[PATCH v2 13/17] drivers/event: use previous value atomic fetch operations

[Tyler Retzlaff]

Use __atomic_fetch_{add,and,or,sub,xor} instead of
__atomic_{add,and,or,sub,xor}_fetch when we have no interest in the
result of the operation.

Reduces unnecessary codegen that provided the result of the atomic
operation that was not used.

Change brings closer alignment with atomics available in C11 standard
and will reduce review effort when they are integrated.

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
Acked-by: Morten Brørup <mb at smartsharesystems.com>
---
 drivers/event/cnxk/cnxk_eventdev_selftest.c | 12 ++++++------
 drivers/event/cnxk/cnxk_tim_worker.h        |  6 +++---
 drivers/event/dsw/dsw_event.c               |  6 +++---
 drivers/event/octeontx/timvf_worker.h       |  6 +++---
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/event/cnxk/cnxk_eventdev_selftest.c b/drivers/event/cnxk/cnxk_eventdev_selftest.c
index 577c99b..95c0f1b 100644
--- a/drivers/event/cnxk/cnxk_eventdev_selftest.c
+++ b/drivers/event/cnxk/cnxk_eventdev_selftest.c
@@ -554,7 +554,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 		ret = validate_event(&ev);
 		RTE_TEST_ASSERT_SUCCESS(ret, "Failed to validate event");
 		rte_pktmbuf_free(ev.mbuf);
-		__atomic_sub_fetch(total_events, 1, __ATOMIC_RELAXED);
+		__atomic_fetch_sub(total_events, 1, __ATOMIC_RELAXED);
 	}
 
 	return 0;
@@ -916,7 +916,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 
 			if (seqn_list_update(seqn) == 0) {
 				rte_pktmbuf_free(ev.mbuf);
-				__atomic_sub_fetch(total_events, 1,
+				__atomic_fetch_sub(total_events, 1,
 						   __ATOMIC_RELAXED);
 			} else {
 				plt_err("Failed to update seqn_list");
@@ -1072,7 +1072,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 
 			if (seqn_list_update(seqn) == 0) {
 				rte_pktmbuf_free(ev.mbuf);
-				__atomic_sub_fetch(total_events, 1,
+				__atomic_fetch_sub(total_events, 1,
 						   __ATOMIC_RELAXED);
 			} else {
 				plt_err("Failed to update seqn_list");
@@ -1217,7 +1217,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 
 		if (ev.sub_event_type == MAX_STAGES) { /* last stage */
 			rte_pktmbuf_free(ev.mbuf);
-			__atomic_sub_fetch(total_events, 1, __ATOMIC_RELAXED);
+			__atomic_fetch_sub(total_events, 1, __ATOMIC_RELAXED);
 		} else {
 			ev.event_type = RTE_EVENT_TYPE_CPU;
 			ev.sub_event_type++;
@@ -1293,7 +1293,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 
 		if (ev.queue_id == nr_queues - 1) { /* last stage */
 			rte_pktmbuf_free(ev.mbuf);
-			__atomic_sub_fetch(total_events, 1, __ATOMIC_RELAXED);
+			__atomic_fetch_sub(total_events, 1, __ATOMIC_RELAXED);
 		} else {
 			ev.event_type = RTE_EVENT_TYPE_CPU;
 			ev.queue_id++;
@@ -1338,7 +1338,7 @@ typedef int (*validate_event_cb)(uint32_t index, uint8_t port,
 
 		if (ev.queue_id == nr_queues - 1) { /* Last stage */
 			rte_pktmbuf_free(ev.mbuf);
-			__atomic_sub_fetch(total_events, 1, __ATOMIC_RELAXED);
+			__atomic_fetch_sub(total_events, 1, __ATOMIC_RELAXED);
 		} else {
 			ev.event_type = RTE_EVENT_TYPE_CPU;
 			ev.queue_id++;
diff --git a/drivers/event/cnxk/cnxk_tim_worker.h b/drivers/event/cnxk/cnxk_tim_worker.h
index a326d55..c087fe5 100644
--- a/drivers/event/cnxk/cnxk_tim_worker.h
+++ b/drivers/event/cnxk/cnxk_tim_worker.h
@@ -102,19 +102,19 @@
 static inline void
 cnxk_tim_bkt_inc_nent(struct cnxk_tim_bkt *bktp)
 {
-	__atomic_add_fetch(&bktp->nb_entry, 1, __ATOMIC_RELAXED);
+	__atomic_fetch_add(&bktp->nb_entry, 1, __ATOMIC_RELAXED);
 }
 
 static inline void
 cnxk_tim_bkt_add_nent_relaxed(struct cnxk_tim_bkt *bktp, uint32_t v)
 {
-	__atomic_add_fetch(&bktp->nb_entry, v, __ATOMIC_RELAXED);
+	__atomic_fetch_add(&bktp->nb_entry, v, __ATOMIC_RELAXED);
 }
 
 static inline void
 cnxk_tim_bkt_add_nent(struct cnxk_tim_bkt *bktp, uint32_t v)
 {
-	__atomic_add_fetch(&bktp->nb_entry, v, __ATOMIC_RELEASE);
+	__atomic_fetch_add(&bktp->nb_entry, v, __ATOMIC_RELEASE);
 }
 
 static inline uint64_t
diff --git a/drivers/event/dsw/dsw_event.c b/drivers/event/dsw/dsw_event.c
index 9932caf..89badca 100644
--- a/drivers/event/dsw/dsw_event.c
+++ b/drivers/event/dsw/dsw_event.c
@@ -50,7 +50,7 @@
 
 	if (unlikely(new_total_on_loan > dsw->max_inflight)) {
 		/* Some other port took the last credits */
-		__atomic_sub_fetch(&dsw->credits_on_loan, acquired_credits,
+		__atomic_fetch_sub(&dsw->credits_on_loan, acquired_credits,
 				   __ATOMIC_RELAXED);
 		return false;
 	}
@@ -77,7 +77,7 @@
 
 		port->inflight_credits = leave_credits;
 
-		__atomic_sub_fetch(&dsw->credits_on_loan, return_credits,
+		__atomic_fetch_sub(&dsw->credits_on_loan, return_credits,
 				   __ATOMIC_RELAXED);
 
 		DSW_LOG_DP_PORT(DEBUG, port->id,
@@ -527,7 +527,7 @@ struct dsw_queue_flow_burst {
 	target_qfs[*targets_len] = *candidate_qf;
 	(*targets_len)++;
 
-	__atomic_add_fetch(&dsw->ports[candidate_port_id].immigration_load,
+	__atomic_fetch_add(&dsw->ports[candidate_port_id].immigration_load,
 			   candidate_flow_load, __ATOMIC_RELAXED);
 
 	return true;
diff --git a/drivers/event/octeontx/timvf_worker.h b/drivers/event/octeontx/timvf_worker.h
index 3f1e77f..ad98ca0 100644
--- a/drivers/event/octeontx/timvf_worker.h
+++ b/drivers/event/octeontx/timvf_worker.h
@@ -108,7 +108,7 @@
 static inline void
 timr_bkt_dec_lock(struct tim_mem_bucket *bktp)
 {
-	__atomic_add_fetch(&bktp->lock, 0xff, __ATOMIC_ACQ_REL);
+	__atomic_fetch_add(&bktp->lock, 0xff, __ATOMIC_ACQ_REL);
 }
 
 static inline uint32_t
@@ -121,13 +121,13 @@
 static inline void
 timr_bkt_inc_nent(struct tim_mem_bucket *bktp)
 {
-	__atomic_add_fetch(&bktp->nb_entry, 1, __ATOMIC_RELAXED);
+	__atomic_fetch_add(&bktp->nb_entry, 1, __ATOMIC_RELAXED);
 }
 
 static inline void
 timr_bkt_add_nent(struct tim_mem_bucket *bktp, uint32_t v)
 {
-	__atomic_add_fetch(&bktp->nb_entry, v, __ATOMIC_RELAXED);
+	__atomic_fetch_add(&bktp->nb_entry, v, __ATOMIC_RELAXED);
 }
 
 static inline uint64_t
-- 
1.8.3.1