1 files changed, 138 insertions, 32 deletions

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 8078bc209cac..b15edfc37a59 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -74,6 +74,9 @@ static struct netvsc_device *alloc_net_device(void)
 		return NULL;
 	}
 
+	net_device->mrc[0].buf = vzalloc(NETVSC_RECVSLOT_MAX *
+					 sizeof(struct recv_comp_data));
+
 	init_waitqueue_head(&net_device->wait_drain);
 	net_device->destroy = false;
 	atomic_set(&net_device->open_cnt, 0);
@@ -85,6 +88,11 @@ static struct netvsc_device *alloc_net_device(void)
 
 static void free_netvsc_device(struct netvsc_device *nvdev)
 {
+	int i;
+
+	for (i = 0; i < VRSS_CHANNEL_MAX; i++)
+		vfree(nvdev->mrc[i].buf);
+
 	kfree(nvdev->cb_buffer);
 	kfree(nvdev);
 }
@@ -107,7 +115,8 @@ static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 		goto get_in_err;
 
 	if (net_device->destroy &&
-		atomic_read(&net_device->num_outstanding_sends) == 0)
+	    atomic_read(&net_device->num_outstanding_sends) == 0 &&
+	    atomic_read(&net_device->num_outstanding_recvs) == 0)
 		net_device = NULL;
 
 get_in_err:
@@ -972,49 +981,121 @@ send_now:
 	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)
+static int netvsc_send_recv_completion(struct vmbus_channel *channel,
+				       u64 transaction_id, u32 status)
 {
 	struct nvsp_message recvcompMessage;
-	int retries = 0;
 	int ret;
-	struct net_device *ndev = hv_get_drvdata(device);
 
 	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);
+			       sizeof(struct nvsp_message_header) + sizeof(u32),
+			       transaction_id, VM_PKT_COMP, 0);
+
+	return ret;
+}
+
+static inline void count_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx,
+					u32 *filled, u32 *avail)
+{
+	u32 first = nvdev->mrc[q_idx].first;
+	u32 next = nvdev->mrc[q_idx].next;
+
+	*filled = (first > next) ? NETVSC_RECVSLOT_MAX - first + next :
+		  next - first;
+
+	*avail = NETVSC_RECVSLOT_MAX - *filled - 1;
+}
+
+/* Read the first filled slot, no change to index */
+static inline struct recv_comp_data *read_recv_comp_slot(struct netvsc_device
+							 *nvdev, u16 q_idx)
+{
+	u32 filled, avail;
+
+	if (!nvdev->mrc[q_idx].buf)
+		return NULL;
+
+	count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
+	if (!filled)
+		return NULL;
+
+	return nvdev->mrc[q_idx].buf + nvdev->mrc[q_idx].first *
+	       sizeof(struct recv_comp_data);
+}
+
+/* Put the first filled slot back to available pool */
+static inline void put_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx)
+{
+	int num_recv;
+
+	nvdev->mrc[q_idx].first = (nvdev->mrc[q_idx].first + 1) %
+				  NETVSC_RECVSLOT_MAX;
+
+	num_recv = atomic_dec_return(&nvdev->num_outstanding_recvs);
+
+	if (nvdev->destroy && num_recv == 0)
+		wake_up(&nvdev->wait_drain);
+}
+
+/* Check and send pending recv completions */
+static void netvsc_chk_recv_comp(struct netvsc_device *nvdev,
+				 struct vmbus_channel *channel, u16 q_idx)
+{
+	struct recv_comp_data *rcd;
+	int ret;
+
+	while (true) {
+		rcd = read_recv_comp_slot(nvdev, q_idx);
+		if (!rcd)
+			break;
+
+		ret = netvsc_send_recv_completion(channel, rcd->tid,
+						  rcd->status);
+		if (ret)
+			break;
+
+		put_recv_comp_slot(nvdev, q_idx);
 	}
 }
 
+#define NETVSC_RCD_WATERMARK 80
+
+/* Get next available slot */
+static inline struct recv_comp_data *get_recv_comp_slot(
+	struct netvsc_device *nvdev, struct vmbus_channel *channel, u16 q_idx)
+{
+	u32 filled, avail, next;
+	struct recv_comp_data *rcd;
+
+	if (!nvdev->recv_section)
+		return NULL;
+
+	if (!nvdev->mrc[q_idx].buf)
+		return NULL;
+
+	if (atomic_read(&nvdev->num_outstanding_recvs) >
+	    nvdev->recv_section->num_sub_allocs * NETVSC_RCD_WATERMARK / 100)
+		netvsc_chk_recv_comp(nvdev, channel, q_idx);
+
+	count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
+	if (!avail)
+		return NULL;
+
+	next = nvdev->mrc[q_idx].next;
+	rcd = nvdev->mrc[q_idx].buf + next * sizeof(struct recv_comp_data);
+	nvdev->mrc[q_idx].next = (next + 1) % NETVSC_RECVSLOT_MAX;
+
+	atomic_inc(&nvdev->num_outstanding_recvs);
+
+	return rcd;
+}
+
 static void netvsc_receive(struct netvsc_device *net_device,
 			struct vmbus_channel *channel,
 			struct hv_device *device,
@@ -1029,6 +1110,9 @@ static void netvsc_receive(struct netvsc_device *net_device,
 	int count = 0;
 	struct net_device *ndev = hv_get_drvdata(device);
 	void *data;
+	int ret;
+	struct recv_comp_data *rcd;
+	u16 q_idx = channel->offermsg.offer.sub_channel_index;
 
 	/*
 	 * All inbound packets other than send completion should be xfer page
@@ -1076,8 +1160,26 @@ static void netvsc_receive(struct netvsc_device *net_device,
 
 	}
 
-	netvsc_send_recv_completion(device, channel, net_device,
-				    vmxferpage_packet->d.trans_id, status);
+	if (!net_device->mrc[q_idx].buf) {
+		ret = netvsc_send_recv_completion(channel,
+						  vmxferpage_packet->d.trans_id,
+						  status);
+		if (ret)
+			netdev_err(ndev, "Recv_comp q:%hd, tid:%llx, err:%d\n",
+				   q_idx, vmxferpage_packet->d.trans_id, ret);
+		return;
+	}
+
+	rcd = get_recv_comp_slot(net_device, channel, q_idx);
+
+	if (!rcd) {
+		netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
+			   q_idx, vmxferpage_packet->d.trans_id);
+		return;
+	}
+
+	rcd->tid = vmxferpage_packet->d.trans_id;
+	rcd->status = status;
 }
 
 
@@ -1166,6 +1268,7 @@ void netvsc_channel_cb(void *context)
 {
 	int ret;
 	struct vmbus_channel *channel = (struct vmbus_channel *)context;
+	u16 q_idx = channel->offermsg.offer.sub_channel_index;
 	struct hv_device *device;
 	struct netvsc_device *net_device;
 	u32 bytes_recvd;
@@ -1245,6 +1348,9 @@ void netvsc_channel_cb(void *context)
 
 	if (bufferlen > NETVSC_PACKET_SIZE)
 		kfree(buffer);
+
+	netvsc_chk_recv_comp(net_device, channel, q_idx);
+
 	return;
 }