arch/mips/include/asm/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 int fpu_emulator_save_context(struct sigcontext __user *sc);
  39 extern int fpu_emulator_restore_context(struct sigcontext __user *sc);
  40 extern void _init_fpu(void);
  41 extern void _save_fp(struct task_struct *);
  42 extern void _restore_fp(struct task_struct *);
  43
  44 #define __enable_fpu()                                                  \
  45 do {                                                                    \
  46         set_c0_status(ST0_CU1);                                         \
  47         enable_fpu_hazard();                                            \
  48 } while (0)
  49
  50 #define __disable_fpu()                                                 \
  51 do {                                                                    \
  52         clear_c0_status(ST0_CU1);                                       \
  53         disable_fpu_hazard();                                           \
  54 } while (0)
  55
  56 #define enable_fpu()                                                    \
  57 do {                                                                    \
  58         if (cpu_has_fpu)                                                \
  59                 __enable_fpu();                                         \
  60 } while (0)
  61
  62 #define disable_fpu()                                                   \
  63 do {                                                                    \
  64         if (cpu_has_fpu)                                                \
  65                 __disable_fpu();                                        \
  66 } while (0)
  67
  68
  69 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  70
  71 static inline int __is_fpu_owner(void)
  72 {
  73         return test_thread_flag(TIF_USEDFPU);
  74 }
  75
  76 static inline int is_fpu_owner(void)
  77 {
  78         return cpu_has_fpu && __is_fpu_owner();
  79 }
  80
  81 static inline void __own_fpu(void)
  82 {
  83         __enable_fpu();
  84         KSTK_STATUS(current) |= ST0_CU1;
  85         set_thread_flag(TIF_USEDFPU);
  86 }
  87
  88 static inline void own_fpu_inatomic(int restore)
  89 {
  90         if (cpu_has_fpu && !__is_fpu_owner()) {
  91                 __own_fpu();
  92                 if (restore)
  93                         _restore_fp(current);
  94         }
  95 }
  96
  97 static inline void own_fpu(int restore)
  98 {
  99         preempt_disable();
 100         own_fpu_inatomic(restore);
 101         preempt_enable();
 102 }
 103
 104 static inline void lose_fpu(int save)
 105 {
 106         preempt_disable();
 107         if (is_fpu_owner()) {
 108                 if (save)
 109                         _save_fp(current);
 110                 KSTK_STATUS(current) &= ~ST0_CU1;
 111                 clear_thread_flag(TIF_USEDFPU);
 112                 __disable_fpu();
 113         }
 114         preempt_enable();
 115 }
 116
 117 static inline void init_fpu(void)
 118 {
 119         preempt_disable();
 120         if (cpu_has_fpu) {
 121                 __own_fpu();
 122                 _init_fpu();
 123         } else {
 124                 fpu_emulator_init_fpu();
 125         }
 126         preempt_enable();
 127 }
 128
 129 static inline void save_fp(struct task_struct *tsk)
 130 {
 131         if (cpu_has_fpu)
 132                 _save_fp(tsk);
 133 }
 134
 135 static inline void restore_fp(struct task_struct *tsk)
 136 {
 137         if (cpu_has_fpu)
 138                 _restore_fp(tsk);
 139 }
 140
 141 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 142 {
 143         if (tsk == current) {
 144                 preempt_disable();
 145                 if (is_fpu_owner())
 146                         _save_fp(current);
 147                 preempt_enable();
 148         }
 149
 150         return tsk->thread.fpu.fpr;
 151 }
 152
 153 #endif /* _ASM_FPU_H */