UefiCpuPkg/SmmCpuFeaturesLib: Abstract PcdCpuMaxLogicalProcessorNumber

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3218

Adds a new function called GetCpuMaxLogicalProcessorNumber() to
return the number of maximum CPU logical processors (currently
gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber).

This allows the the mechanism used to retrieve the CPU maximum
logical processor number to be abstracted from the logic that
needs the value.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210217213227.1277-5-mikuback@linux.microsoft.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

UefiCpuPkg/Library/SmmCpuFeaturesLib/CpuFeaturesLib.h

@@ -31,4 +31,18 @@ FinishSmmCpuFeaturesInitializeProcessor (
   VOID
   );
 
+/**
+  Gets the maximum number of logical processors from the PCD PcdCpuMaxLogicalProcessorNumber.
+
+  This access is abstracted from the PCD services to enforce that the PCD be
+  FixedAtBuild in the Standalone MM build of this driver.
+
+  @return  The value of PcdCpuMaxLogicalProcessorNumber.
+
+**/
+UINT32
+GetCpuMaxLogicalProcessorNumber (
+  VOID
+  );
+
 #endif

UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf

@@ -21,6 +21,7 @@
   SmmCpuFeaturesLib.c
   SmmCpuFeaturesLibCommon.c
   SmmCpuFeaturesLibNoStm.c
+  TraditionalMmCpuFeaturesLib.c
 
 [Packages]
   MdePkg/MdePkg.dec

UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c

@@ -157,7 +157,7 @@ CpuFeaturesLibInitialization (
   //
   // Allocate array for state of SMRR enable on all CPUs
   //
-  mSmrrEnabled = (BOOLEAN *)AllocatePool (sizeof (BOOLEAN) * PcdGet32 (PcdCpuMaxLogicalProcessorNumber));
+  mSmrrEnabled = (BOOLEAN *)AllocatePool (sizeof (BOOLEAN) * GetCpuMaxLogicalProcessorNumber ());
   ASSERT (mSmrrEnabled != NULL);
 }
 

UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf

@@ -22,6 +22,7 @@
   SmmCpuFeaturesLibCommon.c
   SmmStm.c
   SmmStm.h
+  TraditionalMmCpuFeaturesLib.c
 
 [Sources.Ia32]
   Ia32/SmmStmSupport.c

UefiCpuPkg/Library/SmmCpuFeaturesLib/TraditionalMmCpuFeaturesLib.c

@@ -0,0 +1,28 @@
+/** @file
+  Traditional MM CPU specific programming.
+
+  Copyright (c) Microsoft Corporation.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Library/PcdLib.h>
+#include "CpuFeaturesLib.h"
+
+/**
+  Gets the maximum number of logical processors from the PCD PcdCpuMaxLogicalProcessorNumber.
+
+  This access is abstracted from the PCD services to enforce that the PCD be
+  FixedAtBuild in the Standalone MM build of this driver.
+
+  @return  The value of PcdCpuMaxLogicalProcessorNumber.
+
+**/
+UINT32
+GetCpuMaxLogicalProcessorNumber (
+  VOID
+  )
+{
+  return PcdGet32 (PcdCpuMaxLogicalProcessorNumber);
+}