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/compiler.h> 13 #include <linux/linkage.h> 14 15 #include <asm/addrspace.h> 16 #include <asm/page.h> 17 #include <asm/cachectl.h> 18 #include <asm/fixmap.h> 19 20 #if CONFIG_PGTABLE_LEVELS == 2 21 #include <asm-generic/pgtable-nopmd.h> 22 #elif CONFIG_PGTABLE_LEVELS == 3 23 #include <asm-generic/pgtable-nopud.h> 24 #else 25 #include <asm-generic/pgtable-nop4d.h> 26 #endif 27 28 /* 29 * Each address space has 2 4K pages as its page directory, giving 1024 30 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a 31 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page 32 * tables. Each page table is also a single 4K page, giving 512 (== 33 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to 34 * invalid_pmd_table, each pmd entry is initialized to point to 35 * invalid_pte_table, each pte is initialized to 0. 36 * 37 * Kernel mappings: kernel mappings are held in the swapper_pg_table. 38 * The layout is identical to userspace except it's indexed with the 39 * fault address - VMALLOC_START. 40 */ 41 42 43 /* PGDIR_SHIFT determines what a third-level page table entry can map */ 44 #ifdef __PAGETABLE_PMD_FOLDED 45 #define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3) 46 #else 47 48 /* PMD_SHIFT determines the size of the area a second-level page table can map */ 49 #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3)) 50 #define PMD_SIZE (1UL << PMD_SHIFT) 51 #define PMD_MASK (~(PMD_SIZE-1)) 52 53 # ifdef __PAGETABLE_PUD_FOLDED 54 # define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3)) 55 # endif 56 #endif 57 58 #ifndef __PAGETABLE_PUD_FOLDED 59 #define PUD_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3)) 60 #define PUD_SIZE (1UL << PUD_SHIFT) 61 #define PUD_MASK (~(PUD_SIZE-1)) 62 #define PGDIR_SHIFT (PUD_SHIFT + (PAGE_SHIFT + PUD_TABLE_ORDER - 3)) 63 #endif 64 65 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 66 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 67 68 /* 69 * For 4kB page size we use a 3 level page tree and an 8kB pud, which 70 * permits us mapping 40 bits of virtual address space. 71 * 72 * We used to implement 41 bits by having an order 1 pmd level but that seemed 73 * rather pointless. 74 * 75 * For 8kB page size we use a 3 level page tree which permits a total of 76 * 8TB of address space. Alternatively a 33-bit / 8GB organization using 77 * two levels would be easy to implement. 78 * 79 * For 16kB page size we use a 2 level page tree which permits a total of 80 * 36 bits of virtual address space. We could add a third level but it seems 81 * like at the moment there's no need for this. 82 * 83 * For 64kB page size we use a 2 level page table tree for a total of 42 bits 84 * of virtual address space. 85 */ 86 #ifdef CONFIG_PAGE_SIZE_4KB 87 # ifdef CONFIG_MIPS_VA_BITS_48 88 # define PGD_TABLE_ORDER 0 89 # define PUD_TABLE_ORDER 0 90 # else 91 # define PGD_TABLE_ORDER 1 92 # define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud 93 # endif 94 #define PMD_TABLE_ORDER 0 95 #endif 96 #ifdef CONFIG_PAGE_SIZE_8KB 97 #define PGD_TABLE_ORDER 0 98 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud 99 #define PMD_TABLE_ORDER 0 100 #endif 101 #ifdef CONFIG_PAGE_SIZE_16KB 102 #ifdef CONFIG_MIPS_VA_BITS_48 103 #define PGD_TABLE_ORDER 1 104 #else 105 #define PGD_TABLE_ORDER 0 106 #endif 107 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud 108 #define PMD_TABLE_ORDER 0 109 #endif 110 #ifdef CONFIG_PAGE_SIZE_32KB 111 #define PGD_TABLE_ORDER 0 112 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud 113 #define PMD_TABLE_ORDER 0 114 #endif 115 #ifdef CONFIG_PAGE_SIZE_64KB 116 #define PGD_TABLE_ORDER 0 117 #define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud 118 #ifdef CONFIG_MIPS_VA_BITS_48 119 #define PMD_TABLE_ORDER 0 120 #else 121 #define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd 122 #endif 123 #endif 124 125 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_TABLE_ORDER) / sizeof(pgd_t)) 126 #ifndef __PAGETABLE_PUD_FOLDED 127 #define PTRS_PER_PUD ((PAGE_SIZE << PUD_TABLE_ORDER) / sizeof(pud_t)) 128 #endif 129 #ifndef __PAGETABLE_PMD_FOLDED 130 #define PTRS_PER_PMD ((PAGE_SIZE << PMD_TABLE_ORDER) / sizeof(pmd_t)) 131 #endif 132 #define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t)) 133 134 #define USER_PTRS_PER_PGD ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1) 135 136 /* 137 * TLB refill handlers also map the vmalloc area into xuseg. Avoid 138 * the first couple of pages so NULL pointer dereferences will still 139 * reliably trap. 140 */ 141 #define VMALLOC_START (MAP_BASE + (2 * PAGE_SIZE)) 142 #define VMALLOC_END \ 143 (MAP_BASE + \ 144 min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \ 145 (1UL << cpu_vmbits)) - (1UL << 32)) 146 147 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \ 148 VMALLOC_START != CKSSEG 149 /* Load modules into 32bit-compatible segment. */ 150 #define MODULES_VADDR CKSSEG 151 #define MODULES_END (FIXADDR_START-2*PAGE_SIZE) 152 #endif 153 154 extern pte_t invalid_pte_table[PTRS_PER_PTE]; 155 156 #ifndef __PAGETABLE_PUD_FOLDED 157 /* 158 * For 4-level pagetables we defines these ourselves, for 3-level the 159 * definitions are below, for 2-level the 160 * definitions are supplied by <asm-generic/pgtable-nopmd.h>. 161 */ 162 typedef struct { unsigned long pud; } pud_t; 163 #define pud_val(x) ((x).pud) 164 #define __pud(x) ((pud_t) { (x) }) 165 166 extern pud_t invalid_pud_table[PTRS_PER_PUD]; 167 168 /* 169 * Empty pgd entries point to the invalid_pud_table. 170 */ 171 static inline int p4d_none(p4d_t p4d) 172 { 173 return p4d_val(p4d) == (unsigned long)invalid_pud_table; 174 } 175 176 static inline int p4d_bad(p4d_t p4d) 177 { 178 if (unlikely(p4d_val(p4d) & ~PAGE_MASK)) 179 return 1; 180 181 return 0; 182 } 183 184 static inline int p4d_present(p4d_t p4d) 185 { 186 return p4d_val(p4d) != (unsigned long)invalid_pud_table; 187 } 188 189 static inline void p4d_clear(p4d_t *p4dp) 190 { 191 p4d_val(*p4dp) = (unsigned long)invalid_pud_table; 192 } 193 194 static inline pud_t *p4d_pgtable(p4d_t p4d) 195 { 196 return (pud_t *)p4d_val(p4d); 197 } 198 199 #define p4d_phys(p4d) virt_to_phys((void *)p4d_val(p4d)) 200 #define p4d_page(p4d) (pfn_to_page(p4d_phys(p4d) >> PAGE_SHIFT)) 201 202 #define p4d_index(address) (((address) >> P4D_SHIFT) & (PTRS_PER_P4D - 1)) 203 204 static inline void set_p4d(p4d_t *p4d, p4d_t p4dval) 205 { 206 *p4d = p4dval; 207 } 208 209 #endif 210 211 #ifndef __PAGETABLE_PMD_FOLDED 212 /* 213 * For 3-level pagetables we defines these ourselves, for 2-level the 214 * definitions are supplied by <asm-generic/pgtable-nopmd.h>. 215 */ 216 typedef struct { unsigned long pmd; } pmd_t; 217 #define pmd_val(x) ((x).pmd) 218 #define __pmd(x) ((pmd_t) { (x) } ) 219 220 221 extern pmd_t invalid_pmd_table[PTRS_PER_PMD]; 222 #endif 223 224 /* 225 * Empty pgd/pmd entries point to the invalid_pte_table. 226 */ 227 static inline int pmd_none(pmd_t pmd) 228 { 229 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 230 } 231 232 static inline int pmd_bad(pmd_t pmd) 233 { 234 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 235 /* pmd_leaf(pmd) but inline */ 236 if (unlikely(pmd_val(pmd) & _PAGE_HUGE)) 237 return 0; 238 #endif 239 240 if (unlikely(pmd_val(pmd) & ~PAGE_MASK)) 241 return 1; 242 243 return 0; 244 } 245 246 static inline int pmd_present(pmd_t pmd) 247 { 248 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 249 if (unlikely(pmd_val(pmd) & _PAGE_HUGE)) 250 return pmd_val(pmd) & _PAGE_PRESENT; 251 #endif 252 253 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 254 } 255 256 static inline void pmd_clear(pmd_t *pmdp) 257 { 258 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 259 } 260 #ifndef __PAGETABLE_PMD_FOLDED 261 262 /* 263 * Empty pud entries point to the invalid_pmd_table. 264 */ 265 static inline int pud_none(pud_t pud) 266 { 267 return pud_val(pud) == (unsigned long) invalid_pmd_table; 268 } 269 270 static inline int pud_bad(pud_t pud) 271 { 272 return pud_val(pud) & ~PAGE_MASK; 273 } 274 275 static inline int pud_present(pud_t pud) 276 { 277 return pud_val(pud) != (unsigned long) invalid_pmd_table; 278 } 279 280 static inline void pud_clear(pud_t *pudp) 281 { 282 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 283 } 284 #endif 285 286 #define pte_page(x) pfn_to_page(pte_pfn(x)) 287 288 #define pte_pfn(x) ((unsigned long)((x).pte >> PFN_PTE_SHIFT)) 289 #define pfn_pte(pfn, prot) __pte(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot)) 290 #define pfn_pmd(pfn, prot) __pmd(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot)) 291 292 #ifndef __PAGETABLE_PMD_FOLDED 293 static inline pmd_t *pud_pgtable(pud_t pud) 294 { 295 return (pmd_t *)pud_val(pud); 296 } 297 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) 298 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) 299 300 #endif 301 302 /* 303 * Initialize a new pgd / pud / pmd table with invalid pointers. 304 */ 305 extern void pgd_init(void *addr); 306 extern void pud_init(void *addr); 307 #define pud_init pud_init 308 extern void pmd_init(void *addr); 309 #define pmd_init pmd_init 310 311 /* 312 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that 313 * are !pte_none() && !pte_present(). 314 * 315 * Format of swap PTEs: 316 * 317 * 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3 318 * 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 319 * <--------------------------- offset --------------------------- 320 * 321 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 322 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 323 * --------------> E <-- type ---> <---------- zeroes -----------> 324 * 325 * E is the exclusive marker that is not stored in swap entries. 326 */ 327 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 328 { pte_t pte; pte_val(pte) = ((type & 0x7f) << 16) | (offset << 24); return pte; } 329 330 #define __swp_type(x) (((x).val >> 16) & 0x7f) 331 #define __swp_offset(x) ((x).val >> 24) 332 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) }) 333 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 334 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 335 336 /* We borrow bit 23 to store the exclusive marker in swap PTEs. */ 337 #define _PAGE_SWP_EXCLUSIVE (1 << 23) 338 339 #endif /* _ASM_PGTABLE_64_H */ 340