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 void fpu_emulator_init_fpu(void);
  32 extern void _init_fpu(void);
  33 extern void _save_fp(struct task_struct *);
  34 extern void _restore_fp(struct task_struct *);
  35
  36 #define __enable_fpu()                                                  \
  37 do {                                                                    \
  38         set_c0_status(ST0_CU1);                                         \
  39         enable_fpu_hazard();                                            \
  40 } while (0)
  41
  42 #define __disable_fpu()                                                 \
  43 do {                                                                    \
  44         clear_c0_status(ST0_CU1);                                       \
  45         disable_fpu_hazard();                                           \
  46 } while (0)
  47
  48 #define enable_fpu()                                                    \
  49 do {                                                                    \
  50         if (cpu_has_fpu)                                                \
  51                 __enable_fpu();                                         \
  52 } while (0)
  53
  54 #define disable_fpu()                                                   \
  55 do {                                                                    \
  56         if (cpu_has_fpu)                                                \
  57                 __disable_fpu();                                        \
  58 } while (0)
  59
  60
  61 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  62
  63 static inline int __is_fpu_owner(void)
  64 {
  65         return test_thread_flag(TIF_USEDFPU);
  66 }
  67
  68 static inline int is_fpu_owner(void)
  69 {
  70         return cpu_has_fpu && __is_fpu_owner();
  71 }
  72
  73 static inline void __own_fpu(void)
  74 {
  75         __enable_fpu();
  76         KSTK_STATUS(current) |= ST0_CU1;
  77         set_thread_flag(TIF_USEDFPU);
  78 }
  79
  80 static inline void own_fpu_inatomic(int restore)
  81 {
  82         if (cpu_has_fpu && !__is_fpu_owner()) {
  83                 __own_fpu();
  84                 if (restore)
  85                         _restore_fp(current);
  86         }
  87 }
  88
  89 static inline void own_fpu(int restore)
  90 {
  91         preempt_disable();
  92         own_fpu_inatomic(restore);
  93         preempt_enable();
  94 }
  95
  96 static inline void lose_fpu(int save)
  97 {
  98         preempt_disable();
  99         if (is_fpu_owner()) {
 100                 if (save)
 101                         _save_fp(current);
 102                 KSTK_STATUS(current) &= ~ST0_CU1;
 103                 clear_thread_flag(TIF_USEDFPU);
 104                 __disable_fpu();
 105         }
 106         preempt_enable();
 107 }
 108
 109 static inline void init_fpu(void)
 110 {
 111         preempt_disable();
 112         if (cpu_has_fpu) {
 113                 __own_fpu();
 114                 _init_fpu();
 115         } else {
 116                 fpu_emulator_init_fpu();
 117         }
 118         preempt_enable();
 119 }
 120
 121 static inline void save_fp(struct task_struct *tsk)
 122 {
 123         if (cpu_has_fpu)
 124                 _save_fp(tsk);
 125 }
 126
 127 static inline void restore_fp(struct task_struct *tsk)
 128 {
 129         if (cpu_has_fpu)
 130                 _restore_fp(tsk);
 131 }
 132
 133 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 134 {
 135         if (tsk == current) {
 136                 preempt_disable();
 137                 if (is_fpu_owner())
 138                         _save_fp(current);
 139                 preempt_enable();
 140         }
 141
 142         return tsk->thread.fpu.fpr;
 143 }
 144
 145 #endif /* _ASM_FPU_H */