diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index cd7606b..a6bb102 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -46,6 +46,8 @@
 #define memblock_dbg(fmt, ...) \
 	if (memblock_debug) printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 
+phys_addr_t memblock_find_in_range_node(phys_addr_t start, phys_addr_t end,
+				phys_addr_t size, phys_addr_t align, int nid);
 phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end,
 				   phys_addr_t size, phys_addr_t align);
 int memblock_free_reserved_regions(void);
@@ -98,6 +100,26 @@
 	     i != (u64)ULLONG_MAX;					\
 	     __next_free_mem_range(&i, nid, p_start, p_end, p_nid))
 
+void __next_free_mem_range_rev(u64 *idx, int nid, phys_addr_t *out_start,
+			       phys_addr_t *out_end, int *out_nid);
+
+/**
+ * for_each_free_mem_range_reverse - rev-iterate through free memblock areas
+ * @i: u64 used as loop variable
+ * @nid: node selector, %MAX_NUMNODES for all nodes
+ * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL
+ * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
+ * @p_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Walks over free (memory && !reserved) areas of memblock in reverse
+ * order.  Available as soon as memblock is initialized.
+ */
+#define for_each_free_mem_range_reverse(i, nid, p_start, p_end, p_nid)	\
+	for (i = (u64)ULLONG_MAX,					\
+	     __next_free_mem_range_rev(&i, nid, p_start, p_end, p_nid);	\
+	     i != (u64)ULLONG_MAX;					\
+	     __next_free_mem_range_rev(&i, nid, p_start, p_end, p_nid))
+
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 int memblock_set_node(phys_addr_t base, phys_addr_t size, int nid);
 
@@ -121,8 +143,6 @@
 }
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
-phys_addr_t memblock_find_in_range_node(phys_addr_t start, phys_addr_t end,
-					phys_addr_t size, phys_addr_t align, int nid);
 phys_addr_t memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid);
 phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid);
 
diff --git a/mm/memblock.c b/mm/memblock.c
index 1adbef0..2f55f19 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -79,80 +79,68 @@
 	return (i < type->cnt) ? i : -1;
 }
 
-/*
- * Find, allocate, deallocate or reserve unreserved regions. All allocations
- * are top-down.
+/**
+ * memblock_find_in_range_node - find free area in given range and node
+ * @start: start of candidate range
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ * @nid: nid of the free area to find, %MAX_NUMNODES for any node
+ *
+ * Find @size free area aligned to @align in the specified range and node.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
  */
-
-static phys_addr_t __init_memblock memblock_find_region(phys_addr_t start, phys_addr_t end,
-					  phys_addr_t size, phys_addr_t align)
+phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
+					phys_addr_t end, phys_addr_t size,
+					phys_addr_t align, int nid)
 {
-	phys_addr_t base, res_base;
-	long j;
+	phys_addr_t this_start, this_end, cand;
+	u64 i;
 
-	/* In case, huge size is requested */
-	if (end < size)
-		return 0;
+	/* align @size to avoid excessive fragmentation on reserved array */
+	size = round_up(size, align);
 
-	base = round_down(end - size, align);
-
-	/* Prevent allocations returning 0 as it's also used to
-	 * indicate an allocation failure
-	 */
-	if (start == 0)
-		start = PAGE_SIZE;
-
-	while (start <= base) {
-		j = memblock_overlaps_region(&memblock.reserved, base, size);
-		if (j < 0)
-			return base;
-		res_base = memblock.reserved.regions[j].base;
-		if (res_base < size)
-			break;
-		base = round_down(res_base - size, align);
-	}
-
-	return 0;
-}
-
-/*
- * Find a free area with specified alignment in a specific range.
- */
-phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start, phys_addr_t end,
-					phys_addr_t size, phys_addr_t align)
-{
-	long i;
-
-	BUG_ON(0 == size);
-
-	/* Pump up max_addr */
+	/* pump up @end */
 	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
 		end = memblock.current_limit;
 
-	/* We do a top-down search, this tends to limit memory
-	 * fragmentation by keeping early boot allocs near the
-	 * top of memory
-	 */
-	for (i = memblock.memory.cnt - 1; i >= 0; i--) {
-		phys_addr_t memblockbase = memblock.memory.regions[i].base;
-		phys_addr_t memblocksize = memblock.memory.regions[i].size;
-		phys_addr_t bottom, top, found;
+	/* adjust @start to avoid underflow and allocating the first page */
+	start = max3(start, size, (phys_addr_t)PAGE_SIZE);
+	end = max(start, end);
 
-		if (memblocksize < size)
-			continue;
-		if ((memblockbase + memblocksize) <= start)
-			break;
-		bottom = max(memblockbase, start);
-		top = min(memblockbase + memblocksize, end);
-		if (bottom >= top)
-			continue;
-		found = memblock_find_region(bottom, top, size, align);
-		if (found)
-			return found;
+	for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
+		this_start = clamp(this_start, start, end);
+		this_end = clamp(this_end, start, end);
+
+		cand = round_down(this_end - size, align);
+		if (cand >= this_start)
+			return cand;
 	}
 	return 0;
 }
 
+/**
+ * memblock_find_in_range - find free area in given range
+ * @start: start of candidate range
+ * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
+ * @size: size of free area to find
+ * @align: alignment of free area to find
+ *
+ * Find @size free area aligned to @align in the specified range.
+ *
+ * RETURNS:
+ * Found address on success, %0 on failure.
+ */
+phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
+					phys_addr_t end, phys_addr_t size,
+					phys_addr_t align)
+{
+	return memblock_find_in_range_node(start, end, size, align,
+					   MAX_NUMNODES);
+}
+
 /*
  * Free memblock.reserved.regions
  */
@@ -607,6 +595,70 @@
 	*idx = ULLONG_MAX;
 }
 
+/**
+ * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
+ * @idx: pointer to u64 loop variable
+ * @nid: nid: node selector, %MAX_NUMNODES for all nodes
+ * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL
+ * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
+ * @p_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Reverse of __next_free_mem_range().
+ */
+void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
+					   phys_addr_t *out_start,
+					   phys_addr_t *out_end, int *out_nid)
+{
+	struct memblock_type *mem = &memblock.memory;
+	struct memblock_type *rsv = &memblock.reserved;
+	int mi = *idx & 0xffffffff;
+	int ri = *idx >> 32;
+
+	if (*idx == (u64)ULLONG_MAX) {
+		mi = mem->cnt - 1;
+		ri = rsv->cnt;
+	}
+
+	for ( ; mi >= 0; mi--) {
+		struct memblock_region *m = &mem->regions[mi];
+		phys_addr_t m_start = m->base;
+		phys_addr_t m_end = m->base + m->size;
+
+		/* only memory regions are associated with nodes, check it */
+		if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
+			continue;
+
+		/* scan areas before each reservation for intersection */
+		for ( ; ri >= 0; ri--) {
+			struct memblock_region *r = &rsv->regions[ri];
+			phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
+			phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
+
+			/* if ri advanced past mi, break out to advance mi */
+			if (r_end <= m_start)
+				break;
+			/* if the two regions intersect, we're done */
+			if (m_end > r_start) {
+				if (out_start)
+					*out_start = max(m_start, r_start);
+				if (out_end)
+					*out_end = min(m_end, r_end);
+				if (out_nid)
+					*out_nid = memblock_get_region_node(m);
+
+				if (m_start >= r_start)
+					mi--;
+				else
+					ri--;
+				*idx = (u32)mi | (u64)ri << 32;
+				return;
+			}
+		}
+	}
+
+	*idx = ULLONG_MAX;
+}
+
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 /*
  * Common iterator interface used to define for_each_mem_range().
@@ -670,22 +722,29 @@
 }
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
-phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
+					phys_addr_t align, phys_addr_t max_addr,
+					int nid)
 {
 	phys_addr_t found;
 
-	/* We align the size to limit fragmentation. Without this, a lot of
-	 * small allocs quickly eat up the whole reserve array on sparc
-	 */
-	size = round_up(size, align);
-
-	found = memblock_find_in_range(0, max_addr, size, align);
+	found = memblock_find_in_range_node(0, max_addr, size, align, nid);
 	if (found && !memblock_reserve(found, size))
 		return found;
 
 	return 0;
 }
 
+phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
+{
+	return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+}
+
+phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+{
+	return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
+}
+
 phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
 {
 	phys_addr_t alloc;
@@ -704,84 +763,6 @@
 	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 }
 
-
-/*
- * Additional node-local top-down allocators.
- *
- * WARNING: Only available after early_node_map[] has been populated,
- * on some architectures, that is after all the calls to add_active_range()
- * have been done to populate it.
- */
-
-static phys_addr_t __init memblock_nid_range_rev(phys_addr_t start,
-						 phys_addr_t end, int *nid)
-{
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
-	unsigned long start_pfn, end_pfn;
-	int i;
-
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, nid)
-		if (end > PFN_PHYS(start_pfn) && end <= PFN_PHYS(end_pfn))
-			return max(start, PFN_PHYS(start_pfn));
-#endif
-	*nid = 0;
-	return start;
-}
-
-phys_addr_t __init memblock_find_in_range_node(phys_addr_t start,
-					       phys_addr_t end,
-					       phys_addr_t size,
-					       phys_addr_t align, int nid)
-{
-	struct memblock_type *mem = &memblock.memory;
-	int i;
-
-	BUG_ON(0 == size);
-
-	/* Pump up max_addr */
-	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
-		end = memblock.current_limit;
-
-	for (i = mem->cnt - 1; i >= 0; i--) {
-		struct memblock_region *r = &mem->regions[i];
-		phys_addr_t base = max(start, r->base);
-		phys_addr_t top = min(end, r->base + r->size);
-
-		while (base < top) {
-			phys_addr_t tbase, ret;
-			int tnid;
-
-			tbase = memblock_nid_range_rev(base, top, &tnid);
-			if (nid == MAX_NUMNODES || tnid == nid) {
-				ret = memblock_find_region(tbase, top, size, align);
-				if (ret)
-					return ret;
-			}
-			top = tbase;
-		}
-	}
-
-	return 0;
-}
-
-phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
-{
-	phys_addr_t found;
-
-	/*
-	 * We align the size to limit fragmentation. Without this, a lot of
-	 * small allocs quickly eat up the whole reserve array on sparc
-	 */
-	size = round_up(size, align);
-
-	found = memblock_find_in_range_node(0, MEMBLOCK_ALLOC_ACCESSIBLE,
-					    size, align, nid);
-	if (found && !memblock_reserve(found, size))
-		return found;
-
-	return 0;
-}
-
 phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
 {
 	phys_addr_t res = memblock_alloc_nid(size, align, nid);