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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.fsave))
  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         if ( cpu_has_fxsr ) {
  47                 asm volatile( "fxsave %0 ; fnclex"
  48                               : "=m" (tsk->thread.i387.fxsave) );
  49         } else {
  50                 asm volatile( "fnsave %0 ; fwait"
  51                               : "=m" (tsk->thread.i387.fsave) );
  52         }
  53         tsk->thread_info->status &= ~TS_USEDFPU;
  54 }
  55
  56 #define __unlazy_fpu( tsk ) do { \
  57         if ((tsk)->thread_info->status & TS_USEDFPU) \
  58                 save_init_fpu( tsk ); \
  59 } while (0)
  60
  61 #define __clear_fpu( tsk )                                      \
  62 do {                                                            \
  63         if ((tsk)->thread_info->status & TS_USEDFPU) {          \
  64                 asm volatile("fnclex ; fwait");                         \
  65                 (tsk)->thread_info->status &= ~TS_USEDFPU;      \
  66                 stts();                                         \
  67         }                                                       \
  68 } while (0)
  69
  70
  71 /*
  72  * These disable preemption on their own and are safe
  73  */
  74 static inline void save_init_fpu( struct task_struct *tsk )
  75 {
  76         preempt_disable();
  77         __save_init_fpu(tsk);
  78         stts();
  79         preempt_enable();
  80 }
  81
  82 #define unlazy_fpu( tsk ) do {  \
  83         preempt_disable();      \
  84         __unlazy_fpu(tsk);      \
  85         preempt_enable();       \
  86 } while (0)
  87
  88 #define clear_fpu( tsk ) do {   \
  89         preempt_disable();      \
  90         __clear_fpu( tsk );     \
  91         preempt_enable();       \
  92 } while (0)
  93                                         \
  94 /*
  95  * FPU state interaction...
  96  */
  97 extern unsigned short get_fpu_cwd( struct task_struct *tsk );
  98 extern unsigned short get_fpu_swd( struct task_struct *tsk );
  99 extern unsigned short get_fpu_mxcsr( struct task_struct *tsk );
 100
 101 /*
 102  * Signal frame handlers...
 103  */
 104 extern int save_i387( struct _fpstate __user *buf );
 105 extern int restore_i387( struct _fpstate __user *buf );
 106
 107 /*
 108  * ptrace request handers...
 109  */
 110 extern int get_fpregs( struct user_i387_struct __user *buf,
 111                        struct task_struct *tsk );
 112 extern int set_fpregs( struct task_struct *tsk,
 113                        struct user_i387_struct __user *buf );
 114
 115 extern int get_fpxregs( struct user_fxsr_struct __user *buf,
 116                         struct task_struct *tsk );
 117 extern int set_fpxregs( struct task_struct *tsk,
 118                         struct user_fxsr_struct __user *buf );
 119
 120 /*
 121  * FPU state for core dumps...
 122  */
 123 extern int dump_fpu( struct pt_regs *regs,
 124                      struct user_i387_struct *fpu );
 125
 126 #endif /* __ASM_I386_I387_H */