[PATCH v3 3/5] MdeModulePkg: implement generic PCI I/O driver for non-discoverable devices

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

This implements support for non-discoverable PCI compatible devices, i.e,
devices that are not on a PCI bus but that can be controlled by generic PCI
drivers in EDK2.

This is implemented as a UEFI driver, which means we take full advantage
of the UEFI driver model, and only instantiate those devices that are
necessary for booting.

Care is taken to deal with DMA addressing limitations: DMA mappings and
allocations are moved below 4 GB if the PCI driver has not informed us
that the device being driven is 64-bit DMA capable. DMA is implemented as
coherent, support for non-coherent DMA is implemented by a subsequent patch.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c                 |  75 ++
 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c   | 223 +++++
 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf |  42 +
 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c    | 868 ++++++++++++++++++++
 MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h    |  84 ++
 MdeModulePkg/MdeModulePkg.dsc                                                    |   1 +
 6 files changed, 1293 insertions(+)

diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c
new file mode 100644
index 000000000000..6e51d00fe434
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/ComponentName.c
@@ -0,0 +1,75 @@
+/** @file
+
+  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 "NonDiscoverablePciDeviceIo.h"
+
+//
+// The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and
+// EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name
+// in English, for display on standard console devices. This is recommended for
+// UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's
+// Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names.
+//
+
+STATIC
+EFI_UNICODE_STRING_TABLE mDriverNameTable[] = {
+  { "eng;en", L"PCI I/O protocol emulation driver for non-discoverable devices" },
+  { NULL,     NULL                   }
+};
+
+EFI_COMPONENT_NAME_PROTOCOL gComponentName;
+
+STATIC
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciGetDriverName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
+  IN  CHAR8                       *Language,
+  OUT CHAR16                      **DriverName
+  )
+{
+  return LookupUnicodeString2 (
+           Language,
+           This->SupportedLanguages,
+           mDriverNameTable,
+           DriverName,
+           (BOOLEAN)(This == &gComponentName) // Iso639Language
+           );
+}
+
+STATIC
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciGetDeviceName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
+  IN  EFI_HANDLE                  DeviceHandle,
+  IN  EFI_HANDLE                  ChildHandle,
+  IN  CHAR8                       *Language,
+  OUT CHAR16                      **ControllerName
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+EFI_COMPONENT_NAME_PROTOCOL gComponentName = {
+  &NonDiscoverablePciGetDriverName,
+  &NonDiscoverablePciGetDeviceName,
+  "eng" // SupportedLanguages, ISO 639-2 language codes
+};
+
+EFI_COMPONENT_NAME2_PROTOCOL gComponentName2 = {
+  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME)     &NonDiscoverablePciGetDriverName,
+  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) &NonDiscoverablePciGetDeviceName,
+  "en" // SupportedLanguages, RFC 4646 language codes
+};
diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
new file mode 100644
index 000000000000..32da576485aa
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.c
@@ -0,0 +1,223 @@
+/** @file
+
+  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 "NonDiscoverablePciDeviceIo.h"
+
+#include <Protocol/DriverBinding.h>
+
+//
+// Probe, start and stop functions of this driver, called by the DXE core for
+// specific devices.
+//
+// The following specifications document these interfaces:
+// - Driver Writer's Guide for UEFI 2.3.1 v1.01, 9 Driver Binding Protocol
+// - UEFI Spec 2.3.1 + Errata C, 10.1 EFI Driver Binding Protocol
+//
+// The implementation follows:
+// - Driver Writer's Guide for UEFI 2.3.1 v1.01
+//   - 5.1.3.4 OpenProtocol() and CloseProtocol()
+// - UEFI Spec 2.3.1 + Errata C
+//   -  6.3 Protocol Handler Services
+//
+
+STATIC
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciDeviceSupported (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
+  )
+{
+  NON_DISCOVERABLE_DEVICE             *Device;
+  EFI_STATUS                          Status;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   *Desc;
+
+  Status = gBS->OpenProtocol (DeviceHandle,
+                  &gEdkiiNonDiscoverableDeviceProtocolGuid, (VOID **)&Device,
+                  This->DriverBindingHandle, DeviceHandle,
+                  EFI_OPEN_PROTOCOL_BY_DRIVER);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  switch (Device->Type) {
+  //
+  // We only support the following device types
+  //
+  case NonDiscoverableDeviceTypeOhci:
+  case NonDiscoverableDeviceTypeUhci:
+  case NonDiscoverableDeviceTypeEhci:
+  case NonDiscoverableDeviceTypeXhci:
+  case NonDiscoverableDeviceTypeAhci:
+  case NonDiscoverableDeviceTypeSdhci:
+  case NonDiscoverableDeviceTypeUfs:
+  case NonDiscoverableDeviceTypeNvme:
+    //
+    // Restricted to DMA coherent for now
+    //
+    if (Device->DmaType == NonDiscoverableDeviceDmaTypeCoherent) {
+      Status = EFI_SUCCESS;
+      break;
+    }
+  default:
+    Status = EFI_UNSUPPORTED;
+    goto CloseProtocol;
+  }
+
+  //
+  // We only support MMIO devices, so iterate over the resources to ensure
+  // that they only describe things that we can handle
+  //
+  for (Desc = Device->Resources; Desc->Desc != ACPI_END_TAG_DESCRIPTOR;
+       Desc = (VOID *)((UINT8 *)Desc + Desc->Len + 3)) {
+    if (Desc->Desc != ACPI_ADDRESS_SPACE_DESCRIPTOR ||
+        Desc->ResType != ACPI_ADDRESS_SPACE_TYPE_MEM) {
+      Status = EFI_UNSUPPORTED;
+      break;
+    }
+  }
+
+CloseProtocol:
+  gBS->CloseProtocol (DeviceHandle, &gEdkiiNonDiscoverableDeviceProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+  return Status;
+}
+
+STATIC
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciDeviceStart (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE   *Dev;
+  EFI_STATUS                    Status;
+
+  Dev = AllocateZeroPool (sizeof *Dev);
+  if (Dev == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Status = gBS->OpenProtocol (DeviceHandle,
+                  &gEdkiiNonDiscoverableDeviceProtocolGuid,
+                  (VOID **)&Dev->Device, This->DriverBindingHandle,
+                  DeviceHandle, EFI_OPEN_PROTOCOL_BY_DRIVER);
+  if (EFI_ERROR (Status)) {
+    goto FreeDev;
+  }
+
+  InitializePciIoProtocol (Dev);
+
+  //
+  // Setup complete, attempt to export the driver instance's
+  // EFI_PCI_IO_PROTOCOL interface.
+  //
+  Dev->Signature = NON_DISCOVERABLE_PCI_DEVICE_SIG;
+  Status = gBS->InstallProtocolInterface (&DeviceHandle, &gEfiPciIoProtocolGuid,
+                  EFI_NATIVE_INTERFACE, &Dev->PciIo);
+  if (EFI_ERROR (Status)) {
+    goto CloseProtocol;
+  }
+
+  return EFI_SUCCESS;
+
+CloseProtocol:
+  gBS->CloseProtocol (DeviceHandle, &gEdkiiNonDiscoverableDeviceProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+FreeDev:
+  FreePool (Dev);
+
+  return Status;
+}
+
+
+STATIC
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciDeviceStop (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN UINTN                       NumberOfChildren,
+  IN EFI_HANDLE                  *ChildHandleBuffer
+  )
+{
+  EFI_STATUS                      Status;
+  EFI_PCI_IO_PROTOCOL             *PciIo;
+  NON_DISCOVERABLE_PCI_DEVICE     *Dev;
+
+  Status = gBS->OpenProtocol (DeviceHandle, &gEfiPciIoProtocolGuid,
+                  (VOID **)&PciIo, This->DriverBindingHandle, DeviceHandle,
+                  EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO (PciIo);
+
+  //
+  // Handle Stop() requests for in-use driver instances gracefully.
+  //
+  Status = gBS->UninstallProtocolInterface (DeviceHandle,
+                  &gEfiPciIoProtocolGuid, &Dev->PciIo);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  gBS->CloseProtocol (DeviceHandle, &gEdkiiNonDiscoverableDeviceProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+  FreePool (Dev);
+
+  return EFI_SUCCESS;
+}
+
+
+//
+// The static object that groups the Supported() (ie. probe), Start() and
+// Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata
+// C, 10.1 EFI Driver Binding Protocol.
+//
+STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding = {
+  &NonDiscoverablePciDeviceSupported,
+  &NonDiscoverablePciDeviceStart,
+  &NonDiscoverablePciDeviceStop,
+  0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers
+  NULL,
+  NULL
+};
+
+//
+// Entry point of this driver.
+//
+EFI_STATUS
+EFIAPI
+NonDiscoverablePciDeviceDxeEntryPoint (
+  IN EFI_HANDLE       ImageHandle,
+  IN EFI_SYSTEM_TABLE *SystemTable
+  )
+{
+  return EfiLibInstallDriverBindingComponentName2 (
+           ImageHandle,
+           SystemTable,
+           &gDriverBinding,
+           ImageHandle,
+           &gComponentName,
+           &gComponentName2
+           );
+}
diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf
new file mode 100644
index 000000000000..543e622694a0
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf
@@ -0,0 +1,42 @@
+## @file
+# Copyright (C) 2016, Linaro Ltd.
+#
+# 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                    = 0x00010019
+  BASE_NAME                      = NonDiscoverablePciDeviceDxe
+  FILE_GUID                      = 71fd84cd-353b-464d-b7a4-6ea7b96995cb
+  MODULE_TYPE                    = UEFI_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = NonDiscoverablePciDeviceDxeEntryPoint
+
+[Sources]
+  ComponentName.c
+  NonDiscoverablePciDeviceDxe.c
+  NonDiscoverablePciDeviceIo.c
+  NonDiscoverablePciDeviceIo.h
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+  BaseMemoryLib
+  DebugLib
+  MemoryAllocationLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  UefiLib
+
+[Protocols]
+  gEfiPciIoProtocolGuid                         ## BY_START
+  gEdkiiNonDiscoverableDeviceProtocolGuid       ## TO_START
diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
new file mode 100644
index 000000000000..23466318bfc1
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.c
@@ -0,0 +1,868 @@
+/** @file
+
+  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+  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 "NonDiscoverablePciDeviceIo.h"
+
+#include <IndustryStandard/Acpi.h>
+
+#include <Protocol/PciRootBridgeIo.h>
+
+typedef struct {
+  EFI_PHYSICAL_ADDRESS            AllocAddress;
+  VOID                            *HostAddress;
+  EFI_PCI_IO_PROTOCOL_OPERATION   Operation;
+  UINTN                           NumberOfBytes;
+} NON_DISCOVERABLE_PCI_DEVICE_MAP_INFO;
+
+//
+// Get the resource associated with BAR number 'BarIndex'. This takes into
+// account that 64-bit resource use up 2 BAR slots, which means that BAR
+// n + 1 is reported as not found if BAR n refers to a 64-bit resource.
+//
+STATIC
+EFI_STATUS
+GetBarResource (
+  IN  NON_DISCOVERABLE_PCI_DEVICE         *Dev,
+  IN  UINT8                               BarIndex,
+  OUT EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   **Descriptor
+  )
+{
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   *Desc;
+
+  if (BarIndex < Dev->BarOffset) {
+    return EFI_NOT_FOUND;
+  }
+
+  BarIndex -= Dev->BarOffset;
+
+  for (Desc = Dev->Device->Resources;
+       Desc->Desc != ACPI_END_TAG_DESCRIPTOR;
+       Desc = (VOID *)((UINT8 *)Desc + Desc->Len + 3)) {
+
+    if (BarIndex == 0) {
+      *Descriptor = Desc;
+      return EFI_SUCCESS;
+    }
+
+    if (Desc->AddrSpaceGranularity == 64) {
+      if (BarIndex == 1) {
+        break;
+      }
+      BarIndex -= 2;
+    } else {
+      BarIndex -= 1;
+    }
+  }
+  return EFI_NOT_FOUND;
+}
+
+STATIC
+EFI_STATUS
+PciIoPollMem (
+  IN  EFI_PCI_IO_PROTOCOL         *This,
+  IN  EFI_PCI_IO_PROTOCOL_WIDTH   Width,
+  IN  UINT8                       BarIndex,
+  IN  UINT64                      Offset,
+  IN  UINT64                      Mask,
+  IN  UINT64                      Value,
+  IN  UINT64                      Delay,
+  OUT UINT64                      *Result
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_STATUS
+PciIoPollIo (
+  IN  EFI_PCI_IO_PROTOCOL         *This,
+  IN  EFI_PCI_IO_PROTOCOL_WIDTH   Width,
+  IN  UINT8                       BarIndex,
+  IN  UINT64                      Offset,
+  IN  UINT64                      Mask,
+  IN  UINT64                      Value,
+  IN  UINT64                      Delay,
+  OUT UINT64                      *Result
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_STATUS
+PciIoMemRW (
+  IN  EFI_PCI_IO_PROTOCOL_WIDTH   Width,
+  IN  UINTN                       Count,
+  IN  UINTN                       DstStride,
+  IN  VOID                        *Dst,
+  IN  UINTN                       SrcStride,
+  OUT CONST VOID                  *Src
+  )
+{
+  volatile UINT8             *Dst8;
+  volatile UINT16            *Dst16;
+  volatile UINT32            *Dst32;
+  volatile CONST UINT8       *Src8;
+  volatile CONST UINT16      *Src16;
+  volatile CONST UINT32      *Src32;
+
+  //
+  // Loop for each iteration and move the data
+  //
+  switch (Width & 0x3) {
+  case EfiPciWidthUint8:
+    Dst8 = (UINT8 *)Dst;
+    Src8 = (UINT8 *)Src;
+    for (;Count > 0; Count--, Dst8 += DstStride, Src8 += SrcStride) {
+      *Dst8 = *Src8;
+    }
+    break;
+  case EfiPciWidthUint16:
+    Dst16 = (UINT16 *)Dst;
+    Src16 = (UINT16 *)Src;
+    for (;Count > 0; Count--, Dst16 += DstStride, Src16 += SrcStride) {
+      *Dst16 = *Src16;
+    }
+    break;
+  case EfiPciWidthUint32:
+    Dst32 = (UINT32 *)Dst;
+    Src32 = (UINT32 *)Src;
+    for (;Count > 0; Count--, Dst32 += DstStride, Src32 += SrcStride) {
+      *Dst32 = *Src32;
+    }
+    break;
+  default:
+    return EFI_INVALID_PARAMETER;
+  }
+
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+PciIoMemRead (
+  IN     EFI_PCI_IO_PROTOCOL          *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT8                        BarIndex,
+  IN     UINT64                       Offset,
+  IN     UINTN                        Count,
+  IN OUT VOID                         *Buffer
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE         *Dev;
+  UINTN                               AlignMask;
+  VOID                                *Address;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   *Desc;
+  EFI_STATUS                          Status;
+
+  if (Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+
+  //
+  // Only allow accesses to the BARs we emulate
+  //
+  Status = GetBarResource (Dev, BarIndex, &Desc);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  if (Offset + (Count << (Width & 0x3)) > Desc->AddrLen) {
+    return EFI_UNSUPPORTED;
+  }
+
+  Address = (VOID *)((UINTN)Desc->AddrRangeMin + Offset);
+  AlignMask = (1 << (Width & 0x03)) - 1;
+  if ((UINTN)Address & AlignMask) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  switch (Width) {
+  case EfiPciWidthUint8:
+  case EfiPciWidthUint16:
+  case EfiPciWidthUint32:
+  case EfiPciWidthUint64:
+    return PciIoMemRW (Width, Count, 1, Buffer, 1, Address);
+
+  case EfiPciWidthFifoUint8:
+  case EfiPciWidthFifoUint16:
+  case EfiPciWidthFifoUint32:
+  case EfiPciWidthFifoUint64:
+    return PciIoMemRW (Width, Count, 1, Buffer, 0, Address);
+
+  case EfiPciWidthFillUint8:
+  case EfiPciWidthFillUint16:
+  case EfiPciWidthFillUint32:
+  case EfiPciWidthFillUint64:
+    return PciIoMemRW (Width, Count, 0, Buffer, 1, Address);
+
+  default:
+    break;
+  }
+  return EFI_INVALID_PARAMETER;
+}
+
+STATIC
+EFI_STATUS
+PciIoMemWrite (
+  IN     EFI_PCI_IO_PROTOCOL          *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT8                        BarIndex,
+  IN     UINT64                       Offset,
+  IN     UINTN                        Count,
+  IN OUT VOID                         *Buffer
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE         *Dev;
+  UINTN                               AlignMask;
+  VOID                                *Address;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   *Desc;
+  EFI_STATUS                          Status;
+
+  if (Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+
+  //
+  // Only allow accesses to the BARs we emulate
+  //
+  Status = GetBarResource (Dev, BarIndex, &Desc);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  if (Offset + (Count << (Width & 0x3)) > Desc->AddrLen) {
+    return EFI_UNSUPPORTED;
+  }
+
+  Address = (VOID *)((UINTN)Desc->AddrRangeMin + Offset);
+  AlignMask = (1 << (Width & 0x03)) - 1;
+  if ((UINTN)Address & AlignMask) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  switch (Width) {
+  case EfiPciWidthUint8:
+  case EfiPciWidthUint16:
+  case EfiPciWidthUint32:
+  case EfiPciWidthUint64:
+    return PciIoMemRW (Width, Count, 1, Address, 1, Buffer);
+
+  case EfiPciWidthFifoUint8:
+  case EfiPciWidthFifoUint16:
+  case EfiPciWidthFifoUint32:
+  case EfiPciWidthFifoUint64:
+    return PciIoMemRW (Width, Count, 0, Address, 1, Buffer);
+
+  case EfiPciWidthFillUint8:
+  case EfiPciWidthFillUint16:
+  case EfiPciWidthFillUint32:
+  case EfiPciWidthFillUint64:
+    return PciIoMemRW (Width, Count, 1, Address, 0, Buffer);
+
+  default:
+    break;
+  }
+  return EFI_INVALID_PARAMETER;
+}
+
+STATIC
+EFI_STATUS
+PciIoIoRead (
+  IN EFI_PCI_IO_PROTOCOL              *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT8                        BarIndex,
+  IN     UINT64                       Offset,
+  IN     UINTN                        Count,
+  IN OUT VOID                         *Buffer
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_STATUS
+PciIoIoWrite (
+  IN     EFI_PCI_IO_PROTOCOL          *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT8                        BarIndex,
+  IN     UINT64                       Offset,
+  IN     UINTN                        Count,
+  IN OUT VOID                         *Buffer
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_STATUS
+PciIoPciRead (
+  IN     EFI_PCI_IO_PROTOCOL        *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT32                     Offset,
+  IN     UINTN                      Count,
+  IN OUT VOID                       *Buffer
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE   *Dev;
+  UINTN                         Length;
+
+  if (Width < 0 || Width >= EfiPciIoWidthMaximum || Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+  Length = Count << ((UINTN)Width & 0x3);
+
+  if (Offset + Length > sizeof (Dev->ConfigSpace)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  return PciIoMemRW (Width, Count, 1, Buffer, 1,
+           (UINT8 *)&Dev->ConfigSpace + Offset);
+}
+
+//
+// taken from MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h
+//
+#define SD_MMC_HC_SLOT_OFFSET         0x40
+
+typedef struct {
+  UINT8    FirstBar:3;        // bit 0:2
+  UINT8    Reserved:1;        // bit 3
+  UINT8    SlotNum:3;         // bit 4:6
+  UINT8    Reserved1:1;       // bit 7
+} SD_MMC_HC_SLOT_INFO;
+
+STATIC
+EFI_STATUS
+PciIoPciReadSdhci (
+  IN     EFI_PCI_IO_PROTOCOL        *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH  Width,
+  IN     UINT32                     Offset,
+  IN     UINTN                      Count,
+  IN OUT VOID                       *Buffer
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE   *Dev;
+  UINTN                         Length;
+  SD_MMC_HC_SLOT_INFO           *SlotInfo;
+
+  if (Width < 0 || Width >= EfiPciIoWidthMaximum || Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+  Length = Count << ((UINTN)Width & 0x3);
+
+  //
+  // The SDHCI driver reads beyond the 64-byte PCI config space to read
+  // the number of slots and the BAR offset. So allow that
+  //
+  if (Offset == SD_MMC_HC_SLOT_OFFSET && Length == 1) {
+    SlotInfo = Buffer;
+
+    SlotInfo->FirstBar = Dev->BarOffset;
+    SlotInfo->SlotNum = Dev->BarCount - 1;
+
+    return EFI_SUCCESS;
+  }
+
+  if (Offset + Length > sizeof (Dev->ConfigSpace)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  return PciIoMemRW (Width, Count, 1, Buffer, 1,
+           (UINT8 *)&Dev->ConfigSpace + Offset);
+}
+
+STATIC
+EFI_STATUS
+PciIoPciWrite (
+  IN EFI_PCI_IO_PROTOCOL              *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT32                       Offset,
+  IN     UINTN                        Count,
+  IN OUT VOID                         *Buffer
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE   *Dev;
+  VOID                          *Address;
+
+  if (Width < 0 || Width >= EfiPciIoWidthMaximum || Buffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+  Address = (UINT8 *)&Dev->ConfigSpace + Offset;
+
+  if (Offset + Count * (1UL << (Width & 0x3)) > sizeof (Dev->ConfigSpace)) {
+    return EFI_UNSUPPORTED;
+  }
+
+  return PciIoMemRW (Width, Count, 1, Address, 1, Buffer);
+}
+
+STATIC
+EFI_STATUS
+PciIoCopyMem (
+  IN EFI_PCI_IO_PROTOCOL              *This,
+  IN     EFI_PCI_IO_PROTOCOL_WIDTH    Width,
+  IN     UINT8                        DestBarIndex,
+  IN     UINT64                       DestOffset,
+  IN     UINT8                        SrcBarIndex,
+  IN     UINT64                       SrcOffset,
+  IN     UINTN                        Count
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_STATUS
+CoherentPciIoMap (
+  IN     EFI_PCI_IO_PROTOCOL            *This,
+  IN     EFI_PCI_IO_PROTOCOL_OPERATION  Operation,
+  IN     VOID                           *HostAddress,
+  IN OUT UINTN                          *NumberOfBytes,
+  OUT    EFI_PHYSICAL_ADDRESS           *DeviceAddress,
+  OUT    VOID                           **Mapping
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE           *Dev;
+  EFI_STATUS                            Status;
+  NON_DISCOVERABLE_PCI_DEVICE_MAP_INFO  *MapInfo;
+
+  //
+  // If HostAddress exceeds 4 GB, and this device does not support 64-bit DMA
+  // addressing, we need to allocate a bounce buffer and copy over the data.
+  //
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+  if ((Dev->Attributes & EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE) == 0 &&
+      (UINTN)HostAddress + *NumberOfBytes > SIZE_4GB) {
+
+    //
+    // Bounce buffering is not possible for consistent mappings
+    //
+    if (Operation == EfiPciIoOperationBusMasterCommonBuffer) {
+      return EFI_UNSUPPORTED;
+    }
+
+    MapInfo = AllocatePool (sizeof *MapInfo);
+    if (MapInfo == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+
+    MapInfo->AllocAddress = MAX_UINT32;
+    MapInfo->HostAddress = HostAddress;
+    MapInfo->Operation = Operation;
+    MapInfo->NumberOfBytes = *NumberOfBytes;
+
+    Status = gBS->AllocatePages (AllocateMaxAddress, EfiBootServicesData,
+                    EFI_SIZE_TO_PAGES (MapInfo->NumberOfBytes),
+                    &MapInfo->AllocAddress);
+    if (EFI_ERROR (Status)) {
+      //
+      // If we fail here, it is likely because the system has no memory below
+      // 4 GB to begin with. There is not much we can do about that other than
+      // fail the map request.
+      //
+      FreePool (MapInfo);
+      return EFI_DEVICE_ERROR;
+    }
+    if (Operation == EfiPciIoOperationBusMasterRead) {
+      gBS->CopyMem ((VOID *)(UINTN)MapInfo->AllocAddress, HostAddress,
+             *NumberOfBytes);
+    }
+    *DeviceAddress = MapInfo->AllocAddress;
+    *Mapping = MapInfo;
+  } else {
+    *DeviceAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)HostAddress;
+    *Mapping = NULL;
+  }
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+CoherentPciIoUnmap (
+  IN  EFI_PCI_IO_PROTOCOL          *This,
+  IN  VOID                         *Mapping
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE_MAP_INFO  *MapInfo;
+
+  MapInfo = Mapping;
+  if (MapInfo != NULL) {
+    if (MapInfo->Operation == EfiPciIoOperationBusMasterWrite) {
+      gBS->CopyMem (MapInfo->HostAddress, (VOID *)(UINTN)MapInfo->AllocAddress,
+             MapInfo->NumberOfBytes);
+    }
+    gBS->FreePages (MapInfo->AllocAddress,
+           EFI_SIZE_TO_PAGES (MapInfo->NumberOfBytes));
+    FreePool (MapInfo);
+  }
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+CoherentPciIoAllocateBuffer (
+  IN  EFI_PCI_IO_PROTOCOL         *This,
+  IN  EFI_ALLOCATE_TYPE           Type,
+  IN  EFI_MEMORY_TYPE             MemoryType,
+  IN  UINTN                       Pages,
+  OUT VOID                        **HostAddress,
+  IN  UINT64                      Attributes
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE       *Dev;
+  EFI_PHYSICAL_ADDRESS              AllocAddress;
+  EFI_ALLOCATE_TYPE                 AllocType;
+  EFI_STATUS                        Status;
+
+  if ((Attributes & ~(EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE |
+                      EFI_PCI_ATTRIBUTE_MEMORY_CACHED)) != 0) {
+    return EFI_UNSUPPORTED;
+  }
+
+  //
+  // Allocate below 4 GB if the dual address cycle attribute has not
+  // been set. If the system has no memory available below 4 GB, there
+  // is little we can do except propagate the error.
+  //
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+  if ((Dev->Attributes & EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE) == 0) {
+    AllocAddress = MAX_UINT32;
+    AllocType = AllocateMaxAddress;
+  } else {
+    AllocType = AllocateAnyPages;
+  }
+
+  Status = gBS->AllocatePages (AllocType, MemoryType, Pages, &AllocAddress);
+  if (!EFI_ERROR (Status)) {
+    *HostAddress = (VOID *)(UINTN)AllocAddress;
+  }
+  return Status;
+}
+
+STATIC
+EFI_STATUS
+CoherentPciIoFreeBuffer (
+  IN  EFI_PCI_IO_PROTOCOL         *This,
+  IN  UINTN                       Pages,
+  IN  VOID                        *HostAddress
+  )
+{
+  FreePages (HostAddress, Pages);
+  return EFI_SUCCESS;
+}
+
+
+STATIC
+EFI_STATUS
+PciIoFlush (
+  IN EFI_PCI_IO_PROTOCOL          *This
+  )
+{
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+PciIoGetLocation (
+  IN   EFI_PCI_IO_PROTOCOL  *This,
+  OUT  UINTN                *SegmentNumber,
+  OUT  UINTN                *BusNumber,
+  OUT  UINTN                *DeviceNumber,
+  OUT  UINTN                *FunctionNumber
+  )
+{
+  if (SegmentNumber == NULL ||
+      BusNumber == NULL ||
+      DeviceNumber == NULL ||
+      FunctionNumber == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  *SegmentNumber  = 0;
+  *BusNumber      = 0xff;
+  *DeviceNumber   = 0;
+  *FunctionNumber = 0;
+
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+PciIoAttributes (
+  IN  EFI_PCI_IO_PROTOCOL                      *This,
+  IN  EFI_PCI_IO_PROTOCOL_ATTRIBUTE_OPERATION  Operation,
+  IN  UINT64                                   Attributes,
+  OUT UINT64                                   *Result OPTIONAL
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE   *Dev;
+  BOOLEAN                       Enable;
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+
+  Enable = FALSE;
+  switch (Operation) {
+  case EfiPciIoAttributeOperationGet:
+    if (Result == NULL) {
+      return EFI_INVALID_PARAMETER;
+    }
+    *Result = Dev->Attributes;
+    break;
+
+  case EfiPciIoAttributeOperationSupported:
+    if (Result == NULL) {
+      return EFI_INVALID_PARAMETER;
+    }
+    *Result = EFI_PCI_DEVICE_ENABLE | EFI_PCI_IO_ATTRIBUTE_DUAL_ADDRESS_CYCLE;
+    break;
+
+  case EfiPciIoAttributeOperationEnable:
+    Attributes |= Dev->Attributes;
+  case EfiPciIoAttributeOperationSet:
+    Enable = ((~Dev->Attributes & Attributes) & EFI_PCI_DEVICE_ENABLE) != 0;
+    Dev->Attributes = Attributes;
+    break;
+
+  case EfiPciIoAttributeOperationDisable:
+    Dev->Attributes &= ~Attributes;
+    break;
+
+  default:
+    return EFI_INVALID_PARAMETER;
+  };
+
+  //
+  // If we're setting any of the EFI_PCI_DEVICE_ENABLE bits, perform
+  // the device specific initialization now.
+  //
+  if (Enable && !Dev->Enabled && Dev->Device->Initialize != NULL) {
+    Dev->Device->Initialize (Dev->Device);
+    Dev->Enabled = TRUE;
+  }
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+PciIoGetBarAttributes (
+  IN EFI_PCI_IO_PROTOCOL             *This,
+  IN  UINT8                          BarIndex,
+  OUT UINT64                         *Supports OPTIONAL,
+  OUT VOID                           **Resources OPTIONAL
+  )
+{
+  NON_DISCOVERABLE_PCI_DEVICE       *Dev;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor, *BarDesc;
+  EFI_ACPI_END_TAG_DESCRIPTOR       *End;
+  EFI_STATUS                        Status;
+
+  if (Supports == NULL && Resources == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Dev = NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(This);
+
+  Status = GetBarResource (Dev, BarIndex, &BarDesc);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Don't expose any configurable attributes for our emulated BAR
+  //
+  if (Supports != NULL) {
+    *Supports = 0;
+  }
+
+  if (Resources != NULL) {
+    Descriptor = AllocatePool (sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) +
+                               sizeof (EFI_ACPI_END_TAG_DESCRIPTOR));
+    if (Descriptor == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+
+    CopyMem (Descriptor, BarDesc, sizeof *Descriptor);
+
+    End           = (EFI_ACPI_END_TAG_DESCRIPTOR *) (Descriptor + 1);
+    End->Desc     = ACPI_END_TAG_DESCRIPTOR;
+    End->Checksum = 0;
+
+    *Resources = Descriptor;
+  }
+  return EFI_SUCCESS;
+}
+
+STATIC
+EFI_STATUS
+PciIoSetBarAttributes (
+  IN     EFI_PCI_IO_PROTOCOL          *This,
+  IN     UINT64                       Attributes,
+  IN     UINT8                        BarIndex,
+  IN OUT UINT64                       *Offset,
+  IN OUT UINT64                       *Length
+  )
+{
+  ASSERT (FALSE);
+  return EFI_UNSUPPORTED;
+}
+
+STATIC CONST EFI_PCI_IO_PROTOCOL PciIoTemplate =
+{
+  PciIoPollMem,
+  PciIoPollIo,
+  { PciIoMemRead, PciIoMemWrite },
+  { PciIoIoRead,  PciIoIoWrite },
+  { PciIoPciRead, PciIoPciWrite },
+  PciIoCopyMem,
+  CoherentPciIoMap,
+  CoherentPciIoUnmap,
+  CoherentPciIoAllocateBuffer,
+  CoherentPciIoFreeBuffer,
+  PciIoFlush,
+  PciIoGetLocation,
+  PciIoAttributes,
+  PciIoGetBarAttributes,
+  PciIoSetBarAttributes,
+  0,
+  0
+};
+
+VOID
+InitializePciIoProtocol (
+  NON_DISCOVERABLE_PCI_DEVICE     *Dev
+  )
+{
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR   *Desc;
+  INTN                                Idx;
+
+  InitializeListHead (&Dev->UncachedAllocationList);
+
+  Dev->ConfigSpace.Hdr.VendorId = PCI_ID_VENDOR_UNKNOWN;
+  Dev->ConfigSpace.Hdr.DeviceId = PCI_ID_DEVICE_DONTCARE;
+
+  // Copy protocol structure
+  CopyMem(&Dev->PciIo, &PciIoTemplate, sizeof PciIoTemplate);
+
+  switch (Dev->Device->Type) {
+  case NonDiscoverableDeviceTypeOhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = PCI_IF_OHCI;
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_CLASS_SERIAL_USB;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_SERIAL;
+    Dev->BarOffset = 0;
+    break;
+
+  case NonDiscoverableDeviceTypeUhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = PCI_IF_UHCI;
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_CLASS_SERIAL_USB;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_SERIAL;
+    Dev->BarOffset = 0;
+    break;
+
+  case NonDiscoverableDeviceTypeEhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = PCI_IF_EHCI;
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_CLASS_SERIAL_USB;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_SERIAL;
+    Dev->BarOffset = 0;
+    break;
+
+  case NonDiscoverableDeviceTypeXhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = PCI_IF_XHCI;
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_CLASS_SERIAL_USB;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_SERIAL;
+    Dev->BarOffset = 0;
+    break;
+
+  case NonDiscoverableDeviceTypeAhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = PCI_IF_MASS_STORAGE_AHCI;
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_CLASS_MASS_STORAGE_SATADPA;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_MASS_STORAGE;
+    Dev->BarOffset = 5;
+    break;
+
+  case NonDiscoverableDeviceTypeSdhci:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = 0x0; // don't care
+    Dev->ConfigSpace.Hdr.ClassCode[1] = PCI_SUBCLASS_SD_HOST_CONTROLLER;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_SYSTEM_PERIPHERAL;
+    Dev->BarOffset = 0;
+
+    //
+    // Use the special config space accessor so that the SDHCI driver
+    // is able to retrieve the number of slots and the BAR offset
+    //
+    Dev->PciIo.Pci.Read = PciIoPciReadSdhci;
+    break;
+
+  case NonDiscoverableDeviceTypeUfs:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = 0x0; // don't care
+    Dev->ConfigSpace.Hdr.ClassCode[1] = 0x9; // UFS controller subclass;
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_MASS_STORAGE;
+    Dev->BarOffset = 0;
+    break;
+
+  case NonDiscoverableDeviceTypeNvme:
+    Dev->ConfigSpace.Hdr.ClassCode[0] = 0x2; // PCI_IF_NVMHCI
+    Dev->ConfigSpace.Hdr.ClassCode[1] = 0x8; // PCI_CLASS_MASS_STORAGE_NVM
+    Dev->ConfigSpace.Hdr.ClassCode[2] = PCI_CLASS_MASS_STORAGE;
+    Dev->BarOffset = 0;
+
+  default:
+    ASSERT_EFI_ERROR (EFI_INVALID_PARAMETER);
+  }
+
+  //
+  // Iterate over the resources to populate the virtual BARs
+  //
+  Idx = Dev->BarOffset;
+  for (Desc = Dev->Device->Resources, Dev->BarCount = 0;
+       Desc->Desc != ACPI_END_TAG_DESCRIPTOR;
+       Desc = (VOID *)((UINT8 *)Desc + Desc->Len + 3)) {
+
+    ASSERT (Desc->Desc == ACPI_ADDRESS_SPACE_DESCRIPTOR);
+    ASSERT (Desc->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM);
+
+    if (Idx >= PCI_MAX_BARS ||
+        (Idx == PCI_MAX_BARS - 1 && Desc->AddrSpaceGranularity == 64)) {
+      DEBUG ((DEBUG_ERROR,
+        "%a: resource count exceeds number of emulated BARs\n",
+        __FUNCTION__));
+      ASSERT (FALSE);
+      break;
+    }
+
+    Dev->ConfigSpace.Device.Bar[Idx] = (UINT32)Desc->AddrRangeMin;
+    Dev->BarCount++;
+
+    if (Desc->AddrSpaceGranularity == 64) {
+      Dev->ConfigSpace.Device.Bar[Idx] |= 0x4;
+      Dev->ConfigSpace.Device.Bar[++Idx] = (UINT32)(Desc->AddrRangeMin >> 32);
+    }
+  }
+}
diff --git a/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h
new file mode 100644
index 000000000000..bc0a3d3258f9
--- /dev/null
+++ b/MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceIo.h
@@ -0,0 +1,84 @@
+/** @file
+
+  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.
+
+**/
+
+#ifndef __NON_DISCOVERABLE_PCI_DEVICE_IO_H__
+#define __NON_DISCOVERABLE_PCI_DEVICE_IO_H__
+
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <IndustryStandard/Pci.h>
+
+#include <Protocol/ComponentName.h>
+#include <Protocol/NonDiscoverableDevice.h>
+#include <Protocol/PciIo.h>
+
+#define NON_DISCOVERABLE_PCI_DEVICE_SIG SIGNATURE_32 ('P', 'P', 'I', 'D')
+
+#define NON_DISCOVERABLE_PCI_DEVICE_FROM_PCI_IO(PciIoPointer) \
+        CR (PciIoPointer, NON_DISCOVERABLE_PCI_DEVICE, PciIo, \
+            NON_DISCOVERABLE_PCI_DEVICE_SIG)
+
+#define PCI_ID_VENDOR_UNKNOWN         0xffff
+#define PCI_ID_DEVICE_DONTCARE        0x0000
+
+#define PCI_MAX_BARS                  6
+
+typedef struct {
+  UINT32                    Signature;
+  //
+  // The bound non-discoverable device protocol instance
+  //
+  NON_DISCOVERABLE_DEVICE   *Device;
+  //
+  // The exposed PCI I/O protocol instance.
+  //
+  EFI_PCI_IO_PROTOCOL       PciIo;
+  //
+  // The emulated PCI config space of the device. Only the minimally required
+  // items are assigned.
+  //
+  PCI_TYPE00                ConfigSpace;
+  //
+  // The first virtual BAR to assign based on the resources described
+  // by the non-discoverable device.
+  //
+  UINT32                    BarOffset;
+  //
+  // The number of virtual BARs we expose based on the number of
+  // resources
+  //
+  UINT32                    BarCount;
+  //
+  // The PCI I/O attributes for this device
+  //
+  UINT64                    Attributes;
+  //
+  // Whether this device has been enabled
+  //
+  BOOLEAN                   Enabled;
+} NON_DISCOVERABLE_PCI_DEVICE;
+
+VOID
+InitializePciIoProtocol (
+  NON_DISCOVERABLE_PCI_DEVICE     *Device
+  );
+
+extern EFI_COMPONENT_NAME_PROTOCOL gComponentName;
+extern EFI_COMPONENT_NAME2_PROTOCOL gComponentName2;
+
+#endif
diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index 43421d610ede..aac05408599d 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -260,6 +260,7 @@ [Components]
   MdeModulePkg/Bus/Isa/IsaBusDxe/IsaBusDxe.inf
   MdeModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2KeyboardDxe.inf
   MdeModulePkg/Bus/Isa/Ps2MouseDxe/Ps2MouseDxe.inf
+  MdeModulePkg/Bus/Pci/NonDiscoverablePciDeviceDxe/NonDiscoverablePciDeviceDxe.inf
 
   MdeModulePkg/Core/Dxe/DxeMain.inf {
     <LibraryClasses>
-- 
2.7.4