xref: /openbmc/linux/arch/arm64/kernel/kuser32.S (revision bef7a78d)
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/arm/kernel_user_helpers.rst for formal definitions.
14 */
15
16#include <asm/unistd.h>
17
18	.align	5
19	.globl	__kuser_helper_start
20__kuser_helper_start:
21
22__kuser_cmpxchg64:			// 0xffff0f60
23	.inst	0xe92d00f0		//	push		{r4, r5, r6, r7}
24	.inst	0xe1c040d0		//	ldrd		r4, r5, [r0]
25	.inst	0xe1c160d0		//	ldrd		r6, r7, [r1]
26	.inst	0xe1b20f9f		// 1:	ldrexd		r0, r1, [r2]
27	.inst	0xe0303004		//	eors		r3, r0, r4
28	.inst	0x00313005		//	eoreqs		r3, r1, r5
29	.inst	0x01a23e96		//	stlexdeq	r3, r6, [r2]
30	.inst	0x03330001		//	teqeq		r3, #1
31	.inst	0x0afffff9		//	beq		1b
32	.inst	0xf57ff05b		//	dmb		ish
33	.inst	0xe2730000		//	rsbs		r0, r3, #0
34	.inst	0xe8bd00f0		//	pop		{r4, r5, r6, r7}
35	.inst	0xe12fff1e		//	bx		lr
36
37	.align	5
38__kuser_memory_barrier:			// 0xffff0fa0
39	.inst	0xf57ff05b		//	dmb		ish
40	.inst	0xe12fff1e		//	bx		lr
41
42	.align	5
43__kuser_cmpxchg:			// 0xffff0fc0
44	.inst	0xe1923f9f		// 1:	ldrex		r3, [r2]
45	.inst	0xe0533000		//	subs		r3, r3, r0
46	.inst	0x01823e91		//	stlexeq		r3, r1, [r2]
47	.inst	0x03330001		//	teqeq		r3, #1
48	.inst	0x0afffffa		//	beq		1b
49	.inst	0xf57ff05b		//	dmb		ish
50	.inst	0xe2730000		//	rsbs		r0, r3, #0
51	.inst	0xe12fff1e		//	bx		lr
52
53	.align	5
54__kuser_get_tls:			// 0xffff0fe0
55	.inst	0xee1d0f70		//	mrc		p15, 0, r0, c13, c0, 3
56	.inst	0xe12fff1e		//	bx		lr
57	.rep	5
58	.word	0
59	.endr
60
61__kuser_helper_version:			// 0xffff0ffc
62	.word	((__kuser_helper_end - __kuser_helper_start) >> 5)
63	.globl	__kuser_helper_end
64__kuser_helper_end:
65