arch/arm64/kernel/kuser32.S

   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: