[dpdk-dev] [PATCH 4/5] net/netvsc: implement link state change callback

[Stephen Hemminger <stephen@networkplumber.org>]

From: Stephen Hemminger <sthemmin@microsoft.com>

Implement callback functionality on link state changes.
This is not really driven off of interrupt file descriptor like most other
PMD's. Instead, it happens when a link state change message arrives
in the common ring buffer.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 doc/guides/nics/netvsc.rst     |  3 ++-
 drivers/net/netvsc/hn_ethdev.c | 12 +++++-------
 drivers/net/netvsc/hn_rndis.c  | 11 ++++++++---
 drivers/net/netvsc/hn_rndis.h  |  2 +-
 drivers/net/netvsc/hn_rxtx.c   |  4 ++--
 drivers/net/netvsc/hn_var.h    |  1 +
 6 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/doc/guides/nics/netvsc.rst b/doc/guides/nics/netvsc.rst
index cc07ce46f885..c5f9b7c6fa1e 100644
--- a/doc/guides/nics/netvsc.rst
+++ b/doc/guides/nics/netvsc.rst
@@ -28,7 +28,8 @@ In this release, the hyper PMD driver provides the basic functionality of packet
 
 *   VLAN tags are always stripped and presented in mbuf tci field.
 
-*   The Hyper-V driver does not use or support Link State or Rx interrupt.
+*   The Hyper-V driver does not use or support interrupts. Link state change
+    callback is done via change events in the packet ring.
 
 *   The maximum number of queues is limited by the host (currently 64).
     When used with 4.16 kernel only a single queue is available.
diff --git a/drivers/net/netvsc/hn_ethdev.c b/drivers/net/netvsc/hn_ethdev.c
index 8643e0b3c057..63e04a453546 100644
--- a/drivers/net/netvsc/hn_ethdev.c
+++ b/drivers/net/netvsc/hn_ethdev.c
@@ -107,6 +107,10 @@ eth_dev_vmbus_allocate(struct rte_vmbus_device *dev, size_t private_data_size)
 	}
 
 	eth_dev->device = &dev->device;
+
+	/* interrupt is simulated */
+	dev->intr_handle.type = RTE_INTR_HANDLE_EXT;
+	eth_dev->data->dev_flags |= RTE_ETH_DEV_INTR_LSC;
 	eth_dev->intr_handle = &dev->intr_handle;
 
 	return eth_dev;
@@ -187,7 +191,7 @@ static int hn_parse_args(const struct rte_eth_dev *dev)
  *   means block this call until link is up.
  *   which is not worth supporting.
  */
-static int
+int
 hn_dev_link_update(struct rte_eth_dev *dev,
 		   __rte_unused int wait_to_complete)
 {
@@ -554,12 +558,6 @@ hn_dev_start(struct rte_eth_dev *dev)
 
 	PMD_INIT_FUNC_TRACE();
 
-	/* check if lsc interrupt feature is enabled */
-	if (dev->data->dev_conf.intr_conf.lsc) {
-		PMD_DRV_LOG(ERR, "link status not supported yet");
-		return -ENOTSUP;
-	}
-
 	return hn_rndis_set_rxfilter(hv,
 				     NDIS_PACKET_TYPE_BROADCAST |
 				     NDIS_PACKET_TYPE_ALL_MULTICAST |
diff --git a/drivers/net/netvsc/hn_rndis.c b/drivers/net/netvsc/hn_rndis.c
index f44add726b91..a5d205ce2636 100644
--- a/drivers/net/netvsc/hn_rndis.c
+++ b/drivers/net/netvsc/hn_rndis.c
@@ -11,6 +11,7 @@
 #include <errno.h>
 #include <unistd.h>
 
+#include <rte_ethdev_driver.h>
 #include <rte_ethdev.h>
 #include <rte_string_fns.h>
 #include <rte_memzone.h>
@@ -281,7 +282,7 @@ static int hn_nvs_send_rndis_ctrl(struct vmbus_channel *chan,
 				  &nvs_rndis, sizeof(nvs_rndis), 0U, NULL);
 }
 
-void hn_rndis_link_status(struct hn_data *hv __rte_unused, const void *msg)
+void hn_rndis_link_status(struct rte_eth_dev *dev, const void *msg)
 {
 	const struct rndis_status_msg *indicate = msg;
 
@@ -290,15 +291,19 @@ void hn_rndis_link_status(struct hn_data *hv __rte_unused, const void *msg)
 	PMD_DRV_LOG(DEBUG, "link status %#x", indicate->status);
 
 	switch (indicate->status) {
-	case RNDIS_STATUS_LINK_SPEED_CHANGE:
 	case RNDIS_STATUS_NETWORK_CHANGE:
 	case RNDIS_STATUS_TASK_OFFLOAD_CURRENT_CONFIG:
 		/* ignore not in DPDK API */
 		break;
 
+	case RNDIS_STATUS_LINK_SPEED_CHANGE:
 	case RNDIS_STATUS_MEDIA_CONNECT:
 	case RNDIS_STATUS_MEDIA_DISCONNECT:
-		/* TODO handle as LSC interrupt  */
+		if (dev->data->dev_conf.intr_conf.lsc &&
+		    hn_dev_link_update(dev, 0) == 0)
+			_rte_eth_dev_callback_process(dev,
+						      RTE_ETH_EVENT_INTR_LSC,
+						      NULL);
 		break;
 	default:
 		PMD_DRV_LOG(NOTICE, "unknown RNDIS indication: %#x",
diff --git a/drivers/net/netvsc/hn_rndis.h b/drivers/net/netvsc/hn_rndis.h
index 89e2e6ba0fcb..01b5120631b1 100644
--- a/drivers/net/netvsc/hn_rndis.h
+++ b/drivers/net/netvsc/hn_rndis.h
@@ -6,7 +6,7 @@ struct hn_data;
 
 void hn_rndis_receive_response(struct hn_data *hv,
 			      const void *data, uint32_t len);
-void	hn_rndis_link_status(struct hn_data *hv, const void *data);
+void	hn_rndis_link_status(struct rte_eth_dev *dev, const void *msg);
 int	hn_rndis_attach(struct hn_data *hv);
 void	hn_rndis_detach(struct hn_data *hv);
 int	hn_rndis_get_eaddr(struct hn_data *hv, uint8_t *eaddr);
diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index 92de5d09e442..ad22a95f6c27 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -601,7 +601,7 @@ static void hn_rndis_rx_data(struct hn_rx_queue *rxq,
 }
 
 static void
-hn_rndis_receive(const struct rte_eth_dev *dev, struct hn_rx_queue *rxq,
+hn_rndis_receive(struct rte_eth_dev *dev, struct hn_rx_queue *rxq,
 		 struct hn_rx_bufinfo *rxb, void *buf, uint32_t len)
 {
 	const struct rndis_msghdr *hdr = buf;
@@ -613,7 +613,7 @@ hn_rndis_receive(const struct rte_eth_dev *dev, struct hn_rx_queue *rxq,
 		break;
 
 	case RNDIS_INDICATE_STATUS_MSG:
-		hn_rndis_link_status(rxq->hv, buf);
+		hn_rndis_link_status(dev, buf);
 		break;
 
 	case RNDIS_INITIALIZE_CMPLT:
diff --git a/drivers/net/netvsc/hn_var.h b/drivers/net/netvsc/hn_var.h
index ff722560d9d9..17b67941dc83 100644
--- a/drivers/net/netvsc/hn_var.h
+++ b/drivers/net/netvsc/hn_var.h
@@ -142,6 +142,7 @@ uint16_t hn_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		      uint16_t nb_pkts);
 
 int	hn_tx_pool_init(struct rte_eth_dev *dev);
+int	hn_dev_link_update(struct rte_eth_dev *dev, int wait);
 int	hn_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t queue_idx,
 			      uint16_t nb_desc, unsigned int socket_id,
 			      const struct rte_eth_txconf *tx_conf);
-- 
2.18.0