/** @file

  Driver for the virtual Xen PCI device

  Copyright (C) 2012, Red Hat, Inc.
  Copyright (c) 2012 - 2016, 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 Execution 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
           );
}