1 /* 2 * arch/arm64/mm/hugetlbpage.c 3 * 4 * Copyright (C) 2013 Linaro Ltd. 5 * 6 * Based on arch/x86/mm/hugetlbpage.c. 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 #ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 35 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 36 { 37 return 0; 38 } 39 #endif 40 41 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, 42 int write) 43 { 44 return ERR_PTR(-EINVAL); 45 } 46 47 int pmd_huge(pmd_t pmd) 48 { 49 return !(pmd_val(pmd) & PMD_TABLE_BIT); 50 } 51 52 int pud_huge(pud_t pud) 53 { 54 return !(pud_val(pud) & PUD_TABLE_BIT); 55 } 56 57 int pmd_huge_support(void) 58 { 59 return 1; 60 } 61 62 static __init int setup_hugepagesz(char *opt) 63 { 64 unsigned long ps = memparse(opt, &opt); 65 if (ps == PMD_SIZE) { 66 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); 67 } else if (ps == PUD_SIZE) { 68 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); 69 } else { 70 pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20); 71 return 0; 72 } 73 return 1; 74 } 75 __setup("hugepagesz=", setup_hugepagesz); 76