MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm

   1 ;
   2 ;  Copyright (c) 2014-2018, Linaro Limited. All rights reserved.
   3 ;
   4 ;  SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6
   7
   8 AREA IoLibMmio, CODE, READONLY
   9
  10 EXPORT MmioRead8Internal
  11 EXPORT MmioWrite8Internal
  12 EXPORT MmioRead16Internal
  13 EXPORT MmioWrite16Internal
  14 EXPORT MmioRead32Internal
  15 EXPORT MmioWrite32Internal
  16 EXPORT MmioRead64Internal
  17 EXPORT MmioWrite64Internal
  18
  19 ;
  20 ;  Reads an 8-bit MMIO register.
  21 ;
  22 ;  Reads the 8-bit MMIO register specified by Address. The 8-bit read value is
  23 ;  returned. This function must guarantee that all MMIO read and write
  24 ;  operations are serialized.
  25 ;
  26 ;  @param  Address The MMIO register to read.
  27 ;
  28 ;  @return The value read.
  29 ;
  30 MmioRead8Internal
  31   ldrb    r0, [r0]
  32   dmb
  33   bx      lr
  34
  35 ;
  36 ;  Writes an 8-bit MMIO register.
  37 ;
  38 ;  Writes the 8-bit MMIO register specified by Address with the value specified
  39 ;  by Value and returns Value. This function must guarantee that all MMIO read
  40 ;  and write operations are serialized.
  41 ;
  42 ;  @param  Address The MMIO register to write.
  43 ;  @param  Value   The value to write to the MMIO register.
  44 ;
  45 MmioWrite8Internal
  46   dmb     st
  47   strb    r1, [r0]
  48   bx      lr
  49
  50 ;
  51 ;  Reads a 16-bit MMIO register.
  52 ;
  53 ;  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
  54 ;  returned. This function must guarantee that all MMIO read and write
  55 ;  operations are serialized.
  56 ;
  57 ;  @param  Address The MMIO register to read.
  58 ;
  59 ;  @return The value read.
  60 ;
  61 MmioRead16Internal
  62   ldrh    r0, [r0]
  63   dmb
  64   bx      lr
  65
  66 ;
  67 ;  Writes a 16-bit MMIO register.
  68 ;
  69 ;  Writes the 16-bit MMIO register specified by Address with the value specified
  70 ;  by Value and returns Value. This function must guarantee that all MMIO read
  71 ;  and write operations are serialized.
  72 ;
  73 ;  @param  Address The MMIO register to write.
  74 ;  @param  Value   The value to write to the MMIO register.
  75 ;
  76 MmioWrite16Internal
  77   dmb     st
  78   strh    r1, [r0]
  79   bx      lr
  80
  81 ;
  82 ;  Reads a 32-bit MMIO register.
  83 ;
  84 ;  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
  85 ;  returned. This function must guarantee that all MMIO read and write
  86 ;  operations are serialized.
  87 ;
  88 ;  @param  Address The MMIO register to read.
  89 ;
  90 ;  @return The value read.
  91 ;
  92 MmioRead32Internal
  93   ldr     r0, [r0]
  94   dmb
  95   bx      lr
  96
  97 ;
  98 ;  Writes a 32-bit MMIO register.
  99 ;
 100 ;  Writes the 32-bit MMIO register specified by Address with the value specified
 101 ;  by Value and returns Value. This function must guarantee that all MMIO read
 102 ;  and write operations are serialized.
 103 ;
 104 ;  @param  Address The MMIO register to write.
 105 ;  @param  Value   The value to write to the MMIO register.
 106 ;
 107 MmioWrite32Internal
 108   dmb     st
 109   str     r1, [r0]
 110   bx      lr
 111
 112 ;
 113 ;  Reads a 64-bit MMIO register.
 114 ;
 115 ;  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
 116 ;  returned. This function must guarantee that all MMIO read and write
 117 ;  operations are serialized.
 118 ;
 119 ;  @param  Address The MMIO register to read.
 120 ;
 121 ;  @return The value read.
 122 ;
 123 MmioRead64Internal
 124   ldr     r1, [r0, #4]
 125   ldr     r0, [r0]
 126   dmb
 127   bx      lr
 128
 129 ;
 130 ;  Writes a 64-bit MMIO register.
 131 ;
 132 ;  Writes the 64-bit MMIO register specified by Address with the value specified
 133 ;  by Value and returns Value. This function must guarantee that all MMIO read
 134 ;  and write operations are serialized.
 135 ;
 136 ;  @param  Address The MMIO register to write.
 137 ;  @param  Value   The value to write to the MMIO register.
 138 ;
 139 MmioWrite64Internal
 140   dmb     st
 141   str     r2, [r0]
 142   str     r3, [r0, #4]
 143   bx      lr
 144
 145   END