/*
* arch/arm/lib/call_with_stack.S
*
* Copyright (C) 2011 ARM Ltd.
* Written by Will Deacon <will.deacon@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* void call_with_stack(void (*fn)(void *), void *arg, void *sp)
*
* Change the stack to that pointed at by sp, then invoke fn(arg) with
* the new stack.
*/
ENTRY(call_with_stack)
str sp, [r2, #-4]!
str lr, [r2, #-4]!
mov sp, r2
mov r2, r0
mov r0, r1
adr lr, BSYM(1f)
ret r2
1: ldr lr, [sp]
ldr sp, [sp, #4]
ret lr
ENDPROC(call_with_stack)
