From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 include/linux/rmap.h | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 include/linux/rmap.h

(limited to 'include/linux/rmap.h')

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
new file mode 100644
index 000000000000..11b484e37ac9
--- /dev/null
+++ b/include/linux/rmap.h
@@ -0,0 +1,118 @@
+#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 */
-- 
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