kcov, usb: hide in_serving_softirq checks in __usb_hcd_giveback_urb
[linux-2.6-microblaze.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 #include <linux/kcov.h>
35
36 #include <linux/phy/phy.h>
37 #include <linux/usb.h>
38 #include <linux/usb/hcd.h>
39 #include <linux/usb/otg.h>
40
41 #include "usb.h"
42 #include "phy.h"
43
44
45 /*-------------------------------------------------------------------------*/
46
47 /*
48  * USB Host Controller Driver framework
49  *
50  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
51  * HCD-specific behaviors/bugs.
52  *
53  * This does error checks, tracks devices and urbs, and delegates to a
54  * "hc_driver" only for code (and data) that really needs to know about
55  * hardware differences.  That includes root hub registers, i/o queues,
56  * and so on ... but as little else as possible.
57  *
58  * Shared code includes most of the "root hub" code (these are emulated,
59  * though each HC's hardware works differently) and PCI glue, plus request
60  * tracking overhead.  The HCD code should only block on spinlocks or on
61  * hardware handshaking; blocking on software events (such as other kernel
62  * threads releasing resources, or completing actions) is all generic.
63  *
64  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
65  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
66  * only by the hub driver ... and that neither should be seen or used by
67  * usb client device drivers.
68  *
69  * Contributors of ideas or unattributed patches include: David Brownell,
70  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
71  *
72  * HISTORY:
73  * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
74  *              associated cleanup.  "usb_hcd" still != "usb_bus".
75  * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
76  */
77
78 /*-------------------------------------------------------------------------*/
79
80 /* Keep track of which host controller drivers are loaded */
81 unsigned long usb_hcds_loaded;
82 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
83
84 /* host controllers we manage */
85 DEFINE_IDR (usb_bus_idr);
86 EXPORT_SYMBOL_GPL (usb_bus_idr);
87
88 /* used when allocating bus numbers */
89 #define USB_MAXBUS              64
90
91 /* used when updating list of hcds */
92 DEFINE_MUTEX(usb_bus_idr_lock); /* exported only for usbfs */
93 EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
94
95 /* used for controlling access to virtual root hubs */
96 static DEFINE_SPINLOCK(hcd_root_hub_lock);
97
98 /* used when updating an endpoint's URB list */
99 static DEFINE_SPINLOCK(hcd_urb_list_lock);
100
101 /* used to protect against unlinking URBs after the device is gone */
102 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
103
104 /* wait queue for synchronous unlinks */
105 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
106
107 /*-------------------------------------------------------------------------*/
108
109 /*
110  * Sharable chunks of root hub code.
111  */
112
113 /*-------------------------------------------------------------------------*/
114 #define KERNEL_REL      bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
115 #define KERNEL_VER      bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
116
117 /* usb 3.1 root hub device descriptor */
118 static const u8 usb31_rh_dev_descriptor[18] = {
119         0x12,       /*  __u8  bLength; */
120         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
121         0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
122
123         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
124         0x00,       /*  __u8  bDeviceSubClass; */
125         0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
126         0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
127
128         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
129         0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
130         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
131
132         0x03,       /*  __u8  iManufacturer; */
133         0x02,       /*  __u8  iProduct; */
134         0x01,       /*  __u8  iSerialNumber; */
135         0x01        /*  __u8  bNumConfigurations; */
136 };
137
138 /* usb 3.0 root hub device descriptor */
139 static const u8 usb3_rh_dev_descriptor[18] = {
140         0x12,       /*  __u8  bLength; */
141         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
142         0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
143
144         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
145         0x00,       /*  __u8  bDeviceSubClass; */
146         0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
147         0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
148
149         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
150         0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
151         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
152
153         0x03,       /*  __u8  iManufacturer; */
154         0x02,       /*  __u8  iProduct; */
155         0x01,       /*  __u8  iSerialNumber; */
156         0x01        /*  __u8  bNumConfigurations; */
157 };
158
159 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
160 static const u8 usb25_rh_dev_descriptor[18] = {
161         0x12,       /*  __u8  bLength; */
162         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
163         0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
164
165         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
166         0x00,       /*  __u8  bDeviceSubClass; */
167         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
168         0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
169
170         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
171         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
172         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
173
174         0x03,       /*  __u8  iManufacturer; */
175         0x02,       /*  __u8  iProduct; */
176         0x01,       /*  __u8  iSerialNumber; */
177         0x01        /*  __u8  bNumConfigurations; */
178 };
179
180 /* usb 2.0 root hub device descriptor */
181 static const u8 usb2_rh_dev_descriptor[18] = {
182         0x12,       /*  __u8  bLength; */
183         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
184         0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
185
186         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
187         0x00,       /*  __u8  bDeviceSubClass; */
188         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
189         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
190
191         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
192         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
193         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
194
195         0x03,       /*  __u8  iManufacturer; */
196         0x02,       /*  __u8  iProduct; */
197         0x01,       /*  __u8  iSerialNumber; */
198         0x01        /*  __u8  bNumConfigurations; */
199 };
200
201 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
202
203 /* usb 1.1 root hub device descriptor */
204 static const u8 usb11_rh_dev_descriptor[18] = {
205         0x12,       /*  __u8  bLength; */
206         USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
207         0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
208
209         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
210         0x00,       /*  __u8  bDeviceSubClass; */
211         0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
212         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
213
214         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
215         0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
216         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
217
218         0x03,       /*  __u8  iManufacturer; */
219         0x02,       /*  __u8  iProduct; */
220         0x01,       /*  __u8  iSerialNumber; */
221         0x01        /*  __u8  bNumConfigurations; */
222 };
223
224
225 /*-------------------------------------------------------------------------*/
226
227 /* Configuration descriptors for our root hubs */
228
229 static const u8 fs_rh_config_descriptor[] = {
230
231         /* one configuration */
232         0x09,       /*  __u8  bLength; */
233         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
234         0x19, 0x00, /*  __le16 wTotalLength; */
235         0x01,       /*  __u8  bNumInterfaces; (1) */
236         0x01,       /*  __u8  bConfigurationValue; */
237         0x00,       /*  __u8  iConfiguration; */
238         0xc0,       /*  __u8  bmAttributes;
239                                  Bit 7: must be set,
240                                      6: Self-powered,
241                                      5: Remote wakeup,
242                                      4..0: resvd */
243         0x00,       /*  __u8  MaxPower; */
244
245         /* USB 1.1:
246          * USB 2.0, single TT organization (mandatory):
247          *      one interface, protocol 0
248          *
249          * USB 2.0, multiple TT organization (optional):
250          *      two interfaces, protocols 1 (like single TT)
251          *      and 2 (multiple TT mode) ... config is
252          *      sometimes settable
253          *      NOT IMPLEMENTED
254          */
255
256         /* one interface */
257         0x09,       /*  __u8  if_bLength; */
258         USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
259         0x00,       /*  __u8  if_bInterfaceNumber; */
260         0x00,       /*  __u8  if_bAlternateSetting; */
261         0x01,       /*  __u8  if_bNumEndpoints; */
262         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
263         0x00,       /*  __u8  if_bInterfaceSubClass; */
264         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
265         0x00,       /*  __u8  if_iInterface; */
266
267         /* one endpoint (status change endpoint) */
268         0x07,       /*  __u8  ep_bLength; */
269         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
270         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
271         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
272         0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
273         0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
274 };
275
276 static const u8 hs_rh_config_descriptor[] = {
277
278         /* one configuration */
279         0x09,       /*  __u8  bLength; */
280         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
281         0x19, 0x00, /*  __le16 wTotalLength; */
282         0x01,       /*  __u8  bNumInterfaces; (1) */
283         0x01,       /*  __u8  bConfigurationValue; */
284         0x00,       /*  __u8  iConfiguration; */
285         0xc0,       /*  __u8  bmAttributes;
286                                  Bit 7: must be set,
287                                      6: Self-powered,
288                                      5: Remote wakeup,
289                                      4..0: resvd */
290         0x00,       /*  __u8  MaxPower; */
291
292         /* USB 1.1:
293          * USB 2.0, single TT organization (mandatory):
294          *      one interface, protocol 0
295          *
296          * USB 2.0, multiple TT organization (optional):
297          *      two interfaces, protocols 1 (like single TT)
298          *      and 2 (multiple TT mode) ... config is
299          *      sometimes settable
300          *      NOT IMPLEMENTED
301          */
302
303         /* one interface */
304         0x09,       /*  __u8  if_bLength; */
305         USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
306         0x00,       /*  __u8  if_bInterfaceNumber; */
307         0x00,       /*  __u8  if_bAlternateSetting; */
308         0x01,       /*  __u8  if_bNumEndpoints; */
309         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
310         0x00,       /*  __u8  if_bInterfaceSubClass; */
311         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
312         0x00,       /*  __u8  if_iInterface; */
313
314         /* one endpoint (status change endpoint) */
315         0x07,       /*  __u8  ep_bLength; */
316         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
317         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
318         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
319                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
320                      * see hub.c:hub_configure() for details. */
321         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
322         0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
323 };
324
325 static const u8 ss_rh_config_descriptor[] = {
326         /* one configuration */
327         0x09,       /*  __u8  bLength; */
328         USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
329         0x1f, 0x00, /*  __le16 wTotalLength; */
330         0x01,       /*  __u8  bNumInterfaces; (1) */
331         0x01,       /*  __u8  bConfigurationValue; */
332         0x00,       /*  __u8  iConfiguration; */
333         0xc0,       /*  __u8  bmAttributes;
334                                  Bit 7: must be set,
335                                      6: Self-powered,
336                                      5: Remote wakeup,
337                                      4..0: resvd */
338         0x00,       /*  __u8  MaxPower; */
339
340         /* one interface */
341         0x09,       /*  __u8  if_bLength; */
342         USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
343         0x00,       /*  __u8  if_bInterfaceNumber; */
344         0x00,       /*  __u8  if_bAlternateSetting; */
345         0x01,       /*  __u8  if_bNumEndpoints; */
346         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
347         0x00,       /*  __u8  if_bInterfaceSubClass; */
348         0x00,       /*  __u8  if_bInterfaceProtocol; */
349         0x00,       /*  __u8  if_iInterface; */
350
351         /* one endpoint (status change endpoint) */
352         0x07,       /*  __u8  ep_bLength; */
353         USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
354         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
355         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
356                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
357                      * see hub.c:hub_configure() for details. */
358         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
359         0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
360
361         /* one SuperSpeed endpoint companion descriptor */
362         0x06,        /* __u8 ss_bLength */
363         USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
364                      /* Companion */
365         0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
366         0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
367         0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
368 };
369
370 /* authorized_default behaviour:
371  * -1 is authorized for all devices except wireless (old behaviour)
372  * 0 is unauthorized for all devices
373  * 1 is authorized for all devices
374  * 2 is authorized for internal devices
375  */
376 #define USB_AUTHORIZE_WIRED     -1
377 #define USB_AUTHORIZE_NONE      0
378 #define USB_AUTHORIZE_ALL       1
379 #define USB_AUTHORIZE_INTERNAL  2
380
381 static int authorized_default = USB_AUTHORIZE_WIRED;
382 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
383 MODULE_PARM_DESC(authorized_default,
384                 "Default USB device authorization: 0 is not authorized, 1 is "
385                 "authorized, 2 is authorized for internal devices, -1 is "
386                 "authorized except for wireless USB (default, old behaviour)");
387 /*-------------------------------------------------------------------------*/
388
389 /**
390  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
391  * @s: Null-terminated ASCII (actually ISO-8859-1) string
392  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
393  * @len: Length (in bytes; may be odd) of descriptor buffer.
394  *
395  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
396  * whichever is less.
397  *
398  * Note:
399  * USB String descriptors can contain at most 126 characters; input
400  * strings longer than that are truncated.
401  */
402 static unsigned
403 ascii2desc(char const *s, u8 *buf, unsigned len)
404 {
405         unsigned n, t = 2 + 2*strlen(s);
406
407         if (t > 254)
408                 t = 254;        /* Longest possible UTF string descriptor */
409         if (len > t)
410                 len = t;
411
412         t += USB_DT_STRING << 8;        /* Now t is first 16 bits to store */
413
414         n = len;
415         while (n--) {
416                 *buf++ = t;
417                 if (!n--)
418                         break;
419                 *buf++ = t >> 8;
420                 t = (unsigned char)*s++;
421         }
422         return len;
423 }
424
425 /**
426  * rh_string() - provides string descriptors for root hub
427  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
428  * @hcd: the host controller for this root hub
429  * @data: buffer for output packet
430  * @len: length of the provided buffer
431  *
432  * Produces either a manufacturer, product or serial number string for the
433  * virtual root hub device.
434  *
435  * Return: The number of bytes filled in: the length of the descriptor or
436  * of the provided buffer, whichever is less.
437  */
438 static unsigned
439 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
440 {
441         char buf[100];
442         char const *s;
443         static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
444
445         /* language ids */
446         switch (id) {
447         case 0:
448                 /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
449                 /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
450                 if (len > 4)
451                         len = 4;
452                 memcpy(data, langids, len);
453                 return len;
454         case 1:
455                 /* Serial number */
456                 s = hcd->self.bus_name;
457                 break;
458         case 2:
459                 /* Product name */
460                 s = hcd->product_desc;
461                 break;
462         case 3:
463                 /* Manufacturer */
464                 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
465                         init_utsname()->release, hcd->driver->description);
466                 s = buf;
467                 break;
468         default:
469                 /* Can't happen; caller guarantees it */
470                 return 0;
471         }
472
473         return ascii2desc(s, data, len);
474 }
475
476
477 /* Root hub control transfers execute synchronously */
478 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
479 {
480         struct usb_ctrlrequest *cmd;
481         u16             typeReq, wValue, wIndex, wLength;
482         u8              *ubuf = urb->transfer_buffer;
483         unsigned        len = 0;
484         int             status;
485         u8              patch_wakeup = 0;
486         u8              patch_protocol = 0;
487         u16             tbuf_size;
488         u8              *tbuf = NULL;
489         const u8        *bufp;
490
491         might_sleep();
492
493         spin_lock_irq(&hcd_root_hub_lock);
494         status = usb_hcd_link_urb_to_ep(hcd, urb);
495         spin_unlock_irq(&hcd_root_hub_lock);
496         if (status)
497                 return status;
498         urb->hcpriv = hcd;      /* Indicate it's queued */
499
500         cmd = (struct usb_ctrlrequest *) urb->setup_packet;
501         typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
502         wValue   = le16_to_cpu (cmd->wValue);
503         wIndex   = le16_to_cpu (cmd->wIndex);
504         wLength  = le16_to_cpu (cmd->wLength);
505
506         if (wLength > urb->transfer_buffer_length)
507                 goto error;
508
509         /*
510          * tbuf should be at least as big as the
511          * USB hub descriptor.
512          */
513         tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
514         tbuf = kzalloc(tbuf_size, GFP_KERNEL);
515         if (!tbuf) {
516                 status = -ENOMEM;
517                 goto err_alloc;
518         }
519
520         bufp = tbuf;
521
522
523         urb->actual_length = 0;
524         switch (typeReq) {
525
526         /* DEVICE REQUESTS */
527
528         /* The root hub's remote wakeup enable bit is implemented using
529          * driver model wakeup flags.  If this system supports wakeup
530          * through USB, userspace may change the default "allow wakeup"
531          * policy through sysfs or these calls.
532          *
533          * Most root hubs support wakeup from downstream devices, for
534          * runtime power management (disabling USB clocks and reducing
535          * VBUS power usage).  However, not all of them do so; silicon,
536          * board, and BIOS bugs here are not uncommon, so these can't
537          * be treated quite like external hubs.
538          *
539          * Likewise, not all root hubs will pass wakeup events upstream,
540          * to wake up the whole system.  So don't assume root hub and
541          * controller capabilities are identical.
542          */
543
544         case DeviceRequest | USB_REQ_GET_STATUS:
545                 tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
546                                         << USB_DEVICE_REMOTE_WAKEUP)
547                                 | (1 << USB_DEVICE_SELF_POWERED);
548                 tbuf[1] = 0;
549                 len = 2;
550                 break;
551         case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
552                 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
553                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
554                 else
555                         goto error;
556                 break;
557         case DeviceOutRequest | USB_REQ_SET_FEATURE:
558                 if (device_can_wakeup(&hcd->self.root_hub->dev)
559                                 && wValue == USB_DEVICE_REMOTE_WAKEUP)
560                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
561                 else
562                         goto error;
563                 break;
564         case DeviceRequest | USB_REQ_GET_CONFIGURATION:
565                 tbuf[0] = 1;
566                 len = 1;
567                 fallthrough;
568         case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
569                 break;
570         case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
571                 switch (wValue & 0xff00) {
572                 case USB_DT_DEVICE << 8:
573                         switch (hcd->speed) {
574                         case HCD_USB32:
575                         case HCD_USB31:
576                                 bufp = usb31_rh_dev_descriptor;
577                                 break;
578                         case HCD_USB3:
579                                 bufp = usb3_rh_dev_descriptor;
580                                 break;
581                         case HCD_USB25:
582                                 bufp = usb25_rh_dev_descriptor;
583                                 break;
584                         case HCD_USB2:
585                                 bufp = usb2_rh_dev_descriptor;
586                                 break;
587                         case HCD_USB11:
588                                 bufp = usb11_rh_dev_descriptor;
589                                 break;
590                         default:
591                                 goto error;
592                         }
593                         len = 18;
594                         if (hcd->has_tt)
595                                 patch_protocol = 1;
596                         break;
597                 case USB_DT_CONFIG << 8:
598                         switch (hcd->speed) {
599                         case HCD_USB32:
600                         case HCD_USB31:
601                         case HCD_USB3:
602                                 bufp = ss_rh_config_descriptor;
603                                 len = sizeof ss_rh_config_descriptor;
604                                 break;
605                         case HCD_USB25:
606                         case HCD_USB2:
607                                 bufp = hs_rh_config_descriptor;
608                                 len = sizeof hs_rh_config_descriptor;
609                                 break;
610                         case HCD_USB11:
611                                 bufp = fs_rh_config_descriptor;
612                                 len = sizeof fs_rh_config_descriptor;
613                                 break;
614                         default:
615                                 goto error;
616                         }
617                         if (device_can_wakeup(&hcd->self.root_hub->dev))
618                                 patch_wakeup = 1;
619                         break;
620                 case USB_DT_STRING << 8:
621                         if ((wValue & 0xff) < 4)
622                                 urb->actual_length = rh_string(wValue & 0xff,
623                                                 hcd, ubuf, wLength);
624                         else /* unsupported IDs --> "protocol stall" */
625                                 goto error;
626                         break;
627                 case USB_DT_BOS << 8:
628                         goto nongeneric;
629                 default:
630                         goto error;
631                 }
632                 break;
633         case DeviceRequest | USB_REQ_GET_INTERFACE:
634                 tbuf[0] = 0;
635                 len = 1;
636                 fallthrough;
637         case DeviceOutRequest | USB_REQ_SET_INTERFACE:
638                 break;
639         case DeviceOutRequest | USB_REQ_SET_ADDRESS:
640                 /* wValue == urb->dev->devaddr */
641                 dev_dbg (hcd->self.controller, "root hub device address %d\n",
642                         wValue);
643                 break;
644
645         /* INTERFACE REQUESTS (no defined feature/status flags) */
646
647         /* ENDPOINT REQUESTS */
648
649         case EndpointRequest | USB_REQ_GET_STATUS:
650                 /* ENDPOINT_HALT flag */
651                 tbuf[0] = 0;
652                 tbuf[1] = 0;
653                 len = 2;
654                 fallthrough;
655         case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
656         case EndpointOutRequest | USB_REQ_SET_FEATURE:
657                 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
658                 break;
659
660         /* CLASS REQUESTS (and errors) */
661
662         default:
663 nongeneric:
664                 /* non-generic request */
665                 switch (typeReq) {
666                 case GetHubStatus:
667                         len = 4;
668                         break;
669                 case GetPortStatus:
670                         if (wValue == HUB_PORT_STATUS)
671                                 len = 4;
672                         else
673                                 /* other port status types return 8 bytes */
674                                 len = 8;
675                         break;
676                 case GetHubDescriptor:
677                         len = sizeof (struct usb_hub_descriptor);
678                         break;
679                 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
680                         /* len is returned by hub_control */
681                         break;
682                 }
683                 status = hcd->driver->hub_control (hcd,
684                         typeReq, wValue, wIndex,
685                         tbuf, wLength);
686
687                 if (typeReq == GetHubDescriptor)
688                         usb_hub_adjust_deviceremovable(hcd->self.root_hub,
689                                 (struct usb_hub_descriptor *)tbuf);
690                 break;
691 error:
692                 /* "protocol stall" on error */
693                 status = -EPIPE;
694         }
695
696         if (status < 0) {
697                 len = 0;
698                 if (status != -EPIPE) {
699                         dev_dbg (hcd->self.controller,
700                                 "CTRL: TypeReq=0x%x val=0x%x "
701                                 "idx=0x%x len=%d ==> %d\n",
702                                 typeReq, wValue, wIndex,
703                                 wLength, status);
704                 }
705         } else if (status > 0) {
706                 /* hub_control may return the length of data copied. */
707                 len = status;
708                 status = 0;
709         }
710         if (len) {
711                 if (urb->transfer_buffer_length < len)
712                         len = urb->transfer_buffer_length;
713                 urb->actual_length = len;
714                 /* always USB_DIR_IN, toward host */
715                 memcpy (ubuf, bufp, len);
716
717                 /* report whether RH hardware supports remote wakeup */
718                 if (patch_wakeup &&
719                                 len > offsetof (struct usb_config_descriptor,
720                                                 bmAttributes))
721                         ((struct usb_config_descriptor *)ubuf)->bmAttributes
722                                 |= USB_CONFIG_ATT_WAKEUP;
723
724                 /* report whether RH hardware has an integrated TT */
725                 if (patch_protocol &&
726                                 len > offsetof(struct usb_device_descriptor,
727                                                 bDeviceProtocol))
728                         ((struct usb_device_descriptor *) ubuf)->
729                                 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
730         }
731
732         kfree(tbuf);
733  err_alloc:
734
735         /* any errors get returned through the urb completion */
736         spin_lock_irq(&hcd_root_hub_lock);
737         usb_hcd_unlink_urb_from_ep(hcd, urb);
738         usb_hcd_giveback_urb(hcd, urb, status);
739         spin_unlock_irq(&hcd_root_hub_lock);
740         return 0;
741 }
742
743 /*-------------------------------------------------------------------------*/
744
745 /*
746  * Root Hub interrupt transfers are polled using a timer if the
747  * driver requests it; otherwise the driver is responsible for
748  * calling usb_hcd_poll_rh_status() when an event occurs.
749  *
750  * Completion handler may not sleep. See usb_hcd_giveback_urb() for details.
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  *
907  * Context: task context, might sleep.
908  *
909  * Assigns a bus number, and links the controller into usbcore data
910  * structures so that it can be seen by scanning the bus list.
911  *
912  * Return: 0 if successful. A negative error code otherwise.
913  */
914 static int usb_register_bus(struct usb_bus *bus)
915 {
916         int result = -E2BIG;
917         int busnum;
918
919         mutex_lock(&usb_bus_idr_lock);
920         busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
921         if (busnum < 0) {
922                 pr_err("%s: failed to get bus number\n", usbcore_name);
923                 goto error_find_busnum;
924         }
925         bus->busnum = busnum;
926         mutex_unlock(&usb_bus_idr_lock);
927
928         usb_notify_add_bus(bus);
929
930         dev_info (bus->controller, "new USB bus registered, assigned bus "
931                   "number %d\n", bus->busnum);
932         return 0;
933
934 error_find_busnum:
935         mutex_unlock(&usb_bus_idr_lock);
936         return result;
937 }
938
939 /**
940  * usb_deregister_bus - deregisters the USB host controller
941  * @bus: pointer to the bus to deregister
942  *
943  * Context: task context, might sleep.
944  *
945  * Recycles the bus number, and unlinks the controller from usbcore data
946  * structures so that it won't be seen by scanning the bus list.
947  */
948 static void usb_deregister_bus (struct usb_bus *bus)
949 {
950         dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
951
952         /*
953          * NOTE: make sure that all the devices are removed by the
954          * controller code, as well as having it call this when cleaning
955          * itself up
956          */
957         mutex_lock(&usb_bus_idr_lock);
958         idr_remove(&usb_bus_idr, bus->busnum);
959         mutex_unlock(&usb_bus_idr_lock);
960
961         usb_notify_remove_bus(bus);
962 }
963
964 /**
965  * register_root_hub - called by usb_add_hcd() to register a root hub
966  * @hcd: host controller for this root hub
967  *
968  * This function registers the root hub with the USB subsystem.  It sets up
969  * the device properly in the device tree and then calls usb_new_device()
970  * to register the usb device.  It also assigns the root hub's USB address
971  * (always 1).
972  *
973  * Return: 0 if successful. A negative error code otherwise.
974  */
975 static int register_root_hub(struct usb_hcd *hcd)
976 {
977         struct device *parent_dev = hcd->self.controller;
978         struct usb_device *usb_dev = hcd->self.root_hub;
979         const int devnum = 1;
980         int retval;
981
982         usb_dev->devnum = devnum;
983         usb_dev->bus->devnum_next = devnum + 1;
984         set_bit (devnum, usb_dev->bus->devmap.devicemap);
985         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
986
987         mutex_lock(&usb_bus_idr_lock);
988
989         usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
990         retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
991         if (retval != sizeof usb_dev->descriptor) {
992                 mutex_unlock(&usb_bus_idr_lock);
993                 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
994                                 dev_name(&usb_dev->dev), retval);
995                 return (retval < 0) ? retval : -EMSGSIZE;
996         }
997
998         if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
999                 retval = usb_get_bos_descriptor(usb_dev);
1000                 if (!retval) {
1001                         usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1002                 } else if (usb_dev->speed >= USB_SPEED_SUPER) {
1003                         mutex_unlock(&usb_bus_idr_lock);
1004                         dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1005                                         dev_name(&usb_dev->dev), retval);
1006                         return retval;
1007                 }
1008         }
1009
1010         retval = usb_new_device (usb_dev);
1011         if (retval) {
1012                 dev_err (parent_dev, "can't register root hub for %s, %d\n",
1013                                 dev_name(&usb_dev->dev), retval);
1014         } else {
1015                 spin_lock_irq (&hcd_root_hub_lock);
1016                 hcd->rh_registered = 1;
1017                 spin_unlock_irq (&hcd_root_hub_lock);
1018
1019                 /* Did the HC die before the root hub was registered? */
1020                 if (HCD_DEAD(hcd))
1021                         usb_hc_died (hcd);      /* This time clean up */
1022         }
1023         mutex_unlock(&usb_bus_idr_lock);
1024
1025         return retval;
1026 }
1027
1028 /*
1029  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1030  * @bus: the bus which the root hub belongs to
1031  * @portnum: the port which is being resumed
1032  *
1033  * HCDs should call this function when they know that a resume signal is
1034  * being sent to a root-hub port.  The root hub will be prevented from
1035  * going into autosuspend until usb_hcd_end_port_resume() is called.
1036  *
1037  * The bus's private lock must be held by the caller.
1038  */
1039 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1040 {
1041         unsigned bit = 1 << portnum;
1042
1043         if (!(bus->resuming_ports & bit)) {
1044                 bus->resuming_ports |= bit;
1045                 pm_runtime_get_noresume(&bus->root_hub->dev);
1046         }
1047 }
1048 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1049
1050 /*
1051  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1052  * @bus: the bus which the root hub belongs to
1053  * @portnum: the port which is being resumed
1054  *
1055  * HCDs should call this function when they know that a resume signal has
1056  * stopped being sent to a root-hub port.  The root hub will be allowed to
1057  * autosuspend again.
1058  *
1059  * The bus's private lock must be held by the caller.
1060  */
1061 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1062 {
1063         unsigned bit = 1 << portnum;
1064
1065         if (bus->resuming_ports & bit) {
1066                 bus->resuming_ports &= ~bit;
1067                 pm_runtime_put_noidle(&bus->root_hub->dev);
1068         }
1069 }
1070 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1071
1072 /*-------------------------------------------------------------------------*/
1073
1074 /**
1075  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1076  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1077  * @is_input: true iff the transaction sends data to the host
1078  * @isoc: true for isochronous transactions, false for interrupt ones
1079  * @bytecount: how many bytes in the transaction.
1080  *
1081  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1082  *
1083  * Note:
1084  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1085  * scheduled in software, this function is only used for such scheduling.
1086  */
1087 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1088 {
1089         unsigned long   tmp;
1090
1091         switch (speed) {
1092         case USB_SPEED_LOW:     /* INTR only */
1093                 if (is_input) {
1094                         tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1095                         return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1096                 } else {
1097                         tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1098                         return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1099                 }
1100         case USB_SPEED_FULL:    /* ISOC or INTR */
1101                 if (isoc) {
1102                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1103                         return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1104                 } else {
1105                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1106                         return 9107L + BW_HOST_DELAY + tmp;
1107                 }
1108         case USB_SPEED_HIGH:    /* ISOC or INTR */
1109                 /* FIXME adjust for input vs output */
1110                 if (isoc)
1111                         tmp = HS_NSECS_ISO (bytecount);
1112                 else
1113                         tmp = HS_NSECS (bytecount);
1114                 return tmp;
1115         default:
1116                 pr_debug ("%s: bogus device speed!\n", usbcore_name);
1117                 return -1;
1118         }
1119 }
1120 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1121
1122
1123 /*-------------------------------------------------------------------------*/
1124
1125 /*
1126  * Generic HC operations.
1127  */
1128
1129 /*-------------------------------------------------------------------------*/
1130
1131 /**
1132  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1133  * @hcd: host controller to which @urb was submitted
1134  * @urb: URB being submitted
1135  *
1136  * Host controller drivers should call this routine in their enqueue()
1137  * method.  The HCD's private spinlock must be held and interrupts must
1138  * be disabled.  The actions carried out here are required for URB
1139  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1140  *
1141  * Return: 0 for no error, otherwise a negative error code (in which case
1142  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1143  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1144  * the private spinlock and returning.
1145  */
1146 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1147 {
1148         int             rc = 0;
1149
1150         spin_lock(&hcd_urb_list_lock);
1151
1152         /* Check that the URB isn't being killed */
1153         if (unlikely(atomic_read(&urb->reject))) {
1154                 rc = -EPERM;
1155                 goto done;
1156         }
1157
1158         if (unlikely(!urb->ep->enabled)) {
1159                 rc = -ENOENT;
1160                 goto done;
1161         }
1162
1163         if (unlikely(!urb->dev->can_submit)) {
1164                 rc = -EHOSTUNREACH;
1165                 goto done;
1166         }
1167
1168         /*
1169          * Check the host controller's state and add the URB to the
1170          * endpoint's queue.
1171          */
1172         if (HCD_RH_RUNNING(hcd)) {
1173                 urb->unlinked = 0;
1174                 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1175         } else {
1176                 rc = -ESHUTDOWN;
1177                 goto done;
1178         }
1179  done:
1180         spin_unlock(&hcd_urb_list_lock);
1181         return rc;
1182 }
1183 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1184
1185 /**
1186  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1187  * @hcd: host controller to which @urb was submitted
1188  * @urb: URB being checked for unlinkability
1189  * @status: error code to store in @urb if the unlink succeeds
1190  *
1191  * Host controller drivers should call this routine in their dequeue()
1192  * method.  The HCD's private spinlock must be held and interrupts must
1193  * be disabled.  The actions carried out here are required for making
1194  * sure than an unlink is valid.
1195  *
1196  * Return: 0 for no error, otherwise a negative error code (in which case
1197  * the dequeue() method must fail).  The possible error codes are:
1198  *
1199  *      -EIDRM: @urb was not submitted or has already completed.
1200  *              The completion function may not have been called yet.
1201  *
1202  *      -EBUSY: @urb has already been unlinked.
1203  */
1204 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1205                 int status)
1206 {
1207         struct list_head        *tmp;
1208
1209         /* insist the urb is still queued */
1210         list_for_each(tmp, &urb->ep->urb_list) {
1211                 if (tmp == &urb->urb_list)
1212                         break;
1213         }
1214         if (tmp != &urb->urb_list)
1215                 return -EIDRM;
1216
1217         /* Any status except -EINPROGRESS means something already started to
1218          * unlink this URB from the hardware.  So there's no more work to do.
1219          */
1220         if (urb->unlinked)
1221                 return -EBUSY;
1222         urb->unlinked = status;
1223         return 0;
1224 }
1225 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1226
1227 /**
1228  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1229  * @hcd: host controller to which @urb was submitted
1230  * @urb: URB being unlinked
1231  *
1232  * Host controller drivers should call this routine before calling
1233  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1234  * interrupts must be disabled.  The actions carried out here are required
1235  * for URB completion.
1236  */
1237 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1238 {
1239         /* clear all state linking urb to this dev (and hcd) */
1240         spin_lock(&hcd_urb_list_lock);
1241         list_del_init(&urb->urb_list);
1242         spin_unlock(&hcd_urb_list_lock);
1243 }
1244 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1245
1246 /*
1247  * Some usb host controllers can only perform dma using a small SRAM area.
1248  * The usb core itself is however optimized for host controllers that can dma
1249  * using regular system memory - like pci devices doing bus mastering.
1250  *
1251  * To support host controllers with limited dma capabilities we provide dma
1252  * bounce buffers. This feature can be enabled by initializing
1253  * hcd->localmem_pool using usb_hcd_setup_local_mem().
1254  *
1255  * The initialized hcd->localmem_pool then tells the usb code to allocate all
1256  * data for dma using the genalloc API.
1257  *
1258  * So, to summarize...
1259  *
1260  * - We need "local" memory, canonical example being
1261  *   a small SRAM on a discrete controller being the
1262  *   only memory that the controller can read ...
1263  *   (a) "normal" kernel memory is no good, and
1264  *   (b) there's not enough to share
1265  *
1266  * - So we use that, even though the primary requirement
1267  *   is that the memory be "local" (hence addressable
1268  *   by that device), not "coherent".
1269  *
1270  */
1271
1272 static int hcd_alloc_coherent(struct usb_bus *bus,
1273                               gfp_t mem_flags, dma_addr_t *dma_handle,
1274                               void **vaddr_handle, size_t size,
1275                               enum dma_data_direction dir)
1276 {
1277         unsigned char *vaddr;
1278
1279         if (*vaddr_handle == NULL) {
1280                 WARN_ON_ONCE(1);
1281                 return -EFAULT;
1282         }
1283
1284         vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1285                                  mem_flags, dma_handle);
1286         if (!vaddr)
1287                 return -ENOMEM;
1288
1289         /*
1290          * Store the virtual address of the buffer at the end
1291          * of the allocated dma buffer. The size of the buffer
1292          * may be uneven so use unaligned functions instead
1293          * of just rounding up. It makes sense to optimize for
1294          * memory footprint over access speed since the amount
1295          * of memory available for dma may be limited.
1296          */
1297         put_unaligned((unsigned long)*vaddr_handle,
1298                       (unsigned long *)(vaddr + size));
1299
1300         if (dir == DMA_TO_DEVICE)
1301                 memcpy(vaddr, *vaddr_handle, size);
1302
1303         *vaddr_handle = vaddr;
1304         return 0;
1305 }
1306
1307 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1308                               void **vaddr_handle, size_t size,
1309                               enum dma_data_direction dir)
1310 {
1311         unsigned char *vaddr = *vaddr_handle;
1312
1313         vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1314
1315         if (dir == DMA_FROM_DEVICE)
1316                 memcpy(vaddr, *vaddr_handle, size);
1317
1318         hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1319
1320         *vaddr_handle = vaddr;
1321         *dma_handle = 0;
1322 }
1323
1324 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1325 {
1326         if (IS_ENABLED(CONFIG_HAS_DMA) &&
1327             (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
1328                 dma_unmap_single(hcd->self.sysdev,
1329                                 urb->setup_dma,
1330                                 sizeof(struct usb_ctrlrequest),
1331                                 DMA_TO_DEVICE);
1332         else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1333                 hcd_free_coherent(urb->dev->bus,
1334                                 &urb->setup_dma,
1335                                 (void **) &urb->setup_packet,
1336                                 sizeof(struct usb_ctrlrequest),
1337                                 DMA_TO_DEVICE);
1338
1339         /* Make it safe to call this routine more than once */
1340         urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1341 }
1342 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1343
1344 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1345 {
1346         if (hcd->driver->unmap_urb_for_dma)
1347                 hcd->driver->unmap_urb_for_dma(hcd, urb);
1348         else
1349                 usb_hcd_unmap_urb_for_dma(hcd, urb);
1350 }
1351
1352 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1353 {
1354         enum dma_data_direction dir;
1355
1356         usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1357
1358         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1359         if (IS_ENABLED(CONFIG_HAS_DMA) &&
1360             (urb->transfer_flags & URB_DMA_MAP_SG))
1361                 dma_unmap_sg(hcd->self.sysdev,
1362                                 urb->sg,
1363                                 urb->num_sgs,
1364                                 dir);
1365         else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1366                  (urb->transfer_flags & URB_DMA_MAP_PAGE))
1367                 dma_unmap_page(hcd->self.sysdev,
1368                                 urb->transfer_dma,
1369                                 urb->transfer_buffer_length,
1370                                 dir);
1371         else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1372                  (urb->transfer_flags & URB_DMA_MAP_SINGLE))
1373                 dma_unmap_single(hcd->self.sysdev,
1374                                 urb->transfer_dma,
1375                                 urb->transfer_buffer_length,
1376                                 dir);
1377         else if (urb->transfer_flags & URB_MAP_LOCAL)
1378                 hcd_free_coherent(urb->dev->bus,
1379                                 &urb->transfer_dma,
1380                                 &urb->transfer_buffer,
1381                                 urb->transfer_buffer_length,
1382                                 dir);
1383
1384         /* Make it safe to call this routine more than once */
1385         urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1386                         URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1387 }
1388 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1389
1390 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1391                            gfp_t mem_flags)
1392 {
1393         if (hcd->driver->map_urb_for_dma)
1394                 return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1395         else
1396                 return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1397 }
1398
1399 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1400                             gfp_t mem_flags)
1401 {
1402         enum dma_data_direction dir;
1403         int ret = 0;
1404
1405         /* Map the URB's buffers for DMA access.
1406          * Lower level HCD code should use *_dma exclusively,
1407          * unless it uses pio or talks to another transport,
1408          * or uses the provided scatter gather list for bulk.
1409          */
1410
1411         if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1412                 if (hcd->self.uses_pio_for_control)
1413                         return ret;
1414                 if (hcd->localmem_pool) {
1415                         ret = hcd_alloc_coherent(
1416                                         urb->dev->bus, mem_flags,
1417                                         &urb->setup_dma,
1418                                         (void **)&urb->setup_packet,
1419                                         sizeof(struct usb_ctrlrequest),
1420                                         DMA_TO_DEVICE);
1421                         if (ret)
1422                                 return ret;
1423                         urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1424                 } else if (hcd_uses_dma(hcd)) {
1425                         if (object_is_on_stack(urb->setup_packet)) {
1426                                 WARN_ONCE(1, "setup packet is on stack\n");
1427                                 return -EAGAIN;
1428                         }
1429
1430                         urb->setup_dma = dma_map_single(
1431                                         hcd->self.sysdev,
1432                                         urb->setup_packet,
1433                                         sizeof(struct usb_ctrlrequest),
1434                                         DMA_TO_DEVICE);
1435                         if (dma_mapping_error(hcd->self.sysdev,
1436                                                 urb->setup_dma))
1437                                 return -EAGAIN;
1438                         urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1439                 }
1440         }
1441
1442         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1443         if (urb->transfer_buffer_length != 0
1444             && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1445                 if (hcd->localmem_pool) {
1446                         ret = hcd_alloc_coherent(
1447                                         urb->dev->bus, mem_flags,
1448                                         &urb->transfer_dma,
1449                                         &urb->transfer_buffer,
1450                                         urb->transfer_buffer_length,
1451                                         dir);
1452                         if (ret == 0)
1453                                 urb->transfer_flags |= URB_MAP_LOCAL;
1454                 } else if (hcd_uses_dma(hcd)) {
1455                         if (urb->num_sgs) {
1456                                 int n;
1457
1458                                 /* We don't support sg for isoc transfers ! */
1459                                 if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1460                                         WARN_ON(1);
1461                                         return -EINVAL;
1462                                 }
1463
1464                                 n = dma_map_sg(
1465                                                 hcd->self.sysdev,
1466                                                 urb->sg,
1467                                                 urb->num_sgs,
1468                                                 dir);
1469                                 if (n <= 0)
1470                                         ret = -EAGAIN;
1471                                 else
1472                                         urb->transfer_flags |= URB_DMA_MAP_SG;
1473                                 urb->num_mapped_sgs = n;
1474                                 if (n != urb->num_sgs)
1475                                         urb->transfer_flags |=
1476                                                         URB_DMA_SG_COMBINED;
1477                         } else if (urb->sg) {
1478                                 struct scatterlist *sg = urb->sg;
1479                                 urb->transfer_dma = dma_map_page(
1480                                                 hcd->self.sysdev,
1481                                                 sg_page(sg),
1482                                                 sg->offset,
1483                                                 urb->transfer_buffer_length,
1484                                                 dir);
1485                                 if (dma_mapping_error(hcd->self.sysdev,
1486                                                 urb->transfer_dma))
1487                                         ret = -EAGAIN;
1488                                 else
1489                                         urb->transfer_flags |= URB_DMA_MAP_PAGE;
1490                         } else if (object_is_on_stack(urb->transfer_buffer)) {
1491                                 WARN_ONCE(1, "transfer buffer is on stack\n");
1492                                 ret = -EAGAIN;
1493                         } else {
1494                                 urb->transfer_dma = dma_map_single(
1495                                                 hcd->self.sysdev,
1496                                                 urb->transfer_buffer,
1497                                                 urb->transfer_buffer_length,
1498                                                 dir);
1499                                 if (dma_mapping_error(hcd->self.sysdev,
1500                                                 urb->transfer_dma))
1501                                         ret = -EAGAIN;
1502                                 else
1503                                         urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1504                         }
1505                 }
1506                 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1507                                 URB_SETUP_MAP_LOCAL)))
1508                         usb_hcd_unmap_urb_for_dma(hcd, urb);
1509         }
1510         return ret;
1511 }
1512 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1513
1514 /*-------------------------------------------------------------------------*/
1515
1516 /* may be called in any context with a valid urb->dev usecount
1517  * caller surrenders "ownership" of urb
1518  * expects usb_submit_urb() to have sanity checked and conditioned all
1519  * inputs in the urb
1520  */
1521 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1522 {
1523         int                     status;
1524         struct usb_hcd          *hcd = bus_to_hcd(urb->dev->bus);
1525
1526         /* increment urb's reference count as part of giving it to the HCD
1527          * (which will control it).  HCD guarantees that it either returns
1528          * an error or calls giveback(), but not both.
1529          */
1530         usb_get_urb(urb);
1531         atomic_inc(&urb->use_count);
1532         atomic_inc(&urb->dev->urbnum);
1533         usbmon_urb_submit(&hcd->self, urb);
1534
1535         /* NOTE requirements on root-hub callers (usbfs and the hub
1536          * driver, for now):  URBs' urb->transfer_buffer must be
1537          * valid and usb_buffer_{sync,unmap}() not be needed, since
1538          * they could clobber root hub response data.  Also, control
1539          * URBs must be submitted in process context with interrupts
1540          * enabled.
1541          */
1542
1543         if (is_root_hub(urb->dev)) {
1544                 status = rh_urb_enqueue(hcd, urb);
1545         } else {
1546                 status = map_urb_for_dma(hcd, urb, mem_flags);
1547                 if (likely(status == 0)) {
1548                         status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1549                         if (unlikely(status))
1550                                 unmap_urb_for_dma(hcd, urb);
1551                 }
1552         }
1553
1554         if (unlikely(status)) {
1555                 usbmon_urb_submit_error(&hcd->self, urb, status);
1556                 urb->hcpriv = NULL;
1557                 INIT_LIST_HEAD(&urb->urb_list);
1558                 atomic_dec(&urb->use_count);
1559                 atomic_dec(&urb->dev->urbnum);
1560                 if (atomic_read(&urb->reject))
1561                         wake_up(&usb_kill_urb_queue);
1562                 usb_put_urb(urb);
1563         }
1564         return status;
1565 }
1566
1567 /*-------------------------------------------------------------------------*/
1568
1569 /* this makes the hcd giveback() the urb more quickly, by kicking it
1570  * off hardware queues (which may take a while) and returning it as
1571  * soon as practical.  we've already set up the urb's return status,
1572  * but we can't know if the callback completed already.
1573  */
1574 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1575 {
1576         int             value;
1577
1578         if (is_root_hub(urb->dev))
1579                 value = usb_rh_urb_dequeue(hcd, urb, status);
1580         else {
1581
1582                 /* The only reason an HCD might fail this call is if
1583                  * it has not yet fully queued the urb to begin with.
1584                  * Such failures should be harmless. */
1585                 value = hcd->driver->urb_dequeue(hcd, urb, status);
1586         }
1587         return value;
1588 }
1589
1590 /*
1591  * called in any context
1592  *
1593  * caller guarantees urb won't be recycled till both unlink()
1594  * and the urb's completion function return
1595  */
1596 int usb_hcd_unlink_urb (struct urb *urb, int status)
1597 {
1598         struct usb_hcd          *hcd;
1599         struct usb_device       *udev = urb->dev;
1600         int                     retval = -EIDRM;
1601         unsigned long           flags;
1602
1603         /* Prevent the device and bus from going away while
1604          * the unlink is carried out.  If they are already gone
1605          * then urb->use_count must be 0, since disconnected
1606          * devices can't have any active URBs.
1607          */
1608         spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1609         if (atomic_read(&urb->use_count) > 0) {
1610                 retval = 0;
1611                 usb_get_dev(udev);
1612         }
1613         spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1614         if (retval == 0) {
1615                 hcd = bus_to_hcd(urb->dev->bus);
1616                 retval = unlink1(hcd, urb, status);
1617                 if (retval == 0)
1618                         retval = -EINPROGRESS;
1619                 else if (retval != -EIDRM && retval != -EBUSY)
1620                         dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
1621                                         urb, retval);
1622                 usb_put_dev(udev);
1623         }
1624         return retval;
1625 }
1626
1627 /*-------------------------------------------------------------------------*/
1628
1629 static void __usb_hcd_giveback_urb(struct urb *urb)
1630 {
1631         struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1632         struct usb_anchor *anchor = urb->anchor;
1633         int status = urb->unlinked;
1634
1635         urb->hcpriv = NULL;
1636         if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1637             urb->actual_length < urb->transfer_buffer_length &&
1638             !status))
1639                 status = -EREMOTEIO;
1640
1641         unmap_urb_for_dma(hcd, urb);
1642         usbmon_urb_complete(&hcd->self, urb, status);
1643         usb_anchor_suspend_wakeups(anchor);
1644         usb_unanchor_urb(urb);
1645         if (likely(status == 0))
1646                 usb_led_activity(USB_LED_EVENT_HOST);
1647
1648         /* pass ownership to the completion handler */
1649         urb->status = status;
1650         /*
1651          * This function can be called in task context inside another remote
1652          * coverage collection section, but kcov doesn't support that kind of
1653          * recursion yet. Only collect coverage in softirq context for now.
1654          */
1655         kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum);
1656         urb->complete(urb);
1657         kcov_remote_stop_softirq();
1658
1659         usb_anchor_resume_wakeups(anchor);
1660         atomic_dec(&urb->use_count);
1661         if (unlikely(atomic_read(&urb->reject)))
1662                 wake_up(&usb_kill_urb_queue);
1663         usb_put_urb(urb);
1664 }
1665
1666 static void usb_giveback_urb_bh(struct tasklet_struct *t)
1667 {
1668         struct giveback_urb_bh *bh = from_tasklet(bh, t, bh);
1669         struct list_head local_list;
1670
1671         spin_lock_irq(&bh->lock);
1672         bh->running = true;
1673  restart:
1674         list_replace_init(&bh->head, &local_list);
1675         spin_unlock_irq(&bh->lock);
1676
1677         while (!list_empty(&local_list)) {
1678                 struct urb *urb;
1679
1680                 urb = list_entry(local_list.next, struct urb, urb_list);
1681                 list_del_init(&urb->urb_list);
1682                 bh->completing_ep = urb->ep;
1683                 __usb_hcd_giveback_urb(urb);
1684                 bh->completing_ep = NULL;
1685         }
1686
1687         /* check if there are new URBs to giveback */
1688         spin_lock_irq(&bh->lock);
1689         if (!list_empty(&bh->head))
1690                 goto restart;
1691         bh->running = false;
1692         spin_unlock_irq(&bh->lock);
1693 }
1694
1695 /**
1696  * usb_hcd_giveback_urb - return URB from HCD to device driver
1697  * @hcd: host controller returning the URB
1698  * @urb: urb being returned to the USB device driver.
1699  * @status: completion status code for the URB.
1700  *
1701  * Context: atomic. The completion callback is invoked in caller's context.
1702  * For HCDs with HCD_BH flag set, the completion callback is invoked in tasklet
1703  * context (except for URBs submitted to the root hub which always complete in
1704  * caller's context).
1705  *
1706  * This hands the URB from HCD to its USB device driver, using its
1707  * completion function.  The HCD has freed all per-urb resources
1708  * (and is done using urb->hcpriv).  It also released all HCD locks;
1709  * the device driver won't cause problems if it frees, modifies,
1710  * or resubmits this URB.
1711  *
1712  * If @urb was unlinked, the value of @status will be overridden by
1713  * @urb->unlinked.  Erroneous short transfers are detected in case
1714  * the HCD hasn't checked for them.
1715  */
1716 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1717 {
1718         struct giveback_urb_bh *bh;
1719         bool running, high_prio_bh;
1720
1721         /* pass status to tasklet via unlinked */
1722         if (likely(!urb->unlinked))
1723                 urb->unlinked = status;
1724
1725         if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1726                 __usb_hcd_giveback_urb(urb);
1727                 return;
1728         }
1729
1730         if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1731                 bh = &hcd->high_prio_bh;
1732                 high_prio_bh = true;
1733         } else {
1734                 bh = &hcd->low_prio_bh;
1735                 high_prio_bh = false;
1736         }
1737
1738         spin_lock(&bh->lock);
1739         list_add_tail(&urb->urb_list, &bh->head);
1740         running = bh->running;
1741         spin_unlock(&bh->lock);
1742
1743         if (running)
1744                 ;
1745         else if (high_prio_bh)
1746                 tasklet_hi_schedule(&bh->bh);
1747         else
1748                 tasklet_schedule(&bh->bh);
1749 }
1750 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1751
1752 /*-------------------------------------------------------------------------*/
1753
1754 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1755  * queue to drain completely.  The caller must first insure that no more
1756  * URBs can be submitted for this endpoint.
1757  */
1758 void usb_hcd_flush_endpoint(struct usb_device *udev,
1759                 struct usb_host_endpoint *ep)
1760 {
1761         struct usb_hcd          *hcd;
1762         struct urb              *urb;
1763
1764         if (!ep)
1765                 return;
1766         might_sleep();
1767         hcd = bus_to_hcd(udev->bus);
1768
1769         /* No more submits can occur */
1770         spin_lock_irq(&hcd_urb_list_lock);
1771 rescan:
1772         list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
1773                 int     is_in;
1774
1775                 if (urb->unlinked)
1776                         continue;
1777                 usb_get_urb (urb);
1778                 is_in = usb_urb_dir_in(urb);
1779                 spin_unlock(&hcd_urb_list_lock);
1780
1781                 /* kick hcd */
1782                 unlink1(hcd, urb, -ESHUTDOWN);
1783                 dev_dbg (hcd->self.controller,
1784                         "shutdown urb %pK ep%d%s-%s\n",
1785                         urb, usb_endpoint_num(&ep->desc),
1786                         is_in ? "in" : "out",
1787                         usb_ep_type_string(usb_endpoint_type(&ep->desc)));
1788                 usb_put_urb (urb);
1789
1790                 /* list contents may have changed */
1791                 spin_lock(&hcd_urb_list_lock);
1792                 goto rescan;
1793         }
1794         spin_unlock_irq(&hcd_urb_list_lock);
1795
1796         /* Wait until the endpoint queue is completely empty */
1797         while (!list_empty (&ep->urb_list)) {
1798                 spin_lock_irq(&hcd_urb_list_lock);
1799
1800                 /* The list may have changed while we acquired the spinlock */
1801                 urb = NULL;
1802                 if (!list_empty (&ep->urb_list)) {
1803                         urb = list_entry (ep->urb_list.prev, struct urb,
1804                                         urb_list);
1805                         usb_get_urb (urb);
1806                 }
1807                 spin_unlock_irq(&hcd_urb_list_lock);
1808
1809                 if (urb) {
1810                         usb_kill_urb (urb);
1811                         usb_put_urb (urb);
1812                 }
1813         }
1814 }
1815
1816 /**
1817  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1818  *                              the bus bandwidth
1819  * @udev: target &usb_device
1820  * @new_config: new configuration to install
1821  * @cur_alt: the current alternate interface setting
1822  * @new_alt: alternate interface setting that is being installed
1823  *
1824  * To change configurations, pass in the new configuration in new_config,
1825  * and pass NULL for cur_alt and new_alt.
1826  *
1827  * To reset a device's configuration (put the device in the ADDRESSED state),
1828  * pass in NULL for new_config, cur_alt, and new_alt.
1829  *
1830  * To change alternate interface settings, pass in NULL for new_config,
1831  * pass in the current alternate interface setting in cur_alt,
1832  * and pass in the new alternate interface setting in new_alt.
1833  *
1834  * Return: An error if the requested bandwidth change exceeds the
1835  * bus bandwidth or host controller internal resources.
1836  */
1837 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1838                 struct usb_host_config *new_config,
1839                 struct usb_host_interface *cur_alt,
1840                 struct usb_host_interface *new_alt)
1841 {
1842         int num_intfs, i, j;
1843         struct usb_host_interface *alt = NULL;
1844         int ret = 0;
1845         struct usb_hcd *hcd;
1846         struct usb_host_endpoint *ep;
1847
1848         hcd = bus_to_hcd(udev->bus);
1849         if (!hcd->driver->check_bandwidth)
1850                 return 0;
1851
1852         /* Configuration is being removed - set configuration 0 */
1853         if (!new_config && !cur_alt) {
1854                 for (i = 1; i < 16; ++i) {
1855                         ep = udev->ep_out[i];
1856                         if (ep)
1857                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1858                         ep = udev->ep_in[i];
1859                         if (ep)
1860                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1861                 }
1862                 hcd->driver->check_bandwidth(hcd, udev);
1863                 return 0;
1864         }
1865         /* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1866          * each interface's alt setting 0 and ask the HCD to check the bandwidth
1867          * of the bus.  There will always be bandwidth for endpoint 0, so it's
1868          * ok to exclude it.
1869          */
1870         if (new_config) {
1871                 num_intfs = new_config->desc.bNumInterfaces;
1872                 /* Remove endpoints (except endpoint 0, which is always on the
1873                  * schedule) from the old config from the schedule
1874                  */
1875                 for (i = 1; i < 16; ++i) {
1876                         ep = udev->ep_out[i];
1877                         if (ep) {
1878                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1879                                 if (ret < 0)
1880                                         goto reset;
1881                         }
1882                         ep = udev->ep_in[i];
1883                         if (ep) {
1884                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1885                                 if (ret < 0)
1886                                         goto reset;
1887                         }
1888                 }
1889                 for (i = 0; i < num_intfs; ++i) {
1890                         struct usb_host_interface *first_alt;
1891                         int iface_num;
1892
1893                         first_alt = &new_config->intf_cache[i]->altsetting[0];
1894                         iface_num = first_alt->desc.bInterfaceNumber;
1895                         /* Set up endpoints for alternate interface setting 0 */
1896                         alt = usb_find_alt_setting(new_config, iface_num, 0);
1897                         if (!alt)
1898                                 /* No alt setting 0? Pick the first setting. */
1899                                 alt = first_alt;
1900
1901                         for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1902                                 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1903                                 if (ret < 0)
1904                                         goto reset;
1905                         }
1906                 }
1907         }
1908         if (cur_alt && new_alt) {
1909                 struct usb_interface *iface = usb_ifnum_to_if(udev,
1910                                 cur_alt->desc.bInterfaceNumber);
1911
1912                 if (!iface)
1913                         return -EINVAL;
1914                 if (iface->resetting_device) {
1915                         /*
1916                          * The USB core just reset the device, so the xHCI host
1917                          * and the device will think alt setting 0 is installed.
1918                          * However, the USB core will pass in the alternate
1919                          * setting installed before the reset as cur_alt.  Dig
1920                          * out the alternate setting 0 structure, or the first
1921                          * alternate setting if a broken device doesn't have alt
1922                          * setting 0.
1923                          */
1924                         cur_alt = usb_altnum_to_altsetting(iface, 0);
1925                         if (!cur_alt)
1926                                 cur_alt = &iface->altsetting[0];
1927                 }
1928
1929                 /* Drop all the endpoints in the current alt setting */
1930                 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1931                         ret = hcd->driver->drop_endpoint(hcd, udev,
1932                                         &cur_alt->endpoint[i]);
1933                         if (ret < 0)
1934                                 goto reset;
1935                 }
1936                 /* Add all the endpoints in the new alt setting */
1937                 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1938                         ret = hcd->driver->add_endpoint(hcd, udev,
1939                                         &new_alt->endpoint[i]);
1940                         if (ret < 0)
1941                                 goto reset;
1942                 }
1943         }
1944         ret = hcd->driver->check_bandwidth(hcd, udev);
1945 reset:
1946         if (ret < 0)
1947                 hcd->driver->reset_bandwidth(hcd, udev);
1948         return ret;
1949 }
1950
1951 /* Disables the endpoint: synchronizes with the hcd to make sure all
1952  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1953  * have been called previously.  Use for set_configuration, set_interface,
1954  * driver removal, physical disconnect.
1955  *
1956  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1957  * type, maxpacket size, toggle, halt status, and scheduling.
1958  */
1959 void usb_hcd_disable_endpoint(struct usb_device *udev,
1960                 struct usb_host_endpoint *ep)
1961 {
1962         struct usb_hcd          *hcd;
1963
1964         might_sleep();
1965         hcd = bus_to_hcd(udev->bus);
1966         if (hcd->driver->endpoint_disable)
1967                 hcd->driver->endpoint_disable(hcd, ep);
1968 }
1969
1970 /**
1971  * usb_hcd_reset_endpoint - reset host endpoint state
1972  * @udev: USB device.
1973  * @ep:   the endpoint to reset.
1974  *
1975  * Resets any host endpoint state such as the toggle bit, sequence
1976  * number and current window.
1977  */
1978 void usb_hcd_reset_endpoint(struct usb_device *udev,
1979                             struct usb_host_endpoint *ep)
1980 {
1981         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1982
1983         if (hcd->driver->endpoint_reset)
1984                 hcd->driver->endpoint_reset(hcd, ep);
1985         else {
1986                 int epnum = usb_endpoint_num(&ep->desc);
1987                 int is_out = usb_endpoint_dir_out(&ep->desc);
1988                 int is_control = usb_endpoint_xfer_control(&ep->desc);
1989
1990                 usb_settoggle(udev, epnum, is_out, 0);
1991                 if (is_control)
1992                         usb_settoggle(udev, epnum, !is_out, 0);
1993         }
1994 }
1995
1996 /**
1997  * usb_alloc_streams - allocate bulk endpoint stream IDs.
1998  * @interface:          alternate setting that includes all endpoints.
1999  * @eps:                array of endpoints that need streams.
2000  * @num_eps:            number of endpoints in the array.
2001  * @num_streams:        number of streams to allocate.
2002  * @mem_flags:          flags hcd should use to allocate memory.
2003  *
2004  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2005  * Drivers may queue multiple transfers to different stream IDs, which may
2006  * complete in a different order than they were queued.
2007  *
2008  * Return: On success, the number of allocated streams. On failure, a negative
2009  * error code.
2010  */
2011 int usb_alloc_streams(struct usb_interface *interface,
2012                 struct usb_host_endpoint **eps, unsigned int num_eps,
2013                 unsigned int num_streams, gfp_t mem_flags)
2014 {
2015         struct usb_hcd *hcd;
2016         struct usb_device *dev;
2017         int i, ret;
2018
2019         dev = interface_to_usbdev(interface);
2020         hcd = bus_to_hcd(dev->bus);
2021         if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2022                 return -EINVAL;
2023         if (dev->speed < USB_SPEED_SUPER)
2024                 return -EINVAL;
2025         if (dev->state < USB_STATE_CONFIGURED)
2026                 return -ENODEV;
2027
2028         for (i = 0; i < num_eps; i++) {
2029                 /* Streams only apply to bulk endpoints. */
2030                 if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2031                         return -EINVAL;
2032                 /* Re-alloc is not allowed */
2033                 if (eps[i]->streams)
2034                         return -EINVAL;
2035         }
2036
2037         ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2038                         num_streams, mem_flags);
2039         if (ret < 0)
2040                 return ret;
2041
2042         for (i = 0; i < num_eps; i++)
2043                 eps[i]->streams = ret;
2044
2045         return ret;
2046 }
2047 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2048
2049 /**
2050  * usb_free_streams - free bulk endpoint stream IDs.
2051  * @interface:  alternate setting that includes all endpoints.
2052  * @eps:        array of endpoints to remove streams from.
2053  * @num_eps:    number of endpoints in the array.
2054  * @mem_flags:  flags hcd should use to allocate memory.
2055  *
2056  * Reverts a group of bulk endpoints back to not using stream IDs.
2057  * Can fail if we are given bad arguments, or HCD is broken.
2058  *
2059  * Return: 0 on success. On failure, a negative error code.
2060  */
2061 int usb_free_streams(struct usb_interface *interface,
2062                 struct usb_host_endpoint **eps, unsigned int num_eps,
2063                 gfp_t mem_flags)
2064 {
2065         struct usb_hcd *hcd;
2066         struct usb_device *dev;
2067         int i, ret;
2068
2069         dev = interface_to_usbdev(interface);
2070         hcd = bus_to_hcd(dev->bus);
2071         if (dev->speed < USB_SPEED_SUPER)
2072                 return -EINVAL;
2073
2074         /* Double-free is not allowed */
2075         for (i = 0; i < num_eps; i++)
2076                 if (!eps[i] || !eps[i]->streams)
2077                         return -EINVAL;
2078
2079         ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2080         if (ret < 0)
2081                 return ret;
2082
2083         for (i = 0; i < num_eps; i++)
2084                 eps[i]->streams = 0;
2085
2086         return ret;
2087 }
2088 EXPORT_SYMBOL_GPL(usb_free_streams);
2089
2090 /* Protect against drivers that try to unlink URBs after the device
2091  * is gone, by waiting until all unlinks for @udev are finished.
2092  * Since we don't currently track URBs by device, simply wait until
2093  * nothing is running in the locked region of usb_hcd_unlink_urb().
2094  */
2095 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2096 {
2097         spin_lock_irq(&hcd_urb_unlink_lock);
2098         spin_unlock_irq(&hcd_urb_unlink_lock);
2099 }
2100
2101 /*-------------------------------------------------------------------------*/
2102
2103 /* called in any context */
2104 int usb_hcd_get_frame_number (struct usb_device *udev)
2105 {
2106         struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
2107
2108         if (!HCD_RH_RUNNING(hcd))
2109                 return -ESHUTDOWN;
2110         return hcd->driver->get_frame_number (hcd);
2111 }
2112
2113 /*-------------------------------------------------------------------------*/
2114
2115 #ifdef  CONFIG_PM
2116
2117 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2118 {
2119         struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2120         int             status;
2121         int             old_state = hcd->state;
2122
2123         dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2124                         (PMSG_IS_AUTO(msg) ? "auto-" : ""),
2125                         rhdev->do_remote_wakeup);
2126         if (HCD_DEAD(hcd)) {
2127                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2128                 return 0;
2129         }
2130
2131         if (!hcd->driver->bus_suspend) {
2132                 status = -ENOENT;
2133         } else {
2134                 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2135                 hcd->state = HC_STATE_QUIESCING;
2136                 status = hcd->driver->bus_suspend(hcd);
2137         }
2138         if (status == 0) {
2139                 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2140                 hcd->state = HC_STATE_SUSPENDED;
2141
2142                 if (!PMSG_IS_AUTO(msg))
2143                         usb_phy_roothub_suspend(hcd->self.sysdev,
2144                                                 hcd->phy_roothub);
2145
2146                 /* Did we race with a root-hub wakeup event? */
2147                 if (rhdev->do_remote_wakeup) {
2148                         char    buffer[6];
2149
2150                         status = hcd->driver->hub_status_data(hcd, buffer);
2151                         if (status != 0) {
2152                                 dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2153                                 hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2154                                 status = -EBUSY;
2155                         }
2156                 }
2157         } else {
2158                 spin_lock_irq(&hcd_root_hub_lock);
2159                 if (!HCD_DEAD(hcd)) {
2160                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2161                         hcd->state = old_state;
2162                 }
2163                 spin_unlock_irq(&hcd_root_hub_lock);
2164                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2165                                 "suspend", status);
2166         }
2167         return status;
2168 }
2169
2170 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2171 {
2172         struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2173         int             status;
2174         int             old_state = hcd->state;
2175
2176         dev_dbg(&rhdev->dev, "usb %sresume\n",
2177                         (PMSG_IS_AUTO(msg) ? "auto-" : ""));
2178         if (HCD_DEAD(hcd)) {
2179                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2180                 return 0;
2181         }
2182
2183         if (!PMSG_IS_AUTO(msg)) {
2184                 status = usb_phy_roothub_resume(hcd->self.sysdev,
2185                                                 hcd->phy_roothub);
2186                 if (status)
2187                         return status;
2188         }
2189
2190         if (!hcd->driver->bus_resume)
2191                 return -ENOENT;
2192         if (HCD_RH_RUNNING(hcd))
2193                 return 0;
2194
2195         hcd->state = HC_STATE_RESUMING;
2196         status = hcd->driver->bus_resume(hcd);
2197         clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2198         if (status == 0)
2199                 status = usb_phy_roothub_calibrate(hcd->phy_roothub);
2200
2201         if (status == 0) {
2202                 struct usb_device *udev;
2203                 int port1;
2204
2205                 spin_lock_irq(&hcd_root_hub_lock);
2206                 if (!HCD_DEAD(hcd)) {
2207                         usb_set_device_state(rhdev, rhdev->actconfig
2208                                         ? USB_STATE_CONFIGURED
2209                                         : USB_STATE_ADDRESS);
2210                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2211                         hcd->state = HC_STATE_RUNNING;
2212                 }
2213                 spin_unlock_irq(&hcd_root_hub_lock);
2214
2215                 /*
2216                  * Check whether any of the enabled ports on the root hub are
2217                  * unsuspended.  If they are then a TRSMRCY delay is needed
2218                  * (this is what the USB-2 spec calls a "global resume").
2219                  * Otherwise we can skip the delay.
2220                  */
2221                 usb_hub_for_each_child(rhdev, port1, udev) {
2222                         if (udev->state != USB_STATE_NOTATTACHED &&
2223                                         !udev->port_is_suspended) {
2224                                 usleep_range(10000, 11000);     /* TRSMRCY */
2225                                 break;
2226                         }
2227                 }
2228         } else {
2229                 hcd->state = old_state;
2230                 usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
2231                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2232                                 "resume", status);
2233                 if (status != -ESHUTDOWN)
2234                         usb_hc_died(hcd);
2235         }
2236         return status;
2237 }
2238
2239 /* Workqueue routine for root-hub remote wakeup */
2240 static void hcd_resume_work(struct work_struct *work)
2241 {
2242         struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2243         struct usb_device *udev = hcd->self.root_hub;
2244
2245         usb_remote_wakeup(udev);
2246 }
2247
2248 /**
2249  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2250  * @hcd: host controller for this root hub
2251  *
2252  * The USB host controller calls this function when its root hub is
2253  * suspended (with the remote wakeup feature enabled) and a remote
2254  * wakeup request is received.  The routine submits a workqueue request
2255  * to resume the root hub (that is, manage its downstream ports again).
2256  */
2257 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2258 {
2259         unsigned long flags;
2260
2261         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2262         if (hcd->rh_registered) {
2263                 pm_wakeup_event(&hcd->self.root_hub->dev, 0);
2264                 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2265                 queue_work(pm_wq, &hcd->wakeup_work);
2266         }
2267         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2268 }
2269 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2270
2271 #endif  /* CONFIG_PM */
2272
2273 /*-------------------------------------------------------------------------*/
2274
2275 #ifdef  CONFIG_USB_OTG
2276
2277 /**
2278  * usb_bus_start_enum - start immediate enumeration (for OTG)
2279  * @bus: the bus (must use hcd framework)
2280  * @port_num: 1-based number of port; usually bus->otg_port
2281  * Context: atomic
2282  *
2283  * Starts enumeration, with an immediate reset followed later by
2284  * hub_wq identifying and possibly configuring the device.
2285  * This is needed by OTG controller drivers, where it helps meet
2286  * HNP protocol timing requirements for starting a port reset.
2287  *
2288  * Return: 0 if successful.
2289  */
2290 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2291 {
2292         struct usb_hcd          *hcd;
2293         int                     status = -EOPNOTSUPP;
2294
2295         /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2296          * boards with root hubs hooked up to internal devices (instead of
2297          * just the OTG port) may need more attention to resetting...
2298          */
2299         hcd = bus_to_hcd(bus);
2300         if (port_num && hcd->driver->start_port_reset)
2301                 status = hcd->driver->start_port_reset(hcd, port_num);
2302
2303         /* allocate hub_wq shortly after (first) root port reset finishes;
2304          * it may issue others, until at least 50 msecs have passed.
2305          */
2306         if (status == 0)
2307                 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2308         return status;
2309 }
2310 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2311
2312 #endif
2313
2314 /*-------------------------------------------------------------------------*/
2315
2316 /**
2317  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2318  * @irq: the IRQ being raised
2319  * @__hcd: pointer to the HCD whose IRQ is being signaled
2320  *
2321  * If the controller isn't HALTed, calls the driver's irq handler.
2322  * Checks whether the controller is now dead.
2323  *
2324  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2325  */
2326 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2327 {
2328         struct usb_hcd          *hcd = __hcd;
2329         irqreturn_t             rc;
2330
2331         if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2332                 rc = IRQ_NONE;
2333         else if (hcd->driver->irq(hcd) == IRQ_NONE)
2334                 rc = IRQ_NONE;
2335         else
2336                 rc = IRQ_HANDLED;
2337
2338         return rc;
2339 }
2340 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2341
2342 /*-------------------------------------------------------------------------*/
2343
2344 /* Workqueue routine for when the root-hub has died. */
2345 static void hcd_died_work(struct work_struct *work)
2346 {
2347         struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
2348         static char *env[] = {
2349                 "ERROR=DEAD",
2350                 NULL
2351         };
2352
2353         /* Notify user space that the host controller has died */
2354         kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);
2355 }
2356
2357 /**
2358  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2359  * @hcd: pointer to the HCD representing the controller
2360  *
2361  * This is called by bus glue to report a USB host controller that died
2362  * while operations may still have been pending.  It's called automatically
2363  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2364  *
2365  * Only call this function with the primary HCD.
2366  */
2367 void usb_hc_died (struct usb_hcd *hcd)
2368 {
2369         unsigned long flags;
2370
2371         dev_err (hcd->self.controller, "HC died; cleaning up\n");
2372
2373         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2374         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2375         set_bit(HCD_FLAG_DEAD, &hcd->flags);
2376         if (hcd->rh_registered) {
2377                 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2378
2379                 /* make hub_wq clean up old urbs and devices */
2380                 usb_set_device_state (hcd->self.root_hub,
2381                                 USB_STATE_NOTATTACHED);
2382                 usb_kick_hub_wq(hcd->self.root_hub);
2383         }
2384         if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2385                 hcd = hcd->shared_hcd;
2386                 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2387                 set_bit(HCD_FLAG_DEAD, &hcd->flags);
2388                 if (hcd->rh_registered) {
2389                         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2390
2391                         /* make hub_wq clean up old urbs and devices */
2392                         usb_set_device_state(hcd->self.root_hub,
2393                                         USB_STATE_NOTATTACHED);
2394                         usb_kick_hub_wq(hcd->self.root_hub);
2395                 }
2396         }
2397
2398         /* Handle the case where this function gets called with a shared HCD */
2399         if (usb_hcd_is_primary_hcd(hcd))
2400                 schedule_work(&hcd->died_work);
2401         else
2402                 schedule_work(&hcd->primary_hcd->died_work);
2403
2404         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2405         /* Make sure that the other roothub is also deallocated. */
2406 }
2407 EXPORT_SYMBOL_GPL (usb_hc_died);
2408
2409 /*-------------------------------------------------------------------------*/
2410
2411 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2412 {
2413
2414         spin_lock_init(&bh->lock);
2415         INIT_LIST_HEAD(&bh->head);
2416         tasklet_setup(&bh->bh, usb_giveback_urb_bh);
2417 }
2418
2419 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
2420                 struct device *sysdev, struct device *dev, const char *bus_name,
2421                 struct usb_hcd *primary_hcd)
2422 {
2423         struct usb_hcd *hcd;
2424
2425         hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2426         if (!hcd)
2427                 return NULL;
2428         if (primary_hcd == NULL) {
2429                 hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
2430                                 GFP_KERNEL);
2431                 if (!hcd->address0_mutex) {
2432                         kfree(hcd);
2433                         dev_dbg(dev, "hcd address0 mutex alloc failed\n");
2434                         return NULL;
2435                 }
2436                 mutex_init(hcd->address0_mutex);
2437                 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2438                                 GFP_KERNEL);
2439                 if (!hcd->bandwidth_mutex) {
2440                         kfree(hcd->address0_mutex);
2441                         kfree(hcd);
2442                         dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2443                         return NULL;
2444                 }
2445                 mutex_init(hcd->bandwidth_mutex);
2446                 dev_set_drvdata(dev, hcd);
2447         } else {
2448                 mutex_lock(&usb_port_peer_mutex);
2449                 hcd->address0_mutex = primary_hcd->address0_mutex;
2450                 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2451                 hcd->primary_hcd = primary_hcd;
2452                 primary_hcd->primary_hcd = primary_hcd;
2453                 hcd->shared_hcd = primary_hcd;
2454                 primary_hcd->shared_hcd = hcd;
2455                 mutex_unlock(&usb_port_peer_mutex);
2456         }
2457
2458         kref_init(&hcd->kref);
2459
2460         usb_bus_init(&hcd->self);
2461         hcd->self.controller = dev;
2462         hcd->self.sysdev = sysdev;
2463         hcd->self.bus_name = bus_name;
2464
2465         timer_setup(&hcd->rh_timer, rh_timer_func, 0);
2466 #ifdef CONFIG_PM
2467         INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2468 #endif
2469
2470         INIT_WORK(&hcd->died_work, hcd_died_work);
2471
2472         hcd->driver = driver;
2473         hcd->speed = driver->flags & HCD_MASK;
2474         hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2475                         "USB Host Controller";
2476         return hcd;
2477 }
2478 EXPORT_SYMBOL_GPL(__usb_create_hcd);
2479
2480 /**
2481  * usb_create_shared_hcd - create and initialize an HCD structure
2482  * @driver: HC driver that will use this hcd
2483  * @dev: device for this HC, stored in hcd->self.controller
2484  * @bus_name: value to store in hcd->self.bus_name
2485  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2486  *              PCI device.  Only allocate certain resources for the primary HCD
2487  *
2488  * Context: task context, might sleep.
2489  *
2490  * Allocate a struct usb_hcd, with extra space at the end for the
2491  * HC driver's private data.  Initialize the generic members of the
2492  * hcd structure.
2493  *
2494  * Return: On success, a pointer to the created and initialized HCD structure.
2495  * On failure (e.g. if memory is unavailable), %NULL.
2496  */
2497 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2498                 struct device *dev, const char *bus_name,
2499                 struct usb_hcd *primary_hcd)
2500 {
2501         return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
2502 }
2503 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2504
2505 /**
2506  * usb_create_hcd - create and initialize an HCD structure
2507  * @driver: HC driver that will use this hcd
2508  * @dev: device for this HC, stored in hcd->self.controller
2509  * @bus_name: value to store in hcd->self.bus_name
2510  *
2511  * Context: task context, might sleep.
2512  *
2513  * Allocate a struct usb_hcd, with extra space at the end for the
2514  * HC driver's private data.  Initialize the generic members of the
2515  * hcd structure.
2516  *
2517  * Return: On success, a pointer to the created and initialized HCD
2518  * structure. On failure (e.g. if memory is unavailable), %NULL.
2519  */
2520 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2521                 struct device *dev, const char *bus_name)
2522 {
2523         return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
2524 }
2525 EXPORT_SYMBOL_GPL(usb_create_hcd);
2526
2527 /*
2528  * Roothubs that share one PCI device must also share the bandwidth mutex.
2529  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2530  * deallocated.
2531  *
2532  * Make sure to deallocate the bandwidth_mutex only when the last HCD is
2533  * freed.  When hcd_release() is called for either hcd in a peer set,
2534  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
2535  */
2536 static void hcd_release(struct kref *kref)
2537 {
2538         struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2539
2540         mutex_lock(&usb_port_peer_mutex);
2541         if (hcd->shared_hcd) {
2542                 struct usb_hcd *peer = hcd->shared_hcd;
2543
2544                 peer->shared_hcd = NULL;
2545                 peer->primary_hcd = NULL;
2546         } else {
2547                 kfree(hcd->address0_mutex);
2548                 kfree(hcd->bandwidth_mutex);
2549         }
2550         mutex_unlock(&usb_port_peer_mutex);
2551         kfree(hcd);
2552 }
2553
2554 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2555 {
2556         if (hcd)
2557                 kref_get (&hcd->kref);
2558         return hcd;
2559 }
2560 EXPORT_SYMBOL_GPL(usb_get_hcd);
2561
2562 void usb_put_hcd (struct usb_hcd *hcd)
2563 {
2564         if (hcd)
2565                 kref_put (&hcd->kref, hcd_release);
2566 }
2567 EXPORT_SYMBOL_GPL(usb_put_hcd);
2568
2569 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2570 {
2571         if (!hcd->primary_hcd)
2572                 return 1;
2573         return hcd == hcd->primary_hcd;
2574 }
2575 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2576
2577 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2578 {
2579         if (!hcd->driver->find_raw_port_number)
2580                 return port1;
2581
2582         return hcd->driver->find_raw_port_number(hcd, port1);
2583 }
2584
2585 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2586                 unsigned int irqnum, unsigned long irqflags)
2587 {
2588         int retval;
2589
2590         if (hcd->driver->irq) {
2591
2592                 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2593                                 hcd->driver->description, hcd->self.busnum);
2594                 retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2595                                 hcd->irq_descr, hcd);
2596                 if (retval != 0) {
2597                         dev_err(hcd->self.controller,
2598                                         "request interrupt %d failed\n",
2599                                         irqnum);
2600                         return retval;
2601                 }
2602                 hcd->irq = irqnum;
2603                 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2604                                 (hcd->driver->flags & HCD_MEMORY) ?
2605                                         "io mem" : "io base",
2606                                         (unsigned long long)hcd->rsrc_start);
2607         } else {
2608                 hcd->irq = 0;
2609                 if (hcd->rsrc_start)
2610                         dev_info(hcd->self.controller, "%s 0x%08llx\n",
2611                                         (hcd->driver->flags & HCD_MEMORY) ?
2612                                         "io mem" : "io base",
2613                                         (unsigned long long)hcd->rsrc_start);
2614         }
2615         return 0;
2616 }
2617
2618 /*
2619  * Before we free this root hub, flush in-flight peering attempts
2620  * and disable peer lookups
2621  */
2622 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2623 {
2624         struct usb_device *rhdev;
2625
2626         mutex_lock(&usb_port_peer_mutex);
2627         rhdev = hcd->self.root_hub;
2628         hcd->self.root_hub = NULL;
2629         mutex_unlock(&usb_port_peer_mutex);
2630         usb_put_dev(rhdev);
2631 }
2632
2633 /**
2634  * usb_add_hcd - finish generic HCD structure initialization and register
2635  * @hcd: the usb_hcd structure to initialize
2636  * @irqnum: Interrupt line to allocate
2637  * @irqflags: Interrupt type flags
2638  *
2639  * Finish the remaining parts of generic HCD initialization: allocate the
2640  * buffers of consistent memory, register the bus, request the IRQ line,
2641  * and call the driver's reset() and start() routines.
2642  */
2643 int usb_add_hcd(struct usb_hcd *hcd,
2644                 unsigned int irqnum, unsigned long irqflags)
2645 {
2646         int retval;
2647         struct usb_device *rhdev;
2648
2649         if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
2650                 hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
2651                 if (IS_ERR(hcd->phy_roothub))
2652                         return PTR_ERR(hcd->phy_roothub);
2653
2654                 retval = usb_phy_roothub_init(hcd->phy_roothub);
2655                 if (retval)
2656                         return retval;
2657
2658                 retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2659                                                   PHY_MODE_USB_HOST_SS);
2660                 if (retval)
2661                         retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2662                                                           PHY_MODE_USB_HOST);
2663                 if (retval)
2664                         goto err_usb_phy_roothub_power_on;
2665
2666                 retval = usb_phy_roothub_power_on(hcd->phy_roothub);
2667                 if (retval)
2668                         goto err_usb_phy_roothub_power_on;
2669         }
2670
2671         dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2672
2673         switch (authorized_default) {
2674         case USB_AUTHORIZE_NONE:
2675                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_NONE;
2676                 break;
2677
2678         case USB_AUTHORIZE_ALL:
2679                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_ALL;
2680                 break;
2681
2682         case USB_AUTHORIZE_INTERNAL:
2683                 hcd->dev_policy = USB_DEVICE_AUTHORIZE_INTERNAL;
2684                 break;
2685
2686         case USB_AUTHORIZE_WIRED:
2687         default:
2688                 hcd->dev_policy = hcd->wireless ?
2689                         USB_DEVICE_AUTHORIZE_NONE : USB_DEVICE_AUTHORIZE_ALL;
2690                 break;
2691         }
2692
2693         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2694
2695         /* per default all interfaces are authorized */
2696         set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
2697
2698         /* HC is in reset state, but accessible.  Now do the one-time init,
2699          * bottom up so that hcds can customize the root hubs before hub_wq
2700          * starts talking to them.  (Note, bus id is assigned early too.)
2701          */
2702         retval = hcd_buffer_create(hcd);
2703         if (retval != 0) {
2704                 dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
2705                 goto err_create_buf;
2706         }
2707
2708         retval = usb_register_bus(&hcd->self);
2709         if (retval < 0)
2710                 goto err_register_bus;
2711
2712         rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
2713         if (rhdev == NULL) {
2714                 dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
2715                 retval = -ENOMEM;
2716                 goto err_allocate_root_hub;
2717         }
2718         mutex_lock(&usb_port_peer_mutex);
2719         hcd->self.root_hub = rhdev;
2720         mutex_unlock(&usb_port_peer_mutex);
2721
2722         rhdev->rx_lanes = 1;
2723         rhdev->tx_lanes = 1;
2724
2725         switch (hcd->speed) {
2726         case HCD_USB11:
2727                 rhdev->speed = USB_SPEED_FULL;
2728                 break;
2729         case HCD_USB2:
2730                 rhdev->speed = USB_SPEED_HIGH;
2731                 break;
2732         case HCD_USB25:
2733                 rhdev->speed = USB_SPEED_WIRELESS;
2734                 break;
2735         case HCD_USB3:
2736                 rhdev->speed = USB_SPEED_SUPER;
2737                 break;
2738         case HCD_USB32:
2739                 rhdev->rx_lanes = 2;
2740                 rhdev->tx_lanes = 2;
2741                 fallthrough;
2742         case HCD_USB31:
2743                 rhdev->speed = USB_SPEED_SUPER_PLUS;
2744                 break;
2745         default:
2746                 retval = -EINVAL;
2747                 goto err_set_rh_speed;
2748         }
2749
2750         /* wakeup flag init defaults to "everything works" for root hubs,
2751          * but drivers can override it in reset() if needed, along with
2752          * recording the overall controller's system wakeup capability.
2753          */
2754         device_set_wakeup_capable(&rhdev->dev, 1);
2755
2756         /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2757          * registered.  But since the controller can die at any time,
2758          * let's initialize the flag before touching the hardware.
2759          */
2760         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2761
2762         /* "reset" is misnamed; its role is now one-time init. the controller
2763          * should already have been reset (and boot firmware kicked off etc).
2764          */
2765         if (hcd->driver->reset) {
2766                 retval = hcd->driver->reset(hcd);
2767                 if (retval < 0) {
2768                         dev_err(hcd->self.controller, "can't setup: %d\n",
2769                                         retval);
2770                         goto err_hcd_driver_setup;
2771                 }
2772         }
2773         hcd->rh_pollable = 1;
2774
2775         retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
2776         if (retval)
2777                 goto err_hcd_driver_setup;
2778
2779         /* NOTE: root hub and controller capabilities may not be the same */
2780         if (device_can_wakeup(hcd->self.controller)
2781                         && device_can_wakeup(&hcd->self.root_hub->dev))
2782                 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2783
2784         /* initialize tasklets */
2785         init_giveback_urb_bh(&hcd->high_prio_bh);
2786         init_giveback_urb_bh(&hcd->low_prio_bh);
2787
2788         /* enable irqs just before we start the controller,
2789          * if the BIOS provides legacy PCI irqs.
2790          */
2791         if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2792                 retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2793                 if (retval)
2794                         goto err_request_irq;
2795         }
2796
2797         hcd->state = HC_STATE_RUNNING;
2798         retval = hcd->driver->start(hcd);
2799         if (retval < 0) {
2800                 dev_err(hcd->self.controller, "startup error %d\n", retval);
2801                 goto err_hcd_driver_start;
2802         }
2803
2804         /* starting here, usbcore will pay attention to this root hub */
2805         retval = register_root_hub(hcd);
2806         if (retval != 0)
2807                 goto err_register_root_hub;
2808
2809         if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2810                 usb_hcd_poll_rh_status(hcd);
2811
2812         return retval;
2813
2814 err_register_root_hub:
2815         hcd->rh_pollable = 0;
2816         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2817         del_timer_sync(&hcd->rh_timer);
2818         hcd->driver->stop(hcd);
2819         hcd->state = HC_STATE_HALT;
2820         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2821         del_timer_sync(&hcd->rh_timer);
2822 err_hcd_driver_start:
2823         if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2824                 free_irq(irqnum, hcd);
2825 err_request_irq:
2826 err_hcd_driver_setup:
2827 err_set_rh_speed:
2828         usb_put_invalidate_rhdev(hcd);
2829 err_allocate_root_hub:
2830         usb_deregister_bus(&hcd->self);
2831 err_register_bus:
2832         hcd_buffer_destroy(hcd);
2833 err_create_buf:
2834         usb_phy_roothub_power_off(hcd->phy_roothub);
2835 err_usb_phy_roothub_power_on:
2836         usb_phy_roothub_exit(hcd->phy_roothub);
2837
2838         return retval;
2839 }
2840 EXPORT_SYMBOL_GPL(usb_add_hcd);
2841
2842 /**
2843  * usb_remove_hcd - shutdown processing for generic HCDs
2844  * @hcd: the usb_hcd structure to remove
2845  *
2846  * Context: task context, might sleep.
2847  *
2848  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2849  * invoking the HCD's stop() method.
2850  */
2851 void usb_remove_hcd(struct usb_hcd *hcd)
2852 {
2853         struct usb_device *rhdev = hcd->self.root_hub;
2854
2855         dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2856
2857         usb_get_dev(rhdev);
2858         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2859         if (HC_IS_RUNNING (hcd->state))
2860                 hcd->state = HC_STATE_QUIESCING;
2861
2862         dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2863         spin_lock_irq (&hcd_root_hub_lock);
2864         hcd->rh_registered = 0;
2865         spin_unlock_irq (&hcd_root_hub_lock);
2866
2867 #ifdef CONFIG_PM
2868         cancel_work_sync(&hcd->wakeup_work);
2869 #endif
2870         cancel_work_sync(&hcd->died_work);
2871
2872         mutex_lock(&usb_bus_idr_lock);
2873         usb_disconnect(&rhdev);         /* Sets rhdev to NULL */
2874         mutex_unlock(&usb_bus_idr_lock);
2875
2876         /*
2877          * tasklet_kill() isn't needed here because:
2878          * - driver's disconnect() called from usb_disconnect() should
2879          *   make sure its URBs are completed during the disconnect()
2880          *   callback
2881          *
2882          * - it is too late to run complete() here since driver may have
2883          *   been removed already now
2884          */
2885
2886         /* Prevent any more root-hub status calls from the timer.
2887          * The HCD might still restart the timer (if a port status change
2888          * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2889          * the hub_status_data() callback.
2890          */
2891         hcd->rh_pollable = 0;
2892         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2893         del_timer_sync(&hcd->rh_timer);
2894
2895         hcd->driver->stop(hcd);
2896         hcd->state = HC_STATE_HALT;
2897
2898         /* In case the HCD restarted the timer, stop it again. */
2899         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2900         del_timer_sync(&hcd->rh_timer);
2901
2902         if (usb_hcd_is_primary_hcd(hcd)) {
2903                 if (hcd->irq > 0)
2904                         free_irq(hcd->irq, hcd);
2905         }
2906
2907         usb_deregister_bus(&hcd->self);
2908         hcd_buffer_destroy(hcd);
2909
2910         usb_phy_roothub_power_off(hcd->phy_roothub);
2911         usb_phy_roothub_exit(hcd->phy_roothub);
2912
2913         usb_put_invalidate_rhdev(hcd);
2914         hcd->flags = 0;
2915 }
2916 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2917
2918 void
2919 usb_hcd_platform_shutdown(struct platform_device *dev)
2920 {
2921         struct usb_hcd *hcd = platform_get_drvdata(dev);
2922
2923         /* No need for pm_runtime_put(), we're shutting down */
2924         pm_runtime_get_sync(&dev->dev);
2925
2926         if (hcd->driver->shutdown)
2927                 hcd->driver->shutdown(hcd);
2928 }
2929 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2930
2931 int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
2932                             dma_addr_t dma, size_t size)
2933 {
2934         int err;
2935         void *local_mem;
2936
2937         hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
2938                                                   dev_to_node(hcd->self.sysdev),
2939                                                   dev_name(hcd->self.sysdev));
2940         if (IS_ERR(hcd->localmem_pool))
2941                 return PTR_ERR(hcd->localmem_pool);
2942
2943         local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
2944                                   size, MEMREMAP_WC);
2945         if (IS_ERR(local_mem))
2946                 return PTR_ERR(local_mem);
2947
2948         /*
2949          * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
2950          * It's not backed by system memory and thus there's no kernel mapping
2951          * for it.
2952          */
2953         err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
2954                                 dma, size, dev_to_node(hcd->self.sysdev));
2955         if (err < 0) {
2956                 dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
2957                         err);
2958                 return err;
2959         }
2960
2961         return 0;
2962 }
2963 EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
2964
2965 /*-------------------------------------------------------------------------*/
2966
2967 #if IS_ENABLED(CONFIG_USB_MON)
2968
2969 const struct usb_mon_operations *mon_ops;
2970
2971 /*
2972  * The registration is unlocked.
2973  * We do it this way because we do not want to lock in hot paths.
2974  *
2975  * Notice that the code is minimally error-proof. Because usbmon needs
2976  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2977  */
2978
2979 int usb_mon_register(const struct usb_mon_operations *ops)
2980 {
2981
2982         if (mon_ops)
2983                 return -EBUSY;
2984
2985         mon_ops = ops;
2986         mb();
2987         return 0;
2988 }
2989 EXPORT_SYMBOL_GPL (usb_mon_register);
2990
2991 void usb_mon_deregister (void)
2992 {
2993
2994         if (mon_ops == NULL) {
2995                 printk(KERN_ERR "USB: monitor was not registered\n");
2996                 return;
2997         }
2998         mon_ops = NULL;
2999         mb();
3000 }
3001 EXPORT_SYMBOL_GPL (usb_mon_deregister);
3002
3003 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */