UefiCpuPkg/MpInitLib: Enhance waiting for AP initialization logic.

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / MpLib.c

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index db923c9917d7be561c96da23a6161c013d2cce7f..48f930b701473de77cabd58d4f929fc4c6091ea1 100644 (file)
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -662,6 +662,7 @@ ApWakeupFunction (
     // AP finished executing C code\r
     //\r
     InterlockedIncrement ((UINT32 *) &CpuMpData->FinishedCount);\r
+    InterlockedDecrement ((UINT32 *) &CpuMpData->MpCpuExchangeInfo->NumApsExecuting);\r
 \r
     //\r
     // Place AP is specified loop mode\r
@@ -765,6 +766,7 @@ FillExchangeInfoData (
 \r
   ExchangeInfo->CFunction       = (UINTN) ApWakeupFunction;\r
   ExchangeInfo->ApIndex         = 0;\r
+  ExchangeInfo->NumApsExecuting = 0;\r
   ExchangeInfo->InitFlag        = (UINTN) CpuMpData->InitFlag;\r
   ExchangeInfo->CpuInfo         = (CPU_INFO_IN_HOB *) (UINTN) CpuMpData->CpuInfoInHob;\r
   ExchangeInfo->CpuMpData       = CpuMpData;\r
@@ -934,13 +936,19 @@ WakeUpAP (
     }\r
     if (CpuMpData->InitFlag == ApInitConfig) {\r
       //\r
-      // Wait for all potential APs waken up in one specified period\r
+      // Wait for one potential AP waken up in one specified period\r
       //\r
-      TimedWaitForApFinish (\r
-        CpuMpData,\r
-        PcdGet32 (PcdCpuMaxLogicalProcessorNumber) - 1,\r
-        PcdGet32 (PcdCpuApInitTimeOutInMicroSeconds)\r
-        );\r
+      if (CpuMpData->CpuCount == 0) {\r
+        TimedWaitForApFinish (\r
+          CpuMpData,\r
+          PcdGet32 (PcdCpuMaxLogicalProcessorNumber) - 1,\r
+          PcdGet32 (PcdCpuApInitTimeOutInMicroSeconds)\r
+          );\r
+      }\r
+\r
+      while (CpuMpData->MpCpuExchangeInfo->NumApsExecuting != 0) {\r
+        CpuPause();\r
+      }\r
     } else {\r
       //\r
       // Wait all APs waken up if this is not the 1st broadcast of SIPI\r