osfmk/vm/vm_external.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60
  61 #ifndef VM_VM_EXTERNAL_H_
  62 #define VM_VM_EXTERNAL_H_
  63
  64 #include <mach/boolean.h>
  65 #include <mach/machine/vm_types.h>
  66
  67 /*
  68  *      External page management hint technology
  69  *
  70  *      The data structure exported by this module maintains
  71  *      a (potentially incomplete) map of the pages written
  72  *      to external storage for a range of virtual memory.
  73  */
  74
  75 typedef char    *vm_external_map_t;
  76 #define VM_EXTERNAL_NULL        ((char *) 0)
  77
  78 /*
  79  *      The states that may be recorded for a page of external storage.
  80  */
  81
  82 typedef int     vm_external_state_t;
  83 #define VM_EXTERNAL_STATE_EXISTS                1
  84 #define VM_EXTERNAL_STATE_UNKNOWN               2
  85 #define VM_EXTERNAL_STATE_ABSENT                3
  86
  87 /*
  88  * Useful macros
  89  */
  90 #define stob(s) ((atop_32((s)) + 07) >> 3)
  91
  92 /*
  93  *      Routines exported by this module.
  94  */
  95                                         /* Initialize the module */
  96 extern void                     vm_external_module_initialize(void);
  97
  98
  99 extern vm_external_map_t        vm_external_create(
 100                                         /* Create a vm_external_map_t */
 101                                         vm_offset_t             size);
 102
 103 extern void                     vm_external_destroy(
 104                                         /* Destroy one */
 105                                         vm_external_map_t       map,
 106                                         vm_size_t               size);
 107
 108 extern vm_size_t                vm_external_map_size(
 109                                         /* Return size of map in bytes */
 110                                         vm_offset_t     size);
 111
 112 extern void                     vm_external_copy(
 113                                         /* Copy one into another */
 114                                         vm_external_map_t       old_map,
 115                                         vm_size_t               old_size,
 116                                         vm_external_map_t       new_map);
 117
 118 extern void                     vm_external_state_set(
 119                                         /* Set state of a page to
 120                                          * VM_EXTERNAL_STATE_EXISTS */
 121                                         vm_external_map_t       map,
 122                                         vm_offset_t             offset);
 123
 124 extern void                     vm_external_state_clr(
 125                                         /* clear page state
 126                                          */
 127                                         vm_external_map_t       map,
 128                                         vm_offset_t             offset);
 129
 130 #define vm_external_state_get(map, offset)                              \
 131                         (((map) != VM_EXTERNAL_NULL) ?                  \
 132                           _vm_external_state_get((map), (offset)) :     \
 133                           VM_EXTERNAL_STATE_UNKNOWN)
 134                                         /* Retrieve the state for a
 135                                          * given page, if known.  */
 136
 137 extern vm_external_state_t      _vm_external_state_get(
 138                                         /* HIDDEN routine */
 139                                         vm_external_map_t       map,
 140                                         vm_offset_t             offset);
 141
 142 boolean_t                       vm_external_within(
 143                                         /* Check if new object size
 144                                          * fits in current map */
 145                                         vm_size_t       new_size,
 146                                         vm_size_t       old_size);
 147 #endif  /* VM_VM_EXTERNAL_H_ */