[PATCH iwl-next v1 2/3] i40e: add support for bpf_xdp_metadata_rx_hash()

[Kohei Enju <kohei@enjuk.jp>]

Introduce i40e_xdp_rx_hash() which takes the same approach as
i40e_rx_hash() to extract the hash from RX descriptors.

Tested with X710 adapter using xdp_hw_metadata, and verified hash
consistency between bpf_xdp_metadata_rx_hash() and skb->hash.

Signed-off-by: Kohei Enju <kohei@enjuk.jp>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 30 +++++++++++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_type.h |  5 ++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 7966d9cb8009..6b7e34b16a8d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4,6 +4,7 @@
 #include <generated/utsrelease.h>
 #include <linux/crash_dump.h>
 #include <linux/intel/libie/pctype.h>
+#include <linux/intel/libie/rx.h>
 #include <linux/if_bridge.h>
 #include <linux/if_macvlan.h>
 #include <linux/module.h>
@@ -13585,6 +13586,34 @@ static int i40e_xdp(struct net_device *dev,
 	}
 }
 
+static int i40e_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash,
+			    enum xdp_rss_hash_type *rss_type)
+{
+	const struct i40e_xdp_buff *ctx = (const void *)_ctx;
+	const union i40e_rx_desc *desc = ctx->desc;
+	struct libeth_rx_pt rx_ptype;
+	u8 raw_rx_ptype;
+	u64 status;
+
+	status = le64_to_cpu(desc->wb.qword1.status_error_len);
+	raw_rx_ptype = FIELD_GET(I40E_RXD_QW1_PTYPE_MASK, status);
+	rx_ptype = libie_rx_pt_parse(raw_rx_ptype);
+
+	if (!libeth_rx_pt_has_hash(ctx->xdp.rxq->dev, rx_ptype) ||
+	    FIELD_GET(I40E_RX_DESC_STATUS_FLTSTAT_MASK, status) !=
+		    I40E_RX_DESC_FLTSTAT_RSS_HASH)
+		return -ENODATA;
+
+	*hash = le32_to_cpu(desc->wb.qword0.hi_dword.rss);
+	*rss_type = rx_ptype.hash_type;
+
+	return 0;
+}
+
+static const struct xdp_metadata_ops i40e_xdp_metadata_ops = {
+	.xmo_rx_hash		= i40e_xdp_rx_hash,
+};
+
 static const struct net_device_ops i40e_netdev_ops = {
 	.ndo_open		= i40e_open,
 	.ndo_stop		= i40e_close,
@@ -13788,6 +13817,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 	i40e_vsi_config_netdev_tc(vsi, vsi->tc_config.enabled_tc);
 
 	netdev->netdev_ops = &i40e_netdev_ops;
+	netdev->xdp_metadata_ops = &i40e_xdp_metadata_ops;
 	netdev->watchdog_timeo = 5 * HZ;
 	i40e_set_ethtool_ops(netdev);
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_type.h b/drivers/net/ethernet/intel/i40e/i40e_type.h
index ed8bbdb586da..16a65c6e5153 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_type.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_type.h
@@ -4,6 +4,7 @@
 #ifndef _I40E_TYPE_H_
 #define _I40E_TYPE_H_
 
+#include <linux/bits.h>
 #include <uapi/linux/if_ether.h>
 #include "i40e_adminq.h"
 #include "i40e_hmc.h"
@@ -699,6 +700,10 @@ enum i40e_rx_desc_status_bits {
 	I40E_RX_DESC_STATUS_LAST /* this entry must be last!!! */
 };
 
+#define I40E_RX_DESC_STATUS_FLTSTAT_MASK                   \
+	GENMASK_ULL(I40E_RX_DESC_STATUS_FLTSTAT_SHIFT + 1, \
+		    I40E_RX_DESC_STATUS_FLTSTAT_SHIFT)
+
 #define I40E_RXD_QW1_STATUS_SHIFT	0
 #define I40E_RXD_QW1_STATUS_MASK	((BIT(I40E_RX_DESC_STATUS_LAST) - 1) \
 					 << I40E_RXD_QW1_STATUS_SHIFT)
-- 
2.51.0