freebsd-src/sys/i386/include/pmap.h
John Dyson 030ad08012 Fixed a problem that the UPAGES of a process were being run down
in a suboptimal manner.  I had also noticed some panics that appeared
to be at least superficially caused by this problem.  Also, included
are some minor mods to support more general handling of page table page
faulting.  More details in a future commit.
1996-04-03 05:23:44 +00:00

205 lines
6.9 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 1.34 1996/02/25 03:02:53 dyson Exp $
*/
#ifndef _MACHINE_PMAP_H_
#define _MACHINE_PMAP_H_
#include <machine/pte.h>
typedef unsigned int *pd_entry_t;
typedef unsigned int *pt_entry_t;
struct vm_map;
/*
* 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
#if 0
#define NKPT 26 /* actual number of kernel page tables */
#else
#define NKPT 9 /* actual number of kernel page tables */
#endif
#endif
#ifndef NKPDE
#define NKPDE 63 /* addressable number of page tables/pde'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 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))
#ifdef KERNEL
/*
* Routine: pmap_kextract
* Function:
* Extract the physical page address associated
* kernel virtual address.
*/
static __inline vm_offset_t
pmap_kextract(vm_offset_t va)
{
vm_offset_t pa = *(int *)vtopte(va);
pa = (pa & PG_FRAME) | (va & ~PG_FRAME);
return pa;
}
#endif
/*
* macros to generate page directory/table indices
*/
#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 */
short pm_dref; /* page directory ref count */
short pm_count; /* pmap reference count */
struct pmap_statistics pm_stats; /* pmap statistics */
struct vm_map *pm_map; /* map that owns this pmap */
};
typedef struct pmap *pmap_t;
#ifdef KERNEL
extern pmap_t kernel_pmap;
#endif
/*
* 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 */
vm_page_t pv_ptem; /* VM page for pte */
} *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
extern caddr_t CADDR1;
extern pt_entry_t *CMAP1;
extern vm_offset_t avail_end;
extern vm_offset_t avail_start;
extern vm_offset_t phys_avail[];
extern pv_entry_t pv_table; /* array of entries, one per page */
extern vm_offset_t virtual_avail;
extern vm_offset_t virtual_end;
#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)
struct pcb;
void pmap_bootstrap __P(( vm_offset_t, vm_offset_t));
pmap_t pmap_kernel __P((void));
void *pmap_mapdev __P((vm_offset_t, vm_size_t));
pt_entry_t * __pure pmap_pte __P((pmap_t, vm_offset_t)) __pure2;
void pmap_unuse_pt __P((pmap_t, vm_offset_t, vm_page_t));
vm_page_t pmap_use_pt __P((pmap_t, vm_offset_t));
#endif /* KERNEL */
#endif /* !_MACHINE_PMAP_H_ */