UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm

   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 extern ASM_PFX(mTopOfApCommonStack)
  15 extern ASM_PFX(ApEntryPointInC)
  16
  17 SECTION .data
  18
  19 ;
  20 ; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
  21 ;
  22 ApStackLock:
  23     dd      0
  24
  25 SECTION .text
  26
  27 ;------------------------------------------------------------------------------
  28 ; VOID
  29 ; EFIAPI
  30 ; AsmApEntryPoint (
  31 ;   VOID
  32 ;   );
  33 ;------------------------------------------------------------------------------
  34 global ASM_PFX(AsmApEntryPoint)
  35 ASM_PFX(AsmApEntryPoint):
  36     cli
  37 AsmApEntryPointAcquireLock:
  38 lock bts    dword [ApStackLock], 0
  39     pause
  40     jc      AsmApEntryPointAcquireLock
  41
  42     mov     esp, [ASM_PFX(mTopOfApCommonStack)]
  43     call    ASM_PFX(ApEntryPointInC)
  44
  45     cli
  46
  47 lock btc    dword [ApStackLock], 0
  48
  49     mov     eax, 0x100
  50 AsmApEntryPointShareLock:
  51     pause
  52     dec     eax
  53     jnz     AsmApEntryPointShareLock
  54
  55     jmp     ASM_PFX(AsmApEntryPoint)
  56
  57 ;------------------------------------------------------------------------------
  58 ; VOID
  59 ; EFIAPI
  60 ; AsmApDoneWithCommonStack (
  61 ;   VOID
  62 ;   );
  63 ;------------------------------------------------------------------------------
  64 global ASM_PFX(AsmApDoneWithCommonStack)
  65 ASM_PFX(AsmApDoneWithCommonStack):
  66 lock btc    dword [ApStackLock], 0
  67     ret
  68