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