From 9bc7a361200215fc5065dfaa6d90d4eb50fec00c Mon Sep 17 00:00:00 2001
From: Zhiguang Liu <zhiguang.liu@intel.com>
Date: Mon, 3 Jun 2024 13:31:19 +0800
Subject: [PATCH] UefiCpuPkg: Removing redundant parameter in
 RestoreVolatileRegisters

Given that the second parameter can be universally set to TRUE across
all use cases, its removal simplifies the function interface and the
associated code paths.

Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/MpLib.c | 45 +++++++++++++---------------
 1 file changed, 20 insertions(+), 25 deletions(-)

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index c3b1620b14..4088e76f45 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -41,8 +41,7 @@ SaveVolatileRegisters (
 **/
 VOID
 RestoreVolatileRegisters (
-  IN CPU_VOLATILE_REGISTERS  *VolatileRegisters,
-  IN BOOLEAN                 IsRestoreDr
+  IN CPU_VOLATILE_REGISTERS  *VolatileRegisters
   );
 
 /**
@@ -118,7 +117,7 @@ FutureBSPProc (
   //
   SaveVolatileRegisters (&DataInHob->APInfo.VolatileRegisters);
   AsmExchangeRole (&DataInHob->APInfo, &DataInHob->BSPInfo);
-  RestoreVolatileRegisters (&DataInHob->APInfo.VolatileRegisters, TRUE);
+  RestoreVolatileRegisters (&DataInHob->APInfo.VolatileRegisters);
 }
 
 /**
@@ -244,13 +243,11 @@ SaveVolatileRegisters (
   Restore the volatile registers following INIT IPI.
 
   @param[in]  VolatileRegisters   Pointer to volatile resisters
-  @param[in]  IsRestoreDr         TRUE:  Restore DRx if supported
-                                  FALSE: Do not restore DRx
+
 **/
 VOID
 RestoreVolatileRegisters (
-  IN CPU_VOLATILE_REGISTERS  *VolatileRegisters,
-  IN BOOLEAN                 IsRestoreDr
+  IN CPU_VOLATILE_REGISTERS  *VolatileRegisters
   )
 {
   CPUID_VERSION_INFO_EDX  VersionInfoEdx;
@@ -260,20 +257,18 @@ RestoreVolatileRegisters (
   AsmWriteCr4 (VolatileRegisters->Cr4);
   AsmWriteCr0 (VolatileRegisters->Cr0);
 
-  if (IsRestoreDr) {
-    AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &VersionInfoEdx.Uint32);
-    if (VersionInfoEdx.Bits.DE != 0) {
-      //
-      // If processor supports Debugging Extensions feature
-      // by CPUID.[EAX=01H]:EDX.BIT2
-      //
-      AsmWriteDr0 (VolatileRegisters->Dr0);
-      AsmWriteDr1 (VolatileRegisters->Dr1);
-      AsmWriteDr2 (VolatileRegisters->Dr2);
-      AsmWriteDr3 (VolatileRegisters->Dr3);
-      AsmWriteDr6 (VolatileRegisters->Dr6);
-      AsmWriteDr7 (VolatileRegisters->Dr7);
-    }
+  AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &VersionInfoEdx.Uint32);
+  if (VersionInfoEdx.Bits.DE != 0) {
+    //
+    // If processor supports Debugging Extensions feature
+    // by CPUID.[EAX=01H]:EDX.BIT2
+    //
+    AsmWriteDr0 (VolatileRegisters->Dr0);
+    AsmWriteDr1 (VolatileRegisters->Dr1);
+    AsmWriteDr2 (VolatileRegisters->Dr2);
+    AsmWriteDr3 (VolatileRegisters->Dr3);
+    AsmWriteDr6 (VolatileRegisters->Dr6);
+    AsmWriteDr7 (VolatileRegisters->Dr7);
   }
 
   AsmWriteGdtr (&VolatileRegisters->Gdtr);
@@ -769,7 +764,7 @@ ApWakeupFunction (
       //   to initialize AP in InitConfig path.
       // NOTE: IDTR.BASE stored in CpuMpData->CpuData[ProcessorNumber].VolatileRegisters points to a different IDT shared by all APs.
       //
-      RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE);
+      RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters);
       InitializeApData (CpuMpData, ProcessorNumber, BistData, ApTopOfStack);
       ApStartupSignalBuffer = CpuMpData->CpuData[ProcessorNumber].StartupApSignal;
     } else {
@@ -796,7 +791,7 @@ ApWakeupFunction (
         0
         );
 
-      RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE);
+      RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters);
 
       if (GetApState (&CpuMpData->CpuData[ProcessorNumber]) == CpuStateReady) {
         Procedure = (EFI_AP_PROCEDURE)CpuMpData->CpuData[ProcessorNumber].ApFunction;
@@ -902,7 +897,7 @@ DxeApEntryPoint (
     AsmWriteMsr64 (MSR_IA32_EFER, EferMsr.Uint64);
   }
 
-  RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE);
+  RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters);
   InterlockedIncrement ((UINT32 *)&CpuMpData->FinishedCount);
   PlaceAPInMwaitLoopOrRunLoop (
     CpuMpData->ApLoopMode,
@@ -2607,7 +2602,7 @@ SwitchBSPWorker (
   //
   SaveVolatileRegisters (&CpuMpData->BSPInfo.VolatileRegisters);
   AsmExchangeRole (&CpuMpData->BSPInfo, &CpuMpData->APInfo);
-  RestoreVolatileRegisters (&CpuMpData->BSPInfo.VolatileRegisters, TRUE);
+  RestoreVolatileRegisters (&CpuMpData->BSPInfo.VolatileRegisters);
   //
   // Set the BSP bit of MSR_IA32_APIC_BASE on new BSP
   //