2 * arch/arm64/mm/hugetlbpage.c
4 * Copyright (C) 2013 Linaro Ltd.
6 * Based on arch/x86/mm/hugetlbpage.c.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/init.h>
21 #include <linux/hugetlb.h>
22 #include <linux/pagemap.h>
23 #include <linux/err.h>
24 #include <linux/sysctl.h>
27 #include <asm/tlbflush.h>
28 #include <asm/pgalloc.h>
30 int pmd_huge(pmd_t pmd)
32 return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
35 int pud_huge(pud_t pud)
37 #ifndef __PAGETABLE_PMD_FOLDED
38 return pud_val(pud) && !(pud_val(pud) & PUD_TABLE_BIT);
44 static int find_num_contig(struct mm_struct *mm, unsigned long addr,
45 pte_t *ptep, size_t *pgsize)
47 pgd_t *pgd = pgd_offset(mm, addr);
52 pud = pud_offset(pgd, addr);
53 pmd = pmd_offset(pud, addr);
54 if ((pte_t *)pmd == ptep) {
61 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
62 pte_t *ptep, pte_t pte)
71 set_pte_at(mm, addr, ptep, pte);
75 ncontig = find_num_contig(mm, addr, ptep, &pgsize);
77 hugeprot = __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
78 for (i = 0; i < ncontig; i++) {
79 pr_debug("%s: set pte %p to 0x%llx\n", __func__, ptep,
80 pte_val(pfn_pte(pfn, hugeprot)));
81 set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
83 pfn += pgsize >> PAGE_SHIFT;
88 pte_t *huge_pte_alloc(struct mm_struct *mm,
89 unsigned long addr, unsigned long sz)
95 pr_debug("%s: addr:0x%lx sz:0x%lx\n", __func__, addr, sz);
96 pgd = pgd_offset(mm, addr);
97 pud = pud_alloc(mm, pgd, addr);
101 if (sz == PUD_SIZE) {
103 } else if (sz == (PAGE_SIZE * CONT_PTES)) {
104 pmd_t *pmd = pmd_alloc(mm, pud, addr);
106 WARN_ON(addr & (sz - 1));
108 * Note that if this code were ever ported to the
109 * 32-bit arm platform then it will cause trouble in
110 * the case where CONFIG_HIGHPTE is set, since there
111 * will be no pte_unmap() to correspond with this
114 pte = pte_alloc_map(mm, pmd, addr);
115 } else if (sz == PMD_SIZE) {
116 if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&
118 pte = huge_pmd_share(mm, addr, pud);
120 pte = (pte_t *)pmd_alloc(mm, pud, addr);
121 } else if (sz == (PMD_SIZE * CONT_PMDS)) {
124 pmd = pmd_alloc(mm, pud, addr);
125 WARN_ON(addr & (sz - 1));
129 pr_debug("%s: addr:0x%lx sz:0x%lx ret pte=%p/0x%llx\n", __func__, addr,
130 sz, pte, pte_val(*pte));
134 pte_t *huge_pte_offset(struct mm_struct *mm,
135 unsigned long addr, unsigned long sz)
141 pgd = pgd_offset(mm, addr);
142 pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
143 if (!pgd_present(*pgd))
146 pud = pud_offset(pgd, addr);
149 /* swap or huge page */
150 if (!pud_present(*pud) || pud_huge(*pud))
152 /* table; check the next level */
154 pmd = pmd_offset(pud, addr);
157 if (!pmd_present(*pmd) || pmd_huge(*pmd))
163 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
164 struct page *page, int writable)
166 size_t pagesize = huge_page_size(hstate_vma(vma));
168 if (pagesize == CONT_PTE_SIZE) {
169 entry = pte_mkcont(entry);
170 } else if (pagesize == CONT_PMD_SIZE) {
171 entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
172 } else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
173 pr_warn("%s: unrecognized huge page size 0x%lx\n",
179 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
180 unsigned long addr, pte_t *ptep)
184 if (pte_cont(*ptep)) {
187 bool is_dirty = false;
189 ncontig = find_num_contig(mm, addr, ptep, &pgsize);
190 /* save the 1st pte to return */
191 pte = ptep_get_and_clear(mm, addr, ptep);
192 for (i = 1, addr += pgsize; i < ncontig; ++i, addr += pgsize) {
194 * If HW_AFDBM is enabled, then the HW could
195 * turn on the dirty bit for any of the page
196 * in the set, so check them all.
199 if (pte_dirty(ptep_get_and_clear(mm, addr, ptep)))
203 return pte_mkdirty(pte);
207 return ptep_get_and_clear(mm, addr, ptep);
211 int huge_ptep_set_access_flags(struct vm_area_struct *vma,
212 unsigned long addr, pte_t *ptep,
213 pte_t pte, int dirty)
216 int ncontig, i, changed = 0;
218 unsigned long pfn = pte_pfn(pte);
219 /* Select all bits except the pfn */
221 __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^
225 ncontig = find_num_contig(vma->vm_mm, addr, ptep,
227 for (i = 0; i < ncontig; ++i, ++ptep, addr += pgsize) {
228 changed |= ptep_set_access_flags(vma, addr, ptep,
232 pfn += pgsize >> PAGE_SHIFT;
236 return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
240 void huge_ptep_set_wrprotect(struct mm_struct *mm,
241 unsigned long addr, pte_t *ptep)
243 if (pte_cont(*ptep)) {
247 ncontig = find_num_contig(mm, addr, ptep, &pgsize);
248 for (i = 0; i < ncontig; ++i, ++ptep, addr += pgsize)
249 ptep_set_wrprotect(mm, addr, ptep);
251 ptep_set_wrprotect(mm, addr, ptep);
255 void huge_ptep_clear_flush(struct vm_area_struct *vma,
256 unsigned long addr, pte_t *ptep)
258 if (pte_cont(*ptep)) {
262 ncontig = find_num_contig(vma->vm_mm, addr, ptep,
264 for (i = 0; i < ncontig; ++i, ++ptep, addr += pgsize)
265 ptep_clear_flush(vma, addr, ptep);
267 ptep_clear_flush(vma, addr, ptep);
271 static __init int setup_hugepagesz(char *opt)
273 unsigned long ps = memparse(opt, &opt);
275 if (ps == PMD_SIZE) {
276 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
277 } else if (ps == PUD_SIZE) {
278 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
281 pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10);
286 __setup("hugepagesz=", setup_hugepagesz);