xref: /netbsd/sys/sys/bufq_impl.h (revision 6550d01e)
1 /*	$NetBSD: bufq_impl.h,v 1.8 2009/01/19 14:54:28 yamt Exp $	*/
2 /*	NetBSD: bufq.h,v 1.3 2005/03/31 11:28:53 yamt Exp	*/
3 /*	NetBSD: buf.h,v 1.75 2004/09/18 16:40:11 yamt Exp 	*/
4 
5 /*-
6  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
11  * NASA Ames Research Center.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * Copyright (c) 1982, 1986, 1989, 1993
37  *	The Regents of the University of California.  All rights reserved.
38  * (c) UNIX System Laboratories, Inc.
39  * All or some portions of this file are derived from material licensed
40  * to the University of California by American Telephone and Telegraph
41  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
42  * the permission of UNIX System Laboratories, Inc.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  * 3. Neither the name of the University nor the names of its contributors
53  *    may be used to endorse or promote products derived from this software
54  *    without specific prior written permission.
55  *
56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66  * SUCH DAMAGE.
67  *
68  *	@(#)buf.h	8.9 (Berkeley) 3/30/95
69  */
70 
71 #if !defined(_KERNEL)
72 #error not supposed to be exposed to userland.
73 #endif
74 
75 struct bufq_strat;
76 
77 /*
78  * Device driver buffer queue.
79  */
80 struct bufq_state {
81 	void (*bq_put)(struct bufq_state *, struct buf *);
82 	struct buf *(*bq_get)(struct bufq_state *, int);
83 	struct buf *(*bq_cancel)(struct bufq_state *, struct buf *);
84 	void (*bq_fini)(struct bufq_state *);
85 	void *bq_private;
86 	int bq_flags;			/* Flags from bufq_alloc() */
87 	const struct bufq_strat *bq_strat;
88 };
89 
90 static __inline void *bufq_private(const struct bufq_state *) __unused;
91 static __inline int buf_inorder(const struct buf *, const struct buf *, int)
92     __unused;
93 
94 #include <sys/null.h> /* for NULL */
95 
96 static __inline void *
97 bufq_private(const struct bufq_state *bufq)
98 {
99 
100 	return bufq->bq_private;
101 }
102 
103 /*
104  * Check if two buf's are in ascending order.
105  */
106 static __inline int
107 buf_inorder(const struct buf *bp, const struct buf *bq, int sortby)
108 {
109 
110 	if (bp == NULL || bq == NULL)
111 		return (bq == NULL);
112 
113 	if (sortby == BUFQ_SORT_CYLINDER) {
114 		if (bp->b_cylinder != bq->b_cylinder)
115 			return bp->b_cylinder < bq->b_cylinder;
116 		else
117 			return bp->b_rawblkno < bq->b_rawblkno;
118 	} else
119 		return bp->b_rawblkno < bq->b_rawblkno;
120 }
121 
122 struct bufq_strat {
123 	const char *bs_name;
124 	void (*bs_initfn)(struct bufq_state *);
125 	int bs_prio;
126 };
127 
128 #define	BUFQ_DEFINE(name, prio, initfn)			\
129 static const struct bufq_strat bufq_strat_##name = {	\
130 	.bs_name = #name,				\
131 	.bs_prio = prio,					\
132 	.bs_initfn = initfn				\
133 };							\
134 __link_set_add_rodata(bufq_strats, bufq_strat_##name)
135