xref: /openbmc/linux/arch/arm/lib/call_with_stack.S (revision 63dc02bd)
1/*
2 * arch/arm/lib/call_with_stack.S
3 *
4 * Copyright (C) 2011 ARM Ltd.
5 * Written by Will Deacon <will.deacon@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/linkage.h>
22#include <asm/assembler.h>
23
24/*
25 * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
26 *
27 * Change the stack to that pointed at by sp, then invoke fn(arg) with
28 * the new stack.
29 */
30ENTRY(call_with_stack)
31	str	sp, [r2, #-4]!
32	str	lr, [r2, #-4]!
33
34	mov	sp, r2
35	mov	r2, r0
36	mov	r0, r1
37
38	adr	lr, BSYM(1f)
39	mov	pc, r2
40
411:	ldr	lr, [sp]
42	ldr	sp, [sp, #4]
43	mov	pc, lr
44ENDPROC(call_with_stack)
45