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 62 int pmd_huge_support(void) 63 { 64 return 0; 65 } 66 #else 67 68 struct page * 69 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 70 { 71 return ERR_PTR(-EINVAL); 72 } 73 74 int pmd_huge(pmd_t pmd) 75 { 76 return !!(pmd_val(pmd) & _PAGE_PSE); 77 } 78 79 int pud_huge(pud_t pud) 80 { 81 return !!(pud_val(pud) & _PAGE_PSE); 82 } 83 84 int pmd_huge_support(void) 85 { 86 return 1; 87 } 88 #endif 89 90 /* x86_64 also uses this file */ 91 92 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA 93 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, 94 unsigned long addr, unsigned long len, 95 unsigned long pgoff, unsigned long flags) 96 { 97 struct hstate *h = hstate_file(file); 98 struct vm_unmapped_area_info info; 99 100 info.flags = 0; 101 info.length = len; 102 info.low_limit = TASK_UNMAPPED_BASE; 103 info.high_limit = TASK_SIZE; 104 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 105 info.align_offset = 0; 106 return vm_unmapped_area(&info); 107 } 108 109 static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, 110 unsigned long addr0, unsigned long len, 111 unsigned long pgoff, unsigned long flags) 112 { 113 struct hstate *h = hstate_file(file); 114 struct vm_unmapped_area_info info; 115 unsigned long addr; 116 117 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 118 info.length = len; 119 info.low_limit = PAGE_SIZE; 120 info.high_limit = current->mm->mmap_base; 121 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 122 info.align_offset = 0; 123 addr = vm_unmapped_area(&info); 124 125 /* 126 * A failed mmap() very likely causes application failure, 127 * so fall back to the bottom-up function here. This scenario 128 * can happen with large stack limits and large mmap() 129 * allocations. 130 */ 131 if (addr & ~PAGE_MASK) { 132 VM_BUG_ON(addr != -ENOMEM); 133 info.flags = 0; 134 info.low_limit = TASK_UNMAPPED_BASE; 135 info.high_limit = TASK_SIZE; 136 addr = vm_unmapped_area(&info); 137 } 138 139 return addr; 140 } 141 142 unsigned long 143 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 144 unsigned long len, unsigned long pgoff, unsigned long flags) 145 { 146 struct hstate *h = hstate_file(file); 147 struct mm_struct *mm = current->mm; 148 struct vm_area_struct *vma; 149 150 if (len & ~huge_page_mask(h)) 151 return -EINVAL; 152 if (len > TASK_SIZE) 153 return -ENOMEM; 154 155 if (flags & MAP_FIXED) { 156 if (prepare_hugepage_range(file, addr, len)) 157 return -EINVAL; 158 return addr; 159 } 160 161 if (addr) { 162 addr = ALIGN(addr, huge_page_size(h)); 163 vma = find_vma(mm, addr); 164 if (TASK_SIZE - len >= addr && 165 (!vma || addr + len <= vma->vm_start)) 166 return addr; 167 } 168 if (mm->get_unmapped_area == arch_get_unmapped_area) 169 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 170 pgoff, flags); 171 else 172 return hugetlb_get_unmapped_area_topdown(file, addr, len, 173 pgoff, flags); 174 } 175 176 #endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/ 177 178 #ifdef CONFIG_X86_64 179 static __init int setup_hugepagesz(char *opt) 180 { 181 unsigned long ps = memparse(opt, &opt); 182 if (ps == PMD_SIZE) { 183 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); 184 } else if (ps == PUD_SIZE && cpu_has_gbpages) { 185 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 186 } else { 187 printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n", 188 ps >> 20); 189 return 0; 190 } 191 return 1; 192 } 193 __setup("hugepagesz=", setup_hugepagesz); 194 #endif 195