OSCL-LXR linux-6.0.1/​drivers/​usb/​core/​hcd.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright Linus Torvalds 1999
  * (C) Copyright Johannes Erdfelt 1999-2001
  * (C) Copyright Andreas Gal 1999
  * (C) Copyright Gregory P. Smith 1999
  * (C) Copyright Deti Fliegl 1999
  * (C) Copyright Randy Dunlap 2000
  * (C) Copyright David Brownell 2000-2002
  */
 
 #include <linux/bcd.h>
 #include <linux/module.h>
 #include <linux/version.h>
 #include <linux/kernel.h>
 #include <linux/sched/task_stack.h>
 #include <linux/slab.h>
 #include <linux/completion.h>
 #include <linux/utsname.h>
 #include <linux/mm.h>
 #include <asm/io.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/mutex.h>
 #include <asm/irq.h>
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
 #include <linux/platform_device.h>
 #include <linux/workqueue.h>
 #include <linux/pm_runtime.h>
 #include <linux/types.h>
 #include <linux/genalloc.h>
 #include <linux/io.h>
 #include <linux/kcov.h>
 
 #include <linux/phy/phy.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
 #include <linux/usb/otg.h>
 
 #include "usb.h"
 #include "phy.h"
 
 
 /*-------------------------------------------------------------------------*/
 
 /*
  * USB Host Controller Driver framework
  *
  * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
  * HCD-specific behaviors/bugs.
  *
  * This does error checks, tracks devices and urbs, and delegates to a
  * "hc_driver" only for code (and data) that really needs to know about
  * hardware differences.  That includes root hub registers, i/o queues,
  * and so on ... but as little else as possible.
  *
  * Shared code includes most of the "root hub" code (these are emulated,
  * though each HC's hardware works differently) and PCI glue, plus request
  * tracking overhead.  The HCD code should only block on spinlocks or on
  * hardware handshaking; blocking on software events (such as other kernel
  * threads releasing resources, or completing actions) is all generic.
  *
  * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
  * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
  * only by the hub driver ... and that neither should be seen or used by
  * usb client device drivers.
  *
  * Contributors of ideas or unattributed patches include: David Brownell,
  * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
  *
  * HISTORY:
  * 2002-02-21   Pull in most of the usb_bus support from usb.c; some
  *      associated cleanup.  "usb_hcd" still != "usb_bus".
  * 2001-12-12   Initial patch version for Linux 2.5.1 kernel.
  */
 
 /*-------------------------------------------------------------------------*/
 
 /* Keep track of which host controller drivers are loaded */
 unsigned long usb_hcds_loaded;
 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
 
 /* host controllers we manage */
 DEFINE_IDR (usb_bus_idr);
 EXPORT_SYMBOL_GPL (usb_bus_idr);
 
 /* used when allocating bus numbers */
 #define USB_MAXBUS      64
 
 /* used when updating list of hcds */
 DEFINE_MUTEX(usb_bus_idr_lock); /* exported only for usbfs */
 EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
 
 /* used for controlling access to virtual root hubs */
 static DEFINE_SPINLOCK(hcd_root_hub_lock);
 
 /* used when updating an endpoint's URB list */
 static DEFINE_SPINLOCK(hcd_urb_list_lock);
 
 /* used to protect against unlinking URBs after the device is gone */
 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
 
 /* wait queue for synchronous unlinks */
 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
 
 /*-------------------------------------------------------------------------*/
 
 /*
  * Sharable chunks of root hub code.
  */
 
 /*-------------------------------------------------------------------------*/
 #define KERNEL_REL  bin2bcd(LINUX_VERSION_MAJOR)
 #define KERNEL_VER  bin2bcd(LINUX_VERSION_PATCHLEVEL)
 
 /* usb 3.1 root hub device descriptor */
 static const u8 usb31_rh_dev_descriptor[18] = {
     0x12,       /*  __u8  bLength; */
     USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
     0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
 
     0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  bDeviceSubClass; */
     0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
     0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
 
     0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
     0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
     KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 
     0x03,       /*  __u8  iManufacturer; */
     0x02,       /*  __u8  iProduct; */
     0x01,       /*  __u8  iSerialNumber; */
     0x01        /*  __u8  bNumConfigurations; */
 };
 
 /* usb 3.0 root hub device descriptor */
 static const u8 usb3_rh_dev_descriptor[18] = {
     0x12,       /*  __u8  bLength; */
     USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
     0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
 
     0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  bDeviceSubClass; */
     0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
     0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
 
     0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
     0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
     KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 
     0x03,       /*  __u8  iManufacturer; */
     0x02,       /*  __u8  iProduct; */
     0x01,       /*  __u8  iSerialNumber; */
     0x01        /*  __u8  bNumConfigurations; */
 };
 
 /* usb 2.5 (wireless USB 1.0) root hub device descriptor */
 static const u8 usb25_rh_dev_descriptor[18] = {
     0x12,       /*  __u8  bLength; */
     USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
     0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
 
     0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  bDeviceSubClass; */
     0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
     0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
 
     0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
     0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
     KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 
     0x03,       /*  __u8  iManufacturer; */
     0x02,       /*  __u8  iProduct; */
     0x01,       /*  __u8  iSerialNumber; */
     0x01        /*  __u8  bNumConfigurations; */
 };
 
 /* usb 2.0 root hub device descriptor */
 static const u8 usb2_rh_dev_descriptor[18] = {
     0x12,       /*  __u8  bLength; */
     USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
     0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
 
     0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  bDeviceSubClass; */
     0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
     0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 
     0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
     0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
     KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 
     0x03,       /*  __u8  iManufacturer; */
     0x02,       /*  __u8  iProduct; */
     0x01,       /*  __u8  iSerialNumber; */
     0x01        /*  __u8  bNumConfigurations; */
 };
 
 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
 
 /* usb 1.1 root hub device descriptor */
 static const u8 usb11_rh_dev_descriptor[18] = {
     0x12,       /*  __u8  bLength; */
     USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
     0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
 
     0x09,       /*  __u8  bDeviceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  bDeviceSubClass; */
     0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
     0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
 
     0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
     0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
     KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
 
     0x03,       /*  __u8  iManufacturer; */
     0x02,       /*  __u8  iProduct; */
     0x01,       /*  __u8  iSerialNumber; */
     0x01        /*  __u8  bNumConfigurations; */
 };
 
 
 /*-------------------------------------------------------------------------*/
 
 /* Configuration descriptors for our root hubs */
 
 static const u8 fs_rh_config_descriptor[] = {
 
     /* one configuration */
     0x09,       /*  __u8  bLength; */
     USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
     0x19, 0x00, /*  __le16 wTotalLength; */
     0x01,       /*  __u8  bNumInterfaces; (1) */
     0x01,       /*  __u8  bConfigurationValue; */
     0x00,       /*  __u8  iConfiguration; */
     0xc0,       /*  __u8  bmAttributes;
                  Bit 7: must be set,
                      6: Self-powered,
                      5: Remote wakeup,
                      4..0: resvd */
     0x00,       /*  __u8  MaxPower; */
 
     /* USB 1.1:
      * USB 2.0, single TT organization (mandatory):
      *  one interface, protocol 0
      *
      * USB 2.0, multiple TT organization (optional):
      *  two interfaces, protocols 1 (like single TT)
      *  and 2 (multiple TT mode) ... config is
      *  sometimes settable
      *  NOT IMPLEMENTED
      */
 
     /* one interface */
     0x09,       /*  __u8  if_bLength; */
     USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
     0x00,       /*  __u8  if_bInterfaceNumber; */
     0x00,       /*  __u8  if_bAlternateSetting; */
     0x01,       /*  __u8  if_bNumEndpoints; */
     0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  if_bInterfaceSubClass; */
     0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
     0x00,       /*  __u8  if_iInterface; */
 
     /* one endpoint (status change endpoint) */
     0x07,       /*  __u8  ep_bLength; */
     USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
     0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
     0x03,       /*  __u8  ep_bmAttributes; Interrupt */
     0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
     0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
 };
 
 static const u8 hs_rh_config_descriptor[] = {
 
     /* one configuration */
     0x09,       /*  __u8  bLength; */
     USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
     0x19, 0x00, /*  __le16 wTotalLength; */
     0x01,       /*  __u8  bNumInterfaces; (1) */
     0x01,       /*  __u8  bConfigurationValue; */
     0x00,       /*  __u8  iConfiguration; */
     0xc0,       /*  __u8  bmAttributes;
                  Bit 7: must be set,
                      6: Self-powered,
                      5: Remote wakeup,
                      4..0: resvd */
     0x00,       /*  __u8  MaxPower; */
 
     /* USB 1.1:
      * USB 2.0, single TT organization (mandatory):
      *  one interface, protocol 0
      *
      * USB 2.0, multiple TT organization (optional):
      *  two interfaces, protocols 1 (like single TT)
      *  and 2 (multiple TT mode) ... config is
      *  sometimes settable
      *  NOT IMPLEMENTED
      */
 
     /* one interface */
     0x09,       /*  __u8  if_bLength; */
     USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
     0x00,       /*  __u8  if_bInterfaceNumber; */
     0x00,       /*  __u8  if_bAlternateSetting; */
     0x01,       /*  __u8  if_bNumEndpoints; */
     0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  if_bInterfaceSubClass; */
     0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
     0x00,       /*  __u8  if_iInterface; */
 
     /* one endpoint (status change endpoint) */
     0x07,       /*  __u8  ep_bLength; */
     USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
     0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
     0x03,       /*  __u8  ep_bmAttributes; Interrupt */
             /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
              * see hub.c:hub_configure() for details. */
     (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
     0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 };
 
 static const u8 ss_rh_config_descriptor[] = {
     /* one configuration */
     0x09,       /*  __u8  bLength; */
     USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
     0x1f, 0x00, /*  __le16 wTotalLength; */
     0x01,       /*  __u8  bNumInterfaces; (1) */
     0x01,       /*  __u8  bConfigurationValue; */
     0x00,       /*  __u8  iConfiguration; */
     0xc0,       /*  __u8  bmAttributes;
                  Bit 7: must be set,
                      6: Self-powered,
                      5: Remote wakeup,
                      4..0: resvd */
     0x00,       /*  __u8  MaxPower; */
 
     /* one interface */
     0x09,       /*  __u8  if_bLength; */
     USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
     0x00,       /*  __u8  if_bInterfaceNumber; */
     0x00,       /*  __u8  if_bAlternateSetting; */
     0x01,       /*  __u8  if_bNumEndpoints; */
     0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
     0x00,       /*  __u8  if_bInterfaceSubClass; */
     0x00,       /*  __u8  if_bInterfaceProtocol; */
     0x00,       /*  __u8  if_iInterface; */
 
     /* one endpoint (status change endpoint) */
     0x07,       /*  __u8  ep_bLength; */
     USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
     0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
     0x03,       /*  __u8  ep_bmAttributes; Interrupt */
             /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
              * see hub.c:hub_configure() for details. */
     (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
     0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
 
     /* one SuperSpeed endpoint companion descriptor */
     0x06,        /* __u8 ss_bLength */
     USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
              /* Companion */
     0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
     0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
     0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
 };
 
 /* authorized_default behaviour:
  * -1 is authorized for all devices except wireless (old behaviour)
  * 0 is unauthorized for all devices
  * 1 is authorized for all devices
  * 2 is authorized for internal devices
  */
 #define USB_AUTHORIZE_WIRED -1
 #define USB_AUTHORIZE_NONE  0
 #define USB_AUTHORIZE_ALL   1
 #define USB_AUTHORIZE_INTERNAL  2
 
 static int authorized_default = USB_AUTHORIZE_WIRED;
 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(authorized_default,
         "Default USB device authorization: 0 is not authorized, 1 is "
         "authorized, 2 is authorized for internal devices, -1 is "
         "authorized except for wireless USB (default, old behaviour)");
 /*-------------------------------------------------------------------------*/
 
 /**
  * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
  * @s: Null-terminated ASCII (actually ISO-8859-1) string
  * @buf: Buffer for USB string descriptor (header + UTF-16LE)
  * @len: Length (in bytes; may be odd) of descriptor buffer.
  *
  * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
  * whichever is less.
  *
  * Note:
  * USB String descriptors can contain at most 126 characters; input
  * strings longer than that are truncated.
  */
 static unsigned
 ascii2desc(char const *s, u8 *buf, unsigned len)
 {
     unsigned n, t = 2 + 2*strlen(s);
 
     if (t > 254)
         t = 254;    /* Longest possible UTF string descriptor */
     if (len > t)
         len = t;
 
     t += USB_DT_STRING << 8;    /* Now t is first 16 bits to store */
 
     n = len;
     while (n--) {
         *buf++ = t;
         if (!n--)
             break;
         *buf++ = t >> 8;
         t = (unsigned char)*s++;
     }
     return len;
 }
 
 /**
  * rh_string() - provides string descriptors for root hub
  * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
  * @hcd: the host controller for this root hub
  * @data: buffer for output packet
  * @len: length of the provided buffer
  *
  * Produces either a manufacturer, product or serial number string for the
  * virtual root hub device.
  *
  * Return: The number of bytes filled in: the length of the descriptor or
  * of the provided buffer, whichever is less.
  */
 static unsigned
 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
 {
     char buf[100];
     char const *s;
     static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
 
     /* language ids */
     switch (id) {
     case 0:
         /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
         /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
         if (len > 4)
             len = 4;
         memcpy(data, langids, len);
         return len;
     case 1:
         /* Serial number */
         s = hcd->self.bus_name;
         break;
     case 2:
         /* Product name */
         s = hcd->product_desc;
         break;
     case 3:
         /* Manufacturer */
         snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
             init_utsname()->release, hcd->driver->description);
         s = buf;
         break;
     default:
         /* Can't happen; caller guarantees it */
         return 0;
     }
 
     return ascii2desc(s, data, len);
 }
 
 
 /* Root hub control transfers execute synchronously */
 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
 {
     struct usb_ctrlrequest *cmd;
     u16     typeReq, wValue, wIndex, wLength;
     u8      *ubuf = urb->transfer_buffer;
     unsigned    len = 0;
     int     status;
     u8      patch_wakeup = 0;
     u8      patch_protocol = 0;
     u16     tbuf_size;
     u8      *tbuf = NULL;
     const u8    *bufp;
 
     might_sleep();
 
     spin_lock_irq(&hcd_root_hub_lock);
     status = usb_hcd_link_urb_to_ep(hcd, urb);
     spin_unlock_irq(&hcd_root_hub_lock);
     if (status)
         return status;
     urb->hcpriv = hcd;  /* Indicate it's queued */
 
     cmd = (struct usb_ctrlrequest *) urb->setup_packet;
     typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
     wValue   = le16_to_cpu (cmd->wValue);
     wIndex   = le16_to_cpu (cmd->wIndex);
     wLength  = le16_to_cpu (cmd->wLength);
 
     if (wLength > urb->transfer_buffer_length)
         goto error;
 
     /*
      * tbuf should be at least as big as the
      * USB hub descriptor.
      */
     tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
     tbuf = kzalloc(tbuf_size, GFP_KERNEL);
     if (!tbuf) {
         status = -ENOMEM;
         goto err_alloc;
     }
 
     bufp = tbuf;
 
 
     urb->actual_length = 0;
     switch (typeReq) {
 
     /* DEVICE REQUESTS */
 
     /* The root hub's remote wakeup enable bit is implemented using
      * driver model wakeup flags.  If this system supports wakeup
      * through USB, userspace may change the default "allow wakeup"
      * policy through sysfs or these calls.
      *
      * Most root hubs support wakeup from downstream devices, for
      * runtime power management (disabling USB clocks and reducing
      * VBUS power usage).  However, not all of them do so; silicon,
      * board, and BIOS bugs here are not uncommon, so these can't
      * be treated quite like external hubs.
      *
      * Likewise, not all root hubs will pass wakeup events upstream,
      * to wake up the whole system.  So don't assume root hub and
      * controller capabilities are identical.
      */
 
     case DeviceRequest | USB_REQ_GET_STATUS:
         tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
                     << USB_DEVICE_REMOTE_WAKEUP)
                 | (1 << USB_DEVICE_SELF_POWERED);
         tbuf[1] = 0;
         len = 2;
         break;
     case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
         if (wValue == USB_DEVICE_REMOTE_WAKEUP)
             device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
         else
             goto error;
         break;
     case DeviceOutRequest | USB_REQ_SET_FEATURE:
         if (device_can_wakeup(&hcd->self.root_hub->dev)
                 && wValue == USB_DEVICE_REMOTE_WAKEUP)
             device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
         else
             goto error;
         break;
     case DeviceRequest | USB_REQ_GET_CONFIGURATION:
         tbuf[0] = 1;
         len = 1;
         fallthrough;
     case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
         break;
     case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
         switch (wValue & 0xff00) {
         case USB_DT_DEVICE << 8:
             switch (hcd->speed) {
             case HCD_USB32:
             case HCD_USB31:
                 bufp = usb31_rh_dev_descriptor;
                 break;
             case HCD_USB3:
                 bufp = usb3_rh_dev_descriptor;
                 break;
             case HCD_USB25:
                 bufp = usb25_rh_dev_descriptor;
                 break;
             case HCD_USB2:
                 bufp = usb2_rh_dev_descriptor;
                 break;
             case HCD_USB11:
                 bufp = usb11_rh_dev_descriptor;
                 break;
             default:
                 goto error;
             }
             len = 18;
             if (hcd->has_tt)
                 patch_protocol = 1;
             break;
         case USB_DT_CONFIG << 8:
             switch (hcd->speed) {
             case HCD_USB32:
             case HCD_USB31:
             case HCD_USB3:
                 bufp = ss_rh_config_descriptor;
                 len = sizeof ss_rh_config_descriptor;
                 break;
             case HCD_USB25:
             case HCD_USB2:
                 bufp = hs_rh_config_descriptor;
                 len = sizeof hs_rh_config_descriptor;
                 break;
             case HCD_USB11:
                 bufp = fs_rh_config_descriptor;
                 len = sizeof fs_rh_config_descriptor;
                 break;
             default:
                 goto error;
             }
             if (device_can_wakeup(&hcd->self.root_hub->dev))
                 patch_wakeup = 1;
             break;
         case USB_DT_STRING << 8:
             if ((wValue & 0xff) < 4)
                 urb->actual_length = rh_string(wValue & 0xff,
                         hcd, ubuf, wLength);
             else /* unsupported IDs --> "protocol stall" */
                 goto error;
             break;
         case USB_DT_BOS << 8:
             goto nongeneric;
         default:
             goto error;
         }
         break;
     case DeviceRequest | USB_REQ_GET_INTERFACE:
         tbuf[0] = 0;
         len = 1;
         fallthrough;
     case DeviceOutRequest | USB_REQ_SET_INTERFACE:
         break;
     case DeviceOutRequest | USB_REQ_SET_ADDRESS:
         /* wValue == urb->dev->devaddr */
         dev_dbg (hcd->self.controller, "root hub device address %d\n",
             wValue);
         break;
 
     /* INTERFACE REQUESTS (no defined feature/status flags) */
 
     /* ENDPOINT REQUESTS */
 
     case EndpointRequest | USB_REQ_GET_STATUS:
         /* ENDPOINT_HALT flag */
         tbuf[0] = 0;
         tbuf[1] = 0;
         len = 2;
         fallthrough;
     case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
     case EndpointOutRequest | USB_REQ_SET_FEATURE:
         dev_dbg (hcd->self.controller, "no endpoint features yet\n");
         break;
 
     /* CLASS REQUESTS (and errors) */
 
     default:
 nongeneric:
         /* non-generic request */
         switch (typeReq) {
         case GetHubStatus:
             len = 4;
             break;
         case GetPortStatus:
             if (wValue == HUB_PORT_STATUS)
                 len = 4;
             else
                 /* other port status types return 8 bytes */
                 len = 8;
             break;
         case GetHubDescriptor:
             len = sizeof (struct usb_hub_descriptor);
             break;
         case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
             /* len is returned by hub_control */
             break;
         }
         status = hcd->driver->hub_control (hcd,
             typeReq, wValue, wIndex,
             tbuf, wLength);
 
         if (typeReq == GetHubDescriptor)
             usb_hub_adjust_deviceremovable(hcd->self.root_hub,
                 (struct usb_hub_descriptor *)tbuf);
         break;
 error:
         /* "protocol stall" on error */
         status = -EPIPE;
     }
 
     if (status < 0) {
         len = 0;
         if (status != -EPIPE) {
             dev_dbg (hcd->self.controller,
                 "CTRL: TypeReq=0x%x val=0x%x "
                 "idx=0x%x len=%d ==> %d\n",
                 typeReq, wValue, wIndex,
                 wLength, status);
         }
     } else if (status > 0) {
         /* hub_control may return the length of data copied. */
         len = status;
         status = 0;
     }
     if (len) {
         if (urb->transfer_buffer_length < len)
             len = urb->transfer_buffer_length;
         urb->actual_length = len;
         /* always USB_DIR_IN, toward host */
         memcpy (ubuf, bufp, len);
 
         /* report whether RH hardware supports remote wakeup */
         if (patch_wakeup &&
                 len > offsetof (struct usb_config_descriptor,
                         bmAttributes))
             ((struct usb_config_descriptor *)ubuf)->bmAttributes
                 |= USB_CONFIG_ATT_WAKEUP;
 
         /* report whether RH hardware has an integrated TT */
         if (patch_protocol &&
                 len > offsetof(struct usb_device_descriptor,
                         bDeviceProtocol))
             ((struct usb_device_descriptor *) ubuf)->
                 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
     }
 
     kfree(tbuf);
  err_alloc:
 
     /* any errors get returned through the urb completion */
     spin_lock_irq(&hcd_root_hub_lock);
     usb_hcd_unlink_urb_from_ep(hcd, urb);
     usb_hcd_giveback_urb(hcd, urb, status);
     spin_unlock_irq(&hcd_root_hub_lock);
     return 0;
 }
 
 /*-------------------------------------------------------------------------*/
 
 /*
  * Root Hub interrupt transfers are polled using a timer if the
  * driver requests it; otherwise the driver is responsible for
  * calling usb_hcd_poll_rh_status() when an event occurs.
  *
  * Completion handler may not sleep. See usb_hcd_giveback_urb() for details.
  */
 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 {
     struct urb  *urb;
     int     length;
     int     status;
     unsigned long   flags;
     char        buffer[6];  /* Any root hubs with > 31 ports? */
 
     if (unlikely(!hcd->rh_pollable))
         return;
     if (!hcd->uses_new_polling && !hcd->status_urb)
         return;
 
     length = hcd->driver->hub_status_data(hcd, buffer);
     if (length > 0) {
 
         /* try to complete the status urb */
         spin_lock_irqsave(&hcd_root_hub_lock, flags);
         urb = hcd->status_urb;
         if (urb) {
             clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
             hcd->status_urb = NULL;
             if (urb->transfer_buffer_length >= length) {
                 status = 0;
             } else {
                 status = -EOVERFLOW;
                 length = urb->transfer_buffer_length;
             }
             urb->actual_length = length;
             memcpy(urb->transfer_buffer, buffer, length);
 
             usb_hcd_unlink_urb_from_ep(hcd, urb);
             usb_hcd_giveback_urb(hcd, urb, status);
         } else {
             length = 0;
             set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
         }
         spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
     }
 
     /* The USB 2.0 spec says 256 ms.  This is close enough and won't
      * exceed that limit if HZ is 100. The math is more clunky than
      * maybe expected, this is to make sure that all timers for USB devices
      * fire at the same time to give the CPU a break in between */
     if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
             (length == 0 && hcd->status_urb != NULL))
         mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 }
 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
 
 /* timer callback */
 static void rh_timer_func (struct timer_list *t)
 {
     struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer);
 
     usb_hcd_poll_rh_status(_hcd);
 }
 
 /*-------------------------------------------------------------------------*/
 
 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 {
     int     retval;
     unsigned long   flags;
     unsigned    len = 1 + (urb->dev->maxchild / 8);
 
     spin_lock_irqsave (&hcd_root_hub_lock, flags);
     if (hcd->status_urb || urb->transfer_buffer_length < len) {
         dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
         retval = -EINVAL;
         goto done;
     }
 
     retval = usb_hcd_link_urb_to_ep(hcd, urb);
     if (retval)
         goto done;
 
     hcd->status_urb = urb;
     urb->hcpriv = hcd;  /* indicate it's queued */
     if (!hcd->uses_new_polling)
         mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 
     /* If a status change has already occurred, report it ASAP */
     else if (HCD_POLL_PENDING(hcd))
         mod_timer(&hcd->rh_timer, jiffies);
     retval = 0;
  done:
     spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
     return retval;
 }
 
 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
 {
     if (usb_endpoint_xfer_int(&urb->ep->desc))
         return rh_queue_status (hcd, urb);
     if (usb_endpoint_xfer_control(&urb->ep->desc))
         return rh_call_control (hcd, urb);
     return -EINVAL;
 }
 
 /*-------------------------------------------------------------------------*/
 
 /* Unlinks of root-hub control URBs are legal, but they don't do anything
  * since these URBs always execute synchronously.
  */
 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 {
     unsigned long   flags;
     int     rc;
 
     spin_lock_irqsave(&hcd_root_hub_lock, flags);
     rc = usb_hcd_check_unlink_urb(hcd, urb, status);
     if (rc)
         goto done;
 
     if (usb_endpoint_num(&urb->ep->desc) == 0) {    /* Control URB */
         ;   /* Do nothing */
 
     } else {                /* Status URB */
         if (!hcd->uses_new_polling)
             del_timer (&hcd->rh_timer);
         if (urb == hcd->status_urb) {
             hcd->status_urb = NULL;
             usb_hcd_unlink_urb_from_ep(hcd, urb);
             usb_hcd_giveback_urb(hcd, urb, status);
         }
     }
  done:
     spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
     return rc;
 }
 
 
 /*-------------------------------------------------------------------------*/
 
 /**
  * usb_bus_init - shared initialization code
  * @bus: the bus structure being initialized
  *
  * This code is used to initialize a usb_bus structure, memory for which is
  * separately managed.
  */
 static void usb_bus_init (struct usb_bus *bus)
 {
     memset (&bus->devmap, 0, sizeof(struct usb_devmap));
 
     bus->devnum_next = 1;
 
     bus->root_hub = NULL;
     bus->busnum = -1;
     bus->bandwidth_allocated = 0;
     bus->bandwidth_int_reqs  = 0;
     bus->bandwidth_isoc_reqs = 0;
     mutex_init(&bus->devnum_next_mutex);
 }
 
 /*-------------------------------------------------------------------------*/
 
 /**
  * usb_register_bus - registers the USB host controller with the usb core
  * @bus: pointer to the bus to register
  *
  * Context: task context, might sleep.
  *
  * Assigns a bus number, and links the controller into usbcore data
  * structures so that it can be seen by scanning the bus list.
  *
  * Return: 0 if successful. A negative error code otherwise.
  */
 static int usb_register_bus(struct usb_bus *bus)
 {
     int result = -E2BIG;
     int busnum;
 
     mutex_lock(&usb_bus_idr_lock);
     busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
     if (busnum < 0) {
         pr_err("%s: failed to get bus number\n", usbcore_name);
         goto error_find_busnum;
     }
     bus->busnum = busnum;
     mutex_unlock(&usb_bus_idr_lock);
 
     usb_notify_add_bus(bus);
 
     dev_info (bus->controller, "new USB bus registered, assigned bus "
           "number %d\n", bus->busnum);
     return 0;
 
 error_find_busnum:
     mutex_unlock(&usb_bus_idr_lock);
     return result;
 }
 
 /**
  * usb_deregister_bus - deregisters the USB host controller
  * @bus: pointer to the bus to deregister
  *
  * Context: task context, might sleep.
  *
  * Recycles the bus number, and unlinks the controller from usbcore data
  * structures so that it won't be seen by scanning the bus list.
  */
 static void usb_deregister_bus (struct usb_bus *bus)
 {
     dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
 
     /*
      * NOTE: make sure that all the devices are removed by the
      * controller code, as well as having it call this when cleaning
      * itself up
      */
     mutex_lock(&usb_bus_idr_lock);
     idr_remove(&usb_bus_idr, bus->busnum);
     mutex_unlock(&usb_bus_idr_lock);
 
     usb_notify_remove_bus(bus);
 }
 
 /**
  * register_root_hub - called by usb_add_hcd() to register a root hub
  * @hcd: host controller for this root hub
  *
  * This function registers the root hub with the USB subsystem.  It sets up
  * the device properly in the device tree and then calls usb_new_device()
  * to register the usb device.  It also assigns the root hub's USB address
  * (always 1).
  *
  * Return: 0 if successful. A negative error code otherwise.
  */
 static int register_root_hub(struct usb_hcd *hcd)
 {
     struct device *parent_dev = hcd->self.controller;
     struct usb_device *usb_dev = hcd->self.root_hub;
     const int devnum = 1;
     int retval;
 
     usb_dev->devnum = devnum;
     usb_dev->bus->devnum_next = devnum + 1;
     set_bit (devnum, usb_dev->bus->devmap.devicemap);
     usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
 
     mutex_lock(&usb_bus_idr_lock);
 
     usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
     retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
     if (retval != sizeof usb_dev->descriptor) {
         mutex_unlock(&usb_bus_idr_lock);
         dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
                 dev_name(&usb_dev->dev), retval);
         return (retval < 0) ? retval : -EMSGSIZE;
     }
 
     if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
         retval = usb_get_bos_descriptor(usb_dev);
         if (!retval) {
             usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
         } else if (usb_dev->speed >= USB_SPEED_SUPER) {
             mutex_unlock(&usb_bus_idr_lock);
             dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
                     dev_name(&usb_dev->dev), retval);
             return retval;
         }
     }
 
     retval = usb_new_device (usb_dev);
     if (retval) {
         dev_err (parent_dev, "can't register root hub for %s, %d\n",
                 dev_name(&usb_dev->dev), retval);
     } else {
         spin_lock_irq (&hcd_root_hub_lock);
         hcd->rh_registered = 1;
         spin_unlock_irq (&hcd_root_hub_lock);
 
         /* Did the HC die before the root hub was registered? */
         if (HCD_DEAD(hcd))
             usb_hc_died (hcd);  /* This time clean up */
     }
     mutex_unlock(&usb_bus_idr_lock);
 
     return retval;
 }
 
 /*
  * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
  * @bus: the bus which the root hub belongs to
  * @portnum: the port which is being resumed
  *
  * HCDs should call this function when they know that a resume signal is
  * being sent to a root-hub port.  The root hub will be prevented from
  * going into autosuspend until usb_hcd_end_port_resume() is called.
  *
  * The bus's private lock must be held by the caller.
  */
 void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
 {
     unsigned bit = 1 << portnum;
 
     if (!(bus->resuming_ports & bit)) {
         bus->resuming_ports |= bit;
         pm_runtime_get_noresume(&bus->root_hub->dev);
     }
 }
 EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
 
 /*
  * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
  * @bus: the bus which the root hub belongs to
  * @portnum: the port which is being resumed
  *
  * HCDs should call this function when they know that a resume signal has
  * stopped being sent to a root-hub port.  The root hub will be allowed to
  * autosuspend again.
  *
  * The bus's private lock must be held by the caller.
  */
 void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
 {
     unsigned bit = 1 << portnum;
 
     if (bus->resuming_ports & bit) {
         bus->resuming_ports &= ~bit;
         pm_runtime_put_noidle(&bus->root_hub->dev);
     }
 }
 EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
 
 /*-------------------------------------------------------------------------*/
 
 /**
  * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
  * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
  * @is_input: true iff the transaction sends data to the host
  * @isoc: true for isochronous transactions, false for interrupt ones
  * @bytecount: how many bytes in the transaction.
  *
  * Return: Approximate bus time in nanoseconds for a periodic transaction.
  *
  * Note:
  * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
  * scheduled in software, this function is only used for such scheduling.
  */
 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
 {
     unsigned long   tmp;
 
     switch (speed) {
     case USB_SPEED_LOW:     /* INTR only */
         if (is_input) {
             tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
             return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
         } else {
             tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
             return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
         }
     case USB_SPEED_FULL:    /* ISOC or INTR */
         if (isoc) {
             tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
             return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
         } else {
             tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
             return 9107L + BW_HOST_DELAY + tmp;
         }
     case USB_SPEED_HIGH:    /* ISOC or INTR */
         /* FIXME adjust for input vs output */
         if (isoc)
             tmp = HS_NSECS_ISO (bytecount);
         else
             tmp = HS_NSECS (bytecount);
         return tmp;
     default:
         pr_debug ("%s: bogus device speed!\n", usbcore_name);
         return -1;
     }
 }
 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
 
 
 /*-------------------------------------------------------------------------*/
 
 /*
  * Generic HC operations.
  */
 
 /*-------------------------------------------------------------------------*/
 
 /**
  * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
  * @hcd: host controller to which @urb was submitted
  * @urb: URB being submitted
  *
  * Host controller drivers should call this routine in their enqueue()
  * method.  The HCD's private spinlock must be held and interrupts must
  * be disabled.  The actions carried out here are required for URB
  * submission, as well as for endpoint shutdown and for usb_kill_urb.
  *
  * Return: 0 for no error, otherwise a negative error code (in which case
  * the enqueue() method must fail).  If no error occurs but enqueue() fails
  * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
  * the private spinlock and returning.
  */
 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
 {
     int     rc = 0;
 
     spin_lock(&hcd_urb_list_lock);
 
     /* Check that the URB isn't being killed */
     if (unlikely(atomic_read(&urb->reject))) {
         rc = -EPERM;
         goto done;
     }
 
     if (unlikely(!urb->ep->enabled)) {
         rc = -ENOENT;
         goto done;
     }
 
     if (unlikely(!urb->dev->can_submit)) {
         rc = -EHOSTUNREACH;
         goto done;
     }
 
     /*
      * Check the host controller's state and add the URB to the
      * endpoint's queue.
      */
     if (HCD_RH_RUNNING(hcd)) {
         urb->unlinked = 0;
         list_add_tail(&urb->urb_list, &urb->ep->urb_list);
     } else {
         rc = -ESHUTDOWN;
         goto done;
     }
  done:
     spin_unlock(&hcd_urb_list_lock);
     return rc;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
 
 /**
  * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
  * @hcd: host controller to which @urb was submitted
  * @urb: URB being checked for unlinkability
  * @status: error code to store in @urb if the unlink succeeds
  *
  * Host controller drivers should call this routine in their dequeue()
  * method.  The HCD's private spinlock must be held and interrupts must
  * be disabled.  The actions carried out here are required for making
  * sure than an unlink is valid.
  *
  * Return: 0 for no error, otherwise a negative error code (in which case
  * the dequeue() method must fail).  The possible error codes are:
  *
  *  -EIDRM: @urb was not submitted or has already completed.
  *      The completion function may not have been called yet.
  *
  *  -EBUSY: @urb has already been unlinked.
  */
 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
         int status)
 {
     struct list_head    *tmp;
 
     /* insist the urb is still queued */
     list_for_each(tmp, &urb->ep->urb_list) {
         if (tmp == &urb->urb_list)
             break;
     }
     if (tmp != &urb->urb_list)
         return -EIDRM;
 
     /* Any status except -EINPROGRESS means something already started to
      * unlink this URB from the hardware.  So there's no more work to do.
      */
     if (urb->unlinked)
         return -EBUSY;
     urb->unlinked = status;
     return 0;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
 
 /**
  * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
  * @hcd: host controller to which @urb was submitted
  * @urb: URB being unlinked
  *
  * Host controller drivers should call this routine before calling
  * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
  * interrupts must be disabled.  The actions carried out here are required
  * for URB completion.
  */
 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
 {
     /* clear all state linking urb to this dev (and hcd) */
     spin_lock(&hcd_urb_list_lock);
     list_del_init(&urb->urb_list);
     spin_unlock(&hcd_urb_list_lock);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
 
 /*
  * Some usb host controllers can only perform dma using a small SRAM area,
  * or have restrictions on addressable DRAM.
  * The usb core itself is however optimized for host controllers that can dma
  * using regular system memory - like pci devices doing bus mastering.
  *
  * To support host controllers with limited dma capabilities we provide dma
  * bounce buffers. This feature can be enabled by initializing
  * hcd->localmem_pool using usb_hcd_setup_local_mem().
  *
  * The initialized hcd->localmem_pool then tells the usb code to allocate all
  * data for dma using the genalloc API.
  *
  * So, to summarize...
  *
  * - We need "local" memory, canonical example being
  *   a small SRAM on a discrete controller being the
  *   only memory that the controller can read ...
  *   (a) "normal" kernel memory is no good, and
  *   (b) there's not enough to share
  *
  * - So we use that, even though the primary requirement
  *   is that the memory be "local" (hence addressable
  *   by that device), not "coherent".
  *
  */
 
 static int hcd_alloc_coherent(struct usb_bus *bus,
                   gfp_t mem_flags, dma_addr_t *dma_handle,
                   void **vaddr_handle, size_t size,
                   enum dma_data_direction dir)
 {
     unsigned char *vaddr;
 
     if (*vaddr_handle == NULL) {
         WARN_ON_ONCE(1);
         return -EFAULT;
     }
 
     vaddr = hcd_buffer_alloc(bus, size + sizeof(unsigned long),
                  mem_flags, dma_handle);
     if (!vaddr)
         return -ENOMEM;
 
     /*
      * Store the virtual address of the buffer at the end
      * of the allocated dma buffer. The size of the buffer
      * may be uneven so use unaligned functions instead
      * of just rounding up. It makes sense to optimize for
      * memory footprint over access speed since the amount
      * of memory available for dma may be limited.
      */
     put_unaligned((unsigned long)*vaddr_handle,
               (unsigned long *)(vaddr + size));
 
     if (dir == DMA_TO_DEVICE)
         memcpy(vaddr, *vaddr_handle, size);
 
     *vaddr_handle = vaddr;
     return 0;
 }
 
 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
                   void **vaddr_handle, size_t size,
                   enum dma_data_direction dir)
 {
     unsigned char *vaddr = *vaddr_handle;
 
     vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
 
     if (dir == DMA_FROM_DEVICE)
         memcpy(vaddr, *vaddr_handle, size);
 
     hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
 
     *vaddr_handle = vaddr;
     *dma_handle = 0;
 }
 
 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
 {
     if (IS_ENABLED(CONFIG_HAS_DMA) &&
         (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
         dma_unmap_single(hcd->self.sysdev,
                 urb->setup_dma,
                 sizeof(struct usb_ctrlrequest),
                 DMA_TO_DEVICE);
     else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
         hcd_free_coherent(urb->dev->bus,
                 &urb->setup_dma,
                 (void **) &urb->setup_packet,
                 sizeof(struct usb_ctrlrequest),
                 DMA_TO_DEVICE);
 
     /* Make it safe to call this routine more than once */
     urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
 
 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 {
     if (hcd->driver->unmap_urb_for_dma)
         hcd->driver->unmap_urb_for_dma(hcd, urb);
     else
         usb_hcd_unmap_urb_for_dma(hcd, urb);
 }
 
 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 {
     enum dma_data_direction dir;
 
     usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
 
     dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
     if (IS_ENABLED(CONFIG_HAS_DMA) &&
         (urb->transfer_flags & URB_DMA_MAP_SG))
         dma_unmap_sg(hcd->self.sysdev,
                 urb->sg,
                 urb->num_sgs,
                 dir);
     else if (IS_ENABLED(CONFIG_HAS_DMA) &&
          (urb->transfer_flags & URB_DMA_MAP_PAGE))
         dma_unmap_page(hcd->self.sysdev,
                 urb->transfer_dma,
                 urb->transfer_buffer_length,
                 dir);
     else if (IS_ENABLED(CONFIG_HAS_DMA) &&
          (urb->transfer_flags & URB_DMA_MAP_SINGLE))
         dma_unmap_single(hcd->self.sysdev,
                 urb->transfer_dma,
                 urb->transfer_buffer_length,
                 dir);
     else if (urb->transfer_flags & URB_MAP_LOCAL)
         hcd_free_coherent(urb->dev->bus,
                 &urb->transfer_dma,
                 &urb->transfer_buffer,
                 urb->transfer_buffer_length,
                 dir);
 
     /* Make it safe to call this routine more than once */
     urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
             URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
 
 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
                gfp_t mem_flags)
 {
     if (hcd->driver->map_urb_for_dma)
         return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
     else
         return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
 }
 
 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
                 gfp_t mem_flags)
 {
     enum dma_data_direction dir;
     int ret = 0;
 
     /* Map the URB's buffers for DMA access.
      * Lower level HCD code should use *_dma exclusively,
      * unless it uses pio or talks to another transport,
      * or uses the provided scatter gather list for bulk.
      */
 
     if (usb_endpoint_xfer_control(&urb->ep->desc)) {
         if (hcd->self.uses_pio_for_control)
             return ret;
         if (hcd->localmem_pool) {
             ret = hcd_alloc_coherent(
                     urb->dev->bus, mem_flags,
                     &urb->setup_dma,
                     (void **)&urb->setup_packet,
                     sizeof(struct usb_ctrlrequest),
                     DMA_TO_DEVICE);
             if (ret)
                 return ret;
             urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
         } else if (hcd_uses_dma(hcd)) {
             if (object_is_on_stack(urb->setup_packet)) {
                 WARN_ONCE(1, "setup packet is on stack\n");
                 return -EAGAIN;
             }
 
             urb->setup_dma = dma_map_single(
                     hcd->self.sysdev,
                     urb->setup_packet,
                     sizeof(struct usb_ctrlrequest),
                     DMA_TO_DEVICE);
             if (dma_mapping_error(hcd->self.sysdev,
                         urb->setup_dma))
                 return -EAGAIN;
             urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
         }
     }
 
     dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
     if (urb->transfer_buffer_length != 0
         && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
         if (hcd->localmem_pool) {
             ret = hcd_alloc_coherent(
                     urb->dev->bus, mem_flags,
                     &urb->transfer_dma,
                     &urb->transfer_buffer,
                     urb->transfer_buffer_length,
                     dir);
             if (ret == 0)
                 urb->transfer_flags |= URB_MAP_LOCAL;
         } else if (hcd_uses_dma(hcd)) {
             if (urb->num_sgs) {
                 int n;
 
                 /* We don't support sg for isoc transfers ! */
                 if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
                     WARN_ON(1);
                     return -EINVAL;
                 }
 
                 n = dma_map_sg(
                         hcd->self.sysdev,
                         urb->sg,
                         urb->num_sgs,
                         dir);
                 if (n <= 0)
                     ret = -EAGAIN;
                 else
                     urb->transfer_flags |= URB_DMA_MAP_SG;
                 urb->num_mapped_sgs = n;
                 if (n != urb->num_sgs)
                     urb->transfer_flags |=
                             URB_DMA_SG_COMBINED;
             } else if (urb->sg) {
                 struct scatterlist *sg = urb->sg;
                 urb->transfer_dma = dma_map_page(
                         hcd->self.sysdev,
                         sg_page(sg),
                         sg->offset,
                         urb->transfer_buffer_length,
                         dir);
                 if (dma_mapping_error(hcd->self.sysdev,
                         urb->transfer_dma))
                     ret = -EAGAIN;
                 else
                     urb->transfer_flags |= URB_DMA_MAP_PAGE;
             } else if (object_is_on_stack(urb->transfer_buffer)) {
                 WARN_ONCE(1, "transfer buffer is on stack\n");
                 ret = -EAGAIN;
             } else {
                 urb->transfer_dma = dma_map_single(
                         hcd->self.sysdev,
                         urb->transfer_buffer,
                         urb->transfer_buffer_length,
                         dir);
                 if (dma_mapping_error(hcd->self.sysdev,
                         urb->transfer_dma))
                     ret = -EAGAIN;
                 else
                     urb->transfer_flags |= URB_DMA_MAP_SINGLE;
             }
         }
         if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
                 URB_SETUP_MAP_LOCAL)))
             usb_hcd_unmap_urb_for_dma(hcd, urb);
     }
     return ret;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
 
 /*-------------------------------------------------------------------------*/
 
 /* may be called in any context with a valid urb->dev usecount
  * caller surrenders "ownership" of urb
  * expects usb_submit_urb() to have sanity checked and conditioned all
  * inputs in the urb
  */
 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 {
     int         status;
     struct usb_hcd      *hcd = bus_to_hcd(urb->dev->bus);
 
     /* increment urb's reference count as part of giving it to the HCD
      * (which will control it).  HCD guarantees that it either returns
      * an error or calls giveback(), but not both.
      */
     usb_get_urb(urb);
     atomic_inc(&urb->use_count);
     atomic_inc(&urb->dev->urbnum);
     usbmon_urb_submit(&hcd->self, urb);
 
     /* NOTE requirements on root-hub callers (usbfs and the hub
      * driver, for now):  URBs' urb->transfer_buffer must be
      * valid and usb_buffer_{sync,unmap}() not be needed, since
      * they could clobber root hub response data.  Also, control
      * URBs must be submitted in process context with interrupts
      * enabled.
      */
 
     if (is_root_hub(urb->dev)) {
         status = rh_urb_enqueue(hcd, urb);
     } else {
         status = map_urb_for_dma(hcd, urb, mem_flags);
         if (likely(status == 0)) {
             status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
             if (unlikely(status))
                 unmap_urb_for_dma(hcd, urb);
         }
     }
 
     if (unlikely(status)) {
         usbmon_urb_submit_error(&hcd->self, urb, status);
         urb->hcpriv = NULL;
         INIT_LIST_HEAD(&urb->urb_list);
         atomic_dec(&urb->use_count);
         /*
          * Order the write of urb->use_count above before the read
          * of urb->reject below.  Pairs with the memory barriers in
          * usb_kill_urb() and usb_poison_urb().
          */
         smp_mb__after_atomic();
 
         atomic_dec(&urb->dev->urbnum);
         if (atomic_read(&urb->reject))
             wake_up(&usb_kill_urb_queue);
         usb_put_urb(urb);
     }
     return status;
 }
 
 /*-------------------------------------------------------------------------*/
 
 /* this makes the hcd giveback() the urb more quickly, by kicking it
  * off hardware queues (which may take a while) and returning it as
  * soon as practical.  we've already set up the urb's return status,
  * but we can't know if the callback completed already.
  */
 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
 {
     int     value;
 
     if (is_root_hub(urb->dev))
         value = usb_rh_urb_dequeue(hcd, urb, status);
     else {
 
         /* The only reason an HCD might fail this call is if
          * it has not yet fully queued the urb to begin with.
          * Such failures should be harmless. */
         value = hcd->driver->urb_dequeue(hcd, urb, status);
     }
     return value;
 }
 
 /*
  * called in any context
  *
  * caller guarantees urb won't be recycled till both unlink()
  * and the urb's completion function return
  */
 int usb_hcd_unlink_urb (struct urb *urb, int status)
 {
     struct usb_hcd      *hcd;
     struct usb_device   *udev = urb->dev;
     int         retval = -EIDRM;
     unsigned long       flags;
 
     /* Prevent the device and bus from going away while
      * the unlink is carried out.  If they are already gone
      * then urb->use_count must be 0, since disconnected
      * devices can't have any active URBs.
      */
     spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
     if (atomic_read(&urb->use_count) > 0) {
         retval = 0;
         usb_get_dev(udev);
     }
     spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
     if (retval == 0) {
         hcd = bus_to_hcd(urb->dev->bus);
         retval = unlink1(hcd, urb, status);
         if (retval == 0)
             retval = -EINPROGRESS;
         else if (retval != -EIDRM && retval != -EBUSY)
             dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
                     urb, retval);
         usb_put_dev(udev);
     }
     return retval;
 }
 
 /*-------------------------------------------------------------------------*/
 
 static void __usb_hcd_giveback_urb(struct urb *urb)
 {
     struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
     struct usb_anchor *anchor = urb->anchor;
     int status = urb->unlinked;
 
     urb->hcpriv = NULL;
     if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
         urb->actual_length < urb->transfer_buffer_length &&
         !status))
         status = -EREMOTEIO;
 
     unmap_urb_for_dma(hcd, urb);
     usbmon_urb_complete(&hcd->self, urb, status);
     usb_anchor_suspend_wakeups(anchor);
     usb_unanchor_urb(urb);
     if (likely(status == 0))
         usb_led_activity(USB_LED_EVENT_HOST);
 
     /* pass ownership to the completion handler */
     urb->status = status;
     /*
      * This function can be called in task context inside another remote
      * coverage collection section, but kcov doesn't support that kind of
      * recursion yet. Only collect coverage in softirq context for now.
      */
     kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum);
     urb->complete(urb);
     kcov_remote_stop_softirq();
 
     usb_anchor_resume_wakeups(anchor);
     atomic_dec(&urb->use_count);
     /*
      * Order the write of urb->use_count above before the read
      * of urb->reject below.  Pairs with the memory barriers in
      * usb_kill_urb() and usb_poison_urb().
      */
     smp_mb__after_atomic();
 
     if (unlikely(atomic_read(&urb->reject)))
         wake_up(&usb_kill_urb_queue);
     usb_put_urb(urb);
 }
 
 static void usb_giveback_urb_bh(struct tasklet_struct *t)
 {
     struct giveback_urb_bh *bh = from_tasklet(bh, t, bh);
     struct list_head local_list;
 
     spin_lock_irq(&bh->lock);
     bh->running = true;
     list_replace_init(&bh->head, &local_list);
     spin_unlock_irq(&bh->lock);
 
     while (!list_empty(&local_list)) {
         struct urb *urb;
 
         urb = list_entry(local_list.next, struct urb, urb_list);
         list_del_init(&urb->urb_list);
         bh->completing_ep = urb->ep;
         __usb_hcd_giveback_urb(urb);
         bh->completing_ep = NULL;
     }
 
     /*
      * giveback new URBs next time to prevent this function
      * from not exiting for a long time.
      */
     spin_lock_irq(&bh->lock);
     if (!list_empty(&bh->head)) {
         if (bh->high_prio)
             tasklet_hi_schedule(&bh->bh);
         else
             tasklet_schedule(&bh->bh);
     }
     bh->running = false;
     spin_unlock_irq(&bh->lock);
 }
 
 /**
  * usb_hcd_giveback_urb - return URB from HCD to device driver
  * @hcd: host controller returning the URB
  * @urb: urb being returned to the USB device driver.
  * @status: completion status code for the URB.
  *
  * Context: atomic. The completion callback is invoked in caller's context.
  * For HCDs with HCD_BH flag set, the completion callback is invoked in tasklet
  * context (except for URBs submitted to the root hub which always complete in
  * caller's context).
  *
  * This hands the URB from HCD to its USB device driver, using its
  * completion function.  The HCD has freed all per-urb resources
  * (and is done using urb->hcpriv).  It also released all HCD locks;
  * the device driver won't cause problems if it frees, modifies,
  * or resubmits this URB.
  *
  * If @urb was unlinked, the value of @status will be overridden by
  * @urb->unlinked.  Erroneous short transfers are detected in case
  * the HCD hasn't checked for them.
  */
 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
 {
     struct giveback_urb_bh *bh;
     bool running;
 
     /* pass status to tasklet via unlinked */
     if (likely(!urb->unlinked))
         urb->unlinked = status;
 
     if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
         __usb_hcd_giveback_urb(urb);
         return;
     }
 
     if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe))
         bh = &hcd->high_prio_bh;
     else
         bh = &hcd->low_prio_bh;
 
     spin_lock(&bh->lock);
     list_add_tail(&urb->urb_list, &bh->head);
     running = bh->running;
     spin_unlock(&bh->lock);
 
     if (running)
         ;
     else if (bh->high_prio)
         tasklet_hi_schedule(&bh->bh);
     else
         tasklet_schedule(&bh->bh);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
 
 /*-------------------------------------------------------------------------*/
 
 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
  * queue to drain completely.  The caller must first insure that no more
  * URBs can be submitted for this endpoint.
  */
 void usb_hcd_flush_endpoint(struct usb_device *udev,
         struct usb_host_endpoint *ep)
 {
     struct usb_hcd      *hcd;
     struct urb      *urb;
 
     if (!ep)
         return;
     might_sleep();
     hcd = bus_to_hcd(udev->bus);
 
     /* No more submits can occur */
     spin_lock_irq(&hcd_urb_list_lock);
 rescan:
     list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
         int is_in;
 
         if (urb->unlinked)
             continue;
         usb_get_urb (urb);
         is_in = usb_urb_dir_in(urb);
         spin_unlock(&hcd_urb_list_lock);
 
         /* kick hcd */
         unlink1(hcd, urb, -ESHUTDOWN);
         dev_dbg (hcd->self.controller,
             "shutdown urb %pK ep%d%s-%s\n",
             urb, usb_endpoint_num(&ep->desc),
             is_in ? "in" : "out",
             usb_ep_type_string(usb_endpoint_type(&ep->desc)));
         usb_put_urb (urb);
 
         /* list contents may have changed */
         spin_lock(&hcd_urb_list_lock);
         goto rescan;
     }
     spin_unlock_irq(&hcd_urb_list_lock);
 
     /* Wait until the endpoint queue is completely empty */
     while (!list_empty (&ep->urb_list)) {
         spin_lock_irq(&hcd_urb_list_lock);
 
         /* The list may have changed while we acquired the spinlock */
         urb = NULL;
         if (!list_empty (&ep->urb_list)) {
             urb = list_entry (ep->urb_list.prev, struct urb,
                     urb_list);
             usb_get_urb (urb);
         }
         spin_unlock_irq(&hcd_urb_list_lock);
 
         if (urb) {
             usb_kill_urb (urb);
             usb_put_urb (urb);
         }
     }
 }
 
 /**
  * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
  *              the bus bandwidth
  * @udev: target &usb_device
  * @new_config: new configuration to install
  * @cur_alt: the current alternate interface setting
  * @new_alt: alternate interface setting that is being installed
  *
  * To change configurations, pass in the new configuration in new_config,
  * and pass NULL for cur_alt and new_alt.
  *
  * To reset a device's configuration (put the device in the ADDRESSED state),
  * pass in NULL for new_config, cur_alt, and new_alt.
  *
  * To change alternate interface settings, pass in NULL for new_config,
  * pass in the current alternate interface setting in cur_alt,
  * and pass in the new alternate interface setting in new_alt.
  *
  * Return: An error if the requested bandwidth change exceeds the
  * bus bandwidth or host controller internal resources.
  */
 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
         struct usb_host_config *new_config,
         struct usb_host_interface *cur_alt,
         struct usb_host_interface *new_alt)
 {
     int num_intfs, i, j;
     struct usb_host_interface *alt = NULL;
     int ret = 0;
     struct usb_hcd *hcd;
     struct usb_host_endpoint *ep;
 
     hcd = bus_to_hcd(udev->bus);
     if (!hcd->driver->check_bandwidth)
         return 0;
 
     /* Configuration is being removed - set configuration 0 */
     if (!new_config && !cur_alt) {
         for (i = 1; i < 16; ++i) {
             ep = udev->ep_out[i];
             if (ep)
                 hcd->driver->drop_endpoint(hcd, udev, ep);
             ep = udev->ep_in[i];
             if (ep)
                 hcd->driver->drop_endpoint(hcd, udev, ep);
         }
         hcd->driver->check_bandwidth(hcd, udev);
         return 0;
     }
     /* Check if the HCD says there's enough bandwidth.  Enable all endpoints
      * each interface's alt setting 0 and ask the HCD to check the bandwidth
      * of the bus.  There will always be bandwidth for endpoint 0, so it's
      * ok to exclude it.
      */
     if (new_config) {
         num_intfs = new_config->desc.bNumInterfaces;
         /* Remove endpoints (except endpoint 0, which is always on the
          * schedule) from the old config from the schedule
          */
         for (i = 1; i < 16; ++i) {
             ep = udev->ep_out[i];
             if (ep) {
                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
                 if (ret < 0)
                     goto reset;
             }
             ep = udev->ep_in[i];
             if (ep) {
                 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
                 if (ret < 0)
                     goto reset;
             }
         }
         for (i = 0; i < num_intfs; ++i) {
             struct usb_host_interface *first_alt;
             int iface_num;
 
             first_alt = &new_config->intf_cache[i]->altsetting[0];
             iface_num = first_alt->desc.bInterfaceNumber;
             /* Set up endpoints for alternate interface setting 0 */
             alt = usb_find_alt_setting(new_config, iface_num, 0);
             if (!alt)
                 /* No alt setting 0? Pick the first setting. */
                 alt = first_alt;
 
             for (j = 0; j < alt->desc.bNumEndpoints; j++) {
                 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
                 if (ret < 0)
                     goto reset;
             }
         }
     }
     if (cur_alt && new_alt) {
         struct usb_interface *iface = usb_ifnum_to_if(udev,
                 cur_alt->desc.bInterfaceNumber);
 
         if (!iface)
             return -EINVAL;
         if (iface->resetting_device) {
             /*
              * The USB core just reset the device, so the xHCI host
              * and the device will think alt setting 0 is installed.
              * However, the USB core will pass in the alternate
              * setting installed before the reset as cur_alt.  Dig
              * out the alternate setting 0 structure, or the first
              * alternate setting if a broken device doesn't have alt
              * setting 0.
              */
             cur_alt = usb_altnum_to_altsetting(iface, 0);
             if (!cur_alt)
                 cur_alt = &iface->altsetting[0];
         }
 
         /* Drop all the endpoints in the current alt setting */
         for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
             ret = hcd->driver->drop_endpoint(hcd, udev,
                     &cur_alt->endpoint[i]);
             if (ret < 0)
                 goto reset;
         }
         /* Add all the endpoints in the new alt setting */
         for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
             ret = hcd->driver->add_endpoint(hcd, udev,
                     &new_alt->endpoint[i]);
             if (ret < 0)
                 goto reset;
         }
     }
     ret = hcd->driver->check_bandwidth(hcd, udev);
 reset:
     if (ret < 0)
         hcd->driver->reset_bandwidth(hcd, udev);
     return ret;
 }
 
 /* Disables the endpoint: synchronizes with the hcd to make sure all
  * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
  * have been called previously.  Use for set_configuration, set_interface,
  * driver removal, physical disconnect.
  *
  * example:  a qh stored in ep->hcpriv, holding state related to endpoint
  * type, maxpacket size, toggle, halt status, and scheduling.
  */
 void usb_hcd_disable_endpoint(struct usb_device *udev,
         struct usb_host_endpoint *ep)
 {
     struct usb_hcd      *hcd;
 
     might_sleep();
     hcd = bus_to_hcd(udev->bus);
     if (hcd->driver->endpoint_disable)
         hcd->driver->endpoint_disable(hcd, ep);
 }
 
 /**
  * usb_hcd_reset_endpoint - reset host endpoint state
  * @udev: USB device.
  * @ep:   the endpoint to reset.
  *
  * Resets any host endpoint state such as the toggle bit, sequence
  * number and current window.
  */
 void usb_hcd_reset_endpoint(struct usb_device *udev,
                 struct usb_host_endpoint *ep)
 {
     struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 
     if (hcd->driver->endpoint_reset)
         hcd->driver->endpoint_reset(hcd, ep);
     else {
         int epnum = usb_endpoint_num(&ep->desc);
         int is_out = usb_endpoint_dir_out(&ep->desc);
         int is_control = usb_endpoint_xfer_control(&ep->desc);
 
         usb_settoggle(udev, epnum, is_out, 0);
         if (is_control)
             usb_settoggle(udev, epnum, !is_out, 0);
     }
 }
 
 /**
  * usb_alloc_streams - allocate bulk endpoint stream IDs.
  * @interface:      alternate setting that includes all endpoints.
  * @eps:        array of endpoints that need streams.
  * @num_eps:        number of endpoints in the array.
  * @num_streams:    number of streams to allocate.
  * @mem_flags:      flags hcd should use to allocate memory.
  *
  * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
  * Drivers may queue multiple transfers to different stream IDs, which may
  * complete in a different order than they were queued.
  *
  * Return: On success, the number of allocated streams. On failure, a negative
  * error code.
  */
 int usb_alloc_streams(struct usb_interface *interface,
         struct usb_host_endpoint **eps, unsigned int num_eps,
         unsigned int num_streams, gfp_t mem_flags)
 {
     struct usb_hcd *hcd;
     struct usb_device *dev;
     int i, ret;
 
     dev = interface_to_usbdev(interface);
     hcd = bus_to_hcd(dev->bus);
     if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
         return -EINVAL;
     if (dev->speed < USB_SPEED_SUPER)
         return -EINVAL;
     if (dev->state < USB_STATE_CONFIGURED)
         return -ENODEV;
 
     for (i = 0; i < num_eps; i++) {
         /* Streams only apply to bulk endpoints. */
         if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
             return -EINVAL;
         /* Re-alloc is not allowed */
         if (eps[i]->streams)
             return -EINVAL;
     }
 
     ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
             num_streams, mem_flags);
     if (ret < 0)
         return ret;
 
     for (i = 0; i < num_eps; i++)
         eps[i]->streams = ret;
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(usb_alloc_streams);
 
 /**
  * usb_free_streams - free bulk endpoint stream IDs.
  * @interface:  alternate setting that includes all endpoints.
  * @eps:    array of endpoints to remove streams from.
  * @num_eps:    number of endpoints in the array.
  * @mem_flags:  flags hcd should use to allocate memory.
  *
  * Reverts a group of bulk endpoints back to not using stream IDs.
  * Can fail if we are given bad arguments, or HCD is broken.
  *
  * Return: 0 on success. On failure, a negative error code.
  */
 int usb_free_streams(struct usb_interface *interface,
         struct usb_host_endpoint **eps, unsigned int num_eps,
         gfp_t mem_flags)
 {
     struct usb_hcd *hcd;
     struct usb_device *dev;
     int i, ret;
 
     dev = interface_to_usbdev(interface);
     hcd = bus_to_hcd(dev->bus);
     if (dev->speed < USB_SPEED_SUPER)
         return -EINVAL;
 
     /* Double-free is not allowed */
     for (i = 0; i < num_eps; i++)
         if (!eps[i] || !eps[i]->streams)
             return -EINVAL;
 
     ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
     if (ret < 0)
         return ret;
 
     for (i = 0; i < num_eps; i++)
         eps[i]->streams = 0;
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(usb_free_streams);
 
 /* Protect against drivers that try to unlink URBs after the device
  * is gone, by waiting until all unlinks for @udev are finished.
  * Since we don't currently track URBs by device, simply wait until
  * nothing is running in the locked region of usb_hcd_unlink_urb().
  */
 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
 {
     spin_lock_irq(&hcd_urb_unlink_lock);
     spin_unlock_irq(&hcd_urb_unlink_lock);
 }
 
 /*-------------------------------------------------------------------------*/
 
 /* called in any context */
 int usb_hcd_get_frame_number (struct usb_device *udev)
 {
     struct usb_hcd  *hcd = bus_to_hcd(udev->bus);
 
     if (!HCD_RH_RUNNING(hcd))
         return -ESHUTDOWN;
     return hcd->driver->get_frame_number (hcd);
 }
 
 /*-------------------------------------------------------------------------*/
 #ifdef CONFIG_USB_HCD_TEST_MODE
 
 static void usb_ehset_completion(struct urb *urb)
 {
     struct completion  *done = urb->context;
 
     complete(done);
 }
 /*
  * Allocate and initialize a control URB. This request will be used by the
  * EHSET SINGLE_STEP_SET_FEATURE test in which the DATA and STATUS stages
  * of the GetDescriptor request are sent 15 seconds after the SETUP stage.
  * Return NULL if failed.
  */
 static struct urb *request_single_step_set_feature_urb(
     struct usb_device   *udev,
     void            *dr,
     void            *buf,
     struct completion   *done)
 {
     struct urb *urb;
     struct usb_hcd *hcd = bus_to_hcd(udev->bus);
     struct usb_host_endpoint *ep;
 
     urb = usb_alloc_urb(0, GFP_KERNEL);
     if (!urb)
         return NULL;
 
     urb->pipe = usb_rcvctrlpipe(udev, 0);
     ep = (usb_pipein(urb->pipe) ? udev->ep_in : udev->ep_out)
                 [usb_pipeendpoint(urb->pipe)];
     if (!ep) {
         usb_free_urb(urb);
         return NULL;
     }
 
     urb->ep = ep;
     urb->dev = udev;
     urb->setup_packet = (void *)dr;
     urb->transfer_buffer = buf;
     urb->transfer_buffer_length = USB_DT_DEVICE_SIZE;
     urb->complete = usb_ehset_completion;
     urb->status = -EINPROGRESS;
     urb->actual_length = 0;
     urb->transfer_flags = URB_DIR_IN;
     usb_get_urb(urb);
     atomic_inc(&urb->use_count);
     atomic_inc(&urb->dev->urbnum);
     if (map_urb_for_dma(hcd, urb, GFP_KERNEL)) {
         usb_put_urb(urb);
         usb_free_urb(urb);
         return NULL;
     }
 
     urb->context = done;
     return urb;
 }
 
 int ehset_single_step_set_feature(struct usb_hcd *hcd, int port)
 {
     int retval = -ENOMEM;
     struct usb_ctrlrequest *dr;
     struct urb *urb;
     struct usb_device *udev;
     struct usb_device_descriptor *buf;
     DECLARE_COMPLETION_ONSTACK(done);
 
     /* Obtain udev of the rhub's child port */
     udev = usb_hub_find_child(hcd->self.root_hub, port);
     if (!udev) {
         dev_err(hcd->self.controller, "No device attached to the RootHub\n");
         return -ENODEV;
     }
     buf = kmalloc(USB_DT_DEVICE_SIZE, GFP_KERNEL);
     if (!buf)
         return -ENOMEM;
 
     dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
     if (!dr) {
         kfree(buf);
         return -ENOMEM;
     }
 
     /* Fill Setup packet for GetDescriptor */
     dr->bRequestType = USB_DIR_IN;
     dr->bRequest = USB_REQ_GET_DESCRIPTOR;
     dr->wValue = cpu_to_le16(USB_DT_DEVICE << 8);
     dr->wIndex = 0;
     dr->wLength = cpu_to_le16(USB_DT_DEVICE_SIZE);
     urb = request_single_step_set_feature_urb(udev, dr, buf, &done);
     if (!urb)
         goto cleanup;
 
     /* Submit just the SETUP stage */
     retval = hcd->driver->submit_single_step_set_feature(hcd, urb, 1);
     if (retval)
         goto out1;
     if (!wait_for_completion_timeout(&done, msecs_to_jiffies(2000))) {
         usb_kill_urb(urb);
         retval = -ETIMEDOUT;
         dev_err(hcd->self.controller,
             "%s SETUP stage timed out on ep0\n", __func__);
         goto out1;
     }
     msleep(15 * 1000);
 
     /* Complete remaining DATA and STATUS stages using the same URB */
     urb->status = -EINPROGRESS;
     usb_get_urb(urb);
     atomic_inc(&urb->use_count);
     atomic_inc(&urb->dev->urbnum);
     retval = hcd->driver->submit_single_step_set_feature(hcd, urb, 0);
     if (!retval && !wait_for_completion_timeout(&done,
                         msecs_to_jiffies(2000))) {
         usb_kill_urb(urb);
         retval = -ETIMEDOUT;
         dev_err(hcd->self.controller,
             "%s IN stage timed out on ep0\n", __func__);
     }
 out1:
     usb_free_urb(urb);
 cleanup:
     kfree(dr);
     kfree(buf);
     return retval;
 }
 EXPORT_SYMBOL_GPL(ehset_single_step_set_feature);
 #endif /* CONFIG_USB_HCD_TEST_MODE */
 
 /*-------------------------------------------------------------------------*/
 
 #ifdef  CONFIG_PM
 
 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
 {
     struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
     int     status;
     int     old_state = hcd->state;
 
     dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
             (PMSG_IS_AUTO(msg) ? "auto-" : ""),
             rhdev->do_remote_wakeup);
     if (HCD_DEAD(hcd)) {
         dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
         return 0;
     }
 
     if (!hcd->driver->bus_suspend) {
         status = -ENOENT;
     } else {
         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
         hcd->state = HC_STATE_QUIESCING;
         status = hcd->driver->bus_suspend(hcd);
     }
     if (status == 0) {
         usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
         hcd->state = HC_STATE_SUSPENDED;
 
         if (!PMSG_IS_AUTO(msg))
             usb_phy_roothub_suspend(hcd->self.sysdev,
                         hcd->phy_roothub);
 
         /* Did we race with a root-hub wakeup event? */
         if (rhdev->do_remote_wakeup) {
             char    buffer[6];
 
             status = hcd->driver->hub_status_data(hcd, buffer);
             if (status != 0) {
                 dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
                 hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
                 status = -EBUSY;
             }
         }
     } else {
         spin_lock_irq(&hcd_root_hub_lock);
         if (!HCD_DEAD(hcd)) {
             set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
             hcd->state = old_state;
         }
         spin_unlock_irq(&hcd_root_hub_lock);
         dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
                 "suspend", status);
     }
     return status;
 }
 
 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 {
     struct usb_hcd  *hcd = bus_to_hcd(rhdev->bus);
     int     status;
     int     old_state = hcd->state;
 
     dev_dbg(&rhdev->dev, "usb %sresume\n",
             (PMSG_IS_AUTO(msg) ? "auto-" : ""));
     if (HCD_DEAD(hcd)) {
         dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
         return 0;
     }
 
     if (!PMSG_IS_AUTO(msg)) {
         status = usb_phy_roothub_resume(hcd->self.sysdev,
                         hcd->phy_roothub);
         if (status)
             return status;
     }
 
     if (!hcd->driver->bus_resume)
         return -ENOENT;
     if (HCD_RH_RUNNING(hcd))
         return 0;
 
     hcd->state = HC_STATE_RESUMING;
     status = hcd->driver->bus_resume(hcd);
     clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
     if (status == 0)
         status = usb_phy_roothub_calibrate(hcd->phy_roothub);
 
     if (status == 0) {
         struct usb_device *udev;
         int port1;
 
         spin_lock_irq(&hcd_root_hub_lock);
         if (!HCD_DEAD(hcd)) {
             usb_set_device_state(rhdev, rhdev->actconfig
                     ? USB_STATE_CONFIGURED
                     : USB_STATE_ADDRESS);
             set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
             hcd->state = HC_STATE_RUNNING;
         }
         spin_unlock_irq(&hcd_root_hub_lock);
 
         /*
          * Check whether any of the enabled ports on the root hub are
          * unsuspended.  If they are then a TRSMRCY delay is needed
          * (this is what the USB-2 spec calls a "global resume").
          * Otherwise we can skip the delay.
          */
         usb_hub_for_each_child(rhdev, port1, udev) {
             if (udev->state != USB_STATE_NOTATTACHED &&
                     !udev->port_is_suspended) {
                 usleep_range(10000, 11000); /* TRSMRCY */
                 break;
             }
         }
     } else {
         hcd->state = old_state;
         usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
         dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
                 "resume", status);
         if (status != -ESHUTDOWN)
             usb_hc_died(hcd);
     }
     return status;
 }
 
 /* Workqueue routine for root-hub remote wakeup */
 static void hcd_resume_work(struct work_struct *work)
 {
     struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
     struct usb_device *udev = hcd->self.root_hub;
 
     usb_remote_wakeup(udev);
 }
 
 /**
  * usb_hcd_resume_root_hub - called by HCD to resume its root hub
  * @hcd: host controller for this root hub
  *
  * The USB host controller calls this function when its root hub is
  * suspended (with the remote wakeup feature enabled) and a remote
  * wakeup request is received.  The routine submits a workqueue request
  * to resume the root hub (that is, manage its downstream ports again).
  */
 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
 {
     unsigned long flags;
 
     spin_lock_irqsave (&hcd_root_hub_lock, flags);
     if (hcd->rh_registered) {
         pm_wakeup_event(&hcd->self.root_hub->dev, 0);
         set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
         queue_work(pm_wq, &hcd->wakeup_work);
     }
     spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
 
 #endif  /* CONFIG_PM */
 
 /*-------------------------------------------------------------------------*/
 
 #ifdef  CONFIG_USB_OTG
 
 /**
  * usb_bus_start_enum - start immediate enumeration (for OTG)
  * @bus: the bus (must use hcd framework)
  * @port_num: 1-based number of port; usually bus->otg_port
  * Context: atomic
  *
  * Starts enumeration, with an immediate reset followed later by
  * hub_wq identifying and possibly configuring the device.
  * This is needed by OTG controller drivers, where it helps meet
  * HNP protocol timing requirements for starting a port reset.
  *
  * Return: 0 if successful.
  */
 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
 {
     struct usb_hcd      *hcd;
     int         status = -EOPNOTSUPP;
 
     /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
      * boards with root hubs hooked up to internal devices (instead of
      * just the OTG port) may need more attention to resetting...
      */
     hcd = bus_to_hcd(bus);
     if (port_num && hcd->driver->start_port_reset)
         status = hcd->driver->start_port_reset(hcd, port_num);
 
     /* allocate hub_wq shortly after (first) root port reset finishes;
      * it may issue others, until at least 50 msecs have passed.
      */
     if (status == 0)
         mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
     return status;
 }
 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
 
 #endif
 
 /*-------------------------------------------------------------------------*/
 
 /**
  * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
  * @irq: the IRQ being raised
  * @__hcd: pointer to the HCD whose IRQ is being signaled
  *
  * If the controller isn't HALTed, calls the driver's irq handler.
  * Checks whether the controller is now dead.
  *
  * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
  */
 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
 {
     struct usb_hcd      *hcd = __hcd;
     irqreturn_t     rc;
 
     if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
         rc = IRQ_NONE;
     else if (hcd->driver->irq(hcd) == IRQ_NONE)
         rc = IRQ_NONE;
     else
         rc = IRQ_HANDLED;
 
     return rc;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_irq);
 
 /*-------------------------------------------------------------------------*/
 
 /* Workqueue routine for when the root-hub has died. */
 static void hcd_died_work(struct work_struct *work)
 {
     struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
     static char *env[] = {
         "ERROR=DEAD",
         NULL
     };
 
     /* Notify user space that the host controller has died */
     kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);
 }
 
 /**
  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
  * @hcd: pointer to the HCD representing the controller
  *
  * This is called by bus glue to report a USB host controller that died
  * while operations may still have been pending.  It's called automatically
  * by the PCI glue, so only glue for non-PCI busses should need to call it.
  *
  * Only call this function with the primary HCD.
  */
 void usb_hc_died (struct usb_hcd *hcd)
 {
     unsigned long flags;
 
     dev_err (hcd->self.controller, "HC died; cleaning up\n");
 
     spin_lock_irqsave (&hcd_root_hub_lock, flags);
     clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
     set_bit(HCD_FLAG_DEAD, &hcd->flags);
     if (hcd->rh_registered) {
         clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
         /* make hub_wq clean up old urbs and devices */
         usb_set_device_state (hcd->self.root_hub,
                 USB_STATE_NOTATTACHED);
         usb_kick_hub_wq(hcd->self.root_hub);
     }
     if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
         hcd = hcd->shared_hcd;
         clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
         set_bit(HCD_FLAG_DEAD, &hcd->flags);
         if (hcd->rh_registered) {
             clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
             /* make hub_wq clean up old urbs and devices */
             usb_set_device_state(hcd->self.root_hub,
                     USB_STATE_NOTATTACHED);
             usb_kick_hub_wq(hcd->self.root_hub);
         }
     }
 
     /* Handle the case where this function gets called with a shared HCD */
     if (usb_hcd_is_primary_hcd(hcd))
         schedule_work(&hcd->died_work);
     else
         schedule_work(&hcd->primary_hcd->died_work);
 
     spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
     /* Make sure that the other roothub is also deallocated. */
 }
 EXPORT_SYMBOL_GPL (usb_hc_died);
 
 /*-------------------------------------------------------------------------*/
 
 static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
 {
 
     spin_lock_init(&bh->lock);
     INIT_LIST_HEAD(&bh->head);
     tasklet_setup(&bh->bh, usb_giveback_urb_bh);
 }
 
 struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
         struct device *sysdev, struct device *dev, const char *bus_name,
         struct usb_hcd *primary_hcd)
 {
     struct usb_hcd *hcd;
 
     hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
     if (!hcd)
         return NULL;
     if (primary_hcd == NULL) {
         hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
                 GFP_KERNEL);
         if (!hcd->address0_mutex) {
             kfree(hcd);
             dev_dbg(dev, "hcd address0 mutex alloc failed\n");
             return NULL;
         }
         mutex_init(hcd->address0_mutex);
         hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
                 GFP_KERNEL);
         if (!hcd->bandwidth_mutex) {
             kfree(hcd->address0_mutex);
             kfree(hcd);
             dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
             return NULL;
         }
         mutex_init(hcd->bandwidth_mutex);
         dev_set_drvdata(dev, hcd);
     } else {
         mutex_lock(&usb_port_peer_mutex);
         hcd->address0_mutex = primary_hcd->address0_mutex;
         hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
         hcd->primary_hcd = primary_hcd;
         primary_hcd->primary_hcd = primary_hcd;
         hcd->shared_hcd = primary_hcd;
         primary_hcd->shared_hcd = hcd;
         mutex_unlock(&usb_port_peer_mutex);
     }
 
     kref_init(&hcd->kref);
 
     usb_bus_init(&hcd->self);
     hcd->self.controller = dev;
     hcd->self.sysdev = sysdev;
     hcd->self.bus_name = bus_name;
 
     timer_setup(&hcd->rh_timer, rh_timer_func, 0);
 #ifdef CONFIG_PM
     INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
 #endif
 
     INIT_WORK(&hcd->died_work, hcd_died_work);
 
     hcd->driver = driver;
     hcd->speed = driver->flags & HCD_MASK;
     hcd->product_desc = (driver->product_desc) ? driver->product_desc :
             "USB Host Controller";
     return hcd;
 }
 EXPORT_SYMBOL_GPL(__usb_create_hcd);
 
 /**
  * usb_create_shared_hcd - create and initialize an HCD structure
  * @driver: HC driver that will use this hcd
  * @dev: device for this HC, stored in hcd->self.controller
  * @bus_name: value to store in hcd->self.bus_name
  * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
  *              PCI device.  Only allocate certain resources for the primary HCD
  *
  * Context: task context, might sleep.
  *
  * Allocate a struct usb_hcd, with extra space at the end for the
  * HC driver's private data.  Initialize the generic members of the
  * hcd structure.
  *
  * Return: On success, a pointer to the created and initialized HCD structure.
  * On failure (e.g. if memory is unavailable), %NULL.
  */
 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
         struct device *dev, const char *bus_name,
         struct usb_hcd *primary_hcd)
 {
     return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
 }
 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
 
 /**
  * usb_create_hcd - create and initialize an HCD structure
  * @driver: HC driver that will use this hcd
  * @dev: device for this HC, stored in hcd->self.controller
  * @bus_name: value to store in hcd->self.bus_name
  *
  * Context: task context, might sleep.
  *
  * Allocate a struct usb_hcd, with extra space at the end for the
  * HC driver's private data.  Initialize the generic members of the
  * hcd structure.
  *
  * Return: On success, a pointer to the created and initialized HCD
  * structure. On failure (e.g. if memory is unavailable), %NULL.
  */
 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
         struct device *dev, const char *bus_name)
 {
     return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
 }
 EXPORT_SYMBOL_GPL(usb_create_hcd);
 
 /*
  * Roothubs that share one PCI device must also share the bandwidth mutex.
  * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
  * deallocated.
  *
  * Make sure to deallocate the bandwidth_mutex only when the last HCD is
  * freed.  When hcd_release() is called for either hcd in a peer set,
  * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
  */
 static void hcd_release(struct kref *kref)
 {
     struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
 
     mutex_lock(&usb_port_peer_mutex);
     if (hcd->shared_hcd) {
         struct usb_hcd *peer = hcd->shared_hcd;
 
         peer->shared_hcd = NULL;
         peer->primary_hcd = NULL;
     } else {
         kfree(hcd->address0_mutex);
         kfree(hcd->bandwidth_mutex);
     }
     mutex_unlock(&usb_port_peer_mutex);
     kfree(hcd);
 }
 
 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
 {
     if (hcd)
         kref_get (&hcd->kref);
     return hcd;
 }
 EXPORT_SYMBOL_GPL(usb_get_hcd);
 
 void usb_put_hcd (struct usb_hcd *hcd)
 {
     if (hcd)
         kref_put (&hcd->kref, hcd_release);
 }
 EXPORT_SYMBOL_GPL(usb_put_hcd);
 
 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
 {
     if (!hcd->primary_hcd)
         return 1;
     return hcd == hcd->primary_hcd;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
 
 int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
 {
     if (!hcd->driver->find_raw_port_number)
         return port1;
 
     return hcd->driver->find_raw_port_number(hcd, port1);
 }
 
 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
         unsigned int irqnum, unsigned long irqflags)
 {
     int retval;
 
     if (hcd->driver->irq) {
 
         snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
                 hcd->driver->description, hcd->self.busnum);
         retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
                 hcd->irq_descr, hcd);
         if (retval != 0) {
             dev_err(hcd->self.controller,
                     "request interrupt %d failed\n",
                     irqnum);
             return retval;
         }
         hcd->irq = irqnum;
         dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
                 (hcd->driver->flags & HCD_MEMORY) ?
                     "io mem" : "io port",
                 (unsigned long long)hcd->rsrc_start);
     } else {
         hcd->irq = 0;
         if (hcd->rsrc_start)
             dev_info(hcd->self.controller, "%s 0x%08llx\n",
                     (hcd->driver->flags & HCD_MEMORY) ?
                         "io mem" : "io port",
                     (unsigned long long)hcd->rsrc_start);
     }
     return 0;
 }
 
 /*
  * Before we free this root hub, flush in-flight peering attempts
  * and disable peer lookups
  */
 static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
 {
     struct usb_device *rhdev;
 
     mutex_lock(&usb_port_peer_mutex);
     rhdev = hcd->self.root_hub;
     hcd->self.root_hub = NULL;
     mutex_unlock(&usb_port_peer_mutex);
     usb_put_dev(rhdev);
 }
 
 /**
  * usb_stop_hcd - Halt the HCD
  * @hcd: the usb_hcd that has to be halted
  *
  * Stop the root-hub polling timer and invoke the HCD's ->stop callback.
  */
 static void usb_stop_hcd(struct usb_hcd *hcd)
 {
     hcd->rh_pollable = 0;
     clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
     del_timer_sync(&hcd->rh_timer);
 
     hcd->driver->stop(hcd);
     hcd->state = HC_STATE_HALT;
 
     /* In case the HCD restarted the timer, stop it again. */
     clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
     del_timer_sync(&hcd->rh_timer);
 }
 
 /**
  * usb_add_hcd - finish generic HCD structure initialization and register
  * @hcd: the usb_hcd structure to initialize
  * @irqnum: Interrupt line to allocate
  * @irqflags: Interrupt type flags
  *
  * Finish the remaining parts of generic HCD initialization: allocate the
  * buffers of consistent memory, register the bus, request the IRQ line,
  * and call the driver's reset() and start() routines.
  */
 int usb_add_hcd(struct usb_hcd *hcd,
         unsigned int irqnum, unsigned long irqflags)
 {
     int retval;
     struct usb_device *rhdev;
     struct usb_hcd *shared_hcd;
 
     if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
         hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
         if (IS_ERR(hcd->phy_roothub))
             return PTR_ERR(hcd->phy_roothub);
 
         retval = usb_phy_roothub_init(hcd->phy_roothub);
         if (retval)
             return retval;
 
         retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
                           PHY_MODE_USB_HOST_SS);
         if (retval)
             retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
                               PHY_MODE_USB_HOST);
         if (retval)
             goto err_usb_phy_roothub_power_on;
 
         retval = usb_phy_roothub_power_on(hcd->phy_roothub);
         if (retval)
             goto err_usb_phy_roothub_power_on;
     }
 
     dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
 
     switch (authorized_default) {
     case USB_AUTHORIZE_NONE:
         hcd->dev_policy = USB_DEVICE_AUTHORIZE_NONE;
         break;
 
     case USB_AUTHORIZE_ALL:
         hcd->dev_policy = USB_DEVICE_AUTHORIZE_ALL;
         break;
 
     case USB_AUTHORIZE_INTERNAL:
         hcd->dev_policy = USB_DEVICE_AUTHORIZE_INTERNAL;
         break;
 
     case USB_AUTHORIZE_WIRED:
     default:
         hcd->dev_policy = hcd->wireless ?
             USB_DEVICE_AUTHORIZE_NONE : USB_DEVICE_AUTHORIZE_ALL;
         break;
     }
 
     set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 
     /* per default all interfaces are authorized */
     set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
 
     /* HC is in reset state, but accessible.  Now do the one-time init,
      * bottom up so that hcds can customize the root hubs before hub_wq
      * starts talking to them.  (Note, bus id is assigned early too.)
      */
     retval = hcd_buffer_create(hcd);
     if (retval != 0) {
         dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
         goto err_create_buf;
     }
 
     retval = usb_register_bus(&hcd->self);
     if (retval < 0)
         goto err_register_bus;
 
     rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
     if (rhdev == NULL) {
         dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
         retval = -ENOMEM;
         goto err_allocate_root_hub;
     }
     mutex_lock(&usb_port_peer_mutex);
     hcd->self.root_hub = rhdev;
     mutex_unlock(&usb_port_peer_mutex);
 
     rhdev->rx_lanes = 1;
     rhdev->tx_lanes = 1;
     rhdev->ssp_rate = USB_SSP_GEN_UNKNOWN;
 
     switch (hcd->speed) {
     case HCD_USB11:
         rhdev->speed = USB_SPEED_FULL;
         break;
     case HCD_USB2:
         rhdev->speed = USB_SPEED_HIGH;
         break;
     case HCD_USB25:
         rhdev->speed = USB_SPEED_WIRELESS;
         break;
     case HCD_USB3:
         rhdev->speed = USB_SPEED_SUPER;
         break;
     case HCD_USB32:
         rhdev->rx_lanes = 2;
         rhdev->tx_lanes = 2;
         rhdev->ssp_rate = USB_SSP_GEN_2x2;
         rhdev->speed = USB_SPEED_SUPER_PLUS;
         break;
     case HCD_USB31:
         rhdev->ssp_rate = USB_SSP_GEN_2x1;
         rhdev->speed = USB_SPEED_SUPER_PLUS;
         break;
     default:
         retval = -EINVAL;
         goto err_set_rh_speed;
     }
 
     /* wakeup flag init defaults to "everything works" for root hubs,
      * but drivers can override it in reset() if needed, along with
      * recording the overall controller's system wakeup capability.
      */
     device_set_wakeup_capable(&rhdev->dev, 1);
 
     /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
      * registered.  But since the controller can die at any time,
      * let's initialize the flag before touching the hardware.
      */
     set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
 
     /* "reset" is misnamed; its role is now one-time init. the controller
      * should already have been reset (and boot firmware kicked off etc).
      */
     if (hcd->driver->reset) {
         retval = hcd->driver->reset(hcd);
         if (retval < 0) {
             dev_err(hcd->self.controller, "can't setup: %d\n",
                     retval);
             goto err_hcd_driver_setup;
         }
     }
     hcd->rh_pollable = 1;
 
     retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
     if (retval)
         goto err_hcd_driver_setup;
 
     /* NOTE: root hub and controller capabilities may not be the same */
     if (device_can_wakeup(hcd->self.controller)
             && device_can_wakeup(&hcd->self.root_hub->dev))
         dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
 
     /* initialize tasklets */
     init_giveback_urb_bh(&hcd->high_prio_bh);
     hcd->high_prio_bh.high_prio = true;
     init_giveback_urb_bh(&hcd->low_prio_bh);
 
     /* enable irqs just before we start the controller,
      * if the BIOS provides legacy PCI irqs.
      */
     if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
         retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
         if (retval)
             goto err_request_irq;
     }
 
     hcd->state = HC_STATE_RUNNING;
     retval = hcd->driver->start(hcd);
     if (retval < 0) {
         dev_err(hcd->self.controller, "startup error %d\n", retval);
         goto err_hcd_driver_start;
     }
 
     /* starting here, usbcore will pay attention to the shared HCD roothub */
     shared_hcd = hcd->shared_hcd;
     if (!usb_hcd_is_primary_hcd(hcd) && shared_hcd && HCD_DEFER_RH_REGISTER(shared_hcd)) {
         retval = register_root_hub(shared_hcd);
         if (retval != 0)
             goto err_register_root_hub;
 
         if (shared_hcd->uses_new_polling && HCD_POLL_RH(shared_hcd))
             usb_hcd_poll_rh_status(shared_hcd);
     }
 
     /* starting here, usbcore will pay attention to this root hub */
     if (!HCD_DEFER_RH_REGISTER(hcd)) {
         retval = register_root_hub(hcd);
         if (retval != 0)
             goto err_register_root_hub;
 
         if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
             usb_hcd_poll_rh_status(hcd);
     }
 
     return retval;
 
 err_register_root_hub:
     usb_stop_hcd(hcd);
 err_hcd_driver_start:
     if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
         free_irq(irqnum, hcd);
 err_request_irq:
 err_hcd_driver_setup:
 err_set_rh_speed:
     usb_put_invalidate_rhdev(hcd);
 err_allocate_root_hub:
     usb_deregister_bus(&hcd->self);
 err_register_bus:
     hcd_buffer_destroy(hcd);
 err_create_buf:
     usb_phy_roothub_power_off(hcd->phy_roothub);
 err_usb_phy_roothub_power_on:
     usb_phy_roothub_exit(hcd->phy_roothub);
 
     return retval;
 }
 EXPORT_SYMBOL_GPL(usb_add_hcd);
 
 /**
  * usb_remove_hcd - shutdown processing for generic HCDs
  * @hcd: the usb_hcd structure to remove
  *
  * Context: task context, might sleep.
  *
  * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
  * invoking the HCD's stop() method.
  */
 void usb_remove_hcd(struct usb_hcd *hcd)
 {
     struct usb_device *rhdev;
     bool rh_registered;
 
     if (!hcd) {
         pr_debug("%s: hcd is NULL\n", __func__);
         return;
     }
     rhdev = hcd->self.root_hub;
 
     dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
 
     usb_get_dev(rhdev);
     clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
     if (HC_IS_RUNNING (hcd->state))
         hcd->state = HC_STATE_QUIESCING;
 
     dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
     spin_lock_irq (&hcd_root_hub_lock);
     rh_registered = hcd->rh_registered;
     hcd->rh_registered = 0;
     spin_unlock_irq (&hcd_root_hub_lock);
 
 #ifdef CONFIG_PM
     cancel_work_sync(&hcd->wakeup_work);
 #endif
     cancel_work_sync(&hcd->died_work);
 
     mutex_lock(&usb_bus_idr_lock);
     if (rh_registered)
         usb_disconnect(&rhdev);     /* Sets rhdev to NULL */
     mutex_unlock(&usb_bus_idr_lock);
 
     /*
      * tasklet_kill() isn't needed here because:
      * - driver's disconnect() called from usb_disconnect() should
      *   make sure its URBs are completed during the disconnect()
      *   callback
      *
      * - it is too late to run complete() here since driver may have
      *   been removed already now
      */
 
     /* Prevent any more root-hub status calls from the timer.
      * The HCD might still restart the timer (if a port status change
      * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
      * the hub_status_data() callback.
      */
     usb_stop_hcd(hcd);
 
     if (usb_hcd_is_primary_hcd(hcd)) {
         if (hcd->irq > 0)
             free_irq(hcd->irq, hcd);
     }
 
     usb_deregister_bus(&hcd->self);
     hcd_buffer_destroy(hcd);
 
     usb_phy_roothub_power_off(hcd->phy_roothub);
     usb_phy_roothub_exit(hcd->phy_roothub);
 
     usb_put_invalidate_rhdev(hcd);
     hcd->flags = 0;
 }
 EXPORT_SYMBOL_GPL(usb_remove_hcd);
 
 void
 usb_hcd_platform_shutdown(struct platform_device *dev)
 {
     struct usb_hcd *hcd = platform_get_drvdata(dev);
 
     /* No need for pm_runtime_put(), we're shutting down */
     pm_runtime_get_sync(&dev->dev);
 
     if (hcd->driver->shutdown)
         hcd->driver->shutdown(hcd);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
 
 int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
                 dma_addr_t dma, size_t size)
 {
     int err;
     void *local_mem;
 
     hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
                           dev_to_node(hcd->self.sysdev),
                           dev_name(hcd->self.sysdev));
     if (IS_ERR(hcd->localmem_pool))
         return PTR_ERR(hcd->localmem_pool);
 
     /*
      * if a physical SRAM address was passed, map it, otherwise
      * allocate system memory as a buffer.
      */
     if (phys_addr)
         local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
                       size, MEMREMAP_WC);
     else
         local_mem = dmam_alloc_attrs(hcd->self.sysdev, size, &dma,
                          GFP_KERNEL,
                          DMA_ATTR_WRITE_COMBINE);
 
     if (IS_ERR(local_mem))
         return PTR_ERR(local_mem);
 
     /*
      * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
      * It's not backed by system memory and thus there's no kernel mapping
      * for it.
      */
     err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
                 dma, size, dev_to_node(hcd->self.sysdev));
     if (err < 0) {
         dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
             err);
         return err;
     }
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
 
 /*-------------------------------------------------------------------------*/
 
 #if IS_ENABLED(CONFIG_USB_MON)
 
 const struct usb_mon_operations *mon_ops;
 
 /*
  * The registration is unlocked.
  * We do it this way because we do not want to lock in hot paths.
  *
  * Notice that the code is minimally error-proof. Because usbmon needs
  * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
  */
 
 int usb_mon_register(const struct usb_mon_operations *ops)
 {
 
     if (mon_ops)
         return -EBUSY;
 
     mon_ops = ops;
     mb();
     return 0;
 }
 EXPORT_SYMBOL_GPL (usb_mon_register);
 
 void usb_mon_deregister (void)
 {
 
     if (mon_ops == NULL) {
         printk(KERN_ERR "USB: monitor was not registered\n");
         return;
     }
     mon_ops = NULL;
     mb();
 }
 EXPORT_SYMBOL_GPL (usb_mon_deregister);
 
 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */