xref: /netbsd-src/sys/arch/mips/include/pmap.h (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: pmap.h,v 1.8 1995/04/12 01:55:35 mellon Exp $	*/
2 
3 /*
4  * Copyright (c) 1987 Carnegie-Mellon University
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Ralph Campbell.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	@(#)pmap.h	8.1 (Berkeley) 6/10/93
40  */
41 
42 #ifndef	_PMAP_MACHINE_
43 #define	_PMAP_MACHINE_
44 
45 /*
46  * The user address space is 2Gb (0x0 - 0x80000000).
47  * User programs are laid out in memory as follows:
48  *			address
49  *	USRTEXT		0x00001000
50  *	USRDATA		USRTEXT + text_size
51  *	USRSTACK	0x7FFFFFFF
52  *
53  * The user address space is mapped using a two level structure where
54  * virtual address bits 30..22 are used to index into a segment table which
55  * points to a page worth of PTEs (4096 page can hold 1024 PTEs).
56  * Bits 21..12 are then used to index a PTE which describes a page within
57  * a segment.
58  *
59  * The wired entries in the TLB will contain the following:
60  *	0-1	(UPAGES)	for curproc user struct and kernel stack.
61  *
62  * Note: The kernel doesn't use the same data structures as user programs.
63  * All the PTE entries are stored in a single array in Sysmap which is
64  * dynamically allocated at boot time.
65  */
66 
67 #define pmax_trunc_seg(x)	((vm_offset_t)(x) & ~SEGOFSET)
68 #define pmax_round_seg(x)	(((vm_offset_t)(x) + SEGOFSET) & ~SEGOFSET)
69 #define pmap_segmap(m, v)	((m)->pm_segtab->seg_tab[((v) >> SEGSHIFT)])
70 
71 #define PMAP_SEGTABSIZE		512
72 
73 union pt_entry;
74 
75 struct segtab {
76 	union pt_entry	*seg_tab[PMAP_SEGTABSIZE];
77 };
78 
79 /*
80  * Machine dependent pmap structure.
81  */
82 typedef struct pmap {
83 	int			pm_count;	/* pmap reference count */
84 	simple_lock_data_t	pm_lock;	/* lock on pmap */
85 	struct pmap_statistics	pm_stats;	/* pmap statistics */
86 	int			pm_tlbpid;	/* address space tag */
87 	u_int			pm_tlbgen;	/* TLB PID generation number */
88 	struct segtab		*pm_segtab;	/* pointers to pages of PTEs */
89 } *pmap_t;
90 
91 /*
92  * Defines for pmap_attributes[phys_mach_page];
93  */
94 #define PMAP_ATTR_MOD	0x01	/* page has been modified */
95 #define PMAP_ATTR_REF	0x02	/* page has been referenced */
96 
97 #ifdef	_KERNEL
98 char *pmap_attributes;		/* reference and modify bits */
99 struct pmap kernel_pmap_store;
100 
101 #define	pmap_wired_count(pmap) 	((pmap)->pm_stats.wired_count)
102 #define pmap_kernel()		(&kernel_pmap_store)
103 #endif	/* _KERNEL */
104 
105 #endif	/* _PMAP_MACHINE_ */
106