xref: /linux/arch/sh/mm/hugetlbpage.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  * arch/sh/mm/hugetlbpage.c
3  *
4  * SuperH HugeTLB page support.
5  *
6  * Cloned from sparc64 by Paul Mundt.
7  *
8  * Copyright (C) 2002, 2003 David S. Miller (davem@redhat.com)
9  */
10 
11 #include <linux/init.h>
12 #include <linux/fs.h>
13 #include <linux/mm.h>
14 #include <linux/hugetlb.h>
15 #include <linux/pagemap.h>
16 #include <linux/smp_lock.h>
17 #include <linux/slab.h>
18 #include <linux/sysctl.h>
19 
20 #include <asm/mman.h>
21 #include <asm/pgalloc.h>
22 #include <asm/tlb.h>
23 #include <asm/tlbflush.h>
24 #include <asm/cacheflush.h>
25 
26 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
27 {
28 	pgd_t *pgd;
29 	pmd_t *pmd;
30 	pte_t *pte = NULL;
31 
32 	pgd = pgd_offset(mm, addr);
33 	if (pgd) {
34 		pmd = pmd_alloc(mm, pgd, addr);
35 		if (pmd)
36 			pte = pte_alloc_map(mm, pmd, 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 	pmd_t *pmd;
45 	pte_t *pte = NULL;
46 
47 	pgd = pgd_offset(mm, addr);
48 	if (pgd) {
49 		pmd = pmd_offset(pgd, addr);
50 		if (pmd)
51 			pte = pte_offset_map(pmd, addr);
52 	}
53 	return pte;
54 }
55 
56 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
57 		     pte_t *ptep, pte_t entry)
58 {
59 	int i;
60 
61 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
62 		set_pte_at(mm, addr, ptep, entry);
63 		ptep++;
64 		addr += PAGE_SIZE;
65 		pte_val(entry) += PAGE_SIZE;
66 	}
67 }
68 
69 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
70 			      pte_t *ptep)
71 {
72 	pte_t entry;
73 	int i;
74 
75 	entry = *ptep;
76 
77 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
78 		pte_clear(mm, addr, ptep);
79 		addr += PAGE_SIZE;
80 		ptep++;
81 	}
82 
83 	return entry;
84 }
85 
86 struct page *follow_huge_addr(struct mm_struct *mm,
87 			      unsigned long address, int write)
88 {
89 	return ERR_PTR(-EINVAL);
90 }
91 
92 int pmd_huge(pmd_t pmd)
93 {
94 	return 0;
95 }
96 
97 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
98 			     pmd_t *pmd, int write)
99 {
100 	return NULL;
101 }
102