projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1355e2a6 CM |
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 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
| 40 | { | |
| 41 | pgd_t *pgd; | |
| 42 | pud_t *pud; | |
| 43 | pmd_t *pmd = NULL; | |
| 44 | ||
| 45 | pgd = pgd_offset(mm, addr); | |
| 46 | if (pgd_present(*pgd)) { | |
| 47 | pud = pud_offset(pgd, addr); | |
| 48 | if (pud_present(*pud)) | |
| 49 | pmd = pmd_offset(pud, addr); | |
| 50 | } | |
| 51 | ||
| 52 | return (pte_t *)pmd; | |
| 53 | } | |
| 54 | ||
| 55 | struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, | |
| 56 | int write) | |
| 57 | { | |
| 58 | return ERR_PTR(-EINVAL); | |
| 59 | } | |
| 60 | ||
| 61 | int pud_huge(pud_t pud) | |
| 62 | { | |
| 63 | return 0; | |
| 64 | } | |
| 65 | ||
| 66 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
| 67 | { | |
| 68 | return 0; | |
| 69 | } | |
| 70 | ||
| 71 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
| 72 | unsigned long addr, unsigned long sz) | |
| 73 | { | |
| 74 | pgd_t *pgd; | |
| 75 | pud_t *pud; | |
| 76 | pte_t *pte = NULL; | |
| 77 | ||
| 78 | pgd = pgd_offset(mm, addr); | |
| 79 | pud = pud_alloc(mm, pgd, addr); | |
| 80 | if (pud) | |
| 81 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
| 82 | ||
| 83 | return pte; | |
| 84 | } | |
| 85 | ||
| 86 | struct page * | |
| 87 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, | |
| 88 | pmd_t *pmd, int write) | |
| 89 | { | |
| 90 | struct page *page; | |
| 91 | ||
| 92 | page = pte_page(*(pte_t *)pmd); | |
| 93 | if (page) | |
| 94 | page += ((address & ~PMD_MASK) >> PAGE_SHIFT); | |
| 95 | return page; | |
| 96 | } | |
| 97 | ||
| 98 | int pmd_huge(pmd_t pmd) | |
| 99 | { | |
| 100 | return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT); | |
| 101 | } |