xref: /openbmc/linux/drivers/usb/core/hcd.c (revision db181ce0)
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 	mutex_init(&bus->usb_address0_mutex);
922 
923 	INIT_LIST_HEAD (&bus->bus_list);
924 }
925 
926 /*-------------------------------------------------------------------------*/
927 
928 /**
929  * usb_register_bus - registers the USB host controller with the usb core
930  * @bus: pointer to the bus to register
931  * Context: !in_interrupt()
932  *
933  * Assigns a bus number, and links the controller into usbcore data
934  * structures so that it can be seen by scanning the bus list.
935  *
936  * Return: 0 if successful. A negative error code otherwise.
937  */
938 static int usb_register_bus(struct usb_bus *bus)
939 {
940 	int result = -E2BIG;
941 	int busnum;
942 
943 	mutex_lock(&usb_bus_list_lock);
944 	busnum = find_next_zero_bit(busmap, USB_MAXBUS, 1);
945 	if (busnum >= USB_MAXBUS) {
946 		printk (KERN_ERR "%s: too many buses\n", usbcore_name);
947 		goto error_find_busnum;
948 	}
949 	set_bit(busnum, busmap);
950 	bus->busnum = busnum;
951 
952 	/* Add it to the local list of buses */
953 	list_add (&bus->bus_list, &usb_bus_list);
954 	mutex_unlock(&usb_bus_list_lock);
955 
956 	usb_notify_add_bus(bus);
957 
958 	dev_info (bus->controller, "new USB bus registered, assigned bus "
959 		  "number %d\n", bus->busnum);
960 	return 0;
961 
962 error_find_busnum:
963 	mutex_unlock(&usb_bus_list_lock);
964 	return result;
965 }
966 
967 /**
968  * usb_deregister_bus - deregisters the USB host controller
969  * @bus: pointer to the bus to deregister
970  * Context: !in_interrupt()
971  *
972  * Recycles the bus number, and unlinks the controller from usbcore data
973  * structures so that it won't be seen by scanning the bus list.
974  */
975 static void usb_deregister_bus (struct usb_bus *bus)
976 {
977 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
978 
979 	/*
980 	 * NOTE: make sure that all the devices are removed by the
981 	 * controller code, as well as having it call this when cleaning
982 	 * itself up
983 	 */
984 	mutex_lock(&usb_bus_list_lock);
985 	list_del (&bus->bus_list);
986 	mutex_unlock(&usb_bus_list_lock);
987 
988 	usb_notify_remove_bus(bus);
989 
990 	clear_bit(bus->busnum, busmap);
991 }
992 
993 /**
994  * register_root_hub - called by usb_add_hcd() to register a root hub
995  * @hcd: host controller for this root hub
996  *
997  * This function registers the root hub with the USB subsystem.  It sets up
998  * the device properly in the device tree and then calls usb_new_device()
999  * to register the usb device.  It also assigns the root hub's USB address
1000  * (always 1).
1001  *
1002  * Return: 0 if successful. A negative error code otherwise.
1003  */
1004 static int register_root_hub(struct usb_hcd *hcd)
1005 {
1006 	struct device *parent_dev = hcd->self.controller;
1007 	struct usb_device *usb_dev = hcd->self.root_hub;
1008 	const int devnum = 1;
1009 	int retval;
1010 
1011 	usb_dev->devnum = devnum;
1012 	usb_dev->bus->devnum_next = devnum + 1;
1013 	memset (&usb_dev->bus->devmap.devicemap, 0,
1014 			sizeof usb_dev->bus->devmap.devicemap);
1015 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1016 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1017 
1018 	mutex_lock(&usb_bus_list_lock);
1019 
1020 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1021 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1022 	if (retval != sizeof usb_dev->descriptor) {
1023 		mutex_unlock(&usb_bus_list_lock);
1024 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1025 				dev_name(&usb_dev->dev), retval);
1026 		return (retval < 0) ? retval : -EMSGSIZE;
1027 	}
1028 	if (usb_dev->speed == USB_SPEED_SUPER) {
1029 		retval = usb_get_bos_descriptor(usb_dev);
1030 		if (retval < 0) {
1031 			mutex_unlock(&usb_bus_list_lock);
1032 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1033 					dev_name(&usb_dev->dev), retval);
1034 			return retval;
1035 		}
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 if (is_vmalloc_addr(urb->transfer_buffer)) {
1507 				WARN_ONCE(1, "transfer buffer not dma capable\n");
1508 				ret = -EAGAIN;
1509 			} else {
1510 				urb->transfer_dma = dma_map_single(
1511 						hcd->self.controller,
1512 						urb->transfer_buffer,
1513 						urb->transfer_buffer_length,
1514 						dir);
1515 				if (dma_mapping_error(hcd->self.controller,
1516 						urb->transfer_dma))
1517 					ret = -EAGAIN;
1518 				else
1519 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1520 			}
1521 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1522 			ret = hcd_alloc_coherent(
1523 					urb->dev->bus, mem_flags,
1524 					&urb->transfer_dma,
1525 					&urb->transfer_buffer,
1526 					urb->transfer_buffer_length,
1527 					dir);
1528 			if (ret == 0)
1529 				urb->transfer_flags |= URB_MAP_LOCAL;
1530 		}
1531 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1532 				URB_SETUP_MAP_LOCAL)))
1533 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1534 	}
1535 	return ret;
1536 }
1537 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1538 
1539 /*-------------------------------------------------------------------------*/
1540 
1541 /* may be called in any context with a valid urb->dev usecount
1542  * caller surrenders "ownership" of urb
1543  * expects usb_submit_urb() to have sanity checked and conditioned all
1544  * inputs in the urb
1545  */
1546 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1547 {
1548 	int			status;
1549 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1550 
1551 	/* increment urb's reference count as part of giving it to the HCD
1552 	 * (which will control it).  HCD guarantees that it either returns
1553 	 * an error or calls giveback(), but not both.
1554 	 */
1555 	usb_get_urb(urb);
1556 	atomic_inc(&urb->use_count);
1557 	atomic_inc(&urb->dev->urbnum);
1558 	usbmon_urb_submit(&hcd->self, urb);
1559 
1560 	/* NOTE requirements on root-hub callers (usbfs and the hub
1561 	 * driver, for now):  URBs' urb->transfer_buffer must be
1562 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1563 	 * they could clobber root hub response data.  Also, control
1564 	 * URBs must be submitted in process context with interrupts
1565 	 * enabled.
1566 	 */
1567 
1568 	if (is_root_hub(urb->dev)) {
1569 		status = rh_urb_enqueue(hcd, urb);
1570 	} else {
1571 		status = map_urb_for_dma(hcd, urb, mem_flags);
1572 		if (likely(status == 0)) {
1573 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1574 			if (unlikely(status))
1575 				unmap_urb_for_dma(hcd, urb);
1576 		}
1577 	}
1578 
1579 	if (unlikely(status)) {
1580 		usbmon_urb_submit_error(&hcd->self, urb, status);
1581 		urb->hcpriv = NULL;
1582 		INIT_LIST_HEAD(&urb->urb_list);
1583 		atomic_dec(&urb->use_count);
1584 		atomic_dec(&urb->dev->urbnum);
1585 		if (atomic_read(&urb->reject))
1586 			wake_up(&usb_kill_urb_queue);
1587 		usb_put_urb(urb);
1588 	}
1589 	return status;
1590 }
1591 
1592 /*-------------------------------------------------------------------------*/
1593 
1594 /* this makes the hcd giveback() the urb more quickly, by kicking it
1595  * off hardware queues (which may take a while) and returning it as
1596  * soon as practical.  we've already set up the urb's return status,
1597  * but we can't know if the callback completed already.
1598  */
1599 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1600 {
1601 	int		value;
1602 
1603 	if (is_root_hub(urb->dev))
1604 		value = usb_rh_urb_dequeue(hcd, urb, status);
1605 	else {
1606 
1607 		/* The only reason an HCD might fail this call is if
1608 		 * it has not yet fully queued the urb to begin with.
1609 		 * Such failures should be harmless. */
1610 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1611 	}
1612 	return value;
1613 }
1614 
1615 /*
1616  * called in any context
1617  *
1618  * caller guarantees urb won't be recycled till both unlink()
1619  * and the urb's completion function return
1620  */
1621 int usb_hcd_unlink_urb (struct urb *urb, int status)
1622 {
1623 	struct usb_hcd		*hcd;
1624 	int			retval = -EIDRM;
1625 	unsigned long		flags;
1626 
1627 	/* Prevent the device and bus from going away while
1628 	 * the unlink is carried out.  If they are already gone
1629 	 * then urb->use_count must be 0, since disconnected
1630 	 * devices can't have any active URBs.
1631 	 */
1632 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1633 	if (atomic_read(&urb->use_count) > 0) {
1634 		retval = 0;
1635 		usb_get_dev(urb->dev);
1636 	}
1637 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1638 	if (retval == 0) {
1639 		hcd = bus_to_hcd(urb->dev->bus);
1640 		retval = unlink1(hcd, urb, status);
1641 		usb_put_dev(urb->dev);
1642 	}
1643 
1644 	if (retval == 0)
1645 		retval = -EINPROGRESS;
1646 	else if (retval != -EIDRM && retval != -EBUSY)
1647 		dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1648 				urb, retval);
1649 	return retval;
1650 }
1651 
1652 /*-------------------------------------------------------------------------*/
1653 
1654 static void __usb_hcd_giveback_urb(struct urb *urb)
1655 {
1656 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1657 	struct usb_anchor *anchor = urb->anchor;
1658 	int status = urb->unlinked;
1659 	unsigned long flags;
1660 
1661 	urb->hcpriv = NULL;
1662 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1663 	    urb->actual_length < urb->transfer_buffer_length &&
1664 	    !status))
1665 		status = -EREMOTEIO;
1666 
1667 	unmap_urb_for_dma(hcd, urb);
1668 	usbmon_urb_complete(&hcd->self, urb, status);
1669 	usb_anchor_suspend_wakeups(anchor);
1670 	usb_unanchor_urb(urb);
1671 
1672 	/* pass ownership to the completion handler */
1673 	urb->status = status;
1674 
1675 	/*
1676 	 * We disable local IRQs here avoid possible deadlock because
1677 	 * drivers may call spin_lock() to hold lock which might be
1678 	 * acquired in one hard interrupt handler.
1679 	 *
1680 	 * The local_irq_save()/local_irq_restore() around complete()
1681 	 * will be removed if current USB drivers have been cleaned up
1682 	 * and no one may trigger the above deadlock situation when
1683 	 * running complete() in tasklet.
1684 	 */
1685 	local_irq_save(flags);
1686 	urb->complete(urb);
1687 	local_irq_restore(flags);
1688 
1689 	usb_anchor_resume_wakeups(anchor);
1690 	atomic_dec(&urb->use_count);
1691 	if (unlikely(atomic_read(&urb->reject)))
1692 		wake_up(&usb_kill_urb_queue);
1693 	usb_put_urb(urb);
1694 }
1695 
1696 static void usb_giveback_urb_bh(unsigned long param)
1697 {
1698 	struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1699 	struct list_head local_list;
1700 
1701 	spin_lock_irq(&bh->lock);
1702 	bh->running = true;
1703  restart:
1704 	list_replace_init(&bh->head, &local_list);
1705 	spin_unlock_irq(&bh->lock);
1706 
1707 	while (!list_empty(&local_list)) {
1708 		struct urb *urb;
1709 
1710 		urb = list_entry(local_list.next, struct urb, urb_list);
1711 		list_del_init(&urb->urb_list);
1712 		bh->completing_ep = urb->ep;
1713 		__usb_hcd_giveback_urb(urb);
1714 		bh->completing_ep = NULL;
1715 	}
1716 
1717 	/* check if there are new URBs to giveback */
1718 	spin_lock_irq(&bh->lock);
1719 	if (!list_empty(&bh->head))
1720 		goto restart;
1721 	bh->running = false;
1722 	spin_unlock_irq(&bh->lock);
1723 }
1724 
1725 /**
1726  * usb_hcd_giveback_urb - return URB from HCD to device driver
1727  * @hcd: host controller returning the URB
1728  * @urb: urb being returned to the USB device driver.
1729  * @status: completion status code for the URB.
1730  * Context: in_interrupt()
1731  *
1732  * This hands the URB from HCD to its USB device driver, using its
1733  * completion function.  The HCD has freed all per-urb resources
1734  * (and is done using urb->hcpriv).  It also released all HCD locks;
1735  * the device driver won't cause problems if it frees, modifies,
1736  * or resubmits this URB.
1737  *
1738  * If @urb was unlinked, the value of @status will be overridden by
1739  * @urb->unlinked.  Erroneous short transfers are detected in case
1740  * the HCD hasn't checked for them.
1741  */
1742 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1743 {
1744 	struct giveback_urb_bh *bh;
1745 	bool running, high_prio_bh;
1746 
1747 	/* pass status to tasklet via unlinked */
1748 	if (likely(!urb->unlinked))
1749 		urb->unlinked = status;
1750 
1751 	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1752 		__usb_hcd_giveback_urb(urb);
1753 		return;
1754 	}
1755 
1756 	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1757 		bh = &hcd->high_prio_bh;
1758 		high_prio_bh = true;
1759 	} else {
1760 		bh = &hcd->low_prio_bh;
1761 		high_prio_bh = false;
1762 	}
1763 
1764 	spin_lock(&bh->lock);
1765 	list_add_tail(&urb->urb_list, &bh->head);
1766 	running = bh->running;
1767 	spin_unlock(&bh->lock);
1768 
1769 	if (running)
1770 		;
1771 	else if (high_prio_bh)
1772 		tasklet_hi_schedule(&bh->bh);
1773 	else
1774 		tasklet_schedule(&bh->bh);
1775 }
1776 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1777 
1778 /*-------------------------------------------------------------------------*/
1779 
1780 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1781  * queue to drain completely.  The caller must first insure that no more
1782  * URBs can be submitted for this endpoint.
1783  */
1784 void usb_hcd_flush_endpoint(struct usb_device *udev,
1785 		struct usb_host_endpoint *ep)
1786 {
1787 	struct usb_hcd		*hcd;
1788 	struct urb		*urb;
1789 
1790 	if (!ep)
1791 		return;
1792 	might_sleep();
1793 	hcd = bus_to_hcd(udev->bus);
1794 
1795 	/* No more submits can occur */
1796 	spin_lock_irq(&hcd_urb_list_lock);
1797 rescan:
1798 	list_for_each_entry (urb, &ep->urb_list, urb_list) {
1799 		int	is_in;
1800 
1801 		if (urb->unlinked)
1802 			continue;
1803 		usb_get_urb (urb);
1804 		is_in = usb_urb_dir_in(urb);
1805 		spin_unlock(&hcd_urb_list_lock);
1806 
1807 		/* kick hcd */
1808 		unlink1(hcd, urb, -ESHUTDOWN);
1809 		dev_dbg (hcd->self.controller,
1810 			"shutdown urb %p ep%d%s%s\n",
1811 			urb, usb_endpoint_num(&ep->desc),
1812 			is_in ? "in" : "out",
1813 			({	char *s;
1814 
1815 				 switch (usb_endpoint_type(&ep->desc)) {
1816 				 case USB_ENDPOINT_XFER_CONTROL:
1817 					s = ""; break;
1818 				 case USB_ENDPOINT_XFER_BULK:
1819 					s = "-bulk"; break;
1820 				 case USB_ENDPOINT_XFER_INT:
1821 					s = "-intr"; break;
1822 				 default:
1823 					s = "-iso"; break;
1824 				};
1825 				s;
1826 			}));
1827 		usb_put_urb (urb);
1828 
1829 		/* list contents may have changed */
1830 		spin_lock(&hcd_urb_list_lock);
1831 		goto rescan;
1832 	}
1833 	spin_unlock_irq(&hcd_urb_list_lock);
1834 
1835 	/* Wait until the endpoint queue is completely empty */
1836 	while (!list_empty (&ep->urb_list)) {
1837 		spin_lock_irq(&hcd_urb_list_lock);
1838 
1839 		/* The list may have changed while we acquired the spinlock */
1840 		urb = NULL;
1841 		if (!list_empty (&ep->urb_list)) {
1842 			urb = list_entry (ep->urb_list.prev, struct urb,
1843 					urb_list);
1844 			usb_get_urb (urb);
1845 		}
1846 		spin_unlock_irq(&hcd_urb_list_lock);
1847 
1848 		if (urb) {
1849 			usb_kill_urb (urb);
1850 			usb_put_urb (urb);
1851 		}
1852 	}
1853 }
1854 
1855 /**
1856  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1857  *				the bus bandwidth
1858  * @udev: target &usb_device
1859  * @new_config: new configuration to install
1860  * @cur_alt: the current alternate interface setting
1861  * @new_alt: alternate interface setting that is being installed
1862  *
1863  * To change configurations, pass in the new configuration in new_config,
1864  * and pass NULL for cur_alt and new_alt.
1865  *
1866  * To reset a device's configuration (put the device in the ADDRESSED state),
1867  * pass in NULL for new_config, cur_alt, and new_alt.
1868  *
1869  * To change alternate interface settings, pass in NULL for new_config,
1870  * pass in the current alternate interface setting in cur_alt,
1871  * and pass in the new alternate interface setting in new_alt.
1872  *
1873  * Return: An error if the requested bandwidth change exceeds the
1874  * bus bandwidth or host controller internal resources.
1875  */
1876 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1877 		struct usb_host_config *new_config,
1878 		struct usb_host_interface *cur_alt,
1879 		struct usb_host_interface *new_alt)
1880 {
1881 	int num_intfs, i, j;
1882 	struct usb_host_interface *alt = NULL;
1883 	int ret = 0;
1884 	struct usb_hcd *hcd;
1885 	struct usb_host_endpoint *ep;
1886 
1887 	hcd = bus_to_hcd(udev->bus);
1888 	if (!hcd->driver->check_bandwidth)
1889 		return 0;
1890 
1891 	/* Configuration is being removed - set configuration 0 */
1892 	if (!new_config && !cur_alt) {
1893 		for (i = 1; i < 16; ++i) {
1894 			ep = udev->ep_out[i];
1895 			if (ep)
1896 				hcd->driver->drop_endpoint(hcd, udev, ep);
1897 			ep = udev->ep_in[i];
1898 			if (ep)
1899 				hcd->driver->drop_endpoint(hcd, udev, ep);
1900 		}
1901 		hcd->driver->check_bandwidth(hcd, udev);
1902 		return 0;
1903 	}
1904 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1905 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1906 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1907 	 * ok to exclude it.
1908 	 */
1909 	if (new_config) {
1910 		num_intfs = new_config->desc.bNumInterfaces;
1911 		/* Remove endpoints (except endpoint 0, which is always on the
1912 		 * schedule) from the old config from the schedule
1913 		 */
1914 		for (i = 1; i < 16; ++i) {
1915 			ep = udev->ep_out[i];
1916 			if (ep) {
1917 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1918 				if (ret < 0)
1919 					goto reset;
1920 			}
1921 			ep = udev->ep_in[i];
1922 			if (ep) {
1923 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1924 				if (ret < 0)
1925 					goto reset;
1926 			}
1927 		}
1928 		for (i = 0; i < num_intfs; ++i) {
1929 			struct usb_host_interface *first_alt;
1930 			int iface_num;
1931 
1932 			first_alt = &new_config->intf_cache[i]->altsetting[0];
1933 			iface_num = first_alt->desc.bInterfaceNumber;
1934 			/* Set up endpoints for alternate interface setting 0 */
1935 			alt = usb_find_alt_setting(new_config, iface_num, 0);
1936 			if (!alt)
1937 				/* No alt setting 0? Pick the first setting. */
1938 				alt = first_alt;
1939 
1940 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1941 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1942 				if (ret < 0)
1943 					goto reset;
1944 			}
1945 		}
1946 	}
1947 	if (cur_alt && new_alt) {
1948 		struct usb_interface *iface = usb_ifnum_to_if(udev,
1949 				cur_alt->desc.bInterfaceNumber);
1950 
1951 		if (!iface)
1952 			return -EINVAL;
1953 		if (iface->resetting_device) {
1954 			/*
1955 			 * The USB core just reset the device, so the xHCI host
1956 			 * and the device will think alt setting 0 is installed.
1957 			 * However, the USB core will pass in the alternate
1958 			 * setting installed before the reset as cur_alt.  Dig
1959 			 * out the alternate setting 0 structure, or the first
1960 			 * alternate setting if a broken device doesn't have alt
1961 			 * setting 0.
1962 			 */
1963 			cur_alt = usb_altnum_to_altsetting(iface, 0);
1964 			if (!cur_alt)
1965 				cur_alt = &iface->altsetting[0];
1966 		}
1967 
1968 		/* Drop all the endpoints in the current alt setting */
1969 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1970 			ret = hcd->driver->drop_endpoint(hcd, udev,
1971 					&cur_alt->endpoint[i]);
1972 			if (ret < 0)
1973 				goto reset;
1974 		}
1975 		/* Add all the endpoints in the new alt setting */
1976 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1977 			ret = hcd->driver->add_endpoint(hcd, udev,
1978 					&new_alt->endpoint[i]);
1979 			if (ret < 0)
1980 				goto reset;
1981 		}
1982 	}
1983 	ret = hcd->driver->check_bandwidth(hcd, udev);
1984 reset:
1985 	if (ret < 0)
1986 		hcd->driver->reset_bandwidth(hcd, udev);
1987 	return ret;
1988 }
1989 
1990 /* Disables the endpoint: synchronizes with the hcd to make sure all
1991  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1992  * have been called previously.  Use for set_configuration, set_interface,
1993  * driver removal, physical disconnect.
1994  *
1995  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1996  * type, maxpacket size, toggle, halt status, and scheduling.
1997  */
1998 void usb_hcd_disable_endpoint(struct usb_device *udev,
1999 		struct usb_host_endpoint *ep)
2000 {
2001 	struct usb_hcd		*hcd;
2002 
2003 	might_sleep();
2004 	hcd = bus_to_hcd(udev->bus);
2005 	if (hcd->driver->endpoint_disable)
2006 		hcd->driver->endpoint_disable(hcd, ep);
2007 }
2008 
2009 /**
2010  * usb_hcd_reset_endpoint - reset host endpoint state
2011  * @udev: USB device.
2012  * @ep:   the endpoint to reset.
2013  *
2014  * Resets any host endpoint state such as the toggle bit, sequence
2015  * number and current window.
2016  */
2017 void usb_hcd_reset_endpoint(struct usb_device *udev,
2018 			    struct usb_host_endpoint *ep)
2019 {
2020 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2021 
2022 	if (hcd->driver->endpoint_reset)
2023 		hcd->driver->endpoint_reset(hcd, ep);
2024 	else {
2025 		int epnum = usb_endpoint_num(&ep->desc);
2026 		int is_out = usb_endpoint_dir_out(&ep->desc);
2027 		int is_control = usb_endpoint_xfer_control(&ep->desc);
2028 
2029 		usb_settoggle(udev, epnum, is_out, 0);
2030 		if (is_control)
2031 			usb_settoggle(udev, epnum, !is_out, 0);
2032 	}
2033 }
2034 
2035 /**
2036  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2037  * @interface:		alternate setting that includes all endpoints.
2038  * @eps:		array of endpoints that need streams.
2039  * @num_eps:		number of endpoints in the array.
2040  * @num_streams:	number of streams to allocate.
2041  * @mem_flags:		flags hcd should use to allocate memory.
2042  *
2043  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2044  * Drivers may queue multiple transfers to different stream IDs, which may
2045  * complete in a different order than they were queued.
2046  *
2047  * Return: On success, the number of allocated streams. On failure, a negative
2048  * error code.
2049  */
2050 int usb_alloc_streams(struct usb_interface *interface,
2051 		struct usb_host_endpoint **eps, unsigned int num_eps,
2052 		unsigned int num_streams, gfp_t mem_flags)
2053 {
2054 	struct usb_hcd *hcd;
2055 	struct usb_device *dev;
2056 	int i, ret;
2057 
2058 	dev = interface_to_usbdev(interface);
2059 	hcd = bus_to_hcd(dev->bus);
2060 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2061 		return -EINVAL;
2062 	if (dev->speed != USB_SPEED_SUPER)
2063 		return -EINVAL;
2064 
2065 	for (i = 0; i < num_eps; i++) {
2066 		/* Streams only apply to bulk endpoints. */
2067 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2068 			return -EINVAL;
2069 		/* Re-alloc is not allowed */
2070 		if (eps[i]->streams)
2071 			return -EINVAL;
2072 	}
2073 
2074 	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2075 			num_streams, mem_flags);
2076 	if (ret < 0)
2077 		return ret;
2078 
2079 	for (i = 0; i < num_eps; i++)
2080 		eps[i]->streams = ret;
2081 
2082 	return ret;
2083 }
2084 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2085 
2086 /**
2087  * usb_free_streams - free bulk endpoint stream IDs.
2088  * @interface:	alternate setting that includes all endpoints.
2089  * @eps:	array of endpoints to remove streams from.
2090  * @num_eps:	number of endpoints in the array.
2091  * @mem_flags:	flags hcd should use to allocate memory.
2092  *
2093  * Reverts a group of bulk endpoints back to not using stream IDs.
2094  * Can fail if we are given bad arguments, or HCD is broken.
2095  *
2096  * Return: 0 on success. On failure, a negative error code.
2097  */
2098 int usb_free_streams(struct usb_interface *interface,
2099 		struct usb_host_endpoint **eps, unsigned int num_eps,
2100 		gfp_t mem_flags)
2101 {
2102 	struct usb_hcd *hcd;
2103 	struct usb_device *dev;
2104 	int i, ret;
2105 
2106 	dev = interface_to_usbdev(interface);
2107 	hcd = bus_to_hcd(dev->bus);
2108 	if (dev->speed != USB_SPEED_SUPER)
2109 		return -EINVAL;
2110 
2111 	/* Double-free is not allowed */
2112 	for (i = 0; i < num_eps; i++)
2113 		if (!eps[i] || !eps[i]->streams)
2114 			return -EINVAL;
2115 
2116 	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2117 	if (ret < 0)
2118 		return ret;
2119 
2120 	for (i = 0; i < num_eps; i++)
2121 		eps[i]->streams = 0;
2122 
2123 	return ret;
2124 }
2125 EXPORT_SYMBOL_GPL(usb_free_streams);
2126 
2127 /* Protect against drivers that try to unlink URBs after the device
2128  * is gone, by waiting until all unlinks for @udev are finished.
2129  * Since we don't currently track URBs by device, simply wait until
2130  * nothing is running in the locked region of usb_hcd_unlink_urb().
2131  */
2132 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2133 {
2134 	spin_lock_irq(&hcd_urb_unlink_lock);
2135 	spin_unlock_irq(&hcd_urb_unlink_lock);
2136 }
2137 
2138 /*-------------------------------------------------------------------------*/
2139 
2140 /* called in any context */
2141 int usb_hcd_get_frame_number (struct usb_device *udev)
2142 {
2143 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2144 
2145 	if (!HCD_RH_RUNNING(hcd))
2146 		return -ESHUTDOWN;
2147 	return hcd->driver->get_frame_number (hcd);
2148 }
2149 
2150 /*-------------------------------------------------------------------------*/
2151 
2152 #ifdef	CONFIG_PM
2153 
2154 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2155 {
2156 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2157 	int		status;
2158 	int		old_state = hcd->state;
2159 
2160 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2161 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2162 			rhdev->do_remote_wakeup);
2163 	if (HCD_DEAD(hcd)) {
2164 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2165 		return 0;
2166 	}
2167 
2168 	if (!hcd->driver->bus_suspend) {
2169 		status = -ENOENT;
2170 	} else {
2171 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2172 		hcd->state = HC_STATE_QUIESCING;
2173 		status = hcd->driver->bus_suspend(hcd);
2174 	}
2175 	if (status == 0) {
2176 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2177 		hcd->state = HC_STATE_SUSPENDED;
2178 
2179 		/* Did we race with a root-hub wakeup event? */
2180 		if (rhdev->do_remote_wakeup) {
2181 			char	buffer[6];
2182 
2183 			status = hcd->driver->hub_status_data(hcd, buffer);
2184 			if (status != 0) {
2185 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2186 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2187 				status = -EBUSY;
2188 			}
2189 		}
2190 	} else {
2191 		spin_lock_irq(&hcd_root_hub_lock);
2192 		if (!HCD_DEAD(hcd)) {
2193 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2194 			hcd->state = old_state;
2195 		}
2196 		spin_unlock_irq(&hcd_root_hub_lock);
2197 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2198 				"suspend", status);
2199 	}
2200 	return status;
2201 }
2202 
2203 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2204 {
2205 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
2206 	int		status;
2207 	int		old_state = hcd->state;
2208 
2209 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2210 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2211 	if (HCD_DEAD(hcd)) {
2212 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2213 		return 0;
2214 	}
2215 	if (!hcd->driver->bus_resume)
2216 		return -ENOENT;
2217 	if (HCD_RH_RUNNING(hcd))
2218 		return 0;
2219 
2220 	hcd->state = HC_STATE_RESUMING;
2221 	status = hcd->driver->bus_resume(hcd);
2222 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2223 	if (status == 0) {
2224 		struct usb_device *udev;
2225 		int port1;
2226 
2227 		spin_lock_irq(&hcd_root_hub_lock);
2228 		if (!HCD_DEAD(hcd)) {
2229 			usb_set_device_state(rhdev, rhdev->actconfig
2230 					? USB_STATE_CONFIGURED
2231 					: USB_STATE_ADDRESS);
2232 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2233 			hcd->state = HC_STATE_RUNNING;
2234 		}
2235 		spin_unlock_irq(&hcd_root_hub_lock);
2236 
2237 		/*
2238 		 * Check whether any of the enabled ports on the root hub are
2239 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2240 		 * (this is what the USB-2 spec calls a "global resume").
2241 		 * Otherwise we can skip the delay.
2242 		 */
2243 		usb_hub_for_each_child(rhdev, port1, udev) {
2244 			if (udev->state != USB_STATE_NOTATTACHED &&
2245 					!udev->port_is_suspended) {
2246 				usleep_range(10000, 11000);	/* TRSMRCY */
2247 				break;
2248 			}
2249 		}
2250 	} else {
2251 		hcd->state = old_state;
2252 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2253 				"resume", status);
2254 		if (status != -ESHUTDOWN)
2255 			usb_hc_died(hcd);
2256 	}
2257 	return status;
2258 }
2259 
2260 #endif	/* CONFIG_PM */
2261 
2262 #ifdef	CONFIG_PM_RUNTIME
2263 
2264 /* Workqueue routine for root-hub remote wakeup */
2265 static void hcd_resume_work(struct work_struct *work)
2266 {
2267 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2268 	struct usb_device *udev = hcd->self.root_hub;
2269 
2270 	usb_remote_wakeup(udev);
2271 }
2272 
2273 /**
2274  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2275  * @hcd: host controller for this root hub
2276  *
2277  * The USB host controller calls this function when its root hub is
2278  * suspended (with the remote wakeup feature enabled) and a remote
2279  * wakeup request is received.  The routine submits a workqueue request
2280  * to resume the root hub (that is, manage its downstream ports again).
2281  */
2282 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2283 {
2284 	unsigned long flags;
2285 
2286 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2287 	if (hcd->rh_registered) {
2288 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2289 		queue_work(pm_wq, &hcd->wakeup_work);
2290 	}
2291 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2292 }
2293 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2294 
2295 #endif	/* CONFIG_PM_RUNTIME */
2296 
2297 /*-------------------------------------------------------------------------*/
2298 
2299 #ifdef	CONFIG_USB_OTG
2300 
2301 /**
2302  * usb_bus_start_enum - start immediate enumeration (for OTG)
2303  * @bus: the bus (must use hcd framework)
2304  * @port_num: 1-based number of port; usually bus->otg_port
2305  * Context: in_interrupt()
2306  *
2307  * Starts enumeration, with an immediate reset followed later by
2308  * khubd identifying and possibly configuring the device.
2309  * This is needed by OTG controller drivers, where it helps meet
2310  * HNP protocol timing requirements for starting a port reset.
2311  *
2312  * Return: 0 if successful.
2313  */
2314 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2315 {
2316 	struct usb_hcd		*hcd;
2317 	int			status = -EOPNOTSUPP;
2318 
2319 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2320 	 * boards with root hubs hooked up to internal devices (instead of
2321 	 * just the OTG port) may need more attention to resetting...
2322 	 */
2323 	hcd = container_of (bus, struct usb_hcd, self);
2324 	if (port_num && hcd->driver->start_port_reset)
2325 		status = hcd->driver->start_port_reset(hcd, port_num);
2326 
2327 	/* run khubd shortly after (first) root port reset finishes;
2328 	 * it may issue others, until at least 50 msecs have passed.
2329 	 */
2330 	if (status == 0)
2331 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2332 	return status;
2333 }
2334 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2335 
2336 #endif
2337 
2338 /*-------------------------------------------------------------------------*/
2339 
2340 /**
2341  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2342  * @irq: the IRQ being raised
2343  * @__hcd: pointer to the HCD whose IRQ is being signaled
2344  *
2345  * If the controller isn't HALTed, calls the driver's irq handler.
2346  * Checks whether the controller is now dead.
2347  *
2348  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2349  */
2350 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2351 {
2352 	struct usb_hcd		*hcd = __hcd;
2353 	irqreturn_t		rc;
2354 
2355 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2356 		rc = IRQ_NONE;
2357 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2358 		rc = IRQ_NONE;
2359 	else
2360 		rc = IRQ_HANDLED;
2361 
2362 	return rc;
2363 }
2364 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2365 
2366 /*-------------------------------------------------------------------------*/
2367 
2368 /**
2369  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2370  * @hcd: pointer to the HCD representing the controller
2371  *
2372  * This is called by bus glue to report a USB host controller that died
2373  * while operations may still have been pending.  It's called automatically
2374  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2375  *
2376  * Only call this function with the primary HCD.
2377  */
2378 void usb_hc_died (struct usb_hcd *hcd)
2379 {
2380 	unsigned long flags;
2381 
2382 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2383 
2384 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2385 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2386 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2387 	if (hcd->rh_registered) {
2388 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2389 
2390 		/* make khubd clean up old urbs and devices */
2391 		usb_set_device_state (hcd->self.root_hub,
2392 				USB_STATE_NOTATTACHED);
2393 		usb_kick_khubd (hcd->self.root_hub);
2394 	}
2395 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2396 		hcd = hcd->shared_hcd;
2397 		if (hcd->rh_registered) {
2398 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2399 
2400 			/* make khubd clean up old urbs and devices */
2401 			usb_set_device_state(hcd->self.root_hub,
2402 					USB_STATE_NOTATTACHED);
2403 			usb_kick_khubd(hcd->self.root_hub);
2404 		}
2405 	}
2406 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2407 	/* Make sure that the other roothub is also deallocated. */
2408 }
2409 EXPORT_SYMBOL_GPL (usb_hc_died);
2410 
2411 /*-------------------------------------------------------------------------*/
2412 
2413 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2414 {
2415 
2416 	spin_lock_init(&bh->lock);
2417 	INIT_LIST_HEAD(&bh->head);
2418 	tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2419 }
2420 
2421 /**
2422  * usb_create_shared_hcd - create and initialize an HCD structure
2423  * @driver: HC driver that will use this hcd
2424  * @dev: device for this HC, stored in hcd->self.controller
2425  * @bus_name: value to store in hcd->self.bus_name
2426  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2427  *              PCI device.  Only allocate certain resources for the primary HCD
2428  * Context: !in_interrupt()
2429  *
2430  * Allocate a struct usb_hcd, with extra space at the end for the
2431  * HC driver's private data.  Initialize the generic members of the
2432  * hcd structure.
2433  *
2434  * Return: On success, a pointer to the created and initialized HCD structure.
2435  * On failure (e.g. if memory is unavailable), %NULL.
2436  */
2437 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2438 		struct device *dev, const char *bus_name,
2439 		struct usb_hcd *primary_hcd)
2440 {
2441 	struct usb_hcd *hcd;
2442 
2443 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2444 	if (!hcd) {
2445 		dev_dbg (dev, "hcd alloc failed\n");
2446 		return NULL;
2447 	}
2448 	if (primary_hcd == NULL) {
2449 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2450 				GFP_KERNEL);
2451 		if (!hcd->bandwidth_mutex) {
2452 			kfree(hcd);
2453 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2454 			return NULL;
2455 		}
2456 		mutex_init(hcd->bandwidth_mutex);
2457 		dev_set_drvdata(dev, hcd);
2458 	} else {
2459 		mutex_lock(&usb_port_peer_mutex);
2460 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2461 		hcd->primary_hcd = primary_hcd;
2462 		primary_hcd->primary_hcd = primary_hcd;
2463 		hcd->shared_hcd = primary_hcd;
2464 		primary_hcd->shared_hcd = hcd;
2465 		mutex_unlock(&usb_port_peer_mutex);
2466 	}
2467 
2468 	kref_init(&hcd->kref);
2469 
2470 	usb_bus_init(&hcd->self);
2471 	hcd->self.controller = dev;
2472 	hcd->self.bus_name = bus_name;
2473 	hcd->self.uses_dma = (dev->dma_mask != NULL);
2474 
2475 	init_timer(&hcd->rh_timer);
2476 	hcd->rh_timer.function = rh_timer_func;
2477 	hcd->rh_timer.data = (unsigned long) hcd;
2478 #ifdef CONFIG_PM_RUNTIME
2479 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2480 #endif
2481 
2482 	hcd->driver = driver;
2483 	hcd->speed = driver->flags & HCD_MASK;
2484 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2485 			"USB Host Controller";
2486 	return hcd;
2487 }
2488 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2489 
2490 /**
2491  * usb_create_hcd - create and initialize an HCD structure
2492  * @driver: HC driver that will use this hcd
2493  * @dev: device for this HC, stored in hcd->self.controller
2494  * @bus_name: value to store in hcd->self.bus_name
2495  * Context: !in_interrupt()
2496  *
2497  * Allocate a struct usb_hcd, with extra space at the end for the
2498  * HC driver's private data.  Initialize the generic members of the
2499  * hcd structure.
2500  *
2501  * Return: On success, a pointer to the created and initialized HCD
2502  * structure. On failure (e.g. if memory is unavailable), %NULL.
2503  */
2504 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2505 		struct device *dev, const char *bus_name)
2506 {
2507 	return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2508 }
2509 EXPORT_SYMBOL_GPL(usb_create_hcd);
2510 
2511 /*
2512  * Roothubs that share one PCI device must also share the bandwidth mutex.
2513  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2514  * deallocated.
2515  *
2516  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2517  * freed.  When hcd_release() is called for either hcd in a peer set
2518  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers to
2519  * block new peering attempts
2520  */
2521 static void hcd_release(struct kref *kref)
2522 {
2523 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2524 
2525 	mutex_lock(&usb_port_peer_mutex);
2526 	if (usb_hcd_is_primary_hcd(hcd))
2527 		kfree(hcd->bandwidth_mutex);
2528 	if (hcd->shared_hcd) {
2529 		struct usb_hcd *peer = hcd->shared_hcd;
2530 
2531 		peer->shared_hcd = NULL;
2532 		if (peer->primary_hcd == hcd)
2533 			peer->primary_hcd = NULL;
2534 	}
2535 	mutex_unlock(&usb_port_peer_mutex);
2536 	kfree(hcd);
2537 }
2538 
2539 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2540 {
2541 	if (hcd)
2542 		kref_get (&hcd->kref);
2543 	return hcd;
2544 }
2545 EXPORT_SYMBOL_GPL(usb_get_hcd);
2546 
2547 void usb_put_hcd (struct usb_hcd *hcd)
2548 {
2549 	if (hcd)
2550 		kref_put (&hcd->kref, hcd_release);
2551 }
2552 EXPORT_SYMBOL_GPL(usb_put_hcd);
2553 
2554 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2555 {
2556 	if (!hcd->primary_hcd)
2557 		return 1;
2558 	return hcd == hcd->primary_hcd;
2559 }
2560 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2561 
2562 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2563 {
2564 	if (!hcd->driver->find_raw_port_number)
2565 		return port1;
2566 
2567 	return hcd->driver->find_raw_port_number(hcd, port1);
2568 }
2569 
2570 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2571 		unsigned int irqnum, unsigned long irqflags)
2572 {
2573 	int retval;
2574 
2575 	if (hcd->driver->irq) {
2576 
2577 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2578 				hcd->driver->description, hcd->self.busnum);
2579 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2580 				hcd->irq_descr, hcd);
2581 		if (retval != 0) {
2582 			dev_err(hcd->self.controller,
2583 					"request interrupt %d failed\n",
2584 					irqnum);
2585 			return retval;
2586 		}
2587 		hcd->irq = irqnum;
2588 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2589 				(hcd->driver->flags & HCD_MEMORY) ?
2590 					"io mem" : "io base",
2591 					(unsigned long long)hcd->rsrc_start);
2592 	} else {
2593 		hcd->irq = 0;
2594 		if (hcd->rsrc_start)
2595 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2596 					(hcd->driver->flags & HCD_MEMORY) ?
2597 					"io mem" : "io base",
2598 					(unsigned long long)hcd->rsrc_start);
2599 	}
2600 	return 0;
2601 }
2602 
2603 /*
2604  * Before we free this root hub, flush in-flight peering attempts
2605  * and disable peer lookups
2606  */
2607 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2608 {
2609 	struct usb_device *rhdev;
2610 
2611 	mutex_lock(&usb_port_peer_mutex);
2612 	rhdev = hcd->self.root_hub;
2613 	hcd->self.root_hub = NULL;
2614 	mutex_unlock(&usb_port_peer_mutex);
2615 	usb_put_dev(rhdev);
2616 }
2617 
2618 /**
2619  * usb_add_hcd - finish generic HCD structure initialization and register
2620  * @hcd: the usb_hcd structure to initialize
2621  * @irqnum: Interrupt line to allocate
2622  * @irqflags: Interrupt type flags
2623  *
2624  * Finish the remaining parts of generic HCD initialization: allocate the
2625  * buffers of consistent memory, register the bus, request the IRQ line,
2626  * and call the driver's reset() and start() routines.
2627  */
2628 int usb_add_hcd(struct usb_hcd *hcd,
2629 		unsigned int irqnum, unsigned long irqflags)
2630 {
2631 	int retval;
2632 	struct usb_device *rhdev;
2633 
2634 	if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->phy) {
2635 		struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0);
2636 
2637 		if (IS_ERR(phy)) {
2638 			retval = PTR_ERR(phy);
2639 			if (retval == -EPROBE_DEFER)
2640 				return retval;
2641 		} else {
2642 			retval = usb_phy_init(phy);
2643 			if (retval) {
2644 				usb_put_phy(phy);
2645 				return retval;
2646 			}
2647 			hcd->phy = phy;
2648 			hcd->remove_phy = 1;
2649 		}
2650 	}
2651 
2652 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2653 
2654 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2655 	if (authorized_default < 0 || authorized_default > 1)
2656 		hcd->authorized_default = hcd->wireless ? 0 : 1;
2657 	else
2658 		hcd->authorized_default = authorized_default;
2659 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2660 
2661 	/* HC is in reset state, but accessible.  Now do the one-time init,
2662 	 * bottom up so that hcds can customize the root hubs before khubd
2663 	 * starts talking to them.  (Note, bus id is assigned early too.)
2664 	 */
2665 	if ((retval = hcd_buffer_create(hcd)) != 0) {
2666 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
2667 		goto err_remove_phy;
2668 	}
2669 
2670 	if ((retval = usb_register_bus(&hcd->self)) < 0)
2671 		goto err_register_bus;
2672 
2673 	if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2674 		dev_err(hcd->self.controller, "unable to allocate root hub\n");
2675 		retval = -ENOMEM;
2676 		goto err_allocate_root_hub;
2677 	}
2678 	mutex_lock(&usb_port_peer_mutex);
2679 	hcd->self.root_hub = rhdev;
2680 	mutex_unlock(&usb_port_peer_mutex);
2681 
2682 	switch (hcd->speed) {
2683 	case HCD_USB11:
2684 		rhdev->speed = USB_SPEED_FULL;
2685 		break;
2686 	case HCD_USB2:
2687 		rhdev->speed = USB_SPEED_HIGH;
2688 		break;
2689 	case HCD_USB25:
2690 		rhdev->speed = USB_SPEED_WIRELESS;
2691 		break;
2692 	case HCD_USB3:
2693 		rhdev->speed = USB_SPEED_SUPER;
2694 		break;
2695 	default:
2696 		retval = -EINVAL;
2697 		goto err_set_rh_speed;
2698 	}
2699 
2700 	/* wakeup flag init defaults to "everything works" for root hubs,
2701 	 * but drivers can override it in reset() if needed, along with
2702 	 * recording the overall controller's system wakeup capability.
2703 	 */
2704 	device_set_wakeup_capable(&rhdev->dev, 1);
2705 
2706 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2707 	 * registered.  But since the controller can die at any time,
2708 	 * let's initialize the flag before touching the hardware.
2709 	 */
2710 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2711 
2712 	/* "reset" is misnamed; its role is now one-time init. the controller
2713 	 * should already have been reset (and boot firmware kicked off etc).
2714 	 */
2715 	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2716 		dev_err(hcd->self.controller, "can't setup: %d\n", retval);
2717 		goto err_hcd_driver_setup;
2718 	}
2719 	hcd->rh_pollable = 1;
2720 
2721 	/* NOTE: root hub and controller capabilities may not be the same */
2722 	if (device_can_wakeup(hcd->self.controller)
2723 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2724 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2725 
2726 	/* initialize tasklets */
2727 	init_giveback_urb_bh(&hcd->high_prio_bh);
2728 	init_giveback_urb_bh(&hcd->low_prio_bh);
2729 
2730 	/* enable irqs just before we start the controller,
2731 	 * if the BIOS provides legacy PCI irqs.
2732 	 */
2733 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2734 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2735 		if (retval)
2736 			goto err_request_irq;
2737 	}
2738 
2739 	hcd->state = HC_STATE_RUNNING;
2740 	retval = hcd->driver->start(hcd);
2741 	if (retval < 0) {
2742 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2743 		goto err_hcd_driver_start;
2744 	}
2745 
2746 	/* starting here, usbcore will pay attention to this root hub */
2747 	if ((retval = register_root_hub(hcd)) != 0)
2748 		goto err_register_root_hub;
2749 
2750 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2751 	if (retval < 0) {
2752 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2753 		       retval);
2754 		goto error_create_attr_group;
2755 	}
2756 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2757 		usb_hcd_poll_rh_status(hcd);
2758 
2759 	return retval;
2760 
2761 error_create_attr_group:
2762 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2763 	if (HC_IS_RUNNING(hcd->state))
2764 		hcd->state = HC_STATE_QUIESCING;
2765 	spin_lock_irq(&hcd_root_hub_lock);
2766 	hcd->rh_registered = 0;
2767 	spin_unlock_irq(&hcd_root_hub_lock);
2768 
2769 #ifdef CONFIG_PM_RUNTIME
2770 	cancel_work_sync(&hcd->wakeup_work);
2771 #endif
2772 	mutex_lock(&usb_bus_list_lock);
2773 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2774 	mutex_unlock(&usb_bus_list_lock);
2775 err_register_root_hub:
2776 	hcd->rh_pollable = 0;
2777 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2778 	del_timer_sync(&hcd->rh_timer);
2779 	hcd->driver->stop(hcd);
2780 	hcd->state = HC_STATE_HALT;
2781 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2782 	del_timer_sync(&hcd->rh_timer);
2783 err_hcd_driver_start:
2784 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2785 		free_irq(irqnum, hcd);
2786 err_request_irq:
2787 err_hcd_driver_setup:
2788 err_set_rh_speed:
2789 	usb_put_invalidate_rhdev(hcd);
2790 err_allocate_root_hub:
2791 	usb_deregister_bus(&hcd->self);
2792 err_register_bus:
2793 	hcd_buffer_destroy(hcd);
2794 err_remove_phy:
2795 	if (hcd->remove_phy && hcd->phy) {
2796 		usb_phy_shutdown(hcd->phy);
2797 		usb_put_phy(hcd->phy);
2798 		hcd->phy = NULL;
2799 	}
2800 	return retval;
2801 }
2802 EXPORT_SYMBOL_GPL(usb_add_hcd);
2803 
2804 /**
2805  * usb_remove_hcd - shutdown processing for generic HCDs
2806  * @hcd: the usb_hcd structure to remove
2807  * Context: !in_interrupt()
2808  *
2809  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2810  * invoking the HCD's stop() method.
2811  */
2812 void usb_remove_hcd(struct usb_hcd *hcd)
2813 {
2814 	struct usb_device *rhdev = hcd->self.root_hub;
2815 
2816 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2817 
2818 	usb_get_dev(rhdev);
2819 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2820 
2821 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2822 	if (HC_IS_RUNNING (hcd->state))
2823 		hcd->state = HC_STATE_QUIESCING;
2824 
2825 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2826 	spin_lock_irq (&hcd_root_hub_lock);
2827 	hcd->rh_registered = 0;
2828 	spin_unlock_irq (&hcd_root_hub_lock);
2829 
2830 #ifdef CONFIG_PM_RUNTIME
2831 	cancel_work_sync(&hcd->wakeup_work);
2832 #endif
2833 
2834 	mutex_lock(&usb_bus_list_lock);
2835 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2836 	mutex_unlock(&usb_bus_list_lock);
2837 
2838 	/*
2839 	 * tasklet_kill() isn't needed here because:
2840 	 * - driver's disconnect() called from usb_disconnect() should
2841 	 *   make sure its URBs are completed during the disconnect()
2842 	 *   callback
2843 	 *
2844 	 * - it is too late to run complete() here since driver may have
2845 	 *   been removed already now
2846 	 */
2847 
2848 	/* Prevent any more root-hub status calls from the timer.
2849 	 * The HCD might still restart the timer (if a port status change
2850 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2851 	 * the hub_status_data() callback.
2852 	 */
2853 	hcd->rh_pollable = 0;
2854 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2855 	del_timer_sync(&hcd->rh_timer);
2856 
2857 	hcd->driver->stop(hcd);
2858 	hcd->state = HC_STATE_HALT;
2859 
2860 	/* In case the HCD restarted the timer, stop it again. */
2861 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2862 	del_timer_sync(&hcd->rh_timer);
2863 
2864 	if (usb_hcd_is_primary_hcd(hcd)) {
2865 		if (hcd->irq > 0)
2866 			free_irq(hcd->irq, hcd);
2867 	}
2868 
2869 	usb_deregister_bus(&hcd->self);
2870 	hcd_buffer_destroy(hcd);
2871 	if (hcd->remove_phy && hcd->phy) {
2872 		usb_phy_shutdown(hcd->phy);
2873 		usb_put_phy(hcd->phy);
2874 		hcd->phy = NULL;
2875 	}
2876 
2877 	usb_put_invalidate_rhdev(hcd);
2878 }
2879 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2880 
2881 void
2882 usb_hcd_platform_shutdown(struct platform_device *dev)
2883 {
2884 	struct usb_hcd *hcd = platform_get_drvdata(dev);
2885 
2886 	if (hcd->driver->shutdown)
2887 		hcd->driver->shutdown(hcd);
2888 }
2889 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2890 
2891 /*-------------------------------------------------------------------------*/
2892 
2893 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2894 
2895 struct usb_mon_operations *mon_ops;
2896 
2897 /*
2898  * The registration is unlocked.
2899  * We do it this way because we do not want to lock in hot paths.
2900  *
2901  * Notice that the code is minimally error-proof. Because usbmon needs
2902  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2903  */
2904 
2905 int usb_mon_register (struct usb_mon_operations *ops)
2906 {
2907 
2908 	if (mon_ops)
2909 		return -EBUSY;
2910 
2911 	mon_ops = ops;
2912 	mb();
2913 	return 0;
2914 }
2915 EXPORT_SYMBOL_GPL (usb_mon_register);
2916 
2917 void usb_mon_deregister (void)
2918 {
2919 
2920 	if (mon_ops == NULL) {
2921 		printk(KERN_ERR "USB: monitor was not registered\n");
2922 		return;
2923 	}
2924 	mon_ops = NULL;
2925 	mb();
2926 }
2927 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2928 
2929 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2930