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 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc); 32 extern asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc); 33 34 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc); 35 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc); 36 37 extern void fpu_emulator_init_fpu(void); 38 extern int fpu_emulator_save_context(struct sigcontext __user *sc); 39 extern int fpu_emulator_restore_context(struct sigcontext __user *sc); 40 extern void _init_fpu(void); 41 extern void _save_fp(struct task_struct *); 42 extern void _restore_fp(struct task_struct *); 43 44 #define __enable_fpu() \ 45 do { \ 46 set_c0_status(ST0_CU1); \ 47 enable_fpu_hazard(); \ 48 } while (0) 49 50 #define __disable_fpu() \ 51 do { \ 52 clear_c0_status(ST0_CU1); \ 53 disable_fpu_hazard(); \ 54 } while (0) 55 56 #define enable_fpu() \ 57 do { \ 58 if (cpu_has_fpu) \ 59 __enable_fpu(); \ 60 } while (0) 61 62 #define disable_fpu() \ 63 do { \ 64 if (cpu_has_fpu) \ 65 __disable_fpu(); \ 66 } while (0) 67 68 69 #define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU) 70 71 static inline int __is_fpu_owner(void) 72 { 73 return test_thread_flag(TIF_USEDFPU); 74 } 75 76 static inline int is_fpu_owner(void) 77 { 78 return cpu_has_fpu && __is_fpu_owner(); 79 } 80 81 static inline void __own_fpu(void) 82 { 83 __enable_fpu(); 84 KSTK_STATUS(current) |= ST0_CU1; 85 set_thread_flag(TIF_USEDFPU); 86 } 87 88 static inline void own_fpu_inatomic(int restore) 89 { 90 if (cpu_has_fpu && !__is_fpu_owner()) { 91 __own_fpu(); 92 if (restore) 93 _restore_fp(current); 94 } 95 } 96 97 static inline void own_fpu(int restore) 98 { 99 preempt_disable(); 100 own_fpu_inatomic(restore); 101 preempt_enable(); 102 } 103 104 static inline void lose_fpu(int save) 105 { 106 preempt_disable(); 107 if (is_fpu_owner()) { 108 if (save) 109 _save_fp(current); 110 KSTK_STATUS(current) &= ~ST0_CU1; 111 clear_thread_flag(TIF_USEDFPU); 112 __disable_fpu(); 113 } 114 preempt_enable(); 115 } 116 117 static inline void init_fpu(void) 118 { 119 preempt_disable(); 120 if (cpu_has_fpu) { 121 __own_fpu(); 122 _init_fpu(); 123 } else { 124 fpu_emulator_init_fpu(); 125 } 126 preempt_enable(); 127 } 128 129 static inline void save_fp(struct task_struct *tsk) 130 { 131 if (cpu_has_fpu) 132 _save_fp(tsk); 133 } 134 135 static inline void restore_fp(struct task_struct *tsk) 136 { 137 if (cpu_has_fpu) 138 _restore_fp(tsk); 139 } 140 141 static inline fpureg_t *get_fpu_regs(struct task_struct *tsk) 142 { 143 if (tsk == current) { 144 preempt_disable(); 145 if (is_fpu_owner()) 146 _save_fp(current); 147 preempt_enable(); 148 } 149 150 return tsk->thread.fpu.fpr; 151 } 152 153 #endif /* _ASM_FPU_H */ 154