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/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/bitops.h>
20#include <asm/processor.h>
21#include <asm/current.h>
22
23#ifdef CONFIG_MIPS_MT_FPAFF
24#include <asm/mips_mt.h>
25#endif
26
27struct sigcontext;
28struct sigcontext32;
29
30extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
31extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
32
33extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
34extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
35
36extern void fpu_emulator_init_fpu(void);
37extern void _init_fpu(void);
38extern void _save_fp(struct task_struct *);
39extern void _restore_fp(struct task_struct *);
40
41#if defined(CONFIG_CPU_SB1)
42#define __enable_fpu_hazard() \
43do { \
44 asm(".set push \n\t" \
45 ".set mips64 \n\t" \
46 ".set noreorder \n\t" \
47 "ssnop \n\t" \
48 "bnezl $0, .+4 \n\t" \
49 "ssnop \n\t" \
50 ".set pop"); \
51} while (0)
52#else
53#define __enable_fpu_hazard() \
54do { \
55 asm("nop;nop;nop;nop"); /* max. hazard */ \
56} while (0)
57#endif
58
59#define __enable_fpu() \
60do { \
61 set_c0_status(ST0_CU1); \
62 __enable_fpu_hazard(); \
63} while (0)
64
65#define __disable_fpu() \
66do { \
67 clear_c0_status(ST0_CU1); \
68 /* We don't care about the c0 hazard here */ \
69} while (0)
70
71#define enable_fpu() \
72do { \
73 if (cpu_has_fpu) \
74 __enable_fpu(); \
75} while (0)
76
77#define disable_fpu() \
78do { \
79 if (cpu_has_fpu) \
80 __disable_fpu(); \
81} while (0)
82
83
84#define clear_fpu_owner() clear_thread_flag(TIF_USEDFPU)
85
86static inline int __is_fpu_owner(void)
87{
88 return test_thread_flag(TIF_USEDFPU);
89}
90
91static inline int is_fpu_owner(void)
92{
93 return cpu_has_fpu && __is_fpu_owner();
94}
95
96static inline void own_fpu(void)
97{
98 if (cpu_has_fpu) {
99 __enable_fpu();
100 KSTK_STATUS(current) |= ST0_CU1;
101 set_thread_flag(TIF_USEDFPU);
102 }
103}
104
105static inline void lose_fpu(void)
106{
107 if (cpu_has_fpu) {
108 KSTK_STATUS(current) &= ~ST0_CU1;
109 clear_thread_flag(TIF_USEDFPU);
110 __disable_fpu();
111 }
112}
113
114static inline void init_fpu(void)
115{
116 if (cpu_has_fpu) {
117 _init_fpu();
118 } else {
119 fpu_emulator_init_fpu();
120 }
121}
122
123static inline void save_fp(struct task_struct *tsk)
124{
125 if (cpu_has_fpu)
126 _save_fp(tsk);
127}
128
129static inline void restore_fp(struct task_struct *tsk)
130{
131 if (cpu_has_fpu)
132 _restore_fp(tsk);
133}
134
135static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
136{
137 if (tsk == current) {
138 preempt_disable();
139 if (is_fpu_owner())
140 _save_fp(current);
141 preempt_enable();
142 }
143
144 return tsk->thread.fpu.fpr;
145}
146
147#endif /* _ASM_FPU_H */