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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | #ifndef _LINUX_RMAP_H #define _LINUX_RMAP_H /* * Declarations for Reverse Mapping functions in mm/rmap.c */ #include <linux/config.h> #include <linux/list.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/spinlock.h> /* * The anon_vma heads a list of private "related" vmas, to scan if * an anonymous page pointing to this anon_vma needs to be unmapped: * the vmas on the list will be related by forking, or by splitting. * * Since vmas come and go as they are split and merged (particularly * in mprotect), the mapping field of an anonymous page cannot point * directly to a vma: instead it points to an anon_vma, on whose list * the related vmas can be easily linked or unlinked. * * After unlinking the last vma on the list, we must garbage collect * the anon_vma object itself: we're guaranteed no page can be * pointing to this anon_vma once its vma list is empty. */ struct anon_vma { spinlock_t lock; /* Serialize access to vma list */ struct list_head head; /* List of private "related" vmas */ }; #ifdef CONFIG_MMU extern kmem_cache_t *anon_vma_cachep; static inline struct anon_vma *anon_vma_alloc(void) { return kmem_cache_alloc(anon_vma_cachep, SLAB_KERNEL); } static inline void anon_vma_free(struct anon_vma *anon_vma) { kmem_cache_free(anon_vma_cachep, anon_vma); } static inline void anon_vma_lock(struct vm_area_struct *vma) { struct anon_vma *anon_vma = vma->anon_vma; if (anon_vma) spin_lock(&anon_vma->lock); } static inline void anon_vma_unlock(struct vm_area_struct *vma) { struct anon_vma *anon_vma = vma->anon_vma; if (anon_vma) spin_unlock(&anon_vma->lock); } /* * anon_vma helper functions. */ void anon_vma_init(void); /* create anon_vma_cachep */ int anon_vma_prepare(struct vm_area_struct *); void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *); void anon_vma_unlink(struct vm_area_struct *); void anon_vma_link(struct vm_area_struct *); void __anon_vma_link(struct vm_area_struct *); /* * rmap interfaces called when adding or removing pte of page */ void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_file_rmap(struct page *); void page_remove_rmap(struct page *); /** * page_dup_rmap - duplicate pte mapping to a page * @page: the page to add the mapping to * * For copy_page_range only: minimal extract from page_add_rmap, * avoiding unnecessary tests (already checked) so it's quicker. */ static inline void page_dup_rmap(struct page *page) { atomic_inc(&page->_mapcount); } /* * Called from mm/vmscan.c to handle paging out */ int page_referenced(struct page *, int is_locked, int ignore_token); int try_to_unmap(struct page *); /* * Used by swapoff to help locate where page is expected in vma. */ unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); #else /* !CONFIG_MMU */ #define anon_vma_init() do {} while (0) #define anon_vma_prepare(vma) (0) #define anon_vma_link(vma) do {} while (0) #define page_referenced(page,l,i) TestClearPageReferenced(page) #define try_to_unmap(page) SWAP_FAIL #endif /* CONFIG_MMU */ /* * Return values of try_to_unmap */ #define SWAP_SUCCESS 0 #define SWAP_AGAIN 1 #define SWAP_FAIL 2 #endif /* _LINUX_RMAP_H */ |