1 /*
2 * arch/arm64/mm/hugetlbpage.c
3 *
4 * Copyright (C) 2013 Linaro Ltd.
5 *
6 * Based on arch/x86/mm/hugetlbpage.c.
7 *
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.
11 *
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.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/init.h>
23 #include <linux/fs.h>
24 #include <linux/mm.h>
25 #include <linux/hugetlb.h>
26 #include <linux/pagemap.h>
27 #include <linux/err.h>
28 #include <linux/sysctl.h>
29 #include <asm/mman.h>
30 #include <asm/tlb.h>
31 #include <asm/tlbflush.h>
32 #include <asm/pgalloc.h>
33
34 #ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
huge_pmd_unshare(struct mm_struct * mm,unsigned long * addr,pte_t * ptep)35 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
36 {
37 return 0;
38 }
39 #endif
40
follow_huge_addr(struct mm_struct * mm,unsigned long address,int write)41 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
42 int write)
43 {
44 return ERR_PTR(-EINVAL);
45 }
46
pmd_huge(pmd_t pmd)47 int pmd_huge(pmd_t pmd)
48 {
49 return !(pmd_val(pmd) & PMD_TABLE_BIT);
50 }
51
pud_huge(pud_t pud)52 int pud_huge(pud_t pud)
53 {
54 return !(pud_val(pud) & PUD_TABLE_BIT);
55 }
56
setup_hugepagesz(char * opt)57 static __init int setup_hugepagesz(char *opt)
58 {
59 unsigned long ps = memparse(opt, &opt);
60 if (ps == PMD_SIZE) {
61 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
62 } else if (ps == PUD_SIZE) {
63 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
64 } else {
65 pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
66 return 0;
67 }
68 return 1;
69 }
70 __setup("hugepagesz=", setup_hugepagesz);
71