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
|
#ifndef __ASM_X86_XSAVE_H
#define __ASM_X86_XSAVE_H
#include <linux/types.h>
#include <asm/processor.h>
#include <asm/i387.h>
#define XSTATE_FP 0x1
#define XSTATE_SSE 0x2
#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
#define FXSAVE_SIZE 512
/*
* These are the features that the OS can handle currently.
*/
#define XCNTXT_MASK (XSTATE_FP | XSTATE_SSE)
#ifdef CONFIG_X86_64
#define REX_PREFIX "0x48, "
#else
#define REX_PREFIX
#endif
extern unsigned int xstate_size;
extern u64 pcntxt_mask;
extern struct xsave_struct *init_xstate_buf;
extern void xsave_cntxt_init(void);
extern void xsave_init(void);
extern int init_fpu(struct task_struct *child);
extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
void __user *fpstate,
struct _fpx_sw_bytes *sw);
static inline int xrstor_checking(struct xsave_struct *fx)
{
int err;
asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
"3: movl $-1,%[err]\n"
" jmp 2b\n"
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err)
: "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
: "memory");
return err;
}
static inline int xsave_user(struct xsave_struct __user *buf)
{
int err;
__asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
"2:\n"
".section .fixup,\"ax\"\n"
"3: movl $-1,%[err]\n"
" jmp 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
_ASM_ALIGN "\n"
_ASM_PTR "1b,3b\n"
".previous"
: [err] "=r" (err)
: "D" (buf), "a" (-1), "d" (-1), "0" (0)
: "memory");
if (unlikely(err) && __clear_user(buf, xstate_size))
err = -EFAULT;
/* No need to clear here because the caller clears USED_MATH */
return err;
}
static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
{
int err;
struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
u32 lmask = mask;
u32 hmask = mask >> 32;
__asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
"2:\n"
".section .fixup,\"ax\"\n"
"3: movl $-1,%[err]\n"
" jmp 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
_ASM_ALIGN "\n"
_ASM_PTR "1b,3b\n"
".previous"
: [err] "=r" (err)
: "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
: "memory"); /* memory required? */
return err;
}
static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
{
u32 lmask = mask;
u32 hmask = mask >> 32;
asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
: : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
: "memory");
}
static inline void xsave(struct task_struct *tsk)
{
/* This, however, we can work around by forcing the compiler to select
an addressing mode that doesn't require extended registers. */
__asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
: : "D" (&(tsk->thread.xstate->xsave)),
"a" (-1), "d"(-1) : "memory");
}
#endif
|
