ArmVirtPkg/ArmVirtXen: move from VirtFdtDxe to new XenioFdtDxe driver

Now that the only functionality that remains in VirtFdtDxe is enumerating
the respective virtual I/O buses, it no longer makes sense to have a driver
that is shared between Xen domU and QEMU. So move the Xen I/O DT node
handling to a new driver, and update ArmVirtXen to switch to it.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

ArmVirtPkg/ArmVirtXen.dsc

@@ -195,7 +195,7 @@
   #
   # Platform Driver
   #
-  ArmVirtPkg/VirtFdtDxe/VirtFdtDxe.inf
+  ArmVirtPkg/XenioFdtDxe/XenioFdtDxe.inf
   ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf
 
   #

ArmVirtPkg/ArmVirtXen.fdf

@@ -125,7 +125,7 @@ READ_LOCK_STATUS   = TRUE
 
   INF MdeModulePkg/Core/Dxe/DxeMain.inf
   INF MdeModulePkg/Universal/PCD/Dxe/Pcd.inf
-  INF ArmVirtPkg/VirtFdtDxe/VirtFdtDxe.inf
+  INF ArmVirtPkg/XenioFdtDxe/XenioFdtDxe.inf
   INF ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf
 
   #

ArmVirtPkg/XenioFdtDxe/XenioFdtDxe.c

@@ -0,0 +1,68 @@
+/** @file
+*  Xenio FDT client protocol driver for xen,xen DT node
+*
+*  Copyright (c) 2016, Linaro Ltd. 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 <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/XenIoMmioLib.h>
+
+#include <Protocol/FdtClient.h>
+
+EFI_STATUS
+EFIAPI
+InitializeXenioFdtDxe (
+  IN EFI_HANDLE           ImageHandle,
+  IN EFI_SYSTEM_TABLE     *SystemTable
+  )
+{
+  EFI_STATUS            Status;
+  FDT_CLIENT_PROTOCOL   *FdtClient;
+  CONST UINT64          *Reg;
+  UINT32                RegElemSize, RegSize;
+  EFI_HANDLE            Handle;
+  UINT64                RegBase;
+
+  Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
+                  (VOID **)&FdtClient);
+  ASSERT_EFI_ERROR (Status);
+
+  Status = FdtClient->FindCompatibleNodeReg (FdtClient, "xen,xen",
+                        (CONST VOID **)&Reg, &RegElemSize, &RegSize);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((EFI_D_WARN, "%a: No 'xen,xen' compatible DT node found\n",
+      __FUNCTION__));
+    return EFI_UNSUPPORTED;
+  }
+
+  ASSERT (RegSize == 16);
+
+  //
+  // Retrieve the reg base from this node and wire it up to the
+  // MMIO flavor of the XenBus root device I/O protocol
+  //
+  RegBase = SwapBytes64 (Reg[0]);
+  Handle = NULL;
+  Status = XenIoMmioInstall (&Handle, RegBase);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((EFI_D_ERROR, "%a: XenIoMmioInstall () failed on a new handle "
+      "(Status == %r)\n", __FUNCTION__, Status));
+    return Status;
+  }
+
+  DEBUG ((EFI_D_INFO, "Found Xen node with Grant table @ 0x%Lx\n", RegBase));
+
+  return EFI_SUCCESS;
+}

ArmVirtPkg/XenioFdtDxe/XenioFdtDxe.inf

@@ -0,0 +1,44 @@
+## @file
+#  Xenio FDT client protocol driver for xen,xen DT node
+#
+#  Copyright (c) 2016, Linaro Ltd. 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.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = XenioFdtDxe
+  FILE_GUID                      = 338695EA-CA84-4FA2-9DA8-5C4BB87905C6
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+
+  ENTRY_POINT                    = InitializeXenioFdtDxe
+
+[Sources]
+  XenioFdtDxe.c
+
+[Packages]
+  ArmVirtPkg/ArmVirtPkg.dec
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  XenIoMmioLib
+
+[Protocols]
+  gFdtClientProtocolGuid                                ## CONSUMES
+
+[Depex]
+  gFdtClientProtocolGuid