diff --git a/mm/sparse.c b/mm/sparse.c
index 191e29c..33406ea 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -16,8 +16,6 @@
 
 #include "internal.h"
 #include <asm/dma.h>
-#include <asm/pgalloc.h>
-#include <asm/pgtable.h>
 
 /*
  * Permanent SPARSEMEM data:
@@ -198,16 +196,6 @@
 	ms->section_mem_map |= SECTION_MARKED_PRESENT;
 }
 
-static inline unsigned long next_present_section_nr(unsigned long section_nr)
-{
-	do {
-		section_nr++;
-		if (present_section_nr(section_nr))
-			return section_nr;
-	} while ((section_nr <= __highest_present_section_nr));
-
-	return -1;
-}
 #define for_each_present_section_nr(start, section_nr)		\
 	for (section_nr = next_present_section_nr(start-1);	\
 	     ((section_nr != -1) &&				\
@@ -219,6 +207,7 @@
 	return next_present_section_nr(-1);
 }
 
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
 static void subsection_mask_set(unsigned long *map, unsigned long pfn,
 		unsigned long nr_pages)
 {
@@ -253,9 +242,14 @@
 		nr_pages -= pfns;
 	}
 }
+#else
+void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
+{
+}
+#endif
 
 /* Record a memory area against a node. */
-void __init memory_present(int nid, unsigned long start, unsigned long end)
+static void __init memory_present(int nid, unsigned long start, unsigned long end)
 {
 	unsigned long pfn;
 
@@ -291,19 +285,17 @@
 }
 
 /*
- * Mark all memblocks as present using memory_present(). This is a
- * convienence function that is useful for a number of arches
- * to mark all of the systems memory as present during initialization.
+ * Mark all memblocks as present using memory_present().
+ * This is a convenience function that is useful to mark all of the systems
+ * memory as present during initialization.
  */
-void __init memblocks_present(void)
+static void __init memblocks_present(void)
 {
-	struct memblock_region *reg;
+	unsigned long start, end;
+	int i, nid;
 
-	for_each_memblock(memory, reg) {
-		memory_present(memblock_get_region_node(reg),
-			       memblock_region_memory_base_pfn(reg),
-			       memblock_region_memory_end_pfn(reg));
-	}
+	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
+		memory_present(nid, start, end);
 }
 
 /*
@@ -320,6 +312,7 @@
 	return coded_mem_map;
 }
 
+#ifdef CONFIG_MEMORY_HOTPLUG
 /*
  * Decode mem_map from the coded memmap
  */
@@ -329,6 +322,7 @@
 	coded_mem_map &= SECTION_MAP_MASK;
 	return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
 }
+#endif /* CONFIG_MEMORY_HOTPLUG */
 
 static void __meminit sparse_init_one_section(struct mem_section *ms,
 		unsigned long pnum, struct page *mem_map,
@@ -458,8 +452,7 @@
 	if (map)
 		return map;
 
-	map = memblock_alloc_try_nid(size,
-					  PAGE_SIZE, addr,
+	map = memblock_alloc_try_nid_raw(size, size, addr,
 					  MEMBLOCK_ALLOC_ACCESSIBLE, nid);
 	if (!map)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
@@ -482,10 +475,13 @@
 {
 	phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
 	WARN_ON(sparsemap_buf);	/* forgot to call sparse_buffer_fini()? */
-	sparsemap_buf =
-		memblock_alloc_try_nid_raw(size, PAGE_SIZE,
-						addr,
-						MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+	/*
+	 * Pre-allocated buffer is mainly used by __populate_section_memmap
+	 * and we want it to be properly aligned to the section size - this is
+	 * especially the case for VMEMMAP which maps memmap to PMDs
+	 */
+	sparsemap_buf = memblock_alloc_exact_nid_raw(size, section_map_size(),
+					addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
 	sparsemap_buf_end = sparsemap_buf + size;
 }
 
@@ -579,9 +575,13 @@
  */
 void __init sparse_init(void)
 {
-	unsigned long pnum_begin = first_present_section_nr();
-	int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
-	unsigned long pnum_end, map_count = 1;
+	unsigned long pnum_end, pnum_begin, map_count = 1;
+	int nid_begin;
+
+	memblocks_present();
+
+	pnum_begin = first_present_section_nr();
+	nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
 
 	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 	set_pageblock_order();
@@ -669,39 +669,67 @@
 
 	vmemmap_free(start, end, NULL);
 }
+
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+	DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
+	DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
+	struct mem_section *ms = __pfn_to_section(pfn);
+	unsigned long *subsection_map = ms->usage
+		? &ms->usage->subsection_map[0] : NULL;
+
+	subsection_mask_set(map, pfn, nr_pages);
+	if (subsection_map)
+		bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
+
+	if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
+				"section already deactivated (%#lx + %ld)\n",
+				pfn, nr_pages))
+		return -EINVAL;
+
+	bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
+	return 0;
+}
+
+static bool is_subsection_map_empty(struct mem_section *ms)
+{
+	return bitmap_empty(&ms->usage->subsection_map[0],
+			    SUBSECTIONS_PER_SECTION);
+}
+
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+	struct mem_section *ms = __pfn_to_section(pfn);
+	DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
+	unsigned long *subsection_map;
+	int rc = 0;
+
+	subsection_mask_set(map, pfn, nr_pages);
+
+	subsection_map = &ms->usage->subsection_map[0];
+
+	if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
+		rc = -EINVAL;
+	else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
+		rc = -EEXIST;
+	else
+		bitmap_or(subsection_map, map, subsection_map,
+				SUBSECTIONS_PER_SECTION);
+
+	return rc;
+}
 #else
 struct page * __meminit populate_section_memmap(unsigned long pfn,
 		unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
 {
-	struct page *page, *ret;
-	unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
-
-	page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
-	if (page)
-		goto got_map_page;
-
-	ret = vmalloc(memmap_size);
-	if (ret)
-		goto got_map_ptr;
-
-	return NULL;
-got_map_page:
-	ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
-got_map_ptr:
-
-	return ret;
+	return kvmalloc_node(array_size(sizeof(struct page),
+					PAGES_PER_SECTION), GFP_KERNEL, nid);
 }
 
 static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
 		struct vmem_altmap *altmap)
 {
-	struct page *memmap = pfn_to_page(pfn);
-
-	if (is_vmalloc_addr(memmap))
-		vfree(memmap);
-	else
-		free_pages((unsigned long)memmap,
-			   get_order(sizeof(struct page) * PAGES_PER_SECTION));
+	kvfree(pfn_to_page(pfn));
 }
 
 static void free_map_bootmem(struct page *memmap)
@@ -733,48 +761,51 @@
 			put_page_bootmem(page);
 	}
 }
+
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+	return 0;
+}
+
+static bool is_subsection_map_empty(struct mem_section *ms)
+{
+	return true;
+}
+
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
+{
+	return 0;
+}
 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 
+/*
+ * To deactivate a memory region, there are 3 cases to handle across
+ * two configurations (SPARSEMEM_VMEMMAP={y,n}):
+ *
+ * 1. deactivation of a partial hot-added section (only possible in
+ *    the SPARSEMEM_VMEMMAP=y case).
+ *      a) section was present at memory init.
+ *      b) section was hot-added post memory init.
+ * 2. deactivation of a complete hot-added section.
+ * 3. deactivation of a complete section from memory init.
+ *
+ * For 1, when subsection_map does not empty we will not be freeing the
+ * usage map, but still need to free the vmemmap range.
+ *
+ * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
+ */
 static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
 		struct vmem_altmap *altmap)
 {
-	DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
-	DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
 	struct mem_section *ms = __pfn_to_section(pfn);
 	bool section_is_early = early_section(ms);
 	struct page *memmap = NULL;
 	bool empty;
-	unsigned long *subsection_map = ms->usage
-		? &ms->usage->subsection_map[0] : NULL;
 
-	subsection_mask_set(map, pfn, nr_pages);
-	if (subsection_map)
-		bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
-
-	if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
-				"section already deactivated (%#lx + %ld)\n",
-				pfn, nr_pages))
+	if (clear_subsection_map(pfn, nr_pages))
 		return;
 
-	/*
-	 * There are 3 cases to handle across two configurations
-	 * (SPARSEMEM_VMEMMAP={y,n}):
-	 *
-	 * 1/ deactivation of a partial hot-added section (only possible
-	 * in the SPARSEMEM_VMEMMAP=y case).
-	 *    a/ section was present at memory init
-	 *    b/ section was hot-added post memory init
-	 * 2/ deactivation of a complete hot-added section
-	 * 3/ deactivation of a complete section from memory init
-	 *
-	 * For 1/, when subsection_map does not empty we will not be
-	 * freeing the usage map, but still need to free the vmemmap
-	 * range.
-	 *
-	 * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
-	 */
-	bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
-	empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION);
+	empty = is_subsection_map_empty(ms);
 	if (empty) {
 		unsigned long section_nr = pfn_to_section_nr(pfn);
 
@@ -798,10 +829,14 @@
 		ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
 	}
 
-	if (section_is_early && memmap)
-		free_map_bootmem(memmap);
-	else
+	/*
+	 * The memmap of early sections is always fully populated. See
+	 * section_activate() and pfn_valid() .
+	 */
+	if (!section_is_early)
 		depopulate_section_memmap(pfn, nr_pages, altmap);
+	else if (memmap)
+		free_map_bootmem(memmap);
 
 	if (empty)
 		ms->section_mem_map = (unsigned long)NULL;
@@ -810,31 +845,19 @@
 static struct page * __meminit section_activate(int nid, unsigned long pfn,
 		unsigned long nr_pages, struct vmem_altmap *altmap)
 {
-	DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
 	struct mem_section *ms = __pfn_to_section(pfn);
 	struct mem_section_usage *usage = NULL;
-	unsigned long *subsection_map;
 	struct page *memmap;
 	int rc = 0;
 
-	subsection_mask_set(map, pfn, nr_pages);
-
 	if (!ms->usage) {
 		usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
 		if (!usage)
 			return ERR_PTR(-ENOMEM);
 		ms->usage = usage;
 	}
-	subsection_map = &ms->usage->subsection_map[0];
 
-	if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
-		rc = -EINVAL;
-	else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
-		rc = -EEXIST;
-	else
-		bitmap_or(subsection_map, map, subsection_map,
-				SUBSECTIONS_PER_SECTION);
-
+	rc = fill_subsection_map(pfn, nr_pages);
 	if (rc) {
 		if (usage)
 			ms->usage = NULL;
@@ -870,6 +893,10 @@
  *
  * This is only intended for hotplug.
  *
+ * Note that only VMEMMAP supports sub-section aligned hotplug,
+ * the proper alignment and size are gated by check_pfn_span().
+ *
+ *
  * Return:
  * * 0		- On success.
  * * -EEXIST	- Section has been present.
@@ -903,7 +930,7 @@
 
 	/* Align memmap to section boundary in the subsection case */
 	if (section_nr_to_pfn(section_nr) != start_pfn)
-		memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr));
+		memmap = pfn_to_page(section_nr_to_pfn(section_nr));
 	sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
 
 	return 0;