Current File : //usr/src/vboxhost-6.0.14/vboxdrv/r0drv/linux/time-r0drv-linux.c
/* $Id: time-r0drv-linux.c 127855 2019-01-01 01:45:53Z bird $ */
/** @file
* IPRT - Time, Ring-0 Driver, Linux.
*/
/*
* Copyright (C) 2006-2019 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 *
*********************************************************************************************************************************/
#define LOG_GROUP RTLOGGROUP_TIME
#include "the-linux-kernel.h"
#include "internal/iprt.h"
#include <iprt/time.h>
#include <iprt/asm.h>
DECLINLINE(uint64_t) rtTimeGetSystemNanoTS(void)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 16) /* This must match timer-r0drv-linux.c! */
/*
* Use ktime_get_ts, this is also what clock_gettime(CLOCK_MONOTONIC,) is using.
*/
uint64_t u64;
struct timespec Ts;
ktime_get_ts(&Ts);
u64 = Ts.tv_sec * RT_NS_1SEC_64 + Ts.tv_nsec;
return u64;
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 60)
/*
* Seems there is no way of getting to the exact source of
* sys_clock_gettime(CLOCK_MONOTONIC, &ts) here, I think. But
* 64-bit jiffies adjusted for the initial value should be pretty
* much the same I hope.
*/
uint64_t u64 = get_jiffies_64();
# ifdef INITIAL_JIFFIES
u64 += INITIAL_JIFFIES;
# endif
u64 *= TICK_NSEC;
return u64;
#else /* < 2.5.60 */
# if BITS_PER_LONG >= 64
/*
* This is the same as above, except that there is no get_jiffies_64()
* here and we rely on long, and therefor jiffies, being 64-bit instead.
*/
uint64_t u64 = jiffies;
# ifdef INITIAL_JIFFIES
u64 += INITIAL_JIFFIES;
# endif
u64 *= TICK_NSEC;
return u64;
# else /* 32 bit jiffies */
/*
* We'll have to try track jiffy rollovers here or we'll be
* in trouble every time it flips.
*
* The high dword of the s_u64Last is the rollover count, the
* low dword is the previous jiffies. Updating is done by
* atomic compare & exchange of course.
*/
static uint64_t volatile s_u64Last = 0;
uint64_t u64;
for (;;)
{
uint64_t u64NewLast;
int32_t iDelta;
uint32_t cRollovers;
uint32_t u32LastJiffies;
/* sample the values */
unsigned long ulNow = jiffies;
uint64_t u64Last = s_u64Last;
if (ulNow != jiffies)
continue; /* try again */
# ifdef INITIAL_JIFFIES
ulNow += INITIAL_JIFFIES;
# endif
u32LastJiffies = (uint32_t)u64Last;
cRollovers = u64Last >> 32;
/*
* Check for rollover and update the static last value.
*
* We have to make sure we update it successfully to rule out
* an underrun because of racing someone.
*/
iDelta = ulNow - u32LastJiffies;
if (iDelta < 0)
{
cRollovers++;
u64NewLast = RT_MAKE_U64(ulNow, cRollovers);
if (!ASMAtomicCmpXchgU64(&s_u64Last, u64NewLast, u64Last))
continue; /* race, try again */
}
else
{
u64NewLast = RT_MAKE_U64(ulNow, cRollovers);
ASMAtomicCmpXchgU64(&s_u64Last, u64NewLast, u64Last);
}
/* calculate the return value */
u64 = ulNow;
u64 *= TICK_NSEC;
u64 += cRollovers * (_4G * TICK_NSEC);
break;
}
return u64;
# endif /* 32 bit jiffies */
#endif /* < 2.5.60 */
}
RTDECL(uint64_t) RTTimeNanoTS(void)
{
return rtTimeGetSystemNanoTS();
}
RT_EXPORT_SYMBOL(RTTimeNanoTS);
RTDECL(uint64_t) RTTimeMilliTS(void)
{
return rtTimeGetSystemNanoTS() / RT_NS_1MS;
}
RT_EXPORT_SYMBOL(RTTimeMilliTS);
RTDECL(uint64_t) RTTimeSystemNanoTS(void)
{
return rtTimeGetSystemNanoTS();
}
RT_EXPORT_SYMBOL(RTTimeSystemNanoTS);
RTDECL(uint64_t) RTTimeSystemMilliTS(void)
{
return rtTimeGetSystemNanoTS() / RT_NS_1MS;
}
RT_EXPORT_SYMBOL(RTTimeSystemMilliTS);
RTDECL(PRTTIMESPEC) RTTimeNow(PRTTIMESPEC pTime)
{
IPRT_LINUX_SAVE_EFL_AC();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 16)
/* On Linux 4.20, time.h includes time64.h and we have to use 64-bit times. */
# ifdef _LINUX_TIME64_H
struct timespec64 Ts;
ktime_get_real_ts64(&Ts);
# else
struct timespec Ts;
ktime_get_real_ts(&Ts);
# endif
IPRT_LINUX_RESTORE_EFL_AC();
# ifdef _LINUX_TIME64_H
return RTTimeSpecSetTimespec64(pTime, &Ts);
#else
return RTTimeSpecSetTimespec(pTime, &Ts);
#endif
#else /* < 2.6.16 */
struct timeval Tv;
do_gettimeofday(&Tv);
IPRT_LINUX_RESTORE_EFL_AC();
return RTTimeSpecSetTimeval(pTime, &Tv);
#endif
}
RT_EXPORT_SYMBOL(RTTimeNow);
Mini Shell