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, pte_t pte, size_t *pgsize)
47 pgd_t *pgd = pgd_offset(mm, addr);
54 if (!pgd_present(*pgd)) {
55 VM_BUG_ON(!pgd_present(*pgd));
58 pud = pud_offset(pgd, addr);
59 if (!pud_present(*pud)) {
60 VM_BUG_ON(!pud_present(*pud));
63 pmd = pmd_offset(pud, addr);
64 if (!pmd_present(*pmd)) {
65 VM_BUG_ON(!pmd_present(*pmd));
68 if ((pte_t *)pmd == ptep) {
75 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
76 pte_t *ptep, pte_t pte)
80 int ncontig = find_num_contig(mm, addr, ptep, pte, &pgsize);
85 set_pte_at(mm, addr, ptep, pte);
90 hugeprot = __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
91 for (i = 0; i < ncontig; i++) {
92 pr_debug("%s: set pte %p to 0x%llx\n", __func__, ptep,
93 pte_val(pfn_pte(pfn, hugeprot)));
94 set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
96 pfn += pgsize >> PAGE_SHIFT;
101 pte_t *huge_pte_alloc(struct mm_struct *mm,
102 unsigned long addr, unsigned long sz)
108 pr_debug("%s: addr:0x%lx sz:0x%lx\n", __func__, addr, sz);
109 pgd = pgd_offset(mm, addr);
110 pud = pud_alloc(mm, pgd, addr);
114 if (sz == PUD_SIZE) {
116 } else if (sz == (PAGE_SIZE * CONT_PTES)) {
117 pmd_t *pmd = pmd_alloc(mm, pud, addr);
119 WARN_ON(addr & (sz - 1));
121 * Note that if this code were ever ported to the
122 * 32-bit arm platform then it will cause trouble in
123 * the case where CONFIG_HIGHPTE is set, since there
124 * will be no pte_unmap() to correspond with this
127 pte = pte_alloc_map(mm, pmd, addr);
128 } else if (sz == PMD_SIZE) {
129 if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&
131 pte = huge_pmd_share(mm, addr, pud);
133 pte = (pte_t *)pmd_alloc(mm, pud, addr);
134 } else if (sz == (PMD_SIZE * CONT_PMDS)) {
137 pmd = pmd_alloc(mm, pud, addr);
138 WARN_ON(addr & (sz - 1));
142 pr_debug("%s: addr:0x%lx sz:0x%lx ret pte=%p/0x%llx\n", __func__, addr,
143 sz, pte, pte_val(*pte));
147 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
154 pgd = pgd_offset(mm, addr);
155 pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
156 if (!pgd_present(*pgd))
158 pud = pud_offset(pgd, addr);
159 if (!pud_present(*pud))
164 pmd = pmd_offset(pud, addr);
165 if (!pmd_present(*pmd))
168 if (pte_cont(pmd_pte(*pmd))) {
170 pud, (addr & CONT_PMD_MASK));
175 pte = pte_offset_kernel(pmd, addr);
176 if (pte_present(*pte) && pte_cont(*pte)) {
177 pte = pte_offset_kernel(
178 pmd, (addr & CONT_PTE_MASK));
184 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
185 struct page *page, int writable)
187 size_t pagesize = huge_page_size(hstate_vma(vma));
189 if (pagesize == CONT_PTE_SIZE) {
190 entry = pte_mkcont(entry);
191 } else if (pagesize == CONT_PMD_SIZE) {
192 entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
193 } else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
194 pr_warn("%s: unrecognized huge page size 0x%lx\n",
200 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
201 unsigned long addr, pte_t *ptep)
205 if (pte_cont(*ptep)) {
209 bool is_dirty = false;
211 cpte = huge_pte_offset(mm, addr);
212 ncontig = find_num_contig(mm, addr, cpte, *cpte, &pgsize);
213 /* save the 1st pte to return */
214 pte = ptep_get_and_clear(mm, addr, cpte);
215 for (i = 1; i < ncontig; ++i) {
217 * If HW_AFDBM is enabled, then the HW could
218 * turn on the dirty bit for any of the page
219 * in the set, so check them all.
222 if (pte_dirty(ptep_get_and_clear(mm, addr, cpte)))
226 return pte_mkdirty(pte);
230 return ptep_get_and_clear(mm, addr, ptep);
234 int huge_ptep_set_access_flags(struct vm_area_struct *vma,
235 unsigned long addr, pte_t *ptep,
236 pte_t pte, int dirty)
241 int ncontig, i, changed = 0;
243 unsigned long pfn = pte_pfn(pte);
244 /* Select all bits except the pfn */
246 __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^
249 cpte = huge_pte_offset(vma->vm_mm, addr);
250 pfn = pte_pfn(*cpte);
251 ncontig = find_num_contig(vma->vm_mm, addr, cpte,
253 for (i = 0; i < ncontig; ++i, ++cpte) {
254 changed = ptep_set_access_flags(vma, addr, cpte,
258 pfn += pgsize >> PAGE_SHIFT;
262 return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
266 void huge_ptep_set_wrprotect(struct mm_struct *mm,
267 unsigned long addr, pte_t *ptep)
269 if (pte_cont(*ptep)) {
274 cpte = huge_pte_offset(mm, addr);
275 ncontig = find_num_contig(mm, addr, cpte, *cpte, &pgsize);
276 for (i = 0; i < ncontig; ++i, ++cpte)
277 ptep_set_wrprotect(mm, addr, cpte);
279 ptep_set_wrprotect(mm, addr, ptep);
283 void huge_ptep_clear_flush(struct vm_area_struct *vma,
284 unsigned long addr, pte_t *ptep)
286 if (pte_cont(*ptep)) {
291 cpte = huge_pte_offset(vma->vm_mm, addr);
292 ncontig = find_num_contig(vma->vm_mm, addr, cpte,
294 for (i = 0; i < ncontig; ++i, ++cpte)
295 ptep_clear_flush(vma, addr, cpte);
297 ptep_clear_flush(vma, addr, ptep);
301 static __init int setup_hugepagesz(char *opt)
303 unsigned long ps = memparse(opt, &opt);
305 if (ps == PMD_SIZE) {
306 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
307 } else if (ps == PUD_SIZE) {
308 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
309 } else if (ps == (PAGE_SIZE * CONT_PTES)) {
310 hugetlb_add_hstate(CONT_PTE_SHIFT);
311 } else if (ps == (PMD_SIZE * CONT_PMDS)) {
312 hugetlb_add_hstate((PMD_SHIFT + CONT_PMD_SHIFT) - PAGE_SHIFT);
315 pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10);
320 __setup("hugepagesz=", setup_hugepagesz);
322 #ifdef CONFIG_ARM64_64K_PAGES
323 static __init int add_default_hugepagesz(void)
325 if (size_to_hstate(CONT_PTES * PAGE_SIZE) == NULL)
326 hugetlb_add_hstate(CONT_PMD_SHIFT);
329 arch_initcall(add_default_hugepagesz);