/*
* Low-level user helpers placed in the vectors page for AArch32.
* Based on the kuser helpers in arch/arm/kernel/entry-armv.S.
*
* Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net>
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* AArch32 user helpers.
*
* Each segment is 32-byte aligned and will be moved to the top of the high
* vector page. New segments (if ever needed) must be added in front of
* existing ones. This mechanism should be used only for things that are
* really small and justified, and not be abused freely.
*
* See Documentation/arm/kernel_user_helpers.txt for formal definitions.
*/
#include <asm/unistd.h>
.align 5
.globl __kuser_helper_start
__kuser_helper_start:
__kuser_cmpxchg64: // 0xffff0f60
.inst 0xe92d00f0 // push {r4, r5, r6, r7}
.inst 0xe1c040d0 // ldrd r4, r5, [r0]
.inst 0xe1c160d0 // ldrd r6, r7, [r1]
.inst 0xe1b20f9f // 1: ldrexd r0, r1, [r2]
.inst 0xe0303004 // eors r3, r0, r4
.inst 0x00313005 // eoreqs r3, r1, r5
.inst 0x01a23e96 // stlexdeq r3, r6, [r2]
.inst 0x03330001 // teqeq r3, #1
.inst 0x0afffff9 // beq 1b
.inst 0xf57ff05b // dmb ish
.inst 0xe2730000 // rsbs r0, r3, #0
.inst 0xe8bd00f0 // pop {r4, r5, r6, r7}
.inst 0xe12fff1e // bx lr
.align 5
__kuser_memory_barrier: // 0xffff0fa0
.inst 0xf57ff05b // dmb ish
.inst 0xe12fff1e // bx lr
.align 5
__kuser_cmpxchg: // 0xffff0fc0
.inst 0xe1923f9f // 1: ldrex r3, [r2]
.inst 0xe0533000 // subs r3, r3, r0
.inst 0x01823e91 // stlexeq r3, r1, [r2]
.inst 0x03330001 // teqeq r3, #1
.inst 0x0afffffa // beq 1b
.inst 0xf57ff05b // dmb ish
.inst 0xe2730000 // rsbs r0, r3, #0
.inst 0xe12fff1e // bx lr
.align 5
__kuser_get_tls: // 0xffff0fe0
.inst 0xee1d0f70 // mrc p15, 0, r0, c13, c0, 3
.inst 0xe12fff1e // bx lr
.rep 5
.word 0
.endr
__kuser_helper_version: // 0xffff0ffc
.word ((__kuser_helper_end - __kuser_helper_start) >> 5)
.globl __kuser_helper_end
__kuser_helper_end:
/*
* AArch32 sigreturn code
*
* For ARM syscalls, the syscall number has to be loaded into r7.
* We do not support an OABI userspace.
*
* For Thumb syscalls, we also pass the syscall number via r7. We therefore
* need two 16-bit instructions.
*/
.globl __aarch32_sigret_code_start
__aarch32_sigret_code_start:
/*
* ARM Code
*/
.byte __NR_compat_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_sigreturn
.byte __NR_compat_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_sigreturn
/*
* Thumb code
*/
.byte __NR_compat_sigreturn, 0x27 // svc #__NR_compat_sigreturn
.byte __NR_compat_sigreturn, 0xdf // mov r7, #__NR_compat_sigreturn
/*
* ARM code
*/
.byte __NR_compat_rt_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_rt_sigreturn
.byte __NR_compat_rt_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_rt_sigreturn
/*
* Thumb code
*/
.byte __NR_compat_rt_sigreturn, 0x27 // svc #__NR_compat_rt_sigreturn
.byte __NR_compat_rt_sigreturn, 0xdf // mov r7, #__NR_compat_rt_sigreturn
.globl __aarch32_sigret_code_end
__aarch32_sigret_code_end:
