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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 MS |
33 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
34 | struct mmu_table_batch *batch; | |
35 | #endif | |
ba8a9229 | 36 | unsigned int fullmm; |
36409f63 | 37 | unsigned int need_flush; |
ba8a9229 MS |
38 | }; |
39 | ||
36409f63 MS |
40 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
41 | struct mmu_table_batch { | |
42 | struct rcu_head rcu; | |
43 | unsigned int nr; | |
44 | void *tables[0]; | |
45 | }; | |
ba8a9229 | 46 | |
36409f63 MS |
47 | #define MAX_TABLE_BATCH \ |
48 | ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) | |
49 | ||
50 | extern void tlb_table_flush(struct mmu_gather *tlb); | |
51 | extern void tlb_remove_table(struct mmu_gather *tlb, void *table); | |
52 | #endif | |
68f03921 PZ |
53 | |
54 | static inline void tlb_gather_mmu(struct mmu_gather *tlb, | |
55 | struct mm_struct *mm, | |
56 | unsigned int full_mm_flush) | |
57 | { | |
ba8a9229 | 58 | tlb->mm = mm; |
050eef36 | 59 | tlb->fullmm = full_mm_flush; |
36409f63 MS |
60 | tlb->need_flush = 0; |
61 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE | |
62 | tlb->batch = NULL; | |
63 | #endif | |
ba8a9229 MS |
64 | if (tlb->fullmm) |
65 | __tlb_flush_mm(mm); | |
ba8a9229 MS |
66 | } |
67 | ||
68f03921 | 68 | static inline void tlb_flush_mmu(struct mmu_gather *tlb) |
ba8a9229 | 69 | { |
36409f63 MS |
70 | if (!tlb->need_flush) |
71 | return; | |
72 | tlb->need_flush = 0; | |
73 | __tlb_flush_mm(tlb->mm); | |
74 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE | |
75 | tlb_table_flush(tlb); | |
76 | #endif | |
ba8a9229 MS |
77 | } |
78 | ||
79 | static inline void tlb_finish_mmu(struct mmu_gather *tlb, | |
80 | unsigned long start, unsigned long end) | |
81 | { | |
68f03921 | 82 | tlb_flush_mmu(tlb); |
ba8a9229 | 83 | } |
1da177e4 LT |
84 | |
85 | /* | |
ba8a9229 | 86 | * Release the page cache reference for a pte removed by |
68f03921 | 87 | * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page |
ba8a9229 | 88 | * has already been freed, so just do free_page_and_swap_cache. |
1da177e4 | 89 | */ |
68f03921 PZ |
90 | static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) |
91 | { | |
92 | free_page_and_swap_cache(page); | |
93 | return 1; /* avoid calling tlb_flush_mmu */ | |
94 | } | |
95 | ||
ba8a9229 MS |
96 | static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) |
97 | { | |
98 | free_page_and_swap_cache(page); | |
99 | } | |
1da177e4 | 100 | |
ba8a9229 MS |
101 | /* |
102 | * pte_free_tlb frees a pte table and clears the CRSTE for the | |
103 | * page table from the tlb. | |
104 | */ | |
9e1b32ca BH |
105 | static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, |
106 | unsigned long address) | |
ba8a9229 | 107 | { |
36409f63 MS |
108 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
109 | if (!tlb->fullmm) | |
110 | return page_table_free_rcu(tlb, (unsigned long *) pte); | |
111 | #endif | |
112 | page_table_free(tlb->mm, (unsigned long *) pte); | |
ba8a9229 | 113 | } |
1da177e4 | 114 | |
ba8a9229 MS |
115 | /* |
116 | * pmd_free_tlb frees a pmd table and clears the CRSTE for the | |
117 | * segment table entry from the tlb. | |
6252d702 MS |
118 | * If the mm uses a two level page table the single pmd is freed |
119 | * as the pgd. pmd_free_tlb checks the asce_limit against 2GB | |
120 | * to avoid the double free of the pmd in this case. | |
ba8a9229 | 121 | */ |
9e1b32ca BH |
122 | static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, |
123 | unsigned long address) | |
ba8a9229 MS |
124 | { |
125 | #ifdef __s390x__ | |
6252d702 MS |
126 | if (tlb->mm->context.asce_limit <= (1UL << 31)) |
127 | return; | |
36409f63 MS |
128 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
129 | if (!tlb->fullmm) | |
130 | return tlb_remove_table(tlb, pmd); | |
131 | #endif | |
132 | crst_table_free(tlb->mm, (unsigned long *) pmd); | |
1da177e4 | 133 | #endif |
ba8a9229 MS |
134 | } |
135 | ||
5a216a20 MS |
136 | /* |
137 | * pud_free_tlb frees a pud table and clears the CRSTE for the | |
138 | * region third table entry from the tlb. | |
6252d702 MS |
139 | * If the mm uses a three level page table the single pud is freed |
140 | * as the pgd. pud_free_tlb checks the asce_limit against 4TB | |
141 | * to avoid the double free of the pud in this case. | |
5a216a20 | 142 | */ |
9e1b32ca BH |
143 | static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, |
144 | unsigned long address) | |
5a216a20 MS |
145 | { |
146 | #ifdef __s390x__ | |
6252d702 MS |
147 | if (tlb->mm->context.asce_limit <= (1UL << 42)) |
148 | return; | |
36409f63 MS |
149 | #ifdef CONFIG_HAVE_RCU_TABLE_FREE |
150 | if (!tlb->fullmm) | |
151 | return tlb_remove_table(tlb, pud); | |
152 | #endif | |
153 | crst_table_free(tlb->mm, (unsigned long *) pud); | |
5a216a20 MS |
154 | #endif |
155 | } | |
190a1d72 | 156 | |
ba8a9229 MS |
157 | #define tlb_start_vma(tlb, vma) do { } while (0) |
158 | #define tlb_end_vma(tlb, vma) do { } while (0) | |
159 | #define tlb_remove_tlb_entry(tlb, ptep, addr) do { } while (0) | |
160 | #define tlb_migrate_finish(mm) do { } while (0) | |
161 | ||
162 | #endif /* _S390_TLB_H */ |