usr/src/sys/i386/include/pte.h

/*
 * 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 ptd
{
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 */
                :1,                     /* not used */
                pg_mbz2:2,              /* reserved, must be zero */
                :3,                     /* reserved for software */
                pg_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 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_PFNUM        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

/*
 * 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