[deliverable/linux.git] / drivers / staging / usbip / usbip_event.c

/*
 * 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;
		}

		/* 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)) {
		printk(KERN_WARNING
			"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)
{
	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);
Commit	Line	Data
05a1f28e TH	1	/*
	2	* Copyright (C) 2003-2008 Takahiro Hirofuchi
	3	*
	4	* This is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
	17	* USA.
	18	*/
	19
	20	#include "usbip_common.h"
b8868e45	21	#include <linux/kthread.h>
05a1f28e TH	22
	23	static int event_handler(struct usbip_device *ud)
	24	{
b8868e45	25	usbip_dbg_eh("enter\n");
05a1f28e TH	26
	27	/*
	28	* Events are handled by only this thread.
	29	*/
b8868e45 BM	30	while (usbip_event_happened(ud)) {
b8868e45 BM	31	usbip_dbg_eh("pending event %lx\n", ud->event);
05a1f28e TH	32
	33	/*
	34	* NOTE: shutdown must come first.
	35	* Shutdown the device.
	36	*/
	37	if (ud->event & USBIP_EH_SHUTDOWN) {
	38	ud->eh_ops.shutdown(ud);
	39
	40	ud->event &= ~USBIP_EH_SHUTDOWN;
05a1f28e TH	41	}
05a1f28e TH	42
05a1f28e TH	43	/* Reset the device. */
	44	if (ud->event & USBIP_EH_RESET) {
	45	ud->eh_ops.reset(ud);
	46
	47	ud->event &= ~USBIP_EH_RESET;
05a1f28e TH	48	}
	49
	50	/* Mark the device as unusable. */
	51	if (ud->event & USBIP_EH_UNUSABLE) {
	52	ud->eh_ops.unusable(ud);
	53
	54	ud->event &= ~USBIP_EH_UNUSABLE;
05a1f28e TH	55	}
05a1f28e TH	56
584c5b7c MV	57	/* Stop the error handler. */
	58	if (ud->event & USBIP_EH_BYE)
	59	return -1;
05a1f28e TH	60	}
	61
	62	return 0;
	63	}
	64
9720b4bc	65	static int event_handler_loop(void *data)
05a1f28e	66	{
9720b4bc	67	struct usbip_device *ud = data;
05a1f28e	68
9720b4bc AB	69	while (!kthread_should_stop()) {
	70	wait_event_interruptible(ud->eh_waitq,
	71	usbip_event_happened(ud) \|\|
	72	kthread_should_stop());
	73	usbip_dbg_eh("wakeup\n");
05a1f28e TH	74
	75	if (event_handler(ud) < 0)
	76	break;
05a1f28e	77	}
9720b4bc	78	return 0;
05a1f28e TH	79	}
05a1f28e TH	80
b8868e45	81	int usbip_start_eh(struct usbip_device *ud)
05a1f28e	82	{
05a1f28e TH	83	init_waitqueue_head(&ud->eh_waitq);
	84	ud->event = 0;
	85
9720b4bc AB	86	ud->eh = kthread_run(event_handler_loop, ud, "usbip_eh");
9720b4bc AB	87	if (IS_ERR(ud->eh)) {
b8868e45 BM	88	printk(KERN_WARNING
b8868e45 BM	89	"Unable to start control thread\n");
9720b4bc	90	return PTR_ERR(ud->eh);
b8868e45	91	}
b8868e45	92	return 0;
05a1f28e TH	93	}
	94	EXPORT_SYMBOL_GPL(usbip_start_eh);
	95
	96	void usbip_stop_eh(struct usbip_device *ud)
	97	{
9720b4bc	98	if (ud->eh == current)
d01f42a2 EL	99	return; /* do not wait for myself */
d01f42a2 EL	100
9720b4bc	101	kthread_stop(ud->eh);
b8868e45	102	usbip_dbg_eh("usbip_eh has finished\n");
05a1f28e TH	103	}
	104	EXPORT_SYMBOL_GPL(usbip_stop_eh);
	105
	106	void usbip_event_add(struct usbip_device *ud, unsigned long event)
	107	{
	108	spin_lock(&ud->lock);
	109
	110	ud->event \|= event;
	111
	112	wake_up(&ud->eh_waitq);
	113
	114	spin_unlock(&ud->lock);
	115	}
	116	EXPORT_SYMBOL_GPL(usbip_event_add);
	117
b8868e45	118	int usbip_event_happened(struct usbip_device *ud)
05a1f28e	119	{
b8868e45	120	int happened = 0;
05a1f28e TH	121
	122	spin_lock(&ud->lock);
	123
	124	if (ud->event != 0)
b8868e45	125	happened = 1;
05a1f28e TH	126
	127	spin_unlock(&ud->lock);
	128
b8868e45	129	return happened;
05a1f28e	130	}
b8868e45	131	EXPORT_SYMBOL_GPL(usbip_event_happened);