We can reduce the memory allocated at mem-map
by flatmem.

currently, the default memory-model in arm64 is
sparse memory. The mem-map array is not freed in
this scene. If the physical address is too long,
it will reserved too much memory for the mem-map
array.

Signed-off-by: Chen Feng <redacted>
Signed-off-by: Fu Jun <redacted>
---
 arch/arm64/Kconfig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4f43622..c18930d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -559,6 +559,9 @@ config ARCH_SPARSEMEM_ENABLE
 	def_bool y
 	select SPARSEMEM_VMEMMAP_ENABLE
 
+config ARCH_FLATMEM_ENABLE
+	def_bool y
+
 config ARCH_SPARSEMEM_DEFAULT
 	def_bool ARCH_SPARSEMEM_ENABLE
 

-- 
1.9.1