From 484dc05005ea80280e184b20a6b8a08636276777 Mon Sep 17 00:00:00 2001
From: Star Zeng <star.zeng@intel.com>
Date: Sat, 25 May 2019 15:05:47 +0800
Subject: [PATCH] UefiCpuPkg CpuCommFeaturesLib: Disable TraceEn at the
 beginning

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1809

Current code disables TraceEn at the end of ProcTraceInitialize(),
then there will be much memory allocated even when ProcTrace feature
is disabled.

This patch updates code to disable TraceEn and return at the beginning
of ProcTraceInitialize() when when ProcTrace feature is disabled.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Chandana Kumar <chandana.c.kumar@intel.com>
Cc: Kevin Li <kevin.y.li@intel.com>
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
---
 .../Library/CpuCommonFeaturesLib/ProcTrace.c  | 42 +++++++++----------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/ProcTrace.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/ProcTrace.c
index da6f6beb94..b98eb116b7 100644
--- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/ProcTrace.c
+++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/ProcTrace.c
@@ -199,22 +199,6 @@ ProcTraceInitialize (
   ProcTraceData = (PROC_TRACE_DATA *) ConfigData;
   ASSERT (ProcTraceData != NULL);
 
-  MemRegionBaseAddr = 0;
-  FirstIn = FALSE;
-
-  if (ProcTraceData->ThreadMemRegionTable == NULL) {
-    FirstIn = TRUE;
-    DEBUG ((DEBUG_INFO, "Initialize Processor Trace\n"));
-  }
-
-  ///
-  /// Refer to PROC_TRACE_MEM_SIZE Table for Size Encoding
-  ///
-  MemRegionSize = (UINT32) (1 << (ProcTraceData->ProcTraceMemSize + 12));
-  if (FirstIn) {
-    DEBUG ((DEBUG_INFO, "ProcTrace: MemSize requested: 0x%X \n", MemRegionSize));
-  }
-
   //
   // Clear MSR_IA32_RTIT_CTL[0] and IA32_RTIT_STS only if MSR_IA32_RTIT_CTL[0]==1b
   //
@@ -243,6 +227,26 @@ ProcTraceInitialize (
       );
   }
 
+  if (!State) {
+    return RETURN_SUCCESS;
+  }
+
+  MemRegionBaseAddr = 0;
+  FirstIn = FALSE;
+
+  if (ProcTraceData->ThreadMemRegionTable == NULL) {
+    FirstIn = TRUE;
+    DEBUG ((DEBUG_INFO, "Initialize Processor Trace\n"));
+  }
+
+  ///
+  /// Refer to PROC_TRACE_MEM_SIZE Table for Size Encoding
+  ///
+  MemRegionSize = (UINT32) (1 << (ProcTraceData->ProcTraceMemSize + 12));
+  if (FirstIn) {
+    DEBUG ((DEBUG_INFO, "ProcTrace: MemSize requested: 0x%X \n", MemRegionSize));
+  }
+
   if (FirstIn) {
     //
     //   Let BSP allocate and create the necessary memory region (Aligned to the size of
@@ -459,11 +463,7 @@ ProcTraceInitialize (
   CtrlReg.Bits.OS = 1;
   CtrlReg.Bits.User = 1;
   CtrlReg.Bits.BranchEn = 1;
-  if (!State) {
-    CtrlReg.Bits.TraceEn = 0;
-  } else {
-    CtrlReg.Bits.TraceEn = 1;
-  }
+  CtrlReg.Bits.TraceEn = 1;
   CPU_REGISTER_TABLE_WRITE64 (
     ProcessorNumber,
     Msr,