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. 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 12 #include <linux/linkage.h> 13 14 #include <asm/addrspace.h> 15 #include <asm/page.h> 16 #include <asm/cachectl.h> 17 #include <asm/fixmap.h> 18 19 #include <asm-generic/pgtable-nopud.h> 20 21 /* 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. 34 * 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. 38 */ 39 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)) 44 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)) 49 50 /* 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. 53 * 54 * We used to implement 41 bits by having an order 1 pmd level but that seemed 55 * rather pointless. 56 * 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. 60 * 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. 64 * 65 * For 64kB page size we use a 2 level page table tree for a total of 42 bits 66 * of virtual address space. 67 */ 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 92 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)) 96 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 103 104 #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 114 115 #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)) 121 122 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]; 126 127 /* 128 * Empty pgd/pmd entries point to the invalid_pte_table. 129 */ 130 static inline int pmd_none(pmd_t pmd) 131 { 132 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 133 } 134 135 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) 136 137 static inline int pmd_present(pmd_t pmd) 138 { 139 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 140 } 141 142 static inline void pmd_clear(pmd_t *pmdp) 143 { 144 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 145 } 146 147 /* 148 * Empty pud entries point to the invalid_pmd_table. 149 */ 150 static inline int pud_none(pud_t pud) 151 { 152 return pud_val(pud) == (unsigned long) invalid_pmd_table; 153 } 154 155 static inline int pud_bad(pud_t pud) 156 { 157 return pud_val(pud) & ~PAGE_MASK; 158 } 159 160 static inline int pud_present(pud_t pud) 161 { 162 return pud_val(pud) != (unsigned long) invalid_pmd_table; 163 } 164 165 static inline void pud_clear(pud_t *pudp) 166 { 167 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 168 } 169 170 #define pte_page(x) pfn_to_page(pte_pfn(x)) 171 172 #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 179 180 #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) 183 184 /* 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 191 192 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 193 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 194 195 /* to find an entry in a page-table-directory */ 196 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 197 198 static inline unsigned long pud_page_vaddr(pud_t pud) 199 { 200 return pud_val(pud); 201 } 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)) 204 205 /* Find an entry in the second-level page table.. */ 206 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) 207 { 208 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); 209 } 210 211 /* 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)) 224 225 /* 226 * Initialize a new pgd / pmd table with invalid pointers. 227 */ 228 extern void pgd_init(unsigned long page); 229 extern void pmd_init(unsigned long page, unsigned long pagetable); 230 231 /* 232 * Non-present pages: high 24 bits are offset, next 8 bits type, 233 * low 32 bits zero. 234 */ 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; } 237 238 #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 }) 243 244 /* 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... 247 */ 248 #define PTE_FILE_MAX_BITS 56 249 250 #define pte_to_pgoff(_pte) ((_pte).pte >> 8) 251 #define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE }) 252 253 #endif /* _ASM_PGTABLE_64_H */ 254