xref: /openbmc/linux/include/scsi/scsi_transport.h (revision a1e58bbd)
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 #include <scsi/scsi_device.h>
26 
27 struct scsi_transport_template {
28 	/* the attribute containers */
29 	struct transport_container host_attrs;
30 	struct transport_container target_attrs;
31 	struct transport_container device_attrs;
32 
33 	/*
34 	 * If set, called from sysfs and legacy procfs rescanning code.
35 	 */
36 	int (*user_scan)(struct Scsi_Host *, uint, uint, uint);
37 
38 	/* The size of the specific transport attribute structure (a
39 	 * space of this size will be left at the end of the
40 	 * scsi_* structure */
41 	int	device_size;
42 	int	device_private_offset;
43 	int	target_size;
44 	int	target_private_offset;
45 	int	host_size;
46 	/* no private offset for the host; there's an alternative mechanism */
47 
48 	/*
49 	 * True if the transport wants to use a host-based work-queue
50 	 */
51 	unsigned int create_work_queue : 1;
52 
53 	/*
54 	 * Allows a transport to override the default error handler.
55 	 */
56 	void (* eh_strategy_handler)(struct Scsi_Host *);
57 
58 	/*
59 	 * This is an optional routine that allows the transport to become
60 	 * involved when a scsi io timer fires. The return value tells the
61 	 * timer routine how to finish the io timeout handling:
62 	 * EH_HANDLED:		I fixed the error, please complete the command
63 	 * EH_RESET_TIMER:	I need more time, reset the timer and
64 	 *			begin counting again
65 	 * EH_NOT_HANDLED	Begin normal error recovery
66 	 */
67 	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
68 
69 	/*
70 	 * Used as callback for the completion of i_t_nexus request
71 	 * for target drivers.
72 	 */
73 	int (* it_nexus_response)(struct Scsi_Host *, u64, int);
74 
75 	/*
76 	 * Used as callback for the completion of task management
77 	 * request for target drivers.
78 	 */
79 	int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
80 };
81 
82 #define transport_class_to_shost(tc) \
83 	dev_to_shost((tc)->dev)
84 
85 
86 /* Private area maintenance. The driver requested allocations come
87  * directly after the transport class allocations (if any).  The idea
88  * is that you *must* call these only once.  The code assumes that the
89  * initial values are the ones the transport specific code requires */
90 static inline void
91 scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
92 {
93 	BUG_ON(t->target_private_offset != 0);
94 	t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
95 	t->target_size = t->target_private_offset + space;
96 }
97 static inline void
98 scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
99 {
100 	BUG_ON(t->device_private_offset != 0);
101 	t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
102 	t->device_size = t->device_private_offset + space;
103 }
104 static inline void *
105 scsi_transport_target_data(struct scsi_target *starget)
106 {
107 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
108 	return (u8 *)starget->starget_data
109 		+ shost->transportt->target_private_offset;
110 
111 }
112 static inline void *
113 scsi_transport_device_data(struct scsi_device *sdev)
114 {
115 	struct Scsi_Host *shost = sdev->host;
116 	return (u8 *)sdev->sdev_data
117 		+ shost->transportt->device_private_offset;
118 }
119 
120 #endif /* SCSI_TRANSPORT_H */
121