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: