[PATCH 1/6] MdePkg UefiLib: Add new EfiFindAcpiTableBySignature() API

[Star Zeng <star.zeng@intel.com>]

https://bugzilla.tianocore.org/show_bug.cgi?id=967
Request to add a library function for GetAcpiTable() in order
to get ACPI table using signature as input.

After evaluation, we found there are many duplicated code to
find ACPI table by signature in different modules.

This patch adds new EfiFindAcpiTableBySignature() API in UefiLib
for the request and also the following patch to remove the
duplicated code.

Cc: Younas khan <pmdyounaskhan786@gmail.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdePkg/Include/Library/UefiLib.h   |  17 +++
 MdePkg/Library/UefiLib/Acpi.c      | 226 +++++++++++++++++++++++++++++++++++++
 MdePkg/Library/UefiLib/UefiLib.inf |   3 +
 3 files changed, 246 insertions(+)
 create mode 100644 MdePkg/Library/UefiLib/Acpi.c

diff --git a/MdePkg/Include/Library/UefiLib.h b/MdePkg/Include/Library/UefiLib.h
index f80067f11103..8dd25f324fd2 100644
--- a/MdePkg/Include/Library/UefiLib.h
+++ b/MdePkg/Include/Library/UefiLib.h
@@ -1595,4 +1595,21 @@ EfiOpenFileByDevicePath (
   IN     UINT64                    OpenMode,
   IN     UINT64                    Attributes
   );
+
+/**
+  This function finds ACPI table by signature.
+  It will find the table in gEfiAcpi20TableGuid system configuration table first,
+  and then gEfiAcpi10TableGuid system configuration table.
+
+  @param Signature  ACPI table signature.
+
+  @return ACPI table or NULL if not found.
+
+**/
+VOID *
+EFIAPI
+EfiFindAcpiTableBySignature (
+  IN UINT32     Signature
+  );
+
 #endif
diff --git a/MdePkg/Library/UefiLib/Acpi.c b/MdePkg/Library/UefiLib/Acpi.c
new file mode 100644
index 000000000000..5cb93966b59f
--- /dev/null
+++ b/MdePkg/Library/UefiLib/Acpi.c
@@ -0,0 +1,226 @@
+/** @file
+  This module provides help function for finding ACPI table.
+
+  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "UefiLibInternal.h"
+#include <IndustryStandard/Acpi.h>
+#include <Guid/Acpi.h>
+
+/**
+  This function scans ACPI table in RSDT.
+
+  @param Rsdt       ACPI RSDT
+  @param Signature  ACPI table signature
+
+  @return ACPI table or NULL if not found.
+
+**/
+VOID *
+ScanTableInRSDT (
+  IN EFI_ACPI_DESCRIPTION_HEADER    *Rsdt,
+  IN UINT32                         Signature
+  )
+{
+  UINTN                              Index;
+  UINT32                             EntryCount;
+  UINT32                             *EntryPtr;
+  EFI_ACPI_DESCRIPTION_HEADER        *Table;
+
+  if (Rsdt == NULL) {
+    return NULL;
+  }
+
+  EntryCount = (Rsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT32);
+
+  EntryPtr = (UINT32 *)(Rsdt + 1);
+  for (Index = 0; Index < EntryCount; Index ++, EntryPtr ++) {
+    Table = (EFI_ACPI_DESCRIPTION_HEADER *)((UINTN)(*EntryPtr));
+    if (Table->Signature == Signature) {
+      return Table;
+    }
+  }
+
+  return NULL;
+}
+
+/**
+  This function scans ACPI table in XSDT.
+
+  @param Xsdt       ACPI XSDT
+  @param Signature  ACPI table signature
+
+  @return ACPI table or NULL if not found.
+
+**/
+VOID *
+ScanTableInXSDT (
+  IN EFI_ACPI_DESCRIPTION_HEADER    *Xsdt,
+  IN UINT32                         Signature
+  )
+{
+  UINTN                          Index;
+  UINT32                         EntryCount;
+  UINT64                         EntryPtr;
+  UINTN                          BasePtr;
+  EFI_ACPI_DESCRIPTION_HEADER    *Table;
+
+  if (Xsdt == NULL) {
+    return NULL;
+  }
+
+  EntryCount = (Xsdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / sizeof(UINT64);
+
+  BasePtr = (UINTN)(Xsdt + 1);
+  for (Index = 0; Index < EntryCount; Index ++) {
+    CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * sizeof(UINT64)), sizeof(UINT64));
+    Table = (EFI_ACPI_DESCRIPTION_HEADER *)((UINTN)(EntryPtr));
+    if (Table->Signature == Signature) {
+      return Table;
+    }
+  }
+
+  return NULL;
+}
+
+/**
+  To find Facs in FADT.
+
+  @param Fadt   FADT table pointer
+
+  @return Facs table pointer or NULL if not found.
+
+**/
+EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *
+FindAcpiFacsFromFadt (
+  IN EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE  *Fadt
+  )
+{
+  EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE  *Facs;
+  UINT64                                        Data64;
+
+  if (Fadt == NULL) {
+    return NULL;
+  }
+
+  if (Fadt->Header.Revision < EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_REVISION) {
+    Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
+  } else {
+    CopyMem (&Data64, &Fadt->XFirmwareCtrl, sizeof(UINT64));
+    if (Data64 != 0) {
+      Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Data64;
+    } else {
+      Facs = (EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE *)(UINTN)Fadt->FirmwareCtrl;
+    }
+  }
+  return Facs;
+}
+
+/**
+  To find ACPI table in ACPI ConfigurationTable.
+
+  @param AcpiTableGuid  The guid used to find ACPI ConfigurationTable.
+  @param Signature      ACPI table signature.
+
+  @return ACPI table or NULL if not found.
+
+**/
+VOID  *
+FindAcpiTableInAcpiConfigurationTable (
+  IN EFI_GUID   *AcpiGuid,
+  IN UINT32     Signature
+
+  )
+{
+  EFI_STATUS                                    Status;
+  VOID                                          *Table;
+  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *Rsdp;
+  EFI_ACPI_DESCRIPTION_HEADER                   *Rsdt;
+  EFI_ACPI_DESCRIPTION_HEADER                   *Xsdt;
+  EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt;
+
+  Rsdp = NULL;
+  //
+  // Find ACPI ConfigurationTable (RSD_PTR)
+  //
+  Status = EfiGetSystemConfigurationTable(AcpiGuid, (VOID **)&Rsdp);
+  if (EFI_ERROR (Status) || (Rsdp == NULL)) {
+    return NULL;
+  }
+
+  Table = NULL;
+
+  //
+  // Search XSDT
+  //
+  if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {
+    Xsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->XsdtAddress;
+    if (Signature == EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) {
+      //
+      // It is to find FACS ACPI table,
+      // need find FADT first.
+      //
+      Fadt = ScanTableInXSDT (Xsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
+      Table = FindAcpiFacsFromFadt (Fadt);
+    } else {
+      Table = ScanTableInXSDT (Xsdt, Signature);
+    }
+  }
+
+  if (Table != NULL) {
+    return Table;
+  }
+
+  //
+  // Search RSDT
+  //
+  Rsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN) Rsdp->RsdtAddress;
+  if (Signature == EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) {
+    //
+    // It is to find FACS ACPI table,
+    // need find FADT first.
+    //
+    Fadt = ScanTableInRSDT (Rsdt, EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE);
+    Table = FindAcpiFacsFromFadt (Fadt);
+  } else {
+    Table = ScanTableInRSDT (Rsdt, Signature);
+  }
+
+  return Table;
+}
+
+/**
+  This function finds ACPI table by signature.
+  It will find the table in gEfiAcpi20TableGuid system configuration table first,
+  and then gEfiAcpi10TableGuid system configuration table.
+
+  @param Signature  ACPI table signature.
+
+  @return ACPI table or NULL if not found.
+
+**/
+VOID *
+EFIAPI
+EfiFindAcpiTableBySignature (
+  IN UINT32     Signature
+  )
+{
+  VOID          *Table;
+
+  Table = FindAcpiTableInAcpiConfigurationTable (&gEfiAcpi20TableGuid, Signature);
+  if (Table != NULL) {
+    return Table;
+  }
+
+  return FindAcpiTableInAcpiConfigurationTable (&gEfiAcpi10TableGuid, Signature);
+}
+
diff --git a/MdePkg/Library/UefiLib/UefiLib.inf b/MdePkg/Library/UefiLib/UefiLib.inf
index a6c739ef3d6d..aea20fe67153 100644
--- a/MdePkg/Library/UefiLib/UefiLib.inf
+++ b/MdePkg/Library/UefiLib/UefiLib.inf
@@ -41,6 +41,7 @@ [Sources]
   Console.c
   UefiLib.c
   UefiLibInternal.h
+  Acpi.c
 
 
 [Packages]
@@ -62,6 +63,8 @@ [Guids]
   gEfiEventReadyToBootGuid                      ## SOMETIMES_CONSUMES  ## Event
   gEfiEventLegacyBootGuid                       ## SOMETIMES_CONSUMES  ## Event
   gEfiGlobalVariableGuid                        ## SOMETIMES_CONSUMES  ## Variable
+  gEfiAcpi20TableGuid                           ## SOMETIMES_CONSUMES  ## SystemTable
+  gEfiAcpi10TableGuid                           ## SOMETIMES_CONSUMES  ## SystemTable
 
 [Protocols]
   gEfiDriverBindingProtocolGuid                   ## SOMETIMES_PRODUCES
-- 
2.7.0.windows.1