Branch: refs/heads/UDK2015
  Commit: bb0034fd8e45e6021f0998e6771f208916e8fcca
  Author: Jeff Fan <>
  Date:   2016-12-02 (Fri, 02 Dec 2016)

  Changed paths:
    M UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c

  Log Message:
  UefiCpuPkg/PiSmmCpuDxeSmm: Clear some semaphores on S3 boot path

Some semaphores are not cleared on S3 boot path. For example,
mSmmMpSyncData->CpuData[CpuIndex].Present. It may still keeps the value set at
SMM runtime during S3 resume. It may causes BSP have the wrong judgement on SMM
AP's present state.

We have one related fix at e78a2a49ee6b0c0d7c6997c87ace31d7761cf636. But that is
not completed.

This fix is to clear Busy/Run/Present semaphores in InitializeMpSyncData().

Cc: Laszlo Ersek <>
Cc: Feng Tian <>
Cc: Jiewen Yao <>
Cc: Michael D Kinney <>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <>
Acked-by: Laszlo Ersek <>
Tested-by: Laszlo Ersek <>
Reviewed-by: Feng Tian <>
(cherry picked from commit 56e4a7d72660b229be333bbb5e1b5790d3c17890)

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