3 files changed, 54 insertions, 35 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2fb32d1561eb..4ace5d50a892 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2671,6 +2671,10 @@ void sparse_mem_maps_populate_node(struct page **map_map,
                                    unsigned long map_count,
                                    int nodeid);
 
+unsigned long __init section_map_size(void);
+void sparse_buffer_init(unsigned long size, int nid);
+void sparse_buffer_fini(void);
+void *sparse_buffer_alloc(unsigned long size);
 struct page *sparse_mem_map_populate(unsigned long pnum, int nid,
                 struct vmem_altmap *altmap);
 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 95e2c7638a5c..b05c7663c640 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -43,12 +43,9 @@ static void * __ref __earlyonly_bootmem_alloc(int node,
                                 unsigned long goal)
 {
         return memblock_virt_alloc_try_nid_raw(size, align, goal,
-                                            BOOTMEM_ALLOC_ACCESSIBLE, node);
+                                               BOOTMEM_ALLOC_ACCESSIBLE, node);
 }
 
-static void *vmemmap_buf;
-static void *vmemmap_buf_end;
-
 void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 {
         /* If the main allocator is up use that, fallback to bootmem. */
@@ -76,18 +73,10 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 /* need to make sure size is all the same during early stage */
 void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
 {
-        void *ptr;
-
-        if (!vmemmap_buf)
-                return vmemmap_alloc_block(size, node);
-
-        /* take the from buf */
-        ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
-        if (ptr + size > vmemmap_buf_end)
-                return vmemmap_alloc_block(size, node);
-
-        vmemmap_buf = ptr + size;
+        void *ptr = sparse_buffer_alloc(size);
 
+        if (!ptr)
+                ptr = vmemmap_alloc_block(size, node);
         return ptr;
 }
 
@@ -279,19 +268,9 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
                                           unsigned long map_count, int nodeid)
 {
         unsigned long pnum;
-        unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
-        void *vmemmap_buf_start;
         int nr_consumed_maps = 0;
 
-        size = ALIGN(size, PMD_SIZE);
-        vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
-                         PMD_SIZE, __pa(MAX_DMA_ADDRESS));
-
-        if (vmemmap_buf_start) {
-                vmemmap_buf = vmemmap_buf_start;
-                vmemmap_buf_end = vmemmap_buf_start + size * map_count;
-        }
-
+        sparse_buffer_init(section_map_size() * map_count, nodeid);
         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
                 if (!present_section_nr(pnum))
                         continue;
@@ -303,12 +282,5 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
                 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
                        __func__);
         }
-
-        if (vmemmap_buf_start) {
-                /* need to free left buf */
-                memblock_free_early(__pa(vmemmap_buf),
-                                    vmemmap_buf_end - vmemmap_buf);
-                vmemmap_buf = NULL;
-                vmemmap_buf_end = NULL;
-        }
+        sparse_buffer_fini();
 }
diff --git a/mm/sparse.c b/mm/sparse.c
index 2ea8b3dbd0df..9a0a5f598469 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -400,7 +400,14 @@ static void __init sparse_early_usemaps_alloc_node(void *data,
         }
 }
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+unsigned long __init section_map_size(void)
+
+{
+        return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
+}
+
+#else
 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
                 struct vmem_altmap *altmap)
 {
@@ -457,6 +464,42 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 }
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
+static void *sparsemap_buf __meminitdata;
+static void *sparsemap_buf_end __meminitdata;
+
+void __init sparse_buffer_init(unsigned long size, int nid)
+{
+        WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
+        sparsemap_buf =
+                memblock_virt_alloc_try_nid_raw(size, PAGE_SIZE,
+                                                __pa(MAX_DMA_ADDRESS),
+                                                BOOTMEM_ALLOC_ACCESSIBLE, nid);
+        sparsemap_buf_end = sparsemap_buf + size;
+}
+
+void __init sparse_buffer_fini(void)
+{
+        unsigned long size = sparsemap_buf_end - sparsemap_buf;
+
+        if (sparsemap_buf && size > 0)
+                memblock_free_early(__pa(sparsemap_buf), size);
+        sparsemap_buf = NULL;
+}
+
+void * __meminit sparse_buffer_alloc(unsigned long size)
+{
+        void *ptr = NULL;
+
+        if (sparsemap_buf) {
+                ptr = PTR_ALIGN(sparsemap_buf, size);
+                if (ptr + size > sparsemap_buf_end)
+                        ptr = NULL;
+                else
+                        sparsemap_buf = ptr + size;
+        }
+        return ptr;
+}
+
 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 static void __init sparse_early_mem_maps_alloc_node(void *data,
                                  unsigned long pnum_begin,