hugetlbpage.c 4.7 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201
  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * IA-64 Huge TLB Page Support for Kernel.
  4. *
  5. * Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
  6. * Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
  7. *
  8. * Sep, 2003: add numa support
  9. * Feb, 2004: dynamic hugetlb page size via boot parameter
  10. */
  11. #include <linux/init.h>
  12. #include <linux/fs.h>
  13. #include <linux/mm.h>
  14. #include <linux/hugetlb.h>
  15. #include <linux/pagemap.h>
  16. #include <linux/module.h>
  17. #include <linux/sysctl.h>
  18. #include <linux/log2.h>
  19. #include <asm/mman.h>
  20. #include <asm/tlb.h>
  21. #include <asm/tlbflush.h>
  22. unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
  23. EXPORT_SYMBOL(hpage_shift);
  24. pte_t *
  25. huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
  26. unsigned long addr, unsigned long sz)
  27. {
  28. unsigned long taddr = htlbpage_to_page(addr);
  29. pgd_t *pgd;
  30. p4d_t *p4d;
  31. pud_t *pud;
  32. pmd_t *pmd;
  33. pte_t *pte = NULL;
  34. pgd = pgd_offset(mm, taddr);
  35. p4d = p4d_offset(pgd, taddr);
  36. pud = pud_alloc(mm, p4d, taddr);
  37. if (pud) {
  38. pmd = pmd_alloc(mm, pud, taddr);
  39. if (pmd)
  40. pte = pte_alloc_map(mm, pmd, taddr);
  41. }
  42. return pte;
  43. }
  44. pte_t *
  45. huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz)
  46. {
  47. unsigned long taddr = htlbpage_to_page(addr);
  48. pgd_t *pgd;
  49. p4d_t *p4d;
  50. pud_t *pud;
  51. pmd_t *pmd;
  52. pte_t *pte = NULL;
  53. pgd = pgd_offset(mm, taddr);
  54. if (pgd_present(*pgd)) {
  55. p4d = p4d_offset(pgd, addr);
  56. if (p4d_present(*p4d)) {
  57. pud = pud_offset(p4d, taddr);
  58. if (pud_present(*pud)) {
  59. pmd = pmd_offset(pud, taddr);
  60. if (pmd_present(*pmd))
  61. pte = pte_offset_map(pmd, taddr);
  62. }
  63. }
  64. }
  65. return pte;
  66. }
  67. #define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
  68. /*
  69. * Don't actually need to do any preparation, but need to make sure
  70. * the address is in the right region.
  71. */
  72. int prepare_hugepage_range(struct file *file,
  73. unsigned long addr, unsigned long len)
  74. {
  75. if (len & ~HPAGE_MASK)
  76. return -EINVAL;
  77. if (addr & ~HPAGE_MASK)
  78. return -EINVAL;
  79. if (REGION_NUMBER(addr) != RGN_HPAGE)
  80. return -EINVAL;
  81. return 0;
  82. }
  83. struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
  84. {
  85. struct page *page;
  86. pte_t *ptep;
  87. if (REGION_NUMBER(addr) != RGN_HPAGE)
  88. return ERR_PTR(-EINVAL);
  89. ptep = huge_pte_offset(mm, addr, HPAGE_SIZE);
  90. if (!ptep || pte_none(*ptep))
  91. return NULL;
  92. page = pte_page(*ptep);
  93. page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
  94. return page;
  95. }
  96. int pmd_huge(pmd_t pmd)
  97. {
  98. return 0;
  99. }
  100. int pud_huge(pud_t pud)
  101. {
  102. return 0;
  103. }
  104. void hugetlb_free_pgd_range(struct mmu_gather *tlb,
  105. unsigned long addr, unsigned long end,
  106. unsigned long floor, unsigned long ceiling)
  107. {
  108. /*
  109. * This is called to free hugetlb page tables.
  110. *
  111. * The offset of these addresses from the base of the hugetlb
  112. * region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
  113. * the standard free_pgd_range will free the right page tables.
  114. *
  115. * If floor and ceiling are also in the hugetlb region, they
  116. * must likewise be scaled down; but if outside, left unchanged.
  117. */
  118. addr = htlbpage_to_page(addr);
  119. end = htlbpage_to_page(end);
  120. if (REGION_NUMBER(floor) == RGN_HPAGE)
  121. floor = htlbpage_to_page(floor);
  122. if (REGION_NUMBER(ceiling) == RGN_HPAGE)
  123. ceiling = htlbpage_to_page(ceiling);
  124. free_pgd_range(tlb, addr, end, floor, ceiling);
  125. }
  126. unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
  127. unsigned long pgoff, unsigned long flags)
  128. {
  129. struct vm_unmapped_area_info info;
  130. if (len > RGN_MAP_LIMIT)
  131. return -ENOMEM;
  132. if (len & ~HPAGE_MASK)
  133. return -EINVAL;
  134. /* Handle MAP_FIXED */
  135. if (flags & MAP_FIXED) {
  136. if (prepare_hugepage_range(file, addr, len))
  137. return -EINVAL;
  138. return addr;
  139. }
  140. /* This code assumes that RGN_HPAGE != 0. */
  141. if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
  142. addr = HPAGE_REGION_BASE;
  143. info.flags = 0;
  144. info.length = len;
  145. info.low_limit = addr;
  146. info.high_limit = HPAGE_REGION_BASE + RGN_MAP_LIMIT;
  147. info.align_mask = PAGE_MASK & (HPAGE_SIZE - 1);
  148. info.align_offset = 0;
  149. return vm_unmapped_area(&info);
  150. }
  151. static int __init hugetlb_setup_sz(char *str)
  152. {
  153. u64 tr_pages;
  154. unsigned long long size;
  155. if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
  156. /*
  157. * shouldn't happen, but just in case.
  158. */
  159. tr_pages = 0x15557000UL;
  160. size = memparse(str, &str);
  161. if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
  162. size <= PAGE_SIZE ||
  163. size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
  164. printk(KERN_WARNING "Invalid huge page size specified\n");
  165. return 1;
  166. }
  167. hpage_shift = __ffs(size);
  168. /*
  169. * boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
  170. * override here with new page shift.
  171. */
  172. ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
  173. return 0;
  174. }
  175. early_param("hugepagesz", hugetlb_setup_sz);