MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S

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