Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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/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 */