531 lines
12 KiB
C
531 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2003-2008 Takahiro Hirofuchi
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*/
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#include <linux/device.h>
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#include <linux/file.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include "usbip_common.h"
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#include "stub.h"
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/*
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* usbip_status shows the status of usbip-host as long as this driver is bound
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* to the target device.
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*/
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static ssize_t usbip_status_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct stub_device *sdev = dev_get_drvdata(dev);
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int status;
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if (!sdev) {
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dev_err(dev, "sdev is null\n");
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return -ENODEV;
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}
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spin_lock_irq(&sdev->ud.lock);
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status = sdev->ud.status;
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spin_unlock_irq(&sdev->ud.lock);
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return snprintf(buf, PAGE_SIZE, "%d\n", status);
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}
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static DEVICE_ATTR_RO(usbip_status);
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/*
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* usbip_sockfd gets a socket descriptor of an established TCP connection that
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* is used to transfer usbip requests by kernel threads. -1 is a magic number
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* by which usbip connection is finished.
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*/
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static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct stub_device *sdev = dev_get_drvdata(dev);
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int sockfd = 0;
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struct socket *socket;
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int rv;
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struct task_struct *tcp_rx = NULL;
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struct task_struct *tcp_tx = NULL;
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if (!sdev) {
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dev_err(dev, "sdev is null\n");
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return -ENODEV;
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}
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rv = sscanf(buf, "%d", &sockfd);
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if (rv != 1)
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return -EINVAL;
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if (sockfd != -1) {
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int err;
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dev_info(dev, "stub up\n");
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mutex_lock(&sdev->ud.sysfs_lock);
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spin_lock_irq(&sdev->ud.lock);
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if (sdev->ud.status != SDEV_ST_AVAILABLE) {
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dev_err(dev, "not ready\n");
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goto err;
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}
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socket = sockfd_lookup(sockfd, &err);
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if (!socket) {
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dev_err(dev, "failed to lookup sock");
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goto err;
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}
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if (socket->type != SOCK_STREAM) {
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dev_err(dev, "Expecting SOCK_STREAM - found %d",
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socket->type);
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goto sock_err;
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}
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/* unlock and create threads and get tasks */
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spin_unlock_irq(&sdev->ud.lock);
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tcp_rx = kthread_create(stub_rx_loop, &sdev->ud, "stub_rx");
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if (IS_ERR(tcp_rx)) {
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sockfd_put(socket);
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goto unlock_mutex;
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}
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tcp_tx = kthread_create(stub_tx_loop, &sdev->ud, "stub_tx");
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if (IS_ERR(tcp_tx)) {
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kthread_stop(tcp_rx);
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sockfd_put(socket);
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goto unlock_mutex;
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}
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/* get task structs now */
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get_task_struct(tcp_rx);
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get_task_struct(tcp_tx);
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/* lock and update sdev->ud state */
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spin_lock_irq(&sdev->ud.lock);
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sdev->ud.tcp_socket = socket;
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sdev->ud.sockfd = sockfd;
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sdev->ud.tcp_rx = tcp_rx;
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sdev->ud.tcp_tx = tcp_tx;
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sdev->ud.status = SDEV_ST_USED;
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spin_unlock_irq(&sdev->ud.lock);
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wake_up_process(sdev->ud.tcp_rx);
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wake_up_process(sdev->ud.tcp_tx);
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mutex_unlock(&sdev->ud.sysfs_lock);
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} else {
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dev_info(dev, "stub down\n");
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spin_lock_irq(&sdev->ud.lock);
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if (sdev->ud.status != SDEV_ST_USED)
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goto err;
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spin_unlock_irq(&sdev->ud.lock);
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usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
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mutex_unlock(&sdev->ud.sysfs_lock);
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}
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return count;
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sock_err:
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sockfd_put(socket);
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err:
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spin_unlock_irq(&sdev->ud.lock);
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unlock_mutex:
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mutex_unlock(&sdev->ud.sysfs_lock);
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return -EINVAL;
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}
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static DEVICE_ATTR_WO(usbip_sockfd);
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static struct attribute *usbip_attrs[] = {
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&dev_attr_usbip_status.attr,
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&dev_attr_usbip_sockfd.attr,
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&dev_attr_usbip_debug.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(usbip);
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static void stub_shutdown_connection(struct usbip_device *ud)
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{
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struct stub_device *sdev = container_of(ud, struct stub_device, ud);
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/*
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* When removing an exported device, kernel panic sometimes occurred
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* and then EIP was sk_wait_data of stub_rx thread. Is this because
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* sk_wait_data returned though stub_rx thread was already finished by
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* step 1?
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*/
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if (ud->tcp_socket) {
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dev_dbg(&sdev->udev->dev, "shutdown sockfd %d\n", ud->sockfd);
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kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
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}
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/* 1. stop threads */
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if (ud->tcp_rx) {
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kthread_stop_put(ud->tcp_rx);
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ud->tcp_rx = NULL;
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}
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if (ud->tcp_tx) {
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kthread_stop_put(ud->tcp_tx);
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ud->tcp_tx = NULL;
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}
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/*
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* 2. close the socket
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*
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* tcp_socket is freed after threads are killed so that usbip_xmit does
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* not touch NULL socket.
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*/
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if (ud->tcp_socket) {
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sockfd_put(ud->tcp_socket);
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ud->tcp_socket = NULL;
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ud->sockfd = -1;
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}
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/* 3. free used data */
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stub_device_cleanup_urbs(sdev);
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/* 4. free stub_unlink */
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{
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unsigned long flags;
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struct stub_unlink *unlink, *tmp;
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spin_lock_irqsave(&sdev->priv_lock, flags);
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list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
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list_del(&unlink->list);
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kfree(unlink);
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}
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list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
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list) {
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list_del(&unlink->list);
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kfree(unlink);
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}
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spin_unlock_irqrestore(&sdev->priv_lock, flags);
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}
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}
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static void stub_device_reset(struct usbip_device *ud)
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{
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struct stub_device *sdev = container_of(ud, struct stub_device, ud);
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struct usb_device *udev = sdev->udev;
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int ret;
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dev_dbg(&udev->dev, "device reset");
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ret = usb_lock_device_for_reset(udev, NULL);
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if (ret < 0) {
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dev_err(&udev->dev, "lock for reset\n");
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spin_lock_irq(&ud->lock);
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ud->status = SDEV_ST_ERROR;
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spin_unlock_irq(&ud->lock);
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return;
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}
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/* try to reset the device */
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ret = usb_reset_device(udev);
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usb_unlock_device(udev);
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spin_lock_irq(&ud->lock);
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if (ret) {
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dev_err(&udev->dev, "device reset\n");
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ud->status = SDEV_ST_ERROR;
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} else {
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dev_info(&udev->dev, "device reset\n");
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ud->status = SDEV_ST_AVAILABLE;
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}
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spin_unlock_irq(&ud->lock);
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}
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static void stub_device_unusable(struct usbip_device *ud)
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{
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spin_lock_irq(&ud->lock);
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ud->status = SDEV_ST_ERROR;
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spin_unlock_irq(&ud->lock);
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}
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/**
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* stub_device_alloc - allocate a new stub_device struct
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* @udev: usb_device of a new device
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*
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* Allocates and initializes a new stub_device struct.
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*/
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static struct stub_device *stub_device_alloc(struct usb_device *udev)
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{
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struct stub_device *sdev;
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int busnum = udev->bus->busnum;
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int devnum = udev->devnum;
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dev_dbg(&udev->dev, "allocating stub device");
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/* yes, it's a new device */
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sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
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if (!sdev)
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return NULL;
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sdev->udev = usb_get_dev(udev);
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/*
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* devid is defined with devnum when this driver is first allocated.
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* devnum may change later if a device is reset. However, devid never
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* changes during a usbip connection.
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*/
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sdev->devid = (busnum << 16) | devnum;
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sdev->ud.side = USBIP_STUB;
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sdev->ud.status = SDEV_ST_AVAILABLE;
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spin_lock_init(&sdev->ud.lock);
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mutex_init(&sdev->ud.sysfs_lock);
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sdev->ud.tcp_socket = NULL;
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sdev->ud.sockfd = -1;
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INIT_LIST_HEAD(&sdev->priv_init);
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INIT_LIST_HEAD(&sdev->priv_tx);
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INIT_LIST_HEAD(&sdev->priv_free);
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INIT_LIST_HEAD(&sdev->unlink_free);
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INIT_LIST_HEAD(&sdev->unlink_tx);
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spin_lock_init(&sdev->priv_lock);
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init_waitqueue_head(&sdev->tx_waitq);
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sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
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sdev->ud.eh_ops.reset = stub_device_reset;
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sdev->ud.eh_ops.unusable = stub_device_unusable;
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usbip_start_eh(&sdev->ud);
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dev_dbg(&udev->dev, "register new device\n");
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return sdev;
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}
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static void stub_device_free(struct stub_device *sdev)
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{
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kfree(sdev);
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}
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static int stub_probe(struct usb_device *udev)
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{
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struct stub_device *sdev = NULL;
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const char *udev_busid = dev_name(&udev->dev);
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struct bus_id_priv *busid_priv;
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int rc = 0;
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char save_status;
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dev_dbg(&udev->dev, "Enter probe\n");
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/* Not sure if this is our device. Allocate here to avoid
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* calling alloc while holding busid_table lock.
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*/
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sdev = stub_device_alloc(udev);
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if (!sdev)
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return -ENOMEM;
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/* check we should claim or not by busid_table */
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busid_priv = get_busid_priv(udev_busid);
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if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
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(busid_priv->status == STUB_BUSID_OTHER)) {
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dev_info(&udev->dev,
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"%s is not in match_busid table... skip!\n",
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udev_busid);
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/*
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* Return value should be ENODEV or ENOXIO to continue trying
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* other matched drivers by the driver core.
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* See driver_probe_device() in driver/base/dd.c
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*/
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rc = -ENODEV;
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if (!busid_priv)
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goto sdev_free;
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goto call_put_busid_priv;
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}
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if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
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dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
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udev_busid);
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rc = -ENODEV;
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goto call_put_busid_priv;
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}
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if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
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dev_dbg(&udev->dev,
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"%s is attached on vhci_hcd... skip!\n",
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udev_busid);
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rc = -ENODEV;
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goto call_put_busid_priv;
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}
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dev_info(&udev->dev,
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"usbip-host: register new device (bus %u dev %u)\n",
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udev->bus->busnum, udev->devnum);
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busid_priv->shutdown_busid = 0;
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/* set private data to usb_device */
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dev_set_drvdata(&udev->dev, sdev);
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busid_priv->sdev = sdev;
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busid_priv->udev = udev;
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save_status = busid_priv->status;
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busid_priv->status = STUB_BUSID_ALLOC;
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/* release the busid_lock */
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put_busid_priv(busid_priv);
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/*
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* Claim this hub port.
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* It doesn't matter what value we pass as owner
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* (struct dev_state) as long as it is unique.
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*/
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rc = usb_hub_claim_port(udev->parent, udev->portnum,
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(struct usb_dev_state *) udev);
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if (rc) {
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dev_dbg(&udev->dev, "unable to claim port\n");
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goto err_port;
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}
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return 0;
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err_port:
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dev_set_drvdata(&udev->dev, NULL);
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usb_put_dev(udev);
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/* we already have busid_priv, just lock busid_lock */
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spin_lock(&busid_priv->busid_lock);
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busid_priv->sdev = NULL;
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busid_priv->status = save_status;
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spin_unlock(&busid_priv->busid_lock);
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/* lock is released - go to free */
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goto sdev_free;
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call_put_busid_priv:
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/* release the busid_lock */
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put_busid_priv(busid_priv);
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sdev_free:
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stub_device_free(sdev);
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return rc;
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}
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static void shutdown_busid(struct bus_id_priv *busid_priv)
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{
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usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
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/* wait for the stop of the event handler */
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usbip_stop_eh(&busid_priv->sdev->ud);
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}
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/*
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* called in usb_disconnect() or usb_deregister()
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* but only if actconfig(active configuration) exists
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*/
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static void stub_disconnect(struct usb_device *udev)
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{
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struct stub_device *sdev;
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const char *udev_busid = dev_name(&udev->dev);
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struct bus_id_priv *busid_priv;
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int rc;
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dev_dbg(&udev->dev, "Enter disconnect\n");
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busid_priv = get_busid_priv(udev_busid);
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if (!busid_priv) {
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BUG();
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return;
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}
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sdev = dev_get_drvdata(&udev->dev);
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/* get stub_device */
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if (!sdev) {
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dev_err(&udev->dev, "could not get device");
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/* release busid_lock */
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put_busid_priv(busid_priv);
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return;
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}
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dev_set_drvdata(&udev->dev, NULL);
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/* release busid_lock before call to remove device files */
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put_busid_priv(busid_priv);
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/*
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* NOTE: rx/tx threads are invoked for each usb_device.
|
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*/
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/* release port */
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rc = usb_hub_release_port(udev->parent, udev->portnum,
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(struct usb_dev_state *) udev);
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if (rc) {
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dev_dbg(&udev->dev, "unable to release port\n");
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return;
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}
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|
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/* If usb reset is called from event handler */
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if (usbip_in_eh(current))
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return;
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|
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/* we already have busid_priv, just lock busid_lock */
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spin_lock(&busid_priv->busid_lock);
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if (!busid_priv->shutdown_busid)
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busid_priv->shutdown_busid = 1;
|
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/* release busid_lock */
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spin_unlock(&busid_priv->busid_lock);
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|
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/* shutdown the current connection */
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shutdown_busid(busid_priv);
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|
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usb_put_dev(sdev->udev);
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|
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/* we already have busid_priv, just lock busid_lock */
|
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spin_lock(&busid_priv->busid_lock);
|
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/* free sdev */
|
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busid_priv->sdev = NULL;
|
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stub_device_free(sdev);
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|
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if (busid_priv->status == STUB_BUSID_ALLOC)
|
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busid_priv->status = STUB_BUSID_ADDED;
|
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/* release busid_lock */
|
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spin_unlock(&busid_priv->busid_lock);
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return;
|
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}
|
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|
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#ifdef CONFIG_PM
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|
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/* These functions need usb_port_suspend and usb_port_resume,
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* which reside in drivers/usb/core/usb.h. Skip for now. */
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|
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static int stub_suspend(struct usb_device *udev, pm_message_t message)
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{
|
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dev_dbg(&udev->dev, "stub_suspend\n");
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|
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return 0;
|
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}
|
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|
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static int stub_resume(struct usb_device *udev, pm_message_t message)
|
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{
|
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dev_dbg(&udev->dev, "stub_resume\n");
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|
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return 0;
|
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}
|
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|
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#endif /* CONFIG_PM */
|
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|
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struct usb_device_driver stub_driver = {
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.name = "usbip-host",
|
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.probe = stub_probe,
|
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.disconnect = stub_disconnect,
|
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#ifdef CONFIG_PM
|
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.suspend = stub_suspend,
|
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.resume = stub_resume,
|
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#endif
|
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.supports_autosuspend = 0,
|
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.dev_groups = usbip_groups,
|
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};
|