pageattr.c 2.9 KB

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  1. /*
  2. * Copyright IBM Corp. 2011
  3. * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
  4. */
  5. #include <linux/hugetlb.h>
  6. #include <linux/module.h>
  7. #include <linux/mm.h>
  8. #include <asm/cacheflush.h>
  9. #include <asm/pgtable.h>
  10. #include <asm/page.h>
  11. #if PAGE_DEFAULT_KEY
  12. static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
  13. {
  14. asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
  15. : [addr] "+a" (addr) : [skey] "d" (skey));
  16. return addr;
  17. }
  18. void __storage_key_init_range(unsigned long start, unsigned long end)
  19. {
  20. unsigned long boundary, size;
  21. while (start < end) {
  22. if (MACHINE_HAS_EDAT1) {
  23. /* set storage keys for a 1MB frame */
  24. size = 1UL << 20;
  25. boundary = (start + size) & ~(size - 1);
  26. if (boundary <= end) {
  27. do {
  28. start = sske_frame(start, PAGE_DEFAULT_KEY);
  29. } while (start < boundary);
  30. continue;
  31. }
  32. }
  33. page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
  34. start += PAGE_SIZE;
  35. }
  36. }
  37. #endif
  38. static pte_t *walk_page_table(unsigned long addr)
  39. {
  40. pgd_t *pgdp;
  41. pud_t *pudp;
  42. pmd_t *pmdp;
  43. pte_t *ptep;
  44. pgdp = pgd_offset_k(addr);
  45. if (pgd_none(*pgdp))
  46. return NULL;
  47. pudp = pud_offset(pgdp, addr);
  48. if (pud_none(*pudp) || pud_large(*pudp))
  49. return NULL;
  50. pmdp = pmd_offset(pudp, addr);
  51. if (pmd_none(*pmdp) || pmd_large(*pmdp))
  52. return NULL;
  53. ptep = pte_offset_kernel(pmdp, addr);
  54. if (pte_none(*ptep))
  55. return NULL;
  56. return ptep;
  57. }
  58. static void change_page_attr(unsigned long addr, int numpages,
  59. pte_t (*set) (pte_t))
  60. {
  61. pte_t *ptep, pte;
  62. int i;
  63. for (i = 0; i < numpages; i++) {
  64. ptep = walk_page_table(addr);
  65. if (WARN_ON_ONCE(!ptep))
  66. break;
  67. pte = *ptep;
  68. pte = set(pte);
  69. __ptep_ipte(addr, ptep);
  70. *ptep = pte;
  71. addr += PAGE_SIZE;
  72. }
  73. }
  74. int set_memory_ro(unsigned long addr, int numpages)
  75. {
  76. change_page_attr(addr, numpages, pte_wrprotect);
  77. return 0;
  78. }
  79. int set_memory_rw(unsigned long addr, int numpages)
  80. {
  81. change_page_attr(addr, numpages, pte_mkwrite);
  82. return 0;
  83. }
  84. /* not possible */
  85. int set_memory_nx(unsigned long addr, int numpages)
  86. {
  87. return 0;
  88. }
  89. int set_memory_x(unsigned long addr, int numpages)
  90. {
  91. return 0;
  92. }
  93. #ifdef CONFIG_DEBUG_PAGEALLOC
  94. void kernel_map_pages(struct page *page, int numpages, int enable)
  95. {
  96. unsigned long address;
  97. pgd_t *pgd;
  98. pud_t *pud;
  99. pmd_t *pmd;
  100. pte_t *pte;
  101. int i;
  102. for (i = 0; i < numpages; i++) {
  103. address = page_to_phys(page + i);
  104. pgd = pgd_offset_k(address);
  105. pud = pud_offset(pgd, address);
  106. pmd = pmd_offset(pud, address);
  107. pte = pte_offset_kernel(pmd, address);
  108. if (!enable) {
  109. __ptep_ipte(address, pte);
  110. pte_val(*pte) = _PAGE_INVALID;
  111. continue;
  112. }
  113. pte_val(*pte) = __pa(address);
  114. }
  115. }
  116. #ifdef CONFIG_HIBERNATION
  117. bool kernel_page_present(struct page *page)
  118. {
  119. unsigned long addr;
  120. int cc;
  121. addr = page_to_phys(page);
  122. asm volatile(
  123. " lra %1,0(%1)\n"
  124. " ipm %0\n"
  125. " srl %0,28"
  126. : "=d" (cc), "+a" (addr) : : "cc");
  127. return cc == 0;
  128. }
  129. #endif /* CONFIG_HIBERNATION */
  130. #endif /* CONFIG_DEBUG_PAGEALLOC */