Lock down the network interface queues. The queue mutex must be obtained

before adding/removing packets from the queue.  Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.

IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue.  An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.

Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.

2 files changed, 7 insertions, 12 deletions

diff --git a/sys/i4b/layer1/isic/i4b_bchan.c b/sys/i4b/layer1/isic/i4b_bchan.c
index f1db0ea..c937790 100644
--- a/sys/i4b/layer1/isic/i4b_bchan.c
+++ b/sys/i4b/layer1/isic/i4b_bchan.c
@@ -91,9 +91,10 @@ isic_bchannel_setup(int unit, int h_chan, int bprot, int activate)
 
 	/* receiver part */
 
-	i4b_Bcleanifq(&chan->rx_queue);	/* clean rx queue */
-
 	chan->rx_queue.ifq_maxlen = IFQ_MAXLEN;
+	mtx_init(&chan->rx_queue.ifq_mtx, "i4b_isic_rx", MTX_DEF);
+
+	i4b_Bcleanifq(&chan->rx_queue);	/* clean rx queue */
 
 	chan->rxcount = 0;		/* reset rx counter */
 	
@@ -105,10 +106,11 @@ isic_bchannel_setup(int unit, int h_chan, int bprot, int activate)
 	
 	/* transmitter part */
 
-	i4b_Bcleanifq(&chan->tx_queue);	/* clean tx queue */
-
 	chan->tx_queue.ifq_maxlen = IFQ_MAXLEN;
+	mtx_init(&chan->tx_queue.ifq_mtx, "i4b_isic_tx", MTX_DEF);
 	
+	i4b_Bcleanifq(&chan->tx_queue);	/* clean tx queue */
+
 	chan->txcount = 0;		/* reset tx counter */
 	
 	i4b_Bfreembuf(chan->out_mbuf_head);	/* clean tx mbuf */
diff --git a/sys/i4b/layer1/isic/i4b_hscx.c b/sys/i4b/layer1/isic/i4b_hscx.c
index 121b8c5..79e74b8 100644
--- a/sys/i4b/layer1/isic/i4b_hscx.c
+++ b/sys/i4b/layer1/isic/i4b_hscx.c
@@ -270,14 +270,7 @@ isic_hscx_irq(register struct l1_softc *sc, u_char ista, int h_chan, u_char ex_i
 				if(!(i4b_l1_bchan_tel_silence(chan->in_mbuf->m_data, chan->in_mbuf->m_len)))
 					activity = ACT_RX;
 
-				if(!(IF_QFULL(&chan->rx_queue)))
-				{
-					IF_ENQUEUE(&chan->rx_queue, chan->in_mbuf);
-				}
-				else
-				{
-					i4b_Bfreembuf(chan->in_mbuf);
-				}
+				(void) IF_HANDOFF(&chan->rx_queue, chan->in_mbuf, NULL);
 
 				/* signal upper driver that data is available */