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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
40static inline void __get_page_tail_foll(struct page *page,
41 bool get_page_head)
42{
43 /*
44 * If we're getting a tail page, the elevated page->_count is
45 * required only in the head page and we will elevate the head
46 * page->_count and tail page->_mapcount.
47 *
48 * We elevate page_tail->_mapcount for tail pages to force
49 * page_tail->_count to be zero at all times to avoid getting
50 * false positives from get_page_unless_zero() with
51 * speculative page access (like in
52 * page_cache_get_speculative()) on tail pages.
53 */
54 VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
55 VM_BUG_ON(atomic_read(&page->_count) != 0);
56 VM_BUG_ON(page_mapcount(page) < 0);
57 if (get_page_head)
58 atomic_inc(&page->first_page->_count);
59 atomic_inc(&page->_mapcount);
60}
61
62/*
63 * This is meant to be called as the FOLL_GET operation of
64 * follow_page() and it must be called while holding the proper PT
65 * lock while the pte (or pmd_trans_huge) is still mapping the page.
66 */
67static inline void get_page_foll(struct page *page)
68{
69 if (unlikely(PageTail(page)))
70 /*
71 * This is safe only because
72 * __split_huge_page_refcount() can't run under
73 * get_page_foll() because we hold the proper PT lock.
74 */
75 __get_page_tail_foll(page, true);
76 else {
77 /*
78 * Getting a normal page or the head of a compound page
79 * requires to already have an elevated page->_count.
80 */
81 VM_BUG_ON(atomic_read(&page->_count) <= 0);
82 atomic_inc(&page->_count);
83 }
84}
85
86extern unsigned long highest_memmap_pfn;
87
88/*
89 * in mm/vmscan.c:
90 */
91extern int isolate_lru_page(struct page *page);
92extern void putback_lru_page(struct page *page);
93
94/*
95 * in mm/page_alloc.c
96 */
97extern void __free_pages_bootmem(struct page *page, unsigned int order);
98extern void prep_compound_page(struct page *page, unsigned long order);
99#ifdef CONFIG_MEMORY_FAILURE
100extern bool is_free_buddy_page(struct page *page);
101#endif
102
103
104/*
105 * function for dealing with page's order in buddy system.
106 * zone->lock is already acquired when we use these.
107 * So, we don't need atomic page->flags operations here.
108 */
109static inline unsigned long page_order(struct page *page)
110{
111 /* PageBuddy() must be checked by the caller */
112 return page_private(page);
113}
114
115/* mm/util.c */
116void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
117 struct vm_area_struct *prev, struct rb_node *rb_parent);
118
119#ifdef CONFIG_MMU
120extern long mlock_vma_pages_range(struct vm_area_struct *vma,
121 unsigned long start, unsigned long end);
122extern void munlock_vma_pages_range(struct vm_area_struct *vma,
123 unsigned long start, unsigned long end);
124static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
125{
126 munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
127}
128
129/*
130 * Called only in fault path via page_evictable() for a new page
131 * to determine if it's being mapped into a LOCKED vma.
132 * If so, mark page as mlocked.
133 */
134static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
135{
136 VM_BUG_ON(PageLRU(page));
137
138 if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
139 return 0;
140
141 if (!TestSetPageMlocked(page)) {
142 inc_zone_page_state(page, NR_MLOCK);
143 count_vm_event(UNEVICTABLE_PGMLOCKED);
144 }
145 return 1;
146}
147
148/*
149 * must be called with vma's mmap_sem held for read or write, and page locked.
150 */
151extern void mlock_vma_page(struct page *page);
152extern void munlock_vma_page(struct page *page);
153
154/*
155 * Clear the page's PageMlocked(). This can be useful in a situation where
156 * we want to unconditionally remove a page from the pagecache -- e.g.,
157 * on truncation or freeing.
158 *
159 * It is legal to call this function for any page, mlocked or not.
160 * If called for a page that is still mapped by mlocked vmas, all we do
161 * is revert to lazy LRU behaviour -- semantics are not broken.
162 */
163extern void __clear_page_mlock(struct page *page);
164static inline void clear_page_mlock(struct page *page)
165{
166 if (unlikely(TestClearPageMlocked(page)))
167 __clear_page_mlock(page);
168}
169
170/*
171 * mlock_migrate_page - called only from migrate_page_copy() to
172 * migrate the Mlocked page flag; update statistics.
173 */
174static inline void mlock_migrate_page(struct page *newpage, struct page *page)
175{
176 if (TestClearPageMlocked(page)) {
177 unsigned long flags;
178
179 local_irq_save(flags);
180 __dec_zone_page_state(page, NR_MLOCK);
181 SetPageMlocked(newpage);
182 __inc_zone_page_state(newpage, NR_MLOCK);
183 local_irq_restore(flags);
184 }
185}
186
187#ifdef CONFIG_TRANSPARENT_HUGEPAGE
188extern unsigned long vma_address(struct page *page,
189 struct vm_area_struct *vma);
190#endif
191#else /* !CONFIG_MMU */
192static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
193{
194 return 0;
195}
196static inline void clear_page_mlock(struct page *page) { }
197static inline void mlock_vma_page(struct page *page) { }
198static inline void mlock_migrate_page(struct page *new, struct page *old) { }
199
200#endif /* !CONFIG_MMU */
201
202/*
203 * Return the mem_map entry representing the 'offset' subpage within
204 * the maximally aligned gigantic page 'base'. Handle any discontiguity
205 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
206 */
207static inline struct page *mem_map_offset(struct page *base, int offset)
208{
209 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
210 return pfn_to_page(page_to_pfn(base) + offset);
211 return base + offset;
212}
213
214/*
215 * Iterator over all subpages within the maximally aligned gigantic
216 * page 'base'. Handle any discontiguity in the mem_map.
217 */
218static inline struct page *mem_map_next(struct page *iter,
219 struct page *base, int offset)
220{
221 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
222 unsigned long pfn = page_to_pfn(base) + offset;
223 if (!pfn_valid(pfn))
224 return NULL;
225 return pfn_to_page(pfn);
226 }
227 return iter + 1;
228}
229
230/*
231 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
232 * so all functions starting at paging_init should be marked __init
233 * in those cases. SPARSEMEM, however, allows for memory hotplug,
234 * and alloc_bootmem_node is not used.
235 */
236#ifdef CONFIG_SPARSEMEM
237#define __paginginit __meminit
238#else
239#define __paginginit __init
240#endif
241
242/* Memory initialisation debug and verification */
243enum mminit_level {
244 MMINIT_WARNING,
245 MMINIT_VERIFY,
246 MMINIT_TRACE
247};
248
249#ifdef CONFIG_DEBUG_MEMORY_INIT
250
251extern int mminit_loglevel;
252
253#define mminit_dprintk(level, prefix, fmt, arg...) \
254do { \
255 if (level < mminit_loglevel) { \
256 printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG); \
257 printk(KERN_CONT "mminit::" prefix " " fmt, ##arg); \
258 } \
259} while (0)
260
261extern void mminit_verify_pageflags_layout(void);
262extern void mminit_verify_page_links(struct page *page,
263 enum zone_type zone, unsigned long nid, unsigned long pfn);
264extern void mminit_verify_zonelist(void);
265
266#else
267
268static inline void mminit_dprintk(enum mminit_level level,
269 const char *prefix, const char *fmt, ...)
270{
271}
272
273static inline void mminit_verify_pageflags_layout(void)
274{
275}
276
277static inline void mminit_verify_page_links(struct page *page,
278 enum zone_type zone, unsigned long nid, unsigned long pfn)
279{
280}
281
282static inline void mminit_verify_zonelist(void)
283{
284}
285#endif /* CONFIG_DEBUG_MEMORY_INIT */
286
287/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
288#if defined(CONFIG_SPARSEMEM)
289extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
290 unsigned long *end_pfn);
291#else
292static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
293 unsigned long *end_pfn)
294{
295}
296#endif /* CONFIG_SPARSEMEM */
297
298#define ZONE_RECLAIM_NOSCAN -2
299#define ZONE_RECLAIM_FULL -1
300#define ZONE_RECLAIM_SOME 0
301#define ZONE_RECLAIM_SUCCESS 1
302#endif
303
304extern int hwpoison_filter(struct page *p);
305
306extern u32 hwpoison_filter_dev_major;
307extern u32 hwpoison_filter_dev_minor;
308extern u64 hwpoison_filter_flags_mask;
309extern u64 hwpoison_filter_flags_value;
310extern u64 hwpoison_filter_memcg;
311extern u32 hwpoison_filter_enable;