internal.h revision af8e3354b4bbd1ee5a3a55d11a5e1fe37e77f0ba 
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
54
55/*
56 * function for dealing with page's order in buddy system.
57 * zone->lock is already acquired when we use these.
58 * So, we don't need atomic page->flags operations here.
59 */
60static inline unsigned long page_order(struct page *page)
61{
62	VM_BUG_ON(!PageBuddy(page));
63	return page_private(page);
64}
65
66/*
67 * unevictable_migrate_page() called only from migrate_page_copy() to
68 * migrate unevictable flag to new page.
69 * Note that the old page has been isolated from the LRU lists at this
70 * point so we don't need to worry about LRU statistics.
71 */
72static inline void unevictable_migrate_page(struct page *new, struct page *old)
73{
74	if (TestClearPageUnevictable(old))
75		SetPageUnevictable(new);
76}
77
78#ifdef CONFIG_MMU
79extern long mlock_vma_pages_range(struct vm_area_struct *vma,
80			unsigned long start, unsigned long end);
81extern void munlock_vma_pages_range(struct vm_area_struct *vma,
82			unsigned long start, unsigned long end);
83static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
84{
85	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
86}
87
88/*
89 * Called only in fault path via page_evictable() for a new page
90 * to determine if it's being mapped into a LOCKED vma.
91 * If so, mark page as mlocked.
92 */
93static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
94{
95	VM_BUG_ON(PageLRU(page));
96
97	if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
98		return 0;
99
100	if (!TestSetPageMlocked(page)) {
101		inc_zone_page_state(page, NR_MLOCK);
102		count_vm_event(UNEVICTABLE_PGMLOCKED);
103	}
104	return 1;
105}
106
107/*
108 * must be called with vma's mmap_sem held for read, and page locked.
109 */
110extern void mlock_vma_page(struct page *page);
111
112/*
113 * Clear the page's PageMlocked().  This can be useful in a situation where
114 * we want to unconditionally remove a page from the pagecache -- e.g.,
115 * on truncation or freeing.
116 *
117 * It is legal to call this function for any page, mlocked or not.
118 * If called for a page that is still mapped by mlocked vmas, all we do
119 * is revert to lazy LRU behaviour -- semantics are not broken.
120 */
121extern void __clear_page_mlock(struct page *page);
122static inline void clear_page_mlock(struct page *page)
123{
124	if (unlikely(TestClearPageMlocked(page)))
125		__clear_page_mlock(page);
126}
127
128/*
129 * mlock_migrate_page - called only from migrate_page_copy() to
130 * migrate the Mlocked page flag; update statistics.
131 */
132static inline void mlock_migrate_page(struct page *newpage, struct page *page)
133{
134	if (TestClearPageMlocked(page)) {
135		unsigned long flags;
136
137		local_irq_save(flags);
138		__dec_zone_page_state(page, NR_MLOCK);
139		SetPageMlocked(newpage);
140		__inc_zone_page_state(newpage, NR_MLOCK);
141		local_irq_restore(flags);
142	}
143}
144
145#else /* !CONFIG_MMU */
146static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
147{
148	return 0;
149}
150static inline void clear_page_mlock(struct page *page) { }
151static inline void mlock_vma_page(struct page *page) { }
152static inline void mlock_migrate_page(struct page *new, struct page *old) { }
153
154#endif /* !CONFIG_MMU */
155
156/*
157 * Return the mem_map entry representing the 'offset' subpage within
158 * the maximally aligned gigantic page 'base'.  Handle any discontiguity
159 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
160 */
161static inline struct page *mem_map_offset(struct page *base, int offset)
162{
163	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
164		return pfn_to_page(page_to_pfn(base) + offset);
165	return base + offset;
166}
167
168/*
169 * Iterator over all subpages withing the maximally aligned gigantic
170 * page 'base'.  Handle any discontiguity in the mem_map.
171 */
172static inline struct page *mem_map_next(struct page *iter,
173						struct page *base, int offset)
174{
175	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
176		unsigned long pfn = page_to_pfn(base) + offset;
177		if (!pfn_valid(pfn))
178			return NULL;
179		return pfn_to_page(pfn);
180	}
181	return iter + 1;
182}
183
184/*
185 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
186 * so all functions starting at paging_init should be marked __init
187 * in those cases. SPARSEMEM, however, allows for memory hotplug,
188 * and alloc_bootmem_node is not used.
189 */
190#ifdef CONFIG_SPARSEMEM
191#define __paginginit __meminit
192#else
193#define __paginginit __init
194#endif
195
196/* Memory initialisation debug and verification */
197enum mminit_level {
198	MMINIT_WARNING,
199	MMINIT_VERIFY,
200	MMINIT_TRACE
201};
202
203#ifdef CONFIG_DEBUG_MEMORY_INIT
204
205extern int mminit_loglevel;
206
207#define mminit_dprintk(level, prefix, fmt, arg...) \
208do { \
209	if (level < mminit_loglevel) { \
210		printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
211		printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
212	} \
213} while (0)
214
215extern void mminit_verify_pageflags_layout(void);
216extern void mminit_verify_page_links(struct page *page,
217		enum zone_type zone, unsigned long nid, unsigned long pfn);
218extern void mminit_verify_zonelist(void);
219
220#else
221
222static inline void mminit_dprintk(enum mminit_level level,
223				const char *prefix, const char *fmt, ...)
224{
225}
226
227static inline void mminit_verify_pageflags_layout(void)
228{
229}
230
231static inline void mminit_verify_page_links(struct page *page,
232		enum zone_type zone, unsigned long nid, unsigned long pfn)
233{
234}
235
236static inline void mminit_verify_zonelist(void)
237{
238}
239#endif /* CONFIG_DEBUG_MEMORY_INIT */
240
241/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
242#if defined(CONFIG_SPARSEMEM)
243extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
244				unsigned long *end_pfn);
245#else
246static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
247				unsigned long *end_pfn)
248{
249}
250#endif /* CONFIG_SPARSEMEM */
251
252int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
253		     unsigned long start, int len, unsigned int foll_flags,
254		     struct page **pages, struct vm_area_struct **vmas);
255
256#define ZONE_RECLAIM_NOSCAN	-2
257#define ZONE_RECLAIM_FULL	-1
258#define ZONE_RECLAIM_SOME	0
259#define ZONE_RECLAIM_SUCCESS	1
260#endif
261