Pileus Git - ~andy/linux/blob - 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 clear_fpu_owner()       clear_thread_flag(TIF_USEDFPU)
  49
  50 static inline int __is_fpu_owner(void)
  51 {
  52         return test_thread_flag(TIF_USEDFPU);
  53 }
  54
  55 static inline int is_fpu_owner(void)
  56 {
  57         return cpu_has_fpu && __is_fpu_owner();
  58 }
  59
  60 static inline void __own_fpu(void)
  61 {
  62         __enable_fpu();
  63         KSTK_STATUS(current) |= ST0_CU1;
  64         set_thread_flag(TIF_USEDFPU);
  65 }
  66
  67 static inline void own_fpu_inatomic(int restore)
  68 {
  69         if (cpu_has_fpu && !__is_fpu_owner()) {
  70                 __own_fpu();
  71                 if (restore)
  72                         _restore_fp(current);
  73         }
  74 }
  75
  76 static inline void own_fpu(int restore)
  77 {
  78         preempt_disable();
  79         own_fpu_inatomic(restore);
  80         preempt_enable();
  81 }
  82
  83 static inline void lose_fpu(int save)
  84 {
  85         preempt_disable();
  86         if (is_fpu_owner()) {
  87                 if (save)
  88                         _save_fp(current);
  89                 KSTK_STATUS(current) &= ~ST0_CU1;
  90                 clear_thread_flag(TIF_USEDFPU);
  91                 __disable_fpu();
  92         }
  93         preempt_enable();
  94 }
  95
  96 static inline void init_fpu(void)
  97 {
  98         preempt_disable();
  99         if (cpu_has_fpu) {
 100                 __own_fpu();
 101                 _init_fpu();
 102         } else {
 103                 fpu_emulator_init_fpu();
 104         }
 105         preempt_enable();
 106 }
 107
 108 static inline void save_fp(struct task_struct *tsk)
 109 {
 110         if (cpu_has_fpu)
 111                 _save_fp(tsk);
 112 }
 113
 114 static inline void restore_fp(struct task_struct *tsk)
 115 {
 116         if (cpu_has_fpu)
 117                 _restore_fp(tsk);
 118 }
 119
 120 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 121 {
 122         if (tsk == current) {
 123                 preempt_disable();
 124                 if (is_fpu_owner())
 125                         _save_fp(current);
 126                 preempt_enable();
 127         }
 128
 129         return tsk->thread.fpu.fpr;
 130 }
 131
 132 #endif /* _ASM_FPU_H */