/* SPDX-License-Identifier: GPL-2.0-only */
/*
* arch/arm/lib/call_with_stack.S
*
* Copyright (C) 2011 ARM Ltd.
* Written by Will Deacon <[email protected]>
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unwind.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.
*
* The sequence below follows the APCS frame convention for frame pointer
* unwinding, and implements the unwinder annotations needed by the EABI
* unwinder.
*/
ENTRY(call_with_stack)
#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC)
mov ip, sp
push {fp, ip, lr, pc}
sub fp, ip, #4
#else
UNWIND( .fnstart )
UNWIND( .save {fpreg, lr} )
push {fpreg, lr}
UNWIND( .setfp fpreg, sp )
mov fpreg, sp
#endif
mov sp, r2
mov r2, r0
mov r0, r1
bl_r r2
#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC)
ldmdb fp, {fp, sp, pc}
#else
mov sp, fpreg
pop {fpreg, pc}
UNWIND( .fnend )
#endif
.globl call_with_stack_end
call_with_stack_end:
ENDPROC(call_with_stack)