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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> | |
589ee628 | 11 | #include <linux/mm_types.h> |
fa4531f7 | 12 | #include <misc/cxl-base.h> |
589ee628 | 13 | |
3df33f12 AK |
14 | #include <asm/pgalloc.h> |
15 | #include <asm/tlb.h> | |
16 | ||
17 | #include "mmu_decl.h" | |
18 | #include <trace/events/thp.h> | |
19 | ||
eea8148c ME |
20 | int (*register_process_table)(unsigned long base, unsigned long page_size, |
21 | unsigned long tbl_size); | |
22 | ||
3df33f12 AK |
23 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
24 | /* | |
25 | * This is called when relaxing access to a hugepage. It's also called in the page | |
26 | * fault path when we don't hit any of the major fault cases, ie, a minor | |
27 | * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have | |
28 | * handled those two for us, we additionally deal with missing execute | |
29 | * permission here on some processors | |
30 | */ | |
31 | int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address, | |
32 | pmd_t *pmdp, pmd_t entry, int dirty) | |
33 | { | |
34 | int changed; | |
35 | #ifdef CONFIG_DEBUG_VM | |
ebd31197 | 36 | WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); |
3df33f12 AK |
37 | assert_spin_locked(&vma->vm_mm->page_table_lock); |
38 | #endif | |
39 | changed = !pmd_same(*(pmdp), entry); | |
40 | if (changed) { | |
b3603e17 AK |
41 | __ptep_set_access_flags(vma->vm_mm, pmdp_ptep(pmdp), |
42 | pmd_pte(entry), address); | |
d8e91e93 | 43 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
3df33f12 AK |
44 | } |
45 | return changed; | |
46 | } | |
47 | ||
48 | int pmdp_test_and_clear_young(struct vm_area_struct *vma, | |
49 | unsigned long address, pmd_t *pmdp) | |
50 | { | |
51 | return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp); | |
52 | } | |
53 | /* | |
54 | * set a new huge pmd. We should not be called for updating | |
55 | * an existing pmd entry. That should go via pmd_hugepage_update. | |
56 | */ | |
57 | void set_pmd_at(struct mm_struct *mm, unsigned long addr, | |
58 | pmd_t *pmdp, pmd_t pmd) | |
59 | { | |
60 | #ifdef CONFIG_DEBUG_VM | |
61 | WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp))); | |
62 | assert_spin_locked(&mm->page_table_lock); | |
ebd31197 | 63 | WARN_ON(!(pmd_trans_huge(pmd) || pmd_devmap(pmd))); |
3df33f12 AK |
64 | #endif |
65 | trace_hugepage_set_pmd(addr, pmd_val(pmd)); | |
66 | return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); | |
67 | } | |
fa4531f7 AK |
68 | |
69 | static void do_nothing(void *unused) | |
70 | { | |
71 | ||
72 | } | |
73 | /* | |
74 | * Serialize against find_current_mm_pte which does lock-less | |
75 | * lookup in page tables with local interrupts disabled. For huge pages | |
76 | * it casts pmd_t to pte_t. Since format of pte_t is different from | |
77 | * pmd_t we want to prevent transit from pmd pointing to page table | |
78 | * to pmd pointing to huge page (and back) while interrupts are disabled. | |
79 | * We clear pmd to possibly replace it with page table pointer in | |
80 | * different code paths. So make sure we wait for the parallel | |
81 | * find_current_mm_pte to finish. | |
82 | */ | |
83 | void serialize_against_pte_lookup(struct mm_struct *mm) | |
84 | { | |
85 | smp_mb(); | |
0f4bc093 | 86 | smp_call_function_many(mm_cpumask(mm), do_nothing, NULL, 1); |
fa4531f7 AK |
87 | } |
88 | ||
3df33f12 AK |
89 | /* |
90 | * We use this to invalidate a pmdp entry before switching from a | |
91 | * hugepte to regular pmd entry. | |
92 | */ | |
8cc931e0 | 93 | pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, |
3df33f12 AK |
94 | pmd_t *pmdp) |
95 | { | |
8cc931e0 AK |
96 | unsigned long old_pmd; |
97 | ||
98 | old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0); | |
d8e91e93 | 99 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
3df33f12 AK |
100 | /* |
101 | * This ensures that generic code that rely on IRQ disabling | |
102 | * to prevent a parallel THP split work as expected. | |
103 | */ | |
fa4531f7 | 104 | serialize_against_pte_lookup(vma->vm_mm); |
8cc931e0 | 105 | return __pmd(old_pmd); |
3df33f12 AK |
106 | } |
107 | ||
108 | static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot) | |
109 | { | |
110 | return __pmd(pmd_val(pmd) | pgprot_val(pgprot)); | |
111 | } | |
112 | ||
113 | pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot) | |
114 | { | |
115 | unsigned long pmdv; | |
116 | ||
117 | pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK; | |
118 | return pmd_set_protbits(__pmd(pmdv), pgprot); | |
119 | } | |
120 | ||
121 | pmd_t mk_pmd(struct page *page, pgprot_t pgprot) | |
122 | { | |
123 | return pfn_pmd(page_to_pfn(page), pgprot); | |
124 | } | |
125 | ||
126 | pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) | |
127 | { | |
128 | unsigned long pmdv; | |
129 | ||
130 | pmdv = pmd_val(pmd); | |
131 | pmdv &= _HPAGE_CHG_MASK; | |
132 | return pmd_set_protbits(__pmd(pmdv), newprot); | |
133 | } | |
134 | ||
135 | /* | |
136 | * This is called at the end of handling a user page fault, when the | |
137 | * fault has been handled by updating a HUGE PMD entry in the linux page tables. | |
138 | * We use it to preload an HPTE into the hash table corresponding to | |
139 | * the updated linux HUGE PMD entry. | |
140 | */ | |
141 | void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, | |
142 | pmd_t *pmd) | |
143 | { | |
144 | return; | |
145 | } | |
146 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ | |
fe036a06 BH |
147 | |
148 | /* For use by kexec */ | |
149 | void mmu_cleanup_all(void) | |
150 | { | |
151 | if (radix_enabled()) | |
152 | radix__mmu_cleanup_all(); | |
153 | else if (mmu_hash_ops.hpte_clear_all) | |
154 | mmu_hash_ops.hpte_clear_all(); | |
155 | } | |
32b53c01 RA |
156 | |
157 | #ifdef CONFIG_MEMORY_HOTPLUG | |
29ab6c47 | 158 | int create_section_mapping(unsigned long start, unsigned long end, int nid) |
32b53c01 RA |
159 | { |
160 | if (radix_enabled()) | |
29ab6c47 | 161 | return radix__create_section_mapping(start, end, nid); |
32b53c01 | 162 | |
29ab6c47 | 163 | return hash__create_section_mapping(start, end, nid); |
32b53c01 RA |
164 | } |
165 | ||
166 | int remove_section_mapping(unsigned long start, unsigned long end) | |
167 | { | |
168 | if (radix_enabled()) | |
4b5d62ca | 169 | return radix__remove_section_mapping(start, end); |
32b53c01 RA |
170 | |
171 | return hash__remove_section_mapping(start, end); | |
172 | } | |
173 | #endif /* CONFIG_MEMORY_HOTPLUG */ |