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
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/* 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>
#include <asm/vdso/compat_barrier.h>
#define __VDSO_USE_SYSCALL ULLONG_MAX
#define VDSO_HAS_CLOCK_GETRES 1
#define BUILD_VDSO32 1
static __always_inline
int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
register struct timezone *tz asm("r1") = _tz;
register struct __kernel_old_timeval *tv asm("r0") = _tv;
register long ret asm ("r0");
register long nr asm("r7") = __NR_compat_gettimeofday;
asm volatile(
" swi #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("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_compat_clock_gettime64;
asm volatile(
" swi #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline
long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_compat_clock_gettime;
asm volatile(
" swi #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("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_compat_clock_getres_time64;
/* The checks below are required for ABI consistency with arm */
if ((_clkid >= MAX_CLOCKS) && (_ts == NULL))
return -EINVAL;
asm volatile(
" swi #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline
int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_compat_clock_getres;
/* The checks below are required for ABI consistency with arm */
if ((_clkid >= MAX_CLOCKS) && (_ts == NULL))
return -EINVAL;
asm volatile(
" swi #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("mrrc p15, 1, %Q0, %R0, c14" : "=r" (res));
/*
* 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)
{
const struct vdso_data *ret;
/*
* This simply puts &_vdso_data into ret. The reason why we don't use
* `ret = _vdso_data` is that the compiler tends to optimise this in a
* very suboptimal way: instead of keeping &_vdso_data in a register,
* it goes through a relocation almost every time _vdso_data must be
* accessed (even in subfunctions). This is both time and space
* consuming: each relocation uses a word in the code section, and it
* has to be loaded at runtime.
*
* This trick hides the assignment from the compiler. Since it cannot
* track where the pointer comes from, it will only use one relocation
* where __arch_get_vdso_data() is called, and then keep the result in
* a register.
*/
asm volatile("mov %0, %1" : "=r"(ret) : "r"(_vdso_data));
return ret;
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
|
