diff options
Diffstat (limited to 'kernel/drivers/usb/usbip/stub_dev.c')
| -rw-r--r-- | kernel/drivers/usb/usbip/stub_dev.c | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/kernel/drivers/usb/usbip/stub_dev.c b/kernel/drivers/usb/usbip/stub_dev.c new file mode 100644 index 000000000..a3ec49bdc --- /dev/null +++ b/kernel/drivers/usb/usbip/stub_dev.c @@ -0,0 +1,502 @@ +/* + * Copyright (C) 2003-2008 Takahiro Hirofuchi + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + */ + +#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 store_sockfd(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; + + 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"); + + 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) + goto err; + + sdev->ud.tcp_socket = socket; + + spin_unlock_irq(&sdev->ud.lock); + + sdev->ud.tcp_rx = kthread_get_run(stub_rx_loop, &sdev->ud, + "stub_rx"); + sdev->ud.tcp_tx = kthread_get_run(stub_tx_loop, &sdev->ud, + "stub_tx"); + + spin_lock_irq(&sdev->ud.lock); + sdev->ud.status = SDEV_ST_USED; + spin_unlock_irq(&sdev->ud.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); + } + + return count; + +err: + spin_unlock_irq(&sdev->ud.lock); + return -EINVAL; +} +static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd); + +static int stub_add_files(struct device *dev) +{ + int err = 0; + + err = device_create_file(dev, &dev_attr_usbip_status); + if (err) + goto err_status; + + err = device_create_file(dev, &dev_attr_usbip_sockfd); + if (err) + goto err_sockfd; + + err = device_create_file(dev, &dev_attr_usbip_debug); + if (err) + goto err_debug; + + return 0; + +err_debug: + device_remove_file(dev, &dev_attr_usbip_sockfd); +err_sockfd: + device_remove_file(dev, &dev_attr_usbip_status); +err_status: + return err; +} + +static void stub_remove_files(struct device *dev) +{ + device_remove_file(dev, &dev_attr_usbip_status); + device_remove_file(dev, &dev_attr_usbip_sockfd); + device_remove_file(dev, &dev_attr_usbip_debug); +} + +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 tcp_socket %p\n", + ud->tcp_socket); + 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; + } + + /* 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, sdev->interface); + 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 + * @interface: usb_interface 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); + sdev->ud.tcp_socket = NULL; + + 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; + + dev_dbg(&udev->dev, "Enter\n"); + + /* 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 + */ + return -ENODEV; + } + + if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) { + dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n", + udev_busid); + return -ENODEV; + } + + if (!strcmp(udev->bus->bus_name, "vhci_hcd")) { + dev_dbg(&udev->dev, + "%s is attached on vhci_hcd... skip!\n", + udev_busid); + + return -ENODEV; + } + + /* ok, this is my device */ + sdev = stub_device_alloc(udev); + if (!sdev) + return -ENOMEM; + + 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; + + /* + * 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; + } + + rc = stub_add_files(&udev->dev); + if (rc) { + dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid); + goto err_files; + } + busid_priv->status = STUB_BUSID_ALLOC; + + return 0; +err_files: + usb_hub_release_port(udev->parent, udev->portnum, + (struct usb_dev_state *) udev); +err_port: + dev_set_drvdata(&udev->dev, NULL); + usb_put_dev(udev); + kthread_stop_put(sdev->ud.eh); + + busid_priv->sdev = NULL; + stub_device_free(sdev); + return rc; +} + +static void shutdown_busid(struct bus_id_priv *busid_priv) +{ + if (busid_priv->sdev && !busid_priv->shutdown_busid) { + busid_priv->shutdown_busid = 1; + 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\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"); + return; + } + + dev_set_drvdata(&udev->dev, NULL); + + /* + * NOTE: rx/tx threads are invoked for each usb_device. + */ + stub_remove_files(&udev->dev); + + /* 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 (busid_priv->sdev->ud.eh == current) + return; + + /* shutdown the current connection */ + shutdown_busid(busid_priv); + + usb_put_dev(sdev->udev); + + /* free sdev */ + busid_priv->sdev = NULL; + stub_device_free(sdev); + + if (busid_priv->status == STUB_BUSID_ALLOC) { + busid_priv->status = STUB_BUSID_ADDED; + } else { + busid_priv->status = STUB_BUSID_OTHER; + del_match_busid((char *)udev_busid); + } +} + +#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, +}; |