internal.h revision 5344b7e648980cc2ca613ec03a56a8222ff48820 
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
19extern void prep_compound_page(struct page *page, unsigned long order);
20
21static inline void set_page_count(struct page *page, int v)
22{
23	atomic_set(&page->_count, v);
24}
25
26/*
27 * Turn a non-refcounted page (->_count == 0) into refcounted with
28 * a count of one.
29 */
30static inline void set_page_refcounted(struct page *page)
31{
32	VM_BUG_ON(PageTail(page));
33	VM_BUG_ON(atomic_read(&page->_count));
34	set_page_count(page, 1);
35}
36
37static inline void __put_page(struct page *page)
38{
39	atomic_dec(&page->_count);
40}
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);
52
53/*
54 * function for dealing with page's order in buddy system.
55 * zone->lock is already acquired when we use these.
56 * So, we don't need atomic page->flags operations here.
57 */
58static inline unsigned long page_order(struct page *page)
59{
60	VM_BUG_ON(!PageBuddy(page));
61	return page_private(page);
62}
63
64extern long mlock_vma_pages_range(struct vm_area_struct *vma,
65			unsigned long start, unsigned long end);
66extern void munlock_vma_pages_range(struct vm_area_struct *vma,
67			unsigned long start, unsigned long end);
68static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
69{
70	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
71}
72
73#ifdef CONFIG_UNEVICTABLE_LRU
74/*
75 * unevictable_migrate_page() called only from migrate_page_copy() to
76 * migrate unevictable flag to new page.
77 * Note that the old page has been isolated from the LRU lists at this
78 * point so we don't need to worry about LRU statistics.
79 */
80static inline void unevictable_migrate_page(struct page *new, struct page *old)
81{
82	if (TestClearPageUnevictable(old))
83		SetPageUnevictable(new);
84}
85#else
86static inline void unevictable_migrate_page(struct page *new, struct page *old)
87{
88}
89#endif
90
91#ifdef CONFIG_UNEVICTABLE_LRU
92/*
93 * Called only in fault path via page_evictable() for a new page
94 * to determine if it's being mapped into a LOCKED vma.
95 * If so, mark page as mlocked.
96 */
97static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
98{
99	VM_BUG_ON(PageLRU(page));
100
101	if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
102		return 0;
103
104	if (!TestSetPageMlocked(page)) {
105		inc_zone_page_state(page, NR_MLOCK);
106		count_vm_event(UNEVICTABLE_PGMLOCKED);
107	}
108	return 1;
109}
110
111/*
112 * must be called with vma's mmap_sem held for read, and page locked.
113 */
114extern void mlock_vma_page(struct page *page);
115
116/*
117 * Clear the page's PageMlocked().  This can be useful in a situation where
118 * we want to unconditionally remove a page from the pagecache -- e.g.,
119 * on truncation or freeing.
120 *
121 * It is legal to call this function for any page, mlocked or not.
122 * If called for a page that is still mapped by mlocked vmas, all we do
123 * is revert to lazy LRU behaviour -- semantics are not broken.
124 */
125extern void __clear_page_mlock(struct page *page);
126static inline void clear_page_mlock(struct page *page)
127{
128	if (unlikely(TestClearPageMlocked(page)))
129		__clear_page_mlock(page);
130}
131
132/*
133 * mlock_migrate_page - called only from migrate_page_copy() to
134 * migrate the Mlocked page flag; update statistics.
135 */
136static inline void mlock_migrate_page(struct page *newpage, struct page *page)
137{
138	if (TestClearPageMlocked(page)) {
139		unsigned long flags;
140
141		local_irq_save(flags);
142		__dec_zone_page_state(page, NR_MLOCK);
143		SetPageMlocked(newpage);
144		__inc_zone_page_state(newpage, NR_MLOCK);
145		local_irq_restore(flags);
146	}
147}
148
149
150#else /* CONFIG_UNEVICTABLE_LRU */
151static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
152{
153	return 0;
154}
155static inline void clear_page_mlock(struct page *page) { }
156static inline void mlock_vma_page(struct page *page) { }
157static inline void mlock_migrate_page(struct page *new, struct page *old) { }
158
159#endif /* CONFIG_UNEVICTABLE_LRU */
160
161/*
162 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
163 * so all functions starting at paging_init should be marked __init
164 * in those cases. SPARSEMEM, however, allows for memory hotplug,
165 * and alloc_bootmem_node is not used.
166 */
167#ifdef CONFIG_SPARSEMEM
168#define __paginginit __meminit
169#else
170#define __paginginit __init
171#endif
172
173/* Memory initialisation debug and verification */
174enum mminit_level {
175	MMINIT_WARNING,
176	MMINIT_VERIFY,
177	MMINIT_TRACE
178};
179
180#ifdef CONFIG_DEBUG_MEMORY_INIT
181
182extern int mminit_loglevel;
183
184#define mminit_dprintk(level, prefix, fmt, arg...) \
185do { \
186	if (level < mminit_loglevel) { \
187		printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
188		printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
189	} \
190} while (0)
191
192extern void mminit_verify_pageflags_layout(void);
193extern void mminit_verify_page_links(struct page *page,
194		enum zone_type zone, unsigned long nid, unsigned long pfn);
195extern void mminit_verify_zonelist(void);
196
197#else
198
199static inline void mminit_dprintk(enum mminit_level level,
200				const char *prefix, const char *fmt, ...)
201{
202}
203
204static inline void mminit_verify_pageflags_layout(void)
205{
206}
207
208static inline void mminit_verify_page_links(struct page *page,
209		enum zone_type zone, unsigned long nid, unsigned long pfn)
210{
211}
212
213static inline void mminit_verify_zonelist(void)
214{
215}
216#endif /* CONFIG_DEBUG_MEMORY_INIT */
217
218/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
219#if defined(CONFIG_SPARSEMEM)
220extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
221				unsigned long *end_pfn);
222#else
223static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
224				unsigned long *end_pfn)
225{
226}
227#endif /* CONFIG_SPARSEMEM */
228
229#define GUP_FLAGS_WRITE                  0x1
230#define GUP_FLAGS_FORCE                  0x2
231#define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
232
233int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
234		     unsigned long start, int len, int flags,
235		     struct page **pages, struct vm_area_struct **vmas);
236
237#endif
238