MdePkg/Library/BaseLib/Ipf/AccessMsr.s

   1 /// @file
   2 ///  IPF specific Machine Specific Registers accessing functions.
   3 ///
   4 /// Copyright (c) 2008, Intel Corporation. All rights reserved.<BR>
   5 /// This program and the accompanying materials
   6 /// are licensed and made available under the terms and conditions of the BSD License
   7 /// which accompanies this distribution.  The full text of the license may be found at
   8 /// http://opensource.org/licenses/bsd-license.php
   9 ///
  10 /// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 /// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 ///
  13 ///
  14 ///
  15
  16
  17 //---------------------------------------------------------------------------------
  18 //++
  19 // AsmReadMsr
  20 //
  21 // Reads the current value of a Machine Specific Register (MSR).
  22 //
  23 // Reads and returns the current value of the Machine Specific Register specified by Index.  No
  24 // parameter checking is performed on Index, and if the Index value is beyond the implemented MSR
  25 // register range, a Reserved Register/Field fault may occur.  The caller must either guarantee that
  26 // Index is valid, or the caller must set up fault handlers to catch the faults.  This function is
  27 // only available on IPF.
  28 //
  29 // Arguments :
  30 //
  31 // On Entry : The 8-bit Machine Specific Register index to read.
  32 //
  33 // Return Value: The current value of the Machine Specific Register specified by Index.
  34 //
  35 //--
  36 //----------------------------------------------------------------------------------
  37 .text
  38 .type   AsmReadMsr, @function
  39 .proc   AsmReadMsr
  40 .regstk 1, 0, 0, 0
  41
  42 AsmReadMsr::
  43   mov    r8=msr[in0];;
  44   br.ret.sptk  b0;;
  45 .endp   AsmReadMsr
  46
  47 //---------------------------------------------------------------------------------
  48 //++
  49 // AsmWriteMsr
  50 //
  51 // Writes the current value of a Machine Specific Register (MSR).
  52 //
  53 // Writes Value to the Machine Specific Register specified by Index.  Value is returned.  No
  54 // parameter checking is performed on Index, and if the Index value is beyond the implemented MSR
  55 // register range, a Reserved Register/Field fault may occur.  The caller must either guarantee that
  56 // Index is valid, or the caller must set up fault handlers to catch the faults.  This function is
  57 // only available on IPF.
  58 //
  59 // Arguments :
  60 //
  61 // On Entry : The 8-bit Machine Specific Register index to write.
  62 //            The 64-bit value to write to the Machine Specific Register.
  63 //
  64 // Return Value: The 64-bit value to write to the Machine Specific Register.
  65 //
  66 //--
  67 //----------------------------------------------------------------------------------
  68 .text
  69 .type   AsmWriteMsr, @function
  70 .proc   AsmWriteMsr
  71 .regstk 2, 0, 0, 0
  72
  73 AsmWriteMsr::
  74   mov             msr[in0] = in1
  75   mov             r8 = in1;;
  76   srlz.d;;
  77   br.ret.sptk     b0;;
  78 .endp   AsmWriteMsr
  79