linux/drivers/usb/core/hcd.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright Linus Torvalds 1999
   4 * (C) Copyright Johannes Erdfelt 1999-2001
   5 * (C) Copyright Andreas Gal 1999
   6 * (C) Copyright Gregory P. Smith 1999
   7 * (C) Copyright Deti Fliegl 1999
   8 * (C) Copyright Randy Dunlap 2000
   9 * (C) Copyright David Brownell 2000-2002
  10 */
  11
  12#include <linux/bcd.h>
  13#include <linux/module.h>
  14#include <linux/version.h>
  15#include <linux/kernel.h>
  16#include <linux/sched/task_stack.h>
  17#include <linux/slab.h>
  18#include <linux/completion.h>
  19#include <linux/utsname.h>
  20#include <linux/mm.h>
  21#include <asm/io.h>
  22#include <linux/device.h>
  23#include <linux/dma-mapping.h>
  24#include <linux/mutex.h>
  25#include <asm/irq.h>
  26#include <asm/byteorder.h>
  27#include <asm/unaligned.h>
  28#include <linux/platform_device.h>
  29#include <linux/workqueue.h>
  30#include <linux/pm_runtime.h>
  31#include <linux/types.h>
  32#include <linux/genalloc.h>
  33#include <linux/io.h>
  34#include <linux/kcov.h>
  35
  36#include <linux/phy/phy.h>
  37#include <linux/usb.h>
  38#include <linux/usb/hcd.h>
  39#include <linux/usb/otg.h>
  40
  41#include "usb.h"
  42#include "phy.h"
  43
  44
  45/*-------------------------------------------------------------------------*/
  46
  47/*
  48 * USB Host Controller Driver framework
  49 *
  50 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
  51 * HCD-specific behaviors/bugs.
  52 *
  53 * This does error checks, tracks devices and urbs, and delegates to a
  54 * "hc_driver" only for code (and data) that really needs to know about
  55 * hardware differences.  That includes root hub registers, i/o queues,
  56 * and so on ... but as little else as possible.
  57 *
  58 * Shared code includes most of the "root hub" code (these are emulated,
  59 * though each HC's hardware works differently) and PCI glue, plus request
  60 * tracking overhead.  The HCD code should only block on spinlocks or on
  61 * hardware handshaking; blocking on software events (such as other kernel
  62 * threads releasing resources, or completing actions) is all generic.
  63 *
  64 * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
  65 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
  66 * only by the hub driver ... and that neither should be seen or used by
  67 * usb client device drivers.
  68 *
  69 * Contributors of ideas or unattributed patches include: David Brownell,
  70 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
  71 *
  72 * HISTORY:
  73 * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
  74 *              associated cleanup.  "usb_hcd" still != "usb_bus".
  75 * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
  76 */
  77
  78/*-------------------------------------------------------------------------*/
  79
  80/* Keep track of which host controller drivers are loaded */
  81unsigned long usb_hcds_loaded;
  82EXPORT_SYMBOL_GPL(usb_hcds_loaded);
  83
  84/* host controllers we manage */
  85DEFINE_IDR (usb_bus_idr);
  86EXPORT_SYMBOL_GPL (usb_bus_idr);
  87
  88/* used when allocating bus numbers */
  89#define USB_MAXBUS              64
  90
  91/* used when updating list of hcds */
  92DEFINE_MUTEX(usb_bus_idr_lock); /* exported only for usbfs */
  93EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
  94
  95/* used for controlling access to virtual root hubs */
  96static DEFINE_SPINLOCK(hcd_root_hub_lock);
  97
  98/* used when updating an endpoint's URB list */
  99static DEFINE_SPINLOCK(hcd_urb_list_lock);
 100
 101/* used to protect against unlinking URBs after the device is gone */
 102static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
 103
 104/* wait queue for synchronous unlinks */
 105DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 106
 107/*-------------------------------------------------------------------------*/
 108
 109/*
 110 * Sharable chunks of root hub code.
 111 */
 112
 113/*-------------------------------------------------------------------------*/
 114#define KERNEL_REL      bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
 115#define KERNEL_VER      bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
 116
 117/* usb 3.1 root hub device descriptor */
 118static const u8 usb31_rh_dev_descriptor[18] = {
 119        0x12,       /*  __u8  bLength; */
 120        USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
 121        0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
 122
 123        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 124        0x00,       /*  __u8  bDeviceSubClass; */
 125        0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
 126        0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
 127
 128        0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 129        0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
 130        KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 131
 132        0x03,       /*  __u8  iManufacturer; */
 133        0x02,       /*  __u8  iProduct; */
 134        0x01,       /*  __u8  iSerialNumber; */
 135        0x01        /*  __u8  bNumConfigurations; */
 136};
 137
 138/* usb 3.0 root hub device descriptor */
 139static const u8 usb3_rh_dev_descriptor[18] = {
 140        0x12,       /*  __u8  bLength; */
 141        USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
 142        0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
 143
 144        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 145        0x00,       /*  __u8  bDeviceSubClass; */
 146        0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
 147        0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
 148
 149        0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 150        0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
 151        KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 152
 153        0x03,       /*  __u8  iManufacturer; */
 154        0x02,       /*  __u8  iProduct; */
 155        0x01,       /*  __u8  iSerialNumber; */
 156        0x01        /*  __u8  bNumConfigurations; */
 157};
 158
 159/* usb 2.5 (wireless USB 1.0) root hub device descriptor */
 160static const u8 usb25_rh_dev_descriptor[18] = {
 161        0x12,       /*  __u8  bLength; */
 162        USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
 163        0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
 164
 165        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 166        0x00,       /*  __u8  bDeviceSubClass; */
 167        0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
 168        0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
 169
 170        0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 171        0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
 172        KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 173
 174        0x03,       /*  __u8  iManufacturer; */
 175        0x02,       /*  __u8  iProduct; */
 176        0x01,       /*  __u8  iSerialNumber; */
 177        0x01        /*  __u8  bNumConfigurations; */
 178};
 179
 180/* usb 2.0 root hub device descriptor */
 181static const u8 usb2_rh_dev_descriptor[18] = {
 182        0x12,       /*  __u8  bLength; */
 183        USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
 184        0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
 185
 186        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 187        0x00,       /*  __u8  bDeviceSubClass; */
 188        0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
 189        0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 190
 191        0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 192        0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
 193        KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 194
 195        0x03,       /*  __u8  iManufacturer; */
 196        0x02,       /*  __u8  iProduct; */
 197        0x01,       /*  __u8  iSerialNumber; */
 198        0x01        /*  __u8  bNumConfigurations; */
 199};
 200
 201/* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
 202
 203/* usb 1.1 root hub device descriptor */
 204static const u8 usb11_rh_dev_descriptor[18] = {
 205        0x12,       /*  __u8  bLength; */
 206        USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
 207        0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
 208
 209        0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
 210        0x00,       /*  __u8  bDeviceSubClass; */
 211        0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
 212        0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 213
 214        0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
 215        0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
 216        KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 217
 218        0x03,       /*  __u8  iManufacturer; */
 219        0x02,       /*  __u8  iProduct; */
 220        0x01,       /*  __u8  iSerialNumber; */
 221        0x01        /*  __u8  bNumConfigurations; */
 222};
 223
 224
 225/*-------------------------------------------------------------------------*/
 226
 227/* Configuration descriptors for our root hubs */
 228
 229static const u8 fs_rh_config_descriptor[] = {
 230
 231        /* one configuration */
 232        0x09,       /*  __u8  bLength; */
 233        USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
 234        0x19, 0x00, /*  __le16 wTotalLength; */
 235        0x01,       /*  __u8  bNumInterfaces; (1) */
 236        0x01,       /*  __u8  bConfigurationValue; */
 237        0x00,       /*  __u8  iConfiguration; */
 238        0xc0,       /*  __u8  bmAttributes;
 239                                 Bit 7: must be set,
 240                                     6: Self-powered,
 241                                     5: Remote wakeup,
 242                                     4..0: resvd */
 243        0x00,       /*  __u8  MaxPower; */
 244
 245        /* USB 1.1:
 246         * USB 2.0, single TT organization (mandatory):
 247         *      one interface, protocol 0
 248         *
 249         * USB 2.0, multiple TT organization (optional):
 250         *      two interfaces, protocols 1 (like single TT)
 251         *      and 2 (multiple TT mode) ... config is
 252         *      sometimes settable
 253         *      NOT IMPLEMENTED
 254         */
 255
 256        /* one interface */
 257        0x09,       /*  __u8  if_bLength; */
 258        USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
 259        0x00,       /*  __u8  if_bInterfaceNumber; */
 260        0x00,       /*  __u8  if_bAlternateSetting; */
 261        0x01,       /*  __u8  if_bNumEndpoints; */
 262        0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 263        0x00,       /*  __u8  if_bInterfaceSubClass; */
 264        0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 265        0x00,       /*  __u8  if_iInterface; */
 266
 267        /* one endpoint (status change endpoint) */
 268        0x07,       /*  __u8  ep_bLength; */
 269        USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
 270        0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 271        0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 272        0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
 273        0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
 274};
 275
 276static const u8 hs_rh_config_descriptor[] = {
 277
 278        /* one configuration */
 279        0x09,       /*  __u8  bLength; */
 280        USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
 281        0x19, 0x00, /*  __le16 wTotalLength; */
 282        0x01,       /*  __u8  bNumInterfaces; (1) */
 283        0x01,       /*  __u8  bConfigurationValue; */
 284        0x00,       /*  __u8  iConfiguration; */
 285        0xc0,       /*  __u8  bmAttributes;
 286                                 Bit 7: must be set,
 287                                     6: Self-powered,
 288                                     5: Remote wakeup,
 289                                     4..0: resvd */
 290        0x00,       /*  __u8  MaxPower; */
 291
 292        /* USB 1.1:
 293         * USB 2.0, single TT organization (mandatory):
 294         *      one interface, protocol 0
 295         *
 296         * USB 2.0, multiple TT organization (optional):
 297         *      two interfaces, protocols 1 (like single TT)
 298         *      and 2 (multiple TT mode) ... config is
 299         *      sometimes settable
 300         *      NOT IMPLEMENTED
 301         */
 302
 303        /* one interface */
 304        0x09,       /*  __u8  if_bLength; */
 305        USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
 306        0x00,       /*  __u8  if_bInterfaceNumber; */
 307        0x00,       /*  __u8  if_bAlternateSetting; */
 308        0x01,       /*  __u8  if_bNumEndpoints; */
 309        0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 310        0x00,       /*  __u8  if_bInterfaceSubClass; */
 311        0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
 312        0x00,       /*  __u8  if_iInterface; */
 313
 314        /* one endpoint (status change endpoint) */
 315        0x07,       /*  __u8  ep_bLength; */
 316        USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
 317        0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 318        0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 319                    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
 320                     * see hub.c:hub_configure() for details. */
 321        (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
 322        0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 323};
 324
 325static const u8 ss_rh_config_descriptor[] = {
 326        /* one configuration */
 327        0x09,       /*  __u8  bLength; */
 328        USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
 329        0x1f, 0x00, /*  __le16 wTotalLength; */
 330        0x01,       /*  __u8  bNumInterfaces; (1) */
 331        0x01,       /*  __u8  bConfigurationValue; */
 332        0x00,       /*  __u8  iConfiguration; */
 333        0xc0,       /*  __u8  bmAttributes;
 334                                 Bit 7: must be set,
 335                                     6: Self-powered,
 336                                     5: Remote wakeup,
 337                                     4..0: resvd */
 338        0x00,       /*  __u8  MaxPower; */
 339
 340        /* one interface */
 341        0x09,       /*  __u8  if_bLength; */
 342        USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
 343        0x00,       /*  __u8  if_bInterfaceNumber; */
 344        0x00,       /*  __u8  if_bAlternateSetting; */
 345        0x01,       /*  __u8  if_bNumEndpoints; */
 346        0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
 347        0x00,       /*  __u8  if_bInterfaceSubClass; */
 348        0x00,       /*  __u8  if_bInterfaceProtocol; */
 349        0x00,       /*  __u8  if_iInterface; */
 350
 351        /* one endpoint (status change endpoint) */
 352        0x07,       /*  __u8  ep_bLength; */
 353        USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
 354        0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 355        0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 356                    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
 357                     * see hub.c:hub_configure() for details. */
 358        (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
 359        0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 360
 361        /* one SuperSpeed endpoint companion descriptor */
 362        0x06,        /* __u8 ss_bLength */
 363        USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
 364                     /* Companion */
 365        0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
 366        0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
 367        0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
 368};
 369
 370/* authorized_default behaviour:
 371 * -1 is authorized for all devices except wireless (old behaviour)
 372 * 0 is unauthorized for all devices
 373 * 1 is authorized for all devices
 374 * 2 is authorized for internal devices
 375 */
 376#define USB_AUTHORIZE_WIRED     -1
 377#define USB_AUTHORIZE_NONE      0
 378#define USB_AUTHORIZE_ALL       1
 379#define USB_AUTHORIZE_INTERNAL  2
 380
 381static int authorized_default = USB_AUTHORIZE_WIRED;
 382module_param(authorized_default, int, S_IRUGO|S_IWUSR);
 383MODULE_PARM_DESC(authorized_default,
 384                "Default USB device authorization: 0 is not authorized, 1 is "
 385                "authorized, 2 is authorized for internal devices, -1 is "
 386                "authorized except for wireless USB (default, old behaviour)");
 387/*-------------------------------------------------------------------------*/
 388
 389/**
 390 * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
 391 * @s: Null-terminated ASCII (actually ISO-8859-1) string
 392 * @buf: Buffer for USB string descriptor (header + UTF-16LE)
 393 * @len: Length (in bytes; may be odd) of descriptor buffer.
 394 *
 395 * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
 396 * whichever is less.
 397 *
 398 * Note:
 399 * USB String descriptors can contain at most 126 characters; input
 400 * strings longer than that are truncated.
 401 */
 402static unsigned
 403ascii2desc(char const *s, u8 *buf, unsigned len)
 404{
 405        unsigned n, t = 2 + 2*strlen(s);
 406
 407        if (t > 254)
 408                t = 254;        /* Longest possible UTF string descriptor */
 409        if (len > t)
 410                len = t;
 411
 412        t += USB_DT_STRING << 8;        /* Now t is first 16 bits to store */
 413
 414        n = len;
 415        while (n--) {
 416                *buf++ = t;
 417                if (!n--)
 418                        break;
 419                *buf++ = t >> 8;
 420                t = (unsigned char)*s++;
 421        }
 422        return len;
 423}
 424
 425/**
 426 * rh_string() - provides string descriptors for root hub
 427 * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
 428 * @hcd: the host controller for this root hub
 429 * @data: buffer for output packet
 430 * @len: length of the provided buffer
 431 *
 432 * Produces either a manufacturer, product or serial number string for the
 433 * virtual root hub device.
 434 *
 435 * Return: The number of bytes filled in: the length of the descriptor or
 436 * of the provided buffer, whichever is less.
 437 */
 438static unsigned
 439rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
 440{
 441        char buf[100];
 442        char const *s;
 443        static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
 444
 445        /* language ids */
 446        switch (id) {
 447        case 0:
 448                /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
 449                /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
 450                if (len > 4)
 451                        len = 4;
 452                memcpy(data, langids, len);
 453                return len;
 454        case 1:
 455                /* Serial number */
 456                s = hcd->self.bus_name;
 457                break;
 458        case 2:
 459                /* Product name */
 460                s = hcd->product_desc;
 461                break;
 462        case 3:
 463                /* Manufacturer */
 464                snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
 465                        init_utsname()->release, hcd->driver->description);
 466                s = buf;
 467                break;
 468        default:
 469                /* Can't happen; caller guarantees it */
 470                return 0;
 471        }
 472
 473        return ascii2desc(s, data, len);
 474}
 475
 476
 477/* Root hub control transfers execute synchronously */
 478static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
 479{
 480        struct usb_ctrlrequest *cmd;
 481        u16             typeReq, wValue, wIndex, wLength;
 482        u8              *ubuf = urb->transfer_buffer;
 483        unsigned        len = 0;
 484        int             status;
 485        u8              patch_wakeup = 0;
 486        u8              patch_protocol = 0;
 487        u16             tbuf_size;
 488        u8              *tbuf = NULL;
 489        const u8        *bufp;
 490
 491        might_sleep();
 492
 493        spin_lock_irq(&hcd_root_hub_lock);
 494        status = usb_hcd_link_urb_to_ep(hcd, urb);
 495        spin_unlock_irq(&hcd_root_hub_lock);
 496        if (status)
 497                return status;
 498        urb->hcpriv = hcd;      /* Indicate it's queued */
 499
 500        cmd = (struct usb_ctrlrequest *) urb->setup_packet;
 501        typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
 502        wValue   = le16_to_cpu (cmd->wValue);
 503        wIndex   = le16_to_cpu (cmd->wIndex);
 504        wLength  = le16_to_cpu (cmd->wLength);
 505
 506        if (wLength > urb->transfer_buffer_length)
 507                goto error;
 508
 509        /*
 510         * tbuf should be at least as big as the
 511         * USB hub descriptor.
 512         */
 513        tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
 514        tbuf = kzalloc(tbuf_size, GFP_KERNEL);
 515        if (!tbuf) {
 516                status = -ENOMEM;
 517                goto err_alloc;
 518        }
 519
 520        bufp = tbuf;
 521
 522
 523        urb->actual_length = 0;
 524        switch (typeReq) {
 525
 526        /* DEVICE REQUESTS */
 527
 528        /* The root hub's remote wakeup enable bit is implemented using
 529         * driver model wakeup flags.  If this system supports wakeup
 530         * through USB, userspace may change the default "allow wakeup"
 531         * policy through sysfs or these calls.
 532         *
 533         * Most root hubs support wakeup from downstream devices, for
 534         * runtime power management (disabling USB clocks and reducing
 535         * VBUS power usage).  However, not all of them do so; silicon,
 536         * board, and BIOS bugs here are not uncommon, so these can't
 537         * be treated quite like external hubs.
 538         *
 539         * Likewise, not all root hubs will pass wakeup events upstream,
 540         * to wake up the whole system.  So don't assume root hub and
 541         * controller capabilities are identical.
 542         */
 543
 544        case DeviceRequest | USB_REQ_GET_STATUS:
 545                tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
 546                                        << USB_DEVICE_REMOTE_WAKEUP)
 547                                | (1 << USB_DEVICE_SELF_POWERED);
 548                tbuf[1] = 0;
 549                len = 2;
 550                break;
 551        case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
 552                if (wValue == USB_DEVICE_REMOTE_WAKEUP)
 553                        device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
 554                else
 555                        goto error;
 556                break;
 557        case DeviceOutRequest | USB_REQ_SET_FEATURE:
 558                if (device_can_wakeup(&hcd->self.root_hub->dev)
 559                                && wValue == USB_DEVICE_REMOTE_WAKEUP)
 560                        device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
 561                else
 562                        goto error;
 563                break;
 564        case DeviceRequest | USB_REQ_GET_CONFIGURATION:
 565                tbuf[0] = 1;
 566                len = 1;
 567                fallthrough;
 568        case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
 569                break;
 570        case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
 571                switch (wValue & 0xff00) {
 572                case USB_DT_DEVICE << 8:
 573                        switch (hcd->speed) {
 574                        case HCD_USB32:
 575                        case HCD_USB31:
 576                                bufp = usb31_rh_dev_descriptor;
 577                                break;
 578                        case HCD_USB3:
 579                                bufp = usb3_rh_dev_descriptor;
 580                                break;
 581                        case HCD_USB25:
 582                                bufp = usb25_rh_dev_descriptor;
 583                                break;
 584                        case HCD_USB2:
 585                                bufp = usb2_rh_dev_descriptor;
 586                                break;
 587                        case HCD_USB11:
 588                                bufp = usb11_rh_dev_descriptor;
 589                                break;
 590                        default:
 591                                goto error;
 592                        }
 593                        len = 18;
 594                        if (hcd->has_tt)
 595                                patch_protocol = 1;
 596                        break;
 597                case USB_DT_CONFIG << 8:
 598                        switch (hcd->speed) {
 599                        case HCD_USB32:
 600                        case HCD_USB31:
 601                        case HCD_USB3:
 602                                bufp = ss_rh_config_descriptor;
 603                                len = sizeof ss_rh_config_descriptor;
 604                                break;
 605                        case HCD_USB25:
 606                        case HCD_USB2:
 607                                bufp = hs_rh_config_descriptor;
 608                                len = sizeof hs_rh_config_descriptor;
 609                                break;
 610                        case HCD_USB11:
 611                                bufp = fs_rh_config_descriptor;
 612                                len = sizeof fs_rh_config_descriptor;
 613                                break;
 614                        default:
 615                                goto error;
 616                        }
 617                        if (device_can_wakeup(&hcd->self.root_hub->dev))
 618                                patch_wakeup = 1;
 619                        break;
 620                case USB_DT_STRING << 8:
 621                        if ((wValue & 0xff) < 4)
 622                                urb->actual_length = rh_string(wValue & 0xff,
 623                                                hcd, ubuf, wLength);
 624                        else /* unsupported IDs --> "protocol stall" */
 625                                goto error;
 626                        break;
 627                case USB_DT_BOS << 8:
 628                        goto nongeneric;
 629                default:
 630                        goto error;
 631                }
 632                break;
 633        case DeviceRequest | USB_REQ_GET_INTERFACE:
 634                tbuf[0] = 0;
 635                len = 1;
 636                fallthrough;
 637        case DeviceOutRequest | USB_REQ_SET_INTERFACE:
 638                break;
 639        case DeviceOutRequest | USB_REQ_SET_ADDRESS:
 640                /* wValue == urb->dev->devaddr */
 641                dev_dbg (hcd->self.controller, "root hub device address %d\n",
 642                        wValue);
 643                break;
 644
 645        /* INTERFACE REQUESTS (no defined feature/status flags) */
 646
 647        /* ENDPOINT REQUESTS */
 648
 649        case EndpointRequest | USB_REQ_GET_STATUS:
 650                /* ENDPOINT_HALT flag */
 651                tbuf[0] = 0;
 652                tbuf[1] = 0;
 653                len = 2;
 654                fallthrough;
 655        case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
 656        case EndpointOutRequest | USB_REQ_SET_FEATURE:
 657                dev_dbg (hcd->self.controller, "no endpoint features yet\n");
 658                break;
 659
 660        /* CLASS REQUESTS (and errors) */
 661
 662        default:
 663nongeneric:
 664                /* non-generic request */
 665                switch (typeReq) {
 666                case GetHubStatus:
 667                        len = 4;
 668                        break;
 669                case GetPortStatus:
 670                        if (wValue == HUB_PORT_STATUS)
 671                                len = 4;
 672                        else
 673                                /* other port status types return 8 bytes */
 674                                len = 8;
 675                        break;
 676                case GetHubDescriptor:
 677                        len = sizeof (struct usb_hub_descriptor);
 678                        break;
 679                case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
 680                        /* len is returned by hub_control */
 681                        break;
 682                }
 683                status = hcd->driver->hub_control (hcd,
 684                        typeReq, wValue, wIndex,
 685                        tbuf, wLength);
 686
 687                if (typeReq == GetHubDescriptor)
 688                        usb_hub_adjust_deviceremovable(hcd->self.root_hub,
 689                                (struct usb_hub_descriptor *)tbuf);
 690                break;
 691error:
 692                /* "protocol stall" on error */
 693                status = -EPIPE;
 694        }
 695
 696        if (status < 0) {
 697                len = 0;
 698                if (status != -EPIPE) {
 699                        dev_dbg (hcd->self.controller,
 700                                "CTRL: TypeReq=0x%x val=0x%x "
 701                                "idx=0x%x len=%d ==> %d\n",
 702                                typeReq, wValue, wIndex,
 703                                wLength, status);
 704                }
 705        } else if (status > 0) {
 706                /* hub_control may return the length of data copied. */
 707                len = status;
 708                status = 0;
 709        }
 710        if (len) {
 711                if (urb->transfer_buffer_length < len)
 712                        len = urb->transfer_buffer_length;
 713                urb->actual_length = len;
 714                /* always USB_DIR_IN, toward host */
 715                memcpy (ubuf, bufp, len);
 716
 717                /* report whether RH hardware supports remote wakeup */
 718                if (patch_wakeup &&
 719                                len > offsetof (struct usb_config_descriptor,
 720                                                bmAttributes))
 721                        ((struct usb_config_descriptor *)ubuf)->bmAttributes
 722                                |= USB_CONFIG_ATT_WAKEUP;
 723
 724                /* report whether RH hardware has an integrated TT */
 725                if (patch_protocol &&
 726                                len > offsetof(struct usb_device_descriptor,
 727                                                bDeviceProtocol))
 728                        ((struct usb_device_descriptor *) ubuf)->
 729                                bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
 730        }
 731
 732        kfree(tbuf);
 733 err_alloc:
 734
 735        /* any errors get returned through the urb completion */
 736        spin_lock_irq(&hcd_root_hub_lock);
 737        usb_hcd_unlink_urb_from_ep(hcd, urb);
 738        usb_hcd_giveback_urb(hcd, urb, status);
 739        spin_unlock_irq(&hcd_root_hub_lock);
 740        return 0;
 741}
 742
 743/*-------------------------------------------------------------------------*/
 744
 745/*
 746 * Root Hub interrupt transfers are polled using a timer if the
 747 * driver requests it; otherwise the driver is responsible for
 748 * calling usb_hcd_poll_rh_status() when an event occurs.
 749 *
 750 * Completions are called in_interrupt(), but they may or may not
 751 * be in_irq().
 752 */
 753void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 754{
 755        struct urb      *urb;
 756        int             length;
 757        unsigned long   flags;
 758        char            buffer[6];      /* Any root hubs with > 31 ports? */
 759
 760        if (unlikely(!hcd->rh_pollable))
 761                return;
 762        if (!hcd->uses_new_polling && !hcd->status_urb)
 763                return;
 764
 765        length = hcd->driver->hub_status_data(hcd, buffer);
 766        if (length > 0) {
 767
 768                /* try to complete the status urb */
 769                spin_lock_irqsave(&hcd_root_hub_lock, flags);
 770                urb = hcd->status_urb;
 771                if (urb) {
 772                        clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 773                        hcd->status_urb = NULL;
 774                        urb->actual_length = length;
 775                        memcpy(urb->transfer_buffer, buffer, length);
 776
 777                        usb_hcd_unlink_urb_from_ep(hcd, urb);
 778                        usb_hcd_giveback_urb(hcd, urb, 0);
 779                } else {
 780                        length = 0;
 781                        set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 782                }
 783                spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 784        }
 785
 786        /* The USB 2.0 spec says 256 ms.  This is close enough and won't
 787         * exceed that limit if HZ is 100. The math is more clunky than
 788         * maybe expected, this is to make sure that all timers for USB devices
 789         * fire at the same time to give the CPU a break in between */
 790        if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
 791                        (length == 0 && hcd->status_urb != NULL))
 792                mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 793}
 794EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
 795
 796/* timer callback */
 797static void rh_timer_func (struct timer_list *t)
 798{
 799        struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer);
 800
 801        usb_hcd_poll_rh_status(_hcd);
 802}
 803
 804/*-------------------------------------------------------------------------*/
 805
 806static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 807{
 808        int             retval;
 809        unsigned long   flags;
 810        unsigned        len = 1 + (urb->dev->maxchild / 8);
 811
 812        spin_lock_irqsave (&hcd_root_hub_lock, flags);
 813        if (hcd->status_urb || urb->transfer_buffer_length < len) {
 814                dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
 815                retval = -EINVAL;
 816                goto done;
 817        }
 818
 819        retval = usb_hcd_link_urb_to_ep(hcd, urb);
 820        if (retval)
 821                goto done;
 822
 823        hcd->status_urb = urb;
 824        urb->hcpriv = hcd;      /* indicate it's queued */
 825        if (!hcd->uses_new_polling)
 826                mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 827
 828        /* If a status change has already occurred, report it ASAP */
 829        else if (HCD_POLL_PENDING(hcd))
 830                mod_timer(&hcd->rh_timer, jiffies);
 831        retval = 0;
 832 done:
 833        spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
 834        return retval;
 835}
 836
 837static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
 838{
 839        if (usb_endpoint_xfer_int(&urb->ep->desc))
 840                return rh_queue_status (hcd, urb);
 841        if (usb_endpoint_xfer_control(&urb->ep->desc))
 842                return rh_call_control (hcd, urb);
 843        return -EINVAL;
 844}
 845
 846/*-------------------------------------------------------------------------*/
 847
 848/* Unlinks of root-hub control URBs are legal, but they don't do anything
 849 * since these URBs always execute synchronously.
 850 */
 851static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 852{
 853        unsigned long   flags;
 854        int             rc;
 855
 856        spin_lock_irqsave(&hcd_root_hub_lock, flags);
 857        rc = usb_hcd_check_unlink_urb(hcd, urb, status);
 858        if (rc)
 859                goto done;
 860
 861        if (usb_endpoint_num(&urb->ep->desc) == 0) {    /* Control URB */
 862                ;       /* Do nothing */
 863
 864        } else {                                /* Status URB */
 865                if (!hcd->uses_new_polling)
 866                        del_timer (&hcd->rh_timer);
 867                if (urb == hcd->status_urb) {
 868                        hcd->status_urb = NULL;
 869                        usb_hcd_unlink_urb_from_ep(hcd, urb);
 870                        usb_hcd_giveback_urb(hcd, urb, status);
 871                }
 872        }
 873 done:
 874        spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 875        return rc;
 876}
 877
 878
 879/*-------------------------------------------------------------------------*/
 880
 881/**
 882 * usb_bus_init - shared initialization code
 883 * @bus: the bus structure being initialized
 884 *
 885 * This code is used to initialize a usb_bus structure, memory for which is
 886 * separately managed.
 887 */
 888static void usb_bus_init (struct usb_bus *bus)
 889{
 890        memset (&bus->devmap, 0, sizeof(struct usb_devmap));
 891
 892        bus->devnum_next = 1;
 893
 894        bus->root_hub = NULL;
 895        bus->busnum = -1;
 896        bus->bandwidth_allocated = 0;
 897        bus->bandwidth_int_reqs  = 0;
 898        bus->bandwidth_isoc_reqs = 0;
 899        mutex_init(&bus->devnum_next_mutex);
 900}
 901
 902/*-------------------------------------------------------------------------*/
 903
 904/**
 905 * usb_register_bus - registers the USB host controller with the usb core
 906 * @bus: pointer to the bus to register
 907 * Context: !in_interrupt()
 908 *
 909 * Assigns a bus number, and links the controller into usbcore data
 910 * structures so that it can be seen by scanning the bus list.
 911 *
 912 * Return: 0 if successful. A negative error code otherwise.
 913 */
 914static int usb_register_bus(struct usb_bus *bus)
 915{
 916        int result = -E2BIG;
 917        int busnum;
 918
 919        mutex_lock(&usb_bus_idr_lock);
 920        busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
 921        if (busnum < 0) {
 922                pr_err("%s: failed to get bus number\n", usbcore_name);
 923                goto error_find_busnum;
 924        }
 925        bus->busnum = busnum;
 926        mutex_unlock(&usb_bus_idr_lock);
 927
 928        usb_notify_add_bus(bus);
 929
 930        dev_info (bus->controller, "new USB bus registered, assigned bus "
 931                  "number %d\n", bus->busnum);
 932        return 0;
 933
 934error_find_busnum:
 935        mutex_unlock(&usb_bus_idr_lock);
 936        return result;
 937}
 938
 939/**
 940 * usb_deregister_bus - deregisters the USB host controller
 941 * @bus: pointer to the bus to deregister
 942 * Context: !in_interrupt()
 943 *
 944 * Recycles the bus number, and unlinks the controller from usbcore data
 945 * structures so that it won't be seen by scanning the bus list.
 946 */
 947static void usb_deregister_bus (struct usb_bus *bus)
 948{
 949        dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
 950
 951        /*
 952         * NOTE: make sure that all the devices are removed by the
 953         * controller code, as well as having it call this when cleaning
 954         * itself up
 955         */
 956        mutex_lock(&usb_bus_idr_lock);
 957        idr_remove(&usb_bus_idr, bus->busnum);
 958        mutex_unlock(&usb_bus_idr_lock);
 959
 960        usb_notify_remove_bus(bus);
 961}
 962
 963/**
 964 * register_root_hub - called by usb_add_hcd() to register a root hub
 965 * @hcd: host controller for this root hub
 966 *
 967 * This function registers the root hub with the USB subsystem.  It sets up
 968 * the device properly in the device tree and then calls usb_new_device()
 969 * to register the usb device.  It also assigns the root hub's USB address
 970 * (always 1).
 971 *
 972 * Return: 0 if successful. A negative error code otherwise.
 973 */
 974static int register_root_hub(struct usb_hcd *hcd)
 975{
 976        struct device *parent_dev = hcd->self.controller;
 977        struct usb_device *usb_dev = hcd->self.root_hub;
 978        const int devnum = 1;
 979        int retval;
 980
 981        usb_dev->devnum = devnum;
 982        usb_dev->bus->devnum_next = devnum + 1;
 983        set_bit (devnum, usb_dev->bus->devmap.devicemap);
 984        usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
 985
 986        mutex_lock(&usb_bus_idr_lock);
 987
 988        usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
 989        retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
 990        if (retval != sizeof usb_dev->descriptor) {
 991                mutex_unlock(&usb_bus_idr_lock);
 992                dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
 993                                dev_name(&usb_dev->dev), retval);
 994                return (retval < 0) ? retval : -EMSGSIZE;
 995        }
 996
 997        if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
 998                retval = usb_get_bos_descriptor(usb_dev);
 999                if (!retval) {
1000                        usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
1001                } else if (usb_dev->speed >= USB_SPEED_SUPER) {
1002                        mutex_unlock(&usb_bus_idr_lock);
1003                        dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
1004                                        dev_name(&usb_dev->dev), retval);
1005                        return retval;
1006                }
1007        }
1008
1009        retval = usb_new_device (usb_dev);
1010        if (retval) {
1011                dev_err (parent_dev, "can't register root hub for %s, %d\n",
1012                                dev_name(&usb_dev->dev), retval);
1013        } else {
1014                spin_lock_irq (&hcd_root_hub_lock);
1015                hcd->rh_registered = 1;
1016                spin_unlock_irq (&hcd_root_hub_lock);
1017
1018                /* Did the HC die before the root hub was registered? */
1019                if (HCD_DEAD(hcd))
1020                        usb_hc_died (hcd);      /* This time clean up */
1021        }
1022        mutex_unlock(&usb_bus_idr_lock);
1023
1024        return retval;
1025}
1026
1027/*
1028 * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
1029 * @bus: the bus which the root hub belongs to
1030 * @portnum: the port which is being resumed
1031 *
1032 * HCDs should call this function when they know that a resume signal is
1033 * being sent to a root-hub port.  The root hub will be prevented from
1034 * going into autosuspend until usb_hcd_end_port_resume() is called.
1035 *
1036 * The bus's private lock must be held by the caller.
1037 */
1038void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
1039{
1040        unsigned bit = 1 << portnum;
1041
1042        if (!(bus->resuming_ports & bit)) {
1043                bus->resuming_ports |= bit;
1044                pm_runtime_get_noresume(&bus->root_hub->dev);
1045        }
1046}
1047EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
1048
1049/*
1050 * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
1051 * @bus: the bus which the root hub belongs to
1052 * @portnum: the port which is being resumed
1053 *
1054 * HCDs should call this function when they know that a resume signal has
1055 * stopped being sent to a root-hub port.  The root hub will be allowed to
1056 * autosuspend again.
1057 *
1058 * The bus's private lock must be held by the caller.
1059 */
1060void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
1061{
1062        unsigned bit = 1 << portnum;
1063
1064        if (bus->resuming_ports & bit) {
1065                bus->resuming_ports &= ~bit;
1066                pm_runtime_put_noidle(&bus->root_hub->dev);
1067        }
1068}
1069EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
1070
1071/*-------------------------------------------------------------------------*/
1072
1073/**
1074 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1075 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1076 * @is_input: true iff the transaction sends data to the host
1077 * @isoc: true for isochronous transactions, false for interrupt ones
1078 * @bytecount: how many bytes in the transaction.
1079 *
1080 * Return: Approximate bus time in nanoseconds for a periodic transaction.
1081 *
1082 * Note:
1083 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1084 * scheduled in software, this function is only used for such scheduling.
1085 */
1086long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1087{
1088        unsigned long   tmp;
1089
1090        switch (speed) {
1091        case USB_SPEED_LOW:     /* INTR only */
1092                if (is_input) {
1093                        tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1094                        return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1095                } else {
1096                        tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1097                        return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
1098                }
1099        case USB_SPEED_FULL:    /* ISOC or INTR */
1100                if (isoc) {
1101                        tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1102                        return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
1103                } else {
1104                        tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1105                        return 9107L + BW_HOST_DELAY + tmp;
1106                }
1107        case USB_SPEED_HIGH:    /* ISOC or INTR */
1108                /* FIXME adjust for input vs output */
1109                if (isoc)
1110                        tmp = HS_NSECS_ISO (bytecount);
1111                else
1112                        tmp = HS_NSECS (bytecount);
1113                return tmp;
1114        default:
1115                pr_debug ("%s: bogus device speed!\n", usbcore_name);
1116                return -1;
1117        }
1118}
1119EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1120
1121
1122/*-------------------------------------------------------------------------*/
1123
1124/*
1125 * Generic HC operations.
1126 */
1127
1128/*-------------------------------------------------------------------------*/
1129
1130/**
1131 * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1132 * @hcd: host controller to which @urb was submitted
1133 * @urb: URB being submitted
1134 *
1135 * Host controller drivers should call this routine in their enqueue()
1136 * method.  The HCD's private spinlock must be held and interrupts must
1137 * be disabled.  The actions carried out here are required for URB
1138 * submission, as well as for endpoint shutdown and for usb_kill_urb.
1139 *
1140 * Return: 0 for no error, otherwise a negative error code (in which case
1141 * the enqueue() method must fail).  If no error occurs but enqueue() fails
1142 * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1143 * the private spinlock and returning.
1144 */
1145int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1146{
1147        int             rc = 0;
1148
1149        spin_lock(&hcd_urb_list_lock);
1150
1151        /* Check that the URB isn't being killed */
1152        if (unlikely(atomic_read(&urb->reject))) {
1153                rc = -EPERM;
1154                goto done;
1155        }
1156
1157        if (unlikely(!urb->ep->enabled)) {
1158                rc = -ENOENT;
1159                goto done;
1160        }
1161
1162        if (unlikely(!urb->dev->can_submit)) {
1163                rc = -EHOSTUNREACH;
1164                goto done;
1165        }
1166
1167        /*
1168         * Check the host controller's state and add the URB to the
1169         * endpoint's queue.
1170         */
1171        if (HCD_RH_RUNNING(hcd)) {
1172                urb->unlinked = 0;
1173                list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1174        } else {
1175                rc = -ESHUTDOWN;
1176                goto done;
1177        }
1178 done:
1179        spin_unlock(&hcd_urb_list_lock);
1180        return rc;
1181}
1182EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1183
1184/**
1185 * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1186 * @hcd: host controller to which @urb was submitted
1187 * @urb: URB being checked for unlinkability
1188 * @status: error code to store in @urb if the unlink succeeds
1189 *
1190 * Host controller drivers should call this routine in their dequeue()
1191 * method.  The HCD's private spinlock must be held and interrupts must
1192 * be disabled.  The actions carried out here are required for making
1193 * sure than an unlink is valid.
1194 *
1195 * Return: 0 for no error, otherwise a negative error code (in which case
1196 * the dequeue() method must fail).  The possible error codes are:
1197 *
1198 *      -EIDRM: @urb was not submitted or has already completed.
1199 *              The completion function may not have been called yet.
1200 *
1201 *      -EBUSY: @urb has already been unlinked.
1202 */
1203int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1204                int status)
1205{
1206        struct list_head        *tmp;
1207
1208        /* insist the urb is still queued */
1209        list_for_each(tmp, &urb->ep->urb_list) {
1210                if (tmp == &urb->urb_list)
1211                        break;
1212        }
1213        if (tmp != &urb->urb_list)
1214                return -EIDRM;
1215
1216        /* Any status except -EINPROGRESS means something already started to
1217         * unlink this URB from the hardware.  So there's no more work to do.
1218         */
1219        if (urb->unlinked)
1220                return -EBUSY;
1221        urb->unlinked = status;
1222        return 0;
1223}
1224EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1225
1226/**
1227 * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1228 * @hcd: host controller to which @urb was submitted
1229 * @urb: URB being unlinked
1230 *
1231 * Host controller drivers should call this routine before calling
1232 * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
1233 * interrupts must be disabled.  The actions carried out here are required
1234 * for URB completion.
1235 */
1236void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1237{
1238        /* clear all state linking urb to this dev (and hcd) */
1239        spin_lock(&hcd_urb_list_lock);
1240        list_del_init(&urb->urb_list);
1241        spin_unlock(&hcd_urb_list_lock);
1242}
1243EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1244
1245/*
1246 * Some usb host controllers can only perform dma using a small SRAM area.
1247 * The usb core itself is however optimized for host controllers that can dma
1248 * using regular system memory - like pci devices doing bus mastering.
1249 *
1250 * To support host controllers with limited dma capabilities we provide dma
1251 * bounce buffers. This feature can be enabled by initializing
1252 * hcd->localmem_pool using usb_hcd_setup_local_mem().
1253 *
1254 * The initialized hcd->localmem_pool then tells the usb code to allocate all
1255 * data for dma using the genalloc API.
1256 *
1257 * So, to summarize...
1258 *
1259 * - We need "local" memory, canonical example being
1260 *   a small SRAM on a discrete controller being the
1261 *   only memory that the controller can read ...
1262 *   (a) "normal" kernel memory is no good, and
1263 *   (b) there's not enough to share
1264 *
1265 * - So we use that, even though the primary requirement
1266 *   is that the memory be "local" (hence addressable
1267 *   by that device), not "coherent".
1268 *
1269 */
1270
1271static int hcd_alloc_coherent(struct usb_bus *bus,
1272                              gfp_t mem_flags, dma_addr_t *dma_handle,
1273                              void **vaddr_handle, size_t size,
1274                              enum dma_data_direction dir)
1275{
1276        unsigned char *vaddr;
1277
1278        if (*vaddr_handle == NULL) {
1279                WARN_ON_ONCE(1);
1280                return -EFAULT;
1281        }
1282
1283        vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1284                                 mem_flags, dma_handle);
1285        if (!vaddr)
1286                return -ENOMEM;
1287
1288        /*
1289         * Store the virtual address of the buffer at the end
1290         * of the allocated dma buffer. The size of the buffer
1291         * may be uneven so use unaligned functions instead
1292         * of just rounding up. It makes sense to optimize for
1293         * memory footprint over access speed since the amount
1294         * of memory available for dma may be limited.
1295         */
1296        put_unaligned((unsigned long)*vaddr_handle,
1297                      (unsigned long *)(vaddr + size));
1298
1299        if (dir == DMA_TO_DEVICE)
1300                memcpy(vaddr, *vaddr_handle, size);
1301
1302        *vaddr_handle = vaddr;
1303        return 0;
1304}
1305
1306static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1307                              void **vaddr_handle, size_t size,
1308                              enum dma_data_direction dir)
1309{
1310        unsigned char *vaddr = *vaddr_handle;
1311
1312        vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1313
1314        if (dir == DMA_FROM_DEVICE)
1315                memcpy(vaddr, *vaddr_handle, size);
1316
1317        hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1318
1319        *vaddr_handle = vaddr;
1320        *dma_handle = 0;
1321}
1322
1323void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1324{
1325        if (IS_ENABLED(CONFIG_HAS_DMA) &&
1326            (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
1327                dma_unmap_single(hcd->self.sysdev,
1328                                urb->setup_dma,
1329                                sizeof(struct usb_ctrlrequest),
1330                                DMA_TO_DEVICE);
1331        else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1332                hcd_free_coherent(urb->dev->bus,
1333                                &urb->setup_dma,
1334                                (void **) &urb->setup_packet,
1335                                sizeof(struct usb_ctrlrequest),
1336                                DMA_TO_DEVICE);
1337
1338        /* Make it safe to call this routine more than once */
1339        urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1340}
1341EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1342
1343static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1344{
1345        if (hcd->driver->unmap_urb_for_dma)
1346                hcd->driver->unmap_urb_for_dma(hcd, urb);
1347        else
1348                usb_hcd_unmap_urb_for_dma(hcd, urb);
1349}
1350
1351void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1352{
1353        enum dma_data_direction dir;
1354
1355        usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1356
1357        dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1358        if (IS_ENABLED(CONFIG_HAS_DMA) &&
1359            (urb->transfer_flags & URB_DMA_MAP_SG))
1360                dma_unmap_sg(hcd->self.sysdev,
1361                                urb->sg,
1362                                urb->num_sgs,
1363                                dir);
1364        else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1365                 (urb->transfer_flags & URB_DMA_MAP_PAGE))
1366                dma_unmap_page(hcd->self.sysdev,
1367                                urb->transfer_dma,
1368                                urb->transfer_buffer_length,
1369                                dir);
1370        else if (IS_ENABLED(CONFIG_HAS_DMA) &&
1371                 (urb->transfer_flags & URB_DMA_MAP_SINGLE))
1372                dma_unmap_single(hcd->self.sysdev,
1373                                urb->transfer_dma,
1374                                urb->transfer_buffer_length,
1375                                dir);
1376        else if (urb->transfer_flags & URB_MAP_LOCAL)
1377                hcd_free_coherent(urb->dev->bus,
1378                                &urb->transfer_dma,
1379                                &urb->transfer_buffer,
1380                                urb->transfer_buffer_length,
1381                                dir);
1382
1383        /* Make it safe to call this routine more than once */
1384        urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1385                        URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1386}
1387EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1388
1389static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1390                           gfp_t mem_flags)
1391{
1392        if (hcd->driver->map_urb_for_dma)
1393                return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1394        else
1395                return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1396}
1397
1398int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1399                            gfp_t mem_flags)
1400{
1401        enum dma_data_direction dir;
1402        int ret = 0;
1403
1404        /* Map the URB's buffers for DMA access.
1405         * Lower level HCD code should use *_dma exclusively,
1406         * unless it uses pio or talks to another transport,
1407         * or uses the provided scatter gather list for bulk.
1408         */
1409
1410        if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1411                if (hcd->self.uses_pio_for_control)
1412                        return ret;
1413                if (hcd->localmem_pool) {
1414                        ret = hcd_alloc_coherent(
1415                                        urb->dev->bus, mem_flags,
1416                                        &urb->setup_dma,
1417                                        (void **)&urb->setup_packet,
1418                                        sizeof(struct usb_ctrlrequest),
1419                                        DMA_TO_DEVICE);
1420                        if (ret)
1421                                return ret;
1422                        urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1423                } else if (hcd_uses_dma(hcd)) {
1424                        if (object_is_on_stack(urb->setup_packet)) {
1425                                WARN_ONCE(1, "setup packet is on stack\n");
1426                                return -EAGAIN;
1427                        }
1428
1429                        urb->setup_dma = dma_map_single(
1430                                        hcd->self.sysdev,
1431                                        urb->setup_packet,
1432                                        sizeof(struct usb_ctrlrequest),
1433                                        DMA_TO_DEVICE);
1434                        if (dma_mapping_error(hcd->self.sysdev,
1435                                                urb->setup_dma))
1436                                return -EAGAIN;
1437                        urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1438                }
1439        }
1440
1441        dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1442        if (urb->transfer_buffer_length != 0
1443            && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1444                if (hcd->localmem_pool) {
1445                        ret = hcd_alloc_coherent(
1446                                        urb->dev->bus, mem_flags,
1447                                        &urb->transfer_dma,
1448                                        &urb->transfer_buffer,
1449                                        urb->transfer_buffer_length,
1450                                        dir);
1451                        if (ret == 0)
1452                                urb->transfer_flags |= URB_MAP_LOCAL;
1453                } else if (hcd_uses_dma(hcd)) {
1454                        if (urb->num_sgs) {
1455                                int n;
1456
1457                                /* We don't support sg for isoc transfers ! */
1458                                if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
1459                                        WARN_ON(1);
1460                                        return -EINVAL;
1461                                }
1462
1463                                n = dma_map_sg(
1464                                                hcd->self.sysdev,
1465                                                urb->sg,
1466                                                urb->num_sgs,
1467                                                dir);
1468                                if (n <= 0)
1469                                        ret = -EAGAIN;
1470                                else
1471                                        urb->transfer_flags |= URB_DMA_MAP_SG;
1472                                urb->num_mapped_sgs = n;
1473                                if (n != urb->num_sgs)
1474                                        urb->transfer_flags |=
1475                                                        URB_DMA_SG_COMBINED;
1476                        } else if (urb->sg) {
1477                                struct scatterlist *sg = urb->sg;
1478                                urb->transfer_dma = dma_map_page(
1479                                                hcd->self.sysdev,
1480                                                sg_page(sg),
1481                                                sg->offset,
1482                                                urb->transfer_buffer_length,
1483                                                dir);
1484                                if (dma_mapping_error(hcd->self.sysdev,
1485                                                urb->transfer_dma))
1486                                        ret = -EAGAIN;
1487                                else
1488                                        urb->transfer_flags |= URB_DMA_MAP_PAGE;
1489                        } else if (object_is_on_stack(urb->transfer_buffer)) {
1490                                WARN_ONCE(1, "transfer buffer is on stack\n");
1491                                ret = -EAGAIN;
1492                        } else {
1493                                urb->transfer_dma = dma_map_single(
1494                                                hcd->self.sysdev,
1495                                                urb->transfer_buffer,
1496                                                urb->transfer_buffer_length,
1497                                                dir);
1498                                if (dma_mapping_error(hcd->self.sysdev,
1499                                                urb->transfer_dma))
1500                                        ret = -EAGAIN;
1501                                else
1502                                        urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1503                        }
1504                }
1505                if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1506                                URB_SETUP_MAP_LOCAL)))
1507                        usb_hcd_unmap_urb_for_dma(hcd, urb);
1508        }
1509        return ret;
1510}
1511EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1512
1513/*-------------------------------------------------------------------------*/
1514
1515/* may be called in any context with a valid urb->dev usecount
1516 * caller surrenders "ownership" of urb
1517 * expects usb_submit_urb() to have sanity checked and conditioned all
1518 * inputs in the urb
1519 */
1520int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1521{
1522        int                     status;
1523        struct usb_hcd          *hcd = bus_to_hcd(urb->dev->bus);
1524
1525        /* increment urb's reference count as part of giving it to the HCD
1526         * (which will control it).  HCD guarantees that it either returns
1527         * an error or calls giveback(), but not both.
1528         */
1529        usb_get_urb(urb);
1530        atomic_inc(&urb->use_count);
1531        atomic_inc(&urb->dev->urbnum);
1532        usbmon_urb_submit(&hcd->self, urb);
1533
1534        /* NOTE requirements on root-hub callers (usbfs and the hub
1535         * driver, for now):  URBs' urb->transfer_buffer must be
1536         * valid and usb_buffer_{sync,unmap}() not be needed, since
1537         * they could clobber root hub response data.  Also, control
1538         * URBs must be submitted in process context with interrupts
1539         * enabled.
1540         */
1541
1542        if (is_root_hub(urb->dev)) {
1543                status = rh_urb_enqueue(hcd, urb);
1544        } else {
1545                status = map_urb_for_dma(hcd, urb, mem_flags);
1546                if (likely(status == 0)) {
1547                        status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1548                        if (unlikely(status))
1549                                unmap_urb_for_dma(hcd, urb);
1550                }
1551        }
1552
1553        if (unlikely(status)) {
1554                usbmon_urb_submit_error(&hcd->self, urb, status);
1555                urb->hcpriv = NULL;
1556                INIT_LIST_HEAD(&urb->urb_list);
1557                atomic_dec(&urb->use_count);
1558                atomic_dec(&urb->dev->urbnum);
1559                if (atomic_read(&urb->reject))
1560                        wake_up(&usb_kill_urb_queue);
1561                usb_put_urb(urb);
1562        }
1563        return status;
1564}
1565
1566/*-------------------------------------------------------------------------*/
1567
1568/* this makes the hcd giveback() the urb more quickly, by kicking it
1569 * off hardware queues (which may take a while) and returning it as
1570 * soon as practical.  we've already set up the urb's return status,
1571 * but we can't know if the callback completed already.
1572 */
1573static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1574{
1575        int             value;
1576
1577        if (is_root_hub(urb->dev))
1578                value = usb_rh_urb_dequeue(hcd, urb, status);
1579        else {
1580
1581                /* The only reason an HCD might fail this call is if
1582                 * it has not yet fully queued the urb to begin with.
1583                 * Such failures should be harmless. */
1584                value = hcd->driver->urb_dequeue(hcd, urb, status);
1585        }
1586        return value;
1587}
1588
1589/*
1590 * called in any context
1591 *
1592 * caller guarantees urb won't be recycled till both unlink()
1593 * and the urb's completion function return
1594 */
1595int usb_hcd_unlink_urb (struct urb *urb, int status)
1596{
1597        struct usb_hcd          *hcd;
1598        struct usb_device       *udev = urb->dev;
1599        int                     retval = -EIDRM;
1600        unsigned long           flags;
1601
1602        /* Prevent the device and bus from going away while
1603         * the unlink is carried out.  If they are already gone
1604         * then urb->use_count must be 0, since disconnected
1605         * devices can't have any active URBs.
1606         */
1607        spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1608        if (atomic_read(&urb->use_count) > 0) {
1609                retval = 0;
1610                usb_get_dev(udev);
1611        }
1612        spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1613        if (retval == 0) {
1614                hcd = bus_to_hcd(urb->dev->bus);
1615                retval = unlink1(hcd, urb, status);
1616                if (retval == 0)
1617                        retval = -EINPROGRESS;
1618                else if (retval != -EIDRM && retval != -EBUSY)
1619                        dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
1620                                        urb, retval);
1621                usb_put_dev(udev);
1622        }
1623        return retval;
1624}
1625
1626/*-------------------------------------------------------------------------*/
1627
1628static void __usb_hcd_giveback_urb(struct urb *urb)
1629{
1630        struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1631        struct usb_anchor *anchor = urb->anchor;
1632        int status = urb->unlinked;
1633
1634        urb->hcpriv = NULL;
1635        if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1636            urb->actual_length < urb->transfer_buffer_length &&
1637            !status))
1638                status = -EREMOTEIO;
1639
1640        unmap_urb_for_dma(hcd, urb);
1641        usbmon_urb_complete(&hcd->self, urb, status);
1642        usb_anchor_suspend_wakeups(anchor);
1643        usb_unanchor_urb(urb);
1644        if (likely(status == 0))
1645                usb_led_activity(USB_LED_EVENT_HOST);
1646
1647        /* pass ownership to the completion handler */
1648        urb->status = status;
1649        kcov_remote_start_usb((u64)urb->dev->bus->busnum);
1650        urb->complete(urb);
1651        kcov_remote_stop();
1652
1653        usb_anchor_resume_wakeups(anchor);
1654        atomic_dec(&urb->use_count);
1655        if (unlikely(atomic_read(&urb->reject)))
1656                wake_up(&usb_kill_urb_queue);
1657        usb_put_urb(urb);
1658}
1659
1660static void usb_giveback_urb_bh(unsigned long param)
1661{
1662        struct giveback_urb_bh *bh = (struct giveback_urb_bh *)param;
1663        struct list_head local_list;
1664
1665        spin_lock_irq(&bh->lock);
1666        bh->running = true;
1667 restart:
1668        list_replace_init(&bh->head, &local_list);
1669        spin_unlock_irq(&bh->lock);
1670
1671        while (!list_empty(&local_list)) {
1672                struct urb *urb;
1673
1674                urb = list_entry(local_list.next, struct urb, urb_list);
1675                list_del_init(&urb->urb_list);
1676                bh->completing_ep = urb->ep;
1677                __usb_hcd_giveback_urb(urb);
1678                bh->completing_ep = NULL;
1679        }
1680
1681        /* check if there are new URBs to giveback */
1682        spin_lock_irq(&bh->lock);
1683        if (!list_empty(&bh->head))
1684                goto restart;
1685        bh->running = false;
1686        spin_unlock_irq(&bh->lock);
1687}
1688
1689/**
1690 * usb_hcd_giveback_urb - return URB from HCD to device driver
1691 * @hcd: host controller returning the URB
1692 * @urb: urb being returned to the USB device driver.
1693 * @status: completion status code for the URB.
1694 * Context: in_interrupt()
1695 *
1696 * This hands the URB from HCD to its USB device driver, using its
1697 * completion function.  The HCD has freed all per-urb resources
1698 * (and is done using urb->hcpriv).  It also released all HCD locks;
1699 * the device driver won't cause problems if it frees, modifies,
1700 * or resubmits this URB.
1701 *
1702 * If @urb was unlinked, the value of @status will be overridden by
1703 * @urb->unlinked.  Erroneous short transfers are detected in case
1704 * the HCD hasn't checked for them.
1705 */
1706void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1707{
1708        struct giveback_urb_bh *bh;
1709        bool running, high_prio_bh;
1710
1711        /* pass status to tasklet via unlinked */
1712        if (likely(!urb->unlinked))
1713                urb->unlinked = status;
1714
1715        if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
1716                __usb_hcd_giveback_urb(urb);
1717                return;
1718        }
1719
1720        if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
1721                bh = &hcd->high_prio_bh;
1722                high_prio_bh = true;
1723        } else {
1724                bh = &hcd->low_prio_bh;
1725                high_prio_bh = false;
1726        }
1727
1728        spin_lock(&bh->lock);
1729        list_add_tail(&urb->urb_list, &bh->head);
1730        running = bh->running;
1731        spin_unlock(&bh->lock);
1732
1733        if (running)
1734                ;
1735        else if (high_prio_bh)
1736                tasklet_hi_schedule(&bh->bh);
1737        else
1738                tasklet_schedule(&bh->bh);
1739}
1740EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1741
1742/*-------------------------------------------------------------------------*/
1743
1744/* Cancel all URBs pending on this endpoint and wait for the endpoint's
1745 * queue to drain completely.  The caller must first insure that no more
1746 * URBs can be submitted for this endpoint.
1747 */
1748void usb_hcd_flush_endpoint(struct usb_device *udev,
1749                struct usb_host_endpoint *ep)
1750{
1751        struct usb_hcd          *hcd;
1752        struct urb              *urb;
1753
1754        if (!ep)
1755                return;
1756        might_sleep();
1757        hcd = bus_to_hcd(udev->bus);
1758
1759        /* No more submits can occur */
1760        spin_lock_irq(&hcd_urb_list_lock);
1761rescan:
1762        list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
1763                int     is_in;
1764
1765                if (urb->unlinked)
1766                        continue;
1767                usb_get_urb (urb);
1768                is_in = usb_urb_dir_in(urb);
1769                spin_unlock(&hcd_urb_list_lock);
1770
1771                /* kick hcd */
1772                unlink1(hcd, urb, -ESHUTDOWN);
1773                dev_dbg (hcd->self.controller,
1774                        "shutdown urb %pK ep%d%s-%s\n",
1775                        urb, usb_endpoint_num(&ep->desc),
1776                        is_in ? "in" : "out",
1777                        usb_ep_type_string(usb_endpoint_type(&ep->desc)));
1778                usb_put_urb (urb);
1779
1780                /* list contents may have changed */
1781                spin_lock(&hcd_urb_list_lock);
1782                goto rescan;
1783        }
1784        spin_unlock_irq(&hcd_urb_list_lock);
1785
1786        /* Wait until the endpoint queue is completely empty */
1787        while (!list_empty (&ep->urb_list)) {
1788                spin_lock_irq(&hcd_urb_list_lock);
1789
1790                /* The list may have changed while we acquired the spinlock */
1791                urb = NULL;
1792                if (!list_empty (&ep->urb_list)) {
1793                        urb = list_entry (ep->urb_list.prev, struct urb,
1794                                        urb_list);
1795                        usb_get_urb (urb);
1796                }
1797                spin_unlock_irq(&hcd_urb_list_lock);
1798
1799                if (urb) {
1800                        usb_kill_urb (urb);
1801                        usb_put_urb (urb);
1802                }
1803        }
1804}
1805
1806/**
1807 * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1808 *                              the bus bandwidth
1809 * @udev: target &usb_device
1810 * @new_config: new configuration to install
1811 * @cur_alt: the current alternate interface setting
1812 * @new_alt: alternate interface setting that is being installed
1813 *
1814 * To change configurations, pass in the new configuration in new_config,
1815 * and pass NULL for cur_alt and new_alt.
1816 *
1817 * To reset a device's configuration (put the device in the ADDRESSED state),
1818 * pass in NULL for new_config, cur_alt, and new_alt.
1819 *
1820 * To change alternate interface settings, pass in NULL for new_config,
1821 * pass in the current alternate interface setting in cur_alt,
1822 * and pass in the new alternate interface setting in new_alt.
1823 *
1824 * Return: An error if the requested bandwidth change exceeds the
1825 * bus bandwidth or host controller internal resources.
1826 */
1827int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1828                struct usb_host_config *new_config,
1829                struct usb_host_interface *cur_alt,
1830                struct usb_host_interface *new_alt)
1831{
1832        int num_intfs, i, j;
1833        struct usb_host_interface *alt = NULL;
1834        int ret = 0;
1835        struct usb_hcd *hcd;
1836        struct usb_host_endpoint *ep;
1837
1838        hcd = bus_to_hcd(udev->bus);
1839        if (!hcd->driver->check_bandwidth)
1840                return 0;
1841
1842        /* Configuration is being removed - set configuration 0 */
1843        if (!new_config && !cur_alt) {
1844                for (i = 1; i < 16; ++i) {
1845                        ep = udev->ep_out[i];
1846                        if (ep)
1847                                hcd->driver->drop_endpoint(hcd, udev, ep);
1848                        ep = udev->ep_in[i];
1849                        if (ep)
1850                                hcd->driver->drop_endpoint(hcd, udev, ep);
1851                }
1852                hcd->driver->check_bandwidth(hcd, udev);
1853                return 0;
1854        }
1855        /* Check if the HCD says there's enough bandwidth.  Enable all endpoints
1856         * each interface's alt setting 0 and ask the HCD to check the bandwidth
1857         * of the bus.  There will always be bandwidth for endpoint 0, so it's
1858         * ok to exclude it.
1859         */
1860        if (new_config) {
1861                num_intfs = new_config->desc.bNumInterfaces;
1862                /* Remove endpoints (except endpoint 0, which is always on the
1863                 * schedule) from the old config from the schedule
1864                 */
1865                for (i = 1; i < 16; ++i) {
1866                        ep = udev->ep_out[i];
1867                        if (ep) {
1868                                ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1869                                if (ret < 0)
1870                                        goto reset;
1871                        }
1872                        ep = udev->ep_in[i];
1873                        if (ep) {
1874                                ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1875                                if (ret < 0)
1876                                        goto reset;
1877                        }
1878                }
1879                for (i = 0; i < num_intfs; ++i) {
1880                        struct usb_host_interface *first_alt;
1881                        int iface_num;
1882
1883                        first_alt = &new_config->intf_cache[i]->altsetting[0];
1884                        iface_num = first_alt->desc.bInterfaceNumber;
1885                        /* Set up endpoints for alternate interface setting 0 */
1886                        alt = usb_find_alt_setting(new_config, iface_num, 0);
1887                        if (!alt)
1888                                /* No alt setting 0? Pick the first setting. */
1889                                alt = first_alt;
1890
1891                        for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1892                                ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1893                                if (ret < 0)
1894                                        goto reset;
1895                        }
1896                }
1897        }
1898        if (cur_alt && new_alt) {
1899                struct usb_interface *iface = usb_ifnum_to_if(udev,
1900                                cur_alt->desc.bInterfaceNumber);
1901
1902                if (!iface)
1903                        return -EINVAL;
1904                if (iface->resetting_device) {
1905                        /*
1906                         * The USB core just reset the device, so the xHCI host
1907                         * and the device will think alt setting 0 is installed.
1908                         * However, the USB core will pass in the alternate
1909                         * setting installed before the reset as cur_alt.  Dig
1910                         * out the alternate setting 0 structure, or the first
1911                         * alternate setting if a broken device doesn't have alt
1912                         * setting 0.
1913                         */
1914                        cur_alt = usb_altnum_to_altsetting(iface, 0);
1915                        if (!cur_alt)
1916                                cur_alt = &iface->altsetting[0];
1917                }
1918
1919                /* Drop all the endpoints in the current alt setting */
1920                for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1921                        ret = hcd->driver->drop_endpoint(hcd, udev,
1922                                        &cur_alt->endpoint[i]);
1923                        if (ret < 0)
1924                                goto reset;
1925                }
1926                /* Add all the endpoints in the new alt setting */
1927                for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1928                        ret = hcd->driver->add_endpoint(hcd, udev,
1929                                        &new_alt->endpoint[i]);
1930                        if (ret < 0)
1931                                goto reset;
1932                }
1933        }
1934        ret = hcd->driver->check_bandwidth(hcd, udev);
1935reset:
1936        if (ret < 0)
1937                hcd->driver->reset_bandwidth(hcd, udev);
1938        return ret;
1939}
1940
1941/* Disables the endpoint: synchronizes with the hcd to make sure all
1942 * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
1943 * have been called previously.  Use for set_configuration, set_interface,
1944 * driver removal, physical disconnect.
1945 *
1946 * example:  a qh stored in ep->hcpriv, holding state related to endpoint
1947 * type, maxpacket size, toggle, halt status, and scheduling.
1948 */
1949void usb_hcd_disable_endpoint(struct usb_device *udev,
1950                struct usb_host_endpoint *ep)
1951{
1952        struct usb_hcd          *hcd;
1953
1954        might_sleep();
1955        hcd = bus_to_hcd(udev->bus);
1956        if (hcd->driver->endpoint_disable)
1957                hcd->driver->endpoint_disable(hcd, ep);
1958}
1959
1960/**
1961 * usb_hcd_reset_endpoint - reset host endpoint state
1962 * @udev: USB device.
1963 * @ep:   the endpoint to reset.
1964 *
1965 * Resets any host endpoint state such as the toggle bit, sequence
1966 * number and current window.
1967 */
1968void usb_hcd_reset_endpoint(struct usb_device *udev,
1969                            struct usb_host_endpoint *ep)
1970{
1971        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1972
1973        if (hcd->driver->endpoint_reset)
1974                hcd->driver->endpoint_reset(hcd, ep);
1975        else {
1976                int epnum = usb_endpoint_num(&ep->desc);
1977                int is_out = usb_endpoint_dir_out(&ep->desc);
1978                int is_control = usb_endpoint_xfer_control(&ep->desc);
1979
1980                usb_settoggle(udev, epnum, is_out, 0);
1981                if (is_control)
1982                        usb_settoggle(udev, epnum, !is_out, 0);
1983        }
1984}
1985
1986/**
1987 * usb_alloc_streams - allocate bulk endpoint stream IDs.
1988 * @interface:          alternate setting that includes all endpoints.
1989 * @eps:                array of endpoints that need streams.
1990 * @num_eps:            number of endpoints in the array.
1991 * @num_streams:        number of streams to allocate.
1992 * @mem_flags:          flags hcd should use to allocate memory.
1993 *
1994 * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
1995 * Drivers may queue multiple transfers to different stream IDs, which may
1996 * complete in a different order than they were queued.
1997 *
1998 * Return: On success, the number of allocated streams. On failure, a negative
1999 * error code.
2000 */
2001int usb_alloc_streams(struct usb_interface *interface,
2002                struct usb_host_endpoint **eps, unsigned int num_eps,
2003                unsigned int num_streams, gfp_t mem_flags)
2004{
2005        struct usb_hcd *hcd;
2006        struct usb_device *dev;
2007        int i, ret;
2008
2009        dev = interface_to_usbdev(interface);
2010        hcd = bus_to_hcd(dev->bus);
2011        if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
2012                return -EINVAL;
2013        if (dev->speed < USB_SPEED_SUPER)
2014                return -EINVAL;
2015        if (dev->state < USB_STATE_CONFIGURED)
2016                return -ENODEV;
2017
2018        for (i = 0; i < num_eps; i++) {
2019                /* Streams only apply to bulk endpoints. */
2020                if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
2021                        return -EINVAL;
2022                /* Re-alloc is not allowed */
2023                if (eps[i]->streams)
2024                        return -EINVAL;
2025        }
2026
2027        ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
2028                        num_streams, mem_flags);
2029        if (ret < 0)
2030                return ret;
2031
2032        for (i = 0; i < num_eps; i++)
2033                eps[i]->streams = ret;
2034
2035        return ret;
2036}
2037EXPORT_SYMBOL_GPL(usb_alloc_streams);
2038
2039/**
2040 * usb_free_streams - free bulk endpoint stream IDs.
2041 * @interface:  alternate setting that includes all endpoints.
2042 * @eps:        array of endpoints to remove streams from.
2043 * @num_eps:    number of endpoints in the array.
2044 * @mem_flags:  flags hcd should use to allocate memory.
2045 *
2046 * Reverts a group of bulk endpoints back to not using stream IDs.
2047 * Can fail if we are given bad arguments, or HCD is broken.
2048 *
2049 * Return: 0 on success. On failure, a negative error code.
2050 */
2051int usb_free_streams(struct usb_interface *interface,
2052                struct usb_host_endpoint **eps, unsigned int num_eps,
2053                gfp_t mem_flags)
2054{
2055        struct usb_hcd *hcd;
2056        struct usb_device *dev;
2057        int i, ret;
2058
2059        dev = interface_to_usbdev(interface);
2060        hcd = bus_to_hcd(dev->bus);
2061        if (dev->speed < USB_SPEED_SUPER)
2062                return -EINVAL;
2063
2064        /* Double-free is not allowed */
2065        for (i = 0; i < num_eps; i++)
2066                if (!eps[i] || !eps[i]->streams)
2067                        return -EINVAL;
2068
2069        ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
2070        if (ret < 0)
2071                return ret;
2072
2073        for (i = 0; i < num_eps; i++)
2074                eps[i]->streams = 0;
2075
2076        return ret;
2077}
2078EXPORT_SYMBOL_GPL(usb_free_streams);
2079
2080/* Protect against drivers that try to unlink URBs after the device
2081 * is gone, by waiting until all unlinks for @udev are finished.
2082 * Since we don't currently track URBs by device, simply wait until
2083 * nothing is running in the locked region of usb_hcd_unlink_urb().
2084 */
2085void usb_hcd_synchronize_unlinks(struct usb_device *udev)
2086{
2087        spin_lock_irq(&hcd_urb_unlink_lock);
2088        spin_unlock_irq(&hcd_urb_unlink_lock);
2089}
2090
2091/*-------------------------------------------------------------------------*/
2092
2093/* called in any context */
2094int usb_hcd_get_frame_number (struct usb_device *udev)
2095{
2096        struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
2097
2098        if (!HCD_RH_RUNNING(hcd))
2099                return -ESHUTDOWN;
2100        return hcd->driver->get_frame_number (hcd);
2101}
2102
2103/*-------------------------------------------------------------------------*/
2104
2105#ifdef  CONFIG_PM
2106
2107int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
2108{
2109        struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2110        int             status;
2111        int             old_state = hcd->state;
2112
2113        dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
2114                        (PMSG_IS_AUTO(msg) ? "auto-" : ""),
2115                        rhdev->do_remote_wakeup);
2116        if (HCD_DEAD(hcd)) {
2117                dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
2118                return 0;
2119        }
2120
2121        if (!hcd->driver->bus_suspend) {
2122                status = -ENOENT;
2123        } else {
2124                clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2125                hcd->state = HC_STATE_QUIESCING;
2126                status = hcd->driver->bus_suspend(hcd);
2127        }
2128        if (status == 0) {
2129                usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
2130                hcd->state = HC_STATE_SUSPENDED;
2131
2132                if (!PMSG_IS_AUTO(msg))
2133                        usb_phy_roothub_suspend(hcd->self.sysdev,
2134                                                hcd->phy_roothub);
2135
2136                /* Did we race with a root-hub wakeup event? */
2137                if (rhdev->do_remote_wakeup) {
2138                        char    buffer[6];
2139
2140                        status = hcd->driver->hub_status_data(hcd, buffer);
2141                        if (status != 0) {
2142                                dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
2143                                hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
2144                                status = -EBUSY;
2145                        }
2146                }
2147        } else {
2148                spin_lock_irq(&hcd_root_hub_lock);
2149                if (!HCD_DEAD(hcd)) {
2150                        set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2151                        hcd->state = old_state;
2152                }
2153                spin_unlock_irq(&hcd_root_hub_lock);
2154                dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2155                                "suspend", status);
2156        }
2157        return status;
2158}
2159
2160int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
2161{
2162        struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
2163        int             status;
2164        int             old_state = hcd->state;
2165
2166        dev_dbg(&rhdev->dev, "usb %sresume\n",
2167                        (PMSG_IS_AUTO(msg) ? "auto-" : ""));
2168        if (HCD_DEAD(hcd)) {
2169                dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2170                return 0;
2171        }
2172
2173        if (!PMSG_IS_AUTO(msg)) {
2174                status = usb_phy_roothub_resume(hcd->self.sysdev,
2175                                                hcd->phy_roothub);
2176                if (status)
2177                        return status;
2178        }
2179
2180        if (!hcd->driver->bus_resume)
2181                return -ENOENT;
2182        if (HCD_RH_RUNNING(hcd))
2183                return 0;
2184
2185        hcd->state = HC_STATE_RESUMING;
2186        status = hcd->driver->bus_resume(hcd);
2187        clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2188        if (status == 0)
2189                status = usb_phy_roothub_calibrate(hcd->phy_roothub);
2190
2191        if (status == 0) {
2192                struct usb_device *udev;
2193                int port1;
2194
2195                spin_lock_irq(&hcd_root_hub_lock);
2196                if (!HCD_DEAD(hcd)) {
2197                        usb_set_device_state(rhdev, rhdev->actconfig
2198                                        ? USB_STATE_CONFIGURED
2199                                        : USB_STATE_ADDRESS);
2200                        set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2201                        hcd->state = HC_STATE_RUNNING;
2202                }
2203                spin_unlock_irq(&hcd_root_hub_lock);
2204
2205                /*
2206                 * Check whether any of the enabled ports on the root hub are
2207                 * unsuspended.  If they are then a TRSMRCY delay is needed
2208                 * (this is what the USB-2 spec calls a "global resume").
2209                 * Otherwise we can skip the delay.
2210                 */
2211                usb_hub_for_each_child(rhdev, port1, udev) {
2212                        if (udev->state != USB_STATE_NOTATTACHED &&
2213                                        !udev->port_is_suspended) {
2214                                usleep_range(10000, 11000);     /* TRSMRCY */
2215                                break;
2216                        }
2217                }
2218        } else {
2219                hcd->state = old_state;
2220                usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
2221                dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2222                                "resume", status);
2223                if (status != -ESHUTDOWN)
2224                        usb_hc_died(hcd);
2225        }
2226        return status;
2227}
2228
2229/* Workqueue routine for root-hub remote wakeup */
2230static void hcd_resume_work(struct work_struct *work)
2231{
2232        struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2233        struct usb_device *udev = hcd->self.root_hub;
2234
2235        usb_remote_wakeup(udev);
2236}
2237
2238/**
2239 * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2240 * @hcd: host controller for this root hub
2241 *
2242 * The USB host controller calls this function when its root hub is
2243 * suspended (with the remote wakeup feature enabled) and a remote
2244 * wakeup request is received.  The routine submits a workqueue request
2245 * to resume the root hub (that is, manage its downstream ports again).
2246 */
2247void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2248{
2249        unsigned long flags;
2250
2251        spin_lock_irqsave (&hcd_root_hub_lock, flags);
2252        if (hcd->rh_registered) {
2253                pm_wakeup_event(&hcd->self.root_hub->dev, 0);
2254                set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2255                queue_work(pm_wq, &hcd->wakeup_work);
2256        }
2257        spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2258}
2259EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2260
2261#endif  /* CONFIG_PM */
2262
2263/*-------------------------------------------------------------------------*/
2264
2265#ifdef  CONFIG_USB_OTG
2266
2267/**
2268 * usb_bus_start_enum - start immediate enumeration (for OTG)
2269 * @bus: the bus (must use hcd framework)
2270 * @port_num: 1-based number of port; usually bus->otg_port
2271 * Context: in_interrupt()
2272 *
2273 * Starts enumeration, with an immediate reset followed later by
2274 * hub_wq identifying and possibly configuring the device.
2275 * This is needed by OTG controller drivers, where it helps meet
2276 * HNP protocol timing requirements for starting a port reset.
2277 *
2278 * Return: 0 if successful.
2279 */
2280int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2281{
2282        struct usb_hcd          *hcd;
2283        int                     status = -EOPNOTSUPP;
2284
2285        /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2286         * boards with root hubs hooked up to internal devices (instead of
2287         * just the OTG port) may need more attention to resetting...
2288         */
2289        hcd = bus_to_hcd(bus);
2290        if (port_num && hcd->driver->start_port_reset)
2291                status = hcd->driver->start_port_reset(hcd, port_num);
2292
2293        /* allocate hub_wq shortly after (first) root port reset finishes;
2294         * it may issue others, until at least 50 msecs have passed.
2295         */
2296        if (status == 0)
2297                mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2298        return status;
2299}
2300EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2301
2302#endif
2303
2304/*-------------------------------------------------------------------------*/
2305
2306/**
2307 * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2308 * @irq: the IRQ being raised
2309 * @__hcd: pointer to the HCD whose IRQ is being signaled
2310 *
2311 * If the controller isn't HALTed, calls the driver's irq handler.
2312 * Checks whether the controller is now dead.
2313 *
2314 * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
2315 */
2316irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2317{
2318        struct usb_hcd          *hcd = __hcd;
2319        irqreturn_t             rc;
2320
2321        if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2322                rc = IRQ_NONE;
2323        else if (hcd->driver->irq(hcd) == IRQ_NONE)
2324                rc = IRQ_NONE;
2325        else
2326                rc = IRQ_HANDLED;
2327
2328        return rc;
2329}
2330EXPORT_SYMBOL_GPL(usb_hcd_irq);
2331
2332/*-------------------------------------------------------------------------*/
2333
2334/* Workqueue routine for when the root-hub has died. */
2335static void hcd_died_work(struct work_struct *work)
2336{
2337        struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
2338        static char *env[] = {
2339                "ERROR=DEAD",
2340                NULL
2341        };
2342
2343        /* Notify user space that the host controller has died */
2344        kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);
2345}
2346
2347/**
2348 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2349 * @hcd: pointer to the HCD representing the controller
2350 *
2351 * This is called by bus glue to report a USB host controller that died
2352 * while operations may still have been pending.  It's called automatically
2353 * by the PCI glue, so only glue for non-PCI busses should need to call it.
2354 *
2355 * Only call this function with the primary HCD.
2356 */
2357void usb_hc_died (struct usb_hcd *hcd)
2358{
2359        unsigned long flags;
2360
2361        dev_err (hcd->self.controller, "HC died; cleaning up\n");
2362
2363        spin_lock_irqsave (&hcd_root_hub_lock, flags);
2364        clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2365        set_bit(HCD_FLAG_DEAD, &hcd->flags);
2366        if (hcd->rh_registered) {
2367                clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2368
2369                /* make hub_wq clean up old urbs and devices */
2370                usb_set_device_state (hcd->self.root_hub,
2371                                USB_STATE_NOTATTACHED);
2372                usb_kick_hub_wq(hcd->self.root_hub);
2373        }
2374        if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2375                hcd = hcd->shared_hcd;
2376                clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2377                set_bit(HCD_FLAG_DEAD, &hcd->flags);
2378                if (hcd->rh_registered) {
2379                        clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2380
2381                        /* make hub_wq clean up old urbs and devices */
2382                        usb_set_device_state(hcd->self.root_hub,
2383                                        USB_STATE_NOTATTACHED);
2384                        usb_kick_hub_wq(hcd->self.root_hub);
2385                }
2386        }
2387
2388        /* Handle the case where this function gets called with a shared HCD */
2389        if (usb_hcd_is_primary_hcd(hcd))
2390                schedule_work(&hcd->died_work);
2391        else
2392                schedule_work(&hcd->primary_hcd->died_work);
2393
2394        spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2395        /* Make sure that the other roothub is also deallocated. */
2396}
2397EXPORT_SYMBOL_GPL (usb_hc_died);
2398
2399/*-------------------------------------------------------------------------*/
2400
2401static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
2402{
2403
2404        spin_lock_init(&bh->lock);
2405        INIT_LIST_HEAD(&bh->head);
2406        tasklet_init(&bh->bh, usb_giveback_urb_bh, (unsigned long)bh);
2407}
2408
2409struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
2410                struct device *sysdev, struct device *dev, const char *bus_name,
2411                struct usb_hcd *primary_hcd)
2412{
2413        struct usb_hcd *hcd;
2414
2415        hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2416        if (!hcd)
2417                return NULL;
2418        if (primary_hcd == NULL) {
2419                hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
2420                                GFP_KERNEL);
2421                if (!hcd->address0_mutex) {
2422                        kfree(hcd);
2423                        dev_dbg(dev, "hcd address0 mutex alloc failed\n");
2424                        return NULL;
2425                }
2426                mutex_init(hcd->address0_mutex);
2427                hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2428                                GFP_KERNEL);
2429                if (!hcd->bandwidth_mutex) {
2430                        kfree(hcd->address0_mutex);
2431                        kfree(hcd);
2432                        dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2433                        return NULL;
2434                }
2435                mutex_init(hcd->bandwidth_mutex);
2436                dev_set_drvdata(dev, hcd);
2437        } else {
2438                mutex_lock(&usb_port_peer_mutex);
2439                hcd->address0_mutex = primary_hcd->address0_mutex;
2440                hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2441                hcd->primary_hcd = primary_hcd;
2442                primary_hcd->primary_hcd = primary_hcd;
2443                hcd->shared_hcd = primary_hcd;
2444                primary_hcd->shared_hcd = hcd;
2445                mutex_unlock(&usb_port_peer_mutex);
2446        }
2447
2448        kref_init(&hcd->kref);
2449
2450        usb_bus_init(&hcd->self);
2451        hcd->self.controller = dev;
2452        hcd->self.sysdev = sysdev;
2453        hcd->self.bus_name = bus_name;
2454
2455        timer_setup(&hcd->rh_timer, rh_timer_func, 0);
2456#ifdef CONFIG_PM
2457        INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2458#endif
2459
2460        INIT_WORK(&hcd->died_work, hcd_died_work);
2461
2462        hcd->driver = driver;
2463        hcd->speed = driver->flags & HCD_MASK;
2464        hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2465                        "USB Host Controller";
2466        return hcd;
2467}
2468EXPORT_SYMBOL_GPL(__usb_create_hcd);
2469
2470/**
2471 * usb_create_shared_hcd - create and initialize an HCD structure
2472 * @driver: HC driver that will use this hcd
2473 * @dev: device for this HC, stored in hcd->self.controller
2474 * @bus_name: value to store in hcd->self.bus_name
2475 * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2476 *              PCI device.  Only allocate certain resources for the primary HCD
2477 * Context: !in_interrupt()
2478 *
2479 * Allocate a struct usb_hcd, with extra space at the end for the
2480 * HC driver's private data.  Initialize the generic members of the
2481 * hcd structure.
2482 *
2483 * Return: On success, a pointer to the created and initialized HCD structure.
2484 * On failure (e.g. if memory is unavailable), %NULL.
2485 */
2486struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2487                struct device *dev, const char *bus_name,
2488                struct usb_hcd *primary_hcd)
2489{
2490        return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
2491}
2492EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2493
2494/**
2495 * usb_create_hcd - create and initialize an HCD structure
2496 * @driver: HC driver that will use this hcd
2497 * @dev: device for this HC, stored in hcd->self.controller
2498 * @bus_name: value to store in hcd->self.bus_name
2499 * Context: !in_interrupt()
2500 *
2501 * Allocate a struct usb_hcd, with extra space at the end for the
2502 * HC driver's private data.  Initialize the generic members of the
2503 * hcd structure.
2504 *
2505 * Return: On success, a pointer to the created and initialized HCD
2506 * structure. On failure (e.g. if memory is unavailable), %NULL.
2507 */
2508struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2509                struct device *dev, const char *bus_name)
2510{
2511        return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
2512}
2513EXPORT_SYMBOL_GPL(usb_create_hcd);
2514
2515/*
2516 * Roothubs that share one PCI device must also share the bandwidth mutex.
2517 * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2518 * deallocated.
2519 *
2520 * Make sure to deallocate the bandwidth_mutex only when the last HCD is
2521 * freed.  When hcd_release() is called for either hcd in a peer set,
2522 * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
2523 */
2524static void hcd_release(struct kref *kref)
2525{
2526        struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2527
2528        mutex_lock(&usb_port_peer_mutex);
2529        if (hcd->shared_hcd) {
2530                struct usb_hcd *peer = hcd->shared_hcd;
2531
2532                peer->shared_hcd = NULL;
2533                peer->primary_hcd = NULL;
2534        } else {
2535                kfree(hcd->address0_mutex);
2536                kfree(hcd->bandwidth_mutex);
2537        }
2538        mutex_unlock(&usb_port_peer_mutex);
2539        kfree(hcd);
2540}
2541
2542struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2543{
2544        if (hcd)
2545                kref_get (&hcd->kref);
2546        return hcd;
2547}
2548EXPORT_SYMBOL_GPL(usb_get_hcd);
2549
2550void usb_put_hcd (struct usb_hcd *hcd)
2551{
2552        if (hcd)
2553                kref_put (&hcd->kref, hcd_release);
2554}
2555EXPORT_SYMBOL_GPL(usb_put_hcd);
2556
2557int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2558{
2559        if (!hcd->primary_hcd)
2560                return 1;
2561        return hcd == hcd->primary_hcd;
2562}
2563EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2564
2565int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
2566{
2567        if (!hcd->driver->find_raw_port_number)
2568                return port1;
2569
2570        return hcd->driver->find_raw_port_number(hcd, port1);
2571}
2572
2573static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2574                unsigned int irqnum, unsigned long irqflags)
2575{
2576        int retval;
2577
2578        if (hcd->driver->irq) {
2579
2580                snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2581                                hcd->driver->description, hcd->self.busnum);
2582                retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2583                                hcd->irq_descr, hcd);
2584                if (retval != 0) {
2585                        dev_err(hcd->self.controller,
2586                                        "request interrupt %d failed\n",
2587                                        irqnum);
2588                        return retval;
2589                }
2590                hcd->irq = irqnum;
2591                dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2592                                (hcd->driver->flags & HCD_MEMORY) ?
2593                                        "io mem" : "io base",
2594                                        (unsigned long long)hcd->rsrc_start);
2595        } else {
2596                hcd->irq = 0;
2597                if (hcd->rsrc_start)
2598                        dev_info(hcd->self.controller, "%s 0x%08llx\n",
2599                                        (hcd->driver->flags & HCD_MEMORY) ?
2600                                        "io mem" : "io base",
2601                                        (unsigned long long)hcd->rsrc_start);
2602        }
2603        return 0;
2604}
2605
2606/*
2607 * Before we free this root hub, flush in-flight peering attempts
2608 * and disable peer lookups
2609 */
2610static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
2611{
2612        struct usb_device *rhdev;
2613
2614        mutex_lock(&usb_port_peer_mutex);
2615        rhdev = hcd->self.root_hub;
2616        hcd->self.root_hub = NULL;
2617        mutex_unlock(&usb_port_peer_mutex);
2618        usb_put_dev(rhdev);
2619}
2620
2621/**
2622 * usb_add_hcd - finish generic HCD structure initialization and register
2623 * @hcd: the usb_hcd structure to initialize
2624 * @irqnum: Interrupt line to allocate
2625 * @irqflags: Interrupt type flags
2626 *
2627 * Finish the remaining parts of generic HCD initialization: allocate the
2628 * buffers of consistent memory, register the bus, request the IRQ line,
2629 * and call the driver's reset() and start() routines.
2630 */
2631int usb_add_hcd(struct usb_hcd *hcd,
2632                unsigned int irqnum, unsigned long irqflags)
2633{
2634        int retval;
2635        struct usb_device *rhdev;
2636
2637        if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
2638                hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
2639                if (IS_ERR(hcd->phy_roothub))
2640                        return PTR_ERR(hcd->phy_roothub);
2641
2642                retval = usb_phy_roothub_init(hcd->phy_roothub);
2643                if (retval)
2644                        return retval;
2645
2646                retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2647                                                  PHY_MODE_USB_HOST_SS);
2648                if (retval)
2649                        retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
2650                                                          PHY_MODE_USB_HOST);
2651                if (retval)
2652                        goto err_usb_phy_roothub_power_on;
2653
2654                retval = usb_phy_roothub_power_on(hcd->phy_roothub);
2655                if (retval)
2656                        goto err_usb_phy_roothub_power_on;
2657        }
2658
2659        dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2660
2661        switch (authorized_default) {
2662        case USB_AUTHORIZE_NONE:
2663                hcd->dev_policy = USB_DEVICE_AUTHORIZE_NONE;
2664                break;
2665
2666        case USB_AUTHORIZE_ALL:
2667                hcd->dev_policy = USB_DEVICE_AUTHORIZE_ALL;
2668                break;
2669
2670        case USB_AUTHORIZE_INTERNAL:
2671                hcd->dev_policy = USB_DEVICE_AUTHORIZE_INTERNAL;
2672                break;
2673
2674        case USB_AUTHORIZE_WIRED:
2675        default:
2676                hcd->dev_policy = hcd->wireless ?
2677                        USB_DEVICE_AUTHORIZE_NONE : USB_DEVICE_AUTHORIZE_ALL;
2678                break;
2679        }
2680
2681        set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2682
2683        /* per default all interfaces are authorized */
2684        set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
2685
2686        /* HC is in reset state, but accessible.  Now do the one-time init,
2687         * bottom up so that hcds can customize the root hubs before hub_wq
2688         * starts talking to them.  (Note, bus id is assigned early too.)
2689         */
2690        retval = hcd_buffer_create(hcd);
2691        if (retval != 0) {
2692                dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
2693                goto err_create_buf;
2694        }
2695
2696        retval = usb_register_bus(&hcd->self);
2697        if (retval < 0)
2698                goto err_register_bus;
2699
2700        rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
2701        if (rhdev == NULL) {
2702                dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
2703                retval = -ENOMEM;
2704                goto err_allocate_root_hub;
2705        }
2706        mutex_lock(&usb_port_peer_mutex);
2707        hcd->self.root_hub = rhdev;
2708        mutex_unlock(&usb_port_peer_mutex);
2709
2710        rhdev->rx_lanes = 1;
2711        rhdev->tx_lanes = 1;
2712
2713        switch (hcd->speed) {
2714        case HCD_USB11:
2715                rhdev->speed = USB_SPEED_FULL;
2716                break;
2717        case HCD_USB2:
2718                rhdev->speed = USB_SPEED_HIGH;
2719                break;
2720        case HCD_USB25:
2721                rhdev->speed = USB_SPEED_WIRELESS;
2722                break;
2723        case HCD_USB3:
2724                rhdev->speed = USB_SPEED_SUPER;
2725                break;
2726        case HCD_USB32:
2727                rhdev->rx_lanes = 2;
2728                rhdev->tx_lanes = 2;
2729                fallthrough;
2730        case HCD_USB31:
2731                rhdev->speed = USB_SPEED_SUPER_PLUS;
2732                break;
2733        default:
2734                retval = -EINVAL;
2735                goto err_set_rh_speed;
2736        }
2737
2738        /* wakeup flag init defaults to "everything works" for root hubs,
2739         * but drivers can override it in reset() if needed, along with
2740         * recording the overall controller's system wakeup capability.
2741         */
2742        device_set_wakeup_capable(&rhdev->dev, 1);
2743
2744        /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2745         * registered.  But since the controller can die at any time,
2746         * let's initialize the flag before touching the hardware.
2747         */
2748        set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2749
2750        /* "reset" is misnamed; its role is now one-time init. the controller
2751         * should already have been reset (and boot firmware kicked off etc).
2752         */
2753        if (hcd->driver->reset) {
2754                retval = hcd->driver->reset(hcd);
2755                if (retval < 0) {
2756                        dev_err(hcd->self.controller, "can't setup: %d\n",
2757                                        retval);
2758                        goto err_hcd_driver_setup;
2759                }
2760        }
2761        hcd->rh_pollable = 1;
2762
2763        retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
2764        if (retval)
2765                goto err_hcd_driver_setup;
2766
2767        /* NOTE: root hub and controller capabilities may not be the same */
2768        if (device_can_wakeup(hcd->self.controller)
2769                        && device_can_wakeup(&hcd->self.root_hub->dev))
2770                dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2771
2772        /* initialize tasklets */
2773        init_giveback_urb_bh(&hcd->high_prio_bh);
2774        init_giveback_urb_bh(&hcd->low_prio_bh);
2775
2776        /* enable irqs just before we start the controller,
2777         * if the BIOS provides legacy PCI irqs.
2778         */
2779        if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
2780                retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2781                if (retval)
2782                        goto err_request_irq;
2783        }
2784
2785        hcd->state = HC_STATE_RUNNING;
2786        retval = hcd->driver->start(hcd);
2787        if (retval < 0) {
2788                dev_err(hcd->self.controller, "startup error %d\n", retval);
2789                goto err_hcd_driver_start;
2790        }
2791
2792        /* starting here, usbcore will pay attention to this root hub */
2793        retval = register_root_hub(hcd);
2794        if (retval != 0)
2795                goto err_register_root_hub;
2796
2797        if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2798                usb_hcd_poll_rh_status(hcd);
2799
2800        return retval;
2801
2802err_register_root_hub:
2803        hcd->rh_pollable = 0;
2804        clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2805        del_timer_sync(&hcd->rh_timer);
2806        hcd->driver->stop(hcd);
2807        hcd->state = HC_STATE_HALT;
2808        clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2809        del_timer_sync(&hcd->rh_timer);
2810err_hcd_driver_start:
2811        if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
2812                free_irq(irqnum, hcd);
2813err_request_irq:
2814err_hcd_driver_setup:
2815err_set_rh_speed:
2816        usb_put_invalidate_rhdev(hcd);
2817err_allocate_root_hub:
2818        usb_deregister_bus(&hcd->self);
2819err_register_bus:
2820        hcd_buffer_destroy(hcd);
2821err_create_buf:
2822        usb_phy_roothub_power_off(hcd->phy_roothub);
2823err_usb_phy_roothub_power_on:
2824        usb_phy_roothub_exit(hcd->phy_roothub);
2825
2826        return retval;
2827}
2828EXPORT_SYMBOL_GPL(usb_add_hcd);
2829
2830/**
2831 * usb_remove_hcd - shutdown processing for generic HCDs
2832 * @hcd: the usb_hcd structure to remove
2833 * Context: !in_interrupt()
2834 *
2835 * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2836 * invoking the HCD's stop() method.
2837 */
2838void usb_remove_hcd(struct usb_hcd *hcd)
2839{
2840        struct usb_device *rhdev = hcd->self.root_hub;
2841
2842        dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2843
2844        usb_get_dev(rhdev);
2845        clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2846        if (HC_IS_RUNNING (hcd->state))
2847                hcd->state = HC_STATE_QUIESCING;
2848
2849        dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2850        spin_lock_irq (&hcd_root_hub_lock);
2851        hcd->rh_registered = 0;
2852        spin_unlock_irq (&hcd_root_hub_lock);
2853
2854#ifdef CONFIG_PM
2855        cancel_work_sync(&hcd->wakeup_work);
2856#endif
2857        cancel_work_sync(&hcd->died_work);
2858
2859        mutex_lock(&usb_bus_idr_lock);
2860        usb_disconnect(&rhdev);         /* Sets rhdev to NULL */
2861        mutex_unlock(&usb_bus_idr_lock);
2862
2863        /*
2864         * tasklet_kill() isn't needed here because:
2865         * - driver's disconnect() called from usb_disconnect() should
2866         *   make sure its URBs are completed during the disconnect()
2867         *   callback
2868         *
2869         * - it is too late to run complete() here since driver may have
2870         *   been removed already now
2871         */
2872
2873        /* Prevent any more root-hub status calls from the timer.
2874         * The HCD might still restart the timer (if a port status change
2875         * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2876         * the hub_status_data() callback.
2877         */
2878        hcd->rh_pollable = 0;
2879        clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2880        del_timer_sync(&hcd->rh_timer);
2881
2882        hcd->driver->stop(hcd);
2883        hcd->state = HC_STATE_HALT;
2884
2885        /* In case the HCD restarted the timer, stop it again. */
2886        clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2887        del_timer_sync(&hcd->rh_timer);
2888
2889        if (usb_hcd_is_primary_hcd(hcd)) {
2890                if (hcd->irq > 0)
2891                        free_irq(hcd->irq, hcd);
2892        }
2893
2894        usb_deregister_bus(&hcd->self);
2895        hcd_buffer_destroy(hcd);
2896
2897        usb_phy_roothub_power_off(hcd->phy_roothub);
2898        usb_phy_roothub_exit(hcd->phy_roothub);
2899
2900        usb_put_invalidate_rhdev(hcd);
2901        hcd->flags = 0;
2902}
2903EXPORT_SYMBOL_GPL(usb_remove_hcd);
2904
2905void
2906usb_hcd_platform_shutdown(struct platform_device *dev)
2907{
2908        struct usb_hcd *hcd = platform_get_drvdata(dev);
2909
2910        /* No need for pm_runtime_put(), we're shutting down */
2911        pm_runtime_get_sync(&dev->dev);
2912
2913        if (hcd->driver->shutdown)
2914                hcd->driver->shutdown(hcd);
2915}
2916EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2917
2918int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
2919                            dma_addr_t dma, size_t size)
2920{
2921        int err;
2922        void *local_mem;
2923
2924        hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
2925                                                  dev_to_node(hcd->self.sysdev),
2926                                                  dev_name(hcd->self.sysdev));
2927        if (IS_ERR(hcd->localmem_pool))
2928                return PTR_ERR(hcd->localmem_pool);
2929
2930        local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
2931                                  size, MEMREMAP_WC);
2932        if (IS_ERR(local_mem))
2933                return PTR_ERR(local_mem);
2934
2935        /*
2936         * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
2937         * It's not backed by system memory and thus there's no kernel mapping
2938         * for it.
2939         */
2940        err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
2941                                dma, size, dev_to_node(hcd->self.sysdev));
2942        if (err < 0) {
2943                dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
2944                        err);
2945                return err;
2946        }
2947
2948        return 0;
2949}
2950EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
2951
2952/*-------------------------------------------------------------------------*/
2953
2954#if IS_ENABLED(CONFIG_USB_MON)
2955
2956const struct usb_mon_operations *mon_ops;
2957
2958/*
2959 * The registration is unlocked.
2960 * We do it this way because we do not want to lock in hot paths.
2961 *
2962 * Notice that the code is minimally error-proof. Because usbmon needs
2963 * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2964 */
2965
2966int usb_mon_register(const struct usb_mon_operations *ops)
2967{
2968
2969        if (mon_ops)
2970                return -EBUSY;
2971
2972        mon_ops = ops;
2973        mb();
2974        return 0;
2975}
2976EXPORT_SYMBOL_GPL (usb_mon_register);
2977
2978void usb_mon_deregister (void)
2979{
2980
2981        if (mon_ops == NULL) {
2982                printk(KERN_ERR "USB: monitor was not registered\n");
2983                return;
2984        }
2985        mon_ops = NULL;
2986        mb();
2987}
2988EXPORT_SYMBOL_GPL (usb_mon_deregister);
2989
2990#endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */
2991