| /* |
| * 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 "usbip_common.h" |
| #include <linux/kthread.h> |
| |
| static int event_handler(struct usbip_device *ud) |
| { |
| usbip_dbg_eh("enter\n"); |
| |
| /* |
| * Events are handled by only this thread. |
| */ |
| while (usbip_event_happened(ud)) { |
| usbip_dbg_eh("pending event %lx\n", ud->event); |
| |
| /* |
| * NOTE: shutdown must come first. |
| * Shutdown the device. |
| */ |
| if (ud->event & USBIP_EH_SHUTDOWN) { |
| ud->eh_ops.shutdown(ud); |
| |
| ud->event &= ~USBIP_EH_SHUTDOWN; |
| |
| break; |
| } |
| |
| /* Stop the error handler. */ |
| if (ud->event & USBIP_EH_BYE) |
| return -1; |
| |
| /* Reset the device. */ |
| if (ud->event & USBIP_EH_RESET) { |
| ud->eh_ops.reset(ud); |
| |
| ud->event &= ~USBIP_EH_RESET; |
| |
| break; |
| } |
| |
| /* Mark the device as unusable. */ |
| if (ud->event & USBIP_EH_UNUSABLE) { |
| ud->eh_ops.unusable(ud); |
| |
| ud->event &= ~USBIP_EH_UNUSABLE; |
| |
| break; |
| } |
| |
| /* NOTREACHED */ |
| printk(KERN_ERR "%s: unknown event\n", __func__); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static void event_handler_loop(struct usbip_task *ut) |
| { |
| struct usbip_device *ud = container_of(ut, struct usbip_device, eh); |
| |
| while (1) { |
| if (signal_pending(current)) { |
| usbip_dbg_eh("signal catched!\n"); |
| break; |
| } |
| |
| if (event_handler(ud) < 0) |
| break; |
| |
| wait_event_interruptible(ud->eh_waitq, |
| usbip_event_happened(ud)); |
| usbip_dbg_eh("wakeup\n"); |
| } |
| } |
| |
| int usbip_start_eh(struct usbip_device *ud) |
| { |
| struct usbip_task *eh = &ud->eh; |
| struct task_struct *th; |
| |
| init_waitqueue_head(&ud->eh_waitq); |
| ud->event = 0; |
| |
| usbip_task_init(eh, "usbip_eh", event_handler_loop); |
| |
| th = kthread_run(usbip_thread, (void *)eh, "usbip"); |
| if (IS_ERR(th)) { |
| printk(KERN_WARNING |
| "Unable to start control thread\n"); |
| return PTR_ERR(th); |
| } |
| |
| wait_for_completion(&eh->thread_done); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(usbip_start_eh); |
| |
| void usbip_stop_eh(struct usbip_device *ud) |
| { |
| struct usbip_task *eh = &ud->eh; |
| |
| if (eh->thread == current) |
| return; /* do not wait for myself */ |
| |
| wait_for_completion(&eh->thread_done); |
| usbip_dbg_eh("usbip_eh has finished\n"); |
| } |
| EXPORT_SYMBOL_GPL(usbip_stop_eh); |
| |
| void usbip_event_add(struct usbip_device *ud, unsigned long event) |
| { |
| spin_lock(&ud->lock); |
| |
| ud->event |= event; |
| |
| wake_up(&ud->eh_waitq); |
| |
| spin_unlock(&ud->lock); |
| } |
| EXPORT_SYMBOL_GPL(usbip_event_add); |
| |
| int usbip_event_happened(struct usbip_device *ud) |
| { |
| int happened = 0; |
| |
| spin_lock(&ud->lock); |
| |
| if (ud->event != 0) |
| happened = 1; |
| |
| spin_unlock(&ud->lock); |
| |
| return happened; |
| } |
| EXPORT_SYMBOL_GPL(usbip_event_happened); |