kernel/drivers/usb/core/hcd.c

   1 /*
   2  * (C) Copyright Linus Torvalds 1999
   3  * (C) Copyright Johannes Erdfelt 1999-2001
   4  * (C) Copyright Andreas Gal 1999
   5  * (C) Copyright Gregory P. Smith 1999
   6  * (C) Copyright Deti Fliegl 1999
   7  * (C) Copyright Randy Dunlap 2000
   8  * (C) Copyright David Brownell 2000-2002
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the
  12  * Free Software Foundation; either version 2 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  * for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/bcd.h>
  26 #include <linux/module.h>
  27 #include <linux/version.h>
  28 #include <linux/kernel.h>
  29 #include <linux/slab.h>
  30 #include <linux/completion.h>
  31 #include <linux/utsname.h>
  32 #include <linux/mm.h>
  33 #include <asm/io.h>
  34 #include <linux/device.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/mutex.h>
  37 #include <asm/irq.h>
  38 #include <asm/byteorder.h>
  39 #include <asm/unaligned.h>
  40 #include <linux/platform_device.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/pm_runtime.h>
  43 #include <linux/types.h>
  44
  45 #include <linux/phy/phy.h>
  46 #include <linux/usb.h>
  47 #include <linux/usb/hcd.h>
  48 #include <linux/usb/phy.h>
  49
  50 #include "usb.h"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * USB Host Controller Driver framework
  57  *
  58  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
  59  * HCD-specific behaviors/bugs.
  60  *
  61  * This does error checks, tracks devices and urbs, and delegates to a
  62  * "hc_driver" only for code (and data) that really needs to know about
  63  * hardware differences.  That includes root hub registers, i/o queues,
  64  * and so on ... but as little else as possible.
  65  *
  66  * Shared code includes most of the "root hub" code (these are emulated,
  67  * though each HC's hardware works differently) and PCI glue, plus request
  68  * tracking overhead.  The HCD code should only block on spinlocks or on
  69  * hardware handshaking; blocking on software events (such as other kernel
  70  * threads releasing resources, or completing actions) is all generic.
  71  *
  72  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
  73  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
  74  * only by the hub driver ... and that neither should be seen or used by
  75  * usb client device drivers.
  76  *
  77  * Contributors of ideas or unattributed patches include: David Brownell,
  78  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
  79  *
  80  * HISTORY:
  81  * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
  82  *              associated cleanup.  "usb_hcd" still != "usb_bus".
  83  * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
  84  */
  85
  86 /*-------------------------------------------------------------------------*/
  87
  88 /* Keep track of which host controller drivers are loaded */
  89 unsigned long usb_hcds_loaded;
  90 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
  91
  92 /* host controllers we manage */
  93 LIST_HEAD (usb_bus_list);
  94 EXPORT_SYMBOL_GPL (usb_bus_list);
  95
  96 /* used when allocating bus numbers */
  97 #define USB_MAXBUS              64
  98 static DECLARE_BITMAP(busmap, USB_MAXBUS);
  99
 100 /* used when updating list of hcds */
 101 DEFINE_MUTEX(usb_bus_list_lock);        /* exported only for usbfs */
 102 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
 103
 104 /* used for controlling access to virtual root hubs */
 105 static DEFINE_SPINLOCK(hcd_root_hub_lock);
 106
 107 /* used when updating an endpoint's URB list */
 108 static DEFINE_SPINLOCK(hcd_urb_list_lock);
 109
 110 /* used to protect against unlinking URBs after the device is gone */
 111 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
 112
 113 /* wait queue for synchronous unlinks */
 114 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 115
 116 static inline int is_root_hub(struct usb_device *udev)
 117 {
 118         return (udev->parent == NULL);
 119 }
 120
 121 /*-------------------------------------------------------------------------*/
 122
 123 /*
 124  * Sharable chunks of root hub code.
 125  */
 126
 127 /*-------------------------------------------------------------------------*/
 128 #define KERNEL_REL      bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
 129 #define KERNEL_VER      bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
 130
 131 /* usb 3.0 root hub device descriptor */
 132 static const u8 usb3_rh_dev_descriptor[18] = {
 133         0x12,       /*  __u8  bLength; */
 134         0x01,       /*  __u8  bDescriptorType; Device */
 135         0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
 136
 137         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 138         0x00,       /*  __u8  bDeviceSubClass; */
 139         0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
 140         0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
 141
 142         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 143         0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
 144         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 145
 146         0x03,       /*  __u8  iManufacturer; */
 147         0x02,       /*  __u8  iProduct; */
 148         0x01,       /*  __u8  iSerialNumber; */
 149         0x01        /*  __u8  bNumConfigurations; */
 150 };
 151
 152 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
 153 static const u8 usb25_rh_dev_descriptor[18] = {
 154         0x12,       /*  __u8  bLength; */
 155         0x01,       /*  __u8  bDescriptorType; Device */
 156         0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
 157
 158         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 159         0x00,       /*  __u8  bDeviceSubClass; */
 160         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
 161         0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
 162
 163         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 164         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
 165         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 166
 167         0x03,       /*  __u8  iManufacturer; */
 168         0x02,       /*  __u8  iProduct; */
 169         0x01,       /*  __u8  iSerialNumber; */
 170         0x01        /*  __u8  bNumConfigurations; */
 171 };
 172
 173 /* usb 2.0 root hub device descriptor */
 174 static const u8 usb2_rh_dev_descriptor[18] = {
 175         0x12,       /*  __u8  bLength; */
 176         0x01,       /*  __u8  bDescriptorType; Device */
 177         0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
 178
 179         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 180         0x00,       /*  __u8  bDeviceSubClass; */
 181         0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
 182         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 183
 184         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 185         0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
 186         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 187
 188         0x03,       /*  __u8  iManufacturer; */
 189         0x02,       /*  __u8  iProduct; */
 190         0x01,       /*  __u8  iSerialNumber; */
 191         0x01        /*  __u8  bNumConfigurations; */
 192 };
 193
 194 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
 195
 196 /* usb 1.1 root hub device descriptor */
 197 static const u8 usb11_rh_dev_descriptor[18] = {
 198         0x12,       /*  __u8  bLength; */
 199         0x01,       /*  __u8  bDescriptorType; Device */
 200         0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
 201
 202         0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 203         0x00,       /*  __u8  bDeviceSubClass; */
 204         0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
 205         0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 206
 207         0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 208         0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
 209         KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 210
 211         0x03,       /*  __u8  iManufacturer; */
 212         0x02,       /*  __u8  iProduct; */
 213         0x01,       /*  __u8  iSerialNumber; */
 214         0x01        /*  __u8  bNumConfigurations; */
 215 };
 216
 217
 218 /*-------------------------------------------------------------------------*/
 219
 220 /* Configuration descriptors for our root hubs */
 221
 222 static const u8 fs_rh_config_descriptor[] = {
 223
 224         /* one configuration */
 225         0x09,       /*  __u8  bLength; */
 226         0x02,       /*  __u8  bDescriptorType; Configuration */
 227         0x19, 0x00, /*  __le16 wTotalLength; */
 228         0x01,       /*  __u8  bNumInterfaces; (1) */
 229         0x01,       /*  __u8  bConfigurationValue; */
 230         0x00,       /*  __u8  iConfiguration; */
 231         0xc0,       /*  __u8  bmAttributes;
 232                                  Bit 7: must be set,
 233                                      6: Self-powered,
 234                                      5: Remote wakeup,
 235                                      4..0: resvd */
 236         0x00,       /*  __u8  MaxPower; */
 237
 238         /* USB 1.1:
 239          * USB 2.0, single TT organization (mandatory):
 240          *      one interface, protocol 0
 241          *
 242          * USB 2.0, multiple TT organization (optional):
 243          *      two interfaces, protocols 1 (like single TT)
 244          *      and 2 (multiple TT mode) ... config is
 245          *      sometimes settable
 246          *      NOT IMPLEMENTED
 247          */
 248
 249         /* one interface */
 250         0x09,       /*  __u8  if_bLength; */
 251         0x04,       /*  __u8  if_bDescriptorType; Interface */
 252         0x00,       /*  __u8  if_bInterfaceNumber; */
 253         0x00,       /*  __u8  if_bAlternateSetting; */
 254         0x01,       /*  __u8  if_bNumEndpoints; */
 255         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 256         0x00,       /*  __u8  if_bInterfaceSubClass; */
 257         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 258         0x00,       /*  __u8  if_iInterface; */
 259
 260         /* one endpoint (status change endpoint) */
 261         0x07,       /*  __u8  ep_bLength; */
 262         0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
 263         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 264         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 265         0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
 266         0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
 267 };
 268
 269 static const u8 hs_rh_config_descriptor[] = {
 270
 271         /* one configuration */
 272         0x09,       /*  __u8  bLength; */
 273         0x02,       /*  __u8  bDescriptorType; Configuration */
 274         0x19, 0x00, /*  __le16 wTotalLength; */
 275         0x01,       /*  __u8  bNumInterfaces; (1) */
 276         0x01,       /*  __u8  bConfigurationValue; */
 277         0x00,       /*  __u8  iConfiguration; */
 278         0xc0,       /*  __u8  bmAttributes;
 279                                  Bit 7: must be set,
 280                                      6: Self-powered,
 281                                      5: Remote wakeup,
 282                                      4..0: resvd */
 283         0x00,       /*  __u8  MaxPower; */
 284
 285         /* USB 1.1:
 286          * USB 2.0, single TT organization (mandatory):
 287          *      one interface, protocol 0
 288          *
 289          * USB 2.0, multiple TT organization (optional):
 290          *      two interfaces, protocols 1 (like single TT)
 291          *      and 2 (multiple TT mode) ... config is
 292          *      sometimes settable
 293          *      NOT IMPLEMENTED
 294          */
 295
 296         /* one interface */
 297         0x09,       /*  __u8  if_bLength; */
 298         0x04,       /*  __u8  if_bDescriptorType; Interface */
 299         0x00,       /*  __u8  if_bInterfaceNumber; */
 300         0x00,       /*  __u8  if_bAlternateSetting; */
 301         0x01,       /*  __u8  if_bNumEndpoints; */
 302         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 303         0x00,       /*  __u8  if_bInterfaceSubClass; */
 304         0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 305         0x00,       /*  __u8  if_iInterface; */
 306
 307         /* one endpoint (status change endpoint) */
 308         0x07,       /*  __u8  ep_bLength; */
 309         0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
 310         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 311         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 312                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
 313                      * see hub.c:hub_configure() for details. */
 314         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
 315         0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 316 };
 317
 318 static const u8 ss_rh_config_descriptor[] = {
 319         /* one configuration */
 320         0x09,       /*  __u8  bLength; */
 321         0x02,       /*  __u8  bDescriptorType; Configuration */
 322         0x1f, 0x00, /*  __le16 wTotalLength; */
 323         0x01,       /*  __u8  bNumInterfaces; (1) */
 324         0x01,       /*  __u8  bConfigurationValue; */
 325         0x00,       /*  __u8  iConfiguration; */
 326         0xc0,       /*  __u8  bmAttributes;
 327                                  Bit 7: must be set,
 328                                      6: Self-powered,
 329                                      5: Remote wakeup,
 330                                      4..0: resvd */
 331         0x00,       /*  __u8  MaxPower; */
 332
 333         /* one interface */
 334         0x09,       /*  __u8  if_bLength; */
 335         0x04,       /*  __u8  if_bDescriptorType; Interface */
 336         0x00,       /*  __u8  if_bInterfaceNumber; */
 337         0x00,       /*  __u8  if_bAlternateSetting; */
 338         0x01,       /*  __u8  if_bNumEndpoints; */
 339         0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 340         0x00,       /*  __u8  if_bInterfaceSubClass; */
 341         0x00,       /*  __u8  if_bInterfaceProtocol; */
 342         0x00,       /*  __u8  if_iInterface; */
 343
 344         /* one endpoint (status change endpoint) */
 345         0x07,       /*  __u8  ep_bLength; */
 346         0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
 347         0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 348         0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 349                     /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
 350                      * see hub.c:hub_configure() for details. */
 351         (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
 352         0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 353
 354         /* one SuperSpeed endpoint companion descriptor */
 355         0x06,        /* __u8 ss_bLength */
 356         0x30,        /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
 357         0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
 358         0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
 359         0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
 360 };
 361
 362 /* authorized_default behaviour:
 363  * -1 is authorized for all devices except wireless (old behaviour)
 364  * 0 is unauthorized for all devices
 365  * 1 is authorized for all devices
 366  */
 367 static int authorized_default = -1;
 368 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
 369 MODULE_PARM_DESC(authorized_default,
 370                 "Default USB device authorization: 0 is not authorized, 1 is "
 371                 "authorized, -1 is authorized except for wireless USB (default, "
 372                 "old behaviour");
 373 /*-------------------------------------------------------------------------*/
 374
 375 /**
 376  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
 377  * @s: Null-terminated ASCII (actually ISO-8859-1) string
 378  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
 379  * @len: Length (in bytes; may be odd) of descriptor buffer.
 380  *
 381  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
 382  * whichever is less.
 383  *
 384  * Note:
 385  * USB String descriptors can contain at most 126 characters; input
 386  * strings longer than that are truncated.
 387  */
 388 static unsigned
 389 ascii2desc(char const *s, u8 *buf, unsigned len)
 390 {
 391         unsigned n, t = 2 + 2*strlen(s);
 392
 393         if (t > 254)
 394                 t = 254;        /* Longest possible UTF string descriptor */
 395         if (len > t)
 396                 len = t;
 397
 398         t += USB_DT_STRING << 8;        /* Now t is first 16 bits to store */
 399
 400         n = len;
 401         while (n--) {
 402                 *buf++ = t;
 403                 if (!n--)
 404                         break;
 405                 *buf++ = t >> 8;
 406                 t = (unsigned char)*s++;
 407         }
 408         return len;
 409 }
 410
 411 /**
 412  * rh_string() - provides string descriptors for root hub
 413  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
 414  * @hcd: the host controller for this root hub
 415  * @data: buffer for output packet
 416  * @len: length of the provided buffer
 417  *
 418  * Produces either a manufacturer, product or serial number string for the
 419  * virtual root hub device.
 420  *
 421  * Return: The number of bytes filled in: the length of the descriptor or
 422  * of the provided buffer, whichever is less.
 423  */
 424 static unsigned
 425 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
 426 {
 427         char buf[100];
 428         char const *s;
 429         static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
 430
 431         /* language ids */
 432         switch (id) {
 433         case 0:
 434                 /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
 435                 /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
 436                 if (len > 4)
 437                         len = 4;
 438                 memcpy(data, langids, len);
 439                 return len;
 440         case 1:
 441                 /* Serial number */
 442                 s = hcd->self.bus_name;
 443                 break;
 444         case 2:
 445                 /* Product name */
 446                 s = hcd->product_desc;
 447                 break;
 448         case 3:
 449                 /* Manufacturer */
 450                 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
 451                         init_utsname()->release, hcd->driver->description);
 452                 s = buf;
 453                 break;
 454         default:
 455                 /* Can't happen; caller guarantees it */
 456                 return 0;
 457         }
 458
 459         return ascii2desc(s, data, len);
 460 }
 461
 462
 463 /* Root hub control transfers execute synchronously */
 464 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
 465 {
 466         struct usb_ctrlrequest *cmd;
 467         u16             typeReq, wValue, wIndex, wLength;
 468         u8              *ubuf = urb->transfer_buffer;
 469         unsigned        len = 0;
 470         int             status;
 471         u8              patch_wakeup = 0;
 472         u8              patch_protocol = 0;
 473         u16             tbuf_size;
 474         u8              *tbuf = NULL;
 475         const u8        *bufp;
 476
 477         might_sleep();
 478
 479         spin_lock_irq(&hcd_root_hub_lock);
 480         status = usb_hcd_link_urb_to_ep(hcd, urb);
 481         spin_unlock_irq(&hcd_root_hub_lock);
 482         if (status)
 483                 return status;
 484         urb->hcpriv = hcd;      /* Indicate it's queued */
 485
 486         cmd = (struct usb_ctrlrequest *) urb->setup_packet;
 487         typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
 488         wValue   = le16_to_cpu (cmd->wValue);
 489         wIndex   = le16_to_cpu (cmd->wIndex);
 490         wLength  = le16_to_cpu (cmd->wLength);
 491
 492         if (wLength > urb->transfer_buffer_length)
 493                 goto error;
 494
 495         /*
 496          * tbuf should be at least as big as the
 497          * USB hub descriptor.
 498          */
 499         tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
 500         tbuf = kzalloc(tbuf_size, GFP_KERNEL);
 501         if (!tbuf)
 502                 return -ENOMEM;
 503
 504         bufp = tbuf;
 505
 506
 507         urb->actual_length = 0;
 508         switch (typeReq) {
 509
 510         /* DEVICE REQUESTS */
 511
 512         /* The root hub's remote wakeup enable bit is implemented using
 513          * driver model wakeup flags.  If this system supports wakeup
 514          * through USB, userspace may change the default "allow wakeup"
 515          * policy through sysfs or these calls.
 516          *
 517          * Most root hubs support wakeup from downstream devices, for
 518          * runtime power management (disabling USB clocks and reducing
 519          * VBUS power usage).  However, not all of them do so; silicon,
 520          * board, and BIOS bugs here are not uncommon, so these can't
 521          * be treated quite like external hubs.
 522          *
 523          * Likewise, not all root hubs will pass wakeup events upstream,
 524          * to wake up the whole system.  So don't assume root hub and
 525          * controller capabilities are identical.
 526          */
 527
 528         case DeviceRequest | USB_REQ_GET_STATUS:
 529                 tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
 530                                         << USB_DEVICE_REMOTE_WAKEUP)
 531                                 | (1 << USB_DEVICE_SELF_POWERED);
 532                 tbuf[1] = 0;
 533                 len = 2;
 534                 break;
 535         case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
 536                 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
 537                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
 538                 else
 539                         goto error;
 540                 break;
 541         case DeviceOutRequest | USB_REQ_SET_FEATURE:
 542                 if (device_can_wakeup(&hcd->self.root_hub->dev)
 543                                 && wValue == USB_DEVICE_REMOTE_WAKEUP)
 544                         device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
 545                 else
 546                         goto error;
 547                 break;
 548         case DeviceRequest | USB_REQ_GET_CONFIGURATION:
 549                 tbuf[0] = 1;
 550                 len = 1;
 551                         /* FALLTHROUGH */
 552         case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
 553                 break;
 554         case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
 555                 switch (wValue & 0xff00) {
 556                 case USB_DT_DEVICE << 8:
 557                         switch (hcd->speed) {
 558                         case HCD_USB3:
 559                                 bufp = usb3_rh_dev_descriptor;
 560                                 break;
 561                         case HCD_USB25:
 562                                 bufp = usb25_rh_dev_descriptor;
 563                                 break;
 564                         case HCD_USB2:
 565                                 bufp = usb2_rh_dev_descriptor;
 566                                 break;
 567                         case HCD_USB11:
 568                                 bufp = usb11_rh_dev_descriptor;
 569                                 break;
 570                         default:
 571                                 goto error;
 572                         }
 573                         len = 18;
 574                         if (hcd->has_tt)
 575                                 patch_protocol = 1;
 576                         break;
 577                 case USB_DT_CONFIG << 8:
 578                         switch (hcd->speed) {
 579                         case HCD_USB3:
 580                                 bufp = ss_rh_config_descriptor;
 581                                 len = sizeof ss_rh_config_descriptor;
 582                                 break;
 583                         case HCD_USB25:
 584                         case HCD_USB2:
 585                                 bufp = hs_rh_config_descriptor;
 586                                 len = sizeof hs_rh_config_descriptor;
 587                                 break;
 588                         case HCD_USB11:
 589                                 bufp = fs_rh_config_descriptor;
 590                                 len = sizeof fs_rh_config_descriptor;
 591                                 break;
 592                         default:
 593                                 goto error;
 594                         }
 595                         if (device_can_wakeup(&hcd->self.root_hub->dev))
 596                                 patch_wakeup = 1;
 597                         break;
 598                 case USB_DT_STRING << 8:
 599                         if ((wValue & 0xff) < 4)
 600                                 urb->actual_length = rh_string(wValue & 0xff,
 601                                                 hcd, ubuf, wLength);
 602                         else /* unsupported IDs --> "protocol stall" */
 603                                 goto error;
 604                         break;
 605                 case USB_DT_BOS << 8:
 606                         goto nongeneric;
 607                 default:
 608                         goto error;
 609                 }
 610                 break;
 611         case DeviceRequest | USB_REQ_GET_INTERFACE:
 612                 tbuf[0] = 0;
 613                 len = 1;
 614                         /* FALLTHROUGH */
 615         case DeviceOutRequest | USB_REQ_SET_INTERFACE:
 616                 break;
 617         case DeviceOutRequest | USB_REQ_SET_ADDRESS:
 618                 /* wValue == urb->dev->devaddr */
 619                 dev_dbg (hcd->self.controller, "root hub device address %d\n",
 620                         wValue);
 621                 break;
 622
 623         /* INTERFACE REQUESTS (no defined feature/status flags) */
 624
 625         /* ENDPOINT REQUESTS */
 626
 627         case EndpointRequest | USB_REQ_GET_STATUS:
 628                 /* ENDPOINT_HALT flag */
 629                 tbuf[0] = 0;
 630                 tbuf[1] = 0;
 631                 len = 2;
 632                         /* FALLTHROUGH */
 633         case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
 634         case EndpointOutRequest | USB_REQ_SET_FEATURE:
 635                 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
 636                 break;
 637
 638         /* CLASS REQUESTS (and errors) */
 639
 640         default:
 641 nongeneric:
 642                 /* non-generic request */
 643                 switch (typeReq) {
 644                 case GetHubStatus:
 645                 case GetPortStatus:
 646                         len = 4;
 647                         break;
 648                 case GetHubDescriptor:
 649                         len = sizeof (struct usb_hub_descriptor);
 650                         break;
 651                 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
 652                         /* len is returned by hub_control */
 653                         break;
 654                 }
 655                 status = hcd->driver->hub_control (hcd,
 656                         typeReq, wValue, wIndex,
 657                         tbuf, wLength);
 658
 659                 if (typeReq == GetHubDescriptor)
 660                         usb_hub_adjust_deviceremovable(hcd->self.root_hub,
 661                                 (struct usb_hub_descriptor *)tbuf);
 662                 break;
 663 error:
 664                 /* "protocol stall" on error */
 665                 status = -EPIPE;
 666         }
 667
 668         if (status < 0) {
 669                 len = 0;
 670                 if (status != -EPIPE) {
 671                         dev_dbg (hcd->self.controller,
 672                                 "CTRL: TypeReq=0x%x val=0x%x "
 673                                 "idx=0x%x len=%d ==> %d\n",
 674                                 typeReq, wValue, wIndex,
 675                                 wLength, status);
 676                 }
 677         } else if (status > 0) {
 678                 /* hub_control may return the length of data copied. */
 679                 len = status;
 680                 status = 0;
 681         }
 682         if (len) {
 683                 if (urb->transfer_buffer_length < len)
 684                         len = urb->transfer_buffer_length;
 685                 urb->actual_length = len;
 686                 /* always USB_DIR_IN, toward host */
 687                 memcpy (ubuf, bufp, len);
 688
 689                 /* report whether RH hardware supports remote wakeup */
 690                 if (patch_wakeup &&
 691                                 len > offsetof (struct usb_config_descriptor,
 692                                                 bmAttributes))
 693                         ((struct usb_config_descriptor *)ubuf)->bmAttributes
 694                                 |= USB_CONFIG_ATT_WAKEUP;
 695
 696                 /* report whether RH hardware has an integrated TT */
 697                 if (patch_protocol &&
 698                                 len > offsetof(struct usb_device_descriptor,
 699                                                 bDeviceProtocol))
 700                         ((struct usb_device_descriptor *) ubuf)->
 701                                 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
 702         }
 703
 704         kfree(tbuf);
 705
 706         /* any errors get returned through the urb completion */
 707         spin_lock_irq(&hcd_root_hub_lock);
 708         usb_hcd_unlink_urb_from_ep(hcd, urb);
 709         usb_hcd_giveback_urb(hcd, urb, status);
 710         spin_unlock_irq(&hcd_root_hub_lock);
 711         return 0;
 712 }
 713
 714 /*-------------------------------------------------------------------------*/
 715
 716 /*
 717  * Root Hub interrupt transfers are polled using a timer if the
 718  * driver requests it; otherwise the driver is responsible for
 719  * calling usb_hcd_poll_rh_status() when an event occurs.
 720  *
 721  * Completions are called in_interrupt(), but they may or may not
 722  * be in_irq().
 723  */
 724 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 725 {
 726         struct urb      *urb;
 727         int             length;
 728         unsigned long   flags;
 729         char            buffer[6];      /* Any root hubs with > 31 ports? */
 730
 731         if (unlikely(!hcd->rh_pollable))
 732                 return;
 733         if (!hcd->uses_new_polling && !hcd->status_urb)
 734                 return;
 735
 736         length = hcd->driver->hub_status_data(hcd, buffer);
 737         if (length > 0) {
 738
 739                 /* try to complete the status urb */
 740                 spin_lock_irqsave(&hcd_root_hub_lock, flags);
 741                 urb = hcd->status_urb;
 742                 if (urb) {
 743                         clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 744                         hcd->status_urb = NULL;
 745                         urb->actual_length = length;
 746                         memcpy(urb->transfer_buffer, buffer, length);
 747
 748                         usb_hcd_unlink_urb_from_ep(hcd, urb);
 749                         usb_hcd_giveback_urb(hcd, urb, 0);
 750                 } else {
 751                         length = 0;
 752                         set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 753                 }
 754                 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 755         }
 756
 757         /* The USB 2.0 spec says 256 ms.  This is close enough and won't
 758          * exceed that limit if HZ is 100. The math is more clunky than
 759          * maybe expected, this is to make sure that all timers for USB devices
 760          * fire at the same time to give the CPU a break in between */
 761         if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
 762                         (length == 0 && hcd->status_urb != NULL))
 763                 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 764 }
 765 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
 766
 767 /* timer callback */
 768 static void rh_timer_func (unsigned long _hcd)
 769 {
 770         usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
 771 }
 772
 773 /*-------------------------------------------------------------------------*/
 774
 775 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 776 {
 777         int             retval;
 778         unsigned long   flags;
 779         unsigned        len = 1 + (urb->dev->maxchild / 8);
 780
 781         spin_lock_irqsave (&hcd_root_hub_lock, flags);
 782         if (hcd->status_urb || urb->transfer_buffer_length < len) {
 783                 dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
 784                 retval = -EINVAL;
 785                 goto done;
 786         }
 787
 788         retval = usb_hcd_link_urb_to_ep(hcd, urb);
 789         if (retval)
 790                 goto done;
 791
 792         hcd->status_urb = urb;
 793         urb->hcpriv = hcd;      /* indicate it's queued */
 794         if (!hcd->uses_new_polling)
 795                 mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 796
 797         /* If a status change has already occurred, report it ASAP */
 798         else if (HCD_POLL_PENDING(hcd))
 799                 mod_timer(&hcd->rh_timer, jiffies);
 800         retval = 0;
 801  done:
 802         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
 803         return retval;
 804 }
 805
 806 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
 807 {
 808         if (usb_endpoint_xfer_int(&urb->ep->desc))
 809                 return rh_queue_status (hcd, urb);
 810         if (usb_endpoint_xfer_control(&urb->ep->desc))
 811                 return rh_call_control (hcd, urb);
 812         return -EINVAL;
 813 }
 814
 815 /*-------------------------------------------------------------------------*/
 816
 817 /* Unlinks of root-hub control URBs are legal, but they don't do anything
 818  * since these URBs always execute synchronously.
 819  */
 820 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 821 {
 822         unsigned long   flags;
 823         int             rc;
 824
 825         spin_lock_irqsave(&hcd_root_hub_lock, flags);
 826         rc = usb_hcd_check_unlink_urb(hcd, urb, status);
 827         if (rc)
 828                 goto done;
 829
 830         if (usb_endpoint_num(&urb->ep->desc) == 0) {    /* Control URB */
 831                 ;       /* Do nothing */
 832
 833         } else {                                /* Status URB */
 834                 if (!hcd->uses_new_polling)
 835                         del_timer (&hcd->rh_timer);
 836                 if (urb == hcd->status_urb) {
 837                         hcd->status_urb = NULL;
 838                         usb_hcd_unlink_urb_from_ep(hcd, urb);
 839                         usb_hcd_giveback_urb(hcd, urb, status);
 840                 }
 841         }
 842  done:
 843         spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 844         return rc;
 845 }
 846
 847
 848
 849 /*
 850  * Show & store the current value of authorized_default
 851  */
 852 static ssize_t authorized_default_show(struct device *dev,
 853                                        struct device_attribute *attr, char *buf)
 854 {
 855         struct usb_device *rh_usb_dev = to_usb_device(dev);
 856         struct usb_bus *usb_bus = rh_usb_dev->bus;
 857         struct usb_hcd *usb_hcd;
 858
 859         usb_hcd = bus_to_hcd(usb_bus);
 860         return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
 861 }
 862
 863 static ssize_t authorized_default_store(struct device *dev,
 864                                         struct device_attribute *attr,
 865                                         const char *buf, size_t size)
 866 {
 867         ssize_t result;
 868         unsigned val;
 869         struct usb_device *rh_usb_dev = to_usb_device(dev);
 870         struct usb_bus *usb_bus = rh_usb_dev->bus;
 871         struct usb_hcd *usb_hcd;
 872
 873         usb_hcd = bus_to_hcd(usb_bus);
 874         result = sscanf(buf, "%u\n", &val);
 875         if (result == 1) {
 876                 usb_hcd->authorized_default = val ? 1 : 0;
 877                 result = size;
 878         } else {
 879                 result = -EINVAL;
 880         }
 881         return result;
 882 }
 883 static DEVICE_ATTR_RW(authorized_default);
 884
 885 /* Group all the USB bus attributes */
 886 static struct attribute *usb_bus_attrs[] = {
 887                 &dev_attr_authorized_default.attr,
 888                 NULL,
 889 };
 890
 891 static struct attribute_group usb_bus_attr_group = {
 892         .name = NULL,   /* we want them in the same directory */
 893         .attrs = usb_bus_attrs,
 894 };
 895
 896
 897
 898 /*-------------------------------------------------------------------------*/
 899
 900 /**
 901  * usb_bus_init - shared initialization code
 902  * @bus: the bus structure being initialized
 903  *
 904  * This code is used to initialize a usb_bus structure, memory for which is
 905  * separately managed.
 906  */
 907 static void usb_bus_init (struct usb_bus *bus)
 908 {
 909         memset (&bus->devmap, 0, sizeof(struct usb_devmap));
 910
 911         bus->devnum_next = 1;
 912
 913         bus->root_hub = NULL;
 914         bus->busnum = -1;
 915         bus->bandwidth_allocated = 0;
 916         bus->bandwidth_int_reqs  = 0;
 917         bus->bandwidth_isoc_reqs = 0;
 918         mutex_init(&bus->usb_address0_mutex);
 919
 920         INIT_LIST_HEAD (&bus->bus_list);
 921 }
 922
 923 /*-------------------------------------------------------------------------*/
 924
 925 /**
 926  * usb_register_bus - registers the USB host controller with the usb core
 927  * @bus: pointer to the bus to register
 928  * Context: !in_interrupt()
 929  *
 930  * Assigns a bus number, and links the controller into usbcore data
 931  * structures so that it can be seen by scanning the bus list.
 932  *
 933  * Return: 0 if successful. A negative error code otherwise.
 934  */
 935 static int usb_register_bus(struct usb_bus *bus)
 936 {
 937         int result = -E2BIG;
 938         int busnum;
 939
 940         mutex_lock(&usb_bus_list_lock);
 941         busnum = find_next_zero_bit(busmap, USB_MAXBUS, 1);
 942         if (busnum >= USB_MAXBUS) {
 943                 printk (KERN_ERR "%s: too many buses\n", usbcore_name);
 944                 goto error_find_busnum;
 945         }
 946         set_bit(busnum, busmap);
 947         bus->busnum = busnum;
 948
 949         /* Add it to the local list of buses */
 950         list_add (&bus->bus_list, &usb_bus_list);
 951         mutex_unlock(&usb_bus_list_lock);
 952
 953         usb_notify_add_bus(bus);
 954
 955         dev_info (bus->controller, "new USB bus registered, assigned bus "
 956                   "number %d\n", bus->busnum);
 957         return 0;
 958
 959 error_find_busnum:
 960         mutex_unlock(&usb_bus_list_lock);
 961         return result;
 962 }
 963
 964 /**
 965  * usb_deregister_bus - deregisters the USB host controller
 966  * @bus: pointer to the bus to deregister
 967  * Context: !in_interrupt()
 968  *
 969  * Recycles the bus number, and unlinks the controller from usbcore data
 970  * structures so that it won't be seen by scanning the bus list.
 971  */
 972 static void usb_deregister_bus (struct usb_bus *bus)
 973 {
 974         dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
 975
 976         /*
 977          * NOTE: make sure that all the devices are removed by the
 978          * controller code, as well as having it call this when cleaning
 979          * itself up
 980          */
 981         mutex_lock(&usb_bus_list_lock);
 982         list_del (&bus->bus_list);
 983         mutex_unlock(&usb_bus_list_lock);
 984
 985         usb_notify_remove_bus(bus);
 986
 987         clear_bit(bus->busnum, busmap);
 988 }
 989
 990 /**
 991  * register_root_hub - called by usb_add_hcd() to register a root hub
 992  * @hcd: host controller for this root hub
 993  *
 994  * This function registers the root hub with the USB subsystem.  It sets up
 995  * the device properly in the device tree and then calls usb_new_device()
 996  * to register the usb device.  It also assigns the root hub's USB address
 997  * (always 1).
 998  *
 999  * Return: 0 if successful. A negative error code otherwise.
1000  */
1001 static int register_root_hub(struct usb_hcd *hcd)
1002 {
1003         struct device *parent_dev = hcd->self.controller;
1004         struct usb_device *usb_dev = hcd->self.root_hub;
1005         const int devnum = 1;
1006         int retval;
1007
1008         usb_dev->devnum = devnum;
1009         usb_dev->bus->devnum_next = devnum + 1;
1010         memset (&usb_dev->bus->devmap.devicemap, 0,
1011                         sizeof usb_dev->bus->devmap.devicemap);
1012         set_bit (devnum, usb_dev->bus->devmap.devicemap);
1013         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
1014
1015         mutex_lock(&usb_bus_list_lock);
1016
1017         usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
1018         retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
1019         if (retval != sizeof usb_dev->descriptor) {
1020                 mutex_unlock(&usb_bus_list_lock);
1021                 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
1022                                 dev_name(&usb_dev->dev), retval);
1023                 return (retval < 0) ? retval : -EMSGSIZE;
1024         }
1025
1026         if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
1027                 retval = usb_get_bos_descriptor(usb_dev);
1028                 if (!retval) {
1029                         usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1030                 } else if (usb_dev->speed == USB_SPEED_SUPER) {
1031                         mutex_unlock(&usb_bus_list_lock);
1032                         dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1033                                         dev_name(&usb_dev->dev), retval);
1034                         return retval;
1035                 }
1036         }
1037
1038         retval = usb_new_device (usb_dev);
1039         if (retval) {
1040                 dev_err (parent_dev, "can't register root hub for %s, %d\n",
1041                                 dev_name(&usb_dev->dev), retval);
1042         } else {
1043                 spin_lock_irq (&hcd_root_hub_lock);
1044                 hcd->rh_registered = 1;
1045                 spin_unlock_irq (&hcd_root_hub_lock);
1046
1047                 /* Did the HC die before the root hub was registered? */
1048                 if (HCD_DEAD(hcd))
1049                         usb_hc_died (hcd);      /* This time clean up */
1050         }
1051         mutex_unlock(&usb_bus_list_lock);
1052
1053         return retval;
1054 }
1055
1056 /*
1057  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1058  * @bus: the bus which the root hub belongs to
1059  * @portnum: the port which is being resumed
1060  *
1061  * HCDs should call this function when they know that a resume signal is
1062  * being sent to a root-hub port.  The root hub will be prevented from
1063  * going into autosuspend until usb_hcd_end_port_resume() is called.
1064  *
1065  * The bus's private lock must be held by the caller.
1066  */
1067 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1068 {
1069         unsigned bit = 1 << portnum;
1070
1071         if (!(bus->resuming_ports & bit)) {
1072                 bus->resuming_ports |= bit;
1073                 pm_runtime_get_noresume(&bus->root_hub->dev);
1074         }
1075 }
1076 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1077
1078 /*
1079  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1080  * @bus: the bus which the root hub belongs to
1081  * @portnum: the port which is being resumed
1082  *
1083  * HCDs should call this function when they know that a resume signal has
1084  * stopped being sent to a root-hub port.  The root hub will be allowed to
1085  * autosuspend again.
1086  *
1087  * The bus's private lock must be held by the caller.
1088  */
1089 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1090 {
1091         unsigned bit = 1 << portnum;
1092
1093         if (bus->resuming_ports & bit) {
1094                 bus->resuming_ports &= ~bit;
1095                 pm_runtime_put_noidle(&bus->root_hub->dev);
1096         }
1097 }
1098 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1099
1100 /*-------------------------------------------------------------------------*/
1101
1102 /**
1103  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1104  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1105  * @is_input: true iff the transaction sends data to the host
1106  * @isoc: true for isochronous transactions, false for interrupt ones
1107  * @bytecount: how many bytes in the transaction.
1108  *
1109  * Return: Approximate bus time in nanoseconds for a periodic transaction.
1110  *
1111  * Note:
1112  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1113  * scheduled in software, this function is only used for such scheduling.
1114  */
1115 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1116 {
1117         unsigned long   tmp;
1118
1119         switch (speed) {
1120         case USB_SPEED_LOW:     /* INTR only */
1121                 if (is_input) {
1122                         tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1123                         return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1124                 } else {
1125                         tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1126                         return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1127                 }
1128         case USB_SPEED_FULL:    /* ISOC or INTR */
1129                 if (isoc) {
1130                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1131                         return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1132                 } else {
1133                         tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1134                         return 9107L + BW_HOST_DELAY + tmp;
1135                 }
1136         case USB_SPEED_HIGH:    /* ISOC or INTR */
1137                 /* FIXME adjust for input vs output */
1138                 if (isoc)
1139                         tmp = HS_NSECS_ISO (bytecount);
1140                 else
1141                         tmp = HS_NSECS (bytecount);
1142                 return tmp;
1143         default:
1144                 pr_debug ("%s: bogus device speed!\n", usbcore_name);
1145                 return -1;
1146         }
1147 }
1148 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1149
1150
1151 /*-------------------------------------------------------------------------*/
1152
1153 /*
1154  * Generic HC operations.
1155  */
1156
1157 /*-------------------------------------------------------------------------*/
1158
1159 /**
1160  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1161  * @hcd: host controller to which @urb was submitted
1162  * @urb: URB being submitted
1163  *
1164  * Host controller drivers should call this routine in their enqueue()
1165  * method.  The HCD's private spinlock must be held and interrupts must
1166  * be disabled.  The actions carried out here are required for URB
1167  * submission, as well as for endpoint shutdown and for usb_kill_urb.
1168  *
1169  * Return: 0 for no error, otherwise a negative error code (in which case
1170  * the enqueue() method must fail).  If no error occurs but enqueue() fails
1171  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1172  * the private spinlock and returning.
1173  */
1174 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1175 {
1176         int             rc = 0;
1177
1178         spin_lock(&hcd_urb_list_lock);
1179
1180         /* Check that the URB isn't being killed */
1181         if (unlikely(atomic_read(&urb->reject))) {
1182                 rc = -EPERM;
1183                 goto done;
1184         }
1185
1186         if (unlikely(!urb->ep->enabled)) {
1187                 rc = -ENOENT;
1188                 goto done;
1189         }
1190
1191         if (unlikely(!urb->dev->can_submit)) {
1192                 rc = -EHOSTUNREACH;
1193                 goto done;
1194         }
1195
1196         /*
1197          * Check the host controller's state and add the URB to the
1198          * endpoint's queue.
1199          */
1200         if (HCD_RH_RUNNING(hcd)) {
1201                 urb->unlinked = 0;
1202                 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1203         } else {
1204                 rc = -ESHUTDOWN;
1205                 goto done;
1206         }
1207  done:
1208         spin_unlock(&hcd_urb_list_lock);
1209         return rc;
1210 }
1211 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1212
1213 /**
1214  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1215  * @hcd: host controller to which @urb was submitted
1216  * @urb: URB being checked for unlinkability
1217  * @status: error code to store in @urb if the unlink succeeds
1218  *
1219  * Host controller drivers should call this routine in their dequeue()
1220  * method.  The HCD's private spinlock must be held and interrupts must
1221  * be disabled.  The actions carried out here are required for making
1222  * sure than an unlink is valid.
1223  *
1224  * Return: 0 for no error, otherwise a negative error code (in which case
1225  * the dequeue() method must fail).  The possible error codes are:
1226  *
1227  *      -EIDRM: @urb was not submitted or has already completed.
1228  *              The completion function may not have been called yet.
1229  *
1230  *      -EBUSY: @urb has already been unlinked.
1231  */
1232 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1233                 int status)
1234 {
1235         struct list_head        *tmp;
1236
1237         /* insist the urb is still queued */
1238         list_for_each(tmp, &urb->ep->urb_list) {
1239                 if (tmp == &urb->urb_list)
1240                         break;
1241         }
1242         if (tmp != &urb->urb_list)
1243                 return -EIDRM;
1244
1245         /* Any status except -EINPROGRESS means something already started to
1246          * unlink this URB from the hardware.  So there's no more work to do.
1247          */
1248         if (urb->unlinked)
1249                 return -EBUSY;
1250         urb->unlinked = status;
1251         return 0;
1252 }
1253 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1254
1255 /**
1256  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1257  * @hcd: host controller to which @urb was submitted
1258  * @urb: URB being unlinked
1259  *
1260  * Host controller drivers should call this routine before calling
1261  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1262  * interrupts must be disabled.  The actions carried out here are required
1263  * for URB completion.
1264  */
1265 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1266 {
1267         /* clear all state linking urb to this dev (and hcd) */
1268         spin_lock(&hcd_urb_list_lock);
1269         list_del_init(&urb->urb_list);
1270         spin_unlock(&hcd_urb_list_lock);
1271 }
1272 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1273
1274 /*
1275  * Some usb host controllers can only perform dma using a small SRAM area.
1276  * The usb core itself is however optimized for host controllers that can dma
1277  * using regular system memory - like pci devices doing bus mastering.
1278  *
1279  * To support host controllers with limited dma capabilities we provide dma
1280  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1281  * For this to work properly the host controller code must first use the
1282  * function dma_declare_coherent_memory() to point out which memory area
1283  * that should be used for dma allocations.
1284  *
1285  * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1286  * dma using dma_alloc_coherent() which in turn allocates from the memory
1287  * area pointed out with dma_declare_coherent_memory().
1288  *
1289  * So, to summarize...
1290  *
1291  * - We need "local" memory, canonical example being
1292  *   a small SRAM on a discrete controller being the
1293  *   only memory that the controller can read ...
1294  *   (a) "normal" kernel memory is no good, and
1295  *   (b) there's not enough to share
1296  *
1297  * - The only *portable* hook for such stuff in the
1298  *   DMA framework is dma_declare_coherent_memory()
1299  *
1300  * - So we use that, even though the primary requirement
1301  *   is that the memory be "local" (hence addressable
1302  *   by that device), not "coherent".
1303  *
1304  */
1305
1306 static int hcd_alloc_coherent(struct usb_bus *bus,
1307                               gfp_t mem_flags, dma_addr_t *dma_handle,
1308                               void **vaddr_handle, size_t size,
1309                               enum dma_data_direction dir)
1310 {
1311         unsigned char *vaddr;
1312
1313         if (*vaddr_handle == NULL) {
1314                 WARN_ON_ONCE(1);
1315                 return -EFAULT;
1316         }
1317
1318         vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1319                                  mem_flags, dma_handle);
1320         if (!vaddr)
1321                 return -ENOMEM;
1322
1323         /*
1324          * Store the virtual address of the buffer at the end
1325          * of the allocated dma buffer. The size of the buffer
1326          * may be uneven so use unaligned functions instead
1327          * of just rounding up. It makes sense to optimize for
1328          * memory footprint over access speed since the amount
1329          * of memory available for dma may be limited.
1330          */
1331         put_unaligned((unsigned long)*vaddr_handle,
1332                       (unsigned long *)(vaddr + size));
1333
1334         if (dir == DMA_TO_DEVICE)
1335                 memcpy(vaddr, *vaddr_handle, size);
1336
1337         *vaddr_handle = vaddr;
1338         return 0;
1339 }
1340
1341 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1342                               void **vaddr_handle, size_t size,
1343                               enum dma_data_direction dir)
1344 {
1345         unsigned char *vaddr = *vaddr_handle;
1346
1347         vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1348
1349         if (dir == DMA_FROM_DEVICE)
1350                 memcpy(vaddr, *vaddr_handle, size);
1351
1352         hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1353
1354         *vaddr_handle = vaddr;
1355         *dma_handle = 0;
1356 }
1357
1358 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1359 {
1360         if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1361                 dma_unmap_single(hcd->self.controller,
1362                                 urb->setup_dma,
1363                                 sizeof(struct usb_ctrlrequest),
1364                                 DMA_TO_DEVICE);
1365         else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1366                 hcd_free_coherent(urb->dev->bus,
1367                                 &urb->setup_dma,
1368                                 (void **) &urb->setup_packet,
1369                                 sizeof(struct usb_ctrlrequest),
1370                                 DMA_TO_DEVICE);
1371
1372         /* Make it safe to call this routine more than once */
1373         urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1374 }
1375 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1376
1377 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1378 {
1379         if (hcd->driver->unmap_urb_for_dma)
1380                 hcd->driver->unmap_urb_for_dma(hcd, urb);
1381         else
1382                 usb_hcd_unmap_urb_for_dma(hcd, urb);
1383 }
1384
1385 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1386 {
1387         enum dma_data_direction dir;
1388
1389         usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1390
1391         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1392         if (urb->transfer_flags & URB_DMA_MAP_SG)
1393                 dma_unmap_sg(hcd->self.controller,
1394                                 urb->sg,
1395                                 urb->num_sgs,
1396                                 dir);
1397         else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1398                 dma_unmap_page(hcd->self.controller,
1399                                 urb->transfer_dma,
1400                                 urb->transfer_buffer_length,
1401                                 dir);
1402         else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1403                 dma_unmap_single(hcd->self.controller,
1404                                 urb->transfer_dma,
1405                                 urb->transfer_buffer_length,
1406                                 dir);
1407         else if (urb->transfer_flags & URB_MAP_LOCAL)
1408                 hcd_free_coherent(urb->dev->bus,
1409                                 &urb->transfer_dma,
1410                                 &urb->transfer_buffer,
1411                                 urb->transfer_buffer_length,
1412                                 dir);
1413
1414         /* Make it safe to call this routine more than once */
1415         urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1416                         URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1417 }
1418 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1419
1420 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1421                            gfp_t mem_flags)
1422 {
1423         if (hcd->driver->map_urb_for_dma)
1424                 return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1425         else
1426                 return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1427 }
1428
1429 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1430                             gfp_t mem_flags)
1431 {
1432         enum dma_data_direction dir;
1433         int ret = 0;
1434
1435         /* Map the URB's buffers for DMA access.
1436          * Lower level HCD code should use *_dma exclusively,
1437          * unless it uses pio or talks to another transport,
1438          * or uses the provided scatter gather list for bulk.
1439          */
1440
1441         if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1442                 if (hcd->self.uses_pio_for_control)
1443                         return ret;
1444                 if (hcd->self.uses_dma) {
1445                         urb->setup_dma = dma_map_single(
1446                                         hcd->self.controller,
1447                                         urb->setup_packet,
1448                                         sizeof(struct usb_ctrlrequest),
1449                                         DMA_TO_DEVICE);
1450                         if (dma_mapping_error(hcd->self.controller,
1451                                                 urb->setup_dma))
1452                                 return -EAGAIN;
1453                         urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1454                 } else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1455                         ret = hcd_alloc_coherent(
1456                                         urb->dev->bus, mem_flags,
1457                                         &urb->setup_dma,
1458                                         (void **)&urb->setup_packet,
1459                                         sizeof(struct usb_ctrlrequest),
1460                                         DMA_TO_DEVICE);
1461                         if (ret)
1462                                 return ret;
1463                         urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1464                 }
1465         }
1466
1467         dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1468         if (urb->transfer_buffer_length != 0
1469             && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1470                 if (hcd->self.uses_dma) {
1471                         if (urb->num_sgs) {
1472                                 int n;
1473
1474                                 /* We don't support sg for isoc transfers ! */
1475                                 if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1476                                         WARN_ON(1);
1477                                         return -EINVAL;
1478                                 }
1479
1480                                 n = dma_map_sg(
1481                                                 hcd->self.controller,
1482                                                 urb->sg,
1483                                                 urb->num_sgs,
1484                                                 dir);
1485                                 if (n <= 0)
1486                                         ret = -EAGAIN;
1487                                 else
1488                                         urb->transfer_flags |= URB_DMA_MAP_SG;
1489                                 urb->num_mapped_sgs = n;
1490                                 if (n != urb->num_sgs)
1491                                         urb->transfer_flags |=
1492                                                         URB_DMA_SG_COMBINED;
1493                         } else if (urb->sg) {
1494                                 struct scatterlist *sg = urb->sg;
1495                                 urb->transfer_dma = dma_map_page(
1496                                                 hcd->self.controller,
1497                                                 sg_page(sg),
1498                                                 sg->offset,
1499                                                 urb->transfer_buffer_length,
1500                                                 dir);
1501                                 if (dma_mapping_error(hcd->self.controller,
1502                                                 urb->transfer_dma))
1503                                         ret = -EAGAIN;
1504                                 else
1505                                         urb->transfer_flags |= URB_DMA_MAP_PAGE;
1506                         } else if (is_vmalloc_addr(urb->transfer_buffer)) {
1507                                 WARN_ONCE(1, "transfer buffer not dma capable\n");
1508                                 ret = -EAGAIN;
1509                         } else {
1510                                 urb->transfer_dma = dma_map_single(
1511                                                 hcd->self.controller,
1512                                                 urb->transfer_buffer,
1513                                                 urb->transfer_buffer_length,
1514                                                 dir);
1515                                 if (dma_mapping_error(hcd->self.controller,
1516                                                 urb->transfer_dma))
1517                                         ret = -EAGAIN;
1518                                 else
1519                                         urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1520                         }
1521                 } else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1522                         ret = hcd_alloc_coherent(
1523                                         urb->dev->bus, mem_flags,
1524                                         &urb->transfer_dma,
1525                                         &urb->transfer_buffer,
1526                                         urb->transfer_buffer_length,
1527                                         dir);
1528                         if (ret == 0)
1529                                 urb->transfer_flags |= URB_MAP_LOCAL;
1530                 }
1531                 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1532                                 URB_SETUP_MAP_LOCAL)))
1533                         usb_hcd_unmap_urb_for_dma(hcd, urb);
1534         }
1535         return ret;
1536 }
1537 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1538
1539 /*-------------------------------------------------------------------------*/
1540
1541 /* may be called in any context with a valid urb->dev usecount
1542  * caller surrenders "ownership" of urb
1543  * expects usb_submit_urb() to have sanity checked and conditioned all
1544  * inputs in the urb
1545  */
1546 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1547 {
1548         int                     status;
1549         struct usb_hcd          *hcd = bus_to_hcd(urb->dev->bus);
1550
1551         /* increment urb's reference count as part of giving it to the HCD
1552          * (which will control it).  HCD guarantees that it either returns
1553          * an error or calls giveback(), but not both.
1554          */
1555         usb_get_urb(urb);
1556         atomic_inc(&urb->use_count);
1557         atomic_inc(&urb->dev->urbnum);
1558         usbmon_urb_submit(&hcd->self, urb);
1559
1560         /* NOTE requirements on root-hub callers (usbfs and the hub
1561          * driver, for now):  URBs' urb->transfer_buffer must be
1562          * valid and usb_buffer_{sync,unmap}() not be needed, since
1563          * they could clobber root hub response data.  Also, control
1564          * URBs must be submitted in process context with interrupts
1565          * enabled.
1566          */
1567
1568         if (is_root_hub(urb->dev)) {
1569                 status = rh_urb_enqueue(hcd, urb);
1570         } else {
1571                 status = map_urb_for_dma(hcd, urb, mem_flags);
1572                 if (likely(status == 0)) {
1573                         status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1574                         if (unlikely(status))
1575                                 unmap_urb_for_dma(hcd, urb);
1576                 }
1577         }
1578
1579         if (unlikely(status)) {
1580                 usbmon_urb_submit_error(&hcd->self, urb, status);
1581                 urb->hcpriv = NULL;
1582                 INIT_LIST_HEAD(&urb->urb_list);
1583                 atomic_dec(&urb->use_count);
1584                 atomic_dec(&urb->dev->urbnum);
1585                 if (atomic_read(&urb->reject))
1586                         wake_up(&usb_kill_urb_queue);
1587                 usb_put_urb(urb);
1588         }
1589         return status;
1590 }
1591
1592 /*-------------------------------------------------------------------------*/
1593
1594 /* this makes the hcd giveback() the urb more quickly, by kicking it
1595  * off hardware queues (which may take a while) and returning it as
1596  * soon as practical.  we've already set up the urb's return status,
1597  * but we can't know if the callback completed already.
1598  */
1599 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1600 {
1601         int             value;
1602
1603         if (is_root_hub(urb->dev))
1604                 value = usb_rh_urb_dequeue(hcd, urb, status);
1605         else {
1606
1607                 /* The only reason an HCD might fail this call is if
1608                  * it has not yet fully queued the urb to begin with.
1609                  * Such failures should be harmless. */
1610                 value = hcd->driver->urb_dequeue(hcd, urb, status);
1611         }
1612         return value;
1613 }
1614
1615 /*
1616  * called in any context
1617  *
1618  * caller guarantees urb won't be recycled till both unlink()
1619  * and the urb's completion function return
1620  */
1621 int usb_hcd_unlink_urb (struct urb *urb, int status)
1622 {
1623         struct usb_hcd          *hcd;
1624         struct usb_device       *udev = urb->dev;
1625         int                     retval = -EIDRM;
1626         unsigned long           flags;
1627
1628         /* Prevent the device and bus from going away while
1629          * the unlink is carried out.  If they are already gone
1630          * then urb->use_count must be 0, since disconnected
1631          * devices can't have any active URBs.
1632          */
1633         spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1634         if (atomic_read(&urb->use_count) > 0) {
1635                 retval = 0;
1636                 usb_get_dev(udev);
1637         }
1638         spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1639         if (retval == 0) {
1640                 hcd = bus_to_hcd(urb->dev->bus);
1641                 retval = unlink1(hcd, urb, status);
1642                 if (retval == 0)
1643                         retval = -EINPROGRESS;
1644                 else if (retval != -EIDRM && retval != -EBUSY)
1645                         dev_dbg(&udev->dev, "hcd_unlink_urb %p fail %d\n",
1646                                         urb, retval);
1647                 usb_put_dev(udev);
1648         }
1649         return retval;
1650 }
1651
1652 /*-------------------------------------------------------------------------*/
1653
1654 static void __usb_hcd_giveback_urb(struct urb *urb)
1655 {
1656         struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1657         struct usb_anchor *anchor = urb->anchor;
1658         int status = urb->unlinked;
1659         unsigned long flags;
1660
1661         urb->hcpriv = NULL;
1662         if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1663             urb->actual_length < urb->transfer_buffer_length &&
1664             !status))
1665                 status = -EREMOTEIO;
1666
1667         unmap_urb_for_dma(hcd, urb);
1668         usbmon_urb_complete(&hcd->self, urb, status);
1669         usb_anchor_suspend_wakeups(anchor);
1670         usb_unanchor_urb(urb);
1671         if (likely(status == 0))
1672                 usb_led_activity(USB_LED_EVENT_HOST);
1673
1674         /* pass ownership to the completion handler */
1675         urb->status = status;
1676
1677         /*
1678          * We disable local IRQs here avoid possible deadlock because
1679          * drivers may call spin_lock() to hold lock which might be
1680          * acquired in one hard interrupt handler.
1681          *
1682          * The local_irq_save()/local_irq_restore() around complete()
1683          * will be removed if current USB drivers have been cleaned up
1684          * and no one may trigger the above deadlock situation when
1685          * running complete() in tasklet.
1686          */
1687         local_irq_save_nort(flags);
1688         urb->complete(urb);
1689         local_irq_restore_nort(flags);
1690
1691         usb_anchor_resume_wakeups(anchor);
1692         atomic_dec(&urb->use_count);
1693         if (unlikely(atomic_read(&urb->reject)))
1694                 wake_up(&usb_kill_urb_queue);
1695         usb_put_urb(urb);
1696 }
1697
1698 static void usb_giveback_urb_bh(unsigned long param)
1699 {
1700         struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1701         struct list_head local_list;
1702
1703         spin_lock_irq(&bh->lock);
1704         bh->running = true;
1705  restart:
1706         list_replace_init(&bh->head, &local_list);
1707         spin_unlock_irq(&bh->lock);
1708
1709         while (!list_empty(&local_list)) {
1710                 struct urb *urb;
1711
1712                 urb = list_entry(local_list.next, struct urb, urb_list);
1713                 list_del_init(&urb->urb_list);
1714                 bh->completing_ep = urb->ep;
1715                 __usb_hcd_giveback_urb(urb);
1716                 bh->completing_ep = NULL;
1717         }
1718
1719         /* check if there are new URBs to giveback */
1720         spin_lock_irq(&bh->lock);
1721         if (!list_empty(&bh->head))
1722                 goto restart;
1723         bh->running = false;
1724         spin_unlock_irq(&bh->lock);
1725 }
1726
1727 /**
1728  * usb_hcd_giveback_urb - return URB from HCD to device driver
1729  * @hcd: host controller returning the URB
1730  * @urb: urb being returned to the USB device driver.
1731  * @status: completion status code for the URB.
1732  * Context: in_interrupt()
1733  *
1734  * This hands the URB from HCD to its USB device driver, using its
1735  * completion function.  The HCD has freed all per-urb resources
1736  * (and is done using urb->hcpriv).  It also released all HCD locks;
1737  * the device driver won't cause problems if it frees, modifies,
1738  * or resubmits this URB.
1739  *
1740  * If @urb was unlinked, the value of @status will be overridden by
1741  * @urb->unlinked.  Erroneous short transfers are detected in case
1742  * the HCD hasn't checked for them.
1743  */
1744 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1745 {
1746         struct giveback_urb_bh *bh;
1747         bool running, high_prio_bh;
1748
1749         /* pass status to tasklet via unlinked */
1750         if (likely(!urb->unlinked))
1751                 urb->unlinked = status;
1752
1753         if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1754                 __usb_hcd_giveback_urb(urb);
1755                 return;
1756         }
1757
1758         if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1759                 bh = &hcd->high_prio_bh;
1760                 high_prio_bh = true;
1761         } else {
1762                 bh = &hcd->low_prio_bh;
1763                 high_prio_bh = false;
1764         }
1765
1766         spin_lock(&bh->lock);
1767         list_add_tail(&urb->urb_list, &bh->head);
1768         running = bh->running;
1769         spin_unlock(&bh->lock);
1770
1771         if (running)
1772                 ;
1773         else if (high_prio_bh)
1774                 tasklet_hi_schedule(&bh->bh);
1775         else
1776                 tasklet_schedule(&bh->bh);
1777 }
1778 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1779
1780 /*-------------------------------------------------------------------------*/
1781
1782 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1783  * queue to drain completely.  The caller must first insure that no more
1784  * URBs can be submitted for this endpoint.
1785  */
1786 void usb_hcd_flush_endpoint(struct usb_device *udev,
1787                 struct usb_host_endpoint *ep)
1788 {
1789         struct usb_hcd          *hcd;
1790         struct urb              *urb;
1791
1792         if (!ep)
1793                 return;
1794         might_sleep();
1795         hcd = bus_to_hcd(udev->bus);
1796
1797         /* No more submits can occur */
1798         spin_lock_irq(&hcd_urb_list_lock);
1799 rescan:
1800         list_for_each_entry (urb, &ep->urb_list, urb_list) {
1801                 int     is_in;
1802
1803                 if (urb->unlinked)
1804                         continue;
1805                 usb_get_urb (urb);
1806                 is_in = usb_urb_dir_in(urb);
1807                 spin_unlock(&hcd_urb_list_lock);
1808
1809                 /* kick hcd */
1810                 unlink1(hcd, urb, -ESHUTDOWN);
1811                 dev_dbg (hcd->self.controller,
1812                         "shutdown urb %p ep%d%s%s\n",
1813                         urb, usb_endpoint_num(&ep->desc),
1814                         is_in ? "in" : "out",
1815                         ({      char *s;
1816
1817                                  switch (usb_endpoint_type(&ep->desc)) {
1818                                  case USB_ENDPOINT_XFER_CONTROL:
1819                                         s = ""; break;
1820                                  case USB_ENDPOINT_XFER_BULK:
1821                                         s = "-bulk"; break;
1822                                  case USB_ENDPOINT_XFER_INT:
1823                                         s = "-intr"; break;
1824                                  default:
1825                                         s = "-iso"; break;
1826                                 };
1827                                 s;
1828                         }));
1829                 usb_put_urb (urb);
1830
1831                 /* list contents may have changed */
1832                 spin_lock(&hcd_urb_list_lock);
1833                 goto rescan;
1834         }
1835         spin_unlock_irq(&hcd_urb_list_lock);
1836
1837         /* Wait until the endpoint queue is completely empty */
1838         while (!list_empty (&ep->urb_list)) {
1839                 spin_lock_irq(&hcd_urb_list_lock);
1840
1841                 /* The list may have changed while we acquired the spinlock */
1842                 urb = NULL;
1843                 if (!list_empty (&ep->urb_list)) {
1844                         urb = list_entry (ep->urb_list.prev, struct urb,
1845                                         urb_list);
1846                         usb_get_urb (urb);
1847                 }
1848                 spin_unlock_irq(&hcd_urb_list_lock);
1849
1850                 if (urb) {
1851                         usb_kill_urb (urb);
1852                         usb_put_urb (urb);
1853                 }
1854         }
1855 }
1856
1857 /**
1858  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1859  *                              the bus bandwidth
1860  * @udev: target &usb_device
1861  * @new_config: new configuration to install
1862  * @cur_alt: the current alternate interface setting
1863  * @new_alt: alternate interface setting that is being installed
1864  *
1865  * To change configurations, pass in the new configuration in new_config,
1866  * and pass NULL for cur_alt and new_alt.
1867  *
1868  * To reset a device's configuration (put the device in the ADDRESSED state),
1869  * pass in NULL for new_config, cur_alt, and new_alt.
1870  *
1871  * To change alternate interface settings, pass in NULL for new_config,
1872  * pass in the current alternate interface setting in cur_alt,
1873  * and pass in the new alternate interface setting in new_alt.
1874  *
1875  * Return: An error if the requested bandwidth change exceeds the
1876  * bus bandwidth or host controller internal resources.
1877  */
1878 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1879                 struct usb_host_config *new_config,
1880                 struct usb_host_interface *cur_alt,
1881                 struct usb_host_interface *new_alt)
1882 {
1883         int num_intfs, i, j;
1884         struct usb_host_interface *alt = NULL;
1885         int ret = 0;
1886         struct usb_hcd *hcd;
1887         struct usb_host_endpoint *ep;
1888
1889         hcd = bus_to_hcd(udev->bus);
1890         if (!hcd->driver->check_bandwidth)
1891                 return 0;
1892
1893         /* Configuration is being removed - set configuration 0 */
1894         if (!new_config && !cur_alt) {
1895                 for (i = 1; i < 16; ++i) {
1896                         ep = udev->ep_out[i];
1897                         if (ep)
1898                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1899                         ep = udev->ep_in[i];
1900                         if (ep)
1901                                 hcd->driver->drop_endpoint(hcd, udev, ep);
1902                 }
1903                 hcd->driver->check_bandwidth(hcd, udev);
1904                 return 0;
1905         }
1906         /* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1907          * each interface's alt setting 0 and ask the HCD to check the bandwidth
1908          * of the bus.  There will always be bandwidth for endpoint 0, so it's
1909          * ok to exclude it.
1910          */
1911         if (new_config) {
1912                 num_intfs = new_config->desc.bNumInterfaces;
1913                 /* Remove endpoints (except endpoint 0, which is always on the
1914                  * schedule) from the old config from the schedule
1915                  */
1916                 for (i = 1; i < 16; ++i) {
1917                         ep = udev->ep_out[i];
1918                         if (ep) {
1919                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1920                                 if (ret < 0)
1921                                         goto reset;
1922                         }
1923                         ep = udev->ep_in[i];
1924                         if (ep) {
1925                                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1926                                 if (ret < 0)
1927                                         goto reset;
1928                         }
1929                 }
1930                 for (i = 0; i < num_intfs; ++i) {
1931                         struct usb_host_interface *first_alt;
1932                         int iface_num;
1933
1934                         first_alt = &new_config->intf_cache[i]->altsetting[0];
1935                         iface_num = first_alt->desc.bInterfaceNumber;
1936                         /* Set up endpoints for alternate interface setting 0 */
1937                         alt = usb_find_alt_setting(new_config, iface_num, 0);
1938                         if (!alt)
1939                                 /* No alt setting 0? Pick the first setting. */
1940                                 alt = first_alt;
1941
1942                         for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1943                                 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1944                                 if (ret < 0)
1945                                         goto reset;
1946                         }
1947                 }
1948         }
1949         if (cur_alt && new_alt) {
1950                 struct usb_interface *iface = usb_ifnum_to_if(udev,
1951                                 cur_alt->desc.bInterfaceNumber);
1952
1953                 if (!iface)
1954                         return -EINVAL;
1955                 if (iface->resetting_device) {
1956                         /*
1957                          * The USB core just reset the device, so the xHCI host
1958                          * and the device will think alt setting 0 is installed.
1959                          * However, the USB core will pass in the alternate
1960                          * setting installed before the reset as cur_alt.  Dig
1961                          * out the alternate setting 0 structure, or the first
1962                          * alternate setting if a broken device doesn't have alt
1963                          * setting 0.
1964                          */
1965                         cur_alt = usb_altnum_to_altsetting(iface, 0);
1966                         if (!cur_alt)
1967                                 cur_alt = &iface->altsetting[0];
1968                 }
1969
1970                 /* Drop all the endpoints in the current alt setting */
1971                 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1972                         ret = hcd->driver->drop_endpoint(hcd, udev,
1973                                         &cur_alt->endpoint[i]);
1974                         if (ret < 0)
1975                                 goto reset;
1976                 }
1977                 /* Add all the endpoints in the new alt setting */
1978                 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1979                         ret = hcd->driver->add_endpoint(hcd, udev,
1980                                         &new_alt->endpoint[i]);
1981                         if (ret < 0)
1982                                 goto reset;
1983                 }
1984         }
1985         ret = hcd->driver->check_bandwidth(hcd, udev);
1986 reset:
1987         if (ret < 0)
1988                 hcd->driver->reset_bandwidth(hcd, udev);
1989         return ret;
1990 }
1991
1992 /* Disables the endpoint: synchronizes with the hcd to make sure all
1993  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1994  * have been called previously.  Use for set_configuration, set_interface,
1995  * driver removal, physical disconnect.
1996  *
1997  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1998  * type, maxpacket size, toggle, halt status, and scheduling.
1999  */
2000 void usb_hcd_disable_endpoint(struct usb_device *udev,
2001                 struct usb_host_endpoint *ep)
2002 {
2003         struct usb_hcd          *hcd;
2004
2005         might_sleep();
2006         hcd = bus_to_hcd(udev->bus);
2007         if (hcd->driver->endpoint_disable)
2008                 hcd->driver->endpoint_disable(hcd, ep);
2009 }
2010
2011 /**
2012  * usb_hcd_reset_endpoint - reset host endpoint state
2013  * @udev: USB device.
2014  * @ep:   the endpoint to reset.
2015  *
2016  * Resets any host endpoint state such as the toggle bit, sequence
2017  * number and current window.
2018  */
2019 void usb_hcd_reset_endpoint(struct usb_device *udev,
2020                             struct usb_host_endpoint *ep)
2021 {
2022         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2023
2024         if (hcd->driver->endpoint_reset)
2025                 hcd->driver->endpoint_reset(hcd, ep);
2026         else {
2027                 int epnum = usb_endpoint_num(&ep->desc);
2028                 int is_out = usb_endpoint_dir_out(&ep->desc);
2029                 int is_control = usb_endpoint_xfer_control(&ep->desc);
2030
2031                 usb_settoggle(udev, epnum, is_out, 0);
2032                 if (is_control)
2033                         usb_settoggle(udev, epnum, !is_out, 0);
2034         }
2035 }
2036
2037 /**
2038  * usb_alloc_streams - allocate bulk endpoint stream IDs.
2039  * @interface:          alternate setting that includes all endpoints.
2040  * @eps:                array of endpoints that need streams.
2041  * @num_eps:            number of endpoints in the array.
2042  * @num_streams:        number of streams to allocate.
2043  * @mem_flags:          flags hcd should use to allocate memory.
2044  *
2045  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
2046  * Drivers may queue multiple transfers to different stream IDs, which may
2047  * complete in a different order than they were queued.
2048  *
2049  * Return: On success, the number of allocated streams. On failure, a negative
2050  * error code.
2051  */
2052 int usb_alloc_streams(struct usb_interface *interface,
2053                 struct usb_host_endpoint **eps, unsigned int num_eps,
2054                 unsigned int num_streams, gfp_t mem_flags)
2055 {
2056         struct usb_hcd *hcd;
2057         struct usb_device *dev;
2058         int i, ret;
2059
2060         dev = interface_to_usbdev(interface);
2061         hcd = bus_to_hcd(dev->bus);
2062         if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2063                 return -EINVAL;
2064         if (dev->speed != USB_SPEED_SUPER)
2065                 return -EINVAL;
2066         if (dev->state < USB_STATE_CONFIGURED)
2067                 return -ENODEV;
2068
2069         for (i = 0; i < num_eps; i++) {
2070                 /* Streams only apply to bulk endpoints. */
2071                 if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2072                         return -EINVAL;
2073                 /* Re-alloc is not allowed */
2074                 if (eps[i]->streams)
2075                         return -EINVAL;
2076         }
2077
2078         ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2079                         num_streams, mem_flags);
2080         if (ret < 0)
2081                 return ret;
2082
2083         for (i = 0; i < num_eps; i++)
2084                 eps[i]->streams = ret;
2085
2086         return ret;
2087 }
2088 EXPORT_SYMBOL_GPL(usb_alloc_streams);
2089
2090 /**
2091  * usb_free_streams - free bulk endpoint stream IDs.
2092  * @interface:  alternate setting that includes all endpoints.
2093  * @eps:        array of endpoints to remove streams from.
2094  * @num_eps:    number of endpoints in the array.
2095  * @mem_flags:  flags hcd should use to allocate memory.
2096  *
2097  * Reverts a group of bulk endpoints back to not using stream IDs.
2098  * Can fail if we are given bad arguments, or HCD is broken.
2099  *
2100  * Return: 0 on success. On failure, a negative error code.
2101  */
2102 int usb_free_streams(struct usb_interface *interface,
2103                 struct usb_host_endpoint **eps, unsigned int num_eps,
2104                 gfp_t mem_flags)
2105 {
2106         struct usb_hcd *hcd;
2107         struct usb_device *dev;
2108         int i, ret;
2109
2110         dev = interface_to_usbdev(interface);
2111         hcd = bus_to_hcd(dev->bus);
2112         if (dev->speed != USB_SPEED_SUPER)
2113                 return -EINVAL;
2114
2115         /* Double-free is not allowed */
2116         for (i = 0; i < num_eps; i++)
2117                 if (!eps[i] || !eps[i]->streams)
2118                         return -EINVAL;
2119
2120         ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2121         if (ret < 0)
2122                 return ret;
2123
2124         for (i = 0; i < num_eps; i++)
2125                 eps[i]->streams = 0;
2126
2127         return ret;
2128 }
2129 EXPORT_SYMBOL_GPL(usb_free_streams);
2130
2131 /* Protect against drivers that try to unlink URBs after the device
2132  * is gone, by waiting until all unlinks for @udev are finished.
2133  * Since we don't currently track URBs by device, simply wait until
2134  * nothing is running in the locked region of usb_hcd_unlink_urb().
2135  */
2136 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2137 {
2138         spin_lock_irq(&hcd_urb_unlink_lock);
2139         spin_unlock_irq(&hcd_urb_unlink_lock);
2140 }
2141
2142 /*-------------------------------------------------------------------------*/
2143
2144 /* called in any context */
2145 int usb_hcd_get_frame_number (struct usb_device *udev)
2146 {
2147         struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
2148
2149         if (!HCD_RH_RUNNING(hcd))
2150                 return -ESHUTDOWN;
2151         return hcd->driver->get_frame_number (hcd);
2152 }
2153
2154 /*-------------------------------------------------------------------------*/
2155
2156 #ifdef  CONFIG_PM
2157
2158 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2159 {
2160         struct usb_hcd  *hcd = container_of(rhdev->bus, struct usb_hcd, self);
2161         int             status;
2162         int             old_state = hcd->state;
2163
2164         dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2165                         (PMSG_IS_AUTO(msg) ? "auto-" : ""),
2166                         rhdev->do_remote_wakeup);
2167         if (HCD_DEAD(hcd)) {
2168                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2169                 return 0;
2170         }
2171
2172         if (!hcd->driver->bus_suspend) {
2173                 status = -ENOENT;
2174         } else {
2175                 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2176                 hcd->state = HC_STATE_QUIESCING;
2177                 status = hcd->driver->bus_suspend(hcd);
2178         }
2179         if (status == 0) {
2180                 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2181                 hcd->state = HC_STATE_SUSPENDED;
2182
2183                 /* Did we race with a root-hub wakeup event? */
2184                 if (rhdev->do_remote_wakeup) {
2185                         char    buffer[6];
2186
2187                         status = hcd->driver->hub_status_data(hcd, buffer);
2188                         if (status != 0) {
2189                                 dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2190                                 hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2191                                 status = -EBUSY;
2192                         }
2193                 }
2194         } else {
2195                 spin_lock_irq(&hcd_root_hub_lock);
2196                 if (!HCD_DEAD(hcd)) {
2197                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2198                         hcd->state = old_state;
2199                 }
2200                 spin_unlock_irq(&hcd_root_hub_lock);
2201                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2202                                 "suspend", status);
2203         }
2204         return status;
2205 }
2206
2207 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2208 {
2209         struct usb_hcd  *hcd = container_of(rhdev->bus, struct usb_hcd, self);
2210         int             status;
2211         int             old_state = hcd->state;
2212
2213         dev_dbg(&rhdev->dev, "usb %sresume\n",
2214                         (PMSG_IS_AUTO(msg) ? "auto-" : ""));
2215         if (HCD_DEAD(hcd)) {
2216                 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2217                 return 0;
2218         }
2219         if (!hcd->driver->bus_resume)
2220                 return -ENOENT;
2221         if (HCD_RH_RUNNING(hcd))
2222                 return 0;
2223
2224         hcd->state = HC_STATE_RESUMING;
2225         status = hcd->driver->bus_resume(hcd);
2226         clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2227         if (status == 0) {
2228                 struct usb_device *udev;
2229                 int port1;
2230
2231                 spin_lock_irq(&hcd_root_hub_lock);
2232                 if (!HCD_DEAD(hcd)) {
2233                         usb_set_device_state(rhdev, rhdev->actconfig
2234                                         ? USB_STATE_CONFIGURED
2235                                         : USB_STATE_ADDRESS);
2236                         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2237                         hcd->state = HC_STATE_RUNNING;
2238                 }
2239                 spin_unlock_irq(&hcd_root_hub_lock);
2240
2241                 /*
2242                  * Check whether any of the enabled ports on the root hub are
2243                  * unsuspended.  If they are then a TRSMRCY delay is needed
2244                  * (this is what the USB-2 spec calls a "global resume").
2245                  * Otherwise we can skip the delay.
2246                  */
2247                 usb_hub_for_each_child(rhdev, port1, udev) {
2248                         if (udev->state != USB_STATE_NOTATTACHED &&
2249                                         !udev->port_is_suspended) {
2250                                 usleep_range(10000, 11000);     /* TRSMRCY */
2251                                 break;
2252                         }
2253                 }
2254         } else {
2255                 hcd->state = old_state;
2256                 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2257                                 "resume", status);
2258                 if (status != -ESHUTDOWN)
2259                         usb_hc_died(hcd);
2260         }
2261         return status;
2262 }
2263
2264 /* Workqueue routine for root-hub remote wakeup */
2265 static void hcd_resume_work(struct work_struct *work)
2266 {
2267         struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2268         struct usb_device *udev = hcd->self.root_hub;
2269
2270         usb_remote_wakeup(udev);
2271 }
2272
2273 /**
2274  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2275  * @hcd: host controller for this root hub
2276  *
2277  * The USB host controller calls this function when its root hub is
2278  * suspended (with the remote wakeup feature enabled) and a remote
2279  * wakeup request is received.  The routine submits a workqueue request
2280  * to resume the root hub (that is, manage its downstream ports again).
2281  */
2282 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2283 {
2284         unsigned long flags;
2285
2286         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2287         if (hcd->rh_registered) {
2288                 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2289                 queue_work(pm_wq, &hcd->wakeup_work);
2290         }
2291         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2292 }
2293 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2294
2295 #endif  /* CONFIG_PM */
2296
2297 /*-------------------------------------------------------------------------*/
2298
2299 #ifdef  CONFIG_USB_OTG
2300
2301 /**
2302  * usb_bus_start_enum - start immediate enumeration (for OTG)
2303  * @bus: the bus (must use hcd framework)
2304  * @port_num: 1-based number of port; usually bus->otg_port
2305  * Context: in_interrupt()
2306  *
2307  * Starts enumeration, with an immediate reset followed later by
2308  * hub_wq identifying and possibly configuring the device.
2309  * This is needed by OTG controller drivers, where it helps meet
2310  * HNP protocol timing requirements for starting a port reset.
2311  *
2312  * Return: 0 if successful.
2313  */
2314 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2315 {
2316         struct usb_hcd          *hcd;
2317         int                     status = -EOPNOTSUPP;
2318
2319         /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2320          * boards with root hubs hooked up to internal devices (instead of
2321          * just the OTG port) may need more attention to resetting...
2322          */
2323         hcd = container_of (bus, struct usb_hcd, self);
2324         if (port_num && hcd->driver->start_port_reset)
2325                 status = hcd->driver->start_port_reset(hcd, port_num);
2326
2327         /* allocate hub_wq shortly after (first) root port reset finishes;
2328          * it may issue others, until at least 50 msecs have passed.
2329          */
2330         if (status == 0)
2331                 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2332         return status;
2333 }
2334 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2335
2336 #endif
2337
2338 /*-------------------------------------------------------------------------*/
2339
2340 /**
2341  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2342  * @irq: the IRQ being raised
2343  * @__hcd: pointer to the HCD whose IRQ is being signaled
2344  *
2345  * If the controller isn't HALTed, calls the driver's irq handler.
2346  * Checks whether the controller is now dead.
2347  *
2348  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2349  */
2350 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2351 {
2352         struct usb_hcd          *hcd = __hcd;
2353         irqreturn_t             rc;
2354
2355         if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2356                 rc = IRQ_NONE;
2357         else if (hcd->driver->irq(hcd) == IRQ_NONE)
2358                 rc = IRQ_NONE;
2359         else
2360                 rc = IRQ_HANDLED;
2361
2362         return rc;
2363 }
2364 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2365
2366 /*-------------------------------------------------------------------------*/
2367
2368 /**
2369  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2370  * @hcd: pointer to the HCD representing the controller
2371  *
2372  * This is called by bus glue to report a USB host controller that died
2373  * while operations may still have been pending.  It's called automatically
2374  * by the PCI glue, so only glue for non-PCI busses should need to call it.
2375  *
2376  * Only call this function with the primary HCD.
2377  */
2378 void usb_hc_died (struct usb_hcd *hcd)
2379 {
2380         unsigned long flags;
2381
2382         dev_err (hcd->self.controller, "HC died; cleaning up\n");
2383
2384         spin_lock_irqsave (&hcd_root_hub_lock, flags);
2385         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2386         set_bit(HCD_FLAG_DEAD, &hcd->flags);
2387         if (hcd->rh_registered) {
2388                 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2389
2390                 /* make hub_wq clean up old urbs and devices */
2391                 usb_set_device_state (hcd->self.root_hub,
2392                                 USB_STATE_NOTATTACHED);
2393                 usb_kick_hub_wq(hcd->self.root_hub);
2394         }
2395         if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2396                 hcd = hcd->shared_hcd;
2397                 if (hcd->rh_registered) {
2398                         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2399
2400                         /* make hub_wq clean up old urbs and devices */
2401                         usb_set_device_state(hcd->self.root_hub,
2402                                         USB_STATE_NOTATTACHED);
2403                         usb_kick_hub_wq(hcd->self.root_hub);
2404                 }
2405         }
2406         spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2407         /* Make sure that the other roothub is also deallocated. */
2408 }
2409 EXPORT_SYMBOL_GPL (usb_hc_died);
2410
2411 /*-------------------------------------------------------------------------*/
2412
2413 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2414 {
2415
2416         spin_lock_init(&bh->lock);
2417         INIT_LIST_HEAD(&bh->head);
2418         tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2419 }
2420
2421 /**
2422  * usb_create_shared_hcd - create and initialize an HCD structure
2423  * @driver: HC driver that will use this hcd
2424  * @dev: device for this HC, stored in hcd->self.controller
2425  * @bus_name: value to store in hcd->self.bus_name
2426  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2427  *              PCI device.  Only allocate certain resources for the primary HCD
2428  * Context: !in_interrupt()
2429  *
2430  * Allocate a struct usb_hcd, with extra space at the end for the
2431  * HC driver's private data.  Initialize the generic members of the
2432  * hcd structure.
2433  *
2434  * Return: On success, a pointer to the created and initialized HCD structure.
2435  * On failure (e.g. if memory is unavailable), %NULL.
2436  */
2437 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2438                 struct device *dev, const char *bus_name,
2439                 struct usb_hcd *primary_hcd)
2440 {
2441         struct usb_hcd *hcd;
2442
2443         hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2444         if (!hcd) {
2445                 dev_dbg (dev, "hcd alloc failed\n");
2446                 return NULL;
2447         }
2448         if (primary_hcd == NULL) {
2449                 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2450                                 GFP_KERNEL);
2451                 if (!hcd->bandwidth_mutex) {
2452                         kfree(hcd);
2453                         dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2454                         return NULL;
2455                 }
2456                 mutex_init(hcd->bandwidth_mutex);
2457                 dev_set_drvdata(dev, hcd);
2458         } else {
2459                 mutex_lock(&usb_port_peer_mutex);
2460                 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2461                 hcd->primary_hcd = primary_hcd;
2462                 primary_hcd->primary_hcd = primary_hcd;
2463                 hcd->shared_hcd = primary_hcd;
2464                 primary_hcd->shared_hcd = hcd;
2465                 mutex_unlock(&usb_port_peer_mutex);
2466         }
2467
2468         kref_init(&hcd->kref);
2469
2470         usb_bus_init(&hcd->self);
2471         hcd->self.controller = dev;
2472         hcd->self.bus_name = bus_name;
2473         hcd->self.uses_dma = (dev->dma_mask != NULL);
2474
2475         init_timer(&hcd->rh_timer);
2476         hcd->rh_timer.function = rh_timer_func;
2477         hcd->rh_timer.data = (unsigned long) hcd;
2478 #ifdef CONFIG_PM
2479         INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2480 #endif
2481
2482         hcd->driver = driver;
2483         hcd->speed = driver->flags & HCD_MASK;
2484         hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2485                         "USB Host Controller";
2486         return hcd;
2487 }
2488 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2489
2490 /**
2491  * usb_create_hcd - create and initialize an HCD structure
2492  * @driver: HC driver that will use this hcd
2493  * @dev: device for this HC, stored in hcd->self.controller
2494  * @bus_name: value to store in hcd->self.bus_name
2495  * Context: !in_interrupt()
2496  *
2497  * Allocate a struct usb_hcd, with extra space at the end for the
2498  * HC driver's private data.  Initialize the generic members of the
2499  * hcd structure.
2500  *
2501  * Return: On success, a pointer to the created and initialized HCD
2502  * structure. On failure (e.g. if memory is unavailable), %NULL.
2503  */
2504 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2505                 struct device *dev, const char *bus_name)
2506 {
2507         return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2508 }
2509 EXPORT_SYMBOL_GPL(usb_create_hcd);
2510
2511 /*
2512  * Roothubs that share one PCI device must also share the bandwidth mutex.
2513  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2514  * deallocated.
2515  *
2516  * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2517  * freed.  When hcd_release() is called for either hcd in a peer set
2518  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers to
2519  * block new peering attempts
2520  */
2521 static void hcd_release(struct kref *kref)
2522 {
2523         struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2524
2525         mutex_lock(&usb_port_peer_mutex);
2526         if (usb_hcd_is_primary_hcd(hcd))
2527                 kfree(hcd->bandwidth_mutex);
2528         if (hcd->shared_hcd) {
2529                 struct usb_hcd *peer = hcd->shared_hcd;
2530
2531                 peer->shared_hcd = NULL;
2532                 if (peer->primary_hcd == hcd)
2533                         peer->primary_hcd = NULL;
2534         }
2535         mutex_unlock(&usb_port_peer_mutex);
2536         kfree(hcd);
2537 }
2538
2539 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2540 {
2541         if (hcd)
2542                 kref_get (&hcd->kref);
2543         return hcd;
2544 }
2545 EXPORT_SYMBOL_GPL(usb_get_hcd);
2546
2547 void usb_put_hcd (struct usb_hcd *hcd)
2548 {
2549         if (hcd)
2550                 kref_put (&hcd->kref, hcd_release);
2551 }
2552 EXPORT_SYMBOL_GPL(usb_put_hcd);
2553
2554 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2555 {
2556         if (!hcd->primary_hcd)
2557                 return 1;
2558         return hcd == hcd->primary_hcd;
2559 }
2560 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2561
2562 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2563 {
2564         if (!hcd->driver->find_raw_port_number)
2565                 return port1;
2566
2567         return hcd->driver->find_raw_port_number(hcd, port1);
2568 }
2569
2570 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2571                 unsigned int irqnum, unsigned long irqflags)
2572 {
2573         int retval;
2574
2575         if (hcd->driver->irq) {
2576
2577                 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2578                                 hcd->driver->description, hcd->self.busnum);
2579                 retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2580                                 hcd->irq_descr, hcd);
2581                 if (retval != 0) {
2582                         dev_err(hcd->self.controller,
2583                                         "request interrupt %d failed\n",
2584                                         irqnum);
2585                         return retval;
2586                 }
2587                 hcd->irq = irqnum;
2588                 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2589                                 (hcd->driver->flags & HCD_MEMORY) ?
2590                                         "io mem" : "io base",
2591                                         (unsigned long long)hcd->rsrc_start);
2592         } else {
2593                 hcd->irq = 0;
2594                 if (hcd->rsrc_start)
2595                         dev_info(hcd->self.controller, "%s 0x%08llx\n",
2596                                         (hcd->driver->flags & HCD_MEMORY) ?
2597                                         "io mem" : "io base",
2598                                         (unsigned long long)hcd->rsrc_start);
2599         }
2600         return 0;
2601 }
2602
2603 /*
2604  * Before we free this root hub, flush in-flight peering attempts
2605  * and disable peer lookups
2606  */
2607 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2608 {
2609         struct usb_device *rhdev;
2610
2611         mutex_lock(&usb_port_peer_mutex);
2612         rhdev = hcd->self.root_hub;
2613         hcd->self.root_hub = NULL;
2614         mutex_unlock(&usb_port_peer_mutex);
2615         usb_put_dev(rhdev);
2616 }
2617
2618 /**
2619  * usb_add_hcd - finish generic HCD structure initialization and register
2620  * @hcd: the usb_hcd structure to initialize
2621  * @irqnum: Interrupt line to allocate
2622  * @irqflags: Interrupt type flags
2623  *
2624  * Finish the remaining parts of generic HCD initialization: allocate the
2625  * buffers of consistent memory, register the bus, request the IRQ line,
2626  * and call the driver's reset() and start() routines.
2627  */
2628 int usb_add_hcd(struct usb_hcd *hcd,
2629                 unsigned int irqnum, unsigned long irqflags)
2630 {
2631         int retval;
2632         struct usb_device *rhdev;
2633
2634         if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) {
2635                 struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller, 0);
2636
2637                 if (IS_ERR(phy)) {
2638                         retval = PTR_ERR(phy);
2639                         if (retval == -EPROBE_DEFER)
2640                                 return retval;
2641                 } else {
2642                         retval = usb_phy_init(phy);
2643                         if (retval) {
2644                                 usb_put_phy(phy);
2645                                 return retval;
2646                         }
2647                         hcd->usb_phy = phy;
2648                         hcd->remove_phy = 1;
2649                 }
2650         }
2651
2652         if (IS_ENABLED(CONFIG_GENERIC_PHY) && !hcd->phy) {
2653                 struct phy *phy = phy_get(hcd->self.controller, "usb");
2654
2655                 if (IS_ERR(phy)) {
2656                         retval = PTR_ERR(phy);
2657                         if (retval == -EPROBE_DEFER)
2658                                 goto err_phy;
2659                 } else {
2660                         retval = phy_init(phy);
2661                         if (retval) {
2662                                 phy_put(phy);
2663                                 goto err_phy;
2664                         }
2665                         retval = phy_power_on(phy);
2666                         if (retval) {
2667                                 phy_exit(phy);
2668                                 phy_put(phy);
2669                                 goto err_phy;
2670                         }
2671                         hcd->phy = phy;
2672                         hcd->remove_phy = 1;
2673                 }
2674         }
2675
2676         dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2677
2678         /* Keep old behaviour if authorized_default is not in [0, 1]. */
2679         if (authorized_default < 0 || authorized_default > 1)
2680                 hcd->authorized_default = hcd->wireless ? 0 : 1;
2681         else
2682                 hcd->authorized_default = authorized_default;
2683         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2684
2685         /* HC is in reset state, but accessible.  Now do the one-time init,
2686          * bottom up so that hcds can customize the root hubs before hub_wq
2687          * starts talking to them.  (Note, bus id is assigned early too.)
2688          */
2689         if ((retval = hcd_buffer_create(hcd)) != 0) {
2690                 dev_dbg(hcd->self.controller, "pool alloc failed\n");
2691                 goto err_create_buf;
2692         }
2693
2694         if ((retval = usb_register_bus(&hcd->self)) < 0)
2695                 goto err_register_bus;
2696
2697         if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2698                 dev_err(hcd->self.controller, "unable to allocate root hub\n");
2699                 retval = -ENOMEM;
2700                 goto err_allocate_root_hub;
2701         }
2702         mutex_lock(&usb_port_peer_mutex);
2703         hcd->self.root_hub = rhdev;
2704         mutex_unlock(&usb_port_peer_mutex);
2705
2706         switch (hcd->speed) {
2707         case HCD_USB11:
2708                 rhdev->speed = USB_SPEED_FULL;
2709                 break;
2710         case HCD_USB2:
2711                 rhdev->speed = USB_SPEED_HIGH;
2712                 break;
2713         case HCD_USB25:
2714                 rhdev->speed = USB_SPEED_WIRELESS;
2715                 break;
2716         case HCD_USB3:
2717                 rhdev->speed = USB_SPEED_SUPER;
2718                 break;
2719         default:
2720                 retval = -EINVAL;
2721                 goto err_set_rh_speed;
2722         }
2723
2724         /* wakeup flag init defaults to "everything works" for root hubs,
2725          * but drivers can override it in reset() if needed, along with
2726          * recording the overall controller's system wakeup capability.
2727          */
2728         device_set_wakeup_capable(&rhdev->dev, 1);
2729
2730         /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2731          * registered.  But since the controller can die at any time,
2732          * let's initialize the flag before touching the hardware.
2733          */
2734         set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2735
2736         /* "reset" is misnamed; its role is now one-time init. the controller
2737          * should already have been reset (and boot firmware kicked off etc).
2738          */
2739         if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2740                 dev_err(hcd->self.controller, "can't setup: %d\n", retval);
2741                 goto err_hcd_driver_setup;
2742         }
2743         hcd->rh_pollable = 1;
2744
2745         /* NOTE: root hub and controller capabilities may not be the same */
2746         if (device_can_wakeup(hcd->self.controller)
2747                         && device_can_wakeup(&hcd->self.root_hub->dev))
2748                 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2749
2750         /* initialize tasklets */
2751         init_giveback_urb_bh(&hcd->high_prio_bh);
2752         init_giveback_urb_bh(&hcd->low_prio_bh);
2753
2754         /* enable irqs just before we start the controller,
2755          * if the BIOS provides legacy PCI irqs.
2756          */
2757         if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2758                 retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2759                 if (retval)
2760                         goto err_request_irq;
2761         }
2762
2763         hcd->state = HC_STATE_RUNNING;
2764         retval = hcd->driver->start(hcd);
2765         if (retval < 0) {
2766                 dev_err(hcd->self.controller, "startup error %d\n", retval);
2767                 goto err_hcd_driver_start;
2768         }
2769
2770         /* starting here, usbcore will pay attention to this root hub */
2771         if ((retval = register_root_hub(hcd)) != 0)
2772                 goto err_register_root_hub;
2773
2774         retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2775         if (retval < 0) {
2776                 printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2777                        retval);
2778                 goto error_create_attr_group;
2779         }
2780         if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2781                 usb_hcd_poll_rh_status(hcd);
2782
2783         return retval;
2784
2785 error_create_attr_group:
2786         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2787         if (HC_IS_RUNNING(hcd->state))
2788                 hcd->state = HC_STATE_QUIESCING;
2789         spin_lock_irq(&hcd_root_hub_lock);
2790         hcd->rh_registered = 0;
2791         spin_unlock_irq(&hcd_root_hub_lock);
2792
2793 #ifdef CONFIG_PM
2794         cancel_work_sync(&hcd->wakeup_work);
2795 #endif
2796         mutex_lock(&usb_bus_list_lock);
2797         usb_disconnect(&rhdev);         /* Sets rhdev to NULL */
2798         mutex_unlock(&usb_bus_list_lock);
2799 err_register_root_hub:
2800         hcd->rh_pollable = 0;
2801         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2802         del_timer_sync(&hcd->rh_timer);
2803         hcd->driver->stop(hcd);
2804         hcd->state = HC_STATE_HALT;
2805         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2806         del_timer_sync(&hcd->rh_timer);
2807 err_hcd_driver_start:
2808         if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2809                 free_irq(irqnum, hcd);
2810 err_request_irq:
2811 err_hcd_driver_setup:
2812 err_set_rh_speed:
2813         usb_put_invalidate_rhdev(hcd);
2814 err_allocate_root_hub:
2815         usb_deregister_bus(&hcd->self);
2816 err_register_bus:
2817         hcd_buffer_destroy(hcd);
2818 err_create_buf:
2819         if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2820                 phy_power_off(hcd->phy);
2821                 phy_exit(hcd->phy);
2822                 phy_put(hcd->phy);
2823                 hcd->phy = NULL;
2824         }
2825 err_phy:
2826         if (hcd->remove_phy && hcd->usb_phy) {
2827                 usb_phy_shutdown(hcd->usb_phy);
2828                 usb_put_phy(hcd->usb_phy);
2829                 hcd->usb_phy = NULL;
2830         }
2831         return retval;
2832 }
2833 EXPORT_SYMBOL_GPL(usb_add_hcd);
2834
2835 /**
2836  * usb_remove_hcd - shutdown processing for generic HCDs
2837  * @hcd: the usb_hcd structure to remove
2838  * Context: !in_interrupt()
2839  *
2840  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2841  * invoking the HCD's stop() method.
2842  */
2843 void usb_remove_hcd(struct usb_hcd *hcd)
2844 {
2845         struct usb_device *rhdev = hcd->self.root_hub;
2846
2847         dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2848
2849         usb_get_dev(rhdev);
2850         sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2851
2852         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2853         if (HC_IS_RUNNING (hcd->state))
2854                 hcd->state = HC_STATE_QUIESCING;
2855
2856         dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2857         spin_lock_irq (&hcd_root_hub_lock);
2858         hcd->rh_registered = 0;
2859         spin_unlock_irq (&hcd_root_hub_lock);
2860
2861 #ifdef CONFIG_PM
2862         cancel_work_sync(&hcd->wakeup_work);
2863 #endif
2864
2865         mutex_lock(&usb_bus_list_lock);
2866         usb_disconnect(&rhdev);         /* Sets rhdev to NULL */
2867         mutex_unlock(&usb_bus_list_lock);
2868
2869         /*
2870          * tasklet_kill() isn't needed here because:
2871          * - driver's disconnect() called from usb_disconnect() should
2872          *   make sure its URBs are completed during the disconnect()
2873          *   callback
2874          *
2875          * - it is too late to run complete() here since driver may have
2876          *   been removed already now
2877          */
2878
2879         /* Prevent any more root-hub status calls from the timer.
2880          * The HCD might still restart the timer (if a port status change
2881          * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2882          * the hub_status_data() callback.
2883          */
2884         hcd->rh_pollable = 0;
2885         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2886         del_timer_sync(&hcd->rh_timer);
2887
2888         hcd->driver->stop(hcd);
2889         hcd->state = HC_STATE_HALT;
2890
2891         /* In case the HCD restarted the timer, stop it again. */
2892         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2893         del_timer_sync(&hcd->rh_timer);
2894
2895         if (usb_hcd_is_primary_hcd(hcd)) {
2896                 if (hcd->irq > 0)
2897                         free_irq(hcd->irq, hcd);
2898         }
2899
2900         usb_deregister_bus(&hcd->self);
2901         hcd_buffer_destroy(hcd);
2902
2903         if (IS_ENABLED(CONFIG_GENERIC_PHY) && hcd->remove_phy && hcd->phy) {
2904                 phy_power_off(hcd->phy);
2905                 phy_exit(hcd->phy);
2906                 phy_put(hcd->phy);
2907                 hcd->phy = NULL;
2908         }
2909         if (hcd->remove_phy && hcd->usb_phy) {
2910                 usb_phy_shutdown(hcd->usb_phy);
2911                 usb_put_phy(hcd->usb_phy);
2912                 hcd->usb_phy = NULL;
2913         }
2914
2915         usb_put_invalidate_rhdev(hcd);
2916 }
2917 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2918
2919 void
2920 usb_hcd_platform_shutdown(struct platform_device *dev)
2921 {
2922         struct usb_hcd *hcd = platform_get_drvdata(dev);
2923
2924         if (hcd->driver->shutdown)
2925                 hcd->driver->shutdown(hcd);
2926 }
2927 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2928
2929 /*-------------------------------------------------------------------------*/
2930
2931 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2932
2933 struct usb_mon_operations *mon_ops;
2934
2935 /*
2936  * The registration is unlocked.
2937  * We do it this way because we do not want to lock in hot paths.
2938  *
2939  * Notice that the code is minimally error-proof. Because usbmon needs
2940  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2941  */
2942
2943 int usb_mon_register (struct usb_mon_operations *ops)
2944 {
2945
2946         if (mon_ops)
2947                 return -EBUSY;
2948
2949         mon_ops = ops;
2950         mb();
2951         return 0;
2952 }
2953 EXPORT_SYMBOL_GPL (usb_mon_register);
2954
2955 void usb_mon_deregister (void)
2956 {
2957
2958         if (mon_ops == NULL) {
2959                 printk(KERN_ERR "USB: monitor was not registered\n");
2960                 return;
2961         }
2962         mon_ops = NULL;
2963         mb();
2964 }
2965 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2966
2967 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */