1 /* 2 * MIPS Huge TLB Page Support for Kernel. 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> 9 * Copyright 2005, Embedded Alley Solutions, Inc. 10 * Matt Porter <mporter@embeddedalley.com> 11 * Copyright (C) 2008, 2009 Cavium Networks, Inc. 12 */ 13 14 #include <linux/init.h> 15 #include <linux/fs.h> 16 #include <linux/mm.h> 17 #include <linux/hugetlb.h> 18 #include <linux/pagemap.h> 19 #include <linux/slab.h> 20 #include <linux/err.h> 21 #include <linux/sysctl.h> 22 #include <asm/mman.h> 23 #include <asm/tlb.h> 24 #include <asm/tlbflush.h> 25 26 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, 27 unsigned long sz) 28 { 29 pgd_t *pgd; 30 pud_t *pud; 31 pte_t *pte = NULL; 32 33 pgd = pgd_offset(mm, addr); 34 pud = pud_alloc(mm, pgd, addr); 35 if (pud) 36 pte = (pte_t *)pmd_alloc(mm, pud, addr); 37 38 return pte; 39 } 40 41 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) 42 { 43 pgd_t *pgd; 44 pud_t *pud; 45 pmd_t *pmd = NULL; 46 47 pgd = pgd_offset(mm, addr); 48 if (pgd_present(*pgd)) { 49 pud = pud_offset(pgd, addr); 50 if (pud_present(*pud)) 51 pmd = pmd_offset(pud, addr); 52 } 53 return (pte_t *) pmd; 54 } 55 56 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 57 { 58 return 0; 59 } 60 61 /* 62 * This function checks for proper alignment of input addr and len parameters. 63 */ 64 int is_aligned_hugepage_range(unsigned long addr, unsigned long len) 65 { 66 if (len & ~HPAGE_MASK) 67 return -EINVAL; 68 if (addr & ~HPAGE_MASK) 69 return -EINVAL; 70 return 0; 71 } 72 73 struct page * 74 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 75 { 76 return ERR_PTR(-EINVAL); 77 } 78 79 int pmd_huge(pmd_t pmd) 80 { 81 return (pmd_val(pmd) & _PAGE_HUGE) != 0; 82 } 83 84 int pud_huge(pud_t pud) 85 { 86 return (pud_val(pud) & _PAGE_HUGE) != 0; 87 } 88 89 struct page * 90 follow_huge_pmd(struct mm_struct *mm, unsigned long address, 91 pmd_t *pmd, int write) 92 { 93 struct page *page; 94 95 page = pte_page(*(pte_t *)pmd); 96 if (page) 97 page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); 98 return page; 99 } 100 101