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/config.h>
  14 #include <linux/sched.h>
  15 #include <linux/thread_info.h>
  16
  17 #include <asm/mipsregs.h>
  18 #include <asm/cpu.h>
  19 #include <asm/cpu-features.h>
  20 #include <asm/bitops.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 *sc);
  32 extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
  33
  34 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
  35 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *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 #if defined(CONFIG_CPU_SB1)
  43 #define __enable_fpu_hazard()                                           \
  44 do {                                                                    \
  45         asm(".set       push            \n\t"                           \
  46             ".set       mips64          \n\t"                           \
  47             ".set       noreorder       \n\t"                           \
  48             "ssnop                      \n\t"                           \
  49             "bnezl      $0, .+4         \n\t"                           \
  50             "ssnop                      \n\t"                           \
  51             ".set pop");                                                \
  52 } while (0)
  53 #else
  54 #define __enable_fpu_hazard()                                           \
  55 do {                                                                    \
  56         asm("nop;nop;nop;nop");         /* max. hazard */               \
  57 } while (0)
  58 #endif
  59
  60 #define __enable_fpu()                                                  \
  61 do {                                                                    \
  62         set_c0_status(ST0_CU1);                                         \
  63         __enable_fpu_hazard();                                          \
  64 } while (0)
  65
  66 #define __disable_fpu()                                                 \
  67 do {                                                                    \
  68         clear_c0_status(ST0_CU1);                                       \
  69         /* We don't care about the c0 hazard here  */                   \
  70 } while (0)
  71
  72 #define enable_fpu()                                                    \
  73 do {                                                                    \
  74         if (cpu_has_fpu)                                                \
  75                 __enable_fpu();                                         \
  76 } while (0)
  77
  78 #define disable_fpu()                                                   \
  79 do {                                                                    \
  80         if (cpu_has_fpu)                                                \
  81                 __disable_fpu();                                        \
  82 } while (0)
  83
  84
  85 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  86
  87 static inline int __is_fpu_owner(void)
  88 {
  89         return test_thread_flag(TIF_USEDFPU);
  90 }
  91
  92 static inline int is_fpu_owner(void)
  93 {
  94         return cpu_has_fpu && __is_fpu_owner();
  95 }
  96
  97 static inline void own_fpu(void)
  98 {
  99         if (cpu_has_fpu) {
 100                 __enable_fpu();
 101                 KSTK_STATUS(current) |= ST0_CU1;
 102                 set_thread_flag(TIF_USEDFPU);
 103         }
 104 }
 105
 106 static inline void lose_fpu(void)
 107 {
 108         if (cpu_has_fpu) {
 109                 KSTK_STATUS(current) &= ~ST0_CU1;
 110                 clear_thread_flag(TIF_USEDFPU);
 111                 __disable_fpu();
 112         }
 113 }
 114
 115 static inline void init_fpu(void)
 116 {
 117         if (cpu_has_fpu) {
 118                 _init_fpu();
 119         } else {
 120                 fpu_emulator_init_fpu();
 121         }
 122 }
 123
 124 static inline void save_fp(struct task_struct *tsk)
 125 {
 126         if (cpu_has_fpu)
 127                 _save_fp(tsk);
 128 }
 129
 130 static inline void restore_fp(struct task_struct *tsk)
 131 {
 132         if (cpu_has_fpu)
 133                 _restore_fp(tsk);
 134 }
 135
 136 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 137 {
 138         if (cpu_has_fpu) {
 139                 if ((tsk == current) && __is_fpu_owner())
 140                         _save_fp(current);
 141                 return tsk->thread.fpu.hard.fpr;
 142         }
 143
 144         return tsk->thread.fpu.soft.fpr;
 145 }
 146
 147 #endif /* _ASM_FPU_H */