1#ifndef _ALPHA_PGTABLE_H 2#define _ALPHA_PGTABLE_H 3 4/* 5 * This file contains the functions and defines necessary to modify and use 6 * the Alpha page table tree. 7 * 8 * This hopefully works with any standard Alpha page-size, as defined 9 * in <asm/page.h> (currently 8192). 10 */ 11#include <linux/config.h> 12#include <linux/mmzone.h> 13 14#include <asm/page.h> 15#include <asm/processor.h> /* For TASK_SIZE */ 16#include <asm/machvec.h> 17 18/* Certain architectures need to do special things when PTEs 19 * within a page table are directly modified. Thus, the following 20 * hook is made available. 21 */ 22#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) 23 24/* PMD_SHIFT determines the size of the area a second-level page table can map */ 25#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-3)) 26#define PMD_SIZE (1UL << PMD_SHIFT) 27#define PMD_MASK (~(PMD_SIZE-1)) 28 29/* PGDIR_SHIFT determines what a third-level page table entry can map */ 30#define PGDIR_SHIFT (PAGE_SHIFT + 2*(PAGE_SHIFT-3)) 31#define PGDIR_SIZE (1UL << PGDIR_SHIFT) 32#define PGDIR_MASK (~(PGDIR_SIZE-1)) 33 34/* 35 * Entries per page directory level: the Alpha is three-level, with 36 * all levels having a one-page page table. 37 */ 38#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-3)) 39#define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3)) 40#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-3)) 41#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) 42#define FIRST_USER_PGD_NR 0 43 44/* Number of pointers that fit on a page: this will go away. */ 45#define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3)) 46 47#ifdef CONFIG_ALPHA_LARGE_VMALLOC 48#define VMALLOC_START 0xfffffe0000000000 49#else 50#define VMALLOC_START (-2*PGDIR_SIZE) 51#endif 52#define VMALLOC_VMADDR(x) ((unsigned long)(x)) 53#define VMALLOC_END (-PGDIR_SIZE) 54 55/* 56 * OSF/1 PAL-code-imposed page table bits 57 */ 58#define _PAGE_VALID 0x0001 59#define _PAGE_FOR 0x0002 /* used for page protection (fault on read) */ 60#define _PAGE_FOW 0x0004 /* used for page protection (fault on write) */ 61#define _PAGE_FOE 0x0008 /* used for page protection (fault on exec) */ 62#define _PAGE_ASM 0x0010 63#define _PAGE_KRE 0x0100 64#define _PAGE_URE 0x0200 65#define _PAGE_KWE 0x1000 /* used to do the dirty bit in software */ 66#define _PAGE_UWE 0x2000 /* used to do the dirty bit in software */ 67 68/* .. and these are ours ... */ 69#define _PAGE_DIRTY 0x20000 70#define _PAGE_ACCESSED 0x40000 71 72/* 73 * NOTE! The "accessed" bit isn't necessarily exact: it can be kept exactly 74 * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it. 75 * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use 76 * the KRE/URE bits to watch for it. That way we don't need to overload the 77 * KWE/UWE bits with both handling dirty and accessed. 78 * 79 * Note that the kernel uses the accessed bit just to check whether to page 80 * out a page or not, so it doesn't have to be exact anyway. 81 */ 82 83#define __DIRTY_BITS (_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE) 84#define __ACCESS_BITS (_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE) 85 86#define _PFN_MASK 0xFFFFFFFF00000000 87 88#define _PAGE_TABLE (_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS) 89#define _PAGE_CHG_MASK (_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS) 90 91/* 92 * All the normal masks have the "page accessed" bits on, as any time they are used, 93 * the page is accessed. They are cleared only by the page-out routines 94 */ 95#define PAGE_NONE __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE) 96#define PAGE_SHARED __pgprot(_PAGE_VALID | __ACCESS_BITS) 97#define PAGE_COPY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW) 98#define PAGE_READONLY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW) 99#define PAGE_KERNEL __pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE) 100 101#define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x)) 102 103#define _PAGE_P(x) _PAGE_NORMAL((x) | (((x) & _PAGE_FOW)?0:_PAGE_FOW)) 104#define _PAGE_S(x) _PAGE_NORMAL(x) 105 106/* 107 * The hardware can handle write-only mappings, but as the Alpha 108 * architecture does byte-wide writes with a read-modify-write 109 * sequence, it's not practical to have write-without-read privs. 110 * Thus the "-w- -> rw-" and "-wx -> rwx" mapping here (and in 111 * arch/alpha/mm/fault.c) 112 */ 113 /* xwr */ 114#define __P000 _PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) 115#define __P001 _PAGE_P(_PAGE_FOE | _PAGE_FOW) 116#define __P010 _PAGE_P(_PAGE_FOE) 117#define __P011 _PAGE_P(_PAGE_FOE) 118#define __P100 _PAGE_P(_PAGE_FOW | _PAGE_FOR) 119#define __P101 _PAGE_P(_PAGE_FOW) 120#define __P110 _PAGE_P(0) 121#define __P111 _PAGE_P(0) 122 123#define __S000 _PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR) 124#define __S001 _PAGE_S(_PAGE_FOE | _PAGE_FOW) 125#define __S010 _PAGE_S(_PAGE_FOE) 126#define __S011 _PAGE_S(_PAGE_FOE) 127#define __S100 _PAGE_S(_PAGE_FOW | _PAGE_FOR) 128#define __S101 _PAGE_S(_PAGE_FOW) 129#define __S110 _PAGE_S(0) 130#define __S111 _PAGE_S(0) 131 132/* 133 * BAD_PAGETABLE is used when we need a bogus page-table, while 134 * BAD_PAGE is used for a bogus page. 135 * 136 * ZERO_PAGE is a global shared page that is always zero: used 137 * for zero-mapped memory areas etc.. 138 */ 139extern pte_t __bad_page(void); 140extern pmd_t * __bad_pagetable(void); 141 142extern unsigned long __zero_page(void); 143 144#define BAD_PAGETABLE __bad_pagetable() 145#define BAD_PAGE __bad_page() 146#define ZERO_PAGE(vaddr) (virt_to_page(ZERO_PGE)) 147 148/* number of bits that fit into a memory pointer */ 149#define BITS_PER_PTR (8*sizeof(unsigned long)) 150 151/* to align the pointer to a pointer address */ 152#define PTR_MASK (~(sizeof(void*)-1)) 153 154/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */ 155#define SIZEOF_PTR_LOG2 3 156 157/* to find an entry in a page-table */ 158#define PAGE_PTR(address) \ 159 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) 160 161/* 162 * On certain platforms whose physical address space can overlap KSEG, 163 * namely EV6 and above, we must re-twiddle the physaddr to restore the 164 * correct high-order bits. 165 * 166 * This is extremely confusing until you realize that this is actually 167 * just working around a userspace bug. The X server was intending to 168 * provide the physical address but instead provided the KSEG address. 169 * Or tried to, except it's not representable. 170 * 171 * On Tsunami there's nothing meaningful at 0x40000000000, so this is 172 * a safe thing to do. Come the first core logic that does put something 173 * in this area -- memory or whathaveyou -- then this hack will have 174 * to go away. So be prepared! 175 */ 176 177#if defined(CONFIG_ALPHA_GENERIC) && defined(USE_48_BIT_KSEG) 178#error "EV6-only feature in a generic kernel" 179#endif 180#if defined(CONFIG_ALPHA_GENERIC) || \ 181 (defined(CONFIG_ALPHA_EV6) && !defined(USE_48_BIT_KSEG)) 182#define PHYS_TWIDDLE(phys) \ 183 ((((phys) & 0xc0000000000UL) == 0x40000000000UL) \ 184 ? ((phys) ^= 0xc0000000000UL) : (phys)) 185#else 186#define PHYS_TWIDDLE(phys) (phys) 187#endif 188 189/* 190 * Conversion functions: convert a page and protection to a page entry, 191 * and a page entry and page directory to the page they refer to. 192 */ 193#ifndef CONFIG_DISCONTIGMEM 194#define PAGE_TO_PA(page) ((page - mem_map) << PAGE_SHIFT) 195#else 196#define PAGE_TO_PA(page) \ 197 ((((page)-page_zone(page)->zone_mem_map) << PAGE_SHIFT) \ 198 + page_zone(page)->zone_start_paddr) 199#endif 200 201#ifndef CONFIG_DISCONTIGMEM 202#define mk_pte(page, pgprot) \ 203({ \ 204 pte_t pte; \ 205 \ 206 pte_val(pte) = ((unsigned long)(page - mem_map) << 32) | \ 207 pgprot_val(pgprot); \ 208 pte; \ 209}) 210#else 211#define mk_pte(page, pgprot) \ 212({ \ 213 pte_t pte; \ 214 unsigned long pfn; \ 215 \ 216 pfn = ((unsigned long)((page)-page_zone(page)->zone_mem_map)) << 32; \ 217 pfn += page_zone(page)->zone_start_paddr << (32-PAGE_SHIFT); \ 218 pte_val(pte) = pfn | pgprot_val(pgprot); \ 219 \ 220 pte; \ 221}) 222#endif 223 224extern inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot) 225{ pte_t pte; pte_val(pte) = (PHYS_TWIDDLE(physpage) << (32-PAGE_SHIFT)) | pgprot_val(pgprot); return pte; } 226 227extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 228{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; } 229 230extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep) 231{ pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } 232 233extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp) 234{ pgd_val(*pgdp) = _PAGE_TABLE | ((((unsigned long) pmdp) - PAGE_OFFSET) << (32-PAGE_SHIFT)); } 235 236#ifndef CONFIG_DISCONTIGMEM 237#define pte_page(x) (mem_map+(unsigned long)((pte_val(x) >> 32))) 238#else 239#define pte_page(x) \ 240({ \ 241 unsigned long kvirt; \ 242 struct page * __xx; \ 243 \ 244 kvirt = (unsigned long)__va(pte_val(x) >> (32-PAGE_SHIFT)); \ 245 __xx = virt_to_page(kvirt); \ 246 \ 247 __xx; \ 248}) 249#endif 250 251extern inline unsigned long pmd_page(pmd_t pmd) 252{ return PAGE_OFFSET + ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)); } 253 254extern inline unsigned long pgd_page(pgd_t pgd) 255{ return PAGE_OFFSET + ((pgd_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); } 256 257extern inline int pte_none(pte_t pte) { return !pte_val(pte); } 258extern inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_VALID; } 259extern inline void pte_clear(pte_t *ptep) { pte_val(*ptep) = 0; } 260 261extern inline int pmd_none(pmd_t pmd) { return !pmd_val(pmd); } 262extern inline int pmd_bad(pmd_t pmd) { return (pmd_val(pmd) & ~_PFN_MASK) != _PAGE_TABLE; } 263extern inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _PAGE_VALID; } 264extern inline void pmd_clear(pmd_t * pmdp) { pmd_val(*pmdp) = 0; } 265 266extern inline int pgd_none(pgd_t pgd) { return !pgd_val(pgd); } 267extern inline int pgd_bad(pgd_t pgd) { return (pgd_val(pgd) & ~_PFN_MASK) != _PAGE_TABLE; } 268extern inline int pgd_present(pgd_t pgd) { return pgd_val(pgd) & _PAGE_VALID; } 269extern inline void pgd_clear(pgd_t * pgdp) { pgd_val(*pgdp) = 0; } 270 271/* 272 * The following only work if pte_present() is true. 273 * Undefined behaviour if not.. 274 */ 275extern inline int pte_read(pte_t pte) { return !(pte_val(pte) & _PAGE_FOR); } 276extern inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_FOW); } 277extern inline int pte_exec(pte_t pte) { return !(pte_val(pte) & _PAGE_FOE); } 278extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } 279extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } 280 281extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOW; return pte; } 282extern inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOR; return pte; } 283extern inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) |= _PAGE_FOE; return pte; } 284extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(__DIRTY_BITS); return pte; } 285extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~(__ACCESS_BITS); return pte; } 286extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_FOW; return pte; } 287extern inline pte_t pte_mkread(pte_t pte) { pte_val(pte) &= ~_PAGE_FOR; return pte; } 288extern inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) &= ~_PAGE_FOE; return pte; } 289extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= __DIRTY_BITS; return pte; } 290extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= __ACCESS_BITS; return pte; } 291 292#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address)) 293 294/* to find an entry in a kernel page-table-directory */ 295#define pgd_offset_k(address) pgd_offset(&init_mm, address) 296 297/* to find an entry in a page-table-directory. */ 298#define pgd_index(address) ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 299#define __pgd_offset(address) pgd_index(address) 300#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) 301 302/* Find an entry in the second-level page table.. */ 303extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address) 304{ 305 return (pmd_t *) pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1)); 306} 307 308/* Find an entry in the third-level page table.. */ 309extern inline pte_t * pte_offset(pmd_t * dir, unsigned long address) 310{ 311 return (pte_t *) pmd_page(*dir) + ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1)); 312} 313 314extern pgd_t swapper_pg_dir[1024]; 315 316/* 317 * The Alpha doesn't have any external MMU info: the kernel page 318 * tables contain all the necessary information. 319 */ 320extern inline void update_mmu_cache(struct vm_area_struct * vma, 321 unsigned long address, pte_t pte) 322{ 323} 324 325/* 326 * Non-present pages: high 24 bits are offset, next 8 bits type, 327 * low 32 bits zero. 328 */ 329extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) 330{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } 331 332#define SWP_TYPE(x) (((x).val >> 32) & 0xff) 333#define SWP_OFFSET(x) ((x).val >> 40) 334#define SWP_ENTRY(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) }) 335#define pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 336#define swp_entry_to_pte(x) ((pte_t) { (x).val }) 337 338/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ 339#define PageSkip(page) (0) 340 341#ifndef CONFIG_DISCONTIGMEM 342#define kern_addr_valid(addr) (1) 343#endif 344 345#define io_remap_page_range(start, busaddr, size, prot) \ 346 remap_page_range(start, virt_to_phys(__ioremap(busaddr, size)), size, prot) 347 348#define pte_ERROR(e) \ 349 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) 350#define pmd_ERROR(e) \ 351 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) 352#define pgd_ERROR(e) \ 353 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) 354 355extern void paging_init(void); 356 357#include <asm-generic/pgtable.h> 358 359/* 360 * No page table caches to initialise 361 */ 362#define pgtable_cache_init() do { } while (0) 363 364/* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT. */ 365#define HAVE_ARCH_UNMAPPED_AREA 366 367#endif /* _ALPHA_PGTABLE_H */ 368