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
31static struct kmem_cache *pgd_cache;
32
33pgd_t *pgd_alloc(struct mm_struct *mm)
34{
35	if (PGD_SIZE == PAGE_SIZE)
36		return (pgd_t *)__get_free_page(PGALLOC_GFP);
37	else
38		return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
39}
40
41void pgd_free(struct mm_struct *mm, pgd_t *pgd)
42{
43	if (PGD_SIZE == PAGE_SIZE)
44		free_page((unsigned long)pgd);
45	else
46		kmem_cache_free(pgd_cache, pgd);
47}
48
49static int __init pgd_cache_init(void)
50{
51	/*
52	 * Naturally aligned pgds required by the architecture.
53	 */
54	if (PGD_SIZE != PAGE_SIZE)
55		pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,
56					      SLAB_PANIC, NULL);
57	return 0;
58}
59core_initcall(pgd_cache_init);
60