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git.proxmox.com Git - mirror_ubuntu-focal-kernel.git/blob - arch/s390/include/asm/tlb.h
5 * TLB flushing on s390 is complicated. The following requirement
6 * from the principles of operation is the most arduous:
8 * "A valid table entry must not be changed while it is attached
9 * to any CPU and may be used for translation by that CPU except to
10 * (1) invalidate the entry by using INVALIDATE PAGE TABLE ENTRY,
11 * or INVALIDATE DAT TABLE ENTRY, (2) alter bits 56-63 of a page
12 * table entry, or (3) make a change by means of a COMPARE AND SWAP
13 * AND PURGE instruction that purges the TLB."
15 * The modification of a pte of an active mm struct therefore is
16 * a two step process: i) invalidate the pte, ii) store the new pte.
17 * This is true for the page protection bit as well.
18 * The only possible optimization is to flush at the beginning of
19 * a tlb_gather_mmu cycle if the mm_struct is currently not in use.
21 * Pages used for the page tables is a different story. FIXME: more
25 #include <linux/pagemap.h>
26 #include <linux/swap.h>
27 #include <asm/processor.h>
28 #include <asm/pgalloc.h>
29 #include <asm/tlbflush.h>
33 struct mmu_table_batch
*batch
;
35 unsigned long start
, end
;
38 struct mmu_table_batch
{
44 #define MAX_TABLE_BATCH \
45 ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
47 extern void tlb_table_flush(struct mmu_gather
*tlb
);
48 extern void tlb_remove_table(struct mmu_gather
*tlb
, void *table
);
51 arch_tlb_gather_mmu(struct mmu_gather
*tlb
, struct mm_struct
*mm
,
52 unsigned long start
, unsigned long end
)
57 tlb
->fullmm
= !(start
| (end
+1));
61 static inline void tlb_flush_mmu_tlbonly(struct mmu_gather
*tlb
)
63 __tlb_flush_mm_lazy(tlb
->mm
);
66 static inline void tlb_flush_mmu_free(struct mmu_gather
*tlb
)
72 static inline void tlb_flush_mmu(struct mmu_gather
*tlb
)
74 tlb_flush_mmu_tlbonly(tlb
);
75 tlb_flush_mmu_free(tlb
);
79 arch_tlb_finish_mmu(struct mmu_gather
*tlb
,
80 unsigned long start
, unsigned long end
, bool force
)
91 * Release the page cache reference for a pte removed by
92 * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page
93 * has already been freed, so just do free_page_and_swap_cache.
95 static inline bool __tlb_remove_page(struct mmu_gather
*tlb
, struct page
*page
)
97 free_page_and_swap_cache(page
);
98 return false; /* avoid calling tlb_flush_mmu */
101 static inline void tlb_remove_page(struct mmu_gather
*tlb
, struct page
*page
)
103 free_page_and_swap_cache(page
);
106 static inline bool __tlb_remove_page_size(struct mmu_gather
*tlb
,
107 struct page
*page
, int page_size
)
109 return __tlb_remove_page(tlb
, page
);
112 static inline void tlb_remove_page_size(struct mmu_gather
*tlb
,
113 struct page
*page
, int page_size
)
115 return tlb_remove_page(tlb
, page
);
119 * pte_free_tlb frees a pte table and clears the CRSTE for the
120 * page table from the tlb.
122 static inline void pte_free_tlb(struct mmu_gather
*tlb
, pgtable_t pte
,
123 unsigned long address
)
125 page_table_free_rcu(tlb
, (unsigned long *) pte
, address
);
129 * pmd_free_tlb frees a pmd table and clears the CRSTE for the
130 * segment table entry from the tlb.
131 * If the mm uses a two level page table the single pmd is freed
132 * as the pgd. pmd_free_tlb checks the asce_limit against 2GB
133 * to avoid the double free of the pmd in this case.
135 static inline void pmd_free_tlb(struct mmu_gather
*tlb
, pmd_t
*pmd
,
136 unsigned long address
)
138 if (tlb
->mm
->context
.asce_limit
<= _REGION3_SIZE
)
140 pgtable_pmd_page_dtor(virt_to_page(pmd
));
141 tlb_remove_table(tlb
, pmd
);
145 * p4d_free_tlb frees a pud table and clears the CRSTE for the
146 * region second table entry from the tlb.
147 * If the mm uses a four level page table the single p4d is freed
148 * as the pgd. p4d_free_tlb checks the asce_limit against 8PB
149 * to avoid the double free of the p4d in this case.
151 static inline void p4d_free_tlb(struct mmu_gather
*tlb
, p4d_t
*p4d
,
152 unsigned long address
)
154 if (tlb
->mm
->context
.asce_limit
<= _REGION1_SIZE
)
156 tlb_remove_table(tlb
, p4d
);
160 * pud_free_tlb frees a pud table and clears the CRSTE for the
161 * region third table entry from the tlb.
162 * If the mm uses a three level page table the single pud is freed
163 * as the pgd. pud_free_tlb checks the asce_limit against 4TB
164 * to avoid the double free of the pud in this case.
166 static inline void pud_free_tlb(struct mmu_gather
*tlb
, pud_t
*pud
,
167 unsigned long address
)
169 if (tlb
->mm
->context
.asce_limit
<= _REGION2_SIZE
)
171 tlb_remove_table(tlb
, pud
);
174 #define tlb_start_vma(tlb, vma) do { } while (0)
175 #define tlb_end_vma(tlb, vma) do { } while (0)
176 #define tlb_remove_tlb_entry(tlb, ptep, addr) do { } while (0)
177 #define tlb_remove_pmd_tlb_entry(tlb, pmdp, addr) do { } while (0)
178 #define tlb_migrate_finish(mm) do { } while (0)
179 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
180 tlb_remove_tlb_entry(tlb, ptep, address)
182 #define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
183 static inline void tlb_remove_check_page_size_change(struct mmu_gather
*tlb
,
184 unsigned int page_size
)
188 #endif /* _S390_TLB_H */