summaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/vdso/gettimeofday.h
blob: b08f476b72b4d917d93edc5c61bae1c6178bf5f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
/* 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/unistd.h>
#include <uapi/linux/time.h>

#define __VDSO_USE_SYSCALL		ULLONG_MAX

#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)
{
	u64 res;

	/*
	 * clock_mode == 0 implies that vDSO are enabled otherwise
	 * fallback on syscall.
	 */
	if (clock_mode)
		return __VDSO_USE_SYSCALL;

	/*
	 * This isb() is required to prevent that the counter value
	 * is speculated.
	 */
	isb();
	asm volatile("mrs %0, cntvct_el0" : "=r" (res) :: "memory");
	/*
	 * This isb() is required to prevent that the seq lock is
	 * speculated.#
	 */
	isb();

	return res;
}

static __always_inline
const struct vdso_data *__arch_get_vdso_data(void)
{
	return _vdso_data;
}

#endif /* !__ASSEMBLY__ */

#endif /* __ASM_VDSO_GETTIMEOFDAY_H */