| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/cpu-features.h> |
| 20 | #include <asm/bitops.h> |
| 21 | #include <asm/processor.h> |
| 22 | #include <asm/current.h> |
| 23 | |
| 24 | struct sigcontext; |
| 25 | struct sigcontext32; |
| 26 | |
| 27 | extern asmlinkage int (*save_fp_context)(struct sigcontext *sc); |
| 28 | extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc); |
| 29 | |
| 30 | extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc); |
| 31 | extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc); |
| 32 | |
| 33 | extern void fpu_emulator_init_fpu(void); |
| 34 | extern void _init_fpu(void); |
| 35 | extern void _save_fp(struct task_struct *); |
| 36 | extern void _restore_fp(struct task_struct *); |
| 37 | |
| 38 | #if defined(CONFIG_CPU_SB1) |
| 39 | #define __enable_fpu_hazard() \ |
| 40 | do { \ |
| 41 | asm(".set push \n\t" \ |
| 42 | ".set mips64 \n\t" \ |
| 43 | ".set noreorder \n\t" \ |
| 44 | "ssnop \n\t" \ |
| 45 | "bnezl $0, .+4 \n\t" \ |
| 46 | "ssnop \n\t" \ |
| 47 | ".set pop"); \ |
| 48 | } while (0) |
| 49 | #else |
| 50 | #define __enable_fpu_hazard() \ |
| 51 | do { \ |
| 52 | asm("nop;nop;nop;nop"); /* max. hazard */ \ |
| 53 | } while (0) |
| 54 | #endif |
| 55 | |
| 56 | #define __enable_fpu() \ |
| 57 | do { \ |
| 58 | set_c0_status(ST0_CU1); \ |
| 59 | __enable_fpu_hazard(); \ |
| 60 | } while (0) |
| 61 | |
| 62 | #define __disable_fpu() \ |
| 63 | do { \ |
| 64 | clear_c0_status(ST0_CU1); \ |
| 65 | /* We don't care about the c0 hazard here */ \ |
| 66 | } while (0) |
| 67 | |
| 68 | #define enable_fpu() \ |
| 69 | do { \ |
| 70 | if (cpu_has_fpu) \ |
| 71 | __enable_fpu(); \ |
| 72 | } while (0) |
| 73 | |
| 74 | #define disable_fpu() \ |
| 75 | do { \ |
| 76 | if (cpu_has_fpu) \ |
| 77 | __disable_fpu(); \ |
| 78 | } while (0) |
| 79 | |
| 80 | |
| 81 | #define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU) |
| 82 | |
| 83 | static inline int is_fpu_owner(void) |
| 84 | { |
| 85 | return cpu_has_fpu && test_thread_flag(TIF_USEDFPU); |
| 86 | } |
| 87 | |
| 88 | static inline void own_fpu(void) |
| 89 | { |
| 90 | if (cpu_has_fpu) { |
| 91 | __enable_fpu(); |
| 92 | KSTK_STATUS(current) |= ST0_CU1; |
| 93 | set_thread_flag(TIF_USEDFPU); |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | static inline void lose_fpu(void) |
| 98 | { |
| 99 | if (cpu_has_fpu) { |
| 100 | KSTK_STATUS(current) &= ~ST0_CU1; |
| 101 | clear_thread_flag(TIF_USEDFPU); |
| 102 | __disable_fpu(); |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | static inline void init_fpu(void) |
| 107 | { |
| 108 | if (cpu_has_fpu) { |
| 109 | _init_fpu(); |
| 110 | } else { |
| 111 | fpu_emulator_init_fpu(); |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | static inline void save_fp(struct task_struct *tsk) |
| 116 | { |
| 117 | if (cpu_has_fpu) |
| 118 | _save_fp(tsk); |
| 119 | } |
| 120 | |
| 121 | static inline void restore_fp(struct task_struct *tsk) |
| 122 | { |
| 123 | if (cpu_has_fpu) |
| 124 | _restore_fp(tsk); |
| 125 | } |
| 126 | |
| 127 | static inline fpureg_t *get_fpu_regs(struct task_struct *tsk) |
| 128 | { |
| 129 | if (cpu_has_fpu) { |
| 130 | if ((tsk == current) && is_fpu_owner()) |
| 131 | _save_fp(current); |
| 132 | return tsk->thread.fpu.hard.fpr; |
| 133 | } |
| 134 | |
| 135 | return tsk->thread.fpu.soft.fpr; |
| 136 | } |
| 137 | |
| 138 | #endif /* _ASM_FPU_H */ |