xref: /linux/drivers/usb/core/hcd.c (revision ff5599816711d2e67da2d7561fd36ac48debd433)
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 2.5 (wireless USB 1.0) root hub device descriptor */
153 static const u8 usb25_rh_dev_descriptor[18] = {
154 	0x12,       /*  __u8  bLength; */
155 	0x01,       /*  __u8  bDescriptorType; Device */
156 	0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
157 
158 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
159 	0x00,	    /*  __u8  bDeviceSubClass; */
160 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
161 	0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
162 
163 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
164 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
165 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
166 
167 	0x03,       /*  __u8  iManufacturer; */
168 	0x02,       /*  __u8  iProduct; */
169 	0x01,       /*  __u8  iSerialNumber; */
170 	0x01        /*  __u8  bNumConfigurations; */
171 };
172 
173 /* usb 2.0 root hub device descriptor */
174 static const u8 usb2_rh_dev_descriptor [18] = {
175 	0x12,       /*  __u8  bLength; */
176 	0x01,       /*  __u8  bDescriptorType; Device */
177 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
178 
179 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
180 	0x00,	    /*  __u8  bDeviceSubClass; */
181 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
182 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
183 
184 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
185 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
186 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
187 
188 	0x03,       /*  __u8  iManufacturer; */
189 	0x02,       /*  __u8  iProduct; */
190 	0x01,       /*  __u8  iSerialNumber; */
191 	0x01        /*  __u8  bNumConfigurations; */
192 };
193 
194 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
195 
196 /* usb 1.1 root hub device descriptor */
197 static const u8 usb11_rh_dev_descriptor [18] = {
198 	0x12,       /*  __u8  bLength; */
199 	0x01,       /*  __u8  bDescriptorType; Device */
200 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
201 
202 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
203 	0x00,	    /*  __u8  bDeviceSubClass; */
204 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
205 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
206 
207 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
208 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
209 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
210 
211 	0x03,       /*  __u8  iManufacturer; */
212 	0x02,       /*  __u8  iProduct; */
213 	0x01,       /*  __u8  iSerialNumber; */
214 	0x01        /*  __u8  bNumConfigurations; */
215 };
216 
217 
218 /*-------------------------------------------------------------------------*/
219 
220 /* Configuration descriptors for our root hubs */
221 
222 static const u8 fs_rh_config_descriptor [] = {
223 
224 	/* one configuration */
225 	0x09,       /*  __u8  bLength; */
226 	0x02,       /*  __u8  bDescriptorType; Configuration */
227 	0x19, 0x00, /*  __le16 wTotalLength; */
228 	0x01,       /*  __u8  bNumInterfaces; (1) */
229 	0x01,       /*  __u8  bConfigurationValue; */
230 	0x00,       /*  __u8  iConfiguration; */
231 	0xc0,       /*  __u8  bmAttributes;
232 				 Bit 7: must be set,
233 				     6: Self-powered,
234 				     5: Remote wakeup,
235 				     4..0: resvd */
236 	0x00,       /*  __u8  MaxPower; */
237 
238 	/* USB 1.1:
239 	 * USB 2.0, single TT organization (mandatory):
240 	 *	one interface, protocol 0
241 	 *
242 	 * USB 2.0, multiple TT organization (optional):
243 	 *	two interfaces, protocols 1 (like single TT)
244 	 *	and 2 (multiple TT mode) ... config is
245 	 *	sometimes settable
246 	 *	NOT IMPLEMENTED
247 	 */
248 
249 	/* one interface */
250 	0x09,       /*  __u8  if_bLength; */
251 	0x04,       /*  __u8  if_bDescriptorType; Interface */
252 	0x00,       /*  __u8  if_bInterfaceNumber; */
253 	0x00,       /*  __u8  if_bAlternateSetting; */
254 	0x01,       /*  __u8  if_bNumEndpoints; */
255 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
256 	0x00,       /*  __u8  if_bInterfaceSubClass; */
257 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
258 	0x00,       /*  __u8  if_iInterface; */
259 
260 	/* one endpoint (status change endpoint) */
261 	0x07,       /*  __u8  ep_bLength; */
262 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
263 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
264  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
265  	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
266 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
267 };
268 
269 static const u8 hs_rh_config_descriptor [] = {
270 
271 	/* one configuration */
272 	0x09,       /*  __u8  bLength; */
273 	0x02,       /*  __u8  bDescriptorType; Configuration */
274 	0x19, 0x00, /*  __le16 wTotalLength; */
275 	0x01,       /*  __u8  bNumInterfaces; (1) */
276 	0x01,       /*  __u8  bConfigurationValue; */
277 	0x00,       /*  __u8  iConfiguration; */
278 	0xc0,       /*  __u8  bmAttributes;
279 				 Bit 7: must be set,
280 				     6: Self-powered,
281 				     5: Remote wakeup,
282 				     4..0: resvd */
283 	0x00,       /*  __u8  MaxPower; */
284 
285 	/* USB 1.1:
286 	 * USB 2.0, single TT organization (mandatory):
287 	 *	one interface, protocol 0
288 	 *
289 	 * USB 2.0, multiple TT organization (optional):
290 	 *	two interfaces, protocols 1 (like single TT)
291 	 *	and 2 (multiple TT mode) ... config is
292 	 *	sometimes settable
293 	 *	NOT IMPLEMENTED
294 	 */
295 
296 	/* one interface */
297 	0x09,       /*  __u8  if_bLength; */
298 	0x04,       /*  __u8  if_bDescriptorType; Interface */
299 	0x00,       /*  __u8  if_bInterfaceNumber; */
300 	0x00,       /*  __u8  if_bAlternateSetting; */
301 	0x01,       /*  __u8  if_bNumEndpoints; */
302 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
303 	0x00,       /*  __u8  if_bInterfaceSubClass; */
304 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
305 	0x00,       /*  __u8  if_iInterface; */
306 
307 	/* one endpoint (status change endpoint) */
308 	0x07,       /*  __u8  ep_bLength; */
309 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
310 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
311  	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
312 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
313 		     * see hub.c:hub_configure() for details. */
314 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
315 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
316 };
317 
318 static const u8 ss_rh_config_descriptor[] = {
319 	/* one configuration */
320 	0x09,       /*  __u8  bLength; */
321 	0x02,       /*  __u8  bDescriptorType; Configuration */
322 	0x1f, 0x00, /*  __le16 wTotalLength; */
323 	0x01,       /*  __u8  bNumInterfaces; (1) */
324 	0x01,       /*  __u8  bConfigurationValue; */
325 	0x00,       /*  __u8  iConfiguration; */
326 	0xc0,       /*  __u8  bmAttributes;
327 				 Bit 7: must be set,
328 				     6: Self-powered,
329 				     5: Remote wakeup,
330 				     4..0: resvd */
331 	0x00,       /*  __u8  MaxPower; */
332 
333 	/* one interface */
334 	0x09,       /*  __u8  if_bLength; */
335 	0x04,       /*  __u8  if_bDescriptorType; Interface */
336 	0x00,       /*  __u8  if_bInterfaceNumber; */
337 	0x00,       /*  __u8  if_bAlternateSetting; */
338 	0x01,       /*  __u8  if_bNumEndpoints; */
339 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
340 	0x00,       /*  __u8  if_bInterfaceSubClass; */
341 	0x00,       /*  __u8  if_bInterfaceProtocol; */
342 	0x00,       /*  __u8  if_iInterface; */
343 
344 	/* one endpoint (status change endpoint) */
345 	0x07,       /*  __u8  ep_bLength; */
346 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
347 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
348 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
349 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
350 		     * see hub.c:hub_configure() for details. */
351 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
352 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
353 
354 	/* one SuperSpeed endpoint companion descriptor */
355 	0x06,        /* __u8 ss_bLength */
356 	0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
357 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
358 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
359 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
360 };
361 
362 /* authorized_default behaviour:
363  * -1 is authorized for all devices except wireless (old behaviour)
364  * 0 is unauthorized for all devices
365  * 1 is authorized for all devices
366  */
367 static int authorized_default = -1;
368 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
369 MODULE_PARM_DESC(authorized_default,
370 		"Default USB device authorization: 0 is not authorized, 1 is "
371 		"authorized, -1 is authorized except for wireless USB (default, "
372 		"old behaviour");
373 /*-------------------------------------------------------------------------*/
374 
375 /**
376  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
377  * @s: Null-terminated ASCII (actually ISO-8859-1) string
378  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
379  * @len: Length (in bytes; may be odd) of descriptor buffer.
380  *
381  * The return value is the number of bytes filled in: 2 + 2*strlen(s) or
382  * buflen, whichever is less.
383  *
384  * USB String descriptors can contain at most 126 characters; input
385  * strings longer than that are truncated.
386  */
387 static unsigned
388 ascii2desc(char const *s, u8 *buf, unsigned len)
389 {
390 	unsigned n, t = 2 + 2*strlen(s);
391 
392 	if (t > 254)
393 		t = 254;	/* Longest possible UTF string descriptor */
394 	if (len > t)
395 		len = t;
396 
397 	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
398 
399 	n = len;
400 	while (n--) {
401 		*buf++ = t;
402 		if (!n--)
403 			break;
404 		*buf++ = t >> 8;
405 		t = (unsigned char)*s++;
406 	}
407 	return len;
408 }
409 
410 /**
411  * rh_string() - provides string descriptors for root hub
412  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
413  * @hcd: the host controller for this root hub
414  * @data: buffer for output packet
415  * @len: length of the provided buffer
416  *
417  * Produces either a manufacturer, product or serial number string for the
418  * virtual root hub device.
419  * Returns the number of bytes filled in: the length of the descriptor or
420  * of the provided buffer, whichever is less.
421  */
422 static unsigned
423 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
424 {
425 	char buf[100];
426 	char const *s;
427 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
428 
429 	// language ids
430 	switch (id) {
431 	case 0:
432 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
433 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
434 		if (len > 4)
435 			len = 4;
436 		memcpy(data, langids, len);
437 		return len;
438 	case 1:
439 		/* Serial number */
440 		s = hcd->self.bus_name;
441 		break;
442 	case 2:
443 		/* Product name */
444 		s = hcd->product_desc;
445 		break;
446 	case 3:
447 		/* Manufacturer */
448 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
449 			init_utsname()->release, hcd->driver->description);
450 		s = buf;
451 		break;
452 	default:
453 		/* Can't happen; caller guarantees it */
454 		return 0;
455 	}
456 
457 	return ascii2desc(s, data, len);
458 }
459 
460 
461 /* Root hub control transfers execute synchronously */
462 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
463 {
464 	struct usb_ctrlrequest *cmd;
465  	u16		typeReq, wValue, wIndex, wLength;
466 	u8		*ubuf = urb->transfer_buffer;
467 	/*
468 	 * tbuf should be as big as the BOS descriptor and
469 	 * the USB hub descriptor.
470 	 */
471 	u8		tbuf[USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE]
472 		__attribute__((aligned(4)));
473 	const u8	*bufp = tbuf;
474 	unsigned	len = 0;
475 	int		status;
476 	u8		patch_wakeup = 0;
477 	u8		patch_protocol = 0;
478 
479 	might_sleep();
480 
481 	spin_lock_irq(&hcd_root_hub_lock);
482 	status = usb_hcd_link_urb_to_ep(hcd, urb);
483 	spin_unlock_irq(&hcd_root_hub_lock);
484 	if (status)
485 		return status;
486 	urb->hcpriv = hcd;	/* Indicate it's queued */
487 
488 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
489 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
490 	wValue   = le16_to_cpu (cmd->wValue);
491 	wIndex   = le16_to_cpu (cmd->wIndex);
492 	wLength  = le16_to_cpu (cmd->wLength);
493 
494 	if (wLength > urb->transfer_buffer_length)
495 		goto error;
496 
497 	urb->actual_length = 0;
498 	switch (typeReq) {
499 
500 	/* DEVICE REQUESTS */
501 
502 	/* The root hub's remote wakeup enable bit is implemented using
503 	 * driver model wakeup flags.  If this system supports wakeup
504 	 * through USB, userspace may change the default "allow wakeup"
505 	 * policy through sysfs or these calls.
506 	 *
507 	 * Most root hubs support wakeup from downstream devices, for
508 	 * runtime power management (disabling USB clocks and reducing
509 	 * VBUS power usage).  However, not all of them do so; silicon,
510 	 * board, and BIOS bugs here are not uncommon, so these can't
511 	 * be treated quite like external hubs.
512 	 *
513 	 * Likewise, not all root hubs will pass wakeup events upstream,
514 	 * to wake up the whole system.  So don't assume root hub and
515 	 * controller capabilities are identical.
516 	 */
517 
518 	case DeviceRequest | USB_REQ_GET_STATUS:
519 		tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
520 					<< USB_DEVICE_REMOTE_WAKEUP)
521 				| (1 << USB_DEVICE_SELF_POWERED);
522 		tbuf [1] = 0;
523 		len = 2;
524 		break;
525 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
526 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
527 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
528 		else
529 			goto error;
530 		break;
531 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
532 		if (device_can_wakeup(&hcd->self.root_hub->dev)
533 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
534 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
535 		else
536 			goto error;
537 		break;
538 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
539 		tbuf [0] = 1;
540 		len = 1;
541 			/* FALLTHROUGH */
542 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
543 		break;
544 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
545 		switch (wValue & 0xff00) {
546 		case USB_DT_DEVICE << 8:
547 			switch (hcd->speed) {
548 			case HCD_USB3:
549 				bufp = usb3_rh_dev_descriptor;
550 				break;
551 			case HCD_USB25:
552 				bufp = usb25_rh_dev_descriptor;
553 				break;
554 			case HCD_USB2:
555 				bufp = usb2_rh_dev_descriptor;
556 				break;
557 			case HCD_USB11:
558 				bufp = usb11_rh_dev_descriptor;
559 				break;
560 			default:
561 				goto error;
562 			}
563 			len = 18;
564 			if (hcd->has_tt)
565 				patch_protocol = 1;
566 			break;
567 		case USB_DT_CONFIG << 8:
568 			switch (hcd->speed) {
569 			case HCD_USB3:
570 				bufp = ss_rh_config_descriptor;
571 				len = sizeof ss_rh_config_descriptor;
572 				break;
573 			case HCD_USB25:
574 			case HCD_USB2:
575 				bufp = hs_rh_config_descriptor;
576 				len = sizeof hs_rh_config_descriptor;
577 				break;
578 			case HCD_USB11:
579 				bufp = fs_rh_config_descriptor;
580 				len = sizeof fs_rh_config_descriptor;
581 				break;
582 			default:
583 				goto error;
584 			}
585 			if (device_can_wakeup(&hcd->self.root_hub->dev))
586 				patch_wakeup = 1;
587 			break;
588 		case USB_DT_STRING << 8:
589 			if ((wValue & 0xff) < 4)
590 				urb->actual_length = rh_string(wValue & 0xff,
591 						hcd, ubuf, wLength);
592 			else /* unsupported IDs --> "protocol stall" */
593 				goto error;
594 			break;
595 		case USB_DT_BOS << 8:
596 			goto nongeneric;
597 		default:
598 			goto error;
599 		}
600 		break;
601 	case DeviceRequest | USB_REQ_GET_INTERFACE:
602 		tbuf [0] = 0;
603 		len = 1;
604 			/* FALLTHROUGH */
605 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
606 		break;
607 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
608 		// wValue == urb->dev->devaddr
609 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
610 			wValue);
611 		break;
612 
613 	/* INTERFACE REQUESTS (no defined feature/status flags) */
614 
615 	/* ENDPOINT REQUESTS */
616 
617 	case EndpointRequest | USB_REQ_GET_STATUS:
618 		// ENDPOINT_HALT flag
619 		tbuf [0] = 0;
620 		tbuf [1] = 0;
621 		len = 2;
622 			/* FALLTHROUGH */
623 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
624 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
625 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
626 		break;
627 
628 	/* CLASS REQUESTS (and errors) */
629 
630 	default:
631 nongeneric:
632 		/* non-generic request */
633 		switch (typeReq) {
634 		case GetHubStatus:
635 		case GetPortStatus:
636 			len = 4;
637 			break;
638 		case GetHubDescriptor:
639 			len = sizeof (struct usb_hub_descriptor);
640 			break;
641 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
642 			/* len is returned by hub_control */
643 			break;
644 		}
645 		status = hcd->driver->hub_control (hcd,
646 			typeReq, wValue, wIndex,
647 			tbuf, wLength);
648 
649 		if (typeReq == GetHubDescriptor)
650 			usb_hub_adjust_deviceremovable(hcd->self.root_hub,
651 				(struct usb_hub_descriptor *)tbuf);
652 		break;
653 error:
654 		/* "protocol stall" on error */
655 		status = -EPIPE;
656 	}
657 
658 	if (status < 0) {
659 		len = 0;
660 		if (status != -EPIPE) {
661 			dev_dbg (hcd->self.controller,
662 				"CTRL: TypeReq=0x%x val=0x%x "
663 				"idx=0x%x len=%d ==> %d\n",
664 				typeReq, wValue, wIndex,
665 				wLength, status);
666 		}
667 	} else if (status > 0) {
668 		/* hub_control may return the length of data copied. */
669 		len = status;
670 		status = 0;
671 	}
672 	if (len) {
673 		if (urb->transfer_buffer_length < len)
674 			len = urb->transfer_buffer_length;
675 		urb->actual_length = len;
676 		// always USB_DIR_IN, toward host
677 		memcpy (ubuf, bufp, len);
678 
679 		/* report whether RH hardware supports remote wakeup */
680 		if (patch_wakeup &&
681 				len > offsetof (struct usb_config_descriptor,
682 						bmAttributes))
683 			((struct usb_config_descriptor *)ubuf)->bmAttributes
684 				|= USB_CONFIG_ATT_WAKEUP;
685 
686 		/* report whether RH hardware has an integrated TT */
687 		if (patch_protocol &&
688 				len > offsetof(struct usb_device_descriptor,
689 						bDeviceProtocol))
690 			((struct usb_device_descriptor *) ubuf)->
691 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
692 	}
693 
694 	/* any errors get returned through the urb completion */
695 	spin_lock_irq(&hcd_root_hub_lock);
696 	usb_hcd_unlink_urb_from_ep(hcd, urb);
697 
698 	/* This peculiar use of spinlocks echoes what real HC drivers do.
699 	 * Avoiding calls to local_irq_disable/enable makes the code
700 	 * RT-friendly.
701 	 */
702 	spin_unlock(&hcd_root_hub_lock);
703 	usb_hcd_giveback_urb(hcd, urb, status);
704 	spin_lock(&hcd_root_hub_lock);
705 
706 	spin_unlock_irq(&hcd_root_hub_lock);
707 	return 0;
708 }
709 
710 /*-------------------------------------------------------------------------*/
711 
712 /*
713  * Root Hub interrupt transfers are polled using a timer if the
714  * driver requests it; otherwise the driver is responsible for
715  * calling usb_hcd_poll_rh_status() when an event occurs.
716  *
717  * Completions are called in_interrupt(), but they may or may not
718  * be in_irq().
719  */
720 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
721 {
722 	struct urb	*urb;
723 	int		length;
724 	unsigned long	flags;
725 	char		buffer[6];	/* Any root hubs with > 31 ports? */
726 
727 	if (unlikely(!hcd->rh_pollable))
728 		return;
729 	if (!hcd->uses_new_polling && !hcd->status_urb)
730 		return;
731 
732 	length = hcd->driver->hub_status_data(hcd, buffer);
733 	if (length > 0) {
734 
735 		/* try to complete the status urb */
736 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
737 		urb = hcd->status_urb;
738 		if (urb) {
739 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
740 			hcd->status_urb = NULL;
741 			urb->actual_length = length;
742 			memcpy(urb->transfer_buffer, buffer, length);
743 
744 			usb_hcd_unlink_urb_from_ep(hcd, urb);
745 			spin_unlock(&hcd_root_hub_lock);
746 			usb_hcd_giveback_urb(hcd, urb, 0);
747 			spin_lock(&hcd_root_hub_lock);
748 		} else {
749 			length = 0;
750 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
751 		}
752 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
753 	}
754 
755 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
756 	 * exceed that limit if HZ is 100. The math is more clunky than
757 	 * maybe expected, this is to make sure that all timers for USB devices
758 	 * fire at the same time to give the CPU a break in between */
759 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
760 			(length == 0 && hcd->status_urb != NULL))
761 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
762 }
763 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
764 
765 /* timer callback */
766 static void rh_timer_func (unsigned long _hcd)
767 {
768 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
769 }
770 
771 /*-------------------------------------------------------------------------*/
772 
773 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
774 {
775 	int		retval;
776 	unsigned long	flags;
777 	unsigned	len = 1 + (urb->dev->maxchild / 8);
778 
779 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
780 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
781 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
782 		retval = -EINVAL;
783 		goto done;
784 	}
785 
786 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
787 	if (retval)
788 		goto done;
789 
790 	hcd->status_urb = urb;
791 	urb->hcpriv = hcd;	/* indicate it's queued */
792 	if (!hcd->uses_new_polling)
793 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
794 
795 	/* If a status change has already occurred, report it ASAP */
796 	else if (HCD_POLL_PENDING(hcd))
797 		mod_timer(&hcd->rh_timer, jiffies);
798 	retval = 0;
799  done:
800 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
801 	return retval;
802 }
803 
804 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
805 {
806 	if (usb_endpoint_xfer_int(&urb->ep->desc))
807 		return rh_queue_status (hcd, urb);
808 	if (usb_endpoint_xfer_control(&urb->ep->desc))
809 		return rh_call_control (hcd, urb);
810 	return -EINVAL;
811 }
812 
813 /*-------------------------------------------------------------------------*/
814 
815 /* Unlinks of root-hub control URBs are legal, but they don't do anything
816  * since these URBs always execute synchronously.
817  */
818 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
819 {
820 	unsigned long	flags;
821 	int		rc;
822 
823 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
824 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
825 	if (rc)
826 		goto done;
827 
828 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
829 		;	/* Do nothing */
830 
831 	} else {				/* Status URB */
832 		if (!hcd->uses_new_polling)
833 			del_timer (&hcd->rh_timer);
834 		if (urb == hcd->status_urb) {
835 			hcd->status_urb = NULL;
836 			usb_hcd_unlink_urb_from_ep(hcd, urb);
837 
838 			spin_unlock(&hcd_root_hub_lock);
839 			usb_hcd_giveback_urb(hcd, urb, status);
840 			spin_lock(&hcd_root_hub_lock);
841 		}
842 	}
843  done:
844 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
845 	return rc;
846 }
847 
848 
849 
850 /*
851  * Show & store the current value of authorized_default
852  */
853 static ssize_t usb_host_authorized_default_show(struct device *dev,
854 						struct device_attribute *attr,
855 						char *buf)
856 {
857 	struct usb_device *rh_usb_dev = to_usb_device(dev);
858 	struct usb_bus *usb_bus = rh_usb_dev->bus;
859 	struct usb_hcd *usb_hcd;
860 
861 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
862 		return -ENODEV;
863 	usb_hcd = bus_to_hcd(usb_bus);
864 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
865 }
866 
867 static ssize_t usb_host_authorized_default_store(struct device *dev,
868 						 struct device_attribute *attr,
869 						 const char *buf, size_t size)
870 {
871 	ssize_t result;
872 	unsigned val;
873 	struct usb_device *rh_usb_dev = to_usb_device(dev);
874 	struct usb_bus *usb_bus = rh_usb_dev->bus;
875 	struct usb_hcd *usb_hcd;
876 
877 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
878 		return -ENODEV;
879 	usb_hcd = bus_to_hcd(usb_bus);
880 	result = sscanf(buf, "%u\n", &val);
881 	if (result == 1) {
882 		usb_hcd->authorized_default = val? 1 : 0;
883 		result = size;
884 	}
885 	else
886 		result = -EINVAL;
887 	return result;
888 }
889 
890 static DEVICE_ATTR(authorized_default, 0644,
891 	    usb_host_authorized_default_show,
892 	    usb_host_authorized_default_store);
893 
894 
895 /* Group all the USB bus attributes */
896 static struct attribute *usb_bus_attrs[] = {
897 		&dev_attr_authorized_default.attr,
898 		NULL,
899 };
900 
901 static struct attribute_group usb_bus_attr_group = {
902 	.name = NULL,	/* we want them in the same directory */
903 	.attrs = usb_bus_attrs,
904 };
905 
906 
907 
908 /*-------------------------------------------------------------------------*/
909 
910 /**
911  * usb_bus_init - shared initialization code
912  * @bus: the bus structure being initialized
913  *
914  * This code is used to initialize a usb_bus structure, memory for which is
915  * separately managed.
916  */
917 static void usb_bus_init (struct usb_bus *bus)
918 {
919 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
920 
921 	bus->devnum_next = 1;
922 
923 	bus->root_hub = NULL;
924 	bus->busnum = -1;
925 	bus->bandwidth_allocated = 0;
926 	bus->bandwidth_int_reqs  = 0;
927 	bus->bandwidth_isoc_reqs = 0;
928 
929 	INIT_LIST_HEAD (&bus->bus_list);
930 }
931 
932 /*-------------------------------------------------------------------------*/
933 
934 /**
935  * usb_register_bus - registers the USB host controller with the usb core
936  * @bus: pointer to the bus to register
937  * Context: !in_interrupt()
938  *
939  * Assigns a bus number, and links the controller into usbcore data
940  * structures so that it can be seen by scanning the bus list.
941  */
942 static int usb_register_bus(struct usb_bus *bus)
943 {
944 	int result = -E2BIG;
945 	int busnum;
946 
947 	mutex_lock(&usb_bus_list_lock);
948 	busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
949 	if (busnum >= USB_MAXBUS) {
950 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
951 		goto error_find_busnum;
952 	}
953 	set_bit (busnum, busmap.busmap);
954 	bus->busnum = busnum;
955 
956 	/* Add it to the local list of buses */
957 	list_add (&bus->bus_list, &usb_bus_list);
958 	mutex_unlock(&usb_bus_list_lock);
959 
960 	usb_notify_add_bus(bus);
961 
962 	dev_info (bus->controller, "new USB bus registered, assigned bus "
963 		  "number %d\n", bus->busnum);
964 	return 0;
965 
966 error_find_busnum:
967 	mutex_unlock(&usb_bus_list_lock);
968 	return result;
969 }
970 
971 /**
972  * usb_deregister_bus - deregisters the USB host controller
973  * @bus: pointer to the bus to deregister
974  * Context: !in_interrupt()
975  *
976  * Recycles the bus number, and unlinks the controller from usbcore data
977  * structures so that it won't be seen by scanning the bus list.
978  */
979 static void usb_deregister_bus (struct usb_bus *bus)
980 {
981 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
982 
983 	/*
984 	 * NOTE: make sure that all the devices are removed by the
985 	 * controller code, as well as having it call this when cleaning
986 	 * itself up
987 	 */
988 	mutex_lock(&usb_bus_list_lock);
989 	list_del (&bus->bus_list);
990 	mutex_unlock(&usb_bus_list_lock);
991 
992 	usb_notify_remove_bus(bus);
993 
994 	clear_bit (bus->busnum, busmap.busmap);
995 }
996 
997 /**
998  * register_root_hub - called by usb_add_hcd() to register a root hub
999  * @hcd: host controller for this root hub
1000  *
1001  * This function registers the root hub with the USB subsystem.  It sets up
1002  * the device properly in the device tree and then calls usb_new_device()
1003  * to register the usb device.  It also assigns the root hub's USB address
1004  * (always 1).
1005  */
1006 static int register_root_hub(struct usb_hcd *hcd)
1007 {
1008 	struct device *parent_dev = hcd->self.controller;
1009 	struct usb_device *usb_dev = hcd->self.root_hub;
1010 	const int devnum = 1;
1011 	int retval;
1012 
1013 	usb_dev->devnum = devnum;
1014 	usb_dev->bus->devnum_next = devnum + 1;
1015 	memset (&usb_dev->bus->devmap.devicemap, 0,
1016 			sizeof usb_dev->bus->devmap.devicemap);
1017 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1018 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1019 
1020 	mutex_lock(&usb_bus_list_lock);
1021 
1022 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1023 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1024 	if (retval != sizeof usb_dev->descriptor) {
1025 		mutex_unlock(&usb_bus_list_lock);
1026 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1027 				dev_name(&usb_dev->dev), retval);
1028 		return (retval < 0) ? retval : -EMSGSIZE;
1029 	}
1030 	if (usb_dev->speed == USB_SPEED_SUPER) {
1031 		retval = usb_get_bos_descriptor(usb_dev);
1032 		if (retval < 0) {
1033 			mutex_unlock(&usb_bus_list_lock);
1034 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1035 					dev_name(&usb_dev->dev), retval);
1036 			return retval;
1037 		}
1038 	}
1039 
1040 	retval = usb_new_device (usb_dev);
1041 	if (retval) {
1042 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1043 				dev_name(&usb_dev->dev), retval);
1044 	} else {
1045 		spin_lock_irq (&hcd_root_hub_lock);
1046 		hcd->rh_registered = 1;
1047 		spin_unlock_irq (&hcd_root_hub_lock);
1048 
1049 		/* Did the HC die before the root hub was registered? */
1050 		if (HCD_DEAD(hcd))
1051 			usb_hc_died (hcd);	/* This time clean up */
1052 	}
1053 	mutex_unlock(&usb_bus_list_lock);
1054 
1055 	return retval;
1056 }
1057 
1058 /*
1059  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1060  * @bus: the bus which the root hub belongs to
1061  * @portnum: the port which is being resumed
1062  *
1063  * HCDs should call this function when they know that a resume signal is
1064  * being sent to a root-hub port.  The root hub will be prevented from
1065  * going into autosuspend until usb_hcd_end_port_resume() is called.
1066  *
1067  * The bus's private lock must be held by the caller.
1068  */
1069 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1070 {
1071 	unsigned bit = 1 << portnum;
1072 
1073 	if (!(bus->resuming_ports & bit)) {
1074 		bus->resuming_ports |= bit;
1075 		pm_runtime_get_noresume(&bus->root_hub->dev);
1076 	}
1077 }
1078 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1079 
1080 /*
1081  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1082  * @bus: the bus which the root hub belongs to
1083  * @portnum: the port which is being resumed
1084  *
1085  * HCDs should call this function when they know that a resume signal has
1086  * stopped being sent to a root-hub port.  The root hub will be allowed to
1087  * autosuspend again.
1088  *
1089  * The bus's private lock must be held by the caller.
1090  */
1091 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1092 {
1093 	unsigned bit = 1 << portnum;
1094 
1095 	if (bus->resuming_ports & bit) {
1096 		bus->resuming_ports &= ~bit;
1097 		pm_runtime_put_noidle(&bus->root_hub->dev);
1098 	}
1099 }
1100 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1101 
1102 /*-------------------------------------------------------------------------*/
1103 
1104 /**
1105  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1106  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1107  * @is_input: true iff the transaction sends data to the host
1108  * @isoc: true for isochronous transactions, false for interrupt ones
1109  * @bytecount: how many bytes in the transaction.
1110  *
1111  * Returns approximate bus time in nanoseconds for a periodic transaction.
1112  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1113  * scheduled in software, this function is only used for such scheduling.
1114  */
1115 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1116 {
1117 	unsigned long	tmp;
1118 
1119 	switch (speed) {
1120 	case USB_SPEED_LOW: 	/* INTR only */
1121 		if (is_input) {
1122 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1123 			return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1124 		} else {
1125 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1126 			return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1127 		}
1128 	case USB_SPEED_FULL:	/* ISOC or INTR */
1129 		if (isoc) {
1130 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1131 			return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
1132 		} else {
1133 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1134 			return (9107L + BW_HOST_DELAY + tmp);
1135 		}
1136 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1137 		// FIXME adjust for input vs output
1138 		if (isoc)
1139 			tmp = HS_NSECS_ISO (bytecount);
1140 		else
1141 			tmp = HS_NSECS (bytecount);
1142 		return tmp;
1143 	default:
1144 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1145 		return -1;
1146 	}
1147 }
1148 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1149 
1150 
1151 /*-------------------------------------------------------------------------*/
1152 
1153 /*
1154  * Generic HC operations.
1155  */
1156 
1157 /*-------------------------------------------------------------------------*/
1158 
1159 /**
1160  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1161  * @hcd: host controller to which @urb was submitted
1162  * @urb: URB being submitted
1163  *
1164  * Host controller drivers should call this routine in their enqueue()
1165  * method.  The HCD's private spinlock must be held and interrupts must
1166  * be disabled.  The actions carried out here are required for URB
1167  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1168  *
1169  * Returns 0 for no error, otherwise a negative error code (in which case
1170  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1171  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1172  * the private spinlock and returning.
1173  */
1174 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1175 {
1176 	int		rc = 0;
1177 
1178 	spin_lock(&hcd_urb_list_lock);
1179 
1180 	/* Check that the URB isn't being killed */
1181 	if (unlikely(atomic_read(&urb->reject))) {
1182 		rc = -EPERM;
1183 		goto done;
1184 	}
1185 
1186 	if (unlikely(!urb->ep->enabled)) {
1187 		rc = -ENOENT;
1188 		goto done;
1189 	}
1190 
1191 	if (unlikely(!urb->dev->can_submit)) {
1192 		rc = -EHOSTUNREACH;
1193 		goto done;
1194 	}
1195 
1196 	/*
1197 	 * Check the host controller's state and add the URB to the
1198 	 * endpoint's queue.
1199 	 */
1200 	if (HCD_RH_RUNNING(hcd)) {
1201 		urb->unlinked = 0;
1202 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1203 	} else {
1204 		rc = -ESHUTDOWN;
1205 		goto done;
1206 	}
1207  done:
1208 	spin_unlock(&hcd_urb_list_lock);
1209 	return rc;
1210 }
1211 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1212 
1213 /**
1214  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1215  * @hcd: host controller to which @urb was submitted
1216  * @urb: URB being checked for unlinkability
1217  * @status: error code to store in @urb if the unlink succeeds
1218  *
1219  * Host controller drivers should call this routine in their dequeue()
1220  * method.  The HCD's private spinlock must be held and interrupts must
1221  * be disabled.  The actions carried out here are required for making
1222  * sure than an unlink is valid.
1223  *
1224  * Returns 0 for no error, otherwise a negative error code (in which case
1225  * the dequeue() method must fail).  The possible error codes are:
1226  *
1227  *	-EIDRM: @urb was not submitted or has already completed.
1228  *		The completion function may not have been called yet.
1229  *
1230  *	-EBUSY: @urb has already been unlinked.
1231  */
1232 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1233 		int status)
1234 {
1235 	struct list_head	*tmp;
1236 
1237 	/* insist the urb is still queued */
1238 	list_for_each(tmp, &urb->ep->urb_list) {
1239 		if (tmp == &urb->urb_list)
1240 			break;
1241 	}
1242 	if (tmp != &urb->urb_list)
1243 		return -EIDRM;
1244 
1245 	/* Any status except -EINPROGRESS means something already started to
1246 	 * unlink this URB from the hardware.  So there's no more work to do.
1247 	 */
1248 	if (urb->unlinked)
1249 		return -EBUSY;
1250 	urb->unlinked = status;
1251 	return 0;
1252 }
1253 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1254 
1255 /**
1256  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1257  * @hcd: host controller to which @urb was submitted
1258  * @urb: URB being unlinked
1259  *
1260  * Host controller drivers should call this routine before calling
1261  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1262  * interrupts must be disabled.  The actions carried out here are required
1263  * for URB completion.
1264  */
1265 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1266 {
1267 	/* clear all state linking urb to this dev (and hcd) */
1268 	spin_lock(&hcd_urb_list_lock);
1269 	list_del_init(&urb->urb_list);
1270 	spin_unlock(&hcd_urb_list_lock);
1271 }
1272 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1273 
1274 /*
1275  * Some usb host controllers can only perform dma using a small SRAM area.
1276  * The usb core itself is however optimized for host controllers that can dma
1277  * using regular system memory - like pci devices doing bus mastering.
1278  *
1279  * To support host controllers with limited dma capabilites we provide dma
1280  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1281  * For this to work properly the host controller code must first use the
1282  * function dma_declare_coherent_memory() to point out which memory area
1283  * that should be used for dma allocations.
1284  *
1285  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1286  * dma using dma_alloc_coherent() which in turn allocates from the memory
1287  * area pointed out with dma_declare_coherent_memory().
1288  *
1289  * So, to summarize...
1290  *
1291  * - We need "local" memory, canonical example being
1292  *   a small SRAM on a discrete controller being the
1293  *   only memory that the controller can read ...
1294  *   (a) "normal" kernel memory is no good, and
1295  *   (b) there's not enough to share
1296  *
1297  * - The only *portable* hook for such stuff in the
1298  *   DMA framework is dma_declare_coherent_memory()
1299  *
1300  * - So we use that, even though the primary requirement
1301  *   is that the memory be "local" (hence addressible
1302  *   by that device), not "coherent".
1303  *
1304  */
1305 
1306 static int hcd_alloc_coherent(struct usb_bus *bus,
1307 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1308 			      void **vaddr_handle, size_t size,
1309 			      enum dma_data_direction dir)
1310 {
1311 	unsigned char *vaddr;
1312 
1313 	if (*vaddr_handle == NULL) {
1314 		WARN_ON_ONCE(1);
1315 		return -EFAULT;
1316 	}
1317 
1318 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1319 				 mem_flags, dma_handle);
1320 	if (!vaddr)
1321 		return -ENOMEM;
1322 
1323 	/*
1324 	 * Store the virtual address of the buffer at the end
1325 	 * of the allocated dma buffer. The size of the buffer
1326 	 * may be uneven so use unaligned functions instead
1327 	 * of just rounding up. It makes sense to optimize for
1328 	 * memory footprint over access speed since the amount
1329 	 * of memory available for dma may be limited.
1330 	 */
1331 	put_unaligned((unsigned long)*vaddr_handle,
1332 		      (unsigned long *)(vaddr + size));
1333 
1334 	if (dir == DMA_TO_DEVICE)
1335 		memcpy(vaddr, *vaddr_handle, size);
1336 
1337 	*vaddr_handle = vaddr;
1338 	return 0;
1339 }
1340 
1341 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1342 			      void **vaddr_handle, size_t size,
1343 			      enum dma_data_direction dir)
1344 {
1345 	unsigned char *vaddr = *vaddr_handle;
1346 
1347 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1348 
1349 	if (dir == DMA_FROM_DEVICE)
1350 		memcpy(vaddr, *vaddr_handle, size);
1351 
1352 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1353 
1354 	*vaddr_handle = vaddr;
1355 	*dma_handle = 0;
1356 }
1357 
1358 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1359 {
1360 	if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1361 		dma_unmap_single(hcd->self.controller,
1362 				urb->setup_dma,
1363 				sizeof(struct usb_ctrlrequest),
1364 				DMA_TO_DEVICE);
1365 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1366 		hcd_free_coherent(urb->dev->bus,
1367 				&urb->setup_dma,
1368 				(void **) &urb->setup_packet,
1369 				sizeof(struct usb_ctrlrequest),
1370 				DMA_TO_DEVICE);
1371 
1372 	/* Make it safe to call this routine more than once */
1373 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1374 }
1375 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1376 
1377 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1378 {
1379 	if (hcd->driver->unmap_urb_for_dma)
1380 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1381 	else
1382 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1383 }
1384 
1385 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1386 {
1387 	enum dma_data_direction dir;
1388 
1389 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1390 
1391 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1392 	if (urb->transfer_flags & URB_DMA_MAP_SG)
1393 		dma_unmap_sg(hcd->self.controller,
1394 				urb->sg,
1395 				urb->num_sgs,
1396 				dir);
1397 	else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1398 		dma_unmap_page(hcd->self.controller,
1399 				urb->transfer_dma,
1400 				urb->transfer_buffer_length,
1401 				dir);
1402 	else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1403 		dma_unmap_single(hcd->self.controller,
1404 				urb->transfer_dma,
1405 				urb->transfer_buffer_length,
1406 				dir);
1407 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1408 		hcd_free_coherent(urb->dev->bus,
1409 				&urb->transfer_dma,
1410 				&urb->transfer_buffer,
1411 				urb->transfer_buffer_length,
1412 				dir);
1413 
1414 	/* Make it safe to call this routine more than once */
1415 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1416 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1417 }
1418 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1419 
1420 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1421 			   gfp_t mem_flags)
1422 {
1423 	if (hcd->driver->map_urb_for_dma)
1424 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1425 	else
1426 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1427 }
1428 
1429 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1430 			    gfp_t mem_flags)
1431 {
1432 	enum dma_data_direction dir;
1433 	int ret = 0;
1434 
1435 	/* Map the URB's buffers for DMA access.
1436 	 * Lower level HCD code should use *_dma exclusively,
1437 	 * unless it uses pio or talks to another transport,
1438 	 * or uses the provided scatter gather list for bulk.
1439 	 */
1440 
1441 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1442 		if (hcd->self.uses_pio_for_control)
1443 			return ret;
1444 		if (hcd->self.uses_dma) {
1445 			urb->setup_dma = dma_map_single(
1446 					hcd->self.controller,
1447 					urb->setup_packet,
1448 					sizeof(struct usb_ctrlrequest),
1449 					DMA_TO_DEVICE);
1450 			if (dma_mapping_error(hcd->self.controller,
1451 						urb->setup_dma))
1452 				return -EAGAIN;
1453 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1454 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1455 			ret = hcd_alloc_coherent(
1456 					urb->dev->bus, mem_flags,
1457 					&urb->setup_dma,
1458 					(void **)&urb->setup_packet,
1459 					sizeof(struct usb_ctrlrequest),
1460 					DMA_TO_DEVICE);
1461 			if (ret)
1462 				return ret;
1463 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1464 		}
1465 	}
1466 
1467 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1468 	if (urb->transfer_buffer_length != 0
1469 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1470 		if (hcd->self.uses_dma) {
1471 			if (urb->num_sgs) {
1472 				int n;
1473 
1474 				/* We don't support sg for isoc transfers ! */
1475 				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1476 					WARN_ON(1);
1477 					return -EINVAL;
1478 				}
1479 
1480 				n = dma_map_sg(
1481 						hcd->self.controller,
1482 						urb->sg,
1483 						urb->num_sgs,
1484 						dir);
1485 				if (n <= 0)
1486 					ret = -EAGAIN;
1487 				else
1488 					urb->transfer_flags |= URB_DMA_MAP_SG;
1489 				urb->num_mapped_sgs = n;
1490 				if (n != urb->num_sgs)
1491 					urb->transfer_flags |=
1492 							URB_DMA_SG_COMBINED;
1493 			} else if (urb->sg) {
1494 				struct scatterlist *sg = urb->sg;
1495 				urb->transfer_dma = dma_map_page(
1496 						hcd->self.controller,
1497 						sg_page(sg),
1498 						sg->offset,
1499 						urb->transfer_buffer_length,
1500 						dir);
1501 				if (dma_mapping_error(hcd->self.controller,
1502 						urb->transfer_dma))
1503 					ret = -EAGAIN;
1504 				else
1505 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1506 			} else {
1507 				urb->transfer_dma = dma_map_single(
1508 						hcd->self.controller,
1509 						urb->transfer_buffer,
1510 						urb->transfer_buffer_length,
1511 						dir);
1512 				if (dma_mapping_error(hcd->self.controller,
1513 						urb->transfer_dma))
1514 					ret = -EAGAIN;
1515 				else
1516 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1517 			}
1518 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1519 			ret = hcd_alloc_coherent(
1520 					urb->dev->bus, mem_flags,
1521 					&urb->transfer_dma,
1522 					&urb->transfer_buffer,
1523 					urb->transfer_buffer_length,
1524 					dir);
1525 			if (ret == 0)
1526 				urb->transfer_flags |= URB_MAP_LOCAL;
1527 		}
1528 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1529 				URB_SETUP_MAP_LOCAL)))
1530 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1531 	}
1532 	return ret;
1533 }
1534 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1535 
1536 /*-------------------------------------------------------------------------*/
1537 
1538 /* may be called in any context with a valid urb->dev usecount
1539  * caller surrenders "ownership" of urb
1540  * expects usb_submit_urb() to have sanity checked and conditioned all
1541  * inputs in the urb
1542  */
1543 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1544 {
1545 	int			status;
1546 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1547 
1548 	/* increment urb's reference count as part of giving it to the HCD
1549 	 * (which will control it).  HCD guarantees that it either returns
1550 	 * an error or calls giveback(), but not both.
1551 	 */
1552 	usb_get_urb(urb);
1553 	atomic_inc(&urb->use_count);
1554 	atomic_inc(&urb->dev->urbnum);
1555 	usbmon_urb_submit(&hcd->self, urb);
1556 
1557 	/* NOTE requirements on root-hub callers (usbfs and the hub
1558 	 * driver, for now):  URBs' urb->transfer_buffer must be
1559 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1560 	 * they could clobber root hub response data.  Also, control
1561 	 * URBs must be submitted in process context with interrupts
1562 	 * enabled.
1563 	 */
1564 
1565 	if (is_root_hub(urb->dev)) {
1566 		status = rh_urb_enqueue(hcd, urb);
1567 	} else {
1568 		status = map_urb_for_dma(hcd, urb, mem_flags);
1569 		if (likely(status == 0)) {
1570 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1571 			if (unlikely(status))
1572 				unmap_urb_for_dma(hcd, urb);
1573 		}
1574 	}
1575 
1576 	if (unlikely(status)) {
1577 		usbmon_urb_submit_error(&hcd->self, urb, status);
1578 		urb->hcpriv = NULL;
1579 		INIT_LIST_HEAD(&urb->urb_list);
1580 		atomic_dec(&urb->use_count);
1581 		atomic_dec(&urb->dev->urbnum);
1582 		if (atomic_read(&urb->reject))
1583 			wake_up(&usb_kill_urb_queue);
1584 		usb_put_urb(urb);
1585 	}
1586 	return status;
1587 }
1588 
1589 /*-------------------------------------------------------------------------*/
1590 
1591 /* this makes the hcd giveback() the urb more quickly, by kicking it
1592  * off hardware queues (which may take a while) and returning it as
1593  * soon as practical.  we've already set up the urb's return status,
1594  * but we can't know if the callback completed already.
1595  */
1596 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1597 {
1598 	int		value;
1599 
1600 	if (is_root_hub(urb->dev))
1601 		value = usb_rh_urb_dequeue(hcd, urb, status);
1602 	else {
1603 
1604 		/* The only reason an HCD might fail this call is if
1605 		 * it has not yet fully queued the urb to begin with.
1606 		 * Such failures should be harmless. */
1607 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1608 	}
1609 	return value;
1610 }
1611 
1612 /*
1613  * called in any context
1614  *
1615  * caller guarantees urb won't be recycled till both unlink()
1616  * and the urb's completion function return
1617  */
1618 int usb_hcd_unlink_urb (struct urb *urb, int status)
1619 {
1620 	struct usb_hcd		*hcd;
1621 	int			retval = -EIDRM;
1622 	unsigned long		flags;
1623 
1624 	/* Prevent the device and bus from going away while
1625 	 * the unlink is carried out.  If they are already gone
1626 	 * then urb->use_count must be 0, since disconnected
1627 	 * devices can't have any active URBs.
1628 	 */
1629 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1630 	if (atomic_read(&urb->use_count) > 0) {
1631 		retval = 0;
1632 		usb_get_dev(urb->dev);
1633 	}
1634 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1635 	if (retval == 0) {
1636 		hcd = bus_to_hcd(urb->dev->bus);
1637 		retval = unlink1(hcd, urb, status);
1638 		usb_put_dev(urb->dev);
1639 	}
1640 
1641 	if (retval == 0)
1642 		retval = -EINPROGRESS;
1643 	else if (retval != -EIDRM && retval != -EBUSY)
1644 		dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1645 				urb, retval);
1646 	return retval;
1647 }
1648 
1649 /*-------------------------------------------------------------------------*/
1650 
1651 /**
1652  * usb_hcd_giveback_urb - return URB from HCD to device driver
1653  * @hcd: host controller returning the URB
1654  * @urb: urb being returned to the USB device driver.
1655  * @status: completion status code for the URB.
1656  * Context: in_interrupt()
1657  *
1658  * This hands the URB from HCD to its USB device driver, using its
1659  * completion function.  The HCD has freed all per-urb resources
1660  * (and is done using urb->hcpriv).  It also released all HCD locks;
1661  * the device driver won't cause problems if it frees, modifies,
1662  * or resubmits this URB.
1663  *
1664  * If @urb was unlinked, the value of @status will be overridden by
1665  * @urb->unlinked.  Erroneous short transfers are detected in case
1666  * the HCD hasn't checked for them.
1667  */
1668 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1669 {
1670 	urb->hcpriv = NULL;
1671 	if (unlikely(urb->unlinked))
1672 		status = urb->unlinked;
1673 	else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1674 			urb->actual_length < urb->transfer_buffer_length &&
1675 			!status))
1676 		status = -EREMOTEIO;
1677 
1678 	unmap_urb_for_dma(hcd, urb);
1679 	usbmon_urb_complete(&hcd->self, urb, status);
1680 	usb_unanchor_urb(urb);
1681 
1682 	/* pass ownership to the completion handler */
1683 	urb->status = status;
1684 	urb->complete (urb);
1685 	atomic_dec (&urb->use_count);
1686 	if (unlikely(atomic_read(&urb->reject)))
1687 		wake_up (&usb_kill_urb_queue);
1688 	usb_put_urb (urb);
1689 }
1690 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1691 
1692 /*-------------------------------------------------------------------------*/
1693 
1694 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1695  * queue to drain completely.  The caller must first insure that no more
1696  * URBs can be submitted for this endpoint.
1697  */
1698 void usb_hcd_flush_endpoint(struct usb_device *udev,
1699 		struct usb_host_endpoint *ep)
1700 {
1701 	struct usb_hcd		*hcd;
1702 	struct urb		*urb;
1703 
1704 	if (!ep)
1705 		return;
1706 	might_sleep();
1707 	hcd = bus_to_hcd(udev->bus);
1708 
1709 	/* No more submits can occur */
1710 	spin_lock_irq(&hcd_urb_list_lock);
1711 rescan:
1712 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1713 		int	is_in;
1714 
1715 		if (urb->unlinked)
1716 			continue;
1717 		usb_get_urb (urb);
1718 		is_in = usb_urb_dir_in(urb);
1719 		spin_unlock(&hcd_urb_list_lock);
1720 
1721 		/* kick hcd */
1722 		unlink1(hcd, urb, -ESHUTDOWN);
1723 		dev_dbg (hcd->self.controller,
1724 			"shutdown urb %p ep%d%s%s\n",
1725 			urb, usb_endpoint_num(&ep->desc),
1726 			is_in ? "in" : "out",
1727 			({	char *s;
1728 
1729 				 switch (usb_endpoint_type(&ep->desc)) {
1730 				 case USB_ENDPOINT_XFER_CONTROL:
1731 					s = ""; break;
1732 				 case USB_ENDPOINT_XFER_BULK:
1733 					s = "-bulk"; break;
1734 				 case USB_ENDPOINT_XFER_INT:
1735 					s = "-intr"; break;
1736 				 default:
1737 			 		s = "-iso"; break;
1738 				};
1739 				s;
1740 			}));
1741 		usb_put_urb (urb);
1742 
1743 		/* list contents may have changed */
1744 		spin_lock(&hcd_urb_list_lock);
1745 		goto rescan;
1746 	}
1747 	spin_unlock_irq(&hcd_urb_list_lock);
1748 
1749 	/* Wait until the endpoint queue is completely empty */
1750 	while (!list_empty (&ep->urb_list)) {
1751 		spin_lock_irq(&hcd_urb_list_lock);
1752 
1753 		/* The list may have changed while we acquired the spinlock */
1754 		urb = NULL;
1755 		if (!list_empty (&ep->urb_list)) {
1756 			urb = list_entry (ep->urb_list.prev, struct urb,
1757 					urb_list);
1758 			usb_get_urb (urb);
1759 		}
1760 		spin_unlock_irq(&hcd_urb_list_lock);
1761 
1762 		if (urb) {
1763 			usb_kill_urb (urb);
1764 			usb_put_urb (urb);
1765 		}
1766 	}
1767 }
1768 
1769 /**
1770  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1771  *				the bus bandwidth
1772  * @udev: target &usb_device
1773  * @new_config: new configuration to install
1774  * @cur_alt: the current alternate interface setting
1775  * @new_alt: alternate interface setting that is being installed
1776  *
1777  * To change configurations, pass in the new configuration in new_config,
1778  * and pass NULL for cur_alt and new_alt.
1779  *
1780  * To reset a device's configuration (put the device in the ADDRESSED state),
1781  * pass in NULL for new_config, cur_alt, and new_alt.
1782  *
1783  * To change alternate interface settings, pass in NULL for new_config,
1784  * pass in the current alternate interface setting in cur_alt,
1785  * and pass in the new alternate interface setting in new_alt.
1786  *
1787  * Returns an error if the requested bandwidth change exceeds the
1788  * bus bandwidth or host controller internal resources.
1789  */
1790 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1791 		struct usb_host_config *new_config,
1792 		struct usb_host_interface *cur_alt,
1793 		struct usb_host_interface *new_alt)
1794 {
1795 	int num_intfs, i, j;
1796 	struct usb_host_interface *alt = NULL;
1797 	int ret = 0;
1798 	struct usb_hcd *hcd;
1799 	struct usb_host_endpoint *ep;
1800 
1801 	hcd = bus_to_hcd(udev->bus);
1802 	if (!hcd->driver->check_bandwidth)
1803 		return 0;
1804 
1805 	/* Configuration is being removed - set configuration 0 */
1806 	if (!new_config && !cur_alt) {
1807 		for (i = 1; i < 16; ++i) {
1808 			ep = udev->ep_out[i];
1809 			if (ep)
1810 				hcd->driver->drop_endpoint(hcd, udev, ep);
1811 			ep = udev->ep_in[i];
1812 			if (ep)
1813 				hcd->driver->drop_endpoint(hcd, udev, ep);
1814 		}
1815 		hcd->driver->check_bandwidth(hcd, udev);
1816 		return 0;
1817 	}
1818 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1819 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1820 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1821 	 * ok to exclude it.
1822 	 */
1823 	if (new_config) {
1824 		num_intfs = new_config->desc.bNumInterfaces;
1825 		/* Remove endpoints (except endpoint 0, which is always on the
1826 		 * schedule) from the old config from the schedule
1827 		 */
1828 		for (i = 1; i < 16; ++i) {
1829 			ep = udev->ep_out[i];
1830 			if (ep) {
1831 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1832 				if (ret < 0)
1833 					goto reset;
1834 			}
1835 			ep = udev->ep_in[i];
1836 			if (ep) {
1837 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1838 				if (ret < 0)
1839 					goto reset;
1840 			}
1841 		}
1842 		for (i = 0; i < num_intfs; ++i) {
1843 			struct usb_host_interface *first_alt;
1844 			int iface_num;
1845 
1846 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1847 			iface_num = first_alt->desc.bInterfaceNumber;
1848 			/* Set up endpoints for alternate interface setting 0 */
1849 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1850 			if (!alt)
1851 				/* No alt setting 0? Pick the first setting. */
1852 				alt = first_alt;
1853 
1854 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1855 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1856 				if (ret < 0)
1857 					goto reset;
1858 			}
1859 		}
1860 	}
1861 	if (cur_alt && new_alt) {
1862 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1863 				cur_alt->desc.bInterfaceNumber);
1864 
1865 		if (!iface)
1866 			return -EINVAL;
1867 		if (iface->resetting_device) {
1868 			/*
1869 			 * The USB core just reset the device, so the xHCI host
1870 			 * and the device will think alt setting 0 is installed.
1871 			 * However, the USB core will pass in the alternate
1872 			 * setting installed before the reset as cur_alt.  Dig
1873 			 * out the alternate setting 0 structure, or the first
1874 			 * alternate setting if a broken device doesn't have alt
1875 			 * setting 0.
1876 			 */
1877 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1878 			if (!cur_alt)
1879 				cur_alt = &iface->altsetting[0];
1880 		}
1881 
1882 		/* Drop all the endpoints in the current alt setting */
1883 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1884 			ret = hcd->driver->drop_endpoint(hcd, udev,
1885 					&cur_alt->endpoint[i]);
1886 			if (ret < 0)
1887 				goto reset;
1888 		}
1889 		/* Add all the endpoints in the new alt setting */
1890 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1891 			ret = hcd->driver->add_endpoint(hcd, udev,
1892 					&new_alt->endpoint[i]);
1893 			if (ret < 0)
1894 				goto reset;
1895 		}
1896 	}
1897 	ret = hcd->driver->check_bandwidth(hcd, udev);
1898 reset:
1899 	if (ret < 0)
1900 		hcd->driver->reset_bandwidth(hcd, udev);
1901 	return ret;
1902 }
1903 
1904 /* Disables the endpoint: synchronizes with the hcd to make sure all
1905  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1906  * have been called previously.  Use for set_configuration, set_interface,
1907  * driver removal, physical disconnect.
1908  *
1909  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1910  * type, maxpacket size, toggle, halt status, and scheduling.
1911  */
1912 void usb_hcd_disable_endpoint(struct usb_device *udev,
1913 		struct usb_host_endpoint *ep)
1914 {
1915 	struct usb_hcd		*hcd;
1916 
1917 	might_sleep();
1918 	hcd = bus_to_hcd(udev->bus);
1919 	if (hcd->driver->endpoint_disable)
1920 		hcd->driver->endpoint_disable(hcd, ep);
1921 }
1922 
1923 /**
1924  * usb_hcd_reset_endpoint - reset host endpoint state
1925  * @udev: USB device.
1926  * @ep:   the endpoint to reset.
1927  *
1928  * Resets any host endpoint state such as the toggle bit, sequence
1929  * number and current window.
1930  */
1931 void usb_hcd_reset_endpoint(struct usb_device *udev,
1932 			    struct usb_host_endpoint *ep)
1933 {
1934 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1935 
1936 	if (hcd->driver->endpoint_reset)
1937 		hcd->driver->endpoint_reset(hcd, ep);
1938 	else {
1939 		int epnum = usb_endpoint_num(&ep->desc);
1940 		int is_out = usb_endpoint_dir_out(&ep->desc);
1941 		int is_control = usb_endpoint_xfer_control(&ep->desc);
1942 
1943 		usb_settoggle(udev, epnum, is_out, 0);
1944 		if (is_control)
1945 			usb_settoggle(udev, epnum, !is_out, 0);
1946 	}
1947 }
1948 
1949 /**
1950  * usb_alloc_streams - allocate bulk endpoint stream IDs.
1951  * @interface:		alternate setting that includes all endpoints.
1952  * @eps:		array of endpoints that need streams.
1953  * @num_eps:		number of endpoints in the array.
1954  * @num_streams:	number of streams to allocate.
1955  * @mem_flags:		flags hcd should use to allocate memory.
1956  *
1957  * Sets up a group of bulk endpoints to have num_streams stream IDs available.
1958  * Drivers may queue multiple transfers to different stream IDs, which may
1959  * complete in a different order than they were queued.
1960  */
1961 int usb_alloc_streams(struct usb_interface *interface,
1962 		struct usb_host_endpoint **eps, unsigned int num_eps,
1963 		unsigned int num_streams, gfp_t mem_flags)
1964 {
1965 	struct usb_hcd *hcd;
1966 	struct usb_device *dev;
1967 	int i;
1968 
1969 	dev = interface_to_usbdev(interface);
1970 	hcd = bus_to_hcd(dev->bus);
1971 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
1972 		return -EINVAL;
1973 	if (dev->speed != USB_SPEED_SUPER)
1974 		return -EINVAL;
1975 
1976 	/* Streams only apply to bulk endpoints. */
1977 	for (i = 0; i < num_eps; i++)
1978 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
1979 			return -EINVAL;
1980 
1981 	return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
1982 			num_streams, mem_flags);
1983 }
1984 EXPORT_SYMBOL_GPL(usb_alloc_streams);
1985 
1986 /**
1987  * usb_free_streams - free bulk endpoint stream IDs.
1988  * @interface:	alternate setting that includes all endpoints.
1989  * @eps:	array of endpoints to remove streams from.
1990  * @num_eps:	number of endpoints in the array.
1991  * @mem_flags:	flags hcd should use to allocate memory.
1992  *
1993  * Reverts a group of bulk endpoints back to not using stream IDs.
1994  * Can fail if we are given bad arguments, or HCD is broken.
1995  */
1996 void usb_free_streams(struct usb_interface *interface,
1997 		struct usb_host_endpoint **eps, unsigned int num_eps,
1998 		gfp_t mem_flags)
1999 {
2000 	struct usb_hcd *hcd;
2001 	struct usb_device *dev;
2002 	int i;
2003 
2004 	dev = interface_to_usbdev(interface);
2005 	hcd = bus_to_hcd(dev->bus);
2006 	if (dev->speed != USB_SPEED_SUPER)
2007 		return;
2008 
2009 	/* Streams only apply to bulk endpoints. */
2010 	for (i = 0; i < num_eps; i++)
2011 		if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
2012 			return;
2013 
2014 	hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2015 }
2016 EXPORT_SYMBOL_GPL(usb_free_streams);
2017 
2018 /* Protect against drivers that try to unlink URBs after the device
2019  * is gone, by waiting until all unlinks for @udev are finished.
2020  * Since we don't currently track URBs by device, simply wait until
2021  * nothing is running in the locked region of usb_hcd_unlink_urb().
2022  */
2023 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2024 {
2025 	spin_lock_irq(&hcd_urb_unlink_lock);
2026 	spin_unlock_irq(&hcd_urb_unlink_lock);
2027 }
2028 
2029 /*-------------------------------------------------------------------------*/
2030 
2031 /* called in any context */
2032 int usb_hcd_get_frame_number (struct usb_device *udev)
2033 {
2034 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2035 
2036 	if (!HCD_RH_RUNNING(hcd))
2037 		return -ESHUTDOWN;
2038 	return hcd->driver->get_frame_number (hcd);
2039 }
2040 
2041 /*-------------------------------------------------------------------------*/
2042 
2043 #ifdef	CONFIG_PM
2044 
2045 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2046 {
2047 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2048 	int		status;
2049 	int		old_state = hcd->state;
2050 
2051 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2052 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2053 			rhdev->do_remote_wakeup);
2054 	if (HCD_DEAD(hcd)) {
2055 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2056 		return 0;
2057 	}
2058 
2059 	if (!hcd->driver->bus_suspend) {
2060 		status = -ENOENT;
2061 	} else {
2062 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2063 		hcd->state = HC_STATE_QUIESCING;
2064 		status = hcd->driver->bus_suspend(hcd);
2065 	}
2066 	if (status == 0) {
2067 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2068 		hcd->state = HC_STATE_SUSPENDED;
2069 
2070 		/* Did we race with a root-hub wakeup event? */
2071 		if (rhdev->do_remote_wakeup) {
2072 			char	buffer[6];
2073 
2074 			status = hcd->driver->hub_status_data(hcd, buffer);
2075 			if (status != 0) {
2076 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2077 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2078 				status = -EBUSY;
2079 			}
2080 		}
2081 	} else {
2082 		spin_lock_irq(&hcd_root_hub_lock);
2083 		if (!HCD_DEAD(hcd)) {
2084 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2085 			hcd->state = old_state;
2086 		}
2087 		spin_unlock_irq(&hcd_root_hub_lock);
2088 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2089 				"suspend", status);
2090 	}
2091 	return status;
2092 }
2093 
2094 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2095 {
2096 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2097 	int		status;
2098 	int		old_state = hcd->state;
2099 
2100 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2101 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2102 	if (HCD_DEAD(hcd)) {
2103 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2104 		return 0;
2105 	}
2106 	if (!hcd->driver->bus_resume)
2107 		return -ENOENT;
2108 	if (HCD_RH_RUNNING(hcd))
2109 		return 0;
2110 
2111 	hcd->state = HC_STATE_RESUMING;
2112 	status = hcd->driver->bus_resume(hcd);
2113 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2114 	if (status == 0) {
2115 		struct usb_device *udev;
2116 		int port1;
2117 
2118 		spin_lock_irq(&hcd_root_hub_lock);
2119 		if (!HCD_DEAD(hcd)) {
2120 			usb_set_device_state(rhdev, rhdev->actconfig
2121 					? USB_STATE_CONFIGURED
2122 					: USB_STATE_ADDRESS);
2123 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2124 			hcd->state = HC_STATE_RUNNING;
2125 		}
2126 		spin_unlock_irq(&hcd_root_hub_lock);
2127 
2128 		/*
2129 		 * Check whether any of the enabled ports on the root hub are
2130 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2131 		 * (this is what the USB-2 spec calls a "global resume").
2132 		 * Otherwise we can skip the delay.
2133 		 */
2134 		usb_hub_for_each_child(rhdev, port1, udev) {
2135 			if (udev->state != USB_STATE_NOTATTACHED &&
2136 					!udev->port_is_suspended) {
2137 				usleep_range(10000, 11000);	/* TRSMRCY */
2138 				break;
2139 			}
2140 		}
2141 	} else {
2142 		hcd->state = old_state;
2143 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2144 				"resume", status);
2145 		if (status != -ESHUTDOWN)
2146 			usb_hc_died(hcd);
2147 	}
2148 	return status;
2149 }
2150 
2151 #endif	/* CONFIG_PM */
2152 
2153 #ifdef	CONFIG_PM_RUNTIME
2154 
2155 /* Workqueue routine for root-hub remote wakeup */
2156 static void hcd_resume_work(struct work_struct *work)
2157 {
2158 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2159 	struct usb_device *udev = hcd->self.root_hub;
2160 
2161 	usb_lock_device(udev);
2162 	usb_remote_wakeup(udev);
2163 	usb_unlock_device(udev);
2164 }
2165 
2166 /**
2167  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2168  * @hcd: host controller for this root hub
2169  *
2170  * The USB host controller calls this function when its root hub is
2171  * suspended (with the remote wakeup feature enabled) and a remote
2172  * wakeup request is received.  The routine submits a workqueue request
2173  * to resume the root hub (that is, manage its downstream ports again).
2174  */
2175 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2176 {
2177 	unsigned long flags;
2178 
2179 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2180 	if (hcd->rh_registered) {
2181 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2182 		queue_work(pm_wq, &hcd->wakeup_work);
2183 	}
2184 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2185 }
2186 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2187 
2188 #endif	/* CONFIG_PM_RUNTIME */
2189 
2190 /*-------------------------------------------------------------------------*/
2191 
2192 #ifdef	CONFIG_USB_OTG
2193 
2194 /**
2195  * usb_bus_start_enum - start immediate enumeration (for OTG)
2196  * @bus: the bus (must use hcd framework)
2197  * @port_num: 1-based number of port; usually bus->otg_port
2198  * Context: in_interrupt()
2199  *
2200  * Starts enumeration, with an immediate reset followed later by
2201  * khubd identifying and possibly configuring the device.
2202  * This is needed by OTG controller drivers, where it helps meet
2203  * HNP protocol timing requirements for starting a port reset.
2204  */
2205 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2206 {
2207 	struct usb_hcd		*hcd;
2208 	int			status = -EOPNOTSUPP;
2209 
2210 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2211 	 * boards with root hubs hooked up to internal devices (instead of
2212 	 * just the OTG port) may need more attention to resetting...
2213 	 */
2214 	hcd = container_of (bus, struct usb_hcd, self);
2215 	if (port_num && hcd->driver->start_port_reset)
2216 		status = hcd->driver->start_port_reset(hcd, port_num);
2217 
2218 	/* run khubd shortly after (first) root port reset finishes;
2219 	 * it may issue others, until at least 50 msecs have passed.
2220 	 */
2221 	if (status == 0)
2222 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2223 	return status;
2224 }
2225 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2226 
2227 #endif
2228 
2229 /*-------------------------------------------------------------------------*/
2230 
2231 /**
2232  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2233  * @irq: the IRQ being raised
2234  * @__hcd: pointer to the HCD whose IRQ is being signaled
2235  *
2236  * If the controller isn't HALTed, calls the driver's irq handler.
2237  * Checks whether the controller is now dead.
2238  */
2239 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2240 {
2241 	struct usb_hcd		*hcd = __hcd;
2242 	unsigned long		flags;
2243 	irqreturn_t		rc;
2244 
2245 	/* IRQF_DISABLED doesn't work correctly with shared IRQs
2246 	 * when the first handler doesn't use it.  So let's just
2247 	 * assume it's never used.
2248 	 */
2249 	local_irq_save(flags);
2250 
2251 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2252 		rc = IRQ_NONE;
2253 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2254 		rc = IRQ_NONE;
2255 	else
2256 		rc = IRQ_HANDLED;
2257 
2258 	local_irq_restore(flags);
2259 	return rc;
2260 }
2261 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2262 
2263 /*-------------------------------------------------------------------------*/
2264 
2265 /**
2266  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2267  * @hcd: pointer to the HCD representing the controller
2268  *
2269  * This is called by bus glue to report a USB host controller that died
2270  * while operations may still have been pending.  It's called automatically
2271  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2272  *
2273  * Only call this function with the primary HCD.
2274  */
2275 void usb_hc_died (struct usb_hcd *hcd)
2276 {
2277 	unsigned long flags;
2278 
2279 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2280 
2281 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2282 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2283 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2284 	if (hcd->rh_registered) {
2285 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2286 
2287 		/* make khubd clean up old urbs and devices */
2288 		usb_set_device_state (hcd->self.root_hub,
2289 				USB_STATE_NOTATTACHED);
2290 		usb_kick_khubd (hcd->self.root_hub);
2291 	}
2292 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2293 		hcd = hcd->shared_hcd;
2294 		if (hcd->rh_registered) {
2295 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2296 
2297 			/* make khubd clean up old urbs and devices */
2298 			usb_set_device_state(hcd->self.root_hub,
2299 					USB_STATE_NOTATTACHED);
2300 			usb_kick_khubd(hcd->self.root_hub);
2301 		}
2302 	}
2303 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2304 	/* Make sure that the other roothub is also deallocated. */
2305 }
2306 EXPORT_SYMBOL_GPL (usb_hc_died);
2307 
2308 /*-------------------------------------------------------------------------*/
2309 
2310 /**
2311  * usb_create_shared_hcd - create and initialize an HCD structure
2312  * @driver: HC driver that will use this hcd
2313  * @dev: device for this HC, stored in hcd->self.controller
2314  * @bus_name: value to store in hcd->self.bus_name
2315  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2316  *              PCI device.  Only allocate certain resources for the primary HCD
2317  * Context: !in_interrupt()
2318  *
2319  * Allocate a struct usb_hcd, with extra space at the end for the
2320  * HC driver's private data.  Initialize the generic members of the
2321  * hcd structure.
2322  *
2323  * If memory is unavailable, returns NULL.
2324  */
2325 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2326 		struct device *dev, const char *bus_name,
2327 		struct usb_hcd *primary_hcd)
2328 {
2329 	struct usb_hcd *hcd;
2330 
2331 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2332 	if (!hcd) {
2333 		dev_dbg (dev, "hcd alloc failed\n");
2334 		return NULL;
2335 	}
2336 	if (primary_hcd == NULL) {
2337 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2338 				GFP_KERNEL);
2339 		if (!hcd->bandwidth_mutex) {
2340 			kfree(hcd);
2341 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2342 			return NULL;
2343 		}
2344 		mutex_init(hcd->bandwidth_mutex);
2345 		dev_set_drvdata(dev, hcd);
2346 	} else {
2347 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2348 		hcd->primary_hcd = primary_hcd;
2349 		primary_hcd->primary_hcd = primary_hcd;
2350 		hcd->shared_hcd = primary_hcd;
2351 		primary_hcd->shared_hcd = hcd;
2352 	}
2353 
2354 	kref_init(&hcd->kref);
2355 
2356 	usb_bus_init(&hcd->self);
2357 	hcd->self.controller = dev;
2358 	hcd->self.bus_name = bus_name;
2359 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2360 
2361 	init_timer(&hcd->rh_timer);
2362 	hcd->rh_timer.function = rh_timer_func;
2363 	hcd->rh_timer.data = (unsigned long) hcd;
2364 #ifdef CONFIG_PM_RUNTIME
2365 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2366 #endif
2367 
2368 	hcd->driver = driver;
2369 	hcd->speed = driver->flags & HCD_MASK;
2370 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2371 			"USB Host Controller";
2372 	return hcd;
2373 }
2374 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2375 
2376 /**
2377  * usb_create_hcd - create and initialize an HCD structure
2378  * @driver: HC driver that will use this hcd
2379  * @dev: device for this HC, stored in hcd->self.controller
2380  * @bus_name: value to store in hcd->self.bus_name
2381  * Context: !in_interrupt()
2382  *
2383  * Allocate a struct usb_hcd, with extra space at the end for the
2384  * HC driver's private data.  Initialize the generic members of the
2385  * hcd structure.
2386  *
2387  * If memory is unavailable, returns NULL.
2388  */
2389 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2390 		struct device *dev, const char *bus_name)
2391 {
2392 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2393 }
2394 EXPORT_SYMBOL_GPL(usb_create_hcd);
2395 
2396 /*
2397  * Roothubs that share one PCI device must also share the bandwidth mutex.
2398  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2399  * deallocated.
2400  *
2401  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2402  * freed.  When hcd_release() is called for the non-primary HCD, set the
2403  * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2404  * freed shortly).
2405  */
2406 static void hcd_release (struct kref *kref)
2407 {
2408 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2409 
2410 	if (usb_hcd_is_primary_hcd(hcd))
2411 		kfree(hcd->bandwidth_mutex);
2412 	else
2413 		hcd->shared_hcd->shared_hcd = NULL;
2414 	kfree(hcd);
2415 }
2416 
2417 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2418 {
2419 	if (hcd)
2420 		kref_get (&hcd->kref);
2421 	return hcd;
2422 }
2423 EXPORT_SYMBOL_GPL(usb_get_hcd);
2424 
2425 void usb_put_hcd (struct usb_hcd *hcd)
2426 {
2427 	if (hcd)
2428 		kref_put (&hcd->kref, hcd_release);
2429 }
2430 EXPORT_SYMBOL_GPL(usb_put_hcd);
2431 
2432 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2433 {
2434 	if (!hcd->primary_hcd)
2435 		return 1;
2436 	return hcd == hcd->primary_hcd;
2437 }
2438 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2439 
2440 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2441 {
2442 	if (!hcd->driver->find_raw_port_number)
2443 		return port1;
2444 
2445 	return hcd->driver->find_raw_port_number(hcd, port1);
2446 }
2447 
2448 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2449 		unsigned int irqnum, unsigned long irqflags)
2450 {
2451 	int retval;
2452 
2453 	if (hcd->driver->irq) {
2454 
2455 		/* IRQF_DISABLED doesn't work as advertised when used together
2456 		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
2457 		 * interrupts we can remove it here.
2458 		 */
2459 		if (irqflags & IRQF_SHARED)
2460 			irqflags &= ~IRQF_DISABLED;
2461 
2462 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2463 				hcd->driver->description, hcd->self.busnum);
2464 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2465 				hcd->irq_descr, hcd);
2466 		if (retval != 0) {
2467 			dev_err(hcd->self.controller,
2468 					"request interrupt %d failed\n",
2469 					irqnum);
2470 			return retval;
2471 		}
2472 		hcd->irq = irqnum;
2473 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2474 				(hcd->driver->flags & HCD_MEMORY) ?
2475 					"io mem" : "io base",
2476 					(unsigned long long)hcd->rsrc_start);
2477 	} else {
2478 		hcd->irq = 0;
2479 		if (hcd->rsrc_start)
2480 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2481 					(hcd->driver->flags & HCD_MEMORY) ?
2482 					"io mem" : "io base",
2483 					(unsigned long long)hcd->rsrc_start);
2484 	}
2485 	return 0;
2486 }
2487 
2488 /**
2489  * usb_add_hcd - finish generic HCD structure initialization and register
2490  * @hcd: the usb_hcd structure to initialize
2491  * @irqnum: Interrupt line to allocate
2492  * @irqflags: Interrupt type flags
2493  *
2494  * Finish the remaining parts of generic HCD initialization: allocate the
2495  * buffers of consistent memory, register the bus, request the IRQ line,
2496  * and call the driver's reset() and start() routines.
2497  */
2498 int usb_add_hcd(struct usb_hcd *hcd,
2499 		unsigned int irqnum, unsigned long irqflags)
2500 {
2501 	int retval;
2502 	struct usb_device *rhdev;
2503 
2504 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2505 
2506 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2507 	if (authorized_default < 0 || authorized_default > 1)
2508 		hcd->authorized_default = hcd->wireless? 0 : 1;
2509 	else
2510 		hcd->authorized_default = authorized_default;
2511 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2512 
2513 	/* HC is in reset state, but accessible.  Now do the one-time init,
2514 	 * bottom up so that hcds can customize the root hubs before khubd
2515 	 * starts talking to them.  (Note, bus id is assigned early too.)
2516 	 */
2517 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2518 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2519 		return retval;
2520 	}
2521 
2522 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2523 		goto err_register_bus;
2524 
2525 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2526 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2527 		retval = -ENOMEM;
2528 		goto err_allocate_root_hub;
2529 	}
2530 	hcd->self.root_hub = rhdev;
2531 
2532 	switch (hcd->speed) {
2533 	case HCD_USB11:
2534 		rhdev->speed = USB_SPEED_FULL;
2535 		break;
2536 	case HCD_USB2:
2537 		rhdev->speed = USB_SPEED_HIGH;
2538 		break;
2539 	case HCD_USB25:
2540 		rhdev->speed = USB_SPEED_WIRELESS;
2541 		break;
2542 	case HCD_USB3:
2543 		rhdev->speed = USB_SPEED_SUPER;
2544 		break;
2545 	default:
2546 		retval = -EINVAL;
2547 		goto err_set_rh_speed;
2548 	}
2549 
2550 	/* wakeup flag init defaults to "everything works" for root hubs,
2551 	 * but drivers can override it in reset() if needed, along with
2552 	 * recording the overall controller's system wakeup capability.
2553 	 */
2554 	device_set_wakeup_capable(&rhdev->dev, 1);
2555 
2556 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2557 	 * registered.  But since the controller can die at any time,
2558 	 * let's initialize the flag before touching the hardware.
2559 	 */
2560 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2561 
2562 	/* "reset" is misnamed; its role is now one-time init. the controller
2563 	 * should already have been reset (and boot firmware kicked off etc).
2564 	 */
2565 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2566 		dev_err(hcd->self.controller, "can't setup\n");
2567 		goto err_hcd_driver_setup;
2568 	}
2569 	hcd->rh_pollable = 1;
2570 
2571 	/* NOTE: root hub and controller capabilities may not be the same */
2572 	if (device_can_wakeup(hcd->self.controller)
2573 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2574 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2575 
2576 	/* enable irqs just before we start the controller,
2577 	 * if the BIOS provides legacy PCI irqs.
2578 	 */
2579 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2580 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2581 		if (retval)
2582 			goto err_request_irq;
2583 	}
2584 
2585 	hcd->state = HC_STATE_RUNNING;
2586 	retval = hcd->driver->start(hcd);
2587 	if (retval < 0) {
2588 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2589 		goto err_hcd_driver_start;
2590 	}
2591 
2592 	/* starting here, usbcore will pay attention to this root hub */
2593 	if ((retval = register_root_hub(hcd)) != 0)
2594 		goto err_register_root_hub;
2595 
2596 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2597 	if (retval < 0) {
2598 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2599 		       retval);
2600 		goto error_create_attr_group;
2601 	}
2602 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2603 		usb_hcd_poll_rh_status(hcd);
2604 
2605 	/*
2606 	 * Host controllers don't generate their own wakeup requests;
2607 	 * they only forward requests from the root hub.  Therefore
2608 	 * controllers should always be enabled for remote wakeup.
2609 	 */
2610 	device_wakeup_enable(hcd->self.controller);
2611 	return retval;
2612 
2613 error_create_attr_group:
2614 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2615 	if (HC_IS_RUNNING(hcd->state))
2616 		hcd->state = HC_STATE_QUIESCING;
2617 	spin_lock_irq(&hcd_root_hub_lock);
2618 	hcd->rh_registered = 0;
2619 	spin_unlock_irq(&hcd_root_hub_lock);
2620 
2621 #ifdef CONFIG_PM_RUNTIME
2622 	cancel_work_sync(&hcd->wakeup_work);
2623 #endif
2624 	mutex_lock(&usb_bus_list_lock);
2625 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2626 	mutex_unlock(&usb_bus_list_lock);
2627 err_register_root_hub:
2628 	hcd->rh_pollable = 0;
2629 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2630 	del_timer_sync(&hcd->rh_timer);
2631 	hcd->driver->stop(hcd);
2632 	hcd->state = HC_STATE_HALT;
2633 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2634 	del_timer_sync(&hcd->rh_timer);
2635 err_hcd_driver_start:
2636 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2637 		free_irq(irqnum, hcd);
2638 err_request_irq:
2639 err_hcd_driver_setup:
2640 err_set_rh_speed:
2641 	usb_put_dev(hcd->self.root_hub);
2642 err_allocate_root_hub:
2643 	usb_deregister_bus(&hcd->self);
2644 err_register_bus:
2645 	hcd_buffer_destroy(hcd);
2646 	return retval;
2647 }
2648 EXPORT_SYMBOL_GPL(usb_add_hcd);
2649 
2650 /**
2651  * usb_remove_hcd - shutdown processing for generic HCDs
2652  * @hcd: the usb_hcd structure to remove
2653  * Context: !in_interrupt()
2654  *
2655  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2656  * invoking the HCD's stop() method.
2657  */
2658 void usb_remove_hcd(struct usb_hcd *hcd)
2659 {
2660 	struct usb_device *rhdev = hcd->self.root_hub;
2661 
2662 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2663 
2664 	usb_get_dev(rhdev);
2665 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2666 
2667 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2668 	if (HC_IS_RUNNING (hcd->state))
2669 		hcd->state = HC_STATE_QUIESCING;
2670 
2671 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2672 	spin_lock_irq (&hcd_root_hub_lock);
2673 	hcd->rh_registered = 0;
2674 	spin_unlock_irq (&hcd_root_hub_lock);
2675 
2676 #ifdef CONFIG_PM_RUNTIME
2677 	cancel_work_sync(&hcd->wakeup_work);
2678 #endif
2679 
2680 	mutex_lock(&usb_bus_list_lock);
2681 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2682 	mutex_unlock(&usb_bus_list_lock);
2683 
2684 	/* Prevent any more root-hub status calls from the timer.
2685 	 * The HCD might still restart the timer (if a port status change
2686 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2687 	 * the hub_status_data() callback.
2688 	 */
2689 	hcd->rh_pollable = 0;
2690 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2691 	del_timer_sync(&hcd->rh_timer);
2692 
2693 	hcd->driver->stop(hcd);
2694 	hcd->state = HC_STATE_HALT;
2695 
2696 	/* In case the HCD restarted the timer, stop it again. */
2697 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2698 	del_timer_sync(&hcd->rh_timer);
2699 
2700 	if (usb_hcd_is_primary_hcd(hcd)) {
2701 		if (hcd->irq > 0)
2702 			free_irq(hcd->irq, hcd);
2703 	}
2704 
2705 	usb_put_dev(hcd->self.root_hub);
2706 	usb_deregister_bus(&hcd->self);
2707 	hcd_buffer_destroy(hcd);
2708 }
2709 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2710 
2711 void
2712 usb_hcd_platform_shutdown(struct platform_device* dev)
2713 {
2714 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2715 
2716 	if (hcd->driver->shutdown)
2717 		hcd->driver->shutdown(hcd);
2718 }
2719 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2720 
2721 /*-------------------------------------------------------------------------*/
2722 
2723 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2724 
2725 struct usb_mon_operations *mon_ops;
2726 
2727 /*
2728  * The registration is unlocked.
2729  * We do it this way because we do not want to lock in hot paths.
2730  *
2731  * Notice that the code is minimally error-proof. Because usbmon needs
2732  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2733  */
2734 
2735 int usb_mon_register (struct usb_mon_operations *ops)
2736 {
2737 
2738 	if (mon_ops)
2739 		return -EBUSY;
2740 
2741 	mon_ops = ops;
2742 	mb();
2743 	return 0;
2744 }
2745 EXPORT_SYMBOL_GPL (usb_mon_register);
2746 
2747 void usb_mon_deregister (void)
2748 {
2749 
2750 	if (mon_ops == NULL) {
2751 		printk(KERN_ERR "USB: monitor was not registered\n");
2752 		return;
2753 	}
2754 	mon_ops = NULL;
2755 	mb();
2756 }
2757 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2758 
2759 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2760