freebsd-src/sys/i386/include/pmap.h
David Greenman 04f1835605 1) "Pre-faulting" in of pages into process address space
Eliminates vm_fault overhead on process startup and
		mmap referenced data for in-memory pages.

		(process startup time using in-memory segments *much* faster)

	2)	Even more efficient pmap code.  Code partially cleaned up.
		More comments yet to follow.

		(generally more efficient pte management)

	3)	Pageout clustering ( in addition to the FreeBSD V1.1 pagein
		clustering.)

		(much faster paging performance on non-write behind disk
		subsystems, slightly faster performance on other systems.)

	4)	Slightly changed vm_pageout code for more efficiency and
		better statistics.  Also, resist swapout a little more.

		(less likely to pageout a recently used page)

	5)	Slight improvement to the page table page trap efficiency.

		(generally faster system VM fault performance)

	6)	Defer creation of unnamed anonymous regions pager until needed.

		(speeds up shared memory bss creation)

	7)	Remove possible deadlock from swap_pager initialization.

	8)	Enhanced procfs to provide "vminfo" about vm objects and user
		pmaps.

	9)	Increased MCLSHIFT/MCLBYTES from 2K to 4K to improve net &
		socket performance and to prepare for things to come.

John Dyson
dyson@implode.root.com
David Greenman
davidg@root.com
1994-03-07 11:38:49 +00:00

269 lines
9.2 KiB
C

/*
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department and William Jolitz of UUNET Technologies Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Derived from hp300 version by Mike Hibler, this version by William
* Jolitz uses a recursive map [a pde points to the page directory] to
* map the page tables using the pagetables themselves. This is done to
* reduce the impact on kernel virtual memory for lots of sparse address
* space, and to reduce the cost of memory to each process.
*
* from: hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90
* from: @(#)pmap.h 7.4 (Berkeley) 5/12/91
* $Id: pmap.h,v 1.10 1994/01/31 04:19:00 davidg Exp $
*/
#ifndef _PMAP_MACHINE_
#define _PMAP_MACHINE_ 1
#include "vm/vm_prot.h"
/*
* 386 page table entry and page table directory
* W.Jolitz, 8/89
*/
struct pde
{
unsigned int
pd_v:1, /* valid bit */
pd_prot:2, /* access control */
pd_mbz1:2, /* reserved, must be zero */
pd_u:1, /* hardware maintained 'used' bit */
:1, /* not used */
pd_mbz2:2, /* reserved, must be zero */
:3, /* reserved for software */
pd_pfnum:20; /* physical page frame number of pte's*/
};
#define PD_MASK 0xffc00000UL /* page directory address bits */
#define PT_MASK 0x003ff000UL /* page table address bits */
#define PD_SHIFT 22 /* page directory address shift */
#define PG_SHIFT 12 /* page table address shift */
struct pte
{
unsigned int
pg_v:1, /* valid bit */
pg_prot:2, /* access control */
pg_mbz1:2, /* reserved, must be zero */
pg_u:1, /* hardware maintained 'used' bit */
pg_m:1, /* hardware maintained modified bit */
pg_mbz2:2, /* reserved, must be zero */
pg_w:1, /* software, wired down page */
:1, /* software (unused) */
pg_nc:1, /* 'uncacheable page' bit */
pg_pfnum:20; /* physical page frame number */
};
#define PG_V 0x00000001
#define PG_RO 0x00000000
#define PG_RW 0x00000002
#define PG_u 0x00000004
#define PG_PROT 0x00000006 /* all protection bits . */
#define PG_W 0x00000200
#define PG_N 0x00000800 /* Non-cacheable */
#define PG_M 0x00000040
#define PG_U 0x00000020
#define PG_FRAME 0xfffff000UL
#define PG_NOACC 0
#define PG_KR 0x00000000
#define PG_KW 0x00000002
#define PG_URKR 0x00000004
#define PG_URKW 0x00000004
#define PG_UW 0x00000006
/* Garbage for current bastardized pager that assumes a hp300 */
#define PG_NV 0
#define PG_CI 0
/*
* Page Protection Exception bits
*/
#define PGEX_P 0x01 /* Protection violation vs. not present */
#define PGEX_W 0x02 /* during a Write cycle */
#define PGEX_U 0x04 /* access from User mode (UPL) */
/* typedef struct pde pd_entry_t; */ /* page directory entry */
/* typedef struct pte pt_entry_t; */ /* Mach page table entry */
typedef unsigned int *pd_entry_t;
typedef unsigned int *pt_entry_t;
/*
* NKPDE controls the virtual space of the kernel, what ever is left, minus
* the alternate page table area is given to the user (NUPDE)
*/
/*
* NKPDE controls the virtual space of the kernel, what ever is left is
* given to the user (NUPDE)
*/
#ifndef NKPT
#define NKPT 15 /* actual number of kernel pte's */
#endif
#ifndef NKPDE
#define NKPDE 63 /* addressable number of kpte's */
#endif
#define NUPDE (NPTEPG-NKPDE) /* number of user pde's */
/*
* The *PTDI values control the layout of virtual memory
*
* XXX This works for now, but I am not real happy with it, I'll fix it
* right after I fix locore.s and the magic 28K hole
*/
#define APTDPTDI (NPTEPG-1) /* alt ptd entry that points to APTD */
#define KPTDI (APTDPTDI-NKPDE)/* start of kernel virtual pde's */
#define PTDPTDI (KPTDI-1) /* ptd entry that points to ptd! */
#define KSTKPTDI (PTDPTDI-1) /* ptd entry for u./kernel&user stack */
#define KSTKPTEOFF (NBPG/sizeof(pd_entry_t)-UPAGES) /* pte entry for kernel stack */
#define PDESIZE sizeof(pd_entry_t) /* for assembly files */
#define PTESIZE sizeof(pt_entry_t) /* for assembly files */
/*
* Address of current and alternate address space page table maps
* and directories.
*/
#ifdef KERNEL
extern pt_entry_t PTmap[], APTmap[], Upte;
extern pd_entry_t PTD[], APTD[], PTDpde, APTDpde, Upde;
extern pt_entry_t *Sysmap;
extern int IdlePTD; /* physical address of "Idle" state directory */
#endif
/*
* virtual address to page table entry and
* to physical address. Likewise for alternate address space.
* Note: these work recursively, thus vtopte of a pte will give
* the corresponding pde that in turn maps it.
*/
#define vtopte(va) (PTmap + i386_btop(va))
#define kvtopte(va) vtopte(va)
#define ptetov(pt) (i386_ptob(pt - PTmap))
#define vtophys(va) (((int) (*vtopte(va))&PG_FRAME) | ((int)(va) & PGOFSET))
#define ispt(va) ((va) >= UPT_MIN_ADDRESS && (va) <= KPT_MAX_ADDRESS)
#define avtopte(va) (APTmap + i386_btop(va))
#define ptetoav(pt) (i386_ptob(pt - APTmap))
#define avtophys(va) (((int) (*avtopte(va))&PG_FRAME) | ((int)(va) & PGOFSET))
/*
* macros to generate page directory/table indicies
*/
#define pdei(va) (((va)&PD_MASK)>>PD_SHIFT)
#define ptei(va) (((va)&PT_MASK)>>PG_SHIFT)
/*
* Pmap stuff
*/
struct pmap {
pd_entry_t *pm_pdir; /* KVA of page directory */
boolean_t pm_pdchanged; /* pdir changed */
short pm_dref; /* page directory ref count */
short pm_count; /* pmap reference count */
simple_lock_data_t pm_lock; /* lock on pmap */
struct pmap_statistics pm_stats; /* pmap statistics */
long pm_ptpages; /* more stats: PT pages */
};
typedef struct pmap *pmap_t;
#ifdef KERNEL
extern pmap_t kernel_pmap;
#endif
/*
* Macros for speed
*/
#define PMAP_ACTIVATE(pmapp, pcbp) \
if ((pmapp) != NULL /*&& (pmapp)->pm_pdchanged */) { \
(pcbp)->pcb_cr3 = \
pmap_extract(kernel_pmap, (vm_offset_t)(pmapp)->pm_pdir); \
if ((pmapp) == &curproc->p_vmspace->vm_pmap) \
load_cr3((pcbp)->pcb_cr3); \
(pmapp)->pm_pdchanged = FALSE; \
}
#define PMAP_DEACTIVATE(pmapp, pcbp)
/*
* For each vm_page_t, there is a list of all currently valid virtual
* mappings of that page. An entry is a pv_entry_t, the list is pv_table.
*/
typedef struct pv_entry {
struct pv_entry *pv_next; /* next pv_entry */
pmap_t pv_pmap; /* pmap where mapping lies */
vm_offset_t pv_va; /* virtual address for mapping */
} *pv_entry_t;
#define PV_ENTRY_NULL ((pv_entry_t) 0)
#define PV_CI 0x01 /* all entries must be cache inhibited */
#define PV_PTPAGE 0x02 /* entry maps a page table page */
#ifdef KERNEL
pv_entry_t pv_table; /* array of entries, one per page */
#define pa_index(pa) atop(pa - vm_first_phys)
#define pa_to_pvh(pa) (&pv_table[pa_index(pa)])
#define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count)
extern pmap_t pmap_create(vm_size_t);
extern void pmap_pinit(struct pmap *);
extern void pmap_destroy(pmap_t);
extern void pmap_release(struct pmap *);
extern void pmap_reference(pmap_t);
extern void pmap_remove(struct pmap *, vm_offset_t, vm_offset_t);
extern void pmap_protect(struct pmap *, vm_offset_t, vm_offset_t, vm_prot_t);
extern void pmap_enter(pmap_t, vm_offset_t, vm_offset_t, vm_prot_t, boolean_t);
extern void pmap_change_wiring(pmap_t, vm_offset_t, boolean_t);
extern inline pt_entry_t *pmap_pte(pmap_t, vm_offset_t);
extern vm_offset_t pmap_extract(pmap_t, vm_offset_t);
extern void pmap_copy(pmap_t, pmap_t, vm_offset_t, vm_size_t, vm_offset_t);
extern void pmap_collect(pmap_t);
struct pcb; extern void pmap_activate(pmap_t, struct pcb *);
extern pmap_t pmap_kernel(void);
extern void pmap_pageable(pmap_t, vm_offset_t, vm_offset_t, boolean_t);
#endif /* KERNEL */
#endif /* _PMAP_MACHINE_ */