mm/sparse: add common helper to mark all memblocks present

Presently the arches arm64, arm and sh have a function which loops
through each memblock and calls memory present.  riscv will require a
similar function.

Introduce a common memblocks_present() function that can be used by all
the arches.  Subsequent patches will cleanup the arches that make use of
this.

Link: http://lkml.kernel.org/r/20181107205433.3875-3-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index 33307fc05c4d..3abc8cc50201 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -240,6 +240,22 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
 }
 
 /*
+ * 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.
+ */
+void __init memblocks_present(void)
+{
+        struct memblock_region *reg;
+
+        for_each_memblock(memory, reg) {
+                memory_present(memblock_get_region_node(reg),
+                               memblock_region_memory_base_pfn(reg),
+                               memblock_region_memory_end_pfn(reg));
+        }
+}
+
+/*
  * Subtle, we encode the real pfn into the mem_map such that
  * the identity pfn - section_mem_map will return the actual
  * physical page frame number.