diff options
Diffstat (limited to 'src/VBox/Runtime/r0drv/linux/time-r0drv-linux.c')
| -rw-r--r-- | src/VBox/Runtime/r0drv/linux/time-r0drv-linux.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/linux/time-r0drv-linux.c b/src/VBox/Runtime/r0drv/linux/time-r0drv-linux.c new file mode 100644 index 00000000..4f9af4a5 --- /dev/null +++ b/src/VBox/Runtime/r0drv/linux/time-r0drv-linux.c @@ -0,0 +1,221 @@ +/* $Id: time-r0drv-linux.c $ */ +/** @file + * IPRT - Time, Ring-0 Driver, Linux. + */ + +/* + * Copyright (C) 2006-2022 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program 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 3 of the + * License. + * + * This program 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, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox 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. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#define LOG_GROUP RTLOGGROUP_TIME +#include "the-linux-kernel.h" +#include "internal/iprt.h" +/* Make sure we have the setting functions we need for RTTimeNow: */ +#if RTLNX_VER_MAX(2,6,16) +# define RTTIME_INCL_TIMEVAL +#elif RTLNX_VER_MAX(3,17,0) +# define RTTIME_INCL_TIMESPEC +#endif +#include <iprt/time.h> +#include <iprt/asm.h> + + + +DECLINLINE(uint64_t) rtTimeGetSystemNanoTS(void) +{ +#if RTLNX_VER_MIN(5,6,0) + /* + * Starting with kernel version 5.6-rc3 only 64-bit time interfaces + * are allowed in the kernel. + */ + uint64_t u64; + struct timespec64 Ts = { 0, 0 }; + + ktime_get_ts64(&Ts); + u64 = Ts.tv_sec * RT_NS_1SEC_64 + Ts.tv_nsec; + return u64; + +#elif RTLNX_VER_MIN(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 = { 0, 0 }; + ktime_get_ts(&Ts); + u64 = Ts.tv_sec * RT_NS_1SEC_64 + Ts.tv_nsec; + return u64; + +#elif RTLNX_VER_MIN(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 RTLNX_VER_MIN(3,17,0) + struct timespec64 Ts; + ktime_get_real_ts64(&Ts); /* ktime_get_real_ts64 was added as a macro in 3.17, function since 4.18. */ + IPRT_LINUX_RESTORE_EFL_AC(); + return RTTimeSpecSetTimespec64(pTime, &Ts); + +#elif RTLNX_VER_MIN(2,6,16) + struct timespec Ts; + ktime_get_real_ts(&Ts); /* ktime_get_real_ts was removed in Linux 4.20. */ + IPRT_LINUX_RESTORE_EFL_AC(); + return RTTimeSpecSetTimespec(pTime, &Ts); + +#else /* < 2.6.16 */ + struct timeval Tv; + do_gettimeofday(&Tv); + IPRT_LINUX_RESTORE_EFL_AC(); + return RTTimeSpecSetTimeval(pTime, &Tv); +#endif +} +RT_EXPORT_SYMBOL(RTTimeNow); + |