usr/src/sys/vm/vm_map.h

/*
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * The Mach Operating System project at Carnegie-Mellon University.
 *
 * 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 University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *      @(#)vm_map.h    8.3 (Berkeley) 3/15/94
 *
 *
 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

/*
 *      Virtual memory map module definitions.
 */

#ifndef _VM_MAP_
#define _VM_MAP_

/*
 *      Types defined:
 *
 *      vm_map_t                the high-level address map data structure.
 *      vm_map_entry_t          an entry in an address map.
 *      vm_map_version_t        a timestamp of a map, for use with vm_map_lookup
 */

/*
 *      Objects which live in maps may be either VM objects, or
 *      another map (called a "sharing map") which denotes read-write
 *      sharing with other maps.
 */

union vm_map_object {
        struct vm_object        *vm_object;     /* object object */
        struct vm_map           *share_map;     /* share map */
        struct vm_map           *sub_map;       /* belongs to another map */
};

/*
 *      Address map entries consist of start and end addresses,
 *      a VM object (or sharing map) and offset into that object,
 *      and user-exported inheritance and protection information.
 *      Also included is control information for virtual copy operations.
 */
struct vm_map_entry {
        struct vm_map_entry     *prev;          /* previous entry */
        struct vm_map_entry     *next;          /* next entry */
        vm_offset_t             start;          /* start address */
        vm_offset_t             end;            /* end address */
        union vm_map_object     object;         /* object I point to */
        vm_offset_t             offset;         /* offset into object */
        boolean_t               is_a_map;       /* Is "object" a map? */
        boolean_t               is_sub_map;     /* Is "object" a submap? */
                /* Only in sharing maps: */
        boolean_t               copy_on_write;  /* is data copy-on-write */
        boolean_t               needs_copy;     /* does object need to be copied */
                /* Only in task maps: */
        vm_prot_t               protection;     /* protection code */
        vm_prot_t               max_protection; /* maximum protection */
        vm_inherit_t            inheritance;    /* inheritance */
        int                     wired_count;    /* can be paged if = 0 */
};

/*
 *      Maps are doubly-linked lists of map entries, kept sorted
 *      by address.  A single hint is provided to start
 *      searches again from the last successful search,
 *      insertion, or removal.
 */
struct vm_map {
        struct pmap *           pmap;           /* Physical map */
        lock_data_t             lock;           /* Lock for map data */
        struct vm_map_entry     header;         /* List of entries */
        int                     nentries;       /* Number of entries */
        vm_size_t               size;           /* virtual size */
        boolean_t               is_main_map;    /* Am I a main map? */
        int                     ref_count;      /* Reference count */
        simple_lock_data_t      ref_lock;       /* Lock for ref_count field */
        vm_map_entry_t          hint;           /* hint for quick lookups */
        simple_lock_data_t      hint_lock;      /* lock for hint storage */
        vm_map_entry_t          first_free;     /* First free space hint */
        boolean_t               entries_pageable; /* map entries pageable?? */
        unsigned int            timestamp;      /* Version number */
#define min_offset              header.start
#define max_offset              header.end
};

/*
 *      Map versions are used to validate a previous lookup attempt.
 *
 *      Since lookup operations may involve both a main map and
 *      a sharing map, it is necessary to have a timestamp from each.
 *      [If the main map timestamp has changed, the share_map and
 *      associated timestamp are no longer valid; the map version
 *      does not include a reference for the imbedded share_map.]
 */
typedef struct {
        int             main_timestamp;
        vm_map_t        share_map;
        int             share_timestamp;
} vm_map_version_t;

/*
 *      Macros:         vm_map_lock, etc.
 *      Function:
 *              Perform locking on the data portion of a map.
 */

#define vm_map_lock(map) { \
        lock_write(&(map)->lock); \
        (map)->timestamp++; \
}
#define vm_map_unlock(map)      lock_write_done(&(map)->lock)
#define vm_map_lock_read(map)   lock_read(&(map)->lock)
#define vm_map_unlock_read(map) lock_read_done(&(map)->lock)

/*
 *      Functions implemented as macros
 */
#define         vm_map_min(map)         ((map)->min_offset)
#define         vm_map_max(map)         ((map)->max_offset)
#define         vm_map_pmap(map)        ((map)->pmap)

/* XXX: number of kernel maps and entries to statically allocate */
#define MAX_KMAP        10
#define MAX_KMAPENT     500

#ifdef KERNEL
boolean_t        vm_map_check_protection __P((vm_map_t,
                    vm_offset_t, vm_offset_t, vm_prot_t));
int              vm_map_copy __P((vm_map_t, vm_map_t, vm_offset_t,
                    vm_size_t, vm_offset_t, boolean_t, boolean_t));
void             vm_map_copy_entry __P((vm_map_t,
                    vm_map_t, vm_map_entry_t, vm_map_entry_t));
struct pmap;
vm_map_t         vm_map_create __P((struct pmap *,
                    vm_offset_t, vm_offset_t, boolean_t));
void             vm_map_deallocate __P((vm_map_t));
int              vm_map_delete __P((vm_map_t, vm_offset_t, vm_offset_t));
vm_map_entry_t   vm_map_entry_create __P((vm_map_t));
void             vm_map_entry_delete __P((vm_map_t, vm_map_entry_t));
void             vm_map_entry_dispose __P((vm_map_t, vm_map_entry_t));
void             vm_map_entry_unwire __P((vm_map_t, vm_map_entry_t));
int              vm_map_find __P((vm_map_t, vm_object_t,
                    vm_offset_t, vm_offset_t *, vm_size_t, boolean_t));
int              vm_map_findspace __P((vm_map_t,
                    vm_offset_t, vm_size_t, vm_offset_t *));
int              vm_map_inherit __P((vm_map_t,
                    vm_offset_t, vm_offset_t, vm_inherit_t));
void             vm_map_init __P((struct vm_map *,
                    vm_offset_t, vm_offset_t, boolean_t));
int              vm_map_insert __P((vm_map_t,
                    vm_object_t, vm_offset_t, vm_offset_t, vm_offset_t));
int              vm_map_lookup __P((vm_map_t *, vm_offset_t, vm_prot_t,
                    vm_map_entry_t *, vm_object_t *, vm_offset_t *, vm_prot_t *,
                    boolean_t *, boolean_t *));
void             vm_map_lookup_done __P((vm_map_t, vm_map_entry_t));
boolean_t        vm_map_lookup_entry __P((vm_map_t,
                    vm_offset_t, vm_map_entry_t *));
int              vm_map_pageable __P((vm_map_t,
                    vm_offset_t, vm_offset_t, boolean_t));
int              vm_map_clean __P((vm_map_t,
                    vm_offset_t, vm_offset_t, boolean_t, boolean_t));
void             vm_map_print __P((vm_map_t, boolean_t));
int              vm_map_protect __P((vm_map_t,
                    vm_offset_t, vm_offset_t, vm_prot_t, boolean_t));
void             vm_map_reference __P((vm_map_t));
int              vm_map_remove __P((vm_map_t, vm_offset_t, vm_offset_t));
void             vm_map_simplify __P((vm_map_t, vm_offset_t));
void             vm_map_simplify_entry __P((vm_map_t, vm_map_entry_t));
void             vm_map_startup __P((void));
int              vm_map_submap __P((vm_map_t,
                    vm_offset_t, vm_offset_t, vm_map_t));
#endif
#endif /* _VM_MAP_ */