MdePkg/Library/BaseLib/Ipf/AccessPsr.s

   1 /// @file
   2 ///  IPF specific Processor Status Register accessing functions
   3 ///
   4 /// Copyright (c) 2006, Intel Corporation
   5 /// All rights reserved. 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 /// Module Name: AccessPsr.s
  14 ///
  15 ///
  16
  17 #define CpuModeMask           0x0000001008020000
  18
  19 #define CpuInVirtualMode             0x1
  20 #define CpuInPhysicalMode            0x0
  21 #define CpuInMixMode                 (0x0 - 0x1)
  22
  23 //---------------------------------------------------------------------------------
  24 //++
  25 // AsmReadPsr
  26 //
  27 // This routine is used to read the current value of Processor Status Register (PSR).
  28 //
  29 // Arguments :
  30 //
  31 // On Entry :
  32 //
  33 // Return Value: The current PSR value.
  34 //
  35 //--
  36 //----------------------------------------------------------------------------------
  37 .text
  38 .type   AsmReadPsr, @function
  39 .proc   AsmReadPsr
  40
  41 AsmReadPsr::
  42         mov             r8 = psr;;
  43         br.ret.dpnt     b0;;
  44 .endp   AsmReadPsr
  45
  46 //---------------------------------------------------------------------------------
  47 //++
  48 // AsmWritePsr
  49 //
  50 // This routine is used to write the value of Processor Status Register (PSR).
  51 //
  52 // Arguments :
  53 //
  54 // On Entry : The value need to be written.
  55 //
  56 // Return Value: The value have been written.
  57 //
  58 //--
  59 //----------------------------------------------------------------------------------
  60 .text
  61 .type   AsmWritePsr, @function
  62 .proc   AsmWritePsr
  63 .regstk 1, 0, 0, 0
  64
  65 AsmWritePsr::
  66         mov             psr.l = in0
  67         mov             r8 = in0;;
  68         srlz.d;;
  69         srlz.i;;
  70         br.ret.dpnt     b0;;
  71 .endp   AsmWritePsr
  72
  73 //---------------------------------------------------------------------------------
  74 //++
  75 // AsmCpuVirtual
  76 //
  77 // This routine is used to determines if the CPU is currently executing
  78 // in virtual, physical, or mixed mode.
  79 //
  80 // If the CPU is in virtual mode(PSR.RT=1, PSR.DT=1, PSR.IT=1), then 1 is returned.
  81 // If the CPU is in physical mode(PSR.RT=0, PSR.DT=0, PSR.IT=0), then 0 is returned.
  82 // If the CPU is not in physical mode or virtual mode, then it is in mixed mode,
  83 // and -1 is returned.
  84 //
  85 // Arguments:
  86 //
  87 // On Entry: None
  88 //
  89 // Return Value: The CPU mode flag
  90 //               return  1  The CPU is in virtual mode.
  91 //               return  0  The CPU is in physical mode.
  92 //               return -1  The CPU is in mixed mode.
  93 //
  94 //--
  95 //----------------------------------------------------------------------------------
  96 .text
  97 .type   AsmCpuVirtual, @function
  98 .proc   AsmCpuVirtual
  99
 100 AsmCpuVirtual::
 101         mov            r29 = psr
 102         movl           r30 = CpuModeMask;;
 103         and            r28 = r30, r29;;
 104         cmp.eq         p6, p7 = r30, r28;;
 105 (p6)    mov            r8 = CpuInVirtualMode;;
 106 (p7)    cmp.eq         p6, p7 = 0x0, r28;;
 107 (p6)    mov            r8 = CpuInPhysicalMode;;
 108 (p7)    mov            r8 = CpuInMixMode;;
 109         br.ret.dpnt    b0;;
 110 .endp   AsmCpuVirtual