[PATCH net-next] Add hash value into RNDIS Per-packet info

[Haiyang Zhang <haiyangz@microsoft.com>]

It passes the hash value as the RNDIS Per-packet info to the Hyper-V host,
so that the send completion notices can be spread across multiple channels.
MS-TFS: 140273

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

---
 drivers/net/hyperv/hyperv_net.h |    4 ++++
 drivers/net/hyperv/netvsc_drv.c |   18 ++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 4b7df5a..6cc37c1 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -791,6 +791,7 @@ enum ndis_per_pkt_info_type {
 	IEEE_8021Q_INFO,
 	ORIGINAL_PKTINFO,
 	PACKET_CANCEL_ID,
+	NBL_HASH_VALUE = PACKET_CANCEL_ID,
 	ORIGINAL_NET_BUFLIST,
 	CACHED_NET_BUFLIST,
 	SHORT_PKT_PADINFO,
@@ -937,6 +938,9 @@ struct ndis_tcp_lso_info {
 #define NDIS_LSO_PPI_SIZE (sizeof(struct rndis_per_packet_info) + \
 		sizeof(struct ndis_tcp_lso_info))
 
+#define NDIS_HASH_PPI_SIZE (sizeof(struct rndis_per_packet_info) + \
+		sizeof(u32))
+
 /* Format of Information buffer passed in a SetRequest for the OID */
 /* OID_GEN_RNDIS_CONFIG_PARAMETER. */
 struct rndis_config_parameter_info {
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 2e967a7..4fd71b7 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -224,9 +224,11 @@ static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
 	if (nvsc_dev == NULL || ndev->real_num_tx_queues <= 1)
 		return 0;
 
-	if (netvsc_set_hash(&hash, skb))
+	if (netvsc_set_hash(&hash, skb)) {
 		q_idx = nvsc_dev->send_table[hash % VRSS_SEND_TAB_SIZE] %
 			ndev->real_num_tx_queues;
+		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
+	}
 
 	return q_idx;
 }
@@ -384,6 +386,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	struct ndis_tcp_lso_info *lso_info;
 	int  hdr_offset;
 	u32 net_trans_info;
+	u32 hash;
 
 
 	/* We will atmost need two pages to describe the rndis
@@ -402,9 +405,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 			 (num_data_pgs * sizeof(struct hv_page_buffer)) +
 			 sizeof(struct rndis_message) +
-			 NDIS_VLAN_PPI_SIZE +
-			 NDIS_CSUM_PPI_SIZE +
-			 NDIS_LSO_PPI_SIZE, GFP_ATOMIC);
+			 NDIS_VLAN_PPI_SIZE + NDIS_CSUM_PPI_SIZE +
+			 NDIS_LSO_PPI_SIZE + NDIS_HASH_PPI_SIZE, GFP_ATOMIC);
 	if (!packet) {
 		/* out of memory, drop packet */
 		netdev_err(net, "unable to allocate hv_netvsc_packet\n");
@@ -443,6 +445,14 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 
 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 
+	hash = skb_get_hash_raw(skb);
+	if (hash != 0 && net->real_num_tx_queues > 1) {
+		rndis_msg_size += NDIS_HASH_PPI_SIZE;
+		ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
+				    NBL_HASH_VALUE);
+		*(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
+	}
+
 	if (isvlan) {
 		struct ndis_pkt_8021q_info *vlan;
 
-- 
1.7.4.1