1/*
2 * PGD allocation/freeing
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Catalin Marinas <catalin.marinas@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/mm.h>
21#include <linux/gfp.h>
22#include <linux/highmem.h>
23#include <linux/slab.h>
24
25#include <asm/pgalloc.h>
26#include <asm/page.h>
27#include <asm/tlbflush.h>
28
29#include "mm.h"
30
31#define PGD_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
32
33static struct kmem_cache *pgd_cache;
34
35pgd_t *pgd_alloc(struct mm_struct *mm)
36{
37	if (PGD_SIZE == PAGE_SIZE)
38		return (pgd_t *)__get_free_page(PGALLOC_GFP);
39	else
40		return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
41}
42
43void pgd_free(struct mm_struct *mm, pgd_t *pgd)
44{
45	if (PGD_SIZE == PAGE_SIZE)
46		free_page((unsigned long)pgd);
47	else
48		kmem_cache_free(pgd_cache, pgd);
49}
50
51static int __init pgd_cache_init(void)
52{
53	/*
54	 * Naturally aligned pgds required by the architecture.
55	 */
56	if (PGD_SIZE != PAGE_SIZE)
57		pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,
58					      SLAB_PANIC, NULL);
59	return 0;
60}
61core_initcall(pgd_cache_init);
62