osfmk/vm/vm_external.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53 /*
  54  */
  55
  56 #ifndef VM_VM_EXTERNAL_H_
  57 #define VM_VM_EXTERNAL_H_
  58
  59 #include <mach/boolean.h>
  60 #include <mach/machine/vm_types.h>
  61
  62 /*
  63  *      External page management hint technology
  64  *
  65  *      The data structure exported by this module maintains
  66  *      a (potentially incomplete) map of the pages written
  67  *      to external storage for a range of virtual memory.
  68  */
  69
  70 typedef char    *vm_external_map_t;
  71 #define VM_EXTERNAL_NULL        ((char *) 0)
  72
  73 /*
  74  *      The states that may be recorded for a page of external storage.
  75  */
  76
  77 typedef int     vm_external_state_t;
  78 #define VM_EXTERNAL_STATE_EXISTS                1
  79 #define VM_EXTERNAL_STATE_UNKNOWN               2
  80 #define VM_EXTERNAL_STATE_ABSENT                3
  81
  82 /*
  83  * Useful macros
  84  */
  85 #define stob(s) ((atop_32((s)) + 07) >> 3)
  86
  87 /*
  88  *      Routines exported by this module.
  89  */
  90                                         /* Initialize the module */
  91 extern void                     vm_external_module_initialize(void);
  92
  93
  94 extern vm_external_map_t        vm_external_create(
  95                                         /* Create a vm_external_map_t */
  96                                         vm_offset_t             size);
  97
  98 extern void                     vm_external_destroy(
  99                                         /* Destroy one */
 100                                         vm_external_map_t       map,
 101                                         vm_size_t               size);
 102
 103 extern vm_size_t                vm_external_map_size(
 104                                         /* Return size of map in bytes */
 105                                         vm_offset_t     size);
 106
 107 extern void                     vm_external_copy(
 108                                         /* Copy one into another */
 109                                         vm_external_map_t       old_map,
 110                                         vm_size_t               old_size,
 111                                         vm_external_map_t       new_map);
 112
 113 extern void                     vm_external_state_set(
 114                                         /* Set state of a page to
 115                                          * VM_EXTERNAL_STATE_EXISTS */
 116                                         vm_external_map_t       map,
 117                                         vm_offset_t             offset);
 118
 119 extern void                     vm_external_state_clr(
 120                                         /* clear page state
 121                                          */
 122                                         vm_external_map_t       map,
 123                                         vm_offset_t             offset);
 124
 125 #define vm_external_state_get(map, offset)                              \
 126                         (((map) != VM_EXTERNAL_NULL) ?                  \
 127                           _vm_external_state_get((map), (offset)) :     \
 128                           VM_EXTERNAL_STATE_UNKNOWN)
 129                                         /* Retrieve the state for a
 130                                          * given page, if known.  */
 131
 132 extern vm_external_state_t      _vm_external_state_get(
 133                                         /* HIDDEN routine */
 134                                         vm_external_map_t       map,
 135                                         vm_offset_t             offset);
 136
 137 boolean_t                       vm_external_within(
 138                                         /* Check if new object size
 139                                          * fits in current map */
 140                                         vm_size_t       new_size,
 141                                         vm_size_t       old_size);
 142 #endif  /* VM_VM_EXTERNAL_H_ */