diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index fc6d0c6de741..731054ef6da5 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -124,6 +124,9 @@ struct ndis_tcp_ip_checksum_info; /* * Represent netvsc packet which contains 1 RNDIS and 1 ethernet frame * within the RNDIS + * + * The size of this structure is less than 48 bytes and we can now + * place this structure in the skb->cb field. */ struct hv_netvsc_packet { /* Bookkeeping stuff */ diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 7e356a11c1d7..b820888409bc 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -433,7 +433,6 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) u32 net_trans_info; u32 hash; u32 skb_length; - u32 pkt_sz; struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT]; struct netvsc_stats *tx_stats = this_cpu_ptr(net_device_ctx->tx_stats); @@ -461,16 +460,21 @@ check_size: goto check_size; } - pkt_sz = sizeof(struct hv_netvsc_packet) + RNDIS_AND_PPI_SIZE; - - ret = skb_cow_head(skb, pkt_sz); + /* + * Place the rndis header in the skb head room and + * the skb->cb will be used for hv_netvsc_packet + * structure. + */ + ret = skb_cow_head(skb, RNDIS_AND_PPI_SIZE); if (ret) { netdev_err(net, "unable to alloc hv_netvsc_packet\n"); ret = -ENOMEM; goto drop; } - /* Use the headroom for building up the packet */ - packet = (struct hv_netvsc_packet *)skb->head; + /* Use the skb control buffer for building up the packet */ + BUILD_BUG_ON(sizeof(struct hv_netvsc_packet) > + FIELD_SIZEOF(struct sk_buff, cb)); + packet = (struct hv_netvsc_packet *)skb->cb; packet->status = 0; packet->xmit_more = skb->xmit_more; @@ -483,8 +487,7 @@ check_size: packet->is_data_pkt = true; packet->total_data_buflen = skb->len; - rndis_msg = (struct rndis_message *)((unsigned long)packet + - sizeof(struct hv_netvsc_packet)); + rndis_msg = (struct rndis_message *)skb->head; memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE); @@ -1118,16 +1121,12 @@ static int netvsc_probe(struct hv_device *dev, struct netvsc_device_info device_info; struct netvsc_device *nvdev; int ret; - u32 max_needed_headroom; net = alloc_etherdev_mq(sizeof(struct net_device_context), num_online_cpus()); if (!net) return -ENOMEM; - max_needed_headroom = sizeof(struct hv_netvsc_packet) + - RNDIS_AND_PPI_SIZE; - netif_carrier_off(net); net_device_ctx = netdev_priv(net); @@ -1166,13 +1165,6 @@ static int netvsc_probe(struct hv_device *dev, net->ethtool_ops = ðtool_ops; SET_NETDEV_DEV(net, &dev->device); - /* - * Request additional head room in the skb. - * We will use this space to build the rndis - * heaser and other state we need to maintain. - */ - net->needed_headroom = max_needed_headroom; - /* Notify the netvsc driver of the new device */ memset(&device_info, 0, sizeof(device_info)); device_info.ring_size = ring_size; diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 7d2d1d7aaec7..fcbc5259c630 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -132,7 +132,9 @@ static inline bool dev_xmit_complete(int rc) * used. */ -#if defined(CONFIG_WLAN) || IS_ENABLED(CONFIG_AX25) +#if defined(CONFIG_HYPERV_NET) +# define LL_MAX_HEADER 128 +#elif defined(CONFIG_WLAN) || IS_ENABLED(CONFIG_AX25) # if defined(CONFIG_MAC80211_MESH) # define LL_MAX_HEADER 128 # else