include/asm-mips64/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  */
  11 #ifndef _ASM_FPU_H
  12 #define _ASM_FPU_H
  13
  14 #include <linux/config.h>
  15 #include <linux/sched.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 struct sigcontext32;
  25
  26 extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
  27 extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
  28
  29 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
  30 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
  31
  32 extern void fpu_emulator_init_fpu(void);
  33 extern void _init_fpu(void);
  34 extern void _save_fp(struct task_struct *);
  35 extern void _restore_fp(struct task_struct *);
  36
  37 #if defined(CONFIG_CPU_SB1)
  38 #define __enable_fpu_hazard()                                           \
  39 do {                                                                    \
  40         asm(".set push          \n\t"                                   \
  41             ".set mips64        \n\t"                                   \
  42             ".set noreorder     \n\t"                                   \
  43             "ssnop              \n\t"                                   \
  44             "bnezl $0, .+4      \n\t"                                   \
  45             "ssnop              \n\t"                                   \
  46             ".set pop");                                                \
  47 } while (0)
  48 #else
  49 #define __enable_fpu_hazard()                                           \
  50 do {                                                                    \
  51         asm("nop;nop;nop;nop");         /* max. hazard */               \
  52 } while (0)
  53 #endif
  54
  55 #define __enable_fpu()                                                  \
  56 do {                                                                    \
  57         set_c0_status(ST0_CU1);                                         \
  58         __enable_fpu_hazard();                                          \
  59 } while (0)
  60
  61 #define __disable_fpu()                                                 \
  62 do {                                                                    \
  63         clear_c0_status(ST0_CU1);                                       \
  64         /* We don't care about the c0 hazard here  */                   \
  65 } while (0)
  66
  67 #define enable_fpu()                                                    \
  68 do {                                                                    \
  69         if (cpu_has_fpu)                                                \
  70                 __enable_fpu();                                         \
  71 } while (0)
  72
  73 #define disable_fpu()                                                   \
  74 do {                                                                    \
  75         if (cpu_has_fpu)                                                \
  76                 __disable_fpu();                                        \
  77 } while (0)
  78
  79
  80 #define clear_fpu_owner() do { current->flags &= ~PF_USEDFPU; } while(0)
  81
  82 static inline int is_fpu_owner(void)
  83 {
  84         return cpu_has_fpu && ((current->flags & PF_USEDFPU) != 0);
  85 }
  86
  87 static inline void own_fpu(void)
  88 {
  89         if (cpu_has_fpu) {
  90                 __enable_fpu();
  91                 KSTK_STATUS(current) |= ST0_CU1;
  92                 current->flags |= PF_USEDFPU;
  93         }
  94 }
  95
  96 static inline void lose_fpu(void)
  97 {
  98         if (cpu_has_fpu) {
  99                 KSTK_STATUS(current) &= ~ST0_CU1;
 100                 current->flags &= ~PF_USEDFPU;
 101                 __disable_fpu();
 102         }
 103 }
 104
 105 static inline void init_fpu(void)
 106 {
 107         if (cpu_has_fpu) {
 108                 _init_fpu();
 109         } else {
 110                 fpu_emulator_init_fpu();
 111         }
 112 }
 113
 114 static inline void save_fp(struct task_struct *tsk)
 115 {
 116         if (cpu_has_fpu)
 117                 _save_fp(tsk);
 118 }
 119
 120 static inline void restore_fp(struct task_struct *tsk)
 121 {
 122         if (cpu_has_fpu)
 123                 _restore_fp(tsk);
 124 }
 125
 126 static inline unsigned long *get_fpu_regs(struct task_struct *tsk)
 127 {
 128         if (cpu_has_fpu) {
 129                 if ((tsk == current) && is_fpu_owner())
 130                         _save_fp(current);
 131                 return (unsigned long *)&tsk->thread.fpu.hard.fp_regs[0];
 132         } else {
 133                 return (unsigned long *)tsk->thread.fpu.soft.regs;
 134         }
 135 }
 136
 137 #endif /* _ASM_FPU_H */