netvsc: Use the new in-place consumption APIs in the rx path

Use the new APIs for eliminating a copy on the receive path. These new APIs also
help in minimizing the number of memory barriers we end up issuing (in the
ringbuffer code) since we can better control when we want to expose the ring
state to the host.

The patch is being resent to address earlier email issues.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 6909c322de4e76b838d77d91564c911fadab41e0..20e09174ff6240bb5b1ba2eb4f13f0a4fd0d5bf3 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1128,6 +1128,39 @@ static inline void netvsc_receive_inband(struct hv_device *hdev,
        }
 }
 
+static void netvsc_process_raw_pkt(struct hv_device *device,
+                                  struct vmbus_channel *channel,
+                                  struct netvsc_device *net_device,
+                                  struct net_device *ndev,
+                                  u64 request_id,
+                                  struct vmpacket_descriptor *desc)
+{
+       struct nvsp_message *nvmsg;
+
+       nvmsg = (struct nvsp_message *)((unsigned long)
+               desc + (desc->offset8 << 3));
+
+       switch (desc->type) {
+       case VM_PKT_COMP:
+               netvsc_send_completion(net_device, channel, device, desc);
+               break;
+
+       case VM_PKT_DATA_USING_XFER_PAGES:
+               netvsc_receive(net_device, channel, device, desc);
+               break;
+
+       case VM_PKT_DATA_INBAND:
+               netvsc_receive_inband(device, net_device, nvmsg);
+               break;
+
+       default:
+               netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
+                          desc->type, request_id);
+               break;
+       }
+}
+
+
 void netvsc_channel_cb(void *context)
 {
        int ret;
@@ -1140,7 +1173,7 @@ void netvsc_channel_cb(void *context)
        unsigned char *buffer;
        int bufferlen = NETVSC_PACKET_SIZE;
        struct net_device *ndev;
-       struct nvsp_message *nvmsg;
+       bool need_to_commit = false;
 
        if (channel->primary_channel != NULL)
                device = channel->primary_channel->device_obj;
@@ -1154,39 +1187,36 @@ void netvsc_channel_cb(void *context)
        buffer = get_per_channel_state(channel);
 
        do {
+               desc = get_next_pkt_raw(channel);
+               if (desc != NULL) {
+                       netvsc_process_raw_pkt(device,
+                                              channel,
+                                              net_device,
+                                              ndev,
+                                              desc->trans_id,
+                                              desc);
+
+                       put_pkt_raw(channel, desc);
+                       need_to_commit = true;
+                       continue;
+               }
+               if (need_to_commit) {
+                       need_to_commit = false;
+                       commit_rd_index(channel);
+               }
+
                ret = vmbus_recvpacket_raw(channel, buffer, bufferlen,
                                           &bytes_recvd, &request_id);
                if (ret == 0) {
                        if (bytes_recvd > 0) {
                                desc = (struct vmpacket_descriptor *)buffer;
-                               nvmsg = (struct nvsp_message *)((unsigned long)
-                                        desc + (desc->offset8 << 3));
-                               switch (desc->type) {
-                               case VM_PKT_COMP:
-                                       netvsc_send_completion(net_device,
-                                                               channel,
-                                                               device, desc);
-                                       break;
-
-                               case VM_PKT_DATA_USING_XFER_PAGES:
-                                       netvsc_receive(net_device, channel,
-                                                      device, desc);
-                                       break;
-
-                               case VM_PKT_DATA_INBAND:
-                                       netvsc_receive_inband(device,
-                                                             net_device,
-                                                             nvmsg);
-                                       break;
-
-                               default:
-                                       netdev_err(ndev,
-                                                  "unhandled packet type %d, "
-                                                  "tid %llx len %d\n",
-                                                  desc->type, request_id,
-                                                  bytes_recvd);
-                                       break;
-                               }
+                               netvsc_process_raw_pkt(device,
+                                                      channel,
+                                                      net_device,
+                                                      ndev,
+                                                      request_id,
+                                                      desc);
+
 
                        } else {
                                /*