Change defines in the igb driver to allow an easier selection of

the older if_start/non-multiqueue interface from the stack. This
is not the default, but can be turned on in the Makefile now regardless
of the OS level to allow either testing or use of ALTQ.

MFC after: one week

2 files changed, 24 insertions, 18 deletions

diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index 30bb052..03c5123 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -42,7 +42,7 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 #include <sys/buf_ring.h>
 #endif
 #include <sys/bus.h>
@@ -179,7 +179,7 @@ static int	igb_detach(device_t);
 static int	igb_shutdown(device_t);
 static int	igb_suspend(device_t);
 static int	igb_resume(device_t);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 static int	igb_mq_start(struct ifnet *, struct mbuf *);
 static int	igb_mq_start_locked(struct ifnet *, struct tx_ring *);
 static void	igb_qflush(struct ifnet *);
@@ -850,7 +850,7 @@ igb_resume(device_t dev)
 	    (ifp->if_drv_flags & IFF_DRV_RUNNING) && adapter->link_active) {
 		for (int i = 0; i < adapter->num_queues; i++, txr++) {
 			IGB_TX_LOCK(txr);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 			/* Process the stack queue only if not depleted */
 			if (((txr->queue_status & IGB_QUEUE_DEPLETED) == 0) &&
 			    !drbr_empty(ifp, txr->br))
@@ -868,7 +868,7 @@ igb_resume(device_t dev)
 }
 
 
-#if __FreeBSD_version < 800000
+#ifdef IGB_LEGACY_TX
 
 /*********************************************************************
  *  Transmit entry point
@@ -946,7 +946,7 @@ igb_start(struct ifnet *ifp)
 	return;
 }
 
-#else /* __FreeBSD_version >= 800000 */
+#else /* ~IGB_LEGACY_TX */
 
 /*
 ** Multiqueue Transmit Entry:
@@ -1061,7 +1061,7 @@ igb_qflush(struct ifnet *ifp)
 	}
 	if_qflush(ifp);
 }
-#endif /* __FreeBSD_version >= 800000 */
+#endif /* ~IGB_LEGACY_TX */
 
 /*********************************************************************
  *  Ioctl entry point
@@ -1387,7 +1387,7 @@ igb_handle_que(void *context, int pending)
 
 		IGB_TX_LOCK(txr);
 		igb_txeof(txr);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 		/* Process the stack queue only if not depleted */
 		if (((txr->queue_status & IGB_QUEUE_DEPLETED) == 0) &&
 		    !drbr_empty(ifp, txr->br))
@@ -1438,7 +1438,7 @@ igb_handle_link_locked(struct adapter *adapter)
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) && adapter->link_active) {
 		for (int i = 0; i < adapter->num_queues; i++, txr++) {
 			IGB_TX_LOCK(txr);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 			/* Process the stack queue only if not depleted */
 			if (((txr->queue_status & IGB_QUEUE_DEPLETED) == 0) &&
 			    !drbr_empty(ifp, txr->br))
@@ -1540,7 +1540,7 @@ igb_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
 		do {
 			more = igb_txeof(txr);
 		} while (loop-- && more);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 		if (!drbr_empty(ifp, txr->br))
 			igb_mq_start_locked(ifp, txr);
 #else
@@ -1575,7 +1575,7 @@ igb_msix_que(void *arg)
 
 	IGB_TX_LOCK(txr);
 	igb_txeof(txr);
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 	/* Process the stack queue only if not depleted */
 	if (((txr->queue_status & IGB_QUEUE_DEPLETED) == 0) &&
 	    !drbr_empty(ifp, txr->br))
@@ -2466,7 +2466,7 @@ igb_allocate_legacy(struct adapter *adapter)
 		return (ENXIO);
 	}
 
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 	TASK_INIT(&txr->txq_task, 0, igb_deferred_mq_start, txr);
 #endif
 
@@ -2550,7 +2550,7 @@ igb_allocate_msix(struct adapter *adapter)
 				i,igb_last_bind_cpu);
 			igb_last_bind_cpu = CPU_NEXT(igb_last_bind_cpu);
 		}
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 		TASK_INIT(&que->txr->txq_task, 0, igb_deferred_mq_start,
 		    que->txr);
 #endif
@@ -2776,7 +2776,7 @@ igb_free_pci_resources(struct adapter *adapter)
 
 	for (int i = 0; i < adapter->num_queues; i++, que++) {
 		if (que->tq != NULL) {
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 			taskqueue_drain(que->tq, &que->txr->txq_task);
 #endif
 			taskqueue_drain(que->tq, &que->que_task);
@@ -3086,7 +3086,7 @@ igb_setup_interface(device_t dev, struct adapter *adapter)
 	ifp->if_softc = adapter;
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
 	ifp->if_ioctl = igb_ioctl;
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 	ifp->if_transmit = igb_mq_start;
 	ifp->if_qflush = igb_qflush;
 #else
@@ -3330,7 +3330,7 @@ igb_allocate_queues(struct adapter *adapter)
 			error = ENOMEM;
 			goto err_tx_desc;
         	}
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 		/* Allocate a buf ring */
 		txr->br = buf_ring_alloc(igb_buf_ring_size, M_DEVBUF,
 		    M_WAITOK, &txr->tx_mtx);
@@ -3391,7 +3391,7 @@ err_tx_desc:
 		igb_dma_free(adapter, &txr->txdma);
 	free(adapter->rx_rings, M_DEVBUF);
 rx_fail:
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 	buf_ring_free(txr->br, M_DEVBUF);
 #endif
 	free(adapter->tx_rings, M_DEVBUF);
@@ -3649,7 +3649,7 @@ igb_free_transmit_buffers(struct tx_ring *txr)
 			tx_buffer->map = NULL;
 		}
 	}
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 	if (txr->br != NULL)
 		buf_ring_free(txr->br, M_DEVBUF);
 #endif
@@ -4870,7 +4870,7 @@ igb_rxeof(struct igb_queue *que, int count, int *done)
 				rxr->fmp->m_pkthdr.ether_vtag = vtag;
 				rxr->fmp->m_flags |= M_VLANTAG;
 			}
-#if __FreeBSD_version >= 800000
+#ifndef IGB_LEGACY_TX
 			rxr->fmp->m_pkthdr.flowid = que->msix;
 			rxr->fmp->m_flags |= M_FLOWID;
 #endif
diff --git a/sys/modules/igb/Makefile b/sys/modules/igb/Makefile
index 45b7ec2..1906b5a 100644
--- a/sys/modules/igb/Makefile
+++ b/sys/modules/igb/Makefile
@@ -14,4 +14,10 @@ CFLAGS += -I${.CURDIR}/../../dev/e1000 -DSMP
 # not advisable since MSIX gives better results
 #CFLAGS  += -DDEVICE_POLLING
 
+# IGB_LEGACY_TX will override the stack if_transmit path and
+# instead use the older if_start non-multiqueue capable interface.
+# This might be desireable for testing, or to enable the use of
+# ALTQ. 
+#CFLAGS  += -DIGB_LEGACY_TX
+
 .include <bsd.kmod.mk>