MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm

   1 ;
   2 ;  Copyright (c) 2014-2018, Linaro Limited. All rights reserved.
   3 ;
   4 ;  This program and the accompanying materials are licensed and made available
   5 ;  under the terms and conditions of the BSD License which accompanies this
   6 ;  distribution.  The full text of the license may be found at
   7 ;  http:;opensource.org/licenses/bsd-license.php
   8 ;
   9 ;  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 ;  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 ;
  12
  13
  14 AREA IoLibMmio, CODE, READONLY
  15
  16 EXPORT MmioRead8Internal
  17 EXPORT MmioWrite8Internal
  18 EXPORT MmioRead16Internal
  19 EXPORT MmioWrite16Internal
  20 EXPORT MmioRead32Internal
  21 EXPORT MmioWrite32Internal
  22 EXPORT MmioRead64Internal
  23 EXPORT MmioWrite64Internal
  24
  25 ;
  26 ;  Reads an 8-bit MMIO register.
  27 ;
  28 ;  Reads the 8-bit MMIO register specified by Address. The 8-bit read value is
  29 ;  returned. This function must guarantee that all MMIO read and write
  30 ;  operations are serialized.
  31 ;
  32 ;  @param  Address The MMIO register to read.
  33 ;
  34 ;  @return The value read.
  35 ;
  36 MmioRead8Internal
  37   ldrb    r0, [r0]
  38   dmb
  39   bx      lr
  40
  41 ;
  42 ;  Writes an 8-bit MMIO register.
  43 ;
  44 ;  Writes the 8-bit MMIO register specified by Address with the value specified
  45 ;  by Value and returns Value. This function must guarantee that all MMIO read
  46 ;  and write operations are serialized.
  47 ;
  48 ;  @param  Address The MMIO register to write.
  49 ;  @param  Value   The value to write to the MMIO register.
  50 ;
  51 MmioWrite8Internal
  52   dmb     st
  53   strb    r1, [r0]
  54   bx      lr
  55
  56 ;
  57 ;  Reads a 16-bit MMIO register.
  58 ;
  59 ;  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
  60 ;  returned. This function must guarantee that all MMIO read and write
  61 ;  operations are serialized.
  62 ;
  63 ;  @param  Address The MMIO register to read.
  64 ;
  65 ;  @return The value read.
  66 ;
  67 MmioRead16Internal
  68   ldrh    r0, [r0]
  69   dmb
  70   bx      lr
  71
  72 ;
  73 ;  Writes a 16-bit MMIO register.
  74 ;
  75 ;  Writes the 16-bit MMIO register specified by Address with the value specified
  76 ;  by Value and returns Value. This function must guarantee that all MMIO read
  77 ;  and write operations are serialized.
  78 ;
  79 ;  @param  Address The MMIO register to write.
  80 ;  @param  Value   The value to write to the MMIO register.
  81 ;
  82 MmioWrite16Internal
  83   dmb     st
  84   strh    r1, [r0]
  85   bx      lr
  86
  87 ;
  88 ;  Reads a 32-bit MMIO register.
  89 ;
  90 ;  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
  91 ;  returned. This function must guarantee that all MMIO read and write
  92 ;  operations are serialized.
  93 ;
  94 ;  @param  Address The MMIO register to read.
  95 ;
  96 ;  @return The value read.
  97 ;
  98 MmioRead32Internal
  99   ldr     r0, [r0]
 100   dmb
 101   bx      lr
 102
 103 ;
 104 ;  Writes a 32-bit MMIO register.
 105 ;
 106 ;  Writes the 32-bit MMIO register specified by Address with the value specified
 107 ;  by Value and returns Value. This function must guarantee that all MMIO read
 108 ;  and write operations are serialized.
 109 ;
 110 ;  @param  Address The MMIO register to write.
 111 ;  @param  Value   The value to write to the MMIO register.
 112 ;
 113 MmioWrite32Internal
 114   dmb     st
 115   str     r1, [r0]
 116   bx      lr
 117
 118 ;
 119 ;  Reads a 64-bit MMIO register.
 120 ;
 121 ;  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
 122 ;  returned. This function must guarantee that all MMIO read and write
 123 ;  operations are serialized.
 124 ;
 125 ;  @param  Address The MMIO register to read.
 126 ;
 127 ;  @return The value read.
 128 ;
 129 MmioRead64Internal
 130   ldr     r1, [r0, #4]
 131   ldr     r0, [r0]
 132   dmb
 133   bx      lr
 134
 135 ;
 136 ;  Writes a 64-bit MMIO register.
 137 ;
 138 ;  Writes the 64-bit MMIO register specified by Address with the value specified
 139 ;  by Value and returns Value. This function must guarantee that all MMIO read
 140 ;  and write operations are serialized.
 141 ;
 142 ;  @param  Address The MMIO register to write.
 143 ;  @param  Value   The value to write to the MMIO register.
 144 ;
 145 MmioWrite64Internal
 146   dmb     st
 147   str     r2, [r0]
 148   str     r3, [r0, #4]
 149   bx      lr
 150
 151   END