root/include/asm-alpha/pgtable.h

/* */

INCLUDED FROM

DEFINITIONS

1. mk_pte
2. pte_modify
3. pmd_set
4. pgd_set
5. pte_page
6. pmd_page
7. pgd_page
8. pte_none
9. pte_present
10. pte_inuse
11. pte_clear
12. pte_reuse
13. pmd_none
14. pmd_bad
15. pmd_present
16. pmd_inuse
17. pmd_clear
18. pmd_reuse
19. pgd_none
20. pgd_bad
21. pgd_present
22. pgd_inuse
23. pgd_clear
24. pgd_reuse
25. pte_read
26. pte_write
27. pte_exec
28. pte_dirty
29. pte_young
30. pte_cow
31. pte_wrprotect
32. pte_rdprotect
33. pte_exprotect
34. pte_mkclean
35. pte_mkold
36. pte_uncow
37. pte_mkwrite
38. pte_mkread
39. pte_mkexec
40. pte_mkdirty
41. pte_mkyoung
42. pte_mkcow
43. SET_PAGE_DIR
44. pgd_offset
45. pmd_offset
46. pte_offset
47. pte_free_kernel
48. pte_alloc_kernel
49. pmd_free_kernel
50. pmd_alloc_kernel
51. pte_free
52. pte_alloc
53. pmd_free
54. pmd_alloc
55. pgd_free
56. pgd_alloc
57. update_mmu_cache

   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 
  12 /* PMD_SHIFT determines the size of the area a second-level page table can map */
  13 #define PMD_SHIFT       (PAGE_SHIFT + (PAGE_SHIFT-3))
  14 #define PMD_SIZE        (1UL << PMD_SHIFT)
  15 #define PMD_MASK        (~(PMD_SIZE-1))
  16 
  17 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  18 #define PGDIR_SHIFT     (PAGE_SHIFT + 2*(PAGE_SHIFT-3))
  19 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  20 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  21 
  22 /*
  23  * entries per page directory level: the alpha is three-level, with
  24  * all levels having a one-page page table.
  25  *
  26  * The PGD is special: the last entry is reserved for self-mapping.
  27  */
  28 #define PTRS_PER_PTE    (1UL << (PAGE_SHIFT-3))
  29 #define PTRS_PER_PMD    (1UL << (PAGE_SHIFT-3))
  30 #define PTRS_PER_PGD    ((1UL << (PAGE_SHIFT-3))-1)
  31 
  32 /* the no. of pointers that fit on a page: this will go away */
  33 #define PTRS_PER_PAGE   (1UL << (PAGE_SHIFT-3))
  34 
  35 #define VMALLOC_START           0xFFFFFE0000000000
  36 #define VMALLOC_VMADDR(x)       ((unsigned long)(x))
  37 
  38 /*
  39  * OSF/1 PAL-code-imposed page table bits
  40  */
  41 #define _PAGE_VALID     0x0001
  42 #define _PAGE_FOR       0x0002  /* used for page protection (fault on read) */
  43 #define _PAGE_FOW       0x0004  /* used for page protection (fault on write) */
  44 #define _PAGE_FOE       0x0008  /* used for page protection (fault on exec) */
  45 #define _PAGE_ASM       0x0010
  46 #define _PAGE_KRE       0x0100  /* xxx - see below on the "accessed" bit */
  47 #define _PAGE_URE       0x0200  /* xxx */
  48 #define _PAGE_KWE       0x1000  /* used to do the dirty bit in software */
  49 #define _PAGE_UWE       0x2000  /* used to do the dirty bit in software */
  50 
  51 /* .. and these are ours ... */
  52 #define _PAGE_COW       0x10000
  53 #define _PAGE_DIRTY     0x20000
  54 #define _PAGE_ACCESSED  0x40000
  55 
  56 /*
  57  * NOTE! The "accessed" bit isn't necessarily exact: it can be kept exactly
  58  * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it.
  59  * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use
  60  * the KRE/URE bits to watch for it. That way we don't need to overload the
  61  * KWE/UWE bits with both handling dirty and accessed.
  62  *
  63  * Note that the kernel uses the accessed bit just to check whether to page
  64  * out a page or not, so it doesn't have to be exact anyway.
  65  */
  66 
  67 #define __DIRTY_BITS    (_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE)
  68 #define __ACCESS_BITS   (_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE)
  69 
  70 #define _PFN_MASK       0xFFFFFFFF00000000
  71 
  72 #define _PAGE_TABLE     (_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS)
  73 #define _PAGE_CHG_MASK  (_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS)
  74 
  75 /*
  76  * All the normal masks have the "page accessed" bits on, as any time they are used,
  77  * the page is accessed. They are cleared only by the page-out routines
  78  */
  79 #define PAGE_NONE       __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE)
  80 #define PAGE_SHARED     __pgprot(_PAGE_VALID | __ACCESS_BITS)
  81 #define PAGE_COPY       __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW | _PAGE_COW)
  82 #define PAGE_READONLY   __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW)
  83 #define PAGE_KERNEL     __pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE)
  84 
  85 #define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x))
  86 
  87 #define __P000  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE)
  88 #define __P001  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOW | _PAGE_FOE)
  89 #define __P010  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOR | _PAGE_FOE)
  90 #define __P011  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOE)
  91 #define __P100  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOR | _PAGE_FOW)
  92 #define __P101  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOW)
  93 #define __P110  _PAGE_NORMAL(_PAGE_COW | _PAGE_FOR)
  94 #define __P111  _PAGE_NORMAL(_PAGE_COW)
  95 
  96 #define __S000  _PAGE_NORMAL(_PAGE_FOR | _PAGE_FOW | _PAGE_FOE)
  97 #define __S001  _PAGE_NORMAL(_PAGE_FOW | _PAGE_FOE)
  98 #define __S010  _PAGE_NORMAL(_PAGE_FOR | _PAGE_FOE)
  99 #define __S011  _PAGE_NORMAL(_PAGE_FOE)
 100 #define __S100  _PAGE_NORMAL(_PAGE_FOR | _PAGE_FOW)
 101 #define __S101  _PAGE_NORMAL(_PAGE_FOW)
 102 #define __S110  _PAGE_NORMAL(_PAGE_FOR)
 103 #define __S111  _PAGE_NORMAL(0)
 104 
 105 /*
 106  * BAD_PAGETABLE is used when we need a bogus page-table, while
 107  * BAD_PAGE is used for a bogus page.
 108  *
 109  * ZERO_PAGE is a global shared page that is always zero: used
 110  * for zero-mapped memory areas etc..
 111  */
 112 extern pte_t __bad_page(void);
 113 extern pmd_t * __bad_pagetable(void);
 114 
 115 extern unsigned long __zero_page(void);
 116 
 117 #define BAD_PAGETABLE __bad_pagetable()
 118 #define BAD_PAGE __bad_page()
 119 #define ZERO_PAGE __zero_page()
 120 
 121 /* number of bits that fit into a memory pointer */
 122 #define BITS_PER_PTR                    (8*sizeof(unsigned long))
 123 
 124 /* to align the pointer to a pointer address */
 125 #define PTR_MASK                        (~(sizeof(void*)-1))
 126 
 127 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 128 #define SIZEOF_PTR_LOG2                 3
 129 
 130 /* to find an entry in a page-table */
 131 #define PAGE_PTR(address)               \
 132   ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
 133 
 134 extern unsigned long high_memory;
 135 
 136 /*
 137  * Conversion functions: convert a page and protection to a page entry,
 138  * and a page entry and page directory to the page they refer to.
 139  */
 140 extern inline pte_t mk_pte(unsigned long page, pgprot_t pgprot)
     /*  */
 141 { pte_t pte; pte_val(pte) = ((page-PAGE_OFFSET) << (32-PAGE_SHIFT)) | pgprot_val(pgprot); return pte; }
 142 
 143 extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
     /*  */
 144 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
 145 
 146 extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
     /*  */
 147 { pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); }
 148 
 149 extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp)
     /*  */
 150 { pgd_val(*pgdp) = _PAGE_TABLE | ((((unsigned long) pmdp) - PAGE_OFFSET) << (32-PAGE_SHIFT)); }
 151 
 152 extern inline unsigned long pte_page(pte_t pte)
     /*  */
 153 { return PAGE_OFFSET + ((pte_val(pte) & _PFN_MASK) >> (32-PAGE_SHIFT)); }
 154 
 155 extern inline unsigned long pmd_page(pmd_t pmd)
     /*  */
 156 { return PAGE_OFFSET + ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)); }
 157 
 158 extern inline unsigned long pgd_page(pgd_t pgd)
     /*  */
 159 { return PAGE_OFFSET + ((pgd_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); }
 160 
 161 extern inline int pte_none(pte_t pte)           { return !pte_val(pte); }
     /*  */
 162 extern inline int pte_present(pte_t pte)        { return pte_val(pte) & _PAGE_VALID; }
     /*  */
 163 extern inline int pte_inuse(pte_t *ptep)        { return mem_map[MAP_NR(ptep)] != 1; }
     /*  */
 164 extern inline void pte_clear(pte_t *ptep)       { pte_val(*ptep) = 0; }
     /*  */
 165 extern inline void pte_reuse(pte_t * ptep)
     /*  */
 166 {
 167         if (!(mem_map[MAP_NR(ptep)] & MAP_PAGE_RESERVED))
 168                 mem_map[MAP_NR(ptep)]++;
 169 }
 170 
 171 extern inline int pmd_none(pmd_t pmd)           { return !pmd_val(pmd); }
     /*  */
 172 extern inline int pmd_bad(pmd_t pmd)            { return (pmd_val(pmd) & ~_PFN_MASK) != _PAGE_TABLE || pmd_page(pmd) > high_memory; }
     /*  */
 173 extern inline int pmd_present(pmd_t pmd)        { return pmd_val(pmd) & _PAGE_VALID; }
     /*  */
 174 extern inline int pmd_inuse(pmd_t *pmdp)        { return mem_map[MAP_NR(pmdp)] != 1; }
     /*  */
 175 extern inline void pmd_clear(pmd_t * pmdp)      { pmd_val(*pmdp) = 0; }
     /*  */
 176 extern inline void pmd_reuse(pmd_t * pmdp)
     /*  */
 177 {
 178         if (!(mem_map[MAP_NR(pmdp)] & MAP_PAGE_RESERVED))
 179                 mem_map[MAP_NR(pmdp)]++;
 180 }
 181 
 182 extern inline int pgd_none(pgd_t pgd)           { return !pgd_val(pgd); }
     /*  */
 183 extern inline int pgd_bad(pgd_t pgd)            { return (pgd_val(pgd) & ~_PFN_MASK) != _PAGE_TABLE || pgd_page(pgd) > high_memory; }
     /*  */
 184 extern inline int pgd_present(pgd_t pgd)        { return pgd_val(pgd) & _PAGE_VALID; }
     /*  */
 185 extern inline int pgd_inuse(pgd_t *pgdp)        { return mem_map[MAP_NR(pgdp)] != 1; }
     /*  */
 186 extern inline void pgd_clear(pgd_t * pgdp)      { pgd_val(*pgdp) = 0; }
     /*  */
 187 extern inline void pgd_reuse(pgd_t * pgdp)
     /*  */
 188 {
 189         if (!(mem_map[MAP_NR(pgdp)] & MAP_PAGE_RESERVED))
 190                 mem_map[MAP_NR(pgdp)]++;
 191 }
 192 
 193 /*
 194  * The following only work if pte_present() is true.
 195  * Undefined behaviour if not..
 196  */
 197 extern inline int pte_read(pte_t pte)           { return !(pte_val(pte) & _PAGE_FOR); }
     /*  */
 198 extern inline int pte_write(pte_t pte)          { return !(pte_val(pte) & _PAGE_FOW); }
     /*  */
 199 extern inline int pte_exec(pte_t pte)           { return !(pte_val(pte) & _PAGE_FOE); }
     /*  */
 200 extern inline int pte_dirty(pte_t pte)          { return pte_val(pte) & _PAGE_DIRTY; }
     /*  */
 201 extern inline int pte_young(pte_t pte)          { return pte_val(pte) & _PAGE_ACCESSED; }
     /*  */
 202 extern inline int pte_cow(pte_t pte)            { return pte_val(pte) & _PAGE_COW; }
     /*  */
 203 
 204 extern inline pte_t pte_wrprotect(pte_t pte)    { pte_val(pte) |= _PAGE_FOW; return pte; }
     /*  */
 205 extern inline pte_t pte_rdprotect(pte_t pte)    { pte_val(pte) |= _PAGE_FOR; return pte; }
     /*  */
 206 extern inline pte_t pte_exprotect(pte_t pte)    { pte_val(pte) |= _PAGE_FOE; return pte; }
     /*  */
 207 extern inline pte_t pte_mkclean(pte_t pte)      { pte_val(pte) &= ~(__DIRTY_BITS); return pte; }
     /*  */
 208 extern inline pte_t pte_mkold(pte_t pte)        { pte_val(pte) &= ~(__ACCESS_BITS); return pte; }
     /*  */
 209 extern inline pte_t pte_uncow(pte_t pte)        { pte_val(pte) &= ~_PAGE_COW; return pte; }
     /*  */
 210 extern inline pte_t pte_mkwrite(pte_t pte)      { pte_val(pte) &= _PAGE_FOW; return pte; }
     /*  */
 211 extern inline pte_t pte_mkread(pte_t pte)       { pte_val(pte) &= _PAGE_FOR; return pte; }
     /*  */
 212 extern inline pte_t pte_mkexec(pte_t pte)       { pte_val(pte) &= _PAGE_FOE; return pte; }
     /*  */
 213 extern inline pte_t pte_mkdirty(pte_t pte)      { pte_val(pte) |= __DIRTY_BITS; return pte; }
     /*  */
 214 extern inline pte_t pte_mkyoung(pte_t pte)      { pte_val(pte) |= __ACCESS_BITS; return pte; }
     /*  */
 215 extern inline pte_t pte_mkcow(pte_t pte)        { pte_val(pte) |= _PAGE_COW; return pte; }
     /*  */
 216 
 217 /* to set the page-dir. Note the self-mapping in the last entry */
 218 extern inline void SET_PAGE_DIR(struct task_struct * tsk, pgd_t * pgdir)
     /*  */
 219 {
 220         pgd_val(pgdir[PTRS_PER_PGD]) = pte_val(mk_pte((unsigned long) pgdir, PAGE_KERNEL));
 221         tsk->tss.ptbr = ((unsigned long) pgdir - PAGE_OFFSET) >> PAGE_SHIFT;
 222         if (tsk == current)
 223                 invalidate();
 224 }
 225 
 226 #define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
 227 
 228 /* to find an entry in a page-table-directory. */
 229 extern inline pgd_t * pgd_offset(struct task_struct * tsk, unsigned long address)
     /*  */
 230 {
 231         return (pgd_t *) ((tsk->tss.ptbr << PAGE_SHIFT) + PAGE_OFFSET) +
 232                 ((address >> PGDIR_SHIFT) & (PTRS_PER_PAGE - 1));
 233 }
 234 
 235 /* Find an entry in the second-level page table.. */
 236 extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
     /*  */
 237 {
 238         return (pmd_t *) pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1));
 239 }
 240 
 241 /* Find an entry in the third-level page table.. */
 242 extern inline pte_t * pte_offset(pmd_t * dir, unsigned long address)
     /*  */
 243 {
 244         return (pte_t *) pmd_page(*dir) + ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1));
 245 }
 246 
 247 /*              
 248  * Allocate and free page tables. The xxx_kernel() versions are
 249  * used to allocate a kernel page table - this turns on ASN bits
 250  * if any, and marks the page tables reserved.
 251  */
 252 extern inline void pte_free_kernel(pte_t * pte)
     /*  */
 253 {
 254         mem_map[MAP_NR(pte)] = 1;
 255         free_page((unsigned long) pte);
 256 }
 257 
 258 extern inline pte_t * pte_alloc_kernel(pmd_t *pmd, unsigned long address)
     /*  */
 259 {
 260         address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
 261         if (pmd_none(*pmd)) {
 262                 pte_t *page = (pte_t *) get_free_page(GFP_KERNEL);
 263                 if (pmd_none(*pmd)) {
 264                         if (page) {
 265                                 pmd_set(pmd, page);
 266                                 mem_map[MAP_NR(page)] = MAP_PAGE_RESERVED;
 267                                 return page + address;
 268                         }
 269                         pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
 270                         return NULL;
 271                 }
 272                 free_page((unsigned long) page);
 273         }
 274         if (pmd_bad(*pmd)) {
 275                 printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
 276                 pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
 277                 return NULL;
 278         }
 279         return (pte_t *) pmd_page(*pmd) + address;
 280 }
 281 
 282 extern inline void pmd_free_kernel(pmd_t * pmd)
     /*  */
 283 {
 284         mem_map[MAP_NR(pmd)] = 1;
 285         free_page((unsigned long) pmd);
 286 }
 287 
 288 extern inline pmd_t * pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
     /*  */
 289 {
 290         address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
 291         if (pgd_none(*pgd)) {
 292                 pmd_t *page = (pmd_t *) get_free_page(GFP_KERNEL);
 293                 if (pgd_none(*pgd)) {
 294                         if (page) {
 295                                 pgd_set(pgd, page);
 296                                 mem_map[MAP_NR(page)] = MAP_PAGE_RESERVED;
 297                                 return page + address;
 298                         }
 299                         pgd_set(pgd, BAD_PAGETABLE);
 300                         return NULL;
 301                 }
 302                 free_page((unsigned long) page);
 303         }
 304         if (pgd_bad(*pgd)) {
 305                 printk("Bad pgd in pmd_alloc: %08lx\n", pgd_val(*pgd));
 306                 pgd_set(pgd, BAD_PAGETABLE);
 307                 return NULL;
 308         }
 309         return (pmd_t *) pgd_page(*pgd) + address;
 310 }
 311 
 312 extern inline void pte_free(pte_t * pte)
     /*  */
 313 {
 314         free_page((unsigned long) pte);
 315 }
 316 
 317 extern inline pte_t * pte_alloc(pmd_t *pmd, unsigned long address)
     /*  */
 318 {
 319         address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
 320         if (pmd_none(*pmd)) {
 321                 pte_t *page = (pte_t *) get_free_page(GFP_KERNEL);
 322                 if (pmd_none(*pmd)) {
 323                         if (page) {
 324                                 pmd_set(pmd, page);
 325                                 return page + address;
 326                         }
 327                         pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
 328                         return NULL;
 329                 }
 330                 free_page((unsigned long) page);
 331         }
 332         if (pmd_bad(*pmd)) {
 333                 printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
 334                 pmd_set(pmd, (pte_t *) BAD_PAGETABLE);
 335                 return NULL;
 336         }
 337         return (pte_t *) pmd_page(*pmd) + address;
 338 }
 339 
 340 extern inline void pmd_free(pmd_t * pmd)
     /*  */
 341 {
 342         free_page((unsigned long) pmd);
 343 }
 344 
 345 extern inline pmd_t * pmd_alloc(pgd_t *pgd, unsigned long address)
     /*  */
 346 {
 347         address = (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
 348         if (pgd_none(*pgd)) {
 349                 pmd_t *page = (pmd_t *) get_free_page(GFP_KERNEL);
 350                 if (pgd_none(*pgd)) {
 351                         if (page) {
 352                                 pgd_set(pgd, page);
 353                                 return page + address;
 354                         }
 355                         pgd_set(pgd, BAD_PAGETABLE);
 356                         return NULL;
 357                 }
 358                 free_page((unsigned long) page);
 359         }
 360         if (pgd_bad(*pgd)) {
 361                 printk("Bad pgd in pmd_alloc: %08lx\n", pgd_val(*pgd));
 362                 pgd_set(pgd, BAD_PAGETABLE);
 363                 return NULL;
 364         }
 365         return (pmd_t *) pgd_page(*pgd) + address;
 366 }
 367 
 368 extern inline void pgd_free(pgd_t * pgd)
     /*  */
 369 {
 370         free_page((unsigned long) pgd);
 371 }
 372 
 373 extern inline pgd_t * pgd_alloc(void)
     /*  */
 374 {
 375         return (pgd_t *) get_free_page(GFP_KERNEL);
 376 }
 377 
 378 extern pgd_t swapper_pg_dir[1024];
 379 
 380 /*
 381  * The alpha doesn't have any external MMU info: the kernel page
 382  * tables contain all the necessary information.
 383  */
 384 extern inline void update_mmu_cache(struct vm_area_struct * vma,
     /*  */
 385         unsigned long address, pte_t pte)
 386 {
 387 }
 388 
 389 #endif /* _ALPHA_PGTABLE_H */

/* */