UefiCpuPkg/CpuDxe/X64/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 DEFAULT REL
  18
  19 SECTION .data
  20
  21 ;
  22 ; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
  23 ;
  24 ApStackLock:
  25     dd      0
  26
  27 SECTION .text
  28
  29 ;------------------------------------------------------------------------------
  30 ; VOID
  31 ; EFIAPI
  32 ; AsmApEntryPoint (
  33 ;   VOID
  34 ;   );
  35 ;------------------------------------------------------------------------------
  36 global ASM_PFX(AsmApEntryPoint)
  37 ASM_PFX(AsmApEntryPoint):
  38     cli
  39 AsmApEntryPointAcquireLock:
  40 lock bts    dword [ApStackLock], 0
  41     pause
  42     jc      AsmApEntryPointAcquireLock
  43
  44     mov     rsp, [ASM_PFX(mTopOfApCommonStack)]
  45     call    ASM_PFX(ApEntryPointInC)
  46
  47     cli
  48
  49 lock btc    dword [ApStackLock], 0
  50
  51     mov     eax, 0x100
  52 AsmApEntryPointShareLock:
  53     pause
  54     dec     eax
  55     jnz     AsmApEntryPointShareLock
  56
  57     jmp     ASM_PFX(AsmApEntryPoint)
  58
  59 ;------------------------------------------------------------------------------
  60 ; VOID
  61 ; EFIAPI
  62 ; AsmApDoneWithCommonStack (
  63 ;   VOID
  64 ;   );
  65 ;------------------------------------------------------------------------------
  66 global ASM_PFX(AsmApDoneWithCommonStack)
  67 ASM_PFX(AsmApDoneWithCommonStack):
  68 lock btc    dword [ApStackLock], 0
  69     ret
  70