1/* MN10300 FPU definitions
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from include/asm-i386/i387.h: Copyright (C) 1994 Linus Torvalds
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12#ifndef _ASM_FPU_H
13#define _ASM_FPU_H
14
15#ifndef __ASSEMBLY__
16
17#include <linux/sched.h>
18#include <asm/exceptions.h>
19#include <asm/sigcontext.h>
20
21#ifdef __KERNEL__
22
23extern asmlinkage void fpu_disabled(void);
24
25#ifdef CONFIG_FPU
26
27#ifdef CONFIG_LAZY_SAVE_FPU
28/* the task that currently owns the FPU state */
29extern struct task_struct *fpu_state_owner;
30#endif
31
32#if (THREAD_USING_FPU & ~0xff)
33#error THREAD_USING_FPU must be smaller than 0x100.
34#endif
35
36static inline void set_using_fpu(struct task_struct *tsk)
37{
38	asm volatile(
39		"bset %0,(0,%1)"
40		:
41		: "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
42		: "memory", "cc");
43}
44
45static inline void clear_using_fpu(struct task_struct *tsk)
46{
47	asm volatile(
48		"bclr %0,(0,%1)"
49		:
50		: "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
51		: "memory", "cc");
52}
53
54#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU)
55
56extern asmlinkage void fpu_kill_state(struct task_struct *);
57extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
58extern asmlinkage void fpu_init_state(void);
59extern asmlinkage void fpu_save(struct fpu_state_struct *);
60extern int fpu_setup_sigcontext(struct fpucontext *buf);
61extern int fpu_restore_sigcontext(struct fpucontext *buf);
62
63static inline void unlazy_fpu(struct task_struct *tsk)
64{
65	preempt_disable();
66#ifndef CONFIG_LAZY_SAVE_FPU
67	if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
68		fpu_save(&tsk->thread.fpu_state);
69		tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
70		tsk->thread.uregs->epsw &= ~EPSW_FE;
71	}
72#else
73	if (fpu_state_owner == tsk)
74		fpu_save(&tsk->thread.fpu_state);
75#endif
76	preempt_enable();
77}
78
79static inline void exit_fpu(void)
80{
81#ifdef CONFIG_LAZY_SAVE_FPU
82	struct task_struct *tsk = current;
83
84	preempt_disable();
85	if (fpu_state_owner == tsk)
86		fpu_state_owner = NULL;
87	preempt_enable();
88#endif
89}
90
91static inline void flush_fpu(void)
92{
93	struct task_struct *tsk = current;
94
95	preempt_disable();
96#ifndef CONFIG_LAZY_SAVE_FPU
97	if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
98		tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
99		tsk->thread.uregs->epsw &= ~EPSW_FE;
100	}
101#else
102	if (fpu_state_owner == tsk) {
103		fpu_state_owner = NULL;
104		tsk->thread.uregs->epsw &= ~EPSW_FE;
105	}
106#endif
107	preempt_enable();
108	clear_using_fpu(tsk);
109}
110
111#else /* CONFIG_FPU */
112
113extern asmlinkage
114void unexpected_fpu_exception(struct pt_regs *, enum exception_code);
115#define fpu_exception unexpected_fpu_exception
116
117struct task_struct;
118struct fpu_state_struct;
119static inline bool is_using_fpu(struct task_struct *tsk) { return false; }
120static inline void set_using_fpu(struct task_struct *tsk) {}
121static inline void clear_using_fpu(struct task_struct *tsk) {}
122static inline void fpu_init_state(void) {}
123static inline void fpu_save(struct fpu_state_struct *s) {}
124static inline void fpu_kill_state(struct task_struct *tsk) {}
125static inline void unlazy_fpu(struct task_struct *tsk) {}
126static inline void exit_fpu(void) {}
127static inline void flush_fpu(void) {}
128static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; }
129static inline int fpu_restore_sigcontext(struct fpucontext *buf) { return 0; }
130#endif /* CONFIG_FPU  */
131
132#endif /* __KERNEL__ */
133#endif /* !__ASSEMBLY__ */
134#endif /* _ASM_FPU_H */
135