[dpdk-dev] [PATCH] event/dsw: use custom element size ring for control

["Mattias Rönnblom" <mattias.ronnblom@ericsson.com>]

Replace DSW's use of regular DPDK rings (and code for
packing/unpacking control messages into void pointers) with custom
size rings.

In addition to cleaner code, this change allows DSW to support up to
the eventdev API's maximum of 255 ports by tweaking DSW_MAX_PORTS.

Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
---
 drivers/event/dsw/Makefile    |  3 +++
 drivers/event/dsw/dsw_evdev.c |  9 ++++++---
 drivers/event/dsw/dsw_evdev.h | 10 +++-------
 drivers/event/dsw/dsw_event.c | 16 ++--------------
 drivers/event/dsw/meson.build |  3 +++
 5 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/drivers/event/dsw/Makefile b/drivers/event/dsw/Makefile
index f6e7dda1f..68d681fab 100644
--- a/drivers/event/dsw/Makefile
+++ b/drivers/event/dsw/Makefile
@@ -11,6 +11,9 @@ ifneq ($(CONFIG_RTE_TOOLCHAIN_ICC),y)
 CFLAGS += -Wno-format-nonliteral
 endif
 
+# Depends on rte_ring_elem_*()
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
 LDLIBS += -lrte_eal
 LDLIBS += -lrte_mbuf
 LDLIBS += -lrte_mempool
diff --git a/drivers/event/dsw/dsw_evdev.c b/drivers/event/dsw/dsw_evdev.c
index 9387d4149..7798a38ad 100644
--- a/drivers/event/dsw/dsw_evdev.c
+++ b/drivers/event/dsw/dsw_evdev.c
@@ -8,6 +8,7 @@
 #include <rte_eventdev_pmd.h>
 #include <rte_eventdev_pmd_vdev.h>
 #include <rte_random.h>
+#include <rte_ring_elem.h>
 
 #include "dsw_evdev.h"
 
@@ -46,9 +47,11 @@ dsw_port_setup(struct rte_eventdev *dev, uint8_t port_id,
 	snprintf(ring_name, sizeof(ring_name), "dswctl%d_p%u",
 		 dev->data->dev_id, port_id);
 
-	ctl_in_ring = rte_ring_create(ring_name, DSW_CTL_IN_RING_SIZE,
-				      dev->data->socket_id,
-				      RING_F_SC_DEQ|RING_F_EXACT_SZ);
+	ctl_in_ring = rte_ring_create_elem(ring_name,
+					   sizeof(struct dsw_ctl_msg),
+					   DSW_CTL_IN_RING_SIZE,
+					   dev->data->socket_id,
+					   RING_F_SC_DEQ|RING_F_EXACT_SZ);
 
 	if (ctl_in_ring == NULL) {
 		rte_event_ring_free(in_ring);
diff --git a/drivers/event/dsw/dsw_evdev.h b/drivers/event/dsw/dsw_evdev.h
index dc28ab125..5c7b6108d 100644
--- a/drivers/event/dsw/dsw_evdev.h
+++ b/drivers/event/dsw/dsw_evdev.h
@@ -10,7 +10,6 @@
 
 #define DSW_PMD_NAME RTE_STR(event_dsw)
 
-/* Code changes are required to allow more ports. */
 #define DSW_MAX_PORTS (64)
 #define DSW_MAX_PORT_DEQUEUE_DEPTH (128)
 #define DSW_MAX_PORT_ENQUEUE_DEPTH (128)
@@ -226,15 +225,12 @@ struct dsw_evdev {
 #define DSW_CTL_UNPAUS_REQ (1)
 #define DSW_CTL_CFM (2)
 
-/* sizeof(struct dsw_ctl_msg) must be equal or less than
- * sizeof(void *), to fit on the control ring.
- */
 struct dsw_ctl_msg {
-	uint8_t type:2;
-	uint8_t originating_port_id:6;
+	uint8_t type;
+	uint8_t originating_port_id;
 	uint8_t queue_id;
 	uint16_t flow_hash;
-} __rte_packed;
+} __rte_aligned(4);
 
 uint16_t dsw_event_enqueue(void *port, const struct rte_event *event);
 uint16_t dsw_event_enqueue_burst(void *port,
diff --git a/drivers/event/dsw/dsw_event.c b/drivers/event/dsw/dsw_event.c
index eae53b240..d68b71b98 100644
--- a/drivers/event/dsw/dsw_event.c
+++ b/drivers/event/dsw/dsw_event.c
@@ -176,27 +176,15 @@ dsw_port_consider_load_update(struct dsw_port *port, uint64_t now)
 static void
 dsw_port_ctl_enqueue(struct dsw_port *port, struct dsw_ctl_msg *msg)
 {
-	void *raw_msg;
-
-	memcpy(&raw_msg, msg, sizeof(*msg));
-
 	/* there's always room on the ring */
-	while (rte_ring_enqueue(port->ctl_in_ring, raw_msg) != 0)
+	while (rte_ring_enqueue_elem(port->ctl_in_ring, msg, sizeof(*msg)) != 0)
 		rte_pause();
 }
 
 static int
 dsw_port_ctl_dequeue(struct dsw_port *port, struct dsw_ctl_msg *msg)
 {
-	void *raw_msg;
-	int rc;
-
-	rc = rte_ring_dequeue(port->ctl_in_ring, &raw_msg);
-
-	if (rc == 0)
-		memcpy(msg, &raw_msg, sizeof(*msg));
-
-	return rc;
+	return rte_ring_dequeue_elem(port->ctl_in_ring, msg, sizeof(*msg));
 }
 
 static void
diff --git a/drivers/event/dsw/meson.build b/drivers/event/dsw/meson.build
index 60ab13d90..3b39cb653 100644
--- a/drivers/event/dsw/meson.build
+++ b/drivers/event/dsw/meson.build
@@ -6,3 +6,6 @@ if cc.has_argument('-Wno-format-nonliteral')
 	cflags += '-Wno-format-nonliteral'
 endif
 sources = files('dsw_evdev.c', 'dsw_event.c', 'dsw_xstats.c')
+
+# Depends on rte_ring_elem_*()
+allow_experimental_apis = true
-- 
2.17.1