xen/arm: introduce new helper device_tree_get_meminfo

This commit creates a new helper device_tree_get_meminfo to iterate over a
device tree property to get memory info, like "reg".

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/arch/arm/bootfdt.c

@@ -63,6 +63,52 @@ void __init device_tree_get_reg(const __be32 **cell, u32 address_cells,
     *size = dt_next_cell(size_cells, cell);
 }
 
+static int __init device_tree_get_meminfo(const void *fdt, int node,
+                                          const char *prop_name,
+                                          u32 address_cells, u32 size_cells,
+                                          void *data)
+{
+    const struct fdt_property *prop;
+    unsigned int i, banks;
+    const __be32 *cell;
+    u32 reg_cells = address_cells + size_cells;
+    paddr_t start, size;
+    struct meminfo *mem = data;
+
+    if ( address_cells < 1 || size_cells < 1 )
+    {
+        printk("fdt: property `%s': invalid #address-cells or #size-cells",
+               prop_name);
+        return -EINVAL;
+    }
+
+    prop = fdt_get_property(fdt, node, prop_name, NULL);
+    if ( !prop )
+        return -ENOENT;
+
+    cell = (const __be32 *)prop->data;
+    banks = fdt32_to_cpu(prop->len) / (reg_cells * sizeof (u32));
+
+    for ( i = 0; i < banks && mem->nr_banks < NR_MEM_BANKS; i++ )
+    {
+        device_tree_get_reg(&cell, address_cells, size_cells, &start, &size);
+        /* Some DT may describe empty bank, ignore them */
+        if ( !size )
+            continue;
+        mem->bank[mem->nr_banks].start = start;
+        mem->bank[mem->nr_banks].size = size;
+        mem->nr_banks++;
+    }
+
+    if ( i < banks )
+    {
+        printk("Warning: Max number of supported memory regions reached.\n");
+        return -ENOSPC;
+    }
+
+    return 0;
+}
+
 u32 __init device_tree_get_u32(const void *fdt, int node,
                                const char *prop_name, u32 dflt)
 {
@@ -139,42 +185,7 @@ static int __init process_memory_node(const void *fdt, int node,
                                       u32 address_cells, u32 size_cells,
                                       void *data)
 {
-    const struct fdt_property *prop;
-    int i;
-    int banks;
-    const __be32 *cell;
-    paddr_t start, size;
-    u32 reg_cells = address_cells + size_cells;
-    struct meminfo *mem = data;
-
-    if ( address_cells < 1 || size_cells < 1 )
-    {
-        printk("fdt: node `%s': invalid #address-cells or #size-cells",
-               name);
-        return -EINVAL;
-    }
-
-    prop = fdt_get_property(fdt, node, "reg", NULL);
-    if ( !prop )
-        return -ENOENT;
-
-    cell = (const __be32 *)prop->data;
-    banks = fdt32_to_cpu(prop->len) / (reg_cells * sizeof (u32));
-
-    for ( i = 0; i < banks && mem->nr_banks < NR_MEM_BANKS; i++ )
-    {
-        device_tree_get_reg(&cell, address_cells, size_cells, &start, &size);
-        /* Some DT may describe empty bank, ignore them */
-        if ( !size )
-            continue;
-        mem->bank[mem->nr_banks].start = start;
-        mem->bank[mem->nr_banks].size = size;
-        mem->nr_banks++;
-    }
-
-    if ( i < banks )
-        return -ENOSPC;
-    return 0;
+    return device_tree_get_meminfo(fdt, node, "reg", address_cells, size_cells, data);
 }
 
 static int __init process_reserved_memory_node(const void *fdt, int node,