/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
*/ #ifndef _ASM_PGTABLE_64_H #define _ASM_PGTABLE_64_H
/* * Each address space has 2 4K pages as its page directory, giving 1024 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page * tables. Each page table is also a single 4K page, giving 512 (== * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to * invalid_pmd_table, each pmd entry is initialized to point to * invalid_pte_table, each pte is initialized to 0. * * Kernel mappings: kernel mappings are held in the swapper_pg_table. * The layout is identical to userspace except it's indexed with the * fault address - VMALLOC_START.
*/
/* PGDIR_SHIFT determines what a third-level page table entry can map */ #ifdef __PAGETABLE_PMD_FOLDED #define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3) #else
/* PMD_SHIFT determines the size of the area a second-level page table can map */ #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3)) #define PMD_SIZE (1UL << PMD_SHIFT) #define PMD_MASK (~(PMD_SIZE-1))
/* * For 4kB page size we use a 3 level page tree and an 8kB pud, which * permits us mapping 40 bits of virtual address space. * * We used to implement 41 bits by having an order 1 pmd level but that seemed * rather pointless. * * For 8kB page size we use a 3 level page tree which permits a total of * 8TB of address space. Alternatively a 33-bit / 8GB organization using * two levels would be easy to implement. * * For 16kB page size we use a 2 level page tree which permits a total of * 36 bits of virtual address space. We could add a third level but it seems * like at the moment there's no need for this. * * For 64kB page size we use a 2 level page table tree for a total of 42 bits * of virtual address space.
*/ #ifdef CONFIG_PAGE_SIZE_4KB # ifdef CONFIG_MIPS_VA_BITS_48 # define PGD_TABLE_ORDER 0 # define PUD_TABLE_ORDER 0 # else # define PGD_TABLE_ORDER 1 # define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud # endif #define PMD_TABLE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_8KB #define PGD_TABLE_ORDER 0 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud #define PMD_TABLE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_16KB #ifdef CONFIG_MIPS_VA_BITS_48 #define PGD_TABLE_ORDER 1 #else #define PGD_TABLE_ORDER 0 #endif #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud #define PMD_TABLE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_32KB #define PGD_TABLE_ORDER 0 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud #define PMD_TABLE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_64KB #define PGD_TABLE_ORDER 0 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud #ifdef CONFIG_MIPS_VA_BITS_48 #define PMD_TABLE_ORDER 0 #else #define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd #endif #endif
#ifndef __PAGETABLE_PUD_FOLDED /* * For 4-level pagetables we defines these ourselves, for 3-level the * definitions are below, for 2-level the * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
*/ typedefstruct { unsignedlong pud; } pud_t; #define pud_val(x) ((x).pud) #define __pud(x) ((pud_t) { (x) })
extern pud_t invalid_pud_table[PTRS_PER_PUD];
/* * Empty pgd entries point to the invalid_pud_table.
*/ staticinlineint p4d_none(p4d_t p4d)
{ return p4d_val(p4d) == (unsignedlong)invalid_pud_table;
}
staticinlineint p4d_bad(p4d_t p4d)
{ if (unlikely(p4d_val(p4d) & ~PAGE_MASK)) return 1;
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