1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _S390_TLB_H
#define _S390_TLB_H
/*
* TLB flushing on s390 is complicated. The following requirement
* from the principles of operation is the most arduous:
*
* "A valid table entry must not be changed while it is attached
* to any CPU and may be used for translation by that CPU except to
* (1) invalidate the entry by using INVALIDATE PAGE TABLE ENTRY,
* or INVALIDATE DAT TABLE ENTRY, (2) alter bits 56-63 of a page
* table entry, or (3) make a change by means of a COMPARE AND SWAP
* AND PURGE instruction that purges the TLB."
*
* The modification of a pte of an active mm struct therefore is
* a two step process: i) invalidate the pte, ii) store the new pte.
* This is true for the page protection bit as well.
* The only possible optimization is to flush at the beginning of
* a tlb_gather_mmu cycle if the mm_struct is currently not in use.
*
* Pages used for the page tables is a different story. FIXME: more
*/
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <asm/processor.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
struct mmu_gather {
struct mm_struct *mm;
struct mmu_table_batch *batch;
unsigned int fullmm;
unsigned long start, end;
};
struct mmu_table_batch {
struct rcu_head rcu;
unsigned int nr;
void *tables[0];
};
#define MAX_TABLE_BATCH \
((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
extern void tlb_table_flush(struct mmu_gather *tlb);
extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
static inline void
arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
unsigned long start, unsigned long end)
{
tlb->mm = mm;
tlb->start = start;
tlb->end = end;
tlb->fullmm = !(start | (end+1));
tlb->batch = NULL;
}
static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
__tlb_flush_mm_lazy(tlb->mm);
}
static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
{
tlb_table_flush(tlb);
}
static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
tlb_flush_mmu_tlbonly(tlb);
tlb_flush_mmu_free(tlb);
}
static inline void
arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force)
{
if (force) {
tlb->start = start;
tlb->end = end;
}
tlb_flush_mmu(tlb);
}
/*
* Release the page cache reference for a pte removed by
* tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page
* has already been freed, so just do free_page_and_swap_cache.
*/
static inline bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
free_page_and_swap_cache(page);
return false; /* avoid calling tlb_flush_mmu */
}
static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
free_page_and_swap_cache(page);
}
static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
struct page *page, int page_size)
{
return __tlb_remove_page(tlb, page);
}
static inline void tlb_remove_page_size(struct mmu_gather *tlb,
struct page *page, int page_size)
{
return tlb_remove_page(tlb, page);
}
static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
unsigned long address, unsigned long size)
{
/*
* the range might exceed the original range that was provided to
* tlb_gather_mmu(), so we need to update it despite the fact it is
* usually not updated.
*/
if (tlb->start > address)
tlb->start = address;
if (tlb->end < address + size)
tlb->end = address + size;
}
/*
* pte_free_tlb frees a pte table and clears the CRSTE for the
* page table from the tlb.
*/
static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long address)
{
page_table_free_rcu(tlb, (unsigned long *) pte, address);
}
/*
* pmd_free_tlb frees a pmd table and clears the CRSTE for the
* segment table entry from the tlb.
* If the mm uses a two level page table the single pmd is freed
* as the pgd. pmd_free_tlb checks the asce_limit against 2GB
* to avoid the double free of the pmd in this case.
*/
static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
unsigned long address)
{
if (mm_pmd_folded(tlb->mm))
return;
pgtable_pmd_page_dtor(virt_to_page(pmd));
tlb_remove_table(tlb, pmd);
}
/*
* p4d_free_tlb frees a pud table and clears the CRSTE for the
* region second table entry from the tlb.
* If the mm uses a four level page table the single p4d is freed
* as the pgd. p4d_free_tlb checks the asce_limit against 8PB
* to avoid the double free of the p4d in this case.
*/
static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long address)
{
if (mm_p4d_folded(tlb->mm))
return;
tlb_remove_table(tlb, p4d);
}
/*
* pud_free_tlb frees a pud table and clears the CRSTE for the
* region third table entry from the tlb.
* If the mm uses a three level page table the single pud is freed
* as the pgd. pud_free_tlb checks the asce_limit against 4TB
* to avoid the double free of the pud in this case.
*/
static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
unsigned long address)
{
if (mm_pud_folded(tlb->mm))
return;
tlb_remove_table(tlb, pud);
}
#define tlb_start_vma(tlb, vma) do { } while (0)
#define tlb_end_vma(tlb, vma) do { } while (0)
#define tlb_remove_tlb_entry(tlb, ptep, addr) do { } while (0)
#define tlb_remove_pmd_tlb_entry(tlb, pmdp, addr) do { } while (0)
#define tlb_migrate_finish(mm) do { } while (0)
#define tlb_flush_pmd_range(tlb, addr, sz) do { } while (0)
#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
tlb_remove_tlb_entry(tlb, ptep, address)
#define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
unsigned int page_size)
{
}
#endif /* _S390_TLB_H */
|
