Commit | Line | Data |
---|---|---|
53492b1d GS |
1 | /* |
2 | * IBM System z Huge TLB Page Support for Kernel. | |
3 | * | |
a53c8fab | 4 | * Copyright IBM Corp. 2007 |
53492b1d GS |
5 | * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> |
6 | */ | |
7 | ||
8 | #include <linux/mm.h> | |
9 | #include <linux/hugetlb.h> | |
10 | ||
e5098611 MS |
11 | static inline pmd_t __pte_to_pmd(pte_t pte) |
12 | { | |
e5098611 MS |
13 | pmd_t pmd; |
14 | ||
15 | /* | |
152125b7 | 16 | * Convert encoding pte bits pmd bits |
a1c843b8 MS |
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 | |
e5098611 MS |
34 | */ |
35 | if (pte_present(pte)) { | |
36 | pmd_val(pmd) = pte_val(pte) & PAGE_MASK; | |
152125b7 MS |
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; | |
e5098611 MS |
43 | } else |
44 | pmd_val(pmd) = _SEGMENT_ENTRY_INVALID; | |
45 | return pmd; | |
46 | } | |
47 | ||
48 | static inline pte_t __pmd_to_pte(pmd_t pmd) | |
49 | { | |
50 | pte_t pte; | |
51 | ||
52 | /* | |
152125b7 | 53 | * Convert encoding pmd bits pte bits |
a1c843b8 MS |
54 | * dy..R...I...wr lIR.uswrdy.p |
55 | * empty 00..0...1...00 -> 010.000000.0 | |
56 | * prot-none, clean, old 00..1...1...00 -> 111.000000.1 | |
57 | * prot-none, clean, young 01..1...1...00 -> 111.000001.1 | |
58 | * prot-none, dirty, old 10..1...1...00 -> 111.000010.1 | |
59 | * prot-none, dirty, young 11..1...1...00 -> 111.000011.1 | |
60 | * read-only, clean, old 00..1...1...01 -> 111.000100.1 | |
61 | * read-only, clean, young 01..1...0...01 -> 101.000101.1 | |
62 | * read-only, dirty, old 10..1...1...01 -> 111.000110.1 | |
63 | * read-only, dirty, young 11..1...0...01 -> 101.000111.1 | |
64 | * read-write, clean, old 00..1...1...11 -> 111.001100.1 | |
65 | * read-write, clean, young 01..1...0...11 -> 101.001101.1 | |
66 | * read-write, dirty, old 10..0...1...11 -> 110.001110.1 | |
67 | * read-write, dirty, young 11..0...0...11 -> 100.001111.1 | |
68 | * HW-bits: R read-only, I invalid | |
69 | * SW-bits: p present, y young, d dirty, r read, w write, s special, | |
70 | * u unused, l large | |
e5098611 MS |
71 | */ |
72 | if (pmd_present(pmd)) { | |
152125b7 MS |
73 | pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE; |
74 | pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT; | |
75 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4; | |
76 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4; | |
77 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5; | |
78 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT); | |
b7d14f3a MS |
79 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10; |
80 | pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10; | |
e5098611 MS |
81 | } else |
82 | pte_val(pte) = _PAGE_INVALID; | |
83 | return pte; | |
84 | } | |
53492b1d GS |
85 | |
86 | void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, | |
e5098611 | 87 | pte_t *ptep, pte_t pte) |
53492b1d | 88 | { |
e5098611 | 89 | pmd_t pmd; |
53492b1d | 90 | |
e5098611 | 91 | pmd = __pte_to_pmd(pte); |
53492b1d | 92 | if (!MACHINE_HAS_HPAGE) { |
152125b7 | 93 | /* Emulated huge ptes loose the dirty and young bit */ |
e5098611 MS |
94 | pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; |
95 | pmd_val(pmd) |= pte_page(pte)[1].index; | |
96 | } else | |
6a5c1482 | 97 | pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE; |
e5098611 MS |
98 | *(pmd_t *) ptep = pmd; |
99 | } | |
100 | ||
101 | pte_t huge_ptep_get(pte_t *ptep) | |
102 | { | |
103 | unsigned long origin; | |
104 | pmd_t pmd; | |
105 | ||
106 | pmd = *(pmd_t *) ptep; | |
107 | if (!MACHINE_HAS_HPAGE && pmd_present(pmd)) { | |
108 | origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN; | |
109 | pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; | |
110 | pmd_val(pmd) |= *(unsigned long *) origin; | |
152125b7 MS |
111 | /* Emulated huge ptes are young and dirty by definition */ |
112 | pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG | _SEGMENT_ENTRY_DIRTY; | |
53492b1d | 113 | } |
e5098611 MS |
114 | return __pmd_to_pte(pmd); |
115 | } | |
116 | ||
117 | pte_t huge_ptep_get_and_clear(struct mm_struct *mm, | |
118 | unsigned long addr, pte_t *ptep) | |
119 | { | |
120 | pmd_t *pmdp = (pmd_t *) ptep; | |
121 | pte_t pte = huge_ptep_get(ptep); | |
53492b1d | 122 | |
1b948d6c | 123 | pmdp_flush_direct(mm, addr, pmdp); |
e5098611 MS |
124 | pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY; |
125 | return pte; | |
53492b1d GS |
126 | } |
127 | ||
128 | int arch_prepare_hugepage(struct page *page) | |
129 | { | |
130 | unsigned long addr = page_to_phys(page); | |
131 | pte_t pte; | |
132 | pte_t *ptep; | |
133 | int i; | |
134 | ||
135 | if (MACHINE_HAS_HPAGE) | |
136 | return 0; | |
137 | ||
e5992f2e | 138 | ptep = (pte_t *) pte_alloc_one(&init_mm, addr); |
53492b1d GS |
139 | if (!ptep) |
140 | return -ENOMEM; | |
141 | ||
106c992a | 142 | pte_val(pte) = addr; |
53492b1d GS |
143 | for (i = 0; i < PTRS_PER_PTE; i++) { |
144 | set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte); | |
145 | pte_val(pte) += PAGE_SIZE; | |
146 | } | |
147 | page[1].index = (unsigned long) ptep; | |
148 | return 0; | |
149 | } | |
150 | ||
151 | void arch_release_hugepage(struct page *page) | |
152 | { | |
153 | pte_t *ptep; | |
154 | ||
155 | if (MACHINE_HAS_HPAGE) | |
156 | return; | |
157 | ||
158 | ptep = (pte_t *) page[1].index; | |
159 | if (!ptep) | |
160 | return; | |
e5098611 | 161 | clear_table((unsigned long *) ptep, _PAGE_INVALID, |
a686425b | 162 | PTRS_PER_PTE * sizeof(pte_t)); |
80217147 | 163 | page_table_free(&init_mm, (unsigned long *) ptep); |
53492b1d GS |
164 | page[1].index = 0; |
165 | } | |
166 | ||
a5516438 AK |
167 | pte_t *huge_pte_alloc(struct mm_struct *mm, |
168 | unsigned long addr, unsigned long sz) | |
53492b1d GS |
169 | { |
170 | pgd_t *pgdp; | |
171 | pud_t *pudp; | |
172 | pmd_t *pmdp = NULL; | |
173 | ||
174 | pgdp = pgd_offset(mm, addr); | |
175 | pudp = pud_alloc(mm, pgdp, addr); | |
176 | if (pudp) | |
177 | pmdp = pmd_alloc(mm, pudp, addr); | |
178 | return (pte_t *) pmdp; | |
179 | } | |
180 | ||
181 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
182 | { | |
183 | pgd_t *pgdp; | |
184 | pud_t *pudp; | |
185 | pmd_t *pmdp = NULL; | |
186 | ||
187 | pgdp = pgd_offset(mm, addr); | |
188 | if (pgd_present(*pgdp)) { | |
189 | pudp = pud_offset(pgdp, addr); | |
190 | if (pud_present(*pudp)) | |
191 | pmdp = pmd_offset(pudp, addr); | |
192 | } | |
193 | return (pte_t *) pmdp; | |
194 | } | |
195 | ||
196 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
197 | { | |
198 | return 0; | |
199 | } | |
200 | ||
53492b1d GS |
201 | int pmd_huge(pmd_t pmd) |
202 | { | |
203 | if (!MACHINE_HAS_HPAGE) | |
204 | return 0; | |
205 | ||
206 | return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE); | |
207 | } | |
208 | ||
ceb86879 AK |
209 | int pud_huge(pud_t pud) |
210 | { | |
211 | return 0; | |
212 | } |