From 3f373e1a0a5c9f581d16bd8abea51b7dde4cdae5 Mon Sep 17 00:00:00 2001
From: Shahed Shaikh <shahed.shaikh@cavium.com>
Date: Sat, 8 Sep 2018 13:31:04 -0700
Subject: [PATCH] net/qede: support Rx descriptor status

This patch implement eth_dev_ops->rx_descriptor_status
callback.
Walk through receive completion ring to calculate receive
descriptors used by firmware and then provide the status of
offset accordingly.

Signed-off-by: Shahed Shaikh <shahed.shaikh@cavium.com>
---
 drivers/net/qede/qede_ethdev.c |  2 +
 drivers/net/qede/qede_rxtx.c   | 81 ++++++++++++++++++++++++++++++++++
 drivers/net/qede/qede_rxtx.h   |  2 +
 3 files changed, 85 insertions(+)

diff --git a/drivers/net/qede/qede_ethdev.c b/drivers/net/qede/qede_ethdev.c
index 3e4cac7389..9d4591ea62 100644
--- a/drivers/net/qede/qede_ethdev.c
+++ b/drivers/net/qede/qede_ethdev.c
@@ -2299,6 +2299,7 @@ static const struct eth_dev_ops qede_eth_dev_ops = {
 	.dev_infos_get = qede_dev_info_get,
 	.rx_queue_setup = qede_rx_queue_setup,
 	.rx_queue_release = qede_rx_queue_release,
+	.rx_descriptor_status = qede_rx_descriptor_status,
 	.tx_queue_setup = qede_tx_queue_setup,
 	.tx_queue_release = qede_tx_queue_release,
 	.dev_start = qede_dev_start,
@@ -2340,6 +2341,7 @@ static const struct eth_dev_ops qede_eth_vf_dev_ops = {
 	.dev_infos_get = qede_dev_info_get,
 	.rx_queue_setup = qede_rx_queue_setup,
 	.rx_queue_release = qede_rx_queue_release,
+	.rx_descriptor_status = qede_rx_descriptor_status,
 	.tx_queue_setup = qede_tx_queue_setup,
 	.tx_queue_release = qede_tx_queue_release,
 	.dev_start = qede_dev_start,
diff --git a/drivers/net/qede/qede_rxtx.c b/drivers/net/qede/qede_rxtx.c
index 675c0a0333..8a4772f463 100644
--- a/drivers/net/qede/qede_rxtx.c
+++ b/drivers/net/qede/qede_rxtx.c
@@ -2151,3 +2151,84 @@ qede_rxtx_pkts_dummy(__rte_unused void *p_rxq,
 {
 	return 0;
 }
+
+
+/* this function does a fake walk through over completion queue
+ * to calculate number of BDs used by HW.
+ * At the end, it restores the state of completion queue.
+ */
+static uint16_t
+qede_parse_fp_cqe(struct qede_rx_queue *rxq)
+{
+	uint16_t hw_comp_cons, sw_comp_cons, bd_count = 0;
+	union eth_rx_cqe *cqe, *orig_cqe = NULL;
+
+	hw_comp_cons = rte_le_to_cpu_16(*rxq->hw_cons_ptr);
+	sw_comp_cons = ecore_chain_get_cons_idx(&rxq->rx_comp_ring);
+
+	if (hw_comp_cons == sw_comp_cons)
+		return 0;
+
+	/* Get the CQE from the completion ring */
+	cqe = (union eth_rx_cqe *)ecore_chain_consume(&rxq->rx_comp_ring);
+	orig_cqe = cqe;
+
+	while (sw_comp_cons != hw_comp_cons) {
+		switch (cqe->fast_path_regular.type) {
+		case ETH_RX_CQE_TYPE_REGULAR:
+			bd_count += cqe->fast_path_regular.bd_num;
+			break;
+		case ETH_RX_CQE_TYPE_TPA_END:
+			bd_count += cqe->fast_path_tpa_end.num_of_bds;
+			break;
+		default:
+			break;
+		}
+
+		cqe =
+		(union eth_rx_cqe *)ecore_chain_consume(&rxq->rx_comp_ring);
+		sw_comp_cons = ecore_chain_get_cons_idx(&rxq->rx_comp_ring);
+	}
+
+	/* revert comp_ring to original state */
+	ecore_chain_set_cons(&rxq->rx_comp_ring, sw_comp_cons, orig_cqe);
+
+	return bd_count;
+}
+
+int
+qede_rx_descriptor_status(void *p_rxq, uint16_t offset)
+{
+	uint16_t hw_bd_cons, sw_bd_cons, sw_bd_prod;
+	uint16_t produced, consumed;
+	struct qede_rx_queue *rxq = p_rxq;
+
+	if (offset > rxq->nb_rx_desc)
+		return -EINVAL;
+
+	sw_bd_cons = ecore_chain_get_cons_idx(&rxq->rx_bd_ring);
+	sw_bd_prod = ecore_chain_get_prod_idx(&rxq->rx_bd_ring);
+
+	/* find BDs used by HW from completion queue elements */
+	hw_bd_cons = sw_bd_cons + qede_parse_fp_cqe(rxq);
+
+	if (hw_bd_cons < sw_bd_cons)
+		/* wraparound case */
+		consumed = (0xffff - sw_bd_cons) + hw_bd_cons;
+	else
+		consumed = hw_bd_cons - sw_bd_cons;
+
+	if (offset <= consumed)
+		return RTE_ETH_RX_DESC_DONE;
+
+	if (sw_bd_prod < sw_bd_cons)
+		/* wraparound case */
+		produced = (0xffff - sw_bd_cons) + sw_bd_prod;
+	else
+		produced = sw_bd_prod - sw_bd_cons;
+
+	if (offset <= produced)
+		return RTE_ETH_RX_DESC_AVAIL;
+
+	return RTE_ETH_RX_DESC_UNAVAIL;
+}
diff --git a/drivers/net/qede/qede_rxtx.h b/drivers/net/qede/qede_rxtx.h
index 8bd8d1c5a7..d3a41e92e8 100644
--- a/drivers/net/qede/qede_rxtx.h
+++ b/drivers/net/qede/qede_rxtx.h
@@ -276,6 +276,8 @@ int qede_start_queues(struct rte_eth_dev *eth_dev);
 void qede_stop_queues(struct rte_eth_dev *eth_dev);
 int qede_calc_rx_buf_size(struct rte_eth_dev *dev, uint16_t mbufsz,
 			  uint16_t max_frame_size);
+int
+qede_rx_descriptor_status(void *rxq, uint16_t offset);
 
 /* Fastpath resource alloc/dealloc helpers */
 int qede_alloc_fp_resc(struct qede_dev *qdev);