xref: /linux/drivers/usb/core/hcd.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright Linus Torvalds 1999
4  * (C) Copyright Johannes Erdfelt 1999-2001
5  * (C) Copyright Andreas Gal 1999
6  * (C) Copyright Gregory P. Smith 1999
7  * (C) Copyright Deti Fliegl 1999
8  * (C) Copyright Randy Dunlap 2000
9  * (C) Copyright David Brownell 2000-2002
10  */
11 
12 #include <linux/bcd.h>
13 #include <linux/module.h>
14 #include <linux/version.h>
15 #include <linux/kernel.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/slab.h>
18 #include <linux/completion.h>
19 #include <linux/utsname.h>
20 #include <linux/mm.h>
21 #include <asm/io.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/mutex.h>
25 #include <asm/irq.h>
26 #include <asm/byteorder.h>
27 #include <asm/unaligned.h>
28 #include <linux/platform_device.h>
29 #include <linux/workqueue.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/types.h>
32 
33 #include <linux/phy/phy.h>
34 #include <linux/usb.h>
35 #include <linux/usb/hcd.h>
36 #include <linux/usb/phy.h>
37 #include <linux/usb/otg.h>
38 
39 #include "usb.h"
40 
41 
42 /*-------------------------------------------------------------------------*/
43 
44 /*
45  * USB Host Controller Driver framework
46  *
47  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
48  * HCD-specific behaviors/bugs.
49  *
50  * This does error checks, tracks devices and urbs, and delegates to a
51  * "hc_driver" only for code (and data) that really needs to know about
52  * hardware differences.  That includes root hub registers, i/o queues,
53  * and so on ... but as little else as possible.
54  *
55  * Shared code includes most of the "root hub" code (these are emulated,
56  * though each HC's hardware works differently) and PCI glue, plus request
57  * tracking overhead.  The HCD code should only block on spinlocks or on
58  * hardware handshaking; blocking on software events (such as other kernel
59  * threads releasing resources, or completing actions) is all generic.
60  *
61  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
62  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
63  * only by the hub driver ... and that neither should be seen or used by
64  * usb client device drivers.
65  *
66  * Contributors of ideas or unattributed patches include: David Brownell,
67  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
68  *
69  * HISTORY:
70  * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
71  *		associated cleanup.  "usb_hcd" still != "usb_bus".
72  * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
73  */
74 
75 /*-------------------------------------------------------------------------*/
76 
77 /* Keep track of which host controller drivers are loaded */
78 unsigned long usb_hcds_loaded;
79 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
80 
81 /* host controllers we manage */
82 DEFINE_IDR (usb_bus_idr);
83 EXPORT_SYMBOL_GPL (usb_bus_idr);
84 
85 /* used when allocating bus numbers */
86 #define USB_MAXBUS		64
87 
88 /* used when updating list of hcds */
89 DEFINE_MUTEX(usb_bus_idr_lock);	/* exported only for usbfs */
90 EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
91 
92 /* used for controlling access to virtual root hubs */
93 static DEFINE_SPINLOCK(hcd_root_hub_lock);
94 
95 /* used when updating an endpoint's URB list */
96 static DEFINE_SPINLOCK(hcd_urb_list_lock);
97 
98 /* used to protect against unlinking URBs after the device is gone */
99 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
100 
101 /* wait queue for synchronous unlinks */
102 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
103 
104 static inline int is_root_hub(struct usb_device *udev)
105 {
106 	return (udev->parent == NULL);
107 }
108 
109 /*-------------------------------------------------------------------------*/
110 
111 /*
112  * Sharable chunks of root hub code.
113  */
114 
115 /*-------------------------------------------------------------------------*/
116 #define KERNEL_REL	bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
117 #define KERNEL_VER	bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
118 
119 /* usb 3.1 root hub device descriptor */
120 static const u8 usb31_rh_dev_descriptor[18] = {
121 	0x12,       /*  __u8  bLength; */
122 	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
123 	0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
124 
125 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
126 	0x00,	    /*  __u8  bDeviceSubClass; */
127 	0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
128 	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
129 
130 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
131 	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
132 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
133 
134 	0x03,       /*  __u8  iManufacturer; */
135 	0x02,       /*  __u8  iProduct; */
136 	0x01,       /*  __u8  iSerialNumber; */
137 	0x01        /*  __u8  bNumConfigurations; */
138 };
139 
140 /* usb 3.0 root hub device descriptor */
141 static const u8 usb3_rh_dev_descriptor[18] = {
142 	0x12,       /*  __u8  bLength; */
143 	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
144 	0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
145 
146 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
147 	0x00,	    /*  __u8  bDeviceSubClass; */
148 	0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
149 	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
150 
151 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
152 	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
153 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
154 
155 	0x03,       /*  __u8  iManufacturer; */
156 	0x02,       /*  __u8  iProduct; */
157 	0x01,       /*  __u8  iSerialNumber; */
158 	0x01        /*  __u8  bNumConfigurations; */
159 };
160 
161 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
162 static const u8 usb25_rh_dev_descriptor[18] = {
163 	0x12,       /*  __u8  bLength; */
164 	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
165 	0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
166 
167 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
168 	0x00,	    /*  __u8  bDeviceSubClass; */
169 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
170 	0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
171 
172 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
173 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
174 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
175 
176 	0x03,       /*  __u8  iManufacturer; */
177 	0x02,       /*  __u8  iProduct; */
178 	0x01,       /*  __u8  iSerialNumber; */
179 	0x01        /*  __u8  bNumConfigurations; */
180 };
181 
182 /* usb 2.0 root hub device descriptor */
183 static const u8 usb2_rh_dev_descriptor[18] = {
184 	0x12,       /*  __u8  bLength; */
185 	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
186 	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
187 
188 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
189 	0x00,	    /*  __u8  bDeviceSubClass; */
190 	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
191 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
192 
193 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
194 	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
195 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
196 
197 	0x03,       /*  __u8  iManufacturer; */
198 	0x02,       /*  __u8  iProduct; */
199 	0x01,       /*  __u8  iSerialNumber; */
200 	0x01        /*  __u8  bNumConfigurations; */
201 };
202 
203 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
204 
205 /* usb 1.1 root hub device descriptor */
206 static const u8 usb11_rh_dev_descriptor[18] = {
207 	0x12,       /*  __u8  bLength; */
208 	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
209 	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
210 
211 	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
212 	0x00,	    /*  __u8  bDeviceSubClass; */
213 	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
214 	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
215 
216 	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
217 	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
218 	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
219 
220 	0x03,       /*  __u8  iManufacturer; */
221 	0x02,       /*  __u8  iProduct; */
222 	0x01,       /*  __u8  iSerialNumber; */
223 	0x01        /*  __u8  bNumConfigurations; */
224 };
225 
226 
227 /*-------------------------------------------------------------------------*/
228 
229 /* Configuration descriptors for our root hubs */
230 
231 static const u8 fs_rh_config_descriptor[] = {
232 
233 	/* one configuration */
234 	0x09,       /*  __u8  bLength; */
235 	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
236 	0x19, 0x00, /*  __le16 wTotalLength; */
237 	0x01,       /*  __u8  bNumInterfaces; (1) */
238 	0x01,       /*  __u8  bConfigurationValue; */
239 	0x00,       /*  __u8  iConfiguration; */
240 	0xc0,       /*  __u8  bmAttributes;
241 				 Bit 7: must be set,
242 				     6: Self-powered,
243 				     5: Remote wakeup,
244 				     4..0: resvd */
245 	0x00,       /*  __u8  MaxPower; */
246 
247 	/* USB 1.1:
248 	 * USB 2.0, single TT organization (mandatory):
249 	 *	one interface, protocol 0
250 	 *
251 	 * USB 2.0, multiple TT organization (optional):
252 	 *	two interfaces, protocols 1 (like single TT)
253 	 *	and 2 (multiple TT mode) ... config is
254 	 *	sometimes settable
255 	 *	NOT IMPLEMENTED
256 	 */
257 
258 	/* one interface */
259 	0x09,       /*  __u8  if_bLength; */
260 	USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
261 	0x00,       /*  __u8  if_bInterfaceNumber; */
262 	0x00,       /*  __u8  if_bAlternateSetting; */
263 	0x01,       /*  __u8  if_bNumEndpoints; */
264 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
265 	0x00,       /*  __u8  if_bInterfaceSubClass; */
266 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
267 	0x00,       /*  __u8  if_iInterface; */
268 
269 	/* one endpoint (status change endpoint) */
270 	0x07,       /*  __u8  ep_bLength; */
271 	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
272 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
273 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
274 	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
275 	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
276 };
277 
278 static const u8 hs_rh_config_descriptor[] = {
279 
280 	/* one configuration */
281 	0x09,       /*  __u8  bLength; */
282 	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
283 	0x19, 0x00, /*  __le16 wTotalLength; */
284 	0x01,       /*  __u8  bNumInterfaces; (1) */
285 	0x01,       /*  __u8  bConfigurationValue; */
286 	0x00,       /*  __u8  iConfiguration; */
287 	0xc0,       /*  __u8  bmAttributes;
288 				 Bit 7: must be set,
289 				     6: Self-powered,
290 				     5: Remote wakeup,
291 				     4..0: resvd */
292 	0x00,       /*  __u8  MaxPower; */
293 
294 	/* USB 1.1:
295 	 * USB 2.0, single TT organization (mandatory):
296 	 *	one interface, protocol 0
297 	 *
298 	 * USB 2.0, multiple TT organization (optional):
299 	 *	two interfaces, protocols 1 (like single TT)
300 	 *	and 2 (multiple TT mode) ... config is
301 	 *	sometimes settable
302 	 *	NOT IMPLEMENTED
303 	 */
304 
305 	/* one interface */
306 	0x09,       /*  __u8  if_bLength; */
307 	USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
308 	0x00,       /*  __u8  if_bInterfaceNumber; */
309 	0x00,       /*  __u8  if_bAlternateSetting; */
310 	0x01,       /*  __u8  if_bNumEndpoints; */
311 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
312 	0x00,       /*  __u8  if_bInterfaceSubClass; */
313 	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
314 	0x00,       /*  __u8  if_iInterface; */
315 
316 	/* one endpoint (status change endpoint) */
317 	0x07,       /*  __u8  ep_bLength; */
318 	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
319 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
320 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
321 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
322 		     * see hub.c:hub_configure() for details. */
323 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
324 	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
325 };
326 
327 static const u8 ss_rh_config_descriptor[] = {
328 	/* one configuration */
329 	0x09,       /*  __u8  bLength; */
330 	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
331 	0x1f, 0x00, /*  __le16 wTotalLength; */
332 	0x01,       /*  __u8  bNumInterfaces; (1) */
333 	0x01,       /*  __u8  bConfigurationValue; */
334 	0x00,       /*  __u8  iConfiguration; */
335 	0xc0,       /*  __u8  bmAttributes;
336 				 Bit 7: must be set,
337 				     6: Self-powered,
338 				     5: Remote wakeup,
339 				     4..0: resvd */
340 	0x00,       /*  __u8  MaxPower; */
341 
342 	/* one interface */
343 	0x09,       /*  __u8  if_bLength; */
344 	USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
345 	0x00,       /*  __u8  if_bInterfaceNumber; */
346 	0x00,       /*  __u8  if_bAlternateSetting; */
347 	0x01,       /*  __u8  if_bNumEndpoints; */
348 	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
349 	0x00,       /*  __u8  if_bInterfaceSubClass; */
350 	0x00,       /*  __u8  if_bInterfaceProtocol; */
351 	0x00,       /*  __u8  if_iInterface; */
352 
353 	/* one endpoint (status change endpoint) */
354 	0x07,       /*  __u8  ep_bLength; */
355 	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
356 	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
357 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
358 		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
359 		     * see hub.c:hub_configure() for details. */
360 	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
361 	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
362 
363 	/* one SuperSpeed endpoint companion descriptor */
364 	0x06,        /* __u8 ss_bLength */
365 	USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
366 		     /* Companion */
367 	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
368 	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
369 	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
370 };
371 
372 /* authorized_default behaviour:
373  * -1 is authorized for all devices except wireless (old behaviour)
374  * 0 is unauthorized for all devices
375  * 1 is authorized for all devices
376  */
377 static int authorized_default = -1;
378 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
379 MODULE_PARM_DESC(authorized_default,
380 		"Default USB device authorization: 0 is not authorized, 1 is "
381 		"authorized, -1 is authorized except for wireless USB (default, "
382 		"old behaviour");
383 /*-------------------------------------------------------------------------*/
384 
385 /**
386  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
387  * @s: Null-terminated ASCII (actually ISO-8859-1) string
388  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
389  * @len: Length (in bytes; may be odd) of descriptor buffer.
390  *
391  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
392  * whichever is less.
393  *
394  * Note:
395  * USB String descriptors can contain at most 126 characters; input
396  * strings longer than that are truncated.
397  */
398 static unsigned
399 ascii2desc(char const *s, u8 *buf, unsigned len)
400 {
401 	unsigned n, t = 2 + 2*strlen(s);
402 
403 	if (t > 254)
404 		t = 254;	/* Longest possible UTF string descriptor */
405 	if (len > t)
406 		len = t;
407 
408 	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
409 
410 	n = len;
411 	while (n--) {
412 		*buf++ = t;
413 		if (!n--)
414 			break;
415 		*buf++ = t >> 8;
416 		t = (unsigned char)*s++;
417 	}
418 	return len;
419 }
420 
421 /**
422  * rh_string() - provides string descriptors for root hub
423  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
424  * @hcd: the host controller for this root hub
425  * @data: buffer for output packet
426  * @len: length of the provided buffer
427  *
428  * Produces either a manufacturer, product or serial number string for the
429  * virtual root hub device.
430  *
431  * Return: The number of bytes filled in: the length of the descriptor or
432  * of the provided buffer, whichever is less.
433  */
434 static unsigned
435 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
436 {
437 	char buf[100];
438 	char const *s;
439 	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
440 
441 	/* language ids */
442 	switch (id) {
443 	case 0:
444 		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
445 		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
446 		if (len > 4)
447 			len = 4;
448 		memcpy(data, langids, len);
449 		return len;
450 	case 1:
451 		/* Serial number */
452 		s = hcd->self.bus_name;
453 		break;
454 	case 2:
455 		/* Product name */
456 		s = hcd->product_desc;
457 		break;
458 	case 3:
459 		/* Manufacturer */
460 		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
461 			init_utsname()->release, hcd->driver->description);
462 		s = buf;
463 		break;
464 	default:
465 		/* Can't happen; caller guarantees it */
466 		return 0;
467 	}
468 
469 	return ascii2desc(s, data, len);
470 }
471 
472 
473 /* Root hub control transfers execute synchronously */
474 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
475 {
476 	struct usb_ctrlrequest *cmd;
477 	u16		typeReq, wValue, wIndex, wLength;
478 	u8		*ubuf = urb->transfer_buffer;
479 	unsigned	len = 0;
480 	int		status;
481 	u8		patch_wakeup = 0;
482 	u8		patch_protocol = 0;
483 	u16		tbuf_size;
484 	u8		*tbuf = NULL;
485 	const u8	*bufp;
486 
487 	might_sleep();
488 
489 	spin_lock_irq(&hcd_root_hub_lock);
490 	status = usb_hcd_link_urb_to_ep(hcd, urb);
491 	spin_unlock_irq(&hcd_root_hub_lock);
492 	if (status)
493 		return status;
494 	urb->hcpriv = hcd;	/* Indicate it's queued */
495 
496 	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
497 	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
498 	wValue   = le16_to_cpu (cmd->wValue);
499 	wIndex   = le16_to_cpu (cmd->wIndex);
500 	wLength  = le16_to_cpu (cmd->wLength);
501 
502 	if (wLength > urb->transfer_buffer_length)
503 		goto error;
504 
505 	/*
506 	 * tbuf should be at least as big as the
507 	 * USB hub descriptor.
508 	 */
509 	tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
510 	tbuf = kzalloc(tbuf_size, GFP_KERNEL);
511 	if (!tbuf) {
512 		status = -ENOMEM;
513 		goto err_alloc;
514 	}
515 
516 	bufp = tbuf;
517 
518 
519 	urb->actual_length = 0;
520 	switch (typeReq) {
521 
522 	/* DEVICE REQUESTS */
523 
524 	/* The root hub's remote wakeup enable bit is implemented using
525 	 * driver model wakeup flags.  If this system supports wakeup
526 	 * through USB, userspace may change the default "allow wakeup"
527 	 * policy through sysfs or these calls.
528 	 *
529 	 * Most root hubs support wakeup from downstream devices, for
530 	 * runtime power management (disabling USB clocks and reducing
531 	 * VBUS power usage).  However, not all of them do so; silicon,
532 	 * board, and BIOS bugs here are not uncommon, so these can't
533 	 * be treated quite like external hubs.
534 	 *
535 	 * Likewise, not all root hubs will pass wakeup events upstream,
536 	 * to wake up the whole system.  So don't assume root hub and
537 	 * controller capabilities are identical.
538 	 */
539 
540 	case DeviceRequest | USB_REQ_GET_STATUS:
541 		tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
542 					<< USB_DEVICE_REMOTE_WAKEUP)
543 				| (1 << USB_DEVICE_SELF_POWERED);
544 		tbuf[1] = 0;
545 		len = 2;
546 		break;
547 	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
548 		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
549 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
550 		else
551 			goto error;
552 		break;
553 	case DeviceOutRequest | USB_REQ_SET_FEATURE:
554 		if (device_can_wakeup(&hcd->self.root_hub->dev)
555 				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
556 			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
557 		else
558 			goto error;
559 		break;
560 	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
561 		tbuf[0] = 1;
562 		len = 1;
563 			/* FALLTHROUGH */
564 	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
565 		break;
566 	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
567 		switch (wValue & 0xff00) {
568 		case USB_DT_DEVICE << 8:
569 			switch (hcd->speed) {
570 			case HCD_USB31:
571 				bufp = usb31_rh_dev_descriptor;
572 				break;
573 			case HCD_USB3:
574 				bufp = usb3_rh_dev_descriptor;
575 				break;
576 			case HCD_USB25:
577 				bufp = usb25_rh_dev_descriptor;
578 				break;
579 			case HCD_USB2:
580 				bufp = usb2_rh_dev_descriptor;
581 				break;
582 			case HCD_USB11:
583 				bufp = usb11_rh_dev_descriptor;
584 				break;
585 			default:
586 				goto error;
587 			}
588 			len = 18;
589 			if (hcd->has_tt)
590 				patch_protocol = 1;
591 			break;
592 		case USB_DT_CONFIG << 8:
593 			switch (hcd->speed) {
594 			case HCD_USB31:
595 			case HCD_USB3:
596 				bufp = ss_rh_config_descriptor;
597 				len = sizeof ss_rh_config_descriptor;
598 				break;
599 			case HCD_USB25:
600 			case HCD_USB2:
601 				bufp = hs_rh_config_descriptor;
602 				len = sizeof hs_rh_config_descriptor;
603 				break;
604 			case HCD_USB11:
605 				bufp = fs_rh_config_descriptor;
606 				len = sizeof fs_rh_config_descriptor;
607 				break;
608 			default:
609 				goto error;
610 			}
611 			if (device_can_wakeup(&hcd->self.root_hub->dev))
612 				patch_wakeup = 1;
613 			break;
614 		case USB_DT_STRING << 8:
615 			if ((wValue & 0xff) < 4)
616 				urb->actual_length = rh_string(wValue & 0xff,
617 						hcd, ubuf, wLength);
618 			else /* unsupported IDs --> "protocol stall" */
619 				goto error;
620 			break;
621 		case USB_DT_BOS << 8:
622 			goto nongeneric;
623 		default:
624 			goto error;
625 		}
626 		break;
627 	case DeviceRequest | USB_REQ_GET_INTERFACE:
628 		tbuf[0] = 0;
629 		len = 1;
630 			/* FALLTHROUGH */
631 	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
632 		break;
633 	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
634 		/* wValue == urb->dev->devaddr */
635 		dev_dbg (hcd->self.controller, "root hub device address %d\n",
636 			wValue);
637 		break;
638 
639 	/* INTERFACE REQUESTS (no defined feature/status flags) */
640 
641 	/* ENDPOINT REQUESTS */
642 
643 	case EndpointRequest | USB_REQ_GET_STATUS:
644 		/* ENDPOINT_HALT flag */
645 		tbuf[0] = 0;
646 		tbuf[1] = 0;
647 		len = 2;
648 			/* FALLTHROUGH */
649 	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
650 	case EndpointOutRequest | USB_REQ_SET_FEATURE:
651 		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
652 		break;
653 
654 	/* CLASS REQUESTS (and errors) */
655 
656 	default:
657 nongeneric:
658 		/* non-generic request */
659 		switch (typeReq) {
660 		case GetHubStatus:
661 			len = 4;
662 			break;
663 		case GetPortStatus:
664 			if (wValue == HUB_PORT_STATUS)
665 				len = 4;
666 			else
667 				/* other port status types return 8 bytes */
668 				len = 8;
669 			break;
670 		case GetHubDescriptor:
671 			len = sizeof (struct usb_hub_descriptor);
672 			break;
673 		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
674 			/* len is returned by hub_control */
675 			break;
676 		}
677 		status = hcd->driver->hub_control (hcd,
678 			typeReq, wValue, wIndex,
679 			tbuf, wLength);
680 
681 		if (typeReq == GetHubDescriptor)
682 			usb_hub_adjust_deviceremovable(hcd->self.root_hub,
683 				(struct usb_hub_descriptor *)tbuf);
684 		break;
685 error:
686 		/* "protocol stall" on error */
687 		status = -EPIPE;
688 	}
689 
690 	if (status < 0) {
691 		len = 0;
692 		if (status != -EPIPE) {
693 			dev_dbg (hcd->self.controller,
694 				"CTRL: TypeReq=0x%x val=0x%x "
695 				"idx=0x%x len=%d ==> %d\n",
696 				typeReq, wValue, wIndex,
697 				wLength, status);
698 		}
699 	} else if (status > 0) {
700 		/* hub_control may return the length of data copied. */
701 		len = status;
702 		status = 0;
703 	}
704 	if (len) {
705 		if (urb->transfer_buffer_length < len)
706 			len = urb->transfer_buffer_length;
707 		urb->actual_length = len;
708 		/* always USB_DIR_IN, toward host */
709 		memcpy (ubuf, bufp, len);
710 
711 		/* report whether RH hardware supports remote wakeup */
712 		if (patch_wakeup &&
713 				len > offsetof (struct usb_config_descriptor,
714 						bmAttributes))
715 			((struct usb_config_descriptor *)ubuf)->bmAttributes
716 				|= USB_CONFIG_ATT_WAKEUP;
717 
718 		/* report whether RH hardware has an integrated TT */
719 		if (patch_protocol &&
720 				len > offsetof(struct usb_device_descriptor,
721 						bDeviceProtocol))
722 			((struct usb_device_descriptor *) ubuf)->
723 				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
724 	}
725 
726 	kfree(tbuf);
727  err_alloc:
728 
729 	/* any errors get returned through the urb completion */
730 	spin_lock_irq(&hcd_root_hub_lock);
731 	usb_hcd_unlink_urb_from_ep(hcd, urb);
732 	usb_hcd_giveback_urb(hcd, urb, status);
733 	spin_unlock_irq(&hcd_root_hub_lock);
734 	return 0;
735 }
736 
737 /*-------------------------------------------------------------------------*/
738 
739 /*
740  * Root Hub interrupt transfers are polled using a timer if the
741  * driver requests it; otherwise the driver is responsible for
742  * calling usb_hcd_poll_rh_status() when an event occurs.
743  *
744  * Completions are called in_interrupt(), but they may or may not
745  * be in_irq().
746  */
747 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
748 {
749 	struct urb	*urb;
750 	int		length;
751 	unsigned long	flags;
752 	char		buffer[6];	/* Any root hubs with > 31 ports? */
753 
754 	if (unlikely(!hcd->rh_pollable))
755 		return;
756 	if (!hcd->uses_new_polling && !hcd->status_urb)
757 		return;
758 
759 	length = hcd->driver->hub_status_data(hcd, buffer);
760 	if (length > 0) {
761 
762 		/* try to complete the status urb */
763 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
764 		urb = hcd->status_urb;
765 		if (urb) {
766 			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
767 			hcd->status_urb = NULL;
768 			urb->actual_length = length;
769 			memcpy(urb->transfer_buffer, buffer, length);
770 
771 			usb_hcd_unlink_urb_from_ep(hcd, urb);
772 			usb_hcd_giveback_urb(hcd, urb, 0);
773 		} else {
774 			length = 0;
775 			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
776 		}
777 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
778 	}
779 
780 	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
781 	 * exceed that limit if HZ is 100. The math is more clunky than
782 	 * maybe expected, this is to make sure that all timers for USB devices
783 	 * fire at the same time to give the CPU a break in between */
784 	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
785 			(length == 0 && hcd->status_urb != NULL))
786 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
787 }
788 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
789 
790 /* timer callback */
791 static void rh_timer_func (struct timer_list *t)
792 {
793 	struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer);
794 
795 	usb_hcd_poll_rh_status(_hcd);
796 }
797 
798 /*-------------------------------------------------------------------------*/
799 
800 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
801 {
802 	int		retval;
803 	unsigned long	flags;
804 	unsigned	len = 1 + (urb->dev->maxchild / 8);
805 
806 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
807 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
808 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
809 		retval = -EINVAL;
810 		goto done;
811 	}
812 
813 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
814 	if (retval)
815 		goto done;
816 
817 	hcd->status_urb = urb;
818 	urb->hcpriv = hcd;	/* indicate it's queued */
819 	if (!hcd->uses_new_polling)
820 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
821 
822 	/* If a status change has already occurred, report it ASAP */
823 	else if (HCD_POLL_PENDING(hcd))
824 		mod_timer(&hcd->rh_timer, jiffies);
825 	retval = 0;
826  done:
827 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
828 	return retval;
829 }
830 
831 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
832 {
833 	if (usb_endpoint_xfer_int(&urb->ep->desc))
834 		return rh_queue_status (hcd, urb);
835 	if (usb_endpoint_xfer_control(&urb->ep->desc))
836 		return rh_call_control (hcd, urb);
837 	return -EINVAL;
838 }
839 
840 /*-------------------------------------------------------------------------*/
841 
842 /* Unlinks of root-hub control URBs are legal, but they don't do anything
843  * since these URBs always execute synchronously.
844  */
845 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
846 {
847 	unsigned long	flags;
848 	int		rc;
849 
850 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
851 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
852 	if (rc)
853 		goto done;
854 
855 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
856 		;	/* Do nothing */
857 
858 	} else {				/* Status URB */
859 		if (!hcd->uses_new_polling)
860 			del_timer (&hcd->rh_timer);
861 		if (urb == hcd->status_urb) {
862 			hcd->status_urb = NULL;
863 			usb_hcd_unlink_urb_from_ep(hcd, urb);
864 			usb_hcd_giveback_urb(hcd, urb, status);
865 		}
866 	}
867  done:
868 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
869 	return rc;
870 }
871 
872 
873 
874 /*
875  * Show & store the current value of authorized_default
876  */
877 static ssize_t authorized_default_show(struct device *dev,
878 				       struct device_attribute *attr, char *buf)
879 {
880 	struct usb_device *rh_usb_dev = to_usb_device(dev);
881 	struct usb_bus *usb_bus = rh_usb_dev->bus;
882 	struct usb_hcd *hcd;
883 
884 	hcd = bus_to_hcd(usb_bus);
885 	return snprintf(buf, PAGE_SIZE, "%u\n", !!HCD_DEV_AUTHORIZED(hcd));
886 }
887 
888 static ssize_t authorized_default_store(struct device *dev,
889 					struct device_attribute *attr,
890 					const char *buf, size_t size)
891 {
892 	ssize_t result;
893 	unsigned val;
894 	struct usb_device *rh_usb_dev = to_usb_device(dev);
895 	struct usb_bus *usb_bus = rh_usb_dev->bus;
896 	struct usb_hcd *hcd;
897 
898 	hcd = bus_to_hcd(usb_bus);
899 	result = sscanf(buf, "%u\n", &val);
900 	if (result == 1) {
901 		if (val)
902 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
903 		else
904 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
905 
906 		result = size;
907 	} else {
908 		result = -EINVAL;
909 	}
910 	return result;
911 }
912 static DEVICE_ATTR_RW(authorized_default);
913 
914 /*
915  * interface_authorized_default_show - show default authorization status
916  * for USB interfaces
917  *
918  * note: interface_authorized_default is the default value
919  *       for initializing the authorized attribute of interfaces
920  */
921 static ssize_t interface_authorized_default_show(struct device *dev,
922 		struct device_attribute *attr, char *buf)
923 {
924 	struct usb_device *usb_dev = to_usb_device(dev);
925 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
926 
927 	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));
928 }
929 
930 /*
931  * interface_authorized_default_store - store default authorization status
932  * for USB interfaces
933  *
934  * note: interface_authorized_default is the default value
935  *       for initializing the authorized attribute of interfaces
936  */
937 static ssize_t interface_authorized_default_store(struct device *dev,
938 		struct device_attribute *attr, const char *buf, size_t count)
939 {
940 	struct usb_device *usb_dev = to_usb_device(dev);
941 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
942 	int rc = count;
943 	bool val;
944 
945 	if (strtobool(buf, &val) != 0)
946 		return -EINVAL;
947 
948 	if (val)
949 		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
950 	else
951 		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
952 
953 	return rc;
954 }
955 static DEVICE_ATTR_RW(interface_authorized_default);
956 
957 /* Group all the USB bus attributes */
958 static struct attribute *usb_bus_attrs[] = {
959 		&dev_attr_authorized_default.attr,
960 		&dev_attr_interface_authorized_default.attr,
961 		NULL,
962 };
963 
964 static const struct attribute_group usb_bus_attr_group = {
965 	.name = NULL,	/* we want them in the same directory */
966 	.attrs = usb_bus_attrs,
967 };
968 
969 
970 
971 /*-------------------------------------------------------------------------*/
972 
973 /**
974  * usb_bus_init - shared initialization code
975  * @bus: the bus structure being initialized
976  *
977  * This code is used to initialize a usb_bus structure, memory for which is
978  * separately managed.
979  */
980 static void usb_bus_init (struct usb_bus *bus)
981 {
982 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
983 
984 	bus->devnum_next = 1;
985 
986 	bus->root_hub = NULL;
987 	bus->busnum = -1;
988 	bus->bandwidth_allocated = 0;
989 	bus->bandwidth_int_reqs  = 0;
990 	bus->bandwidth_isoc_reqs = 0;
991 	mutex_init(&bus->devnum_next_mutex);
992 }
993 
994 /*-------------------------------------------------------------------------*/
995 
996 /**
997  * usb_register_bus - registers the USB host controller with the usb core
998  * @bus: pointer to the bus to register
999  * Context: !in_interrupt()
1000  *
1001  * Assigns a bus number, and links the controller into usbcore data
1002  * structures so that it can be seen by scanning the bus list.
1003  *
1004  * Return: 0 if successful. A negative error code otherwise.
1005  */
1006 static int usb_register_bus(struct usb_bus *bus)
1007 {
1008 	int result = -E2BIG;
1009 	int busnum;
1010 
1011 	mutex_lock(&usb_bus_idr_lock);
1012 	busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
1013 	if (busnum < 0) {
1014 		pr_err("%s: failed to get bus number\n", usbcore_name);
1015 		goto error_find_busnum;
1016 	}
1017 	bus->busnum = busnum;
1018 	mutex_unlock(&usb_bus_idr_lock);
1019 
1020 	usb_notify_add_bus(bus);
1021 
1022 	dev_info (bus->controller, "new USB bus registered, assigned bus "
1023 		  "number %d\n", bus->busnum);
1024 	return 0;
1025 
1026 error_find_busnum:
1027 	mutex_unlock(&usb_bus_idr_lock);
1028 	return result;
1029 }
1030 
1031 /**
1032  * usb_deregister_bus - deregisters the USB host controller
1033  * @bus: pointer to the bus to deregister
1034  * Context: !in_interrupt()
1035  *
1036  * Recycles the bus number, and unlinks the controller from usbcore data
1037  * structures so that it won't be seen by scanning the bus list.
1038  */
1039 static void usb_deregister_bus (struct usb_bus *bus)
1040 {
1041 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
1042 
1043 	/*
1044 	 * NOTE: make sure that all the devices are removed by the
1045 	 * controller code, as well as having it call this when cleaning
1046 	 * itself up
1047 	 */
1048 	mutex_lock(&usb_bus_idr_lock);
1049 	idr_remove(&usb_bus_idr, bus->busnum);
1050 	mutex_unlock(&usb_bus_idr_lock);
1051 
1052 	usb_notify_remove_bus(bus);
1053 }
1054 
1055 /**
1056  * register_root_hub - called by usb_add_hcd() to register a root hub
1057  * @hcd: host controller for this root hub
1058  *
1059  * This function registers the root hub with the USB subsystem.  It sets up
1060  * the device properly in the device tree and then calls usb_new_device()
1061  * to register the usb device.  It also assigns the root hub's USB address
1062  * (always 1).
1063  *
1064  * Return: 0 if successful. A negative error code otherwise.
1065  */
1066 static int register_root_hub(struct usb_hcd *hcd)
1067 {
1068 	struct device *parent_dev = hcd->self.controller;
1069 	struct usb_device *usb_dev = hcd->self.root_hub;
1070 	const int devnum = 1;
1071 	int retval;
1072 
1073 	usb_dev->devnum = devnum;
1074 	usb_dev->bus->devnum_next = devnum + 1;
1075 	memset (&usb_dev->bus->devmap.devicemap, 0,
1076 			sizeof usb_dev->bus->devmap.devicemap);
1077 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1078 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1079 
1080 	mutex_lock(&usb_bus_idr_lock);
1081 
1082 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1083 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1084 	if (retval != sizeof usb_dev->descriptor) {
1085 		mutex_unlock(&usb_bus_idr_lock);
1086 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1087 				dev_name(&usb_dev->dev), retval);
1088 		return (retval < 0) ? retval : -EMSGSIZE;
1089 	}
1090 
1091 	if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
1092 		retval = usb_get_bos_descriptor(usb_dev);
1093 		if (!retval) {
1094 			usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1095 		} else if (usb_dev->speed >= USB_SPEED_SUPER) {
1096 			mutex_unlock(&usb_bus_idr_lock);
1097 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1098 					dev_name(&usb_dev->dev), retval);
1099 			return retval;
1100 		}
1101 	}
1102 
1103 	retval = usb_new_device (usb_dev);
1104 	if (retval) {
1105 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1106 				dev_name(&usb_dev->dev), retval);
1107 	} else {
1108 		spin_lock_irq (&hcd_root_hub_lock);
1109 		hcd->rh_registered = 1;
1110 		spin_unlock_irq (&hcd_root_hub_lock);
1111 
1112 		/* Did the HC die before the root hub was registered? */
1113 		if (HCD_DEAD(hcd))
1114 			usb_hc_died (hcd);	/* This time clean up */
1115 	}
1116 	mutex_unlock(&usb_bus_idr_lock);
1117 
1118 	return retval;
1119 }
1120 
1121 /*
1122  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1123  * @bus: the bus which the root hub belongs to
1124  * @portnum: the port which is being resumed
1125  *
1126  * HCDs should call this function when they know that a resume signal is
1127  * being sent to a root-hub port.  The root hub will be prevented from
1128  * going into autosuspend until usb_hcd_end_port_resume() is called.
1129  *
1130  * The bus's private lock must be held by the caller.
1131  */
1132 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1133 {
1134 	unsigned bit = 1 << portnum;
1135 
1136 	if (!(bus->resuming_ports & bit)) {
1137 		bus->resuming_ports |= bit;
1138 		pm_runtime_get_noresume(&bus->root_hub->dev);
1139 	}
1140 }
1141 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1142 
1143 /*
1144  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1145  * @bus: the bus which the root hub belongs to
1146  * @portnum: the port which is being resumed
1147  *
1148  * HCDs should call this function when they know that a resume signal has
1149  * stopped being sent to a root-hub port.  The root hub will be allowed to
1150  * autosuspend again.
1151  *
1152  * The bus's private lock must be held by the caller.
1153  */
1154 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1155 {
1156 	unsigned bit = 1 << portnum;
1157 
1158 	if (bus->resuming_ports & bit) {
1159 		bus->resuming_ports &= ~bit;
1160 		pm_runtime_put_noidle(&bus->root_hub->dev);
1161 	}
1162 }
1163 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1164 
1165 /*-------------------------------------------------------------------------*/
1166 
1167 /**
1168  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1169  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1170  * @is_input: true iff the transaction sends data to the host
1171  * @isoc: true for isochronous transactions, false for interrupt ones
1172  * @bytecount: how many bytes in the transaction.
1173  *
1174  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1175  *
1176  * Note:
1177  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1178  * scheduled in software, this function is only used for such scheduling.
1179  */
1180 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1181 {
1182 	unsigned long	tmp;
1183 
1184 	switch (speed) {
1185 	case USB_SPEED_LOW: 	/* INTR only */
1186 		if (is_input) {
1187 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1188 			return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1189 		} else {
1190 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1191 			return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1192 		}
1193 	case USB_SPEED_FULL:	/* ISOC or INTR */
1194 		if (isoc) {
1195 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1196 			return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1197 		} else {
1198 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1199 			return 9107L + BW_HOST_DELAY + tmp;
1200 		}
1201 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1202 		/* FIXME adjust for input vs output */
1203 		if (isoc)
1204 			tmp = HS_NSECS_ISO (bytecount);
1205 		else
1206 			tmp = HS_NSECS (bytecount);
1207 		return tmp;
1208 	default:
1209 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1210 		return -1;
1211 	}
1212 }
1213 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1214 
1215 
1216 /*-------------------------------------------------------------------------*/
1217 
1218 /*
1219  * Generic HC operations.
1220  */
1221 
1222 /*-------------------------------------------------------------------------*/
1223 
1224 /**
1225  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1226  * @hcd: host controller to which @urb was submitted
1227  * @urb: URB being submitted
1228  *
1229  * Host controller drivers should call this routine in their enqueue()
1230  * method.  The HCD's private spinlock must be held and interrupts must
1231  * be disabled.  The actions carried out here are required for URB
1232  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1233  *
1234  * Return: 0 for no error, otherwise a negative error code (in which case
1235  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1236  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1237  * the private spinlock and returning.
1238  */
1239 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1240 {
1241 	int		rc = 0;
1242 
1243 	spin_lock(&hcd_urb_list_lock);
1244 
1245 	/* Check that the URB isn't being killed */
1246 	if (unlikely(atomic_read(&urb->reject))) {
1247 		rc = -EPERM;
1248 		goto done;
1249 	}
1250 
1251 	if (unlikely(!urb->ep->enabled)) {
1252 		rc = -ENOENT;
1253 		goto done;
1254 	}
1255 
1256 	if (unlikely(!urb->dev->can_submit)) {
1257 		rc = -EHOSTUNREACH;
1258 		goto done;
1259 	}
1260 
1261 	/*
1262 	 * Check the host controller's state and add the URB to the
1263 	 * endpoint's queue.
1264 	 */
1265 	if (HCD_RH_RUNNING(hcd)) {
1266 		urb->unlinked = 0;
1267 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1268 	} else {
1269 		rc = -ESHUTDOWN;
1270 		goto done;
1271 	}
1272  done:
1273 	spin_unlock(&hcd_urb_list_lock);
1274 	return rc;
1275 }
1276 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1277 
1278 /**
1279  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1280  * @hcd: host controller to which @urb was submitted
1281  * @urb: URB being checked for unlinkability
1282  * @status: error code to store in @urb if the unlink succeeds
1283  *
1284  * Host controller drivers should call this routine in their dequeue()
1285  * method.  The HCD's private spinlock must be held and interrupts must
1286  * be disabled.  The actions carried out here are required for making
1287  * sure than an unlink is valid.
1288  *
1289  * Return: 0 for no error, otherwise a negative error code (in which case
1290  * the dequeue() method must fail).  The possible error codes are:
1291  *
1292  *	-EIDRM: @urb was not submitted or has already completed.
1293  *		The completion function may not have been called yet.
1294  *
1295  *	-EBUSY: @urb has already been unlinked.
1296  */
1297 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1298 		int status)
1299 {
1300 	struct list_head	*tmp;
1301 
1302 	/* insist the urb is still queued */
1303 	list_for_each(tmp, &urb->ep->urb_list) {
1304 		if (tmp == &urb->urb_list)
1305 			break;
1306 	}
1307 	if (tmp != &urb->urb_list)
1308 		return -EIDRM;
1309 
1310 	/* Any status except -EINPROGRESS means something already started to
1311 	 * unlink this URB from the hardware.  So there's no more work to do.
1312 	 */
1313 	if (urb->unlinked)
1314 		return -EBUSY;
1315 	urb->unlinked = status;
1316 	return 0;
1317 }
1318 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1319 
1320 /**
1321  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1322  * @hcd: host controller to which @urb was submitted
1323  * @urb: URB being unlinked
1324  *
1325  * Host controller drivers should call this routine before calling
1326  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1327  * interrupts must be disabled.  The actions carried out here are required
1328  * for URB completion.
1329  */
1330 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1331 {
1332 	/* clear all state linking urb to this dev (and hcd) */
1333 	spin_lock(&hcd_urb_list_lock);
1334 	list_del_init(&urb->urb_list);
1335 	spin_unlock(&hcd_urb_list_lock);
1336 }
1337 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1338 
1339 /*
1340  * Some usb host controllers can only perform dma using a small SRAM area.
1341  * The usb core itself is however optimized for host controllers that can dma
1342  * using regular system memory - like pci devices doing bus mastering.
1343  *
1344  * To support host controllers with limited dma capabilities we provide dma
1345  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1346  * For this to work properly the host controller code must first use the
1347  * function dma_declare_coherent_memory() to point out which memory area
1348  * that should be used for dma allocations.
1349  *
1350  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1351  * dma using dma_alloc_coherent() which in turn allocates from the memory
1352  * area pointed out with dma_declare_coherent_memory().
1353  *
1354  * So, to summarize...
1355  *
1356  * - We need "local" memory, canonical example being
1357  *   a small SRAM on a discrete controller being the
1358  *   only memory that the controller can read ...
1359  *   (a) "normal" kernel memory is no good, and
1360  *   (b) there's not enough to share
1361  *
1362  * - The only *portable* hook for such stuff in the
1363  *   DMA framework is dma_declare_coherent_memory()
1364  *
1365  * - So we use that, even though the primary requirement
1366  *   is that the memory be "local" (hence addressable
1367  *   by that device), not "coherent".
1368  *
1369  */
1370 
1371 static int hcd_alloc_coherent(struct usb_bus *bus,
1372 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1373 			      void **vaddr_handle, size_t size,
1374 			      enum dma_data_direction dir)
1375 {
1376 	unsigned char *vaddr;
1377 
1378 	if (*vaddr_handle == NULL) {
1379 		WARN_ON_ONCE(1);
1380 		return -EFAULT;
1381 	}
1382 
1383 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1384 				 mem_flags, dma_handle);
1385 	if (!vaddr)
1386 		return -ENOMEM;
1387 
1388 	/*
1389 	 * Store the virtual address of the buffer at the end
1390 	 * of the allocated dma buffer. The size of the buffer
1391 	 * may be uneven so use unaligned functions instead
1392 	 * of just rounding up. It makes sense to optimize for
1393 	 * memory footprint over access speed since the amount
1394 	 * of memory available for dma may be limited.
1395 	 */
1396 	put_unaligned((unsigned long)*vaddr_handle,
1397 		      (unsigned long *)(vaddr + size));
1398 
1399 	if (dir == DMA_TO_DEVICE)
1400 		memcpy(vaddr, *vaddr_handle, size);
1401 
1402 	*vaddr_handle = vaddr;
1403 	return 0;
1404 }
1405 
1406 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1407 			      void **vaddr_handle, size_t size,
1408 			      enum dma_data_direction dir)
1409 {
1410 	unsigned char *vaddr = *vaddr_handle;
1411 
1412 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1413 
1414 	if (dir == DMA_FROM_DEVICE)
1415 		memcpy(vaddr, *vaddr_handle, size);
1416 
1417 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1418 
1419 	*vaddr_handle = vaddr;
1420 	*dma_handle = 0;
1421 }
1422 
1423 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1424 {
1425 	if (IS_ENABLED(CONFIG_HAS_DMA) &&
1426 	    (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
1427 		dma_unmap_single(hcd->self.sysdev,
1428 				urb->setup_dma,
1429 				sizeof(struct usb_ctrlrequest),
1430 				DMA_TO_DEVICE);
1431 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1432 		hcd_free_coherent(urb->dev->bus,
1433 				&urb->setup_dma,
1434 				(void **) &urb->setup_packet,
1435 				sizeof(struct usb_ctrlrequest),
1436 				DMA_TO_DEVICE);
1437 
1438 	/* Make it safe to call this routine more than once */
1439 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1440 }
1441 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1442 
1443 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1444 {
1445 	if (hcd->driver->unmap_urb_for_dma)
1446 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1447 	else
1448 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1449 }
1450 
1451 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1452 {
1453 	enum dma_data_direction dir;
1454 
1455 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1456 
1457 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1458 	if (IS_ENABLED(CONFIG_HAS_DMA) &&
1459 	    (urb->transfer_flags & URB_DMA_MAP_SG))
1460 		dma_unmap_sg(hcd->self.sysdev,
1461 				urb->sg,
1462 				urb->num_sgs,
1463 				dir);
1464 	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1465 		 (urb->transfer_flags & URB_DMA_MAP_PAGE))
1466 		dma_unmap_page(hcd->self.sysdev,
1467 				urb->transfer_dma,
1468 				urb->transfer_buffer_length,
1469 				dir);
1470 	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1471 		 (urb->transfer_flags & URB_DMA_MAP_SINGLE))
1472 		dma_unmap_single(hcd->self.sysdev,
1473 				urb->transfer_dma,
1474 				urb->transfer_buffer_length,
1475 				dir);
1476 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1477 		hcd_free_coherent(urb->dev->bus,
1478 				&urb->transfer_dma,
1479 				&urb->transfer_buffer,
1480 				urb->transfer_buffer_length,
1481 				dir);
1482 
1483 	/* Make it safe to call this routine more than once */
1484 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1485 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1486 }
1487 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1488 
1489 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1490 			   gfp_t mem_flags)
1491 {
1492 	if (hcd->driver->map_urb_for_dma)
1493 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1494 	else
1495 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1496 }
1497 
1498 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1499 			    gfp_t mem_flags)
1500 {
1501 	enum dma_data_direction dir;
1502 	int ret = 0;
1503 
1504 	/* Map the URB's buffers for DMA access.
1505 	 * Lower level HCD code should use *_dma exclusively,
1506 	 * unless it uses pio or talks to another transport,
1507 	 * or uses the provided scatter gather list for bulk.
1508 	 */
1509 
1510 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1511 		if (hcd->self.uses_pio_for_control)
1512 			return ret;
1513 		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
1514 			if (is_vmalloc_addr(urb->setup_packet)) {
1515 				WARN_ONCE(1, "setup packet is not dma capable\n");
1516 				return -EAGAIN;
1517 			} else if (object_is_on_stack(urb->setup_packet)) {
1518 				WARN_ONCE(1, "setup packet is on stack\n");
1519 				return -EAGAIN;
1520 			}
1521 
1522 			urb->setup_dma = dma_map_single(
1523 					hcd->self.sysdev,
1524 					urb->setup_packet,
1525 					sizeof(struct usb_ctrlrequest),
1526 					DMA_TO_DEVICE);
1527 			if (dma_mapping_error(hcd->self.sysdev,
1528 						urb->setup_dma))
1529 				return -EAGAIN;
1530 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1531 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1532 			ret = hcd_alloc_coherent(
1533 					urb->dev->bus, mem_flags,
1534 					&urb->setup_dma,
1535 					(void **)&urb->setup_packet,
1536 					sizeof(struct usb_ctrlrequest),
1537 					DMA_TO_DEVICE);
1538 			if (ret)
1539 				return ret;
1540 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1541 		}
1542 	}
1543 
1544 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1545 	if (urb->transfer_buffer_length != 0
1546 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1547 		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
1548 			if (urb->num_sgs) {
1549 				int n;
1550 
1551 				/* We don't support sg for isoc transfers ! */
1552 				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1553 					WARN_ON(1);
1554 					return -EINVAL;
1555 				}
1556 
1557 				n = dma_map_sg(
1558 						hcd->self.sysdev,
1559 						urb->sg,
1560 						urb->num_sgs,
1561 						dir);
1562 				if (n <= 0)
1563 					ret = -EAGAIN;
1564 				else
1565 					urb->transfer_flags |= URB_DMA_MAP_SG;
1566 				urb->num_mapped_sgs = n;
1567 				if (n != urb->num_sgs)
1568 					urb->transfer_flags |=
1569 							URB_DMA_SG_COMBINED;
1570 			} else if (urb->sg) {
1571 				struct scatterlist *sg = urb->sg;
1572 				urb->transfer_dma = dma_map_page(
1573 						hcd->self.sysdev,
1574 						sg_page(sg),
1575 						sg->offset,
1576 						urb->transfer_buffer_length,
1577 						dir);
1578 				if (dma_mapping_error(hcd->self.sysdev,
1579 						urb->transfer_dma))
1580 					ret = -EAGAIN;
1581 				else
1582 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1583 			} else if (is_vmalloc_addr(urb->transfer_buffer)) {
1584 				WARN_ONCE(1, "transfer buffer not dma capable\n");
1585 				ret = -EAGAIN;
1586 			} else if (object_is_on_stack(urb->transfer_buffer)) {
1587 				WARN_ONCE(1, "transfer buffer is on stack\n");
1588 				ret = -EAGAIN;
1589 			} else {
1590 				urb->transfer_dma = dma_map_single(
1591 						hcd->self.sysdev,
1592 						urb->transfer_buffer,
1593 						urb->transfer_buffer_length,
1594 						dir);
1595 				if (dma_mapping_error(hcd->self.sysdev,
1596 						urb->transfer_dma))
1597 					ret = -EAGAIN;
1598 				else
1599 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1600 			}
1601 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1602 			ret = hcd_alloc_coherent(
1603 					urb->dev->bus, mem_flags,
1604 					&urb->transfer_dma,
1605 					&urb->transfer_buffer,
1606 					urb->transfer_buffer_length,
1607 					dir);
1608 			if (ret == 0)
1609 				urb->transfer_flags |= URB_MAP_LOCAL;
1610 		}
1611 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1612 				URB_SETUP_MAP_LOCAL)))
1613 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1614 	}
1615 	return ret;
1616 }
1617 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1618 
1619 /*-------------------------------------------------------------------------*/
1620 
1621 /* may be called in any context with a valid urb->dev usecount
1622  * caller surrenders "ownership" of urb
1623  * expects usb_submit_urb() to have sanity checked and conditioned all
1624  * inputs in the urb
1625  */
1626 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1627 {
1628 	int			status;
1629 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1630 
1631 	/* increment urb's reference count as part of giving it to the HCD
1632 	 * (which will control it).  HCD guarantees that it either returns
1633 	 * an error or calls giveback(), but not both.
1634 	 */
1635 	usb_get_urb(urb);
1636 	atomic_inc(&urb->use_count);
1637 	atomic_inc(&urb->dev->urbnum);
1638 	usbmon_urb_submit(&hcd->self, urb);
1639 
1640 	/* NOTE requirements on root-hub callers (usbfs and the hub
1641 	 * driver, for now):  URBs' urb->transfer_buffer must be
1642 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1643 	 * they could clobber root hub response data.  Also, control
1644 	 * URBs must be submitted in process context with interrupts
1645 	 * enabled.
1646 	 */
1647 
1648 	if (is_root_hub(urb->dev)) {
1649 		status = rh_urb_enqueue(hcd, urb);
1650 	} else {
1651 		status = map_urb_for_dma(hcd, urb, mem_flags);
1652 		if (likely(status == 0)) {
1653 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1654 			if (unlikely(status))
1655 				unmap_urb_for_dma(hcd, urb);
1656 		}
1657 	}
1658 
1659 	if (unlikely(status)) {
1660 		usbmon_urb_submit_error(&hcd->self, urb, status);
1661 		urb->hcpriv = NULL;
1662 		INIT_LIST_HEAD(&urb->urb_list);
1663 		atomic_dec(&urb->use_count);
1664 		atomic_dec(&urb->dev->urbnum);
1665 		if (atomic_read(&urb->reject))
1666 			wake_up(&usb_kill_urb_queue);
1667 		usb_put_urb(urb);
1668 	}
1669 	return status;
1670 }
1671 
1672 /*-------------------------------------------------------------------------*/
1673 
1674 /* this makes the hcd giveback() the urb more quickly, by kicking it
1675  * off hardware queues (which may take a while) and returning it as
1676  * soon as practical.  we've already set up the urb's return status,
1677  * but we can't know if the callback completed already.
1678  */
1679 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1680 {
1681 	int		value;
1682 
1683 	if (is_root_hub(urb->dev))
1684 		value = usb_rh_urb_dequeue(hcd, urb, status);
1685 	else {
1686 
1687 		/* The only reason an HCD might fail this call is if
1688 		 * it has not yet fully queued the urb to begin with.
1689 		 * Such failures should be harmless. */
1690 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1691 	}
1692 	return value;
1693 }
1694 
1695 /*
1696  * called in any context
1697  *
1698  * caller guarantees urb won't be recycled till both unlink()
1699  * and the urb's completion function return
1700  */
1701 int usb_hcd_unlink_urb (struct urb *urb, int status)
1702 {
1703 	struct usb_hcd		*hcd;
1704 	struct usb_device	*udev = urb->dev;
1705 	int			retval = -EIDRM;
1706 	unsigned long		flags;
1707 
1708 	/* Prevent the device and bus from going away while
1709 	 * the unlink is carried out.  If they are already gone
1710 	 * then urb->use_count must be 0, since disconnected
1711 	 * devices can't have any active URBs.
1712 	 */
1713 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1714 	if (atomic_read(&urb->use_count) > 0) {
1715 		retval = 0;
1716 		usb_get_dev(udev);
1717 	}
1718 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1719 	if (retval == 0) {
1720 		hcd = bus_to_hcd(urb->dev->bus);
1721 		retval = unlink1(hcd, urb, status);
1722 		if (retval == 0)
1723 			retval = -EINPROGRESS;
1724 		else if (retval != -EIDRM && retval != -EBUSY)
1725 			dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
1726 					urb, retval);
1727 		usb_put_dev(udev);
1728 	}
1729 	return retval;
1730 }
1731 
1732 /*-------------------------------------------------------------------------*/
1733 
1734 static void __usb_hcd_giveback_urb(struct urb *urb)
1735 {
1736 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1737 	struct usb_anchor *anchor = urb->anchor;
1738 	int status = urb->unlinked;
1739 	unsigned long flags;
1740 
1741 	urb->hcpriv = NULL;
1742 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1743 	    urb->actual_length < urb->transfer_buffer_length &&
1744 	    !status))
1745 		status = -EREMOTEIO;
1746 
1747 	unmap_urb_for_dma(hcd, urb);
1748 	usbmon_urb_complete(&hcd->self, urb, status);
1749 	usb_anchor_suspend_wakeups(anchor);
1750 	usb_unanchor_urb(urb);
1751 	if (likely(status == 0))
1752 		usb_led_activity(USB_LED_EVENT_HOST);
1753 
1754 	/* pass ownership to the completion handler */
1755 	urb->status = status;
1756 
1757 	/*
1758 	 * We disable local IRQs here avoid possible deadlock because
1759 	 * drivers may call spin_lock() to hold lock which might be
1760 	 * acquired in one hard interrupt handler.
1761 	 *
1762 	 * The local_irq_save()/local_irq_restore() around complete()
1763 	 * will be removed if current USB drivers have been cleaned up
1764 	 * and no one may trigger the above deadlock situation when
1765 	 * running complete() in tasklet.
1766 	 */
1767 	local_irq_save(flags);
1768 	urb->complete(urb);
1769 	local_irq_restore(flags);
1770 
1771 	usb_anchor_resume_wakeups(anchor);
1772 	atomic_dec(&urb->use_count);
1773 	if (unlikely(atomic_read(&urb->reject)))
1774 		wake_up(&usb_kill_urb_queue);
1775 	usb_put_urb(urb);
1776 }
1777 
1778 static void usb_giveback_urb_bh(unsigned long param)
1779 {
1780 	struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1781 	struct list_head local_list;
1782 
1783 	spin_lock_irq(&bh->lock);
1784 	bh->running = true;
1785  restart:
1786 	list_replace_init(&bh->head, &local_list);
1787 	spin_unlock_irq(&bh->lock);
1788 
1789 	while (!list_empty(&local_list)) {
1790 		struct urb *urb;
1791 
1792 		urb = list_entry(local_list.next, struct urb, urb_list);
1793 		list_del_init(&urb->urb_list);
1794 		bh->completing_ep = urb->ep;
1795 		__usb_hcd_giveback_urb(urb);
1796 		bh->completing_ep = NULL;
1797 	}
1798 
1799 	/* check if there are new URBs to giveback */
1800 	spin_lock_irq(&bh->lock);
1801 	if (!list_empty(&bh->head))
1802 		goto restart;
1803 	bh->running = false;
1804 	spin_unlock_irq(&bh->lock);
1805 }
1806 
1807 /**
1808  * usb_hcd_giveback_urb - return URB from HCD to device driver
1809  * @hcd: host controller returning the URB
1810  * @urb: urb being returned to the USB device driver.
1811  * @status: completion status code for the URB.
1812  * Context: in_interrupt()
1813  *
1814  * This hands the URB from HCD to its USB device driver, using its
1815  * completion function.  The HCD has freed all per-urb resources
1816  * (and is done using urb->hcpriv).  It also released all HCD locks;
1817  * the device driver won't cause problems if it frees, modifies,
1818  * or resubmits this URB.
1819  *
1820  * If @urb was unlinked, the value of @status will be overridden by
1821  * @urb->unlinked.  Erroneous short transfers are detected in case
1822  * the HCD hasn't checked for them.
1823  */
1824 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1825 {
1826 	struct giveback_urb_bh *bh;
1827 	bool running, high_prio_bh;
1828 
1829 	/* pass status to tasklet via unlinked */
1830 	if (likely(!urb->unlinked))
1831 		urb->unlinked = status;
1832 
1833 	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1834 		__usb_hcd_giveback_urb(urb);
1835 		return;
1836 	}
1837 
1838 	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1839 		bh = &hcd->high_prio_bh;
1840 		high_prio_bh = true;
1841 	} else {
1842 		bh = &hcd->low_prio_bh;
1843 		high_prio_bh = false;
1844 	}
1845 
1846 	spin_lock(&bh->lock);
1847 	list_add_tail(&urb->urb_list, &bh->head);
1848 	running = bh->running;
1849 	spin_unlock(&bh->lock);
1850 
1851 	if (running)
1852 		;
1853 	else if (high_prio_bh)
1854 		tasklet_hi_schedule(&bh->bh);
1855 	else
1856 		tasklet_schedule(&bh->bh);
1857 }
1858 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1859 
1860 /*-------------------------------------------------------------------------*/
1861 
1862 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1863  * queue to drain completely.  The caller must first insure that no more
1864  * URBs can be submitted for this endpoint.
1865  */
1866 void usb_hcd_flush_endpoint(struct usb_device *udev,
1867 		struct usb_host_endpoint *ep)
1868 {
1869 	struct usb_hcd		*hcd;
1870 	struct urb		*urb;
1871 
1872 	if (!ep)
1873 		return;
1874 	might_sleep();
1875 	hcd = bus_to_hcd(udev->bus);
1876 
1877 	/* No more submits can occur */
1878 	spin_lock_irq(&hcd_urb_list_lock);
1879 rescan:
1880 	list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
1881 		int	is_in;
1882 
1883 		if (urb->unlinked)
1884 			continue;
1885 		usb_get_urb (urb);
1886 		is_in = usb_urb_dir_in(urb);
1887 		spin_unlock(&hcd_urb_list_lock);
1888 
1889 		/* kick hcd */
1890 		unlink1(hcd, urb, -ESHUTDOWN);
1891 		dev_dbg (hcd->self.controller,
1892 			"shutdown urb %pK ep%d%s%s\n",
1893 			urb, usb_endpoint_num(&ep->desc),
1894 			is_in ? "in" : "out",
1895 			({	char *s;
1896 
1897 				 switch (usb_endpoint_type(&ep->desc)) {
1898 				 case USB_ENDPOINT_XFER_CONTROL:
1899 					s = ""; break;
1900 				 case USB_ENDPOINT_XFER_BULK:
1901 					s = "-bulk"; break;
1902 				 case USB_ENDPOINT_XFER_INT:
1903 					s = "-intr"; break;
1904 				 default:
1905 					s = "-iso"; break;
1906 				};
1907 				s;
1908 			}));
1909 		usb_put_urb (urb);
1910 
1911 		/* list contents may have changed */
1912 		spin_lock(&hcd_urb_list_lock);
1913 		goto rescan;
1914 	}
1915 	spin_unlock_irq(&hcd_urb_list_lock);
1916 
1917 	/* Wait until the endpoint queue is completely empty */
1918 	while (!list_empty (&ep->urb_list)) {
1919 		spin_lock_irq(&hcd_urb_list_lock);
1920 
1921 		/* The list may have changed while we acquired the spinlock */
1922 		urb = NULL;
1923 		if (!list_empty (&ep->urb_list)) {
1924 			urb = list_entry (ep->urb_list.prev, struct urb,
1925 					urb_list);
1926 			usb_get_urb (urb);
1927 		}
1928 		spin_unlock_irq(&hcd_urb_list_lock);
1929 
1930 		if (urb) {
1931 			usb_kill_urb (urb);
1932 			usb_put_urb (urb);
1933 		}
1934 	}
1935 }
1936 
1937 /**
1938  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1939  *				the bus bandwidth
1940  * @udev: target &usb_device
1941  * @new_config: new configuration to install
1942  * @cur_alt: the current alternate interface setting
1943  * @new_alt: alternate interface setting that is being installed
1944  *
1945  * To change configurations, pass in the new configuration in new_config,
1946  * and pass NULL for cur_alt and new_alt.
1947  *
1948  * To reset a device's configuration (put the device in the ADDRESSED state),
1949  * pass in NULL for new_config, cur_alt, and new_alt.
1950  *
1951  * To change alternate interface settings, pass in NULL for new_config,
1952  * pass in the current alternate interface setting in cur_alt,
1953  * and pass in the new alternate interface setting in new_alt.
1954  *
1955  * Return: An error if the requested bandwidth change exceeds the
1956  * bus bandwidth or host controller internal resources.
1957  */
1958 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1959 		struct usb_host_config *new_config,
1960 		struct usb_host_interface *cur_alt,
1961 		struct usb_host_interface *new_alt)
1962 {
1963 	int num_intfs, i, j;
1964 	struct usb_host_interface *alt = NULL;
1965 	int ret = 0;
1966 	struct usb_hcd *hcd;
1967 	struct usb_host_endpoint *ep;
1968 
1969 	hcd = bus_to_hcd(udev->bus);
1970 	if (!hcd->driver->check_bandwidth)
1971 		return 0;
1972 
1973 	/* Configuration is being removed - set configuration 0 */
1974 	if (!new_config && !cur_alt) {
1975 		for (i = 1; i < 16; ++i) {
1976 			ep = udev->ep_out[i];
1977 			if (ep)
1978 				hcd->driver->drop_endpoint(hcd, udev, ep);
1979 			ep = udev->ep_in[i];
1980 			if (ep)
1981 				hcd->driver->drop_endpoint(hcd, udev, ep);
1982 		}
1983 		hcd->driver->check_bandwidth(hcd, udev);
1984 		return 0;
1985 	}
1986 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1987 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1988 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1989 	 * ok to exclude it.
1990 	 */
1991 	if (new_config) {
1992 		num_intfs = new_config->desc.bNumInterfaces;
1993 		/* Remove endpoints (except endpoint 0, which is always on the
1994 		 * schedule) from the old config from the schedule
1995 		 */
1996 		for (i = 1; i < 16; ++i) {
1997 			ep = udev->ep_out[i];
1998 			if (ep) {
1999 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
2000 				if (ret < 0)
2001 					goto reset;
2002 			}
2003 			ep = udev->ep_in[i];
2004 			if (ep) {
2005 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
2006 				if (ret < 0)
2007 					goto reset;
2008 			}
2009 		}
2010 		for (i = 0; i < num_intfs; ++i) {
2011 			struct usb_host_interface *first_alt;
2012 			int iface_num;
2013 
2014 			first_alt = &new_config->intf_cache[i]->altsetting[0];
2015 			iface_num = first_alt->desc.bInterfaceNumber;
2016 			/* Set up endpoints for alternate interface setting 0 */
2017 			alt = usb_find_alt_setting(new_config, iface_num, 0);
2018 			if (!alt)
2019 				/* No alt setting 0? Pick the first setting. */
2020 				alt = first_alt;
2021 
2022 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
2023 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
2024 				if (ret < 0)
2025 					goto reset;
2026 			}
2027 		}
2028 	}
2029 	if (cur_alt && new_alt) {
2030 		struct usb_interface *iface = usb_ifnum_to_if(udev,
2031 				cur_alt->desc.bInterfaceNumber);
2032 
2033 		if (!iface)
2034 			return -EINVAL;
2035 		if (iface->resetting_device) {
2036 			/*
2037 			 * The USB core just reset the device, so the xHCI host
2038 			 * and the device will think alt setting 0 is installed.
2039 			 * However, the USB core will pass in the alternate
2040 			 * setting installed before the reset as cur_alt.  Dig
2041 			 * out the alternate setting 0 structure, or the first
2042 			 * alternate setting if a broken device doesn't have alt
2043 			 * setting 0.
2044 			 */
2045 			cur_alt = usb_altnum_to_altsetting(iface, 0);
2046 			if (!cur_alt)
2047 				cur_alt = &iface->altsetting[0];
2048 		}
2049 
2050 		/* Drop all the endpoints in the current alt setting */
2051 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
2052 			ret = hcd->driver->drop_endpoint(hcd, udev,
2053 					&cur_alt->endpoint[i]);
2054 			if (ret < 0)
2055 				goto reset;
2056 		}
2057 		/* Add all the endpoints in the new alt setting */
2058 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
2059 			ret = hcd->driver->add_endpoint(hcd, udev,
2060 					&new_alt->endpoint[i]);
2061 			if (ret < 0)
2062 				goto reset;
2063 		}
2064 	}
2065 	ret = hcd->driver->check_bandwidth(hcd, udev);
2066 reset:
2067 	if (ret < 0)
2068 		hcd->driver->reset_bandwidth(hcd, udev);
2069 	return ret;
2070 }
2071 
2072 /* Disables the endpoint: synchronizes with the hcd to make sure all
2073  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
2074  * have been called previously.  Use for set_configuration, set_interface,
2075  * driver removal, physical disconnect.
2076  *
2077  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
2078  * type, maxpacket size, toggle, halt status, and scheduling.
2079  */
2080 void usb_hcd_disable_endpoint(struct usb_device *udev,
2081 		struct usb_host_endpoint *ep)
2082 {
2083 	struct usb_hcd		*hcd;
2084 
2085 	might_sleep();
2086 	hcd = bus_to_hcd(udev->bus);
2087 	if (hcd->driver->endpoint_disable)
2088 		hcd->driver->endpoint_disable(hcd, ep);
2089 }
2090 
2091 /**
2092  * usb_hcd_reset_endpoint - reset host endpoint state
2093  * @udev: USB device.
2094  * @ep:   the endpoint to reset.
2095  *
2096  * Resets any host endpoint state such as the toggle bit, sequence
2097  * number and current window.
2098  */
2099 void usb_hcd_reset_endpoint(struct usb_device *udev,
2100 			    struct usb_host_endpoint *ep)
2101 {
2102 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2103 
2104 	if (hcd->driver->endpoint_reset)
2105 		hcd->driver->endpoint_reset(hcd, ep);
2106 	else {
2107 		int epnum = usb_endpoint_num(&ep->desc);
2108 		int is_out = usb_endpoint_dir_out(&ep->desc);
2109 		int is_control = usb_endpoint_xfer_control(&ep->desc);
2110 
2111 		usb_settoggle(udev, epnum, is_out, 0);
2112 		if (is_control)
2113 			usb_settoggle(udev, epnum, !is_out, 0);
2114 	}
2115 }
2116 
2117 /**
2118  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2119  * @interface:		alternate setting that includes all endpoints.
2120  * @eps:		array of endpoints that need streams.
2121  * @num_eps:		number of endpoints in the array.
2122  * @num_streams:	number of streams to allocate.
2123  * @mem_flags:		flags hcd should use to allocate memory.
2124  *
2125  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2126  * Drivers may queue multiple transfers to different stream IDs, which may
2127  * complete in a different order than they were queued.
2128  *
2129  * Return: On success, the number of allocated streams. On failure, a negative
2130  * error code.
2131  */
2132 int usb_alloc_streams(struct usb_interface *interface,
2133 		struct usb_host_endpoint **eps, unsigned int num_eps,
2134 		unsigned int num_streams, gfp_t mem_flags)
2135 {
2136 	struct usb_hcd *hcd;
2137 	struct usb_device *dev;
2138 	int i, ret;
2139 
2140 	dev = interface_to_usbdev(interface);
2141 	hcd = bus_to_hcd(dev->bus);
2142 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2143 		return -EINVAL;
2144 	if (dev->speed < USB_SPEED_SUPER)
2145 		return -EINVAL;
2146 	if (dev->state < USB_STATE_CONFIGURED)
2147 		return -ENODEV;
2148 
2149 	for (i = 0; i < num_eps; i++) {
2150 		/* Streams only apply to bulk endpoints. */
2151 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2152 			return -EINVAL;
2153 		/* Re-alloc is not allowed */
2154 		if (eps[i]->streams)
2155 			return -EINVAL;
2156 	}
2157 
2158 	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2159 			num_streams, mem_flags);
2160 	if (ret < 0)
2161 		return ret;
2162 
2163 	for (i = 0; i < num_eps; i++)
2164 		eps[i]->streams = ret;
2165 
2166 	return ret;
2167 }
2168 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2169 
2170 /**
2171  * usb_free_streams - free bulk endpoint stream IDs.
2172  * @interface:	alternate setting that includes all endpoints.
2173  * @eps:	array of endpoints to remove streams from.
2174  * @num_eps:	number of endpoints in the array.
2175  * @mem_flags:	flags hcd should use to allocate memory.
2176  *
2177  * Reverts a group of bulk endpoints back to not using stream IDs.
2178  * Can fail if we are given bad arguments, or HCD is broken.
2179  *
2180  * Return: 0 on success. On failure, a negative error code.
2181  */
2182 int usb_free_streams(struct usb_interface *interface,
2183 		struct usb_host_endpoint **eps, unsigned int num_eps,
2184 		gfp_t mem_flags)
2185 {
2186 	struct usb_hcd *hcd;
2187 	struct usb_device *dev;
2188 	int i, ret;
2189 
2190 	dev = interface_to_usbdev(interface);
2191 	hcd = bus_to_hcd(dev->bus);
2192 	if (dev->speed < USB_SPEED_SUPER)
2193 		return -EINVAL;
2194 
2195 	/* Double-free is not allowed */
2196 	for (i = 0; i < num_eps; i++)
2197 		if (!eps[i] || !eps[i]->streams)
2198 			return -EINVAL;
2199 
2200 	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2201 	if (ret < 0)
2202 		return ret;
2203 
2204 	for (i = 0; i < num_eps; i++)
2205 		eps[i]->streams = 0;
2206 
2207 	return ret;
2208 }
2209 EXPORT_SYMBOL_GPL(usb_free_streams);
2210 
2211 /* Protect against drivers that try to unlink URBs after the device
2212  * is gone, by waiting until all unlinks for @udev are finished.
2213  * Since we don't currently track URBs by device, simply wait until
2214  * nothing is running in the locked region of usb_hcd_unlink_urb().
2215  */
2216 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2217 {
2218 	spin_lock_irq(&hcd_urb_unlink_lock);
2219 	spin_unlock_irq(&hcd_urb_unlink_lock);
2220 }
2221 
2222 /*-------------------------------------------------------------------------*/
2223 
2224 /* called in any context */
2225 int usb_hcd_get_frame_number (struct usb_device *udev)
2226 {
2227 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2228 
2229 	if (!HCD_RH_RUNNING(hcd))
2230 		return -ESHUTDOWN;
2231 	return hcd->driver->get_frame_number (hcd);
2232 }
2233 
2234 /*-------------------------------------------------------------------------*/
2235 
2236 #ifdef	CONFIG_PM
2237 
2238 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2239 {
2240 	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
2241 	int		status;
2242 	int		old_state = hcd->state;
2243 
2244 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2245 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2246 			rhdev->do_remote_wakeup);
2247 	if (HCD_DEAD(hcd)) {
2248 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2249 		return 0;
2250 	}
2251 
2252 	if (!hcd->driver->bus_suspend) {
2253 		status = -ENOENT;
2254 	} else {
2255 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2256 		hcd->state = HC_STATE_QUIESCING;
2257 		status = hcd->driver->bus_suspend(hcd);
2258 	}
2259 	if (status == 0) {
2260 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2261 		hcd->state = HC_STATE_SUSPENDED;
2262 
2263 		/* Did we race with a root-hub wakeup event? */
2264 		if (rhdev->do_remote_wakeup) {
2265 			char	buffer[6];
2266 
2267 			status = hcd->driver->hub_status_data(hcd, buffer);
2268 			if (status != 0) {
2269 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2270 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2271 				status = -EBUSY;
2272 			}
2273 		}
2274 	} else {
2275 		spin_lock_irq(&hcd_root_hub_lock);
2276 		if (!HCD_DEAD(hcd)) {
2277 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2278 			hcd->state = old_state;
2279 		}
2280 		spin_unlock_irq(&hcd_root_hub_lock);
2281 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2282 				"suspend", status);
2283 	}
2284 	return status;
2285 }
2286 
2287 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2288 {
2289 	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
2290 	int		status;
2291 	int		old_state = hcd->state;
2292 
2293 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2294 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2295 	if (HCD_DEAD(hcd)) {
2296 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2297 		return 0;
2298 	}
2299 	if (!hcd->driver->bus_resume)
2300 		return -ENOENT;
2301 	if (HCD_RH_RUNNING(hcd))
2302 		return 0;
2303 
2304 	hcd->state = HC_STATE_RESUMING;
2305 	status = hcd->driver->bus_resume(hcd);
2306 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2307 	if (status == 0) {
2308 		struct usb_device *udev;
2309 		int port1;
2310 
2311 		spin_lock_irq(&hcd_root_hub_lock);
2312 		if (!HCD_DEAD(hcd)) {
2313 			usb_set_device_state(rhdev, rhdev->actconfig
2314 					? USB_STATE_CONFIGURED
2315 					: USB_STATE_ADDRESS);
2316 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2317 			hcd->state = HC_STATE_RUNNING;
2318 		}
2319 		spin_unlock_irq(&hcd_root_hub_lock);
2320 
2321 		/*
2322 		 * Check whether any of the enabled ports on the root hub are
2323 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2324 		 * (this is what the USB-2 spec calls a "global resume").
2325 		 * Otherwise we can skip the delay.
2326 		 */
2327 		usb_hub_for_each_child(rhdev, port1, udev) {
2328 			if (udev->state != USB_STATE_NOTATTACHED &&
2329 					!udev->port_is_suspended) {
2330 				usleep_range(10000, 11000);	/* TRSMRCY */
2331 				break;
2332 			}
2333 		}
2334 	} else {
2335 		hcd->state = old_state;
2336 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2337 				"resume", status);
2338 		if (status != -ESHUTDOWN)
2339 			usb_hc_died(hcd);
2340 	}
2341 	return status;
2342 }
2343 
2344 /* Workqueue routine for root-hub remote wakeup */
2345 static void hcd_resume_work(struct work_struct *work)
2346 {
2347 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2348 	struct usb_device *udev = hcd->self.root_hub;
2349 
2350 	usb_remote_wakeup(udev);
2351 }
2352 
2353 /**
2354  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2355  * @hcd: host controller for this root hub
2356  *
2357  * The USB host controller calls this function when its root hub is
2358  * suspended (with the remote wakeup feature enabled) and a remote
2359  * wakeup request is received.  The routine submits a workqueue request
2360  * to resume the root hub (that is, manage its downstream ports again).
2361  */
2362 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2363 {
2364 	unsigned long flags;
2365 
2366 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2367 	if (hcd->rh_registered) {
2368 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2369 		queue_work(pm_wq, &hcd->wakeup_work);
2370 	}
2371 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2372 }
2373 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2374 
2375 #endif	/* CONFIG_PM */
2376 
2377 /*-------------------------------------------------------------------------*/
2378 
2379 #ifdef	CONFIG_USB_OTG
2380 
2381 /**
2382  * usb_bus_start_enum - start immediate enumeration (for OTG)
2383  * @bus: the bus (must use hcd framework)
2384  * @port_num: 1-based number of port; usually bus->otg_port
2385  * Context: in_interrupt()
2386  *
2387  * Starts enumeration, with an immediate reset followed later by
2388  * hub_wq identifying and possibly configuring the device.
2389  * This is needed by OTG controller drivers, where it helps meet
2390  * HNP protocol timing requirements for starting a port reset.
2391  *
2392  * Return: 0 if successful.
2393  */
2394 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2395 {
2396 	struct usb_hcd		*hcd;
2397 	int			status = -EOPNOTSUPP;
2398 
2399 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2400 	 * boards with root hubs hooked up to internal devices (instead of
2401 	 * just the OTG port) may need more attention to resetting...
2402 	 */
2403 	hcd = bus_to_hcd(bus);
2404 	if (port_num && hcd->driver->start_port_reset)
2405 		status = hcd->driver->start_port_reset(hcd, port_num);
2406 
2407 	/* allocate hub_wq shortly after (first) root port reset finishes;
2408 	 * it may issue others, until at least 50 msecs have passed.
2409 	 */
2410 	if (status == 0)
2411 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2412 	return status;
2413 }
2414 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2415 
2416 #endif
2417 
2418 /*-------------------------------------------------------------------------*/
2419 
2420 /**
2421  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2422  * @irq: the IRQ being raised
2423  * @__hcd: pointer to the HCD whose IRQ is being signaled
2424  *
2425  * If the controller isn't HALTed, calls the driver's irq handler.
2426  * Checks whether the controller is now dead.
2427  *
2428  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2429  */
2430 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2431 {
2432 	struct usb_hcd		*hcd = __hcd;
2433 	irqreturn_t		rc;
2434 
2435 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2436 		rc = IRQ_NONE;
2437 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2438 		rc = IRQ_NONE;
2439 	else
2440 		rc = IRQ_HANDLED;
2441 
2442 	return rc;
2443 }
2444 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2445 
2446 /*-------------------------------------------------------------------------*/
2447 
2448 /**
2449  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2450  * @hcd: pointer to the HCD representing the controller
2451  *
2452  * This is called by bus glue to report a USB host controller that died
2453  * while operations may still have been pending.  It's called automatically
2454  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2455  *
2456  * Only call this function with the primary HCD.
2457  */
2458 void usb_hc_died (struct usb_hcd *hcd)
2459 {
2460 	unsigned long flags;
2461 
2462 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2463 
2464 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2465 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2466 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2467 	if (hcd->rh_registered) {
2468 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2469 
2470 		/* make hub_wq clean up old urbs and devices */
2471 		usb_set_device_state (hcd->self.root_hub,
2472 				USB_STATE_NOTATTACHED);
2473 		usb_kick_hub_wq(hcd->self.root_hub);
2474 	}
2475 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2476 		hcd = hcd->shared_hcd;
2477 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2478 		set_bit(HCD_FLAG_DEAD, &hcd->flags);
2479 		if (hcd->rh_registered) {
2480 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2481 
2482 			/* make hub_wq clean up old urbs and devices */
2483 			usb_set_device_state(hcd->self.root_hub,
2484 					USB_STATE_NOTATTACHED);
2485 			usb_kick_hub_wq(hcd->self.root_hub);
2486 		}
2487 	}
2488 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2489 	/* Make sure that the other roothub is also deallocated. */
2490 }
2491 EXPORT_SYMBOL_GPL (usb_hc_died);
2492 
2493 /*-------------------------------------------------------------------------*/
2494 
2495 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2496 {
2497 
2498 	spin_lock_init(&bh->lock);
2499 	INIT_LIST_HEAD(&bh->head);
2500 	tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2501 }
2502 
2503 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
2504 		struct device *sysdev, struct device *dev, const char *bus_name,
2505 		struct usb_hcd *primary_hcd)
2506 {
2507 	struct usb_hcd *hcd;
2508 
2509 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2510 	if (!hcd)
2511 		return NULL;
2512 	if (primary_hcd == NULL) {
2513 		hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
2514 				GFP_KERNEL);
2515 		if (!hcd->address0_mutex) {
2516 			kfree(hcd);
2517 			dev_dbg(dev, "hcd address0 mutex alloc failed\n");
2518 			return NULL;
2519 		}
2520 		mutex_init(hcd->address0_mutex);
2521 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2522 				GFP_KERNEL);
2523 		if (!hcd->bandwidth_mutex) {
2524 			kfree(hcd->address0_mutex);
2525 			kfree(hcd);
2526 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2527 			return NULL;
2528 		}
2529 		mutex_init(hcd->bandwidth_mutex);
2530 		dev_set_drvdata(dev, hcd);
2531 	} else {
2532 		mutex_lock(&usb_port_peer_mutex);
2533 		hcd->address0_mutex = primary_hcd->address0_mutex;
2534 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2535 		hcd->primary_hcd = primary_hcd;
2536 		primary_hcd->primary_hcd = primary_hcd;
2537 		hcd->shared_hcd = primary_hcd;
2538 		primary_hcd->shared_hcd = hcd;
2539 		mutex_unlock(&usb_port_peer_mutex);
2540 	}
2541 
2542 	kref_init(&hcd->kref);
2543 
2544 	usb_bus_init(&hcd->self);
2545 	hcd->self.controller = dev;
2546 	hcd->self.sysdev = sysdev;
2547 	hcd->self.bus_name = bus_name;
2548 	hcd->self.uses_dma = (sysdev->dma_mask != NULL);
2549 
2550 	timer_setup(&hcd->rh_timer, rh_timer_func, 0);
2551 #ifdef CONFIG_PM
2552 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2553 #endif
2554 
2555 	hcd->driver = driver;
2556 	hcd->speed = driver->flags & HCD_MASK;
2557 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2558 			"USB Host Controller";
2559 	return hcd;
2560 }
2561 EXPORT_SYMBOL_GPL(__usb_create_hcd);
2562 
2563 /**
2564  * usb_create_shared_hcd - create and initialize an HCD structure
2565  * @driver: HC driver that will use this hcd
2566  * @dev: device for this HC, stored in hcd->self.controller
2567  * @bus_name: value to store in hcd->self.bus_name
2568  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2569  *              PCI device.  Only allocate certain resources for the primary HCD
2570  * Context: !in_interrupt()
2571  *
2572  * Allocate a struct usb_hcd, with extra space at the end for the
2573  * HC driver's private data.  Initialize the generic members of the
2574  * hcd structure.
2575  *
2576  * Return: On success, a pointer to the created and initialized HCD structure.
2577  * On failure (e.g. if memory is unavailable), %NULL.
2578  */
2579 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2580 		struct device *dev, const char *bus_name,
2581 		struct usb_hcd *primary_hcd)
2582 {
2583 	return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
2584 }
2585 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2586 
2587 /**
2588  * usb_create_hcd - create and initialize an HCD structure
2589  * @driver: HC driver that will use this hcd
2590  * @dev: device for this HC, stored in hcd->self.controller
2591  * @bus_name: value to store in hcd->self.bus_name
2592  * Context: !in_interrupt()
2593  *
2594  * Allocate a struct usb_hcd, with extra space at the end for the
2595  * HC driver's private data.  Initialize the generic members of the
2596  * hcd structure.
2597  *
2598  * Return: On success, a pointer to the created and initialized HCD
2599  * structure. On failure (e.g. if memory is unavailable), %NULL.
2600  */
2601 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2602 		struct device *dev, const char *bus_name)
2603 {
2604 	return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
2605 }
2606 EXPORT_SYMBOL_GPL(usb_create_hcd);
2607 
2608 /*
2609  * Roothubs that share one PCI device must also share the bandwidth mutex.
2610  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2611  * deallocated.
2612  *
2613  * Make sure to deallocate the bandwidth_mutex only when the last HCD is
2614  * freed.  When hcd_release() is called for either hcd in a peer set,
2615  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
2616  */
2617 static void hcd_release(struct kref *kref)
2618 {
2619 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2620 
2621 	mutex_lock(&usb_port_peer_mutex);
2622 	if (hcd->shared_hcd) {
2623 		struct usb_hcd *peer = hcd->shared_hcd;
2624 
2625 		peer->shared_hcd = NULL;
2626 		peer->primary_hcd = NULL;
2627 	} else {
2628 		kfree(hcd->address0_mutex);
2629 		kfree(hcd->bandwidth_mutex);
2630 	}
2631 	mutex_unlock(&usb_port_peer_mutex);
2632 	kfree(hcd);
2633 }
2634 
2635 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2636 {
2637 	if (hcd)
2638 		kref_get (&hcd->kref);
2639 	return hcd;
2640 }
2641 EXPORT_SYMBOL_GPL(usb_get_hcd);
2642 
2643 void usb_put_hcd (struct usb_hcd *hcd)
2644 {
2645 	if (hcd)
2646 		kref_put (&hcd->kref, hcd_release);
2647 }
2648 EXPORT_SYMBOL_GPL(usb_put_hcd);
2649 
2650 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2651 {
2652 	if (!hcd->primary_hcd)
2653 		return 1;
2654 	return hcd == hcd->primary_hcd;
2655 }
2656 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2657 
2658 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2659 {
2660 	if (!hcd->driver->find_raw_port_number)
2661 		return port1;
2662 
2663 	return hcd->driver->find_raw_port_number(hcd, port1);
2664 }
2665 
2666 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2667 		unsigned int irqnum, unsigned long irqflags)
2668 {
2669 	int retval;
2670 
2671 	if (hcd->driver->irq) {
2672 
2673 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2674 				hcd->driver->description, hcd->self.busnum);
2675 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2676 				hcd->irq_descr, hcd);
2677 		if (retval != 0) {
2678 			dev_err(hcd->self.controller,
2679 					"request interrupt %d failed\n",
2680 					irqnum);
2681 			return retval;
2682 		}
2683 		hcd->irq = irqnum;
2684 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2685 				(hcd->driver->flags & HCD_MEMORY) ?
2686 					"io mem" : "io base",
2687 					(unsigned long long)hcd->rsrc_start);
2688 	} else {
2689 		hcd->irq = 0;
2690 		if (hcd->rsrc_start)
2691 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2692 					(hcd->driver->flags & HCD_MEMORY) ?
2693 					"io mem" : "io base",
2694 					(unsigned long long)hcd->rsrc_start);
2695 	}
2696 	return 0;
2697 }
2698 
2699 /*
2700  * Before we free this root hub, flush in-flight peering attempts
2701  * and disable peer lookups
2702  */
2703 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2704 {
2705 	struct usb_device *rhdev;
2706 
2707 	mutex_lock(&usb_port_peer_mutex);
2708 	rhdev = hcd->self.root_hub;
2709 	hcd->self.root_hub = NULL;
2710 	mutex_unlock(&usb_port_peer_mutex);
2711 	usb_put_dev(rhdev);
2712 }
2713 
2714 /**
2715  * usb_add_hcd - finish generic HCD structure initialization and register
2716  * @hcd: the usb_hcd structure to initialize
2717  * @irqnum: Interrupt line to allocate
2718  * @irqflags: Interrupt type flags
2719  *
2720  * Finish the remaining parts of generic HCD initialization: allocate the
2721  * buffers of consistent memory, register the bus, request the IRQ line,
2722  * and call the driver's reset() and start() routines.
2723  */
2724 int usb_add_hcd(struct usb_hcd *hcd,
2725 		unsigned int irqnum, unsigned long irqflags)
2726 {
2727 	int retval;
2728 	struct usb_device *rhdev;
2729 
2730 	if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) {
2731 		struct usb_phy *phy = usb_get_phy_dev(hcd->self.sysdev, 0);
2732 
2733 		if (IS_ERR(phy)) {
2734 			retval = PTR_ERR(phy);
2735 			if (retval == -EPROBE_DEFER)
2736 				return retval;
2737 		} else {
2738 			retval = usb_phy_init(phy);
2739 			if (retval) {
2740 				usb_put_phy(phy);
2741 				return retval;
2742 			}
2743 			hcd->usb_phy = phy;
2744 			hcd->remove_phy = 1;
2745 		}
2746 	}
2747 
2748 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) {
2749 		struct phy *phy = phy_get(hcd->self.sysdev, "usb");
2750 
2751 		if (IS_ERR(phy)) {
2752 			retval = PTR_ERR(phy);
2753 			if (retval == -EPROBE_DEFER)
2754 				goto err_phy;
2755 		} else {
2756 			retval = phy_init(phy);
2757 			if (retval) {
2758 				phy_put(phy);
2759 				goto err_phy;
2760 			}
2761 			retval = phy_power_on(phy);
2762 			if (retval) {
2763 				phy_exit(phy);
2764 				phy_put(phy);
2765 				goto err_phy;
2766 			}
2767 			hcd->phy = phy;
2768 			hcd->remove_phy = 1;
2769 		}
2770 	}
2771 
2772 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2773 
2774 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2775 	if (authorized_default < 0 || authorized_default > 1) {
2776 		if (hcd->wireless)
2777 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2778 		else
2779 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2780 	} else {
2781 		if (authorized_default)
2782 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2783 		else
2784 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2785 	}
2786 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2787 
2788 	/* per default all interfaces are authorized */
2789 	set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
2790 
2791 	/* HC is in reset state, but accessible.  Now do the one-time init,
2792 	 * bottom up so that hcds can customize the root hubs before hub_wq
2793 	 * starts talking to them.  (Note, bus id is assigned early too.)
2794 	 */
2795 	retval = hcd_buffer_create(hcd);
2796 	if (retval != 0) {
2797 		dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
2798 		goto err_create_buf;
2799 	}
2800 
2801 	retval = usb_register_bus(&hcd->self);
2802 	if (retval < 0)
2803 		goto err_register_bus;
2804 
2805 	rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
2806 	if (rhdev == NULL) {
2807 		dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
2808 		retval = -ENOMEM;
2809 		goto err_allocate_root_hub;
2810 	}
2811 	mutex_lock(&usb_port_peer_mutex);
2812 	hcd->self.root_hub = rhdev;
2813 	mutex_unlock(&usb_port_peer_mutex);
2814 
2815 	switch (hcd->speed) {
2816 	case HCD_USB11:
2817 		rhdev->speed = USB_SPEED_FULL;
2818 		break;
2819 	case HCD_USB2:
2820 		rhdev->speed = USB_SPEED_HIGH;
2821 		break;
2822 	case HCD_USB25:
2823 		rhdev->speed = USB_SPEED_WIRELESS;
2824 		break;
2825 	case HCD_USB3:
2826 		rhdev->speed = USB_SPEED_SUPER;
2827 		break;
2828 	case HCD_USB31:
2829 		rhdev->speed = USB_SPEED_SUPER_PLUS;
2830 		break;
2831 	default:
2832 		retval = -EINVAL;
2833 		goto err_set_rh_speed;
2834 	}
2835 
2836 	/* wakeup flag init defaults to "everything works" for root hubs,
2837 	 * but drivers can override it in reset() if needed, along with
2838 	 * recording the overall controller's system wakeup capability.
2839 	 */
2840 	device_set_wakeup_capable(&rhdev->dev, 1);
2841 
2842 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2843 	 * registered.  But since the controller can die at any time,
2844 	 * let's initialize the flag before touching the hardware.
2845 	 */
2846 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2847 
2848 	/* "reset" is misnamed; its role is now one-time init. the controller
2849 	 * should already have been reset (and boot firmware kicked off etc).
2850 	 */
2851 	if (hcd->driver->reset) {
2852 		retval = hcd->driver->reset(hcd);
2853 		if (retval < 0) {
2854 			dev_err(hcd->self.controller, "can't setup: %d\n",
2855 					retval);
2856 			goto err_hcd_driver_setup;
2857 		}
2858 	}
2859 	hcd->rh_pollable = 1;
2860 
2861 	/* NOTE: root hub and controller capabilities may not be the same */
2862 	if (device_can_wakeup(hcd->self.controller)
2863 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2864 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2865 
2866 	/* initialize tasklets */
2867 	init_giveback_urb_bh(&hcd->high_prio_bh);
2868 	init_giveback_urb_bh(&hcd->low_prio_bh);
2869 
2870 	/* enable irqs just before we start the controller,
2871 	 * if the BIOS provides legacy PCI irqs.
2872 	 */
2873 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2874 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2875 		if (retval)
2876 			goto err_request_irq;
2877 	}
2878 
2879 	hcd->state = HC_STATE_RUNNING;
2880 	retval = hcd->driver->start(hcd);
2881 	if (retval < 0) {
2882 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2883 		goto err_hcd_driver_start;
2884 	}
2885 
2886 	/* starting here, usbcore will pay attention to this root hub */
2887 	retval = register_root_hub(hcd);
2888 	if (retval != 0)
2889 		goto err_register_root_hub;
2890 
2891 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2892 	if (retval < 0) {
2893 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2894 		       retval);
2895 		goto error_create_attr_group;
2896 	}
2897 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2898 		usb_hcd_poll_rh_status(hcd);
2899 
2900 	return retval;
2901 
2902 error_create_attr_group:
2903 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2904 	if (HC_IS_RUNNING(hcd->state))
2905 		hcd->state = HC_STATE_QUIESCING;
2906 	spin_lock_irq(&hcd_root_hub_lock);
2907 	hcd->rh_registered = 0;
2908 	spin_unlock_irq(&hcd_root_hub_lock);
2909 
2910 #ifdef CONFIG_PM
2911 	cancel_work_sync(&hcd->wakeup_work);
2912 #endif
2913 	mutex_lock(&usb_bus_idr_lock);
2914 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2915 	mutex_unlock(&usb_bus_idr_lock);
2916 err_register_root_hub:
2917 	hcd->rh_pollable = 0;
2918 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2919 	del_timer_sync(&hcd->rh_timer);
2920 	hcd->driver->stop(hcd);
2921 	hcd->state = HC_STATE_HALT;
2922 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2923 	del_timer_sync(&hcd->rh_timer);
2924 err_hcd_driver_start:
2925 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2926 		free_irq(irqnum, hcd);
2927 err_request_irq:
2928 err_hcd_driver_setup:
2929 err_set_rh_speed:
2930 	usb_put_invalidate_rhdev(hcd);
2931 err_allocate_root_hub:
2932 	usb_deregister_bus(&hcd->self);
2933 err_register_bus:
2934 	hcd_buffer_destroy(hcd);
2935 err_create_buf:
2936 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2937 		phy_power_off(hcd->phy);
2938 		phy_exit(hcd->phy);
2939 		phy_put(hcd->phy);
2940 		hcd->phy = NULL;
2941 	}
2942 err_phy:
2943 	if (hcd->remove_phy && hcd->usb_phy) {
2944 		usb_phy_shutdown(hcd->usb_phy);
2945 		usb_put_phy(hcd->usb_phy);
2946 		hcd->usb_phy = NULL;
2947 	}
2948 	return retval;
2949 }
2950 EXPORT_SYMBOL_GPL(usb_add_hcd);
2951 
2952 /**
2953  * usb_remove_hcd - shutdown processing for generic HCDs
2954  * @hcd: the usb_hcd structure to remove
2955  * Context: !in_interrupt()
2956  *
2957  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2958  * invoking the HCD's stop() method.
2959  */
2960 void usb_remove_hcd(struct usb_hcd *hcd)
2961 {
2962 	struct usb_device *rhdev = hcd->self.root_hub;
2963 
2964 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2965 
2966 	usb_get_dev(rhdev);
2967 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2968 
2969 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2970 	if (HC_IS_RUNNING (hcd->state))
2971 		hcd->state = HC_STATE_QUIESCING;
2972 
2973 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2974 	spin_lock_irq (&hcd_root_hub_lock);
2975 	hcd->rh_registered = 0;
2976 	spin_unlock_irq (&hcd_root_hub_lock);
2977 
2978 #ifdef CONFIG_PM
2979 	cancel_work_sync(&hcd->wakeup_work);
2980 #endif
2981 
2982 	mutex_lock(&usb_bus_idr_lock);
2983 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2984 	mutex_unlock(&usb_bus_idr_lock);
2985 
2986 	/*
2987 	 * tasklet_kill() isn't needed here because:
2988 	 * - driver's disconnect() called from usb_disconnect() should
2989 	 *   make sure its URBs are completed during the disconnect()
2990 	 *   callback
2991 	 *
2992 	 * - it is too late to run complete() here since driver may have
2993 	 *   been removed already now
2994 	 */
2995 
2996 	/* Prevent any more root-hub status calls from the timer.
2997 	 * The HCD might still restart the timer (if a port status change
2998 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2999 	 * the hub_status_data() callback.
3000 	 */
3001 	hcd->rh_pollable = 0;
3002 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
3003 	del_timer_sync(&hcd->rh_timer);
3004 
3005 	hcd->driver->stop(hcd);
3006 	hcd->state = HC_STATE_HALT;
3007 
3008 	/* In case the HCD restarted the timer, stop it again. */
3009 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
3010 	del_timer_sync(&hcd->rh_timer);
3011 
3012 	if (usb_hcd_is_primary_hcd(hcd)) {
3013 		if (hcd->irq > 0)
3014 			free_irq(hcd->irq, hcd);
3015 	}
3016 
3017 	usb_deregister_bus(&hcd->self);
3018 	hcd_buffer_destroy(hcd);
3019 
3020 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
3021 		phy_power_off(hcd->phy);
3022 		phy_exit(hcd->phy);
3023 		phy_put(hcd->phy);
3024 		hcd->phy = NULL;
3025 	}
3026 	if (hcd->remove_phy && hcd->usb_phy) {
3027 		usb_phy_shutdown(hcd->usb_phy);
3028 		usb_put_phy(hcd->usb_phy);
3029 		hcd->usb_phy = NULL;
3030 	}
3031 
3032 	usb_put_invalidate_rhdev(hcd);
3033 	hcd->flags = 0;
3034 }
3035 EXPORT_SYMBOL_GPL(usb_remove_hcd);
3036 
3037 void
3038 usb_hcd_platform_shutdown(struct platform_device *dev)
3039 {
3040 	struct usb_hcd *hcd = platform_get_drvdata(dev);
3041 
3042 	if (hcd->driver->shutdown)
3043 		hcd->driver->shutdown(hcd);
3044 }
3045 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
3046 
3047 /*-------------------------------------------------------------------------*/
3048 
3049 #if IS_ENABLED(CONFIG_USB_MON)
3050 
3051 const struct usb_mon_operations *mon_ops;
3052 
3053 /*
3054  * The registration is unlocked.
3055  * We do it this way because we do not want to lock in hot paths.
3056  *
3057  * Notice that the code is minimally error-proof. Because usbmon needs
3058  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
3059  */
3060 
3061 int usb_mon_register(const struct usb_mon_operations *ops)
3062 {
3063 
3064 	if (mon_ops)
3065 		return -EBUSY;
3066 
3067 	mon_ops = ops;
3068 	mb();
3069 	return 0;
3070 }
3071 EXPORT_SYMBOL_GPL (usb_mon_register);
3072 
3073 void usb_mon_deregister (void)
3074 {
3075 
3076 	if (mon_ops == NULL) {
3077 		printk(KERN_ERR "USB: monitor was not registered\n");
3078 		return;
3079 	}
3080 	mon_ops = NULL;
3081 	mb();
3082 }
3083 EXPORT_SYMBOL_GPL (usb_mon_deregister);
3084 
3085 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
3086