1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * IA-32 Huge TLB Page Support for Kernel. 4 * 5 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> 6 */ 7 8 #include <linux/init.h> 9 #include <linux/fs.h> 10 #include <linux/mm.h> 11 #include <linux/sched/mm.h> 12 #include <linux/hugetlb.h> 13 #include <linux/pagemap.h> 14 #include <linux/err.h> 15 #include <linux/sysctl.h> 16 #include <linux/compat.h> 17 #include <asm/mman.h> 18 #include <asm/tlb.h> 19 #include <asm/tlbflush.h> 20 #include <asm/elf.h> 21 22 /* 23 * pmd_huge() returns 1 if @pmd is hugetlb related entry, that is normal 24 * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. 25 * Otherwise, returns 0. 26 */ 27 int pmd_huge(pmd_t pmd) 28 { 29 return !pmd_none(pmd) && 30 (pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; 31 } 32 33 /* 34 * pud_huge() returns 1 if @pud is hugetlb related entry, that is normal 35 * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. 36 * Otherwise, returns 0. 37 */ 38 int pud_huge(pud_t pud) 39 { 40 return !pud_none(pud) && 41 (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; 42 } 43 44 #ifdef CONFIG_HUGETLB_PAGE 45 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, 46 unsigned long addr, unsigned long len, 47 unsigned long pgoff, unsigned long flags) 48 { 49 struct hstate *h = hstate_file(file); 50 struct vm_unmapped_area_info info; 51 52 info.flags = 0; 53 info.length = len; 54 info.low_limit = get_mmap_base(1); 55 56 /* 57 * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area 58 * in the full address space. 59 */ 60 info.high_limit = in_32bit_syscall() ? 61 task_size_32bit() : task_size_64bit(addr > DEFAULT_MAP_WINDOW); 62 63 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 64 info.align_offset = 0; 65 return vm_unmapped_area(&info); 66 } 67 68 static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, 69 unsigned long addr, unsigned long len, 70 unsigned long pgoff, unsigned long flags) 71 { 72 struct hstate *h = hstate_file(file); 73 struct vm_unmapped_area_info info; 74 75 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 76 info.length = len; 77 info.low_limit = PAGE_SIZE; 78 info.high_limit = get_mmap_base(0); 79 80 /* 81 * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area 82 * in the full address space. 83 */ 84 if (addr > DEFAULT_MAP_WINDOW && !in_32bit_syscall()) 85 info.high_limit += TASK_SIZE_MAX - DEFAULT_MAP_WINDOW; 86 87 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 88 info.align_offset = 0; 89 addr = vm_unmapped_area(&info); 90 91 /* 92 * A failed mmap() very likely causes application failure, 93 * so fall back to the bottom-up function here. This scenario 94 * can happen with large stack limits and large mmap() 95 * allocations. 96 */ 97 if (addr & ~PAGE_MASK) { 98 VM_BUG_ON(addr != -ENOMEM); 99 info.flags = 0; 100 info.low_limit = TASK_UNMAPPED_BASE; 101 info.high_limit = TASK_SIZE_LOW; 102 addr = vm_unmapped_area(&info); 103 } 104 105 return addr; 106 } 107 108 unsigned long 109 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 110 unsigned long len, unsigned long pgoff, unsigned long flags) 111 { 112 struct hstate *h = hstate_file(file); 113 struct mm_struct *mm = current->mm; 114 struct vm_area_struct *vma; 115 116 if (len & ~huge_page_mask(h)) 117 return -EINVAL; 118 119 if (len > TASK_SIZE) 120 return -ENOMEM; 121 122 /* No address checking. See comment at mmap_address_hint_valid() */ 123 if (flags & MAP_FIXED) { 124 if (prepare_hugepage_range(file, addr, len)) 125 return -EINVAL; 126 return addr; 127 } 128 129 if (addr) { 130 addr &= huge_page_mask(h); 131 if (!mmap_address_hint_valid(addr, len)) 132 goto get_unmapped_area; 133 134 vma = find_vma(mm, addr); 135 if (!vma || addr + len <= vm_start_gap(vma)) 136 return addr; 137 } 138 139 get_unmapped_area: 140 if (mm->get_unmapped_area == arch_get_unmapped_area) 141 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 142 pgoff, flags); 143 else 144 return hugetlb_get_unmapped_area_topdown(file, addr, len, 145 pgoff, flags); 146 } 147 #endif /* CONFIG_HUGETLB_PAGE */ 148 149 #ifdef CONFIG_X86_64 150 bool __init arch_hugetlb_valid_size(unsigned long size) 151 { 152 if (size == PMD_SIZE) 153 return true; 154 else if (size == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES)) 155 return true; 156 else 157 return false; 158 } 159 160 #ifdef CONFIG_CONTIG_ALLOC 161 static __init int gigantic_pages_init(void) 162 { 163 /* With compaction or CMA we can allocate gigantic pages at runtime */ 164 if (boot_cpu_has(X86_FEATURE_GBPAGES)) 165 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 166 return 0; 167 } 168 arch_initcall(gigantic_pages_init); 169 #endif 170 #endif 171