[PATCH 2/4] linux/array_size.h: Add ARRAY_SIZE_OF_FIELD()

[Lucas Segarra Fernandez]

Introduce ARRAY_SIZE_OF_FIELD() in order to get the number of elements
of an array struct field.

Signed-off-by: Lucas Segarra Fernandez <lucas.segarra.fernandez@xxxxxxxxx>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
 include/linux/array_size.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/array_size.h b/include/linux/array_size.h
index 06d7d83196ca..37dac0473b5c 100644
--- a/include/linux/array_size.h
+++ b/include/linux/array_size.h
@@ -10,4 +10,12 @@
  */
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 
+/*
+ * ARRAY_SIZE_OF_FIELD - get the number of elements of an array struct field
+ *
+ * @TYPE: The structure containing the field of interest
+ * @MEMBER: The array field to be sized
+ */
+#define ARRAY_SIZE_OF_FIELD(TYPE, MEMBER) ARRAY_SIZE((((TYPE *)0)->MEMBER))
+
 #endif  /* _LINUX_ARRAY_SIZE_H */
-- 
2.41.0