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
29 struct 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 */
92 static inline void
scsi_transport_reserve_target(struct scsi_transport_template * t,int space)93 scsi_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 }
99 static inline void
scsi_transport_reserve_device(struct scsi_transport_template * t,int space)100 scsi_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 }
106 static inline void *
scsi_transport_target_data(struct scsi_target * starget)107 scsi_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 }
114 static inline void *
scsi_transport_device_data(struct scsi_device * sdev)115 scsi_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