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/fs.h> 15 #include <linux/mm.h> 16 #include <linux/hugetlb.h> 17 #include <linux/pagemap.h> 18 #include <linux/err.h> 19 #include <linux/sysctl.h> 20 #include <asm/mman.h> 21 #include <asm/tlb.h> 22 #include <asm/tlbflush.h> 23 24 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, 25 unsigned long sz) 26 { 27 pgd_t *pgd; 28 pud_t *pud; 29 pte_t *pte = NULL; 30 31 pgd = pgd_offset(mm, addr); 32 pud = pud_alloc(mm, pgd, addr); 33 if (pud) 34 pte = (pte_t *)pmd_alloc(mm, pud, addr); 35 36 return pte; 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 return (pte_t *) pmd; 52 } 53 54 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 55 { 56 return 0; 57 } 58 59 /* 60 * This function checks for proper alignment of input addr and len parameters. 61 */ 62 int is_aligned_hugepage_range(unsigned long addr, unsigned long len) 63 { 64 if (len & ~HPAGE_MASK) 65 return -EINVAL; 66 if (addr & ~HPAGE_MASK) 67 return -EINVAL; 68 return 0; 69 } 70 71 struct page * 72 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 73 { 74 return ERR_PTR(-EINVAL); 75 } 76 77 int pmd_huge(pmd_t pmd) 78 { 79 return (pmd_val(pmd) & _PAGE_HUGE) != 0; 80 } 81 82 int pud_huge(pud_t pud) 83 { 84 return (pud_val(pud) & _PAGE_HUGE) != 0; 85 } 86 87 struct page * 88 follow_huge_pmd(struct mm_struct *mm, unsigned long address, 89 pmd_t *pmd, int write) 90 { 91 struct page *page; 92 93 page = pte_page(*(pte_t *)pmd); 94 if (page) 95 page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); 96 return page; 97 } 98