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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
  20 extern void mxcsr_feature_mask_init(void);
  21 extern 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
  38 extern 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  */
  44 static 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         tsk->thread_info->status &= ~TS_USEDFPU;
  53 }
  54
  55 #define __unlazy_fpu( tsk ) do { \
  56         if ((tsk)->thread_info->status & TS_USEDFPU) \
  57                 save_init_fpu( tsk ); \
  58 } while (0)
  59
  60 #define __clear_fpu( tsk )                                      \
  61 do {                                                            \
  62         if ((tsk)->thread_info->status & TS_USEDFPU) {          \
  63                 asm volatile("fnclex ; fwait");                         \
  64                 (tsk)->thread_info->status &= ~TS_USEDFPU;      \
  65                 stts();                                         \
  66         }                                                       \
  67 } while (0)
  68
  69
  70 /*
  71  * These disable preemption on their own and are safe
  72  */
  73 static 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  */
  96 extern unsigned short get_fpu_cwd( struct task_struct *tsk );
  97 extern unsigned short get_fpu_swd( struct task_struct *tsk );
  98 extern unsigned short get_fpu_mxcsr( struct task_struct *tsk );
  99
 100 /*
 101  * Signal frame handlers...
 102  */
 103 extern int save_i387( struct _fpstate __user *buf );
 104 extern int restore_i387( struct _fpstate __user *buf );
 105
 106 /*
 107  * ptrace request handers...
 108  */
 109 extern int get_fpregs( struct user_i387_struct __user *buf,
 110                        struct task_struct *tsk );
 111 extern int set_fpregs( struct task_struct *tsk,
 112                        struct user_i387_struct __user *buf );
 113
 114 extern int get_fpxregs( struct user_fxsr_struct __user *buf,
 115                         struct task_struct *tsk );
 116 extern int set_fpxregs( struct task_struct *tsk,
 117                         struct user_fxsr_struct __user *buf );
 118
 119 /*
 120  * FPU state for core dumps...
 121  */
 122 extern int dump_fpu( struct pt_regs *regs,
 123                      struct user_i387_struct *fpu );
 124
 125 #endif /* __ASM_I386_I387_H */