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-rw-r--r--mm/internal.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h
index e4e728bdf324..f482460de3e6 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -176,6 +176,34 @@ static inline void free_page_mlock(struct page *page) { }
176#endif /* CONFIG_UNEVICTABLE_LRU */ 176#endif /* CONFIG_UNEVICTABLE_LRU */
177 177
178/* 178/*
179 * Return the mem_map entry representing the 'offset' subpage within
180 * the maximally aligned gigantic page 'base'. Handle any discontiguity
181 * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
182 */
183static inline struct page *mem_map_offset(struct page *base, int offset)
184{
185 if (unlikely(offset >= MAX_ORDER_NR_PAGES))
186 return pfn_to_page(page_to_pfn(base) + offset);
187 return base + offset;
188}
189
190/*
191 * Iterator over all subpages withing the maximally aligned gigantic
192 * page 'base'. Handle any discontiguity in the mem_map.
193 */
194static inline struct page *mem_map_next(struct page *iter,
195 struct page *base, int offset)
196{
197 if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
198 unsigned long pfn = page_to_pfn(base) + offset;
199 if (!pfn_valid(pfn))
200 return NULL;
201 return pfn_to_page(pfn);
202 }
203 return iter + 1;
204}
205
206/*
179 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, 207 * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
180 * so all functions starting at paging_init should be marked __init 208 * so all functions starting at paging_init should be marked __init
181 * in those cases. SPARSEMEM, however, allows for memory hotplug, 209 * in those cases. SPARSEMEM, however, allows for memory hotplug,