1 /* 2 * arch/arm/mm/hugetlbpage.c 3 * 4 * Copyright (C) 2012 ARM Ltd. 5 * 6 * Based on arch/x86/include/asm/hugetlb.h and Bill Carson's patches 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/init.h> 23 #include <linux/fs.h> 24 #include <linux/mm.h> 25 #include <linux/hugetlb.h> 26 #include <linux/pagemap.h> 27 #include <linux/err.h> 28 #include <linux/sysctl.h> 29 #include <asm/mman.h> 30 #include <asm/tlb.h> 31 #include <asm/tlbflush.h> 32 #include <asm/pgalloc.h> 33 34 /* 35 * On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot 36 * of type casting from pmd_t * to pte_t *. 37 */ 38 39 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, 40 int write) 41 { 42 return ERR_PTR(-EINVAL); 43 } 44 45 int pud_huge(pud_t pud) 46 { 47 return 0; 48 } 49 50 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 51 { 52 return 0; 53 } 54 55 int pmd_huge(pmd_t pmd) 56 { 57 return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT); 58 } 59 60 int pmd_huge_support(void) 61 { 62 return 1; 63 } 64