xref: /titanic_41/usr/src/uts/common/sys/blkdev.h (revision aa98ce2c4ecbce8afe8b7b253a911ab24fdded32)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2012 DEY Storage Systems, Inc.  All rights reserved.
23  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
24  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
25  */
26 
27 #ifndef	_SYS_BLKDEV_H
28 #define	_SYS_BLKDEV_H
29 
30 #include <sys/types.h>
31 #include <sys/ksynch.h>
32 #include <sys/ddi.h>
33 #include <sys/sunddi.h>
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /*
40  * This describes a fairly simple block device.  The idea here is that
41  * these things want to take advantage of the common labelling support,
42  * but do not need all the capabilities of SCSA.  So we make quite a few
43  * simplifications:
44  *
45  * 1) Device block size is a power of 2 greater or equal to 512 bytes.
46  *    An optional physical block size can be reported if the underlying
47  *    device uses larger block sizes internally, so that writes can be
48  *    aligned properly.
49  *
50  * 2) Non-rotating media.  We assume a simple linear layout.
51  *
52  * 3) Fixed queue depth, for each device.  The adapter driver reports
53  *    the queue depth at registration.  We don't have any form of
54  *    dynamic flow control.
55  *
56  * 4) Negligible power management support.  The framework does not support
57  *    fine grained power management.  If the adapter driver wants to use
58  *    such, it will need to manage power on its own.
59  *
60  * 5) Suspend/resume support managed by the adapter driver.  We don't
61  *    support suspend/resume directly.  The adapter device driver will
62  *    need to manage this on its own behalf.
63  *
64  * 6) No request priorities.  Transfers are assumed to execute in
65  *    roughly FIFO order.  The adapter driver may reorder them, but the
66  *    submitter has no control over that.
67  *
68  * 7) No request cancellation.  Once submitted, the job completes or
69  *    fails.  It cannot be canceled.
70  *
71  * 8) Limited support for removable media.  There is no support for
72  *    locking bay doors or mechanised media bays.  This could be
73  *    added, but at present the only such interesting devices are
74  *    covered by the SCSI disk driver.
75  */
76 
77 typedef struct bd_handle *bd_handle_t;
78 typedef struct bd_xfer bd_xfer_t;
79 typedef struct bd_drive bd_drive_t;
80 typedef struct bd_media bd_media_t;
81 typedef struct bd_ops bd_ops_t;
82 
83 
84 struct bd_xfer {
85 	/*
86 	 * NB: If using DMA the br_ndmac will be non-zero.  Otherwise
87 	 * the br_kaddr will be non-NULL.
88 	 */
89 	diskaddr_t		x_blkno;
90 	size_t			x_nblks;
91 	ddi_dma_handle_t	x_dmah;
92 	ddi_dma_cookie_t	x_dmac;
93 	unsigned		x_ndmac;
94 	caddr_t			x_kaddr;
95 	unsigned		x_flags;
96 };
97 
98 #define	BD_XFER_POLL		(1U << 0)	/* no interrupts (dump) */
99 
100 struct bd_drive {
101 	uint32_t		d_qsize;
102 	uint32_t		d_maxxfer;
103 	boolean_t		d_removable;
104 	boolean_t		d_hotpluggable;
105 	int			d_target;
106 	int			d_lun;
107 };
108 
109 struct bd_media {
110 	/*
111 	 * NB: The block size must be a power of two not less than
112 	 * DEV_BSIZE (512).  Other values of the block size will
113 	 * simply not function and the media will be rejected.
114 	 *
115 	 * The block size must also divide evenly into the device's
116 	 * d_maxxfer field.  If the maxxfer is a power of two larger
117 	 * than the block size, then this will automatically be
118 	 * satisfied.
119 	 *
120 	 * The physical block size (m_pblksize) must be 0 or a power
121 	 * of two not less than the block size.
122 	 */
123 	uint64_t		m_nblks;
124 	uint32_t		m_blksize;
125 	boolean_t		m_readonly;
126 	boolean_t		m_solidstate;
127 	uint32_t		m_pblksize;
128 };
129 
130 #define	BD_INFO_FLAG_REMOVABLE		(1U << 0)
131 #define	BD_INFO_FLAG_HOTPLUGGABLE	(1U << 1)
132 #define	BD_INFO_FLAG_READ_ONLY		(1U << 2)
133 
134 struct bd_ops {
135 	int	o_version;
136 	void	(*o_drive_info)(void *, bd_drive_t *);
137 	int	(*o_media_info)(void *, bd_media_t *);
138 	int	(*o_devid_init)(void *, dev_info_t *, ddi_devid_t *);
139 	int	(*o_sync_cache)(void *, bd_xfer_t *);
140 	int	(*o_read)(void *, bd_xfer_t *);
141 	int	(*o_write)(void *, bd_xfer_t *);
142 };
143 
144 #define	BD_OPS_VERSION_0		0
145 
146 /*
147  * Note, one handler *per* address.  Drivers with multiple targets at
148  * different addresses must use separate handles.
149  */
150 bd_handle_t	bd_alloc_handle(void *, bd_ops_t *, ddi_dma_attr_t *, int);
151 void		bd_free_handle(bd_handle_t);
152 int		bd_attach_handle(dev_info_t *, bd_handle_t);
153 int		bd_detach_handle(bd_handle_t);
154 void		bd_state_change(bd_handle_t);
155 void		bd_xfer_done(bd_xfer_t *, int);
156 void		bd_mod_init(struct dev_ops *);
157 void		bd_mod_fini(struct dev_ops *);
158 
159 #ifdef __cplusplus
160 }
161 #endif
162 
163 #endif	/* _SYS_BLKDEV_H */
164