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/*
* 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/kthread.h>
#include <linux/export.h>
#include "usbip_common.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;
}
/* Reset the device. */
if (ud->event & USBIP_EH_RESET) {
ud->eh_ops.reset(ud);
ud->event &= ~USBIP_EH_RESET;
}
/* Mark the device as unusable. */
if (ud->event & USBIP_EH_UNUSABLE) {
ud->eh_ops.unusable(ud);
ud->event &= ~USBIP_EH_UNUSABLE;
}
/* Stop the error handler. */
if (ud->event & USBIP_EH_BYE)
return -1;
}
return 0;
}
static int event_handler_loop(void *data)
{
struct usbip_device *ud = data;
while (!kthread_should_stop()) {
wait_event_interruptible(ud->eh_waitq,
usbip_event_happened(ud) ||
kthread_should_stop());
usbip_dbg_eh("wakeup\n");
if (event_handler(ud) < 0)
break;
}
return 0;
}
int usbip_start_eh(struct usbip_device *ud)
{
init_waitqueue_head(&ud->eh_waitq);
ud->event = 0;
ud->eh = kthread_run(event_handler_loop, ud, "usbip_eh");
if (IS_ERR(ud->eh)) {
pr_warn("Unable to start control thread\n");
return PTR_ERR(ud->eh);
}
return 0;
}
EXPORT_SYMBOL_GPL(usbip_start_eh);
void usbip_stop_eh(struct usbip_device *ud)
{
if (ud->eh == current)
return; /* do not wait for myself */
kthread_stop(ud->eh);
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)
{
unsigned long flags;
spin_lock_irqsave(&ud->lock, flags);
ud->event |= event;
wake_up(&ud->eh_waitq);
spin_unlock_irqrestore(&ud->lock, flags);
}
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);
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