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 25pte_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 40pte_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 55int 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 */ 63int 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 72struct page * 73follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 74{ 75 return ERR_PTR(-EINVAL); 76} 77 78int pmd_huge(pmd_t pmd) 79{ 80 return (pmd_val(pmd) & _PAGE_HUGE) != 0; 81} 82 83int pud_huge(pud_t pud) 84{ 85 return (pud_val(pud) & _PAGE_HUGE) != 0; 86} 87 88struct page * 89follow_huge_pmd(struct mm_struct *mm, unsigned long address, 90 pmd_t *pmd, int write) 91{ 92 struct page *page; 93 94 page = pte_page(*(pte_t *)pmd); 95 if (page) 96 page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); 97 return page; 98} 99