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1#ifndef _ASM_X86_PGTABLE_32_H
2#define _ASM_X86_PGTABLE_32_H
3
4
5/*
6 * The Linux memory management assumes a three-level page table setup. On
7 * the i386, we use that, but "fold" the mid level into the top-level page
8 * table, so that we physically have the same two-level page table as the
9 * i386 mmu expects.
10 *
11 * This file contains the functions and defines necessary to modify and use
12 * the i386 page table tree.
13 */
14#ifndef __ASSEMBLY__
15#include <asm/processor.h>
16#include <asm/fixmap.h>
17#include <linux/threads.h>
18#include <asm/paravirt.h>
19
20#include <linux/bitops.h>
21#include <linux/slab.h>
22#include <linux/list.h>
23#include <linux/spinlock.h>
24
25struct mm_struct;
26struct vm_area_struct;
27
28extern pgd_t swapper_pg_dir[1024];
29
30static inline void pgtable_cache_init(void) { }
31static inline void check_pgt_cache(void) { }
32void paging_init(void);
33
34extern void set_pmd_pfn(unsigned long, unsigned long, pgprot_t);
35
36/*
37 * The Linux x86 paging architecture is 'compile-time dual-mode', it
38 * implements both the traditional 2-level x86 page tables and the
39 * newer 3-level PAE-mode page tables.
40 */
41#ifdef CONFIG_X86_PAE
42# include <asm/pgtable-3level-defs.h>
43# define PMD_SIZE (1UL << PMD_SHIFT)
44# define PMD_MASK (~(PMD_SIZE - 1))
45#else
46# include <asm/pgtable-2level-defs.h>
47#endif
48
49#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
50#define PGDIR_MASK (~(PGDIR_SIZE - 1))
51
52/* Just any arbitrary offset to the start of the vmalloc VM area: the
53 * current 8MB value just means that there will be a 8MB "hole" after the
54 * physical memory until the kernel virtual memory starts. That means that
55 * any out-of-bounds memory accesses will hopefully be caught.
56 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
57 * area for the same reason. ;)
58 */
59#define VMALLOC_OFFSET (8 * 1024 * 1024)
60#define VMALLOC_START ((unsigned long)high_memory + VMALLOC_OFFSET)
61#ifdef CONFIG_X86_PAE
62#define LAST_PKMAP 512
63#else
64#define LAST_PKMAP 1024
65#endif
66
67#define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
68 & PMD_MASK)
69
70#ifdef CONFIG_HIGHMEM
71# define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE)
72#else
73# define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE)
74#endif
75
76#define MAXMEM (VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE)
77
78/*
79 * Define this if things work differently on an i386 and an i486:
80 * it will (on an i486) warn about kernel memory accesses that are
81 * done without a 'access_ok(VERIFY_WRITE,..)'
82 */
83#undef TEST_ACCESS_OK
84
85/* The boot page tables (all created as a single array) */
86extern unsigned long pg0[];
87
88#define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
89
90/* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
91#define pmd_none(x) (!(unsigned long)pmd_val((x)))
92#define pmd_present(x) (pmd_val((x)) & _PAGE_PRESENT)
93#define pmd_bad(x) ((pmd_val(x) & (PTE_FLAGS_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
94
95#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
96
97#ifdef CONFIG_X86_PAE
98# include <asm/pgtable-3level.h>
99#else
100# include <asm/pgtable-2level.h>
101#endif
102
103/*
104 * Conversion functions: convert a page and protection to a page entry,
105 * and a page entry and page directory to the page they refer to.
106 */
107#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
108
109
110static inline int pud_large(pud_t pud) { return 0; }
111
112/*
113 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
114 *
115 * this macro returns the index of the entry in the pmd page which would
116 * control the given virtual address
117 */
118#define pmd_index(address) \
119 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
120
121/*
122 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
123 *
124 * this macro returns the index of the entry in the pte page which would
125 * control the given virtual address
126 */
127#define pte_index(address) \
128 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
129#define pte_offset_kernel(dir, address) \
130 ((pte_t *)pmd_page_vaddr(*(dir)) + pte_index((address)))
131
132#define pmd_page(pmd) (pfn_to_page(pmd_val((pmd)) >> PAGE_SHIFT))
133
134#define pmd_page_vaddr(pmd) \
135 ((unsigned long)__va(pmd_val((pmd)) & PTE_PFN_MASK))
136
137#if defined(CONFIG_HIGHPTE)
138#define pte_offset_map(dir, address) \
139 ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), KM_PTE0) + \
140 pte_index((address)))
141#define pte_offset_map_nested(dir, address) \
142 ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), KM_PTE1) + \
143 pte_index((address)))
144#define pte_unmap(pte) kunmap_atomic((pte), KM_PTE0)
145#define pte_unmap_nested(pte) kunmap_atomic((pte), KM_PTE1)
146#else
147#define pte_offset_map(dir, address) \
148 ((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
149#define pte_offset_map_nested(dir, address) pte_offset_map((dir), (address))
150#define pte_unmap(pte) do { } while (0)
151#define pte_unmap_nested(pte) do { } while (0)
152#endif
153
154/* Clear a kernel PTE and flush it from the TLB */
155#define kpte_clear_flush(ptep, vaddr) \
156do { \
157 pte_clear(&init_mm, (vaddr), (ptep)); \
158 __flush_tlb_one((vaddr)); \
159} while (0)
160
161/*
162 * The i386 doesn't have any external MMU info: the kernel page
163 * tables contain all the necessary information.
164 */
165#define update_mmu_cache(vma, address, pte) do { } while (0)
166
167#endif /* !__ASSEMBLY__ */
168
169/*
170 * kern_addr_valid() is (1) for FLATMEM and (0) for
171 * SPARSEMEM and DISCONTIGMEM
172 */
173#ifdef CONFIG_FLATMEM
174#define kern_addr_valid(addr) (1)
175#else
176#define kern_addr_valid(kaddr) (0)
177#endif
178
179#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
180 remap_pfn_range(vma, vaddr, pfn, size, prot)
181
182#endif /* _ASM_X86_PGTABLE_32_H */