extent.h

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/*	$NetBSD: extent.h,v 1.10 1998/09/13 14:46:24 christos Exp $	*/

/*-
 * Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _SYS_EXTENT_H_
#define _SYS_EXTENT_H_

#include <sys/lock.h>
#include <sys/queue.h>

struct extent_region {
	LIST_ENTRY(extent_region) er_link;	/* link in region list */
	u_long 	er_start;		/* start of region */
	u_long	er_end;			/* end of region */
	int	er_flags;		/* misc. flags */
};

/* er_flags */
#define ER_ALLOC	0x01	/* region descriptor dynamically allocated */

struct extent {
	const char *ex_name;		/* name of extent */
	struct simplelock ex_slock;	/* lock on this extent */
					/* allocated regions in extent */
	LIST_HEAD(, extent_region) ex_regions;
	u_long	ex_start;		/* start of extent */
	u_long	ex_end;			/* end of extent */
	int	ex_mtype;		/* memory type */
	int	ex_flags;		/* misc. information */
};

struct extent_fixed {
	struct extent	fex_extent;	/* MUST BE FIRST */
					/* freelist of region descriptors */
	LIST_HEAD(, extent_region) fex_freelist;
	caddr_t		fex_storage;	/* storage space for descriptors */
	size_t		fex_storagesize; /* size of storage space */
};

/* ex_flags; for internal use only */
#define EXF_FIXED	0x01		/* extent uses fixed storage */
#define EXF_NOCOALESCE	0x02		/* coalescing of regions not allowed */
#define EXF_WANTED	0x04		/* someone asleep on extent */
#define EXF_FLWANTED	0x08		/* someone asleep on freelist */

#define EXF_BITS	"\20\4FLWANTED\3WANTED\2NOCOALESCE\1FIXED"

/* misc. flags passed to extent functions */
#define EX_NOWAIT	0x00		/* not safe to sleep */
#define EX_WAITOK	0x01		/* safe to sleep */
#define EX_FAST		0x02		/* take first fit in extent_alloc() */
#define EX_CATCH	0x04		/* catch signals while sleeping */
#define EX_NOCOALESCE	0x08		/* create a non-coalescing extent */
#define EX_MALLOCOK	0x10		/* safe to call malloc() */
#define EX_WAITSPACE	0x20		/* wait for space to become free */
#define EX_BOUNDZERO	0x40		/* boundary lines start at 0 */

/*
 * Special place holders for "alignment" and "boundary" arguments,
 * in the event the caller doesn't wish to use those features.
 */
#define EX_NOALIGN	1		/* don't do alignment */
#define EX_NOBOUNDARY	0		/* don't do boundary checking */

#if defined(_KERNEL) || defined(_EXTENT_TESTING)
#define EXTENT_FIXED_STORAGE_SIZE(_nregions)		\
	(ALIGN(sizeof(struct extent_fixed)) +		\
	((ALIGN(sizeof(struct extent_region))) *	\
	 (_nregions)))

struct	extent *extent_create __P((const char *, u_long, u_long, int,
	    caddr_t, size_t, int));
void	extent_destroy __P((struct extent *));
int	extent_alloc_subregion1 __P((struct extent *, u_long, u_long,
	    u_long, u_long, u_long, u_long, int, u_long *));
int	extent_alloc_region __P((struct extent *, u_long, u_long, int));
int	extent_free __P((struct extent *, u_long, u_long, int));
void	extent_print __P((struct extent *));

/* Simple case of extent_alloc_subregion() */
#define extent_alloc(_ex, _size, _alignment, _boundary, _flags, _result) \
	extent_alloc_subregion1((_ex), (_ex)->ex_start, (_ex)->ex_end,	\
	(_size), (_alignment), 0, (_boundary), (_flags), (_result))
#define extent_alloc1(_ex, _size, _alignment, _skew, _boundary, \
			_flags, _result) \
	extent_alloc_subregion1((_ex), (_ex)->ex_start, (_ex)->ex_end,	\
	(_size), (_alignment), (_skew), (_boundary), (_flags), (_result))
/* Compat version of extent_alloc_subregion() */
#define extent_alloc_subregion(_ex, _start, _end, _size, _alignment, \
				_boundary, _flags, _result) \
	extent_alloc_subregion1((_ex), (_start), (_end),	\
	(_size), (_alignment), 0, (_boundary), (_flags), (_result))
#endif /* _KERNEL || _EXTENT_TESTING */

#endif /* ! _SYS_EXTENT_H_ */