From e542e05d4fc2e4aeae752db5d429e2f4650cd5ee Mon Sep 17 00:00:00 2001
From: Michael Kubacki <michael.kubacki@microsoft.com>
Date: Wed, 17 Feb 2021 13:32:26 -0800
Subject: [PATCH] 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>
---
 .../SmmCpuFeaturesLib/CpuFeaturesLib.h        | 14 ++++++++++
 .../SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf   |  1 +
 .../SmmCpuFeaturesLibCommon.c                 |  2 +-
 .../SmmCpuFeaturesLibStm.inf                  |  1 +
 .../TraditionalMmCpuFeaturesLib.c             | 28 +++++++++++++++++++
 5 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 UefiCpuPkg/Library/SmmCpuFeaturesLib/TraditionalMmCpuFeaturesLib.c

diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/CpuFeaturesLib.h b/UefiCpuPkg/Library/SmmCpuFeaturesLib/CpuFeaturesLib.h
index c18521fd9c..8a1c2adc5c 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/CpuFeaturesLib.h
+++ b/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
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
index ddd00eeceb..35292dac31 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
@@ -21,6 +21,7 @@
   SmmCpuFeaturesLib.c
   SmmCpuFeaturesLibCommon.c
   SmmCpuFeaturesLibNoStm.c
+  TraditionalMmCpuFeaturesLib.c
 
 [Packages]
   MdePkg/MdePkg.dec
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c
index 7a919c5ee7..50379f3aea 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibCommon.c
+++ b/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);
 }
 
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
index 78f8e4b42c..022351f593 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
@@ -22,6 +22,7 @@
   SmmCpuFeaturesLibCommon.c
   SmmStm.c
   SmmStm.h
+  TraditionalMmCpuFeaturesLib.c
 
 [Sources.Ia32]
   Ia32/SmmStmSupport.c
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/TraditionalMmCpuFeaturesLib.c b/UefiCpuPkg/Library/SmmCpuFeaturesLib/TraditionalMmCpuFeaturesLib.c
new file mode 100644
index 0000000000..b7a5c1926e
--- /dev/null
+++ b/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);
+}