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 __get_page_tail_foll(struct page *page,
36                    bool get_page_head)
37{
38    /*
39     * If we're getting a tail page, the elevated page->_count is
40     * required only in the head page and we will elevate the head
41     * page->_count and tail page->_mapcount.
42     *
43     * We elevate page_tail->_mapcount for tail pages to force
44     * page_tail->_count to be zero at all times to avoid getting
45     * false positives from get_page_unless_zero() with
46     * speculative page access (like in
47     * page_cache_get_speculative()) on tail pages.
48     */
49    VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
50    VM_BUG_ON(atomic_read(&page->_count) != 0);
51    VM_BUG_ON(page_mapcount(page) < 0);
52    if (get_page_head)
53        atomic_inc(&page->first_page->_count);
54    atomic_inc(&page->_mapcount);
55}
56
57/*
58 * This is meant to be called as the FOLL_GET operation of
59 * follow_page() and it must be called while holding the proper PT
60 * lock while the pte (or pmd_trans_huge) is still mapping the page.
61 */
62static inline void get_page_foll(struct page *page)
63{
64    if (unlikely(PageTail(page)))
65        /*
66         * This is safe only because
67         * __split_huge_page_refcount() can't run under
68         * get_page_foll() because we hold the proper PT lock.
69         */
70        __get_page_tail_foll(page, true);
71    else {
72        /*
73         * Getting a normal page or the head of a compound page
74         * requires to already have an elevated page->_count.
75         */
76        VM_BUG_ON(atomic_read(&page->_count) <= 0);
77        atomic_inc(&page->_count);
78    }
79}
80
81extern unsigned long highest_memmap_pfn;
82
83/*
84 * in mm/vmscan.c:
85 */
86extern int isolate_lru_page(struct page *page);
87extern void putback_lru_page(struct page *page);
88extern unsigned long zone_reclaimable_pages(struct zone *zone);
89extern bool zone_reclaimable(struct zone *zone);
90
91/*
92 * in mm/rmap.c:
93 */
94extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
95
96/*
97 * in mm/page_alloc.c
98 */
99extern void __free_pages_bootmem(struct page *page, unsigned int order);
100extern void prep_compound_page(struct page *page, unsigned long order);
101#ifdef CONFIG_MEMORY_FAILURE
102extern bool is_free_buddy_page(struct page *page);
103#endif
104
105#if defined CONFIG_COMPACTION || defined CONFIG_CMA
106
107/*
108 * in mm/compaction.c
109 */
110/*
111 * compact_control is used to track pages being migrated and the free pages
112 * they are being migrated to during memory compaction. The free_pfn starts
113 * at the end of a zone and migrate_pfn begins at the start. Movable pages
114 * are moved to the end of a zone during a compaction run and the run
115 * completes when free_pfn <= migrate_pfn
116 */
117struct compact_control {
118    struct list_head freepages; /* List of free pages to migrate to */
119    struct list_head migratepages; /* List of pages being migrated */
120    unsigned long nr_freepages; /* Number of isolated free pages */
121    unsigned long nr_migratepages; /* Number of pages to migrate */
122    unsigned long free_pfn; /* isolate_freepages search base */
123    unsigned long migrate_pfn; /* isolate_migratepages search base */
124    bool sync; /* Synchronous migration */
125    bool ignore_skip_hint; /* Scan blocks even if marked skip */
126    bool finished_update_free; /* True when the zone cached pfns are
127                     * no longer being updated
128                     */
129    bool finished_update_migrate;
130
131    int order; /* order a direct compactor needs */
132    int migratetype; /* MOVABLE, RECLAIMABLE etc */
133    struct zone *zone;
134    bool contended; /* True if a lock was contended */
135};
136
137unsigned long
138isolate_freepages_range(struct compact_control *cc,
139            unsigned long start_pfn, unsigned long end_pfn);
140unsigned long
141isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
142    unsigned long low_pfn, unsigned long end_pfn, bool unevictable);
143
144#endif
145
146/*
147 * function for dealing with page's order in buddy system.
148 * zone->lock is already acquired when we use these.
149 * So, we don't need atomic page->flags operations here.
150 */
151static inline unsigned long page_order(struct page *page)
152{
153    /* PageBuddy() must be checked by the caller */
154    return page_private(page);
155}
156
157/* mm/util.c */
158void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
159        struct vm_area_struct *prev, struct rb_node *rb_parent);
160
161#ifdef CONFIG_MMU
162extern long __mlock_vma_pages_range(struct vm_area_struct *vma,
163        unsigned long start, unsigned long end, int *nonblocking);
164extern void munlock_vma_pages_range(struct vm_area_struct *vma,
165            unsigned long start, unsigned long end);
166static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
167{
168    munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
169}
170
171/*
172 * Called only in fault path, to determine if a new page is being
173 * mapped into a LOCKED vma. If it is, mark page as mlocked.
174 */
175static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
176                    struct page *page)
177{
178    VM_BUG_ON(PageLRU(page));
179
180    if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
181        return 0;
182
183    if (!TestSetPageMlocked(page)) {
184        mod_zone_page_state(page_zone(page), NR_MLOCK,
185                    hpage_nr_pages(page));
186        count_vm_event(UNEVICTABLE_PGMLOCKED);
187    }
188    return 1;
189}
190
191/*
192 * must be called with vma's mmap_sem held for read or write, and page locked.
193 */
194extern void mlock_vma_page(struct page *page);
195extern unsigned int munlock_vma_page(struct page *page);
196
197/*
198 * Clear the page's PageMlocked(). This can be useful in a situation where
199 * we want to unconditionally remove a page from the pagecache -- e.g.,
200 * on truncation or freeing.
201 *
202 * It is legal to call this function for any page, mlocked or not.
203 * If called for a page that is still mapped by mlocked vmas, all we do
204 * is revert to lazy LRU behaviour -- semantics are not broken.
205 */
206extern void clear_page_mlock(struct page *page);
207
208/*
209 * mlock_migrate_page - called only from migrate_page_copy() to
210 * migrate the Mlocked page flag; update statistics.
211 */
212static inline void mlock_migrate_page(struct page *newpage, struct page *page)
213{
214    if (TestClearPageMlocked(page)) {
215        unsigned long flags;
216        int nr_pages = hpage_nr_pages(page);
217
218        local_irq_save(flags);
219        __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
220        SetPageMlocked(newpage);
221        __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
222        local_irq_restore(flags);
223    }
224}
225
226extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
227
228#ifdef CONFIG_TRANSPARENT_HUGEPAGE
229extern unsigned long vma_address(struct page *page,
230                 struct vm_area_struct *vma);
231#endif
232#else /* !CONFIG_MMU */
233static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p)
234{
235    return 0;
236}
237static inline void clear_page_mlock(struct page *page) { }
238static inline void mlock_vma_page(struct page *page) { }
239static inline void mlock_migrate_page(struct page *new, struct page *old) { }
240
241#endif /* !CONFIG_MMU */
242
243/*
244 * Return the mem_map entry representing the 'offset' subpage within
245 * the maximally aligned gigantic page 'base'. Handle any discontiguity
246 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
247 */
248static inline struct page *mem_map_offset(struct page *base, int offset)
249{
250    if (unlikely(offset >= MAX_ORDER_NR_PAGES))
251        return pfn_to_page(page_to_pfn(base) + offset);
252    return base + offset;
253}
254
255/*
256 * Iterator over all subpages within the maximally aligned gigantic
257 * page 'base'. Handle any discontiguity in the mem_map.
258 */
259static inline struct page *mem_map_next(struct page *iter,
260                        struct page *base, int offset)
261{
262    if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
263        unsigned long pfn = page_to_pfn(base) + offset;
264        if (!pfn_valid(pfn))
265            return NULL;
266        return pfn_to_page(pfn);
267    }
268    return iter + 1;
269}
270
271/*
272 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
273 * so all functions starting at paging_init should be marked __init
274 * in those cases. SPARSEMEM, however, allows for memory hotplug,
275 * and alloc_bootmem_node is not used.
276 */
277#ifdef CONFIG_SPARSEMEM
278#define __paginginit __meminit
279#else
280#define __paginginit __init
281#endif
282
283/* Memory initialisation debug and verification */
284enum mminit_level {
285    MMINIT_WARNING,
286    MMINIT_VERIFY,
287    MMINIT_TRACE
288};
289
290#ifdef CONFIG_DEBUG_MEMORY_INIT
291
292extern int mminit_loglevel;
293
294#define mminit_dprintk(level, prefix, fmt, arg...) \
295do { \
296    if (level < mminit_loglevel) { \
297        printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
298        printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
299    } \
300} while (0)
301
302extern void mminit_verify_pageflags_layout(void);
303extern void mminit_verify_page_links(struct page *page,
304        enum zone_type zone, unsigned long nid, unsigned long pfn);
305extern void mminit_verify_zonelist(void);
306
307#else
308
309static inline void mminit_dprintk(enum mminit_level level,
310                const char *prefix, const char *fmt, ...)
311{
312}
313
314static inline void mminit_verify_pageflags_layout(void)
315{
316}
317
318static inline void mminit_verify_page_links(struct page *page,
319        enum zone_type zone, unsigned long nid, unsigned long pfn)
320{
321}
322
323static inline void mminit_verify_zonelist(void)
324{
325}
326#endif /* CONFIG_DEBUG_MEMORY_INIT */
327
328/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
329#if defined(CONFIG_SPARSEMEM)
330extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
331                unsigned long *end_pfn);
332#else
333static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
334                unsigned long *end_pfn)
335{
336}
337#endif /* CONFIG_SPARSEMEM */
338
339#define ZONE_RECLAIM_NOSCAN -2
340#define ZONE_RECLAIM_FULL -1
341#define ZONE_RECLAIM_SOME 0
342#define ZONE_RECLAIM_SUCCESS 1
343
344extern int hwpoison_filter(struct page *p);
345
346extern u32 hwpoison_filter_dev_major;
347extern u32 hwpoison_filter_dev_minor;
348extern u64 hwpoison_filter_flags_mask;
349extern u64 hwpoison_filter_flags_value;
350extern u64 hwpoison_filter_memcg;
351extern u32 hwpoison_filter_enable;
352
353extern unsigned long vm_mmap_pgoff(struct file *, unsigned long,
354        unsigned long, unsigned long,
355        unsigned long, unsigned long);
356
357extern void set_pageblock_order(void);
358unsigned long reclaim_clean_pages_from_list(struct zone *zone,
359                        struct list_head *page_list);
360/* The ALLOC_WMARK bits are used as an index to zone->watermark */
361#define ALLOC_WMARK_MIN WMARK_MIN
362#define ALLOC_WMARK_LOW WMARK_LOW
363#define ALLOC_WMARK_HIGH WMARK_HIGH
364#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
365
366/* Mask to get the watermark bits */
367#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
368
369#define ALLOC_HARDER 0x10 /* try to alloc harder */
370#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
371#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
372#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
373
374#endif /* __MM_INTERNAL_H */
375

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