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
35int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
36{
37	return 0;
38}
39#endif
40
41int pmd_huge(pmd_t pmd)
42{
43	return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
44}
45
46int pud_huge(pud_t pud)
47{
48#ifndef __PAGETABLE_PMD_FOLDED
49	return pud_val(pud) && !(pud_val(pud) & PUD_TABLE_BIT);
50#else
51	return 0;
52#endif
53}
54
55static __init int setup_hugepagesz(char *opt)
56{
57	unsigned long ps = memparse(opt, &opt);
58	if (ps == PMD_SIZE) {
59		hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
60	} else if (ps == PUD_SIZE) {
61		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
62	} else {
63		pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
64		return 0;
65	}
66	return 1;
67}
68__setup("hugepagesz=", setup_hugepagesz);
69