Don't fail on device attach if jumbo frame support was unsuccessful.

Because nfe(4) hardware doesn't support SG on Rx path, supporting
jumbo frame requires very large contiguous kernel memory(i.e. several
mega bytes). In case of lack of contiguous kernel memory that
allocation request may always fail. However nfe(4) can operate on normal
sized MTU frames, so go ahead and just disable jumbo frame support.
While I'm here add a new tunable "hw.nfe.jumbo_disable" to disable
jumbo frame support.
In nfe_poll, make sure to invoke correct Rx handler.

Approved by:	re (kensmith)

2 files changed, 26 insertions, 9 deletions

diff --git a/sys/dev/nfe/if_nfe.c b/sys/dev/nfe/if_nfe.c
index c620c42..1eda743 100644
--- a/sys/dev/nfe/if_nfe.c
+++ b/sys/dev/nfe/if_nfe.c
@@ -108,7 +108,7 @@ static void nfe_init(void *);
 static void nfe_init_locked(void *);
 static void nfe_stop(struct ifnet *);
 static int  nfe_alloc_rx_ring(struct nfe_softc *, struct nfe_rx_ring *);
-static int  nfe_alloc_jrx_ring(struct nfe_softc *, struct nfe_jrx_ring *);
+static void nfe_alloc_jrx_ring(struct nfe_softc *, struct nfe_jrx_ring *);
 static int  nfe_init_rx_ring(struct nfe_softc *, struct nfe_rx_ring *);
 static int  nfe_init_jrx_ring(struct nfe_softc *, struct nfe_jrx_ring *);
 static void nfe_free_rx_ring(struct nfe_softc *, struct nfe_rx_ring *);
@@ -151,8 +151,10 @@ static int nfedebug = 0;
 /* Tunables. */
 static int msi_disable = 0;
 static int msix_disable = 0;
+static int jumbo_disable = 0;
 TUNABLE_INT("hw.nfe.msi_disable", &msi_disable);
 TUNABLE_INT("hw.nfe.msix_disable", &msix_disable);
+TUNABLE_INT("hw.nfe.jumbo_disable", &jumbo_disable);
 
 static device_method_t nfe_methods[] = {
 	/* Device interface */
@@ -513,8 +515,7 @@ nfe_attach(device_t dev)
 	if ((error = nfe_alloc_rx_ring(sc, &sc->rxq)) != 0)
 		goto fail;
 
-	if ((error = nfe_alloc_jrx_ring(sc, &sc->jrxq)) != 0)
-		goto fail;
+	nfe_alloc_jrx_ring(sc, &sc->jrxq);
 
 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
@@ -1140,7 +1141,7 @@ fail:
 }
 
 
-static int
+static void
 nfe_alloc_jrx_ring(struct nfe_softc *sc, struct nfe_jrx_ring *ring)
 {
 	struct nfe_dmamap_arg ctx;
@@ -1151,7 +1152,12 @@ nfe_alloc_jrx_ring(struct nfe_softc *sc, struct nfe_jrx_ring *ring)
 	int i, error, descsize;
 
 	if ((sc->nfe_flags & NFE_JUMBO_SUP) == 0)
-		return (0);
+		return;
+	if (jumbo_disable != 0) {
+		device_printf(sc->nfe_dev, "disabling jumbo frame support\n");
+		sc->nfe_jumbo_disable = 1;
+		return;
+	}
 
 	if (sc->nfe_flags & NFE_40BIT_ADDR) {
 		desc = ring->jdesc64;
@@ -1301,11 +1307,17 @@ nfe_alloc_jrx_ring(struct nfe_softc *sc, struct nfe_jrx_ring *ring)
 		    jpool_entries);
 	}
 
-	return (0);
+	return;
 
 fail:
+	/*
+	 * Running without jumbo frame support is ok for most cases
+	 * so don't fail on creating dma tag/map for jumbo frame.
+	 */
 	nfe_free_jrx_ring(sc, ring);
-	return (error);
+	device_printf(sc->nfe_dev, "disabling jumbo frame support due to "
+	    "resource shortage\n");
+	sc->nfe_jumbo_disable = 1;
 }
 
 
@@ -1671,7 +1683,10 @@ nfe_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
 		return;
 	}
 
-	nfe_rxeof(sc, count);
+	if (sc->nfe_framesize > MCLBYTES - ETHER_HDR_LEN)
+		nfe_jrxeof(sc, count);
+	else
+		nfe_rxeof(sc, count);
 	nfe_txeof(sc);
 	if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
 		taskqueue_enqueue_fast(taskqueue_fast, &sc->nfe_tx_task);
@@ -1746,7 +1761,8 @@ nfe_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		if (ifr->ifr_mtu < ETHERMIN || ifr->ifr_mtu > NFE_JUMBO_MTU)
 			error = EINVAL;
 		else if (ifp->if_mtu != ifr->ifr_mtu) {
-			if ((sc->nfe_flags & NFE_JUMBO_SUP) == 0 &&
+			if ((((sc->nfe_flags & NFE_JUMBO_SUP) == 0) ||
+			    (sc->nfe_jumbo_disable != 0)) &&
 			    ifr->ifr_mtu > ETHERMTU)
 				error = EINVAL;
 			else {
diff --git a/sys/dev/nfe/if_nfevar.h b/sys/dev/nfe/if_nfevar.h
index 7a320e3..cd00d0b 100644
--- a/sys/dev/nfe/if_nfevar.h
+++ b/sys/dev/nfe/if_nfevar.h
@@ -103,6 +103,7 @@ struct nfe_softc {
 #define	NFE_PWR_MGMT		0x0010
 #define	NFE_CORRECT_MACADDR	0x0020
 #define	NFE_TX_FLOW_CTRL	0x0040
+	int			nfe_jumbo_disable;
 	uint32_t		rxtxctl;
 	uint8_t			mii_phyaddr;
 	uint8_t			eaddr[ETHER_ADDR_LEN];