UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
   4 ; This program and the accompanying materials
   5 ; are licensed and made available under the terms and conditions of the BSD License
   6 ; which accompanies this 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 .686
  15 .xmm
  16 .model flat, C
  17
  18 extern mTopOfApCommonStack:DWORD
  19 extern ApEntryPointInC:PROC
  20
  21 .code
  22
  23 ;
  24 ; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
  25 ;
  26 ApStackLock dd      0
  27
  28 ;.code
  29
  30 ;------------------------------------------------------------------------------
  31 ; VOID
  32 ; EFIAPI
  33 ; AsmApEntryPoint (
  34 ;   VOID
  35 ;   );
  36 ;------------------------------------------------------------------------------
  37 AsmApEntryPoint PROC
  38
  39     cli
  40 AsmApEntryPointAcquireLock:
  41 lock bts    dword ptr [ApStackLock], 0
  42     pause
  43     jc      AsmApEntryPointAcquireLock
  44
  45     mov     esp, [mTopOfApCommonStack]
  46     call    ApEntryPointInC
  47
  48     cli
  49
  50 lock btc    dword ptr [ApStackLock], 0
  51
  52     mov     eax, 100h
  53 AsmApEntryPointShareLock:
  54     pause
  55     dec     eax
  56     jnz     AsmApEntryPointShareLock
  57
  58     jmp     AsmApEntryPoint
  59
  60 AsmApEntryPoint ENDP
  61
  62 ;------------------------------------------------------------------------------
  63 ; VOID
  64 ; EFIAPI
  65 ; AsmApDoneWithCommonStack (
  66 ;   VOID
  67 ;   );
  68 ;------------------------------------------------------------------------------
  69 AsmApDoneWithCommonStack PROC PUBLIC
  70
  71 lock btc    dword ptr [ApStackLock], 0
  72     ret
  73
  74 AsmApDoneWithCommonStack ENDP
  75
  76 END