/* $Id: TMAllCpu.cpp 23 2007-01-15 14:08:28Z vboxsync $ */
/** @file
 * TM - Timeout Manager, CPU Time, All Contexts.
 */

/*
 * Copyright (C) 2006 InnoTek Systemberatung GmbH
 *
 * 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 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.
 *
 * If you received this file as part of a commercial VirtualBox
 * distribution, then only the terms of your commercial VirtualBox
 * license agreement apply instead of the previous paragraph.
 */


/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#define LOG_GROUP LOG_GROUP_TM
#include <VBox/tm.h>
#include "TMInternal.h"
#include <VBox/vm.h>

#include <VBox/param.h>
#include <VBox/err.h>
#include <iprt/assert.h>
#include <iprt/asm.h>


/**
 * Resumes the CPU timestamp counter ticking.
 *
 * @returns VBox status code.
 * @param   pVM         The VM to operate on.
 */
TMDECL(int) TMCpuTickResume(PVM pVM)
{
    if (!pVM->tm.s.fTSCTicking)
    {
        pVM->tm.s.fTSCTicking = true;
#ifndef TM_REAL_CPU_TICK
        pVM->tm.s.u64TSCOffset = ASMReadTSC() - pVM->tm.s.u64TSC;
#endif
        return VINF_SUCCESS;
    }
    AssertFailed();
    return VERR_INTERNAL_ERROR;
}


/**
 * Pauses the CPU timestamp counter ticking.
 *
 * @returns VBox status code.
 * @param   pVM         The VM to operate on.
 */
TMDECL(int) TMCpuTickPause(PVM pVM)
{
    if (pVM->tm.s.fTSCTicking)
    {
#ifndef TM_REAL_CPU_TICK
        pVM->tm.s.u64TSC = ASMReadTSC() - pVM->tm.s.u64TSCOffset;
#endif
        pVM->tm.s.fTSCTicking = false;
        return VINF_SUCCESS;
    }
    AssertFailed();
    return VERR_INTERNAL_ERROR;
}



/**
 * Read the current CPU timstamp counter.
 *
 * @returns Gets the CPU tsc.
 * @param   pVM         The VM to operate on.
 */
TMDECL(uint64_t) TMCpuTickGet(PVM pVM)
{
#ifdef TM_REAL_CPU_TICK
    return ASMReadTSC();
#else
    if (pVM->tm.s.fTSCTicking)
        return ASMReadTSC() - pVM->tm.s.u64TSCOffset;
    return pVM->tm.s.u64TSC;
#endif
}


/**
 * Sets the current CPU timestamp counter.
 *
 * @returns VBox status code.
 * @param   pVM         The VM to operate on.
 * @param   u64Tick     The new timestamp value.
 */
TMDECL(int) TMCpuTickSet(PVM pVM, uint64_t u64Tick)
{
    Assert(!pVM->tm.s.fTSCTicking);
    pVM->tm.s.u64TSC = u64Tick;
    return VINF_SUCCESS;
}


/**
 * Get the timestamp frequency.
 *
 * @returns Number of ticks per second.
 * @param   pVM     The VM.
 */
TMDECL(uint64_t) TMCpuTicksPerSecond(PVM pVM)
{
    return pVM->tm.s.cTSCTicksPerSecond;
}