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/bitops.h>
  20 #include <asm/processor.h>
  21 #include <asm/current.h>
  22
  23 struct sigcontext;
  24
  25 extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
  26 extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
  27
  28 extern void fpu_emulator_init_fpu(void);
  29 extern void _init_fpu(void);
  30 extern void _save_fp(struct task_struct *);
  31 extern void _restore_fp(struct task_struct *);
  32
  33 #if defined(CONFIG_CPU_SB1)
  34 #define __enable_fpu_hazard()                                           \
  35 do {                                                                    \
  36         asm(".set       push            \n\t"                           \
  37             ".set       mips64          \n\t"                           \
  38             ".set       noreorder       \n\t"                           \
  39             "ssnop                      \n\t"                           \
  40             "bnezl      $0, .+4         \n\t"                           \
  41             "ssnop                      \n\t"                           \
  42             ".set pop");                                                \
  43 } while (0)
  44 #else
  45 #define __enable_fpu_hazard()                                           \
  46 do {                                                                    \
  47         asm("nop;nop;nop;nop");         /* max. hazard */               \
  48 } while (0)
  49 #endif
  50
  51 #define __enable_fpu()                                                  \
  52 do {                                                                    \
  53         set_c0_status(ST0_CU1);                                         \
  54         __enable_fpu_hazard();                                          \
  55 } while (0)
  56
  57 #define __disable_fpu()                                                 \
  58 do {                                                                    \
  59         clear_c0_status(ST0_CU1);                                       \
  60         /* We don't care about the c0 hazard here  */                   \
  61 } while (0)
  62
  63 #define enable_fpu()                                                    \
  64 do {                                                                    \
  65         if (cpu_has_fpu)                                                \
  66                 __enable_fpu();                                         \
  67 } while (0)
  68
  69 #define disable_fpu()                                                   \
  70 do {                                                                    \
  71         if (cpu_has_fpu)                                                \
  72                 __disable_fpu();                                        \
  73 } while (0)
  74
  75
  76 #define clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  77
  78 static inline int is_fpu_owner(void)
  79 {
  80         return cpu_has_fpu && test_thread_flag(TIF_USEDFPU);
  81 }
  82
  83 static inline void own_fpu(void)
  84 {
  85         if (cpu_has_fpu) {
  86                 __enable_fpu();
  87                 KSTK_STATUS(current) |= ST0_CU1;
  88                 set_thread_flag(TIF_USEDFPU);
  89         }
  90 }
  91
  92 static inline void loose_fpu(void)
  93 {
  94         if (cpu_has_fpu) {
  95                 KSTK_STATUS(current) &= ~ST0_CU1;
  96                 clear_thread_flag(TIF_USEDFPU);
  97                 __disable_fpu();
  98         }
  99 }
 100
 101 static inline void init_fpu(void)
 102 {
 103         if (cpu_has_fpu) {
 104                 _init_fpu();
 105         } else {
 106                 fpu_emulator_init_fpu();
 107         }
 108 }
 109
 110 static inline void save_fp(struct task_struct *tsk)
 111 {
 112         if (cpu_has_fpu)
 113                 _save_fp(tsk);
 114 }
 115
 116 static inline void restore_fp(struct task_struct *tsk)
 117 {
 118         if (cpu_has_fpu)
 119                 _restore_fp(tsk);
 120 }
 121
 122 static inline unsigned long long *get_fpu_regs(struct task_struct *tsk)
 123 {
 124         if (cpu_has_fpu) {
 125                 if ((tsk == current) && is_fpu_owner())
 126                         _save_fp(current);
 127                 return (unsigned long long *)&tsk->thread.fpu.hard.fp_regs[0];
 128         } else {
 129                 return (unsigned long long *)tsk->thread.fpu.soft.regs;
 130         }
 131 }
 132
 133 #endif /* _ASM_FPU_H */