Avoid repition in walkpgdir

This commit is contained in:
Frans Kaashoek 2018-10-02 07:37:49 -04:00
parent 572e106e6f
commit 155c13b7f8
2 changed files with 24 additions and 60 deletions

26
mmu.h
View file

@ -91,26 +91,22 @@ struct segdesc {
// +------+-------+--------------+----------+------------+-------------+
// \-PMX(va)-/\-PDPX(va)--/ \-PDX(va)-/ \-PTX(va)-/
#define PMX(va) (((uint64)(va) >> PML4XSHIFT) & PXMASK)
#define PDPX(va) (((uint64)(va) >> PDPXSHIFT) & PXMASK)
// page directory index
#define PDX(va) (((uint64)(va) >> PDXSHIFT) & PXMASK)
// page table index
#define PTX(va) (((uint64)(va) >> PTXSHIFT) & PXMASK)
// construct virtual address from indexes and offset
#define PGADDR(d, t, o) ((uint64)((d) << PDXSHIFT | (t) << PTXSHIFT | (o)))
// Page directory and page table constants.
#define NPDENTRIES 512 // # directory entries per page directory
#define NPTENTRIES 512 // # PTEs per page table
#define PGSIZE 4096 // bytes mapped by a page
#define PTXSHIFT 12 // offset of PTX in a linear address
#define PGSHIFT 12 // offset of PTX in a linear address
#define PDXSHIFT 21 // offset of PDX in a linear address
#define PDPXSHIFT 30 // offset of PDPX in a linear address
#define PML4XSHIFT 39 // offset of PML4X in a linear address
#define PXMASK 0X1FF
#define PXMASK 0x1FF
#define PXSHIFT(n) (PGSHIFT+(9*(n)))
#define PDX(va) (((uint64)(va) >> PDXSHIFT) & PXMASK)
#define PTX(va) (((uint64)(va) >> PGSHIFT) & PXMASK)
#define PX(n, va) ((((uint64) (va)) >> PXSHIFT(n)) & PXMASK)
#define L_PML4 3
// construct virtual address from indexes and offset
#define PGADDR(d, t, o) ((uint64)((d) << PDXSHIFT | (t) << PGSHIFT | (o)))
#define PGROUNDUP(sz) (((sz)+PGSIZE-1) & ~(PGSIZE-1))
#define PGROUNDDOWN(a) (((a)) & ~(PGSIZE-1))