* 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.
unsigned int pg_pfnum
:21, /* core page frame number or 0 */
pg_vreadm
:1, /* modified since vread (or with _m) */
pg_swapm
:1, /* have to write back to swap */
pg_fod
:1, /* is fill on demand (=0) */
pg_m
:1, /* hardware maintained modified bit */
pg_prot
:4, /* access control */
unsigned int pg_pfnum
:21,
pg_high
:9; /* special for clustering */
unsigned int pg_blkno
:20, /* file system block number */
pg_fileno
:5, /* file mapped from or TEXT or ZERO */
pg_fod
:1, /* is fill on demand (=1) */
#define PG_PROT 0x78000000
#define PG_FOD 0x02000000
#define PG_VREADM 0x00800000
#define PG_PFNUM 0x001fffff
#define PG_FZERO (NOFILE)
#define PG_FTEXT (NOFILE+1)
#define PG_FMAX (PG_FTEXT)
#define PG_URKW 0x70000000
#define PG_URKR 0x78000000
#define dirty(pte) ((pte)->pg_fod == 0 && (pte)->pg_pfnum && \
((pte)->pg_m || (pte)->pg_swapm))
/* 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 camap
[];
extern struct pte Nexmap
[][16];