osfmk/vm/vm_external.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51 /*
  52  */
  53
  54 #ifndef VM_VM_EXTERNAL_H_
  55 #define VM_VM_EXTERNAL_H_
  56
  57 #include <mach/boolean.h>
  58 #include <mach/machine/vm_types.h>
  59
  60 /*
  61  *      External page management hint technology
  62  *
  63  *      The data structure exported by this module maintains
  64  *      a (potentially incomplete) map of the pages written
  65  *      to external storage for a range of virtual memory.
  66  */
  67
  68 typedef char    *vm_external_map_t;
  69 #define VM_EXTERNAL_NULL        ((char *) 0)
  70
  71 /*
  72  *      The states that may be recorded for a page of external storage.
  73  */
  74
  75 typedef int     vm_external_state_t;
  76 #define VM_EXTERNAL_STATE_EXISTS                1
  77 #define VM_EXTERNAL_STATE_UNKNOWN               2
  78 #define VM_EXTERNAL_STATE_ABSENT                3
  79
  80 /*
  81  * Useful macros
  82  */
  83 #define stob(s) ((atop_32((s)) + 07) >> 3)
  84
  85 /*
  86  *      Routines exported by this module.
  87  */
  88                                         /* Initialize the module */
  89 extern void                     vm_external_module_initialize(void);
  90
  91
  92 extern vm_external_map_t        vm_external_create(
  93                                         /* Create a vm_external_map_t */
  94                                         vm_offset_t             size);
  95
  96 extern void                     vm_external_destroy(
  97                                         /* Destroy one */
  98                                         vm_external_map_t       map,
  99                                         vm_size_t               size);
 100
 101 extern vm_size_t                vm_external_map_size(
 102                                         /* Return size of map in bytes */
 103                                         vm_offset_t     size);
 104
 105 extern void                     vm_external_copy(
 106                                         /* Copy one into another */
 107                                         vm_external_map_t       old_map,
 108                                         vm_size_t               old_size,
 109                                         vm_external_map_t       new_map);
 110
 111 extern void                     vm_external_state_set(
 112                                         /* Set state of a page to
 113                                          * VM_EXTERNAL_STATE_EXISTS */
 114                                         vm_external_map_t       map,
 115                                         vm_offset_t             offset);
 116
 117 extern void                     vm_external_state_clr(
 118                                         /* clear page state
 119                                          */
 120                                         vm_external_map_t       map,
 121                                         vm_offset_t             offset);
 122
 123 #define vm_external_state_get(map, offset)                              \
 124                         (((map) != VM_EXTERNAL_NULL) ?                  \
 125                           _vm_external_state_get((map), (offset)) :     \
 126                           VM_EXTERNAL_STATE_UNKNOWN)
 127                                         /* Retrieve the state for a
 128                                          * given page, if known.  */
 129
 130 extern vm_external_state_t      _vm_external_state_get(
 131                                         /* HIDDEN routine */
 132                                         vm_external_map_t       map,
 133                                         vm_offset_t             offset);
 134
 135 boolean_t                       vm_external_within(
 136                                         /* Check if new object size
 137                                          * fits in current map */
 138                                         vm_size_t       new_size,
 139                                         vm_size_t       old_size);
 140 #endif  /* VM_VM_EXTERNAL_H_ */