[PATCH 3/6] UefiCpuPkg/MpInitLib: Move save/restore interrupt to SwitchBSPWorker()

[Jeff Fan <jeff.fan@intel.com>]

During switching BSP phase, we need to disable CPU interruput to prevent stack
crashed by Timer interrupt handle. But when we enabled source debugging feature,
debug timer interrupt handler (existing on both PEI and DXE) also could crash
the stack used during switching BSP. So,we need to move save/restore interrupt
to SwitchBSPWorker().

Cc: Feng Tian <feng.tian@intel.com>
Cc: Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/DxeMpLib.c | 19 -------------------
 UefiCpuPkg/Library/MpInitLib/MpLib.c    | 21 +++++++++++++++++++++
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index 1204abd..733a9fb 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -646,29 +646,10 @@ MpInitLibSwitchBSP (
   )
 {
   EFI_STATUS            Status;
-  BOOLEAN               OldInterruptState;
 
-  //
-  // Before send both BSP and AP to a procedure to exchange their roles,
-  // interrupt must be disabled. This is because during the exchange role
-  // process, 2 CPU may use 1 stack. If interrupt happens, the stack will
-  // be corrupted, since interrupt return address will be pushed to stack
-  // by hardware.
-  //
-  OldInterruptState = SaveAndDisableInterrupts ();
-
-  //
-  // Mask LINT0 & LINT1 for the old BSP
-  //
-  DisableLvtInterrupts ();
 
   Status = SwitchBSPWorker (ProcessorNumber, EnableOldBSP);
 
-  //
-  // Restore interrupt state.
-  //
-  SetInterruptState (OldInterruptState);
-
   return Status;
 }
 
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index e5842ef..9dae827 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -1511,6 +1511,21 @@ SwitchBSPWorker (
   UINTN                        CallerNumber;
   CPU_STATE                    State;
   MSR_IA32_APIC_BASE_REGISTER  ApicBaseMsr;
+  BOOLEAN                      OldInterruptState;
+
+  //
+  // Before send both BSP and AP to a procedure to exchange their roles,
+  // interrupt must be disabled. This is because during the exchange role
+  // process, 2 CPU may use 1 stack. If interrupt happens, the stack will
+  // be corrupted, since interrupt return address will be pushed to stack
+  // by hardware.
+  //
+  OldInterruptState = SaveAndDisableInterrupts ();
+
+  //
+  // Mask LINT0 & LINT1 for the old BSP
+  //
+  DisableLvtInterrupts ();
 
   CpuMpData = GetCpuMpData ();
 
@@ -1593,6 +1608,12 @@ SwitchBSPWorker (
   //
   CpuMpData->BspNumber = (UINT32) ProcessorNumber;
 
+  //
+  // Restore interrupt state.
+  //
+  SetInterruptState (OldInterruptState);
+
+
   return EFI_SUCCESS;
 }
 
-- 
2.9.3.windows.2