include/asm-mips/fpu.h

   1 /*
   2  * Copyright (C) 2002 MontaVista Software Inc.
   3  * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation;  either version 2 of the  License, or (at your
   8  * option) any later version.
   9  */
  10 #ifndef _ASM_FPU_H
  11 #define _ASM_FPU_H
  12
  13 #include <linux/sched.h>
  14 #include <linux/thread_info.h>
  15 #include <linux/bitops.h>
  16
  17 #include <asm/mipsregs.h>
  18 #include <asm/cpu.h>
  19 #include <asm/cpu-features.h>
  20 #include <asm/hazards.h>
  21 #include <asm/processor.h>
  22 #include <asm/current.h>
  23
  24 #ifdef CONFIG_MIPS_MT_FPAFF
  25 #include <asm/mips_mt.h>
  26 #endif
  27
  28 struct sigcontext;
  29 struct sigcontext32;
  30
  31 extern asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
  32 extern asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
  33
  34 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
  35 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
  36
  37 extern void fpu_emulator_init_fpu(void);
  38 extern void _init_fpu(void);
  39 extern void _save_fp(struct task_struct *);
  40 extern void _restore_fp(struct task_struct *);
  41
  42 #define __enable_fpu()                                                  \
  43 do {                                                                    \
  44         set_c0_status(ST0_CU1);                                         \
  45         enable_fpu_hazard();                                            \
  46 } while (0)
  47
  48 #define __disable_fpu()                                                 \
  49 do {                                                                    \
  50         clear_c0_status(ST0_CU1);                                       \
  51         disable_fpu_hazard();                                           \
  52 } while (0)
  53
  54 #define enable_fpu()                                                    \
  55 do {                                                                    \
  56         if (cpu_has_fpu)                                                \
  57                 __enable_fpu();                                         \
  58 } while (0)
  59
  60 #define disable_fpu()                                                   \
  61 do {                                                                    \
  62         if (cpu_has_fpu)                                                \
  63                 __disable_fpu();                                        \
  64 } while (0)
  65
  66
  67 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  68
  69 static inline int __is_fpu_owner(void)
  70 {
  71         return test_thread_flag(TIF_USEDFPU);
  72 }
  73
  74 static inline int is_fpu_owner(void)
  75 {
  76         return cpu_has_fpu && __is_fpu_owner();
  77 }
  78
  79 static inline void __own_fpu(void)
  80 {
  81         __enable_fpu();
  82         KSTK_STATUS(current) |= ST0_CU1;
  83         set_thread_flag(TIF_USEDFPU);
  84 }
  85
  86 static inline void own_fpu_inatomic(int restore)
  87 {
  88         if (cpu_has_fpu && !__is_fpu_owner()) {
  89                 __own_fpu();
  90                 if (restore)
  91                         _restore_fp(current);
  92         }
  93 }
  94
  95 static inline void own_fpu(int restore)
  96 {
  97         preempt_disable();
  98         own_fpu_inatomic(restore);
  99         preempt_enable();
 100 }
 101
 102 static inline void lose_fpu(int save)
 103 {
 104         preempt_disable();
 105         if (is_fpu_owner()) {
 106                 if (save)
 107                         _save_fp(current);
 108                 KSTK_STATUS(current) &= ~ST0_CU1;
 109                 clear_thread_flag(TIF_USEDFPU);
 110                 __disable_fpu();
 111         }
 112         preempt_enable();
 113 }
 114
 115 static inline void init_fpu(void)
 116 {
 117         preempt_disable();
 118         if (cpu_has_fpu) {
 119                 __own_fpu();
 120                 _init_fpu();
 121         } else {
 122                 fpu_emulator_init_fpu();
 123         }
 124         preempt_enable();
 125 }
 126
 127 static inline void save_fp(struct task_struct *tsk)
 128 {
 129         if (cpu_has_fpu)
 130                 _save_fp(tsk);
 131 }
 132
 133 static inline void restore_fp(struct task_struct *tsk)
 134 {
 135         if (cpu_has_fpu)
 136                 _restore_fp(tsk);
 137 }
 138
 139 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 140 {
 141         if (tsk == current) {
 142                 preempt_disable();
 143                 if (is_fpu_owner())
 144                         _save_fp(current);
 145                 preempt_enable();
 146         }
 147
 148         return tsk->thread.fpu.fpr;
 149 }
 150
 151 #endif /* _ASM_FPU_H */