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 #ifdef CONFIG_PAGE_SIZE_64KB 21 #include <asm-generic/pgtable-nopmd.h> 22 #else 23 #include <asm-generic/pgtable-nopud.h> 24 #endif 25 26 /* 27 * Each address space has 2 4K pages as its page directory, giving 1024 28 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a 29 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page 30 * tables. Each page table is also a single 4K page, giving 512 (== 31 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to 32 * invalid_pmd_table, each pmd entry is initialized to point to 33 * invalid_pte_table, each pte is initialized to 0. When memory is low, 34 * and a pmd table or a page table allocation fails, empty_bad_pmd_table 35 * and empty_bad_page_table is returned back to higher layer code, so 36 * that the failure is recognized later on. Linux does not seem to 37 * handle these failures very well though. The empty_bad_page_table has 38 * invalid pte entries in it, to force page faults. 39 * 40 * Kernel mappings: kernel mappings are held in the swapper_pg_table. 41 * The layout is identical to userspace except it's indexed with the 42 * fault address - VMALLOC_START. 43 */ 44 45 46 /* PGDIR_SHIFT determines what a third-level page table entry can map */ 47 #ifdef __PAGETABLE_PMD_FOLDED 48 #define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3) 49 #else 50 51 /* PMD_SHIFT determines the size of the area a second-level page table can map */ 52 #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3)) 53 #define PMD_SIZE (1UL << PMD_SHIFT) 54 #define PMD_MASK (~(PMD_SIZE-1)) 55 56 57 #define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) 58 #endif 59 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 60 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 61 62 /* 63 * For 4kB page size we use a 3 level page tree and an 8kB pud, which 64 * permits us mapping 40 bits of virtual address space. 65 * 66 * We used to implement 41 bits by having an order 1 pmd level but that seemed 67 * rather pointless. 68 * 69 * For 8kB page size we use a 3 level page tree which permits a total of 70 * 8TB of address space. Alternatively a 33-bit / 8GB organization using 71 * two levels would be easy to implement. 72 * 73 * For 16kB page size we use a 2 level page tree which permits a total of 74 * 36 bits of virtual address space. We could add a third level but it seems 75 * like at the moment there's no need for this. 76 * 77 * For 64kB page size we use a 2 level page table tree for a total of 42 bits 78 * of virtual address space. 79 */ 80 #ifdef CONFIG_PAGE_SIZE_4KB 81 #define PGD_ORDER 1 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_8KB 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 #ifdef CONFIG_PAGE_SIZE_16KB 93 #define PGD_ORDER 0 94 #define PUD_ORDER aieeee_attempt_to_allocate_pud 95 #define PMD_ORDER 0 96 #define PTE_ORDER 0 97 #endif 98 #ifdef CONFIG_PAGE_SIZE_32KB 99 #define PGD_ORDER 0 100 #define PUD_ORDER aieeee_attempt_to_allocate_pud 101 #define PMD_ORDER 0 102 #define PTE_ORDER 0 103 #endif 104 #ifdef CONFIG_PAGE_SIZE_64KB 105 #define PGD_ORDER 0 106 #define PUD_ORDER aieeee_attempt_to_allocate_pud 107 #define PMD_ORDER aieeee_attempt_to_allocate_pmd 108 #define PTE_ORDER 0 109 #endif 110 111 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t)) 112 #ifndef __PAGETABLE_PMD_FOLDED 113 #define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t)) 114 #endif 115 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) 116 117 #if PGDIR_SIZE >= TASK_SIZE64 118 #define USER_PTRS_PER_PGD (1) 119 #else 120 #define USER_PTRS_PER_PGD (TASK_SIZE64 / PGDIR_SIZE) 121 #endif 122 #define FIRST_USER_ADDRESS 0UL 123 124 /* 125 * TLB refill handlers also map the vmalloc area into xuseg. Avoid 126 * the first couple of pages so NULL pointer dereferences will still 127 * reliably trap. 128 */ 129 #define VMALLOC_START (MAP_BASE + (2 * PAGE_SIZE)) 130 #define VMALLOC_END \ 131 (MAP_BASE + \ 132 min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \ 133 (1UL << cpu_vmbits)) - (1UL << 32)) 134 135 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \ 136 VMALLOC_START != CKSSEG 137 /* Load modules into 32bit-compatible segment. */ 138 #define MODULE_START CKSSEG 139 #define MODULE_END (FIXADDR_START-2*PAGE_SIZE) 140 #endif 141 142 #define pte_ERROR(e) \ 143 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 144 #ifndef __PAGETABLE_PMD_FOLDED 145 #define pmd_ERROR(e) \ 146 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 147 #endif 148 #define pgd_ERROR(e) \ 149 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 150 151 extern pte_t invalid_pte_table[PTRS_PER_PTE]; 152 extern pte_t empty_bad_page_table[PTRS_PER_PTE]; 153 154 155 #ifndef __PAGETABLE_PMD_FOLDED 156 /* 157 * For 3-level pagetables we defines these ourselves, for 2-level the 158 * definitions are supplied by <asm-generic/pgtable-nopmd.h>. 159 */ 160 typedef struct { unsigned long pmd; } pmd_t; 161 #define pmd_val(x) ((x).pmd) 162 #define __pmd(x) ((pmd_t) { (x) } ) 163 164 165 extern pmd_t invalid_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 static inline int pmd_bad(pmd_t pmd) 177 { 178 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 179 /* pmd_huge(pmd) but inline */ 180 if (unlikely(pmd_val(pmd) & _PAGE_HUGE)) 181 return 0; 182 #endif 183 184 if (unlikely(pmd_val(pmd) & ~PAGE_MASK)) 185 return 1; 186 187 return 0; 188 } 189 190 static inline int pmd_present(pmd_t pmd) 191 { 192 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 193 } 194 195 static inline void pmd_clear(pmd_t *pmdp) 196 { 197 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 198 } 199 #ifndef __PAGETABLE_PMD_FOLDED 200 201 /* 202 * Empty pud entries point to the invalid_pmd_table. 203 */ 204 static inline int pud_none(pud_t pud) 205 { 206 return pud_val(pud) == (unsigned long) invalid_pmd_table; 207 } 208 209 static inline int pud_bad(pud_t pud) 210 { 211 return pud_val(pud) & ~PAGE_MASK; 212 } 213 214 static inline int pud_present(pud_t pud) 215 { 216 return pud_val(pud) != (unsigned long) invalid_pmd_table; 217 } 218 219 static inline void pud_clear(pud_t *pudp) 220 { 221 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 222 } 223 #endif 224 225 #define pte_page(x) pfn_to_page(pte_pfn(x)) 226 227 #ifdef CONFIG_CPU_VR41XX 228 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) 229 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) 230 #else 231 #define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT)) 232 #define pfn_pte(pfn, prot) __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot)) 233 #define pfn_pmd(pfn, prot) __pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot)) 234 #endif 235 236 #define __pgd_offset(address) pgd_index(address) 237 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) 238 #define __pmd_offset(address) pmd_index(address) 239 240 /* to find an entry in a kernel page-table-directory */ 241 #define pgd_offset_k(address) pgd_offset(&init_mm, address) 242 243 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 244 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 245 246 /* to find an entry in a page-table-directory */ 247 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 248 249 #ifndef __PAGETABLE_PMD_FOLDED 250 static inline unsigned long pud_page_vaddr(pud_t pud) 251 { 252 return pud_val(pud); 253 } 254 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) 255 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) 256 257 /* Find an entry in the second-level page table.. */ 258 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) 259 { 260 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); 261 } 262 #endif 263 264 /* Find an entry in the third-level page table.. */ 265 #define __pte_offset(address) \ 266 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 267 #define pte_offset(dir, address) \ 268 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 269 #define pte_offset_kernel(dir, address) \ 270 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 271 #define pte_offset_map(dir, address) \ 272 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 273 #define pte_unmap(pte) ((void)(pte)) 274 275 /* 276 * Initialize a new pgd / pmd table with invalid pointers. 277 */ 278 extern void pgd_init(unsigned long page); 279 extern void pmd_init(unsigned long page, unsigned long pagetable); 280 281 /* 282 * Non-present pages: high 40 bits are offset, next 8 bits type, 283 * low 16 bits zero. 284 */ 285 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 286 { pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; } 287 288 #define __swp_type(x) (((x).val >> 16) & 0xff) 289 #define __swp_offset(x) ((x).val >> 24) 290 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) }) 291 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 292 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 293 294 #endif /* _ASM_PGTABLE_64_H */ 295