pgtable.c

 1/*
 2 * This file is subject to the terms and conditions of the GNU General Public
 3 * License.  See the file "COPYING" in the main directory of this archive
 4 * for more details.
 5 */
 6#include <linux/export.h>
 7#include <linux/mm.h>
 8#include <linux/string.h>
 9#include <asm/pgalloc.h>
10
11pgd_t *pgd_alloc(struct mm_struct *mm)
12{
13	pgd_t *init, *ret;
14
15	ret = __pgd_alloc(mm, PGD_TABLE_ORDER);
16	if (ret) {
17		init = pgd_offset(&init_mm, 0UL);
18		pgd_init(ret);
19		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
20		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
21	}
22
23	return ret;
24}
25EXPORT_SYMBOL_GPL(pgd_alloc);