Do not allocate multicast array memory in multicast filter

configuration function. For failed memory allocations, em(4)/lem(4)
called panic(9) which is not acceptable on production box.
igb(4)/ixgb(4)/ix(4) allocated the required memory in stack which
consumed 768 bytes of stack memory which looks too big.

To address these issues, allocate multicast array memory in device
attach time and make multicast configuration success under any
conditions. This change also removes the excessive use of memory in
stack.

Reviewed by:	jfv

2 files changed, 18 insertions, 1 deletions

diff --git a/sys/dev/ixgb/if_ixgb.c b/sys/dev/ixgb/if_ixgb.c
index edb352f..e5cddb3 100644
--- a/sys/dev/ixgb/if_ixgb.c
+++ b/sys/dev/ixgb/if_ixgb.c
@@ -324,6 +324,15 @@ ixgb_attach(device_t dev)
 	}
 	adapter->rx_desc_base = (struct ixgb_rx_desc *) adapter->rxdma.dma_vaddr;
 
+	/* Allocate multicast array memory. */
+	adapter->mta = malloc(sizeof(u_int8_t) * IXGB_ETH_LENGTH_OF_ADDRESS *
+	    MAX_NUM_MULTICAST_ADDRESSES, M_DEVBUF, M_NOWAIT);
+	if (adapter->mta == NULL) {
+		device_printf(dev, "Can not allocate multicast setup array\n");
+		error = ENOMEM;
+		goto err_hw_init;
+	}
+
 	/* Initialize the hardware */
 	if (ixgb_hardware_init(adapter)) {
 		device_printf(dev, "Unable to initialize the hardware\n");
@@ -351,6 +360,7 @@ err_pci:
 		if_free(adapter->ifp);
 	ixgb_free_pci_resources(adapter);
 	sysctl_ctx_free(&adapter->sysctl_ctx);
+	free(adapter->mta, M_DEVBUF);
 	return (error);
 
 }
@@ -412,6 +422,7 @@ ixgb_detach(device_t dev)
 		adapter->next->prev = adapter->prev;
 	if (adapter->prev != NULL)
 		adapter->prev->next = adapter->next;
+	free(adapter->mta, M_DEVBUF);
 
 	IXGB_LOCK_DESTROY(adapter);
 	return (0);
@@ -1069,13 +1080,17 @@ static void
 ixgb_set_multi(struct adapter * adapter)
 {
 	u_int32_t       reg_rctl = 0;
-	u_int8_t        mta[MAX_NUM_MULTICAST_ADDRESSES * IXGB_ETH_LENGTH_OF_ADDRESS];
+	u_int8_t        *mta;
 	struct ifmultiaddr *ifma;
 	int             mcnt = 0;
 	struct ifnet   *ifp = adapter->ifp;
 
 	IOCTL_DEBUGOUT("ixgb_set_multi: begin");
 
+	mta = adapter->mta;
+	bzero(mta, sizeof(u_int8_t) * IXGB_ETH_LENGTH_OF_ADDRESS *
+	    MAX_NUM_MULTICAST_ADDRESSES);
+
 	if_maddr_rlock(ifp);
 #if __FreeBSD_version < 500000
 	LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
diff --git a/sys/dev/ixgb/if_ixgb.h b/sys/dev/ixgb/if_ixgb.h
index 9e5355a..4e88db7 100644
--- a/sys/dev/ixgb/if_ixgb.h
+++ b/sys/dev/ixgb/if_ixgb.h
@@ -344,6 +344,8 @@ struct adapter {
 	struct sysctl_ctx_list sysctl_ctx;
 	struct sysctl_oid *sysctl_tree;
 
+	/* Multicast array memory */
+	u_int8_t	*mta;
 	/* Misc stats maintained by the driver */
 	unsigned long   dropped_pkts;
 	unsigned long   mbuf_alloc_failed;