include/asm-i386/i387.h

   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  * FPU lazy state save handling...
  24  */
  25 extern void restore_fpu( struct task_struct *tsk );
  26
  27 extern void kernel_fpu_begin(void);
  28 #define kernel_fpu_end() do { stts(); preempt_enable(); } while(0)
  29
  30 /*
  31  * These must be called with preempt disabled
  32  */
  33 static inline void __save_init_fpu( struct task_struct *tsk )
  34 {
  35         if ( cpu_has_fxsr ) {
  36                 asm volatile( "fxsave %0 ; fnclex"
  37                               : "=m" (tsk->thread.i387.fxsave) );
  38         } else {
  39                 asm volatile( "fnsave %0 ; fwait"
  40                               : "=m" (tsk->thread.i387.fsave) );
  41         }
  42         tsk->thread_info->status &= ~TS_USEDFPU;
  43 }
  44
  45 #define __unlazy_fpu( tsk ) do { \
  46         if ((tsk)->thread_info->status & TS_USEDFPU) \
  47                 save_init_fpu( tsk ); \
  48 } while (0)
  49
  50 #define __clear_fpu( tsk )                                      \
  51 do {                                                            \
  52         if ((tsk)->thread_info->status & TS_USEDFPU) {          \
  53                 asm volatile("fnclex ; fwait");                         \
  54                 (tsk)->thread_info->status &= ~TS_USEDFPU;      \
  55                 stts();                                         \
  56         }                                                       \
  57 } while (0)
  58
  59
  60 /*
  61  * These disable preemption on their own and are safe
  62  */
  63 static inline void save_init_fpu( struct task_struct *tsk )
  64 {
  65         preempt_disable();
  66         __save_init_fpu(tsk);
  67         stts();
  68         preempt_enable();
  69 }
  70
  71 #define unlazy_fpu( tsk ) do {  \
  72         preempt_disable();      \
  73         __unlazy_fpu(tsk);      \
  74         preempt_enable();       \
  75 } while (0)
  76
  77 #define clear_fpu( tsk ) do {   \
  78         preempt_disable();      \
  79         __clear_fpu( tsk );     \
  80         preempt_enable();       \
  81 } while (0)
  82                                         \
  83 /*
  84  * FPU state interaction...
  85  */
  86 extern unsigned short get_fpu_cwd( struct task_struct *tsk );
  87 extern unsigned short get_fpu_swd( struct task_struct *tsk );
  88 extern unsigned short get_fpu_mxcsr( struct task_struct *tsk );
  89
  90 /*
  91  * Signal frame handlers...
  92  */
  93 extern int save_i387( struct _fpstate __user *buf );
  94 extern int restore_i387( struct _fpstate __user *buf );
  95
  96 /*
  97  * ptrace request handers...
  98  */
  99 extern int get_fpregs( struct user_i387_struct __user *buf,
 100                        struct task_struct *tsk );
 101 extern int set_fpregs( struct task_struct *tsk,
 102                        struct user_i387_struct __user *buf );
 103
 104 extern int get_fpxregs( struct user_fxsr_struct __user *buf,
 105                         struct task_struct *tsk );
 106 extern int set_fpxregs( struct task_struct *tsk,
 107                         struct user_fxsr_struct __user *buf );
 108
 109 /*
 110  * FPU state for core dumps...
 111  */
 112 extern int dump_fpu( struct pt_regs *regs,
 113                      struct user_i387_struct *fpu );
 114
 115 #endif /* __ASM_I386_I387_H */