xref: /linux/include/scsi/scsi_transport.h (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
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 
26 struct scsi_transport_template {
27 	/* the attribute containers */
28 	struct transport_container host_attrs;
29 	struct transport_container target_attrs;
30 	struct transport_container device_attrs;
31 
32 	/*
33 	 * If set, call target_parent prior to allocating a scsi_target,
34 	 * so we get the appropriate parent for the target. This function
35 	 * is required for transports like FC and iSCSI that do not put the
36 	 * scsi_target under scsi_host.
37 	 */
38 	struct device *(*target_parent)(struct Scsi_Host *, int, 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 #define transport_class_to_shost(tc) \
57 	dev_to_shost((tc)->dev)
58 
59 
60 /* Private area maintenance. The driver requested allocations come
61  * directly after the transport class allocations (if any).  The idea
62  * is that you *must* call these only once.  The code assumes that the
63  * initial values are the ones the transport specific code requires */
64 static inline void
65 scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
66 {
67 	BUG_ON(t->target_private_offset != 0);
68 	t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
69 	t->target_size = t->target_private_offset + space;
70 }
71 static inline void
72 scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
73 {
74 	BUG_ON(t->device_private_offset != 0);
75 	t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
76 	t->device_size = t->device_private_offset + space;
77 }
78 static inline void *
79 scsi_transport_target_data(struct scsi_target *starget)
80 {
81 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
82 	return (u8 *)starget->starget_data
83 		+ shost->transportt->target_private_offset;
84 
85 }
86 static inline void *
87 scsi_transport_device_data(struct scsi_device *sdev)
88 {
89 	struct Scsi_Host *shost = sdev->host;
90 	return (u8 *)sdev->sdev_data
91 		+ shost->transportt->device_private_offset;
92 }
93 
94 #endif /* SCSI_TRANSPORT_H */
95