1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * arch/arm/lib/call_with_stack.S
4  *
5  * Copyright (C) 2011 ARM Ltd.
6  * Written by Will Deacon <will.deacon@arm.com>
7  */
8 
9 #include <linux/linkage.h>
10 #include <asm/assembler.h>
11 
12 /*
13  * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
14  *
15  * Change the stack to that pointed at by sp, then invoke fn(arg) with
16  * the new stack.
17  */
18 ENTRY(call_with_stack)
19 	str	sp, [r2, #-4]!
20 	str	lr, [r2, #-4]!
21 
22 	mov	sp, r2
23 	mov	r2, r0
24 	mov	r0, r1
25 
26 	badr	lr, 1f
27 	ret	r2
28 
29 1:	ldr	lr, [sp]
30 	ldr	sp, [sp, #4]
31 	ret	lr
32 ENDPROC(call_with_stack)
33