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
24pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
25 unsigned long addr, unsigned long sz)
26{
27 pgd_t *pgd;
28 p4d_t *p4d;
29 pud_t *pud;
30 pte_t *pte = NULL;
31
32 pgd = pgd_offset(mm, addr);
33 p4d = p4d_alloc(mm, pgd, address: addr);
34 pud = pud_alloc(mm, p4d, address: addr);
35 if (pud)
36 pte = (pte_t *)pmd_alloc(mm, pud, address: addr);
37
38 return pte;
39}
40
41pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
42 unsigned long sz)
43{
44 pgd_t *pgd;
45 p4d_t *p4d;
46 pud_t *pud;
47 pmd_t *pmd = NULL;
48
49 pgd = pgd_offset(mm, addr);
50 if (pgd_present(pgd: *pgd)) {
51 p4d = p4d_offset(pgd, address: addr);
52 if (p4d_present(p4d: *p4d)) {
53 pud = pud_offset(p4d, address: addr);
54 if (pud_present(pud: *pud))
55 pmd = pmd_offset(pud, address: addr);
56 }
57 }
58 return (pte_t *) pmd;
59}
60
61int pmd_huge(pmd_t pmd)
62{
63 return (pmd_val(pmd) & _PAGE_HUGE) != 0;
64}
65
66int pud_huge(pud_t pud)
67{
68 return (pud_val(pud) & _PAGE_HUGE) != 0;
69}
70

source code of linux/arch/mips/mm/hugetlbpage.c