[PATCH v2 net-next] liquidio: store the L4 hash of rx packets in skb

[Felix Manlunas <felix.manlunas@cavium.com>]

From: Prasad Kanneganti <prasad.kanneganti@cavium.com>

Store the L4 hash of received packets in the skb; the hash is computed in
the NIC firmware.

Signed-off-by: Prasad Kanneganti <prasad.kanneganti@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
---
Note: The location of the L4 hash within the 8-byte DHLEN unit is the first
      4 bytes; also that location is endian-independent.  The raw L4 hash
      (in its original form) is big endian.

Patch Changelog:
 v2: Fix two instances of sparse "warning: cast to restricted __be32":  one
     in lio_main.c and one in lio_vf_main.c.  The fix is to replace the
     cast to (u32 *) with a cast to (__be32 *).

 drivers/net/ethernet/cavium/liquidio/lio_main.c        | 18 ++++++++++++++++--
 drivers/net/ethernet/cavium/liquidio/lio_vf_main.c     | 16 +++++++++++++++-
 drivers/net/ethernet/cavium/liquidio/liquidio_common.h |  2 ++
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c
index 13f67a3..b8b579d 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c
@@ -2263,6 +2263,7 @@ liquidio_push_packet(u32 octeon_id __attribute__((unused)),
 	struct skb_shared_hwtstamps *shhwtstamps;
 	u64 ns;
 	u16 vtag = 0;
+	u32 r_dh_off;
 	struct net_device *netdev = (struct net_device *)arg;
 	struct octeon_droq *droq = container_of(param, struct octeon_droq,
 						napi);
@@ -2308,6 +2309,8 @@ liquidio_push_packet(u32 octeon_id __attribute__((unused)),
 			put_page(pg_info->page);
 		}
 
+		r_dh_off = (rh->r_dh.len - 1) * BYTES_PER_DHLEN_UNIT;
+
 		if (((oct->chip_id == OCTEON_CN66XX) ||
 		     (oct->chip_id == OCTEON_CN68XX)) &&
 		    ptp_enable) {
@@ -2320,16 +2323,27 @@ liquidio_push_packet(u32 octeon_id __attribute__((unused)),
 					/* Nanoseconds are in the first 64-bits
 					 * of the packet.
 					 */
-					memcpy(&ns, (skb->data), sizeof(ns));
+					memcpy(&ns, (skb->data + r_dh_off),
+					       sizeof(ns));
+					r_dh_off -= BYTES_PER_DHLEN_UNIT;
 					shhwtstamps = skb_hwtstamps(skb);
 					shhwtstamps->hwtstamp =
 						ns_to_ktime(ns +
 							    lio->ptp_adjust);
 				}
-				skb_pull(skb, sizeof(ns));
 			}
 		}
 
+		if (rh->r_dh.has_hash) {
+			__be32 *hash_be = (__be32 *)(skb->data + r_dh_off);
+			u32 hash = be32_to_cpu(*hash_be);
+
+			skb_set_hash(skb, hash, PKT_HASH_TYPE_L4);
+			r_dh_off -= BYTES_PER_DHLEN_UNIT;
+		}
+
+		skb_pull(skb, rh->r_dh.len * BYTES_PER_DHLEN_UNIT);
+
 		skb->protocol = eth_type_trans(skb, skb->dev);
 		if ((netdev->features & NETIF_F_RXCSUM) &&
 		    (((rh->r_dh.encap_on) &&
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 55846f2..ad2e72d 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -1497,6 +1497,7 @@ liquidio_push_packet(u32 octeon_id __attribute__((unused)),
 	struct net_device *netdev = (struct net_device *)arg;
 	struct sk_buff *skb = (struct sk_buff *)skbuff;
 	u16 vtag = 0;
+	u32 r_dh_off;
 
 	if (netdev) {
 		struct lio *lio = GET_LIO(netdev);
@@ -1540,7 +1541,20 @@ liquidio_push_packet(u32 octeon_id __attribute__((unused)),
 			put_page(pg_info->page);
 		}
 
-		skb_pull(skb, rh->r_dh.len * 8);
+		r_dh_off = (rh->r_dh.len - 1) * BYTES_PER_DHLEN_UNIT;
+
+		if (rh->r_dh.has_hwtstamp)
+			r_dh_off -= BYTES_PER_DHLEN_UNIT;
+
+		if (rh->r_dh.has_hash) {
+			__be32 *hash_be = (__be32 *)(skb->data + r_dh_off);
+			u32 hash = be32_to_cpu(*hash_be);
+
+			skb_set_hash(skb, hash, PKT_HASH_TYPE_L4);
+			r_dh_off -= BYTES_PER_DHLEN_UNIT;
+		}
+
+		skb_pull(skb, rh->r_dh.len * BYTES_PER_DHLEN_UNIT);
 		skb->protocol = eth_type_trans(skb, skb->dev);
 
 		if ((netdev->features & NETIF_F_RXCSUM) &&
diff --git a/drivers/net/ethernet/cavium/liquidio/liquidio_common.h b/drivers/net/ethernet/cavium/liquidio/liquidio_common.h
index ba329f6..bc0af8a 100644
--- a/drivers/net/ethernet/cavium/liquidio/liquidio_common.h
+++ b/drivers/net/ethernet/cavium/liquidio/liquidio_common.h
@@ -98,6 +98,8 @@ enum octeon_tag_type {
 #define CVM_DRV_INVALID_APP         (CVM_DRV_APP_START + 0x2)
 #define CVM_DRV_APP_END             (CVM_DRV_INVALID_APP - 1)
 
+#define BYTES_PER_DHLEN_UNIT        8
+
 static inline u32 incr_index(u32 index, u32 count, u32 max)
 {
 	if ((index + count) >= max)