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1/*
2 * include/asm-i386/i387.h
3 *
4 * Copyright (C) 1994 Linus Torvalds
5 *
6 * Pentium III FXSR, SSE support
7 * General FPU state handling cleanups
8 * Gareth Hughes <gareth@valinux.com>, May 2000
9 */
10
11#ifndef __ASM_I386_I387_H
12#define __ASM_I386_I387_H
13
14#include <linux/sched.h>
15#include <linux/init.h>
16#include <asm/processor.h>
17#include <asm/sigcontext.h>
18#include <asm/user.h>
19
20extern void mxcsr_feature_mask_init(void);
21extern void init_fpu(struct task_struct *);
22
23/*
24 * FPU lazy state save handling...
25 */
26
27/*
28 * The "nop" is needed to make the instructions the same
29 * length.
30 */
31#define restore_fpu(tsk) \
32 alternative_input( \
33 "nop ; frstor %1", \
34 "fxrstor %1", \
35 X86_FEATURE_FXSR, \
36 "m" ((tsk)->thread.i387.fxsave))
37
38extern void kernel_fpu_begin(void);
39#define kernel_fpu_end() do { stts(); preempt_enable(); } while(0)
40
41/*
42 * These must be called with preempt disabled
43 */
44static inline void __save_init_fpu( struct task_struct *tsk )
45{
46 alternative_input(
47 "fnsave %1 ; fwait ;" GENERIC_NOP2,
48 "fxsave %1 ; fnclex",
49 X86_FEATURE_FXSR,
50 "m" (tsk->thread.i387.fxsave)
51 :"memory");
52 task_thread_info(tsk)->status &= ~TS_USEDFPU;
53}
54
55#define __unlazy_fpu( tsk ) do { \
56 if (task_thread_info(tsk)->status & TS_USEDFPU) \
57 save_init_fpu( tsk ); \
58} while (0)
59
60#define __clear_fpu( tsk ) \
61do { \
62 if (task_thread_info(tsk)->status & TS_USEDFPU) { \
63 asm volatile("fnclex ; fwait"); \
64 task_thread_info(tsk)->status &= ~TS_USEDFPU; \
65 stts(); \
66 } \
67} while (0)
68
69
70/*
71 * These disable preemption on their own and are safe
72 */
73static inline void save_init_fpu( struct task_struct *tsk )
74{
75 preempt_disable();
76 __save_init_fpu(tsk);
77 stts();
78 preempt_enable();
79}
80
81#define unlazy_fpu( tsk ) do { \
82 preempt_disable(); \
83 __unlazy_fpu(tsk); \
84 preempt_enable(); \
85} while (0)
86
87#define clear_fpu( tsk ) do { \
88 preempt_disable(); \
89 __clear_fpu( tsk ); \
90 preempt_enable(); \
91} while (0)
92 \
93/*
94 * FPU state interaction...
95 */
96extern unsigned short get_fpu_cwd( struct task_struct *tsk );
97extern unsigned short get_fpu_swd( struct task_struct *tsk );
98extern unsigned short get_fpu_mxcsr( struct task_struct *tsk );
99
100/*
101 * Signal frame handlers...
102 */
103extern int save_i387( struct _fpstate __user *buf );
104extern int restore_i387( struct _fpstate __user *buf );
105
106/*
107 * ptrace request handers...
108 */
109extern int get_fpregs( struct user_i387_struct __user *buf,
110 struct task_struct *tsk );
111extern int set_fpregs( struct task_struct *tsk,
112 struct user_i387_struct __user *buf );
113
114extern int get_fpxregs( struct user_fxsr_struct __user *buf,
115 struct task_struct *tsk );
116extern int set_fpxregs( struct task_struct *tsk,
117 struct user_fxsr_struct __user *buf );
118
119/*
120 * FPU state for core dumps...
121 */
122extern int dump_fpu( struct pt_regs *regs,
123 struct user_i387_struct *fpu );
124
125#endif /* __ASM_I386_I387_H */