hyperv/hn: Avoid sub-channel creation callback.

Since the sub-channel offers are synchronized, we can do our own
channel setup without using the sub-channel creation callback.

This paves the way to whack the sub-channel creation callback.

MFC after:	1 week
Sponsored by:	Microsoft OSTC

4 files changed, 27 insertions, 39 deletions

diff --git a/sys/dev/hyperv/netvsc/hv_net_vsc.c b/sys/dev/hyperv/netvsc/hv_net_vsc.c
index c193a7b..2e3e5cf 100644
--- a/sys/dev/hyperv/netvsc/hv_net_vsc.c
+++ b/sys/dev/hyperv/netvsc/hv_net_vsc.c
@@ -661,30 +661,12 @@ hv_nv_disconnect_from_vsp(netvsc_dev *net_dev)
 	hv_nv_destroy_send_buffer(net_dev);
 }
 
-/*
- * Callback handler for subchannel offer
- * @@param context new subchannel
- */
-static void
-hv_nv_subchan_callback(void *xchan)
+void
+hv_nv_subchan_attach(struct hv_vmbus_channel *chan)
 {
-	struct hv_vmbus_channel *chan = xchan;
-	netvsc_dev *net_dev;
-	uint16_t chn_index = chan->offer_msg.offer.sub_channel_index;
-	struct hv_device *device = chan->device;
-	hn_softc_t *sc = device_get_softc(device->device);
-	int ret;
-
-	net_dev = sc->net_dev;
-
-	if (chn_index >= net_dev->num_channel) {
-		/* Would this ever happen? */
-		return;
-	}
-	netvsc_subchan_callback(sc, chan);
 
 	chan->hv_chan_rdbuf = malloc(NETVSC_PACKET_SIZE, M_NETVSC, M_WAITOK);
-	ret = hv_vmbus_channel_open(chan, NETVSC_DEVICE_RING_BUFFER_SIZE,
+	hv_vmbus_channel_open(chan, NETVSC_DEVICE_RING_BUFFER_SIZE,
 	    NETVSC_DEVICE_RING_BUFFER_SIZE, NULL, 0,
 	    hv_nv_on_channel_callback, chan);
 }
@@ -721,7 +703,6 @@ hv_nv_on_device_add(struct hv_device *device, void *additional_info)
 		free(chan->hv_chan_rdbuf, M_NETVSC);
 		goto cleanup;
 	}
-	chan->sc_creation_callback = hv_nv_subchan_callback;
 
 	/*
 	 * Connect with the NetVsp
diff --git a/sys/dev/hyperv/netvsc/hv_net_vsc.h b/sys/dev/hyperv/netvsc/hv_net_vsc.h
index e1a034c..3dbd6ef 100644
--- a/sys/dev/hyperv/netvsc/hv_net_vsc.h
+++ b/sys/dev/hyperv/netvsc/hv_net_vsc.h
@@ -1266,6 +1266,7 @@ int hv_nv_on_device_remove(struct hv_device *device,
     boolean_t destroy_channel);
 int hv_nv_on_send(struct hv_vmbus_channel *chan, netvsc_packet *pkt);
 int hv_nv_get_next_send_section(netvsc_dev *net_dev);
+void hv_nv_subchan_attach(struct hv_vmbus_channel *chan);
 
 #endif  /* __HV_NET_VSC_H__ */
 
diff --git a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
index 757ea40..909177a 100644
--- a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
+++ b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
@@ -332,6 +332,7 @@ static void hn_create_rx_data(struct hn_softc *sc, int);
 static void hn_destroy_rx_data(struct hn_softc *sc);
 static void hn_set_tx_chimney_size(struct hn_softc *, int);
 static void hn_channel_attach(struct hn_softc *, struct hv_vmbus_channel *);
+static void hn_subchan_attach(struct hn_softc *, struct hv_vmbus_channel *);
 
 static int hn_transmit(struct ifnet *, struct mbuf *);
 static void hn_xmit_qflush(struct ifnet *);
@@ -547,19 +548,6 @@ netvsc_attach(device_t dev)
 	error = hv_rf_on_device_add(device_ctx, &device_info, ring_cnt);
 	if (error)
 		goto failed;
-
-	if (sc->net_dev->num_channel > 1) {
-		struct hv_vmbus_channel **subchan;
-		int subchan_cnt = sc->net_dev->num_channel - 1;
-
-		/*
-		 * Wait for sub-channels setup to complete.
-		 */
-		subchan = vmbus_get_subchan(pri_chan, subchan_cnt);
-		vmbus_rel_subchan(subchan, subchan_cnt);
-		device_printf(dev, "%d sub-channels setup done\n", subchan_cnt);
-	}
-
 	KASSERT(sc->net_dev->num_channel > 0 &&
 	    sc->net_dev->num_channel <= sc->hn_rx_ring_inuse,
 	    ("invalid channel count %u, should be less than %d",
@@ -575,6 +563,26 @@ netvsc_attach(device_t dev)
 	device_printf(dev, "%d TX ring, %d RX ring\n",
 	    sc->hn_tx_ring_inuse, sc->hn_rx_ring_inuse);
 
+	if (sc->net_dev->num_channel > 1) {
+		struct hv_vmbus_channel **subchan;
+		int subchan_cnt = sc->net_dev->num_channel - 1;
+		int i;
+
+		/* Wait for sub-channels setup to complete. */
+		subchan = vmbus_get_subchan(pri_chan, subchan_cnt);
+
+		/* Attach the sub-channels. */
+		for (i = 0; i < subchan_cnt; ++i) {
+			/* NOTE: Calling order is critical. */
+			hn_subchan_attach(sc, subchan[i]);
+			hv_nv_subchan_attach(subchan[i]);
+		}
+
+		/* Release the sub-channels */
+		vmbus_rel_subchan(subchan, subchan_cnt);
+		device_printf(dev, "%d sub-channels setup done\n", subchan_cnt);
+	}
+
 #if __FreeBSD_version >= 1100099
 	if (sc->hn_rx_ring_inuse > 1) {
 		/*
@@ -2867,8 +2875,8 @@ hn_channel_attach(struct hn_softc *sc, struct hv_vmbus_channel *chan)
 	vmbus_channel_cpu_set(chan, (sc->hn_cpu + idx) % mp_ncpus);
 }
 
-void
-netvsc_subchan_callback(struct hn_softc *sc, struct hv_vmbus_channel *chan)
+static void
+hn_subchan_attach(struct hn_softc *sc, struct hv_vmbus_channel *chan)
 {
 
 	KASSERT(!HV_VMBUS_CHAN_ISPRIMARY(chan),
diff --git a/sys/dev/hyperv/netvsc/hv_rndis.h b/sys/dev/hyperv/netvsc/hv_rndis.h
index 4749953..8ece1d0 100644
--- a/sys/dev/hyperv/netvsc/hv_rndis.h
+++ b/sys/dev/hyperv/netvsc/hv_rndis.h
@@ -1068,8 +1068,6 @@ struct hv_vmbus_channel;
 int netvsc_recv(struct hv_vmbus_channel *chan,
     netvsc_packet *packet, rndis_tcp_ip_csum_info *csum_info);
 void netvsc_channel_rollup(struct hv_vmbus_channel *chan);
-void netvsc_subchan_callback(struct hn_softc *sc,
-    struct hv_vmbus_channel *chan);
 
 void* hv_set_rppi_data(rndis_msg *rndis_mesg,
     uint32_t rppi_size,