[PATCH] SourceLevelDebugPkg/DebugCommLibUsb3Pei: Make sure alloc physical mem

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

PI 1.6 has supported pre permanent memory page allocation,
to make sure the allocated memory is physical memory for DMA,
the patch is to check memory discovered PPI installed or not first
before calling AllocatePages.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 .../DebugCommunicationLibUsb3Pei.c                 | 28 +++++++++++++++-------
 .../DebugCommunicationLibUsb3Pei.inf               |  5 +++-
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.c b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.c
index be3174e75fd6..902a3b626acc 100644
--- a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.c
+++ b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.c
@@ -1,7 +1,7 @@
 /** @file
   Debug Port Library implementation based on usb3 debug port.
 
-  Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2014 - 2017, 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
@@ -14,6 +14,7 @@
 
 #include <PiPei.h>
 #include <Library/PeiServicesLib.h>
+#include <Ppi/MemoryDiscovered.h>
 #include "DebugCommunicationLibUsb3Internal.h"
 
 /**
@@ -32,13 +33,24 @@ AllocateAlignBuffer (
   VOID                     *Buf;
   EFI_PHYSICAL_ADDRESS     Address;
   EFI_STATUS               Status;
-  
-  Buf = NULL;  
-  Status = PeiServicesAllocatePages (EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (BufferSize), &Address);
-  if (EFI_ERROR (Status)) {
-    Buf = NULL;
-  } else {
-    Buf = (VOID *)(UINTN) Address;
+  VOID                     *MemoryDiscoveredPpi;
+
+  Buf = NULL;
+
+  //
+  // Make sure the allocated memory is physical memory.
+  //
+  Status = PeiServicesLocatePpi (
+             &gEfiPeiMemoryDiscoveredPpiGuid,
+             0,
+             NULL,
+             (VOID **) &MemoryDiscoveredPpi
+             );
+  if (!EFI_ERROR (Status)) {
+    Status = PeiServicesAllocatePages (EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (BufferSize), &Address);
+    if (!EFI_ERROR (Status)) {
+      Buf = (VOID *)(UINTN) Address;
+    }
   }
   return Buf;
 }
diff --git a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.inf b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.inf
index 74dcdd124b47..6cd5e1068333 100644
--- a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.inf
+++ b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Pei.inf
@@ -1,7 +1,7 @@
 ## @file
 #  Debug Communication Library instance based on usb3 debug port.
 #
-#  Copyright (c) 2014 - 2015, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2014 - 2017, 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
@@ -40,6 +40,9 @@ [Packages]
   IntelFrameworkPkg/IntelFrameworkPkg.dec
   SourceLevelDebugPkg/SourceLevelDebugPkg.dec
 
+[Ppis]
+  gEfiPeiMemoryDiscoveredPpiGuid                ## CONSUMES
+
 [Pcd]
   # The memory BAR of ehci host controller, in which usb debug feature is enabled.
   # Note that the memory BAR address is only used before Pci bus resource allocation.
-- 
2.7.0.windows.1