1/* $NetBSD: extent.h,v 1.26 2017/08/24 11:33:28 jmcneill 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#ifndef _KERNEL
40#include <stdbool.h>
41#endif
42
43struct extent_region {
44 LIST_ENTRY(extent_region) er_link; /* link in region list */
45 u_long er_start; /* start of region */
46 u_long er_end; /* end of region */
47 int er_flags; /* misc. flags */
48};
49
50/* er_flags */
51#define ER_ALLOC 0x01 /* region descriptor dynamically allocated */
52
53struct extent {
54 const char *ex_name; /* name of extent */
55 kmutex_t ex_lock; /* lock on this extent */
56 kcondvar_t ex_cv; /* synchronization */
57 /* allocated regions in extent */
58 LIST_HEAD(, extent_region) ex_regions;
59 u_long ex_start; /* start of extent */
60 u_long ex_end; /* end of extent */
61 int ex_flags; /* misc. information */
62 bool ex_flwanted; /* someone asleep on freelist */
63};
64
65struct extent_fixed {
66 struct extent fex_extent; /* MUST BE FIRST */
67 /* freelist of region descriptors */
68 LIST_HEAD(, extent_region) fex_freelist;
69 void * fex_storage; /* storage space for descriptors */
70 size_t fex_storagesize; /* size of storage space */
71};
72
73/* ex_flags; for internal use only */
74#define EXF_FIXED __BIT(0) /* extent uses fixed storage */
75#define EXF_NOCOALESCE __BIT(1) /* coalescing of regions not allowed */
76#define EXF_EARLY __BIT(2) /* no need to lock */
77
78#define EXF_BITS "\20\3EARLY\2NOCOALESCE\1FIXED"
79
80/* misc. flags passed to extent functions */
81#define EX_NOWAIT 0 /* not safe to sleep */
82#define EX_WAITOK __BIT(0) /* safe to sleep */
83#define EX_FAST __BIT(1) /* take first fit in extent_alloc() */
84#define EX_CATCH __BIT(2) /* catch signals while sleeping */
85#define EX_NOCOALESCE __BIT(3) /* create a non-coalescing extent */
86#define EX_MALLOCOK __BIT(4) /* safe to call kmem_alloc() */
87#define EX_WAITSPACE __BIT(5) /* wait for space to become free */
88#define EX_BOUNDZERO __BIT(6) /* boundary lines start at 0 */
89#define EX_EARLY __BIT(7) /* safe for early kernel bootstrap */
90
91/*
92 * Special place holders for "alignment" and "boundary" arguments,
93 * in the event the caller doesn't wish to use those features.
94 */
95#define EX_NOALIGN 1 /* don't do alignment */
96#define EX_NOBOUNDARY 0 /* don't do boundary checking */
97
98#if defined(_KERNEL) || defined(_EXTENT_TESTING)
99#define EXTENT_FIXED_STORAGE_SIZE(_nregions) \
100 (ALIGN(sizeof(struct extent_fixed)) + \
101 ((ALIGN(sizeof(struct extent_region))) * \
102 (_nregions)))
103
104struct extent *extent_create(const char *, u_long, u_long,
105 void *, size_t, int);
106void extent_destroy(struct extent *);
107int extent_alloc_subregion1(struct extent *, u_long, u_long,
108 u_long, u_long, u_long, u_long, int, u_long *);
109int extent_alloc_subregion(struct extent *, u_long, u_long,
110 u_long, u_long, u_long, int, u_long *);
111int extent_alloc_region(struct extent *, u_long, u_long, int);
112int extent_alloc1(struct extent *, u_long, u_long, u_long, u_long, int,
113 u_long *);
114int extent_alloc(struct extent *, u_long, u_long, u_long, int, u_long *);
115int extent_free(struct extent *, u_long, u_long, int);
116void extent_print(struct extent *);
117void extent_init(void);
118
119#endif /* _KERNEL || _EXTENT_TESTING */
120
121#endif /* ! _SYS_EXTENT_H_ */