xref: /linux/drivers/usb/core/hcd.c (revision 43347d56c8d9dd732cee2f8efd384ad21dd1f6c4)
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 (unsigned long _hcd)
792 {
793 	usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
794 }
795 
796 /*-------------------------------------------------------------------------*/
797 
798 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
799 {
800 	int		retval;
801 	unsigned long	flags;
802 	unsigned	len = 1 + (urb->dev->maxchild / 8);
803 
804 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
805 	if (hcd->status_urb || urb->transfer_buffer_length < len) {
806 		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
807 		retval = -EINVAL;
808 		goto done;
809 	}
810 
811 	retval = usb_hcd_link_urb_to_ep(hcd, urb);
812 	if (retval)
813 		goto done;
814 
815 	hcd->status_urb = urb;
816 	urb->hcpriv = hcd;	/* indicate it's queued */
817 	if (!hcd->uses_new_polling)
818 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
819 
820 	/* If a status change has already occurred, report it ASAP */
821 	else if (HCD_POLL_PENDING(hcd))
822 		mod_timer(&hcd->rh_timer, jiffies);
823 	retval = 0;
824  done:
825 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
826 	return retval;
827 }
828 
829 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
830 {
831 	if (usb_endpoint_xfer_int(&urb->ep->desc))
832 		return rh_queue_status (hcd, urb);
833 	if (usb_endpoint_xfer_control(&urb->ep->desc))
834 		return rh_call_control (hcd, urb);
835 	return -EINVAL;
836 }
837 
838 /*-------------------------------------------------------------------------*/
839 
840 /* Unlinks of root-hub control URBs are legal, but they don't do anything
841  * since these URBs always execute synchronously.
842  */
843 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
844 {
845 	unsigned long	flags;
846 	int		rc;
847 
848 	spin_lock_irqsave(&hcd_root_hub_lock, flags);
849 	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
850 	if (rc)
851 		goto done;
852 
853 	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
854 		;	/* Do nothing */
855 
856 	} else {				/* Status URB */
857 		if (!hcd->uses_new_polling)
858 			del_timer (&hcd->rh_timer);
859 		if (urb == hcd->status_urb) {
860 			hcd->status_urb = NULL;
861 			usb_hcd_unlink_urb_from_ep(hcd, urb);
862 			usb_hcd_giveback_urb(hcd, urb, status);
863 		}
864 	}
865  done:
866 	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
867 	return rc;
868 }
869 
870 
871 
872 /*
873  * Show & store the current value of authorized_default
874  */
875 static ssize_t authorized_default_show(struct device *dev,
876 				       struct device_attribute *attr, char *buf)
877 {
878 	struct usb_device *rh_usb_dev = to_usb_device(dev);
879 	struct usb_bus *usb_bus = rh_usb_dev->bus;
880 	struct usb_hcd *hcd;
881 
882 	hcd = bus_to_hcd(usb_bus);
883 	return snprintf(buf, PAGE_SIZE, "%u\n", !!HCD_DEV_AUTHORIZED(hcd));
884 }
885 
886 static ssize_t authorized_default_store(struct device *dev,
887 					struct device_attribute *attr,
888 					const char *buf, size_t size)
889 {
890 	ssize_t result;
891 	unsigned val;
892 	struct usb_device *rh_usb_dev = to_usb_device(dev);
893 	struct usb_bus *usb_bus = rh_usb_dev->bus;
894 	struct usb_hcd *hcd;
895 
896 	hcd = bus_to_hcd(usb_bus);
897 	result = sscanf(buf, "%u\n", &val);
898 	if (result == 1) {
899 		if (val)
900 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
901 		else
902 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
903 
904 		result = size;
905 	} else {
906 		result = -EINVAL;
907 	}
908 	return result;
909 }
910 static DEVICE_ATTR_RW(authorized_default);
911 
912 /*
913  * interface_authorized_default_show - show default authorization status
914  * for USB interfaces
915  *
916  * note: interface_authorized_default is the default value
917  *       for initializing the authorized attribute of interfaces
918  */
919 static ssize_t interface_authorized_default_show(struct device *dev,
920 		struct device_attribute *attr, char *buf)
921 {
922 	struct usb_device *usb_dev = to_usb_device(dev);
923 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
924 
925 	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));
926 }
927 
928 /*
929  * interface_authorized_default_store - store default authorization status
930  * for USB interfaces
931  *
932  * note: interface_authorized_default is the default value
933  *       for initializing the authorized attribute of interfaces
934  */
935 static ssize_t interface_authorized_default_store(struct device *dev,
936 		struct device_attribute *attr, const char *buf, size_t count)
937 {
938 	struct usb_device *usb_dev = to_usb_device(dev);
939 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
940 	int rc = count;
941 	bool val;
942 
943 	if (strtobool(buf, &val) != 0)
944 		return -EINVAL;
945 
946 	if (val)
947 		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
948 	else
949 		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
950 
951 	return rc;
952 }
953 static DEVICE_ATTR_RW(interface_authorized_default);
954 
955 /* Group all the USB bus attributes */
956 static struct attribute *usb_bus_attrs[] = {
957 		&dev_attr_authorized_default.attr,
958 		&dev_attr_interface_authorized_default.attr,
959 		NULL,
960 };
961 
962 static const struct attribute_group usb_bus_attr_group = {
963 	.name = NULL,	/* we want them in the same directory */
964 	.attrs = usb_bus_attrs,
965 };
966 
967 
968 
969 /*-------------------------------------------------------------------------*/
970 
971 /**
972  * usb_bus_init - shared initialization code
973  * @bus: the bus structure being initialized
974  *
975  * This code is used to initialize a usb_bus structure, memory for which is
976  * separately managed.
977  */
978 static void usb_bus_init (struct usb_bus *bus)
979 {
980 	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
981 
982 	bus->devnum_next = 1;
983 
984 	bus->root_hub = NULL;
985 	bus->busnum = -1;
986 	bus->bandwidth_allocated = 0;
987 	bus->bandwidth_int_reqs  = 0;
988 	bus->bandwidth_isoc_reqs = 0;
989 	mutex_init(&bus->devnum_next_mutex);
990 }
991 
992 /*-------------------------------------------------------------------------*/
993 
994 /**
995  * usb_register_bus - registers the USB host controller with the usb core
996  * @bus: pointer to the bus to register
997  * Context: !in_interrupt()
998  *
999  * Assigns a bus number, and links the controller into usbcore data
1000  * structures so that it can be seen by scanning the bus list.
1001  *
1002  * Return: 0 if successful. A negative error code otherwise.
1003  */
1004 static int usb_register_bus(struct usb_bus *bus)
1005 {
1006 	int result = -E2BIG;
1007 	int busnum;
1008 
1009 	mutex_lock(&usb_bus_idr_lock);
1010 	busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
1011 	if (busnum < 0) {
1012 		pr_err("%s: failed to get bus number\n", usbcore_name);
1013 		goto error_find_busnum;
1014 	}
1015 	bus->busnum = busnum;
1016 	mutex_unlock(&usb_bus_idr_lock);
1017 
1018 	usb_notify_add_bus(bus);
1019 
1020 	dev_info (bus->controller, "new USB bus registered, assigned bus "
1021 		  "number %d\n", bus->busnum);
1022 	return 0;
1023 
1024 error_find_busnum:
1025 	mutex_unlock(&usb_bus_idr_lock);
1026 	return result;
1027 }
1028 
1029 /**
1030  * usb_deregister_bus - deregisters the USB host controller
1031  * @bus: pointer to the bus to deregister
1032  * Context: !in_interrupt()
1033  *
1034  * Recycles the bus number, and unlinks the controller from usbcore data
1035  * structures so that it won't be seen by scanning the bus list.
1036  */
1037 static void usb_deregister_bus (struct usb_bus *bus)
1038 {
1039 	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
1040 
1041 	/*
1042 	 * NOTE: make sure that all the devices are removed by the
1043 	 * controller code, as well as having it call this when cleaning
1044 	 * itself up
1045 	 */
1046 	mutex_lock(&usb_bus_idr_lock);
1047 	idr_remove(&usb_bus_idr, bus->busnum);
1048 	mutex_unlock(&usb_bus_idr_lock);
1049 
1050 	usb_notify_remove_bus(bus);
1051 }
1052 
1053 /**
1054  * register_root_hub - called by usb_add_hcd() to register a root hub
1055  * @hcd: host controller for this root hub
1056  *
1057  * This function registers the root hub with the USB subsystem.  It sets up
1058  * the device properly in the device tree and then calls usb_new_device()
1059  * to register the usb device.  It also assigns the root hub's USB address
1060  * (always 1).
1061  *
1062  * Return: 0 if successful. A negative error code otherwise.
1063  */
1064 static int register_root_hub(struct usb_hcd *hcd)
1065 {
1066 	struct device *parent_dev = hcd->self.controller;
1067 	struct usb_device *usb_dev = hcd->self.root_hub;
1068 	const int devnum = 1;
1069 	int retval;
1070 
1071 	usb_dev->devnum = devnum;
1072 	usb_dev->bus->devnum_next = devnum + 1;
1073 	memset (&usb_dev->bus->devmap.devicemap, 0,
1074 			sizeof usb_dev->bus->devmap.devicemap);
1075 	set_bit (devnum, usb_dev->bus->devmap.devicemap);
1076 	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1077 
1078 	mutex_lock(&usb_bus_idr_lock);
1079 
1080 	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1081 	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1082 	if (retval != sizeof usb_dev->descriptor) {
1083 		mutex_unlock(&usb_bus_idr_lock);
1084 		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1085 				dev_name(&usb_dev->dev), retval);
1086 		return (retval < 0) ? retval : -EMSGSIZE;
1087 	}
1088 
1089 	if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
1090 		retval = usb_get_bos_descriptor(usb_dev);
1091 		if (!retval) {
1092 			usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1093 		} else if (usb_dev->speed >= USB_SPEED_SUPER) {
1094 			mutex_unlock(&usb_bus_idr_lock);
1095 			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1096 					dev_name(&usb_dev->dev), retval);
1097 			return retval;
1098 		}
1099 	}
1100 
1101 	retval = usb_new_device (usb_dev);
1102 	if (retval) {
1103 		dev_err (parent_dev, "can't register root hub for %s, %d\n",
1104 				dev_name(&usb_dev->dev), retval);
1105 	} else {
1106 		spin_lock_irq (&hcd_root_hub_lock);
1107 		hcd->rh_registered = 1;
1108 		spin_unlock_irq (&hcd_root_hub_lock);
1109 
1110 		/* Did the HC die before the root hub was registered? */
1111 		if (HCD_DEAD(hcd))
1112 			usb_hc_died (hcd);	/* This time clean up */
1113 	}
1114 	mutex_unlock(&usb_bus_idr_lock);
1115 
1116 	return retval;
1117 }
1118 
1119 /*
1120  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1121  * @bus: the bus which the root hub belongs to
1122  * @portnum: the port which is being resumed
1123  *
1124  * HCDs should call this function when they know that a resume signal is
1125  * being sent to a root-hub port.  The root hub will be prevented from
1126  * going into autosuspend until usb_hcd_end_port_resume() is called.
1127  *
1128  * The bus's private lock must be held by the caller.
1129  */
1130 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1131 {
1132 	unsigned bit = 1 << portnum;
1133 
1134 	if (!(bus->resuming_ports & bit)) {
1135 		bus->resuming_ports |= bit;
1136 		pm_runtime_get_noresume(&bus->root_hub->dev);
1137 	}
1138 }
1139 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1140 
1141 /*
1142  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1143  * @bus: the bus which the root hub belongs to
1144  * @portnum: the port which is being resumed
1145  *
1146  * HCDs should call this function when they know that a resume signal has
1147  * stopped being sent to a root-hub port.  The root hub will be allowed to
1148  * autosuspend again.
1149  *
1150  * The bus's private lock must be held by the caller.
1151  */
1152 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1153 {
1154 	unsigned bit = 1 << portnum;
1155 
1156 	if (bus->resuming_ports & bit) {
1157 		bus->resuming_ports &= ~bit;
1158 		pm_runtime_put_noidle(&bus->root_hub->dev);
1159 	}
1160 }
1161 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1162 
1163 /*-------------------------------------------------------------------------*/
1164 
1165 /**
1166  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1167  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1168  * @is_input: true iff the transaction sends data to the host
1169  * @isoc: true for isochronous transactions, false for interrupt ones
1170  * @bytecount: how many bytes in the transaction.
1171  *
1172  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1173  *
1174  * Note:
1175  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1176  * scheduled in software, this function is only used for such scheduling.
1177  */
1178 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1179 {
1180 	unsigned long	tmp;
1181 
1182 	switch (speed) {
1183 	case USB_SPEED_LOW: 	/* INTR only */
1184 		if (is_input) {
1185 			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1186 			return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1187 		} else {
1188 			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1189 			return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1190 		}
1191 	case USB_SPEED_FULL:	/* ISOC or INTR */
1192 		if (isoc) {
1193 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1194 			return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1195 		} else {
1196 			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1197 			return 9107L + BW_HOST_DELAY + tmp;
1198 		}
1199 	case USB_SPEED_HIGH:	/* ISOC or INTR */
1200 		/* FIXME adjust for input vs output */
1201 		if (isoc)
1202 			tmp = HS_NSECS_ISO (bytecount);
1203 		else
1204 			tmp = HS_NSECS (bytecount);
1205 		return tmp;
1206 	default:
1207 		pr_debug ("%s: bogus device speed!\n", usbcore_name);
1208 		return -1;
1209 	}
1210 }
1211 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1212 
1213 
1214 /*-------------------------------------------------------------------------*/
1215 
1216 /*
1217  * Generic HC operations.
1218  */
1219 
1220 /*-------------------------------------------------------------------------*/
1221 
1222 /**
1223  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1224  * @hcd: host controller to which @urb was submitted
1225  * @urb: URB being submitted
1226  *
1227  * Host controller drivers should call this routine in their enqueue()
1228  * method.  The HCD's private spinlock must be held and interrupts must
1229  * be disabled.  The actions carried out here are required for URB
1230  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1231  *
1232  * Return: 0 for no error, otherwise a negative error code (in which case
1233  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1234  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1235  * the private spinlock and returning.
1236  */
1237 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1238 {
1239 	int		rc = 0;
1240 
1241 	spin_lock(&hcd_urb_list_lock);
1242 
1243 	/* Check that the URB isn't being killed */
1244 	if (unlikely(atomic_read(&urb->reject))) {
1245 		rc = -EPERM;
1246 		goto done;
1247 	}
1248 
1249 	if (unlikely(!urb->ep->enabled)) {
1250 		rc = -ENOENT;
1251 		goto done;
1252 	}
1253 
1254 	if (unlikely(!urb->dev->can_submit)) {
1255 		rc = -EHOSTUNREACH;
1256 		goto done;
1257 	}
1258 
1259 	/*
1260 	 * Check the host controller's state and add the URB to the
1261 	 * endpoint's queue.
1262 	 */
1263 	if (HCD_RH_RUNNING(hcd)) {
1264 		urb->unlinked = 0;
1265 		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1266 	} else {
1267 		rc = -ESHUTDOWN;
1268 		goto done;
1269 	}
1270  done:
1271 	spin_unlock(&hcd_urb_list_lock);
1272 	return rc;
1273 }
1274 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1275 
1276 /**
1277  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1278  * @hcd: host controller to which @urb was submitted
1279  * @urb: URB being checked for unlinkability
1280  * @status: error code to store in @urb if the unlink succeeds
1281  *
1282  * Host controller drivers should call this routine in their dequeue()
1283  * method.  The HCD's private spinlock must be held and interrupts must
1284  * be disabled.  The actions carried out here are required for making
1285  * sure than an unlink is valid.
1286  *
1287  * Return: 0 for no error, otherwise a negative error code (in which case
1288  * the dequeue() method must fail).  The possible error codes are:
1289  *
1290  *	-EIDRM: @urb was not submitted or has already completed.
1291  *		The completion function may not have been called yet.
1292  *
1293  *	-EBUSY: @urb has already been unlinked.
1294  */
1295 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1296 		int status)
1297 {
1298 	struct list_head	*tmp;
1299 
1300 	/* insist the urb is still queued */
1301 	list_for_each(tmp, &urb->ep->urb_list) {
1302 		if (tmp == &urb->urb_list)
1303 			break;
1304 	}
1305 	if (tmp != &urb->urb_list)
1306 		return -EIDRM;
1307 
1308 	/* Any status except -EINPROGRESS means something already started to
1309 	 * unlink this URB from the hardware.  So there's no more work to do.
1310 	 */
1311 	if (urb->unlinked)
1312 		return -EBUSY;
1313 	urb->unlinked = status;
1314 	return 0;
1315 }
1316 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1317 
1318 /**
1319  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1320  * @hcd: host controller to which @urb was submitted
1321  * @urb: URB being unlinked
1322  *
1323  * Host controller drivers should call this routine before calling
1324  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1325  * interrupts must be disabled.  The actions carried out here are required
1326  * for URB completion.
1327  */
1328 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1329 {
1330 	/* clear all state linking urb to this dev (and hcd) */
1331 	spin_lock(&hcd_urb_list_lock);
1332 	list_del_init(&urb->urb_list);
1333 	spin_unlock(&hcd_urb_list_lock);
1334 }
1335 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1336 
1337 /*
1338  * Some usb host controllers can only perform dma using a small SRAM area.
1339  * The usb core itself is however optimized for host controllers that can dma
1340  * using regular system memory - like pci devices doing bus mastering.
1341  *
1342  * To support host controllers with limited dma capabilities we provide dma
1343  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1344  * For this to work properly the host controller code must first use the
1345  * function dma_declare_coherent_memory() to point out which memory area
1346  * that should be used for dma allocations.
1347  *
1348  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1349  * dma using dma_alloc_coherent() which in turn allocates from the memory
1350  * area pointed out with dma_declare_coherent_memory().
1351  *
1352  * So, to summarize...
1353  *
1354  * - We need "local" memory, canonical example being
1355  *   a small SRAM on a discrete controller being the
1356  *   only memory that the controller can read ...
1357  *   (a) "normal" kernel memory is no good, and
1358  *   (b) there's not enough to share
1359  *
1360  * - The only *portable* hook for such stuff in the
1361  *   DMA framework is dma_declare_coherent_memory()
1362  *
1363  * - So we use that, even though the primary requirement
1364  *   is that the memory be "local" (hence addressable
1365  *   by that device), not "coherent".
1366  *
1367  */
1368 
1369 static int hcd_alloc_coherent(struct usb_bus *bus,
1370 			      gfp_t mem_flags, dma_addr_t *dma_handle,
1371 			      void **vaddr_handle, size_t size,
1372 			      enum dma_data_direction dir)
1373 {
1374 	unsigned char *vaddr;
1375 
1376 	if (*vaddr_handle == NULL) {
1377 		WARN_ON_ONCE(1);
1378 		return -EFAULT;
1379 	}
1380 
1381 	vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1382 				 mem_flags, dma_handle);
1383 	if (!vaddr)
1384 		return -ENOMEM;
1385 
1386 	/*
1387 	 * Store the virtual address of the buffer at the end
1388 	 * of the allocated dma buffer. The size of the buffer
1389 	 * may be uneven so use unaligned functions instead
1390 	 * of just rounding up. It makes sense to optimize for
1391 	 * memory footprint over access speed since the amount
1392 	 * of memory available for dma may be limited.
1393 	 */
1394 	put_unaligned((unsigned long)*vaddr_handle,
1395 		      (unsigned long *)(vaddr + size));
1396 
1397 	if (dir == DMA_TO_DEVICE)
1398 		memcpy(vaddr, *vaddr_handle, size);
1399 
1400 	*vaddr_handle = vaddr;
1401 	return 0;
1402 }
1403 
1404 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1405 			      void **vaddr_handle, size_t size,
1406 			      enum dma_data_direction dir)
1407 {
1408 	unsigned char *vaddr = *vaddr_handle;
1409 
1410 	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1411 
1412 	if (dir == DMA_FROM_DEVICE)
1413 		memcpy(vaddr, *vaddr_handle, size);
1414 
1415 	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1416 
1417 	*vaddr_handle = vaddr;
1418 	*dma_handle = 0;
1419 }
1420 
1421 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1422 {
1423 	if (IS_ENABLED(CONFIG_HAS_DMA) &&
1424 	    (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
1425 		dma_unmap_single(hcd->self.sysdev,
1426 				urb->setup_dma,
1427 				sizeof(struct usb_ctrlrequest),
1428 				DMA_TO_DEVICE);
1429 	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1430 		hcd_free_coherent(urb->dev->bus,
1431 				&urb->setup_dma,
1432 				(void **) &urb->setup_packet,
1433 				sizeof(struct usb_ctrlrequest),
1434 				DMA_TO_DEVICE);
1435 
1436 	/* Make it safe to call this routine more than once */
1437 	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1438 }
1439 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1440 
1441 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1442 {
1443 	if (hcd->driver->unmap_urb_for_dma)
1444 		hcd->driver->unmap_urb_for_dma(hcd, urb);
1445 	else
1446 		usb_hcd_unmap_urb_for_dma(hcd, urb);
1447 }
1448 
1449 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1450 {
1451 	enum dma_data_direction dir;
1452 
1453 	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1454 
1455 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1456 	if (IS_ENABLED(CONFIG_HAS_DMA) &&
1457 	    (urb->transfer_flags & URB_DMA_MAP_SG))
1458 		dma_unmap_sg(hcd->self.sysdev,
1459 				urb->sg,
1460 				urb->num_sgs,
1461 				dir);
1462 	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1463 		 (urb->transfer_flags & URB_DMA_MAP_PAGE))
1464 		dma_unmap_page(hcd->self.sysdev,
1465 				urb->transfer_dma,
1466 				urb->transfer_buffer_length,
1467 				dir);
1468 	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1469 		 (urb->transfer_flags & URB_DMA_MAP_SINGLE))
1470 		dma_unmap_single(hcd->self.sysdev,
1471 				urb->transfer_dma,
1472 				urb->transfer_buffer_length,
1473 				dir);
1474 	else if (urb->transfer_flags & URB_MAP_LOCAL)
1475 		hcd_free_coherent(urb->dev->bus,
1476 				&urb->transfer_dma,
1477 				&urb->transfer_buffer,
1478 				urb->transfer_buffer_length,
1479 				dir);
1480 
1481 	/* Make it safe to call this routine more than once */
1482 	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1483 			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1484 }
1485 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1486 
1487 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1488 			   gfp_t mem_flags)
1489 {
1490 	if (hcd->driver->map_urb_for_dma)
1491 		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1492 	else
1493 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1494 }
1495 
1496 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1497 			    gfp_t mem_flags)
1498 {
1499 	enum dma_data_direction dir;
1500 	int ret = 0;
1501 
1502 	/* Map the URB's buffers for DMA access.
1503 	 * Lower level HCD code should use *_dma exclusively,
1504 	 * unless it uses pio or talks to another transport,
1505 	 * or uses the provided scatter gather list for bulk.
1506 	 */
1507 
1508 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1509 		if (hcd->self.uses_pio_for_control)
1510 			return ret;
1511 		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
1512 			if (is_vmalloc_addr(urb->setup_packet)) {
1513 				WARN_ONCE(1, "setup packet is not dma capable\n");
1514 				return -EAGAIN;
1515 			} else if (object_is_on_stack(urb->setup_packet)) {
1516 				WARN_ONCE(1, "setup packet is on stack\n");
1517 				return -EAGAIN;
1518 			}
1519 
1520 			urb->setup_dma = dma_map_single(
1521 					hcd->self.sysdev,
1522 					urb->setup_packet,
1523 					sizeof(struct usb_ctrlrequest),
1524 					DMA_TO_DEVICE);
1525 			if (dma_mapping_error(hcd->self.sysdev,
1526 						urb->setup_dma))
1527 				return -EAGAIN;
1528 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1529 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1530 			ret = hcd_alloc_coherent(
1531 					urb->dev->bus, mem_flags,
1532 					&urb->setup_dma,
1533 					(void **)&urb->setup_packet,
1534 					sizeof(struct usb_ctrlrequest),
1535 					DMA_TO_DEVICE);
1536 			if (ret)
1537 				return ret;
1538 			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1539 		}
1540 	}
1541 
1542 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1543 	if (urb->transfer_buffer_length != 0
1544 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1545 		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
1546 			if (urb->num_sgs) {
1547 				int n;
1548 
1549 				/* We don't support sg for isoc transfers ! */
1550 				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1551 					WARN_ON(1);
1552 					return -EINVAL;
1553 				}
1554 
1555 				n = dma_map_sg(
1556 						hcd->self.sysdev,
1557 						urb->sg,
1558 						urb->num_sgs,
1559 						dir);
1560 				if (n <= 0)
1561 					ret = -EAGAIN;
1562 				else
1563 					urb->transfer_flags |= URB_DMA_MAP_SG;
1564 				urb->num_mapped_sgs = n;
1565 				if (n != urb->num_sgs)
1566 					urb->transfer_flags |=
1567 							URB_DMA_SG_COMBINED;
1568 			} else if (urb->sg) {
1569 				struct scatterlist *sg = urb->sg;
1570 				urb->transfer_dma = dma_map_page(
1571 						hcd->self.sysdev,
1572 						sg_page(sg),
1573 						sg->offset,
1574 						urb->transfer_buffer_length,
1575 						dir);
1576 				if (dma_mapping_error(hcd->self.sysdev,
1577 						urb->transfer_dma))
1578 					ret = -EAGAIN;
1579 				else
1580 					urb->transfer_flags |= URB_DMA_MAP_PAGE;
1581 			} else if (is_vmalloc_addr(urb->transfer_buffer)) {
1582 				WARN_ONCE(1, "transfer buffer not dma capable\n");
1583 				ret = -EAGAIN;
1584 			} else if (object_is_on_stack(urb->transfer_buffer)) {
1585 				WARN_ONCE(1, "transfer buffer is on stack\n");
1586 				ret = -EAGAIN;
1587 			} else {
1588 				urb->transfer_dma = dma_map_single(
1589 						hcd->self.sysdev,
1590 						urb->transfer_buffer,
1591 						urb->transfer_buffer_length,
1592 						dir);
1593 				if (dma_mapping_error(hcd->self.sysdev,
1594 						urb->transfer_dma))
1595 					ret = -EAGAIN;
1596 				else
1597 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1598 			}
1599 		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1600 			ret = hcd_alloc_coherent(
1601 					urb->dev->bus, mem_flags,
1602 					&urb->transfer_dma,
1603 					&urb->transfer_buffer,
1604 					urb->transfer_buffer_length,
1605 					dir);
1606 			if (ret == 0)
1607 				urb->transfer_flags |= URB_MAP_LOCAL;
1608 		}
1609 		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1610 				URB_SETUP_MAP_LOCAL)))
1611 			usb_hcd_unmap_urb_for_dma(hcd, urb);
1612 	}
1613 	return ret;
1614 }
1615 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1616 
1617 /*-------------------------------------------------------------------------*/
1618 
1619 /* may be called in any context with a valid urb->dev usecount
1620  * caller surrenders "ownership" of urb
1621  * expects usb_submit_urb() to have sanity checked and conditioned all
1622  * inputs in the urb
1623  */
1624 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1625 {
1626 	int			status;
1627 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
1628 
1629 	/* increment urb's reference count as part of giving it to the HCD
1630 	 * (which will control it).  HCD guarantees that it either returns
1631 	 * an error or calls giveback(), but not both.
1632 	 */
1633 	usb_get_urb(urb);
1634 	atomic_inc(&urb->use_count);
1635 	atomic_inc(&urb->dev->urbnum);
1636 	usbmon_urb_submit(&hcd->self, urb);
1637 
1638 	/* NOTE requirements on root-hub callers (usbfs and the hub
1639 	 * driver, for now):  URBs' urb->transfer_buffer must be
1640 	 * valid and usb_buffer_{sync,unmap}() not be needed, since
1641 	 * they could clobber root hub response data.  Also, control
1642 	 * URBs must be submitted in process context with interrupts
1643 	 * enabled.
1644 	 */
1645 
1646 	if (is_root_hub(urb->dev)) {
1647 		status = rh_urb_enqueue(hcd, urb);
1648 	} else {
1649 		status = map_urb_for_dma(hcd, urb, mem_flags);
1650 		if (likely(status == 0)) {
1651 			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1652 			if (unlikely(status))
1653 				unmap_urb_for_dma(hcd, urb);
1654 		}
1655 	}
1656 
1657 	if (unlikely(status)) {
1658 		usbmon_urb_submit_error(&hcd->self, urb, status);
1659 		urb->hcpriv = NULL;
1660 		INIT_LIST_HEAD(&urb->urb_list);
1661 		atomic_dec(&urb->use_count);
1662 		atomic_dec(&urb->dev->urbnum);
1663 		if (atomic_read(&urb->reject))
1664 			wake_up(&usb_kill_urb_queue);
1665 		usb_put_urb(urb);
1666 	}
1667 	return status;
1668 }
1669 
1670 /*-------------------------------------------------------------------------*/
1671 
1672 /* this makes the hcd giveback() the urb more quickly, by kicking it
1673  * off hardware queues (which may take a while) and returning it as
1674  * soon as practical.  we've already set up the urb's return status,
1675  * but we can't know if the callback completed already.
1676  */
1677 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1678 {
1679 	int		value;
1680 
1681 	if (is_root_hub(urb->dev))
1682 		value = usb_rh_urb_dequeue(hcd, urb, status);
1683 	else {
1684 
1685 		/* The only reason an HCD might fail this call is if
1686 		 * it has not yet fully queued the urb to begin with.
1687 		 * Such failures should be harmless. */
1688 		value = hcd->driver->urb_dequeue(hcd, urb, status);
1689 	}
1690 	return value;
1691 }
1692 
1693 /*
1694  * called in any context
1695  *
1696  * caller guarantees urb won't be recycled till both unlink()
1697  * and the urb's completion function return
1698  */
1699 int usb_hcd_unlink_urb (struct urb *urb, int status)
1700 {
1701 	struct usb_hcd		*hcd;
1702 	struct usb_device	*udev = urb->dev;
1703 	int			retval = -EIDRM;
1704 	unsigned long		flags;
1705 
1706 	/* Prevent the device and bus from going away while
1707 	 * the unlink is carried out.  If they are already gone
1708 	 * then urb->use_count must be 0, since disconnected
1709 	 * devices can't have any active URBs.
1710 	 */
1711 	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1712 	if (atomic_read(&urb->use_count) > 0) {
1713 		retval = 0;
1714 		usb_get_dev(udev);
1715 	}
1716 	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1717 	if (retval == 0) {
1718 		hcd = bus_to_hcd(urb->dev->bus);
1719 		retval = unlink1(hcd, urb, status);
1720 		if (retval == 0)
1721 			retval = -EINPROGRESS;
1722 		else if (retval != -EIDRM && retval != -EBUSY)
1723 			dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
1724 					urb, retval);
1725 		usb_put_dev(udev);
1726 	}
1727 	return retval;
1728 }
1729 
1730 /*-------------------------------------------------------------------------*/
1731 
1732 static void __usb_hcd_giveback_urb(struct urb *urb)
1733 {
1734 	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1735 	struct usb_anchor *anchor = urb->anchor;
1736 	int status = urb->unlinked;
1737 	unsigned long flags;
1738 
1739 	urb->hcpriv = NULL;
1740 	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1741 	    urb->actual_length < urb->transfer_buffer_length &&
1742 	    !status))
1743 		status = -EREMOTEIO;
1744 
1745 	unmap_urb_for_dma(hcd, urb);
1746 	usbmon_urb_complete(&hcd->self, urb, status);
1747 	usb_anchor_suspend_wakeups(anchor);
1748 	usb_unanchor_urb(urb);
1749 	if (likely(status == 0))
1750 		usb_led_activity(USB_LED_EVENT_HOST);
1751 
1752 	/* pass ownership to the completion handler */
1753 	urb->status = status;
1754 
1755 	/*
1756 	 * We disable local IRQs here avoid possible deadlock because
1757 	 * drivers may call spin_lock() to hold lock which might be
1758 	 * acquired in one hard interrupt handler.
1759 	 *
1760 	 * The local_irq_save()/local_irq_restore() around complete()
1761 	 * will be removed if current USB drivers have been cleaned up
1762 	 * and no one may trigger the above deadlock situation when
1763 	 * running complete() in tasklet.
1764 	 */
1765 	local_irq_save(flags);
1766 	urb->complete(urb);
1767 	local_irq_restore(flags);
1768 
1769 	usb_anchor_resume_wakeups(anchor);
1770 	atomic_dec(&urb->use_count);
1771 	if (unlikely(atomic_read(&urb->reject)))
1772 		wake_up(&usb_kill_urb_queue);
1773 	usb_put_urb(urb);
1774 }
1775 
1776 static void usb_giveback_urb_bh(unsigned long param)
1777 {
1778 	struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1779 	struct list_head local_list;
1780 
1781 	spin_lock_irq(&bh->lock);
1782 	bh->running = true;
1783  restart:
1784 	list_replace_init(&bh->head, &local_list);
1785 	spin_unlock_irq(&bh->lock);
1786 
1787 	while (!list_empty(&local_list)) {
1788 		struct urb *urb;
1789 
1790 		urb = list_entry(local_list.next, struct urb, urb_list);
1791 		list_del_init(&urb->urb_list);
1792 		bh->completing_ep = urb->ep;
1793 		__usb_hcd_giveback_urb(urb);
1794 		bh->completing_ep = NULL;
1795 	}
1796 
1797 	/* check if there are new URBs to giveback */
1798 	spin_lock_irq(&bh->lock);
1799 	if (!list_empty(&bh->head))
1800 		goto restart;
1801 	bh->running = false;
1802 	spin_unlock_irq(&bh->lock);
1803 }
1804 
1805 /**
1806  * usb_hcd_giveback_urb - return URB from HCD to device driver
1807  * @hcd: host controller returning the URB
1808  * @urb: urb being returned to the USB device driver.
1809  * @status: completion status code for the URB.
1810  * Context: in_interrupt()
1811  *
1812  * This hands the URB from HCD to its USB device driver, using its
1813  * completion function.  The HCD has freed all per-urb resources
1814  * (and is done using urb->hcpriv).  It also released all HCD locks;
1815  * the device driver won't cause problems if it frees, modifies,
1816  * or resubmits this URB.
1817  *
1818  * If @urb was unlinked, the value of @status will be overridden by
1819  * @urb->unlinked.  Erroneous short transfers are detected in case
1820  * the HCD hasn't checked for them.
1821  */
1822 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1823 {
1824 	struct giveback_urb_bh *bh;
1825 	bool running, high_prio_bh;
1826 
1827 	/* pass status to tasklet via unlinked */
1828 	if (likely(!urb->unlinked))
1829 		urb->unlinked = status;
1830 
1831 	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1832 		__usb_hcd_giveback_urb(urb);
1833 		return;
1834 	}
1835 
1836 	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1837 		bh = &hcd->high_prio_bh;
1838 		high_prio_bh = true;
1839 	} else {
1840 		bh = &hcd->low_prio_bh;
1841 		high_prio_bh = false;
1842 	}
1843 
1844 	spin_lock(&bh->lock);
1845 	list_add_tail(&urb->urb_list, &bh->head);
1846 	running = bh->running;
1847 	spin_unlock(&bh->lock);
1848 
1849 	if (running)
1850 		;
1851 	else if (high_prio_bh)
1852 		tasklet_hi_schedule(&bh->bh);
1853 	else
1854 		tasklet_schedule(&bh->bh);
1855 }
1856 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1857 
1858 /*-------------------------------------------------------------------------*/
1859 
1860 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1861  * queue to drain completely.  The caller must first insure that no more
1862  * URBs can be submitted for this endpoint.
1863  */
1864 void usb_hcd_flush_endpoint(struct usb_device *udev,
1865 		struct usb_host_endpoint *ep)
1866 {
1867 	struct usb_hcd		*hcd;
1868 	struct urb		*urb;
1869 
1870 	if (!ep)
1871 		return;
1872 	might_sleep();
1873 	hcd = bus_to_hcd(udev->bus);
1874 
1875 	/* No more submits can occur */
1876 	spin_lock_irq(&hcd_urb_list_lock);
1877 rescan:
1878 	list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
1879 		int	is_in;
1880 
1881 		if (urb->unlinked)
1882 			continue;
1883 		usb_get_urb (urb);
1884 		is_in = usb_urb_dir_in(urb);
1885 		spin_unlock(&hcd_urb_list_lock);
1886 
1887 		/* kick hcd */
1888 		unlink1(hcd, urb, -ESHUTDOWN);
1889 		dev_dbg (hcd->self.controller,
1890 			"shutdown urb %pK ep%d%s%s\n",
1891 			urb, usb_endpoint_num(&ep->desc),
1892 			is_in ? "in" : "out",
1893 			({	char *s;
1894 
1895 				 switch (usb_endpoint_type(&ep->desc)) {
1896 				 case USB_ENDPOINT_XFER_CONTROL:
1897 					s = ""; break;
1898 				 case USB_ENDPOINT_XFER_BULK:
1899 					s = "-bulk"; break;
1900 				 case USB_ENDPOINT_XFER_INT:
1901 					s = "-intr"; break;
1902 				 default:
1903 					s = "-iso"; break;
1904 				};
1905 				s;
1906 			}));
1907 		usb_put_urb (urb);
1908 
1909 		/* list contents may have changed */
1910 		spin_lock(&hcd_urb_list_lock);
1911 		goto rescan;
1912 	}
1913 	spin_unlock_irq(&hcd_urb_list_lock);
1914 
1915 	/* Wait until the endpoint queue is completely empty */
1916 	while (!list_empty (&ep->urb_list)) {
1917 		spin_lock_irq(&hcd_urb_list_lock);
1918 
1919 		/* The list may have changed while we acquired the spinlock */
1920 		urb = NULL;
1921 		if (!list_empty (&ep->urb_list)) {
1922 			urb = list_entry (ep->urb_list.prev, struct urb,
1923 					urb_list);
1924 			usb_get_urb (urb);
1925 		}
1926 		spin_unlock_irq(&hcd_urb_list_lock);
1927 
1928 		if (urb) {
1929 			usb_kill_urb (urb);
1930 			usb_put_urb (urb);
1931 		}
1932 	}
1933 }
1934 
1935 /**
1936  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1937  *				the bus bandwidth
1938  * @udev: target &usb_device
1939  * @new_config: new configuration to install
1940  * @cur_alt: the current alternate interface setting
1941  * @new_alt: alternate interface setting that is being installed
1942  *
1943  * To change configurations, pass in the new configuration in new_config,
1944  * and pass NULL for cur_alt and new_alt.
1945  *
1946  * To reset a device's configuration (put the device in the ADDRESSED state),
1947  * pass in NULL for new_config, cur_alt, and new_alt.
1948  *
1949  * To change alternate interface settings, pass in NULL for new_config,
1950  * pass in the current alternate interface setting in cur_alt,
1951  * and pass in the new alternate interface setting in new_alt.
1952  *
1953  * Return: An error if the requested bandwidth change exceeds the
1954  * bus bandwidth or host controller internal resources.
1955  */
1956 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1957 		struct usb_host_config *new_config,
1958 		struct usb_host_interface *cur_alt,
1959 		struct usb_host_interface *new_alt)
1960 {
1961 	int num_intfs, i, j;
1962 	struct usb_host_interface *alt = NULL;
1963 	int ret = 0;
1964 	struct usb_hcd *hcd;
1965 	struct usb_host_endpoint *ep;
1966 
1967 	hcd = bus_to_hcd(udev->bus);
1968 	if (!hcd->driver->check_bandwidth)
1969 		return 0;
1970 
1971 	/* Configuration is being removed - set configuration 0 */
1972 	if (!new_config && !cur_alt) {
1973 		for (i = 1; i < 16; ++i) {
1974 			ep = udev->ep_out[i];
1975 			if (ep)
1976 				hcd->driver->drop_endpoint(hcd, udev, ep);
1977 			ep = udev->ep_in[i];
1978 			if (ep)
1979 				hcd->driver->drop_endpoint(hcd, udev, ep);
1980 		}
1981 		hcd->driver->check_bandwidth(hcd, udev);
1982 		return 0;
1983 	}
1984 	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1985 	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1986 	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
1987 	 * ok to exclude it.
1988 	 */
1989 	if (new_config) {
1990 		num_intfs = new_config->desc.bNumInterfaces;
1991 		/* Remove endpoints (except endpoint 0, which is always on the
1992 		 * schedule) from the old config from the schedule
1993 		 */
1994 		for (i = 1; i < 16; ++i) {
1995 			ep = udev->ep_out[i];
1996 			if (ep) {
1997 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1998 				if (ret < 0)
1999 					goto reset;
2000 			}
2001 			ep = udev->ep_in[i];
2002 			if (ep) {
2003 				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
2004 				if (ret < 0)
2005 					goto reset;
2006 			}
2007 		}
2008 		for (i = 0; i < num_intfs; ++i) {
2009 			struct usb_host_interface *first_alt;
2010 			int iface_num;
2011 
2012 			first_alt = &new_config->intf_cache[i]->altsetting[0];
2013 			iface_num = first_alt->desc.bInterfaceNumber;
2014 			/* Set up endpoints for alternate interface setting 0 */
2015 			alt = usb_find_alt_setting(new_config, iface_num, 0);
2016 			if (!alt)
2017 				/* No alt setting 0? Pick the first setting. */
2018 				alt = first_alt;
2019 
2020 			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
2021 				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
2022 				if (ret < 0)
2023 					goto reset;
2024 			}
2025 		}
2026 	}
2027 	if (cur_alt && new_alt) {
2028 		struct usb_interface *iface = usb_ifnum_to_if(udev,
2029 				cur_alt->desc.bInterfaceNumber);
2030 
2031 		if (!iface)
2032 			return -EINVAL;
2033 		if (iface->resetting_device) {
2034 			/*
2035 			 * The USB core just reset the device, so the xHCI host
2036 			 * and the device will think alt setting 0 is installed.
2037 			 * However, the USB core will pass in the alternate
2038 			 * setting installed before the reset as cur_alt.  Dig
2039 			 * out the alternate setting 0 structure, or the first
2040 			 * alternate setting if a broken device doesn't have alt
2041 			 * setting 0.
2042 			 */
2043 			cur_alt = usb_altnum_to_altsetting(iface, 0);
2044 			if (!cur_alt)
2045 				cur_alt = &iface->altsetting[0];
2046 		}
2047 
2048 		/* Drop all the endpoints in the current alt setting */
2049 		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
2050 			ret = hcd->driver->drop_endpoint(hcd, udev,
2051 					&cur_alt->endpoint[i]);
2052 			if (ret < 0)
2053 				goto reset;
2054 		}
2055 		/* Add all the endpoints in the new alt setting */
2056 		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
2057 			ret = hcd->driver->add_endpoint(hcd, udev,
2058 					&new_alt->endpoint[i]);
2059 			if (ret < 0)
2060 				goto reset;
2061 		}
2062 	}
2063 	ret = hcd->driver->check_bandwidth(hcd, udev);
2064 reset:
2065 	if (ret < 0)
2066 		hcd->driver->reset_bandwidth(hcd, udev);
2067 	return ret;
2068 }
2069 
2070 /* Disables the endpoint: synchronizes with the hcd to make sure all
2071  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
2072  * have been called previously.  Use for set_configuration, set_interface,
2073  * driver removal, physical disconnect.
2074  *
2075  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
2076  * type, maxpacket size, toggle, halt status, and scheduling.
2077  */
2078 void usb_hcd_disable_endpoint(struct usb_device *udev,
2079 		struct usb_host_endpoint *ep)
2080 {
2081 	struct usb_hcd		*hcd;
2082 
2083 	might_sleep();
2084 	hcd = bus_to_hcd(udev->bus);
2085 	if (hcd->driver->endpoint_disable)
2086 		hcd->driver->endpoint_disable(hcd, ep);
2087 }
2088 
2089 /**
2090  * usb_hcd_reset_endpoint - reset host endpoint state
2091  * @udev: USB device.
2092  * @ep:   the endpoint to reset.
2093  *
2094  * Resets any host endpoint state such as the toggle bit, sequence
2095  * number and current window.
2096  */
2097 void usb_hcd_reset_endpoint(struct usb_device *udev,
2098 			    struct usb_host_endpoint *ep)
2099 {
2100 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2101 
2102 	if (hcd->driver->endpoint_reset)
2103 		hcd->driver->endpoint_reset(hcd, ep);
2104 	else {
2105 		int epnum = usb_endpoint_num(&ep->desc);
2106 		int is_out = usb_endpoint_dir_out(&ep->desc);
2107 		int is_control = usb_endpoint_xfer_control(&ep->desc);
2108 
2109 		usb_settoggle(udev, epnum, is_out, 0);
2110 		if (is_control)
2111 			usb_settoggle(udev, epnum, !is_out, 0);
2112 	}
2113 }
2114 
2115 /**
2116  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2117  * @interface:		alternate setting that includes all endpoints.
2118  * @eps:		array of endpoints that need streams.
2119  * @num_eps:		number of endpoints in the array.
2120  * @num_streams:	number of streams to allocate.
2121  * @mem_flags:		flags hcd should use to allocate memory.
2122  *
2123  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2124  * Drivers may queue multiple transfers to different stream IDs, which may
2125  * complete in a different order than they were queued.
2126  *
2127  * Return: On success, the number of allocated streams. On failure, a negative
2128  * error code.
2129  */
2130 int usb_alloc_streams(struct usb_interface *interface,
2131 		struct usb_host_endpoint **eps, unsigned int num_eps,
2132 		unsigned int num_streams, gfp_t mem_flags)
2133 {
2134 	struct usb_hcd *hcd;
2135 	struct usb_device *dev;
2136 	int i, ret;
2137 
2138 	dev = interface_to_usbdev(interface);
2139 	hcd = bus_to_hcd(dev->bus);
2140 	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2141 		return -EINVAL;
2142 	if (dev->speed < USB_SPEED_SUPER)
2143 		return -EINVAL;
2144 	if (dev->state < USB_STATE_CONFIGURED)
2145 		return -ENODEV;
2146 
2147 	for (i = 0; i < num_eps; i++) {
2148 		/* Streams only apply to bulk endpoints. */
2149 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2150 			return -EINVAL;
2151 		/* Re-alloc is not allowed */
2152 		if (eps[i]->streams)
2153 			return -EINVAL;
2154 	}
2155 
2156 	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2157 			num_streams, mem_flags);
2158 	if (ret < 0)
2159 		return ret;
2160 
2161 	for (i = 0; i < num_eps; i++)
2162 		eps[i]->streams = ret;
2163 
2164 	return ret;
2165 }
2166 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2167 
2168 /**
2169  * usb_free_streams - free bulk endpoint stream IDs.
2170  * @interface:	alternate setting that includes all endpoints.
2171  * @eps:	array of endpoints to remove streams from.
2172  * @num_eps:	number of endpoints in the array.
2173  * @mem_flags:	flags hcd should use to allocate memory.
2174  *
2175  * Reverts a group of bulk endpoints back to not using stream IDs.
2176  * Can fail if we are given bad arguments, or HCD is broken.
2177  *
2178  * Return: 0 on success. On failure, a negative error code.
2179  */
2180 int usb_free_streams(struct usb_interface *interface,
2181 		struct usb_host_endpoint **eps, unsigned int num_eps,
2182 		gfp_t mem_flags)
2183 {
2184 	struct usb_hcd *hcd;
2185 	struct usb_device *dev;
2186 	int i, ret;
2187 
2188 	dev = interface_to_usbdev(interface);
2189 	hcd = bus_to_hcd(dev->bus);
2190 	if (dev->speed < USB_SPEED_SUPER)
2191 		return -EINVAL;
2192 
2193 	/* Double-free is not allowed */
2194 	for (i = 0; i < num_eps; i++)
2195 		if (!eps[i] || !eps[i]->streams)
2196 			return -EINVAL;
2197 
2198 	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2199 	if (ret < 0)
2200 		return ret;
2201 
2202 	for (i = 0; i < num_eps; i++)
2203 		eps[i]->streams = 0;
2204 
2205 	return ret;
2206 }
2207 EXPORT_SYMBOL_GPL(usb_free_streams);
2208 
2209 /* Protect against drivers that try to unlink URBs after the device
2210  * is gone, by waiting until all unlinks for @udev are finished.
2211  * Since we don't currently track URBs by device, simply wait until
2212  * nothing is running in the locked region of usb_hcd_unlink_urb().
2213  */
2214 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2215 {
2216 	spin_lock_irq(&hcd_urb_unlink_lock);
2217 	spin_unlock_irq(&hcd_urb_unlink_lock);
2218 }
2219 
2220 /*-------------------------------------------------------------------------*/
2221 
2222 /* called in any context */
2223 int usb_hcd_get_frame_number (struct usb_device *udev)
2224 {
2225 	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
2226 
2227 	if (!HCD_RH_RUNNING(hcd))
2228 		return -ESHUTDOWN;
2229 	return hcd->driver->get_frame_number (hcd);
2230 }
2231 
2232 /*-------------------------------------------------------------------------*/
2233 
2234 #ifdef	CONFIG_PM
2235 
2236 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2237 {
2238 	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
2239 	int		status;
2240 	int		old_state = hcd->state;
2241 
2242 	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2243 			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
2244 			rhdev->do_remote_wakeup);
2245 	if (HCD_DEAD(hcd)) {
2246 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2247 		return 0;
2248 	}
2249 
2250 	if (!hcd->driver->bus_suspend) {
2251 		status = -ENOENT;
2252 	} else {
2253 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2254 		hcd->state = HC_STATE_QUIESCING;
2255 		status = hcd->driver->bus_suspend(hcd);
2256 	}
2257 	if (status == 0) {
2258 		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2259 		hcd->state = HC_STATE_SUSPENDED;
2260 
2261 		/* Did we race with a root-hub wakeup event? */
2262 		if (rhdev->do_remote_wakeup) {
2263 			char	buffer[6];
2264 
2265 			status = hcd->driver->hub_status_data(hcd, buffer);
2266 			if (status != 0) {
2267 				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2268 				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2269 				status = -EBUSY;
2270 			}
2271 		}
2272 	} else {
2273 		spin_lock_irq(&hcd_root_hub_lock);
2274 		if (!HCD_DEAD(hcd)) {
2275 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2276 			hcd->state = old_state;
2277 		}
2278 		spin_unlock_irq(&hcd_root_hub_lock);
2279 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2280 				"suspend", status);
2281 	}
2282 	return status;
2283 }
2284 
2285 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2286 {
2287 	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
2288 	int		status;
2289 	int		old_state = hcd->state;
2290 
2291 	dev_dbg(&rhdev->dev, "usb %sresume\n",
2292 			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
2293 	if (HCD_DEAD(hcd)) {
2294 		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2295 		return 0;
2296 	}
2297 	if (!hcd->driver->bus_resume)
2298 		return -ENOENT;
2299 	if (HCD_RH_RUNNING(hcd))
2300 		return 0;
2301 
2302 	hcd->state = HC_STATE_RESUMING;
2303 	status = hcd->driver->bus_resume(hcd);
2304 	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2305 	if (status == 0) {
2306 		struct usb_device *udev;
2307 		int port1;
2308 
2309 		spin_lock_irq(&hcd_root_hub_lock);
2310 		if (!HCD_DEAD(hcd)) {
2311 			usb_set_device_state(rhdev, rhdev->actconfig
2312 					? USB_STATE_CONFIGURED
2313 					: USB_STATE_ADDRESS);
2314 			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2315 			hcd->state = HC_STATE_RUNNING;
2316 		}
2317 		spin_unlock_irq(&hcd_root_hub_lock);
2318 
2319 		/*
2320 		 * Check whether any of the enabled ports on the root hub are
2321 		 * unsuspended.  If they are then a TRSMRCY delay is needed
2322 		 * (this is what the USB-2 spec calls a "global resume").
2323 		 * Otherwise we can skip the delay.
2324 		 */
2325 		usb_hub_for_each_child(rhdev, port1, udev) {
2326 			if (udev->state != USB_STATE_NOTATTACHED &&
2327 					!udev->port_is_suspended) {
2328 				usleep_range(10000, 11000);	/* TRSMRCY */
2329 				break;
2330 			}
2331 		}
2332 	} else {
2333 		hcd->state = old_state;
2334 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2335 				"resume", status);
2336 		if (status != -ESHUTDOWN)
2337 			usb_hc_died(hcd);
2338 	}
2339 	return status;
2340 }
2341 
2342 /* Workqueue routine for root-hub remote wakeup */
2343 static void hcd_resume_work(struct work_struct *work)
2344 {
2345 	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2346 	struct usb_device *udev = hcd->self.root_hub;
2347 
2348 	usb_remote_wakeup(udev);
2349 }
2350 
2351 /**
2352  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2353  * @hcd: host controller for this root hub
2354  *
2355  * The USB host controller calls this function when its root hub is
2356  * suspended (with the remote wakeup feature enabled) and a remote
2357  * wakeup request is received.  The routine submits a workqueue request
2358  * to resume the root hub (that is, manage its downstream ports again).
2359  */
2360 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2361 {
2362 	unsigned long flags;
2363 
2364 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2365 	if (hcd->rh_registered) {
2366 		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2367 		queue_work(pm_wq, &hcd->wakeup_work);
2368 	}
2369 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2370 }
2371 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2372 
2373 #endif	/* CONFIG_PM */
2374 
2375 /*-------------------------------------------------------------------------*/
2376 
2377 #ifdef	CONFIG_USB_OTG
2378 
2379 /**
2380  * usb_bus_start_enum - start immediate enumeration (for OTG)
2381  * @bus: the bus (must use hcd framework)
2382  * @port_num: 1-based number of port; usually bus->otg_port
2383  * Context: in_interrupt()
2384  *
2385  * Starts enumeration, with an immediate reset followed later by
2386  * hub_wq identifying and possibly configuring the device.
2387  * This is needed by OTG controller drivers, where it helps meet
2388  * HNP protocol timing requirements for starting a port reset.
2389  *
2390  * Return: 0 if successful.
2391  */
2392 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2393 {
2394 	struct usb_hcd		*hcd;
2395 	int			status = -EOPNOTSUPP;
2396 
2397 	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2398 	 * boards with root hubs hooked up to internal devices (instead of
2399 	 * just the OTG port) may need more attention to resetting...
2400 	 */
2401 	hcd = bus_to_hcd(bus);
2402 	if (port_num && hcd->driver->start_port_reset)
2403 		status = hcd->driver->start_port_reset(hcd, port_num);
2404 
2405 	/* allocate hub_wq shortly after (first) root port reset finishes;
2406 	 * it may issue others, until at least 50 msecs have passed.
2407 	 */
2408 	if (status == 0)
2409 		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2410 	return status;
2411 }
2412 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2413 
2414 #endif
2415 
2416 /*-------------------------------------------------------------------------*/
2417 
2418 /**
2419  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2420  * @irq: the IRQ being raised
2421  * @__hcd: pointer to the HCD whose IRQ is being signaled
2422  *
2423  * If the controller isn't HALTed, calls the driver's irq handler.
2424  * Checks whether the controller is now dead.
2425  *
2426  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2427  */
2428 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2429 {
2430 	struct usb_hcd		*hcd = __hcd;
2431 	irqreturn_t		rc;
2432 
2433 	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2434 		rc = IRQ_NONE;
2435 	else if (hcd->driver->irq(hcd) == IRQ_NONE)
2436 		rc = IRQ_NONE;
2437 	else
2438 		rc = IRQ_HANDLED;
2439 
2440 	return rc;
2441 }
2442 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2443 
2444 /*-------------------------------------------------------------------------*/
2445 
2446 /**
2447  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2448  * @hcd: pointer to the HCD representing the controller
2449  *
2450  * This is called by bus glue to report a USB host controller that died
2451  * while operations may still have been pending.  It's called automatically
2452  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2453  *
2454  * Only call this function with the primary HCD.
2455  */
2456 void usb_hc_died (struct usb_hcd *hcd)
2457 {
2458 	unsigned long flags;
2459 
2460 	dev_err (hcd->self.controller, "HC died; cleaning up\n");
2461 
2462 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
2463 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2464 	set_bit(HCD_FLAG_DEAD, &hcd->flags);
2465 	if (hcd->rh_registered) {
2466 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2467 
2468 		/* make hub_wq clean up old urbs and devices */
2469 		usb_set_device_state (hcd->self.root_hub,
2470 				USB_STATE_NOTATTACHED);
2471 		usb_kick_hub_wq(hcd->self.root_hub);
2472 	}
2473 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2474 		hcd = hcd->shared_hcd;
2475 		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2476 		set_bit(HCD_FLAG_DEAD, &hcd->flags);
2477 		if (hcd->rh_registered) {
2478 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2479 
2480 			/* make hub_wq clean up old urbs and devices */
2481 			usb_set_device_state(hcd->self.root_hub,
2482 					USB_STATE_NOTATTACHED);
2483 			usb_kick_hub_wq(hcd->self.root_hub);
2484 		}
2485 	}
2486 	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2487 	/* Make sure that the other roothub is also deallocated. */
2488 }
2489 EXPORT_SYMBOL_GPL (usb_hc_died);
2490 
2491 /*-------------------------------------------------------------------------*/
2492 
2493 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2494 {
2495 
2496 	spin_lock_init(&bh->lock);
2497 	INIT_LIST_HEAD(&bh->head);
2498 	tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2499 }
2500 
2501 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
2502 		struct device *sysdev, struct device *dev, const char *bus_name,
2503 		struct usb_hcd *primary_hcd)
2504 {
2505 	struct usb_hcd *hcd;
2506 
2507 	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2508 	if (!hcd)
2509 		return NULL;
2510 	if (primary_hcd == NULL) {
2511 		hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
2512 				GFP_KERNEL);
2513 		if (!hcd->address0_mutex) {
2514 			kfree(hcd);
2515 			dev_dbg(dev, "hcd address0 mutex alloc failed\n");
2516 			return NULL;
2517 		}
2518 		mutex_init(hcd->address0_mutex);
2519 		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2520 				GFP_KERNEL);
2521 		if (!hcd->bandwidth_mutex) {
2522 			kfree(hcd->address0_mutex);
2523 			kfree(hcd);
2524 			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2525 			return NULL;
2526 		}
2527 		mutex_init(hcd->bandwidth_mutex);
2528 		dev_set_drvdata(dev, hcd);
2529 	} else {
2530 		mutex_lock(&usb_port_peer_mutex);
2531 		hcd->address0_mutex = primary_hcd->address0_mutex;
2532 		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2533 		hcd->primary_hcd = primary_hcd;
2534 		primary_hcd->primary_hcd = primary_hcd;
2535 		hcd->shared_hcd = primary_hcd;
2536 		primary_hcd->shared_hcd = hcd;
2537 		mutex_unlock(&usb_port_peer_mutex);
2538 	}
2539 
2540 	kref_init(&hcd->kref);
2541 
2542 	usb_bus_init(&hcd->self);
2543 	hcd->self.controller = dev;
2544 	hcd->self.sysdev = sysdev;
2545 	hcd->self.bus_name = bus_name;
2546 	hcd->self.uses_dma = (sysdev->dma_mask != NULL);
2547 
2548 	setup_timer(&hcd->rh_timer, rh_timer_func, (unsigned long)hcd);
2549 #ifdef CONFIG_PM
2550 	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2551 #endif
2552 
2553 	hcd->driver = driver;
2554 	hcd->speed = driver->flags & HCD_MASK;
2555 	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2556 			"USB Host Controller";
2557 	return hcd;
2558 }
2559 EXPORT_SYMBOL_GPL(__usb_create_hcd);
2560 
2561 /**
2562  * usb_create_shared_hcd - create and initialize an HCD structure
2563  * @driver: HC driver that will use this hcd
2564  * @dev: device for this HC, stored in hcd->self.controller
2565  * @bus_name: value to store in hcd->self.bus_name
2566  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2567  *              PCI device.  Only allocate certain resources for the primary HCD
2568  * Context: !in_interrupt()
2569  *
2570  * Allocate a struct usb_hcd, with extra space at the end for the
2571  * HC driver's private data.  Initialize the generic members of the
2572  * hcd structure.
2573  *
2574  * Return: On success, a pointer to the created and initialized HCD structure.
2575  * On failure (e.g. if memory is unavailable), %NULL.
2576  */
2577 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2578 		struct device *dev, const char *bus_name,
2579 		struct usb_hcd *primary_hcd)
2580 {
2581 	return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
2582 }
2583 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2584 
2585 /**
2586  * usb_create_hcd - create and initialize an HCD structure
2587  * @driver: HC driver that will use this hcd
2588  * @dev: device for this HC, stored in hcd->self.controller
2589  * @bus_name: value to store in hcd->self.bus_name
2590  * Context: !in_interrupt()
2591  *
2592  * Allocate a struct usb_hcd, with extra space at the end for the
2593  * HC driver's private data.  Initialize the generic members of the
2594  * hcd structure.
2595  *
2596  * Return: On success, a pointer to the created and initialized HCD
2597  * structure. On failure (e.g. if memory is unavailable), %NULL.
2598  */
2599 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2600 		struct device *dev, const char *bus_name)
2601 {
2602 	return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
2603 }
2604 EXPORT_SYMBOL_GPL(usb_create_hcd);
2605 
2606 /*
2607  * Roothubs that share one PCI device must also share the bandwidth mutex.
2608  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2609  * deallocated.
2610  *
2611  * Make sure to deallocate the bandwidth_mutex only when the last HCD is
2612  * freed.  When hcd_release() is called for either hcd in a peer set,
2613  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
2614  */
2615 static void hcd_release(struct kref *kref)
2616 {
2617 	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2618 
2619 	mutex_lock(&usb_port_peer_mutex);
2620 	if (hcd->shared_hcd) {
2621 		struct usb_hcd *peer = hcd->shared_hcd;
2622 
2623 		peer->shared_hcd = NULL;
2624 		peer->primary_hcd = NULL;
2625 	} else {
2626 		kfree(hcd->address0_mutex);
2627 		kfree(hcd->bandwidth_mutex);
2628 	}
2629 	mutex_unlock(&usb_port_peer_mutex);
2630 	kfree(hcd);
2631 }
2632 
2633 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2634 {
2635 	if (hcd)
2636 		kref_get (&hcd->kref);
2637 	return hcd;
2638 }
2639 EXPORT_SYMBOL_GPL(usb_get_hcd);
2640 
2641 void usb_put_hcd (struct usb_hcd *hcd)
2642 {
2643 	if (hcd)
2644 		kref_put (&hcd->kref, hcd_release);
2645 }
2646 EXPORT_SYMBOL_GPL(usb_put_hcd);
2647 
2648 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2649 {
2650 	if (!hcd->primary_hcd)
2651 		return 1;
2652 	return hcd == hcd->primary_hcd;
2653 }
2654 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2655 
2656 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2657 {
2658 	if (!hcd->driver->find_raw_port_number)
2659 		return port1;
2660 
2661 	return hcd->driver->find_raw_port_number(hcd, port1);
2662 }
2663 
2664 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2665 		unsigned int irqnum, unsigned long irqflags)
2666 {
2667 	int retval;
2668 
2669 	if (hcd->driver->irq) {
2670 
2671 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2672 				hcd->driver->description, hcd->self.busnum);
2673 		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2674 				hcd->irq_descr, hcd);
2675 		if (retval != 0) {
2676 			dev_err(hcd->self.controller,
2677 					"request interrupt %d failed\n",
2678 					irqnum);
2679 			return retval;
2680 		}
2681 		hcd->irq = irqnum;
2682 		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2683 				(hcd->driver->flags & HCD_MEMORY) ?
2684 					"io mem" : "io base",
2685 					(unsigned long long)hcd->rsrc_start);
2686 	} else {
2687 		hcd->irq = 0;
2688 		if (hcd->rsrc_start)
2689 			dev_info(hcd->self.controller, "%s 0x%08llx\n",
2690 					(hcd->driver->flags & HCD_MEMORY) ?
2691 					"io mem" : "io base",
2692 					(unsigned long long)hcd->rsrc_start);
2693 	}
2694 	return 0;
2695 }
2696 
2697 /*
2698  * Before we free this root hub, flush in-flight peering attempts
2699  * and disable peer lookups
2700  */
2701 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2702 {
2703 	struct usb_device *rhdev;
2704 
2705 	mutex_lock(&usb_port_peer_mutex);
2706 	rhdev = hcd->self.root_hub;
2707 	hcd->self.root_hub = NULL;
2708 	mutex_unlock(&usb_port_peer_mutex);
2709 	usb_put_dev(rhdev);
2710 }
2711 
2712 /**
2713  * usb_add_hcd - finish generic HCD structure initialization and register
2714  * @hcd: the usb_hcd structure to initialize
2715  * @irqnum: Interrupt line to allocate
2716  * @irqflags: Interrupt type flags
2717  *
2718  * Finish the remaining parts of generic HCD initialization: allocate the
2719  * buffers of consistent memory, register the bus, request the IRQ line,
2720  * and call the driver's reset() and start() routines.
2721  */
2722 int usb_add_hcd(struct usb_hcd *hcd,
2723 		unsigned int irqnum, unsigned long irqflags)
2724 {
2725 	int retval;
2726 	struct usb_device *rhdev;
2727 
2728 	if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) {
2729 		struct usb_phy *phy = usb_get_phy_dev(hcd->self.sysdev, 0);
2730 
2731 		if (IS_ERR(phy)) {
2732 			retval = PTR_ERR(phy);
2733 			if (retval == -EPROBE_DEFER)
2734 				return retval;
2735 		} else {
2736 			retval = usb_phy_init(phy);
2737 			if (retval) {
2738 				usb_put_phy(phy);
2739 				return retval;
2740 			}
2741 			hcd->usb_phy = phy;
2742 			hcd->remove_phy = 1;
2743 		}
2744 	}
2745 
2746 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) {
2747 		struct phy *phy = phy_get(hcd->self.sysdev, "usb");
2748 
2749 		if (IS_ERR(phy)) {
2750 			retval = PTR_ERR(phy);
2751 			if (retval == -EPROBE_DEFER)
2752 				goto err_phy;
2753 		} else {
2754 			retval = phy_init(phy);
2755 			if (retval) {
2756 				phy_put(phy);
2757 				goto err_phy;
2758 			}
2759 			retval = phy_power_on(phy);
2760 			if (retval) {
2761 				phy_exit(phy);
2762 				phy_put(phy);
2763 				goto err_phy;
2764 			}
2765 			hcd->phy = phy;
2766 			hcd->remove_phy = 1;
2767 		}
2768 	}
2769 
2770 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2771 
2772 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
2773 	if (authorized_default < 0 || authorized_default > 1) {
2774 		if (hcd->wireless)
2775 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2776 		else
2777 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2778 	} else {
2779 		if (authorized_default)
2780 			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2781 		else
2782 			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
2783 	}
2784 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2785 
2786 	/* per default all interfaces are authorized */
2787 	set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
2788 
2789 	/* HC is in reset state, but accessible.  Now do the one-time init,
2790 	 * bottom up so that hcds can customize the root hubs before hub_wq
2791 	 * starts talking to them.  (Note, bus id is assigned early too.)
2792 	 */
2793 	retval = hcd_buffer_create(hcd);
2794 	if (retval != 0) {
2795 		dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
2796 		goto err_create_buf;
2797 	}
2798 
2799 	retval = usb_register_bus(&hcd->self);
2800 	if (retval < 0)
2801 		goto err_register_bus;
2802 
2803 	rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
2804 	if (rhdev == NULL) {
2805 		dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
2806 		retval = -ENOMEM;
2807 		goto err_allocate_root_hub;
2808 	}
2809 	mutex_lock(&usb_port_peer_mutex);
2810 	hcd->self.root_hub = rhdev;
2811 	mutex_unlock(&usb_port_peer_mutex);
2812 
2813 	switch (hcd->speed) {
2814 	case HCD_USB11:
2815 		rhdev->speed = USB_SPEED_FULL;
2816 		break;
2817 	case HCD_USB2:
2818 		rhdev->speed = USB_SPEED_HIGH;
2819 		break;
2820 	case HCD_USB25:
2821 		rhdev->speed = USB_SPEED_WIRELESS;
2822 		break;
2823 	case HCD_USB3:
2824 		rhdev->speed = USB_SPEED_SUPER;
2825 		break;
2826 	case HCD_USB31:
2827 		rhdev->speed = USB_SPEED_SUPER_PLUS;
2828 		break;
2829 	default:
2830 		retval = -EINVAL;
2831 		goto err_set_rh_speed;
2832 	}
2833 
2834 	/* wakeup flag init defaults to "everything works" for root hubs,
2835 	 * but drivers can override it in reset() if needed, along with
2836 	 * recording the overall controller's system wakeup capability.
2837 	 */
2838 	device_set_wakeup_capable(&rhdev->dev, 1);
2839 
2840 	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2841 	 * registered.  But since the controller can die at any time,
2842 	 * let's initialize the flag before touching the hardware.
2843 	 */
2844 	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2845 
2846 	/* "reset" is misnamed; its role is now one-time init. the controller
2847 	 * should already have been reset (and boot firmware kicked off etc).
2848 	 */
2849 	if (hcd->driver->reset) {
2850 		retval = hcd->driver->reset(hcd);
2851 		if (retval < 0) {
2852 			dev_err(hcd->self.controller, "can't setup: %d\n",
2853 					retval);
2854 			goto err_hcd_driver_setup;
2855 		}
2856 	}
2857 	hcd->rh_pollable = 1;
2858 
2859 	/* NOTE: root hub and controller capabilities may not be the same */
2860 	if (device_can_wakeup(hcd->self.controller)
2861 			&& device_can_wakeup(&hcd->self.root_hub->dev))
2862 		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2863 
2864 	/* initialize tasklets */
2865 	init_giveback_urb_bh(&hcd->high_prio_bh);
2866 	init_giveback_urb_bh(&hcd->low_prio_bh);
2867 
2868 	/* enable irqs just before we start the controller,
2869 	 * if the BIOS provides legacy PCI irqs.
2870 	 */
2871 	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2872 		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2873 		if (retval)
2874 			goto err_request_irq;
2875 	}
2876 
2877 	hcd->state = HC_STATE_RUNNING;
2878 	retval = hcd->driver->start(hcd);
2879 	if (retval < 0) {
2880 		dev_err(hcd->self.controller, "startup error %d\n", retval);
2881 		goto err_hcd_driver_start;
2882 	}
2883 
2884 	/* starting here, usbcore will pay attention to this root hub */
2885 	retval = register_root_hub(hcd);
2886 	if (retval != 0)
2887 		goto err_register_root_hub;
2888 
2889 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2890 	if (retval < 0) {
2891 		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2892 		       retval);
2893 		goto error_create_attr_group;
2894 	}
2895 	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2896 		usb_hcd_poll_rh_status(hcd);
2897 
2898 	return retval;
2899 
2900 error_create_attr_group:
2901 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2902 	if (HC_IS_RUNNING(hcd->state))
2903 		hcd->state = HC_STATE_QUIESCING;
2904 	spin_lock_irq(&hcd_root_hub_lock);
2905 	hcd->rh_registered = 0;
2906 	spin_unlock_irq(&hcd_root_hub_lock);
2907 
2908 #ifdef CONFIG_PM
2909 	cancel_work_sync(&hcd->wakeup_work);
2910 #endif
2911 	mutex_lock(&usb_bus_idr_lock);
2912 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2913 	mutex_unlock(&usb_bus_idr_lock);
2914 err_register_root_hub:
2915 	hcd->rh_pollable = 0;
2916 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2917 	del_timer_sync(&hcd->rh_timer);
2918 	hcd->driver->stop(hcd);
2919 	hcd->state = HC_STATE_HALT;
2920 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2921 	del_timer_sync(&hcd->rh_timer);
2922 err_hcd_driver_start:
2923 	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2924 		free_irq(irqnum, hcd);
2925 err_request_irq:
2926 err_hcd_driver_setup:
2927 err_set_rh_speed:
2928 	usb_put_invalidate_rhdev(hcd);
2929 err_allocate_root_hub:
2930 	usb_deregister_bus(&hcd->self);
2931 err_register_bus:
2932 	hcd_buffer_destroy(hcd);
2933 err_create_buf:
2934 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2935 		phy_power_off(hcd->phy);
2936 		phy_exit(hcd->phy);
2937 		phy_put(hcd->phy);
2938 		hcd->phy = NULL;
2939 	}
2940 err_phy:
2941 	if (hcd->remove_phy && hcd->usb_phy) {
2942 		usb_phy_shutdown(hcd->usb_phy);
2943 		usb_put_phy(hcd->usb_phy);
2944 		hcd->usb_phy = NULL;
2945 	}
2946 	return retval;
2947 }
2948 EXPORT_SYMBOL_GPL(usb_add_hcd);
2949 
2950 /**
2951  * usb_remove_hcd - shutdown processing for generic HCDs
2952  * @hcd: the usb_hcd structure to remove
2953  * Context: !in_interrupt()
2954  *
2955  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2956  * invoking the HCD's stop() method.
2957  */
2958 void usb_remove_hcd(struct usb_hcd *hcd)
2959 {
2960 	struct usb_device *rhdev = hcd->self.root_hub;
2961 
2962 	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2963 
2964 	usb_get_dev(rhdev);
2965 	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2966 
2967 	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2968 	if (HC_IS_RUNNING (hcd->state))
2969 		hcd->state = HC_STATE_QUIESCING;
2970 
2971 	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2972 	spin_lock_irq (&hcd_root_hub_lock);
2973 	hcd->rh_registered = 0;
2974 	spin_unlock_irq (&hcd_root_hub_lock);
2975 
2976 #ifdef CONFIG_PM
2977 	cancel_work_sync(&hcd->wakeup_work);
2978 #endif
2979 
2980 	mutex_lock(&usb_bus_idr_lock);
2981 	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
2982 	mutex_unlock(&usb_bus_idr_lock);
2983 
2984 	/*
2985 	 * tasklet_kill() isn't needed here because:
2986 	 * - driver's disconnect() called from usb_disconnect() should
2987 	 *   make sure its URBs are completed during the disconnect()
2988 	 *   callback
2989 	 *
2990 	 * - it is too late to run complete() here since driver may have
2991 	 *   been removed already now
2992 	 */
2993 
2994 	/* Prevent any more root-hub status calls from the timer.
2995 	 * The HCD might still restart the timer (if a port status change
2996 	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2997 	 * the hub_status_data() callback.
2998 	 */
2999 	hcd->rh_pollable = 0;
3000 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
3001 	del_timer_sync(&hcd->rh_timer);
3002 
3003 	hcd->driver->stop(hcd);
3004 	hcd->state = HC_STATE_HALT;
3005 
3006 	/* In case the HCD restarted the timer, stop it again. */
3007 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
3008 	del_timer_sync(&hcd->rh_timer);
3009 
3010 	if (usb_hcd_is_primary_hcd(hcd)) {
3011 		if (hcd->irq > 0)
3012 			free_irq(hcd->irq, hcd);
3013 	}
3014 
3015 	usb_deregister_bus(&hcd->self);
3016 	hcd_buffer_destroy(hcd);
3017 
3018 	if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
3019 		phy_power_off(hcd->phy);
3020 		phy_exit(hcd->phy);
3021 		phy_put(hcd->phy);
3022 		hcd->phy = NULL;
3023 	}
3024 	if (hcd->remove_phy && hcd->usb_phy) {
3025 		usb_phy_shutdown(hcd->usb_phy);
3026 		usb_put_phy(hcd->usb_phy);
3027 		hcd->usb_phy = NULL;
3028 	}
3029 
3030 	usb_put_invalidate_rhdev(hcd);
3031 	hcd->flags = 0;
3032 }
3033 EXPORT_SYMBOL_GPL(usb_remove_hcd);
3034 
3035 void
3036 usb_hcd_platform_shutdown(struct platform_device *dev)
3037 {
3038 	struct usb_hcd *hcd = platform_get_drvdata(dev);
3039 
3040 	if (hcd->driver->shutdown)
3041 		hcd->driver->shutdown(hcd);
3042 }
3043 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
3044 
3045 /*-------------------------------------------------------------------------*/
3046 
3047 #if IS_ENABLED(CONFIG_USB_MON)
3048 
3049 const struct usb_mon_operations *mon_ops;
3050 
3051 /*
3052  * The registration is unlocked.
3053  * We do it this way because we do not want to lock in hot paths.
3054  *
3055  * Notice that the code is minimally error-proof. Because usbmon needs
3056  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
3057  */
3058 
3059 int usb_mon_register(const struct usb_mon_operations *ops)
3060 {
3061 
3062 	if (mon_ops)
3063 		return -EBUSY;
3064 
3065 	mon_ops = ops;
3066 	mb();
3067 	return 0;
3068 }
3069 EXPORT_SYMBOL_GPL (usb_mon_register);
3070 
3071 void usb_mon_deregister (void)
3072 {
3073 
3074 	if (mon_ops == NULL) {
3075 		printk(KERN_ERR "USB: monitor was not registered\n");
3076 		return;
3077 	}
3078 	mon_ops = NULL;
3079 	mb();
3080 }
3081 EXPORT_SYMBOL_GPL (usb_mon_deregister);
3082 
3083 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
3084