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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
8 */
9#ifndef _ASM_PGTABLE_64_H
10#define _ASM_PGTABLE_64_H
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/linkage.h>
13
14#include <asm/addrspace.h>
15#include <asm/page.h>
16#include <asm/cachectl.h>
17
Ralf Baechlec6e8b582005-02-10 12:19:59 +000018#include <asm-generic/pgtable-nopud.h>
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020/*
21 * Each address space has 2 4K pages as its page directory, giving 1024
22 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
Ralf Baechlec6e8b582005-02-10 12:19:59 +000023 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
24 * tables. Each page table is also a single 4K page, giving 512 (==
25 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
26 * invalid_pmd_table, each pmd entry is initialized to point to
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 * invalid_pte_table, each pte is initialized to 0. When memory is low,
28 * and a pmd table or a page table allocation fails, empty_bad_pmd_table
29 * and empty_bad_page_table is returned back to higher layer code, so
30 * that the failure is recognized later on. Linux does not seem to
31 * handle these failures very well though. The empty_bad_page_table has
32 * invalid pte entries in it, to force page faults.
33 *
34 * Kernel mappings: kernel mappings are held in the swapper_pg_table.
35 * The layout is identical to userspace except it's indexed with the
36 * fault address - VMALLOC_START.
37 */
38
39/* PMD_SHIFT determines the size of the area a second-level page table can map */
Ralf Baechlec6e8b582005-02-10 12:19:59 +000040#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#define PMD_SIZE (1UL << PMD_SHIFT)
42#define PMD_MASK (~(PMD_SIZE-1))
43
44/* PGDIR_SHIFT determines what a third-level page table entry can map */
Ralf Baechlec6e8b582005-02-10 12:19:59 +000045#define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
47#define PGDIR_MASK (~(PGDIR_SIZE-1))
48
49/*
Ralf Baechlec6e8b582005-02-10 12:19:59 +000050 * For 4kB page size we use a 3 level page tree and an 8kB pud, which
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 * permits us mapping 40 bits of virtual address space.
52 *
53 * We used to implement 41 bits by having an order 1 pmd level but that seemed
54 * rather pointless.
55 *
56 * For 8kB page size we use a 3 level page tree which permits a total of
57 * 8TB of address space. Alternatively a 33-bit / 8GB organization using
58 * two levels would be easy to implement.
59 *
60 * For 16kB page size we use a 2 level page tree which permits a total of
Thiemo Seuferf29244a2005-02-21 11:11:32 +000061 * 36 bits of virtual address space. We could add a third level but it seems
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 * like at the moment there's no need for this.
63 *
64 * For 64kB page size we use a 2 level page table tree for a total of 42 bits
65 * of virtual address space.
66 */
67#ifdef CONFIG_PAGE_SIZE_4KB
68#define PGD_ORDER 1
Ralf Baechlec6e8b582005-02-10 12:19:59 +000069#define PUD_ORDER aieeee_attempt_to_allocate_pud
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#define PMD_ORDER 0
71#define PTE_ORDER 0
72#endif
73#ifdef CONFIG_PAGE_SIZE_8KB
74#define PGD_ORDER 0
Ralf Baechlec6e8b582005-02-10 12:19:59 +000075#define PUD_ORDER aieeee_attempt_to_allocate_pud
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#define PMD_ORDER 0
77#define PTE_ORDER 0
78#endif
79#ifdef CONFIG_PAGE_SIZE_16KB
80#define PGD_ORDER 0
Ralf Baechlec6e8b582005-02-10 12:19:59 +000081#define PUD_ORDER aieeee_attempt_to_allocate_pud
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#define PMD_ORDER 0
83#define PTE_ORDER 0
84#endif
85#ifdef CONFIG_PAGE_SIZE_64KB
86#define PGD_ORDER 0
Ralf Baechlec6e8b582005-02-10 12:19:59 +000087#define PUD_ORDER aieeee_attempt_to_allocate_pud
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#define PMD_ORDER 0
89#define PTE_ORDER 0
90#endif
91
92#define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
93#define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
94#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
95
Peter Watkins9dbd7b92006-08-23 11:15:49 -040096#if PGDIR_SIZE >= TASK_SIZE
97#define USER_PTRS_PER_PGD (1)
98#else
Linus Torvalds1da177e2005-04-16 15:20:36 -070099#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
Peter Watkins9dbd7b92006-08-23 11:15:49 -0400100#endif
101#define FIRST_USER_ADDRESS 0UL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Thiemo Seuferf29244a2005-02-21 11:11:32 +0000103#define VMALLOC_START MAP_BASE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104#define VMALLOC_END \
105 (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE)
106
107#define pte_ERROR(e) \
108 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
109#define pmd_ERROR(e) \
110 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
111#define pgd_ERROR(e) \
112 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
113
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000114extern pte_t invalid_pte_table[PTRS_PER_PTE];
115extern pte_t empty_bad_page_table[PTRS_PER_PTE];
116extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
117extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119/*
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +0000120 * Empty pgd/pmd entries point to the invalid_pte_table.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 */
122static inline int pmd_none(pmd_t pmd)
123{
124 return pmd_val(pmd) == (unsigned long) invalid_pte_table;
125}
126
127#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
128
129static inline int pmd_present(pmd_t pmd)
130{
131 return pmd_val(pmd) != (unsigned long) invalid_pte_table;
132}
133
134static inline void pmd_clear(pmd_t *pmdp)
135{
136 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
137}
138
139/*
Thiemo Seuferf29244a2005-02-21 11:11:32 +0000140 * Empty pud entries point to the invalid_pmd_table.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 */
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000142static inline int pud_none(pud_t pud)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000144 return pud_val(pud) == (unsigned long) invalid_pmd_table;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145}
146
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000147static inline int pud_bad(pud_t pud)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000149 return pud_val(pud) & ~PAGE_MASK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150}
151
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000152static inline int pud_present(pud_t pud)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153{
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000154 return pud_val(pud) != (unsigned long) invalid_pmd_table;
155}
156
157static inline void pud_clear(pud_t *pudp)
158{
159 pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160}
161
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +0000162#define pte_page(x) pfn_to_page(pte_pfn(x))
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164#ifdef CONFIG_CPU_VR41XX
165#define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
166#define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
167#else
168#define pte_pfn(x) ((unsigned long)((x).pte >> PAGE_SHIFT))
169#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
170#endif
171
172#define __pgd_offset(address) pgd_index(address)
Thiemo Seuferf29244a2005-02-21 11:11:32 +0000173#define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +0000174#define __pmd_offset(address) pmd_index(address)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176/* to find an entry in a kernel page-table-directory */
177#define pgd_offset_k(address) pgd_offset(&init_mm, 0)
178
Thiemo Seuferf29244a2005-02-21 11:11:32 +0000179#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
Thiemo Seufer1b3a6e92005-04-01 14:07:13 +0000180#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182/* to find an entry in a page-table-directory */
183#define pgd_offset(mm,addr) ((mm)->pgd + pgd_index(addr))
184
Dave McCracken46a82b22006-09-25 23:31:48 -0700185static inline unsigned long pud_page_vaddr(pud_t pud)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000187 return pud_val(pud);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188}
Dave McCracken46a82b22006-09-25 23:31:48 -0700189#define pud_phys(pud) (pud_val(pud) - PAGE_OFFSET)
190#define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192/* Find an entry in the second-level page table.. */
Ralf Baechlec6e8b582005-02-10 12:19:59 +0000193static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
Dave McCracken46a82b22006-09-25 23:31:48 -0700195 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196}
197
198/* Find an entry in the third-level page table.. */
199#define __pte_offset(address) \
200 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
201#define pte_offset(dir, address) \
Dave McCracken46a82b22006-09-25 23:31:48 -0700202 ((pte_t *) (pmd_page_vaddr(*dir)) + __pte_offset(address))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203#define pte_offset_kernel(dir, address) \
Dave McCracken46a82b22006-09-25 23:31:48 -0700204 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205#define pte_offset_map(dir, address) \
206 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
207#define pte_offset_map_nested(dir, address) \
208 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
209#define pte_unmap(pte) ((void)(pte))
210#define pte_unmap_nested(pte) ((void)(pte))
211
212/*
213 * Initialize a new pgd / pmd table with invalid pointers.
214 */
215extern void pgd_init(unsigned long page);
216extern void pmd_init(unsigned long page, unsigned long pagetable);
217
218/*
219 * Non-present pages: high 24 bits are offset, next 8 bits type,
220 * low 32 bits zero.
221 */
222static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
223{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; }
224
225#define __swp_type(x) (((x).val >> 32) & 0xff)
226#define __swp_offset(x) ((x).val >> 40)
227#define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
228#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
229#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
230
231/*
Sergei Shtylyov7cb710c2006-05-27 22:39:39 +0400232 * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to
233 * make things easier, and only use the upper 56 bits for the page offset...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 */
Sergei Shtylyov7cb710c2006-05-27 22:39:39 +0400235#define PTE_FILE_MAX_BITS 56
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Sergei Shtylyov7cb710c2006-05-27 22:39:39 +0400237#define pte_to_pgoff(_pte) ((_pte).pte >> 8)
238#define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240#endif /* _ASM_PGTABLE_64_H */