Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[wrt350n-kernel.git] / include / asm-mips / pgtable-64.h
blob943515f0ef8709c113f8a063ad17fd741820bc4c
1 /*
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.
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
12 #include <linux/linkage.h>
14 #include <asm/addrspace.h>
15 #include <asm/page.h>
16 #include <asm/cachectl.h>
17 #include <asm/fixmap.h>
19 #include <asm-generic/pgtable-nopud.h>
22 * Each address space has 2 4K pages as its page directory, giving 1024
23 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
24 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
25 * tables. Each page table is also a single 4K page, giving 512 (==
26 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
27 * invalid_pmd_table, each pmd entry is initialized to point to
28 * invalid_pte_table, each pte is initialized to 0. When memory is low,
29 * and a pmd table or a page table allocation fails, empty_bad_pmd_table
30 * and empty_bad_page_table is returned back to higher layer code, so
31 * that the failure is recognized later on. Linux does not seem to
32 * handle these failures very well though. The empty_bad_page_table has
33 * invalid pte entries in it, to force page faults.
35 * Kernel mappings: kernel mappings are held in the swapper_pg_table.
36 * The layout is identical to userspace except it's indexed with the
37 * fault address - VMALLOC_START.
40 /* PMD_SHIFT determines the size of the area a second-level page table can map */
41 #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
42 #define PMD_SIZE (1UL << PMD_SHIFT)
43 #define PMD_MASK (~(PMD_SIZE-1))
45 /* PGDIR_SHIFT determines what a third-level page table entry can map */
46 #define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
47 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
48 #define PGDIR_MASK (~(PGDIR_SIZE-1))
51 * For 4kB page size we use a 3 level page tree and an 8kB pud, which
52 * permits us mapping 40 bits of virtual address space.
54 * We used to implement 41 bits by having an order 1 pmd level but that seemed
55 * rather pointless.
57 * For 8kB page size we use a 3 level page tree which permits a total of
58 * 8TB of address space. Alternatively a 33-bit / 8GB organization using
59 * two levels would be easy to implement.
61 * For 16kB page size we use a 2 level page tree which permits a total of
62 * 36 bits of virtual address space. We could add a third level but it seems
63 * like at the moment there's no need for this.
65 * For 64kB page size we use a 2 level page table tree for a total of 42 bits
66 * of virtual address space.
68 #ifdef CONFIG_PAGE_SIZE_4KB
69 #define PGD_ORDER 1
70 #define PUD_ORDER aieeee_attempt_to_allocate_pud
71 #define PMD_ORDER 0
72 #define PTE_ORDER 0
73 #endif
74 #ifdef CONFIG_PAGE_SIZE_8KB
75 #define PGD_ORDER 0
76 #define PUD_ORDER aieeee_attempt_to_allocate_pud
77 #define PMD_ORDER 0
78 #define PTE_ORDER 0
79 #endif
80 #ifdef CONFIG_PAGE_SIZE_16KB
81 #define PGD_ORDER 0
82 #define PUD_ORDER aieeee_attempt_to_allocate_pud
83 #define PMD_ORDER 0
84 #define PTE_ORDER 0
85 #endif
86 #ifdef CONFIG_PAGE_SIZE_64KB
87 #define PGD_ORDER 0
88 #define PUD_ORDER aieeee_attempt_to_allocate_pud
89 #define PMD_ORDER 0
90 #define PTE_ORDER 0
91 #endif
93 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
94 #define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
95 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
97 #if PGDIR_SIZE >= TASK_SIZE
98 #define USER_PTRS_PER_PGD (1)
99 #else
100 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
101 #endif
102 #define FIRST_USER_ADDRESS 0UL
104 #define VMALLOC_START MAP_BASE
105 #define VMALLOC_END \
106 (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE)
107 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
108 VMALLOC_START != CKSSEG
109 /* Load modules into 32bit-compatible segment. */
110 #define MODULE_START CKSSEG
111 #define MODULE_END (FIXADDR_START-2*PAGE_SIZE)
112 extern pgd_t module_pg_dir[PTRS_PER_PGD];
113 #endif
115 #define pte_ERROR(e) \
116 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
117 #define pmd_ERROR(e) \
118 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
119 #define pgd_ERROR(e) \
120 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
122 extern pte_t invalid_pte_table[PTRS_PER_PTE];
123 extern pte_t empty_bad_page_table[PTRS_PER_PTE];
124 extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
125 extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
128 * Empty pgd/pmd entries point to the invalid_pte_table.
130 static inline int pmd_none(pmd_t pmd)
132 return pmd_val(pmd) == (unsigned long) invalid_pte_table;
135 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
137 static inline int pmd_present(pmd_t pmd)
139 return pmd_val(pmd) != (unsigned long) invalid_pte_table;
142 static inline void pmd_clear(pmd_t *pmdp)
144 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
148 * Empty pud entries point to the invalid_pmd_table.
150 static inline int pud_none(pud_t pud)
152 return pud_val(pud) == (unsigned long) invalid_pmd_table;
155 static inline int pud_bad(pud_t pud)
157 return pud_val(pud) & ~PAGE_MASK;
160 static inline int pud_present(pud_t pud)
162 return pud_val(pud) != (unsigned long) invalid_pmd_table;
165 static inline void pud_clear(pud_t *pudp)
167 pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
170 #define pte_page(x) pfn_to_page(pte_pfn(x))
172 #ifdef CONFIG_CPU_VR41XX
173 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
174 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
175 #else
176 #define pte_pfn(x) ((unsigned long)((x).pte >> PAGE_SHIFT))
177 #define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
178 #endif
180 #define __pgd_offset(address) pgd_index(address)
181 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
182 #define __pmd_offset(address) pmd_index(address)
184 /* to find an entry in a kernel page-table-directory */
185 #ifdef MODULE_START
186 #define pgd_offset_k(address) \
187 ((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL))
188 #else
189 #define pgd_offset_k(address) pgd_offset(&init_mm, 0UL)
190 #endif
192 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
193 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
195 /* to find an entry in a page-table-directory */
196 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
198 static inline unsigned long pud_page_vaddr(pud_t pud)
200 return pud_val(pud);
202 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud))
203 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
205 /* Find an entry in the second-level page table.. */
206 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
208 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
211 /* Find an entry in the third-level page table.. */
212 #define __pte_offset(address) \
213 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
214 #define pte_offset(dir, address) \
215 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
216 #define pte_offset_kernel(dir, address) \
217 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
218 #define pte_offset_map(dir, address) \
219 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
220 #define pte_offset_map_nested(dir, address) \
221 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
222 #define pte_unmap(pte) ((void)(pte))
223 #define pte_unmap_nested(pte) ((void)(pte))
226 * Initialize a new pgd / pmd table with invalid pointers.
228 extern void pgd_init(unsigned long page);
229 extern void pmd_init(unsigned long page, unsigned long pagetable);
232 * Non-present pages: high 24 bits are offset, next 8 bits type,
233 * low 32 bits zero.
235 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
236 { pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; }
238 #define __swp_type(x) (((x).val >> 32) & 0xff)
239 #define __swp_offset(x) ((x).val >> 40)
240 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
241 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
242 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
245 * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to
246 * make things easier, and only use the upper 56 bits for the page offset...
248 #define PTE_FILE_MAX_BITS 56
250 #define pte_to_pgoff(_pte) ((_pte).pte >> 8)
251 #define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE })
253 #endif /* _ASM_PGTABLE_64_H */