hv_netvsc: optimize initialization of RNDIS header

The memset of the whole maximum possible RNDIS header is unnecessary.
For the main part of the header use a structure assignment.

No need to memset the whole per packet info. Instead rely on caller to
set what it wants. Also get rid of cast to void and signed/unsigned
conversion. Now return pointer to per packet data (rather than the
header) which simplifies use by code setting up the packet data.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index ba690e1737ab7c9662cd6c2b4dd9f39073777d42..dc70de674ca9111becd276bd48444ad87d09afbe 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -177,17 +177,15 @@ out:
        return ret;
 }
 
-static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
-                          int pkt_type)
+static inline void *init_ppi_data(struct rndis_message *msg,
+                                 u32 ppi_size, u32 pkt_type)
 {
-       struct rndis_packet *rndis_pkt;
+       struct rndis_packet *rndis_pkt = &msg->msg.pkt;
        struct rndis_per_packet_info *ppi;
 
-       rndis_pkt = &msg->msg.pkt;
        rndis_pkt->data_offset += ppi_size;
-
-       ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt +
-               rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len);
+       ppi = (void *)rndis_pkt + rndis_pkt->per_pkt_info_offset
+               + rndis_pkt->per_pkt_info_len;
 
        ppi->size = ppi_size;
        ppi->type = pkt_type;
@@ -195,7 +193,7 @@ static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
 
        rndis_pkt->per_pkt_info_len += ppi_size;
 
-       return ppi;
+       return ppi + 1;
 }
 
 /* Azure hosts don't support non-TCP port numbers in hashing for fragmented
@@ -472,10 +470,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
        int ret;
        unsigned int num_data_pgs;
        struct rndis_message *rndis_msg;
-       struct rndis_packet *rndis_pkt;
        struct net_device *vf_netdev;
        u32 rndis_msg_size;
-       struct rndis_per_packet_info *ppi;
        u32 hash;
        struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT];
 
@@ -530,34 +526,36 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 
        rndis_msg = (struct rndis_message *)skb->head;
 
-       memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE);
-
        /* Add the rndis header */
        rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
        rndis_msg->msg_len = packet->total_data_buflen;
-       rndis_pkt = &rndis_msg->msg.pkt;
-       rndis_pkt->data_offset = sizeof(struct rndis_packet);
-       rndis_pkt->data_len = packet->total_data_buflen;
-       rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
+
+       rndis_msg->msg.pkt = (struct rndis_packet) {
+               .data_offset = sizeof(struct rndis_packet),
+               .data_len = packet->total_data_buflen,
+               .per_pkt_info_offset = sizeof(struct rndis_packet),
+       };
 
        rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 
        hash = skb_get_hash_raw(skb);
        if (hash != 0 && net->real_num_tx_queues > 1) {
+               u32 *hash_info;
+
                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;
+               hash_info = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
+                                         NBL_HASH_VALUE);
+               *hash_info = hash;
        }
 
        if (skb_vlan_tag_present(skb)) {
                struct ndis_pkt_8021q_info *vlan;
 
                rndis_msg_size += NDIS_VLAN_PPI_SIZE;
-               ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
-                                   IEEE_8021Q_INFO);
+               vlan = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
+                                    IEEE_8021Q_INFO);
 
-               vlan = (void *)ppi + ppi->ppi_offset;
+               vlan->value = 0;
                vlan->vlanid = skb->vlan_tci & VLAN_VID_MASK;
                vlan->pri = (skb->vlan_tci & VLAN_PRIO_MASK) >>
                                VLAN_PRIO_SHIFT;
@@ -567,11 +565,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
                struct ndis_tcp_lso_info *lso_info;
 
                rndis_msg_size += NDIS_LSO_PPI_SIZE;
-               ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
-                                   TCP_LARGESEND_PKTINFO);
-
-               lso_info = (void *)ppi + ppi->ppi_offset;
+               lso_info = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
+                                        TCP_LARGESEND_PKTINFO);
 
+               lso_info->value = 0;
                lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
                if (skb->protocol == htons(ETH_P_IP)) {
                        lso_info->lso_v2_transmit.ip_version =
@@ -596,12 +593,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
                        struct ndis_tcp_ip_checksum_info *csum_info;
 
                        rndis_msg_size += NDIS_CSUM_PPI_SIZE;
-                       ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
-                                           TCPIP_CHKSUM_PKTINFO);
-
-                       csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
-                                                                        ppi->ppi_offset);
+                       csum_info = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
+                                                 TCPIP_CHKSUM_PKTINFO);
 
+                       csum_info->value = 0;
                        csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
 
                        if (skb->protocol == htons(ETH_P_IP)) {