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pmap.h revision 1.21 
      1 /*	$NetBSD: pmap.h,v 1.21 1995/10/11 04:20:20 mycroft 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		0x3df		/* ptd entry that points to ptd! */
     69 #define	KPTDI		0x3e0		/* start of kernel virtual pde's */
     70 #define	NKPDE		12
     71 #define	APTDPTDI	0x3ff		/* start of alternate page directory */
     72 
     73 /*
     74  * Address of current and alternate address space page table maps
     75  * and directories.
     76  */
     77 #ifdef _KERNEL
     78 extern pt_entry_t	PTmap[], APTmap[], Upte;
     79 extern pd_entry_t	PTD[], APTD[], PTDpde, APTDpde, Upde;
     80 extern pt_entry_t	*Sysmap;
     81 
     82 extern int	PTDpaddr;	/* physical address of kernel PTD */
     83 
     84 void pmap_bootstrap __P((vm_offset_t start));
     85 boolean_t pmap_testbit __P((vm_offset_t, int));
     86 void pmap_changebit __P((vm_offset_t, int, int));
     87 __pure u_int pmap_page_index __P((vm_offset_t));
     88 #endif
     89 
     90 /*
     91  * virtual address to page table entry and
     92  * to physical address. Likewise for alternate address space.
     93  * Note: these work recursively, thus vtopte of a pte will give
     94  * the corresponding pde that in turn maps it.
     95  */
     96 #define	vtopte(va)	(PTmap + i386_btop(va))
     97 #define	kvtopte(va)	vtopte(va)
     98 #define	ptetov(pt)	(i386_ptob(pt - PTmap))
     99 #define	vtophys(va) \
    100 	((*vtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME))
    101 
    102 #define	avtopte(va)	(APTmap + i386_btop(va))
    103 #define	ptetoav(pt)	(i386_ptob(pt - APTmap))
    104 #define	avtophys(va) \
    105 	((*avtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME))
    106 
    107 /*
    108  * macros to generate page directory/table indicies
    109  */
    110 #define	pdei(va)	(((va) & PD_MASK) >> PDSHIFT)
    111 #define	ptei(va)	(((va) & PT_MASK) >> PGSHIFT)
    112 
    113 /*
    114  * Pmap stuff
    115  */
    116 typedef struct pmap {
    117 	pd_entry_t		*pm_pdir;	/* KVA of page directory */
    118 	boolean_t		pm_pdchanged;	/* pdir changed */
    119 	short			pm_dref;	/* page directory ref count */
    120 	short			pm_count;	/* pmap reference count */
    121 	simple_lock_data_t	pm_lock;	/* lock on pmap */
    122 	struct pmap_statistics	pm_stats;	/* pmap statistics */
    123 	long			pm_ptpages;	/* more stats: PT pages */
    124 } *pmap_t;
    125 
    126 /*
    127  * For each vm_page_t, there is a list of all currently valid virtual
    128  * mappings of that page.  An entry is a pv_entry, the list is pv_table.
    129  */
    130 struct pv_entry {
    131 	struct pv_entry	*pv_next;	/* next pv_entry */
    132 	pmap_t		pv_pmap;	/* pmap where mapping lies */
    133 	vm_offset_t	pv_va;		/* virtual address for mapping */
    134 };
    135 
    136 struct pv_page;
    137 
    138 struct pv_page_info {
    139 	TAILQ_ENTRY(pv_page) pgi_list;
    140 	struct pv_entry *pgi_freelist;
    141 	int pgi_nfree;
    142 };
    143 
    144 /*
    145  * This is basically:
    146  * ((NBPG - sizeof(struct pv_page_info)) / sizeof(struct pv_entry))
    147  */
    148 #define	NPVPPG	340
    149 
    150 struct pv_page {
    151 	struct pv_page_info pvp_pgi;
    152 	struct pv_entry pvp_pv[NPVPPG];
    153 };
    154 
    155 #ifdef	_KERNEL
    156 extern struct pmap	kernel_pmap_store;
    157 struct pv_entry		*pv_table;	/* array of entries, one per page */
    158 
    159 #define	pmap_kernel()			(&kernel_pmap_store)
    160 #define	pmap_resident_count(pmap)	((pmap)->pm_stats.resident_count)
    161 #define	pmap_update()			tlbflush()
    162 
    163 static __inline void
    164 pmap_clear_modify(vm_offset_t pa)
    165 {
    166 	pmap_changebit(pa, 0, ~PG_M);
    167 }
    168 
    169 static __inline void
    170 pmap_clear_reference(vm_offset_t pa)
    171 {
    172 	pmap_changebit(pa, 0, ~PG_U);
    173 }
    174 
    175 static __inline void
    176 pmap_copy_on_write(vm_offset_t pa)
    177 {
    178 	pmap_changebit(pa, PG_RO, ~PG_RW);
    179 }
    180 
    181 static __inline boolean_t
    182 pmap_is_modified(vm_offset_t pa)
    183 {
    184 	return pmap_testbit(pa, PG_M);
    185 }
    186 
    187 static __inline boolean_t
    188 pmap_is_referenced(vm_offset_t pa)
    189 {
    190 	return pmap_testbit(pa, PG_U);
    191 }
    192 
    193 static __inline vm_offset_t
    194 pmap_phys_address(int ppn)
    195 {
    196 	return i386_ptob(ppn);
    197 }
    198 
    199 #endif	/* _KERNEL */
    200 
    201 #endif /* _I386_PMAP_H_ */
    202