xref: /illumos-gate/usr/src/uts/i86pc/vm/hment.h (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_VM_HMENT_H
28 #define	_VM_HMENT_H
29 
30 #ifdef	__cplusplus
31 extern "C" {
32 #endif
33 
34 
35 struct hment;
36 typedef struct hment hment_t;
37 
38 #if defined(_KERNEL)
39 
40 /*
41  * Remove a page mapping, finds the matching mapping and unlinks it from
42  * the page_t. If it returns a non-NULL pointer, the pointer must be
43  * freed via hment_free() after doing x86_hm_exit().
44  */
45 extern hment_t *hment_remove(page_t *, htable_t *ht, uint_t entry);
46 extern void hment_free(hment_t *);
47 
48 /*
49  * Iterator to walk through all mappings of a page.
50  */
51 extern hment_t *hment_walk(page_t *, htable_t **, uint_t *, hment_t *);
52 
53 /*
54  * Prepare a page for a new mapping
55  */
56 extern hment_t *hment_prepare(htable_t *ht, uint_t entry, page_t *);
57 
58 /*
59  * Add a mapping to a page's mapping list
60  */
61 extern void hment_assign(htable_t *ht, uint_t entry, page_t *, hment_t *);
62 
63 /*
64  * initialize hment data structures
65  */
66 extern void hment_init(void);
67 
68 /*
69  * lock/unlock a page_t's mapping list/pte entry
70  */
71 extern void x86_hm_enter(page_t *);
72 extern void x86_hm_exit(page_t *);
73 extern int x86_hm_held(page_t *pp);
74 
75 /*
76  * Called to allocate additional hments for reserve.
77  *
78  * The hment_reserve_count is exported for use by htable_hment_steal()
79  */
80 extern void hment_reserve(uint_t);
81 extern uint_t hment_reserve_count;
82 
83 /*
84  * Used to readjust the hment reserve after the reserve list has been used.
85  * Also called after boot to release left over boot reserves.
86  */
87 extern void hment_adjust_reserve(void);
88 
89 /*
90  * Return the number of mappings of a page_t
91  */
92 extern uint_t hment_mapcnt(page_t *);
93 
94 #endif	/* _KERNEL */
95 
96 
97 #ifdef	__cplusplus
98 }
99 #endif
100 
101 #endif	/* _VM_HMENT_H */
102