[PATCH 2/2] UefiCpuPkg/DxeMpLib: Place APs to suitable state on Legacy OS boot

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

Currently, DxeMpLib only places APs into specified c-state in Exit Boot Service
callback function for UEFI OS boot. We need to put APs into specified c-state
for legacy OS boot also.

https://bugzilla.tianocore.org/show_bug.cgi?id=210

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Paolo Bonzini <pbonzini@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>
---
 UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |  1 +
 UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
index 03a8994..972c9ad 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
@@ -58,6 +58,7 @@
 
 [Guids]
   gEfiEventExitBootServicesGuid                 ## CONSUMES  ## Event
+  gEfiEventLegacyBootGuid                       ## CONSUMES  ## Event
 
 [Pcd]
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber        ## CONSUMES
diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index 7ba4b80..793d947 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -22,6 +22,7 @@
 CPU_MP_DATA      *mCpuMpData = NULL;
 EFI_EVENT        mCheckAllApsEvent = NULL;
 EFI_EVENT        mMpInitExitBootServicesEvent = NULL;
+EFI_EVENT        mLegacyBootEvent = NULL;
 volatile BOOLEAN mStopCheckAllApsStatus = TRUE;
 VOID             *mReservedApLoopFunc = NULL;
 
@@ -340,6 +341,7 @@ InitMpGlobalData (
                   AP_CHECK_INTERVAL
                   );
   ASSERT_EFI_ERROR (Status);
+
   Status = gBS->CreateEvent (
                   EVT_SIGNAL_EXIT_BOOT_SERVICES,
                   TPL_CALLBACK,
@@ -348,6 +350,16 @@ InitMpGlobalData (
                   &mMpInitExitBootServicesEvent
                   );
   ASSERT_EFI_ERROR (Status);
+
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  MpInitChangeApLoopCallback,
+                  NULL,
+                  &gEfiEventLegacyBootGuid,
+                  &mLegacyBootEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
 }
 
 /**
-- 
2.9.3.windows.2