Commit 3271e4f1 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'hv_netvsc-next' 



K. Y. Srinivasan says:

====================
hv_netvsc: Eliminate memory allocation in the send path

The network protocol used to communicate with the host is the remote ndis (rndis)
protocol. We need to decorate each outgoing packet with a rndis header and
additional rndis state (rndis per-packet state). To manage this state, we
currently allocate memory in the transmit path. Eliminate this allocation by
requesting additional head room in the skb.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 4e833c59 b08cc791

drivers/net/hyperv/hyperv_net.h

+2 −1
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ struct ndis_tcp_ip_checksum_info; 
struct hv_netvsc_packet {

	/* Bookkeeping stuff */

	u32 status;

	bool part_of_skb;



	struct hv_device *device;

	bool is_data_pkt;
@@ -150,7 +151,7 @@ struct hv_netvsc_packet { 
	/* Points to the send/receive buffer where the ethernet frame is */

	void *data;

	u32 page_buf_cnt;

	struct hv_page_buffer page_buf[0];

	struct hv_page_buffer *page_buf;

};



struct netvsc_device_info {

drivers/net/hyperv/netvsc.c

+7 −2
Original line number Diff line number Diff line
@@ -866,8 +866,13 @@ int netvsc_send(struct hv_device *device, 
		netvsc_copy_to_send_buf(net_device,

					section_index, msd_len,

					packet);

		if (!packet->part_of_skb) {

			skb = (struct sk_buff *)

		       (unsigned long)packet->send_completion_tid;

				(unsigned long)

				packet->send_completion_tid;



			packet->send_completion_tid = 0;

		}



		packet->page_buf_cnt = 0;

		packet->send_buf_index = section_index;

drivers/net/hyperv/netvsc_drv.c

+50 −20
Original line number Diff line number Diff line
@@ -234,11 +234,11 @@ static void netvsc_xmit_completion(void *context) 
	struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;

	struct sk_buff *skb = (struct sk_buff *)

		(unsigned long)packet->send_completion_tid;

	u32 index = packet->send_buf_index;



	if (!packet->part_of_skb)

		kfree(packet);



	if (skb && (index == NETVSC_INVALID_INDEX))

	if (skb)

		dev_kfree_skb_any(skb);

}
@@ -384,6 +384,9 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) 
	u32 net_trans_info;

	u32 hash;

	u32 skb_length = skb->len;

	u32 head_room = skb_headroom(skb);

	u32 pkt_sz;

	struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];





	/* We will atmost need two pages to describe the rndis
@@ -398,24 +401,32 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) 
		return NETDEV_TX_OK;

	}



	/* Allocate a netvsc packet based on # of frags. */

	packet = kzalloc(sizeof(struct hv_netvsc_packet) +

			 (num_data_pgs * sizeof(struct hv_page_buffer)) +

	pkt_sz = sizeof(struct hv_netvsc_packet) +

			sizeof(struct rndis_message) +

			NDIS_VLAN_PPI_SIZE + NDIS_CSUM_PPI_SIZE +

			 NDIS_LSO_PPI_SIZE + NDIS_HASH_PPI_SIZE, GFP_ATOMIC);

			NDIS_LSO_PPI_SIZE + NDIS_HASH_PPI_SIZE;



	if (head_room < pkt_sz) {

		packet = kmalloc(pkt_sz, GFP_ATOMIC);

		if (!packet) {

			/* out of memory, drop packet */

		netdev_err(net, "unable to allocate hv_netvsc_packet\n");



			netdev_err(net, "unable to alloc hv_netvsc_packet\n");

			dev_kfree_skb(skb);

			net->stats.tx_dropped++;

			return NETDEV_TX_OK;

		}

		packet->part_of_skb = false;

	} else {

		/* Use the headroom for building up the packet */

		packet = (struct hv_netvsc_packet *)skb->head;

		packet->part_of_skb = true;

	}



	packet->status = 0;

	packet->xmit_more = skb->xmit_more;



	packet->vlan_tci = skb->vlan_tci;

	packet->page_buf = page_buf;



	packet->q_idx = skb_get_queue_mapping(skb);
@@ -423,8 +434,13 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) 
	packet->total_data_buflen = skb->len;



	packet->rndis_msg = (struct rndis_message *)((unsigned long)packet +

				sizeof(struct hv_netvsc_packet) +

				(num_data_pgs * sizeof(struct hv_page_buffer)));

				sizeof(struct hv_netvsc_packet));



	memset(packet->rndis_msg, 0, sizeof(struct rndis_message) +

					NDIS_VLAN_PPI_SIZE +

					NDIS_CSUM_PPI_SIZE +

					NDIS_LSO_PPI_SIZE +

					NDIS_HASH_PPI_SIZE);



	/* Set the completion routine */

	packet->send_completion = netvsc_xmit_completion;
@@ -556,7 +572,7 @@ do_send: 
	rndis_msg->msg_len += rndis_msg_size;

	packet->total_data_buflen = rndis_msg->msg_len;

	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,

					skb, &packet->page_buf[0]);

					skb, &page_buf[0]);



	ret = netvsc_send(net_device_ctx->device_ctx, packet);
@@ -565,6 +581,7 @@ drop: 
		net->stats.tx_bytes += skb_length;

		net->stats.tx_packets++;

	} else {

		if (!packet->part_of_skb)

			kfree(packet);

		if (ret != -EAGAIN) {

			dev_kfree_skb_any(skb);
@@ -847,12 +864,18 @@ 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) +

				sizeof(struct rndis_message) +

				NDIS_VLAN_PPI_SIZE + NDIS_CSUM_PPI_SIZE +

				NDIS_LSO_PPI_SIZE + NDIS_HASH_PPI_SIZE;



	netif_carrier_off(net);



	net_device_ctx = netdev_priv(net);
@@ -871,6 +894,13 @@ static int netvsc_probe(struct hv_device *dev, 
	net->ethtool_ops = &ethtool_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 */

	device_info.ring_size = ring_size;

	ret = rndis_filter_device_add(dev, &device_info);

drivers/net/hyperv/rndis_filter.c

+2 −0
Original line number Diff line number Diff line
@@ -210,6 +210,7 @@ static int rndis_filter_send_request(struct rndis_device *dev, 
{

	int ret;

	struct hv_netvsc_packet *packet;

	struct hv_page_buffer page_buf[2];



	/* Setup the packet to send it */

	packet = &req->pkt;
@@ -217,6 +218,7 @@ static int rndis_filter_send_request(struct rndis_device *dev, 
	packet->is_data_pkt = false;

	packet->total_data_buflen = req->request_msg.msg_len;

	packet->page_buf_cnt = 1;

	packet->page_buf = page_buf;



	packet->page_buf[0].pfn = virt_to_phys(&req->request_msg) >>

					PAGE_SHIFT;

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