From eefa8f8bf29a4547b9612159cdb6cf864efc1bb4 Mon Sep 17 00:00:00 2001
From: Krzysztof Koch <krzysztof.koch@arm.com>
Date: Mon, 22 Jul 2019 15:50:22 -0700
Subject: [PATCH] ShellPkg: acpiview: XSDT: Remove redundant ParseAcpi() call

Remove a call to ParseAcpi() responsible for getting the XSDT table
length. This call is not needed because the ACPI table buffer length is
provided as an input argument to the ParseAcpiXsdt() function.

Modify remaining code to use the AcpiTableLength argument of the
ParseAcpiXsdt() function instead of a global static variable.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Zhichao Gao <zhichao.gao@intel.com>
---
 .../Parsers/Xsdt/XsdtParser.c                  | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Xsdt/XsdtParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Xsdt/XsdtParser.c
index 4196168bff..e39061f8e2 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Xsdt/XsdtParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Xsdt/XsdtParser.c
@@ -1,7 +1,7 @@
 /** @file
   XSDT table parser
 
-  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.
+  Copyright (c) 2016 - 2019, ARM Limited. All rights reserved.
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
   @par Reference(s):
@@ -60,22 +60,12 @@ ParseAcpiXsdt (
   UINTN         EntryIndex;
   CHAR16        Buffer[32];
 
-  // Parse the ACPI header to get the length
-  ParseAcpi (
-    FALSE,
-    0,
-    "XSDT",
-    Ptr,
-    ACPI_DESCRIPTION_HEADER_LENGTH,
-    PARSER_PARAMS (XsdtParser)
-    );
-
   Offset = ParseAcpi (
              Trace,
              0,
              "XSDT",
              Ptr,
-             *AcpiHdrInfo.Length,
+             AcpiTableLength,
              PARSER_PARAMS (XsdtParser)
              );
 
@@ -84,7 +74,7 @@ ParseAcpiXsdt (
   if (Trace) {
     EntryIndex = 0;
     TablePointer = (UINT64*)(Ptr + TableOffset);
-    while (Offset < (*AcpiHdrInfo.Length)) {
+    while (Offset < AcpiTableLength) {
       CONST UINT32* Signature;
       CONST UINT32* Length;
       CONST UINT8*  Revision;
@@ -140,7 +130,7 @@ ParseAcpiXsdt (
   // Process the tables
   Offset = TableOffset;
   TablePointer = (UINT64*)(Ptr + TableOffset);
-  while (Offset < (*AcpiHdrInfo.Length)) {
+  while (Offset < AcpiTableLength) {
     if ((UINT64*)(UINTN)(*TablePointer) != NULL) {
       ProcessAcpiTable ((UINT8*)(UINTN)(*TablePointer));
     }