xref: /linux/arch/arm64/kernel/kuser32.S (revision 2697b79a469b68e3ad3640f55284359c1396278d)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * AArch32 user helpers.
4 * Based on the kuser helpers in arch/arm/kernel/entry-armv.S.
5 *
6 * Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net>
7 * Copyright (C) 2012-2018 ARM Ltd.
8 *
9 * The kuser helpers below are mapped at a fixed address by
10 * aarch32_setup_additional_pages() and are provided for compatibility
11 * reasons with 32 bit (aarch32) applications that need them.
12 *
13 * See Documentation/arch/arm/kernel_user_helpers.rst for formal definitions.
14 */
15
16#include <asm/unistd.h>
17
18	.section .rodata
19	.align	5
20	.globl	__kuser_helper_start
21__kuser_helper_start:
22
23__kuser_cmpxchg64:			// 0xffff0f60
24	.inst	0xe92d00f0		//	push		{r4, r5, r6, r7}
25	.inst	0xe1c040d0		//	ldrd		r4, r5, [r0]
26	.inst	0xe1c160d0		//	ldrd		r6, r7, [r1]
27	.inst	0xe1b20f9f		// 1:	ldrexd		r0, r1, [r2]
28	.inst	0xe0303004		//	eors		r3, r0, r4
29	.inst	0x00313005		//	eoreqs		r3, r1, r5
30	.inst	0x01a23e96		//	stlexdeq	r3, r6, [r2]
31	.inst	0x03330001		//	teqeq		r3, #1
32	.inst	0x0afffff9		//	beq		1b
33	.inst	0xf57ff05b		//	dmb		ish
34	.inst	0xe2730000		//	rsbs		r0, r3, #0
35	.inst	0xe8bd00f0		//	pop		{r4, r5, r6, r7}
36	.inst	0xe12fff1e		//	bx		lr
37
38	.align	5
39__kuser_memory_barrier:			// 0xffff0fa0
40	.inst	0xf57ff05b		//	dmb		ish
41	.inst	0xe12fff1e		//	bx		lr
42
43	.align	5
44__kuser_cmpxchg:			// 0xffff0fc0
45	.inst	0xe1923f9f		// 1:	ldrex		r3, [r2]
46	.inst	0xe0533000		//	subs		r3, r3, r0
47	.inst	0x01823e91		//	stlexeq		r3, r1, [r2]
48	.inst	0x03330001		//	teqeq		r3, #1
49	.inst	0x0afffffa		//	beq		1b
50	.inst	0xf57ff05b		//	dmb		ish
51	.inst	0xe2730000		//	rsbs		r0, r3, #0
52	.inst	0xe12fff1e		//	bx		lr
53
54	.align	5
55__kuser_get_tls:			// 0xffff0fe0
56	.inst	0xee1d0f70		//	mrc		p15, 0, r0, c13, c0, 3
57	.inst	0xe12fff1e		//	bx		lr
58	.rep	5
59	.word	0
60	.endr
61
62__kuser_helper_version:			// 0xffff0ffc
63	.word	((__kuser_helper_end - __kuser_helper_start) >> 5)
64	.globl	__kuser_helper_end
65__kuser_helper_end:
66