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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _S390_TLB_H
2#define _S390_TLB_H
3
4/*
Martin Schwidefskyba8a9222007-10-22 12:52:44 +02005 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 */
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020023
24#include <linux/mm.h>
Heiko Carstensc84ca002011-01-31 11:30:06 +010025#include <linux/pagemap.h>
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020026#include <linux/swap.h>
27#include <asm/processor.h>
28#include <asm/pgalloc.h>
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020029#include <asm/tlbflush.h>
30
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020031struct mmu_gather {
32 struct mm_struct *mm;
Martin Schwidefsky36409f62011-06-06 14:14:41 +020033 struct mmu_table_batch *batch;
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020034 unsigned int fullmm;
Guenter Roeck215b28a2013-08-16 20:50:55 -070035 unsigned long start, end;
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020036};
37
Martin Schwidefsky36409f62011-06-06 14:14:41 +020038struct mmu_table_batch {
39 struct rcu_head rcu;
40 unsigned int nr;
41 void *tables[0];
42};
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020043
Martin Schwidefsky36409f62011-06-06 14:14:41 +020044#define MAX_TABLE_BATCH \
45 ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
46
47extern void tlb_table_flush(struct mmu_gather *tlb);
48extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020049
Peter Zijlstra68f03922011-05-24 17:11:51 -070050static inline void tlb_gather_mmu(struct mmu_gather *tlb,
51 struct mm_struct *mm,
Linus Torvalds2b047252013-08-15 11:42:25 -070052 unsigned long start,
53 unsigned long end)
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020054{
Peter Zijlstra68f03922011-05-24 17:11:51 -070055 tlb->mm = mm;
Linus Torvalds2b047252013-08-15 11:42:25 -070056 tlb->start = start;
57 tlb->end = end;
58 tlb->fullmm = !(start | (end+1));
Martin Schwidefsky36409f62011-06-06 14:14:41 +020059 tlb->batch = NULL;
Peter Zijlstra68f03922011-05-24 17:11:51 -070060}
61
Linus Torvalds1cf35d42014-04-25 16:05:40 -070062static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
Peter Zijlstra68f03922011-05-24 17:11:51 -070063{
Martin Schwidefsky5c474a12013-08-16 13:31:40 +020064 __tlb_flush_mm_lazy(tlb->mm);
Linus Torvalds1cf35d42014-04-25 16:05:40 -070065}
66
67static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
68{
Martin Schwidefsky36409f62011-06-06 14:14:41 +020069 tlb_table_flush(tlb);
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020070}
71
Linus Torvalds1cf35d42014-04-25 16:05:40 -070072
73static inline void tlb_flush_mmu(struct mmu_gather *tlb)
74{
75 tlb_flush_mmu_tlbonly(tlb);
76 tlb_flush_mmu_free(tlb);
77}
78
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020079static inline void tlb_finish_mmu(struct mmu_gather *tlb,
80 unsigned long start, unsigned long end)
81{
Martin Schwidefsky5c474a12013-08-16 13:31:40 +020082 tlb_flush_mmu(tlb);
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020083}
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85/*
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020086 * Release the page cache reference for a pte removed by
Peter Zijlstra68f03922011-05-24 17:11:51 -070087 * tlb_ptep_clear_flush. In both flush modes the tlb for a page cache page
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020088 * has already been freed, so just do free_page_and_swap_cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 */
Aneesh Kumar K.Ve9d55e12016-07-26 15:24:09 -070090static inline bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
Peter Zijlstra68f03922011-05-24 17:11:51 -070091{
92 free_page_and_swap_cache(page);
Aneesh Kumar K.Ve9d55e12016-07-26 15:24:09 -070093 return false; /* avoid calling tlb_flush_mmu */
Peter Zijlstra68f03922011-05-24 17:11:51 -070094}
95
Martin Schwidefskyba8a9222007-10-22 12:52:44 +020096static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
97{
98 free_page_and_swap_cache(page);
99}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Aneesh Kumar K.Ve77b0852016-07-26 15:24:12 -0700101static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
102 struct page *page, int page_size)
103{
104 return __tlb_remove_page(tlb, page);
105}
106
Aneesh Kumar K.Ve77b0852016-07-26 15:24:12 -0700107static inline void tlb_remove_page_size(struct mmu_gather *tlb,
108 struct page *page, int page_size)
109{
110 return tlb_remove_page(tlb, page);
111}
112
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200113/*
114 * pte_free_tlb frees a pte table and clears the CRSTE for the
115 * page table from the tlb.
116 */
Benjamin Herrenschmidt9e1b32c2009-07-22 15:44:28 +1000117static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
118 unsigned long address)
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200119{
Martin Schwidefsky527e30b2014-04-30 16:04:25 +0200120 page_table_free_rcu(tlb, (unsigned long *) pte, address);
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200121}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200123/*
124 * pmd_free_tlb frees a pmd table and clears the CRSTE for the
125 * segment table entry from the tlb.
Martin Schwidefsky6252d702008-02-09 18:24:37 +0100126 * If the mm uses a two level page table the single pmd is freed
127 * as the pgd. pmd_free_tlb checks the asce_limit against 2GB
128 * to avoid the double free of the pmd in this case.
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200129 */
Benjamin Herrenschmidt9e1b32c2009-07-22 15:44:28 +1000130static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
131 unsigned long address)
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200132{
Martin Schwidefsky6252d702008-02-09 18:24:37 +0100133 if (tlb->mm->context.asce_limit <= (1UL << 31))
134 return;
Martin Schwidefsky9de45f72014-12-04 11:07:19 +0100135 pgtable_pmd_page_dtor(virt_to_page(pmd));
Martin Schwidefsky02a8f3a2014-04-03 13:54:59 +0200136 tlb_remove_table(tlb, pmd);
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200137}
138
Martin Schwidefsky5a216a22008-02-09 18:24:36 +0100139/*
140 * pud_free_tlb frees a pud table and clears the CRSTE for the
141 * region third table entry from the tlb.
Martin Schwidefsky6252d702008-02-09 18:24:37 +0100142 * If the mm uses a three level page table the single pud is freed
143 * as the pgd. pud_free_tlb checks the asce_limit against 4TB
144 * to avoid the double free of the pud in this case.
Martin Schwidefsky5a216a22008-02-09 18:24:36 +0100145 */
Benjamin Herrenschmidt9e1b32c2009-07-22 15:44:28 +1000146static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
147 unsigned long address)
Martin Schwidefsky5a216a22008-02-09 18:24:36 +0100148{
Martin Schwidefsky6252d702008-02-09 18:24:37 +0100149 if (tlb->mm->context.asce_limit <= (1UL << 42))
150 return;
Martin Schwidefsky02a8f3a2014-04-03 13:54:59 +0200151 tlb_remove_table(tlb, pud);
Martin Schwidefsky5a216a22008-02-09 18:24:36 +0100152}
Martin Schwidefsky190a1d72007-10-22 12:52:48 +0200153
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200154#define tlb_start_vma(tlb, vma) do { } while (0)
155#define tlb_end_vma(tlb, vma) do { } while (0)
156#define tlb_remove_tlb_entry(tlb, ptep, addr) do { } while (0)
Gerald Schaefer1ae1c1d2012-10-08 16:30:24 -0700157#define tlb_remove_pmd_tlb_entry(tlb, pmdp, addr) do { } while (0)
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200158#define tlb_migrate_finish(mm) do { } while (0)
Aneesh Kumar K.Vb528e4b2016-12-12 16:42:37 -0800159#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \
160 tlb_remove_tlb_entry(tlb, ptep, address)
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200161
Aneesh Kumar K.V07e32662016-12-12 16:42:40 -0800162#define tlb_remove_check_page_size_change tlb_remove_check_page_size_change
163static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
164 unsigned int page_size)
165{
166}
167
Martin Schwidefskyba8a9222007-10-22 12:52:44 +0200168#endif /* _S390_TLB_H */