/*
* Transport specific attributes.
*
* Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef SCSI_TRANSPORT_H
#define SCSI_TRANSPORT_H

#include <linux/transport_class.h>
#include <linux/blkdev.h>
#include <linux/bug.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>

struct scsi_transport_template {
/* the attribute containers */
struct transport_container host_attrs;
struct transport_container target_attrs;
struct transport_container device_attrs;

/*
* If set, called from sysfs and legacy procfs rescanning code.
*/
int (*user_scan)(struct Scsi_Host *, uint, uint, uint);

/* The size of the specific transport attribute structure (a
* space of this size will be left at the end of the
* scsi_* structure */
int device_size;
int device_private_offset;
int target_size;
int target_private_offset;
int host_size;
/* no private offset for the host; there's an alternative mechanism */

/*
* True if the transport wants to use a host-based work-queue
*/
unsigned int create_work_queue : 1;

/*
* Allows a transport to override the default error handler.
*/
void (* eh_strategy_handler)(struct Scsi_Host *);

/*
* This is an optional routine that allows the transport to become
* involved when a scsi io timer fires. The return value tells the
* timer routine how to finish the io timeout handling:
* EH_HANDLED: I fixed the error, please complete the command
* EH_RESET_TIMER: I need more time, reset the timer and
* begin counting again
* EH_NOT_HANDLED Begin normal error recovery
*/
enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);

/*
* Used as callback for the completion of i_t_nexus request
* for target drivers.
*/
int (* it_nexus_response)(struct Scsi_Host *, u64, int);

/*
* Used as callback for the completion of task management
* request for target drivers.
*/
int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
};

#define transport_class_to_shost(tc) \
dev_to_shost((tc)->parent)


/* Private area maintenance. The driver requested allocations come
* directly after the transport class allocations (if any). The idea
* is that you *must* call these only once. The code assumes that the
* initial values are the ones the transport specific code requires */
static inline void
scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
{
BUG_ON(t->target_private_offset != 0);
t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
t->target_size = t->target_private_offset + space;
}
static inline void
scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
{
BUG_ON(t->device_private_offset != 0);
t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
t->device_size = t->device_private_offset + space;
}
static inline void *
scsi_transport_target_data(struct scsi_target *starget)
{
struct Scsi_Host *shost = dev_to_shost(&starget->dev);
return (u8 *)starget->starget_data
+ shost->transportt->target_private_offset;

}
static inline void *
scsi_transport_device_data(struct scsi_device *sdev)
{
struct Scsi_Host *shost = sdev->host;
return (u8 *)sdev->sdev_data
+ shost->transportt->device_private_offset;
}

#endif /* SCSI_TRANSPORT_H */