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pmap.h revision 1.17 
      1 /*	$NetBSD: pmap.h,v 1.17 1998/02/25 23:26:41 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 /*
     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 mips_trunc_seg(x)	((vm_offset_t)(x) & ~SEGOFSET)
     68 #define mips_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  * For each vm_page_t, there is a list of all currently valid virtual
     93  * mappings of that page.  An entry is a pv_entry_t, the list is pv_table.
     94  * XXX really should do this as a part of the higher level code.
     95  */
     96 typedef struct pv_entry {
     97 	struct pv_entry	*pv_next;	/* next pv_entry */
     98 	struct pmap	*pv_pmap;	/* pmap where mapping lies */
     99 	vm_offset_t	pv_va;		/* virtual address for mapping */
    100 	int		pv_flags;	/* some flags for the mapping */
    101 } *pv_entry_t;
    102 
    103 #define	PV_UNCACHED	0x0001		/* page is mapped uncached */
    104 
    105 /*
    106  * Defines for pmap_attributes[phys_mach_page];
    107  */
    108 #define PMAP_ATTR_MOD	0x01	/* page has been modified */
    109 #define PMAP_ATTR_REF	0x02	/* page has been referenced */
    110 
    111 
    112 #ifdef	_KERNEL
    113 
    114 char *pmap_attributes;		/* reference and modify bits */
    115 struct pmap kernel_pmap_store;
    116 
    117 #define	pmap_wired_count(pmap) 	((pmap)->pm_stats.wired_count)
    118 #define pmap_kernel()		(&kernel_pmap_store)
    119 #define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count)
    120 
    121 /*
    122  *	Bootstrap the system enough to run with virtual memory.
    123  */
    124 void	pmap_bootstrap __P((void));
    125 
    126 /*
    127  * pmap_prefer()  helps reduce virtual-coherency exceptions in
    128  * the virtually-indexed cache on mips3 CPUs.
    129  */
    130 #ifdef MIPS3
    131 #define PMAP_PREFER(pa, va)             pmap_prefer((pa), (va))
    132 void	pmap_prefer __P((vm_offset_t, vm_offset_t *));
    133 #endif /* MIPS3 */
    134 
    135 #define	PMAP_STEAL_MEMORY	/* enable pmap_steal_memory() */
    136 
    137 /*
    138  * Kernel cache operations for the user-space API
    139  */
    140 int mips_user_cacheflush __P((struct proc *p, vm_offset_t va, int nbytes,
    141 	int whichcache));
    142 int mips_user_cachectl   __P((struct proc *p, vm_offset_t va, int nbytes,
    143 	int ctl));
    144 
    145 #endif	/* _KERNEL */
    146 #endif	/* _PMAP_MACHINE_ */
    147