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