EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ipf/AccessPsr.s

   1 /// Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   2 /// This program and the accompanying materials
   3 /// are licensed and made available under the terms and conditions of the BSD License
   4 /// which accompanies this distribution.  The full text of the license may be found at
   5 /// http://opensource.org/licenses/bsd-license.php
   6 ///
   7 /// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   8 /// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
   9 ///
  10 /// Module Name: AccessPsr.s
  11 ///
  12 ///
  13 ///  IPF specific Processor Status Register accessing functions
  14 ///
  15
  16 #define CpuModeMask           0x0000001008020000
  17
  18 #define CpuInVirtualMode             0x1
  19 #define CpuInPhysicalMode            0x0
  20 #define CpuInMixMode                 (0x0 - 0x1)
  21
  22 //---------------------------------------------------------------------------------
  23 //++
  24 // AsmReadPsr
  25 //
  26 // This routine is used to read the current value of Processor Status Register (PSR).
  27 //
  28 // Arguments :
  29 //
  30 // On Entry :
  31 //
  32 // Return Value: The current PSR value.
  33 //
  34 //--
  35 //----------------------------------------------------------------------------------
  36 .text
  37 .type   AsmReadPsr, @function
  38 .proc   AsmReadPsr
  39
  40 AsmReadPsr::
  41         mov             r8 = psr;;
  42         br.ret.dpnt     b0;;
  43 .endp   AsmReadPsr
  44
  45 //---------------------------------------------------------------------------------
  46 //++
  47 // AsmWritePsr
  48 //
  49 // This routine is used to write the value of Processor Status Register (PSR).
  50 //
  51 // Arguments :
  52 //
  53 // On Entry : The value need to be written.
  54 //
  55 // Return Value: The value have been written.
  56 //
  57 //--
  58 //----------------------------------------------------------------------------------
  59 .text
  60 .type   AsmWritePsr, @function
  61 .proc   AsmWritePsr
  62 .regstk 1, 0, 0, 0
  63
  64 AsmWritePsr::
  65         mov             psr.l = in0
  66         mov             r8 = in0;;
  67         srlz.d;;
  68         srlz.i;;
  69         br.ret.dpnt     b0;;
  70 .endp   AsmWritePsr
  71
  72 //---------------------------------------------------------------------------------
  73 //++
  74 // AsmCpuVirtual
  75 //
  76 // This routine is used to determines if the CPU is currently executing
  77 // in virtual, physical, or mixed mode.
  78 //
  79 // If the CPU is in virtual mode(PSR.RT=1, PSR.DT=1, PSR.IT=1), then 1 is returned.
  80 // If the CPU is in physical mode(PSR.RT=0, PSR.DT=0, PSR.IT=0), then 0 is returned.
  81 // If the CPU is not in physical mode or virtual mode, then it is in mixed mode,
  82 // and -1 is returned.
  83 //
  84 // Arguments:
  85 //
  86 // On Entry: None
  87 //
  88 // Return Value: The CPU mode flag
  89 //               return  1  The CPU is in virtual mode.
  90 //               return  0  The CPU is in physical mode.
  91 //               return -1  The CPU is in mixed mode.
  92 //
  93 //--
  94 //----------------------------------------------------------------------------------
  95 .text
  96 .type   AsmCpuVirtual, @function
  97 .proc   AsmCpuVirtual
  98
  99 AsmCpuVirtual::
 100         mov            r29 = psr
 101         movl           r30 = CpuModeMask;;
 102         and            r28 = r30, r29;;
 103         cmp.eq         p6, p7 = r30, r28;;
 104 (p6)    mov            r8 = CpuInVirtualMode;;
 105 (p7)    cmp.eq         p6, p7 = 0x0, r28;;
 106 (p6)    mov            r8 = CpuInPhysicalMode;;
 107 (p7)    mov            r8 = CpuInMixMode;;
 108         br.ret.dpnt    b0;;
 109 .endp   AsmCpuVirtual