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1/*
2 * IBM System z Huge TLB Page Support for Kernel.
3 *
4 * Copyright IBM Corp. 2007
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#include <linux/mm.h>
9#include <linux/hugetlb.h>
10
11static inline pmd_t __pte_to_pmd(pte_t pte)
12{
13 pmd_t pmd;
14
15 /*
16 * Convert encoding pte bits pmd bits
17 * lIR.uswrdy.p dy..R...I...wr
18 * empty 010.000000.0 -> 00..0...1...00
19 * prot-none, clean, old 111.000000.1 -> 00..1...1...00
20 * prot-none, clean, young 111.000001.1 -> 01..1...1...00
21 * prot-none, dirty, old 111.000010.1 -> 10..1...1...00
22 * prot-none, dirty, young 111.000011.1 -> 11..1...1...00
23 * read-only, clean, old 111.000100.1 -> 00..1...1...01
24 * read-only, clean, young 101.000101.1 -> 01..1...0...01
25 * read-only, dirty, old 111.000110.1 -> 10..1...1...01
26 * read-only, dirty, young 101.000111.1 -> 11..1...0...01
27 * read-write, clean, old 111.001100.1 -> 00..1...1...11
28 * read-write, clean, young 101.001101.1 -> 01..1...0...11
29 * read-write, dirty, old 110.001110.1 -> 10..0...1...11
30 * read-write, dirty, young 100.001111.1 -> 11..0...0...11
31 * HW-bits: R read-only, I invalid
32 * SW-bits: p present, y young, d dirty, r read, w write, s special,
33 * u unused, l large
34 */
35 if (pte_present(pte)) {
36 pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
37 pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
38 pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
39 pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5;
40 pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
41 pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
42 pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
43 pmd_val(pmd) |= (pte_val(pte) & _PAGE_SOFT_DIRTY) << 13;
44 } else
45 pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
46 return pmd;
47}
48
49static inline pte_t __pmd_to_pte(pmd_t pmd)
50{
51 pte_t pte;
52
53 /*
54 * Convert encoding pmd bits pte bits
55 * dy..R...I...wr lIR.uswrdy.p
56 * empty 00..0...1...00 -> 010.000000.0
57 * prot-none, clean, old 00..1...1...00 -> 111.000000.1
58 * prot-none, clean, young 01..1...1...00 -> 111.000001.1
59 * prot-none, dirty, old 10..1...1...00 -> 111.000010.1
60 * prot-none, dirty, young 11..1...1...00 -> 111.000011.1
61 * read-only, clean, old 00..1...1...01 -> 111.000100.1
62 * read-only, clean, young 01..1...0...01 -> 101.000101.1
63 * read-only, dirty, old 10..1...1...01 -> 111.000110.1
64 * read-only, dirty, young 11..1...0...01 -> 101.000111.1
65 * read-write, clean, old 00..1...1...11 -> 111.001100.1
66 * read-write, clean, young 01..1...0...11 -> 101.001101.1
67 * read-write, dirty, old 10..0...1...11 -> 110.001110.1
68 * read-write, dirty, young 11..0...0...11 -> 100.001111.1
69 * HW-bits: R read-only, I invalid
70 * SW-bits: p present, y young, d dirty, r read, w write, s special,
71 * u unused, l large
72 */
73 if (pmd_present(pmd)) {
74 pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
75 pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
76 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
77 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
78 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
79 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
80 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
81 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
82 pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY) >> 13;
83 } else
84 pte_val(pte) = _PAGE_INVALID;
85 return pte;
86}
87
88void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
89 pte_t *ptep, pte_t pte)
90{
91 pmd_t pmd = __pte_to_pmd(pte);
92
93 pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
94 *(pmd_t *) ptep = pmd;
95}
96
97pte_t huge_ptep_get(pte_t *ptep)
98{
99 pmd_t pmd = *(pmd_t *) ptep;
100
101 return __pmd_to_pte(pmd);
102}
103
104pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
105 unsigned long addr, pte_t *ptep)
106{
107 pmd_t *pmdp = (pmd_t *) ptep;
108 pmd_t old;
109
110 old = pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
111 return __pmd_to_pte(old);
112}
113
114pte_t *huge_pte_alloc(struct mm_struct *mm,
115 unsigned long addr, unsigned long sz)
116{
117 pgd_t *pgdp;
118 pud_t *pudp;
119 pmd_t *pmdp = NULL;
120
121 pgdp = pgd_offset(mm, addr);
122 pudp = pud_alloc(mm, pgdp, addr);
123 if (pudp)
124 pmdp = pmd_alloc(mm, pudp, addr);
125 return (pte_t *) pmdp;
126}
127
128pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
129{
130 pgd_t *pgdp;
131 pud_t *pudp;
132 pmd_t *pmdp = NULL;
133
134 pgdp = pgd_offset(mm, addr);
135 if (pgd_present(*pgdp)) {
136 pudp = pud_offset(pgdp, addr);
137 if (pud_present(*pudp))
138 pmdp = pmd_offset(pudp, addr);
139 }
140 return (pte_t *) pmdp;
141}
142
143int pmd_huge(pmd_t pmd)
144{
145 return pmd_large(pmd);
146}
147
148int pud_huge(pud_t pud)
149{
150 return 0;
151}
1/*
2 * IBM System z Huge TLB Page Support for Kernel.
3 *
4 * Copyright IBM Corp. 2007,2016
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#define KMSG_COMPONENT "hugetlb"
9#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11#include <linux/mm.h>
12#include <linux/hugetlb.h>
13
14/*
15 * If the bit selected by single-bit bitmask "a" is set within "x", move
16 * it to the position indicated by single-bit bitmask "b".
17 */
18#define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
19
20static inline unsigned long __pte_to_rste(pte_t pte)
21{
22 unsigned long rste;
23
24 /*
25 * Convert encoding pte bits pmd / pud bits
26 * lIR.uswrdy.p dy..R...I...wr
27 * empty 010.000000.0 -> 00..0...1...00
28 * prot-none, clean, old 111.000000.1 -> 00..1...1...00
29 * prot-none, clean, young 111.000001.1 -> 01..1...1...00
30 * prot-none, dirty, old 111.000010.1 -> 10..1...1...00
31 * prot-none, dirty, young 111.000011.1 -> 11..1...1...00
32 * read-only, clean, old 111.000100.1 -> 00..1...1...01
33 * read-only, clean, young 101.000101.1 -> 01..1...0...01
34 * read-only, dirty, old 111.000110.1 -> 10..1...1...01
35 * read-only, dirty, young 101.000111.1 -> 11..1...0...01
36 * read-write, clean, old 111.001100.1 -> 00..1...1...11
37 * read-write, clean, young 101.001101.1 -> 01..1...0...11
38 * read-write, dirty, old 110.001110.1 -> 10..0...1...11
39 * read-write, dirty, young 100.001111.1 -> 11..0...0...11
40 * HW-bits: R read-only, I invalid
41 * SW-bits: p present, y young, d dirty, r read, w write, s special,
42 * u unused, l large
43 */
44 if (pte_present(pte)) {
45 rste = pte_val(pte) & PAGE_MASK;
46 rste |= move_set_bit(pte_val(pte), _PAGE_READ,
47 _SEGMENT_ENTRY_READ);
48 rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
49 _SEGMENT_ENTRY_WRITE);
50 rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
51 _SEGMENT_ENTRY_INVALID);
52 rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
53 _SEGMENT_ENTRY_PROTECT);
54 rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
55 _SEGMENT_ENTRY_DIRTY);
56 rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
57 _SEGMENT_ENTRY_YOUNG);
58#ifdef CONFIG_MEM_SOFT_DIRTY
59 rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
60 _SEGMENT_ENTRY_SOFT_DIRTY);
61#endif
62 } else
63 rste = _SEGMENT_ENTRY_INVALID;
64 return rste;
65}
66
67static inline pte_t __rste_to_pte(unsigned long rste)
68{
69 int present;
70 pte_t pte;
71
72 if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
73 present = pud_present(__pud(rste));
74 else
75 present = pmd_present(__pmd(rste));
76
77 /*
78 * Convert encoding pmd / pud bits pte bits
79 * dy..R...I...wr lIR.uswrdy.p
80 * empty 00..0...1...00 -> 010.000000.0
81 * prot-none, clean, old 00..1...1...00 -> 111.000000.1
82 * prot-none, clean, young 01..1...1...00 -> 111.000001.1
83 * prot-none, dirty, old 10..1...1...00 -> 111.000010.1
84 * prot-none, dirty, young 11..1...1...00 -> 111.000011.1
85 * read-only, clean, old 00..1...1...01 -> 111.000100.1
86 * read-only, clean, young 01..1...0...01 -> 101.000101.1
87 * read-only, dirty, old 10..1...1...01 -> 111.000110.1
88 * read-only, dirty, young 11..1...0...01 -> 101.000111.1
89 * read-write, clean, old 00..1...1...11 -> 111.001100.1
90 * read-write, clean, young 01..1...0...11 -> 101.001101.1
91 * read-write, dirty, old 10..0...1...11 -> 110.001110.1
92 * read-write, dirty, young 11..0...0...11 -> 100.001111.1
93 * HW-bits: R read-only, I invalid
94 * SW-bits: p present, y young, d dirty, r read, w write, s special,
95 * u unused, l large
96 */
97 if (present) {
98 pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
99 pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
100 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
101 _PAGE_READ);
102 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
103 _PAGE_WRITE);
104 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
105 _PAGE_INVALID);
106 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
107 _PAGE_PROTECT);
108 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
109 _PAGE_DIRTY);
110 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
111 _PAGE_YOUNG);
112#ifdef CONFIG_MEM_SOFT_DIRTY
113 pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
114 _PAGE_DIRTY);
115#endif
116 } else
117 pte_val(pte) = _PAGE_INVALID;
118 return pte;
119}
120
121void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
122 pte_t *ptep, pte_t pte)
123{
124 unsigned long rste = __pte_to_rste(pte);
125
126 /* Set correct table type for 2G hugepages */
127 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
128 rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
129 else
130 rste |= _SEGMENT_ENTRY_LARGE;
131 pte_val(*ptep) = rste;
132}
133
134pte_t huge_ptep_get(pte_t *ptep)
135{
136 return __rste_to_pte(pte_val(*ptep));
137}
138
139pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
140 unsigned long addr, pte_t *ptep)
141{
142 pte_t pte = huge_ptep_get(ptep);
143 pmd_t *pmdp = (pmd_t *) ptep;
144 pud_t *pudp = (pud_t *) ptep;
145
146 if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
147 pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
148 else
149 pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
150 return pte;
151}
152
153pte_t *huge_pte_alloc(struct mm_struct *mm,
154 unsigned long addr, unsigned long sz)
155{
156 pgd_t *pgdp;
157 pud_t *pudp;
158 pmd_t *pmdp = NULL;
159
160 pgdp = pgd_offset(mm, addr);
161 pudp = pud_alloc(mm, pgdp, addr);
162 if (pudp) {
163 if (sz == PUD_SIZE)
164 return (pte_t *) pudp;
165 else if (sz == PMD_SIZE)
166 pmdp = pmd_alloc(mm, pudp, addr);
167 }
168 return (pte_t *) pmdp;
169}
170
171pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
172{
173 pgd_t *pgdp;
174 pud_t *pudp;
175 pmd_t *pmdp = NULL;
176
177 pgdp = pgd_offset(mm, addr);
178 if (pgd_present(*pgdp)) {
179 pudp = pud_offset(pgdp, addr);
180 if (pud_present(*pudp)) {
181 if (pud_large(*pudp))
182 return (pte_t *) pudp;
183 pmdp = pmd_offset(pudp, addr);
184 }
185 }
186 return (pte_t *) pmdp;
187}
188
189int pmd_huge(pmd_t pmd)
190{
191 return pmd_large(pmd);
192}
193
194int pud_huge(pud_t pud)
195{
196 return pud_large(pud);
197}
198
199struct page *
200follow_huge_pud(struct mm_struct *mm, unsigned long address,
201 pud_t *pud, int flags)
202{
203 if (flags & FOLL_GET)
204 return NULL;
205
206 return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
207}
208
209static __init int setup_hugepagesz(char *opt)
210{
211 unsigned long size;
212 char *string = opt;
213
214 size = memparse(opt, &opt);
215 if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
216 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
217 } else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
218 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
219 } else {
220 hugetlb_bad_size();
221 pr_err("hugepagesz= specifies an unsupported page size %s\n",
222 string);
223 return 0;
224 }
225 return 1;
226}
227__setup("hugepagesz=", setup_hugepagesz);