From: Jeff Fan <jeff.fan@intel.com>
Date: Wed, 2 Dec 2015 00:43:45 +0000 (+0000)
Subject: UefiCpuPkg/CpuMpPei: Save/Restore CRx/DRx register for APs waking up
X-Git-Tag: edk2-stable201903~8401
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=f40a7de45070dfa193e47ed0031cc07c275287b3

UefiCpuPkg/CpuMpPei: Save/Restore CRx/DRx register for APs waking up

PeiStartupAllAPs()/PeiStartupThisAP() will send INIT-SIPI-SIPI to wakeup APs to
execute AP function. However, some registers will be reset after APs received
INIT IPI. We need to restore some registers (For example, CRx/DRx) manually
after APs wakeup.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@Intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19089 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
index 53af9489b2..ca48613502 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
@@ -259,6 +259,11 @@ ApCFunction (
     // Execute AP function if AP is not disabled
     //
     GetProcessorNumber (PeiCpuMpData, &ProcessorNumber);
+    //
+    // Restore AP's volatile registers saved
+    //
+    RestoreVolatileRegisters (&PeiCpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE);
+
     if ((PeiCpuMpData->CpuData[ProcessorNumber].State != CpuStateDisabled) &&
         (PeiCpuMpData->ApFunction != 0)) {
       PeiCpuMpData->CpuData[ProcessorNumber].State = CpuStateBusy;
@@ -273,6 +278,11 @@ ApCFunction (
   //
   InterlockedIncrement ((UINT32 *)&PeiCpuMpData->FinishedCount);
 
+  //
+  // Save AP volatile registers
+  //
+  SaveVolatileRegisters (&PeiCpuMpData->CpuData[ProcessorNumber].VolatileRegisters);
+
   AsmCliHltLoop ();
 }