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 <linux/blkdev.h>
25#include <linux/bug.h>
26#include <scsi/scsi_host.h>
27#include <scsi/scsi_device.h>
28
29struct scsi_transport_template {
30	/* the attribute containers */
31	struct transport_container host_attrs;
32	struct transport_container target_attrs;
33	struct transport_container device_attrs;
34
35	/*
36	 * If set, called from sysfs and legacy procfs rescanning code.
37	 */
38	int (*user_scan)(struct Scsi_Host *, uint, uint, uint);
39
40	/* The size of the specific transport attribute structure (a
41	 * space of this size will be left at the end of the
42	 * scsi_* structure */
43	int	device_size;
44	int	device_private_offset;
45	int	target_size;
46	int	target_private_offset;
47	int	host_size;
48	/* no private offset for the host; there's an alternative mechanism */
49
50	/*
51	 * True if the transport wants to use a host-based work-queue
52	 */
53	unsigned int create_work_queue : 1;
54
55	/*
56	 * Allows a transport to override the default error handler.
57	 */
58	void (* eh_strategy_handler)(struct Scsi_Host *);
59
60	/*
61	 * This is an optional routine that allows the transport to become
62	 * involved when a scsi io timer fires. The return value tells the
63	 * timer routine how to finish the io timeout handling:
64	 * EH_HANDLED:		I fixed the error, please complete the command
65	 * EH_RESET_TIMER:	I need more time, reset the timer and
66	 *			begin counting again
67	 * EH_NOT_HANDLED	Begin normal error recovery
68	 */
69	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
70
71	/*
72	 * Used as callback for the completion of i_t_nexus request
73	 * for target drivers.
74	 */
75	int (* it_nexus_response)(struct Scsi_Host *, u64, int);
76
77	/*
78	 * Used as callback for the completion of task management
79	 * request for target drivers.
80	 */
81	int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
82};
83
84#define transport_class_to_shost(tc) \
85	dev_to_shost((tc)->parent)
86
87
88/* Private area maintenance. The driver requested allocations come
89 * directly after the transport class allocations (if any).  The idea
90 * is that you *must* call these only once.  The code assumes that the
91 * initial values are the ones the transport specific code requires */
92static inline void
93scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
94{
95	BUG_ON(t->target_private_offset != 0);
96	t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
97	t->target_size = t->target_private_offset + space;
98}
99static inline void
100scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
101{
102	BUG_ON(t->device_private_offset != 0);
103	t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
104	t->device_size = t->device_private_offset + space;
105}
106static inline void *
107scsi_transport_target_data(struct scsi_target *starget)
108{
109	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
110	return (u8 *)starget->starget_data
111		+ shost->transportt->target_private_offset;
112
113}
114static inline void *
115scsi_transport_device_data(struct scsi_device *sdev)
116{
117	struct Scsi_Host *shost = sdev->host;
118	return (u8 *)sdev->sdev_data
119		+ shost->transportt->device_private_offset;
120}
121
122#endif /* SCSI_TRANSPORT_H */
123