[PATCH v3] 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 PciRootBridgeIo
 protocol to get the root bus count. 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>
Cc: Kolakowski Jacek <Jacek.Kolakowski@intel.com>
---
 .../Feature/VTd/IntelVTdDxe/DmaProtection.h        | 17 +++++
 .../Feature/VTd/IntelVTdDxe/DmarAcpiTable.c        |  2 +-
 .../Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf        |  1 +
 .../Feature/VTd/IntelVTdDxe/PciInfo.c              | 72 ++++++++++++++++++++++
 4 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
index a24fbc37..7dd29a24 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.h
@@ -33,6 +33,7 @@
 #include <Protocol/PciEnumerationComplete.h>
 #include <Protocol/PlatformVtdPolicy.h>
 #include <Protocol/IoMmu.h>
+#include <Protocol/PciRootBridgeIo.h>
 
 #include <IndustryStandard/Pci.h>
 #include <IndustryStandard/DmaRemappingReportingTable.h>
@@ -341,6 +342,22 @@ ScanPciBus (
   IN SCAN_BUS_FUNC_CALLBACK_FUNC  Callback
   );
 
+/**
+  Scan PCI bus and invoke callback function for each PCI devices under all root bus.
+
+  @param[in]  Context               The context of the callback function.
+  @param[in]  Segment               The segment of the source.
+  @param[in]  Callback              The callback function in PCI scan.
+
+  @retval EFI_SUCCESS           The PCI devices under the bus are scaned.
+**/
+EFI_STATUS
+ScanAllPciBus (
+  IN VOID                         *Context,
+  IN UINT16                       Segment,
+  IN SCAN_BUS_FUNC_CALLBACK_FUNC  Callback
+  );
+
 /**
   Dump the PCI device information managed by this VTd engine.
 
diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
index 2d9b4374..1ee290b7 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmarAcpiTable.c
@@ -692,7 +692,7 @@ ProcessDhrd (
     mVtdUnitInformation[VtdIndex].PciDeviceInfo.IncludeAllFlag = TRUE;
     DEBUG ((DEBUG_INFO,"  ProcessDhrd: with INCLUDE ALL\n"));
 
-    Status = ScanPciBus((VOID *)VtdIndex, DmarDrhd->SegmentNumber, 0, ScanBusCallbackRegisterPciDevice);
+    Status = ScanAllPciBus((VOID *)VtdIndex, DmarDrhd->SegmentNumber, ScanBusCallbackRegisterPciDevice);
     if (EFI_ERROR (Status)) {
       return Status;
     }
diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
index 220636ad..387f90e3 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.inf
@@ -70,6 +70,7 @@
   gEfiPciIoProtocolGuid                       ## CONSUMES
   gEfiPciEnumerationCompleteProtocolGuid      ## CONSUMES
   gEdkiiPlatformVTdPolicyProtocolGuid         ## SOMETIMES_CONSUMES
+  gEfiPciRootBridgeIoProtocolGuid             ## CONSUMES
 
 [Pcd]
   gIntelSiliconPkgTokenSpaceGuid.PcdVTdPolicyPropertyMask   ## CONSUMES
diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/PciInfo.c b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/PciInfo.c
index 4af376b3..cffb9f61 100644
--- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/PciInfo.c
+++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/PciInfo.c
@@ -279,6 +279,78 @@ ScanPciBus (
   return EFI_SUCCESS;
 }
 
+/**
+  Scan PCI bus and invoke callback function for each PCI devices under all root bus.
+
+  @param[in]  Context               The context of the callback function.
+  @param[in]  Segment               The segment of the source.
+  @param[in]  Callback              The callback function in PCI scan.
+
+  @retval EFI_SUCCESS           The PCI devices under the bus are scaned.
+**/
+EFI_STATUS
+ScanAllPciBus (
+  IN VOID                         *Context,
+  IN UINT16                       Segment,
+  IN SCAN_BUS_FUNC_CALLBACK_FUNC  Callback
+  )
+{
+  EFI_STATUS                        Status;
+  UINTN                             Index;
+  UINTN                             HandleCount;
+  EFI_HANDLE                        *HandleBuffer;
+  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL   *PciRootBridgeIo;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptors;
+
+  DEBUG ((DEBUG_INFO, "ScanAllPciBus ()\n"));
+
+  Status = gBS->LocateHandleBuffer (
+                  ByProtocol,
+                  &gEfiPciRootBridgeIoProtocolGuid,
+                  NULL,
+                  &HandleCount,
+                  &HandleBuffer
+                  );
+  if (EFI_ERROR (Status)) {
+    //
+    // If PciRootBridgeIo protocol is not support, scan PCI device from root bus 0x00.
+    //
+    Status = ScanPciBus(Context, Segment, 0x00, Callback);
+    return Status;
+  }
+
+  DEBUG ((DEBUG_INFO,"Find %d root bridges\n", HandleCount));
+
+  for (Index = 0; Index < HandleCount; Index++) {
+    Status = gBS->HandleProtocol (
+                    HandleBuffer[Index],
+                    &gEfiPciRootBridgeIoProtocolGuid,
+                    (VOID **) &PciRootBridgeIo
+                    );
+    ASSERT_EFI_ERROR (Status);
+
+    Status = PciRootBridgeIo->Configuration (PciRootBridgeIo, (VOID **) &Descriptors);
+    ASSERT_EFI_ERROR (Status);
+
+    while (Descriptors->Desc != ACPI_END_TAG_DESCRIPTOR) {
+      if (Descriptors->ResType == ACPI_ADDRESS_SPACE_TYPE_BUS) {
+        break;
+      }
+      Descriptors++;
+    }
+
+    DEBUG ((DEBUG_INFO,"Scan root bridges : %d, Segment : %d, Bus : 0x%02X\n", Index, PciRootBridgeIo->SegmentNumber, Descriptors->AddrRangeMin));
+    Status = ScanPciBus(Context, (UINT16) PciRootBridgeIo->SegmentNumber, (UINT8) Descriptors->AddrRangeMin, Callback);
+    if (EFI_ERROR (Status)) {
+      break;
+    }
+  }
+
+  FreePool(HandleBuffer);
+
+  return Status;
+}
+
 /**
   Dump the PCI device information managed by this VTd engine.
 
-- 
2.16.2.windows.1