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 #else 56 57 /* 58 * pmd_huge() returns 1 if @pmd is hugetlb related entry, that is normal 59 * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. 60 * Otherwise, returns 0. 61 */ 62 int pmd_huge(pmd_t pmd) 63 { 64 return !pmd_none(pmd) && 65 (pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; 66 } 67 68 int pud_huge(pud_t pud) 69 { 70 return !!(pud_val(pud) & _PAGE_PSE); 71 } 72 #endif 73 74 #ifdef CONFIG_HUGETLB_PAGE 75 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, 76 unsigned long addr, unsigned long len, 77 unsigned long pgoff, unsigned long flags) 78 { 79 struct hstate *h = hstate_file(file); 80 struct vm_unmapped_area_info info; 81 82 info.flags = 0; 83 info.length = len; 84 info.low_limit = current->mm->mmap_legacy_base; 85 info.high_limit = TASK_SIZE; 86 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 87 info.align_offset = 0; 88 return vm_unmapped_area(&info); 89 } 90 91 static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, 92 unsigned long addr0, unsigned long len, 93 unsigned long pgoff, unsigned long flags) 94 { 95 struct hstate *h = hstate_file(file); 96 struct vm_unmapped_area_info info; 97 unsigned long addr; 98 99 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 100 info.length = len; 101 info.low_limit = PAGE_SIZE; 102 info.high_limit = current->mm->mmap_base; 103 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 104 info.align_offset = 0; 105 addr = vm_unmapped_area(&info); 106 107 /* 108 * A failed mmap() very likely causes application failure, 109 * so fall back to the bottom-up function here. This scenario 110 * can happen with large stack limits and large mmap() 111 * allocations. 112 */ 113 if (addr & ~PAGE_MASK) { 114 VM_BUG_ON(addr != -ENOMEM); 115 info.flags = 0; 116 info.low_limit = TASK_UNMAPPED_BASE; 117 info.high_limit = TASK_SIZE; 118 addr = vm_unmapped_area(&info); 119 } 120 121 return addr; 122 } 123 124 unsigned long 125 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 126 unsigned long len, unsigned long pgoff, unsigned long flags) 127 { 128 struct hstate *h = hstate_file(file); 129 struct mm_struct *mm = current->mm; 130 struct vm_area_struct *vma; 131 132 if (len & ~huge_page_mask(h)) 133 return -EINVAL; 134 if (len > TASK_SIZE) 135 return -ENOMEM; 136 137 if (flags & MAP_FIXED) { 138 if (prepare_hugepage_range(file, addr, len)) 139 return -EINVAL; 140 return addr; 141 } 142 143 if (addr) { 144 addr = ALIGN(addr, huge_page_size(h)); 145 vma = find_vma(mm, addr); 146 if (TASK_SIZE - len >= addr && 147 (!vma || addr + len <= vma->vm_start)) 148 return addr; 149 } 150 if (mm->get_unmapped_area == arch_get_unmapped_area) 151 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 152 pgoff, flags); 153 else 154 return hugetlb_get_unmapped_area_topdown(file, addr, len, 155 pgoff, flags); 156 } 157 #endif /* CONFIG_HUGETLB_PAGE */ 158 159 #ifdef CONFIG_X86_64 160 static __init int setup_hugepagesz(char *opt) 161 { 162 unsigned long ps = memparse(opt, &opt); 163 if (ps == PMD_SIZE) { 164 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); 165 } else if (ps == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES)) { 166 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 167 } else { 168 hugetlb_bad_size(); 169 printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n", 170 ps >> 20); 171 return 0; 172 } 173 return 1; 174 } 175 __setup("hugepagesz=", setup_hugepagesz); 176 177 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA) 178 static __init int gigantic_pages_init(void) 179 { 180 /* With compaction or CMA we can allocate gigantic pages at runtime */ 181 if (boot_cpu_has(X86_FEATURE_GBPAGES) && !size_to_hstate(1UL << PUD_SHIFT)) 182 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 183 return 0; 184 } 185 arch_initcall(gigantic_pages_init); 186 #endif 187 #endif 188