1 /*	$NetBSD: extent.h,v 1.19 2012/01/27 18:53:10 para Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_EXTENT_H_
33 #define _SYS_EXTENT_H_
34 
35 #include <sys/queue.h>
36 #include <sys/mutex.h>
37 #include <sys/condvar.h>
38 
39 struct extent_region {
40 	LIST_ENTRY(extent_region) er_link;	/* link in region list */
41 	u_long 	er_start;		/* start of region */
42 	u_long	er_end;			/* end of region */
43 	int	er_flags;		/* misc. flags */
44 };
45 
46 /* er_flags */
47 #define ER_ALLOC	0x01	/* region descriptor dynamically allocated */
48 
49 struct extent {
50 	const char *ex_name;		/* name of extent */
51 	kmutex_t ex_lock;		/* lock on this extent */
52 	kcondvar_t ex_cv;		/* synchronization */
53 					/* allocated regions in extent */
54 	LIST_HEAD(, extent_region) ex_regions;
55 	u_long	ex_start;		/* start of extent */
56 	u_long	ex_end;			/* end of extent */
57 	int	ex_flags;		/* misc. information */
58 };
59 
60 struct extent_fixed {
61 	struct extent	fex_extent;	/* MUST BE FIRST */
62 					/* freelist of region descriptors */
63 	LIST_HEAD(, extent_region) fex_freelist;
64 	void *		fex_storage;	/* storage space for descriptors */
65 	size_t		fex_storagesize; /* size of storage space */
66 };
67 
68 /* ex_flags; for internal use only */
69 #define EXF_FIXED	0x01		/* extent uses fixed storage */
70 #define EXF_NOCOALESCE	0x02		/* coalescing of regions not allowed */
71 #define EXF_FLWANTED	0x08		/* someone asleep on freelist */
72 
73 #define EXF_BITS	"\20\4FLWANTED\2NOCOALESCE\1FIXED"
74 
75 /* misc. flags passed to extent functions */
76 #define EX_NOWAIT	0x00		/* not safe to sleep */
77 #define EX_WAITOK	0x01		/* safe to sleep */
78 #define EX_FAST		0x02		/* take first fit in extent_alloc() */
79 #define EX_CATCH	0x04		/* catch signals while sleeping */
80 #define EX_NOCOALESCE	0x08		/* create a non-coalescing extent */
81 #define EX_MALLOCOK	0x10		/* safe to call kmem_alloc() */
82 #define EX_WAITSPACE	0x20		/* wait for space to become free */
83 #define EX_BOUNDZERO	0x40		/* boundary lines start at 0 */
84 
85 /*
86  * Special place holders for "alignment" and "boundary" arguments,
87  * in the event the caller doesn't wish to use those features.
88  */
89 #define EX_NOALIGN	1		/* don't do alignment */
90 #define EX_NOBOUNDARY	0		/* don't do boundary checking */
91 
92 #if defined(_KERNEL) || defined(_EXTENT_TESTING)
93 #define EXTENT_FIXED_STORAGE_SIZE(_nregions)		\
94 	(ALIGN(sizeof(struct extent_fixed)) +		\
95 	((ALIGN(sizeof(struct extent_region))) *	\
96 	 (_nregions)))
97 
98 struct	extent *extent_create(const char *, u_long, u_long,
99 	    void *, size_t, int);
100 void	extent_destroy(struct extent *);
101 int	extent_alloc_subregion1(struct extent *, u_long, u_long,
102 	    u_long, u_long, u_long, u_long, int, u_long *);
103 int	extent_alloc_subregion(struct extent *, u_long, u_long,
104 	    u_long, u_long, u_long, int, u_long *);
105 int	extent_alloc_region(struct extent *, u_long, u_long, int);
106 int	extent_alloc1(struct extent *, u_long, u_long, u_long, u_long, int,
107 	    u_long *);
108 int	extent_alloc(struct extent *, u_long, u_long, u_long, int, u_long *);
109 int	extent_free(struct extent *, u_long, u_long, int);
110 void	extent_print(struct extent *);
111 void	extent_init(void);
112 
113 #endif /* _KERNEL || _EXTENT_TESTING */
114 
115 #endif /* ! _SYS_EXTENT_H_ */
116