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