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 #define __ARCH_USE_5LEVEL_HACK 21 #if defined(CONFIG_PAGE_SIZE_64KB) && !defined(CONFIG_MIPS_VA_BITS_48) 22 #include <asm-generic/pgtable-nopmd.h> 23 #else 24 #include <asm-generic/pgtable-nopud.h> 25 #endif 26 27 /* 28 * Each address space has 2 4K pages as its page directory, giving 1024 29 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a 30 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page 31 * tables. Each page table is also a single 4K page, giving 512 (== 32 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to 33 * invalid_pmd_table, each pmd entry is initialized to point to 34 * invalid_pte_table, each pte is initialized to 0. When memory is low, 35 * and a pmd table or a page table allocation fails, empty_bad_pmd_table 36 * and empty_bad_page_table is returned back to higher layer code, so 37 * that the failure is recognized later on. Linux does not seem to 38 * handle these failures very well though. The empty_bad_page_table has 39 * invalid pte entries in it, to force page faults. 40 * 41 * Kernel mappings: kernel mappings are held in the swapper_pg_table. 42 * The layout is identical to userspace except it's indexed with the 43 * fault address - VMALLOC_START. 44 */ 45 46 47 /* PGDIR_SHIFT determines what a third-level page table entry can map */ 48 #ifdef __PAGETABLE_PMD_FOLDED 49 #define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3) 50 #else 51 52 /* PMD_SHIFT determines the size of the area a second-level page table can map */ 53 #define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3)) 54 #define PMD_SIZE (1UL << PMD_SHIFT) 55 #define PMD_MASK (~(PMD_SIZE-1)) 56 57 58 #define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) 59 #endif 60 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 61 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 62 63 /* 64 * For 4kB page size we use a 3 level page tree and an 8kB pud, which 65 * permits us mapping 40 bits of virtual address space. 66 * 67 * We used to implement 41 bits by having an order 1 pmd level but that seemed 68 * rather pointless. 69 * 70 * For 8kB page size we use a 3 level page tree which permits a total of 71 * 8TB of address space. Alternatively a 33-bit / 8GB organization using 72 * two levels would be easy to implement. 73 * 74 * For 16kB page size we use a 2 level page tree which permits a total of 75 * 36 bits of virtual address space. We could add a third level but it seems 76 * like at the moment there's no need for this. 77 * 78 * For 64kB page size we use a 2 level page table tree for a total of 42 bits 79 * of virtual address space. 80 */ 81 #ifdef CONFIG_PAGE_SIZE_4KB 82 #define PGD_ORDER 1 83 #define PUD_ORDER aieeee_attempt_to_allocate_pud 84 #define PMD_ORDER 0 85 #define PTE_ORDER 0 86 #endif 87 #ifdef CONFIG_PAGE_SIZE_8KB 88 #define PGD_ORDER 0 89 #define PUD_ORDER aieeee_attempt_to_allocate_pud 90 #define PMD_ORDER 0 91 #define PTE_ORDER 0 92 #endif 93 #ifdef CONFIG_PAGE_SIZE_16KB 94 #ifdef CONFIG_MIPS_VA_BITS_48 95 #define PGD_ORDER 1 96 #else 97 #define PGD_ORDER 0 98 #endif 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_32KB 104 #define PGD_ORDER 0 105 #define PUD_ORDER aieeee_attempt_to_allocate_pud 106 #define PMD_ORDER 0 107 #define PTE_ORDER 0 108 #endif 109 #ifdef CONFIG_PAGE_SIZE_64KB 110 #define PGD_ORDER 0 111 #define PUD_ORDER aieeee_attempt_to_allocate_pud 112 #ifdef CONFIG_MIPS_VA_BITS_48 113 #define PMD_ORDER 0 114 #else 115 #define PMD_ORDER aieeee_attempt_to_allocate_pmd 116 #endif 117 #define PTE_ORDER 0 118 #endif 119 120 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t)) 121 #ifndef __PAGETABLE_PMD_FOLDED 122 #define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t)) 123 #endif 124 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) 125 126 #define USER_PTRS_PER_PGD ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1) 127 #define FIRST_USER_ADDRESS 0UL 128 129 /* 130 * TLB refill handlers also map the vmalloc area into xuseg. Avoid 131 * the first couple of pages so NULL pointer dereferences will still 132 * reliably trap. 133 */ 134 #define VMALLOC_START (MAP_BASE + (2 * PAGE_SIZE)) 135 #define VMALLOC_END \ 136 (MAP_BASE + \ 137 min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \ 138 (1UL << cpu_vmbits)) - (1UL << 32)) 139 140 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \ 141 VMALLOC_START != CKSSEG 142 /* Load modules into 32bit-compatible segment. */ 143 #define MODULE_START CKSSEG 144 #define MODULE_END (FIXADDR_START-2*PAGE_SIZE) 145 #endif 146 147 #define pte_ERROR(e) \ 148 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 149 #ifndef __PAGETABLE_PMD_FOLDED 150 #define pmd_ERROR(e) \ 151 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 152 #endif 153 #define pgd_ERROR(e) \ 154 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 155 156 extern pte_t invalid_pte_table[PTRS_PER_PTE]; 157 extern pte_t empty_bad_page_table[PTRS_PER_PTE]; 158 159 160 #ifndef __PAGETABLE_PMD_FOLDED 161 /* 162 * For 3-level pagetables we defines these ourselves, for 2-level the 163 * definitions are supplied by <asm-generic/pgtable-nopmd.h>. 164 */ 165 typedef struct { unsigned long pmd; } pmd_t; 166 #define pmd_val(x) ((x).pmd) 167 #define __pmd(x) ((pmd_t) { (x) } ) 168 169 170 extern pmd_t invalid_pmd_table[PTRS_PER_PMD]; 171 #endif 172 173 /* 174 * Empty pgd/pmd entries point to the invalid_pte_table. 175 */ 176 static inline int pmd_none(pmd_t pmd) 177 { 178 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 179 } 180 181 static inline int pmd_bad(pmd_t pmd) 182 { 183 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 184 /* pmd_huge(pmd) but inline */ 185 if (unlikely(pmd_val(pmd) & _PAGE_HUGE)) 186 return 0; 187 #endif 188 189 if (unlikely(pmd_val(pmd) & ~PAGE_MASK)) 190 return 1; 191 192 return 0; 193 } 194 195 static inline int pmd_present(pmd_t pmd) 196 { 197 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 198 } 199 200 static inline void pmd_clear(pmd_t *pmdp) 201 { 202 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 203 } 204 #ifndef __PAGETABLE_PMD_FOLDED 205 206 /* 207 * Empty pud entries point to the invalid_pmd_table. 208 */ 209 static inline int pud_none(pud_t pud) 210 { 211 return pud_val(pud) == (unsigned long) invalid_pmd_table; 212 } 213 214 static inline int pud_bad(pud_t pud) 215 { 216 return pud_val(pud) & ~PAGE_MASK; 217 } 218 219 static inline int pud_present(pud_t pud) 220 { 221 return pud_val(pud) != (unsigned long) invalid_pmd_table; 222 } 223 224 static inline void pud_clear(pud_t *pudp) 225 { 226 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 227 } 228 #endif 229 230 #define pte_page(x) pfn_to_page(pte_pfn(x)) 231 232 #ifdef CONFIG_CPU_VR41XX 233 #define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) 234 #define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) 235 #else 236 #define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT)) 237 #define pfn_pte(pfn, prot) __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot)) 238 #define pfn_pmd(pfn, prot) __pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot)) 239 #endif 240 241 #define __pgd_offset(address) pgd_index(address) 242 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) 243 #define __pmd_offset(address) pmd_index(address) 244 245 /* to find an entry in a kernel page-table-directory */ 246 #define pgd_offset_k(address) pgd_offset(&init_mm, address) 247 248 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 249 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 250 251 /* to find an entry in a page-table-directory */ 252 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 253 254 #ifndef __PAGETABLE_PMD_FOLDED 255 static inline unsigned long pud_page_vaddr(pud_t pud) 256 { 257 return pud_val(pud); 258 } 259 #define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) 260 #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) 261 262 /* Find an entry in the second-level page table.. */ 263 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) 264 { 265 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); 266 } 267 #endif 268 269 /* Find an entry in the third-level page table.. */ 270 #define __pte_offset(address) \ 271 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 272 #define pte_offset(dir, address) \ 273 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 274 #define pte_offset_kernel(dir, address) \ 275 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 276 #define pte_offset_map(dir, address) \ 277 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 278 #define pte_unmap(pte) ((void)(pte)) 279 280 /* 281 * Initialize a new pgd / pmd table with invalid pointers. 282 */ 283 extern void pgd_init(unsigned long page); 284 extern void pmd_init(unsigned long page, unsigned long pagetable); 285 286 /* 287 * Non-present pages: high 40 bits are offset, next 8 bits type, 288 * low 16 bits zero. 289 */ 290 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 291 { pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; } 292 293 #define __swp_type(x) (((x).val >> 16) & 0xff) 294 #define __swp_offset(x) ((x).val >> 24) 295 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) }) 296 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 297 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 298 299 #endif /* _ASM_PGTABLE_64_H */ 300