Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a728fc4..a3c70e2 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/mm/vmalloc.c
  *
@@ -18,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/set_memory.h>
 #include <linux/debugobjects.h>
 #include <linux/kallsyms.h>
 #include <linux/list.h>
@@ -31,6 +33,7 @@
 #include <linux/compiler.h>
 #include <linux/llist.h>
 #include <linux/bitops.h>
+#include <linux/rbtree_augmented.h>
 
 #include <linux/uaccess.h>
 #include <asm/tlbflush.h>
@@ -323,22 +326,89 @@
 
 /*** Global kva allocator ***/
 
-#define VM_LAZY_FREE	0x02
-#define VM_VM_AREA	0x04
+#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
+#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
+
 
 static DEFINE_SPINLOCK(vmap_area_lock);
 /* Export for kexec only */
 LIST_HEAD(vmap_area_list);
 static LLIST_HEAD(vmap_purge_list);
 static struct rb_root vmap_area_root = RB_ROOT;
+static bool vmap_initialized __read_mostly;
 
-/* The vmap cache globals are protected by vmap_area_lock */
-static struct rb_node *free_vmap_cache;
-static unsigned long cached_hole_size;
-static unsigned long cached_vstart;
-static unsigned long cached_align;
+/*
+ * This kmem_cache is used for vmap_area objects. Instead of
+ * allocating from slab we reuse an object from this cache to
+ * make things faster. Especially in "no edge" splitting of
+ * free block.
+ */
+static struct kmem_cache *vmap_area_cachep;
 
-static unsigned long vmap_area_pcpu_hole;
+/*
+ * This linked list is used in pair with free_vmap_area_root.
+ * It gives O(1) access to prev/next to perform fast coalescing.
+ */
+static LIST_HEAD(free_vmap_area_list);
+
+/*
+ * This augment red-black tree represents the free vmap space.
+ * All vmap_area objects in this tree are sorted by va->va_start
+ * address. It is used for allocation and merging when a vmap
+ * object is released.
+ *
+ * Each vmap_area node contains a maximum available free block
+ * of its sub-tree, right or left. Therefore it is possible to
+ * find a lowest match of free area.
+ */
+static struct rb_root free_vmap_area_root = RB_ROOT;
+
+/*
+ * Preload a CPU with one object for "no edge" split case. The
+ * aim is to get rid of allocations from the atomic context, thus
+ * to use more permissive allocation masks.
+ */
+static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
+
+static __always_inline unsigned long
+va_size(struct vmap_area *va)
+{
+	return (va->va_end - va->va_start);
+}
+
+static __always_inline unsigned long
+get_subtree_max_size(struct rb_node *node)
+{
+	struct vmap_area *va;
+
+	va = rb_entry_safe(node, struct vmap_area, rb_node);
+	return va ? va->subtree_max_size : 0;
+}
+
+/*
+ * Gets called when remove the node and rotate.
+ */
+static __always_inline unsigned long
+compute_subtree_max_size(struct vmap_area *va)
+{
+	return max3(va_size(va),
+		get_subtree_max_size(va->rb_node.rb_left),
+		get_subtree_max_size(va->rb_node.rb_right));
+}
+
+RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
+	struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
+
+static void purge_vmap_area_lazy(void);
+static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
+static unsigned long lazy_max_pages(void);
+
+static atomic_long_t nr_vmalloc_pages;
+
+unsigned long vmalloc_nr_pages(void)
+{
+	return atomic_long_read(&nr_vmalloc_pages);
+}
 
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
@@ -359,41 +429,618 @@
 	return NULL;
 }
 
-static void __insert_vmap_area(struct vmap_area *va)
+/*
+ * This function returns back addresses of parent node
+ * and its left or right link for further processing.
+ */
+static __always_inline struct rb_node **
+find_va_links(struct vmap_area *va,
+	struct rb_root *root, struct rb_node *from,
+	struct rb_node **parent)
 {
-	struct rb_node **p = &vmap_area_root.rb_node;
-	struct rb_node *parent = NULL;
-	struct rb_node *tmp;
+	struct vmap_area *tmp_va;
+	struct rb_node **link;
 
-	while (*p) {
-		struct vmap_area *tmp_va;
-
-		parent = *p;
-		tmp_va = rb_entry(parent, struct vmap_area, rb_node);
-		if (va->va_start < tmp_va->va_end)
-			p = &(*p)->rb_left;
-		else if (va->va_end > tmp_va->va_start)
-			p = &(*p)->rb_right;
-		else
-			BUG();
+	if (root) {
+		link = &root->rb_node;
+		if (unlikely(!*link)) {
+			*parent = NULL;
+			return link;
+		}
+	} else {
+		link = &from;
 	}
 
-	rb_link_node(&va->rb_node, parent, p);
-	rb_insert_color(&va->rb_node, &vmap_area_root);
+	/*
+	 * Go to the bottom of the tree. When we hit the last point
+	 * we end up with parent rb_node and correct direction, i name
+	 * it link, where the new va->rb_node will be attached to.
+	 */
+	do {
+		tmp_va = rb_entry(*link, struct vmap_area, rb_node);
 
-	/* address-sort this list */
-	tmp = rb_prev(&va->rb_node);
-	if (tmp) {
-		struct vmap_area *prev;
-		prev = rb_entry(tmp, struct vmap_area, rb_node);
-		list_add_rcu(&va->list, &prev->list);
-	} else
-		list_add_rcu(&va->list, &vmap_area_list);
+		/*
+		 * During the traversal we also do some sanity check.
+		 * Trigger the BUG() if there are sides(left/right)
+		 * or full overlaps.
+		 */
+		if (va->va_start < tmp_va->va_end &&
+				va->va_end <= tmp_va->va_start)
+			link = &(*link)->rb_left;
+		else if (va->va_end > tmp_va->va_start &&
+				va->va_start >= tmp_va->va_end)
+			link = &(*link)->rb_right;
+		else
+			BUG();
+	} while (*link);
+
+	*parent = &tmp_va->rb_node;
+	return link;
 }
 
-static void purge_vmap_area_lazy(void);
+static __always_inline struct list_head *
+get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
+{
+	struct list_head *list;
 
-static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
+	if (unlikely(!parent))
+		/*
+		 * The red-black tree where we try to find VA neighbors
+		 * before merging or inserting is empty, i.e. it means
+		 * there is no free vmap space. Normally it does not
+		 * happen but we handle this case anyway.
+		 */
+		return NULL;
+
+	list = &rb_entry(parent, struct vmap_area, rb_node)->list;
+	return (&parent->rb_right == link ? list->next : list);
+}
+
+static __always_inline void
+link_va(struct vmap_area *va, struct rb_root *root,
+	struct rb_node *parent, struct rb_node **link, struct list_head *head)
+{
+	/*
+	 * VA is still not in the list, but we can
+	 * identify its future previous list_head node.
+	 */
+	if (likely(parent)) {
+		head = &rb_entry(parent, struct vmap_area, rb_node)->list;
+		if (&parent->rb_right != link)
+			head = head->prev;
+	}
+
+	/* Insert to the rb-tree */
+	rb_link_node(&va->rb_node, parent, link);
+	if (root == &free_vmap_area_root) {
+		/*
+		 * Some explanation here. Just perform simple insertion
+		 * to the tree. We do not set va->subtree_max_size to
+		 * its current size before calling rb_insert_augmented().
+		 * It is because of we populate the tree from the bottom
+		 * to parent levels when the node _is_ in the tree.
+		 *
+		 * Therefore we set subtree_max_size to zero after insertion,
+		 * to let __augment_tree_propagate_from() puts everything to
+		 * the correct order later on.
+		 */
+		rb_insert_augmented(&va->rb_node,
+			root, &free_vmap_area_rb_augment_cb);
+		va->subtree_max_size = 0;
+	} else {
+		rb_insert_color(&va->rb_node, root);
+	}
+
+	/* Address-sort this list */
+	list_add(&va->list, head);
+}
+
+static __always_inline void
+unlink_va(struct vmap_area *va, struct rb_root *root)
+{
+	if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
+		return;
+
+	if (root == &free_vmap_area_root)
+		rb_erase_augmented(&va->rb_node,
+			root, &free_vmap_area_rb_augment_cb);
+	else
+		rb_erase(&va->rb_node, root);
+
+	list_del(&va->list);
+	RB_CLEAR_NODE(&va->rb_node);
+}
+
+#if DEBUG_AUGMENT_PROPAGATE_CHECK
+static void
+augment_tree_propagate_check(struct rb_node *n)
+{
+	struct vmap_area *va;
+	struct rb_node *node;
+	unsigned long size;
+	bool found = false;
+
+	if (n == NULL)
+		return;
+
+	va = rb_entry(n, struct vmap_area, rb_node);
+	size = va->subtree_max_size;
+	node = n;
+
+	while (node) {
+		va = rb_entry(node, struct vmap_area, rb_node);
+
+		if (get_subtree_max_size(node->rb_left) == size) {
+			node = node->rb_left;
+		} else {
+			if (va_size(va) == size) {
+				found = true;
+				break;
+			}
+
+			node = node->rb_right;
+		}
+	}
+
+	if (!found) {
+		va = rb_entry(n, struct vmap_area, rb_node);
+		pr_emerg("tree is corrupted: %lu, %lu\n",
+			va_size(va), va->subtree_max_size);
+	}
+
+	augment_tree_propagate_check(n->rb_left);
+	augment_tree_propagate_check(n->rb_right);
+}
+#endif
+
+/*
+ * This function populates subtree_max_size from bottom to upper
+ * levels starting from VA point. The propagation must be done
+ * when VA size is modified by changing its va_start/va_end. Or
+ * in case of newly inserting of VA to the tree.
+ *
+ * It means that __augment_tree_propagate_from() must be called:
+ * - After VA has been inserted to the tree(free path);
+ * - After VA has been shrunk(allocation path);
+ * - After VA has been increased(merging path).
+ *
+ * Please note that, it does not mean that upper parent nodes
+ * and their subtree_max_size are recalculated all the time up
+ * to the root node.
+ *
+ *       4--8
+ *        /\
+ *       /  \
+ *      /    \
+ *    2--2  8--8
+ *
+ * For example if we modify the node 4, shrinking it to 2, then
+ * no any modification is required. If we shrink the node 2 to 1
+ * its subtree_max_size is updated only, and set to 1. If we shrink
+ * the node 8 to 6, then its subtree_max_size is set to 6 and parent
+ * node becomes 4--6.
+ */
+static __always_inline void
+augment_tree_propagate_from(struct vmap_area *va)
+{
+	struct rb_node *node = &va->rb_node;
+	unsigned long new_va_sub_max_size;
+
+	while (node) {
+		va = rb_entry(node, struct vmap_area, rb_node);
+		new_va_sub_max_size = compute_subtree_max_size(va);
+
+		/*
+		 * If the newly calculated maximum available size of the
+		 * subtree is equal to the current one, then it means that
+		 * the tree is propagated correctly. So we have to stop at
+		 * this point to save cycles.
+		 */
+		if (va->subtree_max_size == new_va_sub_max_size)
+			break;
+
+		va->subtree_max_size = new_va_sub_max_size;
+		node = rb_parent(&va->rb_node);
+	}
+
+#if DEBUG_AUGMENT_PROPAGATE_CHECK
+	augment_tree_propagate_check(free_vmap_area_root.rb_node);
+#endif
+}
+
+static void
+insert_vmap_area(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	link = find_va_links(va, root, NULL, &parent);
+	link_va(va, root, parent, link, head);
+}
+
+static void
+insert_vmap_area_augment(struct vmap_area *va,
+	struct rb_node *from, struct rb_root *root,
+	struct list_head *head)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	if (from)
+		link = find_va_links(va, NULL, from, &parent);
+	else
+		link = find_va_links(va, root, NULL, &parent);
+
+	link_va(va, root, parent, link, head);
+	augment_tree_propagate_from(va);
+}
+
+/*
+ * Merge de-allocated chunk of VA memory with previous
+ * and next free blocks. If coalesce is not done a new
+ * free area is inserted. If VA has been merged, it is
+ * freed.
+ */
+static __always_inline void
+merge_or_add_vmap_area(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head)
+{
+	struct vmap_area *sibling;
+	struct list_head *next;
+	struct rb_node **link;
+	struct rb_node *parent;
+	bool merged = false;
+
+	/*
+	 * Find a place in the tree where VA potentially will be
+	 * inserted, unless it is merged with its sibling/siblings.
+	 */
+	link = find_va_links(va, root, NULL, &parent);
+
+	/*
+	 * Get next node of VA to check if merging can be done.
+	 */
+	next = get_va_next_sibling(parent, link);
+	if (unlikely(next == NULL))
+		goto insert;
+
+	/*
+	 * start            end
+	 * |                |
+	 * |<------VA------>|<-----Next----->|
+	 *                  |                |
+	 *                  start            end
+	 */
+	if (next != head) {
+		sibling = list_entry(next, struct vmap_area, list);
+		if (sibling->va_start == va->va_end) {
+			sibling->va_start = va->va_start;
+
+			/* Check and update the tree if needed. */
+			augment_tree_propagate_from(sibling);
+
+			/* Free vmap_area object. */
+			kmem_cache_free(vmap_area_cachep, va);
+
+			/* Point to the new merged area. */
+			va = sibling;
+			merged = true;
+		}
+	}
+
+	/*
+	 * start            end
+	 * |                |
+	 * |<-----Prev----->|<------VA------>|
+	 *                  |                |
+	 *                  start            end
+	 */
+	if (next->prev != head) {
+		sibling = list_entry(next->prev, struct vmap_area, list);
+		if (sibling->va_end == va->va_start) {
+			sibling->va_end = va->va_end;
+
+			/* Check and update the tree if needed. */
+			augment_tree_propagate_from(sibling);
+
+			if (merged)
+				unlink_va(va, root);
+
+			/* Free vmap_area object. */
+			kmem_cache_free(vmap_area_cachep, va);
+			return;
+		}
+	}
+
+insert:
+	if (!merged) {
+		link_va(va, root, parent, link, head);
+		augment_tree_propagate_from(va);
+	}
+}
+
+static __always_inline bool
+is_within_this_va(struct vmap_area *va, unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	unsigned long nva_start_addr;
+
+	if (va->va_start > vstart)
+		nva_start_addr = ALIGN(va->va_start, align);
+	else
+		nva_start_addr = ALIGN(vstart, align);
+
+	/* Can be overflowed due to big size or alignment. */
+	if (nva_start_addr + size < nva_start_addr ||
+			nva_start_addr < vstart)
+		return false;
+
+	return (nva_start_addr + size <= va->va_end);
+}
+
+/*
+ * Find the first free block(lowest start address) in the tree,
+ * that will accomplish the request corresponding to passing
+ * parameters.
+ */
+static __always_inline struct vmap_area *
+find_vmap_lowest_match(unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	struct vmap_area *va;
+	struct rb_node *node;
+	unsigned long length;
+
+	/* Start from the root. */
+	node = free_vmap_area_root.rb_node;
+
+	/* Adjust the search size for alignment overhead. */
+	length = size + align - 1;
+
+	while (node) {
+		va = rb_entry(node, struct vmap_area, rb_node);
+
+		if (get_subtree_max_size(node->rb_left) >= length &&
+				vstart < va->va_start) {
+			node = node->rb_left;
+		} else {
+			if (is_within_this_va(va, size, align, vstart))
+				return va;
+
+			/*
+			 * Does not make sense to go deeper towards the right
+			 * sub-tree if it does not have a free block that is
+			 * equal or bigger to the requested search length.
+			 */
+			if (get_subtree_max_size(node->rb_right) >= length) {
+				node = node->rb_right;
+				continue;
+			}
+
+			/*
+			 * OK. We roll back and find the first right sub-tree,
+			 * that will satisfy the search criteria. It can happen
+			 * only once due to "vstart" restriction.
+			 */
+			while ((node = rb_parent(node))) {
+				va = rb_entry(node, struct vmap_area, rb_node);
+				if (is_within_this_va(va, size, align, vstart))
+					return va;
+
+				if (get_subtree_max_size(node->rb_right) >= length &&
+						vstart <= va->va_start) {
+					node = node->rb_right;
+					break;
+				}
+			}
+		}
+	}
+
+	return NULL;
+}
+
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+#include <linux/random.h>
+
+static struct vmap_area *
+find_vmap_lowest_linear_match(unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	struct vmap_area *va;
+
+	list_for_each_entry(va, &free_vmap_area_list, list) {
+		if (!is_within_this_va(va, size, align, vstart))
+			continue;
+
+		return va;
+	}
+
+	return NULL;
+}
+
+static void
+find_vmap_lowest_match_check(unsigned long size)
+{
+	struct vmap_area *va_1, *va_2;
+	unsigned long vstart;
+	unsigned int rnd;
+
+	get_random_bytes(&rnd, sizeof(rnd));
+	vstart = VMALLOC_START + rnd;
+
+	va_1 = find_vmap_lowest_match(size, 1, vstart);
+	va_2 = find_vmap_lowest_linear_match(size, 1, vstart);
+
+	if (va_1 != va_2)
+		pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
+			va_1, va_2, vstart);
+}
+#endif
+
+enum fit_type {
+	NOTHING_FIT = 0,
+	FL_FIT_TYPE = 1,	/* full fit */
+	LE_FIT_TYPE = 2,	/* left edge fit */
+	RE_FIT_TYPE = 3,	/* right edge fit */
+	NE_FIT_TYPE = 4		/* no edge fit */
+};
+
+static __always_inline enum fit_type
+classify_va_fit_type(struct vmap_area *va,
+	unsigned long nva_start_addr, unsigned long size)
+{
+	enum fit_type type;
+
+	/* Check if it is within VA. */
+	if (nva_start_addr < va->va_start ||
+			nva_start_addr + size > va->va_end)
+		return NOTHING_FIT;
+
+	/* Now classify. */
+	if (va->va_start == nva_start_addr) {
+		if (va->va_end == nva_start_addr + size)
+			type = FL_FIT_TYPE;
+		else
+			type = LE_FIT_TYPE;
+	} else if (va->va_end == nva_start_addr + size) {
+		type = RE_FIT_TYPE;
+	} else {
+		type = NE_FIT_TYPE;
+	}
+
+	return type;
+}
+
+static __always_inline int
+adjust_va_to_fit_type(struct vmap_area *va,
+	unsigned long nva_start_addr, unsigned long size,
+	enum fit_type type)
+{
+	struct vmap_area *lva = NULL;
+
+	if (type == FL_FIT_TYPE) {
+		/*
+		 * No need to split VA, it fully fits.
+		 *
+		 * |               |
+		 * V      NVA      V
+		 * |---------------|
+		 */
+		unlink_va(va, &free_vmap_area_root);
+		kmem_cache_free(vmap_area_cachep, va);
+	} else if (type == LE_FIT_TYPE) {
+		/*
+		 * Split left edge of fit VA.
+		 *
+		 * |       |
+		 * V  NVA  V   R
+		 * |-------|-------|
+		 */
+		va->va_start += size;
+	} else if (type == RE_FIT_TYPE) {
+		/*
+		 * Split right edge of fit VA.
+		 *
+		 *         |       |
+		 *     L   V  NVA  V
+		 * |-------|-------|
+		 */
+		va->va_end = nva_start_addr;
+	} else if (type == NE_FIT_TYPE) {
+		/*
+		 * Split no edge of fit VA.
+		 *
+		 *     |       |
+		 *   L V  NVA  V R
+		 * |---|-------|---|
+		 */
+		lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
+		if (unlikely(!lva)) {
+			/*
+			 * For percpu allocator we do not do any pre-allocation
+			 * and leave it as it is. The reason is it most likely
+			 * never ends up with NE_FIT_TYPE splitting. In case of
+			 * percpu allocations offsets and sizes are aligned to
+			 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
+			 * are its main fitting cases.
+			 *
+			 * There are a few exceptions though, as an example it is
+			 * a first allocation (early boot up) when we have "one"
+			 * big free space that has to be split.
+			 */
+			lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
+			if (!lva)
+				return -1;
+		}
+
+		/*
+		 * Build the remainder.
+		 */
+		lva->va_start = va->va_start;
+		lva->va_end = nva_start_addr;
+
+		/*
+		 * Shrink this VA to remaining size.
+		 */
+		va->va_start = nva_start_addr + size;
+	} else {
+		return -1;
+	}
+
+	if (type != FL_FIT_TYPE) {
+		augment_tree_propagate_from(va);
+
+		if (lva)	/* type == NE_FIT_TYPE */
+			insert_vmap_area_augment(lva, &va->rb_node,
+				&free_vmap_area_root, &free_vmap_area_list);
+	}
+
+	return 0;
+}
+
+/*
+ * Returns a start address of the newly allocated area, if success.
+ * Otherwise a vend is returned that indicates failure.
+ */
+static __always_inline unsigned long
+__alloc_vmap_area(unsigned long size, unsigned long align,
+	unsigned long vstart, unsigned long vend)
+{
+	unsigned long nva_start_addr;
+	struct vmap_area *va;
+	enum fit_type type;
+	int ret;
+
+	va = find_vmap_lowest_match(size, align, vstart);
+	if (unlikely(!va))
+		return vend;
+
+	if (va->va_start > vstart)
+		nva_start_addr = ALIGN(va->va_start, align);
+	else
+		nva_start_addr = ALIGN(vstart, align);
+
+	/* Check the "vend" restriction. */
+	if (nva_start_addr + size > vend)
+		return vend;
+
+	/* Classify what we have found. */
+	type = classify_va_fit_type(va, nva_start_addr, size);
+	if (WARN_ON_ONCE(type == NOTHING_FIT))
+		return vend;
+
+	/* Update the free vmap_area. */
+	ret = adjust_va_to_fit_type(va, nva_start_addr, size, type);
+	if (ret)
+		return vend;
+
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+	find_vmap_lowest_match_check(size);
+#endif
+
+	return nva_start_addr;
+}
 
 /*
  * Allocate a region of KVA of the specified size and alignment, within the
@@ -404,19 +1051,20 @@
 				unsigned long vstart, unsigned long vend,
 				int node, gfp_t gfp_mask)
 {
-	struct vmap_area *va;
-	struct rb_node *n;
+	struct vmap_area *va, *pva;
 	unsigned long addr;
 	int purged = 0;
-	struct vmap_area *first;
 
 	BUG_ON(!size);
 	BUG_ON(offset_in_page(size));
 	BUG_ON(!is_power_of_2(align));
 
+	if (unlikely(!vmap_initialized))
+		return ERR_PTR(-EBUSY);
+
 	might_sleep();
 
-	va = kmalloc_node(sizeof(struct vmap_area),
+	va = kmem_cache_alloc_node(vmap_area_cachep,
 			gfp_mask & GFP_RECLAIM_MASK, node);
 	if (unlikely(!va))
 		return ERR_PTR(-ENOMEM);
@@ -428,84 +1076,46 @@
 	kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
 
 retry:
-	spin_lock(&vmap_area_lock);
 	/*
-	 * Invalidate cache if we have more permissive parameters.
-	 * cached_hole_size notes the largest hole noticed _below_
-	 * the vmap_area cached in free_vmap_cache: if size fits
-	 * into that hole, we want to scan from vstart to reuse
-	 * the hole instead of allocating above free_vmap_cache.
-	 * Note that __free_vmap_area may update free_vmap_cache
-	 * without updating cached_hole_size or cached_align.
+	 * Preload this CPU with one extra vmap_area object to ensure
+	 * that we have it available when fit type of free area is
+	 * NE_FIT_TYPE.
+	 *
+	 * The preload is done in non-atomic context, thus it allows us
+	 * to use more permissive allocation masks to be more stable under
+	 * low memory condition and high memory pressure.
+	 *
+	 * Even if it fails we do not really care about that. Just proceed
+	 * as it is. "overflow" path will refill the cache we allocate from.
 	 */
-	if (!free_vmap_cache ||
-			size < cached_hole_size ||
-			vstart < cached_vstart ||
-			align < cached_align) {
-nocache:
-		cached_hole_size = 0;
-		free_vmap_cache = NULL;
-	}
-	/* record if we encounter less permissive parameters */
-	cached_vstart = vstart;
-	cached_align = align;
+	preempt_disable();
+	if (!__this_cpu_read(ne_fit_preload_node)) {
+		preempt_enable();
+		pva = kmem_cache_alloc_node(vmap_area_cachep, GFP_KERNEL, node);
+		preempt_disable();
 
-	/* find starting point for our search */
-	if (free_vmap_cache) {
-		first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
-		addr = ALIGN(first->va_end, align);
-		if (addr < vstart)
-			goto nocache;
-		if (addr + size < addr)
-			goto overflow;
-
-	} else {
-		addr = ALIGN(vstart, align);
-		if (addr + size < addr)
-			goto overflow;
-
-		n = vmap_area_root.rb_node;
-		first = NULL;
-
-		while (n) {
-			struct vmap_area *tmp;
-			tmp = rb_entry(n, struct vmap_area, rb_node);
-			if (tmp->va_end >= addr) {
-				first = tmp;
-				if (tmp->va_start <= addr)
-					break;
-				n = n->rb_left;
-			} else
-				n = n->rb_right;
+		if (__this_cpu_cmpxchg(ne_fit_preload_node, NULL, pva)) {
+			if (pva)
+				kmem_cache_free(vmap_area_cachep, pva);
 		}
-
-		if (!first)
-			goto found;
 	}
 
-	/* from the starting point, walk areas until a suitable hole is found */
-	while (addr + size > first->va_start && addr + size <= vend) {
-		if (addr + cached_hole_size < first->va_start)
-			cached_hole_size = first->va_start - addr;
-		addr = ALIGN(first->va_end, align);
-		if (addr + size < addr)
-			goto overflow;
+	spin_lock(&vmap_area_lock);
+	preempt_enable();
 
-		if (list_is_last(&first->list, &vmap_area_list))
-			goto found;
-
-		first = list_next_entry(first, list);
-	}
-
-found:
-	if (addr + size > vend)
+	/*
+	 * If an allocation fails, the "vend" address is
+	 * returned. Therefore trigger the overflow path.
+	 */
+	addr = __alloc_vmap_area(size, align, vstart, vend);
+	if (unlikely(addr == vend))
 		goto overflow;
 
 	va->va_start = addr;
 	va->va_end = addr + size;
-	va->flags = 0;
-	__insert_vmap_area(va);
-	free_vmap_cache = &va->rb_node;
+	va->vm = NULL;
+	insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
+
 	spin_unlock(&vmap_area_lock);
 
 	BUG_ON(!IS_ALIGNED(va->va_start, align));
@@ -534,7 +1144,8 @@
 	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
 		pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
 			size);
-	kfree(va);
+
+	kmem_cache_free(vmap_area_cachep, va);
 	return ERR_PTR(-EBUSY);
 }
 
@@ -552,37 +1163,16 @@
 
 static void __free_vmap_area(struct vmap_area *va)
 {
-	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
-
-	if (free_vmap_cache) {
-		if (va->va_end < cached_vstart) {
-			free_vmap_cache = NULL;
-		} else {
-			struct vmap_area *cache;
-			cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
-			if (va->va_start <= cache->va_start) {
-				free_vmap_cache = rb_prev(&va->rb_node);
-				/*
-				 * We don't try to update cached_hole_size or
-				 * cached_align, but it won't go very wrong.
-				 */
-			}
-		}
-	}
-	rb_erase(&va->rb_node, &vmap_area_root);
-	RB_CLEAR_NODE(&va->rb_node);
-	list_del_rcu(&va->list);
+	/*
+	 * Remove from the busy tree/list.
+	 */
+	unlink_va(va, &vmap_area_root);
 
 	/*
-	 * Track the highest possible candidate for pcpu area
-	 * allocation.  Areas outside of vmalloc area can be returned
-	 * here too, consider only end addresses which fall inside
-	 * vmalloc area proper.
+	 * Merge VA with its neighbors, otherwise just add it.
 	 */
-	if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
-		vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
-
-	kfree_rcu(va, rcu_head);
+	merge_or_add_vmap_area(va,
+		&free_vmap_area_root, &free_vmap_area_list);
 }
 
 /*
@@ -628,7 +1218,7 @@
 	return log * (32UL * 1024 * 1024 / PAGE_SIZE);
 }
 
-static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
+static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
 
 /*
  * Serialize vmap purging.  There is no actual criticial section protected
@@ -646,7 +1236,7 @@
  */
 void set_iounmap_nonlazy(void)
 {
-	atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
+	atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
 }
 
 /*
@@ -654,34 +1244,53 @@
  */
 static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
 {
+	unsigned long resched_threshold;
 	struct llist_node *valist;
 	struct vmap_area *va;
 	struct vmap_area *n_va;
-	bool do_free = false;
 
 	lockdep_assert_held(&vmap_purge_lock);
 
 	valist = llist_del_all(&vmap_purge_list);
+	if (unlikely(valist == NULL))
+		return false;
+
+	/*
+	 * First make sure the mappings are removed from all page-tables
+	 * before they are freed.
+	 */
+	vmalloc_sync_all();
+
+	/*
+	 * TODO: to calculate a flush range without looping.
+	 * The list can be up to lazy_max_pages() elements.
+	 */
 	llist_for_each_entry(va, valist, purge_list) {
 		if (va->va_start < start)
 			start = va->va_start;
 		if (va->va_end > end)
 			end = va->va_end;
-		do_free = true;
 	}
 
-	if (!do_free)
-		return false;
-
 	flush_tlb_kernel_range(start, end);
+	resched_threshold = lazy_max_pages() << 1;
 
 	spin_lock(&vmap_area_lock);
 	llist_for_each_entry_safe(va, n_va, valist, purge_list) {
-		int nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
+		unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
 
-		__free_vmap_area(va);
-		atomic_sub(nr, &vmap_lazy_nr);
-		cond_resched_lock(&vmap_area_lock);
+		/*
+		 * Finally insert or merge lazily-freed area. It is
+		 * detached and there is no need to "unlink" it from
+		 * anything.
+		 */
+		merge_or_add_vmap_area(va,
+			&free_vmap_area_root, &free_vmap_area_list);
+
+		atomic_long_sub(nr, &vmap_lazy_nr);
+
+		if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
+			cond_resched_lock(&vmap_area_lock);
 	}
 	spin_unlock(&vmap_area_lock);
 	return true;
@@ -717,10 +1326,14 @@
  */
 static void free_vmap_area_noflush(struct vmap_area *va)
 {
-	int nr_lazy;
+	unsigned long nr_lazy;
 
-	nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT,
-				    &vmap_lazy_nr);
+	spin_lock(&vmap_area_lock);
+	unlink_va(va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
+				PAGE_SHIFT, &vmap_lazy_nr);
 
 	/* After this point, we may free va at any time */
 	llist_add(&va->purge_list, &vmap_purge_list);
@@ -783,8 +1396,6 @@
 
 #define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)
 
-static bool vmap_initialized __read_mostly = false;
-
 struct vmap_block_queue {
 	spinlock_t lock;
 	struct list_head free;
@@ -840,7 +1451,7 @@
  * @order:    how many 2^order pages should be occupied in newly allocated block
  * @gfp_mask: flags for the page level allocator
  *
- * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
+ * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
  */
 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 {
@@ -1055,24 +1666,9 @@
 		spin_unlock(&vb->lock);
 }
 
-/**
- * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
- *
- * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
- * to amortize TLB flushing overheads. What this means is that any page you
- * have now, may, in a former life, have been mapped into kernel virtual
- * address by the vmap layer and so there might be some CPUs with TLB entries
- * still referencing that page (additional to the regular 1:1 kernel mapping).
- *
- * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
- * be sure that none of the pages we have control over will have any aliases
- * from the vmap layer.
- */
-void vm_unmap_aliases(void)
+static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
 {
-	unsigned long start = ULONG_MAX, end = 0;
 	int cpu;
-	int flush = 0;
 
 	if (unlikely(!vmap_initialized))
 		return;
@@ -1109,6 +1705,27 @@
 		flush_tlb_kernel_range(start, end);
 	mutex_unlock(&vmap_purge_lock);
 }
+
+/**
+ * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
+ *
+ * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
+ * to amortize TLB flushing overheads. What this means is that any page you
+ * have now, may, in a former life, have been mapped into kernel virtual
+ * address by the vmap layer and so there might be some CPUs with TLB entries
+ * still referencing that page (additional to the regular 1:1 kernel mapping).
+ *
+ * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
+ * be sure that none of the pages we have control over will have any aliases
+ * from the vmap layer.
+ */
+void vm_unmap_aliases(void)
+{
+	unsigned long start = ULONG_MAX, end = 0;
+	int flush = 0;
+
+	_vm_unmap_aliases(start, end, flush);
+}
 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
 
 /**
@@ -1187,6 +1804,7 @@
 EXPORT_SYMBOL(vm_map_ram);
 
 static struct vm_struct *vmlist __initdata;
+
 /**
  * vm_area_add_early - add vmap area early during boot
  * @vm: vm_struct to add
@@ -1238,12 +1856,58 @@
 	vm_area_add_early(vm);
 }
 
+static void vmap_init_free_space(void)
+{
+	unsigned long vmap_start = 1;
+	const unsigned long vmap_end = ULONG_MAX;
+	struct vmap_area *busy, *free;
+
+	/*
+	 *     B     F     B     B     B     F
+	 * -|-----|.....|-----|-----|-----|.....|-
+	 *  |           The KVA space           |
+	 *  |<--------------------------------->|
+	 */
+	list_for_each_entry(busy, &vmap_area_list, list) {
+		if (busy->va_start - vmap_start > 0) {
+			free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+			if (!WARN_ON_ONCE(!free)) {
+				free->va_start = vmap_start;
+				free->va_end = busy->va_start;
+
+				insert_vmap_area_augment(free, NULL,
+					&free_vmap_area_root,
+						&free_vmap_area_list);
+			}
+		}
+
+		vmap_start = busy->va_end;
+	}
+
+	if (vmap_end - vmap_start > 0) {
+		free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+		if (!WARN_ON_ONCE(!free)) {
+			free->va_start = vmap_start;
+			free->va_end = vmap_end;
+
+			insert_vmap_area_augment(free, NULL,
+				&free_vmap_area_root,
+					&free_vmap_area_list);
+		}
+	}
+}
+
 void __init vmalloc_init(void)
 {
 	struct vmap_area *va;
 	struct vm_struct *tmp;
 	int i;
 
+	/*
+	 * Create the cache for vmap_area objects.
+	 */
+	vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
+
 	for_each_possible_cpu(i) {
 		struct vmap_block_queue *vbq;
 		struct vfree_deferred *p;
@@ -1258,16 +1922,20 @@
 
 	/* Import existing vmlist entries. */
 	for (tmp = vmlist; tmp; tmp = tmp->next) {
-		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
-		va->flags = VM_VM_AREA;
+		va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+		if (WARN_ON_ONCE(!va))
+			continue;
+
 		va->va_start = (unsigned long)tmp->addr;
 		va->va_end = va->va_start + tmp->size;
 		va->vm = tmp;
-		__insert_vmap_area(va);
+		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
 	}
 
-	vmap_area_pcpu_hole = VMALLOC_END;
-
+	/*
+	 * Now we can initialize a free vmap space.
+	 */
+	vmap_init_free_space();
 	vmap_initialized = true;
 }
 
@@ -1355,7 +2023,6 @@
 	vm->size = va->va_end - va->va_start;
 	vm->caller = caller;
 	va->vm = vm;
-	va->flags |= VM_VM_AREA;
 	spin_unlock(&vmap_area_lock);
 }
 
@@ -1421,13 +2088,15 @@
 }
 
 /**
- *	get_vm_area  -  reserve a contiguous kernel virtual area
- *	@size:		size of the area
- *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC
+ * get_vm_area - reserve a contiguous kernel virtual area
+ * @size:	 size of the area
+ * @flags:	 %VM_IOREMAP for I/O mappings or VM_ALLOC
  *
- *	Search an area of @size in the kernel virtual mapping area,
- *	and reserved it for out purposes.  Returns the area descriptor
- *	on success or %NULL on failure.
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserved it for out purposes.  Returns the area descriptor
+ * on success or %NULL on failure.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
  */
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
@@ -1444,31 +2113,35 @@
 }
 
 /**
- *	find_vm_area  -  find a continuous kernel virtual area
- *	@addr:		base address
+ * find_vm_area - find a continuous kernel virtual area
+ * @addr:	  base address
  *
- *	Search for the kernel VM area starting at @addr, and return it.
- *	It is up to the caller to do all required locking to keep the returned
- *	pointer valid.
+ * Search for the kernel VM area starting at @addr, and return it.
+ * It is up to the caller to do all required locking to keep the returned
+ * pointer valid.
+ *
+ * Return: pointer to the found area or %NULL on faulure
  */
 struct vm_struct *find_vm_area(const void *addr)
 {
 	struct vmap_area *va;
 
 	va = find_vmap_area((unsigned long)addr);
-	if (va && va->flags & VM_VM_AREA)
-		return va->vm;
+	if (!va)
+		return NULL;
 
-	return NULL;
+	return va->vm;
 }
 
 /**
- *	remove_vm_area  -  find and remove a continuous kernel virtual area
- *	@addr:		base address
+ * remove_vm_area - find and remove a continuous kernel virtual area
+ * @addr:	    base address
  *
- *	Search for the kernel VM area starting at @addr, and remove it.
- *	This function returns the found VM area, but using it is NOT safe
- *	on SMP machines, except for its size or flags.
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ *
+ * Return: pointer to the found area or %NULL on faulure
  */
 struct vm_struct *remove_vm_area(const void *addr)
 {
@@ -1476,14 +2149,12 @@
 
 	might_sleep();
 
-	va = find_vmap_area((unsigned long)addr);
-	if (va && va->flags & VM_VM_AREA) {
+	spin_lock(&vmap_area_lock);
+	va = __find_vmap_area((unsigned long)addr);
+	if (va && va->vm) {
 		struct vm_struct *vm = va->vm;
 
-		spin_lock(&vmap_area_lock);
 		va->vm = NULL;
-		va->flags &= ~VM_VM_AREA;
-		va->flags |= VM_LAZY_FREE;
 		spin_unlock(&vmap_area_lock);
 
 		kasan_free_shadow(vm);
@@ -1491,9 +2162,68 @@
 
 		return vm;
 	}
+
+	spin_unlock(&vmap_area_lock);
 	return NULL;
 }
 
+static inline void set_area_direct_map(const struct vm_struct *area,
+				       int (*set_direct_map)(struct page *page))
+{
+	int i;
+
+	for (i = 0; i < area->nr_pages; i++)
+		if (page_address(area->pages[i]))
+			set_direct_map(area->pages[i]);
+}
+
+/* Handle removing and resetting vm mappings related to the vm_struct. */
+static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
+{
+	unsigned long start = ULONG_MAX, end = 0;
+	int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
+	int flush_dmap = 0;
+	int i;
+
+	remove_vm_area(area->addr);
+
+	/* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
+	if (!flush_reset)
+		return;
+
+	/*
+	 * If not deallocating pages, just do the flush of the VM area and
+	 * return.
+	 */
+	if (!deallocate_pages) {
+		vm_unmap_aliases();
+		return;
+	}
+
+	/*
+	 * If execution gets here, flush the vm mapping and reset the direct
+	 * map. Find the start and end range of the direct mappings to make sure
+	 * the vm_unmap_aliases() flush includes the direct map.
+	 */
+	for (i = 0; i < area->nr_pages; i++) {
+		unsigned long addr = (unsigned long)page_address(area->pages[i]);
+		if (addr) {
+			start = min(addr, start);
+			end = max(addr + PAGE_SIZE, end);
+			flush_dmap = 1;
+		}
+	}
+
+	/*
+	 * Set direct map to something invalid so that it won't be cached if
+	 * there are any accesses after the TLB flush, then flush the TLB and
+	 * reset the direct map permissions to the default.
+	 */
+	set_area_direct_map(area, set_direct_map_invalid_noflush);
+	_vm_unmap_aliases(start, end, flush_dmap);
+	set_area_direct_map(area, set_direct_map_default_noflush);
+}
+
 static void __vunmap(const void *addr, int deallocate_pages)
 {
 	struct vm_struct *area;
@@ -1505,7 +2235,7 @@
 			addr))
 		return;
 
-	area = find_vmap_area((unsigned long)addr)->vm;
+	area = find_vm_area(addr);
 	if (unlikely(!area)) {
 		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
 				addr);
@@ -1515,7 +2245,8 @@
 	debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
 	debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
 
-	remove_vm_area(addr);
+	vm_remove_mappings(area, deallocate_pages);
+
 	if (deallocate_pages) {
 		int i;
 
@@ -1525,6 +2256,7 @@
 			BUG_ON(!page);
 			__free_pages(page, 0);
 		}
+		atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
 
 		kvfree(area->pages);
 	}
@@ -1548,11 +2280,11 @@
 }
 
 /**
- *	vfree_atomic  -  release memory allocated by vmalloc()
- *	@addr:		memory base address
+ * vfree_atomic - release memory allocated by vmalloc()
+ * @addr:	  memory base address
  *
- *	This one is just like vfree() but can be called in any atomic context
- *	except NMIs.
+ * This one is just like vfree() but can be called in any atomic context
+ * except NMIs.
  */
 void vfree_atomic(const void *addr)
 {
@@ -1565,19 +2297,29 @@
 	__vfree_deferred(addr);
 }
 
+static void __vfree(const void *addr)
+{
+	if (unlikely(in_interrupt()))
+		__vfree_deferred(addr);
+	else
+		__vunmap(addr, 1);
+}
+
 /**
- *	vfree  -  release memory allocated by vmalloc()
- *	@addr:		memory base address
+ * vfree - release memory allocated by vmalloc()
+ * @addr:  memory base address
  *
- *	Free the virtually continuous memory area starting at @addr, as
- *	obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
- *	NULL, no operation is performed.
+ * Free the virtually continuous memory area starting at @addr, as
+ * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
+ * NULL, no operation is performed.
  *
- *	Must not be called in NMI context (strictly speaking, only if we don't
- *	have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
- *	conventions for vfree() arch-depenedent would be a really bad idea)
+ * Must not be called in NMI context (strictly speaking, only if we don't
+ * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-depenedent would be a really bad idea)
  *
- *	NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
+ * May sleep if called *not* from interrupt context.
+ *
+ * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
  */
 void vfree(const void *addr)
 {
@@ -1585,23 +2327,23 @@
 
 	kmemleak_free(addr);
 
+	might_sleep_if(!in_interrupt());
+
 	if (!addr)
 		return;
-	if (unlikely(in_interrupt()))
-		__vfree_deferred(addr);
-	else
-		__vunmap(addr, 1);
+
+	__vfree(addr);
 }
 EXPORT_SYMBOL(vfree);
 
 /**
- *	vunmap  -  release virtual mapping obtained by vmap()
- *	@addr:		memory base address
+ * vunmap - release virtual mapping obtained by vmap()
+ * @addr:   memory base address
  *
- *	Free the virtually contiguous memory area starting at @addr,
- *	which was created from the page array passed to vmap().
+ * Free the virtually contiguous memory area starting at @addr,
+ * which was created from the page array passed to vmap().
  *
- *	Must not be called in interrupt context.
+ * Must not be called in interrupt context.
  */
 void vunmap(const void *addr)
 {
@@ -1613,24 +2355,26 @@
 EXPORT_SYMBOL(vunmap);
 
 /**
- *	vmap  -  map an array of pages into virtually contiguous space
- *	@pages:		array of page pointers
- *	@count:		number of pages to map
- *	@flags:		vm_area->flags
- *	@prot:		page protection for the mapping
+ * vmap - map an array of pages into virtually contiguous space
+ * @pages: array of page pointers
+ * @count: number of pages to map
+ * @flags: vm_area->flags
+ * @prot: page protection for the mapping
  *
- *	Maps @count pages from @pages into contiguous kernel virtual
- *	space.
+ * Maps @count pages from @pages into contiguous kernel virtual
+ * space.
+ *
+ * Return: the address of the area or %NULL on failure
  */
 void *vmap(struct page **pages, unsigned int count,
-		unsigned long flags, pgprot_t prot)
+	   unsigned long flags, pgprot_t prot)
 {
 	struct vm_struct *area;
 	unsigned long size;		/* In bytes */
 
 	might_sleep();
 
-	if (count > totalram_pages)
+	if (count > totalram_pages())
 		return NULL;
 
 	size = (unsigned long)count << PAGE_SHIFT;
@@ -1664,7 +2408,6 @@
 	nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
 	array_size = (nr_pages * sizeof(struct page *));
 
-	area->nr_pages = nr_pages;
 	/* Please note that the recursion is strictly bounded. */
 	if (array_size > PAGE_SIZE) {
 		pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask,
@@ -1672,13 +2415,16 @@
 	} else {
 		pages = kmalloc_node(array_size, nested_gfp, node);
 	}
-	area->pages = pages;
-	if (!area->pages) {
+
+	if (!pages) {
 		remove_vm_area(area->addr);
 		kfree(area);
 		return NULL;
 	}
 
+	area->pages = pages;
+	area->nr_pages = nr_pages;
+
 	for (i = 0; i < area->nr_pages; i++) {
 		struct page *page;
 
@@ -1690,12 +2436,14 @@
 		if (unlikely(!page)) {
 			/* Successfully allocated i pages, free them in __vunmap() */
 			area->nr_pages = i;
+			atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
 			goto fail;
 		}
 		area->pages[i] = page;
 		if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
 			cond_resched();
 	}
+	atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
 
 	if (map_vm_area(area, prot, pages))
 		goto fail;
@@ -1705,25 +2453,27 @@
 	warn_alloc(gfp_mask, NULL,
 			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
 			  (area->nr_pages*PAGE_SIZE), area->size);
-	vfree(area->addr);
+	__vfree(area->addr);
 	return NULL;
 }
 
 /**
- *	__vmalloc_node_range  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	@align:		desired alignment
- *	@start:		vm area range start
- *	@end:		vm area range end
- *	@gfp_mask:	flags for the page level allocator
- *	@prot:		protection mask for the allocated pages
- *	@vm_flags:	additional vm area flags (e.g. %VM_NO_GUARD)
- *	@node:		node to use for allocation or NUMA_NO_NODE
- *	@caller:	caller's return address
+ * __vmalloc_node_range - allocate virtually contiguous memory
+ * @size:		  allocation size
+ * @align:		  desired alignment
+ * @start:		  vm area range start
+ * @end:		  vm area range end
+ * @gfp_mask:		  flags for the page level allocator
+ * @prot:		  protection mask for the allocated pages
+ * @vm_flags:		  additional vm area flags (e.g. %VM_NO_GUARD)
+ * @node:		  node to use for allocation or NUMA_NO_NODE
+ * @caller:		  caller's return address
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator with @gfp_mask flags.  Map them into contiguous
- *	kernel virtual space, using a pagetable protection of @prot.
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags.  Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ *
+ * Return: the address of the area or %NULL on failure
  */
 void *__vmalloc_node_range(unsigned long size, unsigned long align,
 			unsigned long start, unsigned long end, gfp_t gfp_mask,
@@ -1735,7 +2485,7 @@
 	unsigned long real_size = size;
 
 	size = PAGE_ALIGN(size);
-	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
+	if (!size || (size >> PAGE_SHIFT) > totalram_pages())
 		goto fail;
 
 	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
@@ -1764,25 +2514,35 @@
 	return NULL;
 }
 
+/*
+ * This is only for performance analysis of vmalloc and stress purpose.
+ * It is required by vmalloc test module, therefore do not use it other
+ * than that.
+ */
+#ifdef CONFIG_TEST_VMALLOC_MODULE
+EXPORT_SYMBOL_GPL(__vmalloc_node_range);
+#endif
+
 /**
- *	__vmalloc_node  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	@align:		desired alignment
- *	@gfp_mask:	flags for the page level allocator
- *	@prot:		protection mask for the allocated pages
- *	@node:		node to use for allocation or NUMA_NO_NODE
- *	@caller:	caller's return address
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size:	    allocation size
+ * @align:	    desired alignment
+ * @gfp_mask:	    flags for the page level allocator
+ * @prot:	    protection mask for the allocated pages
+ * @node:	    node to use for allocation or NUMA_NO_NODE
+ * @caller:	    caller's return address
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator with @gfp_mask flags.  Map them into contiguous
- *	kernel virtual space, using a pagetable protection of @prot.
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags.  Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
  *
- *	Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
- *	and __GFP_NOFAIL are not supported
+ * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
+ * and __GFP_NOFAIL are not supported
  *
- *	Any use of gfp flags outside of GFP_KERNEL should be consulted
- *	with mm people.
+ * Any use of gfp flags outside of GFP_KERNEL should be consulted
+ * with mm people.
  *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 static void *__vmalloc_node(unsigned long size, unsigned long align,
 			    gfp_t gfp_mask, pgprot_t prot,
@@ -1814,13 +2574,16 @@
 }
 
 /**
- *	vmalloc  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
+ * vmalloc - allocate virtually contiguous memory
+ * @size:    allocation size
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc(unsigned long size)
 {
@@ -1830,14 +2593,17 @@
 EXPORT_SYMBOL(vmalloc);
 
 /**
- *	vzalloc - allocate virtually contiguous memory with zero fill
- *	@size:	allocation size
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
- *	The memory allocated is set to zero.
+ * vzalloc - allocate virtually contiguous memory with zero fill
+ * @size:    allocation size
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vzalloc(unsigned long size)
 {
@@ -1852,34 +2618,30 @@
  *
  * The resulting memory area is zeroed so it can be mapped to userspace
  * without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_user(unsigned long size)
 {
-	struct vm_struct *area;
-	void *ret;
-
-	ret = __vmalloc_node(size, SHMLBA,
-			     GFP_KERNEL | __GFP_ZERO,
-			     PAGE_KERNEL, NUMA_NO_NODE,
-			     __builtin_return_address(0));
-	if (ret) {
-		area = find_vm_area(ret);
-		area->flags |= VM_USERMAP;
-	}
-	return ret;
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_user);
 
 /**
- *	vmalloc_node  -  allocate memory on a specific node
- *	@size:		allocation size
- *	@node:		numa node
+ * vmalloc_node - allocate memory on a specific node
+ * @size:	  allocation size
+ * @node:	  numa node
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_node(unsigned long size, int node)
 {
@@ -1899,6 +2661,8 @@
  *
  * For tight control over page level allocator and protection flags
  * use __vmalloc_node() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vzalloc_node(unsigned long size, int node)
 {
@@ -1908,21 +2672,23 @@
 EXPORT_SYMBOL(vzalloc_node);
 
 /**
- *	vmalloc_exec  -  allocate virtually contiguous, executable memory
- *	@size:		allocation size
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size:	  allocation size
  *
- *	Kernel-internal function to allocate enough pages to cover @size
- *	the page level allocator and map them into contiguous and
- *	executable kernel virtual space.
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
-
 void *vmalloc_exec(unsigned long size)
 {
-	return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC,
-			      NUMA_NO_NODE, __builtin_return_address(0));
+	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+			GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
+			NUMA_NO_NODE, __builtin_return_address(0));
 }
 
 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
@@ -1938,11 +2704,13 @@
 #endif
 
 /**
- *	vmalloc_32  -  allocate virtually contiguous memory (32bit addressable)
- *	@size:		allocation size
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size:	allocation size
  *
- *	Allocate enough 32bit PA addressable pages to cover @size from the
- *	page level allocator and map them into contiguous kernel virtual space.
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into contiguous kernel virtual space.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_32(unsigned long size)
 {
@@ -1953,23 +2721,19 @@
 
 /**
  * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
- *	@size:		allocation size
+ * @size:	     allocation size
  *
  * The resulting memory area is 32bit addressable and zeroed so it can be
  * mapped to userspace without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_32_user(unsigned long size)
 {
-	struct vm_struct *area;
-	void *ret;
-
-	ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
-			     NUMA_NO_NODE, __builtin_return_address(0));
-	if (ret) {
-		area = find_vm_area(ret);
-		area->flags |= VM_USERMAP;
-	}
-	return ret;
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_32_user);
 
@@ -2055,31 +2819,29 @@
 }
 
 /**
- *	vread() -  read vmalloc area in a safe way.
- *	@buf:		buffer for reading data
- *	@addr:		vm address.
- *	@count:		number of bytes to be read.
+ * vread() - read vmalloc area in a safe way.
+ * @buf:     buffer for reading data
+ * @addr:    vm address.
+ * @count:   number of bytes to be read.
  *
- *	Returns # of bytes which addr and buf should be increased.
- *	(same number to @count). Returns 0 if [addr...addr+count) doesn't
- *	includes any intersect with alive vmalloc area.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	copy data from that area to a given buffer. If the given memory range
- *	of [addr...addr+count) includes some valid address, data is copied to
- *	proper area of @buf. If there are memory holes, they'll be zero-filled.
- *	IOREMAP area is treated as memory hole and no copy is done.
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
  *
- *	If [addr...addr+count) doesn't includes any intersects with alive
- *	vm_struct area, returns 0. @buf should be kernel's buffer.
+ * Note: In usual ops, vread() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any information, as /dev/kmem.
  *
- *	Note: In usual ops, vread() is never necessary because the caller
- *	should know vmalloc() area is valid and can use memcpy().
- *	This is for routines which have to access vmalloc area without
- *	any informaion, as /dev/kmem.
- *
+ * Return: number of bytes for which addr and buf should be increased
+ * (same number as @count) or %0 if [addr...addr+count) doesn't
+ * include any intersection with valid vmalloc area
  */
-
 long vread(char *buf, char *addr, unsigned long count)
 {
 	struct vmap_area *va;
@@ -2097,7 +2859,7 @@
 		if (!count)
 			break;
 
-		if (!(va->flags & VM_VM_AREA))
+		if (!va->vm)
 			continue;
 
 		vm = va->vm;
@@ -2136,31 +2898,29 @@
 }
 
 /**
- *	vwrite() -  write vmalloc area in a safe way.
- *	@buf:		buffer for source data
- *	@addr:		vm address.
- *	@count:		number of bytes to be read.
+ * vwrite() - write vmalloc area in a safe way.
+ * @buf:      buffer for source data
+ * @addr:     vm address.
+ * @count:    number of bytes to be read.
  *
- *	Returns # of bytes which addr and buf should be incresed.
- *	(same number to @count).
- *	If [addr...addr+count) doesn't includes any intersect with valid
- *	vmalloc area, returns 0.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from a buffer to the given addr. If specified range of
+ * [addr...addr+count) includes some valid address, data is copied from
+ * proper area of @buf. If there are memory holes, no copy to hole.
+ * IOREMAP area is treated as memory hole and no copy is done.
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	copy data from a buffer to the given addr. If specified range of
- *	[addr...addr+count) includes some valid address, data is copied from
- *	proper area of @buf. If there are memory holes, no copy to hole.
- *	IOREMAP area is treated as memory hole and no copy is done.
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
  *
- *	If [addr...addr+count) doesn't includes any intersects with alive
- *	vm_struct area, returns 0. @buf should be kernel's buffer.
+ * Note: In usual ops, vwrite() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any information, as /dev/kmem.
  *
- *	Note: In usual ops, vwrite() is never necessary because the caller
- *	should know vmalloc() area is valid and can use memcpy().
- *	This is for routines which have to access vmalloc area without
- *	any informaion, as /dev/kmem.
+ * Return: number of bytes for which addr and buf should be
+ * increased (same number as @count) or %0 if [addr...addr+count)
+ * doesn't include any intersection with valid vmalloc area
  */
-
 long vwrite(char *buf, char *addr, unsigned long count)
 {
 	struct vmap_area *va;
@@ -2179,7 +2939,7 @@
 		if (!count)
 			break;
 
-		if (!(va->flags & VM_VM_AREA))
+		if (!va->vm)
 			continue;
 
 		vm = va->vm;
@@ -2212,20 +2972,20 @@
 }
 
 /**
- *	remap_vmalloc_range_partial  -  map vmalloc pages to userspace
- *	@vma:		vma to cover
- *	@uaddr:		target user address to start at
- *	@kaddr:		virtual address of vmalloc kernel memory
- *	@size:		size of map area
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma:		vma to cover
+ * @uaddr:		target user address to start at
+ * @kaddr:		virtual address of vmalloc kernel memory
+ * @size:		size of map area
  *
- *	Returns:	0 for success, -Exxx on failure
+ * Returns:	0 for success, -Exxx on failure
  *
- *	This function checks that @kaddr is a valid vmalloc'ed area,
- *	and that it is big enough to cover the range starting at
- *	@uaddr in @vma. Will return failure if that criteria isn't
- *	met.
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
  *
- *	Similar to remap_pfn_range() (see mm/memory.c)
+ * Similar to remap_pfn_range() (see mm/memory.c)
  */
 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
 				void *kaddr, unsigned long size)
@@ -2241,10 +3001,10 @@
 	if (!area)
 		return -EINVAL;
 
-	if (!(area->flags & VM_USERMAP))
+	if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
 		return -EINVAL;
 
-	if (kaddr + size > area->addr + area->size)
+	if (kaddr + size > area->addr + get_vm_area_size(area))
 		return -EINVAL;
 
 	do {
@@ -2267,18 +3027,18 @@
 EXPORT_SYMBOL(remap_vmalloc_range_partial);
 
 /**
- *	remap_vmalloc_range  -  map vmalloc pages to userspace
- *	@vma:		vma to cover (map full range of vma)
- *	@addr:		vmalloc memory
- *	@pgoff:		number of pages into addr before first page to map
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma:		vma to cover (map full range of vma)
+ * @addr:		vmalloc memory
+ * @pgoff:		number of pages into addr before first page to map
  *
- *	Returns:	0 for success, -Exxx on failure
+ * Returns:	0 for success, -Exxx on failure
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	that it is big enough to cover the vma. Will return failure if
- *	that criteria isn't met.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
  *
- *	Similar to remap_pfn_range() (see mm/memory.c)
+ * Similar to remap_pfn_range() (see mm/memory.c)
  */
 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 						unsigned long pgoff)
@@ -2292,13 +3052,16 @@
 /*
  * Implement a stub for vmalloc_sync_all() if the architecture chose not to
  * have one.
+ *
+ * The purpose of this function is to make sure the vmalloc area
+ * mappings are identical in all page-tables in the system.
  */
 void __weak vmalloc_sync_all(void)
 {
 }
 
 
-static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
+static int f(pte_t *pte, unsigned long addr, void *data)
 {
 	pte_t ***p = data;
 
@@ -2310,18 +3073,18 @@
 }
 
 /**
- *	alloc_vm_area - allocate a range of kernel address space
- *	@size:		size of the area
- *	@ptes:		returns the PTEs for the address space
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size:	   size of the area
+ * @ptes:	   returns the PTEs for the address space
  *
- *	Returns:	NULL on failure, vm_struct on success
+ * Returns:	NULL on failure, vm_struct on success
  *
- *	This function reserves a range of kernel address space, and
- *	allocates pagetables to map that range.  No actual mappings
- *	are created.
+ * This function reserves a range of kernel address space, and
+ * allocates pagetables to map that range.  No actual mappings
+ * are created.
  *
- *	If @ptes is non-NULL, pointers to the PTEs (in init_mm)
- *	allocated for the VM area are returned.
+ * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
+ * allocated for the VM area are returned.
  */
 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
 {
@@ -2362,81 +3125,64 @@
 }
 
 /**
- * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
- * @end: target address
- * @pnext: out arg for the next vmap_area
- * @pprev: out arg for the previous vmap_area
+ * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
+ * @addr: target address
  *
- * Returns: %true if either or both of next and prev are found,
- *	    %false if no vmap_area exists
- *
- * Find vmap_areas end addresses of which enclose @end.  ie. if not
- * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ * Returns: vmap_area if it is found. If there is no such area
+ *   the first highest(reverse order) vmap_area is returned
+ *   i.e. va->va_start < addr && va->va_end < addr or NULL
+ *   if there are no any areas before @addr.
  */
-static bool pvm_find_next_prev(unsigned long end,
-			       struct vmap_area **pnext,
-			       struct vmap_area **pprev)
+static struct vmap_area *
+pvm_find_va_enclose_addr(unsigned long addr)
 {
-	struct rb_node *n = vmap_area_root.rb_node;
-	struct vmap_area *va = NULL;
+	struct vmap_area *va, *tmp;
+	struct rb_node *n;
+
+	n = free_vmap_area_root.rb_node;
+	va = NULL;
 
 	while (n) {
-		va = rb_entry(n, struct vmap_area, rb_node);
-		if (end < va->va_end)
-			n = n->rb_left;
-		else if (end > va->va_end)
+		tmp = rb_entry(n, struct vmap_area, rb_node);
+		if (tmp->va_start <= addr) {
+			va = tmp;
+			if (tmp->va_end >= addr)
+				break;
+
 			n = n->rb_right;
-		else
-			break;
+		} else {
+			n = n->rb_left;
+		}
 	}
 
-	if (!va)
-		return false;
-
-	if (va->va_end > end) {
-		*pnext = va;
-		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
-	} else {
-		*pprev = va;
-		*pnext = node_to_va(rb_next(&(*pprev)->rb_node));
-	}
-	return true;
+	return va;
 }
 
 /**
- * pvm_determine_end - find the highest aligned address between two vmap_areas
- * @pnext: in/out arg for the next vmap_area
- * @pprev: in/out arg for the previous vmap_area
- * @align: alignment
+ * pvm_determine_end_from_reverse - find the highest aligned address
+ * of free block below VMALLOC_END
+ * @va:
+ *   in - the VA we start the search(reverse order);
+ *   out - the VA with the highest aligned end address.
  *
- * Returns: determined end address
- *
- * Find the highest aligned address between *@pnext and *@pprev below
- * VMALLOC_END.  *@pnext and *@pprev are adjusted so that the aligned
- * down address is between the end addresses of the two vmap_areas.
- *
- * Please note that the address returned by this function may fall
- * inside *@pnext vmap_area.  The caller is responsible for checking
- * that.
+ * Returns: determined end address within vmap_area
  */
-static unsigned long pvm_determine_end(struct vmap_area **pnext,
-				       struct vmap_area **pprev,
-				       unsigned long align)
+static unsigned long
+pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
 {
-	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+	unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
 	unsigned long addr;
 
-	if (*pnext)
-		addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
-	else
-		addr = vmalloc_end;
-
-	while (*pprev && (*pprev)->va_end > addr) {
-		*pnext = *pprev;
-		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+	if (likely(*va)) {
+		list_for_each_entry_from_reverse((*va),
+				&free_vmap_area_list, list) {
+			addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
+			if ((*va)->va_start < addr)
+				return addr;
+		}
 	}
 
-	return addr;
+	return 0;
 }
 
 /**
@@ -2456,12 +3202,12 @@
  * to gigabytes.  To avoid interacting with regular vmallocs, these
  * areas are allocated from top.
  *
- * Despite its complicated look, this allocator is rather simple.  It
- * does everything top-down and scans areas from the end looking for
- * matching slot.  While scanning, if any of the areas overlaps with
- * existing vmap_area, the base address is pulled down to fit the
- * area.  Scanning is repeated till all the areas fit and then all
- * necessary data structures are inserted and the result is returned.
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans free blocks from the end looking
+ * for matching base. While scanning, if any of the areas do not fit the
+ * base address is pulled down to fit the area. Scanning is repeated till
+ * all the areas fit and then all necessary data structures are inserted
+ * and the result is returned.
  */
 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 				     const size_t *sizes, int nr_vms,
@@ -2469,11 +3215,12 @@
 {
 	const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
 	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
-	struct vmap_area **vas, *prev, *next;
+	struct vmap_area **vas, *va;
 	struct vm_struct **vms;
 	int area, area2, last_area, term_area;
-	unsigned long base, start, end, last_end;
+	unsigned long base, start, size, end, last_end;
 	bool purged = false;
+	enum fit_type type;
 
 	/* verify parameters and allocate data structures */
 	BUG_ON(offset_in_page(align) || !is_power_of_2(align));
@@ -2509,7 +3256,7 @@
 		goto err_free2;
 
 	for (area = 0; area < nr_vms; area++) {
-		vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
+		vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
 		vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
 		if (!vas[area] || !vms[area])
 			goto err_free;
@@ -2522,49 +3269,39 @@
 	start = offsets[area];
 	end = start + sizes[area];
 
-	if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
-		base = vmalloc_end - last_end;
-		goto found;
-	}
-	base = pvm_determine_end(&next, &prev, align) - end;
+	va = pvm_find_va_enclose_addr(vmalloc_end);
+	base = pvm_determine_end_from_reverse(&va, align) - end;
 
 	while (true) {
-		BUG_ON(next && next->va_end <= base + end);
-		BUG_ON(prev && prev->va_end > base + end);
-
 		/*
 		 * base might have underflowed, add last_end before
 		 * comparing.
 		 */
-		if (base + last_end < vmalloc_start + last_end) {
-			spin_unlock(&vmap_area_lock);
-			if (!purged) {
-				purge_vmap_area_lazy();
-				purged = true;
-				goto retry;
-			}
-			goto err_free;
-		}
+		if (base + last_end < vmalloc_start + last_end)
+			goto overflow;
 
 		/*
-		 * If next overlaps, move base downwards so that it's
-		 * right below next and then recheck.
+		 * Fitting base has not been found.
 		 */
-		if (next && next->va_start < base + end) {
-			base = pvm_determine_end(&next, &prev, align) - end;
+		if (va == NULL)
+			goto overflow;
+
+		/*
+		 * If required width exeeds current VA block, move
+		 * base downwards and then recheck.
+		 */
+		if (base + end > va->va_end) {
+			base = pvm_determine_end_from_reverse(&va, align) - end;
 			term_area = area;
 			continue;
 		}
 
 		/*
-		 * If prev overlaps, shift down next and prev and move
-		 * base so that it's right below new next and then
-		 * recheck.
+		 * If this VA does not fit, move base downwards and recheck.
 		 */
-		if (prev && prev->va_end > base + start)  {
-			next = prev;
-			prev = node_to_va(rb_prev(&next->rb_node));
-			base = pvm_determine_end(&next, &prev, align) - end;
+		if (base + start < va->va_start) {
+			va = node_to_va(rb_prev(&va->rb_node));
+			base = pvm_determine_end_from_reverse(&va, align) - end;
 			term_area = area;
 			continue;
 		}
@@ -2576,22 +3313,41 @@
 		area = (area + nr_vms - 1) % nr_vms;
 		if (area == term_area)
 			break;
+
 		start = offsets[area];
 		end = start + sizes[area];
-		pvm_find_next_prev(base + end, &next, &prev);
+		va = pvm_find_va_enclose_addr(base + end);
 	}
-found:
+
 	/* we've found a fitting base, insert all va's */
 	for (area = 0; area < nr_vms; area++) {
-		struct vmap_area *va = vas[area];
+		int ret;
 
-		va->va_start = base + offsets[area];
-		va->va_end = va->va_start + sizes[area];
-		__insert_vmap_area(va);
+		start = base + offsets[area];
+		size = sizes[area];
+
+		va = pvm_find_va_enclose_addr(start);
+		if (WARN_ON_ONCE(va == NULL))
+			/* It is a BUG(), but trigger recovery instead. */
+			goto recovery;
+
+		type = classify_va_fit_type(va, start, size);
+		if (WARN_ON_ONCE(type == NOTHING_FIT))
+			/* It is a BUG(), but trigger recovery instead. */
+			goto recovery;
+
+		ret = adjust_va_to_fit_type(va, start, size, type);
+		if (unlikely(ret))
+			goto recovery;
+
+		/* Allocated area. */
+		va = vas[area];
+		va->va_start = start;
+		va->va_end = start + size;
+
+		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
 	}
 
-	vmap_area_pcpu_hole = base + offsets[last_area];
-
 	spin_unlock(&vmap_area_lock);
 
 	/* insert all vm's */
@@ -2602,9 +3358,38 @@
 	kfree(vas);
 	return vms;
 
+recovery:
+	/* Remove previously inserted areas. */
+	while (area--) {
+		__free_vmap_area(vas[area]);
+		vas[area] = NULL;
+	}
+
+overflow:
+	spin_unlock(&vmap_area_lock);
+	if (!purged) {
+		purge_vmap_area_lazy();
+		purged = true;
+
+		/* Before "retry", check if we recover. */
+		for (area = 0; area < nr_vms; area++) {
+			if (vas[area])
+				continue;
+
+			vas[area] = kmem_cache_zalloc(
+				vmap_area_cachep, GFP_KERNEL);
+			if (!vas[area])
+				goto err_free;
+		}
+
+		goto retry;
+	}
+
 err_free:
 	for (area = 0; area < nr_vms; area++) {
-		kfree(vas[area]);
+		if (vas[area])
+			kmem_cache_free(vmap_area_cachep, vas[area]);
+
 		kfree(vms[area]);
 	}
 err_free2:
@@ -2673,6 +3458,22 @@
 	}
 }
 
+static void show_purge_info(struct seq_file *m)
+{
+	struct llist_node *head;
+	struct vmap_area *va;
+
+	head = READ_ONCE(vmap_purge_list.first);
+	if (head == NULL)
+		return;
+
+	llist_for_each_entry(va, head, purge_list) {
+		seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
+			(void *)va->va_start, (void *)va->va_end,
+			va->va_end - va->va_start);
+	}
+}
+
 static int s_show(struct seq_file *m, void *p)
 {
 	struct vmap_area *va;
@@ -2681,14 +3482,13 @@
 	va = list_entry(p, struct vmap_area, list);
 
 	/*
-	 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
-	 * behalf of vmap area is being tear down or vm_map_ram allocation.
+	 * s_show can encounter race with remove_vm_area, !vm on behalf
+	 * of vmap area is being tear down or vm_map_ram allocation.
 	 */
-	if (!(va->flags & VM_VM_AREA)) {
-		seq_printf(m, "0x%pK-0x%pK %7ld %s\n",
+	if (!va->vm) {
+		seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
 			(void *)va->va_start, (void *)va->va_end,
-			va->va_end - va->va_start,
-			va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram");
+			va->va_end - va->va_start);
 
 		return 0;
 	}
@@ -2719,11 +3519,24 @@
 	if (v->flags & VM_USERMAP)
 		seq_puts(m, " user");
 
+	if (v->flags & VM_DMA_COHERENT)
+		seq_puts(m, " dma-coherent");
+
 	if (is_vmalloc_addr(v->pages))
 		seq_puts(m, " vpages");
 
 	show_numa_info(m, v);
 	seq_putc(m, '\n');
+
+	/*
+	 * As a final step, dump "unpurged" areas. Note,
+	 * that entire "/proc/vmallocinfo" output will not
+	 * be address sorted, because the purge list is not
+	 * sorted.
+	 */
+	if (list_is_last(&va->list, &vmap_area_list))
+		show_purge_info(m);
+
 	return 0;
 }
 
@@ -2747,4 +3560,3 @@
 module_init(proc_vmalloc_init);
 
 #endif
-