1/* MN10300 task switching definitions
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#ifndef _ASM_SWITCH_TO_H
12#define _ASM_SWITCH_TO_H
13
14#include <asm/barrier.h>
15
16struct task_struct;
17struct thread_struct;
18
19#if !defined(CONFIG_LAZY_SAVE_FPU)
20struct fpu_state_struct;
21extern asmlinkage void fpu_save(struct fpu_state_struct *);
22#define switch_fpu(prev, next)						\
23	do {								\
24		if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) {	\
25			(prev)->thread.fpu_flags &= ~THREAD_HAS_FPU;	\
26			(prev)->thread.uregs->epsw &= ~EPSW_FE;		\
27			fpu_save(&(prev)->thread.fpu_state);		\
28		}							\
29	} while (0)
30#else
31#define switch_fpu(prev, next) do {} while (0)
32#endif
33
34/* context switching is now performed out-of-line in switch_to.S */
35extern asmlinkage
36struct task_struct *__switch_to(struct thread_struct *prev,
37				struct thread_struct *next,
38				struct task_struct *prev_task);
39
40#define switch_to(prev, next, last)					\
41do {									\
42	switch_fpu(prev, next);						\
43	current->thread.wchan = (u_long) __builtin_return_address(0);	\
44	(last) = __switch_to(&(prev)->thread, &(next)->thread, (prev));	\
45	mb();								\
46	current->thread.wchan = 0;					\
47} while (0)
48
49#endif /* _ASM_SWITCH_TO_H */
50