[unix-history] / usr / src / sys / i386 / include / pte.h

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* %sccs.include.redist.c%
*
*      @(#)pte.h       5.4 (Berkeley) %G%
*/

/*
* 386 page table entry and page table directory
* W.Jolitz, 8/89
*
* There are two major kinds of pte's: those which have ever existed (and are
* thus either now in core or on the swap device), and those which have
* never existed, but which will be filled on demand at first reference.
* There is a structure describing each.  There is also an ancillary
* structure used in page clustering.
*/

#ifndef LOCORE
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*/
};
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_fod:1,               /* is fill on demand (=0) */
               :1,                     /* must write back to swap (unused) */
               pg_nc:1,                /* 'uncacheable page' bit */
               pg_pfnum:20;            /* physical page frame number */
};
struct hpte
{
unsigned int    
               pg_high:12,             /* special for clustering */
               pg_pfnum:20;
};
struct fpte
{
unsigned int    
               pg_v:1,                 /* valid bit */
               pg_prot:2,              /* access control */
               :5,
               pg_fileno:1,            /* file mapped from or TEXT or ZERO */
               pg_fod:1,               /* is fill on demand (=1) */
               pg_blkno:22;            /* file system block number */
};
#endif

#define PD_MASK         0xffc00000      /* page directory address bits */
#define PD_SHIFT        22              /* page directory address bits */

#define PG_V            0x00000001
#define PG_PROT         0x00000006 /* all protection bits . */
#define PG_FOD          0x00000200
#define PG_SWAPM        0x00000400
#define PG_N            0x00000800 /* Non-cacheable */
#define PG_M            0x00000040
#define PG_U            0x00000020 /* not currently used */
#define PG_FRAME        0xfffff000

#define PG_FZERO        0
#define PG_FTEXT        1
#define PG_FMAX         (PG_FTEXT)

#define PG_NOACC        0
#define PG_KR           0x00000000
#define PG_KW           0x00000002
#define PG_URKR         0x00000004
#define PG_URKW         0x00000004
#define PG_UW           0x00000006

/*
* 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) */

/*
* Pte related macros
*/
#define dirty(pte)      ((pte)->pg_m)

#ifndef LOCORE
#ifdef KERNEL
/* utilities defined in locore.s */
extern  struct pte Sysmap[];
extern  struct pte Usrptmap[];
extern  struct pte usrpt[];
extern  struct pte Swapmap[];
extern  struct pte Forkmap[];
extern  struct pte Xswapmap[];
extern  struct pte Xswap2map[];
extern  struct pte Pushmap[];
extern  struct pte Vfmap[];
extern  struct pte mmap[];
extern  struct pte msgbufmap[];
extern  struct pte kmempt[], ekmempt[];
#endif
#endif