| Will Deacon | 3dd681d | 2012-03-05 11:49:32 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Low-level user helpers placed in the vectors page for AArch32. |
| 3 | * Based on the kuser helpers in arch/arm/kernel/entry-armv.S. |
| 4 | * |
| 5 | * Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net> |
| 6 | * Copyright (C) 2012 ARM Ltd. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | * |
| 20 | * |
| 21 | * AArch32 user helpers. |
| 22 | * |
| 23 | * Each segment is 32-byte aligned and will be moved to the top of the high |
| 24 | * vector page. New segments (if ever needed) must be added in front of |
| 25 | * existing ones. This mechanism should be used only for things that are |
| 26 | * really small and justified, and not be abused freely. |
| 27 | * |
| 28 | * See Documentation/arm/kernel_user_helpers.txt for formal definitions. |
| 29 | */ |
| 30 | .align 5 |
| 31 | .globl __kuser_helper_start |
| 32 | __kuser_helper_start: |
| 33 | |
| 34 | __kuser_cmpxchg64: // 0xffff0f60 |
| 35 | .inst 0xe92d00f0 // push {r4, r5, r6, r7} |
| 36 | .inst 0xe1c040d0 // ldrd r4, r5, [r0] |
| 37 | .inst 0xe1c160d0 // ldrd r6, r7, [r1] |
| 38 | .inst 0xf57ff05f // dmb sy |
| 39 | .inst 0xe1b20f9f // 1: ldrexd r0, r1, [r2] |
| 40 | .inst 0xe0303004 // eors r3, r0, r4 |
| 41 | .inst 0x00313005 // eoreqs r3, r1, r5 |
| 42 | .inst 0x01a23f96 // strexdeq r3, r6, [r2] |
| 43 | .inst 0x03330001 // teqeq r3, #1 |
| 44 | .inst 0x0afffff9 // beq 1b |
| 45 | .inst 0xf57ff05f // dmb sy |
| 46 | .inst 0xe2730000 // rsbs r0, r3, #0 |
| 47 | .inst 0xe8bd00f0 // pop {r4, r5, r6, r7} |
| 48 | .inst 0xe12fff1e // bx lr |
| 49 | |
| 50 | .align 5 |
| 51 | __kuser_memory_barrier: // 0xffff0fa0 |
| 52 | .inst 0xf57ff05f // dmb sy |
| 53 | .inst 0xe12fff1e // bx lr |
| 54 | |
| 55 | .align 5 |
| 56 | __kuser_cmpxchg: // 0xffff0fc0 |
| 57 | .inst 0xf57ff05f // dmb sy |
| 58 | .inst 0xe1923f9f // 1: ldrex r3, [r2] |
| 59 | .inst 0xe0533000 // subs r3, r3, r0 |
| 60 | .inst 0x01823f91 // strexeq r3, r1, [r2] |
| 61 | .inst 0x03330001 // teqeq r3, #1 |
| 62 | .inst 0x0afffffa // beq 1b |
| 63 | .inst 0xe2730000 // rsbs r0, r3, #0 |
| 64 | .inst 0xeaffffef // b <__kuser_memory_barrier> |
| 65 | |
| 66 | .align 5 |
| 67 | __kuser_get_tls: // 0xffff0fe0 |
| 68 | .inst 0xee1d0f70 // mrc p15, 0, r0, c13, c0, 3 |
| 69 | .inst 0xe12fff1e // bx lr |
| 70 | .rep 5 |
| 71 | .word 0 |
| 72 | .endr |
| 73 | |
| 74 | __kuser_helper_version: // 0xffff0ffc |
| 75 | .word ((__kuser_helper_end - __kuser_helper_start) >> 5) |
| 76 | .globl __kuser_helper_end |
| 77 | __kuser_helper_end: |