tailq: use a single cast macro

No need to cast everywhere, define a common macro for this, plus it can be used
in future commits.

Signed-off-by: David Marchand <david.marchand@6wind.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>

diff --git a/lib/librte_eal/common/include/rte_tailq.h b/lib/librte_eal/common/include/rte_tailq.h
index b34e5ed..6ac4b9b 100644 (file)
--- a/lib/librte_eal/common/include/rte_tailq.h
+++ b/lib/librte_eal/common/include/rte_tailq.h
@@ -69,6 +69,12 @@ struct rte_tailq_head {
        struct rte_tailq_entry_head tailq_head; /**< NOTE: must be first element */
 };
 
+/**
+ * Return the first tailq entry casted to the right struct.
+ */
+#define RTE_TAILQ_CAST(tailq_entry, struct_name) \
+       (struct struct_name *)&(tailq_entry)->tailq_head
+
 /**
  * Utility macro to make reserving a tailqueue for a particular struct easier.
  *
@@ -86,7 +92,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_RESERVE(name, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_reserve(name)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_reserve(name), struct_name)
 
 /**
  * Utility macro to make reserving a tailqueue for a particular struct easier.
@@ -106,7 +112,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_RESERVE_BY_IDX(idx, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_reserve_by_idx(idx)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_reserve_by_idx(idx), struct_name)
 
 /**
  * Utility macro to make looking up a tailqueue for a particular struct easier.
@@ -125,7 +131,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_LOOKUP(name, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_lookup(name)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_lookup(name), struct_name)
 
 /**
  * Utility macro to make looking up a tailqueue for a particular struct easier.
@@ -144,7 +150,7 @@ struct rte_tailq_head {
  *   element in the rte_tailq_head structure.
  */
 #define RTE_TAILQ_LOOKUP_BY_IDX(idx, struct_name) \
-       (struct struct_name *)(&rte_eal_tailq_lookup_by_idx(idx)->tailq_head)
+       RTE_TAILQ_CAST(rte_eal_tailq_lookup_by_idx(idx), struct_name)
 
 /**
  * Reserve a slot in the tailq list for a particular tailq header