/*
* 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.
*
* Copyright (C) 2001 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
#ifndef _ASM_M32R_SWITCH_TO_H
#define _ASM_M32R_SWITCH_TO_H

/*
* switch_to(prev, next) should switch from task `prev' to `next'
* `prev' will never be the same as `next'.
*
* `next' and `prev' should be struct task_struct, but it isn't always defined
*/

#if defined(CONFIG_FRAME_POINTER) || \
!defined(CONFIG_SCHED_OMIT_FRAME_POINTER)
#define M32R_PUSH_FP " push fp\n"
#define M32R_POP_FP " pop fp\n"
#else
#define M32R_PUSH_FP ""
#define M32R_POP_FP ""
#endif

#define switch_to(prev, next, last) do { \
__asm__ __volatile__ ( \
" seth lr, #high(1f) \n" \
" or3 lr, lr, #low(1f) \n" \
" st lr, @%4 ; store old LR \n" \
" ld lr, @%5 ; load new LR \n" \
M32R_PUSH_FP \
" st sp, @%2 ; store old SP \n" \
" ld sp, @%3 ; load new SP \n" \
" push %1 ; store `prev' on new stack \n" \
" jmp lr \n" \
" .fillinsn \n" \
"1: \n" \
" pop %0 ; restore `__last' from new stack \n" \
M32R_POP_FP \
: "=r" (last) \
: "0" (prev), \
"r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
"r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
: "memory", "lr" \
); \
} while(0)

#endif /* _ASM_M32R_SWITCH_TO_H */