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#include <asm/unwind.h>
12
13/*
14 * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
15 *
16 * Change the stack to that pointed at by sp, then invoke fn(arg) with
17 * the new stack.
18 *
19 * The sequence below follows the APCS frame convention for frame pointer
20 * unwinding, and implements the unwinder annotations needed by the EABI
21 * unwinder.
22 */
23
24ENTRY(call_with_stack)
25#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC)
26	mov	ip, sp
27	push	{fp, ip, lr, pc}
28	sub	fp, ip, #4
29#else
30UNWIND( .fnstart		)
31UNWIND( .save	{fpreg, lr}	)
32	push	{fpreg, lr}
33UNWIND( .setfp	fpreg, sp	)
34	mov	fpreg, sp
35#endif
36	mov	sp, r2
37	mov	r2, r0
38	mov	r0, r1
39
40	bl_r	r2
 
41
42#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC)
43	ldmdb	fp, {fp, sp, pc}
44#else
45	mov	sp, fpreg
46	pop	{fpreg, pc}
47UNWIND( .fnend			)
48#endif
49	.globl call_with_stack_end
50call_with_stack_end:
51ENDPROC(call_with_stack)

 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 */
 
18ENTRY(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
291:	ldr	lr, [sp]
30	ldr	sp, [sp, #4]
31	ret	lr
 
 
 
 
 
 
32ENDPROC(call_with_stack)