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53492b1d GS |
1 | /* |
2 | * IBM System z Huge TLB Page Support for Kernel. | |
3 | * | |
d08de8e2 | 4 | * Copyright IBM Corp. 2007,2016 |
53492b1d GS |
5 | * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> |
6 | */ | |
7 | ||
d08de8e2 GS |
8 | #define KMSG_COMPONENT "hugetlb" |
9 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
10 | ||
53492b1d GS |
11 | #include <linux/mm.h> |
12 | #include <linux/hugetlb.h> | |
13 | ||
bc29b7ac GS |
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 | ||
d08de8e2 | 20 | static inline unsigned long __pte_to_rste(pte_t pte) |
e5098611 | 21 | { |
d08de8e2 | 22 | unsigned long rste; |
e5098611 MS |
23 | |
24 | /* | |
d08de8e2 | 25 | * Convert encoding pte bits pmd / pud bits |
a1c843b8 MS |
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 | |
e5098611 MS |
43 | */ |
44 | if (pte_present(pte)) { | |
d08de8e2 | 45 | rste = pte_val(pte) & PAGE_MASK; |
bc29b7ac GS |
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 | |
e5098611 | 62 | } else |
d08de8e2 GS |
63 | rste = _SEGMENT_ENTRY_INVALID; |
64 | return rste; | |
e5098611 MS |
65 | } |
66 | ||
d08de8e2 | 67 | static inline pte_t __rste_to_pte(unsigned long rste) |
e5098611 | 68 | { |
d08de8e2 | 69 | int present; |
e5098611 MS |
70 | pte_t pte; |
71 | ||
d08de8e2 GS |
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 | ||
e5098611 | 77 | /* |
d08de8e2 | 78 | * Convert encoding pmd / pud bits pte bits |
a1c843b8 MS |
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 | |
e5098611 | 96 | */ |
d08de8e2 GS |
97 | if (present) { |
98 | pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE; | |
152125b7 | 99 | pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT; |
bc29b7ac GS |
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 | |
e5098611 MS |
116 | } else |
117 | pte_val(pte) = _PAGE_INVALID; | |
118 | return pte; | |
119 | } | |
53492b1d GS |
120 | |
121 | void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, | |
e5098611 | 122 | pte_t *ptep, pte_t pte) |
53492b1d | 123 | { |
d08de8e2 GS |
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; | |
e5098611 MS |
132 | } |
133 | ||
134 | pte_t huge_ptep_get(pte_t *ptep) | |
135 | { | |
d08de8e2 | 136 | return __rste_to_pte(pte_val(*ptep)); |
e5098611 MS |
137 | } |
138 | ||
139 | pte_t huge_ptep_get_and_clear(struct mm_struct *mm, | |
140 | unsigned long addr, pte_t *ptep) | |
141 | { | |
d08de8e2 | 142 | pte_t pte = huge_ptep_get(ptep); |
e5098611 | 143 | pmd_t *pmdp = (pmd_t *) ptep; |
d08de8e2 | 144 | pud_t *pudp = (pud_t *) ptep; |
53492b1d | 145 | |
d08de8e2 GS |
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; | |
53492b1d GS |
151 | } |
152 | ||
a5516438 AK |
153 | pte_t *huge_pte_alloc(struct mm_struct *mm, |
154 | unsigned long addr, unsigned long sz) | |
53492b1d GS |
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); | |
d08de8e2 GS |
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 | } | |
53492b1d GS |
168 | return (pte_t *) pmdp; |
169 | } | |
170 | ||
171 | pte_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); | |
d08de8e2 GS |
180 | if (pud_present(*pudp)) { |
181 | if (pud_large(*pudp)) | |
182 | return (pte_t *) pudp; | |
53492b1d | 183 | pmdp = pmd_offset(pudp, addr); |
d08de8e2 | 184 | } |
53492b1d GS |
185 | } |
186 | return (pte_t *) pmdp; | |
187 | } | |
188 | ||
53492b1d GS |
189 | int pmd_huge(pmd_t pmd) |
190 | { | |
cbd7d9c2 | 191 | return pmd_large(pmd); |
53492b1d GS |
192 | } |
193 | ||
ceb86879 AK |
194 | int pud_huge(pud_t pud) |
195 | { | |
d08de8e2 GS |
196 | return pud_large(pud); |
197 | } | |
198 | ||
199 | struct page * | |
200 | follow_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 | ||
209 | static __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 | pr_err("hugepagesz= specifies an unsupported page size %s\n", | |
221 | string); | |
222 | return 0; | |
223 | } | |
224 | return 1; | |
ceb86879 | 225 | } |
d08de8e2 | 226 | __setup("hugepagesz=", setup_hugepagesz); |