[dpdk-dev] [PATCH 26/31] net/sfc: support RSS hash offload

[Andrew Rybchenko <arybchenko@solarflare.com>]

From: Ivan Malov <ivan.malov@oktetlabs.ru>

Extract RSS hash provided by the HW in the prefix and put it to mbuf.

Reviewed-by: Andrew Lee <alee@solarflare.com>
Reviewed-by: Robert Stonehouse <rstonehouse@solarflare.com>
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 doc/guides/nics/features/sfc_efx.ini |  1 +
 doc/guides/nics/sfc_efx.rst          |  2 ++
 drivers/net/sfc/sfc_rx.c             | 31 ++++++++++++++++++++++++++++++-
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/doc/guides/nics/features/sfc_efx.ini b/doc/guides/nics/features/sfc_efx.ini
index e7a1143..debea27 100644
--- a/doc/guides/nics/features/sfc_efx.ini
+++ b/doc/guides/nics/features/sfc_efx.ini
@@ -14,6 +14,7 @@ Scattered Rx         = Y
 Promiscuous mode     = Y
 Allmulticast mode    = Y
 Multicast MAC filter = Y
+RSS hash             = Y
 Flow control         = Y
 VLAN offload         = P
 L3 checksum offload  = Y
diff --git a/doc/guides/nics/sfc_efx.rst b/doc/guides/nics/sfc_efx.rst
index 4f674c0..64489de 100644
--- a/doc/guides/nics/sfc_efx.rst
+++ b/doc/guides/nics/sfc_efx.rst
@@ -68,6 +68,8 @@ SFC EFX PMD has support for:
 
 - Receive side scaling (RSS)
 
+- RSS hash
+
 - Scattered Rx DMA for packet that are larger that a single Rx descriptor
 
 - Deferred receive and transmit queue start
diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index f0fe1b8..1e254a8 100644
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -185,6 +185,28 @@ sfc_rx_desc_flags_to_packet_type(const unsigned int desc_flags)
 		((desc_flags & EFX_PKT_UDP) ? RTE_PTYPE_L4_UDP : 0);
 }
 
+static void
+sfc_rx_set_rss_hash(struct sfc_rxq *rxq, unsigned int flags, struct rte_mbuf *m)
+{
+#if EFSYS_OPT_RX_SCALE
+	uint8_t *mbuf_data;
+
+
+	if ((rxq->flags & SFC_RXQ_RSS_HASH) == 0)
+		return;
+
+	mbuf_data = rte_pktmbuf_mtod(m, uint8_t *);
+
+	if (flags & (EFX_PKT_IPV4 | EFX_PKT_IPV6)) {
+		m->hash.rss = efx_pseudo_hdr_hash_get(rxq->common,
+						      EFX_RX_HASHALG_TOEPLITZ,
+						      mbuf_data);
+
+		m->ol_flags |= PKT_RX_RSS_HASH;
+	}
+#endif
+}
+
 uint16_t
 sfc_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 {
@@ -231,7 +253,6 @@ sfc_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 			seg_len = rxd->size - prefix_size;
 		}
 
-		m->data_off += prefix_size;
 		rte_pktmbuf_data_len(m) = seg_len;
 		rte_pktmbuf_pkt_len(m) = seg_len;
 
@@ -261,6 +282,14 @@ sfc_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 		m->ol_flags = sfc_rx_desc_flags_to_offload_flags(desc_flags);
 		m->packet_type = sfc_rx_desc_flags_to_packet_type(desc_flags);
 
+		/*
+		 * Extract RSS hash from the packet prefix and
+		 * set the corresponding field (if needed and possible)
+		 */
+		sfc_rx_set_rss_hash(rxq, desc_flags, m);
+
+		m->data_off += prefix_size;
+
 		*rx_pkts++ = m;
 		done_pkts++;
 		continue;
-- 
2.5.5