blob: 1bf40dce06255f83de9ca93fafd0c6ac49df3b1e (
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
104
105
106
107
108
109
110
|
/*
* Copyright (c) 2010-2014 Richard Braun.
*
* 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, either version 2 of the License, or
* (at your option) any later version.
*
* 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 <http://www.gnu.org/licenses/>.
*/
#ifndef _X86_CPU_H
#define _X86_CPU_H
#include <kern/macros.h>
/*
* EFLAGS register flags.
*/
#define CPU_EFL_ONE 0x00000002
#define CPU_EFL_IF 0x00000200
/*
* Return the content of the EFLAGS register.
*
* Implies a compiler barrier.
*/
static __always_inline unsigned long
cpu_get_eflags(void)
{
unsigned long eflags;
asm volatile("pushf\n"
"pop %0\n"
: "=r" (eflags)
: : "memory");
return eflags;
}
/*
* Enable local interrupts.
*
* Implies a compiler barrier.
*/
static __always_inline void
cpu_intr_enable(void)
{
asm volatile("sti" : : : "memory");
}
/*
* Disable local interrupts.
*
* Implies a compiler barrier.
*/
static __always_inline void
cpu_intr_disable(void)
{
asm volatile("cli" : : : "memory");
}
/*
* Restore the content of the EFLAGS register, possibly enabling interrupts.
*
* Implies a compiler barrier.
*/
static __always_inline void
cpu_intr_restore(unsigned long flags)
{
asm volatile("push %0\n"
"popf\n"
: : "r" (flags)
: "memory");
}
/*
* Disable local interrupts, returning the previous content of the EFLAGS
* register.
*
* Implies a compiler barrier.
*/
static __always_inline void
cpu_intr_save(unsigned long *flags)
{
*flags = cpu_get_eflags();
cpu_intr_disable();
}
/*
* Return true if interrupts are enabled.
*
* Implies a compiler barrier.
*/
static __always_inline int
cpu_intr_enabled(void)
{
unsigned long eflags;
eflags = cpu_get_eflags();
return (eflags & CPU_EFL_IF) ? 1 : 0;
}
#endif /* _X86_CPU_H */
|
