gianfar.c

linux 内核源代码

void inline gfar_tx_vlan(struct sk_buff *skb, struct txfcb *fcb)
{
	fcb->flags |= TXFCB_VLN;
	fcb->vlctl = vlan_tx_tag_get(skb);
}

/* This is called by the kernel when a frame is ready for transmission. */
/* It is pointed to by the dev->hard_start_xmit function pointer */
static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct txfcb *fcb = NULL;
	struct txbd8 *txbdp;
	u16 status;
	unsigned long flags;

	/* Update transmit stats */
	dev->stats.tx_bytes += skb->len;

	/* Lock priv now */
	spin_lock_irqsave(&priv->txlock, flags);

	/* Point at the first free tx descriptor */
	txbdp = priv->cur_tx;

	/* Clear all but the WRAP status flags */
	status = txbdp->status & TXBD_WRAP;

	/* Set up checksumming */
	if (likely((dev->features & NETIF_F_IP_CSUM)
			&& (CHECKSUM_PARTIAL == skb->ip_summed))) {
		fcb = gfar_add_fcb(skb, txbdp);
		status |= TXBD_TOE;
		gfar_tx_checksum(skb, fcb);
	}

	if (priv->vlan_enable &&
			unlikely(priv->vlgrp && vlan_tx_tag_present(skb))) {
		if (unlikely(NULL == fcb)) {
			fcb = gfar_add_fcb(skb, txbdp);
			status |= TXBD_TOE;
		}

		gfar_tx_vlan(skb, fcb);
	}

	/* Set buffer length and pointer */
	txbdp->length = skb->len;
	txbdp->bufPtr = dma_map_single(NULL, skb->data,
			skb->len, DMA_TO_DEVICE);

	/* Save the skb pointer so we can free it later */
	priv->tx_skbuff[priv->skb_curtx] = skb;

	/* Update the current skb pointer (wrapping if this was the last) */
	priv->skb_curtx =
	    (priv->skb_curtx + 1) & TX_RING_MOD_MASK(priv->tx_ring_size);

	/* Flag the BD as interrupt-causing */
	status |= TXBD_INTERRUPT;

	/* Flag the BD as ready to go, last in frame, and  */
	/* in need of CRC */
	status |= (TXBD_READY | TXBD_LAST | TXBD_CRC);

	dev->trans_start = jiffies;

	/* The powerpc-specific eieio() is used, as wmb() has too strong
	 * semantics (it requires synchronization between cacheable and
	 * uncacheable mappings, which eieio doesn't provide and which we
	 * don't need), thus requiring a more expensive sync instruction.  At
	 * some point, the set of architecture-independent barrier functions
	 * should be expanded to include weaker barriers.
	 */

	eieio();
	txbdp->status = status;

	/* If this was the last BD in the ring, the next one */
	/* is at the beginning of the ring */
	if (txbdp->status & TXBD_WRAP)
		txbdp = priv->tx_bd_base;
	else
		txbdp++;

	/* If the next BD still needs to be cleaned up, then the bds
	   are full.  We need to tell the kernel to stop sending us stuff. */
	if (txbdp == priv->dirty_tx) {
		netif_stop_queue(dev);

		dev->stats.tx_fifo_errors++;
	}

	/* Update the current txbd to the next one */
	priv->cur_tx = txbdp;

	/* Tell the DMA to go go go */
	gfar_write(&priv->regs->tstat, TSTAT_CLEAR_THALT);

	/* Unlock priv */
	spin_unlock_irqrestore(&priv->txlock, flags);

	return 0;
}

/* Stops the kernel queue, and halts the controller */
static int gfar_close(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);

#ifdef CONFIG_GFAR_NAPI
	napi_disable(&priv->napi);
#endif

	stop_gfar(dev);

	/* Disconnect from the PHY */
	phy_disconnect(priv->phydev);
	priv->phydev = NULL;

	netif_stop_queue(dev);

	return 0;
}

/* Changes the mac address if the controller is not running. */
int gfar_set_mac_address(struct net_device *dev)
{
	gfar_set_mac_for_addr(dev, 0, dev->dev_addr);

	return 0;
}


/* Enables and disables VLAN insertion/extraction */
static void gfar_vlan_rx_register(struct net_device *dev,
		struct vlan_group *grp)
{
	struct gfar_private *priv = netdev_priv(dev);
	unsigned long flags;
	u32 tempval;

	spin_lock_irqsave(&priv->rxlock, flags);

	priv->vlgrp = grp;

	if (grp) {
		/* Enable VLAN tag insertion */
		tempval = gfar_read(&priv->regs->tctrl);
		tempval |= TCTRL_VLINS;

		gfar_write(&priv->regs->tctrl, tempval);

		/* Enable VLAN tag extraction */
		tempval = gfar_read(&priv->regs->rctrl);
		tempval |= RCTRL_VLEX;
		gfar_write(&priv->regs->rctrl, tempval);
	} else {
		/* Disable VLAN tag insertion */
		tempval = gfar_read(&priv->regs->tctrl);
		tempval &= ~TCTRL_VLINS;
		gfar_write(&priv->regs->tctrl, tempval);

		/* Disable VLAN tag extraction */
		tempval = gfar_read(&priv->regs->rctrl);
		tempval &= ~RCTRL_VLEX;
		gfar_write(&priv->regs->rctrl, tempval);
	}

	spin_unlock_irqrestore(&priv->rxlock, flags);
}

static int gfar_change_mtu(struct net_device *dev, int new_mtu)
{
	int tempsize, tempval;
	struct gfar_private *priv = netdev_priv(dev);
	int oldsize = priv->rx_buffer_size;
	int frame_size = new_mtu + ETH_HLEN;

	if (priv->vlan_enable)
		frame_size += VLAN_ETH_HLEN;

	if (gfar_uses_fcb(priv))
		frame_size += GMAC_FCB_LEN;

	frame_size += priv->padding;

	if ((frame_size < 64) || (frame_size > JUMBO_FRAME_SIZE)) {
		if (netif_msg_drv(priv))
			printk(KERN_ERR "%s: Invalid MTU setting\n",
					dev->name);
		return -EINVAL;
	}

	tempsize =
	    (frame_size & ~(INCREMENTAL_BUFFER_SIZE - 1)) +
	    INCREMENTAL_BUFFER_SIZE;

	/* Only stop and start the controller if it isn't already
	 * stopped, and we changed something */
	if ((oldsize != tempsize) && (dev->flags & IFF_UP))
		stop_gfar(dev);

	priv->rx_buffer_size = tempsize;

	dev->mtu = new_mtu;

	gfar_write(&priv->regs->mrblr, priv->rx_buffer_size);
	gfar_write(&priv->regs->maxfrm, priv->rx_buffer_size);

	/* If the mtu is larger than the max size for standard
	 * ethernet frames (ie, a jumbo frame), then set maccfg2
	 * to allow huge frames, and to check the length */
	tempval = gfar_read(&priv->regs->maccfg2);

	if (priv->rx_buffer_size > DEFAULT_RX_BUFFER_SIZE)
		tempval |= (MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);
	else
		tempval &= ~(MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);

	gfar_write(&priv->regs->maccfg2, tempval);

	if ((oldsize != tempsize) && (dev->flags & IFF_UP))
		startup_gfar(dev);

	return 0;
}

/* gfar_timeout gets called when a packet has not been
 * transmitted after a set amount of time.
 * For now, assume that clearing out all the structures, and
 * starting over will fix the problem. */
static void gfar_timeout(struct net_device *dev)
{
	dev->stats.tx_errors++;

	if (dev->flags & IFF_UP) {
		stop_gfar(dev);
		startup_gfar(dev);
	}

	netif_schedule(dev);
}

/* Interrupt Handler for Transmit complete */
static irqreturn_t gfar_transmit(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *) dev_id;
	struct gfar_private *priv = netdev_priv(dev);
	struct txbd8 *bdp;

	/* Clear IEVENT */
	gfar_write(&priv->regs->ievent, IEVENT_TX_MASK);

	/* Lock priv */
	spin_lock(&priv->txlock);
	bdp = priv->dirty_tx;
	while ((bdp->status & TXBD_READY) == 0) {
		/* If dirty_tx and cur_tx are the same, then either the */
		/* ring is empty or full now (it could only be full in the beginning, */
		/* obviously).  If it is empty, we are done. */
		if ((bdp == priv->cur_tx) && (netif_queue_stopped(dev) == 0))
			break;

		dev->stats.tx_packets++;

		/* Deferred means some collisions occurred during transmit, */
		/* but we eventually sent the packet. */
		if (bdp->status & TXBD_DEF)
			dev->stats.collisions++;

		/* Free the sk buffer associated with this TxBD */
		dev_kfree_skb_irq(priv->tx_skbuff[priv->skb_dirtytx]);
		priv->tx_skbuff[priv->skb_dirtytx] = NULL;
		priv->skb_dirtytx =
		    (priv->skb_dirtytx +
		     1) & TX_RING_MOD_MASK(priv->tx_ring_size);

		/* update bdp to point at next bd in the ring (wrapping if necessary) */
		if (bdp->status & TXBD_WRAP)
			bdp = priv->tx_bd_base;
		else
			bdp++;

		/* Move dirty_tx to be the next bd */
		priv->dirty_tx = bdp;

		/* We freed a buffer, so now we can restart transmission */
		if (netif_queue_stopped(dev))
			netif_wake_queue(dev);
	} /* while ((bdp->status & TXBD_READY) == 0) */

	/* If we are coalescing the interrupts, reset the timer */
	/* Otherwise, clear it */
	if (priv->txcoalescing)
		gfar_write(&priv->regs->txic,
			   mk_ic_value(priv->txcount, priv->txtime));
	else
		gfar_write(&priv->regs->txic, 0);

	spin_unlock(&priv->txlock);

	return IRQ_HANDLED;
}

struct sk_buff * gfar_new_skb(struct net_device *dev, struct rxbd8 *bdp)
{
	unsigned int alignamount;
	struct gfar_private *priv = netdev_priv(dev);
	struct sk_buff *skb = NULL;
	unsigned int timeout = SKB_ALLOC_TIMEOUT;

	/* We have to allocate the skb, so keep trying till we succeed */
	while ((!skb) && timeout--)
		skb = dev_alloc_skb(priv->rx_buffer_size + RXBUF_ALIGNMENT);

	if (NULL == skb)
		return NULL;

	alignamount = RXBUF_ALIGNMENT -
		(((unsigned long) skb->data) & (RXBUF_ALIGNMENT - 1));

	/* We need the data buffer to be aligned properly.  We will reserve
	 * as many bytes as needed to align the data properly
	 */
	skb_reserve(skb, alignamount);

	bdp->bufPtr = dma_map_single(NULL, skb->data,
			priv->rx_buffer_size, DMA_FROM_DEVICE);

	bdp->length = 0;

	/* Mark the buffer empty */
	eieio();
	bdp->status |= (RXBD_EMPTY | RXBD_INTERRUPT);

	return skb;
}

static inline void count_errors(unsigned short status, struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct gfar_extra_stats *estats = &priv->extra_stats;

	/* If the packet was truncated, none of the other errors
	 * matter */
	if (status & RXBD_TRUNCATED) {
		stats->rx_length_errors++;

		estats->rx_trunc++;

		return;
	}
	/* Count the errors, if there were any */
	if (status & (RXBD_LARGE | RXBD_SHORT)) {
		stats->rx_length_errors++;

		if (status & RXBD_LARGE)
			estats->rx_large++;
		else
			estats->rx_short++;
	}
	if (status & RXBD_NONOCTET) {
		stats->rx_frame_errors++;
		estats->rx_nonoctet++;
	}
	if (status & RXBD_CRCERR) {
		estats->rx_crcerr++;
		stats->rx_crc_errors++;
	}
	if (status & RXBD_OVERRUN) {
		estats->rx_overrun++;
		stats->rx_crc_errors++;
	}
}

irqreturn_t gfar_receive(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *) dev_id;
	struct gfar_private *priv = netdev_priv(dev);
#ifdef CONFIG_GFAR_NAPI
	u32 tempval;
#else
	unsigned long flags;
#endif

	/* Clear IEVENT, so rx interrupt isn't called again
	 * because of this interrupt */
	gfar_write(&priv->regs->ievent, IEVENT_RX_MASK);

	/* support NAPI */
#ifdef CONFIG_GFAR_NAPI
	if (netif_rx_schedule_prep(dev, &priv->napi)) {
		tempval = gfar_read(&priv->regs->imask);
		tempval &= IMASK_RX_DISABLED;
		gfar_write(&priv->regs->imask, tempval);

		__netif_rx_schedule(dev, &priv->napi);
	} else {
		if (netif_msg_rx_err(priv))
			printk(KERN_DEBUG "%s: receive called twice (%x)[%x]\n",
				dev->name, gfar_read(&priv->regs->ievent),
				gfar_read(&priv->regs->imask));
	}
#else

	spin_lock_irqsave(&priv->rxlock, flags);
	gfar_clean_rx_ring(dev, priv->rx_ring_size);

	/* If we are coalescing interrupts, update the timer */
	/* Otherwise, clear it */
	if (priv->rxcoalescing)
		gfar_write(&priv->regs->rxic,
			   mk_ic_value(priv->rxcount, priv->rxtime));
	else
		gfar_write(&priv->regs->rxic, 0);

	spin_unlock_irqrestore(&priv->rxlock, flags);
#endif

	return IRQ_HANDLED;
}

static inline int gfar_rx_vlan(struct sk_buff *skb,
		struct vlan_group *vlgrp, unsigned short vlctl)
{
#ifdef CONFIG_GFAR_NAPI
	return vlan_hwaccel_receive_skb(skb, vlgrp, vlctl);
#else
	return vlan_hwaccel_rx(skb, vlgrp, vlctl);
#endif
}

static inline void gfar_rx_checksum(struct sk_buff *skb, struct rxfcb *fcb)
{
	/* If valid headers were found, and valid sums
	 * were verified, then we tell the kernel that no
	 * checksumming is necessary.  Otherwise, it is */
	if ((fcb->flags & RXFCB_CSUM_MASK) == (RXFCB_CIP | RXFCB_CTU))
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	else
		skb->ip_summed = CHECKSUM_NONE;
}


static inline struct rxfcb *gfar_get_fcb(struct sk_buff *skb)
{
	struct rxfcb *fcb = (struct rxfcb *)skb->data;

	/* Remove the FCB from the skb */
	skb_pull(skb, GMAC_FCB_LEN);

	return fcb;
}

/* gfar_process_frame() -- handle one incoming packet if skb
 * isn't NULL.  */
static int gfar_process_frame(struct net_device *dev, struct sk_buff *skb,
		int length)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct rxfcb *fcb = NULL;

	if (NULL == skb) {
		if (netif_msg_rx_err(priv))
			printk(KERN_WARNING "%s: Missing skb!!.\n", dev->name);
		dev->stats.rx_dropped++;
		priv->extra_stats.rx_skbmissing++;
	} else {
		int ret;

		/* Prep the skb for the packet */
		skb_put(skb, length);

		/* Grab the FCB if there is one */
		if (gfar_uses_fcb(priv))
			fcb = gfar_get_fcb(skb);

		/* Remove the padded bytes, if there are any */
		if (priv->padding)
			skb_pull(skb, priv->padding);

		if (priv->rx_csum_enable)
			gfar_rx_checksum(skb, fcb);

		/* Tell the skb what kind of packet this is */
		skb->protocol = eth_type_trans(skb, dev);

		/* Send the packet up the stack */
		if (unlikely(priv->vlgrp && (fcb->flags & RXFCB_VLN)))
			ret = gfar_rx_vlan(skb, priv->vlgrp, fcb->vlctl);
		else
			ret = RECEIVE(skb);

		if (NET_RX_DROP == ret)
			priv->extra_stats.kernel_dropped++;
	}

	return 0;
}