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/err.h> 20 #include <linux/sysctl.h> 21 #include <asm/mman.h> 22 #include <asm/tlb.h> 23 #include <asm/tlbflush.h> 24 25 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, 26 unsigned long sz) 27 { 28 pgd_t *pgd; 29 pud_t *pud; 30 pte_t *pte = NULL; 31 32 pgd = pgd_offset(mm, addr); 33 pud = pud_alloc(mm, pgd, addr); 34 if (pud) 35 pte = (pte_t *)pmd_alloc(mm, pud, addr); 36 37 return pte; 38 } 39 40 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) 41 { 42 pgd_t *pgd; 43 pud_t *pud; 44 pmd_t *pmd = NULL; 45 46 pgd = pgd_offset(mm, addr); 47 if (pgd_present(*pgd)) { 48 pud = pud_offset(pgd, addr); 49 if (pud_present(*pud)) 50 pmd = pmd_offset(pud, addr); 51 } 52 return (pte_t *) pmd; 53 } 54 55 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) 56 { 57 return 0; 58 } 59 60 /* 61 * This function checks for proper alignment of input addr and len parameters. 62 */ 63 int is_aligned_hugepage_range(unsigned long addr, unsigned long len) 64 { 65 if (len & ~HPAGE_MASK) 66 return -EINVAL; 67 if (addr & ~HPAGE_MASK) 68 return -EINVAL; 69 return 0; 70 } 71 72 struct page * 73 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 74 { 75 return ERR_PTR(-EINVAL); 76 } 77 78 int pmd_huge(pmd_t pmd) 79 { 80 return (pmd_val(pmd) & _PAGE_HUGE) != 0; 81 } 82 83 int pud_huge(pud_t pud) 84 { 85 return (pud_val(pud) & _PAGE_HUGE) != 0; 86 } 87 88 int pmd_huge_support(void) 89 { 90 return 1; 91 } 92 93 struct page * 94 follow_huge_pmd(struct mm_struct *mm, unsigned long address, 95 pmd_t *pmd, int write) 96 { 97 struct page *page; 98 99 page = pte_page(*(pte_t *)pmd); 100 if (page) 101 page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); 102 return page; 103 } 104