of/reserved_mem: Simplify the logic of __reserved_mem_reserve_reg()

Use the existing helper functions to simplify the logic of
__reserved_mem_reserve_reg()

Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Link: https://patch.msgid.link/20251115134753.179931-7-yuntao.wang@linux.dev
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: ytcoode

drivers/of/of_reserved_mem.c

@@ -154,27 +154,24 @@ static int __init early_init_dt_reserve_memory(phys_addr_t base,
 static int __init __reserved_mem_reserve_reg(unsigned long node,
 					     const char *uname)
 {
-	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 	phys_addr_t base, size;
-	int len;
+	int i, len;
 	const __be32 *prop;
 	bool nomap;
 
-	prop = of_get_flat_dt_prop(node, "reg", &len);
+	prop = of_flat_dt_get_addr_size_prop(node, "reg", &len);
 	if (!prop)
 		return -ENOENT;
 
-	if (len && len % t_len != 0) {
-		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
-		       uname);
-		return -EINVAL;
-	}
-
 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 
-	while (len >= t_len) {
-		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
-		size = dt_mem_next_cell(dt_root_size_cells, &prop);
+	for (i = 0; i < len; i++) {
+		u64 b, s;
+
+		of_flat_dt_read_addr_size(prop, i, &b, &s);
+
+		base = b;
+		size = s;
 
 		if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) {
 			/* Architecture specific contiguous memory fixup. */
@@ -187,8 +184,6 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 			pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
 			       uname, &base, (unsigned long)(size / SZ_1M));
 		}
-
-		len -= t_len;
 	}
 	return 0;
 }