1/*
2 *  Transport specific attributes.
3 *
4 *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 */
20#ifndef SCSI_TRANSPORT_H
21#define SCSI_TRANSPORT_H
22
23#include <linux/transport_class.h>
24#include <scsi/scsi_host.h>
25#include <scsi/scsi_device.h>
26
27struct scsi_transport_template {
28	/* the attribute containers */
29	struct transport_container host_attrs;
30	struct transport_container target_attrs;
31	struct transport_container device_attrs;
32
33	/*
34	 * If set, called from sysfs and legacy procfs rescanning code.
35	 */
36	int (*user_scan)(struct Scsi_Host *, uint, uint, uint);
37
38	/* The size of the specific transport attribute structure (a
39	 * space of this size will be left at the end of the
40	 * scsi_* structure */
41	int	device_size;
42	int	device_private_offset;
43	int	target_size;
44	int	target_private_offset;
45	int	host_size;
46	/* no private offset for the host; there's an alternative mechanism */
47
48	/*
49	 * True if the transport wants to use a host-based work-queue
50	 */
51	unsigned int create_work_queue : 1;
52
53	/*
54	 * Allows a transport to override the default error handler.
55	 */
56	void (* eh_strategy_handler)(struct Scsi_Host *);
57
58	/*
59	 * This is an optional routine that allows the transport to become
60	 * involved when a scsi io timer fires. The return value tells the
61	 * timer routine how to finish the io timeout handling:
62	 * EH_HANDLED:		I fixed the error, please complete the command
63	 * EH_RESET_TIMER:	I need more time, reset the timer and
64	 *			begin counting again
65	 * EH_NOT_HANDLED	Begin normal error recovery
66	 */
67	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
68};
69
70#define transport_class_to_shost(tc) \
71	dev_to_shost((tc)->dev)
72
73
74/* Private area maintenance. The driver requested allocations come
75 * directly after the transport class allocations (if any).  The idea
76 * is that you *must* call these only once.  The code assumes that the
77 * initial values are the ones the transport specific code requires */
78static inline void
79scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
80{
81	BUG_ON(t->target_private_offset != 0);
82	t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
83	t->target_size = t->target_private_offset + space;
84}
85static inline void
86scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
87{
88	BUG_ON(t->device_private_offset != 0);
89	t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
90	t->device_size = t->device_private_offset + space;
91}
92static inline void *
93scsi_transport_target_data(struct scsi_target *starget)
94{
95	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
96	return (u8 *)starget->starget_data
97		+ shost->transportt->target_private_offset;
98
99}
100static inline void *
101scsi_transport_device_data(struct scsi_device *sdev)
102{
103	struct Scsi_Host *shost = sdev->host;
104	return (u8 *)sdev->sdev_data
105		+ shost->transportt->device_private_offset;
106}
107
108#endif /* SCSI_TRANSPORT_H */
109