xref: /linux/include/scsi/scsi_transport.h (revision 447e140e66fd226350b3ce86cffc965eaae4c856)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  *  Transport specific attributes.
4  *
5  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
6  */
7 #ifndef SCSI_TRANSPORT_H
8 #define SCSI_TRANSPORT_H
9 
10 #include <linux/transport_class.h>
11 #include <linux/blkdev.h>
12 #include <linux/bug.h>
13 #include <scsi/scsi_host.h>
14 #include <scsi/scsi_device.h>
15 
16 struct scsi_transport_template {
17 	/* the attribute containers */
18 	struct transport_container host_attrs;
19 	struct transport_container target_attrs;
20 	struct transport_container device_attrs;
21 
22 	/*
23 	 * If set, called from sysfs and legacy procfs rescanning code.
24 	 */
25 	int (*user_scan)(struct Scsi_Host *, uint, uint, u64);
26 
27 	/* The size of the specific transport attribute structure (a
28 	 * space of this size will be left at the end of the
29 	 * scsi_* structure */
30 	int	device_size;
31 	int	device_private_offset;
32 	int	target_size;
33 	int	target_private_offset;
34 	int	host_size;
35 	/* no private offset for the host; there's an alternative mechanism */
36 
37 	/*
38 	 * True if the transport wants to use a host-based work-queue
39 	 */
40 	unsigned int create_work_queue : 1;
41 
42 	/*
43 	 * Allows a transport to override the default error handler.
44 	 */
45 	void (* eh_strategy_handler)(struct Scsi_Host *);
46 };
47 
48 #define transport_class_to_shost(tc) \
49 	dev_to_shost((tc)->parent)
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 void scsi_init_limits(struct Scsi_Host *shost, struct queue_limits *lim);
87 
88 #endif /* SCSI_TRANSPORT_H */
89