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  */
11 #ifndef _ASM_FPU_H
12 #define _ASM_FPU_H
13 
14 #include <linux/config.h>
15 #include <linux/sched.h>
16 
17 #include <asm/mipsregs.h>
18 #include <asm/cpu.h>
19 #include <asm/bitops.h>
20 #include <asm/processor.h>
21 #include <asm/current.h>
22 
23 struct sigcontext;
24 struct sigcontext32;
25 
26 extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
27 extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
28 
29 extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
30 extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
31 
32 extern void fpu_emulator_init_fpu(void);
33 extern void _init_fpu(void);
34 extern void _save_fp(struct task_struct *);
35 extern void _restore_fp(struct task_struct *);
36 
37 #if defined(CONFIG_CPU_SB1)
38 #define __enable_fpu_hazard()						\
39 do {									\
40 	asm(".set push		\n\t"					\
41 	    ".set mips64	\n\t"					\
42 	    ".set noreorder	\n\t"					\
43 	    "ssnop		\n\t"					\
44 	    "bnezl $0, .+4	\n\t"					\
45 	    "ssnop		\n\t"					\
46 	    ".set pop");						\
47 } while (0)
48 #else
49 #define __enable_fpu_hazard()                                           \
50 do {                                                                    \
51         asm("nop;nop;nop;nop");         /* max. hazard */               \
52 } while (0)
53 #endif
54 
55 #define __enable_fpu()							\
56 do {									\
57         set_c0_status(ST0_CU1);						\
58         __enable_fpu_hazard();						\
59 } while (0)
60 
61 #define __disable_fpu()							\
62 do {									\
63 	clear_c0_status(ST0_CU1);					\
64 	/* We don't care about the c0 hazard here  */			\
65 } while (0)
66 
67 #define enable_fpu()							\
68 do {									\
69 	if (cpu_has_fpu)						\
70 		__enable_fpu();						\
71 } while (0)
72 
73 #define disable_fpu()							\
74 do {									\
75 	if (cpu_has_fpu)						\
76 		__disable_fpu();					\
77 } while (0)
78 
79 
80 #define clear_fpu_owner() do { current->flags &= ~PF_USEDFPU; } while(0)
81 
is_fpu_owner(void)82 static inline int is_fpu_owner(void)
83 {
84 	return cpu_has_fpu && ((current->flags & PF_USEDFPU) != 0);
85 }
86 
own_fpu(void)87 static inline void own_fpu(void)
88 {
89 	if (cpu_has_fpu) {
90 		__enable_fpu();
91 		KSTK_STATUS(current) |= ST0_CU1;
92 		current->flags |= PF_USEDFPU;
93 	}
94 }
95 
lose_fpu(void)96 static inline void lose_fpu(void)
97 {
98 	if (cpu_has_fpu) {
99 		KSTK_STATUS(current) &= ~ST0_CU1;
100 		current->flags &= ~PF_USEDFPU;
101 		__disable_fpu();
102 	}
103 }
104 
init_fpu(void)105 static inline void init_fpu(void)
106 {
107 	if (cpu_has_fpu) {
108 		_init_fpu();
109 	} else {
110 		fpu_emulator_init_fpu();
111 	}
112 }
113 
save_fp(struct task_struct * tsk)114 static inline void save_fp(struct task_struct *tsk)
115 {
116 	if (cpu_has_fpu)
117 		_save_fp(tsk);
118 }
119 
restore_fp(struct task_struct * tsk)120 static inline void restore_fp(struct task_struct *tsk)
121 {
122 	if (cpu_has_fpu)
123 		_restore_fp(tsk);
124 }
125 
get_fpu_regs(struct task_struct * tsk)126 static inline unsigned long *get_fpu_regs(struct task_struct *tsk)
127 {
128 	if (cpu_has_fpu) {
129 		if ((tsk == current) && is_fpu_owner())
130 			_save_fp(current);
131 		return (unsigned long *)&tsk->thread.fpu.hard.fp_regs[0];
132 	} else {
133 		return (unsigned long *)tsk->thread.fpu.soft.regs;
134 	}
135 }
136 
137 #endif /* _ASM_FPU_H */
138