[PATCH v2 1/3] of: reserved_mem: avoid unnecessary memory allocation when __reserved_mem_check_root() fails

[Wandun Chen <chenwandun1@gmail.com>]

total_reserved_mem_cnt will keep the init value (MAX_RESERVED_REGIONS)
in fdt_scan_reserved_mem() if __reserved_mem_check_root() fails.

fdt_scan_reserved_mem_late() calls alloc_reserved_mem_array() to
allocate memory according to total_reserved_mem_cnt before
__reserved_mem_check_root(), so if __reserved_mem_check_root() fails,
the allocated array has nowhere to be used, so no need to allocate
memory.

Move alloc_reserved_mem_array() after __reserved_mem_check_root() to
avoid potential memory waste.

Signed-off-by: Wandun Chen <chenwandun@lixiang.com>
Tested-by: Meijing Zhao <zhaomeijing@lixiang.com>
---
 drivers/of/of_reserved_mem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 8d5777cb5d1b..7856dc857d65 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -265,14 +265,14 @@ void __init fdt_scan_reserved_mem_late(void)
 		return;
 	}
 
-	/* Attempt dynamic allocation of a new reserved_mem array */
-	alloc_reserved_mem_array();
-
 	if (__reserved_mem_check_root(node)) {
 		pr_err("Reserved memory: unsupported node format, ignoring\n");
 		return;
 	}
 
+	/* Attempt dynamic allocation of a new reserved_mem array */
+	alloc_reserved_mem_array();
+
 	fdt_for_each_subnode(child, fdt, node) {
 		const char *uname;
 		u64 b, s;
-- 
2.43.0