[PATCH net-next v3 2/5] bnxt_en: Implement XDP RSS hash metadata extraction

[Chris J Arges <carges@cloudflare.com>]

Add support for extracting RSS hash values and hash types from hardware
completion descriptors in XDP programs for bnxt_en.

Add IP_TYPE definition for determining if completion is ipv4 or ipv6. In
addition add ITYPE_ICMP flag for identifying ICMP completions.

Signed-off-by: Chris J Arges <carges@cloudflare.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |  5 ++
 drivers/net/ethernet/broadcom/bnxt/bnxt.h     |  2 +
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 47 +++++++++++++++++++
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h |  3 ++
 4 files changed, 57 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index ab73aad40593..c06033cf9f82 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -15906,6 +15906,10 @@ static const struct net_device_ops bnxt_netdev_ops = {
 	.ndo_hwtstamp_set	= bnxt_hwtstamp_set,
 };
 
+static const struct xdp_metadata_ops bnxt_xdp_metadata_ops = {
+	.xmo_rx_hash		= bnxt_xdp_rx_hash,
+};
+
 static void bnxt_get_queue_stats_rx(struct net_device *dev, int i,
 				    struct netdev_queue_stats_rx *stats)
 {
@@ -16790,6 +16794,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto init_err_free;
 
 	dev->netdev_ops = &bnxt_netdev_ops;
+	dev->xdp_metadata_ops = &bnxt_xdp_metadata_ops;
 	dev->stat_ops = &bnxt_stat_ops;
 	dev->watchdog_timeo = BNXT_TX_TIMEOUT;
 	dev->ethtool_ops = &bnxt_ethtool_ops;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 90fa3e93c8d6..34bb98709f2b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -232,6 +232,7 @@ struct rx_cmp {
 	 #define RX_CMP_FLAGS_ITYPE_UDP				 (3 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_FCOE			 (4 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_ROCE			 (5 << 12)
+	 #define RX_CMP_FLAGS_ITYPE_ICMP			 (7 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_PTP_WO_TS			 (8 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_PTP_W_TS			 (9 << 12)
 	#define RX_CMP_LEN					(0xffff << 16)
@@ -311,6 +312,7 @@ struct rx_cmp_ext {
 	#define RX_CMP_FLAGS2_T_IP_CS_CALC			(0x1 << 2)
 	#define RX_CMP_FLAGS2_T_L4_CS_CALC			(0x1 << 3)
 	#define RX_CMP_FLAGS2_META_FORMAT_VLAN			(0x1 << 4)
+	#define RX_CMP_FLAGS2_IP_TYPE				(0x1 << 8)
 	__le32 rx_cmp_meta_data;
 	#define RX_CMP_FLAGS2_METADATA_TCI_MASK			0xffff
 	#define RX_CMP_FLAGS2_METADATA_VID_MASK			0xfff
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index 85cbeb35681c..1f920464b426 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -472,3 +472,50 @@ bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
 				  xdp_buff_get_skb_flags(xdp));
 	return skb;
 }
+
+int bnxt_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
+		     enum xdp_rss_hash_type *rss_type)
+{
+	const struct bnxt_xdp_buff *xdp = (void *)ctx;
+	const struct rx_cmp_ext *rxcmp1 = xdp->rxcmp1;
+	const struct rx_cmp *rxcmp = xdp->rxcmp;
+	enum xdp_rss_hash_type hash_type = 0;
+	u32 itypes;
+
+	if (!rxcmp || !RX_CMP_HASH_VALID(rxcmp))
+		return -ENODATA;
+
+	*hash = le32_to_cpu(rxcmp->rx_cmp_rss_hash);
+
+	if (!rxcmp1) {
+		*rss_type = XDP_RSS_TYPE_L2;
+		return 0;
+	}
+
+	if (xdp->cmp_type == CMP_TYPE_RX_L2_CMP) {
+		itypes = RX_CMP_ITYPES(rxcmp);
+		if (rxcmp1->rx_cmp_flags2 &
+		    cpu_to_le32(RX_CMP_FLAGS2_IP_TYPE)) {
+			hash_type |= XDP_RSS_TYPE_L3_IPV6;
+		} else {
+			hash_type |= XDP_RSS_TYPE_L3_IPV4;
+		}
+
+		switch (itypes) {
+		case RX_CMP_FLAGS_ITYPE_TCP:
+			hash_type |= XDP_RSS_L4 | XDP_RSS_L4_TCP;
+			break;
+		case RX_CMP_FLAGS_ITYPE_UDP:
+			hash_type |= XDP_RSS_L4 | XDP_RSS_L4_UDP;
+			break;
+		case RX_CMP_FLAGS_ITYPE_ICMP:
+			hash_type |= XDP_RSS_L4 | XDP_RSS_L4_ICMP;
+			break;
+		default:
+			break;
+		}
+	}
+
+	*rss_type = hash_type;
+	return 0;
+}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
index 8c66698bde11..fb4f9143929f 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h
@@ -41,4 +41,7 @@ void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
 struct sk_buff *bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb,
 				   u8 num_frags, struct bnxt_rx_ring_info *rxr,
 				   struct xdp_buff *xdp);
+int bnxt_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
+		     enum xdp_rss_hash_type *rss_type);
+
 #endif
-- 
2.43.0