[Xen-devel] [PATCH v3 18/27] Ovmf/Xen: add separate driver for Xen PCI device

[Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>]

Prepare for making XenBusDxe suitable for use with non-PCI devices
(such as the DT node exposed by Xen on ARM) by introducing a separate
DXE driver that binds to the Xen virtual PCI device and exposes the
abstract XENIO_PROTOCOL for XenBusDxe to bind against.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
 OvmfPkg/XenIoPciDxe/XenIoPciDxe.c   | 367 ++++++++++++++++++++++++++++++++++++
 OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf |  45 +++++
 2 files changed, 412 insertions(+)
 create mode 100644 OvmfPkg/XenIoPciDxe/XenIoPciDxe.c
 create mode 100644 OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf

diff --git a/OvmfPkg/XenIoPciDxe/XenIoPciDxe.c 
b/OvmfPkg/XenIoPciDxe/XenIoPciDxe.c
new file mode 100644
index 000000000000..c205cf74db34
--- /dev/null
+++ b/OvmfPkg/XenIoPciDxe/XenIoPciDxe.c
@@ -0,0 +1,367 @@
+/** @file
+
+  Driver for the virtual Xen PCI device
+
+  Copyright (C) 2012, Red Hat, Inc.
+  Copyright (c) 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (C) 2013, ARM Ltd.
+  Copyright (C) 2015, 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.
+
+**/
+
+#include <IndustryStandard/Acpi.h>
+#include <IndustryStandard/Pci.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Protocol/PciIo.h>
+#include <Protocol/XenIo.h>
+
+#define PCI_VENDOR_ID_XEN                0x5853
+#define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
+
+/**
+
+  Device probe function for this driver.
+
+  The DXE core calls this function for any given device in order to see if the
+  driver can drive the device.
+
+  @param[in]  This                The EFI_DRIVER_BINDING_PROTOCOL object
+                                  incorporating this driver (independently of
+                                  any device).
+
+  @param[in] DeviceHandle         The device to probe.
+
+  @param[in] RemainingDevicePath  Relevant only for bus drivers, ignored.
+
+
+  @retval EFI_SUCCESS      The driver supports the device being probed.
+
+  @retval EFI_UNSUPPORTED  The driver does not support the device being probed.
+
+  @return                  Error codes from the OpenProtocol() boot service or
+                           the PciIo protocol.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+XenIoPciDeviceBindingSupported (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
+  )
+{
+  EFI_STATUS          Status;
+  EFI_PCI_IO_PROTOCOL *PciIo;
+  PCI_TYPE00          Pci;
+
+  //
+  // Attempt to open the device with the PciIo set of interfaces. On success,
+  // the protocol is "instantiated" for the PCI device. Covers duplicate open
+  // attempts (EFI_ALREADY_STARTED).
+  //
+  Status = gBS->OpenProtocol (
+                  DeviceHandle,               // candidate device
+                  &gEfiPciIoProtocolGuid,     // for generic PCI access
+                  (VOID **)&PciIo,            // handle to instantiate
+                  This->DriverBindingHandle,  // requestor driver identity
+                  DeviceHandle,               // ControllerHandle, according to
+                                              // the UEFI Driver Model
+                  EFI_OPEN_PROTOCOL_BY_DRIVER // get exclusive PciIo access to
+                                              // the device; to be released
+                  );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Read entire PCI configuration header for more extensive check ahead.
+  //
+  Status = PciIo->Pci.Read (
+                        PciIo,                        // (protocol, device)
+                                                      // handle
+                        EfiPciIoWidthUint32,          // access width & copy
+                                                      // mode
+                        0,                            // Offset
+                        sizeof Pci / sizeof (UINT32), // Count
+                        &Pci                          // target buffer
+                        );
+
+  if (Status == EFI_SUCCESS) {
+    if ((Pci.Hdr.VendorId == PCI_VENDOR_ID_XEN) &&
+        (Pci.Hdr.DeviceId == PCI_DEVICE_ID_XEN_PLATFORM)) {
+      Status = EFI_SUCCESS;
+    } else {
+      Status = EFI_UNSUPPORTED;
+    }
+  }
+
+  //
+  // We needed PCI IO access only transitorily, to see whether we support the
+  // device or not.
+  //
+  gBS->CloseProtocol (DeviceHandle, &gEfiPciIoProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+  return Status;
+}
+
+/**
+
+  After we've pronounced support for a specific device in
+  DriverBindingSupported(), we start managing said device (passed in by the
+  Driver Exeuction Environment) with the following service.
+
+  See DriverBindingSupported() for specification references.
+
+  @param[in]  This                The EFI_DRIVER_BINDING_PROTOCOL object
+                                  incorporating this driver (independently of
+                                  any device).
+
+  @param[in] DeviceHandle         The supported device to drive.
+
+  @param[in] RemainingDevicePath  Relevant only for bus drivers, ignored.
+
+
+  @retval EFI_SUCCESS           The device was started.
+
+  @retval EFI_OUT_OF_RESOURCES  Memory allocation failed.
+
+  @return                       Error codes from the OpenProtocol() boot
+                                service, the PciIo protocol or the
+                                InstallProtocolInterface() boot service.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+XenIoPciDeviceBindingStart (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
+  )
+{
+  EFI_STATUS                        Status;
+  XENIO_PROTOCOL                    *XenIo;
+  EFI_PCI_IO_PROTOCOL               *PciIo;
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *BarDesc;
+
+  XenIo = (XENIO_PROTOCOL *) AllocateZeroPool (sizeof *XenIo);
+  if (XenIo == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Status = gBS->OpenProtocol (DeviceHandle, &gEfiPciIoProtocolGuid,
+                  (VOID **)&PciIo, This->DriverBindingHandle,
+                  DeviceHandle, EFI_OPEN_PROTOCOL_BY_DRIVER);
+  if (EFI_ERROR (Status)) {
+    goto FreeXenIo;
+  }
+
+  //
+  // The BAR1 of this PCI device is used for shared memory and is supposed to
+  // look like MMIO. The address space of the BAR1 will be used to map the
+  // Grant Table.
+  //
+  Status = PciIo->GetBarAttributes (PciIo, PCI_BAR_IDX1, NULL, (VOID**) 
&BarDesc);
+  ASSERT_EFI_ERROR (Status);
+  ASSERT (BarDesc->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM);
+
+  /* Get a Memory address for mapping the Grant Table. */
+  DEBUG ((EFI_D_INFO, "XenIoPci: BAR at %LX\n", BarDesc->AddrRangeMin));
+  XenIo->GrantTableAddress = BarDesc->AddrRangeMin;
+  FreePool (BarDesc);
+
+  Status = gBS->InstallProtocolInterface (&DeviceHandle,
+             &gXenIoProtocolGuid, EFI_NATIVE_INTERFACE, XenIo);
+
+  if (!EFI_ERROR (Status)) {
+    return EFI_SUCCESS;
+  }
+
+  gBS->CloseProtocol (DeviceHandle, &gEfiPciIoProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+FreeXenIo:
+  FreePool (XenIo);
+
+  return Status;
+}
+
+/**
+
+  Stop driving the XenIo PCI device
+
+  @param[in] This               The EFI_DRIVER_BINDING_PROTOCOL object
+                                incorporating this driver (independently of any
+                                device).
+
+  @param[in] DeviceHandle       Stop driving this device.
+
+  @param[in] NumberOfChildren   Since this function belongs to a device driver
+                                only (as opposed to a bus driver), the caller
+                                environment sets NumberOfChildren to zero, and
+                                we ignore it.
+
+  @param[in] ChildHandleBuffer  Ignored (corresponding to NumberOfChildren).
+
+  @retval EFI_SUCCESS           Driver instance has been stopped and the PCI
+                                configuration attributes have been restored.
+
+  @return                       Error codes from the OpenProtocol() or
+                                CloseProtocol(), UninstallProtocolInterface()
+                                boot services.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+XenIoPciDeviceBindingStop (
+  IN EFI_DRIVER_BINDING_PROTOCOL *This,
+  IN EFI_HANDLE                  DeviceHandle,
+  IN UINTN                       NumberOfChildren,
+  IN EFI_HANDLE                  *ChildHandleBuffer
+  )
+{
+  EFI_STATUS               Status;
+  XENIO_PROTOCOL           *XenIo;
+
+  Status = gBS->OpenProtocol (
+                  DeviceHandle,                  // candidate device
+                  &gXenIoProtocolGuid,           // retrieve the XenIo iface
+                  (VOID **)&XenIo,               // target pointer
+                  This->DriverBindingHandle,     // requestor driver identity
+                  DeviceHandle,                  // requesting lookup for dev.
+                  EFI_OPEN_PROTOCOL_GET_PROTOCOL // lookup only, no ref. added
+                  );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // Handle Stop() requests for in-use driver instances gracefully.
+  //
+  Status = gBS->UninstallProtocolInterface (DeviceHandle,
+                  &gXenIoProtocolGuid, XenIo);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = gBS->CloseProtocol (DeviceHandle, &gEfiPciIoProtocolGuid,
+         This->DriverBindingHandle, DeviceHandle);
+
+  FreePool (XenIo);
+
+  return Status;
+}
+
+
+//
+// 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 = {
+  &XenIoPciDeviceBindingSupported,
+  &XenIoPciDeviceBindingStart,
+  &XenIoPciDeviceBindingStop,
+  0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers
+  NULL, // ImageHandle, to be overwritten by
+        // EfiLibInstallDriverBindingComponentName2() in 
XenIoPciDeviceEntryPoint()
+  NULL  // DriverBindingHandle, ditto
+};
+
+
+//
+// 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"XenIo PCI Driver" },
+  { NULL,     NULL                }
+};
+
+STATIC
+EFI_COMPONENT_NAME_PROTOCOL gComponentName;
+
+EFI_STATUS
+EFIAPI
+XenIoPciGetDriverName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
+  IN  CHAR8                       *Language,
+  OUT CHAR16                      **DriverName
+  )
+{
+  return LookupUnicodeString2 (
+           Language,
+           This->SupportedLanguages,
+           mDriverNameTable,
+           DriverName,
+           (BOOLEAN)(This == &gComponentName) // Iso639Language
+           );
+}
+
+EFI_STATUS
+EFIAPI
+XenIoPciGetDeviceName (
+  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
+  IN  EFI_HANDLE                  DeviceHandle,
+  IN  EFI_HANDLE                  ChildHandle,
+  IN  CHAR8                       *Language,
+  OUT CHAR16                      **ControllerName
+  )
+{
+  return EFI_UNSUPPORTED;
+}
+
+STATIC
+EFI_COMPONENT_NAME_PROTOCOL gComponentName = {
+  &XenIoPciGetDriverName,
+  &XenIoPciGetDeviceName,
+  "eng" // SupportedLanguages, ISO 639-2 language codes
+};
+
+STATIC
+EFI_COMPONENT_NAME2_PROTOCOL gComponentName2 = {
+  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME)     &XenIoPciGetDriverName,
+  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) &XenIoPciGetDeviceName,
+  "en" // SupportedLanguages, RFC 4646 language codes
+};
+
+
+//
+// Entry point of this driver.
+//
+EFI_STATUS
+EFIAPI
+XenIoPciDeviceEntryPoint (
+  IN EFI_HANDLE       ImageHandle,
+  IN EFI_SYSTEM_TABLE *SystemTable
+  )
+{
+  return EfiLibInstallDriverBindingComponentName2 (
+           ImageHandle,
+           SystemTable,
+           &gDriverBinding,
+           ImageHandle,
+           &gComponentName,
+           &gComponentName2
+           );
+}
diff --git a/OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf 
b/OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
new file mode 100644
index 000000000000..b32075a38163
--- /dev/null
+++ b/OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
@@ -0,0 +1,45 @@
+## @file
+#  Driver for the virtual Xen PCI device
+#
+#  Copyright (C) 2015, 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               = 0x00010005
+  BASE_NAME                 = XenIoPciDxe
+  FILE_GUID                 = cf569f50-de44-4f54-b4d7-f4ae25cda599
+  MODULE_TYPE               = UEFI_DRIVER
+  VERSION_STRING            = 1.0
+  ENTRY_POINT               = XenIoPciDeviceEntryPoint
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[Sources]
+  XenIoPciDxe.c
+
+[LibraryClasses]
+  UefiDriverEntryPoint
+  UefiBootServicesTableLib
+  MemoryAllocationLib
+  BaseMemoryLib
+  BaseLib
+  UefiLib
+  DebugLib
+
+[Protocols]
+  gEfiDriverBindingProtocolGuid
+  gEfiPciIoProtocolGuid
+  gEfiComponentName2ProtocolGuid
+  gEfiComponentNameProtocolGuid
+  gXenIoProtocolGuid
-- 
1.8.3.2


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