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 16 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, 17 unsigned long floor, unsigned long ceiling); 18 19 static 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 */ 28 static 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 35 static inline void __put_page(struct page *page) 36 { 37 atomic_dec(&page->_count); 38 } 39 40 static 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 */ 67 static 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 86 extern unsigned long highest_memmap_pfn; 87 88 /* 89 * in mm/vmscan.c: 90 */ 91 extern int isolate_lru_page(struct page *page); 92 extern void putback_lru_page(struct page *page); 93 94 /* 95 * in mm/page_alloc.c 96 */ 97 extern void __free_pages_bootmem(struct page *page, unsigned int order); 98 extern void prep_compound_page(struct page *page, unsigned long order); 99 #ifdef CONFIG_MEMORY_FAILURE 100 extern 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 */ 109 static 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 */ 116 void __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 120 extern long mlock_vma_pages_range(struct vm_area_struct *vma, 121 unsigned long start, unsigned long end); 122 extern void munlock_vma_pages_range(struct vm_area_struct *vma, 123 unsigned long start, unsigned long end); 124 static 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 */ 134 static 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 */ 151 extern void mlock_vma_page(struct page *page); 152 extern 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 */ 163 extern void __clear_page_mlock(struct page *page); 164 static 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 */ 174 static 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 188 extern unsigned long vma_address(struct page *page, 189 struct vm_area_struct *vma); 190 #endif 191 #else /* !CONFIG_MMU */ 192 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p) 193 { 194 return 0; 195 } 196 static inline void clear_page_mlock(struct page *page) { } 197 static inline void mlock_vma_page(struct page *page) { } 198 static 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 */ 207 static 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 */ 218 static 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 */ 243 enum mminit_level { 244 MMINIT_WARNING, 245 MMINIT_VERIFY, 246 MMINIT_TRACE 247 }; 248 249 #ifdef CONFIG_DEBUG_MEMORY_INIT 250 251 extern int mminit_loglevel; 252 253 #define mminit_dprintk(level, prefix, fmt, arg...) \ 254 do { \ 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) 260 261 extern void mminit_verify_pageflags_layout(void); 262 extern void mminit_verify_page_links(struct page *page, 263 enum zone_type zone, unsigned long nid, unsigned long pfn); 264 extern void mminit_verify_zonelist(void); 265 266 #else 267 268 static inline void mminit_dprintk(enum mminit_level level, 269 const char *prefix, const char *fmt, ...) 270 { 271 } 272 273 static inline void mminit_verify_pageflags_layout(void) 274 { 275 } 276 277 static inline void mminit_verify_page_links(struct page *page, 278 enum zone_type zone, unsigned long nid, unsigned long pfn) 279 { 280 } 281 282 static 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) 289 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn, 290 unsigned long *end_pfn); 291 #else 292 static 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 303 304 extern int hwpoison_filter(struct page *p); 305 306 extern u32 hwpoison_filter_dev_major; 307 extern u32 hwpoison_filter_dev_minor; 308 extern u64 hwpoison_filter_flags_mask; 309 extern u64 hwpoison_filter_flags_value; 310 extern u64 hwpoison_filter_memcg; 311 extern u32 hwpoison_filter_enable; 312