From cd8c700b03e38e9389a8f13e193a431072802593 Mon Sep 17 00:00:00 2001
From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Date: Thu, 13 Nov 2014 18:29:54 +0000
Subject: [PATCH] UefiCpuPkg/MpService: avoid dead lock caused by
 CheckAllAPsStatus

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16369 6f19259b-4bc3-4df7-8a09-765794883524
---
 UefiCpuPkg/CpuDxe/CpuMp.c | 55 ++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index e03c7f1e49..5d5c7db765 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -632,6 +632,11 @@ StartupAllAPs (
     return EFI_INVALID_PARAMETER;
   }
 
+  //
+  // temporarily stop checkAllAPsStatus for avoid resource dead-lock.
+  //
+  mStopCheckAllAPsStatus = TRUE;
+
   for (Number = 0; Number < mMpSystemData.NumberOfProcessors; Number++) {
     CpuData = &mMpSystemData.CpuDatas[Number];
     if (TestCpuStatusFlag (CpuData, PROCESSOR_AS_BSP_BIT)) {
@@ -653,11 +658,6 @@ StartupAllAPs (
     }
   }
 
-  //
-  // temporarily stop checkAllAPsStatus for initialize parameters.
-  //
-  mStopCheckAllAPsStatus = TRUE;
-
   mMpSystemData.Procedure         = Procedure;
   mMpSystemData.ProcedureArgument = ProcedureArgument;
   mMpSystemData.WaitEvent         = WaitEvent;
@@ -716,6 +716,11 @@ StartupAllAPs (
     return EFI_SUCCESS;
   }
 
+  //
+  // Blocking temporarily stop CheckAllAPsStatus()
+  //
+  mStopCheckAllAPsStatus = TRUE;
+
   while (TRUE) {
     CheckAndUpdateAllAPsToIdleState ();
     if (mMpSystemData.FinishCount == mMpSystemData.StartCount) {
@@ -859,6 +864,11 @@ StartupThisAP (
     return EFI_NOT_FOUND;
   }
 
+  //
+  // temporarily stop checkAllAPsStatus for avoid resource dead-lock.
+  //
+  mStopCheckAllAPsStatus = TRUE;
+
   CpuData = &mMpSystemData.CpuDatas[ProcessorNumber];
   if (TestCpuStatusFlag (CpuData, PROCESSOR_AS_BSP_BIT) ||
       !TestCpuStatusFlag (CpuData, PROCESSOR_ENABLED_BIT)) {
@@ -869,11 +879,6 @@ StartupThisAP (
     return EFI_NOT_READY;
   }
 
-  //
-  // temporarily stop checkAllAPsStatus for initialize parameters.
-  //
-  mStopCheckAllAPsStatus = TRUE;
-
   SetApState (CpuData, CpuStateReady);
 
   SetApProcedure (CpuData, Procedure, ProcedureArgument);
@@ -1013,6 +1018,10 @@ EnableDisableAP (
   )
 {
   CPU_DATA_BLOCK *CpuData;
+  BOOLEAN        TempStopCheckState;
+
+  CpuData = NULL;
+  TempStopCheckState = FALSE;
 
   if (!IsBSP ()) {
     return EFI_DEVICE_ERROR;
@@ -1022,6 +1031,14 @@ EnableDisableAP (
     return EFI_NOT_FOUND;
   }
 
+  //
+  // temporarily stop checkAllAPsStatus for initialize parameters.
+  //
+  if (!mStopCheckAllAPsStatus) {
+    mStopCheckAllAPsStatus = TRUE;
+    TempStopCheckState = TRUE;
+  }
+
   CpuData = &mMpSystemData.CpuDatas[ProcessorNumber];
   if (TestCpuStatusFlag (CpuData, PROCESSOR_AS_BSP_BIT)) {
     return EFI_INVALID_PARAMETER;
@@ -1048,6 +1065,10 @@ EnableDisableAP (
     CpuStatusFlagOr (CpuData, (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT));
   }
 
+  if (TempStopCheckState) {
+    mStopCheckAllAPsStatus = FALSE;
+  }
+
   return EFI_SUCCESS;
 }
 
@@ -1303,20 +1324,6 @@ CheckAllAPsStatus (
   //
   for (Number = 0; Number < mMpSystemData.NumberOfProcessors; Number++) {
     CpuData = &mMpSystemData.CpuDatas[Number];
-    if (TestCpuStatusFlag (CpuData, PROCESSOR_AS_BSP_BIT)) {
-      //
-      // Skip BSP
-      //
-      continue;
-    }
-
-    if (!TestCpuStatusFlag (CpuData, PROCESSOR_ENABLED_BIT)) {
-      //
-      // Skip Disabled processors
-      //
-      continue;
-    }
-
     if (CpuData->WaitEvent) {
       CheckThisAPStatus (NULL, (VOID *)CpuData);
     }
-- 
2.39.2