libeth: xdp: add RSS hash hint and XDP features setup helpers

End the XDP section by adding helpers to setup XDP features, flipping
.ndo_xdp_xmit() support at runtime (in case when it's not always on),
and calculating the queue clean/refill threshold.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 90 insertions, 0 deletions

diff --git a/include/net/libeth/xdp.h b/include/net/libeth/xdp.h
index 46a2ec3c3037..c36b2ca0d04c 100644
--- a/include/net/libeth/xdp.h
+++ b/include/net/libeth/xdp.h
@@ -1631,6 +1631,51 @@ void name(struct libeth_xdp_tx_bulk *bq)				      \
 
 #define LIBETH_XDP_DEFINE_END()		__diag_pop()
 
+/* XMO */
+
+/**
+ * libeth_xdp_buff_to_rq - get RQ pointer from an XDP buffer pointer
+ * @xdp: &libeth_xdp_buff corresponding to the queue
+ * @type: typeof() of the driver Rx queue structure
+ * @member: name of &xdp_rxq_info inside @type
+ *
+ * Often times, pointer to the RQ is needed when reading/filling metadata from
+ * HW descriptors. The helper can be used to quickly jump from an XDP buffer
+ * to the queue corresponding to its &xdp_rxq_info without introducing
+ * additional fields (&libeth_xdp_buff is precisely 1 cacheline long on x64).
+ */
+#define libeth_xdp_buff_to_rq(xdp, type, member)			      \
+	container_of_const((xdp)->base.rxq, type, member)
+
+/**
+ * libeth_xdpmo_rx_hash - convert &libeth_rx_pt to an XDP RSS hash metadata
+ * @hash: pointer to the variable to write the hash to
+ * @rss_type: pointer to the variable to write the hash type to
+ * @val: hash value from the HW descriptor
+ * @pt: libeth parsed packet type
+ *
+ * Handle zeroed/non-available hash and convert libeth parsed packet type to
+ * the corresponding XDP RSS hash type. To be called at the end of
+ * xdp_metadata_ops idpf_xdpmo::xmo_rx_hash() implementation.
+ * Note that if the driver doesn't use a constant packet type lookup table but
+ * generates it at runtime, it must call libeth_rx_pt_gen_hash_type(pt) to
+ * generate XDP RSS hash type for each packet type.
+ *
+ * Return: 0 on success, -ENODATA when the hash is not available.
+ */
+static inline int libeth_xdpmo_rx_hash(u32 *hash,
+				       enum xdp_rss_hash_type *rss_type,
+				       u32 val, struct libeth_rx_pt pt)
+{
+	if (unlikely(!val))
+		return -ENODATA;
+
+	*hash = val;
+	*rss_type = pt.hash_type;
+
+	return 0;
+}
+
 /* Tx buffer completion */
 
 void libeth_xdp_return_buff_bulk(const struct skb_shared_info *sinfo,
@@ -1697,4 +1742,49 @@ static inline void libeth_xdp_complete_tx(struct libeth_sqe *sqe,
 	__libeth_xdp_complete_tx(sqe, cp, libeth_xdp_return_buff_bulk);
 }
 
+/* Misc */
+
+u32 libeth_xdp_queue_threshold(u32 count);
+
+void __libeth_xdp_set_features(struct net_device *dev,
+			       const struct xdp_metadata_ops *xmo);
+void libeth_xdp_set_redirect(struct net_device *dev, bool enable);
+
+/**
+ * libeth_xdp_set_features - set XDP features for netdev
+ * @dev: &net_device to configure
+ * @...: optional params, see __libeth_xdp_set_features()
+ *
+ * Set all the features libeth_xdp supports, including .ndo_xdp_xmit(). That
+ * said, it should be used only when XDPSQs are always available regardless
+ * of whether an XDP prog is attached to @dev.
+ */
+#define libeth_xdp_set_features(dev, ...)				      \
+	CONCATENATE(__libeth_xdp_feat,					      \
+		    COUNT_ARGS(__VA_ARGS__))(dev, ##__VA_ARGS__)
+
+#define __libeth_xdp_feat0(dev)						      \
+	__libeth_xdp_set_features(dev, NULL)
+#define __libeth_xdp_feat1(dev, xmo)					      \
+	__libeth_xdp_set_features(dev, xmo)
+
+/**
+ * libeth_xdp_set_features_noredir - enable all libeth_xdp features w/o redir
+ * @dev: target &net_device
+ * @...: optional params, see __libeth_xdp_set_features()
+ *
+ * Enable everything except the .ndo_xdp_xmit() feature, use when XDPSQs are
+ * not available right after netdev registration.
+ */
+#define libeth_xdp_set_features_noredir(dev, ...)			      \
+	__libeth_xdp_set_features_noredir(dev, __UNIQUE_ID(dev_),	      \
+					  ##__VA_ARGS__)
+
+#define __libeth_xdp_set_features_noredir(dev, ud, ...) do {		      \
+	struct net_device *ud = (dev);					      \
+									      \
+	libeth_xdp_set_features(ud, ##__VA_ARGS__);			      \
+	libeth_xdp_set_redirect(ud, false);				      \
+} while (0)
+
 #endif /* __LIBETH_XDP_H */