commit 56e4a7d72660b229be333bbb5e1b5790d3c17890
author Jeff Fan <jeff.fan@intel.com> Tue Nov 29 15:48:32 2016 +0800
committer Jeff Fan <jeff.fan@intel.com> Thu Dec 01 15:22:02 2016 +0800
tree 065bfe446f34343153f1ff9df4b0c186dab8438c
parent eae631bc687c3cbfab01632ce3bc21783d22b590

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 <lersek@redhat.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index cfbf59e..a873b68 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -1357,6 +1357,9 @@
         (UINT32 *)((UINTN)mSmmCpuSemaphores.SemaphoreCpu.Run + mSemaphoreSize * CpuIndex);

       mSmmMpSyncData->CpuData[CpuIndex].Present =

         (BOOLEAN *)((UINTN)mSmmCpuSemaphores.SemaphoreCpu.Present + mSemaphoreSize * CpuIndex);

+      *(mSmmMpSyncData->CpuData[CpuIndex].Busy)    = 0;

+      *(mSmmMpSyncData->CpuData[CpuIndex].Run)     = 0;

+      *(mSmmMpSyncData->CpuData[CpuIndex].Present) = FALSE;

     }

   }

 }