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