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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2018 ARM Limited
*/
#ifndef __ASM_VDSO_GETTIMEOFDAY_H
#define __ASM_VDSO_GETTIMEOFDAY_H
#ifndef __ASSEMBLY__
#include <asm/alternative.h>
#include <asm/barrier.h>
#include <asm/unistd.h>
#include <asm/sysreg.h>
#define VDSO_HAS_CLOCK_GETRES 1
static __always_inline
int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
register struct timezone *tz asm("x1") = _tz;
register struct __kernel_old_timeval *tv asm("x0") = _tv;
register long ret asm ("x0");
register long nr asm("x8") = __NR_gettimeofday;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (tv), "r" (tz), "r" (nr)
: "memory");
return ret;
}
static __always_inline
long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
{
register struct __kernel_timespec *ts asm("x1") = _ts;
register clockid_t clkid asm("x0") = _clkid;
register long ret asm ("x0");
register long nr asm("x8") = __NR_clock_gettime;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline
int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
{
register struct __kernel_timespec *ts asm("x1") = _ts;
register clockid_t clkid asm("x0") = _clkid;
register long ret asm ("x0");
register long nr asm("x8") = __NR_clock_getres;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
const struct vdso_data *vd)
{
u64 res;
/*
* Core checks for mode already, so this raced against a concurrent
* update. Return something. Core will do another round and then
* see the mode change and fallback to the syscall.
*/
if (clock_mode == VDSO_CLOCKMODE_NONE)
return 0;
/*
* If FEAT_ECV is available, use the self-synchronizing counter.
* Otherwise the isb is required to prevent that the counter value
* is speculated.
*/
asm volatile(
ALTERNATIVE("isb\n"
"mrs %0, cntvct_el0",
"nop\n"
__mrs_s("%0", SYS_CNTVCTSS_EL0),
ARM64_HAS_ECV)
: "=r" (res)
:
: "memory");
arch_counter_enforce_ordering(res);
return res;
}
static __always_inline
const struct vdso_data *__arch_get_vdso_data(void)
{
return _vdso_data;
}
#ifdef CONFIG_TIME_NS
static __always_inline
const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
{
return _timens_data;
}
#endif
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
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