push rxed packets to the stack once per interrupt (per port)

pushing to the stack on every packet completion interacts badly
with the backpressure mechanism in ifiq_input when you rx more than
8 or so packets per interrupt.

while here move to ifiq_input and apply backpressure before we start
dropping in software.

the problem was found by olivier taibi and reported on bugs@
i tested this on an overdrive 1000 which uses msk for its onboard nic

1 files changed, 18 insertions, 11 deletions

diff --git a/sys/dev/pci/if_msk.c b/sys/dev/pci/if_msk.c
index 05c7fc9b60d..52d76518eb9 100644
--- a/sys/dev/pci/if_msk.c
+++ b/sys/dev/pci/if_msk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_msk.c,v 1.131 2018/01/06 03:11:04 dlg Exp $	*/
+/*	$OpenBSD: if_msk.c,v 1.132 2019/07/30 12:11:42 dlg Exp $	*/
 
 /*
  * Copyright (c) 1997, 1998, 1999, 2000
@@ -134,7 +134,7 @@ int mskcprint(void *, const char *);
 int msk_intr(void *);
 void msk_intr_yukon(struct sk_if_softc *);
 static inline int msk_rxvalid(struct sk_softc *, u_int32_t, u_int32_t);
-void msk_rxeof(struct sk_if_softc *, uint16_t, uint32_t);
+void msk_rxeof(struct sk_if_softc *, struct mbuf_list *, uint16_t, uint32_t);
 void msk_txeof(struct sk_if_softc *);
 static unsigned int msk_encap(struct sk_if_softc *, struct mbuf *, uint32_t);
 void msk_start(struct ifnet *);
@@ -1591,11 +1591,11 @@ msk_rxvalid(struct sk_softc *sc, u_int32_t stat, u_int32_t len)
 }
 
 void
-msk_rxeof(struct sk_if_softc *sc_if, uint16_t len, uint32_t rxstat)
+msk_rxeof(struct sk_if_softc *sc_if, struct mbuf_list *ml,
+    uint16_t len, uint32_t rxstat)
 {
 	struct sk_softc		*sc = sc_if->sk_softc;
 	struct ifnet		*ifp = &sc_if->arpcom.ac_if;
-	struct mbuf_list	ml = MBUF_LIST_INITIALIZER();
 	struct mbuf		*m = NULL;
 	int			prod, cons, tail;
 	bus_dmamap_t		map;
@@ -1640,8 +1640,7 @@ msk_rxeof(struct sk_if_softc *sc_if, uint16_t len, uint32_t rxstat)
 
 	m->m_pkthdr.len = m->m_len = len;
 
-	ml_enqueue(&ml, m);
-	if_input(ifp, &ml);
+	ml_enqueue(ml, m);
 }
 
 void
@@ -1770,8 +1769,12 @@ msk_intr(void *xsc)
 	struct sk_if_softc	*sc_if;
 	struct sk_if_softc	*sc_if0 = sc->sk_if[SK_PORT_A];
 	struct sk_if_softc	*sc_if1 = sc->sk_if[SK_PORT_B];
+	struct mbuf_list	ml[2] = {
+					MBUF_LIST_INITIALIZER(),
+					MBUF_LIST_INITIALIZER(),
+				};
 	struct ifnet		*ifp0 = NULL, *ifp1 = NULL;
-	int			claimed = 0, rx[2] = {0, 0};
+	int			claimed = 0;
 	u_int32_t		status;
 	struct msk_status_desc	*cur_st;
 
@@ -1809,8 +1812,8 @@ msk_intr(void *xsc)
 		switch (cur_st->sk_opcode) {
 		case SK_Y2_STOPC_RXSTAT:
 			sc_if = sc->sk_if[cur_st->sk_link & 0x01];
-			rx[cur_st->sk_link & 0x01] = 1;
-			msk_rxeof(sc_if, lemtoh16(&cur_st->sk_len),
+			msk_rxeof(sc_if, &ml[cur_st->sk_link & 0x01],
+			    lemtoh16(&cur_st->sk_len),
 			    lemtoh32(&cur_st->sk_status));
 			break;
 		case SK_Y2_STOPC_TXSTAT:
@@ -1837,12 +1840,16 @@ msk_intr(void *xsc)
 
 	CSR_WRITE_4(sc, SK_Y2_ICR, 2);
 
-	if (rx[0]) {
+	if (!ml_empty(&ml[0])) {
+		if (ifiq_input(&ifp0->if_rcv, &ml[0]))
+			if_rxr_livelocked(&sc_if0->sk_cdata.sk_rx_ring);
 		msk_fill_rx_ring(sc_if0);
 		SK_IF_WRITE_2(sc_if0, 0, SK_RXQ1_Y2_PREF_PUTIDX,
 		    sc_if0->sk_cdata.sk_rx_prod);
 	}
-	if (rx[1]) {
+	if (!ml_empty(&ml[1])) {
+		if (ifiq_input(&ifp1->if_rcv, &ml[1]))
+			if_rxr_livelocked(&sc_if1->sk_cdata.sk_rx_ring);
 		msk_fill_rx_ring(sc_if1);
 		SK_IF_WRITE_2(sc_if1, 0, SK_RXQ1_Y2_PREF_PUTIDX,
 		    sc_if1->sk_cdata.sk_rx_prod);