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pmap.h revision 1.18
      1 /*	$NetBSD: pmap.h,v 1.18 1998/07/24 22:03:33 thorpej 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 #include <mips/cpuregs.h>	/* for KSEG0 below */
     46 
     47 /*
     48  * The user address space is 2Gb (0x0 - 0x80000000).
     49  * User programs are laid out in memory as follows:
     50  *			address
     51  *	USRTEXT		0x00001000
     52  *	USRDATA		USRTEXT + text_size
     53  *	USRSTACK	0x7FFFFFFF
     54  *
     55  * The user address space is mapped using a two level structure where
     56  * virtual address bits 30..22 are used to index into a segment table which
     57  * points to a page worth of PTEs (4096 page can hold 1024 PTEs).
     58  * Bits 21..12 are then used to index a PTE which describes a page within
     59  * a segment.
     60  *
     61  * The wired entries in the TLB will contain the following:
     62  *	0-1	(UPAGES)	for curproc user struct and kernel stack.
     63  *
     64  * Note: The kernel doesn't use the same data structures as user programs.
     65  * All the PTE entries are stored in a single array in Sysmap which is
     66  * dynamically allocated at boot time.
     67  */
     68 
     69 #define mips_trunc_seg(x)	((vm_offset_t)(x) & ~SEGOFSET)
     70 #define mips_round_seg(x)	(((vm_offset_t)(x) + SEGOFSET) & ~SEGOFSET)
     71 #define pmap_segmap(m, v)	((m)->pm_segtab->seg_tab[((v) >> SEGSHIFT)])
     72 
     73 #define PMAP_SEGTABSIZE		512
     74 
     75 union pt_entry;
     76 
     77 struct segtab {
     78 	union pt_entry	*seg_tab[PMAP_SEGTABSIZE];
     79 };
     80 
     81 /*
     82  * Machine dependent pmap structure.
     83  */
     84 typedef struct pmap {
     85 	int			pm_count;	/* pmap reference count */
     86 	simple_lock_data_t	pm_lock;	/* lock on pmap */
     87 	struct pmap_statistics	pm_stats;	/* pmap statistics */
     88 	int			pm_tlbpid;	/* address space tag */
     89 	u_int			pm_tlbgen;	/* TLB PID generation number */
     90 	struct segtab		*pm_segtab;	/* pointers to pages of PTEs */
     91 } *pmap_t;
     92 
     93 /*
     94  * For each vm_page_t, there is a list of all currently valid virtual
     95  * mappings of that page.  An entry is a pv_entry_t, the list is pv_table.
     96  * XXX really should do this as a part of the higher level code.
     97  */
     98 typedef struct pv_entry {
     99 	struct pv_entry	*pv_next;	/* next pv_entry */
    100 	struct pmap	*pv_pmap;	/* pmap where mapping lies */
    101 	vm_offset_t	pv_va;		/* virtual address for mapping */
    102 	int		pv_flags;	/* some flags for the mapping */
    103 } *pv_entry_t;
    104 
    105 #define	PV_UNCACHED	0x0001		/* page is mapped uncached */
    106 
    107 /*
    108  * Defines for pmap_attributes[phys_mach_page];
    109  */
    110 #define PMAP_ATTR_MOD	0x01	/* page has been modified */
    111 #define PMAP_ATTR_REF	0x02	/* page has been referenced */
    112 
    113 
    114 #ifdef	_KERNEL
    115 
    116 char *pmap_attributes;		/* reference and modify bits */
    117 struct pmap kernel_pmap_store;
    118 
    119 #define	pmap_wired_count(pmap) 	((pmap)->pm_stats.wired_count)
    120 #define pmap_kernel()		(&kernel_pmap_store)
    121 #define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count)
    122 
    123 /*
    124  *	Bootstrap the system enough to run with virtual memory.
    125  */
    126 void	pmap_bootstrap __P((void));
    127 
    128 /*
    129  * pmap_prefer()  helps reduce virtual-coherency exceptions in
    130  * the virtually-indexed cache on mips3 CPUs.
    131  */
    132 #ifdef MIPS3
    133 #define PMAP_PREFER(pa, va)             pmap_prefer((pa), (va))
    134 void	pmap_prefer __P((vm_offset_t, vm_offset_t *));
    135 #endif /* MIPS3 */
    136 
    137 #define	PMAP_STEAL_MEMORY	/* enable pmap_steal_memory() */
    138 
    139 /*
    140  * Alternate mapping hooks for pool pages.  Avoids thrashing the TLB.
    141  */
    142 #define	PMAP_MAP_POOLPAGE(pa)	MIPS_PHYS_TO_KSEG0((pa))
    143 #define	PMAP_UNMAP_POOLPAGE(pa)	MIPS_KSEG0_TO_PHYS((va))
    144 
    145 /*
    146  * Kernel cache operations for the user-space API
    147  */
    148 int mips_user_cacheflush __P((struct proc *p, vm_offset_t va, int nbytes,
    149 	int whichcache));
    150 int mips_user_cachectl   __P((struct proc *p, vm_offset_t va, int nbytes,
    151 	int ctl));
    152 
    153 #endif	/* _KERNEL */
    154 #endif	/* _PMAP_MACHINE_ */
    155