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 33 pgd_t *pgd_alloc(struct mm_struct *mm) 34 { 35 pgd_t *new_pgd; 36 37 if (PGD_SIZE == PAGE_SIZE) 38 new_pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL); 39 else 40 new_pgd = kzalloc(PGD_SIZE, GFP_KERNEL); 41 42 if (!new_pgd) 43 return NULL; 44 45 return new_pgd; 46 } 47 48 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 49 { 50 if (PGD_SIZE == PAGE_SIZE) 51 free_page((unsigned long)pgd); 52 else 53 kfree(pgd); 54 } 55