normalDataOperation.h 7.0 KB

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  1. #ifndef _ALPHA_PGTABLE_H
  2. #define _ALPHA_PGTABLE_H
  3. #include <asm-generic/4level-fixup.h>
  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/mmzone.h>
  12. #include <asm/page.h>
  13. #include <asm/processor.h> /* For TASK_SIZE */
  14. #include <asm/machvec.h>
  15. #include <asm/setup.h>
  16. struct mm_struct;
  17. struct vm_area_struct;
  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. #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
  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. /* PGDIR_SHIFT determines what a third-level page table entry can map */
  29. #define PGDIR_SHIFT (PAGE_SHIFT + 2*(PAGE_SHIFT-3))
  30. #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
  31. #define PGDIR_MASK (~(PGDIR_SIZE-1))
  32. /*
  33. * Entries per page directory level: the Alpha is three-level, with
  34. * all levels having a one-page page table.
  35. */
  36. #define PTRS_PER_PTE (1UL << (PAGE_SHIFT-3))
  37. #define PTRS_PER_PMD (1UL << (PAGE_SHIFT-3))
  38. #define PTRS_PER_PGD (1UL << (PAGE_SHIFT-3))
  39. #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
  40. #define FIRST_USER_ADDRESS 0
  41. /* Number of pointers that fit on a page: this will go away. */
  42. #define PTRS_PER_PAGE (1UL << (PAGE_SHIFT-3))
  43. #ifdef CONFIG_ALPHA_LARGE_VMALLOC
  44. #define VMALLOC_START 0xfffffe0000000000
  45. #else
  46. #define VMALLOC_START (-2*PGDIR_SIZE)
  47. #endif
  48. #define VMALLOC_END (-PGDIR_SIZE)
  49. /*
  50. * OSF/1 PAL-code-imposed page table bits
  51. */
  52. #define _PAGE_VALID 0x0001
  53. #define _PAGE_FOR 0x0002 /* used for page protection (fault on read) */
  54. #define _PAGE_FOW 0x0004 /* used for page protection (fault on write) */
  55. #define _PAGE_FOE 0x0008 /* used for page protection (fault on exec) */
  56. #define _PAGE_ASM 0x0010
  57. #define _PAGE_KRE 0x0100 /* xxx - see below on the "accessed" bit */
  58. #define _PAGE_URE 0x0200 /* xxx */
  59. #define _PAGE_KWE 0x1000 /* used to do the dirty bit in software */
  60. #define _PAGE_UWE 0x2000 /* used to do the dirty bit in software */
  61. /* .. and these are ours ... */
  62. #define _PAGE_DIRTY 0x20000
  63. #define _PAGE_ACCESSED 0x40000
  64. #define _PAGE_FILE 0x80000 /* set:pagecache, unset:swap */
  65. /*
  66. * NOTE! The "accessed" bit isn't necessarily exact: it can be kept exactly
  67. * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it.
  68. * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use
  69. * the KRE/URE bits to watch for it. That way we don't need to overload the
  70. * KWE/UWE bits with both handling dirty and accessed.
  71. *
  72. * Note that the kernel uses the accessed bit just to check whether to page
  73. * out a page or not, so it doesn't have to be exact anyway.
  74. */
  75. #define __DIRTY_BITS (_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE)
  76. #define __ACCESS_BITS (_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE)
  77. #define _PFN_MASK 0xFFFFFFFF00000000UL
  78. #define _PAGE_TABLE (_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS)
  79. #define _PAGE_CHG_MASK (_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS)
  80. /*
  81. * All the normal masks have the "page accessed" bits on, as any time they are used,
  82. * the page is accessed. They are cleared only by the page-out routines
  83. */
  84. #define PAGE_NONE __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE)
  85. #define PAGE_SHARED __pgprot(_PAGE_VALID | __ACCESS_BITS)
  86. #define PAGE_COPY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW)
  87. #define PAGE_READONLY __pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW)
  88. #define PAGE_KERNEL __pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE)
  89. #define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x))
  90. #define _PAGE_P(x) _PAGE_NORMAL((x) | (((x) & _PAGE_FOW)?0:_PAGE_FOW))
  91. #define _PAGE_S(x) _PAGE_NORMAL(x)
  92. /*
  93. * The hardware can handle write-only mappings, but as the Alpha
  94. * architecture does byte-wide writes with a read-modify-write
  95. * sequence, it's not practical to have write-without-read privs.
  96. * Thus the "-w- -> rw-" and "-wx -> rwx" mapping here (and in
  97. * arch/alpha/mm/fault.c)
  98. */
  99. /* xwr */
  100. #define __P000 _PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)
  101. #define __P001 _PAGE_P(_PAGE_FOE | _PAGE_FOW)
  102. #define __P010 _PAGE_P(_PAGE_FOE)
  103. #define __P011 _PAGE_P(_PAGE_FOE)
  104. #define __P100 _PAGE_P(_PAGE_FOW | _PAGE_FOR)
  105. #define __P101 _PAGE_P(_PAGE_FOW)
  106. #define __P110 _PAGE_P(0)
  107. #define __P111 _PAGE_P(0)
  108. #define __S000 _PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)
  109. #define __S001 _PAGE_S(_PAGE_FOE | _PAGE_FOW)
  110. #define __S010 _PAGE_S(_PAGE_FOE)
  111. #define __S011 _PAGE_S(_PAGE_FOE)
  112. #define __S100 _PAGE_S(_PAGE_FOW | _PAGE_FOR)
  113. #define __S101 _PAGE_S(_PAGE_FOW)
  114. #define __S110 _PAGE_S(0)
  115. #define __S111 _PAGE_S(0)
  116. /*
  117. * pgprot_noncached() is only for infiniband pci support, and a real
  118. * implementation for RAM would be more complicated.
  119. */
  120. #define pgprot_noncached(prot) (prot)
  121. /*
  122. * BAD_PAGETABLE is used when we need a bogus page-table, while
  123. * BAD_PAGE is used for a bogus page.
  124. *
  125. * ZERO_PAGE is a global shared page that is always zero: used
  126. * for zero-mapped memory areas etc..
  127. */
  128. extern pte_t __bad_page(void);
  129. extern pmd_t * __bad_pagetable(void);
  130. extern unsigned long __zero_page(void);
  131. #define BAD_PAGETABLE __bad_pagetable()
  132. #define BAD_PAGE __bad_page()
  133. #define ZERO_PAGE(vaddr) (virt_to_page(ZERO_PGE))
  134. /* number of bits that fit into a memory pointer */
  135. #define BITS_PER_PTR (8*sizeof(unsigned long))
  136. /* to align the pointer to a pointer address */
  137. #define PTR_MASK (~(sizeof(void*)-1))
  138. /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
  139. #define SIZEOF_PTR_LOG2 3
  140. /* to find an entry in a page-table */
  141. #define PAGE_PTR(address) \
  142. ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
  143. /*
  144. * On certain platforms whose physical address space can overlap KSEG,
  145. * namely EV6 and above, we must re-twiddle the physaddr to restore the
  146. * correct high-order bits.
  147. *
  148. * This is extremely confusing until you realize that this is actually
  149. * just working around a userspace bug. The X server was intending to
  150. * provide the physical address but instead provided the KSEG address.
  151. * Or tried to, except it's not representable.
  152. *
  153. * On Tsunami there's nothing meaningful at 0x40000000000, so this is
  154. * a safe thing to do. Come the first core logic that does put something
  155. * in this area -- memory or whathaveyou -- then this hack will have
  156. * to go away. So be prepared!
  157. */
  158. #if defined(CONFIG_ALPHA_GENERIC) && defined(USE_48_BIT_KSEG)
  159. #error "EV6-only feature in a generic kernel"
  160. #endif
  161. #if defined(CONFIG_ALPHA_GENERIC) || \
  162. (defined(CONFIG_ALPHA_EV6) && !defined(USE_48_BIT_KSEG))
  163. #define KSEG_PFN (0xc0000000000UL >> PAGE_SHIFT)
  164. #define PHYS_TWIDDLE(pfn) \
  165. ((((pfn) & KSEG_PFN) == (0x40000000000UL >> PAGE_SHIFT)) \
  166. ? ((pfn) ^= KSEG_PFN) : (pfn))
  167. #else
  168. #define PHYS_TWIDDLE(pfn) (pfn)
  169. #endif
  170. /*
  171. * Conversion functions: convert a page and protection to a page entry,
  172. * and a page entry and page directory to the page they refer to.