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 static struct kmem_cache *pgd_cache; 32 33 pgd_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 41 void 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 49 void __init pgd_cache_init(void) 50 { 51 if (PGD_SIZE == PAGE_SIZE) 52 return; 53 54 /* 55 * Naturally aligned pgds required by the architecture. 56 */ 57 pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE, 58 SLAB_PANIC, NULL); 59 } 60