1 /* 2 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> 3 * Copyright (C) 2009 Wind River Systems Inc 4 * 5 * Based on asm/pgtable-32.h from mips which is: 6 * 7 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle 8 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc. 9 * 10 * This file is subject to the terms and conditions of the GNU General Public 11 * License. See the file "COPYING" in the main directory of this archive 12 * for more details. 13 */ 14 15 #ifndef _ASM_NIOS2_PGTABLE_H 16 #define _ASM_NIOS2_PGTABLE_H 17 18 #include <linux/io.h> 19 #include <linux/bug.h> 20 #include <asm/page.h> 21 #include <asm/cacheflush.h> 22 #include <asm/tlbflush.h> 23 24 #include <asm/pgtable-bits.h> 25 #include <asm-generic/pgtable-nopmd.h> 26 27 #define FIRST_USER_ADDRESS 0UL 28 29 #define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE 30 #define VMALLOC_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1) 31 32 struct mm_struct; 33 34 /* Helper macro */ 35 #define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED | \ 36 ((x) ? _PAGE_EXEC : 0) | \ 37 ((r) ? _PAGE_READ : 0) | \ 38 ((w) ? _PAGE_WRITE : 0)) 39 /* 40 * These are the macros that generic kernel code needs 41 * (to populate protection_map[]) 42 */ 43 44 /* Remove W bit on private pages for COW support */ 45 #define __P000 MKP(0, 0, 0) 46 #define __P001 MKP(0, 0, 1) 47 #define __P010 MKP(0, 0, 0) /* COW */ 48 #define __P011 MKP(0, 0, 1) /* COW */ 49 #define __P100 MKP(1, 0, 0) 50 #define __P101 MKP(1, 0, 1) 51 #define __P110 MKP(1, 0, 0) /* COW */ 52 #define __P111 MKP(1, 0, 1) /* COW */ 53 54 /* Shared pages can have exact HW mapping */ 55 #define __S000 MKP(0, 0, 0) 56 #define __S001 MKP(0, 0, 1) 57 #define __S010 MKP(0, 1, 0) 58 #define __S011 MKP(0, 1, 1) 59 #define __S100 MKP(1, 0, 0) 60 #define __S101 MKP(1, 0, 1) 61 #define __S110 MKP(1, 1, 0) 62 #define __S111 MKP(1, 1, 1) 63 64 /* Used all over the kernel */ 65 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \ 66 _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL) 67 68 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \ 69 _PAGE_WRITE | _PAGE_ACCESSED) 70 71 #define PAGE_COPY MKP(0, 0, 1) 72 73 #define PGD_ORDER 0 74 #define PTE_ORDER 0 75 76 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t)) 77 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) 78 79 #define USER_PTRS_PER_PGD \ 80 (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE) 81 82 #define PGDIR_SHIFT 22 83 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 84 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 85 86 /* 87 * ZERO_PAGE is a global shared page that is always zero: used 88 * for zero-mapped memory areas etc.. 89 */ 90 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; 91 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) 92 93 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 94 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)]; 95 96 /* 97 * (pmds are folded into puds so this doesn't get actually called, 98 * but the define is needed for a generic inline function.) 99 */ 100 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval) 101 { 102 pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd; 103 } 104 105 /* to find an entry in a page-table-directory */ 106 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 107 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 108 109 static inline int pte_write(pte_t pte) \ 110 { return pte_val(pte) & _PAGE_WRITE; } 111 static inline int pte_dirty(pte_t pte) \ 112 { return pte_val(pte) & _PAGE_DIRTY; } 113 static inline int pte_young(pte_t pte) \ 114 { return pte_val(pte) & _PAGE_ACCESSED; } 115 static inline int pte_special(pte_t pte) { return 0; } 116 117 #define pgprot_noncached pgprot_noncached 118 119 static inline pgprot_t pgprot_noncached(pgprot_t _prot) 120 { 121 unsigned long prot = pgprot_val(_prot); 122 123 prot &= ~_PAGE_CACHED; 124 125 return __pgprot(prot); 126 } 127 128 static inline int pte_none(pte_t pte) 129 { 130 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf)); 131 } 132 133 static inline int pte_present(pte_t pte) \ 134 { return pte_val(pte) & _PAGE_PRESENT; } 135 136 /* 137 * The following only work if pte_present() is true. 138 * Undefined behaviour if not.. 139 */ 140 static inline pte_t pte_wrprotect(pte_t pte) 141 { 142 pte_val(pte) &= ~_PAGE_WRITE; 143 return pte; 144 } 145 146 static inline pte_t pte_mkclean(pte_t pte) 147 { 148 pte_val(pte) &= ~_PAGE_DIRTY; 149 return pte; 150 } 151 152 static inline pte_t pte_mkold(pte_t pte) 153 { 154 pte_val(pte) &= ~_PAGE_ACCESSED; 155 return pte; 156 } 157 158 static inline pte_t pte_mkwrite(pte_t pte) 159 { 160 pte_val(pte) |= _PAGE_WRITE; 161 return pte; 162 } 163 164 static inline pte_t pte_mkdirty(pte_t pte) 165 { 166 pte_val(pte) |= _PAGE_DIRTY; 167 return pte; 168 } 169 170 static inline pte_t pte_mkspecial(pte_t pte) { return pte; } 171 172 static inline pte_t pte_mkyoung(pte_t pte) 173 { 174 pte_val(pte) |= _PAGE_ACCESSED; 175 return pte; 176 } 177 178 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 179 { 180 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC; 181 182 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 183 return pte; 184 } 185 186 static inline int pmd_present(pmd_t pmd) 187 { 188 return (pmd_val(pmd) != (unsigned long) invalid_pte_table) 189 && (pmd_val(pmd) != 0UL); 190 } 191 192 static inline void pmd_clear(pmd_t *pmdp) 193 { 194 pmd_val(*pmdp) = (unsigned long) invalid_pte_table; 195 } 196 197 #define pte_pfn(pte) (pte_val(pte) & 0xfffff) 198 #define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot))) 199 #define pte_page(pte) (pfn_to_page(pte_pfn(pte))) 200 201 /* 202 * Store a linux PTE into the linux page table. 203 */ 204 static inline void set_pte(pte_t *ptep, pte_t pteval) 205 { 206 *ptep = pteval; 207 } 208 209 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, 210 pte_t *ptep, pte_t pteval) 211 { 212 unsigned long paddr = page_to_virt(pte_page(pteval)); 213 214 flush_dcache_range(paddr, paddr + PAGE_SIZE); 215 set_pte(ptep, pteval); 216 } 217 218 static inline int pmd_none(pmd_t pmd) 219 { 220 return (pmd_val(pmd) == 221 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL); 222 } 223 224 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) 225 226 static inline void pte_clear(struct mm_struct *mm, 227 unsigned long addr, pte_t *ptep) 228 { 229 pte_t null; 230 231 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf; 232 233 set_pte_at(mm, addr, ptep, null); 234 flush_tlb_one(addr); 235 } 236 237 /* 238 * Conversion functions: convert a page and protection to a page entry, 239 * and a page entry and page directory to the page they refer to. 240 */ 241 #define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot)) 242 243 #define pte_unmap(pte) do { } while (0) 244 245 /* 246 * Conversion functions: convert a page and protection to a page entry, 247 * and a page entry and page directory to the page they refer to. 248 */ 249 #define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd)) 250 #define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT)) 251 #define pmd_page_vaddr(pmd) pmd_val(pmd) 252 253 #define pte_offset_map(dir, addr) \ 254 ((pte_t *) page_address(pmd_page(*dir)) + \ 255 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) 256 257 /* to find an entry in a kernel page-table-directory */ 258 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) 259 260 /* Get the address to the PTE for a vaddr in specific directory */ 261 #define pte_offset_kernel(dir, addr) \ 262 ((pte_t *) pmd_page_vaddr(*(dir)) + \ 263 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) 264 265 #define pte_ERROR(e) \ 266 pr_err("%s:%d: bad pte %08lx.\n", \ 267 __FILE__, __LINE__, pte_val(e)) 268 #define pgd_ERROR(e) \ 269 pr_err("%s:%d: bad pgd %08lx.\n", \ 270 __FILE__, __LINE__, pgd_val(e)) 271 272 /* 273 * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte): 274 * 275 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ... 1 0 276 * 0 0 0 0 type. 0 0 0 0 0 0 offset......... 277 * 278 * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file. 279 * 280 * Note that the offset field is always non-zero, thus !pte_none(pte) is always 281 * true. 282 */ 283 #define __swp_type(swp) (((swp).val >> 26) & 0x3) 284 #define __swp_offset(swp) ((swp).val & 0xfffff) 285 #define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x3) << 26) \ 286 | ((off) & 0xfffff) }) 287 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 288 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 289 290 #define kern_addr_valid(addr) (1) 291 292 #include <asm-generic/pgtable.h> 293 294 #define pgtable_cache_init() do { } while (0) 295 296 extern void __init paging_init(void); 297 extern void __init mmu_init(void); 298 299 extern void update_mmu_cache(struct vm_area_struct *vma, 300 unsigned long address, pte_t *pte); 301 302 #endif /* _ASM_NIOS2_PGTABLE_H */ 303