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[linux.git] / drivers / usb / core / hcd.c
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 #include <linux/genalloc.h>
33 #include <linux/io.h>
34
35 #include <linux/phy/phy.h>
36 #include <linux/usb.h>
37 #include <linux/usb/hcd.h>
38 #include <linux/usb/otg.h>
39
40 #include "usb.h"
41 #include "phy.h"
42
43
44 /*-------------------------------------------------------------------------*/
45
46 /*
47  * USB Host Controller Driver framework
48  *
49  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
50  * HCD-specific behaviors/bugs.
51  *
52  * This does error checks, tracks devices and urbs, and delegates to a
53  * "hc_driver" only for code (and data) that really needs to know about
54  * hardware differences.  That includes root hub registers, i/o queues,
55  * and so on ... but as little else as possible.
56  *
57  * Shared code includes most of the "root hub" code (these are emulated,
58  * though each HC's hardware works differently) and PCI glue, plus request
59  * tracking overhead.  The HCD code should only block on spinlocks or on
60  * hardware handshaking; blocking on software events (such as other kernel
61  * threads releasing resources, or completing actions) is all generic.
62  *
63  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
64  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
65  * only by the hub driver ... and that neither should be seen or used by
66  * usb client device drivers.
67  *
68  * Contributors of ideas or unattributed patches include: David Brownell,
69  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
70  *
71  * HISTORY:
72  * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
73  *              associated cleanup.  "usb_hcd" still != "usb_bus".
74  * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
75  */
76
77 /*-------------------------------------------------------------------------*/
78
79 /* Keep track of which host controller drivers are loaded */
80 unsigned long usb_hcds_loaded;
81 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
82
83 /* host controllers we manage */
84 DEFINE_IDR (usb_bus_idr);
85 EXPORT_SYMBOL_GPL (usb_bus_idr);
86
87 /* used when allocating bus numbers */
88 #define USB_MAXBUS              64
89
90 /* used when updating list of hcds */
91 DEFINE_MUTEX(usb_bus_idr_lock); /* exported only for usbfs */
92 EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
93
94 /* used for controlling access to virtual root hubs */
95 static DEFINE_SPINLOCK(hcd_root_hub_lock);
96
97 /* used when updating an endpoint's URB list */
98 static DEFINE_SPINLOCK(hcd_urb_list_lock);
99
100 /* used to protect against unlinking URBs after the device is gone */
101 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
102
103 /* wait queue for synchronous unlinks */
104 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
105
106 /*-------------------------------------------------------------------------*/
107
108 /*
109  * Sharable chunks of root hub code.
110  */
111
112 /*-------------------------------------------------------------------------*/
113 #define KERNEL_REL      bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
114 #define KERNEL_VER      bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
115
116 /* usb 3.1 root hub device descriptor */
117 static const u8 usb31_rh_dev_descriptor[18] = {
118         0x12,       /*  __u8  bLength; */
119         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
120         0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
121
122         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
123         0x00,       /*  __u8  bDeviceSubClass; */
124         0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
125         0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
126
127         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
128         0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
129         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
130
131         0x03,       /*  __u8  iManufacturer; */
132         0x02,       /*  __u8  iProduct; */
133         0x01,       /*  __u8  iSerialNumber; */
134         0x01        /*  __u8  bNumConfigurations; */
135 };
136
137 /* usb 3.0 root hub device descriptor */
138 static const u8 usb3_rh_dev_descriptor[18] = {
139         0x12,       /*  __u8  bLength; */
140         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
141         0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
142
143         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
144         0x00,       /*  __u8  bDeviceSubClass; */
145         0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
146         0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
147
148         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
149         0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
150         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
151
152         0x03,       /*  __u8  iManufacturer; */
153         0x02,       /*  __u8  iProduct; */
154         0x01,       /*  __u8  iSerialNumber; */
155         0x01        /*  __u8  bNumConfigurations; */
156 };
157
158 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
159 static const u8 usb25_rh_dev_descriptor[18] = {
160         0x12,       /*  __u8  bLength; */
161         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
162         0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
163
164         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
165         0x00,       /*  __u8  bDeviceSubClass; */
166         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
167         0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
168
169         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
170         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
171         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
172
173         0x03,       /*  __u8  iManufacturer; */
174         0x02,       /*  __u8  iProduct; */
175         0x01,       /*  __u8  iSerialNumber; */
176         0x01        /*  __u8  bNumConfigurations; */
177 };
178
179 /* usb 2.0 root hub device descriptor */
180 static const u8 usb2_rh_dev_descriptor[18] = {
181         0x12,       /*  __u8  bLength; */
182         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
183         0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
184
185         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
186         0x00,       /*  __u8  bDeviceSubClass; */
187         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
188         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
189
190         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
191         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
192         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
193
194         0x03,       /*  __u8  iManufacturer; */
195         0x02,       /*  __u8  iProduct; */
196         0x01,       /*  __u8  iSerialNumber; */
197         0x01        /*  __u8  bNumConfigurations; */
198 };
199
200 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
201
202 /* usb 1.1 root hub device descriptor */
203 static const u8 usb11_rh_dev_descriptor[18] = {
204         0x12,       /*  __u8  bLength; */
205         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
206         0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
207
208         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
209         0x00,       /*  __u8  bDeviceSubClass; */
210         0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
211         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
212
213         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
214         0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
215         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
216
217         0x03,       /*  __u8  iManufacturer; */
218         0x02,       /*  __u8  iProduct; */
219         0x01,       /*  __u8  iSerialNumber; */
220         0x01        /*  __u8  bNumConfigurations; */
221 };
222
223
224 /*-------------------------------------------------------------------------*/
225
226 /* Configuration descriptors for our root hubs */
227
228 static const u8 fs_rh_config_descriptor[] = {
229
230         /* one configuration */
231         0x09,       /*  __u8  bLength; */
232         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
233         0x19, 0x00, /*  __le16 wTotalLength; */
234         0x01,       /*  __u8  bNumInterfaces; (1) */
235         0x01,       /*  __u8  bConfigurationValue; */
236         0x00,       /*  __u8  iConfiguration; */
237         0xc0,       /*  __u8  bmAttributes;
238                                  Bit 7: must be set,
239                                      6: Self-powered,
240                                      5: Remote wakeup,
241                                      4..0: resvd */
242         0x00,       /*  __u8  MaxPower; */
243
244         /* USB 1.1:
245          * USB 2.0, single TT organization (mandatory):
246          *      one interface, protocol 0
247          *
248          * USB 2.0, multiple TT organization (optional):
249          *      two interfaces, protocols 1 (like single TT)
250          *      and 2 (multiple TT mode) ... config is
251          *      sometimes settable
252          *      NOT IMPLEMENTED
253          */
254
255         /* one interface */
256         0x09,       /*  __u8  if_bLength; */
257         USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
258         0x00,       /*  __u8  if_bInterfaceNumber; */
259         0x00,       /*  __u8  if_bAlternateSetting; */
260         0x01,       /*  __u8  if_bNumEndpoints; */
261         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
262         0x00,       /*  __u8  if_bInterfaceSubClass; */
263         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
264         0x00,       /*  __u8  if_iInterface; */
265
266         /* one endpoint (status change endpoint) */
267         0x07,       /*  __u8  ep_bLength; */
268         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
269         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
270         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
271         0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
272         0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
273 };
274
275 static const u8 hs_rh_config_descriptor[] = {
276
277         /* one configuration */
278         0x09,       /*  __u8  bLength; */
279         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
280         0x19, 0x00, /*  __le16 wTotalLength; */
281         0x01,       /*  __u8  bNumInterfaces; (1) */
282         0x01,       /*  __u8  bConfigurationValue; */
283         0x00,       /*  __u8  iConfiguration; */
284         0xc0,       /*  __u8  bmAttributes;
285                                  Bit 7: must be set,
286                                      6: Self-powered,
287                                      5: Remote wakeup,
288                                      4..0: resvd */
289         0x00,       /*  __u8  MaxPower; */
290
291         /* USB 1.1:
292          * USB 2.0, single TT organization (mandatory):
293          *      one interface, protocol 0
294          *
295          * USB 2.0, multiple TT organization (optional):
296          *      two interfaces, protocols 1 (like single TT)
297          *      and 2 (multiple TT mode) ... config is
298          *      sometimes settable
299          *      NOT IMPLEMENTED
300          */
301
302         /* one interface */
303         0x09,       /*  __u8  if_bLength; */
304         USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
305         0x00,       /*  __u8  if_bInterfaceNumber; */
306         0x00,       /*  __u8  if_bAlternateSetting; */
307         0x01,       /*  __u8  if_bNumEndpoints; */
308         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
309         0x00,       /*  __u8  if_bInterfaceSubClass; */
310         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
311         0x00,       /*  __u8  if_iInterface; */
312
313         /* one endpoint (status change endpoint) */
314         0x07,       /*  __u8  ep_bLength; */
315         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
316         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
317         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
318                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
319                      * see hub.c:hub_configure() for details. */
320         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
321         0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
322 };
323
324 static const u8 ss_rh_config_descriptor[] = {
325         /* one configuration */
326         0x09,       /*  __u8  bLength; */
327         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
328         0x1f, 0x00, /*  __le16 wTotalLength; */
329         0x01,       /*  __u8  bNumInterfaces; (1) */
330         0x01,       /*  __u8  bConfigurationValue; */
331         0x00,       /*  __u8  iConfiguration; */
332         0xc0,       /*  __u8  bmAttributes;
333                                  Bit 7: must be set,
334                                      6: Self-powered,
335                                      5: Remote wakeup,
336                                      4..0: resvd */
337         0x00,       /*  __u8  MaxPower; */
338
339         /* one interface */
340         0x09,       /*  __u8  if_bLength; */
341         USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
342         0x00,       /*  __u8  if_bInterfaceNumber; */
343         0x00,       /*  __u8  if_bAlternateSetting; */
344         0x01,       /*  __u8  if_bNumEndpoints; */
345         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
346         0x00,       /*  __u8  if_bInterfaceSubClass; */
347         0x00,       /*  __u8  if_bInterfaceProtocol; */
348         0x00,       /*  __u8  if_iInterface; */
349
350         /* one endpoint (status change endpoint) */
351         0x07,       /*  __u8  ep_bLength; */
352         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
353         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
354         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
355                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
356                      * see hub.c:hub_configure() for details. */
357         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
358         0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
359
360         /* one SuperSpeed endpoint companion descriptor */
361         0x06,        /* __u8 ss_bLength */
362         USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
363                      /* Companion */
364         0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
365         0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
366         0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
367 };
368
369 /* authorized_default behaviour:
370  * -1 is authorized for all devices except wireless (old behaviour)
371  * 0 is unauthorized for all devices
372  * 1 is authorized for all devices
373  * 2 is authorized for internal devices
374  */
375 #define USB_AUTHORIZE_WIRED     -1
376 #define USB_AUTHORIZE_NONE      0
377 #define USB_AUTHORIZE_ALL       1
378 #define USB_AUTHORIZE_INTERNAL  2
379
380 static int authorized_default = USB_AUTHORIZE_WIRED;
381 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
382 MODULE_PARM_DESC(authorized_default,
383                 "Default USB device authorization: 0 is not authorized, 1 is "
384                 "authorized, 2 is authorized for internal devices, -1 is "
385                 "authorized except for wireless USB (default, old behaviour)");
386 /*-------------------------------------------------------------------------*/
387
388 /**
389  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
390  * @s: Null-terminated ASCII (actually ISO-8859-1) string
391  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
392  * @len: Length (in bytes; may be odd) of descriptor buffer.
393  *
394  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
395  * whichever is less.
396  *
397  * Note:
398  * USB String descriptors can contain at most 126 characters; input
399  * strings longer than that are truncated.
400  */
401 static unsigned
402 ascii2desc(char const *s, u8 *buf, unsigned len)
403 {
404         unsigned n, t = 2 + 2*strlen(s);
405
406         if (t > 254)
407                 t = 254;        /* Longest possible UTF string descriptor */
408         if (len > t)
409                 len = t;
410
411         t += USB_DT_STRING << 8;        /* Now t is first 16 bits to store */
412
413         n = len;
414         while (n--) {
415                 *buf++ = t;
416                 if (!n--)
417                         break;
418                 *buf++ = t >> 8;
419                 t = (unsigned char)*s++;
420         }
421         return len;
422 }
423
424 /**
425  * rh_string() - provides string descriptors for root hub
426  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
427  * @hcd: the host controller for this root hub
428  * @data: buffer for output packet
429  * @len: length of the provided buffer
430  *
431  * Produces either a manufacturer, product or serial number string for the
432  * virtual root hub device.
433  *
434  * Return: The number of bytes filled in: the length of the descriptor or
435  * of the provided buffer, whichever is less.
436  */
437 static unsigned
438 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
439 {
440         char buf[100];
441         char const *s;
442         static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
443
444         /* language ids */
445         switch (id) {
446         case 0:
447                 /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
448                 /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
449                 if (len > 4)
450                         len = 4;
451                 memcpy(data, langids, len);
452                 return len;
453         case 1:
454                 /* Serial number */
455                 s = hcd->self.bus_name;
456                 break;
457         case 2:
458                 /* Product name */
459                 s = hcd->product_desc;
460                 break;
461         case 3:
462                 /* Manufacturer */
463                 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
464                         init_utsname()->release, hcd->driver->description);
465                 s = buf;
466                 break;
467         default:
468                 /* Can't happen; caller guarantees it */
469                 return 0;
470         }
471
472         return ascii2desc(s, data, len);
473 }
474
475
476 /* Root hub control transfers execute synchronously */
477 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
478 {
479         struct usb_ctrlrequest *cmd;
480         u16             typeReq, wValue, wIndex, wLength;
481         u8              *ubuf = urb->transfer_buffer;
482         unsigned        len = 0;
483         int             status;
484         u8              patch_wakeup = 0;
485         u8              patch_protocol = 0;
486         u16             tbuf_size;
487         u8              *tbuf = NULL;
488         const u8        *bufp;
489
490         might_sleep();
491
492         spin_lock_irq(&hcd_root_hub_lock);
493         status = usb_hcd_link_urb_to_ep(hcd, urb);
494         spin_unlock_irq(&hcd_root_hub_lock);
495         if (status)
496                 return status;
497         urb->hcpriv = hcd;      /* Indicate it's queued */
498
499         cmd = (struct usb_ctrlrequest *) urb->setup_packet;
500         typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
501         wValue   = le16_to_cpu (cmd->wValue);
502         wIndex   = le16_to_cpu (cmd->wIndex);
503         wLength  = le16_to_cpu (cmd->wLength);
504
505         if (wLength > urb->transfer_buffer_length)
506                 goto error;
507
508         /*
509          * tbuf should be at least as big as the
510          * USB hub descriptor.
511          */
512         tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
513         tbuf = kzalloc(tbuf_size, GFP_KERNEL);
514         if (!tbuf) {
515                 status = -ENOMEM;
516                 goto err_alloc;
517         }
518
519         bufp = tbuf;
520
521
522         urb->actual_length = 0;
523         switch (typeReq) {
524
525         /* DEVICE REQUESTS */
526
527         /* The root hub's remote wakeup enable bit is implemented using
528          * driver model wakeup flags.  If this system supports wakeup
529          * through USB, userspace may change the default "allow wakeup"
530          * policy through sysfs or these calls.
531          *
532          * Most root hubs support wakeup from downstream devices, for
533          * runtime power management (disabling USB clocks and reducing
534          * VBUS power usage).  However, not all of them do so; silicon,
535          * board, and BIOS bugs here are not uncommon, so these can't
536          * be treated quite like external hubs.
537          *
538          * Likewise, not all root hubs will pass wakeup events upstream,
539          * to wake up the whole system.  So don't assume root hub and
540          * controller capabilities are identical.
541          */
542
543         case DeviceRequest | USB_REQ_GET_STATUS:
544                 tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
545                                         << USB_DEVICE_REMOTE_WAKEUP)
546                                 | (1 << USB_DEVICE_SELF_POWERED);
547                 tbuf[1] = 0;
548                 len = 2;
549                 break;
550         case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
551                 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
552                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
553                 else
554                         goto error;
555                 break;
556         case DeviceOutRequest | USB_REQ_SET_FEATURE:
557                 if (device_can_wakeup(&hcd->self.root_hub->dev)
558                                 && wValue == USB_DEVICE_REMOTE_WAKEUP)
559                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
560                 else
561                         goto error;
562                 break;
563         case DeviceRequest | USB_REQ_GET_CONFIGURATION:
564                 tbuf[0] = 1;
565                 len = 1;
566                         /* FALLTHROUGH */
567         case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
568                 break;
569         case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
570                 switch (wValue & 0xff00) {
571                 case USB_DT_DEVICE << 8:
572                         switch (hcd->speed) {
573                         case HCD_USB32:
574                         case HCD_USB31:
575                                 bufp = usb31_rh_dev_descriptor;
576                                 break;
577                         case HCD_USB3:
578                                 bufp = usb3_rh_dev_descriptor;
579                                 break;
580                         case HCD_USB25:
581                                 bufp = usb25_rh_dev_descriptor;
582                                 break;
583                         case HCD_USB2:
584                                 bufp = usb2_rh_dev_descriptor;
585                                 break;
586                         case HCD_USB11:
587                                 bufp = usb11_rh_dev_descriptor;
588                                 break;
589                         default:
590                                 goto error;
591                         }
592                         len = 18;
593                         if (hcd->has_tt)
594                                 patch_protocol = 1;
595                         break;
596                 case USB_DT_CONFIG << 8:
597                         switch (hcd->speed) {
598                         case HCD_USB32:
599                         case HCD_USB31:
600                         case HCD_USB3:
601                                 bufp = ss_rh_config_descriptor;
602                                 len = sizeof ss_rh_config_descriptor;
603                                 break;
604                         case HCD_USB25:
605                         case HCD_USB2:
606                                 bufp = hs_rh_config_descriptor;
607                                 len = sizeof hs_rh_config_descriptor;
608                                 break;
609                         case HCD_USB11:
610                                 bufp = fs_rh_config_descriptor;
611                                 len = sizeof fs_rh_config_descriptor;
612                                 break;
613                         default:
614                                 goto error;
615                         }
616                         if (device_can_wakeup(&hcd->self.root_hub->dev))
617                                 patch_wakeup = 1;
618                         break;
619                 case USB_DT_STRING << 8:
620                         if ((wValue & 0xff) < 4)
621                                 urb->actual_length = rh_string(wValue & 0xff,
622                                                 hcd, ubuf, wLength);
623                         else /* unsupported IDs --> "protocol stall" */
624                                 goto error;
625                         break;
626                 case USB_DT_BOS << 8:
627                         goto nongeneric;
628                 default:
629                         goto error;
630                 }
631                 break;
632         case DeviceRequest | USB_REQ_GET_INTERFACE:
633                 tbuf[0] = 0;
634                 len = 1;
635                         /* FALLTHROUGH */
636         case DeviceOutRequest | USB_REQ_SET_INTERFACE:
637                 break;
638         case DeviceOutRequest | USB_REQ_SET_ADDRESS:
639                 /* wValue == urb->dev->devaddr */
640                 dev_dbg (hcd->self.controller, "root hub device address %d\n",
641                         wValue);
642                 break;
643
644         /* INTERFACE REQUESTS (no defined feature/status flags) */
645
646         /* ENDPOINT REQUESTS */
647
648         case EndpointRequest | USB_REQ_GET_STATUS:
649                 /* ENDPOINT_HALT flag */
650                 tbuf[0] = 0;
651                 tbuf[1] = 0;
652                 len = 2;
653                         /* FALLTHROUGH */
654         case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
655         case EndpointOutRequest | USB_REQ_SET_FEATURE:
656                 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
657                 break;
658
659         /* CLASS REQUESTS (and errors) */
660
661         default:
662 nongeneric:
663                 /* non-generic request */
664                 switch (typeReq) {
665                 case GetHubStatus:
666                         len = 4;
667                         break;
668                 case GetPortStatus:
669                         if (wValue == HUB_PORT_STATUS)
670                                 len = 4;
671                         else
672                                 /* other port status types return 8 bytes */
673                                 len = 8;
674                         break;
675                 case GetHubDescriptor:
676                         len = sizeof (struct usb_hub_descriptor);
677                         break;
678                 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
679                         /* len is returned by hub_control */
680                         break;
681                 }
682                 status = hcd->driver->hub_control (hcd,
683                         typeReq, wValue, wIndex,
684                         tbuf, wLength);
685
686                 if (typeReq == GetHubDescriptor)
687                         usb_hub_adjust_deviceremovable(hcd->self.root_hub,
688                                 (struct usb_hub_descriptor *)tbuf);
689                 break;
690 error:
691                 /* "protocol stall" on error */
692                 status = -EPIPE;
693         }
694
695         if (status < 0) {
696                 len = 0;
697                 if (status != -EPIPE) {
698                         dev_dbg (hcd->self.controller,
699                                 "CTRL: TypeReq=0x%x val=0x%x "
700                                 "idx=0x%x len=%d ==> %d\n",
701                                 typeReq, wValue, wIndex,
702                                 wLength, status);
703                 }
704         } else if (status > 0) {
705                 /* hub_control may return the length of data copied. */
706                 len = status;
707                 status = 0;
708         }
709         if (len) {
710                 if (urb->transfer_buffer_length < len)
711                         len = urb->transfer_buffer_length;
712                 urb->actual_length = len;
713                 /* always USB_DIR_IN, toward host */
714                 memcpy (ubuf, bufp, len);
715
716                 /* report whether RH hardware supports remote wakeup */
717                 if (patch_wakeup &&
718                                 len > offsetof (struct usb_config_descriptor,
719                                                 bmAttributes))
720                         ((struct usb_config_descriptor *)ubuf)->bmAttributes
721                                 |= USB_CONFIG_ATT_WAKEUP;
722
723                 /* report whether RH hardware has an integrated TT */
724                 if (patch_protocol &&
725                                 len > offsetof(struct usb_device_descriptor,
726                                                 bDeviceProtocol))
727                         ((struct usb_device_descriptor *) ubuf)->
728                                 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
729         }
730
731         kfree(tbuf);
732  err_alloc:
733
734         /* any errors get returned through the urb completion */
735         spin_lock_irq(&hcd_root_hub_lock);
736         usb_hcd_unlink_urb_from_ep(hcd, urb);
737         usb_hcd_giveback_urb(hcd, urb, status);
738         spin_unlock_irq(&hcd_root_hub_lock);
739         return 0;
740 }
741
742 /*-------------------------------------------------------------------------*/
743
744 /*
745  * Root Hub interrupt transfers are polled using a timer if the
746  * driver requests it; otherwise the driver is responsible for
747  * calling usb_hcd_poll_rh_status() when an event occurs.
748  *
749  * Completions are called in_interrupt(), but they may or may not
750  * be in_irq().
751  */
752 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
753 {
754         struct urb      *urb;
755         int             length;
756         unsigned long   flags;
757         char            buffer[6];      /* Any root hubs with > 31 ports? */
758
759         if (unlikely(!hcd->rh_pollable))
760                 return;
761         if (!hcd->uses_new_polling && !hcd->status_urb)
762                 return;
763
764         length = hcd->driver->hub_status_data(hcd, buffer);
765         if (length > 0) {
766
767                 /* try to complete the status urb */
768                 spin_lock_irqsave(&hcd_root_hub_lock, flags);
769                 urb = hcd->status_urb;
770                 if (urb) {
771                         clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
772                         hcd->status_urb = NULL;
773                         urb->actual_length = length;
774                         memcpy(urb->transfer_buffer, buffer, length);
775
776                         usb_hcd_unlink_urb_from_ep(hcd, urb);
777                         usb_hcd_giveback_urb(hcd, urb, 0);
778                 } else {
779                         length = 0;
780                         set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
781                 }
782                 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
783         }
784
785         /* The USB 2.0 spec says 256 ms.  This is close enough and won't
786          * exceed that limit if HZ is 100. The math is more clunky than
787          * maybe expected, this is to make sure that all timers for USB devices
788          * fire at the same time to give the CPU a break in between */
789         if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
790                         (length == 0 && hcd->status_urb != NULL))
791                 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
792 }
793 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
794
795 /* timer callback */
796 static void rh_timer_func (struct timer_list *t)
797 {
798         struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer);
799
800         usb_hcd_poll_rh_status(_hcd);
801 }
802
803 /*-------------------------------------------------------------------------*/
804
805 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
806 {
807         int             retval;
808         unsigned long   flags;
809         unsigned        len = 1 + (urb->dev->maxchild / 8);
810
811         spin_lock_irqsave (&hcd_root_hub_lock, flags);
812         if (hcd->status_urb || urb->transfer_buffer_length < len) {
813                 dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
814                 retval = -EINVAL;
815                 goto done;
816         }
817
818         retval = usb_hcd_link_urb_to_ep(hcd, urb);
819         if (retval)
820                 goto done;
821
822         hcd->status_urb = urb;
823         urb->hcpriv = hcd;      /* indicate it's queued */
824         if (!hcd->uses_new_polling)
825                 mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
826
827         /* If a status change has already occurred, report it ASAP */
828         else if (HCD_POLL_PENDING(hcd))
829                 mod_timer(&hcd->rh_timer, jiffies);
830         retval = 0;
831  done:
832         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
833         return retval;
834 }
835
836 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
837 {
838         if (usb_endpoint_xfer_int(&urb->ep->desc))
839                 return rh_queue_status (hcd, urb);
840         if (usb_endpoint_xfer_control(&urb->ep->desc))
841                 return rh_call_control (hcd, urb);
842         return -EINVAL;
843 }
844
845 /*-------------------------------------------------------------------------*/
846
847 /* Unlinks of root-hub control URBs are legal, but they don't do anything
848  * since these URBs always execute synchronously.
849  */
850 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
851 {
852         unsigned long   flags;
853         int             rc;
854
855         spin_lock_irqsave(&hcd_root_hub_lock, flags);
856         rc = usb_hcd_check_unlink_urb(hcd, urb, status);
857         if (rc)
858                 goto done;
859
860         if (usb_endpoint_num(&urb->ep->desc) == 0) {    /* Control URB */
861                 ;       /* Do nothing */
862
863         } else {                                /* Status URB */
864                 if (!hcd->uses_new_polling)
865                         del_timer (&hcd->rh_timer);
866                 if (urb == hcd->status_urb) {
867                         hcd->status_urb = NULL;
868                         usb_hcd_unlink_urb_from_ep(hcd, urb);
869                         usb_hcd_giveback_urb(hcd, urb, status);
870                 }
871         }
872  done:
873         spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
874         return rc;
875 }
876
877
878 /*-------------------------------------------------------------------------*/
879
880 /**
881  * usb_bus_init - shared initialization code
882  * @bus: the bus structure being initialized
883  *
884  * This code is used to initialize a usb_bus structure, memory for which is
885  * separately managed.
886  */
887 static void usb_bus_init (struct usb_bus *bus)
888 {
889         memset (&bus->devmap, 0, sizeof(struct usb_devmap));
890
891         bus->devnum_next = 1;
892
893         bus->root_hub = NULL;
894         bus->busnum = -1;
895         bus->bandwidth_allocated = 0;
896         bus->bandwidth_int_reqs  = 0;
897         bus->bandwidth_isoc_reqs = 0;
898         mutex_init(&bus->devnum_next_mutex);
899 }
900
901 /*-------------------------------------------------------------------------*/
902
903 /**
904  * usb_register_bus - registers the USB host controller with the usb core
905  * @bus: pointer to the bus to register
906  * Context: !in_interrupt()
907  *
908  * Assigns a bus number, and links the controller into usbcore data
909  * structures so that it can be seen by scanning the bus list.
910  *
911  * Return: 0 if successful. A negative error code otherwise.
912  */
913 static int usb_register_bus(struct usb_bus *bus)
914 {
915         int result = -E2BIG;
916         int busnum;
917
918         mutex_lock(&usb_bus_idr_lock);
919         busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
920         if (busnum < 0) {
921                 pr_err("%s: failed to get bus number\n", usbcore_name);
922                 goto error_find_busnum;
923         }
924         bus->busnum = busnum;
925         mutex_unlock(&usb_bus_idr_lock);
926
927         usb_notify_add_bus(bus);
928
929         dev_info (bus->controller, "new USB bus registered, assigned bus "
930                   "number %d\n", bus->busnum);
931         return 0;
932
933 error_find_busnum:
934         mutex_unlock(&usb_bus_idr_lock);
935         return result;
936 }
937
938 /**
939  * usb_deregister_bus - deregisters the USB host controller
940  * @bus: pointer to the bus to deregister
941  * Context: !in_interrupt()
942  *
943  * Recycles the bus number, and unlinks the controller from usbcore data
944  * structures so that it won't be seen by scanning the bus list.
945  */
946 static void usb_deregister_bus (struct usb_bus *bus)
947 {
948         dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
949
950         /*
951          * NOTE: make sure that all the devices are removed by the
952          * controller code, as well as having it call this when cleaning
953          * itself up
954          */
955         mutex_lock(&usb_bus_idr_lock);
956         idr_remove(&usb_bus_idr, bus->busnum);
957         mutex_unlock(&usb_bus_idr_lock);
958
959         usb_notify_remove_bus(bus);
960 }
961
962 /**
963  * register_root_hub - called by usb_add_hcd() to register a root hub
964  * @hcd: host controller for this root hub
965  *
966  * This function registers the root hub with the USB subsystem.  It sets up
967  * the device properly in the device tree and then calls usb_new_device()
968  * to register the usb device.  It also assigns the root hub's USB address
969  * (always 1).
970  *
971  * Return: 0 if successful. A negative error code otherwise.
972  */
973 static int register_root_hub(struct usb_hcd *hcd)
974 {
975         struct device *parent_dev = hcd->self.controller;
976         struct usb_device *usb_dev = hcd->self.root_hub;
977         const int devnum = 1;
978         int retval;
979
980         usb_dev->devnum = devnum;
981         usb_dev->bus->devnum_next = devnum + 1;
982         set_bit (devnum, usb_dev->bus->devmap.devicemap);
983         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
984
985         mutex_lock(&usb_bus_idr_lock);
986
987         usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
988         retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
989         if (retval != sizeof usb_dev->descriptor) {
990                 mutex_unlock(&usb_bus_idr_lock);
991                 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
992                                 dev_name(&usb_dev->dev), retval);
993                 return (retval < 0) ? retval : -EMSGSIZE;
994         }
995
996         if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
997                 retval = usb_get_bos_descriptor(usb_dev);
998                 if (!retval) {
999                         usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1000                 } else if (usb_dev->speed >= USB_SPEED_SUPER) {
1001                         mutex_unlock(&usb_bus_idr_lock);
1002                         dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1003                                         dev_name(&usb_dev->dev), retval);
1004                         return retval;
1005                 }
1006         }
1007
1008         retval = usb_new_device (usb_dev);
1009         if (retval) {
1010                 dev_err (parent_dev, "can't register root hub for %s, %d\n",
1011                                 dev_name(&usb_dev->dev), retval);
1012         } else {
1013                 spin_lock_irq (&hcd_root_hub_lock);
1014                 hcd->rh_registered = 1;
1015                 spin_unlock_irq (&hcd_root_hub_lock);
1016
1017                 /* Did the HC die before the root hub was registered? */
1018                 if (HCD_DEAD(hcd))
1019                         usb_hc_died (hcd);      /* This time clean up */
1020         }
1021         mutex_unlock(&usb_bus_idr_lock);
1022
1023         return retval;
1024 }
1025
1026 /*
1027  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1028  * @bus: the bus which the root hub belongs to
1029  * @portnum: the port which is being resumed
1030  *
1031  * HCDs should call this function when they know that a resume signal is
1032  * being sent to a root-hub port.  The root hub will be prevented from
1033  * going into autosuspend until usb_hcd_end_port_resume() is called.
1034  *
1035  * The bus's private lock must be held by the caller.
1036  */
1037 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1038 {
1039         unsigned bit = 1 << portnum;
1040
1041         if (!(bus->resuming_ports & bit)) {
1042                 bus->resuming_ports |= bit;
1043                 pm_runtime_get_noresume(&bus->root_hub->dev);
1044         }
1045 }
1046 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1047
1048 /*
1049  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1050  * @bus: the bus which the root hub belongs to
1051  * @portnum: the port which is being resumed
1052  *
1053  * HCDs should call this function when they know that a resume signal has
1054  * stopped being sent to a root-hub port.  The root hub will be allowed to
1055  * autosuspend again.
1056  *
1057  * The bus's private lock must be held by the caller.
1058  */
1059 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1060 {
1061         unsigned bit = 1 << portnum;
1062
1063         if (bus->resuming_ports & bit) {
1064                 bus->resuming_ports &= ~bit;
1065                 pm_runtime_put_noidle(&bus->root_hub->dev);
1066         }
1067 }
1068 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1069
1070 /*-------------------------------------------------------------------------*/
1071
1072 /**
1073  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1074  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1075  * @is_input: true iff the transaction sends data to the host
1076  * @isoc: true for isochronous transactions, false for interrupt ones
1077  * @bytecount: how many bytes in the transaction.
1078  *
1079  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1080  *
1081  * Note:
1082  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1083  * scheduled in software, this function is only used for such scheduling.
1084  */
1085 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1086 {
1087         unsigned long   tmp;
1088
1089         switch (speed) {
1090         case USB_SPEED_LOW:     /* INTR only */
1091                 if (is_input) {
1092                         tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1093                         return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1094                 } else {
1095                         tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1096                         return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1097                 }
1098         case USB_SPEED_FULL:    /* ISOC or INTR */
1099                 if (isoc) {
1100                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1101                         return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1102                 } else {
1103                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1104                         return 9107L + BW_HOST_DELAY + tmp;
1105                 }
1106         case USB_SPEED_HIGH:    /* ISOC or INTR */
1107                 /* FIXME adjust for input vs output */
1108                 if (isoc)
1109                         tmp = HS_NSECS_ISO (bytecount);
1110                 else
1111                         tmp = HS_NSECS (bytecount);
1112                 return tmp;
1113         default:
1114                 pr_debug ("%s: bogus device speed!\n", usbcore_name);
1115                 return -1;
1116         }
1117 }
1118 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1119
1120
1121 /*-------------------------------------------------------------------------*/
1122
1123 /*
1124  * Generic HC operations.
1125  */
1126
1127 /*-------------------------------------------------------------------------*/
1128
1129 /**
1130  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1131  * @hcd: host controller to which @urb was submitted
1132  * @urb: URB being submitted
1133  *
1134  * Host controller drivers should call this routine in their enqueue()
1135  * method.  The HCD's private spinlock must be held and interrupts must
1136  * be disabled.  The actions carried out here are required for URB
1137  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1138  *
1139  * Return: 0 for no error, otherwise a negative error code (in which case
1140  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1141  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1142  * the private spinlock and returning.
1143  */
1144 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1145 {
1146         int             rc = 0;
1147
1148         spin_lock(&hcd_urb_list_lock);
1149
1150         /* Check that the URB isn't being killed */
1151         if (unlikely(atomic_read(&urb->reject))) {
1152                 rc = -EPERM;
1153                 goto done;
1154         }
1155
1156         if (unlikely(!urb->ep->enabled)) {
1157                 rc = -ENOENT;
1158                 goto done;
1159         }
1160
1161         if (unlikely(!urb->dev->can_submit)) {
1162                 rc = -EHOSTUNREACH;
1163                 goto done;
1164         }
1165
1166         /*
1167          * Check the host controller's state and add the URB to the
1168          * endpoint's queue.
1169          */
1170         if (HCD_RH_RUNNING(hcd)) {
1171                 urb->unlinked = 0;
1172                 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1173         } else {
1174                 rc = -ESHUTDOWN;
1175                 goto done;
1176         }
1177  done:
1178         spin_unlock(&hcd_urb_list_lock);
1179         return rc;
1180 }
1181 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1182
1183 /**
1184  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1185  * @hcd: host controller to which @urb was submitted
1186  * @urb: URB being checked for unlinkability
1187  * @status: error code to store in @urb if the unlink succeeds
1188  *
1189  * Host controller drivers should call this routine in their dequeue()
1190  * method.  The HCD's private spinlock must be held and interrupts must
1191  * be disabled.  The actions carried out here are required for making
1192  * sure than an unlink is valid.
1193  *
1194  * Return: 0 for no error, otherwise a negative error code (in which case
1195  * the dequeue() method must fail).  The possible error codes are:
1196  *
1197  *      -EIDRM: @urb was not submitted or has already completed.
1198  *              The completion function may not have been called yet.
1199  *
1200  *      -EBUSY: @urb has already been unlinked.
1201  */
1202 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1203                 int status)
1204 {
1205         struct list_head        *tmp;
1206
1207         /* insist the urb is still queued */
1208         list_for_each(tmp, &urb->ep->urb_list) {
1209                 if (tmp == &urb->urb_list)
1210                         break;
1211         }
1212         if (tmp != &urb->urb_list)
1213                 return -EIDRM;
1214
1215         /* Any status except -EINPROGRESS means something already started to
1216          * unlink this URB from the hardware.  So there's no more work to do.
1217          */
1218         if (urb->unlinked)
1219                 return -EBUSY;
1220         urb->unlinked = status;
1221         return 0;
1222 }
1223 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1224
1225 /**
1226  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1227  * @hcd: host controller to which @urb was submitted
1228  * @urb: URB being unlinked
1229  *
1230  * Host controller drivers should call this routine before calling
1231  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1232  * interrupts must be disabled.  The actions carried out here are required
1233  * for URB completion.
1234  */
1235 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1236 {
1237         /* clear all state linking urb to this dev (and hcd) */
1238         spin_lock(&hcd_urb_list_lock);
1239         list_del_init(&urb->urb_list);
1240         spin_unlock(&hcd_urb_list_lock);
1241 }
1242 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1243
1244 /*
1245  * Some usb host controllers can only perform dma using a small SRAM area.
1246  * The usb core itself is however optimized for host controllers that can dma
1247  * using regular system memory - like pci devices doing bus mastering.
1248  *
1249  * To support host controllers with limited dma capabilities we provide dma
1250  * bounce buffers. This feature can be enabled by initializing
1251  * hcd->localmem_pool using usb_hcd_setup_local_mem().
1252  *
1253  * The initialized hcd->localmem_pool then tells the usb code to allocate all
1254  * data for dma using the genalloc API.
1255  *
1256  * So, to summarize...
1257  *
1258  * - We need "local" memory, canonical example being
1259  *   a small SRAM on a discrete controller being the
1260  *   only memory that the controller can read ...
1261  *   (a) "normal" kernel memory is no good, and
1262  *   (b) there's not enough to share
1263  *
1264  * - So we use that, even though the primary requirement
1265  *   is that the memory be "local" (hence addressable
1266  *   by that device), not "coherent".
1267  *
1268  */
1269
1270 static int hcd_alloc_coherent(struct usb_bus *bus,
1271                               gfp_t mem_flags, dma_addr_t *dma_handle,
1272                               void **vaddr_handle, size_t size,
1273                               enum dma_data_direction dir)
1274 {
1275         unsigned char *vaddr;
1276
1277         if (*vaddr_handle == NULL) {
1278                 WARN_ON_ONCE(1);
1279                 return -EFAULT;
1280         }
1281
1282         vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1283                                  mem_flags, dma_handle);
1284         if (!vaddr)
1285                 return -ENOMEM;
1286
1287         /*
1288          * Store the virtual address of the buffer at the end
1289          * of the allocated dma buffer. The size of the buffer
1290          * may be uneven so use unaligned functions instead
1291          * of just rounding up. It makes sense to optimize for
1292          * memory footprint over access speed since the amount
1293          * of memory available for dma may be limited.
1294          */
1295         put_unaligned((unsigned long)*vaddr_handle,
1296                       (unsigned long *)(vaddr + size));
1297
1298         if (dir == DMA_TO_DEVICE)
1299                 memcpy(vaddr, *vaddr_handle, size);
1300
1301         *vaddr_handle = vaddr;
1302         return 0;
1303 }
1304
1305 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1306                               void **vaddr_handle, size_t size,
1307                               enum dma_data_direction dir)
1308 {
1309         unsigned char *vaddr = *vaddr_handle;
1310
1311         vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1312
1313         if (dir == DMA_FROM_DEVICE)
1314                 memcpy(vaddr, *vaddr_handle, size);
1315
1316         hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1317
1318         *vaddr_handle = vaddr;
1319         *dma_handle = 0;
1320 }
1321
1322 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1323 {
1324         if (IS_ENABLED(CONFIG_HAS_DMA) &&
1325             (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
1326                 dma_unmap_single(hcd->self.sysdev,
1327                                 urb->setup_dma,
1328                                 sizeof(struct usb_ctrlrequest),
1329                                 DMA_TO_DEVICE);
1330         else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1331                 hcd_free_coherent(urb->dev->bus,
1332                                 &urb->setup_dma,
1333                                 (void **) &urb->setup_packet,
1334                                 sizeof(struct usb_ctrlrequest),
1335                                 DMA_TO_DEVICE);
1336
1337         /* Make it safe to call this routine more than once */
1338         urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1339 }
1340 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1341
1342 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1343 {
1344         if (hcd->driver->unmap_urb_for_dma)
1345                 hcd->driver->unmap_urb_for_dma(hcd, urb);
1346         else
1347                 usb_hcd_unmap_urb_for_dma(hcd, urb);
1348 }
1349
1350 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1351 {
1352         enum dma_data_direction dir;
1353
1354         usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1355
1356         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1357         if (IS_ENABLED(CONFIG_HAS_DMA) &&
1358             (urb->transfer_flags & URB_DMA_MAP_SG))
1359                 dma_unmap_sg(hcd->self.sysdev,
1360                                 urb->sg,
1361                                 urb->num_sgs,
1362                                 dir);
1363         else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1364                  (urb->transfer_flags & URB_DMA_MAP_PAGE))
1365                 dma_unmap_page(hcd->self.sysdev,
1366                                 urb->transfer_dma,
1367                                 urb->transfer_buffer_length,
1368                                 dir);
1369         else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1370                  (urb->transfer_flags & URB_DMA_MAP_SINGLE))
1371                 dma_unmap_single(hcd->self.sysdev,
1372                                 urb->transfer_dma,
1373                                 urb->transfer_buffer_length,
1374                                 dir);
1375         else if (urb->transfer_flags & URB_MAP_LOCAL)
1376                 hcd_free_coherent(urb->dev->bus,
1377                                 &urb->transfer_dma,
1378                                 &urb->transfer_buffer,
1379                                 urb->transfer_buffer_length,
1380                                 dir);
1381
1382         /* Make it safe to call this routine more than once */
1383         urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1384                         URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1385 }
1386 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1387
1388 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1389                            gfp_t mem_flags)
1390 {
1391         if (hcd->driver->map_urb_for_dma)
1392                 return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1393         else
1394                 return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1395 }
1396
1397 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1398                             gfp_t mem_flags)
1399 {
1400         enum dma_data_direction dir;
1401         int ret = 0;
1402
1403         /* Map the URB's buffers for DMA access.
1404          * Lower level HCD code should use *_dma exclusively,
1405          * unless it uses pio or talks to another transport,
1406          * or uses the provided scatter gather list for bulk.
1407          */
1408
1409         if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1410                 if (hcd->self.uses_pio_for_control)
1411                         return ret;
1412                 if (hcd_uses_dma(hcd)) {
1413                         if (object_is_on_stack(urb->setup_packet)) {
1414                                 WARN_ONCE(1, "setup packet is on stack\n");
1415                                 return -EAGAIN;
1416                         }
1417
1418                         urb->setup_dma = dma_map_single(
1419                                         hcd->self.sysdev,
1420                                         urb->setup_packet,
1421                                         sizeof(struct usb_ctrlrequest),
1422                                         DMA_TO_DEVICE);
1423                         if (dma_mapping_error(hcd->self.sysdev,
1424                                                 urb->setup_dma))
1425                                 return -EAGAIN;
1426                         urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1427                 } else if (hcd->localmem_pool) {
1428                         ret = hcd_alloc_coherent(
1429                                         urb->dev->bus, mem_flags,
1430                                         &urb->setup_dma,
1431                                         (void **)&urb->setup_packet,
1432                                         sizeof(struct usb_ctrlrequest),
1433                                         DMA_TO_DEVICE);
1434                         if (ret)
1435                                 return ret;
1436                         urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1437                 }
1438         }
1439
1440         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1441         if (urb->transfer_buffer_length != 0
1442             && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1443                 if (hcd_uses_dma(hcd)) {
1444                         if (urb->num_sgs) {
1445                                 int n;
1446
1447                                 /* We don't support sg for isoc transfers ! */
1448                                 if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1449                                         WARN_ON(1);
1450                                         return -EINVAL;
1451                                 }
1452
1453                                 n = dma_map_sg(
1454                                                 hcd->self.sysdev,
1455                                                 urb->sg,
1456                                                 urb->num_sgs,
1457                                                 dir);
1458                                 if (n <= 0)
1459                                         ret = -EAGAIN;
1460                                 else
1461                                         urb->transfer_flags |= URB_DMA_MAP_SG;
1462                                 urb->num_mapped_sgs = n;
1463                                 if (n != urb->num_sgs)
1464                                         urb->transfer_flags |=
1465                                                         URB_DMA_SG_COMBINED;
1466                         } else if (urb->sg) {
1467                                 struct scatterlist *sg = urb->sg;
1468                                 urb->transfer_dma = dma_map_page(
1469                                                 hcd->self.sysdev,
1470                                                 sg_page(sg),
1471                                                 sg->offset,
1472                                                 urb->transfer_buffer_length,
1473                                                 dir);
1474                                 if (dma_mapping_error(hcd->self.sysdev,
1475                                                 urb->transfer_dma))
1476                                         ret = -EAGAIN;
1477                                 else
1478                                         urb->transfer_flags |= URB_DMA_MAP_PAGE;
1479                         } else if (object_is_on_stack(urb->transfer_buffer)) {
1480                                 WARN_ONCE(1, "transfer buffer is on stack\n");
1481                                 ret = -EAGAIN;
1482                         } else {
1483                                 urb->transfer_dma = dma_map_single(
1484                                                 hcd->self.sysdev,
1485                                                 urb->transfer_buffer,
1486                                                 urb->transfer_buffer_length,
1487                                                 dir);
1488                                 if (dma_mapping_error(hcd->self.sysdev,
1489                                                 urb->transfer_dma))
1490                                         ret = -EAGAIN;
1491                                 else
1492                                         urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1493                         }
1494                 } else if (hcd->localmem_pool) {
1495                         ret = hcd_alloc_coherent(
1496                                         urb->dev->bus, mem_flags,
1497                                         &urb->transfer_dma,
1498                                         &urb->transfer_buffer,
1499                                         urb->transfer_buffer_length,
1500                                         dir);
1501                         if (ret == 0)
1502                                 urb->transfer_flags |= URB_MAP_LOCAL;
1503                 }
1504                 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1505                                 URB_SETUP_MAP_LOCAL)))
1506                         usb_hcd_unmap_urb_for_dma(hcd, urb);
1507         }
1508         return ret;
1509 }
1510 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1511
1512 /*-------------------------------------------------------------------------*/
1513
1514 /* may be called in any context with a valid urb->dev usecount
1515  * caller surrenders "ownership" of urb
1516  * expects usb_submit_urb() to have sanity checked and conditioned all
1517  * inputs in the urb
1518  */
1519 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1520 {
1521         int                     status;
1522         struct usb_hcd          *hcd = bus_to_hcd(urb->dev->bus);
1523
1524         /* increment urb's reference count as part of giving it to the HCD
1525          * (which will control it).  HCD guarantees that it either returns
1526          * an error or calls giveback(), but not both.
1527          */
1528         usb_get_urb(urb);
1529         atomic_inc(&urb->use_count);
1530         atomic_inc(&urb->dev->urbnum);
1531         usbmon_urb_submit(&hcd->self, urb);
1532
1533         /* NOTE requirements on root-hub callers (usbfs and the hub
1534          * driver, for now):  URBs' urb->transfer_buffer must be
1535          * valid and usb_buffer_{sync,unmap}() not be needed, since
1536          * they could clobber root hub response data.  Also, control
1537          * URBs must be submitted in process context with interrupts
1538          * enabled.
1539          */
1540
1541         if (is_root_hub(urb->dev)) {
1542                 status = rh_urb_enqueue(hcd, urb);
1543         } else {
1544                 status = map_urb_for_dma(hcd, urb, mem_flags);
1545                 if (likely(status == 0)) {
1546                         status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1547                         if (unlikely(status))
1548                                 unmap_urb_for_dma(hcd, urb);
1549                 }
1550         }
1551
1552         if (unlikely(status)) {
1553                 usbmon_urb_submit_error(&hcd->self, urb, status);
1554                 urb->hcpriv = NULL;
1555                 INIT_LIST_HEAD(&urb->urb_list);
1556                 atomic_dec(&urb->use_count);
1557                 atomic_dec(&urb->dev->urbnum);
1558                 if (atomic_read(&urb->reject))
1559                         wake_up(&usb_kill_urb_queue);
1560                 usb_put_urb(urb);
1561         }
1562         return status;
1563 }
1564
1565 /*-------------------------------------------------------------------------*/
1566
1567 /* this makes the hcd giveback() the urb more quickly, by kicking it
1568  * off hardware queues (which may take a while) and returning it as
1569  * soon as practical.  we've already set up the urb's return status,
1570  * but we can't know if the callback completed already.
1571  */
1572 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1573 {
1574         int             value;
1575
1576         if (is_root_hub(urb->dev))
1577                 value = usb_rh_urb_dequeue(hcd, urb, status);
1578         else {
1579
1580                 /* The only reason an HCD might fail this call is if
1581                  * it has not yet fully queued the urb to begin with.
1582                  * Such failures should be harmless. */
1583                 value = hcd->driver->urb_dequeue(hcd, urb, status);
1584         }
1585         return value;
1586 }
1587
1588 /*
1589  * called in any context
1590  *
1591  * caller guarantees urb won't be recycled till both unlink()
1592  * and the urb's completion function return
1593  */
1594 int usb_hcd_unlink_urb (struct urb *urb, int status)
1595 {
1596         struct usb_hcd          *hcd;
1597         struct usb_device       *udev = urb->dev;
1598         int                     retval = -EIDRM;
1599         unsigned long           flags;
1600
1601         /* Prevent the device and bus from going away while
1602          * the unlink is carried out.  If they are already gone
1603          * then urb->use_count must be 0, since disconnected
1604          * devices can't have any active URBs.
1605          */
1606         spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1607         if (atomic_read(&urb->use_count) > 0) {
1608                 retval = 0;
1609                 usb_get_dev(udev);
1610         }
1611         spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1612         if (retval == 0) {
1613                 hcd = bus_to_hcd(urb->dev->bus);
1614                 retval = unlink1(hcd, urb, status);
1615                 if (retval == 0)
1616                         retval = -EINPROGRESS;
1617                 else if (retval != -EIDRM && retval != -EBUSY)
1618                         dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
1619                                         urb, retval);
1620                 usb_put_dev(udev);
1621         }
1622         return retval;
1623 }
1624
1625 /*-------------------------------------------------------------------------*/
1626
1627 static void __usb_hcd_giveback_urb(struct urb *urb)
1628 {
1629         struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1630         struct usb_anchor *anchor = urb->anchor;
1631         int status = urb->unlinked;
1632
1633         urb->hcpriv = NULL;
1634         if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1635             urb->actual_length < urb->transfer_buffer_length &&
1636             !status))
1637                 status = -EREMOTEIO;
1638
1639         unmap_urb_for_dma(hcd, urb);
1640         usbmon_urb_complete(&hcd->self, urb, status);
1641         usb_anchor_suspend_wakeups(anchor);
1642         usb_unanchor_urb(urb);
1643         if (likely(status == 0))
1644                 usb_led_activity(USB_LED_EVENT_HOST);
1645
1646         /* pass ownership to the completion handler */
1647         urb->status = status;
1648         urb->complete(urb);
1649
1650         usb_anchor_resume_wakeups(anchor);
1651         atomic_dec(&urb->use_count);
1652         if (unlikely(atomic_read(&urb->reject)))
1653                 wake_up(&usb_kill_urb_queue);
1654         usb_put_urb(urb);
1655 }
1656
1657 static void usb_giveback_urb_bh(unsigned long param)
1658 {
1659         struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1660         struct list_head local_list;
1661
1662         spin_lock_irq(&bh->lock);
1663         bh->running = true;
1664  restart:
1665         list_replace_init(&bh->head, &local_list);
1666         spin_unlock_irq(&bh->lock);
1667
1668         while (!list_empty(&local_list)) {
1669                 struct urb *urb;
1670
1671                 urb = list_entry(local_list.next, struct urb, urb_list);
1672                 list_del_init(&urb->urb_list);
1673                 bh->completing_ep = urb->ep;
1674                 __usb_hcd_giveback_urb(urb);
1675                 bh->completing_ep = NULL;
1676         }
1677
1678         /* check if there are new URBs to giveback */
1679         spin_lock_irq(&bh->lock);
1680         if (!list_empty(&bh->head))
1681                 goto restart;
1682         bh->running = false;
1683         spin_unlock_irq(&bh->lock);
1684 }
1685
1686 /**
1687  * usb_hcd_giveback_urb - return URB from HCD to device driver
1688  * @hcd: host controller returning the URB
1689  * @urb: urb being returned to the USB device driver.
1690  * @status: completion status code for the URB.
1691  * Context: in_interrupt()
1692  *
1693  * This hands the URB from HCD to its USB device driver, using its
1694  * completion function.  The HCD has freed all per-urb resources
1695  * (and is done using urb->hcpriv).  It also released all HCD locks;
1696  * the device driver won't cause problems if it frees, modifies,
1697  * or resubmits this URB.
1698  *
1699  * If @urb was unlinked, the value of @status will be overridden by
1700  * @urb->unlinked.  Erroneous short transfers are detected in case
1701  * the HCD hasn't checked for them.
1702  */
1703 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1704 {
1705         struct giveback_urb_bh *bh;
1706         bool running, high_prio_bh;
1707
1708         /* pass status to tasklet via unlinked */
1709         if (likely(!urb->unlinked))
1710                 urb->unlinked = status;
1711
1712         if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1713                 __usb_hcd_giveback_urb(urb);
1714                 return;
1715         }
1716
1717         if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1718                 bh = &hcd->high_prio_bh;
1719                 high_prio_bh = true;
1720         } else {
1721                 bh = &hcd->low_prio_bh;
1722                 high_prio_bh = false;
1723         }
1724
1725         spin_lock(&bh->lock);
1726         list_add_tail(&urb->urb_list, &bh->head);
1727         running = bh->running;
1728         spin_unlock(&bh->lock);
1729
1730         if (running)
1731                 ;
1732         else if (high_prio_bh)
1733                 tasklet_hi_schedule(&bh->bh);
1734         else
1735                 tasklet_schedule(&bh->bh);
1736 }
1737 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1738
1739 /*-------------------------------------------------------------------------*/
1740
1741 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1742  * queue to drain completely.  The caller must first insure that no more
1743  * URBs can be submitted for this endpoint.
1744  */
1745 void usb_hcd_flush_endpoint(struct usb_device *udev,
1746                 struct usb_host_endpoint *ep)
1747 {
1748         struct usb_hcd          *hcd;
1749         struct urb              *urb;
1750
1751         if (!ep)
1752                 return;
1753         might_sleep();
1754         hcd = bus_to_hcd(udev->bus);
1755
1756         /* No more submits can occur */
1757         spin_lock_irq(&hcd_urb_list_lock);
1758 rescan:
1759         list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
1760                 int     is_in;
1761
1762                 if (urb->unlinked)
1763                         continue;
1764                 usb_get_urb (urb);
1765                 is_in = usb_urb_dir_in(urb);
1766                 spin_unlock(&hcd_urb_list_lock);
1767
1768                 /* kick hcd */
1769                 unlink1(hcd, urb, -ESHUTDOWN);
1770                 dev_dbg (hcd->self.controller,
1771                         "shutdown urb %pK ep%d%s-%s\n",
1772                         urb, usb_endpoint_num(&ep->desc),
1773                         is_in ? "in" : "out",
1774                         usb_ep_type_string(usb_endpoint_type(&ep->desc)));
1775                 usb_put_urb (urb);
1776
1777                 /* list contents may have changed */
1778                 spin_lock(&hcd_urb_list_lock);
1779                 goto rescan;
1780         }
1781         spin_unlock_irq(&hcd_urb_list_lock);
1782
1783         /* Wait until the endpoint queue is completely empty */
1784         while (!list_empty (&ep->urb_list)) {
1785                 spin_lock_irq(&hcd_urb_list_lock);
1786
1787                 /* The list may have changed while we acquired the spinlock */
1788                 urb = NULL;
1789                 if (!list_empty (&ep->urb_list)) {
1790                         urb = list_entry (ep->urb_list.prev, struct urb,
1791                                         urb_list);
1792                         usb_get_urb (urb);
1793                 }
1794                 spin_unlock_irq(&hcd_urb_list_lock);
1795
1796                 if (urb) {
1797                         usb_kill_urb (urb);
1798                         usb_put_urb (urb);
1799                 }
1800         }
1801 }
1802
1803 /**
1804  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1805  *                              the bus bandwidth
1806  * @udev: target &usb_device
1807  * @new_config: new configuration to install
1808  * @cur_alt: the current alternate interface setting
1809  * @new_alt: alternate interface setting that is being installed
1810  *
1811  * To change configurations, pass in the new configuration in new_config,
1812  * and pass NULL for cur_alt and new_alt.
1813  *
1814  * To reset a device's configuration (put the device in the ADDRESSED state),
1815  * pass in NULL for new_config, cur_alt, and new_alt.
1816  *
1817  * To change alternate interface settings, pass in NULL for new_config,
1818  * pass in the current alternate interface setting in cur_alt,
1819  * and pass in the new alternate interface setting in new_alt.
1820  *
1821  * Return: An error if the requested bandwidth change exceeds the
1822  * bus bandwidth or host controller internal resources.
1823  */
1824 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1825                 struct usb_host_config *new_config,
1826                 struct usb_host_interface *cur_alt,
1827                 struct usb_host_interface *new_alt)
1828 {
1829         int num_intfs, i, j;
1830         struct usb_host_interface *alt = NULL;
1831         int ret = 0;
1832         struct usb_hcd *hcd;
1833         struct usb_host_endpoint *ep;
1834
1835         hcd = bus_to_hcd(udev->bus);
1836         if (!hcd->driver->check_bandwidth)
1837                 return 0;
1838
1839         /* Configuration is being removed - set configuration 0 */
1840         if (!new_config && !cur_alt) {
1841                 for (i = 1; i < 16; ++i) {
1842                         ep = udev->ep_out[i];
1843                         if (ep)
1844                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1845                         ep = udev->ep_in[i];
1846                         if (ep)
1847                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1848                 }
1849                 hcd->driver->check_bandwidth(hcd, udev);
1850                 return 0;
1851         }
1852         /* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1853          * each interface's alt setting 0 and ask the HCD to check the bandwidth
1854          * of the bus.  There will always be bandwidth for endpoint 0, so it's
1855          * ok to exclude it.
1856          */
1857         if (new_config) {
1858                 num_intfs = new_config->desc.bNumInterfaces;
1859                 /* Remove endpoints (except endpoint 0, which is always on the
1860                  * schedule) from the old config from the schedule
1861                  */
1862                 for (i = 1; i < 16; ++i) {
1863                         ep = udev->ep_out[i];
1864                         if (ep) {
1865                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1866                                 if (ret < 0)
1867                                         goto reset;
1868                         }
1869                         ep = udev->ep_in[i];
1870                         if (ep) {
1871                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1872                                 if (ret < 0)
1873                                         goto reset;
1874                         }
1875                 }
1876                 for (i = 0; i < num_intfs; ++i) {
1877                         struct usb_host_interface *first_alt;
1878                         int iface_num;
1879
1880                         first_alt = &new_config->intf_cache[i]->altsetting[0];
1881                         iface_num = first_alt->desc.bInterfaceNumber;
1882                         /* Set up endpoints for alternate interface setting 0 */
1883                         alt = usb_find_alt_setting(new_config, iface_num, 0);
1884                         if (!alt)
1885                                 /* No alt setting 0? Pick the first setting. */
1886                                 alt = first_alt;
1887
1888                         for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1889                                 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1890                                 if (ret < 0)
1891                                         goto reset;
1892                         }
1893                 }
1894         }
1895         if (cur_alt && new_alt) {
1896                 struct usb_interface *iface = usb_ifnum_to_if(udev,
1897                                 cur_alt->desc.bInterfaceNumber);
1898
1899                 if (!iface)
1900                         return -EINVAL;
1901                 if (iface->resetting_device) {
1902                         /*
1903                          * The USB core just reset the device, so the xHCI host
1904                          * and the device will think alt setting 0 is installed.
1905                          * However, the USB core will pass in the alternate
1906                          * setting installed before the reset as cur_alt.  Dig
1907                          * out the alternate setting 0 structure, or the first
1908                          * alternate setting if a broken device doesn't have alt
1909                          * setting 0.
1910                          */
1911                         cur_alt = usb_altnum_to_altsetting(iface, 0);
1912                         if (!cur_alt)
1913                                 cur_alt = &iface->altsetting[0];
1914                 }
1915
1916                 /* Drop all the endpoints in the current alt setting */
1917                 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1918                         ret = hcd->driver->drop_endpoint(hcd, udev,
1919                                         &cur_alt->endpoint[i]);
1920                         if (ret < 0)
1921                                 goto reset;
1922                 }
1923                 /* Add all the endpoints in the new alt setting */
1924                 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1925                         ret = hcd->driver->add_endpoint(hcd, udev,
1926                                         &new_alt->endpoint[i]);
1927                         if (ret < 0)
1928                                 goto reset;
1929                 }
1930         }
1931         ret = hcd->driver->check_bandwidth(hcd, udev);
1932 reset:
1933         if (ret < 0)
1934                 hcd->driver->reset_bandwidth(hcd, udev);
1935         return ret;
1936 }
1937
1938 /* Disables the endpoint: synchronizes with the hcd to make sure all
1939  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1940  * have been called previously.  Use for set_configuration, set_interface,
1941  * driver removal, physical disconnect.
1942  *
1943  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1944  * type, maxpacket size, toggle, halt status, and scheduling.
1945  */
1946 void usb_hcd_disable_endpoint(struct usb_device *udev,
1947                 struct usb_host_endpoint *ep)
1948 {
1949         struct usb_hcd          *hcd;
1950
1951         might_sleep();
1952         hcd = bus_to_hcd(udev->bus);
1953         if (hcd->driver->endpoint_disable)
1954                 hcd->driver->endpoint_disable(hcd, ep);
1955 }
1956
1957 /**
1958  * usb_hcd_reset_endpoint - reset host endpoint state
1959  * @udev: USB device.
1960  * @ep:   the endpoint to reset.
1961  *
1962  * Resets any host endpoint state such as the toggle bit, sequence
1963  * number and current window.
1964  */
1965 void usb_hcd_reset_endpoint(struct usb_device *udev,
1966                             struct usb_host_endpoint *ep)
1967 {
1968         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1969
1970         if (hcd->driver->endpoint_reset)
1971                 hcd->driver->endpoint_reset(hcd, ep);
1972         else {
1973                 int epnum = usb_endpoint_num(&ep->desc);
1974                 int is_out = usb_endpoint_dir_out(&ep->desc);
1975                 int is_control = usb_endpoint_xfer_control(&ep->desc);
1976
1977                 usb_settoggle(udev, epnum, is_out, 0);
1978                 if (is_control)
1979                         usb_settoggle(udev, epnum, !is_out, 0);
1980         }
1981 }
1982
1983 /**
1984  * usb_alloc_streams - allocate bulk endpoint stream IDs.
1985  * @interface:          alternate setting that includes all endpoints.
1986  * @eps:                array of endpoints that need streams.
1987  * @num_eps:            number of endpoints in the array.
1988  * @num_streams:        number of streams to allocate.
1989  * @mem_flags:          flags hcd should use to allocate memory.
1990  *
1991  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
1992  * Drivers may queue multiple transfers to different stream IDs, which may
1993  * complete in a different order than they were queued.
1994  *
1995  * Return: On success, the number of allocated streams. On failure, a negative
1996  * error code.
1997  */
1998 int usb_alloc_streams(struct usb_interface *interface,
1999                 struct usb_host_endpoint **eps, unsigned int num_eps,
2000                 unsigned int num_streams, gfp_t mem_flags)
2001 {
2002         struct usb_hcd *hcd;
2003         struct usb_device *dev;
2004         int i, ret;
2005
2006         dev = interface_to_usbdev(interface);
2007         hcd = bus_to_hcd(dev->bus);
2008         if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2009                 return -EINVAL;
2010         if (dev->speed < USB_SPEED_SUPER)
2011                 return -EINVAL;
2012         if (dev->state < USB_STATE_CONFIGURED)
2013                 return -ENODEV;
2014
2015         for (i = 0; i < num_eps; i++) {
2016                 /* Streams only apply to bulk endpoints. */
2017                 if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2018                         return -EINVAL;
2019                 /* Re-alloc is not allowed */
2020                 if (eps[i]->streams)
2021                         return -EINVAL;
2022         }
2023
2024         ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2025                         num_streams, mem_flags);
2026         if (ret < 0)
2027                 return ret;
2028
2029         for (i = 0; i < num_eps; i++)
2030                 eps[i]->streams = ret;
2031
2032         return ret;
2033 }
2034 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2035
2036 /**
2037  * usb_free_streams - free bulk endpoint stream IDs.
2038  * @interface:  alternate setting that includes all endpoints.
2039  * @eps:        array of endpoints to remove streams from.
2040  * @num_eps:    number of endpoints in the array.
2041  * @mem_flags:  flags hcd should use to allocate memory.
2042  *
2043  * Reverts a group of bulk endpoints back to not using stream IDs.
2044  * Can fail if we are given bad arguments, or HCD is broken.
2045  *
2046  * Return: 0 on success. On failure, a negative error code.
2047  */
2048 int usb_free_streams(struct usb_interface *interface,
2049                 struct usb_host_endpoint **eps, unsigned int num_eps,
2050                 gfp_t mem_flags)
2051 {
2052         struct usb_hcd *hcd;
2053         struct usb_device *dev;
2054         int i, ret;
2055
2056         dev = interface_to_usbdev(interface);
2057         hcd = bus_to_hcd(dev->bus);
2058         if (dev->speed < USB_SPEED_SUPER)
2059                 return -EINVAL;
2060
2061         /* Double-free is not allowed */
2062         for (i = 0; i < num_eps; i++)
2063                 if (!eps[i] || !eps[i]->streams)
2064                         return -EINVAL;
2065
2066         ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2067         if (ret < 0)
2068                 return ret;
2069
2070         for (i = 0; i < num_eps; i++)
2071                 eps[i]->streams = 0;
2072
2073         return ret;
2074 }
2075 EXPORT_SYMBOL_GPL(usb_free_streams);
2076
2077 /* Protect against drivers that try to unlink URBs after the device
2078  * is gone, by waiting until all unlinks for @udev are finished.
2079  * Since we don't currently track URBs by device, simply wait until
2080  * nothing is running in the locked region of usb_hcd_unlink_urb().
2081  */
2082 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2083 {
2084         spin_lock_irq(&hcd_urb_unlink_lock);
2085         spin_unlock_irq(&hcd_urb_unlink_lock);
2086 }
2087
2088 /*-------------------------------------------------------------------------*/
2089
2090 /* called in any context */
2091 int usb_hcd_get_frame_number (struct usb_device *udev)
2092 {
2093         struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
2094
2095         if (!HCD_RH_RUNNING(hcd))
2096                 return -ESHUTDOWN;
2097         return hcd->driver->get_frame_number (hcd);
2098 }
2099
2100 /*-------------------------------------------------------------------------*/
2101
2102 #ifdef  CONFIG_PM
2103
2104 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2105 {
2106         struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2107         int             status;
2108         int             old_state = hcd->state;
2109
2110         dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2111                         (PMSG_IS_AUTO(msg) ? "auto-" : ""),
2112                         rhdev->do_remote_wakeup);
2113         if (HCD_DEAD(hcd)) {
2114                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2115                 return 0;
2116         }
2117
2118         if (!hcd->driver->bus_suspend) {
2119                 status = -ENOENT;
2120         } else {
2121                 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2122                 hcd->state = HC_STATE_QUIESCING;
2123                 status = hcd->driver->bus_suspend(hcd);
2124         }
2125         if (status == 0) {
2126                 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2127                 hcd->state = HC_STATE_SUSPENDED;
2128
2129                 if (!PMSG_IS_AUTO(msg))
2130                         usb_phy_roothub_suspend(hcd->self.sysdev,
2131                                                 hcd->phy_roothub);
2132
2133                 /* Did we race with a root-hub wakeup event? */
2134                 if (rhdev->do_remote_wakeup) {
2135                         char    buffer[6];
2136
2137                         status = hcd->driver->hub_status_data(hcd, buffer);
2138                         if (status != 0) {
2139                                 dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2140                                 hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2141                                 status = -EBUSY;
2142                         }
2143                 }
2144         } else {
2145                 spin_lock_irq(&hcd_root_hub_lock);
2146                 if (!HCD_DEAD(hcd)) {
2147                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2148                         hcd->state = old_state;
2149                 }
2150                 spin_unlock_irq(&hcd_root_hub_lock);
2151                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2152                                 "suspend", status);
2153         }
2154         return status;
2155 }
2156
2157 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2158 {
2159         struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2160         int             status;
2161         int             old_state = hcd->state;
2162
2163         dev_dbg(&rhdev->dev, "usb %sresume\n",
2164                         (PMSG_IS_AUTO(msg) ? "auto-" : ""));
2165         if (HCD_DEAD(hcd)) {
2166                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2167                 return 0;
2168         }
2169
2170         if (!PMSG_IS_AUTO(msg)) {
2171                 status = usb_phy_roothub_resume(hcd->self.sysdev,
2172                                                 hcd->phy_roothub);
2173                 if (status)
2174                         return status;
2175         }
2176
2177         if (!hcd->driver->bus_resume)
2178                 return -ENOENT;
2179         if (HCD_RH_RUNNING(hcd))
2180                 return 0;
2181
2182         hcd->state = HC_STATE_RESUMING;
2183         status = hcd->driver->bus_resume(hcd);
2184         clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2185         if (status == 0)
2186                 status = usb_phy_roothub_calibrate(hcd->phy_roothub);
2187
2188         if (status == 0) {
2189                 struct usb_device *udev;
2190                 int port1;
2191
2192                 spin_lock_irq(&hcd_root_hub_lock);
2193                 if (!HCD_DEAD(hcd)) {
2194                         usb_set_device_state(rhdev, rhdev->actconfig
2195                                         ? USB_STATE_CONFIGURED
2196                                         : USB_STATE_ADDRESS);
2197                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2198                         hcd->state = HC_STATE_RUNNING;
2199                 }
2200                 spin_unlock_irq(&hcd_root_hub_lock);
2201
2202                 /*
2203                  * Check whether any of the enabled ports on the root hub are
2204                  * unsuspended.  If they are then a TRSMRCY delay is needed
2205                  * (this is what the USB-2 spec calls a "global resume").
2206                  * Otherwise we can skip the delay.
2207                  */
2208                 usb_hub_for_each_child(rhdev, port1, udev) {
2209                         if (udev->state != USB_STATE_NOTATTACHED &&
2210                                         !udev->port_is_suspended) {
2211                                 usleep_range(10000, 11000);     /* TRSMRCY */
2212                                 break;
2213                         }
2214                 }
2215         } else {
2216                 hcd->state = old_state;
2217                 usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
2218                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2219                                 "resume", status);
2220                 if (status != -ESHUTDOWN)
2221                         usb_hc_died(hcd);
2222         }
2223         return status;
2224 }
2225
2226 /* Workqueue routine for root-hub remote wakeup */
2227 static void hcd_resume_work(struct work_struct *work)
2228 {
2229         struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2230         struct usb_device *udev = hcd->self.root_hub;
2231
2232         usb_remote_wakeup(udev);
2233 }
2234
2235 /**
2236  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2237  * @hcd: host controller for this root hub
2238  *
2239  * The USB host controller calls this function when its root hub is
2240  * suspended (with the remote wakeup feature enabled) and a remote
2241  * wakeup request is received.  The routine submits a workqueue request
2242  * to resume the root hub (that is, manage its downstream ports again).
2243  */
2244 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2245 {
2246         unsigned long flags;
2247
2248         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2249         if (hcd->rh_registered) {
2250                 pm_wakeup_event(&hcd->self.root_hub->dev, 0);
2251                 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2252                 queue_work(pm_wq, &hcd->wakeup_work);
2253         }
2254         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2255 }
2256 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2257
2258 #endif  /* CONFIG_PM */
2259
2260 /*-------------------------------------------------------------------------*/
2261
2262 #ifdef  CONFIG_USB_OTG
2263
2264 /**
2265  * usb_bus_start_enum - start immediate enumeration (for OTG)
2266  * @bus: the bus (must use hcd framework)
2267  * @port_num: 1-based number of port; usually bus->otg_port
2268  * Context: in_interrupt()
2269  *
2270  * Starts enumeration, with an immediate reset followed later by
2271  * hub_wq identifying and possibly configuring the device.
2272  * This is needed by OTG controller drivers, where it helps meet
2273  * HNP protocol timing requirements for starting a port reset.
2274  *
2275  * Return: 0 if successful.
2276  */
2277 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2278 {
2279         struct usb_hcd          *hcd;
2280         int                     status = -EOPNOTSUPP;
2281
2282         /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2283          * boards with root hubs hooked up to internal devices (instead of
2284          * just the OTG port) may need more attention to resetting...
2285          */
2286         hcd = bus_to_hcd(bus);
2287         if (port_num && hcd->driver->start_port_reset)
2288                 status = hcd->driver->start_port_reset(hcd, port_num);
2289
2290         /* allocate hub_wq shortly after (first) root port reset finishes;
2291          * it may issue others, until at least 50 msecs have passed.
2292          */
2293         if (status == 0)
2294                 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2295         return status;
2296 }
2297 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2298
2299 #endif
2300
2301 /*-------------------------------------------------------------------------*/
2302
2303 /**
2304  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2305  * @irq: the IRQ being raised
2306  * @__hcd: pointer to the HCD whose IRQ is being signaled
2307  *
2308  * If the controller isn't HALTed, calls the driver's irq handler.
2309  * Checks whether the controller is now dead.
2310  *
2311  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2312  */
2313 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2314 {
2315         struct usb_hcd          *hcd = __hcd;
2316         irqreturn_t             rc;
2317
2318         if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2319                 rc = IRQ_NONE;
2320         else if (hcd->driver->irq(hcd) == IRQ_NONE)
2321                 rc = IRQ_NONE;
2322         else
2323                 rc = IRQ_HANDLED;
2324
2325         return rc;
2326 }
2327 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2328
2329 /*-------------------------------------------------------------------------*/
2330
2331 /* Workqueue routine for when the root-hub has died. */
2332 static void hcd_died_work(struct work_struct *work)
2333 {
2334         struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
2335         static char *env[] = {
2336                 "ERROR=DEAD",
2337                 NULL
2338         };
2339
2340         /* Notify user space that the host controller has died */
2341         kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);
2342 }
2343
2344 /**
2345  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2346  * @hcd: pointer to the HCD representing the controller
2347  *
2348  * This is called by bus glue to report a USB host controller that died
2349  * while operations may still have been pending.  It's called automatically
2350  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2351  *
2352  * Only call this function with the primary HCD.
2353  */
2354 void usb_hc_died (struct usb_hcd *hcd)
2355 {
2356         unsigned long flags;
2357
2358         dev_err (hcd->self.controller, "HC died; cleaning up\n");
2359
2360         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2361         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2362         set_bit(HCD_FLAG_DEAD, &hcd->flags);
2363         if (hcd->rh_registered) {
2364                 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2365
2366                 /* make hub_wq clean up old urbs and devices */
2367                 usb_set_device_state (hcd->self.root_hub,
2368                                 USB_STATE_NOTATTACHED);
2369                 usb_kick_hub_wq(hcd->self.root_hub);
2370         }
2371         if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2372                 hcd = hcd->shared_hcd;
2373                 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2374                 set_bit(HCD_FLAG_DEAD, &hcd->flags);
2375                 if (hcd->rh_registered) {
2376                         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2377
2378                         /* make hub_wq clean up old urbs and devices */
2379                         usb_set_device_state(hcd->self.root_hub,
2380                                         USB_STATE_NOTATTACHED);
2381                         usb_kick_hub_wq(hcd->self.root_hub);
2382                 }
2383         }
2384
2385         /* Handle the case where this function gets called with a shared HCD */
2386         if (usb_hcd_is_primary_hcd(hcd))
2387                 schedule_work(&hcd->died_work);
2388         else
2389                 schedule_work(&hcd->primary_hcd->died_work);
2390
2391         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2392         /* Make sure that the other roothub is also deallocated. */
2393 }
2394 EXPORT_SYMBOL_GPL (usb_hc_died);
2395
2396 /*-------------------------------------------------------------------------*/
2397
2398 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2399 {
2400
2401         spin_lock_init(&bh->lock);
2402         INIT_LIST_HEAD(&bh->head);
2403         tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2404 }
2405
2406 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
2407                 struct device *sysdev, struct device *dev, const char *bus_name,
2408                 struct usb_hcd *primary_hcd)
2409 {
2410         struct usb_hcd *hcd;
2411
2412         hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2413         if (!hcd)
2414                 return NULL;
2415         if (primary_hcd == NULL) {
2416                 hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
2417                                 GFP_KERNEL);
2418                 if (!hcd->address0_mutex) {
2419                         kfree(hcd);
2420                         dev_dbg(dev, "hcd address0 mutex alloc failed\n");
2421                         return NULL;
2422                 }
2423                 mutex_init(hcd->address0_mutex);
2424                 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2425                                 GFP_KERNEL);
2426                 if (!hcd->bandwidth_mutex) {
2427                         kfree(hcd->address0_mutex);
2428                         kfree(hcd);
2429                         dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2430                         return NULL;
2431                 }
2432                 mutex_init(hcd->bandwidth_mutex);
2433                 dev_set_drvdata(dev, hcd);
2434         } else {
2435                 mutex_lock(&usb_port_peer_mutex);
2436                 hcd->address0_mutex = primary_hcd->address0_mutex;
2437                 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2438                 hcd->primary_hcd = primary_hcd;
2439                 primary_hcd->primary_hcd = primary_hcd;
2440                 hcd->shared_hcd = primary_hcd;
2441                 primary_hcd->shared_hcd = hcd;
2442                 mutex_unlock(&usb_port_peer_mutex);
2443         }
2444
2445         kref_init(&hcd->kref);
2446
2447         usb_bus_init(&hcd->self);
2448         hcd->self.controller = dev;
2449         hcd->self.sysdev = sysdev;
2450         hcd->self.bus_name = bus_name;
2451
2452         timer_setup(&hcd->rh_timer, rh_timer_func, 0);
2453 #ifdef CONFIG_PM
2454         INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2455 #endif
2456
2457         INIT_WORK(&hcd->died_work, hcd_died_work);
2458
2459         hcd->driver = driver;
2460         hcd->speed = driver->flags & HCD_MASK;
2461         hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2462                         "USB Host Controller";
2463         return hcd;
2464 }
2465 EXPORT_SYMBOL_GPL(__usb_create_hcd);
2466
2467 /**
2468  * usb_create_shared_hcd - create and initialize an HCD structure
2469  * @driver: HC driver that will use this hcd
2470  * @dev: device for this HC, stored in hcd->self.controller
2471  * @bus_name: value to store in hcd->self.bus_name
2472  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2473  *              PCI device.  Only allocate certain resources for the primary HCD
2474  * Context: !in_interrupt()
2475  *
2476  * Allocate a struct usb_hcd, with extra space at the end for the
2477  * HC driver's private data.  Initialize the generic members of the
2478  * hcd structure.
2479  *
2480  * Return: On success, a pointer to the created and initialized HCD structure.
2481  * On failure (e.g. if memory is unavailable), %NULL.
2482  */
2483 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2484                 struct device *dev, const char *bus_name,
2485                 struct usb_hcd *primary_hcd)
2486 {
2487         return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
2488 }
2489 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2490
2491 /**
2492  * usb_create_hcd - create and initialize an HCD structure
2493  * @driver: HC driver that will use this hcd
2494  * @dev: device for this HC, stored in hcd->self.controller
2495  * @bus_name: value to store in hcd->self.bus_name
2496  * Context: !in_interrupt()
2497  *
2498  * Allocate a struct usb_hcd, with extra space at the end for the
2499  * HC driver's private data.  Initialize the generic members of the
2500  * hcd structure.
2501  *
2502  * Return: On success, a pointer to the created and initialized HCD
2503  * structure. On failure (e.g. if memory is unavailable), %NULL.
2504  */
2505 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2506                 struct device *dev, const char *bus_name)
2507 {
2508         return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
2509 }
2510 EXPORT_SYMBOL_GPL(usb_create_hcd);
2511
2512 /*
2513  * Roothubs that share one PCI device must also share the bandwidth mutex.
2514  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2515  * deallocated.
2516  *
2517  * Make sure to deallocate the bandwidth_mutex only when the last HCD is
2518  * freed.  When hcd_release() is called for either hcd in a peer set,
2519  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
2520  */
2521 static void hcd_release(struct kref *kref)
2522 {
2523         struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2524
2525         mutex_lock(&usb_port_peer_mutex);
2526         if (hcd->shared_hcd) {
2527                 struct usb_hcd *peer = hcd->shared_hcd;
2528
2529                 peer->shared_hcd = NULL;
2530                 peer->primary_hcd = NULL;
2531         } else {
2532                 kfree(hcd->address0_mutex);
2533                 kfree(hcd->bandwidth_mutex);
2534         }
2535         mutex_unlock(&usb_port_peer_mutex);
2536         kfree(hcd);
2537 }
2538
2539 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2540 {
2541         if (hcd)
2542                 kref_get (&hcd->kref);
2543         return hcd;
2544 }
2545 EXPORT_SYMBOL_GPL(usb_get_hcd);
2546
2547 void usb_put_hcd (struct usb_hcd *hcd)
2548 {
2549         if (hcd)
2550                 kref_put (&hcd->kref, hcd_release);
2551 }
2552 EXPORT_SYMBOL_GPL(usb_put_hcd);
2553
2554 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2555 {
2556         if (!hcd->primary_hcd)
2557                 return 1;
2558         return hcd == hcd->primary_hcd;
2559 }
2560 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2561
2562 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2563 {
2564         if (!hcd->driver->find_raw_port_number)
2565                 return port1;
2566
2567         return hcd->driver->find_raw_port_number(hcd, port1);
2568 }
2569
2570 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2571                 unsigned int irqnum, unsigned long irqflags)
2572 {
2573         int retval;
2574
2575         if (hcd->driver->irq) {
2576
2577                 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2578                                 hcd->driver->description, hcd->self.busnum);
2579                 retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2580                                 hcd->irq_descr, hcd);
2581                 if (retval != 0) {
2582                         dev_err(hcd->self.controller,
2583                                         "request interrupt %d failed\n",
2584                                         irqnum);
2585                         return retval;
2586                 }
2587                 hcd->irq = irqnum;
2588                 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2589                                 (hcd->driver->flags & HCD_MEMORY) ?
2590                                         "io mem" : "io base",
2591                                         (unsigned long long)hcd->rsrc_start);
2592         } else {
2593                 hcd->irq = 0;
2594                 if (hcd->rsrc_start)
2595                         dev_info(hcd->self.controller, "%s 0x%08llx\n",
2596                                         (hcd->driver->flags & HCD_MEMORY) ?
2597                                         "io mem" : "io base",
2598                                         (unsigned long long)hcd->rsrc_start);
2599         }
2600         return 0;
2601 }
2602
2603 /*
2604  * Before we free this root hub, flush in-flight peering attempts
2605  * and disable peer lookups
2606  */
2607 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2608 {
2609         struct usb_device *rhdev;
2610
2611         mutex_lock(&usb_port_peer_mutex);
2612         rhdev = hcd->self.root_hub;
2613         hcd->self.root_hub = NULL;
2614         mutex_unlock(&usb_port_peer_mutex);
2615         usb_put_dev(rhdev);
2616 }
2617
2618 /**
2619  * usb_add_hcd - finish generic HCD structure initialization and register
2620  * @hcd: the usb_hcd structure to initialize
2621  * @irqnum: Interrupt line to allocate
2622  * @irqflags: Interrupt type flags
2623  *
2624  * Finish the remaining parts of generic HCD initialization: allocate the
2625  * buffers of consistent memory, register the bus, request the IRQ line,
2626  * and call the driver's reset() and start() routines.
2627  */
2628 int usb_add_hcd(struct usb_hcd *hcd,
2629                 unsigned int irqnum, unsigned long irqflags)
2630 {
2631         int retval;
2632         struct usb_device *rhdev;
2633
2634         if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
2635                 hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
2636                 if (IS_ERR(hcd->phy_roothub))
2637                         return PTR_ERR(hcd->phy_roothub);
2638
2639                 retval = usb_phy_roothub_init(hcd->phy_roothub);
2640                 if (retval)
2641                         return retval;
2642
2643                 retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2644                                                   PHY_MODE_USB_HOST_SS);
2645                 if (retval)
2646                         retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2647                                                           PHY_MODE_USB_HOST);
2648                 if (retval)
2649                         goto err_usb_phy_roothub_power_on;
2650
2651                 retval = usb_phy_roothub_power_on(hcd->phy_roothub);
2652                 if (retval)
2653                         goto err_usb_phy_roothub_power_on;
2654         }
2655
2656         dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2657
2658         switch (authorized_default) {
2659         case USB_AUTHORIZE_NONE:
2660                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_NONE;
2661                 break;
2662
2663         case USB_AUTHORIZE_ALL:
2664                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_ALL;
2665                 break;
2666
2667         case USB_AUTHORIZE_INTERNAL:
2668                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_INTERNAL;
2669                 break;
2670
2671         case USB_AUTHORIZE_WIRED:
2672         default:
2673                 hcd->dev_policy = hcd->wireless ?
2674                         USB_DEVICE_AUTHORIZE_NONE : USB_DEVICE_AUTHORIZE_ALL;
2675                 break;
2676         }
2677
2678         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2679
2680         /* per default all interfaces are authorized */
2681         set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
2682
2683         /* HC is in reset state, but accessible.  Now do the one-time init,
2684          * bottom up so that hcds can customize the root hubs before hub_wq
2685          * starts talking to them.  (Note, bus id is assigned early too.)
2686          */
2687         retval = hcd_buffer_create(hcd);
2688         if (retval != 0) {
2689                 dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
2690                 goto err_create_buf;
2691         }
2692
2693         retval = usb_register_bus(&hcd->self);
2694         if (retval < 0)
2695                 goto err_register_bus;
2696
2697         rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
2698         if (rhdev == NULL) {
2699                 dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
2700                 retval = -ENOMEM;
2701                 goto err_allocate_root_hub;
2702         }
2703         mutex_lock(&usb_port_peer_mutex);
2704         hcd->self.root_hub = rhdev;
2705         mutex_unlock(&usb_port_peer_mutex);
2706
2707         rhdev->rx_lanes = 1;
2708         rhdev->tx_lanes = 1;
2709
2710         switch (hcd->speed) {
2711         case HCD_USB11:
2712                 rhdev->speed = USB_SPEED_FULL;
2713                 break;
2714         case HCD_USB2:
2715                 rhdev->speed = USB_SPEED_HIGH;
2716                 break;
2717         case HCD_USB25:
2718                 rhdev->speed = USB_SPEED_WIRELESS;
2719                 break;
2720         case HCD_USB3:
2721                 rhdev->speed = USB_SPEED_SUPER;
2722                 break;
2723         case HCD_USB32:
2724                 rhdev->rx_lanes = 2;
2725                 rhdev->tx_lanes = 2;
2726                 /* fall through */
2727         case HCD_USB31:
2728                 rhdev->speed = USB_SPEED_SUPER_PLUS;
2729                 break;
2730         default:
2731                 retval = -EINVAL;
2732                 goto err_set_rh_speed;
2733         }
2734
2735         /* wakeup flag init defaults to "everything works" for root hubs,
2736          * but drivers can override it in reset() if needed, along with
2737          * recording the overall controller's system wakeup capability.
2738          */
2739         device_set_wakeup_capable(&rhdev->dev, 1);
2740
2741         /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2742          * registered.  But since the controller can die at any time,
2743          * let's initialize the flag before touching the hardware.
2744          */
2745         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2746
2747         /* "reset" is misnamed; its role is now one-time init. the controller
2748          * should already have been reset (and boot firmware kicked off etc).
2749          */
2750         if (hcd->driver->reset) {
2751                 retval = hcd->driver->reset(hcd);
2752                 if (retval < 0) {
2753                         dev_err(hcd->self.controller, "can't setup: %d\n",
2754                                         retval);
2755                         goto err_hcd_driver_setup;
2756                 }
2757         }
2758         hcd->rh_pollable = 1;
2759
2760         retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
2761         if (retval)
2762                 goto err_hcd_driver_setup;
2763
2764         /* NOTE: root hub and controller capabilities may not be the same */
2765         if (device_can_wakeup(hcd->self.controller)
2766                         && device_can_wakeup(&hcd->self.root_hub->dev))
2767                 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2768
2769         /* initialize tasklets */
2770         init_giveback_urb_bh(&hcd->high_prio_bh);
2771         init_giveback_urb_bh(&hcd->low_prio_bh);
2772
2773         /* enable irqs just before we start the controller,
2774          * if the BIOS provides legacy PCI irqs.
2775          */
2776         if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2777                 retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2778                 if (retval)
2779                         goto err_request_irq;
2780         }
2781
2782         hcd->state = HC_STATE_RUNNING;
2783         retval = hcd->driver->start(hcd);
2784         if (retval < 0) {
2785                 dev_err(hcd->self.controller, "startup error %d\n", retval);
2786                 goto err_hcd_driver_start;
2787         }
2788
2789         /* starting here, usbcore will pay attention to this root hub */
2790         retval = register_root_hub(hcd);
2791         if (retval != 0)
2792                 goto err_register_root_hub;
2793
2794         if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2795                 usb_hcd_poll_rh_status(hcd);
2796
2797         return retval;
2798
2799 err_register_root_hub:
2800         hcd->rh_pollable = 0;
2801         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2802         del_timer_sync(&hcd->rh_timer);
2803         hcd->driver->stop(hcd);
2804         hcd->state = HC_STATE_HALT;
2805         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2806         del_timer_sync(&hcd->rh_timer);
2807 err_hcd_driver_start:
2808         if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2809                 free_irq(irqnum, hcd);
2810 err_request_irq:
2811 err_hcd_driver_setup:
2812 err_set_rh_speed:
2813         usb_put_invalidate_rhdev(hcd);
2814 err_allocate_root_hub:
2815         usb_deregister_bus(&hcd->self);
2816 err_register_bus:
2817         hcd_buffer_destroy(hcd);
2818 err_create_buf:
2819         usb_phy_roothub_power_off(hcd->phy_roothub);
2820 err_usb_phy_roothub_power_on:
2821         usb_phy_roothub_exit(hcd->phy_roothub);
2822
2823         return retval;
2824 }
2825 EXPORT_SYMBOL_GPL(usb_add_hcd);
2826
2827 /**
2828  * usb_remove_hcd - shutdown processing for generic HCDs
2829  * @hcd: the usb_hcd structure to remove
2830  * Context: !in_interrupt()
2831  *
2832  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2833  * invoking the HCD's stop() method.
2834  */
2835 void usb_remove_hcd(struct usb_hcd *hcd)
2836 {
2837         struct usb_device *rhdev = hcd->self.root_hub;
2838
2839         dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2840
2841         usb_get_dev(rhdev);
2842         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2843         if (HC_IS_RUNNING (hcd->state))
2844                 hcd->state = HC_STATE_QUIESCING;
2845
2846         dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2847         spin_lock_irq (&hcd_root_hub_lock);
2848         hcd->rh_registered = 0;
2849         spin_unlock_irq (&hcd_root_hub_lock);
2850
2851 #ifdef CONFIG_PM
2852         cancel_work_sync(&hcd->wakeup_work);
2853 #endif
2854         cancel_work_sync(&hcd->died_work);
2855
2856         mutex_lock(&usb_bus_idr_lock);
2857         usb_disconnect(&rhdev);         /* Sets rhdev to NULL */
2858         mutex_unlock(&usb_bus_idr_lock);
2859
2860         /*
2861          * tasklet_kill() isn't needed here because:
2862          * - driver's disconnect() called from usb_disconnect() should
2863          *   make sure its URBs are completed during the disconnect()
2864          *   callback
2865          *
2866          * - it is too late to run complete() here since driver may have
2867          *   been removed already now
2868          */
2869
2870         /* Prevent any more root-hub status calls from the timer.
2871          * The HCD might still restart the timer (if a port status change
2872          * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2873          * the hub_status_data() callback.
2874          */
2875         hcd->rh_pollable = 0;
2876         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2877         del_timer_sync(&hcd->rh_timer);
2878
2879         hcd->driver->stop(hcd);
2880         hcd->state = HC_STATE_HALT;
2881
2882         /* In case the HCD restarted the timer, stop it again. */
2883         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2884         del_timer_sync(&hcd->rh_timer);
2885
2886         if (usb_hcd_is_primary_hcd(hcd)) {
2887                 if (hcd->irq > 0)
2888                         free_irq(hcd->irq, hcd);
2889         }
2890
2891         usb_deregister_bus(&hcd->self);
2892         hcd_buffer_destroy(hcd);
2893
2894         usb_phy_roothub_power_off(hcd->phy_roothub);
2895         usb_phy_roothub_exit(hcd->phy_roothub);
2896
2897         usb_put_invalidate_rhdev(hcd);
2898         hcd->flags = 0;
2899 }
2900 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2901
2902 void
2903 usb_hcd_platform_shutdown(struct platform_device *dev)
2904 {
2905         struct usb_hcd *hcd = platform_get_drvdata(dev);
2906
2907         /* No need for pm_runtime_put(), we're shutting down */
2908         pm_runtime_get_sync(&dev->dev);
2909
2910         if (hcd->driver->shutdown)
2911                 hcd->driver->shutdown(hcd);
2912 }
2913 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2914
2915 int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
2916                             dma_addr_t dma, size_t size)
2917 {
2918         int err;
2919         void *local_mem;
2920
2921         hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
2922                                                   dev_to_node(hcd->self.sysdev),
2923                                                   dev_name(hcd->self.sysdev));
2924         if (IS_ERR(hcd->localmem_pool))
2925                 return PTR_ERR(hcd->localmem_pool);
2926
2927         local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
2928                                   size, MEMREMAP_WC);
2929         if (IS_ERR(local_mem))
2930                 return PTR_ERR(local_mem);
2931
2932         /*
2933          * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
2934          * It's not backed by system memory and thus there's no kernel mapping
2935          * for it.
2936          */
2937         err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
2938                                 dma, size, dev_to_node(hcd->self.sysdev));
2939         if (err < 0) {
2940                 dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
2941                         err);
2942                 return err;
2943         }
2944
2945         return 0;
2946 }
2947 EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
2948
2949 /*-------------------------------------------------------------------------*/
2950
2951 #if IS_ENABLED(CONFIG_USB_MON)
2952
2953 const struct usb_mon_operations *mon_ops;
2954
2955 /*
2956  * The registration is unlocked.
2957  * We do it this way because we do not want to lock in hot paths.
2958  *
2959  * Notice that the code is minimally error-proof. Because usbmon needs
2960  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2961  */
2962
2963 int usb_mon_register(const struct usb_mon_operations *ops)
2964 {
2965
2966         if (mon_ops)
2967                 return -EBUSY;
2968
2969         mon_ops = ops;
2970         mb();
2971         return 0;
2972 }
2973 EXPORT_SYMBOL_GPL (usb_mon_register);
2974
2975 void usb_mon_deregister (void)
2976 {
2977
2978         if (mon_ops == NULL) {
2979                 printk(KERN_ERR "USB: monitor was not registered\n");
2980                 return;
2981         }
2982         mon_ops = NULL;
2983         mb();
2984 }
2985 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2986
2987 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */