1/* 2 * CRIS pgtable.h - macros and functions to manipulate page tables. 3 */ 4 5#ifndef _CRIS_PGTABLE_H 6#define _CRIS_PGTABLE_H 7 8#include <asm/page.h> 9#include <asm-generic/pgtable-nopmd.h> 10 11#ifndef __ASSEMBLY__ 12#include <linux/sched.h> 13#include <asm/mmu.h> 14#endif 15#include <asm/arch/pgtable.h> 16 17/* 18 * The Linux memory management assumes a three-level page table setup. On 19 * CRIS, we use that, but "fold" the mid level into the top-level page 20 * table. Since the MMU TLB is software loaded through an interrupt, it 21 * supports any page table structure, so we could have used a three-level 22 * setup, but for the amounts of memory we normally use, a two-level is 23 * probably more efficient. 24 * 25 * This file contains the functions and defines necessary to modify and use 26 * the CRIS page table tree. 27 */ 28#ifndef __ASSEMBLY__ 29extern void paging_init(void); 30#endif 31 32/* Certain architectures need to do special things when pte's 33 * within a page table are directly modified. Thus, the following 34 * hook is made available. 35 */ 36#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) 37#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) 38 39/* 40 * (pmds are folded into pgds so this doesn't get actually called, 41 * but the define is needed for a generic inline function.) 42 */ 43#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) 44#define set_pgu(pudptr, pudval) (*(pudptr) = pudval) 45 46/* PGDIR_SHIFT determines the size of the area a second-level page table can 47 * map. It is equal to the page size times the number of PTE's that fit in 48 * a PMD page. A PTE is 4-bytes in CRIS. Hence the following number. 49 */ 50 51#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2)) 52#define PGDIR_SIZE (1UL << PGDIR_SHIFT) 53#define PGDIR_MASK (~(PGDIR_SIZE-1)) 54 55/* 56 * entries per page directory level: we use a two-level, so 57 * we don't really have any PMD directory physically. 58 * pointers are 4 bytes so we can use the page size and 59 * divide it by 4 (shift by 2). 60 */ 61#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2)) 62#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2)) 63 64/* calculate how many PGD entries a user-level program can use 65 * the first mappable virtual address is 0 66 * (TASK_SIZE is the maximum virtual address space) 67 */ 68 69#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) 70#define FIRST_USER_ADDRESS 0 71 72/* zero page used for uninitialized stuff */ 73#ifndef __ASSEMBLY__ 74extern unsigned long empty_zero_page; 75#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) 76#endif 77 78/* number of bits that fit into a memory pointer */ 79#define BITS_PER_PTR (8*sizeof(unsigned long)) 80 81/* to align the pointer to a pointer address */ 82#define PTR_MASK (~(sizeof(void*)-1)) 83 84/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */ 85/* 64-bit machines, beware! SRB. */ 86#define SIZEOF_PTR_LOG2 2 87 88/* to find an entry in a page-table */ 89#define PAGE_PTR(address) \ 90((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) 91 92/* to set the page-dir */ 93#define SET_PAGE_DIR(tsk,pgdir) 94 95#define pte_none(x) (!pte_val(x)) 96#define pte_present(x) (pte_val(x) & _PAGE_PRESENT) 97#define pte_clear(mm,addr,xp) do { pte_val(*(xp)) = 0; } while (0) 98 99#define pmd_none(x) (!pmd_val(x)) 100/* by removing the _PAGE_KERNEL bit from the comparision, the same pmd_bad 101 * works for both _PAGE_TABLE and _KERNPG_TABLE pmd entries. 102 */ 103#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_KERNEL)) != _PAGE_TABLE) 104#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) 105#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) 106 107#ifndef __ASSEMBLY__ 108 109/* 110 * The following only work if pte_present() is true. 111 * Undefined behaviour if not.. 112 */ 113 114static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; } 115static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } 116static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_READ; } 117static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; } 118static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } 119static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } 120 121static inline pte_t pte_wrprotect(pte_t pte) 122{ 123 pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE); 124 return pte; 125} 126 127static inline pte_t pte_rdprotect(pte_t pte) 128{ 129 pte_val(pte) &= ~(_PAGE_READ | _PAGE_SILENT_READ); 130 return pte; 131} 132 133static inline pte_t pte_exprotect(pte_t pte) 134{ 135 pte_val(pte) &= ~(_PAGE_READ | _PAGE_SILENT_READ); 136 return pte; 137} 138 139static inline pte_t pte_mkclean(pte_t pte) 140{ 141 pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE); 142 return pte; 143} 144 145static inline pte_t pte_mkold(pte_t pte) 146{ 147 pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ); 148 return pte; 149} 150 151static inline pte_t pte_mkwrite(pte_t pte) 152{ 153 pte_val(pte) |= _PAGE_WRITE; 154 if (pte_val(pte) & _PAGE_MODIFIED) 155 pte_val(pte) |= _PAGE_SILENT_WRITE; 156 return pte; 157} 158 159static inline pte_t pte_mkread(pte_t pte) 160{ 161 pte_val(pte) |= _PAGE_READ; 162 if (pte_val(pte) & _PAGE_ACCESSED) 163 pte_val(pte) |= _PAGE_SILENT_READ; 164 return pte; 165} 166 167static inline pte_t pte_mkexec(pte_t pte) 168{ 169 pte_val(pte) |= _PAGE_READ; 170 if (pte_val(pte) & _PAGE_ACCESSED) 171 pte_val(pte) |= _PAGE_SILENT_READ; 172 return pte; 173} 174 175static inline pte_t pte_mkdirty(pte_t pte) 176{ 177 pte_val(pte) |= _PAGE_MODIFIED; 178 if (pte_val(pte) & _PAGE_WRITE) 179 pte_val(pte) |= _PAGE_SILENT_WRITE; 180 return pte; 181} 182 183static inline pte_t pte_mkyoung(pte_t pte) 184{ 185 pte_val(pte) |= _PAGE_ACCESSED; 186 if (pte_val(pte) & _PAGE_READ) 187 { 188 pte_val(pte) |= _PAGE_SILENT_READ; 189 if ((pte_val(pte) & (_PAGE_WRITE | _PAGE_MODIFIED)) == 190 (_PAGE_WRITE | _PAGE_MODIFIED)) 191 pte_val(pte) |= _PAGE_SILENT_WRITE; 192 } 193 return pte; 194} 195 196/* 197 * Conversion functions: convert a page and protection to a page entry, 198 * and a page entry and page directory to the page they refer to. 199 */ 200 201/* What actually goes as arguments to the various functions is less than 202 * obvious, but a rule of thumb is that struct page's goes as struct page *, 203 * really physical DRAM addresses are unsigned long's, and DRAM "virtual" 204 * addresses (the 0xc0xxxxxx's) goes as void *'s. 205 */ 206 207static inline pte_t __mk_pte(void * page, pgprot_t pgprot) 208{ 209 pte_t pte; 210 /* the PTE needs a physical address */ 211 pte_val(pte) = __pa(page) | pgprot_val(pgprot); 212 return pte; 213} 214 215#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot)) 216 217#define mk_pte_phys(physpage, pgprot) \ 218({ \ 219 pte_t __pte; \ 220 \ 221 pte_val(__pte) = (physpage) + pgprot_val(pgprot); \ 222 __pte; \ 223}) 224 225static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 226{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; } 227 228 229/* pte_val refers to a page in the 0x4xxxxxxx physical DRAM interval 230 * __pte_page(pte_val) refers to the "virtual" DRAM interval 231 * pte_pagenr refers to the page-number counted starting from the virtual DRAM start 232 */ 233 234static inline unsigned long __pte_page(pte_t pte) 235{ 236 /* the PTE contains a physical address */ 237 return (unsigned long)__va(pte_val(pte) & PAGE_MASK); 238} 239 240#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT) 241 242/* permanent address of a page */ 243 244#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT)) 245#define pte_page(pte) (mem_map+pte_pagenr(pte)) 246 247/* only the pte's themselves need to point to physical DRAM (see above) 248 * the pagetable links are purely handled within the kernel SW and thus 249 * don't need the __pa and __va transformations. 250 */ 251 252static inline void pmd_set(pmd_t * pmdp, pte_t * ptep) 253{ pmd_val(*pmdp) = _PAGE_TABLE | (unsigned long) ptep; } 254 255#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) 256#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) 257 258/* to find an entry in a page-table-directory. */ 259#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) 260 261/* to find an entry in a page-table-directory */ 262static inline pgd_t * pgd_offset(struct mm_struct * mm, unsigned long address) 263{ 264 return mm->pgd + pgd_index(address); 265} 266 267/* to find an entry in a kernel page-table-directory */ 268#define pgd_offset_k(address) pgd_offset(&init_mm, address) 269 270/* Find an entry in the third-level page table.. */ 271#define __pte_offset(address) \ 272 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 273#define pte_offset_kernel(dir, address) \ 274 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) 275#define pte_offset_map(dir, address) \ 276 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) 277#define pte_offset_map_nested(dir, address) pte_offset_map(dir, address) 278 279#define pte_unmap(pte) do { } while (0) 280#define pte_unmap_nested(pte) do { } while (0) 281#define pte_pfn(x) ((unsigned long)(__va((x).pte)) >> PAGE_SHIFT) 282#define pfn_pte(pfn, prot) __pte((__pa((pfn) << PAGE_SHIFT)) | pgprot_val(prot)) 283 284#define pte_ERROR(e) \ 285 printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e)) 286#define pgd_ERROR(e) \ 287 printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), pgd_val(e)) 288 289 290extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */ 291 292/* 293 * CRIS doesn't have any external MMU info: the kernel page 294 * tables contain all the necessary information. 295 * 296 * Actually I am not sure on what this could be used for. 297 */ 298static inline void update_mmu_cache(struct vm_area_struct * vma, 299 unsigned long address, pte_t pte) 300{ 301} 302 303/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */ 304/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */ 305 306#define __swp_type(x) (((x).val >> 5) & 0x7f) 307#define __swp_offset(x) ((x).val >> 12) 308#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 5) | ((offset) << 12) }) 309#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 310#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 311 312#define kern_addr_valid(addr) (1) 313 314#include <asm-generic/pgtable.h> 315 316/* 317 * No page table caches to initialise 318 */ 319#define pgtable_cache_init() do { } while (0) 320 321#define pte_to_pgoff(x) (pte_val(x) >> 6) 322#define pgoff_to_pte(x) __pte(((x) << 6) | _PAGE_FILE) 323 324typedef pte_t *pte_addr_t; 325 326#endif /* __ASSEMBLY__ */ 327#endif /* _CRIS_PGTABLE_H */ 328