Root/arch/mips/mm/hugetlbpage.c

Source at commit 694c7fbe86b8a9c91392e505afcb9fcfc91deccc created 12 years 8 months ago.
By Maarten ter Huurne, MIPS: JZ4740: Add cpufreq support
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
88int pmd_huge_support(void)
89{
90    return 1;
91}
92
93struct page *
94follow_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

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