1 /*
2  * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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23  * Please see the License for the specific language governing rights and
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26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 #include <vm/vm_page.h>
30 
31 #define         VM_GHOST_OFFSET_BITS    39
32 #define         VM_GHOST_OFFSET_MASK    0x7FFFFFFFFF
33 #define         VM_GHOST_PAGES_PER_ENTRY 4
34 #define         VM_GHOST_PAGE_MASK      0x3
35 #define         VM_GHOST_PAGE_SHIFT     2
36 #define         VM_GHOST_INDEX_BITS     (64 - VM_GHOST_OFFSET_BITS - VM_GHOST_PAGES_PER_ENTRY)
37 
38 struct  vm_ghost {
39 	uint64_t        g_next_index:VM_GHOST_INDEX_BITS,
40 	    g_pages_held:VM_GHOST_PAGES_PER_ENTRY,
41 	    g_obj_offset:VM_GHOST_OFFSET_BITS;
42 	uint32_t        g_obj_id;
43 } __attribute__((packed));
44 
45 typedef struct vm_ghost *vm_ghost_t;
46 
47 
48 extern  void            vm_phantom_cache_init(void);
49 extern  void            vm_phantom_cache_add_ghost(vm_page_t);
50 extern  vm_ghost_t      vm_phantom_cache_lookup_ghost(vm_page_t, uint32_t);
51 extern  void            vm_phantom_cache_update(vm_page_t);
52 extern  boolean_t       vm_phantom_cache_check_pressure(void);
53 extern  void            vm_phantom_cache_restart_sample(void);
54