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      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 
     43 struct 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 
     53 struct 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 
     65 struct 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 
    104 struct	extent *extent_create(const char *, u_long, u_long,
    105 	    void *, size_t, int);
    106 void	extent_destroy(struct extent *);
    107 int	extent_alloc_subregion1(struct extent *, u_long, u_long,
    108 	    u_long, u_long, u_long, u_long, int, u_long *);
    109 int	extent_alloc_subregion(struct extent *, u_long, u_long,
    110 	    u_long, u_long, u_long, int, u_long *);
    111 int	extent_alloc_region(struct extent *, u_long, u_long, int);
    112 int	extent_alloc1(struct extent *, u_long, u_long, u_long, u_long, int,
    113 	    u_long *);
    114 int	extent_alloc(struct extent *, u_long, u_long, u_long, int, u_long *);
    115 int	extent_free(struct extent *, u_long, u_long, int);
    116 void	extent_print(struct extent *);
    117 void	extent_init(void);
    118 
    119 #endif /* _KERNEL || _EXTENT_TESTING */
    120 
    121 #endif /* ! _SYS_EXTENT_H_ */
    122