[PATCH] nfp: add support for new metadata api

[Alejandro Lucero <alejandro.lucero@netronome.com>]

NFP is a smart programmable NIC and firmware is deployed for specific
system needs, like offloading OVS, vRouter, contrack or eBPF into the
hardware. This often requires to give metadata to the host within
packets delivered. Last NFP firmware implementations support richer
metadata api facilitating interaction between firmware and host code.

Old way of handling metadata needs to be still there for supporting
old firmware.

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
---
 drivers/net/nfp/nfp_net.c      | 33 +++++++++++++++++++++++++++------
 drivers/net/nfp/nfp_net_ctrl.h |  6 ++++++
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index cee8f63..69ae6d5 100644
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -1726,6 +1726,7 @@ static void nfp_net_read_mac(struct nfp_net_hw *hw)
 
 #define NFP_HASH_OFFSET      ((uint8_t *)mbuf->buf_addr + mbuf->data_off - 4)
 #define NFP_HASH_TYPE_OFFSET ((uint8_t *)mbuf->buf_addr + mbuf->data_off - 8)
+#define NFP_DESC_META_LEN(d) (d->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK)
 
 /*
  * nfp_net_set_hash - Set mbuf hash data
@@ -1739,16 +1740,38 @@ static void nfp_net_read_mac(struct nfp_net_hw *hw)
 {
 	uint32_t hash;
 	uint32_t hash_type;
+	uint32_t meta_info;
+	uint8_t *meta_offset;
 	struct nfp_net_hw *hw = rxq->hw;
 
 	if (!(hw->ctrl & NFP_NET_CFG_CTRL_RSS))
 		return;
 
-	if (!(rxd->rxd.flags & PCIE_DESC_RX_RSS))
+	if (NFD_CFG_MAJOR_VERSION_of(hw->ver) <= 3) {
+		if (!(rxd->rxd.flags & PCIE_DESC_RX_RSS))
+			return;
+
+		hash = rte_be_to_cpu_32(*(uint32_t *)NFP_HASH_OFFSET);
+		hash_type = rte_be_to_cpu_32(*(uint32_t *)NFP_HASH_TYPE_OFFSET);
+
+	} else if (NFP_DESC_META_LEN(rxd)) {
+		meta_offset = (uint8_t *)mbuf->buf_addr;
+		meta_info = rte_be_to_cpu_32(*(uint32_t *)meta_offset);
+		meta_offset += 4;
+		/* NFP PMD just supports metadata for hashing */
+		switch (meta_info & NFP_NET_META_FIELD_MASK) {
+		case NFP_NET_META_HASH:
+			meta_info >>= NFP_NET_META_FIELD_SIZE;
+			hash = rte_be_to_cpu_32(*(uint32_t *)meta_offset);
+			hash_type = meta_info && NFP_NET_META_FIELD_MASK;
+			break;
+		default:
+			/* Unsupported metadata can be a performance issue */
+			return;
+		}
+	} else {
 		return;
-
-	hash = rte_be_to_cpu_32(*(uint32_t *)NFP_HASH_OFFSET);
-	hash_type = rte_be_to_cpu_32(*(uint32_t *)NFP_HASH_TYPE_OFFSET);
+	}
 
 	mbuf->hash.rss = hash;
 	mbuf->ol_flags |= PKT_RX_RSS_HASH;
@@ -1774,8 +1797,6 @@ static void nfp_net_read_mac(struct nfp_net_hw *hw)
 	rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed++;
 }
 
-#define NFP_DESC_META_LEN(d) (d->rxd.meta_len_dd & PCIE_DESC_RX_META_LEN_MASK)
-
 /*
  * RX path design:
  *
diff --git a/drivers/net/nfp/nfp_net_ctrl.h b/drivers/net/nfp/nfp_net_ctrl.h
index 2c50043..281205d 100644
--- a/drivers/net/nfp/nfp_net_ctrl.h
+++ b/drivers/net/nfp/nfp_net_ctrl.h
@@ -52,6 +52,12 @@
 /* Offset in Freelist buffer where packet starts on RX */
 #define NFP_NET_RX_OFFSET               32
 
+/* Prepend field types */
+#define NFP_NET_META_FIELD_SIZE         4
+#define NFP_NET_META_HASH               1 /* next field carries hash type */
+#define NFP_NET_META_MARK               2
+#define NFP_NET_META_FIELD_MASK         (0xf)
+
 /* Hash type pre-pended when a RSS hash was computed */
 #define NFP_NET_RSS_NONE                0
 #define NFP_NET_RSS_IPV4                1
-- 
1.9.1