summaryrefslogtreecommitdiff
path: root/arch/s390/mm/hugetlbpage.c
blob: d3a5e39756f62549ce53b1a20c91df0cbc787be8 (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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/*
 *  IBM System z Huge TLB Page Support for Kernel.
 *
 *    Copyright IBM Corp. 2007,2016
 *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
 */

#define KMSG_COMPONENT "hugetlb"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

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

/*
 * If the bit selected by single-bit bitmask "a" is set within "x", move
 * it to the position indicated by single-bit bitmask "b".
 */
#define move_set_bit(x, a, b)	(((x) & (a)) >> ilog2(a) << ilog2(b))

static inline unsigned long __pte_to_rste(pte_t pte)
{
	unsigned long rste;

	/*
	 * Convert encoding		  pte bits	pmd / pud 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)) {
		rste = pte_val(pte) & PAGE_MASK;
		rste |= move_set_bit(pte_val(pte), _PAGE_READ,
				     _SEGMENT_ENTRY_READ);
		rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
				     _SEGMENT_ENTRY_WRITE);
		rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
				     _SEGMENT_ENTRY_INVALID);
		rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
				     _SEGMENT_ENTRY_PROTECT);
		rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
				     _SEGMENT_ENTRY_DIRTY);
		rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
				     _SEGMENT_ENTRY_YOUNG);
#ifdef CONFIG_MEM_SOFT_DIRTY
		rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
				     _SEGMENT_ENTRY_SOFT_DIRTY);
#endif
		rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC,
				     _SEGMENT_ENTRY_NOEXEC);
	} else
		rste = _SEGMENT_ENTRY_EMPTY;
	return rste;
}

static inline pte_t __rste_to_pte(unsigned long rste)
{
	int present;
	pte_t pte;

	if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
		present = pud_present(__pud(rste));
	else
		present = pmd_present(__pmd(rste));

	/*
	 * Convert encoding		pmd / pud 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 (present) {
		pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
		pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
					     _PAGE_READ);
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
					     _PAGE_WRITE);
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
					     _PAGE_INVALID);
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
					     _PAGE_PROTECT);
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
					     _PAGE_DIRTY);
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
					     _PAGE_YOUNG);
#ifdef CONFIG_MEM_SOFT_DIRTY
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
					     _PAGE_DIRTY);
#endif
		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
					     _PAGE_NOEXEC);
	} 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)
{
	unsigned long rste;

	rste = __pte_to_rste(pte);
	if (!MACHINE_HAS_NX)
		rste &= ~_SEGMENT_ENTRY_NOEXEC;

	/* Set correct table type for 2G hugepages */
	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
		rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
	else
		rste |= _SEGMENT_ENTRY_LARGE;
	pte_val(*ptep) = rste;
}

pte_t huge_ptep_get(pte_t *ptep)
{
	return __rste_to_pte(pte_val(*ptep));
}

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

	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
		pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
	else
		pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
	return pte;
}

pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz)
{
	pgd_t *pgdp;
	p4d_t *p4dp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	p4dp = p4d_alloc(mm, pgdp, addr);
	if (p4dp) {
		pudp = pud_alloc(mm, p4dp, addr);
		if (pudp) {
			if (sz == PUD_SIZE)
				return (pte_t *) pudp;
			else if (sz == PMD_SIZE)
				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;
	p4d_t *p4dp;
	pud_t *pudp;
	pmd_t *pmdp = NULL;

	pgdp = pgd_offset(mm, addr);
	if (pgd_present(*pgdp)) {
		p4dp = p4d_offset(pgdp, addr);
		if (p4d_present(*p4dp)) {
			pudp = pud_offset(p4dp, addr);
			if (pud_present(*pudp)) {
				if (pud_large(*pudp))
					return (pte_t *) 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 pud_large(pud);
}

struct page *
follow_huge_pud(struct mm_struct *mm, unsigned long address,
		pud_t *pud, int flags)
{
	if (flags & FOLL_GET)
		return NULL;

	return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
}

static __init int setup_hugepagesz(char *opt)
{
	unsigned long size;
	char *string = opt;

	size = memparse(opt, &opt);
	if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
		hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
	} else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
	} else {
		hugetlb_bad_size();
		pr_err("hugepagesz= specifies an unsupported page size %s\n",
			string);
		return 0;
	}
	return 1;
}
__setup("hugepagesz=", setup_hugepagesz);