[09/12] virtchnl: Add a macro to check the size of a union

Message ID 20180112193251.11739-9-jeffrey.t.kirsher@intel.com
State Superseded
Delegated to: Jeff Kirsher
Headers show
Series
  • [01/12] i40evf: Fix link up issue when queues are disabled
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Commit Message

Jeff Kirsher Jan. 12, 2018, 7:32 p.m.
From: Harshitha Ramamurthy <harshitha.ramamurthy@intel.com>

This patch adds a macro to check if the size of a union is correct.
It throws a divide by zero error if the union is not of the correct
size.

Signed-off-by: Harshitha Ramamurthy <harshitha.ramamurthy@intel.com>
---
 include/linux/avf/virtchnl.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Patch

diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
index b6aaecd82c70..3bbe6e080e76 100644
--- a/include/linux/avf/virtchnl.h
+++ b/include/linux/avf/virtchnl.h
@@ -140,13 +140,15 @@  enum virtchnl_ops {
 	VIRTCHNL_OP_DISABLE_CHANNELS = 31,
 };
 
-/* This macro is used to generate a compilation error if a structure
+/* These macros are used to generate compilation errors if a structure/union
  * is not exactly the correct length. It gives a divide by zero error if the
- * structure is not of the correct size, otherwise it creates an enum that is
- * never used.
+ * structure/union is not of the correct size, otherwise it creates an enum
+ * that is never used.
  */
 #define VIRTCHNL_CHECK_STRUCT_LEN(n, X) enum virtchnl_static_assert_enum_##X \
 	{ virtchnl_static_assert_##X = (n)/((sizeof(struct X) == (n)) ? 1 : 0) }
+#define VIRTCHNL_CHECK_UNION_LEN(n, X) enum virtchnl_static_asset_enum_##X \
+	{ virtchnl_static_assert_##X = (n)/((sizeof(union X) == (n)) ? 1 : 0) }
 
 /* Virtual channel message descriptor. This overlays the admin queue
  * descriptor. All other data is passed in external buffers.