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 struct sigcontext;
  25 struct sigcontext32;
  26
  27 extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
  28 extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
  29
  30 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
  31 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
  32
  33 extern void fpu_emulator_init_fpu(void);
  34 extern void _init_fpu(void);
  35 extern void _save_fp(struct task_struct *);
  36 extern void _restore_fp(struct task_struct *);
  37
  38 #if defined(CONFIG_CPU_SB1)
  39 #define __enable_fpu_hazard()                                           \
  40 do {                                                                    \
  41         asm(".set       push            \n\t"                           \
  42             ".set       mips64          \n\t"                           \
  43             ".set       noreorder       \n\t"                           \
  44             "ssnop                      \n\t"                           \
  45             "bnezl      $0, .+4         \n\t"                           \
  46             "ssnop                      \n\t"                           \
  47             ".set pop");                                                \
  48 } while (0)
  49 #else
  50 #define __enable_fpu_hazard()                                           \
  51 do {                                                                    \
  52         asm("nop;nop;nop;nop");         /* max. hazard */               \
  53 } while (0)
  54 #endif
  55
  56 #define __enable_fpu()                                                  \
  57 do {                                                                    \
  58         set_c0_status(ST0_CU1);                                         \
  59         __enable_fpu_hazard();                                          \
  60 } while (0)
  61
  62 #define __disable_fpu()                                                 \
  63 do {                                                                    \
  64         clear_c0_status(ST0_CU1);                                       \
  65         /* We don't care about the c0 hazard here  */                   \
  66 } while (0)
  67
  68 #define enable_fpu()                                                    \
  69 do {                                                                    \
  70         if (cpu_has_fpu)                                                \
  71                 __enable_fpu();                                         \
  72 } while (0)
  73
  74 #define disable_fpu()                                                   \
  75 do {                                                                    \
  76         if (cpu_has_fpu)                                                \
  77                 __disable_fpu();                                        \
  78 } while (0)
  79
  80
  81 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  82
  83 static inline int is_fpu_owner(void)
  84 {
  85         return cpu_has_fpu && test_thread_flag(TIF_USEDFPU);
  86 }
  87
  88 static inline void own_fpu(void)
  89 {
  90         if (cpu_has_fpu) {
  91                 __enable_fpu();
  92                 KSTK_STATUS(current) |= ST0_CU1;
  93                 set_thread_flag(TIF_USEDFPU);
  94         }
  95 }
  96
  97 static inline void lose_fpu(void)
  98 {
  99         if (cpu_has_fpu) {
 100                 KSTK_STATUS(current) &= ~ST0_CU1;
 101                 clear_thread_flag(TIF_USEDFPU);
 102                 __disable_fpu();
 103         }
 104 }
 105
 106 static inline void init_fpu(void)
 107 {
 108         if (cpu_has_fpu) {
 109                 _init_fpu();
 110         } else {
 111                 fpu_emulator_init_fpu();
 112         }
 113 }
 114
 115 static inline void save_fp(struct task_struct *tsk)
 116 {
 117         if (cpu_has_fpu)
 118                 _save_fp(tsk);
 119 }
 120
 121 static inline void restore_fp(struct task_struct *tsk)
 122 {
 123         if (cpu_has_fpu)
 124                 _restore_fp(tsk);
 125 }
 126
 127 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 128 {
 129         if (cpu_has_fpu) {
 130                 if ((tsk == current) && is_fpu_owner())
 131                         _save_fp(current);
 132                 return tsk->thread.fpu.hard.fpr;
 133         }
 134
 135         return tsk->thread.fpu.soft.fpr;
 136 }
 137
 138 #endif /* _ASM_FPU_H */