xref: /openbmc/linux/arch/sh/mm/hugetlbpage.c (revision 87c2ce3b) 
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/config.h>
12 #include <linux/init.h>
13 #include <linux/fs.h>
14 #include <linux/mm.h>
15 #include <linux/hugetlb.h>
16 #include <linux/pagemap.h>
17 #include <linux/smp_lock.h>
18 #include <linux/slab.h>
19 #include <linux/sysctl.h>
20 
21 #include <asm/mman.h>
22 #include <asm/pgalloc.h>
23 #include <asm/tlb.h>
24 #include <asm/tlbflush.h>
25 #include <asm/cacheflush.h>
26 
27 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
28 {
29 	pgd_t *pgd;
30 	pmd_t *pmd;
31 	pte_t *pte = NULL;
32 
33 	pgd = pgd_offset(mm, addr);
34 	if (pgd) {
35 		pmd = pmd_alloc(mm, pgd, addr);
36 		if (pmd)
37 			pte = pte_alloc_map(mm, pmd, addr);
38 	}
39 	return pte;
40 }
41 
42 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
43 {
44 	pgd_t *pgd;
45 	pmd_t *pmd;
46 	pte_t *pte = NULL;
47 
48 	pgd = pgd_offset(mm, addr);
49 	if (pgd) {
50 		pmd = pmd_offset(pgd, addr);
51 		if (pmd)
52 			pte = pte_offset_map(pmd, addr);
53 	}
54 	return pte;
55 }
56 
57 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
58 		     pte_t *ptep, pte_t entry)
59 {
60 	int i;
61 
62 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
63 		set_pte_at(mm, addr, ptep, entry);
64 		ptep++;
65 		addr += PAGE_SIZE;
66 		pte_val(entry) += PAGE_SIZE;
67 	}
68 }
69 
70 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
71 			      pte_t *ptep)
72 {
73 	pte_t entry;
74 	int i;
75 
76 	entry = *ptep;
77 
78 	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
79 		pte_clear(mm, addr, ptep);
80 		addr += PAGE_SIZE;
81 		ptep++;
82 	}
83 
84 	return entry;
85 }
86 
87 /*
88  * This function checks for proper alignment of input addr and len parameters.
89  */
90 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
91 {
92 	if (len & ~HPAGE_MASK)
93 		return -EINVAL;
94 	if (addr & ~HPAGE_MASK)
95 		return -EINVAL;
96 	return 0;
97 }
98 
99 struct page *follow_huge_addr(struct mm_struct *mm,
100 			      unsigned long address, int write)
101 {
102 	return ERR_PTR(-EINVAL);
103 }
104 
105 int pmd_huge(pmd_t pmd)
106 {
107 	return 0;
108 }
109 
110 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
111 			     pmd_t *pmd, int write)
112 {
113 	return NULL;
114 }
115