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 #ifdef CONFIG_PAGE_SIZE_64KB 20 #include <asm-generic/pgtable-nopmd.h> 21 #else 22 #include <asm-generic/pgtable-nopud.h> 23 #endif 24 25 /* 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. 38 * 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. 42 */ 43 44 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) 48 #else 49 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)) 54 55 56 #define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) 57 #endif 58 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 59 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 60 61 /* 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. 64 * 65 * We used to implement 41 bits by having an order 1 pmd level but that seemed 66 * rather pointless. 67 * 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. 71 * 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. 75 * 76 * For 64kB page size we use a 2 level page table tree for a total of 42 bits 77 * of virtual address space. 78 */ 79 #ifdef CONFIG_PAGE_SIZE_4KB 80 #define PGD_ORDER 1 81 #define PUD_ORDER aieeee_attempt_to_allocate_pud 82 #define PMD_ORDER 0 83 #define PTE_ORDER 0 84 #endif 85 #ifdef CONFIG_PAGE_SIZE_8KB 86 #define PGD_ORDER 0 87 #define PUD_ORDER aieeee_attempt_to_allocate_pud 88 #define PMD_ORDER 0 89 #define PTE_ORDER 0 90 #endif 91 #ifdef CONFIG_PAGE_SIZE_16KB 92 #define PGD_ORDER 0 93 #define PUD_ORDER aieeee_attempt_to_allocate_pud 94 #define PMD_ORDER 0 95 #define PTE_ORDER 0 96 #endif 97 #ifdef CONFIG_PAGE_SIZE_32KB 98 #define PGD_ORDER 0 99 #define PUD_ORDER aieeee_attempt_to_allocate_pud 100 #define PMD_ORDER 0 101 #define PTE_ORDER 0 102 #endif 103 #ifdef CONFIG_PAGE_SIZE_64KB 104 #define PGD_ORDER 0 105 #define PUD_ORDER aieeee_attempt_to_allocate_pud 106 #define PMD_ORDER aieeee_attempt_to_allocate_pmd 107 #define PTE_ORDER 0 108 #endif 109 110 #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)) 113 #endif 114 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) 115 116 #if PGDIR_SIZE >= TASK_SIZE64 117 #define USER_PTRS_PER_PGD (1) 118 #else 119 #define USER_PTRS_PER_PGD (TASK_SIZE64 / PGDIR_SIZE) 120 #endif 121 #define FIRST_USER_ADDRESS 0UL 122 123 /* 124 * TLB refill handlers also map the vmalloc area into xuseg. Avoid 125 * the first couple of pages so NULL pointer dereferences will still 126 * reliably trap. 127 */ 128 #define VMALLOC_START (MAP_BASE + (2 * PAGE_SIZE)) 129 #define VMALLOC_END \ 130 (MAP_BASE + \ 131 min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \ 132 (1UL << cpu_vmbits)) - (1UL << 32)) 133 134 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \ 135 VMALLOC_START != CKSSEG 136 /* Load modules into 32bit-compatible segment. */ 137 #define MODULE_START CKSSEG 138 #define MODULE_END (FIXADDR_START-2*PAGE_SIZE) 139 #endif 140 141 #define pte_ERROR(e) \ 142 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 143 #ifndef __PAGETABLE_PMD_FOLDED 144 #define pmd_ERROR(e) \ 145 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 146 #endif 147 #define pgd_ERROR(e) \ 148 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 149 150 extern pte_t invalid_pte_table[PTRS_PER_PTE]; 151 extern pte_t empty_bad_page_table[PTRS_PER_PTE]; 152 153 154 #ifndef __PAGETABLE_PMD_FOLDED 155 /* 156 * For 3-level pagetables we defines these ourselves, for 2-level the 157 * definitions are supplied by <asm-generic/pgtable-nopmd.h>. 158 */ 159 typedef struct { unsigned long pmd; } pmd_t; 160 #define pmd_val(x) ((x).pmd) 161 #define __pmd(x) ((pmd_t) { (x) } ) 162 163 164 extern pmd_t invalid_pmd_table[PTRS_PER_PMD]; 165 extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD]; 166 #endif 167 168 /* 169 * Empty pgd/pmd entries point to the invalid_pte_table. 170 */ 171 static inline int pmd_none(pmd_t pmd) 172 { 173 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 174 } 175 176 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) 177 178 static inline int pmd_present(pmd_t pmd) 179 { 180 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 181 } 182 183 static inline void pmd_clear(pmd_t *pmdp) 184 { 185 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 186 } 187 #ifndef __PAGETABLE_PMD_FOLDED 188 189 /* 190 * Empty pud entries point to the invalid_pmd_table. 191 */ 192 static inline int pud_none(pud_t pud) 193 { 194 return pud_val(pud) == (unsigned long) invalid_pmd_table; 195 } 196 197 static inline int pud_bad(pud_t pud) 198 { 199 return pud_val(pud) & ~PAGE_MASK; 200 } 201 202 static inline int pud_present(pud_t pud) 203 { 204 return pud_val(pud) != (unsigned long) invalid_pmd_table; 205 } 206 207 static inline void pud_clear(pud_t *pudp) 208 { 209 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 210 } 211 #endif 212 213 #define pte_page(x) pfn_to_page(pte_pfn(x)) 214 215 #ifdef CONFIG_CPU_VR41XX 216 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) 217 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) 218 #else 219 #define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT)) 220 #define pfn_pte(pfn, prot) __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot)) 221 #endif 222 223 #define __pgd_offset(address) pgd_index(address) 224 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) 225 #define __pmd_offset(address) pmd_index(address) 226 227 /* to find an entry in a kernel page-table-directory */ 228 #define pgd_offset_k(address) pgd_offset(&init_mm, address) 229 230 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 231 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 232 233 /* to find an entry in a page-table-directory */ 234 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 235 236 #ifndef __PAGETABLE_PMD_FOLDED 237 static inline unsigned long pud_page_vaddr(pud_t pud) 238 { 239 return pud_val(pud); 240 } 241 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) 242 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) 243 244 /* Find an entry in the second-level page table.. */ 245 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) 246 { 247 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); 248 } 249 #endif 250 251 /* Find an entry in the third-level page table.. */ 252 #define __pte_offset(address) \ 253 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 254 #define pte_offset(dir, address) \ 255 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 256 #define pte_offset_kernel(dir, address) \ 257 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 258 #define pte_offset_map(dir, address) \ 259 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 260 #define pte_unmap(pte) ((void)(pte)) 261 262 /* 263 * Initialize a new pgd / pmd table with invalid pointers. 264 */ 265 extern void pgd_init(unsigned long page); 266 extern void pmd_init(unsigned long page, unsigned long pagetable); 267 268 /* 269 * Non-present pages: high 24 bits are offset, next 8 bits type, 270 * low 32 bits zero. 271 */ 272 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 273 { pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } 274 275 #define __swp_type(x) (((x).val >> 32) & 0xff) 276 #define __swp_offset(x) ((x).val >> 40) 277 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) }) 278 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 279 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 280 281 /* 282 * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to 283 * make things easier, and only use the upper 56 bits for the page offset... 284 */ 285 #define PTE_FILE_MAX_BITS 56 286 287 #define pte_to_pgoff(_pte) ((_pte).pte >> 8) 288 #define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE }) 289 290 #endif /* _ASM_PGTABLE_64_H */ 291