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3df33f12 AK |
1 | /* |
2 | * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <asm/pgalloc.h> | |
12 | #include <asm/tlb.h> | |
13 | ||
14 | #include "mmu_decl.h" | |
15 | #include <trace/events/thp.h> | |
16 | ||
17 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
18 | /* | |
19 | * This is called when relaxing access to a hugepage. It's also called in the page | |
20 | * fault path when we don't hit any of the major fault cases, ie, a minor | |
21 | * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have | |
22 | * handled those two for us, we additionally deal with missing execute | |
23 | * permission here on some processors | |
24 | */ | |
25 | int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address, | |
26 | pmd_t *pmdp, pmd_t entry, int dirty) | |
27 | { | |
28 | int changed; | |
29 | #ifdef CONFIG_DEBUG_VM | |
30 | WARN_ON(!pmd_trans_huge(*pmdp)); | |
31 | assert_spin_locked(&vma->vm_mm->page_table_lock); | |
32 | #endif | |
33 | changed = !pmd_same(*(pmdp), entry); | |
34 | if (changed) { | |
35 | __ptep_set_access_flags(pmdp_ptep(pmdp), pmd_pte(entry)); | |
36 | /* | |
37 | * Since we are not supporting SW TLB systems, we don't | |
38 | * have any thing similar to flush_tlb_page_nohash() | |
39 | */ | |
40 | } | |
41 | return changed; | |
42 | } | |
43 | ||
44 | int pmdp_test_and_clear_young(struct vm_area_struct *vma, | |
45 | unsigned long address, pmd_t *pmdp) | |
46 | { | |
47 | return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp); | |
48 | } | |
49 | /* | |
50 | * set a new huge pmd. We should not be called for updating | |
51 | * an existing pmd entry. That should go via pmd_hugepage_update. | |
52 | */ | |
53 | void set_pmd_at(struct mm_struct *mm, unsigned long addr, | |
54 | pmd_t *pmdp, pmd_t pmd) | |
55 | { | |
56 | #ifdef CONFIG_DEBUG_VM | |
57 | WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp))); | |
58 | assert_spin_locked(&mm->page_table_lock); | |
59 | WARN_ON(!pmd_trans_huge(pmd)); | |
60 | #endif | |
61 | trace_hugepage_set_pmd(addr, pmd_val(pmd)); | |
62 | return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); | |
63 | } | |
64 | /* | |
65 | * We use this to invalidate a pmdp entry before switching from a | |
66 | * hugepte to regular pmd entry. | |
67 | */ | |
68 | void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, | |
69 | pmd_t *pmdp) | |
70 | { | |
71 | pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0); | |
bde3eb62 | 72 | flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
3df33f12 AK |
73 | /* |
74 | * This ensures that generic code that rely on IRQ disabling | |
75 | * to prevent a parallel THP split work as expected. | |
76 | */ | |
77 | kick_all_cpus_sync(); | |
78 | } | |
79 | ||
80 | static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot) | |
81 | { | |
82 | return __pmd(pmd_val(pmd) | pgprot_val(pgprot)); | |
83 | } | |
84 | ||
85 | pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot) | |
86 | { | |
87 | unsigned long pmdv; | |
88 | ||
89 | pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK; | |
90 | return pmd_set_protbits(__pmd(pmdv), pgprot); | |
91 | } | |
92 | ||
93 | pmd_t mk_pmd(struct page *page, pgprot_t pgprot) | |
94 | { | |
95 | return pfn_pmd(page_to_pfn(page), pgprot); | |
96 | } | |
97 | ||
98 | pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) | |
99 | { | |
100 | unsigned long pmdv; | |
101 | ||
102 | pmdv = pmd_val(pmd); | |
103 | pmdv &= _HPAGE_CHG_MASK; | |
104 | return pmd_set_protbits(__pmd(pmdv), newprot); | |
105 | } | |
106 | ||
107 | /* | |
108 | * This is called at the end of handling a user page fault, when the | |
109 | * fault has been handled by updating a HUGE PMD entry in the linux page tables. | |
110 | * We use it to preload an HPTE into the hash table corresponding to | |
111 | * the updated linux HUGE PMD entry. | |
112 | */ | |
113 | void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, | |
114 | pmd_t *pmd) | |
115 | { | |
116 | return; | |
117 | } | |
118 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |