1 /* 2 * IA-32 Huge TLB Page Support for Kernel. 3 * 4 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> 5 */ 6 7 #include <linux/init.h> 8 #include <linux/fs.h> 9 #include <linux/mm.h> 10 #include <linux/hugetlb.h> 11 #include <linux/pagemap.h> 12 #include <linux/err.h> 13 #include <linux/sysctl.h> 14 #include <asm/mman.h> 15 #include <asm/tlb.h> 16 #include <asm/tlbflush.h> 17 #include <asm/pgalloc.h> 18 19 #if 0 /* This is just for testing */ 20 struct page * 21 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 22 { 23 unsigned long start = address; 24 int length = 1; 25 int nr; 26 struct page *page; 27 struct vm_area_struct *vma; 28 29 vma = find_vma(mm, addr); 30 if (!vma || !is_vm_hugetlb_page(vma)) 31 return ERR_PTR(-EINVAL); 32 33 pte = huge_pte_offset(mm, address); 34 35 /* hugetlb should be locked, and hence, prefaulted */ 36 WARN_ON(!pte || pte_none(*pte)); 37 38 page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; 39 40 WARN_ON(!PageHead(page)); 41 42 return page; 43 } 44 45 int pmd_huge(pmd_t pmd) 46 { 47 return 0; 48 } 49 50 int pud_huge(pud_t pud) 51 { 52 return 0; 53 } 54 55 struct page * 56 follow_huge_pmd(struct mm_struct *mm, unsigned long address, 57 pmd_t *pmd, int write) 58 { 59 return NULL; 60 } 61 #else 62 63 struct page * 64 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 65 { 66 return ERR_PTR(-EINVAL); 67 } 68 69 int pmd_huge(pmd_t pmd) 70 { 71 return !!(pmd_val(pmd) & _PAGE_PSE); 72 } 73 74 int pud_huge(pud_t pud) 75 { 76 return !!(pud_val(pud) & _PAGE_PSE); 77 } 78 #endif 79 80 #ifdef CONFIG_HUGETLB_PAGE 81 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, 82 unsigned long addr, unsigned long len, 83 unsigned long pgoff, unsigned long flags) 84 { 85 struct hstate *h = hstate_file(file); 86 struct vm_unmapped_area_info info; 87 88 info.flags = 0; 89 info.length = len; 90 info.low_limit = current->mm->mmap_legacy_base; 91 info.high_limit = TASK_SIZE; 92 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 93 info.align_offset = 0; 94 return vm_unmapped_area(&info); 95 } 96 97 static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, 98 unsigned long addr0, unsigned long len, 99 unsigned long pgoff, unsigned long flags) 100 { 101 struct hstate *h = hstate_file(file); 102 struct vm_unmapped_area_info info; 103 unsigned long addr; 104 105 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 106 info.length = len; 107 info.low_limit = PAGE_SIZE; 108 info.high_limit = current->mm->mmap_base; 109 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 110 info.align_offset = 0; 111 addr = vm_unmapped_area(&info); 112 113 /* 114 * A failed mmap() very likely causes application failure, 115 * so fall back to the bottom-up function here. This scenario 116 * can happen with large stack limits and large mmap() 117 * allocations. 118 */ 119 if (addr & ~PAGE_MASK) { 120 VM_BUG_ON(addr != -ENOMEM); 121 info.flags = 0; 122 info.low_limit = TASK_UNMAPPED_BASE; 123 info.high_limit = TASK_SIZE; 124 addr = vm_unmapped_area(&info); 125 } 126 127 return addr; 128 } 129 130 unsigned long 131 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 132 unsigned long len, unsigned long pgoff, unsigned long flags) 133 { 134 struct hstate *h = hstate_file(file); 135 struct mm_struct *mm = current->mm; 136 struct vm_area_struct *vma; 137 138 if (len & ~huge_page_mask(h)) 139 return -EINVAL; 140 if (len > TASK_SIZE) 141 return -ENOMEM; 142 143 if (flags & MAP_FIXED) { 144 if (prepare_hugepage_range(file, addr, len)) 145 return -EINVAL; 146 return addr; 147 } 148 149 if (addr) { 150 addr = ALIGN(addr, huge_page_size(h)); 151 vma = find_vma(mm, addr); 152 if (TASK_SIZE - len >= addr && 153 (!vma || addr + len <= vma->vm_start)) 154 return addr; 155 } 156 if (mm->get_unmapped_area == arch_get_unmapped_area) 157 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 158 pgoff, flags); 159 else 160 return hugetlb_get_unmapped_area_topdown(file, addr, len, 161 pgoff, flags); 162 } 163 #endif /* CONFIG_HUGETLB_PAGE */ 164 165 #ifdef CONFIG_X86_64 166 static __init int setup_hugepagesz(char *opt) 167 { 168 unsigned long ps = memparse(opt, &opt); 169 if (ps == PMD_SIZE) { 170 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); 171 } else if (ps == PUD_SIZE && cpu_has_gbpages) { 172 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 173 } else { 174 printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n", 175 ps >> 20); 176 return 0; 177 } 178 return 1; 179 } 180 __setup("hugepagesz=", setup_hugepagesz); 181 #endif 182