xref: /linux/include/scsi/scsi_transport.h (revision 60b2737de1b1ddfdb90f3ba622634eb49d6f3603)
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 	/* The size of the specific transport attribute structure (a
33 	 * space of this size will be left at the end of the
34 	 * scsi_* structure */
35 	int	device_size;
36 	int	device_private_offset;
37 	int	target_size;
38 	int	target_private_offset;
39 	int	host_size;
40 	/* no private offset for the host; there's an alternative mechanism */
41 
42 	/*
43 	 * True if the transport wants to use a host-based work-queue
44 	 */
45 	unsigned int create_work_queue : 1;
46 };
47 
48 #define transport_class_to_shost(tc) \
49 	dev_to_shost((tc)->dev)
50 
51 
52 /* Private area maintenance. The driver requested allocations come
53  * directly after the transport class allocations (if any).  The idea
54  * is that you *must* call these only once.  The code assumes that the
55  * initial values are the ones the transport specific code requires */
56 static inline void
57 scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
58 {
59 	BUG_ON(t->target_private_offset != 0);
60 	t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
61 	t->target_size = t->target_private_offset + space;
62 }
63 static inline void
64 scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
65 {
66 	BUG_ON(t->device_private_offset != 0);
67 	t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
68 	t->device_size = t->device_private_offset + space;
69 }
70 static inline void *
71 scsi_transport_target_data(struct scsi_target *starget)
72 {
73 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
74 	return (u8 *)starget->starget_data
75 		+ shost->transportt->target_private_offset;
76 
77 }
78 static inline void *
79 scsi_transport_device_data(struct scsi_device *sdev)
80 {
81 	struct Scsi_Host *shost = sdev->host;
82 	return (u8 *)sdev->sdev_data
83 		+ shost->transportt->device_private_offset;
84 }
85 
86 #endif /* SCSI_TRANSPORT_H */
87