[linux-2.6-block.git] / drivers / usb / usbip / stub_dev.c

// 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 sysfs_emit(buf, "%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");

		mutex_lock(&sdev->ud.sysfs_lock);

		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);

	/* 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:
	usb_put_dev(udev);
	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);
	/*
	 * NOTE: If a HUB disconnect triggered disconnect of the down stream
	 * device usb_hub_release_port will return -ENODEV so we can safely ignore
	 * that error here.
	 */
	if (rc && (rc != -ENODEV)) {
		dev_dbg(&udev->dev, "unable to release port (%i)\n", rc);
		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,
};
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* Copyright (C) 2003-2008 Takahiro Hirofuchi
	4	*/
	5
	6	#include <linux/device.h>
	7	#include <linux/file.h>
	8	#include <linux/kthread.h>
	9	#include <linux/module.h>
	10
	11	#include "usbip_common.h"
	12	#include "stub.h"
	13
	14	/*
	15	* usbip_status shows the status of usbip-host as long as this driver is bound
	16	* to the target device.
	17	*/
	18	static ssize_t usbip_status_show(struct device *dev,
	19	struct device_attribute attr, char buf)
	20	{
	21	struct stub_device *sdev = dev_get_drvdata(dev);
	22	int status;
	23
	24	if (!sdev) {
	25	dev_err(dev, "sdev is null\n");
	26	return -ENODEV;
	27	}
	28
	29	spin_lock_irq(&sdev->ud.lock);
	30	status = sdev->ud.status;
	31	spin_unlock_irq(&sdev->ud.lock);
	32
	33	return sysfs_emit(buf, "%d\n", status);
	34	}
	35	static DEVICE_ATTR_RO(usbip_status);
	36
	37	/*
	38	* usbip_sockfd gets a socket descriptor of an established TCP connection that
	39	* is used to transfer usbip requests by kernel threads. -1 is a magic number
	40	* by which usbip connection is finished.
	41	*/
	42	static ssize_t usbip_sockfd_store(struct device dev, struct device_attribute attr,
	43	const char *buf, size_t count)
	44	{
	45	struct stub_device *sdev = dev_get_drvdata(dev);
	46	int sockfd = 0;
	47	struct socket *socket;
	48	int rv;
	49	struct task_struct *tcp_rx = NULL;
	50	struct task_struct *tcp_tx = NULL;
	51
	52	if (!sdev) {
	53	dev_err(dev, "sdev is null\n");
	54	return -ENODEV;
	55	}
	56
	57	rv = sscanf(buf, "%d", &sockfd);
	58	if (rv != 1)
	59	return -EINVAL;
	60
	61	if (sockfd != -1) {
	62	int err;
	63
	64	dev_info(dev, "stub up\n");
	65
	66	mutex_lock(&sdev->ud.sysfs_lock);
	67	spin_lock_irq(&sdev->ud.lock);
	68
	69	if (sdev->ud.status != SDEV_ST_AVAILABLE) {
	70	dev_err(dev, "not ready\n");
	71	goto err;
	72	}
	73
	74	socket = sockfd_lookup(sockfd, &err);
	75	if (!socket) {
	76	dev_err(dev, "failed to lookup sock");
	77	goto err;
	78	}
	79
	80	if (socket->type != SOCK_STREAM) {
	81	dev_err(dev, "Expecting SOCK_STREAM - found %d",
	82	socket->type);
	83	goto sock_err;
	84	}
	85
	86	/* unlock and create threads and get tasks */
	87	spin_unlock_irq(&sdev->ud.lock);
	88	tcp_rx = kthread_create(stub_rx_loop, &sdev->ud, "stub_rx");
	89	if (IS_ERR(tcp_rx)) {
	90	sockfd_put(socket);
	91	goto unlock_mutex;
	92	}
	93	tcp_tx = kthread_create(stub_tx_loop, &sdev->ud, "stub_tx");
	94	if (IS_ERR(tcp_tx)) {
	95	kthread_stop(tcp_rx);
	96	sockfd_put(socket);
	97	goto unlock_mutex;
	98	}
	99
	100	/* get task structs now */
	101	get_task_struct(tcp_rx);
	102	get_task_struct(tcp_tx);
	103
	104	/* lock and update sdev->ud state */
	105	spin_lock_irq(&sdev->ud.lock);
	106	sdev->ud.tcp_socket = socket;
	107	sdev->ud.sockfd = sockfd;
	108	sdev->ud.tcp_rx = tcp_rx;
	109	sdev->ud.tcp_tx = tcp_tx;
	110	sdev->ud.status = SDEV_ST_USED;
	111	spin_unlock_irq(&sdev->ud.lock);
	112
	113	wake_up_process(sdev->ud.tcp_rx);
	114	wake_up_process(sdev->ud.tcp_tx);
	115
	116	mutex_unlock(&sdev->ud.sysfs_lock);
	117
	118	} else {
	119	dev_info(dev, "stub down\n");
	120
	121	mutex_lock(&sdev->ud.sysfs_lock);
	122
	123	spin_lock_irq(&sdev->ud.lock);
	124	if (sdev->ud.status != SDEV_ST_USED)
	125	goto err;
	126
	127	spin_unlock_irq(&sdev->ud.lock);
	128
	129	usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
	130	mutex_unlock(&sdev->ud.sysfs_lock);
	131	}
	132
	133	return count;
	134
	135	sock_err:
	136	sockfd_put(socket);
	137	err:
	138	spin_unlock_irq(&sdev->ud.lock);
	139	unlock_mutex:
	140	mutex_unlock(&sdev->ud.sysfs_lock);
	141	return -EINVAL;
	142	}
	143	static DEVICE_ATTR_WO(usbip_sockfd);
	144
	145	static struct attribute *usbip_attrs[] = {
	146	&dev_attr_usbip_status.attr,
	147	&dev_attr_usbip_sockfd.attr,
	148	&dev_attr_usbip_debug.attr,
	149	NULL,
	150	};
	151	ATTRIBUTE_GROUPS(usbip);
	152
	153	static void stub_shutdown_connection(struct usbip_device *ud)
	154	{
	155	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
	156
	157	/*
	158	* When removing an exported device, kernel panic sometimes occurred
	159	* and then EIP was sk_wait_data of stub_rx thread. Is this because
	160	* sk_wait_data returned though stub_rx thread was already finished by
	161	* step 1?
	162	*/
	163	if (ud->tcp_socket) {
	164	dev_dbg(&sdev->udev->dev, "shutdown sockfd %d\n", ud->sockfd);
	165	kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
	166	}
	167
	168	/* 1. stop threads */
	169	if (ud->tcp_rx) {
	170	kthread_stop_put(ud->tcp_rx);
	171	ud->tcp_rx = NULL;
	172	}
	173	if (ud->tcp_tx) {
	174	kthread_stop_put(ud->tcp_tx);
	175	ud->tcp_tx = NULL;
	176	}
	177
	178	/*
	179	* 2. close the socket
	180	*
	181	* tcp_socket is freed after threads are killed so that usbip_xmit does
	182	* not touch NULL socket.
	183	*/
	184	if (ud->tcp_socket) {
	185	sockfd_put(ud->tcp_socket);
	186	ud->tcp_socket = NULL;
	187	ud->sockfd = -1;
	188	}
	189
	190	/* 3. free used data */
	191	stub_device_cleanup_urbs(sdev);
	192
	193	/* 4. free stub_unlink */
	194	{
	195	unsigned long flags;
	196	struct stub_unlink unlink, tmp;
	197
	198	spin_lock_irqsave(&sdev->priv_lock, flags);
	199	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
	200	list_del(&unlink->list);
	201	kfree(unlink);
	202	}
	203	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
	204	list) {
	205	list_del(&unlink->list);
	206	kfree(unlink);
	207	}
	208	spin_unlock_irqrestore(&sdev->priv_lock, flags);
	209	}
	210	}
	211
	212	static void stub_device_reset(struct usbip_device *ud)
	213	{
	214	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
	215	struct usb_device *udev = sdev->udev;
	216	int ret;
	217
	218	dev_dbg(&udev->dev, "device reset");
	219
	220	ret = usb_lock_device_for_reset(udev, NULL);
	221	if (ret < 0) {
	222	dev_err(&udev->dev, "lock for reset\n");
	223	spin_lock_irq(&ud->lock);
	224	ud->status = SDEV_ST_ERROR;
	225	spin_unlock_irq(&ud->lock);
	226	return;
	227	}
	228
	229	/* try to reset the device */
	230	ret = usb_reset_device(udev);
	231	usb_unlock_device(udev);
	232
	233	spin_lock_irq(&ud->lock);
	234	if (ret) {
	235	dev_err(&udev->dev, "device reset\n");
	236	ud->status = SDEV_ST_ERROR;
	237	} else {
	238	dev_info(&udev->dev, "device reset\n");
	239	ud->status = SDEV_ST_AVAILABLE;
	240	}
	241	spin_unlock_irq(&ud->lock);
	242	}
	243
	244	static void stub_device_unusable(struct usbip_device *ud)
	245	{
	246	spin_lock_irq(&ud->lock);
	247	ud->status = SDEV_ST_ERROR;
	248	spin_unlock_irq(&ud->lock);
	249	}
	250
	251	/**
	252	* stub_device_alloc - allocate a new stub_device struct
	253	* @udev: usb_device of a new device
	254	*
	255	* Allocates and initializes a new stub_device struct.
	256	*/
	257	static struct stub_device stub_device_alloc(struct usb_device udev)
	258	{
	259	struct stub_device *sdev;
	260	int busnum = udev->bus->busnum;
	261	int devnum = udev->devnum;
	262
	263	dev_dbg(&udev->dev, "allocating stub device");
	264
	265	/* yes, it's a new device */
	266	sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
	267	if (!sdev)
	268	return NULL;
	269
	270	sdev->udev = usb_get_dev(udev);
	271
	272	/*
	273	* devid is defined with devnum when this driver is first allocated.
	274	* devnum may change later if a device is reset. However, devid never
	275	* changes during a usbip connection.
	276	*/
	277	sdev->devid = (busnum << 16) \| devnum;
	278	sdev->ud.side = USBIP_STUB;
	279	sdev->ud.status = SDEV_ST_AVAILABLE;
	280	spin_lock_init(&sdev->ud.lock);
	281	mutex_init(&sdev->ud.sysfs_lock);
	282	sdev->ud.tcp_socket = NULL;
	283	sdev->ud.sockfd = -1;
	284
	285	INIT_LIST_HEAD(&sdev->priv_init);
	286	INIT_LIST_HEAD(&sdev->priv_tx);
	287	INIT_LIST_HEAD(&sdev->priv_free);
	288	INIT_LIST_HEAD(&sdev->unlink_free);
	289	INIT_LIST_HEAD(&sdev->unlink_tx);
	290	spin_lock_init(&sdev->priv_lock);
	291
	292	init_waitqueue_head(&sdev->tx_waitq);
	293
	294	sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
	295	sdev->ud.eh_ops.reset = stub_device_reset;
	296	sdev->ud.eh_ops.unusable = stub_device_unusable;
	297
	298	usbip_start_eh(&sdev->ud);
	299
	300	dev_dbg(&udev->dev, "register new device\n");
	301
	302	return sdev;
	303	}
	304
	305	static void stub_device_free(struct stub_device *sdev)
	306	{
	307	kfree(sdev);
	308	}
	309
	310	static int stub_probe(struct usb_device *udev)
	311	{
	312	struct stub_device *sdev = NULL;
	313	const char *udev_busid = dev_name(&udev->dev);
	314	struct bus_id_priv *busid_priv;
	315	int rc = 0;
	316	char save_status;
	317
	318	dev_dbg(&udev->dev, "Enter probe\n");
	319
	320	/* Not sure if this is our device. Allocate here to avoid
	321	* calling alloc while holding busid_table lock.
	322	*/
	323	sdev = stub_device_alloc(udev);
	324	if (!sdev)
	325	return -ENOMEM;
	326
	327	/* check we should claim or not by busid_table */
	328	busid_priv = get_busid_priv(udev_busid);
	329	if (!busid_priv \|\| (busid_priv->status == STUB_BUSID_REMOV) \|\|
	330	(busid_priv->status == STUB_BUSID_OTHER)) {
	331	dev_info(&udev->dev,
	332	"%s is not in match_busid table... skip!\n",
	333	udev_busid);
	334
	335	/*
	336	* Return value should be ENODEV or ENOXIO to continue trying
	337	* other matched drivers by the driver core.
	338	* See driver_probe_device() in driver/base/dd.c
	339	*/
	340	rc = -ENODEV;
	341	if (!busid_priv)
	342	goto sdev_free;
	343
	344	goto call_put_busid_priv;
	345	}
	346
	347	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
	348	dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
	349	udev_busid);
	350	rc = -ENODEV;
	351	goto call_put_busid_priv;
	352	}
	353
	354	if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
	355	dev_dbg(&udev->dev,
	356	"%s is attached on vhci_hcd... skip!\n",
	357	udev_busid);
	358
	359	rc = -ENODEV;
	360	goto call_put_busid_priv;
	361	}
	362
	363
	364	dev_info(&udev->dev,
	365	"usbip-host: register new device (bus %u dev %u)\n",
	366	udev->bus->busnum, udev->devnum);
	367
	368	busid_priv->shutdown_busid = 0;
	369
	370	/* set private data to usb_device */
	371	dev_set_drvdata(&udev->dev, sdev);
	372
	373	busid_priv->sdev = sdev;
	374	busid_priv->udev = udev;
	375
	376	save_status = busid_priv->status;
	377	busid_priv->status = STUB_BUSID_ALLOC;
	378
	379	/* release the busid_lock */
	380	put_busid_priv(busid_priv);
	381
	382	/*
	383	* Claim this hub port.
	384	* It doesn't matter what value we pass as owner
	385	* (struct dev_state) as long as it is unique.
	386	*/
	387	rc = usb_hub_claim_port(udev->parent, udev->portnum,
	388	(struct usb_dev_state *) udev);
	389	if (rc) {
	390	dev_dbg(&udev->dev, "unable to claim port\n");
	391	goto err_port;
	392	}
	393
	394	return 0;
	395
	396	err_port:
	397	dev_set_drvdata(&udev->dev, NULL);
	398
	399	/* we already have busid_priv, just lock busid_lock */
	400	spin_lock(&busid_priv->busid_lock);
	401	busid_priv->sdev = NULL;
	402	busid_priv->status = save_status;
	403	spin_unlock(&busid_priv->busid_lock);
	404	/* lock is released - go to free */
	405	goto sdev_free;
	406
	407	call_put_busid_priv:
	408	/* release the busid_lock */
	409	put_busid_priv(busid_priv);
	410
	411	sdev_free:
	412	usb_put_dev(udev);
	413	stub_device_free(sdev);
	414
	415	return rc;
	416	}
	417
	418	static void shutdown_busid(struct bus_id_priv *busid_priv)
	419	{
	420	usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
	421
	422	/* wait for the stop of the event handler */
	423	usbip_stop_eh(&busid_priv->sdev->ud);
	424	}
	425
	426	/*
	427	* called in usb_disconnect() or usb_deregister()
	428	* but only if actconfig(active configuration) exists
	429	*/
	430	static void stub_disconnect(struct usb_device *udev)
	431	{
	432	struct stub_device *sdev;
	433	const char *udev_busid = dev_name(&udev->dev);
	434	struct bus_id_priv *busid_priv;
	435	int rc;
	436
	437	dev_dbg(&udev->dev, "Enter disconnect\n");
	438
	439	busid_priv = get_busid_priv(udev_busid);
	440	if (!busid_priv) {
	441	BUG();
	442	return;
	443	}
	444
	445	sdev = dev_get_drvdata(&udev->dev);
	446
	447	/* get stub_device */
	448	if (!sdev) {
	449	dev_err(&udev->dev, "could not get device");
	450	/* release busid_lock */
	451	put_busid_priv(busid_priv);
	452	return;
	453	}
	454
	455	dev_set_drvdata(&udev->dev, NULL);
	456
	457	/* release busid_lock before call to remove device files */
	458	put_busid_priv(busid_priv);
	459
	460	/*
	461	* NOTE: rx/tx threads are invoked for each usb_device.
	462	*/
	463
	464	/* release port */
	465	rc = usb_hub_release_port(udev->parent, udev->portnum,
	466	(struct usb_dev_state *) udev);
	467	/*
	468	* NOTE: If a HUB disconnect triggered disconnect of the down stream
	469	* device usb_hub_release_port will return -ENODEV so we can safely ignore
	470	* that error here.
	471	*/
	472	if (rc && (rc != -ENODEV)) {
	473	dev_dbg(&udev->dev, "unable to release port (%i)\n", rc);
	474	return;
	475	}
	476
	477	/* If usb reset is called from event handler */
	478	if (usbip_in_eh(current))
	479	return;
	480
	481	/* we already have busid_priv, just lock busid_lock */
	482	spin_lock(&busid_priv->busid_lock);
	483	if (!busid_priv->shutdown_busid)
	484	busid_priv->shutdown_busid = 1;
	485	/* release busid_lock */
	486	spin_unlock(&busid_priv->busid_lock);
	487
	488	/* shutdown the current connection */
	489	shutdown_busid(busid_priv);
	490
	491	usb_put_dev(sdev->udev);
	492
	493	/* we already have busid_priv, just lock busid_lock */
	494	spin_lock(&busid_priv->busid_lock);
	495	/* free sdev */
	496	busid_priv->sdev = NULL;
	497	stub_device_free(sdev);
	498
	499	if (busid_priv->status == STUB_BUSID_ALLOC)
	500	busid_priv->status = STUB_BUSID_ADDED;
	501	/* release busid_lock */
	502	spin_unlock(&busid_priv->busid_lock);
	503	return;
	504	}
	505
	506	#ifdef CONFIG_PM
	507
	508	/* These functions need usb_port_suspend and usb_port_resume,
	509	* which reside in drivers/usb/core/usb.h. Skip for now. */
	510
	511	static int stub_suspend(struct usb_device *udev, pm_message_t message)
	512	{
	513	dev_dbg(&udev->dev, "stub_suspend\n");
	514
	515	return 0;
	516	}
	517
	518	static int stub_resume(struct usb_device *udev, pm_message_t message)
	519	{
	520	dev_dbg(&udev->dev, "stub_resume\n");
	521
	522	return 0;
	523	}
	524
	525	#endif /* CONFIG_PM */
	526
	527	struct usb_device_driver stub_driver = {
	528	.name = "usbip-host",
	529	.probe = stub_probe,
	530	.disconnect = stub_disconnect,
	531	#ifdef CONFIG_PM
	532	.suspend = stub_suspend,
	533	.resume = stub_resume,
	534	#endif
	535	.supports_autosuspend = 0,
	536	.dev_groups = usbip_groups,
	537	};