Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / hyperv / netvsc.c
diff --git a/kernel/drivers/net/hyperv/netvsc.c b/kernel/drivers/net/hyperv/netvsc.c
new file mode 100644 (file)
index 0000000..ea091bc
--- /dev/null
@@ -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;
+}