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
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
9 #ifndef _ASM_PGTABLE_64_H
10 #define _ASM_PGTABLE_64_H
12 #include <linux/linkage.h>
14 #include <asm/addrspace.h>
16 #include <asm/cachectl.h>
17 #include <asm/fixmap.h>
19 #ifdef CONFIG_PAGE_SIZE_64KB
20 #include <asm-generic/pgtable-nopmd.h>
22 #include <asm-generic/pgtable-nopud.h>
26 * Each address space has 2 4K pages as its page directory, giving 1024
27 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
28 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
29 * tables. Each page table is also a single 4K page, giving 512 (==
30 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
31 * invalid_pmd_table, each pmd entry is initialized to point to
32 * invalid_pte_table, each pte is initialized to 0. When memory is low,
33 * and a pmd table or a page table allocation fails, empty_bad_pmd_table
34 * and empty_bad_page_table is returned back to higher layer code, so
35 * that the failure is recognized later on. Linux does not seem to
36 * handle these failures very well though. The empty_bad_page_table has
37 * invalid pte entries in it, to force page faults.
39 * Kernel mappings: kernel mappings are held in the swapper_pg_table.
40 * The layout is identical to userspace except it's indexed with the
41 * fault address - VMALLOC_START.
45 /* PGDIR_SHIFT determines what a third-level page table entry can map */
46 #ifdef __PAGETABLE_PMD_FOLDED
47 #define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3)
50 /* PMD_SHIFT determines the size of the area a second-level page table can map */
51 #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
52 #define PMD_SIZE (1UL << PMD_SHIFT)
53 #define PMD_MASK (~(PMD_SIZE-1))
56 #define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
58 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
59 #define PGDIR_MASK (~(PGDIR_SIZE-1))
62 * For 4kB page size we use a 3 level page tree and an 8kB pud, which
63 * permits us mapping 40 bits of virtual address space.
65 * We used to implement 41 bits by having an order 1 pmd level but that seemed
68 * For 8kB page size we use a 3 level page tree which permits a total of
69 * 8TB of address space. Alternatively a 33-bit / 8GB organization using
70 * two levels would be easy to implement.
72 * For 16kB page size we use a 2 level page tree which permits a total of
73 * 36 bits of virtual address space. We could add a third level but it seems
74 * like at the moment there's no need for this.
76 * For 64kB page size we use a 2 level page table tree for a total of 42 bits
77 * of virtual address space.
79 #ifdef CONFIG_PAGE_SIZE_4KB
81 #define PUD_ORDER aieeee_attempt_to_allocate_pud
85 #ifdef CONFIG_PAGE_SIZE_8KB
87 #define PUD_ORDER aieeee_attempt_to_allocate_pud
91 #ifdef CONFIG_PAGE_SIZE_16KB
93 #define PUD_ORDER aieeee_attempt_to_allocate_pud
97 #ifdef CONFIG_PAGE_SIZE_32KB
99 #define PUD_ORDER aieeee_attempt_to_allocate_pud
103 #ifdef CONFIG_PAGE_SIZE_64KB
105 #define PUD_ORDER aieeee_attempt_to_allocate_pud
106 #define PMD_ORDER aieeee_attempt_to_allocate_pmd
110 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
111 #ifndef __PAGETABLE_PMD_FOLDED
112 #define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
114 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
116 #if PGDIR_SIZE >= TASK_SIZE
117 #define USER_PTRS_PER_PGD (1)
119 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
121 #define FIRST_USER_ADDRESS 0UL
123 #define VMALLOC_START MAP_BASE
124 #define VMALLOC_END \
126 min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \
127 (1UL << cpu_vmbits)) - (1UL << 32))
129 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
130 VMALLOC_START != CKSSEG
131 /* Load modules into 32bit-compatible segment. */
132 #define MODULE_START CKSSEG
133 #define MODULE_END (FIXADDR_START-2*PAGE_SIZE)
136 #define pte_ERROR(e) \
137 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
138 #ifndef __PAGETABLE_PMD_FOLDED
139 #define pmd_ERROR(e) \
140 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
142 #define pgd_ERROR(e) \
143 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
145 extern pte_t invalid_pte_table[PTRS_PER_PTE];
146 extern pte_t empty_bad_page_table[PTRS_PER_PTE];
149 #ifndef __PAGETABLE_PMD_FOLDED
151 * For 3-level pagetables we defines these ourselves, for 2-level the
152 * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
154 typedef struct { unsigned long pmd; } pmd_t;
155 #define pmd_val(x) ((x).pmd)
156 #define __pmd(x) ((pmd_t) { (x) } )
159 extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
160 extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD];
164 * Empty pgd/pmd entries point to the invalid_pte_table.
166 static inline int pmd_none(pmd_t pmd)
168 return pmd_val(pmd) == (unsigned long) invalid_pte_table;
171 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
173 static inline int pmd_present(pmd_t pmd)
175 return pmd_val(pmd) != (unsigned long) invalid_pte_table;
178 static inline void pmd_clear(pmd_t *pmdp)
180 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
182 #ifndef __PAGETABLE_PMD_FOLDED
185 * Empty pud entries point to the invalid_pmd_table.
187 static inline int pud_none(pud_t pud)
189 return pud_val(pud) == (unsigned long) invalid_pmd_table;
192 static inline int pud_bad(pud_t pud)
194 return pud_val(pud) & ~PAGE_MASK;
197 static inline int pud_present(pud_t pud)
199 return pud_val(pud) != (unsigned long) invalid_pmd_table;
202 static inline void pud_clear(pud_t *pudp)
204 pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
208 #define pte_page(x) pfn_to_page(pte_pfn(x))
210 #ifdef CONFIG_CPU_VR41XX
211 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
212 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
214 #define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT))
215 #define pfn_pte(pfn, prot) __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
218 #define __pgd_offset(address) pgd_index(address)
219 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
220 #define __pmd_offset(address) pmd_index(address)
222 /* to find an entry in a kernel page-table-directory */
223 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
225 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
226 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
228 /* to find an entry in a page-table-directory */
229 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
231 #ifndef __PAGETABLE_PMD_FOLDED
232 static inline unsigned long pud_page_vaddr(pud_t pud)
236 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud))
237 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
239 /* Find an entry in the second-level page table.. */
240 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
242 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
246 /* Find an entry in the third-level page table.. */
247 #define __pte_offset(address) \
248 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
249 #define pte_offset(dir, address) \
250 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
251 #define pte_offset_kernel(dir, address) \
252 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
253 #define pte_offset_map(dir, address) \
254 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
255 #define pte_offset_map_nested(dir, address) \
256 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
257 #define pte_unmap(pte) ((void)(pte))
258 #define pte_unmap_nested(pte) ((void)(pte))
261 * Initialize a new pgd / pmd table with invalid pointers.
263 extern void pgd_init(unsigned long page);
264 extern void pmd_init(unsigned long page, unsigned long pagetable);
267 * Non-present pages: high 24 bits are offset, next 8 bits type,
270 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
271 { pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; }
273 #define __swp_type(x) (((x).val >> 32) & 0xff)
274 #define __swp_offset(x) ((x).val >> 40)
275 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
276 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
277 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
280 * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to
281 * make things easier, and only use the upper 56 bits for the page offset...
283 #define PTE_FILE_MAX_BITS 56
285 #define pte_to_pgoff(_pte) ((_pte).pte >> 8)
286 #define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE })
288 #endif /* _ASM_PGTABLE_64_H */