linux/arch/nios2/include/asm/switch_to.h
Ley Foon Tan 71995e4d00 nios2: Process management
This patch adds support for thread creation and context switching.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
2014-12-08 12:55:53 +08:00

32 lines
866 B
C

/*
* Copyright (C) 2004 Microtronix Datacom Ltd.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef _ASM_NIOS2_SWITCH_TO_H
#define _ASM_NIOS2_SWITCH_TO_H
/*
* switch_to(n) should switch tasks to task ptr, first checking that
* ptr isn't the current task, in which case it does nothing. This
* also clears the TS-flag if the task we switched to has used the
* math co-processor latest.
*/
#define switch_to(prev, next, last) \
{ \
void *_last; \
__asm__ __volatile__ ( \
"mov r4, %1\n" \
"mov r5, %2\n" \
"call resume\n" \
"mov %0,r4\n" \
: "=r" (_last) \
: "r" (prev), "r" (next) \
: "r4", "r5", "r7", "r8", "ra"); \
(last) = _last; \
}
#endif /* _ASM_NIOS2_SWITCH_TO_H */