--- //depot/yahoo/ybsd_6/src/sys/dev/em/if_em.c	2006/09/26 14:59:47
+++ //depot/jhb/bsd6/src/sys/dev/em/if_em.c	2006/10/30 09:54:13
@@ -211,7 +211,7 @@
 static void	em_local_timer(void *);
 static int	em_hardware_init(struct adapter *);
 static void	em_setup_interface(device_t, struct adapter *);
-static int	em_setup_transmit_structures(struct adapter *);
+static void	em_setup_transmit_structures(struct adapter *);
 static void	em_initialize_transmit_unit(struct adapter *);
 static int	em_setup_receive_structures(struct adapter *);
 static void	em_initialize_receive_unit(struct adapter *);
@@ -245,7 +245,6 @@
 static void	em_82547_update_fifo_head(struct adapter *, int);
 static int	em_82547_tx_fifo_reset(struct adapter *);
 static void	em_82547_move_tail(void *arg);
-static void	em_82547_move_tail_locked(struct adapter *);
 static int	em_dma_malloc(struct adapter *, bus_size_t,
 		struct em_dma_alloc *, int);
 static void	em_dma_free(struct adapter *, struct em_dma_alloc *);
@@ -416,8 +415,8 @@
 	    OID_AUTO, "stats", CTLTYPE_INT|CTLFLAG_RW, adapter, 0,
 	    em_sysctl_stats, "I", "Statistics");
 
-	callout_init(&adapter->timer, CALLOUT_MPSAFE);
-	callout_init(&adapter->tx_fifo_timer, CALLOUT_MPSAFE);
+	callout_init_mtx(&adapter->timer, &adapter->mtx, 0);
+	callout_init_mtx(&adapter->tx_fifo_timer, &adapter->mtx, 0);
 
 	/* Determine hardware revision */
 	em_identify_hardware(adapter);
@@ -552,6 +551,20 @@
 		goto err_hw_init;
 	}
 
+	/* Allocate transmit descriptors and buffers */
+	if (em_allocate_transmit_structures(adapter)) {
+		device_printf(dev, "Could not setup transmit structures\n");
+		error = ENOMEM;
+		goto err_tx_struct;
+	}
+
+	/* Allocate receive descriptors and buffers */
+	if (em_allocate_receive_structures(adapter)) {
+		device_printf(dev, "Could not setup receive structures\n");
+		error = ENOMEM;
+		goto err_rx_struct;
+	}
+
 	/* Setup OS specific network interface */
 	em_setup_interface(dev, adapter);
 
@@ -579,6 +592,9 @@
 
 	return (0);
 
+err_rx_struct:
+	em_free_transmit_structures(adapter);
+err_tx_struct:
 err_hw_init:
 	em_dma_free(adapter, &adapter->rxdma);
 err_rx_desc:
@@ -623,10 +639,16 @@
 	EM_UNLOCK(adapter);
 	ether_ifdetach(adapter->ifp);
 
+	callout_drain(&adapter->timer);
+	callout_drain(&adapter->tx_fifo_timer);
+
 	em_free_pci_resources(adapter);
 	bus_generic_detach(dev);
 	if_free(ifp);
 
+	em_free_transmit_structures(adapter);
+	em_free_receive_structures(adapter);
+
 	/* Free Transmit Descriptor ring */
 	if (adapter->tx_desc_base) {
 		em_dma_free(adapter, &adapter->txdma);
@@ -1044,11 +1066,7 @@
 		em_enable_vlans(adapter);
 
 	/* Prepare transmit descriptors and buffers */
-	if (em_setup_transmit_structures(adapter)) {
-		device_printf(dev, "Could not setup transmit structures\n");
-		em_stop(adapter);
-		return;
-	}
+	em_setup_transmit_structures(adapter);
 	em_initialize_transmit_unit(adapter);
 
 	/* Setup Multicast table */
@@ -1213,6 +1231,10 @@
 	ifp = adapter->ifp;
 
 	EM_LOCK(adapter);
+	if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+		EM_UNLOCK(adapter);
+		return;
+	}
 
 	callout_stop(&adapter->timer);
 	adapter->hw.get_link_status = 1;
@@ -1239,14 +1261,20 @@
 		if (em_rxeof(adapter, adapter->rx_process_limit) != 0)
 			taskqueue_enqueue(adapter->tq, &adapter->rxtx_task);
 		EM_LOCK(adapter);
+		if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
+			EM_UNLOCK(adapter);
+			goto out;
+		}
 		em_txeof(adapter);
 
 		if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
 			em_start_locked(ifp);
+
+		em_enable_intr(adapter);
 		EM_UNLOCK(adapter);
 	}
 
-	em_enable_intr(adapter);
+out:
 	NET_UNLOCK_GIANT();
 }
 
@@ -1625,7 +1653,7 @@
 	bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 	if (adapter->hw.mac_type == em_82547 && adapter->link_duplex == HALF_DUPLEX)
-		em_82547_move_tail_locked(adapter);
+		em_82547_move_tail(adapter);
 	else {
 		E1000_WRITE_REG(&adapter->hw, TDT, i);
 		if (adapter->hw.mac_type == em_82547)
@@ -1644,8 +1672,9 @@
  *
  **********************************************************************/
 static void
-em_82547_move_tail_locked(struct adapter *adapter)
+em_82547_move_tail(void *arg)
 {
+	struct adapter *adapter = arg;
 	uint16_t hw_tdt;
 	uint16_t sw_tdt;
 	struct em_tx_desc *tx_desc;
@@ -1678,16 +1707,6 @@
 	}	
 }
 
-static void
-em_82547_move_tail(void *arg)
-{
-	struct adapter *adapter = arg;
-
-	EM_LOCK(adapter);
-	em_82547_move_tail_locked(adapter);
-	EM_UNLOCK(adapter);
-}
-
 static int
 em_82547_fifo_workaround(struct adapter *adapter, int len)
 {	
@@ -1873,7 +1892,7 @@
 	struct adapter	*adapter = arg;
 	struct ifnet	*ifp = adapter->ifp;
 
-	EM_LOCK(adapter);
+	EM_LOCK_ASSERT(adapter);
 
 	em_check_for_link(&adapter->hw);
 	em_update_link_status(adapter);
@@ -1883,8 +1902,6 @@
 	em_smartspeed(adapter);
 
 	callout_reset(&adapter->timer, hz, em_local_timer, adapter);
-
-	EM_UNLOCK(adapter);
 }
 
 static void
@@ -1947,14 +1964,19 @@
 	INIT_DEBUGOUT("em_stop: begin");
 
 	em_disable_intr(adapter);
-	em_reset_hw(&adapter->hw);
 	callout_stop(&adapter->timer);
 	callout_stop(&adapter->tx_fifo_timer);
-	em_free_transmit_structures(adapter);
-	em_free_receive_structures(adapter);
 
 	/* Tell the stack that the interface is no longer active */
 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
+
+	/* Unlock so that the defered contexts can drain without blocking */
+	EM_UNLOCK(adapter);
+	taskqueue_drain(adapter->tq, &adapter->rxtx_task);
+	taskqueue_drain(taskqueue_fast, &adapter->link_task);
+
+	EM_LOCK(adapter);
+	em_reset_hw(&adapter->hw);
 }
 
 
@@ -2469,26 +2491,6 @@
 static int
 em_allocate_transmit_structures(struct adapter *adapter)
 {
-	adapter->tx_buffer_area =  malloc(sizeof(struct em_buffer) *
-	    adapter->num_tx_desc, M_DEVBUF, M_NOWAIT);
-	if (adapter->tx_buffer_area == NULL) {
-		device_printf(adapter->dev, "Unable to allocate tx_buffer memory\n");
-		return (ENOMEM);
-	}
-
-	bzero(adapter->tx_buffer_area, sizeof(struct em_buffer) * adapter->num_tx_desc);
-
-	return (0);
-}
-
-/*********************************************************************
- *
- *  Allocate and initialize transmit structures.
- *
- **********************************************************************/
-static int
-em_setup_transmit_structures(struct adapter *adapter)
-{
 	device_t dev = adapter->dev;
 	struct em_buffer *tx_buffer;
 	bus_size_t size;
@@ -2514,10 +2516,14 @@
 		goto fail;
 	}
 
-	if ((error = em_allocate_transmit_structures(adapter)) != 0)
+	adapter->tx_buffer_area = malloc(sizeof(struct em_buffer) *
+	    adapter->num_tx_desc, M_DEVBUF, M_NOWAIT | M_ZERO);
+	if (adapter->tx_buffer_area == NULL) {
+		device_printf(dev, "Unable to allocate tx_buffer memory\n");
+		error = ENOMEM;
 		goto fail;
+	}
 
-	bzero(adapter->tx_desc_base, (sizeof(struct em_tx_desc)) * adapter->num_tx_desc);
 	tx_buffer = adapter->tx_buffer_area;
 	for (i = 0; i < adapter->num_tx_desc; i++) {
 		error = bus_dmamap_create(adapter->txtag, 0, &tx_buffer->map);
@@ -2528,9 +2534,41 @@
 		tx_buffer++;
 	}
 
+	return (0);
+
+fail:
+	em_free_transmit_structures(adapter);
+	return (error);
+}
+
+/*********************************************************************
+ *
+ *  Initialize transmit structures.
+ *
+ **********************************************************************/
+static void
+em_setup_transmit_structures(struct adapter *adapter)
+{
+	struct em_buffer *tx_buffer;
+	int i;
+
+	bzero(adapter->tx_desc_base, (sizeof(struct em_tx_desc)) * adapter->num_tx_desc);
+
 	adapter->next_avail_tx_desc = 0;
 	adapter->oldest_used_tx_desc = 0;
 
+	/* Free any existing tx buffers. */
+	tx_buffer = adapter->tx_buffer_area;
+	for (i = 0; i < adapter->num_tx_desc; i++, tx_buffer++) {
+		if (tx_buffer->m_head != NULL) {
+			bus_dmamap_sync(adapter->txtag, tx_buffer->map,
+			    BUS_DMASYNC_POSTWRITE);
+			bus_dmamap_unload(adapter->txtag, tx_buffer->map);
+			m_freem(tx_buffer->m_head);
+			tx_buffer->m_head = NULL;
+		}
+	}
+
 	/* Set number of descriptors available */
 	adapter->num_tx_desc_avail = adapter->num_tx_desc;
 
@@ -2538,12 +2576,6 @@
 	adapter->active_checksum_context = OFFLOAD_NONE;
 	bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
-
-	return (0);
-
-fail:
-	em_free_transmit_structures(adapter);
-	return (error);
 }
 
 /*********************************************************************
@@ -2946,14 +2978,6 @@
 		}
 	}
 
-	for (i = 0; i < adapter->num_rx_desc; i++) {
-		error = em_get_buf(adapter, i);
-		if (error)
-			goto fail;
-	}
-	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
-	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
-
 	return (0);
 
 fail:
@@ -2969,15 +2993,34 @@
 static int
 em_setup_receive_structures(struct adapter *adapter)
 {
-	int error;
+	struct em_buffer *rx_buffer;
+	int i, error;
 
 	bzero(adapter->rx_desc_base, (sizeof(struct em_rx_desc)) * adapter->num_rx_desc);
 
-	if ((error = em_allocate_receive_structures(adapter)) != 0)
-		return (error);
+	/* Free current RX buffers. */
+	rx_buffer = adapter->rx_buffer_area;
+	for (i = 0; i < adapter->num_rx_desc; i++, rx_buffer++) {
+		if (rx_buffer->m_head != NULL) {
+			bus_dmamap_sync(adapter->rxtag, rx_buffer->map,
+			    BUS_DMASYNC_POSTREAD);
+			bus_dmamap_unload(adapter->rxtag, rx_buffer->map);
+			m_freem(rx_buffer->m_head);
+			rx_buffer->m_head = NULL;
+		}
+	}
+
+	/* Allocate new ones. */
+	for (i = 0; i < adapter->num_rx_desc; i++) {
+		error = em_get_buf(adapter, i);
+		if (error)
+			return (error);
+	}
 
 	/* Setup our descriptor pointers */
 	adapter->next_rx_desc_to_check = 0;
+	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
+	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
 	return (0);
 }