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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/linux/rmap.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'include/linux/rmap.h')
-rw-r--r--include/linux/rmap.h263
1 files changed, 263 insertions, 0 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
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+++ b/include/linux/rmap.h
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+#ifndef _LINUX_RMAP_H
+#define _LINUX_RMAP_H
+/*
+ * Declarations for Reverse Mapping functions in mm/rmap.c
+ */
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/memcontrol.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 {
+ struct anon_vma *root; /* Root of this anon_vma tree */
+ struct mutex mutex; /* Serialize access to vma list */
+ /*
+ * The refcount is taken on an anon_vma when there is no
+ * guarantee that the vma of page tables will exist for
+ * the duration of the operation. A caller that takes
+ * the reference is responsible for clearing up the
+ * anon_vma if they are the last user on release
+ */
+ atomic_t refcount;
+
+ /*
+ * NOTE: the LSB of the head.next is set by
+ * mm_take_all_locks() _after_ taking the above lock. So the
+ * head must only be read/written after taking the above lock
+ * to be sure to see a valid next pointer. The LSB bit itself
+ * is serialized by a system wide lock only visible to
+ * mm_take_all_locks() (mm_all_locks_mutex).
+ */
+ struct list_head head; /* Chain of private "related" vmas */
+};
+
+/*
+ * The copy-on-write semantics of fork mean that an anon_vma
+ * can become associated with multiple processes. Furthermore,
+ * each child process will have its own anon_vma, where new
+ * pages for that process are instantiated.
+ *
+ * This structure allows us to find the anon_vmas associated
+ * with a VMA, or the VMAs associated with an anon_vma.
+ * The "same_vma" list contains the anon_vma_chains linking
+ * all the anon_vmas associated with this VMA.
+ * The "same_anon_vma" list contains the anon_vma_chains
+ * which link all the VMAs associated with this anon_vma.
+ */
+struct anon_vma_chain {
+ struct vm_area_struct *vma;
+ struct anon_vma *anon_vma;
+ struct list_head same_vma; /* locked by mmap_sem & page_table_lock */
+ struct list_head same_anon_vma; /* locked by anon_vma->mutex */
+};
+
+#ifdef CONFIG_MMU
+static inline void get_anon_vma(struct anon_vma *anon_vma)
+{
+ atomic_inc(&anon_vma->refcount);
+}
+
+void __put_anon_vma(struct anon_vma *anon_vma);
+
+static inline void put_anon_vma(struct anon_vma *anon_vma)
+{
+ if (atomic_dec_and_test(&anon_vma->refcount))
+ __put_anon_vma(anon_vma);
+}
+
+static inline struct anon_vma *page_anon_vma(struct page *page)
+{
+ if (((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) !=
+ PAGE_MAPPING_ANON)
+ return NULL;
+ return page_rmapping(page);
+}
+
+static inline void vma_lock_anon_vma(struct vm_area_struct *vma)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ if (anon_vma)
+ mutex_lock(&anon_vma->root->mutex);
+}
+
+static inline void vma_unlock_anon_vma(struct vm_area_struct *vma)
+{
+ struct anon_vma *anon_vma = vma->anon_vma;
+ if (anon_vma)
+ mutex_unlock(&anon_vma->root->mutex);
+}
+
+static inline void anon_vma_lock(struct anon_vma *anon_vma)
+{
+ mutex_lock(&anon_vma->root->mutex);
+}
+
+static inline void anon_vma_unlock(struct anon_vma *anon_vma)
+{
+ mutex_unlock(&anon_vma->root->mutex);
+}
+
+/*
+ * anon_vma helper functions.
+ */
+void anon_vma_init(void); /* create anon_vma_cachep */
+int anon_vma_prepare(struct vm_area_struct *);
+void unlink_anon_vmas(struct vm_area_struct *);
+int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
+void anon_vma_moveto_tail(struct vm_area_struct *);
+int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
+
+static inline void anon_vma_merge(struct vm_area_struct *vma,
+ struct vm_area_struct *next)
+{
+ VM_BUG_ON(vma->anon_vma != next->anon_vma);
+ unlink_anon_vmas(next);
+}
+
+struct anon_vma *page_get_anon_vma(struct page *page);
+
+/*
+ * rmap interfaces called when adding or removing pte of page
+ */
+void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
+void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
+void do_page_add_anon_rmap(struct page *, struct vm_area_struct *,
+ unsigned long, int);
+void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
+void page_add_file_rmap(struct page *);
+void page_remove_rmap(struct page *);
+
+void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
+ unsigned long);
+void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
+ unsigned long);
+
+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,
+ struct mem_cgroup *memcg, unsigned long *vm_flags);
+int page_referenced_one(struct page *, struct vm_area_struct *,
+ unsigned long address, unsigned int *mapcount, unsigned long *vm_flags);
+
+enum ttu_flags {
+ TTU_UNMAP = 0, /* unmap mode */
+ TTU_MIGRATION = 1, /* migration mode */
+ TTU_MUNLOCK = 2, /* munlock mode */
+ TTU_ACTION_MASK = 0xff,
+
+ TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */
+ TTU_IGNORE_ACCESS = (1 << 9), /* don't age */
+ TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
+};
+#define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
+
+bool is_vma_temporary_stack(struct vm_area_struct *vma);
+
+int try_to_unmap(struct page *, enum ttu_flags flags);
+int try_to_unmap_one(struct page *, struct vm_area_struct *,
+ unsigned long address, enum ttu_flags flags);
+
+/*
+ * Called from mm/filemap_xip.c to unmap empty zero page
+ */
+pte_t *__page_check_address(struct page *, struct mm_struct *,
+ unsigned long, spinlock_t **, int);
+
+static inline pte_t *page_check_address(struct page *page, struct mm_struct *mm,
+ unsigned long address,
+ spinlock_t **ptlp, int sync)
+{
+ pte_t *ptep;
+
+ __cond_lock(*ptlp, ptep = __page_check_address(page, mm, address,
+ ptlp, sync));
+ return ptep;
+}
+
+/*
+ * Used by swapoff to help locate where page is expected in vma.
+ */
+unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
+
+/*
+ * Cleans the PTEs of shared mappings.
+ * (and since clean PTEs should also be readonly, write protects them too)
+ *
+ * returns the number of cleaned PTEs.
+ */
+int page_mkclean(struct page *);
+
+/*
+ * called in munlock()/munmap() path to check for other vmas holding
+ * the page mlocked.
+ */
+int try_to_munlock(struct page *);
+
+/*
+ * Called by memory-failure.c to kill processes.
+ */
+struct anon_vma *page_lock_anon_vma(struct page *page);
+void page_unlock_anon_vma(struct anon_vma *anon_vma);
+int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+
+/*
+ * Called by migrate.c to remove migration ptes, but might be used more later.
+ */
+int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
+ struct vm_area_struct *, unsigned long, void *), void *arg);
+
+#else /* !CONFIG_MMU */
+
+#define anon_vma_init() do {} while (0)
+#define anon_vma_prepare(vma) (0)
+#define anon_vma_link(vma) do {} while (0)
+
+static inline int page_referenced(struct page *page, int is_locked,
+ struct mem_cgroup *memcg,
+ unsigned long *vm_flags)
+{
+ *vm_flags = 0;
+ return 0;
+}
+
+#define try_to_unmap(page, refs) SWAP_FAIL
+
+static inline int page_mkclean(struct page *page)
+{
+ return 0;
+}
+
+
+#endif /* CONFIG_MMU */
+
+/*
+ * Return values of try_to_unmap
+ */
+#define SWAP_SUCCESS 0
+#define SWAP_AGAIN 1
+#define SWAP_FAIL 2
+#define SWAP_MLOCK 3
+
+#endif /* _LINUX_RMAP_H */