osfmk/vm/vm_external.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 #ifndef VM_VM_EXTERNAL_H_
  54 #define VM_VM_EXTERNAL_H_
  55
  56 #include <mach/boolean.h>
  57 #include <mach/machine/vm_types.h>
  58
  59 /*
  60  *      External page management hint technology
  61  *
  62  *      The data structure exported by this module maintains
  63  *      a (potentially incomplete) map of the pages written
  64  *      to external storage for a range of virtual memory.
  65  */
  66
  67 typedef char    *vm_external_map_t;
  68 #define VM_EXTERNAL_NULL        ((char *) 0)
  69
  70 /*
  71  *      The states that may be recorded for a page of external storage.
  72  */
  73
  74 typedef int     vm_external_state_t;
  75 #define VM_EXTERNAL_STATE_EXISTS                1
  76 #define VM_EXTERNAL_STATE_UNKNOWN               2
  77 #define VM_EXTERNAL_STATE_ABSENT                3
  78
  79 /*
  80  * Useful macros
  81  */
  82 #define stob(s) ((atop((s)) + 07) >> 3)
  83
  84 /*
  85  *      Routines exported by this module.
  86  */
  87                                         /* Initialize the module */
  88 extern void                     vm_external_module_initialize(void);
  89
  90
  91 extern vm_external_map_t        vm_external_create(
  92                                         /* Create a vm_external_map_t */
  93                                         vm_offset_t             size);
  94
  95 extern void                     vm_external_destroy(
  96                                         /* Destroy one */
  97                                         vm_external_map_t       map,
  98                                         vm_size_t               size);
  99
 100 extern vm_size_t                vm_external_map_size(
 101                                         /* Return size of map in bytes */
 102                                         vm_offset_t     size);
 103
 104 extern void                     vm_external_copy(
 105                                         /* Copy one into another */
 106                                         vm_external_map_t       old_map,
 107                                         vm_size_t               old_size,
 108                                         vm_external_map_t       new_map);
 109
 110 extern void                     vm_external_state_set(
 111                                         /* Set state of a page to
 112                                          * VM_EXTERNAL_STATE_EXISTS */
 113                                         vm_external_map_t       map,
 114                                         vm_offset_t             offset);
 115
 116 extern void                     vm_external_state_clr(
 117                                         /* clear page state
 118                                          */
 119                                         vm_external_map_t       map,
 120                                         vm_offset_t             offset);
 121
 122 #define vm_external_state_get(map, offset)                              \
 123                         (((map) != VM_EXTERNAL_NULL) ?                  \
 124                           _vm_external_state_get((map), (offset)) :     \
 125                           VM_EXTERNAL_STATE_UNKNOWN)
 126                                         /* Retrieve the state for a
 127                                          * given page, if known.  */
 128
 129 extern vm_external_state_t      _vm_external_state_get(
 130                                         /* HIDDEN routine */
 131                                         vm_external_map_t       map,
 132                                         vm_offset_t             offset);
 133
 134 boolean_t                       vm_external_within(
 135                                         /* Check if new object size
 136                                          * fits in current map */
 137                                         vm_size_t       new_size,
 138                                         vm_size_t       old_size);
 139 #endif  /* VM_VM_EXTERNAL_H_ */