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 .586p
  15 .model flat, C
  16
  17 extern mTopOfApCommonStack:DWORD
  18 extern ApEntryPointInC:PROC
  19
  20 .code
  21
  22 ;
  23 ; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
  24 ;
  25 ApStackLock dd      0
  26
  27 ;.code
  28
  29 ;------------------------------------------------------------------------------
  30 ; VOID
  31 ; EFIAPI
  32 ; AsmApEntryPoint (
  33 ;   VOID
  34 ;   );
  35 ;------------------------------------------------------------------------------
  36 AsmApEntryPoint PROC
  37
  38     cli
  39 AsmApEntryPointAcquireLock:
  40 lock bts    dword ptr [ApStackLock], 0
  41     pause
  42     jc      AsmApEntryPointAcquireLock
  43
  44     mov     esp, [mTopOfApCommonStack]
  45     call    ApEntryPointInC
  46
  47     cli
  48
  49 lock btc    dword ptr [ApStackLock], 0
  50
  51     mov     eax, 100h
  52 AsmApEntryPointShareLock:
  53     pause
  54     dec     eax
  55     jnz     AsmApEntryPointShareLock
  56
  57     jmp     AsmApEntryPoint
  58
  59 AsmApEntryPoint ENDP
  60
  61 ;------------------------------------------------------------------------------
  62 ; VOID
  63 ; EFIAPI
  64 ; AsmApDoneWithCommonStack (
  65 ;   VOID
  66 ;   );
  67 ;------------------------------------------------------------------------------
  68 AsmApDoneWithCommonStack PROC PUBLIC
  69
  70 lock btc    dword ptr [ApStackLock], 0
  71     ret
  72
  73 AsmApDoneWithCommonStack ENDP
  74
  75 END