MdeModulePkg/PiSmmCore: Cache CommunicationBuffer info before using it

[mirror_edk2.git] / UefiCpuPkg / PiSmmCpuDxeSmm / CpuS3.c

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
index ad7dc412fb40af19881d58485fedf5f481888028..532b7c44bd17a5b0213f68f90eeec11496521e5a 100644 (file)
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
@@ -55,7 +55,7 @@ AsmGetAddressMap (
 #define LEGACY_REGION_BASE    (0xA0000 - LEGACY_REGION_SIZE)\r
 \r
 ACPI_CPU_DATA                mAcpiCpuData;\r
-UINT32                       mNumberToFinish;\r
+volatile UINT32              mNumberToFinish;\r
 MP_CPU_EXCHANGE_INFO         *mExchangeInfo;\r
 BOOLEAN                      mRestoreSmmConfigurationInS3 = FALSE;\r
 VOID                         *mGdtForAp = NULL;\r
@@ -79,9 +79,11 @@ BOOLEAN                      mAcpiS3Enable = TRUE;
 \r
 UINT8                        *mApHltLoopCode = NULL;\r
 UINT8                        mApHltLoopCodeTemplate[] = {\r
-                               0xFA,        // cli\r
-                               0xF4,        // hlt\r
-                               0xEB, 0xFC   // jmp $-2\r
+                               0x8B, 0x44, 0x24, 0x04,  // mov  eax, dword ptr [esp+4]\r
+                               0xF0, 0xFF, 0x08,        // lock dec  dword ptr [eax]\r
+                               0xFA,                    // cli\r
+                               0xF4,                    // hlt\r
+                               0xEB, 0xFC               // jmp $-2\r
                                };\r
 \r
 /**\r
@@ -383,7 +385,7 @@ MPRendezvousProcedure (
   CPU_REGISTER_TABLE         *RegisterTableList;\r
   UINT32                     InitApicId;\r
   UINTN                      Index;\r
-  UINT32                     TopOfStack;\r
+  UINTN                      TopOfStack;\r
   UINT8                      Stack[128];\r
 \r
   ProgramVirtualWireMode ();\r
@@ -399,17 +401,12 @@ MPRendezvousProcedure (
   }\r
 \r
   //\r
-  // Count down the number with lock mechanism.\r
-  //\r
-  InterlockedDecrement (&mNumberToFinish);\r
-\r
-  //\r
-  // Place AP into the safe code\r
+  // Place AP into the safe code, count down the number with lock mechanism in the safe code.\r
   //\r
-  TopOfStack  = (UINT32) (UINTN) Stack + sizeof (Stack);\r
-  TopOfStack &= ~(UINT32) (CPU_STACK_ALIGNMENT - 1);\r
+  TopOfStack  = (UINTN) Stack + sizeof (Stack);\r
+  TopOfStack &= ~(UINTN) (CPU_STACK_ALIGNMENT - 1);\r
   CopyMem ((VOID *) (UINTN) mApHltLoopCode, mApHltLoopCodeTemplate, sizeof (mApHltLoopCodeTemplate));\r
-  TransferApToSafeState ((UINT32) (UINTN) mApHltLoopCode, TopOfStack);\r
+  TransferApToSafeState ((UINTN)mApHltLoopCode, TopOfStack, (UINTN)&mNumberToFinish);\r
 }\r
 \r
 /**\r