[v4,05/10] event/dsw: add DSW event scheduling and device start/stop
diff mbox series

Message ID 20180918124514.10615-6-mattias.ronnblom@ericsson.com
State Accepted, archived
Delegated to: Jerin Jacob
Headers show
Series
  • A Distributed Software Event Device
Related show

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Mattias Rönnblom Sept. 18, 2018, 12:45 p.m. UTC
With this patch, the DSW event device can be started and stopped,
and also supports scheduling events between ports.

Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
---
 drivers/event/dsw/Makefile    |   2 +-
 drivers/event/dsw/dsw_evdev.c | 125 ++++++++++++
 drivers/event/dsw/dsw_evdev.h |  56 ++++++
 drivers/event/dsw/dsw_event.c | 359 ++++++++++++++++++++++++++++++++++
 drivers/event/dsw/meson.build |   2 +-
 5 files changed, 542 insertions(+), 2 deletions(-)
 create mode 100644 drivers/event/dsw/dsw_event.c

Patch
diff mbox series

diff --git a/drivers/event/dsw/Makefile b/drivers/event/dsw/Makefile
index 5cbf488ff..6374a454e 100644
--- a/drivers/event/dsw/Makefile
+++ b/drivers/event/dsw/Makefile
@@ -21,6 +21,6 @@  LIBABIVER := 1
 
 EXPORT_MAP := rte_pmd_dsw_event_version.map
 
-SRCS-$(CONFIG_RTE_LIBRTE_PMD_DSW_EVENTDEV) += dsw_evdev.c
+SRCS-$(CONFIG_RTE_LIBRTE_PMD_DSW_EVENTDEV) += dsw_evdev.c dsw_event.c
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/drivers/event/dsw/dsw_evdev.c b/drivers/event/dsw/dsw_evdev.c
index 5dccc232a..40a7435be 100644
--- a/drivers/event/dsw/dsw_evdev.c
+++ b/drivers/event/dsw/dsw_evdev.c
@@ -6,6 +6,7 @@ 
 
 #include <rte_eventdev_pmd.h>
 #include <rte_eventdev_pmd_vdev.h>
+#include <rte_random.h>
 
 #include "dsw_evdev.h"
 
@@ -201,10 +202,125 @@  dsw_configure(const struct rte_eventdev *dev)
 {
 	struct dsw_evdev *dsw = dsw_pmd_priv(dev);
 	const struct rte_event_dev_config *conf = &dev->data->dev_conf;
+	int32_t min_max_in_flight;
 
 	dsw->num_ports = conf->nb_event_ports;
 	dsw->num_queues = conf->nb_event_queues;
 
+	/* Avoid a situation where consumer ports are holding all the
+	 * credits, without making use of them.
+	 */
+	min_max_in_flight = conf->nb_event_ports * DSW_PORT_MAX_CREDITS;
+
+	dsw->max_inflight = RTE_MAX(conf->nb_events_limit, min_max_in_flight);
+
+	return 0;
+}
+
+
+static void
+initial_flow_to_port_assignment(struct dsw_evdev *dsw)
+{
+	uint8_t queue_id;
+	for (queue_id = 0; queue_id < dsw->num_queues; queue_id++) {
+		struct dsw_queue *queue = &dsw->queues[queue_id];
+		uint16_t flow_hash;
+		for (flow_hash = 0; flow_hash < DSW_MAX_FLOWS; flow_hash++) {
+			uint8_t port_idx =
+				rte_rand() % queue->num_serving_ports;
+			uint8_t port_id =
+				queue->serving_ports[port_idx];
+			dsw->queues[queue_id].flow_to_port_map[flow_hash] =
+				port_id;
+		}
+	}
+}
+
+static int
+dsw_start(struct rte_eventdev *dev)
+{
+	struct dsw_evdev *dsw = dsw_pmd_priv(dev);
+
+	rte_atomic32_init(&dsw->credits_on_loan);
+
+	initial_flow_to_port_assignment(dsw);
+
+	return 0;
+}
+
+static void
+dsw_port_drain_buf(uint8_t dev_id, struct rte_event *buf, uint16_t buf_len,
+		   eventdev_stop_flush_t flush, void *flush_arg)
+{
+	uint16_t i;
+
+	for (i = 0; i < buf_len; i++)
+		flush(dev_id, buf[i], flush_arg);
+}
+
+static void
+dsw_port_drain_out(uint8_t dev_id, struct dsw_evdev *dsw, struct dsw_port *port,
+		   eventdev_stop_flush_t flush, void *flush_arg)
+{
+	uint16_t dport_id;
+
+	for (dport_id = 0; dport_id < dsw->num_ports; dport_id++)
+		if (dport_id != port->id)
+			dsw_port_drain_buf(dev_id, port->out_buffer[dport_id],
+					   port->out_buffer_len[dport_id],
+					   flush, flush_arg);
+}
+
+static void
+dsw_port_drain_in_ring(uint8_t dev_id, struct dsw_port *port,
+		       eventdev_stop_flush_t flush, void *flush_arg)
+{
+	struct rte_event ev;
+
+	while (rte_event_ring_dequeue_burst(port->in_ring, &ev, 1, NULL))
+		flush(dev_id, ev, flush_arg);
+}
+
+static void
+dsw_drain(uint8_t dev_id, struct dsw_evdev *dsw,
+	  eventdev_stop_flush_t flush, void *flush_arg)
+{
+	uint16_t port_id;
+
+	if (flush == NULL)
+		return;
+
+	for (port_id = 0; port_id < dsw->num_ports; port_id++) {
+		struct dsw_port *port = &dsw->ports[port_id];
+
+		dsw_port_drain_out(dev_id, dsw, port, flush, flush_arg);
+		dsw_port_drain_in_ring(dev_id, port, flush, flush_arg);
+	}
+}
+
+static void
+dsw_stop(struct rte_eventdev *dev)
+{
+	struct dsw_evdev *dsw = dsw_pmd_priv(dev);
+	uint8_t dev_id;
+	eventdev_stop_flush_t flush;
+	void *flush_arg;
+
+	dev_id = dev->data->dev_id;
+	flush = dev->dev_ops->dev_stop_flush;
+	flush_arg = dev->data->dev_stop_flush_arg;
+
+	dsw_drain(dev_id, dsw, flush, flush_arg);
+}
+
+static int
+dsw_close(struct rte_eventdev *dev)
+{
+	struct dsw_evdev *dsw = dsw_pmd_priv(dev);
+
+	dsw->num_ports = 0;
+	dsw->num_queues = 0;
+
 	return 0;
 }
 
@@ -219,6 +335,9 @@  static struct rte_eventdev_ops dsw_evdev_ops = {
 	.port_unlink = dsw_port_unlink,
 	.dev_infos_get = dsw_info_get,
 	.dev_configure = dsw_configure,
+	.dev_start = dsw_start,
+	.dev_stop = dsw_stop,
+	.dev_close = dsw_close
 };
 
 static int
@@ -236,6 +355,12 @@  dsw_probe(struct rte_vdev_device *vdev)
 		return -EFAULT;
 
 	dev->dev_ops = &dsw_evdev_ops;
+	dev->enqueue = dsw_event_enqueue;
+	dev->enqueue_burst = dsw_event_enqueue_burst;
+	dev->enqueue_new_burst = dsw_event_enqueue_new_burst;
+	dev->enqueue_forward_burst = dsw_event_enqueue_forward_burst;
+	dev->dequeue = dsw_event_dequeue;
+	dev->dequeue_burst = dsw_event_dequeue_burst;
 
 	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
 		return 0;
diff --git a/drivers/event/dsw/dsw_evdev.h b/drivers/event/dsw/dsw_evdev.h
index ad0f857cc..f8e94e4a4 100644
--- a/drivers/event/dsw/dsw_evdev.h
+++ b/drivers/event/dsw/dsw_evdev.h
@@ -14,6 +14,7 @@ 
 #define DSW_MAX_PORTS (64)
 #define DSW_MAX_PORT_DEQUEUE_DEPTH (128)
 #define DSW_MAX_PORT_ENQUEUE_DEPTH (128)
+#define DSW_MAX_PORT_OUT_BUFFER (32)
 
 #define DSW_MAX_QUEUES (16)
 
@@ -24,6 +25,24 @@ 
 #define DSW_MAX_FLOWS (1<<(DSW_MAX_FLOWS_BITS))
 #define DSW_MAX_FLOWS_MASK (DSW_MAX_FLOWS-1)
 
+/* Eventdev RTE_SCHED_TYPE_PARALLEL doesn't have a concept of flows,
+ * but the 'dsw' scheduler (more or less) randomly assign flow id to
+ * events on parallel queues, to be able to reuse some of the
+ * migration mechanism and scheduling logic from
+ * RTE_SCHED_TYPE_ATOMIC. By moving one of the parallel "flows" from a
+ * particular port, the likely-hood of events being scheduled to this
+ * port is reduced, and thus a kind of statistical load balancing is
+ * achieved.
+ */
+#define DSW_PARALLEL_FLOWS (1024)
+
+/* Avoid making small 'loans' from the central in-flight event credit
+ * pool, to improve efficiency.
+ */
+#define DSW_MIN_CREDIT_LOAN (64)
+#define DSW_PORT_MAX_CREDITS (2*DSW_MIN_CREDIT_LOAN)
+#define DSW_PORT_MIN_CREDITS (DSW_MIN_CREDIT_LOAN)
+
 /* The rings are dimensioned so that all in-flight events can reside
  * on any one of the port rings, to avoid the trouble of having to
  * care about the case where there's no room on the destination port's
@@ -44,8 +63,17 @@  struct dsw_port {
 	uint16_t dequeue_depth;
 	uint16_t enqueue_depth;
 
+	int32_t inflight_credits;
+
 	int32_t new_event_threshold;
 
+	uint16_t pending_releases;
+
+	uint16_t next_parallel_flow_id;
+
+	uint16_t out_buffer_len[DSW_MAX_PORTS];
+	struct rte_event out_buffer[DSW_MAX_PORTS][DSW_MAX_PORT_OUT_BUFFER];
+
 	struct rte_event_ring *in_ring __rte_cache_aligned;
 } __rte_cache_aligned;
 
@@ -53,6 +81,8 @@  struct dsw_queue {
 	uint8_t schedule_type;
 	uint8_t serving_ports[DSW_MAX_PORTS];
 	uint16_t num_serving_ports;
+
+	uint8_t flow_to_port_map[DSW_MAX_FLOWS] __rte_cache_aligned;
 };
 
 struct dsw_evdev {
@@ -62,12 +92,38 @@  struct dsw_evdev {
 	uint16_t num_ports;
 	struct dsw_queue queues[DSW_MAX_QUEUES];
 	uint8_t num_queues;
+	int32_t max_inflight;
+
+	rte_atomic32_t credits_on_loan __rte_cache_aligned;
 };
 
+uint16_t dsw_event_enqueue(void *port, const struct rte_event *event);
+uint16_t dsw_event_enqueue_burst(void *port,
+				 const struct rte_event events[],
+				 uint16_t events_len);
+uint16_t dsw_event_enqueue_new_burst(void *port,
+				     const struct rte_event events[],
+				     uint16_t events_len);
+uint16_t dsw_event_enqueue_forward_burst(void *port,
+					 const struct rte_event events[],
+					 uint16_t events_len);
+
+uint16_t dsw_event_dequeue(void *port, struct rte_event *ev, uint64_t wait);
+uint16_t dsw_event_dequeue_burst(void *port, struct rte_event *events,
+				 uint16_t num, uint64_t wait);
+
 static inline struct dsw_evdev *
 dsw_pmd_priv(const struct rte_eventdev *eventdev)
 {
 	return eventdev->data->dev_private;
 }
 
+#define DSW_LOG_DP(level, fmt, args...)					\
+	RTE_LOG_DP(level, EVENTDEV, "[%s] %s() line %u: " fmt,		\
+		   DSW_PMD_NAME,					\
+		   __func__, __LINE__, ## args)
+
+#define DSW_LOG_DP_PORT(level, port_id, fmt, args...)		\
+	DSW_LOG_DP(level, "<Port %d> " fmt, port_id, ## args)
+
 #endif
diff --git a/drivers/event/dsw/dsw_event.c b/drivers/event/dsw/dsw_event.c
new file mode 100644
index 000000000..4a3af8ecd
--- /dev/null
+++ b/drivers/event/dsw/dsw_event.c
@@ -0,0 +1,359 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Ericsson AB
+ */
+
+#include "dsw_evdev.h"
+
+#include <stdbool.h>
+
+#include <rte_atomic.h>
+#include <rte_random.h>
+
+static bool
+dsw_port_acquire_credits(struct dsw_evdev *dsw, struct dsw_port *port,
+			 int32_t credits)
+{
+	int32_t inflight_credits = port->inflight_credits;
+	int32_t missing_credits = credits - inflight_credits;
+	int32_t total_on_loan;
+	int32_t available;
+	int32_t acquired_credits;
+	int32_t new_total_on_loan;
+
+	if (likely(missing_credits <= 0)) {
+		port->inflight_credits -= credits;
+		return true;
+	}
+
+	total_on_loan = rte_atomic32_read(&dsw->credits_on_loan);
+	available = dsw->max_inflight - total_on_loan;
+	acquired_credits = RTE_MAX(missing_credits, DSW_PORT_MIN_CREDITS);
+
+	if (available < acquired_credits)
+		return false;
+
+	/* This is a race, no locks are involved, and thus some other
+	 * thread can allocate tokens in between the check and the
+	 * allocation.
+	 */
+	new_total_on_loan = rte_atomic32_add_return(&dsw->credits_on_loan,
+						    acquired_credits);
+
+	if (unlikely(new_total_on_loan > dsw->max_inflight)) {
+		/* Some other port took the last credits */
+		rte_atomic32_sub(&dsw->credits_on_loan, acquired_credits);
+		return false;
+	}
+
+	DSW_LOG_DP_PORT(DEBUG, port->id, "Acquired %d tokens from pool.\n",
+			acquired_credits);
+
+	port->inflight_credits += acquired_credits;
+	port->inflight_credits -= credits;
+
+	return true;
+}
+
+static void
+dsw_port_return_credits(struct dsw_evdev *dsw, struct dsw_port *port,
+			int32_t credits)
+{
+	port->inflight_credits += credits;
+
+	if (unlikely(port->inflight_credits > DSW_PORT_MAX_CREDITS)) {
+		int32_t leave_credits = DSW_PORT_MIN_CREDITS;
+		int32_t return_credits =
+			port->inflight_credits - leave_credits;
+
+		port->inflight_credits = leave_credits;
+
+		rte_atomic32_sub(&dsw->credits_on_loan, return_credits);
+
+		DSW_LOG_DP_PORT(DEBUG, port->id,
+				"Returned %d tokens to pool.\n",
+				return_credits);
+	}
+}
+
+static uint8_t
+dsw_schedule(struct dsw_evdev *dsw, uint8_t queue_id, uint16_t flow_hash)
+{
+	struct dsw_queue *queue = &dsw->queues[queue_id];
+	uint8_t port_id;
+
+	if (queue->num_serving_ports > 1)
+		port_id = queue->flow_to_port_map[flow_hash];
+	else
+		/* A single-link queue, or atomic/ordered/parallel but
+		 * with just a single serving port.
+		 */
+		port_id = queue->serving_ports[0];
+
+	DSW_LOG_DP(DEBUG, "Event with queue_id %d flow_hash %d is scheduled "
+		   "to port %d.\n", queue_id, flow_hash, port_id);
+
+	return port_id;
+}
+
+static void
+dsw_port_transmit_buffered(struct dsw_evdev *dsw, struct dsw_port *source_port,
+			   uint8_t dest_port_id)
+{
+	struct dsw_port *dest_port = &(dsw->ports[dest_port_id]);
+	uint16_t *buffer_len = &source_port->out_buffer_len[dest_port_id];
+	struct rte_event *buffer = source_port->out_buffer[dest_port_id];
+	uint16_t enqueued = 0;
+
+	if (*buffer_len == 0)
+		return;
+
+	/* The rings are dimensioned to fit all in-flight events (even
+	 * on a single ring), so looping will work.
+	 */
+	do {
+		enqueued +=
+			rte_event_ring_enqueue_burst(dest_port->in_ring,
+						     buffer+enqueued,
+						     *buffer_len-enqueued,
+						     NULL);
+	} while (unlikely(enqueued != *buffer_len));
+
+	(*buffer_len) = 0;
+}
+
+static uint16_t
+dsw_port_get_parallel_flow_id(struct dsw_port *port)
+{
+	uint16_t flow_id = port->next_parallel_flow_id;
+
+	port->next_parallel_flow_id =
+		(port->next_parallel_flow_id + 1) % DSW_PARALLEL_FLOWS;
+
+	return flow_id;
+}
+
+static void
+dsw_port_buffer_non_paused(struct dsw_evdev *dsw, struct dsw_port *source_port,
+			   uint8_t dest_port_id, const struct rte_event *event)
+{
+	struct rte_event *buffer = source_port->out_buffer[dest_port_id];
+	uint16_t *buffer_len = &source_port->out_buffer_len[dest_port_id];
+
+	if (*buffer_len == DSW_MAX_PORT_OUT_BUFFER)
+		dsw_port_transmit_buffered(dsw, source_port, dest_port_id);
+
+	buffer[*buffer_len] = *event;
+
+	(*buffer_len)++;
+}
+
+#define DSW_FLOW_ID_BITS (24)
+static uint16_t
+dsw_flow_id_hash(uint32_t flow_id)
+{
+	uint16_t hash = 0;
+	uint16_t offset = 0;
+
+	do {
+		hash ^= ((flow_id >> offset) & DSW_MAX_FLOWS_MASK);
+		offset += DSW_MAX_FLOWS_BITS;
+	} while (offset < DSW_FLOW_ID_BITS);
+
+	return hash;
+}
+
+static void
+dsw_port_buffer_parallel(struct dsw_evdev *dsw, struct dsw_port *source_port,
+			 struct rte_event event)
+{
+	uint8_t dest_port_id;
+
+	event.flow_id = dsw_port_get_parallel_flow_id(source_port);
+
+	dest_port_id = dsw_schedule(dsw, event.queue_id,
+				    dsw_flow_id_hash(event.flow_id));
+
+	dsw_port_buffer_non_paused(dsw, source_port, dest_port_id, &event);
+}
+
+static void
+dsw_port_buffer_event(struct dsw_evdev *dsw, struct dsw_port *source_port,
+		      const struct rte_event *event)
+{
+	uint16_t flow_hash;
+	uint8_t dest_port_id;
+
+	if (unlikely(dsw->queues[event->queue_id].schedule_type ==
+		     RTE_SCHED_TYPE_PARALLEL)) {
+		dsw_port_buffer_parallel(dsw, source_port, *event);
+		return;
+	}
+
+	flow_hash = dsw_flow_id_hash(event->flow_id);
+
+	dest_port_id = dsw_schedule(dsw, event->queue_id, flow_hash);
+
+	dsw_port_buffer_non_paused(dsw, source_port, dest_port_id, event);
+}
+
+static void
+dsw_port_flush_out_buffers(struct dsw_evdev *dsw, struct dsw_port *source_port)
+{
+	uint16_t dest_port_id;
+
+	for (dest_port_id = 0; dest_port_id < dsw->num_ports; dest_port_id++)
+		dsw_port_transmit_buffered(dsw, source_port, dest_port_id);
+}
+
+uint16_t
+dsw_event_enqueue(void *port, const struct rte_event *ev)
+{
+	return dsw_event_enqueue_burst(port, ev, unlikely(ev == NULL) ? 0 : 1);
+}
+
+static __rte_always_inline uint16_t
+dsw_event_enqueue_burst_generic(void *port, const struct rte_event events[],
+				uint16_t events_len, bool op_types_known,
+				uint16_t num_new, uint16_t num_release,
+				uint16_t num_non_release)
+{
+	struct dsw_port *source_port = port;
+	struct dsw_evdev *dsw = source_port->dsw;
+	bool enough_credits;
+	uint16_t i;
+
+	DSW_LOG_DP_PORT(DEBUG, source_port->id, "Attempting to enqueue %d "
+			"events to port %d.\n", events_len, source_port->id);
+
+	/* XXX: For performance (=ring efficiency) reasons, the
+	 * scheduler relies on internal non-ring buffers instead of
+	 * immediately sending the event to the destination ring. For
+	 * a producer that doesn't intend to produce or consume any
+	 * more events, the scheduler provides a way to flush the
+	 * buffer, by means of doing an enqueue of zero events. In
+	 * addition, a port cannot be left "unattended" (e.g. unused)
+	 * for long periods of time, since that would stall
+	 * migration. Eventdev API extensions to provide a cleaner way
+	 * to archieve both of these functions should be
+	 * considered.
+	 */
+	if (unlikely(events_len == 0)) {
+		dsw_port_flush_out_buffers(dsw, source_port);
+		return 0;
+	}
+
+	if (unlikely(events_len > source_port->enqueue_depth))
+		events_len = source_port->enqueue_depth;
+
+	if (!op_types_known)
+		for (i = 0; i < events_len; i++) {
+			switch (events[i].op) {
+			case RTE_EVENT_OP_RELEASE:
+				num_release++;
+				break;
+			case RTE_EVENT_OP_NEW:
+				num_new++;
+				/* Falls through. */
+			default:
+				num_non_release++;
+				break;
+			}
+		}
+
+	/* Technically, we could allow the non-new events up to the
+	 * first new event in the array into the system, but for
+	 * simplicity reasons, we deny the whole burst if the port is
+	 * above the water mark.
+	 */
+	if (unlikely(num_new > 0 && rte_atomic32_read(&dsw->credits_on_loan) >
+		     source_port->new_event_threshold))
+		return 0;
+
+	enough_credits = dsw_port_acquire_credits(dsw, source_port,
+						  num_non_release);
+	if (unlikely(!enough_credits))
+		return 0;
+
+	source_port->pending_releases -= num_release;
+
+	for (i = 0; i < events_len; i++) {
+		const struct rte_event *event = &events[i];
+
+		if (likely(num_release == 0 ||
+			   event->op != RTE_EVENT_OP_RELEASE))
+			dsw_port_buffer_event(dsw, source_port, event);
+	}
+
+	DSW_LOG_DP_PORT(DEBUG, source_port->id, "%d non-release events "
+			"accepted.\n", num_non_release);
+
+	return num_non_release;
+}
+
+uint16_t
+dsw_event_enqueue_burst(void *port, const struct rte_event events[],
+			uint16_t events_len)
+{
+	return dsw_event_enqueue_burst_generic(port, events, events_len, false,
+					       0, 0, 0);
+}
+
+uint16_t
+dsw_event_enqueue_new_burst(void *port, const struct rte_event events[],
+			    uint16_t events_len)
+{
+	return dsw_event_enqueue_burst_generic(port, events, events_len, true,
+					       events_len, 0, events_len);
+}
+
+uint16_t
+dsw_event_enqueue_forward_burst(void *port, const struct rte_event events[],
+				uint16_t events_len)
+{
+	return dsw_event_enqueue_burst_generic(port, events, events_len, true,
+					       0, 0, events_len);
+}
+
+uint16_t
+dsw_event_dequeue(void *port, struct rte_event *events, uint64_t wait)
+{
+	return dsw_event_dequeue_burst(port, events, 1, wait);
+}
+
+static uint16_t
+dsw_port_dequeue_burst(struct dsw_port *port, struct rte_event *events,
+		       uint16_t num)
+{
+	return rte_event_ring_dequeue_burst(port->in_ring, events, num, NULL);
+}
+
+uint16_t
+dsw_event_dequeue_burst(void *port, struct rte_event *events, uint16_t num,
+			uint64_t wait __rte_unused)
+{
+	struct dsw_port *source_port = port;
+	struct dsw_evdev *dsw = source_port->dsw;
+	uint16_t dequeued;
+
+	source_port->pending_releases = 0;
+
+	if (unlikely(num > source_port->dequeue_depth))
+		num = source_port->dequeue_depth;
+
+	dequeued = dsw_port_dequeue_burst(source_port, events, num);
+
+	source_port->pending_releases = dequeued;
+
+	if (dequeued > 0) {
+		DSW_LOG_DP_PORT(DEBUG, source_port->id, "Dequeued %d events.\n",
+				dequeued);
+
+		dsw_port_return_credits(dsw, source_port, dequeued);
+	}
+	/* XXX: Assuming the port can't produce any more work,
+	 *	consider flushing the output buffer, on dequeued ==
+	 *	0.
+	 */
+
+	return dequeued;
+}
diff --git a/drivers/event/dsw/meson.build b/drivers/event/dsw/meson.build
index 275d051c3..bd2e4c809 100644
--- a/drivers/event/dsw/meson.build
+++ b/drivers/event/dsw/meson.build
@@ -3,4 +3,4 @@ 
 
 allow_experimental_apis = true
 deps += ['bus_vdev']
-sources = files('dsw_evdev.c')
+sources = files('dsw_evdev.c', 'dsw_event.c')