Root/mm/internal.h

1/* internal.h: mm/ internal definitions
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#ifndef __MM_INTERNAL_H
12#define __MM_INTERNAL_H
13
14#include <linux/mm.h>
15
16void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
17        unsigned long floor, unsigned long ceiling);
18
19static inline void set_page_count(struct page *page, int v)
20{
21    atomic_set(&page->_count, v);
22}
23
24/*
25 * Turn a non-refcounted page (->_count == 0) into refcounted with
26 * a count of one.
27 */
28static inline void set_page_refcounted(struct page *page)
29{
30    VM_BUG_ON(PageTail(page));
31    VM_BUG_ON(atomic_read(&page->_count));
32    set_page_count(page, 1);
33}
34
35static inline void __put_page(struct page *page)
36{
37    atomic_dec(&page->_count);
38}
39
40extern unsigned long highest_memmap_pfn;
41
42/*
43 * in mm/vmscan.c:
44 */
45extern int isolate_lru_page(struct page *page);
46extern void putback_lru_page(struct page *page);
47
48/*
49 * in mm/page_alloc.c
50 */
51extern void __free_pages_bootmem(struct page *page, unsigned int order);
52extern void prep_compound_page(struct page *page, unsigned long order);
53#ifdef CONFIG_MEMORY_FAILURE
54extern bool is_free_buddy_page(struct page *page);
55#endif
56
57
58/*
59 * function for dealing with page's order in buddy system.
60 * zone->lock is already acquired when we use these.
61 * So, we don't need atomic page->flags operations here.
62 */
63static inline unsigned long page_order(struct page *page)
64{
65    VM_BUG_ON(!PageBuddy(page));
66    return page_private(page);
67}
68
69#ifdef CONFIG_MMU
70extern long mlock_vma_pages_range(struct vm_area_struct *vma,
71            unsigned long start, unsigned long end);
72extern void munlock_vma_pages_range(struct vm_area_struct *vma,
73            unsigned long start, unsigned long end);
74static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
75{
76    munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
77}
78
79/*
80 * Called only in fault path via page_evictable() for a new page
81 * to determine if it's being mapped into a LOCKED vma.
82 * If so, mark page as mlocked.
83 */
84static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
85{
86    VM_BUG_ON(PageLRU(page));
87
88    if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
89        return 0;
90
91    if (!TestSetPageMlocked(page)) {
92        inc_zone_page_state(page, NR_MLOCK);
93        count_vm_event(UNEVICTABLE_PGMLOCKED);
94    }
95    return 1;
96}
97
98/*
99 * must be called with vma's mmap_sem held for read or write, and page locked.
100 */
101extern void mlock_vma_page(struct page *page);
102extern void munlock_vma_page(struct page *page);
103
104/*
105 * Clear the page's PageMlocked(). This can be useful in a situation where
106 * we want to unconditionally remove a page from the pagecache -- e.g.,
107 * on truncation or freeing.
108 *
109 * It is legal to call this function for any page, mlocked or not.
110 * If called for a page that is still mapped by mlocked vmas, all we do
111 * is revert to lazy LRU behaviour -- semantics are not broken.
112 */
113extern void __clear_page_mlock(struct page *page);
114static inline void clear_page_mlock(struct page *page)
115{
116    if (unlikely(TestClearPageMlocked(page)))
117        __clear_page_mlock(page);
118}
119
120/*
121 * mlock_migrate_page - called only from migrate_page_copy() to
122 * migrate the Mlocked page flag; update statistics.
123 */
124static inline void mlock_migrate_page(struct page *newpage, struct page *page)
125{
126    if (TestClearPageMlocked(page)) {
127        unsigned long flags;
128
129        local_irq_save(flags);
130        __dec_zone_page_state(page, NR_MLOCK);
131        SetPageMlocked(newpage);
132        __inc_zone_page_state(newpage, NR_MLOCK);
133        local_irq_restore(flags);
134    }
135}
136
137#else /* !CONFIG_MMU */
138static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
139{
140    return 0;
141}
142static inline void clear_page_mlock(struct page *page) { }
143static inline void mlock_vma_page(struct page *page) { }
144static inline void mlock_migrate_page(struct page *new, struct page *old) { }
145
146#endif /* !CONFIG_MMU */
147
148/*
149 * Return the mem_map entry representing the 'offset' subpage within
150 * the maximally aligned gigantic page 'base'. Handle any discontiguity
151 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
152 */
153static inline struct page *mem_map_offset(struct page *base, int offset)
154{
155    if (unlikely(offset >= MAX_ORDER_NR_PAGES))
156        return pfn_to_page(page_to_pfn(base) + offset);
157    return base + offset;
158}
159
160/*
161 * Iterator over all subpages withing the maximally aligned gigantic
162 * page 'base'. Handle any discontiguity in the mem_map.
163 */
164static inline struct page *mem_map_next(struct page *iter,
165                        struct page *base, int offset)
166{
167    if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
168        unsigned long pfn = page_to_pfn(base) + offset;
169        if (!pfn_valid(pfn))
170            return NULL;
171        return pfn_to_page(pfn);
172    }
173    return iter + 1;
174}
175
176/*
177 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
178 * so all functions starting at paging_init should be marked __init
179 * in those cases. SPARSEMEM, however, allows for memory hotplug,
180 * and alloc_bootmem_node is not used.
181 */
182#ifdef CONFIG_SPARSEMEM
183#define __paginginit __meminit
184#else
185#define __paginginit __init
186#endif
187
188/* Memory initialisation debug and verification */
189enum mminit_level {
190    MMINIT_WARNING,
191    MMINIT_VERIFY,
192    MMINIT_TRACE
193};
194
195#ifdef CONFIG_DEBUG_MEMORY_INIT
196
197extern int mminit_loglevel;
198
199#define mminit_dprintk(level, prefix, fmt, arg...) \
200do { \
201    if (level < mminit_loglevel) { \
202        printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
203        printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
204    } \
205} while (0)
206
207extern void mminit_verify_pageflags_layout(void);
208extern void mminit_verify_page_links(struct page *page,
209        enum zone_type zone, unsigned long nid, unsigned long pfn);
210extern void mminit_verify_zonelist(void);
211
212#else
213
214static inline void mminit_dprintk(enum mminit_level level,
215                const char *prefix, const char *fmt, ...)
216{
217}
218
219static inline void mminit_verify_pageflags_layout(void)
220{
221}
222
223static inline void mminit_verify_page_links(struct page *page,
224        enum zone_type zone, unsigned long nid, unsigned long pfn)
225{
226}
227
228static inline void mminit_verify_zonelist(void)
229{
230}
231#endif /* CONFIG_DEBUG_MEMORY_INIT */
232
233/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
234#if defined(CONFIG_SPARSEMEM)
235extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
236                unsigned long *end_pfn);
237#else
238static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
239                unsigned long *end_pfn)
240{
241}
242#endif /* CONFIG_SPARSEMEM */
243
244int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
245             unsigned long start, int len, unsigned int foll_flags,
246             struct page **pages, struct vm_area_struct **vmas);
247
248#define ZONE_RECLAIM_NOSCAN -2
249#define ZONE_RECLAIM_FULL -1
250#define ZONE_RECLAIM_SOME 0
251#define ZONE_RECLAIM_SUCCESS 1
252#endif
253
254extern int hwpoison_filter(struct page *p);
255
256extern u32 hwpoison_filter_dev_major;
257extern u32 hwpoison_filter_dev_minor;
258extern u64 hwpoison_filter_flags_mask;
259extern u64 hwpoison_filter_flags_value;
260extern u64 hwpoison_filter_memcg;
261extern u32 hwpoison_filter_enable;
262

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