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Linux kernel mirror (for testing)
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kernel
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linux
1/*
2 * IBM System z Huge TLB Page Support for Kernel.
3 *
4 * Copyright IBM Corp. 2008
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#ifndef _ASM_S390_HUGETLB_H
9#define _ASM_S390_HUGETLB_H
10
11#include <asm/page.h>
12#include <asm/pgtable.h>
13
14
15#define is_hugepage_only_range(mm, addr, len) 0
16#define hugetlb_free_pgd_range free_pgd_range
17
18void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
19 pte_t *ptep, pte_t pte);
20
21/*
22 * If the arch doesn't supply something else, assume that hugepage
23 * size aligned regions are ok without further preparation.
24 */
25static inline int prepare_hugepage_range(unsigned long addr, unsigned long len)
26{
27 if (len & ~HPAGE_MASK)
28 return -EINVAL;
29 if (addr & ~HPAGE_MASK)
30 return -EINVAL;
31 return 0;
32}
33
34#define hugetlb_prefault_arch_hook(mm) do { } while (0)
35
36int arch_prepare_hugepage(struct page *page);
37void arch_release_hugepage(struct page *page);
38
39static inline pte_t pte_mkhuge(pte_t pte)
40{
41 /*
42 * PROT_NONE needs to be remapped from the pte type to the ste type.
43 * The HW invalid bit is also different for pte and ste. The pte
44 * invalid bit happens to be the same as the ste _SEGMENT_ENTRY_LARGE
45 * bit, so we don't have to clear it.
46 */
47 if (pte_val(pte) & _PAGE_INVALID) {
48 if (pte_val(pte) & _PAGE_SWT)
49 pte_val(pte) |= _HPAGE_TYPE_NONE;
50 pte_val(pte) |= _SEGMENT_ENTRY_INV;
51 }
52 /*
53 * Clear SW pte bits SWT and SWX, there are no SW bits in a segment
54 * table entry.
55 */
56 pte_val(pte) &= ~(_PAGE_SWT | _PAGE_SWX);
57 /*
58 * Also set the change-override bit because we don't need dirty bit
59 * tracking for hugetlbfs pages.
60 */
61 pte_val(pte) |= (_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO);
62 return pte;
63}
64
65static inline pte_t huge_pte_wrprotect(pte_t pte)
66{
67 pte_val(pte) |= _PAGE_RO;
68 return pte;
69}
70
71static inline int huge_pte_none(pte_t pte)
72{
73 return (pte_val(pte) & _SEGMENT_ENTRY_INV) &&
74 !(pte_val(pte) & _SEGMENT_ENTRY_RO);
75}
76
77static inline pte_t huge_ptep_get(pte_t *ptep)
78{
79 pte_t pte = *ptep;
80 unsigned long mask;
81
82 if (!MACHINE_HAS_HPAGE) {
83 ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN);
84 if (ptep) {
85 mask = pte_val(pte) &
86 (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
87 pte = pte_mkhuge(*ptep);
88 pte_val(pte) |= mask;
89 }
90 }
91 return pte;
92}
93
94static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
95 unsigned long addr, pte_t *ptep)
96{
97 pte_t pte = huge_ptep_get(ptep);
98
99 pmd_clear((pmd_t *) ptep);
100 return pte;
101}
102
103static inline void __pmd_csp(pmd_t *pmdp)
104{
105 register unsigned long reg2 asm("2") = pmd_val(*pmdp);
106 register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
107 _SEGMENT_ENTRY_INV;
108 register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
109
110 asm volatile(
111 " csp %1,%3"
112 : "=m" (*pmdp)
113 : "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
114 pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
115}
116
117static inline void __pmd_idte(unsigned long address, pmd_t *pmdp)
118{
119 unsigned long sto = (unsigned long) pmdp -
120 pmd_index(address) * sizeof(pmd_t);
121
122 if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) {
123 asm volatile(
124 " .insn rrf,0xb98e0000,%2,%3,0,0"
125 : "=m" (*pmdp)
126 : "m" (*pmdp), "a" (sto),
127 "a" ((address & HPAGE_MASK))
128 );
129 }
130 pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
131}
132
133static inline void huge_ptep_invalidate(struct mm_struct *mm,
134 unsigned long address, pte_t *ptep)
135{
136 pmd_t *pmdp = (pmd_t *) ptep;
137
138 if (!MACHINE_HAS_IDTE) {
139 __pmd_csp(pmdp);
140 if (mm->context.noexec) {
141 pmdp = get_shadow_table(pmdp);
142 __pmd_csp(pmdp);
143 }
144 return;
145 }
146
147 __pmd_idte(address, pmdp);
148 if (mm->context.noexec) {
149 pmdp = get_shadow_table(pmdp);
150 __pmd_idte(address, pmdp);
151 }
152 return;
153}
154
155#define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \
156({ \
157 int __changed = !pte_same(huge_ptep_get(__ptep), __entry); \
158 if (__changed) { \
159 huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \
160 set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \
161 } \
162 __changed; \
163})
164
165#define huge_ptep_set_wrprotect(__mm, __addr, __ptep) \
166({ \
167 pte_t __pte = huge_ptep_get(__ptep); \
168 if (pte_write(__pte)) { \
169 if (atomic_read(&(__mm)->mm_users) > 1 || \
170 (__mm) != current->active_mm) \
171 huge_ptep_invalidate(__mm, __addr, __ptep); \
172 set_huge_pte_at(__mm, __addr, __ptep, \
173 huge_pte_wrprotect(__pte)); \
174 } \
175})
176
177static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
178 unsigned long address, pte_t *ptep)
179{
180 huge_ptep_invalidate(vma->vm_mm, address, ptep);
181}
182
183#endif /* _ASM_S390_HUGETLB_H */