]>
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 | ||
11 | ||
12 | void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, | |
13 | pte_t *pteptr, pte_t pteval) | |
14 | { | |
15 | pmd_t *pmdp = (pmd_t *) pteptr; | |
53492b1d GS |
16 | unsigned long mask; |
17 | ||
18 | if (!MACHINE_HAS_HPAGE) { | |
19 | pteptr = (pte_t *) pte_page(pteval)[1].index; | |
20 | mask = pte_val(pteval) & | |
21 | (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO); | |
22 | pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask; | |
53492b1d GS |
23 | } |
24 | ||
25 | pmd_val(*pmdp) = pte_val(pteval); | |
53492b1d GS |
26 | } |
27 | ||
28 | int arch_prepare_hugepage(struct page *page) | |
29 | { | |
30 | unsigned long addr = page_to_phys(page); | |
31 | pte_t pte; | |
32 | pte_t *ptep; | |
33 | int i; | |
34 | ||
35 | if (MACHINE_HAS_HPAGE) | |
36 | return 0; | |
37 | ||
e5992f2e | 38 | ptep = (pte_t *) pte_alloc_one(&init_mm, addr); |
53492b1d GS |
39 | if (!ptep) |
40 | return -ENOMEM; | |
41 | ||
106c992a | 42 | pte_val(pte) = addr; |
53492b1d GS |
43 | for (i = 0; i < PTRS_PER_PTE; i++) { |
44 | set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte); | |
45 | pte_val(pte) += PAGE_SIZE; | |
46 | } | |
47 | page[1].index = (unsigned long) ptep; | |
48 | return 0; | |
49 | } | |
50 | ||
51 | void arch_release_hugepage(struct page *page) | |
52 | { | |
53 | pte_t *ptep; | |
54 | ||
55 | if (MACHINE_HAS_HPAGE) | |
56 | return; | |
57 | ||
58 | ptep = (pte_t *) page[1].index; | |
59 | if (!ptep) | |
60 | return; | |
a686425b GS |
61 | clear_table((unsigned long *) ptep, _PAGE_TYPE_EMPTY, |
62 | PTRS_PER_PTE * sizeof(pte_t)); | |
80217147 | 63 | page_table_free(&init_mm, (unsigned long *) ptep); |
53492b1d GS |
64 | page[1].index = 0; |
65 | } | |
66 | ||
a5516438 AK |
67 | pte_t *huge_pte_alloc(struct mm_struct *mm, |
68 | unsigned long addr, unsigned long sz) | |
53492b1d GS |
69 | { |
70 | pgd_t *pgdp; | |
71 | pud_t *pudp; | |
72 | pmd_t *pmdp = NULL; | |
73 | ||
74 | pgdp = pgd_offset(mm, addr); | |
75 | pudp = pud_alloc(mm, pgdp, addr); | |
76 | if (pudp) | |
77 | pmdp = pmd_alloc(mm, pudp, addr); | |
78 | return (pte_t *) pmdp; | |
79 | } | |
80 | ||
81 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
82 | { | |
83 | pgd_t *pgdp; | |
84 | pud_t *pudp; | |
85 | pmd_t *pmdp = NULL; | |
86 | ||
87 | pgdp = pgd_offset(mm, addr); | |
88 | if (pgd_present(*pgdp)) { | |
89 | pudp = pud_offset(pgdp, addr); | |
90 | if (pud_present(*pudp)) | |
91 | pmdp = pmd_offset(pudp, addr); | |
92 | } | |
93 | return (pte_t *) pmdp; | |
94 | } | |
95 | ||
96 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
97 | { | |
98 | return 0; | |
99 | } | |
100 | ||
101 | struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, | |
102 | int write) | |
103 | { | |
104 | return ERR_PTR(-EINVAL); | |
105 | } | |
106 | ||
107 | int pmd_huge(pmd_t pmd) | |
108 | { | |
109 | if (!MACHINE_HAS_HPAGE) | |
110 | return 0; | |
111 | ||
112 | return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE); | |
113 | } | |
114 | ||
ceb86879 AK |
115 | int pud_huge(pud_t pud) |
116 | { | |
117 | return 0; | |
118 | } | |
119 | ||
53492b1d GS |
120 | struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, |
121 | pmd_t *pmdp, int write) | |
122 | { | |
123 | struct page *page; | |
124 | ||
125 | if (!MACHINE_HAS_HPAGE) | |
126 | return NULL; | |
127 | ||
128 | page = pmd_page(*pmdp); | |
129 | if (page) | |
130 | page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); | |
131 | return page; | |
132 | } |