Orange Pi5 kernel

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