[PATCH v2 02/37] baseband/acc100: update ring availability calculation

[Hernan Vargas]

Refactor of the queue availability computation to prevent the
application to dequeue more than what may have been enqueued.

Signed-off-by: Hernan Vargas <hernan.vargas at intel.com>
---
 drivers/baseband/acc100/rte_acc100_pmd.c | 39 ++++++++++++++++--------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/baseband/acc100/rte_acc100_pmd.c b/drivers/baseband/acc100/rte_acc100_pmd.c
index 7f698ec3d2..0598d33582 100644
--- a/drivers/baseband/acc100/rte_acc100_pmd.c
+++ b/drivers/baseband/acc100/rte_acc100_pmd.c
@@ -3465,13 +3465,27 @@ acc100_enqueue_queue_full(struct rte_bbdev_queue_data *q_data)
 	acc100_enqueue_status(q_data, RTE_BBDEV_ENQ_STATUS_QUEUE_FULL);
 }
 
+/* Number of available descriptor in ring to enqueue */
+static uint32_t
+acc100_ring_avail_enq(struct acc100_queue *q)
+{
+	return (q->sw_ring_depth - 1 + q->sw_ring_tail - q->sw_ring_head) % q->sw_ring_depth;
+}
+
+/* Number of available descriptor in ring to dequeue */
+static uint32_t
+acc100_ring_avail_deq(struct acc100_queue *q)
+{
+	return (q->sw_ring_depth + q->sw_ring_head - q->sw_ring_tail) % q->sw_ring_depth;
+}
+
 /* Enqueue encode operations for ACC100 device in CB mode. */
 static uint16_t
 acc100_enqueue_enc_cb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_enc_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i;
 	union acc100_dma_desc *desc;
 	int ret;
@@ -3531,7 +3545,7 @@ acc100_enqueue_ldpc_enc_cb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_enc_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i = 0;
 	union acc100_dma_desc *desc;
 	int ret, desc_idx = 0;
@@ -3588,7 +3602,7 @@ acc100_enqueue_enc_tb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_enc_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i, enqueued_cbs = 0;
 	uint8_t cbs_in_tb;
 	int ret;
@@ -3654,7 +3668,7 @@ acc100_enqueue_dec_cb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_dec_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i;
 	union acc100_dma_desc *desc;
 	int ret;
@@ -3711,7 +3725,7 @@ acc100_enqueue_ldpc_dec_tb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_dec_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i, enqueued_cbs = 0;
 	uint8_t cbs_in_tb;
 	int ret;
@@ -3746,7 +3760,7 @@ acc100_enqueue_ldpc_dec_cb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_dec_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i;
 	union acc100_dma_desc *desc;
 	int ret;
@@ -3800,7 +3814,7 @@ acc100_enqueue_dec_tb(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_dec_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	int32_t avail = q->sw_ring_depth + q->sw_ring_tail - q->sw_ring_head;
+	int32_t avail = acc100_ring_avail_enq(q);
 	uint16_t i, enqueued_cbs = 0;
 	uint8_t cbs_in_tb;
 	int ret;
@@ -4179,12 +4193,13 @@ acc100_dequeue_enc(struct rte_bbdev_queue_data *q_data,
 {
 	struct acc100_queue *q = q_data->queue_private;
 	uint16_t dequeue_num;
-	uint32_t avail = q->sw_ring_head - q->sw_ring_tail;
+	uint32_t avail = acc100_ring_avail_deq(q);
 	uint32_t aq_dequeued = 0;
 	uint16_t i, dequeued_cbs = 0;
 	struct rte_bbdev_enc_op *op;
 	int ret;
-
+	if (avail == 0)
+		return 0;
 #ifdef RTE_LIBRTE_BBDEV_DEBUG
 	if (unlikely(ops == NULL || q == NULL)) {
 		rte_bbdev_log_debug("Unexpected undefined pointer");
@@ -4224,7 +4239,7 @@ acc100_dequeue_ldpc_enc(struct rte_bbdev_queue_data *q_data,
 		struct rte_bbdev_enc_op **ops, uint16_t num)
 {
 	struct acc100_queue *q = q_data->queue_private;
-	uint32_t avail = q->sw_ring_head - q->sw_ring_tail;
+	uint32_t avail = acc100_ring_avail_deq(q);
 	uint32_t aq_dequeued = 0;
 	uint16_t dequeue_num, i, dequeued_cbs = 0, dequeued_descs = 0;
 	int ret;
@@ -4264,7 +4279,7 @@ acc100_dequeue_dec(struct rte_bbdev_queue_data *q_data,
 {
 	struct acc100_queue *q = q_data->queue_private;
 	uint16_t dequeue_num;
-	uint32_t avail = q->sw_ring_head - q->sw_ring_tail;
+	uint32_t avail = acc100_ring_avail_deq(q);
 	uint32_t aq_dequeued = 0;
 	uint16_t i;
 	uint16_t dequeued_cbs = 0;
@@ -4309,7 +4324,7 @@ acc100_dequeue_ldpc_dec(struct rte_bbdev_queue_data *q_data,
 {
 	struct acc100_queue *q = q_data->queue_private;
 	uint16_t dequeue_num;
-	uint32_t avail = q->sw_ring_head - q->sw_ring_tail;
+	uint32_t avail = acc100_ring_avail_deq(q);
 	uint32_t aq_dequeued = 0;
 	uint16_t i;
 	uint16_t dequeued_cbs = 0;
-- 
2.37.1