Initial import

1 files changed, 1231 insertions, 0 deletions

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
new file mode 100644
index 000000000..ea091bc5f
--- /dev/null
+++ b/drivers/net/hyperv/netvsc.c
@@ -0,0 +1,1231 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <asm/sync_bitops.h>
+
+#include "hyperv_net.h"
+
+
+static struct netvsc_device *alloc_net_device(struct hv_device *device)
+{
+	struct netvsc_device *net_device;
+	struct net_device *ndev = hv_get_drvdata(device);
+	int i;
+
+	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
+	if (!net_device)
+		return NULL;
+
+	net_device->cb_buffer = kzalloc(NETVSC_PACKET_SIZE, GFP_KERNEL);
+	if (!net_device->cb_buffer) {
+		kfree(net_device);
+		return NULL;
+	}
+
+	init_waitqueue_head(&net_device->wait_drain);
+	net_device->start_remove = false;
+	net_device->destroy = false;
+	net_device->dev = device;
+	net_device->ndev = ndev;
+	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
+	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
+
+	for (i = 0; i < num_online_cpus(); i++)
+		spin_lock_init(&net_device->msd[i].lock);
+
+	hv_set_drvdata(device, net_device);
+	return net_device;
+}
+
+static void free_netvsc_device(struct netvsc_device *nvdev)
+{
+	kfree(nvdev->cb_buffer);
+	kfree(nvdev);
+}
+
+static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
+{
+	struct netvsc_device *net_device;
+
+	net_device = hv_get_drvdata(device);
+	if (net_device && net_device->destroy)
+		net_device = NULL;
+
+	return net_device;
+}
+
+static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
+{
+	struct netvsc_device *net_device;
+
+	net_device = hv_get_drvdata(device);
+
+	if (!net_device)
+		goto get_in_err;
+
+	if (net_device->destroy &&
+		atomic_read(&net_device->num_outstanding_sends) == 0)
+		net_device = NULL;
+
+get_in_err:
+	return net_device;
+}
+
+
+static int netvsc_destroy_buf(struct netvsc_device *net_device)
+{
+	struct nvsp_message *revoke_packet;
+	int ret = 0;
+	struct net_device *ndev = net_device->ndev;
+
+	/*
+	 * If we got a section count, it means we received a
+	 * SendReceiveBufferComplete msg (ie sent
+	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
+	 * to send a revoke msg here
+	 */
+	if (net_device->recv_section_cnt) {
+		/* Send the revoke receive buffer */
+		revoke_packet = &net_device->revoke_packet;
+		memset(revoke_packet, 0, sizeof(struct nvsp_message));
+
+		revoke_packet->hdr.msg_type =
+			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
+		revoke_packet->msg.v1_msg.
+		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
+
+		ret = vmbus_sendpacket(net_device->dev->channel,
+				       revoke_packet,
+				       sizeof(struct nvsp_message),
+				       (unsigned long)revoke_packet,
+				       VM_PKT_DATA_INBAND, 0);
+		/*
+		 * If we failed here, we might as well return and
+		 * have a leak rather than continue and a bugchk
+		 */
+		if (ret != 0) {
+			netdev_err(ndev, "unable to send "
+				"revoke receive buffer to netvsp\n");
+			return ret;
+		}
+	}
+
+	/* Teardown the gpadl on the vsp end */
+	if (net_device->recv_buf_gpadl_handle) {
+		ret = vmbus_teardown_gpadl(net_device->dev->channel,
+			   net_device->recv_buf_gpadl_handle);
+
+		/* If we failed here, we might as well return and have a leak
+		 * rather than continue and a bugchk
+		 */
+		if (ret != 0) {
+			netdev_err(ndev,
+				   "unable to teardown receive buffer's gpadl\n");
+			return ret;
+		}
+		net_device->recv_buf_gpadl_handle = 0;
+	}
+
+	if (net_device->recv_buf) {
+		/* Free up the receive buffer */
+		vfree(net_device->recv_buf);
+		net_device->recv_buf = NULL;
+	}
+
+	if (net_device->recv_section) {
+		net_device->recv_section_cnt = 0;
+		kfree(net_device->recv_section);
+		net_device->recv_section = NULL;
+	}
+
+	/* Deal with the send buffer we may have setup.
+	 * If we got a  send section size, it means we received a
+	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
+	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
+	 * to send a revoke msg here
+	 */
+	if (net_device->send_section_size) {
+		/* Send the revoke receive buffer */
+		revoke_packet = &net_device->revoke_packet;
+		memset(revoke_packet, 0, sizeof(struct nvsp_message));
+
+		revoke_packet->hdr.msg_type =
+			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
+		revoke_packet->msg.v1_msg.revoke_send_buf.id =
+			NETVSC_SEND_BUFFER_ID;
+
+		ret = vmbus_sendpacket(net_device->dev->channel,
+				       revoke_packet,
+				       sizeof(struct nvsp_message),
+				       (unsigned long)revoke_packet,
+				       VM_PKT_DATA_INBAND, 0);
+		/* If we failed here, we might as well return and
+		 * have a leak rather than continue and a bugchk
+		 */
+		if (ret != 0) {
+			netdev_err(ndev, "unable to send "
+				   "revoke send buffer to netvsp\n");
+			return ret;
+		}
+	}
+	/* Teardown the gpadl on the vsp end */
+	if (net_device->send_buf_gpadl_handle) {
+		ret = vmbus_teardown_gpadl(net_device->dev->channel,
+					   net_device->send_buf_gpadl_handle);
+
+		/* If we failed here, we might as well return and have a leak
+		 * rather than continue and a bugchk
+		 */
+		if (ret != 0) {
+			netdev_err(ndev,
+				   "unable to teardown send buffer's gpadl\n");
+			return ret;
+		}
+		net_device->send_buf_gpadl_handle = 0;
+	}
+	if (net_device->send_buf) {
+		/* Free up the send buffer */
+		vfree(net_device->send_buf);
+		net_device->send_buf = NULL;
+	}
+	kfree(net_device->send_section_map);
+
+	return ret;
+}
+
+static int netvsc_init_buf(struct hv_device *device)
+{
+	int ret = 0;
+	unsigned long t;
+	struct netvsc_device *net_device;
+	struct nvsp_message *init_packet;
+	struct net_device *ndev;
+
+	net_device = get_outbound_net_device(device);
+	if (!net_device)
+		return -ENODEV;
+	ndev = net_device->ndev;
+
+	net_device->recv_buf = vzalloc(net_device->recv_buf_size);
+	if (!net_device->recv_buf) {
+		netdev_err(ndev, "unable to allocate receive "
+			"buffer of size %d\n", net_device->recv_buf_size);
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
+	/*
+	 * Establish the gpadl handle for this buffer on this
+	 * channel.  Note: This call uses the vmbus connection rather
+	 * than the channel to establish the gpadl handle.
+	 */
+	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
+				    net_device->recv_buf_size,
+				    &net_device->recv_buf_gpadl_handle);
+	if (ret != 0) {
+		netdev_err(ndev,
+			"unable to establish receive buffer's gpadl\n");
+		goto cleanup;
+	}
+
+
+	/* Notify the NetVsp of the gpadl handle */
+	init_packet = &net_device->channel_init_pkt;
+
+	memset(init_packet, 0, sizeof(struct nvsp_message));
+
+	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
+	init_packet->msg.v1_msg.send_recv_buf.
+		gpadl_handle = net_device->recv_buf_gpadl_handle;
+	init_packet->msg.v1_msg.
+		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
+
+	/* Send the gpadl notification request */
+	ret = vmbus_sendpacket(device->channel, init_packet,
+			       sizeof(struct nvsp_message),
+			       (unsigned long)init_packet,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0) {
+		netdev_err(ndev,
+			"unable to send receive buffer's gpadl to netvsp\n");
+		goto cleanup;
+	}
+
+	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
+	BUG_ON(t == 0);
+
+
+	/* Check the response */
+	if (init_packet->msg.v1_msg.
+	    send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
+		netdev_err(ndev, "Unable to complete receive buffer "
+			   "initialization with NetVsp - status %d\n",
+			   init_packet->msg.v1_msg.
+			   send_recv_buf_complete.status);
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	/* Parse the response */
+
+	net_device->recv_section_cnt = init_packet->msg.
+		v1_msg.send_recv_buf_complete.num_sections;
+
+	net_device->recv_section = kmemdup(
+		init_packet->msg.v1_msg.send_recv_buf_complete.sections,
+		net_device->recv_section_cnt *
+		sizeof(struct nvsp_1_receive_buffer_section),
+		GFP_KERNEL);
+	if (net_device->recv_section == NULL) {
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	/*
+	 * For 1st release, there should only be 1 section that represents the
+	 * entire receive buffer
+	 */
+	if (net_device->recv_section_cnt != 1 ||
+	    net_device->recv_section->offset != 0) {
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	/* Now setup the send buffer.
+	 */
+	net_device->send_buf = vzalloc(net_device->send_buf_size);
+	if (!net_device->send_buf) {
+		netdev_err(ndev, "unable to allocate send "
+			   "buffer of size %d\n", net_device->send_buf_size);
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
+	/* Establish the gpadl handle for this buffer on this
+	 * channel.  Note: This call uses the vmbus connection rather
+	 * than the channel to establish the gpadl handle.
+	 */
+	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
+				    net_device->send_buf_size,
+				    &net_device->send_buf_gpadl_handle);
+	if (ret != 0) {
+		netdev_err(ndev,
+			   "unable to establish send buffer's gpadl\n");
+		goto cleanup;
+	}
+
+	/* Notify the NetVsp of the gpadl handle */
+	init_packet = &net_device->channel_init_pkt;
+	memset(init_packet, 0, sizeof(struct nvsp_message));
+	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
+	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
+		net_device->send_buf_gpadl_handle;
+	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
+
+	/* Send the gpadl notification request */
+	ret = vmbus_sendpacket(device->channel, init_packet,
+			       sizeof(struct nvsp_message),
+			       (unsigned long)init_packet,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0) {
+		netdev_err(ndev,
+			   "unable to send send buffer's gpadl to netvsp\n");
+		goto cleanup;
+	}
+
+	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
+	BUG_ON(t == 0);
+
+	/* Check the response */
+	if (init_packet->msg.v1_msg.
+	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
+		netdev_err(ndev, "Unable to complete send buffer "
+			   "initialization with NetVsp - status %d\n",
+			   init_packet->msg.v1_msg.
+			   send_send_buf_complete.status);
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	/* Parse the response */
+	net_device->send_section_size = init_packet->msg.
+				v1_msg.send_send_buf_complete.section_size;
+
+	/* Section count is simply the size divided by the section size.
+	 */
+	net_device->send_section_cnt =
+		net_device->send_buf_size/net_device->send_section_size;
+
+	dev_info(&device->device, "Send section size: %d, Section count:%d\n",
+		 net_device->send_section_size, net_device->send_section_cnt);
+
+	/* Setup state for managing the send buffer. */
+	net_device->map_words = DIV_ROUND_UP(net_device->send_section_cnt,
+					     BITS_PER_LONG);
+
+	net_device->send_section_map =
+		kzalloc(net_device->map_words * sizeof(ulong), GFP_KERNEL);
+	if (net_device->send_section_map == NULL) {
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
+	goto exit;
+
+cleanup:
+	netvsc_destroy_buf(net_device);
+
+exit:
+	return ret;
+}
+
+
+/* Negotiate NVSP protocol version */
+static int negotiate_nvsp_ver(struct hv_device *device,
+			      struct netvsc_device *net_device,
+			      struct nvsp_message *init_packet,
+			      u32 nvsp_ver)
+{
+	int ret;
+	unsigned long t;
+
+	memset(init_packet, 0, sizeof(struct nvsp_message));
+	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
+	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
+	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
+
+	/* Send the init request */
+	ret = vmbus_sendpacket(device->channel, init_packet,
+			       sizeof(struct nvsp_message),
+			       (unsigned long)init_packet,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		return ret;
+
+	t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ);
+
+	if (t == 0)
+		return -ETIMEDOUT;
+
+	if (init_packet->msg.init_msg.init_complete.status !=
+	    NVSP_STAT_SUCCESS)
+		return -EINVAL;
+
+	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
+		return 0;
+
+	/* NVSPv2 only: Send NDIS config */
+	memset(init_packet, 0, sizeof(struct nvsp_message));
+	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
+	init_packet->msg.v2_msg.send_ndis_config.mtu = net_device->ndev->mtu +
+						       ETH_HLEN;
+	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
+
+	ret = vmbus_sendpacket(device->channel, init_packet,
+				sizeof(struct nvsp_message),
+				(unsigned long)init_packet,
+				VM_PKT_DATA_INBAND, 0);
+
+	return ret;
+}
+
+static int netvsc_connect_vsp(struct hv_device *device)
+{
+	int ret;
+	struct netvsc_device *net_device;
+	struct nvsp_message *init_packet;
+	int ndis_version;
+	struct net_device *ndev;
+	u32 ver_list[] = { NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
+		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
+	int i, num_ver = 4; /* number of different NVSP versions */
+
+	net_device = get_outbound_net_device(device);
+	if (!net_device)
+		return -ENODEV;
+	ndev = net_device->ndev;
+
+	init_packet = &net_device->channel_init_pkt;
+
+	/* Negotiate the latest NVSP protocol supported */
+	for (i = num_ver - 1; i >= 0; i--)
+		if (negotiate_nvsp_ver(device, net_device, init_packet,
+				       ver_list[i])  == 0) {
+			net_device->nvsp_version = ver_list[i];
+			break;
+		}
+
+	if (i < 0) {
+		ret = -EPROTO;
+		goto cleanup;
+	}
+
+	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
+
+	/* Send the ndis version */
+	memset(init_packet, 0, sizeof(struct nvsp_message));
+
+	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
+		ndis_version = 0x00060001;
+	else
+		ndis_version = 0x0006001e;
+
+	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
+	init_packet->msg.v1_msg.
+		send_ndis_ver.ndis_major_ver =
+				(ndis_version & 0xFFFF0000) >> 16;
+	init_packet->msg.v1_msg.
+		send_ndis_ver.ndis_minor_ver =
+				ndis_version & 0xFFFF;
+
+	/* Send the init request */
+	ret = vmbus_sendpacket(device->channel, init_packet,
+				sizeof(struct nvsp_message),
+				(unsigned long)init_packet,
+				VM_PKT_DATA_INBAND, 0);
+	if (ret != 0)
+		goto cleanup;
+
+	/* Post the big receive buffer to NetVSP */
+	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
+		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
+	else
+		net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
+	net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
+
+	ret = netvsc_init_buf(device);
+
+cleanup:
+	return ret;
+}
+
+static void netvsc_disconnect_vsp(struct netvsc_device *net_device)
+{
+	netvsc_destroy_buf(net_device);
+}
+
+/*
+ * netvsc_device_remove - Callback when the root bus device is removed
+ */
+int netvsc_device_remove(struct hv_device *device)
+{
+	struct netvsc_device *net_device;
+	unsigned long flags;
+
+	net_device = hv_get_drvdata(device);
+
+	netvsc_disconnect_vsp(net_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, no one should be accessing net_device
+	 * except in here
+	 */
+	dev_notice(&device->device, "net device safe to remove\n");
+
+	/* Now, we can close the channel safely */
+	vmbus_close(device->channel);
+
+	/* Release all resources */
+	vfree(net_device->sub_cb_buf);
+	free_netvsc_device(net_device);
+	return 0;
+}
+
+
+#define RING_AVAIL_PERCENT_HIWATER 20
+#define RING_AVAIL_PERCENT_LOWATER 10
+
+/*
+ * Get the percentage of available bytes to write in the ring.
+ * The return value is in range from 0 to 100.
+ */
+static inline u32 hv_ringbuf_avail_percent(
+		struct hv_ring_buffer_info *ring_info)
+{
+	u32 avail_read, avail_write;
+
+	hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
+
+	return avail_write * 100 / ring_info->ring_datasize;
+}
+
+static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
+					 u32 index)
+{
+	sync_change_bit(index, net_device->send_section_map);
+}
+
+static void netvsc_send_completion(struct netvsc_device *net_device,
+				   struct hv_device *device,
+				   struct vmpacket_descriptor *packet)
+{
+	struct nvsp_message *nvsp_packet;
+	struct hv_netvsc_packet *nvsc_packet;
+	struct net_device *ndev;
+	u32 send_index;
+
+	ndev = net_device->ndev;
+
+	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
+			(packet->offset8 << 3));
+
+	if ((nvsp_packet->hdr.msg_type == NVSP_MSG_TYPE_INIT_COMPLETE) ||
+	    (nvsp_packet->hdr.msg_type ==
+	     NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE) ||
+	    (nvsp_packet->hdr.msg_type ==
+	     NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE) ||
+	    (nvsp_packet->hdr.msg_type ==
+	     NVSP_MSG5_TYPE_SUBCHANNEL)) {
+		/* Copy the response back */
+		memcpy(&net_device->channel_init_pkt, nvsp_packet,
+		       sizeof(struct nvsp_message));
+		complete(&net_device->channel_init_wait);
+	} else if (nvsp_packet->hdr.msg_type ==
+		   NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE) {
+		int num_outstanding_sends;
+		u16 q_idx = 0;
+		struct vmbus_channel *channel = device->channel;
+		int queue_sends;
+
+		/* Get the send context */
+		nvsc_packet = (struct hv_netvsc_packet *)(unsigned long)
+			packet->trans_id;
+
+		/* Notify the layer above us */
+		if (nvsc_packet) {
+			send_index = nvsc_packet->send_buf_index;
+			if (send_index != NETVSC_INVALID_INDEX)
+				netvsc_free_send_slot(net_device, send_index);
+			q_idx = nvsc_packet->q_idx;
+			channel = nvsc_packet->channel;
+			nvsc_packet->send_completion(nvsc_packet->
+						     send_completion_ctx);
+		}
+
+		num_outstanding_sends =
+			atomic_dec_return(&net_device->num_outstanding_sends);
+		queue_sends = atomic_dec_return(&net_device->
+						queue_sends[q_idx]);
+
+		if (net_device->destroy && num_outstanding_sends == 0)
+			wake_up(&net_device->wait_drain);
+
+		if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
+		    !net_device->start_remove &&
+		    (hv_ringbuf_avail_percent(&channel->outbound) >
+		     RING_AVAIL_PERCENT_HIWATER || queue_sends < 1))
+				netif_tx_wake_queue(netdev_get_tx_queue(
+						    ndev, q_idx));
+	} else {
+		netdev_err(ndev, "Unknown send completion packet type- "
+			   "%d received!!\n", nvsp_packet->hdr.msg_type);
+	}
+
+}
+
+static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
+{
+	unsigned long index;
+	u32 max_words = net_device->map_words;
+	unsigned long *map_addr = (unsigned long *)net_device->send_section_map;
+	u32 section_cnt = net_device->send_section_cnt;
+	int ret_val = NETVSC_INVALID_INDEX;
+	int i;
+	int prev_val;
+
+	for (i = 0; i < max_words; i++) {
+		if (!~(map_addr[i]))
+			continue;
+		index = ffz(map_addr[i]);
+		prev_val = sync_test_and_set_bit(index, &map_addr[i]);
+		if (prev_val)
+			continue;
+		if ((index + (i * BITS_PER_LONG)) >= section_cnt)
+			break;
+		ret_val = (index + (i * BITS_PER_LONG));
+		break;
+	}
+	return ret_val;
+}
+
+static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
+				   unsigned int section_index,
+				   u32 pend_size,
+				   struct hv_netvsc_packet *packet)
+{
+	char *start = net_device->send_buf;
+	char *dest = start + (section_index * net_device->send_section_size)
+		     + pend_size;
+	int i;
+	u32 msg_size = 0;
+	u32 padding = 0;
+	u32 remain = packet->total_data_buflen % net_device->pkt_align;
+	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
+		packet->page_buf_cnt;
+
+	/* Add padding */
+	if (packet->is_data_pkt && packet->xmit_more && remain &&
+	    !packet->cp_partial) {
+		padding = net_device->pkt_align - remain;
+		packet->rndis_msg->msg_len += padding;
+		packet->total_data_buflen += padding;
+	}
+
+	for (i = 0; i < page_count; i++) {
+		char *src = phys_to_virt(packet->page_buf[i].pfn << PAGE_SHIFT);
+		u32 offset = packet->page_buf[i].offset;
+		u32 len = packet->page_buf[i].len;
+
+		memcpy(dest, (src + offset), len);
+		msg_size += len;
+		dest += len;
+	}
+
+	if (padding) {
+		memset(dest, 0, padding);
+		msg_size += padding;
+	}
+
+	return msg_size;
+}
+
+static inline int netvsc_send_pkt(
+	struct hv_netvsc_packet *packet,
+	struct netvsc_device *net_device)
+{
+	struct nvsp_message nvmsg;
+	struct vmbus_channel *out_channel = packet->channel;
+	u16 q_idx = packet->q_idx;
+	struct net_device *ndev = net_device->ndev;
+	u64 req_id;
+	int ret;
+	struct hv_page_buffer *pgbuf;
+
+	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
+	if (packet->is_data_pkt) {
+		/* 0 is RMC_DATA; */
+		nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
+	} else {
+		/* 1 is RMC_CONTROL; */
+		nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
+	}
+
+	nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
+		packet->send_buf_index;
+	if (packet->send_buf_index == NETVSC_INVALID_INDEX)
+		nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
+	else
+		nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
+			packet->total_data_buflen;
+
+	if (packet->send_completion)
+		req_id = (ulong)packet;
+	else
+		req_id = 0;
+
+	if (out_channel->rescind)
+		return -ENODEV;
+
+	if (packet->page_buf_cnt) {
+		pgbuf = packet->cp_partial ? packet->page_buf +
+			packet->rmsg_pgcnt : packet->page_buf;
+		ret = vmbus_sendpacket_pagebuffer(out_channel,
+						  pgbuf,
+						  packet->page_buf_cnt,
+						  &nvmsg,
+						  sizeof(struct nvsp_message),
+						  req_id);
+	} else {
+		ret = vmbus_sendpacket(
+				out_channel, &nvmsg,
+				sizeof(struct nvsp_message),
+				req_id,
+				VM_PKT_DATA_INBAND,
+				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret == 0) {
+		atomic_inc(&net_device->num_outstanding_sends);
+		atomic_inc(&net_device->queue_sends[q_idx]);
+
+		if (hv_ringbuf_avail_percent(&out_channel->outbound) <
+			RING_AVAIL_PERCENT_LOWATER) {
+			netif_tx_stop_queue(netdev_get_tx_queue(
+					    ndev, q_idx));
+
+			if (atomic_read(&net_device->
+				queue_sends[q_idx]) < 1)
+				netif_tx_wake_queue(netdev_get_tx_queue(
+						    ndev, q_idx));
+		}
+	} else if (ret == -EAGAIN) {
+		netif_tx_stop_queue(netdev_get_tx_queue(
+				    ndev, q_idx));
+		if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
+			netif_tx_wake_queue(netdev_get_tx_queue(
+					    ndev, q_idx));
+			ret = -ENOSPC;
+		}
+	} else {
+		netdev_err(ndev, "Unable to send packet %p ret %d\n",
+			   packet, ret);
+	}
+
+	return ret;
+}
+
+int netvsc_send(struct hv_device *device,
+		struct hv_netvsc_packet *packet)
+{
+	struct netvsc_device *net_device;
+	int ret = 0, m_ret = 0;
+	struct vmbus_channel *out_channel;
+	u16 q_idx = packet->q_idx;
+	u32 pktlen = packet->total_data_buflen, msd_len = 0;
+	unsigned int section_index = NETVSC_INVALID_INDEX;
+	unsigned long flag;
+	struct multi_send_data *msdp;
+	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
+	bool try_batch;
+
+	net_device = get_outbound_net_device(device);
+	if (!net_device)
+		return -ENODEV;
+
+	out_channel = net_device->chn_table[q_idx];
+	if (!out_channel) {
+		out_channel = device->channel;
+		q_idx = 0;
+		packet->q_idx = 0;
+	}
+	packet->channel = out_channel;
+	packet->send_buf_index = NETVSC_INVALID_INDEX;
+	packet->cp_partial = false;
+
+	msdp = &net_device->msd[q_idx];
+
+	/* batch packets in send buffer if possible */
+	spin_lock_irqsave(&msdp->lock, flag);
+	if (msdp->pkt)
+		msd_len = msdp->pkt->total_data_buflen;
+
+	try_batch = packet->is_data_pkt && msd_len > 0 && msdp->count <
+		    net_device->max_pkt;
+
+	if (try_batch && msd_len + pktlen + net_device->pkt_align <
+	    net_device->send_section_size) {
+		section_index = msdp->pkt->send_buf_index;
+
+	} else if (try_batch && msd_len + packet->rmsg_size <
+		   net_device->send_section_size) {
+		section_index = msdp->pkt->send_buf_index;
+		packet->cp_partial = true;
+
+	} else if (packet->is_data_pkt && pktlen + net_device->pkt_align <
+		   net_device->send_section_size) {
+		section_index = netvsc_get_next_send_section(net_device);
+		if (section_index != NETVSC_INVALID_INDEX) {
+				msd_send = msdp->pkt;
+				msdp->pkt = NULL;
+				msdp->count = 0;
+				msd_len = 0;
+		}
+	}
+
+	if (section_index != NETVSC_INVALID_INDEX) {
+		netvsc_copy_to_send_buf(net_device,
+					section_index, msd_len,
+					packet);
+
+		packet->send_buf_index = section_index;
+
+		if (packet->cp_partial) {
+			packet->page_buf_cnt -= packet->rmsg_pgcnt;
+			packet->total_data_buflen = msd_len + packet->rmsg_size;
+		} else {
+			packet->page_buf_cnt = 0;
+			packet->total_data_buflen += msd_len;
+		}
+
+		if (msdp->pkt)
+			netvsc_xmit_completion(msdp->pkt);
+
+		if (packet->xmit_more && !packet->cp_partial) {
+			msdp->pkt = packet;
+			msdp->count++;
+		} else {
+			cur_send = packet;
+			msdp->pkt = NULL;
+			msdp->count = 0;
+		}
+	} else {
+		msd_send = msdp->pkt;
+		msdp->pkt = NULL;
+		msdp->count = 0;
+		cur_send = packet;
+	}
+
+	spin_unlock_irqrestore(&msdp->lock, flag);
+
+	if (msd_send) {
+		m_ret = netvsc_send_pkt(msd_send, net_device);
+
+		if (m_ret != 0) {
+			netvsc_free_send_slot(net_device,
+					      msd_send->send_buf_index);
+			netvsc_xmit_completion(msd_send);
+		}
+	}
+
+	if (cur_send)
+		ret = netvsc_send_pkt(cur_send, net_device);
+
+	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
+		netvsc_free_send_slot(net_device, section_index);
+
+	return ret;
+}
+
+static void netvsc_send_recv_completion(struct hv_device *device,
+					struct vmbus_channel *channel,
+					struct netvsc_device *net_device,
+					u64 transaction_id, u32 status)
+{
+	struct nvsp_message recvcompMessage;
+	int retries = 0;
+	int ret;
+	struct net_device *ndev;
+
+	ndev = net_device->ndev;
+
+	recvcompMessage.hdr.msg_type =
+				NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
+
+	recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
+
+retry_send_cmplt:
+	/* Send the completion */
+	ret = vmbus_sendpacket(channel, &recvcompMessage,
+			       sizeof(struct nvsp_message), transaction_id,
+			       VM_PKT_COMP, 0);
+	if (ret == 0) {
+		/* success */
+		/* no-op */
+	} else if (ret == -EAGAIN) {
+		/* no more room...wait a bit and attempt to retry 3 times */
+		retries++;
+		netdev_err(ndev, "unable to send receive completion pkt"
+			" (tid %llx)...retrying %d\n", transaction_id, retries);
+
+		if (retries < 4) {
+			udelay(100);
+			goto retry_send_cmplt;
+		} else {
+			netdev_err(ndev, "unable to send receive "
+				"completion pkt (tid %llx)...give up retrying\n",
+				transaction_id);
+		}
+	} else {
+		netdev_err(ndev, "unable to send receive "
+			"completion pkt - %llx\n", transaction_id);
+	}
+}
+
+static void netvsc_receive(struct netvsc_device *net_device,
+			struct vmbus_channel *channel,
+			struct hv_device *device,
+			struct vmpacket_descriptor *packet)
+{
+	struct vmtransfer_page_packet_header *vmxferpage_packet;
+	struct nvsp_message *nvsp_packet;
+	struct hv_netvsc_packet nv_pkt;
+	struct hv_netvsc_packet *netvsc_packet = &nv_pkt;
+	u32 status = NVSP_STAT_SUCCESS;
+	int i;
+	int count = 0;
+	struct net_device *ndev;
+
+	ndev = net_device->ndev;
+
+	/*
+	 * All inbound packets other than send completion should be xfer page
+	 * packet
+	 */
+	if (packet->type != VM_PKT_DATA_USING_XFER_PAGES) {
+		netdev_err(ndev, "Unknown packet type received - %d\n",
+			   packet->type);
+		return;
+	}
+
+	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
+			(packet->offset8 << 3));
+
+	/* Make sure this is a valid nvsp packet */
+	if (nvsp_packet->hdr.msg_type !=
+	    NVSP_MSG1_TYPE_SEND_RNDIS_PKT) {
+		netdev_err(ndev, "Unknown nvsp packet type received-"
+			" %d\n", nvsp_packet->hdr.msg_type);
+		return;
+	}
+
+	vmxferpage_packet = (struct vmtransfer_page_packet_header *)packet;
+
+	if (vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID) {
+		netdev_err(ndev, "Invalid xfer page set id - "
+			   "expecting %x got %x\n", NETVSC_RECEIVE_BUFFER_ID,
+			   vmxferpage_packet->xfer_pageset_id);
+		return;
+	}
+
+	count = vmxferpage_packet->range_cnt;
+	netvsc_packet->channel = channel;
+
+	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
+	for (i = 0; i < count; i++) {
+		/* Initialize the netvsc packet */
+		netvsc_packet->status = NVSP_STAT_SUCCESS;
+		netvsc_packet->data = (void *)((unsigned long)net_device->
+			recv_buf + vmxferpage_packet->ranges[i].byte_offset);
+		netvsc_packet->total_data_buflen =
+					vmxferpage_packet->ranges[i].byte_count;
+
+		/* Pass it to the upper layer */
+		rndis_filter_receive(device, netvsc_packet);
+
+		if (netvsc_packet->status != NVSP_STAT_SUCCESS)
+			status = NVSP_STAT_FAIL;
+	}
+
+	netvsc_send_recv_completion(device, channel, net_device,
+				    vmxferpage_packet->d.trans_id, status);
+}
+
+
+static void netvsc_send_table(struct hv_device *hdev,
+			      struct vmpacket_descriptor *vmpkt)
+{
+	struct netvsc_device *nvscdev;
+	struct net_device *ndev;
+	struct nvsp_message *nvmsg;
+	int i;
+	u32 count, *tab;
+
+	nvscdev = get_outbound_net_device(hdev);
+	if (!nvscdev)
+		return;
+	ndev = nvscdev->ndev;
+
+	nvmsg = (struct nvsp_message *)((unsigned long)vmpkt +
+					(vmpkt->offset8 << 3));
+
+	if (nvmsg->hdr.msg_type != NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE)
+		return;
+
+	count = nvmsg->msg.v5_msg.send_table.count;
+	if (count != VRSS_SEND_TAB_SIZE) {
+		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
+		return;
+	}
+
+	tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
+		      nvmsg->msg.v5_msg.send_table.offset);
+
+	for (i = 0; i < count; i++)
+		nvscdev->send_table[i] = tab[i];
+}
+
+void netvsc_channel_cb(void *context)
+{
+	int ret;
+	struct vmbus_channel *channel = (struct vmbus_channel *)context;
+	struct hv_device *device;
+	struct netvsc_device *net_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	struct vmpacket_descriptor *desc;
+	unsigned char *buffer;
+	int bufferlen = NETVSC_PACKET_SIZE;
+	struct net_device *ndev;
+
+	if (channel->primary_channel != NULL)
+		device = channel->primary_channel->device_obj;
+	else
+		device = channel->device_obj;
+
+	net_device = get_inbound_net_device(device);
+	if (!net_device)
+		return;
+	ndev = net_device->ndev;
+	buffer = get_per_channel_state(channel);
+
+	do {
+		ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
+					   &bytes_recvd, &request_id);
+		if (ret == 0) {
+			if (bytes_recvd > 0) {
+				desc = (struct vmpacket_descriptor *)buffer;
+				switch (desc->type) {
+				case VM_PKT_COMP:
+					netvsc_send_completion(net_device,
+								device, desc);
+					break;
+
+				case VM_PKT_DATA_USING_XFER_PAGES:
+					netvsc_receive(net_device, channel,
+						       device, desc);
+					break;
+
+				case VM_PKT_DATA_INBAND:
+					netvsc_send_table(device, desc);
+					break;
+
+				default:
+					netdev_err(ndev,
+						   "unhandled packet type %d, "
+						   "tid %llx len %d\n",
+						   desc->type, request_id,
+						   bytes_recvd);
+					break;
+				}
+
+			} else {
+				/*
+				 * We are done for this pass.
+				 */
+				break;
+			}
+
+		} else if (ret == -ENOBUFS) {
+			if (bufferlen > NETVSC_PACKET_SIZE)
+				kfree(buffer);
+			/* Handle large packet */
+			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
+			if (buffer == NULL) {
+				/* Try again next time around */
+				netdev_err(ndev,
+					   "unable to allocate buffer of size "
+					   "(%d)!!\n", bytes_recvd);
+				break;
+			}
+
+			bufferlen = bytes_recvd;
+		}
+	} while (1);
+
+	if (bufferlen > NETVSC_PACKET_SIZE)
+		kfree(buffer);
+	return;
+}
+
+/*
+ * netvsc_device_add - Callback when the device belonging to this
+ * driver is added
+ */
+int netvsc_device_add(struct hv_device *device, void *additional_info)
+{
+	int ret = 0;
+	int ring_size =
+	((struct netvsc_device_info *)additional_info)->ring_size;
+	struct netvsc_device *net_device;
+	struct net_device *ndev;
+
+	net_device = alloc_net_device(device);
+	if (!net_device)
+		return -ENOMEM;
+
+	net_device->ring_size = ring_size;
+
+	/*
+	 * Coming into this function, struct net_device * is
+	 * registered as the driver private data.
+	 * In alloc_net_device(), we register struct netvsc_device *
+	 * as the driver private data and stash away struct net_device *
+	 * in struct netvsc_device *.
+	 */
+	ndev = net_device->ndev;
+
+	/* Add netvsc_device context to netvsc_device */
+	net_device->nd_ctx = netdev_priv(ndev);
+
+	/* Initialize the NetVSC channel extension */
+	init_completion(&net_device->channel_init_wait);
+
+	set_per_channel_state(device->channel, net_device->cb_buffer);
+
+	/* Open the channel */
+	ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
+			 ring_size * PAGE_SIZE, NULL, 0,
+			 netvsc_channel_cb, device->channel);
+
+	if (ret != 0) {
+		netdev_err(ndev, "unable to open channel: %d\n", ret);
+		goto cleanup;
+	}
+
+	/* Channel is opened */
+	pr_info("hv_netvsc channel opened successfully\n");
+
+	net_device->chn_table[0] = device->channel;
+
+	/* Connect with the NetVsp */
+	ret = netvsc_connect_vsp(device);
+	if (ret != 0) {
+		netdev_err(ndev,
+			"unable to connect to NetVSP - %d\n", ret);
+		goto close;
+	}
+
+	return ret;
+
+close:
+	/* Now, we can close the channel safely */
+	vmbus_close(device->channel);
+
+cleanup:
+	free_netvsc_device(net_device);
+
+	return ret;
+}