xref: /netbsd/sys/arch/x86/include/pmap_pv.h (revision 4a75b06b)
1 /*	$NetBSD: pmap_pv.h,v 1.17 2020/03/17 22:29:19 ad Exp $	*/
2 
3 /*-
4  * Copyright (c)2008 YAMAMOTO Takashi,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef _X86_PMAP_PV_H_
30 #define	_X86_PMAP_PV_H_
31 
32 #include <sys/mutex.h>
33 #include <sys/queue.h>
34 #include <sys/rbtree.h>
35 
36 struct vm_page;
37 struct pmap_page;
38 
39 /*
40  * structures to track P->V mapping
41  *
42  * this file is intended to be minimum as it's included by <machine/vmparam.h>.
43  */
44 
45 /*
46  * pv_pte: describe a pte
47  */
48 
49 struct pv_pte {
50 	struct vm_page *pte_ptp;	/* PTP; NULL for pmap_kernel() */
51 	vaddr_t pte_va;			/* VA */
52 };
53 
54 /*
55  * pv_entry: plug pv_pte into lists.  32 bytes on i386, 64 on amd64.
56  */
57 
58 struct pv_entry {
59 	struct pv_pte pve_pte;		/* should be the first member */
60 	LIST_ENTRY(pv_entry) pve_list;	/* on pmap_page::pp_pvlist */
61 	rb_node_t pve_rb;		/* red-black tree node */
62 	struct pmap_page *pve_pp;	/* backpointer to mapped page */
63 };
64 #define	pve_next	pve_list.le_next
65 
66 /*
67  * pmap_page: a structure which is embedded in each vm_page.
68  */
69 
70 struct pmap_page {
71 	union {
72 		/* PTPs */
73 		rb_tree_t rb;
74 
75 		/* PTPs, when being freed */
76 		LIST_ENTRY(vm_page) link;
77 
78 		/* Non-PTPs (i.e. normal pages) */
79 		struct {
80 			struct pv_pte pte;
81 			LIST_HEAD(, pv_entry) pvlist;
82 			uint8_t attrs;
83 		} s;
84 	} pp_u;
85 	kmutex_t	pp_lock;
86 #define	pp_rb		pp_u.rb
87 #define	pp_link		pp_u.link
88 #define	pp_pte		pp_u.s.pte
89 #define pp_pvlist	pp_u.s.pvlist
90 #define	pp_attrs	pp_u.s.attrs
91 };
92 
93 #define PP_ATTRS_D	0x01	/* Dirty */
94 #define PP_ATTRS_A	0x02	/* Accessed */
95 #define PP_ATTRS_W	0x04	/* Writable */
96 
97 #define	PMAP_PAGE_INIT(pp) \
98 do { \
99 	LIST_INIT(&(pp)->pp_pvlist); \
100 	mutex_init(&(pp)->pp_lock, MUTEX_NODEBUG, IPL_VM); \
101 } while (/* CONSTCOND */ 0);
102 
103 #endif /* !_X86_PMAP_PV_H_ */
104