dev_dbg (hcd->self.controller,
1695 			"shutdown urb %p ep%d%s%s\n",
1696 			urb, usb_endpoint_num(&ep->desc),
1697 			is_in ? "in" : "out",
1698 			({	char *s;
1699 
1700 				 switch (usb_endpoint_type(&ep->desc)) {
1701 				 case USB_ENDPOINT_XFER_CONTROL:
1702 					s = ""; break;
1703 				 case USB_ENDPOINT_XFER_BULK:
1704 					s = "-bulk"; break;
1705 				 case USB_ENDPOINT_XFER_INT:
1706 					s = "-intr"; break;
1707 				 default:
1708 			 		s = "-iso"; break;
1709 				};
1710 				s;
1711 			}));
1712 		usb_put_urb (urb);
1713 
1714 		/* list contents may have changed */
1715 		spin_lock(&hcd_urb_list_lock);
1716 		goto rescan;
1717 	}
1718 	spin_unlock_irq(&hcd_urb_list_lock);
1719 
1720 	/* Wait until the endpoint queue is completely empty */
1721 	while (!list_empty (&ep->urb_list)) {
1722 		spin_lock_irq(&hcd_urb_list_lock);
1723 
1724 		/* The list may have changed while we acquired the spinlock */
1725 		urb = NULL;
1726 		if (!list_empty (&ep->urb_list)) {
1727 			urb = list_entry (ep->urb_list.prev, struct urb,
1728 					urb_list);
1729 			usb_get_urb (urb);
1730 		}
1731 		spin_unlock_irq(&hcd_urb_list_lock);
1732 
1733 		if (urb) {
1734 			usb_kill_urb (urb);
1735 			usb_put_urb (urb);
1736 		}
1737 	}
1738 }
1739 
1740 /**
1741  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1742  *				the bus bandwidth
1743  * @udev: target &usb_device
1744  * @new_config: new configuration to install
1745  * @cur_alt: the current alternate interface setting
1746  * @new_alt: alternate interface setting that is being installed
1747  *
1748  * To change configurations, pass in the new configuration in new_config,
1749  * and pass NULL for cur_alt and new_alt.
1750  *
1751  * To reset a device's configuration (put the device in the ADDRESSED state),
1752  * pass in NULL for new_config, cur_alt, and new_alt.
1753  *
1754  * To change alternate interface settings, pass in NULL for new_config,
1755  * pass in the current alternate interface setting in cur_alt,
1756  * and pass in the new alternate interface setting in new_alt.
1757  *
1758  * Returns an error if the requested bandwidth change exceeds the
1759  * bus bandwidth or host controller internal resources.
1760  */
1761 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1762 		struct usb_host_config *new_config,
1763 		struct usb_host_interface *cur_alt,
1764 		struct usb_host_interface *new_alt)
1765 {
1766 	int num_intfs, i, j;
1767 	struct usb_host_interface *alt = NULL;
1768 	int ret = 0;
1769 	struct usb_hcd *hcd;
1770 	struct usb_host_endpoint *ep;
1771 
1772 	hcd = bus_to_hcd(udev->bus);
1773 	if (!hcd->driver->check_bandwidth)
1774 		return 0;
1775 
1776 	/* Configuration is being removed - set configuration 0 */
1777 	if (!new_config && !cur_alt) {
1778 		for (i = 1; i < 16; ++i) {
1779 			ep = udev->ep_out[i];
1780 			if (ep)
1781 				hcd->driver->drop_endpoint(hcd, udev, ep);
1782 			ep = udev->ep_in[i];
1783 			if (ep)
1784 				hcd->driver->drop_endpoint(hcd, udev, ep);
1785 		}
1786 		hcd->driver->check_bandwidth(hcd, udev);
1787 		return 0;
1788 	}
1789 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1790 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1791 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1792 	 * ok to exclude it.
1793 	 */
1794 	if (new_config) {
1795 		num_intfs = new_config->desc.bNumInterfaces;
1796 		/* Remove endpoints (except endpoint 0, which is always on the
1797 		 * schedule) from the old config from the schedule
1798 		 */
1799 		for (i = 1; i < 16; ++i) {
1800 			ep = udev->ep_out[i];
1801 			if (ep) {
1802 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1803 				if (ret < 0)
1804 					goto reset;
1805 			}
1806 			ep = udev->ep_in[i];
1807 			if (ep) {
1808 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1809 				if (ret < 0)
1810 					goto reset;
1811 			}
1812 		}
1813 		for (i = 0; i < num_intfs; ++i) {
1814 			struct usb_host_interface *first_alt;
1815 			int iface_num;
1816 
1817 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1818 			iface_num = first_alt->desc.bInterfaceNumber;
1819 			/* Set up endpoints for alternate interface setting 0 */
1820 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1821 			if (!alt)
1822 				/* No alt setting 0? Pick the first setting. */
1823 				alt = first_alt;
1824 
1825 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1826 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1827 				if (ret < 0)
1828 					goto reset;
1829 			}
1830 		}
1831 	}
1832 	if (cur_alt && new_alt) {
1833 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1834 				cur_alt->desc.bInterfaceNumber);
1835 
1836 		if (!iface)
1837 			return -EINVAL;
1838 		if (iface->resetting_device) {
1839 			/*
1840 			 * The USB core just reset the device, so the xHCI host
1841 			 * and the device will think alt setting 0 is installed.
1842 			 * However, the USB core will pass in the alternate
1843 			 * setting installed before the reset as cur_alt.  Dig
1844 			 * out the alternate setting 0 structure, or the first
1845 			 * alternate setting if a broken device doesn't have alt
1846 			 * setting 0.
1847 			 */
1848 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1849 			if (!cur_alt)
1850 				cur_alt = &iface->altsetting[0];
1851 		}
1852 
1853 		/* Drop all the endpoints in the current alt setting */
1854 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1855 			ret = hcd->driver->drop_endpoint(hcd, udev,
1856 					&cur_alt->endpoint[i]);
1857 			if (ret < 0)
1858 				goto reset;
1859 		}
1860 		/* Add all the endpoints in the new alt setting */
1861 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1862 			ret = hcd->driver->add_endpoint(hcd, udev,
1863 					&new_alt->endpoint[i]);
1864 			if (ret < 0)
1865 				goto reset;
1866 		}
1867 	}
1868 	ret = hcd->driver->check_bandwidth(hcd, udev);
1869 reset:
1870 	if (ret < 0)
1871 		hcd->driver->reset_bandwidth(hcd, udev);
1872 	return ret;
1873 }
1874 
1875 /* Disables the endpoint: synchronizes with the hcd to make sure all
1876  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1877  * have been called previously.  Use for set_configuration, set_interface,
1878  * driver removal, physical disconnect.
1879  *
1880  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1881  * type, maxpacket size, toggle, halt status, and scheduling.
1882  */
1883 void usb_hcd_disable_endpoint(struct usb_device *udev,
1884 		struct usb_host_endpoint *ep)
1885 {
1886 	struct usb_hcd		*hcd;
1887 
1888 	might_sleep();
1889 	hcd = bus_to_hcd(udev->bus);
1890 	if (hcd->driver->endpoint_disable)
1891 		hcd->driver->endpoint_disable(hcd, ep);
1892 }
1893 
1894 /**
1895  * usb_hcd_reset_endpoint - reset host endpoint state
1896  * @udev: USB device.
1897  * @ep:   the endpoint to reset.
1898  *
1899  * Resets any host endpoint state such as the toggle bit, sequence
1900  * number and current window.
1901  */
1902 void usb_hcd_reset_endpoint(struct usb_device *udev,
1903 			    struct usb_host_endpoint *ep)
1904 {
1905 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1906 
1907 	if (hcd->driver->endpoint_reset)
1908 		hcd->driver->endpoint_reset(hcd, ep);
1909 	else {
1910 		int epnum = usb_endpoint_num(&ep->desc);
1911 		int is_out = usb_endpoint_dir_out(&ep->desc);
1912 		int is_control = usb_endpoint_xfer_control(&ep->desc);
1913 
1914 		usb_settoggle(udev, epnum, is_out, 0);
1915 		if (is_control)
1916 			usb_settoggle(udev, epnum, !is_out, 0);
1917 	}
1918 }
1919 
1920 /**
1921  * usb_alloc_streams - allocate bulk endpoint stream IDs.
1922  * @interface:		alternate setting that includes all endpoints.
1923  * @eps:		array of endpoints that need streams.
1924  * @num_eps:		number of endpoints in the array.
1925  * @num_streams:	number of streams to allocate.
1926  * @mem_flags:		flags hcd should use to allocate memory.
1927  *
1928  * Sets up a group of bulk endpoints to have num_streams stream IDs available.
1929  * Drivers may queue multiple transfers to different stream IDs, which may
1930  * complete in a different order than they were queued.
1931  */
1932 int usb_alloc_streams(struct usb_interface *interface,
1933 		struct usb_host_endpoint **eps, unsigned int num_eps,
1934 		unsigned int num_streams, gfp_t mem_flags)
1935 {
1936 	struct usb_hcd *hcd;
1937 	struct usb_device *dev;
1938 	int i;
1939 
1940 	dev = interface_to_usbdev(interface);
1941 	hcd = bus_to_hcd(dev->bus);
1942 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
1943 		return -EINVAL;
1944 	if (dev->speed != USB_SPEED_SUPER)
1945 		return -EINVAL;
1946 
1947 	/* Streams only apply to bulk endpoints. */
1948 	for (i = 0; i < num_eps; i++)
1949 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
1950 			return -EINVAL;
1951 
1952 	return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
1953 			num_streams, mem_flags);
1954 }
1955 EXPORT_SYMBOL_GPL(usb_alloc_streams);
1956 
1957 /**
1958  * usb_free_streams - free bulk endpoint stream IDs.
1959  * @interface:	alternate setting that includes all endpoints.
1960  * @eps:	array of endpoints to remove streams from.
1961  * @num_eps:	number of endpoints in the array.
1962  * @mem_flags:	flags hcd should use to allocate memory.
1963  *
1964  * Reverts a group of bulk endpoints back to not using stream IDs.
1965  * Can fail if we are given bad arguments, or HCD is broken.
1966  */
1967 void usb_free_streams(struct usb_interface *interface,
1968 		struct usb_host_endpoint **eps, unsigned int num_eps,
1969 		gfp_t mem_flags)
1970 {
1971 	struct usb_hcd *hcd;
1972 	struct usb_device *dev;
1973 	int i;
1974 
1975 	dev = interface_to_usbdev(interface);
1976 	hcd = bus_to_hcd(dev->bus);
1977 	if (dev->speed != USB_SPEED_SUPER)
1978 		return;
1979 
1980 	/* Streams only apply to bulk endpoints. */
1981 	for (i = 0; i < num_eps; i++)
1982 		if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
1983 			return;
1984 
1985 	hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
1986 }
1987 EXPORT_SYMBOL_GPL(usb_free_streams);
1988 
1989 /* Protect against drivers that try to unlink URBs after the device
1990  * is gone, by waiting until all unlinks for @udev are finished.
1991  * Since we don't currently track URBs by device, simply wait until
1992  * nothing is running in the locked region of usb_hcd_unlink_urb().
1993  */
1994 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
1995 {
1996 	spin_lock_irq(&hcd_urb_unlink_lock);
1997 	spin_unlock_irq(&hcd_urb_unlink_lock);
1998 }
1999 
2000 /*-------------------------------------------------------------------------*/
2001 
2002 /* called in any context */
2003 int usb_hcd_get_frame_number (struct usb_device *udev)
2004 {
2005 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2006 
2007 	if (!HCD_RH_RUNNING(hcd))
2008 		return -ESHUTDOWN;
2009 	return hcd->driver->get_frame_number (hcd);
2010 }
2011 
2012 /*-------------------------------------------------------------------------*/
2013 
2014 #ifdef	CONFIG_PM
2015 
2016 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2017 {
2018 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2019 	int		status;
2020 	int		old_state = hcd->state;
2021 
2022 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2023 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2024 			rhdev->do_remote_wakeup);
2025 	if (HCD_DEAD(hcd)) {
2026 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2027 		return 0;
2028 	}
2029 
2030 	if (!hcd->driver->bus_suspend) {
2031 		status = -ENOENT;
2032 	} else {
2033 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2034 		hcd->state = HC_STATE_QUIESCING;
2035 		status = hcd->driver->bus_suspend(hcd);
2036 	}
2037 	if (status == 0) {
2038 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2039 		hcd->state = HC_STATE_SUSPENDED;
2040 
2041 		/* Did we race with a root-hub wakeup event? */
2042 		if (rhdev->do_remote_wakeup) {
2043 			char	buffer[6];
2044 
2045 			status = hcd->driver->hub_status_data(hcd, buffer);
2046 			if (status != 0) {
2047 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2048 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2049 				status = -EBUSY;
2050 			}
2051 		}
2052 	} else {
2053 		spin_lock_irq(&hcd_root_hub_lock);
2054 		if (!HCD_DEAD(hcd)) {
2055 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2056 			hcd->state = old_state;
2057 		}
2058 		spin_unlock_irq(&hcd_root_hub_lock);
2059 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2060 				"suspend", status);
2061 	}
2062 	return status;
2063 }
2064 
2065 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2066 {
2067 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2068 	int		status;
2069 	int		old_state = hcd->state;
2070 
2071 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2072 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2073 	if (HCD_DEAD(hcd)) {
2074 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2075 		return 0;
2076 	}
2077 	if (!hcd->driver->bus_resume)
2078 		return -ENOENT;
2079 	if (HCD_RH_RUNNING(hcd))
2080 		return 0;
2081 
2082 	hcd->state = HC_STATE_RESUMING;
2083 	status = hcd->driver->bus_resume(hcd);
2084 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2085 	if (status == 0) {
2086 		struct usb_device *udev;
2087 		int port1;
2088 
2089 		spin_lock_irq(&hcd_root_hub_lock);
2090 		if (!HCD_DEAD(hcd)) {
2091 			usb_set_device_state(rhdev, rhdev->actconfig
2092 					? USB_STATE_CONFIGURED
2093 					: USB_STATE_ADDRESS);
2094 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2095 			hcd->state = HC_STATE_RUNNING;
2096 		}
2097 		spin_unlock_irq(&hcd_root_hub_lock);
2098 
2099 		/*
2100 		 * Check whether any of the enabled ports on the root hub are
2101 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2102 		 * (this is what the USB-2 spec calls a "global resume").
2103 		 * Otherwise we can skip the delay.
2104 		 */
2105 		usb_hub_for_each_child(rhdev, port1, udev) {
2106 			if (udev->state != USB_STATE_NOTATTACHED &&
2107 					!udev->port_is_suspended) {
2108 				usleep_range(10000, 11000);	/* TRSMRCY */
2109 				break;
2110 			}
2111 		}
2112 	} else {
2113 		hcd->state = old_state;
2114 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2115 				"resume", status);
2116 		if (status != -ESHUTDOWN)
2117 			usb_hc_died(hcd);
2118 	}
2119 	return status;
2120 }
2121 
2122 #endif	/* CONFIG_PM */
2123 
2124 #ifdef	CONFIG_USB_SUSPEND
2125 
2126 /* Workqueue routine for root-hub remote wakeup */
2127 static void hcd_resume_work(struct work_struct *work)
2128 {
2129 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2130 	struct usb_device *udev = hcd->self.root_hub;
2131 
2132 	usb_lock_device(udev);
2133 	usb_remote_wakeup(udev);
2134 	usb_unlock_device(udev);
2135 }
2136 
2137 /**
2138  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2139  * @hcd: host controller for this root hub
2140  *
2141  * The USB host controller calls this function when its root hub is
2142  * suspended (with the remote wakeup feature enabled) and a remote
2143  * wakeup request is received.  The routine submits a workqueue request
2144  * to resume the root hub (that is, manage its downstream ports again).
2145  */
2146 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2147 {
2148 	unsigned long flags;
2149 
2150 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2151 	if (hcd->rh_registered) {
2152 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2153 		queue_work(pm_wq, &hcd->wakeup_work);
2154 	}
2155 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2156 }
2157 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2158 
2159 #endif	/* CONFIG_USB_SUSPEND */
2160 
2161 /*-------------------------------------------------------------------------*/
2162 
2163 #ifdef	CONFIG_USB_OTG
2164 
2165 /**
2166  * usb_bus_start_enum - start immediate enumeration (for OTG)
2167  * @bus: the bus (must use hcd framework)
2168  * @port_num: 1-based number of port; usually bus->otg_port
2169  * Context: in_interrupt()
2170  *
2171  * Starts enumeration, with an immediate reset followed later by
2172  * khubd identifying and possibly configuring the device.
2173  * This is needed by OTG controller drivers, where it helps meet
2174  * HNP protocol timing requirements for starting a port reset.
2175  */
2176 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2177 {
2178 	struct usb_hcd		*hcd;
2179 	int			status = -EOPNOTSUPP;
2180 
2181 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2182 	 * boards with root hubs hooked up to internal devices (instead of
2183 	 * just the OTG port) may need more attention to resetting...
2184 	 */
2185 	hcd = container_of (bus, struct usb_hcd, self);
2186 	if (port_num && hcd->driver->start_port_reset)
2187 		status = hcd->driver->start_port_reset(hcd, port_num);
2188 
2189 	/* run khubd shortly after (first) root port reset finishes;
2190 	 * it may issue others, until at least 50 msecs have passed.
2191 	 */
2192 	if (status == 0)
2193 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2194 	return status;
2195 }
2196 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2197 
2198 #endif
2199 
2200 /*-------------------------------------------------------------------------*/
2201 
2202 /**
2203  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2204  * @irq: the IRQ being raised
2205  * @__hcd: pointer to the HCD whose IRQ is being signaled
2206  *
2207  * If the controller isn't HALTed, calls the driver's irq handler.
2208  * Checks whether the controller is now dead.
2209  */
2210 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2211 {
2212 	struct usb_hcd		*hcd = __hcd;
2213 	unsigned long		flags;
2214 	irqreturn_t		rc;
2215 
2216 	/* IRQF_DISABLED doesn't work correctly with shared IRQs
2217 	 * when the first handler doesn't use it.  So let's just
2218 	 * assume it's never used.
2219 	 */
2220 	local_irq_save(flags);
2221 
2222 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2223 		rc = IRQ_NONE;
2224 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2225 		rc = IRQ_NONE;
2226 	else
2227 		rc = IRQ_HANDLED;
2228 
2229 	local_irq_restore(flags);
2230 	return rc;
2231 }
2232 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2233 
2234 /*-------------------------------------------------------------------------*/
2235 
2236 /**
2237  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2238  * @hcd: pointer to the HCD representing the controller
2239  *
2240  * This is called by bus glue to report a USB host controller that died
2241  * while operations may still have been pending.  It's called automatically
2242  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2243  *
2244  * Only call this function with the primary HCD.
2245  */
2246 void usb_hc_died (struct usb_hcd *hcd)
2247 {
2248 	unsigned long flags;
2249 
2250 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2251 
2252 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2253 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2254 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2255 	if (hcd->rh_registered) {
2256 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2257 
2258 		/* make khubd clean up old urbs and devices */
2259 		usb_set_device_state (hcd->self.root_hub,
2260 				USB_STATE_NOTATTACHED);
2261 		usb_kick_khubd (hcd->self.root_hub);
2262 	}
2263 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2264 		hcd = hcd->shared_hcd;
2265 		if (hcd->rh_registered) {
2266 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2267 
2268 			/* make khubd clean up old urbs and devices */
2269 			usb_set_device_state(hcd->self.root_hub,
2270 					USB_STATE_NOTATTACHED);
2271 			usb_kick_khubd(hcd->self.root_hub);
2272 		}
2273 	}
2274 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2275 	/* Make sure that the other roothub is also deallocated. */
2276 }
2277 EXPORT_SYMBOL_GPL (usb_hc_died);
2278 
2279 /*-------------------------------------------------------------------------*/
2280 
2281 /**
2282  * usb_create_shared_hcd - create and initialize an HCD structure
2283  * @driver: HC driver that will use this hcd
2284  * @dev: device for this HC, stored in hcd->self.controller
2285  * @bus_name: value to store in hcd->self.bus_name
2286  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2287  *              PCI device.  Only allocate certain resources for the primary HCD
2288  * Context: !in_interrupt()
2289  *
2290  * Allocate a struct usb_hcd, with extra space at the end for the
2291  * HC driver's private data.  Initialize the generic members of the
2292  * hcd structure.
2293  *
2294  * If memory is unavailable, returns NULL.
2295  */
2296 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2297 		struct device *dev, const char *bus_name,
2298 		struct usb_hcd *primary_hcd)
2299 {
2300 	struct usb_hcd *hcd;
2301 
2302 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2303 	if (!hcd) {
2304 		dev_dbg (dev, "hcd alloc failed\n");
2305 		return NULL;
2306 	}
2307 	if (primary_hcd == NULL) {
2308 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2309 				GFP_KERNEL);
2310 		if (!hcd->bandwidth_mutex) {
2311 			kfree(hcd);
2312 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2313 			return NULL;
2314 		}
2315 		mutex_init(hcd->bandwidth_mutex);
2316 		dev_set_drvdata(dev, hcd);
2317 	} else {
2318 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2319 		hcd->primary_hcd = primary_hcd;
2320 		primary_hcd->primary_hcd = primary_hcd;
2321 		hcd->shared_hcd = primary_hcd;
2322 		primary_hcd->shared_hcd = hcd;
2323 	}
2324 
2325 	kref_init(&hcd->kref);
2326 
2327 	usb_bus_init(&hcd->self);
2328 	hcd->self.controller = dev;
2329 	hcd->self.bus_name = bus_name;
2330 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2331 
2332 	init_timer(&hcd->rh_timer);
2333 	hcd->rh_timer.function = rh_timer_func;
2334 	hcd->rh_timer.data = (unsigned long) hcd;
2335 #ifdef CONFIG_USB_SUSPEND
2336 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2337 #endif
2338 
2339 	hcd->driver = driver;
2340 	hcd->speed = driver->flags & HCD_MASK;
2341 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2342 			"USB Host Controller";
2343 	return hcd;
2344 }
2345 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2346 
2347 /**
2348  * usb_create_hcd - create and initialize an HCD structure
2349  * @driver: HC driver that will use this hcd
2350  * @dev: device for this HC, stored in hcd->self.controller
2351  * @bus_name: value to store in hcd->self.bus_name
2352  * Context: !in_interrupt()
2353  *
2354  * Allocate a struct usb_hcd, with extra space at the end for the
2355  * HC driver's private data.  Initialize the generic members of the
2356  * hcd structure.
2357  *
2358  * If memory is unavailable, returns NULL.
2359  */
2360 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2361 		struct device *dev, const char *bus_name)
2362 {
2363 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2364 }
2365 EXPORT_SYMBOL_GPL(usb_create_hcd);
2366 
2367 /*
2368  * Roothubs that share one PCI device must also share the bandwidth mutex.
2369  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2370  * deallocated.
2371  *
2372  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2373  * freed.  When hcd_release() is called for the non-primary HCD, set the
2374  * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2375  * freed shortly).
2376  */
2377 static void hcd_release (struct kref *kref)
2378 {
2379 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2380 
2381 	if (usb_hcd_is_primary_hcd(hcd))
2382 		kfree(hcd->bandwidth_mutex);
2383 	else
2384 		hcd->shared_hcd->shared_hcd = NULL;
2385 	kfree(hcd);
2386 }
2387 
2388 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2389 {
2390 	if (hcd)
2391 		kref_get (&hcd->kref);
2392 	return hcd;
2393 }
2394 EXPORT_SYMBOL_GPL(usb_get_hcd);
2395 
2396 void usb_put_hcd (struct usb_hcd *hcd)
2397 {
2398 	if (hcd)
2399 		kref_put (&hcd->kref, hcd_release);
2400 }
2401 EXPORT_SYMBOL_GPL(usb_put_hcd);
2402 
2403 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2404 {
2405 	if (!hcd->primary_hcd)
2406 		return 1;
2407 	return hcd == hcd->primary_hcd;
2408 }
2409 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2410 
2411 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2412 		unsigned int irqnum, unsigned long irqflags)
2413 {
2414 	int retval;
2415 
2416 	if (hcd->driver->irq) {
2417 
2418 		/* IRQF_DISABLED doesn't work as advertised when used together
2419 		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
2420 		 * interrupts we can remove it here.
2421 		 */
2422 		if (irqflags & IRQF_SHARED)
2423 			irqflags &= ~IRQF_DISABLED;
2424 
2425 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2426 				hcd->driver->description, hcd->self.busnum);
2427 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2428 				hcd->irq_descr, hcd);
2429 		if (retval != 0) {
2430 			dev_err(hcd->self.controller,
2431 					"request interrupt %d failed\n",
2432 					irqnum);
2433 			return retval;
2434 		}
2435 		hcd->irq = irqnum;
2436 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2437 				(hcd->driver->flags & HCD_MEMORY) ?
2438 					"io mem" : "io base",
2439 					(unsigned long long)hcd->rsrc_start);
2440 	} else {
2441 		hcd->irq = 0;
2442 		if (hcd->rsrc_start)
2443 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2444 					(hcd->driver->flags & HCD_MEMORY) ?
2445 					"io mem" : "io base",
2446 					(unsigned long long)hcd->rsrc_start);
2447 	}
2448 	return 0;
2449 }
2450 
2451 /**
2452  * usb_add_hcd - finish generic HCD structure initialization and register
2453  * @hcd: the usb_hcd structure to initialize
2454  * @irqnum: Interrupt line to allocate
2455  * @irqflags: Interrupt type flags
2456  *
2457  * Finish the remaining parts of generic HCD initialization: allocate the
2458  * buffers of consistent memory, register the bus, request the IRQ line,
2459  * and call the driver's reset() and start() routines.
2460  */
2461 int usb_add_hcd(struct usb_hcd *hcd,
2462 		unsigned int irqnum, unsigned long irqflags)
2463 {
2464 	int retval;
2465 	struct usb_device *rhdev;
2466 
2467 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2468 
2469 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2470 	if (authorized_default < 0 || authorized_default > 1)
2471 		hcd->authorized_default = hcd->wireless? 0 : 1;
2472 	else
2473 		hcd->authorized_default = authorized_default;
2474 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2475 
2476 	/* HC is in reset state, but accessible.  Now do the one-time init,
2477 	 * bottom up so that hcds can customize the root hubs before khubd
2478 	 * starts talking to them.  (Note, bus id is assigned early too.)
2479 	 */
2480 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2481 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2482 		return retval;
2483 	}
2484 
2485 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2486 		goto err_register_bus;
2487 
2488 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2489 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2490 		retval = -ENOMEM;
2491 		goto err_allocate_root_hub;
2492 	}
2493 	hcd->self.root_hub = rhdev;
2494 
2495 	switch (hcd->speed) {
2496 	case HCD_USB11:
2497 		rhdev->speed = USB_SPEED_FULL;
2498 		break;
2499 	case HCD_USB2:
2500 		rhdev->speed = USB_SPEED_HIGH;
2501 		break;
2502 	case HCD_USB3:
2503 		rhdev->speed = USB_SPEED_SUPER;
2504 		break;
2505 	default:
2506 		retval = -EINVAL;
2507 		goto err_set_rh_speed;
2508 	}
2509 
2510 	/* wakeup flag init defaults to "everything works" for root hubs,
2511 	 * but drivers can override it in reset() if needed, along with
2512 	 * recording the overall controller's system wakeup capability.
2513 	 */
2514 	device_set_wakeup_capable(&rhdev->dev, 1);
2515 
2516 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2517 	 * registered.  But since the controller can die at any time,
2518 	 * let's initialize the flag before touching the hardware.
2519 	 */
2520 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2521 
2522 	/* "reset" is misnamed; its role is now one-time init. the controller
2523 	 * should already have been reset (and boot firmware kicked off etc).
2524 	 */
2525 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2526 		dev_err(hcd->self.controller, "can't setup\n");
2527 		goto err_hcd_driver_setup;
2528 	}
2529 	hcd->rh_pollable = 1;
2530 
2531 	/* NOTE: root hub and controller capabilities may not be the same */
2532 	if (device_can_wakeup(hcd->self.controller)
2533 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2534 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2535 
2536 	/* enable irqs just before we start the controller,
2537 	 * if the BIOS provides legacy PCI irqs.
2538 	 */
2539 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2540 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2541 		if (retval)
2542 			goto err_request_irq;
2543 	}
2544 
2545 	hcd->state = HC_STATE_RUNNING;
2546 	retval = hcd->driver->start(hcd);
2547 	if (retval < 0) {
2548 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2549 		goto err_hcd_driver_start;
2550 	}
2551 
2552 	/* starting here, usbcore will pay attention to this root hub */
2553 	rhdev->bus_mA = min(500u, hcd->power_budget);
2554 	if ((retval = register_root_hub(hcd)) != 0)
2555 		goto err_register_root_hub;
2556 
2557 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2558 	if (retval < 0) {
2559 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2560 		       retval);
2561 		goto error_create_attr_group;
2562 	}
2563 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2564 		usb_hcd_poll_rh_status(hcd);
2565 
2566 	/*
2567 	 * Host controllers don't generate their own wakeup requests;
2568 	 * they only forward requests from the root hub.  Therefore
2569 	 * controllers should always be enabled for remote wakeup.
2570 	 */
2571 	device_wakeup_enable(hcd->self.controller);
2572 	return retval;
2573 
2574 error_create_attr_group:
2575 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2576 	if (HC_IS_RUNNING(hcd->state))
2577 		hcd->state = HC_STATE_QUIESCING;
2578 	spin_lock_irq(&hcd_root_hub_lock);
2579 	hcd->rh_registered = 0;
2580 	spin_unlock_irq(&hcd_root_hub_lock);
2581 
2582 #ifdef CONFIG_USB_SUSPEND
2583 	cancel_work_sync(&hcd->wakeup_work);
2584 #endif
2585 	mutex_lock(&usb_bus_list_lock);
2586 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2587 	mutex_unlock(&usb_bus_list_lock);
2588 err_register_root_hub:
2589 	hcd->rh_pollable = 0;
2590 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2591 	del_timer_sync(&hcd->rh_timer);
2592 	hcd->driver->stop(hcd);
2593 	hcd->state = HC_STATE_HALT;
2594 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2595 	del_timer_sync(&hcd->rh_timer);
2596 err_hcd_driver_start:
2597 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2598 		free_irq(irqnum, hcd);
2599 err_request_irq:
2600 err_hcd_driver_setup:
2601 err_set_rh_speed:
2602 	usb_put_dev(hcd->self.root_hub);
2603 err_allocate_root_hub:
2604 	usb_deregister_bus(&hcd->self);
2605 err_register_bus:
2606 	hcd_buffer_destroy(hcd);
2607 	return retval;
2608 }
2609 EXPORT_SYMBOL_GPL(usb_add_hcd);
2610 
2611 /**
2612  * usb_remove_hcd - shutdown processing for generic HCDs
2613  * @hcd: the usb_hcd structure to remove
2614  * Context: !in_interrupt()
2615  *
2616  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2617  * invoking the HCD's stop() method.
2618  */
2619 void usb_remove_hcd(struct usb_hcd *hcd)
2620 {
2621 	struct usb_device *rhdev = hcd->self.root_hub;
2622 
2623 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2624 
2625 	usb_get_dev(rhdev);
2626 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2627 
2628 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2629 	if (HC_IS_RUNNING (hcd->state))
2630 		hcd->state = HC_STATE_QUIESCING;
2631 
2632 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2633 	spin_lock_irq (&hcd_root_hub_lock);
2634 	hcd->rh_registered = 0;
2635 	spin_unlock_irq (&hcd_root_hub_lock);
2636 
2637 #ifdef CONFIG_USB_SUSPEND
2638 	cancel_work_sync(&hcd->wakeup_work);
2639 #endif
2640 
2641 	mutex_lock(&usb_bus_list_lock);
2642 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2643 	mutex_unlock(&usb_bus_list_lock);
2644 
2645 	/* Prevent any more root-hub status calls from the timer.
2646 	 * The HCD might still restart the timer (if a port status change
2647 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2648 	 * the hub_status_data() callback.
2649 	 */
2650 	hcd->rh_pollable = 0;
2651 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2652 	del_timer_sync(&hcd->rh_timer);
2653 
2654 	hcd->driver->stop(hcd);
2655 	hcd->state = HC_STATE_HALT;
2656 
2657 	/* In case the HCD restarted the timer, stop it again. */
2658 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2659 	del_timer_sync(&hcd->rh_timer);
2660 
2661 	if (usb_hcd_is_primary_hcd(hcd)) {
2662 		if (hcd->irq > 0)
2663 			free_irq(hcd->irq, hcd);
2664 	}
2665 
2666 	usb_put_dev(hcd->self.root_hub);
2667 	usb_deregister_bus(&hcd->self);
2668 	hcd_buffer_destroy(hcd);
2669 }
2670 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2671 
2672 void
2673 usb_hcd_platform_shutdown(struct platform_device* dev)
2674 {
2675 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2676 
2677 	if (hcd->driver->shutdown)
2678 		hcd->driver->shutdown(hcd);
2679 }
2680 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2681 
2682 /*-------------------------------------------------------------------------*/
2683 
2684 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2685 
2686 struct usb_mon_operations *mon_ops;
2687 
2688 /*
2689  * The registration is unlocked.
2690  * We do it this way because we do not want to lock in hot paths.
2691  *
2692  * Notice that the code is minimally error-proof. Because usbmon needs
2693  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2694  */
2695 
2696 int usb_mon_register (struct usb_mon_operations *ops)
2697 {
2698 
2699 	if (mon_ops)
2700 		return -EBUSY;
2701 
2702 	mon_ops = ops;
2703 	mb();
2704 	return 0;
2705 }
2706 EXPORT_SYMBOL_GPL (usb_mon_register);
2707 
2708 void usb_mon_deregister (void)
2709 {
2710 
2711 	if (mon_ops == NULL) {
2712 		printk(KERN_ERR "USB: monitor was not registered\n");
2713 		return;
2714 	}
2715 	mon_ops = NULL;
2716 	mb();
2717 }
2718 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2719 
2720 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2721