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pmap.h revision 1.32 
      1 /*	$NetBSD: pmap.h,v 1.32 1998/01/13 12:52:28 mrg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Charles M. Hannum.  All rights reserved.
      5  * Copyright (c) 1991 Regents of the University of California.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * the Systems Programming Group of the University of Utah Computer
     10  * Science Department and William Jolitz of UUNET Technologies Inc.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Berkeley and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)pmap.h	7.4 (Berkeley) 5/12/91
     41  */
     42 
     43 /*
     44  * Derived from hp300 version by Mike Hibler, this version by William
     45  * Jolitz uses a recursive map [a pde points to the page directory] to
     46  * map the page tables using the pagetables themselves. This is done to
     47  * reduce the impact on kernel virtual memory for lots of sparse address
     48  * space, and to reduce the cost of memory to each process.
     49  *
     50  * from hp300:	@(#)pmap.h	7.2 (Berkeley) 12/16/90
     51  */
     52 
     53 #ifndef	_I386_PMAP_H_
     54 #define	_I386_PMAP_H_
     55 
     56 #include <machine/cpufunc.h>
     57 #include <machine/pte.h>
     58 
     59 /*
     60  * 386 page table entry and page table directory
     61  * W.Jolitz, 8/89
     62  */
     63 
     64 /*
     65  * One page directory, shared between
     66  * kernel and user modes.
     67  */
     68 #define	PTDPTDI		0x3bf		/* ptd entry that points to ptd! */
     69 #define	KPTDI		0x3c0		/* start of kernel virtual pde's */
     70 #define	NKPDE_BASE	4		/* min. # of kernel PDEs */
     71 #define	NKPDE_MAX	63		/* max. # of kernel PDEs */
     72 #define	NKPDE_SCALE	1		/* # of kernel PDEs to add per meg. */
     73 #define	APTDPTDI	0x3ff		/* start of alternate page directory */
     74 
     75 #define UPT_MIN_ADDRESS	(PTDPTDI<<PDSHIFT)
     76 #define UPT_MAX_ADDRESS	(UPT_MIN_ADDRESS + (PTDPTDI<<PGSHIFT))
     77 
     78 /*
     79  * Address of current and alternate address space page table maps
     80  * and directories.
     81  */
     82 #ifdef _KERNEL
     83 extern pt_entry_t	PTmap[], APTmap[], Upte;
     84 extern pd_entry_t	PTD[], APTD[], PTDpde, APTDpde, Upde;
     85 extern pt_entry_t	*Sysmap;
     86 
     87 extern int	PTDpaddr;	/* physical address of kernel PTD */
     88 
     89 void pmap_bootstrap __P((vm_offset_t start));
     90 boolean_t pmap_testbit __P((vm_offset_t, int));
     91 void pmap_changebit __P((vm_offset_t, int, int));
     92 #endif
     93 
     94 /*
     95  * virtual address to page table entry and
     96  * to physical address. Likewise for alternate address space.
     97  * Note: these work recursively, thus vtopte of a pte will give
     98  * the corresponding pde that in turn maps it.
     99  */
    100 #define	vtopte(va)	(PTmap + i386_btop(va))
    101 #define	kvtopte(va)	vtopte(va)
    102 #define	ptetov(pt)	(i386_ptob(pt - PTmap))
    103 #define	vtophys(va) \
    104 	((*vtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME))
    105 
    106 #define	avtopte(va)	(APTmap + i386_btop(va))
    107 #define	ptetoav(pt)	(i386_ptob(pt - APTmap))
    108 #define	avtophys(va) \
    109 	((*avtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME))
    110 
    111 /*
    112  * macros to generate page directory/table indicies
    113  */
    114 #define	pdei(va)	(((va) & PD_MASK) >> PDSHIFT)
    115 #define	ptei(va)	(((va) & PT_MASK) >> PGSHIFT)
    116 
    117 /*
    118  * Pmap stuff
    119  */
    120 typedef struct pmap {
    121 	pd_entry_t		*pm_pdir;	/* KVA of page directory */
    122 	short			pm_dref;	/* page directory ref count */
    123 	short			pm_count;	/* pmap reference count */
    124 	simple_lock_data_t	pm_lock;	/* lock on pmap */
    125 	struct pmap_statistics	pm_stats;	/* pmap statistics */
    126 	long			pm_ptpages;	/* more stats: PT pages */
    127 } *pmap_t;
    128 
    129 /*
    130  * For each vm_page_t, there is a list of all currently valid virtual
    131  * mappings of that page.  An entry is a pv_entry, the list is pv_table.
    132  */
    133 struct pv_entry {
    134 	struct pv_entry	*pv_next;	/* next pv_entry */
    135 	pmap_t		pv_pmap;	/* pmap where mapping lies */
    136 	vm_offset_t	pv_va;		/* virtual address for mapping */
    137 };
    138 
    139 struct pv_page;
    140 
    141 struct pv_page_info {
    142 	TAILQ_ENTRY(pv_page) pgi_list;
    143 	struct pv_entry *pgi_freelist;
    144 	int pgi_nfree;
    145 };
    146 
    147 /*
    148  * This is basically:
    149  * ((NBPG - sizeof(struct pv_page_info)) / sizeof(struct pv_entry))
    150  */
    151 #define	NPVPPG	340
    152 
    153 struct pv_page {
    154 	struct pv_page_info pvp_pgi;
    155 	struct pv_entry pvp_pv[NPVPPG];
    156 };
    157 
    158 #ifdef	_KERNEL
    159 extern int		nkpde;		/* number of kernel page dir. ents */
    160 extern struct pmap	kernel_pmap_store;
    161 
    162 #define	pmap_kernel()			(&kernel_pmap_store)
    163 #define	pmap_resident_count(pmap)	((pmap)->pm_stats.resident_count)
    164 #define	pmap_update()			tlbflush()
    165 
    166 vm_offset_t reserve_dumppages __P((vm_offset_t));
    167 
    168 static __inline void
    169 pmap_clear_modify(vm_offset_t pa)
    170 {
    171 	pmap_changebit(pa, 0, ~PG_M);
    172 }
    173 
    174 static __inline void
    175 pmap_clear_reference(vm_offset_t pa)
    176 {
    177 	pmap_changebit(pa, 0, ~PG_U);
    178 }
    179 
    180 static __inline void
    181 pmap_copy_on_write(vm_offset_t pa)
    182 {
    183 	pmap_changebit(pa, PG_RO, ~PG_RW);
    184 }
    185 
    186 static __inline boolean_t
    187 pmap_is_modified(vm_offset_t pa)
    188 {
    189 	return pmap_testbit(pa, PG_M);
    190 }
    191 
    192 static __inline boolean_t
    193 pmap_is_referenced(vm_offset_t pa)
    194 {
    195 	return pmap_testbit(pa, PG_U);
    196 }
    197 
    198 static __inline vm_offset_t
    199 pmap_phys_address(int ppn)
    200 {
    201 	return i386_ptob(ppn);
    202 }
    203 
    204 #endif	/* _KERNEL */
    205 
    206 #endif /* _I386_PMAP_H_ */
    207