/** @file

  This driver produces Virtio Device Protocol instances for Virtio Mmio devices.

  Copyright (C) 2013, ARM 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 <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>

#include "VirtioMmioDevice.h"

static VIRTIO_DEVICE_PROTOCOL mMmioDeviceProtocolTemplate = {
    0,                                     // Revision
    0,                                     // SubSystemDeviceId
    VirtioMmioGetDeviceFeatures,           // GetDeviceFeatures
    VirtioMmioSetGuestFeatures,            // SetGuestFeatures
    VirtioMmioSetQueueAddress,             // SetQueueAddress
    VirtioMmioSetQueueSel,                 // SetQueueSel
    VirtioMmioSetQueueNotify,              // SetQueueNotify
    VirtioMmioSetQueueAlignment,           // SetQueueAlign
    VirtioMmioSetPageSize,                 // SetPageSize
    VirtioMmioGetQueueSize,                // GetQueueNumMax
    VirtioMmioSetQueueSize,                // SetQueueNum
    VirtioMmioGetDeviceStatus,             // GetDeviceStatus
    VirtioMmioSetDeviceStatus,             // SetDeviceStatus
    VirtioMmioDeviceWrite,                 // WriteDevice
    VirtioMmioDeviceRead                   // ReadDevice
};

/**

  Initialize the VirtIo MMIO Device

  @param[in] BaseAddress   Base Address of the VirtIo MMIO Device

  @param[in, out] Device   The driver instance to configure.

  @retval EFI_SUCCESS      Setup complete.

  @retval EFI_UNSUPPORTED  The driver is not a VirtIo MMIO device.

**/
STATIC
EFI_STATUS
EFIAPI
VirtioMmioInit (
  IN PHYSICAL_ADDRESS        BaseAddress,
  IN OUT VIRTIO_MMIO_DEVICE *Device
  )
{
  UINT32     MagicValue;
  UINT32     VendorId;
  UINT32     Version;

  //
  // Initialize VirtIo Mmio Device
  //
  CopyMem (&Device->VirtioDevice, &mMmioDeviceProtocolTemplate,
        sizeof (VIRTIO_DEVICE_PROTOCOL));
  Device->BaseAddress = BaseAddress;
  Device->VirtioDevice.Revision = VIRTIO_SPEC_REVISION (0, 9, 5);
  Device->VirtioDevice.SubSystemDeviceId =
          MmioRead32 (BaseAddress + VIRTIO_MMIO_OFFSET_DEVICE_ID);

  //
  // Double-check MMIO-specific values
  //
  MagicValue = VIRTIO_CFG_READ (Device, VIRTIO_MMIO_OFFSET_MAGIC);
  if (MagicValue != VIRTIO_MMIO_MAGIC) {
    return EFI_UNSUPPORTED;
  }

  Version = VIRTIO_CFG_READ (Device, VIRTIO_MMIO_OFFSET_VERSION);
  if (Version != 1) {
    return EFI_UNSUPPORTED;
  }

  //
  // Double-check MMIO-specific values
  //
  VendorId = VIRTIO_CFG_READ (Device, VIRTIO_MMIO_OFFSET_VENDOR_ID);
  if (VendorId != VIRTIO_VENDOR_ID) {
    //
    // The ARM Base and Foundation Models do not report a valid VirtIo VendorId.
    // They return a value of 0x0 for the VendorId.
    //
    DEBUG((EFI_D_WARN, "VirtioMmioInit: Warning: The VendorId (0x%X) does not "
                       "match the VirtIo VendorId (0x%X).\n",
                       VendorId, VIRTIO_VENDOR_ID));
  }

  return EFI_SUCCESS;
}


/**

  Uninitialize the internals of a virtio-mmio device that has been successfully
  set up with VirtioMmioInit().

  @param[in, out]  Device  The device to clean up.

**/

STATIC
VOID
EFIAPI
VirtioMmioUninit (
  IN VIRTIO_MMIO_DEVICE *Device
  )
{
  //
  // Note: This function mirrors VirtioMmioInit() that does not allocate any
  //       resources - there's nothing to free here.
  //
}

EFI_STATUS
VirtioMmioInstallDevice (
  IN PHYSICAL_ADDRESS       BaseAddress,
  IN EFI_HANDLE             Handle
  )
{
  EFI_STATUS          Status;
  VIRTIO_MMIO_DEVICE *VirtIo;

  if (!BaseAddress) {
    return EFI_INVALID_PARAMETER;
  }
  if (Handle == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Allocate VIRTIO_MMIO_DEVICE
  //
  VirtIo = AllocateZeroPool (sizeof (VIRTIO_MMIO_DEVICE));
  if (VirtIo == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  VirtIo->Signature = VIRTIO_MMIO_DEVICE_SIGNATURE;

  Status = VirtioMmioInit (BaseAddress, VirtIo);
  if (EFI_ERROR (Status)) {
    goto FreeVirtioMem;
  }

  //
  // Install VIRTIO_DEVICE_PROTOCOL to Handle
  //
  Status = gBS->InstallProtocolInterface (&Handle,
                  &gVirtioDeviceProtocolGuid, EFI_NATIVE_INTERFACE,
                  &VirtIo->VirtioDevice);
  if (EFI_ERROR (Status)) {
    goto UninitVirtio;
  }

  return EFI_SUCCESS;

UninitVirtio:
  VirtioMmioUninit (VirtIo);

FreeVirtioMem:
  FreePool (VirtIo);
  return Status;
}

EFI_STATUS
VirtioMmioUninstallDevice (
  IN EFI_HANDLE             DeviceHandle
  )
{
  VIRTIO_DEVICE_PROTOCOL  *VirtioDevice;
  VIRTIO_MMIO_DEVICE      *MmioDevice;
  EFI_STATUS              Status;

  Status = gBS->OpenProtocol (
                  DeviceHandle,                  // candidate device
                  &gVirtioDeviceProtocolGuid,    // retrieve the VirtIo iface
                  (VOID **)&VirtioDevice,        // target pointer
                  DeviceHandle,                  // requestor driver identity
                  DeviceHandle,                  // requesting lookup for dev.
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL // lookup only, no ref. added
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Get the MMIO device from the VirtIo Device instance
  //
  MmioDevice = VIRTIO_MMIO_DEVICE_FROM_VIRTIO_DEVICE (VirtioDevice);

  //
  // Uninstall the protocol interface
  //
  Status = gBS->UninstallProtocolInterface (DeviceHandle,
      &gVirtioDeviceProtocolGuid, &MmioDevice->VirtioDevice
      );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Uninitialize the VirtIo Device
  //
  VirtioMmioUninit (MmioDevice);
  FreePool (MmioDevice);

  return EFI_SUCCESS;
}