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