2 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index dd97fb8408a8..b10ec49ee2dd 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
                               unsigned long addr,
                               unsigned long size);
 extern void free_bootmem(unsigned long addr, unsigned long size);
+extern void free_bootmem_late(unsigned long addr, unsigned long size);
 
 /*
  * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 555d5d2731c6..d1dc23cc7f10 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -143,6 +143,30 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
         return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
 }
 
+/*
+ * free_bootmem_late - free bootmem pages directly to page allocator
+ * @addr: starting address of the range
+ * @size: size of the range in bytes
+ *
+ * This is only useful when the bootmem allocator has already been torn
+ * down, but we are still initializing the system.  Pages are given directly
+ * to the page allocator, no bootmem metadata is updated because it is gone.
+ */
+void __init free_bootmem_late(unsigned long addr, unsigned long size)
+{
+        unsigned long cursor, end;
+
+        kmemleak_free_part(__va(addr), size);
+
+        cursor = PFN_UP(addr);
+        end = PFN_DOWN(addr + size);
+
+        for (; cursor < end; cursor++) {
+                __free_pages_bootmem(pfn_to_page(cursor), 0);
+                totalram_pages++;
+        }
+}
+
 static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
 {
         int aligned;