xref: /netbsd-src/sys/arch/pmax/include/pmap.h (revision 5f7096188587a2c7c95fa3c69b78e1ec9c7923d0)
1 /*
2  * Copyright (c) 1987 Carnegie-Mellon University
3  * Copyright (c) 1992 Regents of the University of California.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Ralph Campbell.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * from: @(#)pmap.h	7.6 (Berkeley) 2/4/93
38  * $Id: pmap.h,v 1.2 1993/10/15 02:57:13 deraadt Exp $
39  */
40 
41 #ifndef	_PMAP_MACHINE_
42 #define	_PMAP_MACHINE_
43 
44 /*
45  * TLB hash table values.
46  * SHIFT2 should shift virtual address bit 22 to the high bit of the index.
47  *			address:	index:
48  *	USRTEXT		0x00400000	10xxxxxxx
49  *	USRDATA		0x10000000	00xxxxxxx
50  *	USRSTACK	0x7FFFFFFF	11xxxxxxx
51  * This gives 1/2 the table to data, 1/4 for text and 1/4 for stack.
52  * Note: the current process has its hash table mapped at PMAP_HASH_UADDR.
53  *	the kernel's hash table is mapped at PMAP_HASH_KADDR.
54  *	The size of the hash table is known in locore.s.
55  * The wired entries in the TLB will contain the following:
56  *	UPAGES			(for curproc)
57  *	PMAP_HASH_UPAGES	(for curproc)
58  *	PMAP_HASH_KPAGES	(for kernel)
59  * The kernel doesn't actually use a pmap_hash_t, the pm_hash field is NULL and
60  * all the PTE entries are stored in a single array at PMAP_HASH_KADDR.
61  * If we need more KPAGES that the TLB has wired entries, then we can switch
62  * to a global pointer for the kernel TLB table.
63  * If we try to use a hash table for the kernel, wired TLB entries become a
64  * problem.
65  * Note: PMAP_HASH_UPAGES should be a multiple of MACH pages (see pmap_enter()).
66  */
67 #define PMAP_HASH_UPAGES	1
68 #define PMAP_HASH_KPAGES	5
69 #define PMAP_HASH_UADDR		(UADDR - PMAP_HASH_UPAGES * NBPG)
70 #define PMAP_HASH_KADDR		(UADDR - (PMAP_HASH_UPAGES + PMAP_HASH_KPAGES) * NBPG)
71 #define PMAP_HASH_NUM_ENTRIES	256
72 #define PMAP_HASH_SIZE_SHIFT	4
73 #define PMAP_HASH_SHIFT1	12
74 #define PMAP_HASH_SHIFT2	21
75 #define PMAP_HASH_MASK1		0x07f
76 #define PMAP_HASH_MASK2		0x080
77 #define PMAP_HASH_SIZE		(PMAP_HASH_NUM_ENTRIES*sizeof(struct pmap_hash))
78 
79 /* compute pointer to pmap hash table */
80 #define PMAP_HASH(va) \
81 	((((va) >> PMAP_HASH_SHIFT1) & PMAP_HASH_MASK1) | \
82 	 (((va) >> PMAP_HASH_SHIFT2) & PMAP_HASH_MASK2))
83 
84 /*
85  * A TLB hash entry.
86  */
87 typedef struct pmap_hash {
88 	struct {
89 		u_int	low;		/* The TLB low register value. */
90 		u_int	high;		/* The TLB high register value. */
91 	} pmh_pte[2];
92 } *pmap_hash_t;
93 
94 /*
95  * Machine dependent pmap structure.
96  */
97 struct pmap {
98 	int			pm_count;	/* pmap reference count */
99 	simple_lock_data_t	pm_lock;	/* lock on pmap */
100 	struct pmap_statistics	pm_stats;	/* pmap statistics */
101 	int			pm_flags;	/* see below */
102 	int			pm_tlbpid;	/* address space tag */
103 	pmap_hash_t		pm_hash;	/* TLB cache */
104 	unsigned		pm_hash_ptes[PMAP_HASH_UPAGES];
105 };
106 
107 typedef struct pmap *pmap_t;
108 
109 #define PM_MODIFIED	1		/* flush tlbpid before resume() */
110 
111 /*
112  * Defines for pmap_attributes[phys_mach_page];
113  */
114 #define PMAP_ATTR_MOD	0x01	/* page has been modified */
115 #define PMAP_ATTR_REF	0x02	/* page has been referenced */
116 
117 #ifdef	KERNEL
118 extern struct pmap kernel_pmap_store;
119 extern pmap_t kernel_pmap;
120 extern	char *pmap_attributes;		/* reference and modify bits */
121 #endif	KERNEL
122 #endif	_PMAP_MACHINE_
123