[PATCH v4 38/39] graph: use C11 alignas

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

* Move __rte_aligned from the end of {struct,union} definitions to
  be between {struct,union} and tag.

  The placement between {struct,union} and the tag allows the desired
  alignment to be imparted on the type regardless of the toolchain being
  used for all of GCC, LLVM, MSVC compilers building both C and C++.

* Replace use of __rte_aligned(a) on variables/fields with alignas(a).

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
---
 lib/graph/graph_private.h           |  4 ++--
 lib/graph/graph_stats.c             |  4 ++--
 lib/graph/rte_graph.h               |  4 ++--
 lib/graph/rte_graph_worker_common.h | 17 ++++++++++-------
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/lib/graph/graph_private.h b/lib/graph/graph_private.h
index fb88d4b..7e4d9f8 100644
--- a/lib/graph/graph_private.h
+++ b/lib/graph/graph_private.h
@@ -71,11 +71,11 @@ struct node {
  * Structure that holds the graph scheduling workqueue node stream.
  * Used for mcore dispatch model.
  */
-struct graph_mcore_dispatch_wq_node {
+struct __rte_cache_aligned graph_mcore_dispatch_wq_node {
 	rte_graph_off_t node_off;
 	uint16_t nb_objs;
 	void *objs[RTE_GRAPH_BURST_SIZE];
-} __rte_cache_aligned;
+};
 
 /**
  * @internal
diff --git a/lib/graph/graph_stats.c b/lib/graph/graph_stats.c
index cc32245..2fb808b 100644
--- a/lib/graph/graph_stats.c
+++ b/lib/graph/graph_stats.c
@@ -28,7 +28,7 @@ struct cluster_node {
 	struct rte_node *nodes[];
 };
 
-struct rte_graph_cluster_stats {
+struct __rte_cache_aligned rte_graph_cluster_stats {
 	/* Header */
 	rte_graph_cluster_stats_cb_t fn;
 	uint32_t cluster_node_size; /* Size of struct cluster_node */
@@ -38,7 +38,7 @@ struct rte_graph_cluster_stats {
 	size_t sz;
 
 	struct cluster_node clusters[];
-} __rte_cache_aligned;
+};
 
 #define boarder_model_dispatch()                                                              \
 	fprintf(f, "+-------------------------------+---------------+--------" \
diff --git a/lib/graph/rte_graph.h b/lib/graph/rte_graph.h
index 2d37d5e..ecfec20 100644
--- a/lib/graph/rte_graph.h
+++ b/lib/graph/rte_graph.h
@@ -200,7 +200,7 @@ struct rte_graph_cluster_stats_param {
  *
  * @see struct rte_graph_cluster_stats_param::fn
  */
-struct rte_graph_cluster_node_stats {
+struct __rte_cache_aligned rte_graph_cluster_node_stats {
 	uint64_t ts;	    /**< Current timestamp. */
 	uint64_t calls;	    /**< Current number of calls made. */
 	uint64_t objs;      /**< Current number of objs processed. */
@@ -225,7 +225,7 @@ struct rte_graph_cluster_node_stats {
 	rte_node_t id;	/**< Node identifier of stats. */
 	uint64_t hz;	/**< Cycles per seconds. */
 	char name[RTE_NODE_NAMESIZE];	/**< Name of the node. */
-} __rte_cache_aligned;
+};
 
 /**
  * Create Graph.
diff --git a/lib/graph/rte_graph_worker_common.h b/lib/graph/rte_graph_worker_common.h
index 4045a7a..36d864e 100644
--- a/lib/graph/rte_graph_worker_common.h
+++ b/lib/graph/rte_graph_worker_common.h
@@ -12,6 +12,8 @@
  * process, enqueue and move streams of objects to the next nodes.
  */
 
+#include <stdalign.h>
+
 #include <rte_common.h>
 #include <rte_cycles.h>
 #include <rte_prefetch.h>
@@ -43,7 +45,7 @@
  *
  * Data structure to hold graph data.
  */
-struct rte_graph {
+struct __rte_cache_aligned rte_graph {
 	/* Fast path area. */
 	uint32_t tail;		     /**< Tail of circular buffer. */
 	uint32_t head;		     /**< Head of circular buffer. */
@@ -57,7 +59,8 @@ struct rte_graph {
 	union {
 		/* Fast schedule area for mcore dispatch model */
 		struct {
-			struct rte_graph_rq_head *rq __rte_cache_aligned; /* The run-queue */
+			alignas(RTE_CACHE_LINE_SIZE) struct rte_graph_rq_head *rq;
+				/* The run-queue */
 			struct rte_graph_rq_head rq_head; /* The head for run-queue list */
 
 			unsigned int lcore_id;  /**< The graph running Lcore. */
@@ -77,14 +80,14 @@ struct rte_graph {
 	uint64_t nb_pkt_to_capture;
 	char pcap_filename[RTE_GRAPH_PCAP_FILE_SZ];  /**< Pcap filename. */
 	uint64_t fence;			/**< Fence. */
-} __rte_cache_aligned;
+};
 
 /**
  * @internal
  *
  * Data structure to hold node data.
  */
-struct rte_node {
+struct __rte_cache_aligned rte_node {
 	/* Slow path area  */
 	uint64_t fence;		/**< Fence. */
 	rte_graph_off_t next;	/**< Index to next node. */
@@ -109,7 +112,7 @@ struct rte_node {
 	};
 	/* Fast path area  */
 #define RTE_NODE_CTX_SZ 16
-	uint8_t ctx[RTE_NODE_CTX_SZ] __rte_cache_aligned; /**< Node Context. */
+	alignas(RTE_CACHE_LINE_SIZE) uint8_t ctx[RTE_NODE_CTX_SZ]; /**< Node Context. */
 	uint16_t size;		/**< Total number of objects available. */
 	uint16_t idx;		/**< Number of objects used. */
 	rte_graph_off_t off;	/**< Offset of node in the graph reel. */
@@ -124,8 +127,8 @@ struct rte_node {
 			rte_node_process_t process; /**< Process function. */
 			uint64_t process_u64;
 		};
-	struct rte_node *nodes[] __rte_cache_min_aligned; /**< Next nodes. */
-} __rte_cache_aligned;
+	alignas(RTE_CACHE_LINE_MIN_SIZE) struct rte_node *nodes[]; /**< Next nodes. */
+};
 
 /**
  * @internal
-- 
1.8.3.1