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(CONFIG_BUILD_ELF64) && VMALLOC_START != CKSSEG 108/* Load modules into 32bit-compatible segment. */ 109#define MODULE_START CKSSEG 110#define MODULE_END (FIXADDR_START-2*PAGE_SIZE) 111extern pgd_t module_pg_dir[PTRS_PER_PGD]; 112#endif 113 114#define pte_ERROR(e) \ 115 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 116#define pmd_ERROR(e) \ 117 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 118#define pgd_ERROR(e) \ 119 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 120 121extern pte_t invalid_pte_table[PTRS_PER_PTE]; 122extern pte_t empty_bad_page_table[PTRS_PER_PTE]; 123extern pmd_t invalid_pmd_table[PTRS_PER_PMD]; 124extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD]; 125 126/* 127 * Empty pgd/pmd entries point to the invalid_pte_table. 128 */ 129static inline int pmd_none(pmd_t pmd) 130{ 131 return pmd_val(pmd) == (unsigned long) invalid_pte_table; 132} 133 134#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) 135 136static inline int pmd_present(pmd_t pmd) 137{ 138 return pmd_val(pmd) != (unsigned long) invalid_pte_table; 139} 140 141static inline void pmd_clear(pmd_t *pmdp) 142{ 143 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); 144} 145 146/* 147 * Empty pud entries point to the invalid_pmd_table. 148 */ 149static inline int pud_none(pud_t pud) 150{ 151 return pud_val(pud) == (unsigned long) invalid_pmd_table; 152} 153 154static inline int pud_bad(pud_t pud) 155{ 156 return pud_val(pud) & ~PAGE_MASK; 157} 158 159static inline int pud_present(pud_t pud) 160{ 161 return pud_val(pud) != (unsigned long) invalid_pmd_table; 162} 163 164static inline void pud_clear(pud_t *pudp) 165{ 166 pud_val(*pudp) = ((unsigned long) invalid_pmd_table); 167} 168 169#define pte_page(x) pfn_to_page(pte_pfn(x)) 170 171#ifdef CONFIG_CPU_VR41XX 172#define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) 173#define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) 174#else 175#define pte_pfn(x) ((unsigned long)((x).pte >> PAGE_SHIFT)) 176#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) 177#endif 178 179#define __pgd_offset(address) pgd_index(address) 180#define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) 181#define __pmd_offset(address) pmd_index(address) 182 183/* to find an entry in a kernel page-table-directory */ 184#ifdef MODULE_START 185#define pgd_offset_k(address) \ 186 ((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL)) 187#else 188#define pgd_offset_k(address) pgd_offset(&init_mm, 0UL) 189#endif 190 191#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 192#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 193 194/* to find an entry in a page-table-directory */ 195#define pgd_offset(mm,addr) ((mm)->pgd + pgd_index(addr)) 196 197static inline unsigned long pud_page_vaddr(pud_t pud) 198{ 199 return pud_val(pud); 200} 201#define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) 202#define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) 203 204/* Find an entry in the second-level page table.. */ 205static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) 206{ 207 return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); 208} 209 210/* Find an entry in the third-level page table.. */ 211#define __pte_offset(address) \ 212 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 213#define pte_offset(dir, address) \ 214 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 215#define pte_offset_kernel(dir, address) \ 216 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 217#define pte_offset_map(dir, address) \ 218 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 219#define pte_offset_map_nested(dir, address) \ 220 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 221#define pte_unmap(pte) ((void)(pte)) 222#define pte_unmap_nested(pte) ((void)(pte)) 223 224/* 225 * Initialize a new pgd / pmd table with invalid pointers. 226 */ 227extern void pgd_init(unsigned long page); 228extern void pmd_init(unsigned long page, unsigned long pagetable); 229 230/* 231 * Non-present pages: high 24 bits are offset, next 8 bits type, 232 * low 32 bits zero. 233 */ 234static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 235{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } 236 237#define __swp_type(x) (((x).val >> 32) & 0xff) 238#define __swp_offset(x) ((x).val >> 40) 239#define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) }) 240#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 241#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 242 243/* 244 * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to 245 * make things easier, and only use the upper 56 bits for the page offset... 246 */ 247#define PTE_FILE_MAX_BITS 56 248 249#define pte_to_pgoff(_pte) ((_pte).pte >> 8) 250#define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE }) 251 252#endif /* _ASM_PGTABLE_64_H */ 253