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1da177e4 LT |
1 | #ifndef _S390_TLB_H |
2 | #define _S390_TLB_H | |
3 | ||
4 | /* | |
ba8a9229 MS |
5 | * TLB flushing on s390 is complicated. The following requirement |
6 | * from the principles of operation is the most arduous: | |
7 | * | |
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." | |
14 | * | |
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. | |
20 | * | |
21 | * Pages used for the page tables is a different story. FIXME: more | |
1da177e4 | 22 | */ |
ba8a9229 MS |
23 | |
24 | #include <linux/mm.h> | |
c84ca008 | 25 | #include <linux/pagemap.h> |
ba8a9229 MS |
26 | #include <linux/swap.h> |
27 | #include <asm/processor.h> | |
28 | #include <asm/pgalloc.h> | |
ba8a9229 MS |
29 | #include <asm/tlbflush.h> |
30 | ||
ba8a9229 MS |
31 | struct mmu_gather { |
32 | struct mm_struct *mm; | |
36409f63 | 33 | struct mmu_table_batch *batch; |
ba8a9229 | 34 | unsigned int fullmm; |
215b28a5 | 35 | unsigned long start, end; |
ba8a9229 MS |
36 | }; |
37 | ||
36409f63 MS |
38 | struct mmu_table_batch { |
39 | struct rcu_head rcu; | |
40 | unsigned int nr; | |
41 | void *tables[0]; | |
42 | }; | |
ba8a9229 | 43 | |
36409f63 MS |
44 | #define MAX_TABLE_BATCH \ |
45 | ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) | |
46 | ||
47 | extern void tlb_table_flush(struct mmu_gather *tlb); | |
48 | extern void tlb_remove_table(struct mmu_gather *tlb, void *table); | |
68f03921 PZ |
49 | |
50 | static inline void tlb_gather_mmu(struct mmu_gather *tlb, | |
51 | struct mm_struct *mm, | |
2b047252 LT |
52 | unsigned long start, |
53 | unsigned long end) | |
68f03921 | 54 | { |
ba8a9229 | 55 | tlb->mm = mm; |
2b047252 LT |
56 | tlb->start = start; |
57 | tlb->end = end; | |
58 | tlb->fullmm = !(start | (end+1)); | |
36409f63 | 59 | tlb->batch = NULL; |
ba8a9229 MS |
60 | if (tlb->fullmm) |
61 | __tlb_flush_mm(mm); | |
ba8a9229 MS |
62 | } |
63 | ||
68f03921 | 64 | static inline void tlb_flush_mmu(struct mmu_gather *tlb) |
ba8a9229 | 65 | { |
36409f63 | 66 | tlb_table_flush(tlb); |
ba8a9229 MS |
67 | } |
68 | ||
69 | static inline void tlb_finish_mmu(struct mmu_gather *tlb, | |
70 | unsigned long start, unsigned long end) | |
71 | { | |
cd94154c | 72 | tlb_table_flush(tlb); |
ba8a9229 | 73 | } |
1da177e4 LT |
74 | |
75 | /* | |
ba8a9229 | 76 | * Release the page cache reference for a pte removed by |
68f03921 | 77 | * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page |
ba8a9229 | 78 | * has already been freed, so just do free_page_and_swap_cache. |
1da177e4 | 79 | */ |
68f03921 PZ |
80 | static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) |
81 | { | |
82 | free_page_and_swap_cache(page); | |
83 | return 1; /* avoid calling tlb_flush_mmu */ | |
84 | } | |
85 | ||
ba8a9229 MS |
86 | static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) |
87 | { | |
88 | free_page_and_swap_cache(page); | |
89 | } | |
1da177e4 | 90 | |
ba8a9229 MS |
91 | /* |
92 | * pte_free_tlb frees a pte table and clears the CRSTE for the | |
93 | * page table from the tlb. | |
94 | */ | |
9e1b32ca BH |
95 | static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, |
96 | unsigned long address) | |
ba8a9229 | 97 | { |
36409f63 MS |
98 | if (!tlb->fullmm) |
99 | return page_table_free_rcu(tlb, (unsigned long *) pte); | |
36409f63 | 100 | page_table_free(tlb->mm, (unsigned long *) pte); |
ba8a9229 | 101 | } |
1da177e4 | 102 | |
ba8a9229 MS |
103 | /* |
104 | * pmd_free_tlb frees a pmd table and clears the CRSTE for the | |
105 | * segment table entry from the tlb. | |
6252d702 MS |
106 | * If the mm uses a two level page table the single pmd is freed |
107 | * as the pgd. pmd_free_tlb checks the asce_limit against 2GB | |
108 | * to avoid the double free of the pmd in this case. | |
ba8a9229 | 109 | */ |
9e1b32ca BH |
110 | static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, |
111 | unsigned long address) | |
ba8a9229 | 112 | { |
f4815ac6 | 113 | #ifdef CONFIG_64BIT |
6252d702 MS |
114 | if (tlb->mm->context.asce_limit <= (1UL << 31)) |
115 | return; | |
36409f63 MS |
116 | if (!tlb->fullmm) |
117 | return tlb_remove_table(tlb, pmd); | |
36409f63 | 118 | crst_table_free(tlb->mm, (unsigned long *) pmd); |
1da177e4 | 119 | #endif |
ba8a9229 MS |
120 | } |
121 | ||
5a216a20 MS |
122 | /* |
123 | * pud_free_tlb frees a pud table and clears the CRSTE for the | |
124 | * region third table entry from the tlb. | |
6252d702 MS |
125 | * If the mm uses a three level page table the single pud is freed |
126 | * as the pgd. pud_free_tlb checks the asce_limit against 4TB | |
127 | * to avoid the double free of the pud in this case. | |
5a216a20 | 128 | */ |
9e1b32ca BH |
129 | static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, |
130 | unsigned long address) | |
5a216a20 | 131 | { |
f4815ac6 | 132 | #ifdef CONFIG_64BIT |
6252d702 MS |
133 | if (tlb->mm->context.asce_limit <= (1UL << 42)) |
134 | return; | |
36409f63 MS |
135 | if (!tlb->fullmm) |
136 | return tlb_remove_table(tlb, pud); | |
36409f63 | 137 | crst_table_free(tlb->mm, (unsigned long *) pud); |
5a216a20 MS |
138 | #endif |
139 | } | |
190a1d72 | 140 | |
ba8a9229 MS |
141 | #define tlb_start_vma(tlb, vma) do { } while (0) |
142 | #define tlb_end_vma(tlb, vma) do { } while (0) | |
143 | #define tlb_remove_tlb_entry(tlb, ptep, addr) do { } while (0) | |
1ae1c1d0 | 144 | #define tlb_remove_pmd_tlb_entry(tlb, pmdp, addr) do { } while (0) |
ba8a9229 MS |
145 | #define tlb_migrate_finish(mm) do { } while (0) |
146 | ||
147 | #endif /* _S390_TLB_H */ |