[PATCH v2] IntelSiliconPkg/IntelVTdDxe: Support Multi PCI Root Bus

["Sheng Wei" <w.sheng@intel.com>]

Some system may has multi PCI root bus. It needs to use function
 PciHostBridgeGetRootBridges () to get the root bus count. Then,
 scan each root bus to get all devices.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3695

Signed-off-by: Robert Kowalewski <robert.kowalewski@intel.com>
Signed-off-by: Sheng Wei <w.sheng@intel.com>
Cc: Jenny Huang <jenny.huang@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Robert Kowalewski <robert.kowalewski@intel.com>
Cc: Albecki Mateusz <mateusz.albecki@intel.com>
---
 .../Feature/VTd/IntelVTdDxe/DmaProtection.h             |  1 +
 .../Feature/VTd/IntelVTdDxe/DmarAcpiTable.c             | 17 ++++++++++++++---
 .../Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf             |  1 +
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
index a24fbc37..97061de5 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
@@ -23,6 +23,7 @@
 #include <Library/PerformanceLib.h>
 #include <Library/PrintLib.h>
 #include <Library/ReportStatusCodeLib.h>
+#include <Library/PciHostBridgeLib.h>
 
 #include <Guid/EventGroup.h>
 #include <Guid/Acpi.h>
diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
index 2d9b4374..e717aeb2 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
@@ -682,6 +682,9 @@ ProcessDhrd (
   UINT8                                             SecondaryBusNumber;
   EFI_STATUS                                        Status;
   VTD_SOURCE_ID                                     SourceId;
+  PCI_ROOT_BRIDGE                                   *RootBridges;
+  UINTN                                             RootBridgeCount;
+  UINTN                                             Index;
 
   mVtdUnitInformation[VtdIndex].VtdUnitBaseAddress = (UINTN)DmarDrhd->RegisterBaseAddress;
   DEBUG ((DEBUG_INFO,"  VTD (%d) BaseAddress -  0x%016lx\n", VtdIndex, DmarDrhd->RegisterBaseAddress));
@@ -692,9 +695,17 @@ ProcessDhrd (
     mVtdUnitInformation[VtdIndex].PciDeviceInfo.IncludeAllFlag = TRUE;
     DEBUG ((DEBUG_INFO,"  ProcessDhrd: with INCLUDE ALL\n"));
 
-    Status = ScanPciBus((VOID *)VtdIndex, DmarDrhd->SegmentNumber, 0, ScanBusCallbackRegisterPciDevice);
-    if (EFI_ERROR (Status)) {
-      return Status;
+    RootBridges = PciHostBridgeGetRootBridges (&RootBridgeCount);
+    if ((RootBridges == NULL) || (RootBridgeCount == 0)) {
+      return EFI_UNSUPPORTED;
+    }
+    DEBUG ((DEBUG_INFO,"Find %d root bridges\n", RootBridgeCount));
+    for (Index = 0; Index < RootBridgeCount; Index++) {
+      DEBUG ((DEBUG_INFO,"Scan root bridges : %d, Segment : %d, Bus : 0x%02X\n", Index, RootBridges[Index].Segment, RootBridges[Index].Bus.Base));
+      Status = ScanPciBus((VOID *)VtdIndex, (UINT16) RootBridges[Index].Segment, (UINT8) RootBridges[Index].Bus.Base, ScanBusCallbackRegisterPciDevice);
+      if (EFI_ERROR (Status)) {
+        return Status;
+      }
     }
   } else {
     mVtdUnitInformation[VtdIndex].PciDeviceInfo.IncludeAllFlag = FALSE;
diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
index 220636ad..25ff86f4 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
@@ -55,6 +55,7 @@
   PerformanceLib
   PrintLib
   ReportStatusCodeLib
+  PciHostBridgeLib
 
 [Guids]
   gEfiEventExitBootServicesGuid   ## CONSUMES ## Event
-- 
2.16.2.windows.1