mips/mm/hugetlbpage.c

0001 /*
0002  * MIPS Huge TLB Page Support for Kernel.
0003  *
0004  * This file is subject to the terms and conditions of the GNU General Public
0005  * License.  See the file "COPYING" in the main directory of this archive
0006  * for more details.
0007  *
0008  * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
0009  * Copyright 2005, Embedded Alley Solutions, Inc.
0010  * Matt Porter <mporter@embeddedalley.com>
0011  * Copyright (C) 2008, 2009 Cavium Networks, Inc.
0012  */
0013
0014 #include <linux/fs.h>
0015 #include <linux/mm.h>
0016 #include <linux/hugetlb.h>
0017 #include <linux/pagemap.h>
0018 #include <linux/err.h>
0019 #include <linux/sysctl.h>
0020 #include <asm/mman.h>
0021 #include <asm/tlb.h>
0022 #include <asm/tlbflush.h>
0023
0024 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
0025               unsigned long addr, unsigned long sz)
0026 {
0027     pgd_t *pgd;
0028     p4d_t *p4d;
0029     pud_t *pud;
0030     pte_t *pte = NULL;
0031
0032     pgd = pgd_offset(mm, addr);
0033     p4d = p4d_alloc(mm, pgd, addr);
0034     pud = pud_alloc(mm, p4d, addr);
0035     if (pud)
0036         pte = (pte_t *)pmd_alloc(mm, pud, addr);
0037
0038     return pte;
0039 }
0040
0041 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
0042                unsigned long sz)
0043 {
0044     pgd_t *pgd;
0045     p4d_t *p4d;
0046     pud_t *pud;
0047     pmd_t *pmd = NULL;
0048
0049     pgd = pgd_offset(mm, addr);
0050     if (pgd_present(*pgd)) {
0051         p4d = p4d_offset(pgd, addr);
0052         if (p4d_present(*p4d)) {
0053             pud = pud_offset(p4d, addr);
0054             if (pud_present(*pud))
0055                 pmd = pmd_offset(pud, addr);
0056         }
0057     }
0058     return (pte_t *) pmd;
0059 }
0060
0061 int pmd_huge(pmd_t pmd)
0062 {
0063     return (pmd_val(pmd) & _PAGE_HUGE) != 0;
0064 }
0065
0066 int pud_huge(pud_t pud)
0067 {
0068     return (pud_val(pud) & _PAGE_HUGE) != 0;
0069 }