fdt: Properly handle "no-map" field in the memory region

stable inclusion
from stable-5.10.20
commit 0674fa99a7d8dca056edbfa8e4e4a0cd03ba3591
bugzilla: 50608

--------------------------------

[ Upstream commit 86588296 ]

Mark the memory region with NOMAP flag instead of completely removing it
from the memory blocks. That makes the FDT handling consistent with the EFI
memory map handling.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: NQuentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210115114544.1830068-2-qperret@google.comSigned-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/of/fdt.c

@@ -1150,7 +1150,7 @@ int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 					phys_addr_t size, bool nomap)
 {
 	if (nomap)
-		return memblock_remove(base, size);
+		return memblock_mark_nomap(base, size);
 	return memblock_reserve(base, size);
 }