Linux kernel mirror (for testing)
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linux
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
24struct sigcontext;
25struct sigcontext32;
26
27extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
28extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
29
30extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
31extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
32
33extern void fpu_emulator_init_fpu(void);
34extern void _init_fpu(void);
35extern void _save_fp(struct task_struct *);
36extern void _restore_fp(struct task_struct *);
37
38#if defined(CONFIG_CPU_SB1)
39#define __enable_fpu_hazard() \
40do { \
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() \
51do { \
52 asm("nop;nop;nop;nop"); /* max. hazard */ \
53} while (0)
54#endif
55
56#define __enable_fpu() \
57do { \
58 set_c0_status(ST0_CU1); \
59 __enable_fpu_hazard(); \
60} while (0)
61
62#define __disable_fpu() \
63do { \
64 clear_c0_status(ST0_CU1); \
65 /* We don't care about the c0 hazard here */ \
66} while (0)
67
68#define enable_fpu() \
69do { \
70 if (cpu_has_fpu) \
71 __enable_fpu(); \
72} while (0)
73
74#define disable_fpu() \
75do { \
76 if (cpu_has_fpu) \
77 __disable_fpu(); \
78} while (0)
79
80
81#define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU)
82
83static inline int __is_fpu_owner(void)
84{
85 return test_thread_flag(TIF_USEDFPU);
86}
87
88static inline int is_fpu_owner(void)
89{
90 return cpu_has_fpu && __is_fpu_owner();
91}
92
93static inline void own_fpu(void)
94{
95 if (cpu_has_fpu) {
96 __enable_fpu();
97 KSTK_STATUS(current) |= ST0_CU1;
98 set_thread_flag(TIF_USEDFPU);
99 }
100}
101
102static inline void lose_fpu(void)
103{
104 if (cpu_has_fpu) {
105 KSTK_STATUS(current) &= ~ST0_CU1;
106 clear_thread_flag(TIF_USEDFPU);
107 __disable_fpu();
108 }
109}
110
111static inline void init_fpu(void)
112{
113 if (cpu_has_fpu) {
114 _init_fpu();
115 } else {
116 fpu_emulator_init_fpu();
117 }
118}
119
120static inline void save_fp(struct task_struct *tsk)
121{
122 if (cpu_has_fpu)
123 _save_fp(tsk);
124}
125
126static inline void restore_fp(struct task_struct *tsk)
127{
128 if (cpu_has_fpu)
129 _restore_fp(tsk);
130}
131
132static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
133{
134 if (cpu_has_fpu) {
135 if ((tsk == current) && __is_fpu_owner())
136 _save_fp(current);
137 return tsk->thread.fpu.hard.fpr;
138 }
139
140 return tsk->thread.fpu.soft.fpr;
141}
142
143#endif /* _ASM_FPU_H */