kernel_liteos_a/kernel/extended/vdso/usr/los_vdso_sys.c

114 lines
3.6 KiB
C

/*
* Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
* Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "asm/page.h"
#include "time.h"
#include "sys/time.h"
#include "los_typedef.h"
#include "los_vdso_datapage.h"
STATIC INT32 VdsoGetRealtimeCoarse(struct timespec *ts, const VdsoDataPage *usrVdsoDataPage)
{
do {
if (!usrVdsoDataPage->lockCount) {
ts->tv_sec = usrVdsoDataPage->realTimeSec;
ts->tv_nsec = usrVdsoDataPage->realTimeNsec;
return 0;
}
} while (1);
}
STATIC INT32 VdsoGetMonotimeCoarse(struct timespec *ts, const VdsoDataPage *usrVdsoDataPage)
{
do {
if (!usrVdsoDataPage->lockCount) {
ts->tv_sec = usrVdsoDataPage->monoTimeSec;
ts->tv_nsec = usrVdsoDataPage->monoTimeNsec;
return 0;
}
} while (1);
}
STATIC size_t LocVdsoStart(size_t vdsoStart, const CHAR *elfHead, const size_t len)
{
CHAR *head = NULL;
INT32 i;
INT32 loop;
for (i = 1; i <= MAX_PAGES; i++) {
head = (CHAR *)((UINTPTR)vdsoStart);
for (loop = len; loop >= 1; loop--) {
if (*head++ != *(elfHead + len - loop)) {
break;
}
}
if (loop) {
vdsoStart -= PAGE_SIZE;
} else {
break;
}
}
if (i > MAX_PAGES) {
return 0;
}
return (vdsoStart - PAGE_SIZE);
}
INT32 VdsoClockGettime(clockid_t clk, struct timespec *ts)
{
INT32 ret;
size_t vdsoStart;
__asm__ __volatile__("mov %0, pc" : "=r"(vdsoStart));
vdsoStart = vdsoStart - (vdsoStart & (PAGE_SIZE - 1));
vdsoStart = LocVdsoStart(vdsoStart, ELF_HEAD, ELF_HEAD_LEN);
if (vdsoStart == 0) {
return -1;
}
VdsoDataPage *usrVdsoDataPage = (VdsoDataPage *)(UINTPTR)vdsoStart;
switch (clk) {
case CLOCK_REALTIME_COARSE:
ret = VdsoGetRealtimeCoarse(ts, usrVdsoDataPage);
break;
case CLOCK_MONOTONIC_COARSE:
ret = VdsoGetMonotimeCoarse(ts, usrVdsoDataPage);
break;
default:
ret = -1;
break;
}
return ret;
}