[PATCH iwl-next v3 18/18] idpf: add XDP RSS hash hint

[Alexander Lobakin <aleksander.lobakin@intel.com>]

Add &xdp_metadata_ops with a callback to get RSS hash hint from the
descriptor. Declare the splitq 32-byte descriptor as 4 u64s to parse
them more efficiently when possible.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/ethernet/intel/idpf/xdp.h | 64 +++++++++++++++++++++++++++
 drivers/net/ethernet/intel/idpf/xdp.c | 28 +++++++++++-
 2 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/idpf/xdp.h b/drivers/net/ethernet/intel/idpf/xdp.h
index db8ecc1843fe..66ad83a0e85e 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.h
+++ b/drivers/net/ethernet/intel/idpf/xdp.h
@@ -99,6 +99,70 @@ static inline void idpf_xdp_tx_finalize(void *_xdpsq, bool sent, bool flush)
 	libeth_xdpsq_unlock(&xdpsq->xdp_lock);
 }
 
+struct idpf_xdp_rx_desc {
+	aligned_u64		qw0;
+#define IDPF_XDP_RX_BUFQ	BIT_ULL(47)
+#define IDPF_XDP_RX_GEN		BIT_ULL(46)
+#define IDPF_XDP_RX_LEN		GENMASK_ULL(45, 32)
+#define IDPF_XDP_RX_PT		GENMASK_ULL(25, 16)
+
+	aligned_u64		qw1;
+#define IDPF_XDP_RX_BUF		GENMASK_ULL(47, 32)
+#define IDPF_XDP_RX_EOP		BIT_ULL(1)
+
+	aligned_u64		qw2;
+#define IDPF_XDP_RX_HASH	GENMASK_ULL(31, 0)
+
+	aligned_u64		qw3;
+} __aligned(4 * sizeof(u64));
+static_assert(sizeof(struct idpf_xdp_rx_desc) ==
+	      sizeof(struct virtchnl2_rx_flex_desc_adv_nic_3));
+
+#define idpf_xdp_rx_bufq(desc)	!!((desc)->qw0 & IDPF_XDP_RX_BUFQ)
+#define idpf_xdp_rx_gen(desc)	!!((desc)->qw0 & IDPF_XDP_RX_GEN)
+#define idpf_xdp_rx_len(desc)	FIELD_GET(IDPF_XDP_RX_LEN, (desc)->qw0)
+#define idpf_xdp_rx_pt(desc)	FIELD_GET(IDPF_XDP_RX_PT, (desc)->qw0)
+#define idpf_xdp_rx_buf(desc)	FIELD_GET(IDPF_XDP_RX_BUF, (desc)->qw1)
+#define idpf_xdp_rx_eop(desc)	!!((desc)->qw1 & IDPF_XDP_RX_EOP)
+#define idpf_xdp_rx_hash(desc)	FIELD_GET(IDPF_XDP_RX_HASH, (desc)->qw2)
+
+static inline void
+idpf_xdp_get_qw0(struct idpf_xdp_rx_desc *desc,
+		 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+	desc->qw0 = ((const typeof(desc))rxd)->qw0;
+#else
+	desc->qw0 = ((u64)le16_to_cpu(rxd->pktlen_gen_bufq_id) << 32) |
+		    ((u64)le16_to_cpu(rxd->ptype_err_fflags0) << 16);
+#endif
+}
+
+static inline void
+idpf_xdp_get_qw1(struct idpf_xdp_rx_desc *desc,
+		 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+	desc->qw1 = ((const typeof(desc))rxd)->qw1;
+#else
+	desc->qw1 = ((u64)le16_to_cpu(rxd->buf_id) << 32) |
+		    rxd->status_err0_qw1;
+#endif
+}
+
+static inline void
+idpf_xdp_get_qw2(struct idpf_xdp_rx_desc *desc,
+		 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+	desc->qw2 = ((const typeof(desc))rxd)->qw2;
+#else
+	desc->qw2 = ((u64)rxd->hash3 << 24) |
+		    ((u64)rxd->ff2_mirrid_hash2.hash2 << 16) |
+		    le16_to_cpu(rxd->hash1);
+#endif
+}
+
 void idpf_xdp_set_features(const struct idpf_vport *vport);
 
 int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);
diff --git a/drivers/net/ethernet/intel/idpf/xdp.c b/drivers/net/ethernet/intel/idpf/xdp.c
index d2549f8b8e24..c143b5dc9e2b 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.c
+++ b/drivers/net/ethernet/intel/idpf/xdp.c
@@ -340,12 +340,38 @@ int idpf_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 				       idpf_xdp_tx_finalize);
 }
 
+static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
+			      enum xdp_rss_hash_type *rss_type)
+{
+	const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
+	struct idpf_xdp_rx_desc desc __uninitialized;
+	const struct idpf_rx_queue *rxq;
+	struct libeth_rx_pt pt;
+
+	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
+
+	idpf_xdp_get_qw0(&desc, xdp->desc);
+
+	pt = rxq->rx_ptype_lkup[idpf_xdp_rx_pt(&desc)];
+	if (!libeth_rx_pt_has_hash(rxq->xdp_rxq.dev, pt))
+		return -ENODATA;
+
+	idpf_xdp_get_qw2(&desc, xdp->desc);
+
+	return libeth_xdpmo_rx_hash(hash, rss_type, idpf_xdp_rx_hash(&desc),
+				    pt);
+}
+
+static const struct xdp_metadata_ops idpf_xdpmo = {
+	.xmo_rx_hash		= idpf_xdpmo_rx_hash,
+};
+
 void idpf_xdp_set_features(const struct idpf_vport *vport)
 {
 	if (!idpf_is_queue_model_split(vport->rxq_model))
 		return;
 
-	libeth_xdp_set_features_noredir(vport->netdev);
+	libeth_xdp_set_features_noredir(vport->netdev, &idpf_xdpmo);
 }
 
 static int idpf_xdp_setup_prog(struct idpf_vport *vport,
-- 
2.50.1