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 16#include <asm/mipsregs.h> 17#include <asm/cpu.h> 18#include <asm/cpu-features.h> 19#include <asm/hazards.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 28struct sigcontext; 29struct sigcontext32; 30 31extern asmlinkage int (*save_fp_context)(struct sigcontext __user *sc); 32extern asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc); 33 34extern asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc); 35extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc); 36 37extern void fpu_emulator_init_fpu(void); 38extern void _init_fpu(void); 39extern void _save_fp(struct task_struct *); 40extern void _restore_fp(struct task_struct *); 41 42#define __enable_fpu() \ 43do { \ 44 set_c0_status(ST0_CU1); \ 45 enable_fpu_hazard(); \ 46} while (0) 47 48#define __disable_fpu() \ 49do { \ 50 clear_c0_status(ST0_CU1); \ 51 disable_fpu_hazard(); \ 52} while (0) 53 54#define enable_fpu() \ 55do { \ 56 if (cpu_has_fpu) \ 57 __enable_fpu(); \ 58} while (0) 59 60#define disable_fpu() \ 61do { \ 62 if (cpu_has_fpu) \ 63 __disable_fpu(); \ 64} while (0) 65 66 67#define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU) 68 69static inline int __is_fpu_owner(void) 70{ 71 return test_thread_flag(TIF_USEDFPU); 72} 73 74static inline int is_fpu_owner(void) 75{ 76 return cpu_has_fpu && __is_fpu_owner(); 77} 78 79static inline void __own_fpu(void) 80{ 81 __enable_fpu(); 82 KSTK_STATUS(current) |= ST0_CU1; 83 set_thread_flag(TIF_USEDFPU); 84} 85 86static inline void own_fpu_inatomic(int restore) 87{ 88 if (cpu_has_fpu && !__is_fpu_owner()) { 89 __own_fpu(); 90 if (restore) 91 _restore_fp(current); 92 } 93} 94 95static inline void own_fpu(int restore) 96{ 97 preempt_disable(); 98 own_fpu_inatomic(restore); 99 preempt_enable(); 100} 101 102static inline void lose_fpu(int save) 103{ 104 preempt_disable(); 105 if (is_fpu_owner()) { 106 if (save) 107 _save_fp(current); 108 KSTK_STATUS(current) &= ~ST0_CU1; 109 clear_thread_flag(TIF_USEDFPU); 110 __disable_fpu(); 111 } 112 preempt_enable(); 113} 114 115static inline void init_fpu(void) 116{ 117 preempt_disable(); 118 if (cpu_has_fpu) { 119 __own_fpu(); 120 _init_fpu(); 121 } else { 122 fpu_emulator_init_fpu(); 123 } 124 preempt_enable(); 125} 126 127static inline void save_fp(struct task_struct *tsk) 128{ 129 if (cpu_has_fpu) 130 _save_fp(tsk); 131} 132 133static inline void restore_fp(struct task_struct *tsk) 134{ 135 if (cpu_has_fpu) 136 _restore_fp(tsk); 137} 138 139static inline fpureg_t *get_fpu_regs(struct task_struct *tsk) 140{ 141 if (tsk == current) { 142 preempt_disable(); 143 if (is_fpu_owner()) 144 _save_fp(current); 145 preempt_enable(); 146 } 147 148 return tsk->thread.fpu.fpr; 149} 150 151#endif /* _ASM_FPU_H */ 152