diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index d012c9e2811b..bd0276d5f66b 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -107,33 +107,16 @@ static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
 }
 
 /**
- * vmem_altmap_alloc - allocate pages from the vmem_altmap reservation
- * @altmap - reserved page pool for the allocation
- * @nr_pfns - size (in pages) of the allocation
+ * altmap_alloc_block_buf - allocate pages from the device page map
+ * @altmap:	device page map
+ * @size:	size (in bytes) of the allocation
  *
- * Allocations are aligned to the size of the request
+ * Allocations are aligned to the size of the request.
  */
-static unsigned long __meminit vmem_altmap_alloc(struct vmem_altmap *altmap,
-		unsigned long nr_pfns)
-{
-	unsigned long pfn = vmem_altmap_next_pfn(altmap);
-	unsigned long nr_align;
-
-	nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
-	nr_align = ALIGN(pfn, nr_align) - pfn;
-
-	if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
-		return ULONG_MAX;
-	altmap->alloc += nr_pfns;
-	altmap->align += nr_align;
-	return pfn + nr_align;
-}
-
 void * __meminit altmap_alloc_block_buf(unsigned long size,
 		struct vmem_altmap *altmap)
 {
-	unsigned long pfn, nr_pfns;
-	void *ptr;
+	unsigned long pfn, nr_pfns, nr_align;
 
 	if (size & ~PAGE_MASK) {
 		pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
@@ -141,16 +124,20 @@ void * __meminit altmap_alloc_block_buf(unsigned long size,
 		return NULL;
 	}
 
+	pfn = vmem_altmap_next_pfn(altmap);
 	nr_pfns = size >> PAGE_SHIFT;
-	pfn = vmem_altmap_alloc(altmap, nr_pfns);
-	if (pfn < ULONG_MAX)
-		ptr = __va(__pfn_to_phys(pfn));
-	else
-		ptr = NULL;
+	nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
+	nr_align = ALIGN(pfn, nr_align) - pfn;
+	if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
+		return NULL;
+
+	altmap->alloc += nr_pfns;
+	altmap->align += nr_align;
+	pfn += nr_align;
+
 	pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
 			__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
-
-	return ptr;
+	return __va(__pfn_to_phys(pfn));
 }
 
 void __meminit vmemmap_verify(pte_t *pte, int node,