[edk2-staging/UEFI_PCI_ENHANCE-2 PATCH 05/15] MdeModulePkg/PciBusDxe: Locate PciePlatform/PcieOverride protocol

["Javeed, Ashraf" <ashraf.javeed@intel.com>]

REF:
  https://bugzilla.tianocore.org/show_bug.cgi?id=1954
  https://bugzilla.tianocore.org/show_bug.cgi?id=2194
  https://bugzilla.tianocore.org/show_bug.cgi?id=2313
  https://bugzilla.tianocore.org/show_bug.cgi?id=2499
  https://bugzilla.tianocore.org/show_bug.cgi?id=2500

Signed-off-by: Ashraf Javeed <ashraf.javeed@intel.com>
Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Ashraf Javeed <ashraf.javeed@intel.com>
---
 MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c             |  5 +++++
 MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h             |  1 +
 MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf        |  2 ++
 MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.h | 25 +++++++++++++++++++++++++
 5 files changed, 77 insertions(+)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c
index 53e6dfa..a139bed 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c
@@ -285,6 +285,11 @@ PciBusDriverBindingStart (
           );
   }
 
+  //
+  // get the PCI Express Protocol or the PCI Express Override Protocol
+  //
+  InitializePciExpressProtocols ();
+
   if (mIoMmuProtocol == NULL) {
     gBS->LocateProtocol (
           &gEdkiiIoMmuProtocolGuid,
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
index 9947203..ccf9ffa 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.h
@@ -82,6 +82,7 @@ typedef enum {
 #include "PciPowerManagement.h"
 #include "PciHotPlugSupport.h"
 #include "PciLib.h"
+#include "PcieFeatureSupport.h"
 
 #define VGABASE1  0x3B0
 #define VGALIMIT1 0x3BB
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
index 3b1559e..0818153 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciBusDxe.inf
@@ -57,6 +57,8 @@
   PciCommand.h
   PciIo.h
   PciBus.h
+  PcieFeatureSupport.c
+  PcieFeatureSupport.h
 
 [Packages]
   MdePkg/MdePkg.dec
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.c
new file mode 100644
index 0000000..13d0e0b
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.c
@@ -0,0 +1,44 @@
+/** @file
+  PCI standard feature support functions implementation for PCI Bus module..
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "PciBus.h"
+#include "PcieFeatureSupport.h"
+EFI_PCI_EXPRESS_PLATFORM_PROTOCOL    *mPciePlatformProtocol;
+
+/**
+  This function retrieves the PCI Express Platform Protocols published by platform
+  @retval EFI_STATUS          direct return status from the LocateProtocol ()
+                              boot service for the PCI Express Override Protocol.
+          EFI_SUCCESS         The PCI Express Platform Protocol is found.
+**/
+EFI_STATUS
+InitializePciExpressProtocols (
+  VOID
+  )
+{
+  EFI_STATUS                      Status;
+
+  Status = gBS->LocateProtocol (
+                  &gEfiPciExpressPlatformProtocolGuid,
+                  NULL,
+                  (VOID **) &mPciePlatformProtocol
+                  );
+  if (EFI_ERROR (Status)) {
+    //
+    // If PCI Express Platform protocol doesn't exist, try to get the Pci Express
+    // Override Protocol and treat it as PCI Express Platform protocol.
+    //
+    Status = gBS->LocateProtocol (
+                    &gEfiPciExpressOverrideProtocolGuid,
+                    NULL,
+                    (VOID **) &mPciePlatformProtocol
+                    );
+  }
+  return Status;
+}
+
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.h b/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.h
new file mode 100644
index 0000000..5d15e0a
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PcieFeatureSupport.h
@@ -0,0 +1,25 @@
+/** @file
+  PCI standard feature support functions implementation for PCI Bus module..
+
+Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef __PCIE_FEATURE_SUPPORT_H__
+#define __PCIE_FEATURE_SUPPORT_H__
+
+extern EFI_PCI_EXPRESS_PLATFORM_PROTOCOL *mPciePlatformProtocol;
+/**
+  This function retrieves the PCI Express Platform Protocols published by platform
+  @retval EFI_STATUS          direct return status from the LocateProtocol ()
+                              boot service for the PCI Express Override Protocol
+          EFI_SUCCESS         The PCI Express Platform Protocol is found
+**/
+EFI_STATUS
+InitializePciExpressProtocols (
+  VOID
+  );
+
+
+#endif
-- 
2.21.0.windows.1