/** @file

  Internal definitions for the virtio-scsi driver, which produces Extended SCSI
  Pass Thru Protocol instances for virtio-scsi devices.

  Copyright (C) 2012, Red Hat, Inc.

  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 _VIRTIO_SCSI_DXE_H_
#define _VIRTIO_SCSI_DXE_H_

#include <Protocol/ComponentName.h>
#include <Protocol/DriverBinding.h>
#include <Protocol/ScsiPassThruExt.h>

#include <IndustryStandard/Virtio.h>


//
// This driver supports 2-byte target identifiers and 4-byte LUN identifiers.
//
// EFI_EXT_SCSI_PASS_THRU_PROTOCOL provides TARGET_MAX_BYTES bytes for target
// identification, and 8 bytes for LUN identification.
//
// EFI_EXT_SCSI_PASS_THRU_MODE.AdapterId is also a target identifier,
// consisting of 4 bytes. Make sure TARGET_MAX_BYTES can accomodate both
// AdapterId and our target identifiers.
//
#if TARGET_MAX_BYTES < 4
#  error "virtio-scsi requires TARGET_MAX_BYTES >= 4"
#endif


#define VSCSI_SIG SIGNATURE_32 ('V', 'S', 'C', 'S')

typedef struct {
  //
  // Parts of this structure are initialized / torn down in various functions
  // at various call depths. The table to the right should make it easier to
  // track them.
  //
  //                              field              init function       init depth
  //                              ----------------   ------------------  ----------
  UINT32                          Signature;      // DriverBindingStart  0
  VIRTIO_DEVICE_PROTOCOL          *VirtIo;        // DriverBindingStart  0
  EFI_EVENT                       ExitBoot;       // DriverBindingStart  0
  BOOLEAN                         InOutSupported; // VirtioScsiInit      1
  UINT16                          MaxTarget;      // VirtioScsiInit      1
  UINT32                          MaxLun;         // VirtioScsiInit      1
  UINT32                          MaxSectors;     // VirtioScsiInit      1
  VRING                           Ring;           // VirtioRingInit      2
  EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;       // VirtioScsiInit      1
  EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;   // VirtioScsiInit      1
} VSCSI_DEV;

#define VIRTIO_SCSI_FROM_PASS_THRU(PassThruPointer) \
        CR (PassThruPointer, VSCSI_DEV, PassThru, VSCSI_SIG)


//
// 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
//

EFI_STATUS
EFIAPI
VirtioScsiDriverBindingSupported (
  IN EFI_DRIVER_BINDING_PROTOCOL *This,
  IN EFI_HANDLE                  DeviceHandle,
  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
  );


EFI_STATUS
EFIAPI
VirtioScsiDriverBindingStart (
  IN EFI_DRIVER_BINDING_PROTOCOL *This,
  IN EFI_HANDLE                  DeviceHandle,
  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
  );


EFI_STATUS
EFIAPI
VirtioScsiDriverBindingStop (
  IN EFI_DRIVER_BINDING_PROTOCOL *This,
  IN EFI_HANDLE                  DeviceHandle,
  IN UINTN                       NumberOfChildren,
  IN EFI_HANDLE                  *ChildHandleBuffer
  );


//
// The next seven functions implement EFI_EXT_SCSI_PASS_THRU_PROTOCOL
// for the virtio-scsi HBA. Refer to UEFI Spec 2.3.1 + Errata C, sections
// - 14.1 SCSI Driver Model Overview,
// - 14.7 Extended SCSI Pass Thru Protocol.
//

EFI_STATUS
EFIAPI
VirtioScsiPassThru (
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL            *This,
  IN     UINT8                                      *Target,
  IN     UINT64                                     Lun,
  IN OUT EFI_EXT_SCSI_PASS_THRU_SCSI_REQUEST_PACKET *Packet,
  IN     EFI_EVENT                                  Event   OPTIONAL
  );


EFI_STATUS
EFIAPI
VirtioScsiGetNextTargetLun (
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This,
  IN OUT UINT8                           **Target,
  IN OUT UINT64                          *Lun
  );


EFI_STATUS
EFIAPI
VirtioScsiBuildDevicePath (
  IN     EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This,
  IN     UINT8                           *Target,
  IN     UINT64                          Lun,
  IN OUT EFI_DEVICE_PATH_PROTOCOL        **DevicePath
  );


EFI_STATUS
EFIAPI
VirtioScsiGetTargetLun (
  IN  EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This,
  IN  EFI_DEVICE_PATH_PROTOCOL        *DevicePath,
  OUT UINT8                           **Target,
  OUT UINT64                          *Lun
  );


EFI_STATUS
EFIAPI
VirtioScsiResetChannel (
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This
  );


EFI_STATUS
EFIAPI
VirtioScsiResetTargetLun (
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This,
  IN UINT8                           *Target,
  IN UINT64                          Lun
  );


EFI_STATUS
EFIAPI
VirtioScsiGetNextTarget (
  IN EFI_EXT_SCSI_PASS_THRU_PROTOCOL *This,
  IN OUT UINT8                       **Target
  );


//
// 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.
//
// Device type names ("Virtio SCSI Host Device") are not formatted because the
// driver supports only that device type. Therefore the driver name suffices
// for unambiguous identification.
//

EFI_STATUS
EFIAPI
VirtioScsiGetDriverName (
  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
  IN  CHAR8                       *Language,
  OUT CHAR16                      **DriverName
  );


EFI_STATUS
EFIAPI
VirtioScsiGetDeviceName (
  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
  IN  EFI_HANDLE                  DeviceHandle,
  IN  EFI_HANDLE                  ChildHandle,
  IN  CHAR8                       *Language,
  OUT CHAR16                      **ControllerName
  );

#endif // _VIRTIO_SCSI_DXE_H_
