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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 2007 IBM Corp.
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#include <linux/mm.h>
9#include <linux/hugetlb.h>
10
11
12void 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;
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;
23 }
24
25 pmd_val(*pmdp) = pte_val(pteval);
26}
27
28int 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
38 ptep = (pte_t *) pte_alloc_one(&init_mm, addr);
39 if (!ptep)
40 return -ENOMEM;
41
42 pte = mk_pte(page, PAGE_RW);
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
51void 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;
61 clear_table((unsigned long *) ptep, _PAGE_TYPE_EMPTY,
62 PTRS_PER_PTE * sizeof(pte_t));
63 page_table_free(&init_mm, (unsigned long *) ptep);
64 page[1].index = 0;
65}
66
67pte_t *huge_pte_alloc(struct mm_struct *mm,
68 unsigned long addr, unsigned long sz)
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
81pte_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
96int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
97{
98 return 0;
99}
100
101struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
102 int write)
103{
104 return ERR_PTR(-EINVAL);
105}
106
107int 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
115int pud_huge(pud_t pud)
116{
117 return 0;
118}
119
120struct 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}