summaryrefslogtreecommitdiffstats
path: root/arch/s390/mm/hugetlbpage.c
blob: f81096b6940d7bd5532b1eced955d5543eb90228 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/*
 *  IBM System z Huge TLB Page Support for Kernel.
 *
 *    Copyright IBM Corp. 2007
 *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
 */

#include <linux/mm.h>
#include <linux/hugetlb.h>

static inline pmd_t __pte_to_pmd(pte_t pte)
{
	pmd_t pmd;

	/*
	 * Convert encoding		  pte bits	   pmd bits
	 *				lIR.uswrdy.p	dy..R...I...wr
	 * empty			010.000000.0 -> 00..0...1...00
	 * prot-none, clean, old	111.000000.1 -> 00..1...1...00
	 * prot-none, clean, young	111.000001.1 -> 01..1...1...00
	 * prot-none, dirty, old	111.000010.1 -> 10..1...1...00
	 * prot-none, dirty, young	111.000011.1 -> 11..1...1...00
	 * read-only, clean, old	111.000100.1 -> 00..1...1...01
	 * read-only, clean, young	101.000101.1 -> 01..1...0...01
	 * read-only, dirty, old	111.000110.1 -> 10..1...1...01
	 * read-only, dirty, young	101.000111.1 -> 11..1...0...01
	 * read-write, clean, old	111.001100.1 -> 00..1...1...11
	 * read-write, clean, young	101.001101.1 -> 01..1...0...11
	 * read-write, dirty, old	110.001110.1 -> 10..0...1...11
	 * read-write, dirty, young	100.001111.1 -> 11..0...0...11
	 * HW-bits: R read-only, I invalid
	 * SW-bits: p present, y young, d dirty, r read, w write, s special,
	 *	    u unused, l large
	 */
	if (pte_present(pte)) {
		pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
		pmd_val(pmd) |=	(pte_val(pte) & _PAGE_INVALID) >> 5;
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
		pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
	} else
		pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
	return pmd;
}

static inline pte_t __pmd_to_pte(pmd_t pmd)
{
	pte_t pte;

	/*
	 * Convert encoding		   pmd bits	    pte bits
	 *				dy..R...I...wr	  lIR.uswrdy.p
	 * empty			00..0...1...00 -> 010.000000.0
	 * prot-none, clean, old	00..1...1...00 -> 111.000000.1
	 * prot-none, clean, young	01..1...1...00 -> 111.000001.1
	 * prot-none, dirty, old	10..1...1...00 -> 111.000010.1
	 * prot-none, dirty, young	11..1...1...00 -> 111.000011.1
	 * read-only, clean, old	00..1...1...01 -> 111.000100.1
	 * read-only, clean, young	01..1...0...01 -> 101.000101.1
	 * read-only, dirty, old	10..1...1...01 -> 111.000110.1
	 * read-only, dirty, young	11..1...0...01 -> 101.000111.1
	 * read-write, clean, old	00..1...1...11 -> 111.001100.1
	 * read-write, clean, young	01..1...0...11 -> 101.001101.1
	 * read-write, dirty, old	10..0...1...11 -> 110.001110.1
	 * read-write, dirty, young	11..0...0...11 -> 100.001111.1
	 * HW-bits: R read-only, I invalid
	 * SW-bits: p present, y young, d dirty, r read, w write, s special,
	 *	    u unused, l large
	 */
	if (pmd_present(pmd)) {
		pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
		pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
		pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
	} else
		pte_val(pte) = _PAGE_INVALID;
	return pte;
}

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
		     pte_t *ptep, pte_t pte)
{
	pmd_t pmd = __pte_to_pmd(pte);

	pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
	*(pmd_t *) ptep = pmd;
}

pte_t huge_ptep_get(pte_t *ptep)
{
	pmd_t pmd = *(pmd_t *) ptep;

	return __pmd_to_pte(pmd);
}

pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
			      unsigned long addr, pte_t *ptep)
{
	pmd_t *pmdp = (pmd_t *) ptep;
	pte_t pte = huge_ptep_get(ptep);

	pmdp_flush_direct(mm, addr, pmdp);
	pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
	return pte;
}

pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	pudp = pud_alloc(mm, pgdp, addr);
	if (pudp)
		pmdp = pmd_alloc(mm, pudp, addr);
	return (pte_t *) pmdp;
}

pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	if (pgd_present(*pgdp)) {
		pudp = pud_offset(pgdp, addr);
		if (pud_present(*pudp))
			pmdp = pmd_offset(pudp, addr);
	}
	return (pte_t *) pmdp;
}

int pmd_huge(pmd_t pmd)
{
	return pmd_large(pmd);
}

int pud_huge(pud_t pud)
{
	return 0;
}
OpenPOWER on IntegriCloud