xref: /openbmc/linux/drivers/usb/core/hcd.c (revision 8a10bc9d)
1 /*
2  * (C) Copyright Linus Torvalds 1999
3  * (C) Copyright Johannes Erdfelt 1999-2001
4  * (C) Copyright Andreas Gal 1999
5  * (C) Copyright Gregory P. Smith 1999
6  * (C) Copyright Deti Fliegl 1999
7  * (C) Copyright Randy Dunlap 2000
8  * (C) Copyright David Brownell 2000-2002
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the
12  * Free Software Foundation; either version 2 of the License, or (at your
13  * option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  * for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software Foundation,
22  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  */
24 
25 #include <linux/bcd.h>
26 #include <linux/module.h>
27 #include <linux/version.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/completion.h>
31 #include <linux/utsname.h>
32 #include <linux/mm.h>
33 #include <asm/io.h>
34 #include <linux/device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/mutex.h>
37 #include <asm/irq.h>
38 #include <asm/byteorder.h>
39 #include <asm/unaligned.h>
40 #include <linux/platform_device.h>
41 #include <linux/workqueue.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/types.h>
44 
45 #include <linux/usb.h>
46 #include <linux/usb/hcd.h>
47 #include <linux/usb/phy.h>
48 
49 #include "usb.h"
50 
51 
52 /*-------------------------------------------------------------------------*/
53 
54 /*
55  * USB Host Controller Driver framework
56  *
57  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
58  * HCD-specific behaviors/bugs.
59  *
60  * This does error checks, tracks devices and urbs, and delegates to a
61  * "hc_driver" only for code (and data) that really needs to know about
62  * hardware differences.  That includes root hub registers, i/o queues,
63  * and so on ... but as little else as possible.
64  *
65  * Shared code includes most of the "root hub" code (these are emulated,
66  * though each HC's hardware works differently) and PCI glue, plus request
67  * tracking overhead.  The HCD code should only block on spinlocks or on
68  * hardware handshaking; blocking on software events (such as other kernel
69  * threads releasing resources, or completing actions) is all generic.
70  *
71  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
72  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
73  * only by the hub driver ... and that neither should be seen or used by
74  * usb client device drivers.
75  *
76  * Contributors of ideas or unattributed patches include: David Brownell,
77  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
78  *
79  * HISTORY:
80  * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
81  *		associated cleanup.  "usb_hcd" still != "usb_bus".
82  * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
83  */
84 
85 /*-------------------------------------------------------------------------*/
86 
87 /* Keep track of which host controller drivers are loaded */
88 unsigned long usb_hcds_loaded;
89 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
90 
91 /* host controllers we manage */
92 LIST_HEAD (usb_bus_list);
93 EXPORT_SYMBOL_GPL (usb_bus_list);
94 
95 /* used when allocating bus numbers */
96 #define USB_MAXBUS		64
97 static DECLARE_BITMAP(busmap, USB_MAXBUS);
98 
99 /* used when updating list of hcds */
100 DEFINE_MUTEX(usb_bus_list_lock);	/* exported only for usbfs */
101 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
102 
103 /* used for controlling access to virtual root hubs */
104 static DEFINE_SPINLOCK(hcd_root_hub_lock);
105 
106 /* used when updating an endpoint's URB list */
107 static DEFINE_SPINLOCK(hcd_urb_list_lock);
108 
109 /* used to protect against unlinking URBs after the device is gone */
110 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
111 
112 /* wait queue for synchronous unlinks */
113 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
114 
115 static inline int is_root_hub(struct usb_device *udev)
116 {
117 	return (udev->parent == NULL);
118 }
119 
120 /*-------------------------------------------------------------------------*/
121 
122 /*
123  * Sharable chunks of root hub code.
124  */
125 
126 /*-------------------------------------------------------------------------*/
127 #define KERNEL_REL	bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
128 #define KERNEL_VER	bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
129 
130 /* usb 3.0 root hub device descriptor */
131 static const u8 usb3_rh_dev_descriptor[18] = {
132 	0x12,       /*  __u8  bLength; */
133 	0x01,       /*  __u8  bDescriptorType; Device */
134 	0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
135 
136 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
137 	0x00,	    /*  __u8  bDeviceSubClass; */
138 	0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
139 	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
140 
141 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
142 	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
143 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
144 
145 	0x03,       /*  __u8  iManufacturer; */
146 	0x02,       /*  __u8  iProduct; */
147 	0x01,       /*  __u8  iSerialNumber; */
148 	0x01        /*  __u8  bNumConfigurations; */
149 };
150 
151 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
152 static const u8 usb25_rh_dev_descriptor[18] = {
153 	0x12,       /*  __u8  bLength; */
154 	0x01,       /*  __u8  bDescriptorType; Device */
155 	0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
156 
157 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
158 	0x00,	    /*  __u8  bDeviceSubClass; */
159 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
160 	0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
161 
162 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
163 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
164 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
165 
166 	0x03,       /*  __u8  iManufacturer; */
167 	0x02,       /*  __u8  iProduct; */
168 	0x01,       /*  __u8  iSerialNumber; */
169 	0x01        /*  __u8  bNumConfigurations; */
170 };
171 
172 /* usb 2.0 root hub device descriptor */
173 static const u8 usb2_rh_dev_descriptor[18] = {
174 	0x12,       /*  __u8  bLength; */
175 	0x01,       /*  __u8  bDescriptorType; Device */
176 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
177 
178 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
179 	0x00,	    /*  __u8  bDeviceSubClass; */
180 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
181 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
182 
183 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
184 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
185 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
186 
187 	0x03,       /*  __u8  iManufacturer; */
188 	0x02,       /*  __u8  iProduct; */
189 	0x01,       /*  __u8  iSerialNumber; */
190 	0x01        /*  __u8  bNumConfigurations; */
191 };
192 
193 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
194 
195 /* usb 1.1 root hub device descriptor */
196 static const u8 usb11_rh_dev_descriptor[18] = {
197 	0x12,       /*  __u8  bLength; */
198 	0x01,       /*  __u8  bDescriptorType; Device */
199 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
200 
201 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
202 	0x00,	    /*  __u8  bDeviceSubClass; */
203 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
204 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
205 
206 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
207 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
208 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
209 
210 	0x03,       /*  __u8  iManufacturer; */
211 	0x02,       /*  __u8  iProduct; */
212 	0x01,       /*  __u8  iSerialNumber; */
213 	0x01        /*  __u8  bNumConfigurations; */
214 };
215 
216 
217 /*-------------------------------------------------------------------------*/
218 
219 /* Configuration descriptors for our root hubs */
220 
221 static const u8 fs_rh_config_descriptor[] = {
222 
223 	/* one configuration */
224 	0x09,       /*  __u8  bLength; */
225 	0x02,       /*  __u8  bDescriptorType; Configuration */
226 	0x19, 0x00, /*  __le16 wTotalLength; */
227 	0x01,       /*  __u8  bNumInterfaces; (1) */
228 	0x01,       /*  __u8  bConfigurationValue; */
229 	0x00,       /*  __u8  iConfiguration; */
230 	0xc0,       /*  __u8  bmAttributes;
231 				 Bit 7: must be set,
232 				     6: Self-powered,
233 				     5: Remote wakeup,
234 				     4..0: resvd */
235 	0x00,       /*  __u8  MaxPower; */
236 
237 	/* USB 1.1:
238 	 * USB 2.0, single TT organization (mandatory):
239 	 *	one interface, protocol 0
240 	 *
241 	 * USB 2.0, multiple TT organization (optional):
242 	 *	two interfaces, protocols 1 (like single TT)
243 	 *	and 2 (multiple TT mode) ... config is
244 	 *	sometimes settable
245 	 *	NOT IMPLEMENTED
246 	 */
247 
248 	/* one interface */
249 	0x09,       /*  __u8  if_bLength; */
250 	0x04,       /*  __u8  if_bDescriptorType; Interface */
251 	0x00,       /*  __u8  if_bInterfaceNumber; */
252 	0x00,       /*  __u8  if_bAlternateSetting; */
253 	0x01,       /*  __u8  if_bNumEndpoints; */
254 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
255 	0x00,       /*  __u8  if_bInterfaceSubClass; */
256 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
257 	0x00,       /*  __u8  if_iInterface; */
258 
259 	/* one endpoint (status change endpoint) */
260 	0x07,       /*  __u8  ep_bLength; */
261 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
262 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
263 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
264 	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
265 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
266 };
267 
268 static const u8 hs_rh_config_descriptor[] = {
269 
270 	/* one configuration */
271 	0x09,       /*  __u8  bLength; */
272 	0x02,       /*  __u8  bDescriptorType; Configuration */
273 	0x19, 0x00, /*  __le16 wTotalLength; */
274 	0x01,       /*  __u8  bNumInterfaces; (1) */
275 	0x01,       /*  __u8  bConfigurationValue; */
276 	0x00,       /*  __u8  iConfiguration; */
277 	0xc0,       /*  __u8  bmAttributes;
278 				 Bit 7: must be set,
279 				     6: Self-powered,
280 				     5: Remote wakeup,
281 				     4..0: resvd */
282 	0x00,       /*  __u8  MaxPower; */
283 
284 	/* USB 1.1:
285 	 * USB 2.0, single TT organization (mandatory):
286 	 *	one interface, protocol 0
287 	 *
288 	 * USB 2.0, multiple TT organization (optional):
289 	 *	two interfaces, protocols 1 (like single TT)
290 	 *	and 2 (multiple TT mode) ... config is
291 	 *	sometimes settable
292 	 *	NOT IMPLEMENTED
293 	 */
294 
295 	/* one interface */
296 	0x09,       /*  __u8  if_bLength; */
297 	0x04,       /*  __u8  if_bDescriptorType; Interface */
298 	0x00,       /*  __u8  if_bInterfaceNumber; */
299 	0x00,       /*  __u8  if_bAlternateSetting; */
300 	0x01,       /*  __u8  if_bNumEndpoints; */
301 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
302 	0x00,       /*  __u8  if_bInterfaceSubClass; */
303 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
304 	0x00,       /*  __u8  if_iInterface; */
305 
306 	/* one endpoint (status change endpoint) */
307 	0x07,       /*  __u8  ep_bLength; */
308 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
309 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
310 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
311 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
312 		     * see hub.c:hub_configure() for details. */
313 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
314 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
315 };
316 
317 static const u8 ss_rh_config_descriptor[] = {
318 	/* one configuration */
319 	0x09,       /*  __u8  bLength; */
320 	0x02,       /*  __u8  bDescriptorType; Configuration */
321 	0x1f, 0x00, /*  __le16 wTotalLength; */
322 	0x01,       /*  __u8  bNumInterfaces; (1) */
323 	0x01,       /*  __u8  bConfigurationValue; */
324 	0x00,       /*  __u8  iConfiguration; */
325 	0xc0,       /*  __u8  bmAttributes;
326 				 Bit 7: must be set,
327 				     6: Self-powered,
328 				     5: Remote wakeup,
329 				     4..0: resvd */
330 	0x00,       /*  __u8  MaxPower; */
331 
332 	/* one interface */
333 	0x09,       /*  __u8  if_bLength; */
334 	0x04,       /*  __u8  if_bDescriptorType; Interface */
335 	0x00,       /*  __u8  if_bInterfaceNumber; */
336 	0x00,       /*  __u8  if_bAlternateSetting; */
337 	0x01,       /*  __u8  if_bNumEndpoints; */
338 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
339 	0x00,       /*  __u8  if_bInterfaceSubClass; */
340 	0x00,       /*  __u8  if_bInterfaceProtocol; */
341 	0x00,       /*  __u8  if_iInterface; */
342 
343 	/* one endpoint (status change endpoint) */
344 	0x07,       /*  __u8  ep_bLength; */
345 	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
346 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
347 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
348 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
349 		     * see hub.c:hub_configure() for details. */
350 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
351 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
352 
353 	/* one SuperSpeed endpoint companion descriptor */
354 	0x06,        /* __u8 ss_bLength */
355 	0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
356 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
357 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
358 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
359 };
360 
361 /* authorized_default behaviour:
362  * -1 is authorized for all devices except wireless (old behaviour)
363  * 0 is unauthorized for all devices
364  * 1 is authorized for all devices
365  */
366 static int authorized_default = -1;
367 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
368 MODULE_PARM_DESC(authorized_default,
369 		"Default USB device authorization: 0 is not authorized, 1 is "
370 		"authorized, -1 is authorized except for wireless USB (default, "
371 		"old behaviour");
372 /*-------------------------------------------------------------------------*/
373 
374 /**
375  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
376  * @s: Null-terminated ASCII (actually ISO-8859-1) string
377  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
378  * @len: Length (in bytes; may be odd) of descriptor buffer.
379  *
380  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
381  * whichever is less.
382  *
383  * Note:
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  *
420  * Return: The number of bytes filled in: the length of the descriptor or
421  * of the provided buffer, whichever is less.
422  */
423 static unsigned
424 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
425 {
426 	char buf[100];
427 	char const *s;
428 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
429 
430 	/* language ids */
431 	switch (id) {
432 	case 0:
433 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
434 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
435 		if (len > 4)
436 			len = 4;
437 		memcpy(data, langids, len);
438 		return len;
439 	case 1:
440 		/* Serial number */
441 		s = hcd->self.bus_name;
442 		break;
443 	case 2:
444 		/* Product name */
445 		s = hcd->product_desc;
446 		break;
447 	case 3:
448 		/* Manufacturer */
449 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
450 			init_utsname()->release, hcd->driver->description);
451 		s = buf;
452 		break;
453 	default:
454 		/* Can't happen; caller guarantees it */
455 		return 0;
456 	}
457 
458 	return ascii2desc(s, data, len);
459 }
460 
461 
462 /* Root hub control transfers execute synchronously */
463 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
464 {
465 	struct usb_ctrlrequest *cmd;
466 	u16		typeReq, wValue, wIndex, wLength;
467 	u8		*ubuf = urb->transfer_buffer;
468 	unsigned	len = 0;
469 	int		status;
470 	u8		patch_wakeup = 0;
471 	u8		patch_protocol = 0;
472 	u16		tbuf_size;
473 	u8		*tbuf = NULL;
474 	const u8	*bufp;
475 
476 	might_sleep();
477 
478 	spin_lock_irq(&hcd_root_hub_lock);
479 	status = usb_hcd_link_urb_to_ep(hcd, urb);
480 	spin_unlock_irq(&hcd_root_hub_lock);
481 	if (status)
482 		return status;
483 	urb->hcpriv = hcd;	/* Indicate it's queued */
484 
485 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
486 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
487 	wValue   = le16_to_cpu (cmd->wValue);
488 	wIndex   = le16_to_cpu (cmd->wIndex);
489 	wLength  = le16_to_cpu (cmd->wLength);
490 
491 	if (wLength > urb->transfer_buffer_length)
492 		goto error;
493 
494 	/*
495 	 * tbuf should be at least as big as the
496 	 * USB hub descriptor.
497 	 */
498 	tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
499 	tbuf = kzalloc(tbuf_size, GFP_KERNEL);
500 	if (!tbuf)
501 		return -ENOMEM;
502 
503 	bufp = tbuf;
504 
505 
506 	urb->actual_length = 0;
507 	switch (typeReq) {
508 
509 	/* DEVICE REQUESTS */
510 
511 	/* The root hub's remote wakeup enable bit is implemented using
512 	 * driver model wakeup flags.  If this system supports wakeup
513 	 * through USB, userspace may change the default "allow wakeup"
514 	 * policy through sysfs or these calls.
515 	 *
516 	 * Most root hubs support wakeup from downstream devices, for
517 	 * runtime power management (disabling USB clocks and reducing
518 	 * VBUS power usage).  However, not all of them do so; silicon,
519 	 * board, and BIOS bugs here are not uncommon, so these can't
520 	 * be treated quite like external hubs.
521 	 *
522 	 * Likewise, not all root hubs will pass wakeup events upstream,
523 	 * to wake up the whole system.  So don't assume root hub and
524 	 * controller capabilities are identical.
525 	 */
526 
527 	case DeviceRequest | USB_REQ_GET_STATUS:
528 		tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
529 					<< USB_DEVICE_REMOTE_WAKEUP)
530 				| (1 << USB_DEVICE_SELF_POWERED);
531 		tbuf[1] = 0;
532 		len = 2;
533 		break;
534 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
535 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
536 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
537 		else
538 			goto error;
539 		break;
540 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
541 		if (device_can_wakeup(&hcd->self.root_hub->dev)
542 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
543 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
544 		else
545 			goto error;
546 		break;
547 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
548 		tbuf[0] = 1;
549 		len = 1;
550 			/* FALLTHROUGH */
551 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
552 		break;
553 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
554 		switch (wValue & 0xff00) {
555 		case USB_DT_DEVICE << 8:
556 			switch (hcd->speed) {
557 			case HCD_USB3:
558 				bufp = usb3_rh_dev_descriptor;
559 				break;
560 			case HCD_USB25:
561 				bufp = usb25_rh_dev_descriptor;
562 				break;
563 			case HCD_USB2:
564 				bufp = usb2_rh_dev_descriptor;
565 				break;
566 			case HCD_USB11:
567 				bufp = usb11_rh_dev_descriptor;
568 				break;
569 			default:
570 				goto error;
571 			}
572 			len = 18;
573 			if (hcd->has_tt)
574 				patch_protocol = 1;
575 			break;
576 		case USB_DT_CONFIG << 8:
577 			switch (hcd->speed) {
578 			case HCD_USB3:
579 				bufp = ss_rh_config_descriptor;
580 				len = sizeof ss_rh_config_descriptor;
581 				break;
582 			case HCD_USB25:
583 			case HCD_USB2:
584 				bufp = hs_rh_config_descriptor;
585 				len = sizeof hs_rh_config_descriptor;
586 				break;
587 			case HCD_USB11:
588 				bufp = fs_rh_config_descriptor;
589 				len = sizeof fs_rh_config_descriptor;
590 				break;
591 			default:
592 				goto error;
593 			}
594 			if (device_can_wakeup(&hcd->self.root_hub->dev))
595 				patch_wakeup = 1;
596 			break;
597 		case USB_DT_STRING << 8:
598 			if ((wValue & 0xff) < 4)
599 				urb->actual_length = rh_string(wValue & 0xff,
600 						hcd, ubuf, wLength);
601 			else /* unsupported IDs --> "protocol stall" */
602 				goto error;
603 			break;
604 		case USB_DT_BOS << 8:
605 			goto nongeneric;
606 		default:
607 			goto error;
608 		}
609 		break;
610 	case DeviceRequest | USB_REQ_GET_INTERFACE:
611 		tbuf[0] = 0;
612 		len = 1;
613 			/* FALLTHROUGH */
614 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
615 		break;
616 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
617 		/* wValue == urb->dev->devaddr */
618 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
619 			wValue);
620 		break;
621 
622 	/* INTERFACE REQUESTS (no defined feature/status flags) */
623 
624 	/* ENDPOINT REQUESTS */
625 
626 	case EndpointRequest | USB_REQ_GET_STATUS:
627 		/* ENDPOINT_HALT flag */
628 		tbuf[0] = 0;
629 		tbuf[1] = 0;
630 		len = 2;
631 			/* FALLTHROUGH */
632 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
633 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
634 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
635 		break;
636 
637 	/* CLASS REQUESTS (and errors) */
638 
639 	default:
640 nongeneric:
641 		/* non-generic request */
642 		switch (typeReq) {
643 		case GetHubStatus:
644 		case GetPortStatus:
645 			len = 4;
646 			break;
647 		case GetHubDescriptor:
648 			len = sizeof (struct usb_hub_descriptor);
649 			break;
650 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
651 			/* len is returned by hub_control */
652 			break;
653 		}
654 		status = hcd->driver->hub_control (hcd,
655 			typeReq, wValue, wIndex,
656 			tbuf, wLength);
657 
658 		if (typeReq == GetHubDescriptor)
659 			usb_hub_adjust_deviceremovable(hcd->self.root_hub,
660 				(struct usb_hub_descriptor *)tbuf);
661 		break;
662 error:
663 		/* "protocol stall" on error */
664 		status = -EPIPE;
665 	}
666 
667 	if (status < 0) {
668 		len = 0;
669 		if (status != -EPIPE) {
670 			dev_dbg (hcd->self.controller,
671 				"CTRL: TypeReq=0x%x val=0x%x "
672 				"idx=0x%x len=%d ==> %d\n",
673 				typeReq, wValue, wIndex,
674 				wLength, status);
675 		}
676 	} else if (status > 0) {
677 		/* hub_control may return the length of data copied. */
678 		len = status;
679 		status = 0;
680 	}
681 	if (len) {
682 		if (urb->transfer_buffer_length < len)
683 			len = urb->transfer_buffer_length;
684 		urb->actual_length = len;
685 		/* always USB_DIR_IN, toward host */
686 		memcpy (ubuf, bufp, len);
687 
688 		/* report whether RH hardware supports remote wakeup */
689 		if (patch_wakeup &&
690 				len > offsetof (struct usb_config_descriptor,
691 						bmAttributes))
692 			((struct usb_config_descriptor *)ubuf)->bmAttributes
693 				|= USB_CONFIG_ATT_WAKEUP;
694 
695 		/* report whether RH hardware has an integrated TT */
696 		if (patch_protocol &&
697 				len > offsetof(struct usb_device_descriptor,
698 						bDeviceProtocol))
699 			((struct usb_device_descriptor *) ubuf)->
700 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
701 	}
702 
703 	kfree(tbuf);
704 
705 	/* any errors get returned through the urb completion */
706 	spin_lock_irq(&hcd_root_hub_lock);
707 	usb_hcd_unlink_urb_from_ep(hcd, urb);
708 	usb_hcd_giveback_urb(hcd, urb, status);
709 	spin_unlock_irq(&hcd_root_hub_lock);
710 	return 0;
711 }
712 
713 /*-------------------------------------------------------------------------*/
714 
715 /*
716  * Root Hub interrupt transfers are polled using a timer if the
717  * driver requests it; otherwise the driver is responsible for
718  * calling usb_hcd_poll_rh_status() when an event occurs.
719  *
720  * Completions are called in_interrupt(), but they may or may not
721  * be in_irq().
722  */
723 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
724 {
725 	struct urb	*urb;
726 	int		length;
727 	unsigned long	flags;
728 	char		buffer[6];	/* Any root hubs with > 31 ports? */
729 
730 	if (unlikely(!hcd->rh_pollable))
731 		return;
732 	if (!hcd->uses_new_polling && !hcd->status_urb)
733 		return;
734 
735 	length = hcd->driver->hub_status_data(hcd, buffer);
736 	if (length > 0) {
737 
738 		/* try to complete the status urb */
739 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
740 		urb = hcd->status_urb;
741 		if (urb) {
742 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
743 			hcd->status_urb = NULL;
744 			urb->actual_length = length;
745 			memcpy(urb->transfer_buffer, buffer, length);
746 
747 			usb_hcd_unlink_urb_from_ep(hcd, urb);
748 			usb_hcd_giveback_urb(hcd, urb, 0);
749 		} else {
750 			length = 0;
751 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
752 		}
753 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
754 	}
755 
756 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
757 	 * exceed that limit if HZ is 100. The math is more clunky than
758 	 * maybe expected, this is to make sure that all timers for USB devices
759 	 * fire at the same time to give the CPU a break in between */
760 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
761 			(length == 0 && hcd->status_urb != NULL))
762 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
763 }
764 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
765 
766 /* timer callback */
767 static void rh_timer_func (unsigned long _hcd)
768 {
769 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
770 }
771 
772 /*-------------------------------------------------------------------------*/
773 
774 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
775 {
776 	int		retval;
777 	unsigned long	flags;
778 	unsigned	len = 1 + (urb->dev->maxchild / 8);
779 
780 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
781 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
782 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
783 		retval = -EINVAL;
784 		goto done;
785 	}
786 
787 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
788 	if (retval)
789 		goto done;
790 
791 	hcd->status_urb = urb;
792 	urb->hcpriv = hcd;	/* indicate it's queued */
793 	if (!hcd->uses_new_polling)
794 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
795 
796 	/* If a status change has already occurred, report it ASAP */
797 	else if (HCD_POLL_PENDING(hcd))
798 		mod_timer(&hcd->rh_timer, jiffies);
799 	retval = 0;
800  done:
801 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
802 	return retval;
803 }
804 
805 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
806 {
807 	if (usb_endpoint_xfer_int(&urb->ep->desc))
808 		return rh_queue_status (hcd, urb);
809 	if (usb_endpoint_xfer_control(&urb->ep->desc))
810 		return rh_call_control (hcd, urb);
811 	return -EINVAL;
812 }
813 
814 /*-------------------------------------------------------------------------*/
815 
816 /* Unlinks of root-hub control URBs are legal, but they don't do anything
817  * since these URBs always execute synchronously.
818  */
819 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
820 {
821 	unsigned long	flags;
822 	int		rc;
823 
824 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
825 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
826 	if (rc)
827 		goto done;
828 
829 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
830 		;	/* Do nothing */
831 
832 	} else {				/* Status URB */
833 		if (!hcd->uses_new_polling)
834 			del_timer (&hcd->rh_timer);
835 		if (urb == hcd->status_urb) {
836 			hcd->status_urb = NULL;
837 			usb_hcd_unlink_urb_from_ep(hcd, urb);
838 			usb_hcd_giveback_urb(hcd, urb, status);
839 		}
840 	}
841  done:
842 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
843 	return rc;
844 }
845 
846 
847 
848 /*
849  * Show & store the current value of authorized_default
850  */
851 static ssize_t authorized_default_show(struct device *dev,
852 				       struct device_attribute *attr, char *buf)
853 {
854 	struct usb_device *rh_usb_dev = to_usb_device(dev);
855 	struct usb_bus *usb_bus = rh_usb_dev->bus;
856 	struct usb_hcd *usb_hcd;
857 
858 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
859 		return -ENODEV;
860 	usb_hcd = bus_to_hcd(usb_bus);
861 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
862 }
863 
864 static ssize_t authorized_default_store(struct device *dev,
865 					struct device_attribute *attr,
866 					const char *buf, size_t size)
867 {
868 	ssize_t result;
869 	unsigned val;
870 	struct usb_device *rh_usb_dev = to_usb_device(dev);
871 	struct usb_bus *usb_bus = rh_usb_dev->bus;
872 	struct usb_hcd *usb_hcd;
873 
874 	if (usb_bus == NULL)	/* FIXME: not sure if this case is possible */
875 		return -ENODEV;
876 	usb_hcd = bus_to_hcd(usb_bus);
877 	result = sscanf(buf, "%u\n", &val);
878 	if (result == 1) {
879 		usb_hcd->authorized_default = val ? 1 : 0;
880 		result = size;
881 	} else {
882 		result = -EINVAL;
883 	}
884 	return result;
885 }
886 static DEVICE_ATTR_RW(authorized_default);
887 
888 /* Group all the USB bus attributes */
889 static struct attribute *usb_bus_attrs[] = {
890 		&dev_attr_authorized_default.attr,
891 		NULL,
892 };
893 
894 static struct attribute_group usb_bus_attr_group = {
895 	.name = NULL,	/* we want them in the same directory */
896 	.attrs = usb_bus_attrs,
897 };
898 
899 
900 
901 /*-------------------------------------------------------------------------*/
902 
903 /**
904  * usb_bus_init - shared initialization code
905  * @bus: the bus structure being initialized
906  *
907  * This code is used to initialize a usb_bus structure, memory for which is
908  * separately managed.
909  */
910 static void usb_bus_init (struct usb_bus *bus)
911 {
912 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
913 
914 	bus->devnum_next = 1;
915 
916 	bus->root_hub = NULL;
917 	bus->busnum = -1;
918 	bus->bandwidth_allocated = 0;
919 	bus->bandwidth_int_reqs  = 0;
920 	bus->bandwidth_isoc_reqs = 0;
921 
922 	INIT_LIST_HEAD (&bus->bus_list);
923 }
924 
925 /*-------------------------------------------------------------------------*/
926 
927 /**
928  * usb_register_bus - registers the USB host controller with the usb core
929  * @bus: pointer to the bus to register
930  * Context: !in_interrupt()
931  *
932  * Assigns a bus number, and links the controller into usbcore data
933  * structures so that it can be seen by scanning the bus list.
934  *
935  * Return: 0 if successful. A negative error code otherwise.
936  */
937 static int usb_register_bus(struct usb_bus *bus)
938 {
939 	int result = -E2BIG;
940 	int busnum;
941 
942 	mutex_lock(&usb_bus_list_lock);
943 	busnum = find_next_zero_bit(busmap, USB_MAXBUS, 1);
944 	if (busnum >= USB_MAXBUS) {
945 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
946 		goto error_find_busnum;
947 	}
948 	set_bit(busnum, busmap);
949 	bus->busnum = busnum;
950 
951 	/* Add it to the local list of buses */
952 	list_add (&bus->bus_list, &usb_bus_list);
953 	mutex_unlock(&usb_bus_list_lock);
954 
955 	usb_notify_add_bus(bus);
956 
957 	dev_info (bus->controller, "new USB bus registered, assigned bus "
958 		  "number %d\n", bus->busnum);
959 	return 0;
960 
961 error_find_busnum:
962 	mutex_unlock(&usb_bus_list_lock);
963 	return result;
964 }
965 
966 /**
967  * usb_deregister_bus - deregisters the USB host controller
968  * @bus: pointer to the bus to deregister
969  * Context: !in_interrupt()
970  *
971  * Recycles the bus number, and unlinks the controller from usbcore data
972  * structures so that it won't be seen by scanning the bus list.
973  */
974 static void usb_deregister_bus (struct usb_bus *bus)
975 {
976 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
977 
978 	/*
979 	 * NOTE: make sure that all the devices are removed by the
980 	 * controller code, as well as having it call this when cleaning
981 	 * itself up
982 	 */
983 	mutex_lock(&usb_bus_list_lock);
984 	list_del (&bus->bus_list);
985 	mutex_unlock(&usb_bus_list_lock);
986 
987 	usb_notify_remove_bus(bus);
988 
989 	clear_bit(bus->busnum, busmap);
990 }
991 
992 /**
993  * register_root_hub - called by usb_add_hcd() to register a root hub
994  * @hcd: host controller for this root hub
995  *
996  * This function registers the root hub with the USB subsystem.  It sets up
997  * the device properly in the device tree and then calls usb_new_device()
998  * to register the usb device.  It also assigns the root hub's USB address
999  * (always 1).
1000  *
1001  * Return: 0 if successful. A negative error code otherwise.
1002  */
1003 static int register_root_hub(struct usb_hcd *hcd)
1004 {
1005 	struct device *parent_dev = hcd->self.controller;
1006 	struct usb_device *usb_dev = hcd->self.root_hub;
1007 	const int devnum = 1;
1008 	int retval;
1009 
1010 	usb_dev->devnum = devnum;
1011 	usb_dev->bus->devnum_next = devnum + 1;
1012 	memset (&usb_dev->bus->devmap.devicemap, 0,
1013 			sizeof usb_dev->bus->devmap.devicemap);
1014 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1015 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1016 
1017 	mutex_lock(&usb_bus_list_lock);
1018 
1019 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1020 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1021 	if (retval != sizeof usb_dev->descriptor) {
1022 		mutex_unlock(&usb_bus_list_lock);
1023 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1024 				dev_name(&usb_dev->dev), retval);
1025 		return (retval < 0) ? retval : -EMSGSIZE;
1026 	}
1027 	if (usb_dev->speed == USB_SPEED_SUPER) {
1028 		retval = usb_get_bos_descriptor(usb_dev);
1029 		if (retval < 0) {
1030 			mutex_unlock(&usb_bus_list_lock);
1031 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1032 					dev_name(&usb_dev->dev), retval);
1033 			return retval;
1034 		}
1035 		usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1036 	}
1037 
1038 	retval = usb_new_device (usb_dev);
1039 	if (retval) {
1040 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1041 				dev_name(&usb_dev->dev), retval);
1042 	} else {
1043 		spin_lock_irq (&hcd_root_hub_lock);
1044 		hcd->rh_registered = 1;
1045 		spin_unlock_irq (&hcd_root_hub_lock);
1046 
1047 		/* Did the HC die before the root hub was registered? */
1048 		if (HCD_DEAD(hcd))
1049 			usb_hc_died (hcd);	/* This time clean up */
1050 	}
1051 	mutex_unlock(&usb_bus_list_lock);
1052 
1053 	return retval;
1054 }
1055 
1056 /*
1057  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1058  * @bus: the bus which the root hub belongs to
1059  * @portnum: the port which is being resumed
1060  *
1061  * HCDs should call this function when they know that a resume signal is
1062  * being sent to a root-hub port.  The root hub will be prevented from
1063  * going into autosuspend until usb_hcd_end_port_resume() is called.
1064  *
1065  * The bus's private lock must be held by the caller.
1066  */
1067 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1068 {
1069 	unsigned bit = 1 << portnum;
1070 
1071 	if (!(bus->resuming_ports & bit)) {
1072 		bus->resuming_ports |= bit;
1073 		pm_runtime_get_noresume(&bus->root_hub->dev);
1074 	}
1075 }
1076 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1077 
1078 /*
1079  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1080  * @bus: the bus which the root hub belongs to
1081  * @portnum: the port which is being resumed
1082  *
1083  * HCDs should call this function when they know that a resume signal has
1084  * stopped being sent to a root-hub port.  The root hub will be allowed to
1085  * autosuspend again.
1086  *
1087  * The bus's private lock must be held by the caller.
1088  */
1089 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1090 {
1091 	unsigned bit = 1 << portnum;
1092 
1093 	if (bus->resuming_ports & bit) {
1094 		bus->resuming_ports &= ~bit;
1095 		pm_runtime_put_noidle(&bus->root_hub->dev);
1096 	}
1097 }
1098 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1099 
1100 /*-------------------------------------------------------------------------*/
1101 
1102 /**
1103  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1104  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1105  * @is_input: true iff the transaction sends data to the host
1106  * @isoc: true for isochronous transactions, false for interrupt ones
1107  * @bytecount: how many bytes in the transaction.
1108  *
1109  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1110  *
1111  * Note:
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  * Return: 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  * Return: 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 addressable
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 static void __usb_hcd_giveback_urb(struct urb *urb)
1652 {
1653 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1654 	struct usb_anchor *anchor = urb->anchor;
1655 	int status = urb->unlinked;
1656 	unsigned long flags;
1657 
1658 	urb->hcpriv = NULL;
1659 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1660 	    urb->actual_length < urb->transfer_buffer_length &&
1661 	    !status))
1662 		status = -EREMOTEIO;
1663 
1664 	unmap_urb_for_dma(hcd, urb);
1665 	usbmon_urb_complete(&hcd->self, urb, status);
1666 	usb_anchor_suspend_wakeups(anchor);
1667 	usb_unanchor_urb(urb);
1668 
1669 	/* pass ownership to the completion handler */
1670 	urb->status = status;
1671 
1672 	/*
1673 	 * We disable local IRQs here avoid possible deadlock because
1674 	 * drivers may call spin_lock() to hold lock which might be
1675 	 * acquired in one hard interrupt handler.
1676 	 *
1677 	 * The local_irq_save()/local_irq_restore() around complete()
1678 	 * will be removed if current USB drivers have been cleaned up
1679 	 * and no one may trigger the above deadlock situation when
1680 	 * running complete() in tasklet.
1681 	 */
1682 	local_irq_save(flags);
1683 	urb->complete(urb);
1684 	local_irq_restore(flags);
1685 
1686 	usb_anchor_resume_wakeups(anchor);
1687 	atomic_dec(&urb->use_count);
1688 	if (unlikely(atomic_read(&urb->reject)))
1689 		wake_up(&usb_kill_urb_queue);
1690 	usb_put_urb(urb);
1691 }
1692 
1693 static void usb_giveback_urb_bh(unsigned long param)
1694 {
1695 	struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1696 	struct list_head local_list;
1697 
1698 	spin_lock_irq(&bh->lock);
1699 	bh->running = true;
1700  restart:
1701 	list_replace_init(&bh->head, &local_list);
1702 	spin_unlock_irq(&bh->lock);
1703 
1704 	while (!list_empty(&local_list)) {
1705 		struct urb *urb;
1706 
1707 		urb = list_entry(local_list.next, struct urb, urb_list);
1708 		list_del_init(&urb->urb_list);
1709 		bh->completing_ep = urb->ep;
1710 		__usb_hcd_giveback_urb(urb);
1711 		bh->completing_ep = NULL;
1712 	}
1713 
1714 	/* check if there are new URBs to giveback */
1715 	spin_lock_irq(&bh->lock);
1716 	if (!list_empty(&bh->head))
1717 		goto restart;
1718 	bh->running = false;
1719 	spin_unlock_irq(&bh->lock);
1720 }
1721 
1722 /**
1723  * usb_hcd_giveback_urb - return URB from HCD to device driver
1724  * @hcd: host controller returning the URB
1725  * @urb: urb being returned to the USB device driver.
1726  * @status: completion status code for the URB.
1727  * Context: in_interrupt()
1728  *
1729  * This hands the URB from HCD to its USB device driver, using its
1730  * completion function.  The HCD has freed all per-urb resources
1731  * (and is done using urb->hcpriv).  It also released all HCD locks;
1732  * the device driver won't cause problems if it frees, modifies,
1733  * or resubmits this URB.
1734  *
1735  * If @urb was unlinked, the value of @status will be overridden by
1736  * @urb->unlinked.  Erroneous short transfers are detected in case
1737  * the HCD hasn't checked for them.
1738  */
1739 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1740 {
1741 	struct giveback_urb_bh *bh;
1742 	bool running, high_prio_bh;
1743 
1744 	/* pass status to tasklet via unlinked */
1745 	if (likely(!urb->unlinked))
1746 		urb->unlinked = status;
1747 
1748 	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1749 		__usb_hcd_giveback_urb(urb);
1750 		return;
1751 	}
1752 
1753 	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1754 		bh = &hcd->high_prio_bh;
1755 		high_prio_bh = true;
1756 	} else {
1757 		bh = &hcd->low_prio_bh;
1758 		high_prio_bh = false;
1759 	}
1760 
1761 	spin_lock(&bh->lock);
1762 	list_add_tail(&urb->urb_list, &bh->head);
1763 	running = bh->running;
1764 	spin_unlock(&bh->lock);
1765 
1766 	if (running)
1767 		;
1768 	else if (high_prio_bh)
1769 		tasklet_hi_schedule(&bh->bh);
1770 	else
1771 		tasklet_schedule(&bh->bh);
1772 }
1773 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1774 
1775 /*-------------------------------------------------------------------------*/
1776 
1777 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1778  * queue to drain completely.  The caller must first insure that no more
1779  * URBs can be submitted for this endpoint.
1780  */
1781 void usb_hcd_flush_endpoint(struct usb_device *udev,
1782 		struct usb_host_endpoint *ep)
1783 {
1784 	struct usb_hcd		*hcd;
1785 	struct urb		*urb;
1786 
1787 	if (!ep)
1788 		return;
1789 	might_sleep();
1790 	hcd = bus_to_hcd(udev->bus);
1791 
1792 	/* No more submits can occur */
1793 	spin_lock_irq(&hcd_urb_list_lock);
1794 rescan:
1795 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1796 		int	is_in;
1797 
1798 		if (urb->unlinked)
1799 			continue;
1800 		usb_get_urb (urb);
1801 		is_in = usb_urb_dir_in(urb);
1802 		spin_unlock(&hcd_urb_list_lock);
1803 
1804 		/* kick hcd */
1805 		unlink1(hcd, urb, -ESHUTDOWN);
1806 		dev_dbg (hcd->self.controller,
1807 			"shutdown urb %p ep%d%s%s\n",
1808 			urb, usb_endpoint_num(&ep->desc),
1809 			is_in ? "in" : "out",
1810 			({	char *s;
1811 
1812 				 switch (usb_endpoint_type(&ep->desc)) {
1813 				 case USB_ENDPOINT_XFER_CONTROL:
1814 					s = ""; break;
1815 				 case USB_ENDPOINT_XFER_BULK:
1816 					s = "-bulk"; break;
1817 				 case USB_ENDPOINT_XFER_INT:
1818 					s = "-intr"; break;
1819 				 default:
1820 					s = "-iso"; break;
1821 				};
1822 				s;
1823 			}));
1824 		usb_put_urb (urb);
1825 
1826 		/* list contents may have changed */
1827 		spin_lock(&hcd_urb_list_lock);
1828 		goto rescan;
1829 	}
1830 	spin_unlock_irq(&hcd_urb_list_lock);
1831 
1832 	/* Wait until the endpoint queue is completely empty */
1833 	while (!list_empty (&ep->urb_list)) {
1834 		spin_lock_irq(&hcd_urb_list_lock);
1835 
1836 		/* The list may have changed while we acquired the spinlock */
1837 		urb = NULL;
1838 		if (!list_empty (&ep->urb_list)) {
1839 			urb = list_entry (ep->urb_list.prev, struct urb,
1840 					urb_list);
1841 			usb_get_urb (urb);
1842 		}
1843 		spin_unlock_irq(&hcd_urb_list_lock);
1844 
1845 		if (urb) {
1846 			usb_kill_urb (urb);
1847 			usb_put_urb (urb);
1848 		}
1849 	}
1850 }
1851 
1852 /**
1853  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1854  *				the bus bandwidth
1855  * @udev: target &usb_device
1856  * @new_config: new configuration to install
1857  * @cur_alt: the current alternate interface setting
1858  * @new_alt: alternate interface setting that is being installed
1859  *
1860  * To change configurations, pass in the new configuration in new_config,
1861  * and pass NULL for cur_alt and new_alt.
1862  *
1863  * To reset a device's configuration (put the device in the ADDRESSED state),
1864  * pass in NULL for new_config, cur_alt, and new_alt.
1865  *
1866  * To change alternate interface settings, pass in NULL for new_config,
1867  * pass in the current alternate interface setting in cur_alt,
1868  * and pass in the new alternate interface setting in new_alt.
1869  *
1870  * Return: An error if the requested bandwidth change exceeds the
1871  * bus bandwidth or host controller internal resources.
1872  */
1873 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1874 		struct usb_host_config *new_config,
1875 		struct usb_host_interface *cur_alt,
1876 		struct usb_host_interface *new_alt)
1877 {
1878 	int num_intfs, i, j;
1879 	struct usb_host_interface *alt = NULL;
1880 	int ret = 0;
1881 	struct usb_hcd *hcd;
1882 	struct usb_host_endpoint *ep;
1883 
1884 	hcd = bus_to_hcd(udev->bus);
1885 	if (!hcd->driver->check_bandwidth)
1886 		return 0;
1887 
1888 	/* Configuration is being removed - set configuration 0 */
1889 	if (!new_config && !cur_alt) {
1890 		for (i = 1; i < 16; ++i) {
1891 			ep = udev->ep_out[i];
1892 			if (ep)
1893 				hcd->driver->drop_endpoint(hcd, udev, ep);
1894 			ep = udev->ep_in[i];
1895 			if (ep)
1896 				hcd->driver->drop_endpoint(hcd, udev, ep);
1897 		}
1898 		hcd->driver->check_bandwidth(hcd, udev);
1899 		return 0;
1900 	}
1901 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1902 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1903 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1904 	 * ok to exclude it.
1905 	 */
1906 	if (new_config) {
1907 		num_intfs = new_config->desc.bNumInterfaces;
1908 		/* Remove endpoints (except endpoint 0, which is always on the
1909 		 * schedule) from the old config from the schedule
1910 		 */
1911 		for (i = 1; i < 16; ++i) {
1912 			ep = udev->ep_out[i];
1913 			if (ep) {
1914 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1915 				if (ret < 0)
1916 					goto reset;
1917 			}
1918 			ep = udev->ep_in[i];
1919 			if (ep) {
1920 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1921 				if (ret < 0)
1922 					goto reset;
1923 			}
1924 		}
1925 		for (i = 0; i < num_intfs; ++i) {
1926 			struct usb_host_interface *first_alt;
1927 			int iface_num;
1928 
1929 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1930 			iface_num = first_alt->desc.bInterfaceNumber;
1931 			/* Set up endpoints for alternate interface setting 0 */
1932 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1933 			if (!alt)
1934 				/* No alt setting 0? Pick the first setting. */
1935 				alt = first_alt;
1936 
1937 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1938 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1939 				if (ret < 0)
1940 					goto reset;
1941 			}
1942 		}
1943 	}
1944 	if (cur_alt && new_alt) {
1945 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1946 				cur_alt->desc.bInterfaceNumber);
1947 
1948 		if (!iface)
1949 			return -EINVAL;
1950 		if (iface->resetting_device) {
1951 			/*
1952 			 * The USB core just reset the device, so the xHCI host
1953 			 * and the device will think alt setting 0 is installed.
1954 			 * However, the USB core will pass in the alternate
1955 			 * setting installed before the reset as cur_alt.  Dig
1956 			 * out the alternate setting 0 structure, or the first
1957 			 * alternate setting if a broken device doesn't have alt
1958 			 * setting 0.
1959 			 */
1960 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1961 			if (!cur_alt)
1962 				cur_alt = &iface->altsetting[0];
1963 		}
1964 
1965 		/* Drop all the endpoints in the current alt setting */
1966 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1967 			ret = hcd->driver->drop_endpoint(hcd, udev,
1968 					&cur_alt->endpoint[i]);
1969 			if (ret < 0)
1970 				goto reset;
1971 		}
1972 		/* Add all the endpoints in the new alt setting */
1973 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1974 			ret = hcd->driver->add_endpoint(hcd, udev,
1975 					&new_alt->endpoint[i]);
1976 			if (ret < 0)
1977 				goto reset;
1978 		}
1979 	}
1980 	ret = hcd->driver->check_bandwidth(hcd, udev);
1981 reset:
1982 	if (ret < 0)
1983 		hcd->driver->reset_bandwidth(hcd, udev);
1984 	return ret;
1985 }
1986 
1987 /* Disables the endpoint: synchronizes with the hcd to make sure all
1988  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1989  * have been called previously.  Use for set_configuration, set_interface,
1990  * driver removal, physical disconnect.
1991  *
1992  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1993  * type, maxpacket size, toggle, halt status, and scheduling.
1994  */
1995 void usb_hcd_disable_endpoint(struct usb_device *udev,
1996 		struct usb_host_endpoint *ep)
1997 {
1998 	struct usb_hcd		*hcd;
1999 
2000 	might_sleep();
2001 	hcd = bus_to_hcd(udev->bus);
2002 	if (hcd->driver->endpoint_disable)
2003 		hcd->driver->endpoint_disable(hcd, ep);
2004 }
2005 
2006 /**
2007  * usb_hcd_reset_endpoint - reset host endpoint state
2008  * @udev: USB device.
2009  * @ep:   the endpoint to reset.
2010  *
2011  * Resets any host endpoint state such as the toggle bit, sequence
2012  * number and current window.
2013  */
2014 void usb_hcd_reset_endpoint(struct usb_device *udev,
2015 			    struct usb_host_endpoint *ep)
2016 {
2017 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2018 
2019 	if (hcd->driver->endpoint_reset)
2020 		hcd->driver->endpoint_reset(hcd, ep);
2021 	else {
2022 		int epnum = usb_endpoint_num(&ep->desc);
2023 		int is_out = usb_endpoint_dir_out(&ep->desc);
2024 		int is_control = usb_endpoint_xfer_control(&ep->desc);
2025 
2026 		usb_settoggle(udev, epnum, is_out, 0);
2027 		if (is_control)
2028 			usb_settoggle(udev, epnum, !is_out, 0);
2029 	}
2030 }
2031 
2032 /**
2033  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2034  * @interface:		alternate setting that includes all endpoints.
2035  * @eps:		array of endpoints that need streams.
2036  * @num_eps:		number of endpoints in the array.
2037  * @num_streams:	number of streams to allocate.
2038  * @mem_flags:		flags hcd should use to allocate memory.
2039  *
2040  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2041  * Drivers may queue multiple transfers to different stream IDs, which may
2042  * complete in a different order than they were queued.
2043  *
2044  * Return: On success, the number of allocated streams. On failure, a negative
2045  * error code.
2046  */
2047 int usb_alloc_streams(struct usb_interface *interface,
2048 		struct usb_host_endpoint **eps, unsigned int num_eps,
2049 		unsigned int num_streams, gfp_t mem_flags)
2050 {
2051 	struct usb_hcd *hcd;
2052 	struct usb_device *dev;
2053 	int i;
2054 
2055 	dev = interface_to_usbdev(interface);
2056 	hcd = bus_to_hcd(dev->bus);
2057 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2058 		return -EINVAL;
2059 	if (dev->speed != USB_SPEED_SUPER)
2060 		return -EINVAL;
2061 
2062 	/* Streams only apply to bulk endpoints. */
2063 	for (i = 0; i < num_eps; i++)
2064 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2065 			return -EINVAL;
2066 
2067 	return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2068 			num_streams, mem_flags);
2069 }
2070 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2071 
2072 /**
2073  * usb_free_streams - free bulk endpoint stream IDs.
2074  * @interface:	alternate setting that includes all endpoints.
2075  * @eps:	array of endpoints to remove streams from.
2076  * @num_eps:	number of endpoints in the array.
2077  * @mem_flags:	flags hcd should use to allocate memory.
2078  *
2079  * Reverts a group of bulk endpoints back to not using stream IDs.
2080  * Can fail if we are given bad arguments, or HCD is broken.
2081  *
2082  * Return: On success, the number of allocated streams. On failure, a negative
2083  * error code.
2084  */
2085 int usb_free_streams(struct usb_interface *interface,
2086 		struct usb_host_endpoint **eps, unsigned int num_eps,
2087 		gfp_t mem_flags)
2088 {
2089 	struct usb_hcd *hcd;
2090 	struct usb_device *dev;
2091 	int i;
2092 
2093 	dev = interface_to_usbdev(interface);
2094 	hcd = bus_to_hcd(dev->bus);
2095 	if (dev->speed != USB_SPEED_SUPER)
2096 		return -EINVAL;
2097 
2098 	/* Streams only apply to bulk endpoints. */
2099 	for (i = 0; i < num_eps; i++)
2100 		if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
2101 			return -EINVAL;
2102 
2103 	return hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2104 }
2105 EXPORT_SYMBOL_GPL(usb_free_streams);
2106 
2107 /* Protect against drivers that try to unlink URBs after the device
2108  * is gone, by waiting until all unlinks for @udev are finished.
2109  * Since we don't currently track URBs by device, simply wait until
2110  * nothing is running in the locked region of usb_hcd_unlink_urb().
2111  */
2112 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2113 {
2114 	spin_lock_irq(&hcd_urb_unlink_lock);
2115 	spin_unlock_irq(&hcd_urb_unlink_lock);
2116 }
2117 
2118 /*-------------------------------------------------------------------------*/
2119 
2120 /* called in any context */
2121 int usb_hcd_get_frame_number (struct usb_device *udev)
2122 {
2123 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2124 
2125 	if (!HCD_RH_RUNNING(hcd))
2126 		return -ESHUTDOWN;
2127 	return hcd->driver->get_frame_number (hcd);
2128 }
2129 
2130 /*-------------------------------------------------------------------------*/
2131 
2132 #ifdef	CONFIG_PM
2133 
2134 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2135 {
2136 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2137 	int		status;
2138 	int		old_state = hcd->state;
2139 
2140 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2141 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2142 			rhdev->do_remote_wakeup);
2143 	if (HCD_DEAD(hcd)) {
2144 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2145 		return 0;
2146 	}
2147 
2148 	if (!hcd->driver->bus_suspend) {
2149 		status = -ENOENT;
2150 	} else {
2151 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2152 		hcd->state = HC_STATE_QUIESCING;
2153 		status = hcd->driver->bus_suspend(hcd);
2154 	}
2155 	if (status == 0) {
2156 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2157 		hcd->state = HC_STATE_SUSPENDED;
2158 
2159 		/* Did we race with a root-hub wakeup event? */
2160 		if (rhdev->do_remote_wakeup) {
2161 			char	buffer[6];
2162 
2163 			status = hcd->driver->hub_status_data(hcd, buffer);
2164 			if (status != 0) {
2165 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2166 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2167 				status = -EBUSY;
2168 			}
2169 		}
2170 	} else {
2171 		spin_lock_irq(&hcd_root_hub_lock);
2172 		if (!HCD_DEAD(hcd)) {
2173 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2174 			hcd->state = old_state;
2175 		}
2176 		spin_unlock_irq(&hcd_root_hub_lock);
2177 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2178 				"suspend", status);
2179 	}
2180 	return status;
2181 }
2182 
2183 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2184 {
2185 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2186 	int		status;
2187 	int		old_state = hcd->state;
2188 
2189 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2190 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2191 	if (HCD_DEAD(hcd)) {
2192 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2193 		return 0;
2194 	}
2195 	if (!hcd->driver->bus_resume)
2196 		return -ENOENT;
2197 	if (HCD_RH_RUNNING(hcd))
2198 		return 0;
2199 
2200 	hcd->state = HC_STATE_RESUMING;
2201 	status = hcd->driver->bus_resume(hcd);
2202 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2203 	if (status == 0) {
2204 		struct usb_device *udev;
2205 		int port1;
2206 
2207 		spin_lock_irq(&hcd_root_hub_lock);
2208 		if (!HCD_DEAD(hcd)) {
2209 			usb_set_device_state(rhdev, rhdev->actconfig
2210 					? USB_STATE_CONFIGURED
2211 					: USB_STATE_ADDRESS);
2212 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2213 			hcd->state = HC_STATE_RUNNING;
2214 		}
2215 		spin_unlock_irq(&hcd_root_hub_lock);
2216 
2217 		/*
2218 		 * Check whether any of the enabled ports on the root hub are
2219 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2220 		 * (this is what the USB-2 spec calls a "global resume").
2221 		 * Otherwise we can skip the delay.
2222 		 */
2223 		usb_hub_for_each_child(rhdev, port1, udev) {
2224 			if (udev->state != USB_STATE_NOTATTACHED &&
2225 					!udev->port_is_suspended) {
2226 				usleep_range(10000, 11000);	/* TRSMRCY */
2227 				break;
2228 			}
2229 		}
2230 	} else {
2231 		hcd->state = old_state;
2232 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2233 				"resume", status);
2234 		if (status != -ESHUTDOWN)
2235 			usb_hc_died(hcd);
2236 	}
2237 	return status;
2238 }
2239 
2240 #endif	/* CONFIG_PM */
2241 
2242 #ifdef	CONFIG_PM_RUNTIME
2243 
2244 /* Workqueue routine for root-hub remote wakeup */
2245 static void hcd_resume_work(struct work_struct *work)
2246 {
2247 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2248 	struct usb_device *udev = hcd->self.root_hub;
2249 
2250 	usb_lock_device(udev);
2251 	usb_remote_wakeup(udev);
2252 	usb_unlock_device(udev);
2253 }
2254 
2255 /**
2256  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2257  * @hcd: host controller for this root hub
2258  *
2259  * The USB host controller calls this function when its root hub is
2260  * suspended (with the remote wakeup feature enabled) and a remote
2261  * wakeup request is received.  The routine submits a workqueue request
2262  * to resume the root hub (that is, manage its downstream ports again).
2263  */
2264 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2265 {
2266 	unsigned long flags;
2267 
2268 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2269 	if (hcd->rh_registered) {
2270 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2271 		queue_work(pm_wq, &hcd->wakeup_work);
2272 	}
2273 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2274 }
2275 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2276 
2277 #endif	/* CONFIG_PM_RUNTIME */
2278 
2279 /*-------------------------------------------------------------------------*/
2280 
2281 #ifdef	CONFIG_USB_OTG
2282 
2283 /**
2284  * usb_bus_start_enum - start immediate enumeration (for OTG)
2285  * @bus: the bus (must use hcd framework)
2286  * @port_num: 1-based number of port; usually bus->otg_port
2287  * Context: in_interrupt()
2288  *
2289  * Starts enumeration, with an immediate reset followed later by
2290  * khubd identifying and possibly configuring the device.
2291  * This is needed by OTG controller drivers, where it helps meet
2292  * HNP protocol timing requirements for starting a port reset.
2293  *
2294  * Return: 0 if successful.
2295  */
2296 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2297 {
2298 	struct usb_hcd		*hcd;
2299 	int			status = -EOPNOTSUPP;
2300 
2301 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2302 	 * boards with root hubs hooked up to internal devices (instead of
2303 	 * just the OTG port) may need more attention to resetting...
2304 	 */
2305 	hcd = container_of (bus, struct usb_hcd, self);
2306 	if (port_num && hcd->driver->start_port_reset)
2307 		status = hcd->driver->start_port_reset(hcd, port_num);
2308 
2309 	/* run khubd shortly after (first) root port reset finishes;
2310 	 * it may issue others, until at least 50 msecs have passed.
2311 	 */
2312 	if (status == 0)
2313 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2314 	return status;
2315 }
2316 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2317 
2318 #endif
2319 
2320 /*-------------------------------------------------------------------------*/
2321 
2322 /**
2323  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2324  * @irq: the IRQ being raised
2325  * @__hcd: pointer to the HCD whose IRQ is being signaled
2326  *
2327  * If the controller isn't HALTed, calls the driver's irq handler.
2328  * Checks whether the controller is now dead.
2329  *
2330  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2331  */
2332 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2333 {
2334 	struct usb_hcd		*hcd = __hcd;
2335 	irqreturn_t		rc;
2336 
2337 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2338 		rc = IRQ_NONE;
2339 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2340 		rc = IRQ_NONE;
2341 	else
2342 		rc = IRQ_HANDLED;
2343 
2344 	return rc;
2345 }
2346 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2347 
2348 /*-------------------------------------------------------------------------*/
2349 
2350 /**
2351  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2352  * @hcd: pointer to the HCD representing the controller
2353  *
2354  * This is called by bus glue to report a USB host controller that died
2355  * while operations may still have been pending.  It's called automatically
2356  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2357  *
2358  * Only call this function with the primary HCD.
2359  */
2360 void usb_hc_died (struct usb_hcd *hcd)
2361 {
2362 	unsigned long flags;
2363 
2364 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2365 
2366 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2367 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2368 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2369 	if (hcd->rh_registered) {
2370 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2371 
2372 		/* make khubd clean up old urbs and devices */
2373 		usb_set_device_state (hcd->self.root_hub,
2374 				USB_STATE_NOTATTACHED);
2375 		usb_kick_khubd (hcd->self.root_hub);
2376 	}
2377 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2378 		hcd = hcd->shared_hcd;
2379 		if (hcd->rh_registered) {
2380 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2381 
2382 			/* make khubd clean up old urbs and devices */
2383 			usb_set_device_state(hcd->self.root_hub,
2384 					USB_STATE_NOTATTACHED);
2385 			usb_kick_khubd(hcd->self.root_hub);
2386 		}
2387 	}
2388 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2389 	/* Make sure that the other roothub is also deallocated. */
2390 }
2391 EXPORT_SYMBOL_GPL (usb_hc_died);
2392 
2393 /*-------------------------------------------------------------------------*/
2394 
2395 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2396 {
2397 
2398 	spin_lock_init(&bh->lock);
2399 	INIT_LIST_HEAD(&bh->head);
2400 	tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2401 }
2402 
2403 /**
2404  * usb_create_shared_hcd - create and initialize an HCD structure
2405  * @driver: HC driver that will use this hcd
2406  * @dev: device for this HC, stored in hcd->self.controller
2407  * @bus_name: value to store in hcd->self.bus_name
2408  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2409  *              PCI device.  Only allocate certain resources for the primary HCD
2410  * Context: !in_interrupt()
2411  *
2412  * Allocate a struct usb_hcd, with extra space at the end for the
2413  * HC driver's private data.  Initialize the generic members of the
2414  * hcd structure.
2415  *
2416  * Return: On success, a pointer to the created and initialized HCD structure.
2417  * On failure (e.g. if memory is unavailable), %NULL.
2418  */
2419 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2420 		struct device *dev, const char *bus_name,
2421 		struct usb_hcd *primary_hcd)
2422 {
2423 	struct usb_hcd *hcd;
2424 
2425 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2426 	if (!hcd) {
2427 		dev_dbg (dev, "hcd alloc failed\n");
2428 		return NULL;
2429 	}
2430 	if (primary_hcd == NULL) {
2431 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2432 				GFP_KERNEL);
2433 		if (!hcd->bandwidth_mutex) {
2434 			kfree(hcd);
2435 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2436 			return NULL;
2437 		}
2438 		mutex_init(hcd->bandwidth_mutex);
2439 		dev_set_drvdata(dev, hcd);
2440 	} else {
2441 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2442 		hcd->primary_hcd = primary_hcd;
2443 		primary_hcd->primary_hcd = primary_hcd;
2444 		hcd->shared_hcd = primary_hcd;
2445 		primary_hcd->shared_hcd = hcd;
2446 	}
2447 
2448 	kref_init(&hcd->kref);
2449 
2450 	usb_bus_init(&hcd->self);
2451 	hcd->self.controller = dev;
2452 	hcd->self.bus_name = bus_name;
2453 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2454 
2455 	init_timer(&hcd->rh_timer);
2456 	hcd->rh_timer.function = rh_timer_func;
2457 	hcd->rh_timer.data = (unsigned long) hcd;
2458 #ifdef CONFIG_PM_RUNTIME
2459 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2460 #endif
2461 
2462 	hcd->driver = driver;
2463 	hcd->speed = driver->flags & HCD_MASK;
2464 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2465 			"USB Host Controller";
2466 	return hcd;
2467 }
2468 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2469 
2470 /**
2471  * usb_create_hcd - create and initialize an HCD structure
2472  * @driver: HC driver that will use this hcd
2473  * @dev: device for this HC, stored in hcd->self.controller
2474  * @bus_name: value to store in hcd->self.bus_name
2475  * Context: !in_interrupt()
2476  *
2477  * Allocate a struct usb_hcd, with extra space at the end for the
2478  * HC driver's private data.  Initialize the generic members of the
2479  * hcd structure.
2480  *
2481  * Return: On success, a pointer to the created and initialized HCD
2482  * structure. On failure (e.g. if memory is unavailable), %NULL.
2483  */
2484 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2485 		struct device *dev, const char *bus_name)
2486 {
2487 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2488 }
2489 EXPORT_SYMBOL_GPL(usb_create_hcd);
2490 
2491 /*
2492  * Roothubs that share one PCI device must also share the bandwidth mutex.
2493  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2494  * deallocated.
2495  *
2496  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2497  * freed.  When hcd_release() is called for the non-primary HCD, set the
2498  * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2499  * freed shortly).
2500  */
2501 static void hcd_release (struct kref *kref)
2502 {
2503 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2504 
2505 	if (usb_hcd_is_primary_hcd(hcd))
2506 		kfree(hcd->bandwidth_mutex);
2507 	else
2508 		hcd->shared_hcd->shared_hcd = NULL;
2509 	kfree(hcd);
2510 }
2511 
2512 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2513 {
2514 	if (hcd)
2515 		kref_get (&hcd->kref);
2516 	return hcd;
2517 }
2518 EXPORT_SYMBOL_GPL(usb_get_hcd);
2519 
2520 void usb_put_hcd (struct usb_hcd *hcd)
2521 {
2522 	if (hcd)
2523 		kref_put (&hcd->kref, hcd_release);
2524 }
2525 EXPORT_SYMBOL_GPL(usb_put_hcd);
2526 
2527 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2528 {
2529 	if (!hcd->primary_hcd)
2530 		return 1;
2531 	return hcd == hcd->primary_hcd;
2532 }
2533 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2534 
2535 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2536 {
2537 	if (!hcd->driver->find_raw_port_number)
2538 		return port1;
2539 
2540 	return hcd->driver->find_raw_port_number(hcd, port1);
2541 }
2542 
2543 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2544 		unsigned int irqnum, unsigned long irqflags)
2545 {
2546 	int retval;
2547 
2548 	if (hcd->driver->irq) {
2549 
2550 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2551 				hcd->driver->description, hcd->self.busnum);
2552 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2553 				hcd->irq_descr, hcd);
2554 		if (retval != 0) {
2555 			dev_err(hcd->self.controller,
2556 					"request interrupt %d failed\n",
2557 					irqnum);
2558 			return retval;
2559 		}
2560 		hcd->irq = irqnum;
2561 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2562 				(hcd->driver->flags & HCD_MEMORY) ?
2563 					"io mem" : "io base",
2564 					(unsigned long long)hcd->rsrc_start);
2565 	} else {
2566 		hcd->irq = 0;
2567 		if (hcd->rsrc_start)
2568 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2569 					(hcd->driver->flags & HCD_MEMORY) ?
2570 					"io mem" : "io base",
2571 					(unsigned long long)hcd->rsrc_start);
2572 	}
2573 	return 0;
2574 }
2575 
2576 /**
2577  * usb_add_hcd - finish generic HCD structure initialization and register
2578  * @hcd: the usb_hcd structure to initialize
2579  * @irqnum: Interrupt line to allocate
2580  * @irqflags: Interrupt type flags
2581  *
2582  * Finish the remaining parts of generic HCD initialization: allocate the
2583  * buffers of consistent memory, register the bus, request the IRQ line,
2584  * and call the driver's reset() and start() routines.
2585  */
2586 int usb_add_hcd(struct usb_hcd *hcd,
2587 		unsigned int irqnum, unsigned long irqflags)
2588 {
2589 	int retval;
2590 	struct usb_device *rhdev;
2591 
2592 	if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->phy) {
2593 		struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0);
2594 
2595 		if (IS_ERR(phy)) {
2596 			retval = PTR_ERR(phy);
2597 			if (retval == -EPROBE_DEFER)
2598 				return retval;
2599 		} else {
2600 			retval = usb_phy_init(phy);
2601 			if (retval) {
2602 				usb_put_phy(phy);
2603 				return retval;
2604 			}
2605 			hcd->phy = phy;
2606 			hcd->remove_phy = 1;
2607 		}
2608 	}
2609 
2610 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2611 
2612 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2613 	if (authorized_default < 0 || authorized_default > 1)
2614 		hcd->authorized_default = hcd->wireless ? 0 : 1;
2615 	else
2616 		hcd->authorized_default = authorized_default;
2617 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2618 
2619 	/* HC is in reset state, but accessible.  Now do the one-time init,
2620 	 * bottom up so that hcds can customize the root hubs before khubd
2621 	 * starts talking to them.  (Note, bus id is assigned early too.)
2622 	 */
2623 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2624 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2625 		goto err_remove_phy;
2626 	}
2627 
2628 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2629 		goto err_register_bus;
2630 
2631 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2632 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2633 		retval = -ENOMEM;
2634 		goto err_allocate_root_hub;
2635 	}
2636 	hcd->self.root_hub = rhdev;
2637 
2638 	switch (hcd->speed) {
2639 	case HCD_USB11:
2640 		rhdev->speed = USB_SPEED_FULL;
2641 		break;
2642 	case HCD_USB2:
2643 		rhdev->speed = USB_SPEED_HIGH;
2644 		break;
2645 	case HCD_USB25:
2646 		rhdev->speed = USB_SPEED_WIRELESS;
2647 		break;
2648 	case HCD_USB3:
2649 		rhdev->speed = USB_SPEED_SUPER;
2650 		break;
2651 	default:
2652 		retval = -EINVAL;
2653 		goto err_set_rh_speed;
2654 	}
2655 
2656 	/* wakeup flag init defaults to "everything works" for root hubs,
2657 	 * but drivers can override it in reset() if needed, along with
2658 	 * recording the overall controller's system wakeup capability.
2659 	 */
2660 	device_set_wakeup_capable(&rhdev->dev, 1);
2661 
2662 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2663 	 * registered.  But since the controller can die at any time,
2664 	 * let's initialize the flag before touching the hardware.
2665 	 */
2666 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2667 
2668 	/* "reset" is misnamed; its role is now one-time init. the controller
2669 	 * should already have been reset (and boot firmware kicked off etc).
2670 	 */
2671 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2672 		dev_err(hcd->self.controller, "can't setup: %d\n", retval);
2673 		goto err_hcd_driver_setup;
2674 	}
2675 	hcd->rh_pollable = 1;
2676 
2677 	/* NOTE: root hub and controller capabilities may not be the same */
2678 	if (device_can_wakeup(hcd->self.controller)
2679 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2680 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2681 
2682 	/* initialize tasklets */
2683 	init_giveback_urb_bh(&hcd->high_prio_bh);
2684 	init_giveback_urb_bh(&hcd->low_prio_bh);
2685 
2686 	/* enable irqs just before we start the controller,
2687 	 * if the BIOS provides legacy PCI irqs.
2688 	 */
2689 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2690 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2691 		if (retval)
2692 			goto err_request_irq;
2693 	}
2694 
2695 	hcd->state = HC_STATE_RUNNING;
2696 	retval = hcd->driver->start(hcd);
2697 	if (retval < 0) {
2698 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2699 		goto err_hcd_driver_start;
2700 	}
2701 
2702 	/* starting here, usbcore will pay attention to this root hub */
2703 	if ((retval = register_root_hub(hcd)) != 0)
2704 		goto err_register_root_hub;
2705 
2706 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2707 	if (retval < 0) {
2708 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2709 		       retval);
2710 		goto error_create_attr_group;
2711 	}
2712 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2713 		usb_hcd_poll_rh_status(hcd);
2714 
2715 	return retval;
2716 
2717 error_create_attr_group:
2718 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2719 	if (HC_IS_RUNNING(hcd->state))
2720 		hcd->state = HC_STATE_QUIESCING;
2721 	spin_lock_irq(&hcd_root_hub_lock);
2722 	hcd->rh_registered = 0;
2723 	spin_unlock_irq(&hcd_root_hub_lock);
2724 
2725 #ifdef CONFIG_PM_RUNTIME
2726 	cancel_work_sync(&hcd->wakeup_work);
2727 #endif
2728 	mutex_lock(&usb_bus_list_lock);
2729 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2730 	mutex_unlock(&usb_bus_list_lock);
2731 err_register_root_hub:
2732 	hcd->rh_pollable = 0;
2733 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2734 	del_timer_sync(&hcd->rh_timer);
2735 	hcd->driver->stop(hcd);
2736 	hcd->state = HC_STATE_HALT;
2737 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2738 	del_timer_sync(&hcd->rh_timer);
2739 err_hcd_driver_start:
2740 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2741 		free_irq(irqnum, hcd);
2742 err_request_irq:
2743 err_hcd_driver_setup:
2744 err_set_rh_speed:
2745 	usb_put_dev(hcd->self.root_hub);
2746 err_allocate_root_hub:
2747 	usb_deregister_bus(&hcd->self);
2748 err_register_bus:
2749 	hcd_buffer_destroy(hcd);
2750 err_remove_phy:
2751 	if (hcd->remove_phy && hcd->phy) {
2752 		usb_phy_shutdown(hcd->phy);
2753 		usb_put_phy(hcd->phy);
2754 		hcd->phy = NULL;
2755 	}
2756 	return retval;
2757 }
2758 EXPORT_SYMBOL_GPL(usb_add_hcd);
2759 
2760 /**
2761  * usb_remove_hcd - shutdown processing for generic HCDs
2762  * @hcd: the usb_hcd structure to remove
2763  * Context: !in_interrupt()
2764  *
2765  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2766  * invoking the HCD's stop() method.
2767  */
2768 void usb_remove_hcd(struct usb_hcd *hcd)
2769 {
2770 	struct usb_device *rhdev = hcd->self.root_hub;
2771 
2772 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2773 
2774 	usb_get_dev(rhdev);
2775 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2776 
2777 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2778 	if (HC_IS_RUNNING (hcd->state))
2779 		hcd->state = HC_STATE_QUIESCING;
2780 
2781 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2782 	spin_lock_irq (&hcd_root_hub_lock);
2783 	hcd->rh_registered = 0;
2784 	spin_unlock_irq (&hcd_root_hub_lock);
2785 
2786 #ifdef CONFIG_PM_RUNTIME
2787 	cancel_work_sync(&hcd->wakeup_work);
2788 #endif
2789 
2790 	mutex_lock(&usb_bus_list_lock);
2791 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2792 	mutex_unlock(&usb_bus_list_lock);
2793 
2794 	/*
2795 	 * tasklet_kill() isn't needed here because:
2796 	 * - driver's disconnect() called from usb_disconnect() should
2797 	 *   make sure its URBs are completed during the disconnect()
2798 	 *   callback
2799 	 *
2800 	 * - it is too late to run complete() here since driver may have
2801 	 *   been removed already now
2802 	 */
2803 
2804 	/* Prevent any more root-hub status calls from the timer.
2805 	 * The HCD might still restart the timer (if a port status change
2806 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2807 	 * the hub_status_data() callback.
2808 	 */
2809 	hcd->rh_pollable = 0;
2810 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2811 	del_timer_sync(&hcd->rh_timer);
2812 
2813 	hcd->driver->stop(hcd);
2814 	hcd->state = HC_STATE_HALT;
2815 
2816 	/* In case the HCD restarted the timer, stop it again. */
2817 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2818 	del_timer_sync(&hcd->rh_timer);
2819 
2820 	if (usb_hcd_is_primary_hcd(hcd)) {
2821 		if (hcd->irq > 0)
2822 			free_irq(hcd->irq, hcd);
2823 	}
2824 
2825 	usb_put_dev(hcd->self.root_hub);
2826 	usb_deregister_bus(&hcd->self);
2827 	hcd_buffer_destroy(hcd);
2828 	if (hcd->remove_phy && hcd->phy) {
2829 		usb_phy_shutdown(hcd->phy);
2830 		usb_put_phy(hcd->phy);
2831 		hcd->phy = NULL;
2832 	}
2833 }
2834 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2835 
2836 void
2837 usb_hcd_platform_shutdown(struct platform_device *dev)
2838 {
2839 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2840 
2841 	if (hcd->driver->shutdown)
2842 		hcd->driver->shutdown(hcd);
2843 }
2844 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2845 
2846 /*-------------------------------------------------------------------------*/
2847 
2848 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2849 
2850 struct usb_mon_operations *mon_ops;
2851 
2852 /*
2853  * The registration is unlocked.
2854  * We do it this way because we do not want to lock in hot paths.
2855  *
2856  * Notice that the code is minimally error-proof. Because usbmon needs
2857  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2858  */
2859 
2860 int usb_mon_register (struct usb_mon_operations *ops)
2861 {
2862 
2863 	if (mon_ops)
2864 		return -EBUSY;
2865 
2866 	mon_ops = ops;
2867 	mb();
2868 	return 0;
2869 }
2870 EXPORT_SYMBOL_GPL (usb_mon_register);
2871 
2872 void usb_mon_deregister (void)
2873 {
2874 
2875 	if (mon_ops == NULL) {
2876 		printk(KERN_ERR "USB: monitor was not registered\n");
2877 		return;
2878 	}
2879 	mon_ops = NULL;
2880 	mb();
2881 }
2882 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2883 
2884 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2885