/* $Id: initterm-r0drv-linux.c 109033 2016-07-22 18:27:37Z bird $ */
/** @file
 * IPRT - Initialization & Termination, R0 Driver, Linux.
 */

/*
 * Copyright (C) 2006-2016 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 */

/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#include "the-linux-kernel.h"
#include "internal/iprt.h"
#include <iprt/err.h>
#include <iprt/assert.h>
#include "internal/initterm.h"

/*********************************************************************************************************************************
*   Global Variables                                                                                                             *
*********************************************************************************************************************************/
/** The IPRT work queue. */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 41)
static struct workqueue_struct *g_prtR0LnxWorkQueue;
#else
static DECLARE_TASK_QUEUE(g_rtR0LnxWorkQueue);
#endif

/*********************************************************************************************************************************
*   Internal Functions                                                                                                           *
*********************************************************************************************************************************/
/* in alloc-r0drv0-linux.c */
DECLHIDDEN(void) rtR0MemExecCleanup(void);

/**
 * Pushes an item onto the IPRT work queue.
 *
 * @param   pWork               The work item.
 * @param   pfnWorker           The callback function.  It will be called back
 *                              with @a pWork as argument.
 */
DECLHIDDEN(void) rtR0LnxWorkqueuePush(RTR0LNXWORKQUEUEITEM * pWork,
				      void (*pfnWorker) (RTR0LNXWORKQUEUEITEM
							 *))
{
	IPRT_LINUX_SAVE_EFL_AC();

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 41)
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
	INIT_WORK(pWork, pfnWorker);
# else
	INIT_WORK(pWork, pfnWorker, pWork);
# endif
	queue_work(g_prtR0LnxWorkQueue, pWork);
#else
	INIT_TQUEUE(pWork, (void (*)(void *))pfnWorker, pWork);
	queue_task(pWork, &g_rtR0LnxWorkQueue);
#endif

	IPRT_LINUX_RESTORE_EFL_AC();
}

/**
 * Flushes all items in the IPRT work queue.
 *
 * @remarks This is mostly for 2.4.x compatability.  Must not be called from
 *          atomic contexts or with unncessary locks held.
 */
DECLHIDDEN(void) rtR0LnxWorkqueueFlush(void)
{
	IPRT_LINUX_SAVE_EFL_AC();

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 41)
	flush_workqueue(g_prtR0LnxWorkQueue);
#else
	run_task_queue(&g_rtR0LnxWorkQueue);
#endif

	IPRT_LINUX_RESTORE_EFL_AC();
}

DECLHIDDEN(int) rtR0InitNative(void)
{
	int rc = VINF_SUCCESS;
	IPRT_LINUX_SAVE_EFL_AC();

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 41)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 13)
	g_prtR0LnxWorkQueue = create_workqueue("iprt-VBoxWQueue");
#else
	g_prtR0LnxWorkQueue = create_workqueue("iprt-VBoxQ");
#endif
	if (!g_prtR0LnxWorkQueue)
		rc = VERR_NO_MEMORY;
#endif

	IPRT_LINUX_RESTORE_EFL_AC();
	return rc;
}

DECLHIDDEN(void)rtR0TermNative(void)
{
	IPRT_LINUX_SAVE_EFL_AC();

	rtR0LnxWorkqueueFlush();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 41)
	destroy_workqueue(g_prtR0LnxWorkQueue);
	g_prtR0LnxWorkQueue = NULL;
#endif

	rtR0MemExecCleanup();

	IPRT_LINUX_RESTORE_EFL_AC();
}
