2 * include/asm-x86_64/i387.h
4 * Copyright (C) 1994 Linus Torvalds
6 * Pentium III FXSR, SSE support
7 * General FPU state handling cleanups
8 * Gareth Hughes <gareth@valinux.com>, May 2000
9 * x86-64 work by Andi Kleen 2002
12 #ifndef __ASM_X86_64_I387_H
13 #define __ASM_X86_64_I387_H
15 #include <linux/sched.h>
16 #include <asm/processor.h>
17 #include <asm/sigcontext.h>
19 #include <asm/thread_info.h>
20 #include <asm/uaccess.h>
22 extern void fpu_init(void);
23 extern unsigned int mxcsr_feature_mask;
24 extern void mxcsr_feature_mask_init(void);
25 extern void init_fpu(struct task_struct *child);
26 extern int save_i387(struct _fpstate *buf);
28 static inline int need_signal_i387(struct task_struct *me)
33 if (me->thread_info->status & TS_USEDFPU)
39 * FPU lazy state save handling...
42 #define kernel_fpu_end() stts()
44 #define unlazy_fpu(tsk) do { \
45 if ((tsk)->thread_info->status & TS_USEDFPU) \
49 #define clear_fpu(tsk) do { \
50 if ((tsk)->thread_info->status & TS_USEDFPU) { \
51 asm volatile("fwait"); \
52 (tsk)->thread_info->status &= ~TS_USEDFPU; \
58 * ptrace request handers...
60 extern int get_fpregs(struct user_i387_struct *buf,
61 struct task_struct *tsk);
62 extern int set_fpregs(struct task_struct *tsk,
63 struct user_i387_struct *buf);
66 * i387 state interaction
68 #define get_fpu_mxcsr(t) ((t)->thread.i387.fxsave.mxcsr)
69 #define get_fpu_cwd(t) ((t)->thread.i387.fxsave.cwd)
70 #define get_fpu_fxsr_twd(t) ((t)->thread.i387.fxsave.twd)
71 #define get_fpu_swd(t) ((t)->thread.i387.fxsave.swd)
72 #define set_fpu_cwd(t,val) ((t)->thread.i387.fxsave.cwd = (val))
73 #define set_fpu_swd(t,val) ((t)->thread.i387.fxsave.swd = (val))
74 #define set_fpu_fxsr_twd(t,val) ((t)->thread.i387.fxsave.twd = (val))
76 static inline int restore_fpu_checking(struct i387_fxsave_struct *fx)
79 asm volatile("1: rex64 ; fxrstor (%[fx])\n\t"
81 ".section .fixup,\"ax\"\n"
82 "3: movl $-1,%[err]\n"
85 ".section __ex_table,\"a\"\n"
90 : [fx] "r" (fx), "0" (0));
96 static inline int save_i387_checking(struct i387_fxsave_struct *fx)
99 asm volatile("1: rex64 ; fxsave (%[fx])\n\t"
101 ".section .fixup,\"ax\"\n"
102 "3: movl $-1,%[err]\n"
105 ".section __ex_table,\"a\"\n"
110 : [fx] "r" (fx), "0" (0));
112 __clear_user(fx, sizeof(struct i387_fxsave_struct));
116 static inline void kernel_fpu_begin(void)
118 struct thread_info *me = current_thread_info();
119 if (me->status & TS_USEDFPU) {
120 asm volatile("rex64 ; fxsave %0 ; fnclex"
121 : "=m" (me->task->thread.i387.fxsave));
122 me->status &= ~TS_USEDFPU;
128 static inline void save_init_fpu( struct task_struct *tsk )
130 asm volatile( "fxsave %0 ; fnclex"
131 : "=m" (tsk->thread.i387.fxsave));
132 tsk->thread_info->status &= ~TS_USEDFPU;
137 * This restores directly out of user space. Exceptions are handled.
139 static inline int restore_i387(struct _fpstate *buf)
141 return restore_fpu_checking((struct i387_fxsave_struct *)buf);
144 #endif /* __ASM_X86_64_I387_H */