Loading...
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 */
27int 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 */
38int pud_huge(pud_t pud)
39{
40#if CONFIG_PGTABLE_LEVELS > 2
41 return !pud_none(pud) &&
42 (pud_val(pud) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT;
43#else
44 return 0;
45#endif
46}
47
48#ifdef CONFIG_HUGETLB_PAGE
49static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
50 unsigned long addr, unsigned long len,
51 unsigned long pgoff, unsigned long flags)
52{
53 struct hstate *h = hstate_file(file);
54 struct vm_unmapped_area_info info;
55
56 info.flags = 0;
57 info.length = len;
58 info.low_limit = get_mmap_base(1);
59
60 /*
61 * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area
62 * in the full address space.
63 */
64 info.high_limit = in_32bit_syscall() ?
65 task_size_32bit() : task_size_64bit(addr > DEFAULT_MAP_WINDOW);
66
67 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
68 info.align_offset = 0;
69 return vm_unmapped_area(&info);
70}
71
72static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
73 unsigned long addr, unsigned long len,
74 unsigned long pgoff, unsigned long flags)
75{
76 struct hstate *h = hstate_file(file);
77 struct vm_unmapped_area_info info;
78
79 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
80 info.length = len;
81 info.low_limit = PAGE_SIZE;
82 info.high_limit = get_mmap_base(0);
83
84 /*
85 * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area
86 * in the full address space.
87 */
88 if (addr > DEFAULT_MAP_WINDOW && !in_32bit_syscall())
89 info.high_limit += TASK_SIZE_MAX - DEFAULT_MAP_WINDOW;
90
91 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
92 info.align_offset = 0;
93 addr = vm_unmapped_area(&info);
94
95 /*
96 * A failed mmap() very likely causes application failure,
97 * so fall back to the bottom-up function here. This scenario
98 * can happen with large stack limits and large mmap()
99 * allocations.
100 */
101 if (addr & ~PAGE_MASK) {
102 VM_BUG_ON(addr != -ENOMEM);
103 info.flags = 0;
104 info.low_limit = TASK_UNMAPPED_BASE;
105 info.high_limit = TASK_SIZE_LOW;
106 addr = vm_unmapped_area(&info);
107 }
108
109 return addr;
110}
111
112unsigned long
113hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
114 unsigned long len, unsigned long pgoff, unsigned long flags)
115{
116 struct hstate *h = hstate_file(file);
117 struct mm_struct *mm = current->mm;
118 struct vm_area_struct *vma;
119
120 if (len & ~huge_page_mask(h))
121 return -EINVAL;
122
123 if (len > TASK_SIZE)
124 return -ENOMEM;
125
126 /* No address checking. See comment at mmap_address_hint_valid() */
127 if (flags & MAP_FIXED) {
128 if (prepare_hugepage_range(file, addr, len))
129 return -EINVAL;
130 return addr;
131 }
132
133 if (addr) {
134 addr &= huge_page_mask(h);
135 if (!mmap_address_hint_valid(addr, len))
136 goto get_unmapped_area;
137
138 vma = find_vma(mm, addr);
139 if (!vma || addr + len <= vm_start_gap(vma))
140 return addr;
141 }
142
143get_unmapped_area:
144 if (mm->get_unmapped_area == arch_get_unmapped_area)
145 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
146 pgoff, flags);
147 else
148 return hugetlb_get_unmapped_area_topdown(file, addr, len,
149 pgoff, flags);
150}
151#endif /* CONFIG_HUGETLB_PAGE */
152
153#ifdef CONFIG_X86_64
154bool __init arch_hugetlb_valid_size(unsigned long size)
155{
156 if (size == PMD_SIZE)
157 return true;
158 else if (size == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES))
159 return true;
160 else
161 return false;
162}
163
164#ifdef CONFIG_CONTIG_ALLOC
165static __init int gigantic_pages_init(void)
166{
167 /* With compaction or CMA we can allocate gigantic pages at runtime */
168 if (boot_cpu_has(X86_FEATURE_GBPAGES))
169 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
170 return 0;
171}
172arch_initcall(gigantic_pages_init);
173#endif
174#endif
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 */
20struct page *
21follow_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
45int pmd_huge(pmd_t pmd)
46{
47 return 0;
48}
49
50int pud_huge(pud_t pud)
51{
52 return 0;
53}
54
55struct page *
56follow_huge_pmd(struct mm_struct *mm, unsigned long address,
57 pmd_t *pmd, int write)
58{
59 return NULL;
60}
61
62int pmd_huge_support(void)
63{
64 return 0;
65}
66#else
67
68struct page *
69follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
70{
71 return ERR_PTR(-EINVAL);
72}
73
74int pmd_huge(pmd_t pmd)
75{
76 return !!(pmd_val(pmd) & _PAGE_PSE);
77}
78
79int pud_huge(pud_t pud)
80{
81 return !!(pud_val(pud) & _PAGE_PSE);
82}
83
84int pmd_huge_support(void)
85{
86 return 1;
87}
88#endif
89
90#ifdef CONFIG_HUGETLB_PAGE
91static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
92 unsigned long addr, 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
98 info.flags = 0;
99 info.length = len;
100 info.low_limit = current->mm->mmap_legacy_base;
101 info.high_limit = TASK_SIZE;
102 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
103 info.align_offset = 0;
104 return vm_unmapped_area(&info);
105}
106
107static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
108 unsigned long addr0, unsigned long len,
109 unsigned long pgoff, unsigned long flags)
110{
111 struct hstate *h = hstate_file(file);
112 struct vm_unmapped_area_info info;
113 unsigned long addr;
114
115 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
116 info.length = len;
117 info.low_limit = PAGE_SIZE;
118 info.high_limit = current->mm->mmap_base;
119 info.align_mask = PAGE_MASK & ~huge_page_mask(h);
120 info.align_offset = 0;
121 addr = vm_unmapped_area(&info);
122
123 /*
124 * A failed mmap() very likely causes application failure,
125 * so fall back to the bottom-up function here. This scenario
126 * can happen with large stack limits and large mmap()
127 * allocations.
128 */
129 if (addr & ~PAGE_MASK) {
130 VM_BUG_ON(addr != -ENOMEM);
131 info.flags = 0;
132 info.low_limit = TASK_UNMAPPED_BASE;
133 info.high_limit = TASK_SIZE;
134 addr = vm_unmapped_area(&info);
135 }
136
137 return addr;
138}
139
140unsigned long
141hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
142 unsigned long len, unsigned long pgoff, unsigned long flags)
143{
144 struct hstate *h = hstate_file(file);
145 struct mm_struct *mm = current->mm;
146 struct vm_area_struct *vma;
147
148 if (len & ~huge_page_mask(h))
149 return -EINVAL;
150 if (len > TASK_SIZE)
151 return -ENOMEM;
152
153 if (flags & MAP_FIXED) {
154 if (prepare_hugepage_range(file, addr, len))
155 return -EINVAL;
156 return addr;
157 }
158
159 if (addr) {
160 addr = ALIGN(addr, huge_page_size(h));
161 vma = find_vma(mm, addr);
162 if (TASK_SIZE - len >= addr &&
163 (!vma || addr + len <= vma->vm_start))
164 return addr;
165 }
166 if (mm->get_unmapped_area == arch_get_unmapped_area)
167 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
168 pgoff, flags);
169 else
170 return hugetlb_get_unmapped_area_topdown(file, addr, len,
171 pgoff, flags);
172}
173#endif /* CONFIG_HUGETLB_PAGE */
174
175#ifdef CONFIG_X86_64
176static __init int setup_hugepagesz(char *opt)
177{
178 unsigned long ps = memparse(opt, &opt);
179 if (ps == PMD_SIZE) {
180 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
181 } else if (ps == PUD_SIZE && cpu_has_gbpages) {
182 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
183 } else {
184 printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n",
185 ps >> 20);
186 return 0;
187 }
188 return 1;
189}
190__setup("hugepagesz=", setup_hugepagesz);
191#endif