gianfar.c

linux 内核源代码

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

	/* Initialize IMASK */
	gfar_write(&priv->regs->imask, IMASK_INIT_CLEAR);

	/* Init hash registers to zero */
	gfar_write(&priv->regs->igaddr0, 0);
	gfar_write(&priv->regs->igaddr1, 0);
	gfar_write(&priv->regs->igaddr2, 0);
	gfar_write(&priv->regs->igaddr3, 0);
	gfar_write(&priv->regs->igaddr4, 0);
	gfar_write(&priv->regs->igaddr5, 0);
	gfar_write(&priv->regs->igaddr6, 0);
	gfar_write(&priv->regs->igaddr7, 0);

	gfar_write(&priv->regs->gaddr0, 0);
	gfar_write(&priv->regs->gaddr1, 0);
	gfar_write(&priv->regs->gaddr2, 0);
	gfar_write(&priv->regs->gaddr3, 0);
	gfar_write(&priv->regs->gaddr4, 0);
	gfar_write(&priv->regs->gaddr5, 0);
	gfar_write(&priv->regs->gaddr6, 0);
	gfar_write(&priv->regs->gaddr7, 0);

	/* Zero out the rmon mib registers if it has them */
	if (priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_RMON) {
		memset_io(&(priv->regs->rmon), 0, sizeof (struct rmon_mib));

		/* Mask off the CAM interrupts */
		gfar_write(&priv->regs->rmon.cam1, 0xffffffff);
		gfar_write(&priv->regs->rmon.cam2, 0xffffffff);
	}

	/* Initialize the max receive buffer length */
	gfar_write(&priv->regs->mrblr, priv->rx_buffer_size);

	/* Initialize the Minimum Frame Length Register */
	gfar_write(&priv->regs->minflr, MINFLR_INIT_SETTINGS);

	/* Assign the TBI an address which won't conflict with the PHYs */
	gfar_write(&priv->regs->tbipa, TBIPA_VALUE);
}


/* Halt the receive and transmit queues */
void gfar_halt(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	u32 tempval;

	/* Mask all interrupts */
	gfar_write(&regs->imask, IMASK_INIT_CLEAR);

	/* Clear all interrupts */
	gfar_write(&regs->ievent, IEVENT_INIT_CLEAR);

	/* Stop the DMA, and wait for it to stop */
	tempval = gfar_read(&priv->regs->dmactrl);
	if ((tempval & (DMACTRL_GRS | DMACTRL_GTS))
	    != (DMACTRL_GRS | DMACTRL_GTS)) {
		tempval |= (DMACTRL_GRS | DMACTRL_GTS);
		gfar_write(&priv->regs->dmactrl, tempval);

		while (!(gfar_read(&priv->regs->ievent) &
			 (IEVENT_GRSC | IEVENT_GTSC)))
			cpu_relax();
	}

	/* Disable Rx and Tx */
	tempval = gfar_read(&regs->maccfg1);
	tempval &= ~(MACCFG1_RX_EN | MACCFG1_TX_EN);
	gfar_write(&regs->maccfg1, tempval);
}

void stop_gfar(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	unsigned long flags;

	phy_stop(priv->phydev);

	/* Lock it down */
	spin_lock_irqsave(&priv->txlock, flags);
	spin_lock(&priv->rxlock);

	gfar_halt(dev);

	spin_unlock(&priv->rxlock);
	spin_unlock_irqrestore(&priv->txlock, flags);

	/* Free the IRQs */
	if (priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
		free_irq(priv->interruptError, dev);
		free_irq(priv->interruptTransmit, dev);
		free_irq(priv->interruptReceive, dev);
	} else {
 		free_irq(priv->interruptTransmit, dev);
	}

	free_skb_resources(priv);

	dma_free_coherent(NULL,
			sizeof(struct txbd8)*priv->tx_ring_size
			+ sizeof(struct rxbd8)*priv->rx_ring_size,
			priv->tx_bd_base,
			gfar_read(&regs->tbase0));
}

/* If there are any tx skbs or rx skbs still around, free them.
 * Then free tx_skbuff and rx_skbuff */
static void free_skb_resources(struct gfar_private *priv)
{
	struct rxbd8 *rxbdp;
	struct txbd8 *txbdp;
	int i;

	/* Go through all the buffer descriptors and free their data buffers */
	txbdp = priv->tx_bd_base;

	for (i = 0; i < priv->tx_ring_size; i++) {

		if (priv->tx_skbuff[i]) {
			dma_unmap_single(NULL, txbdp->bufPtr,
					txbdp->length,
					DMA_TO_DEVICE);
			dev_kfree_skb_any(priv->tx_skbuff[i]);
			priv->tx_skbuff[i] = NULL;
		}
	}

	kfree(priv->tx_skbuff);

	rxbdp = priv->rx_bd_base;

	/* rx_skbuff is not guaranteed to be allocated, so only
	 * free it and its contents if it is allocated */
	if(priv->rx_skbuff != NULL) {
		for (i = 0; i < priv->rx_ring_size; i++) {
			if (priv->rx_skbuff[i]) {
				dma_unmap_single(NULL, rxbdp->bufPtr,
						priv->rx_buffer_size,
						DMA_FROM_DEVICE);

				dev_kfree_skb_any(priv->rx_skbuff[i]);
				priv->rx_skbuff[i] = NULL;
			}

			rxbdp->status = 0;
			rxbdp->length = 0;
			rxbdp->bufPtr = 0;

			rxbdp++;
		}

		kfree(priv->rx_skbuff);
	}
}

void gfar_start(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	u32 tempval;

	/* Enable Rx and Tx in MACCFG1 */
	tempval = gfar_read(&regs->maccfg1);
	tempval |= (MACCFG1_RX_EN | MACCFG1_TX_EN);
	gfar_write(&regs->maccfg1, tempval);

	/* Initialize DMACTRL to have WWR and WOP */
	tempval = gfar_read(&priv->regs->dmactrl);
	tempval |= DMACTRL_INIT_SETTINGS;
	gfar_write(&priv->regs->dmactrl, tempval);

	/* Make sure we aren't stopped */
	tempval = gfar_read(&priv->regs->dmactrl);
	tempval &= ~(DMACTRL_GRS | DMACTRL_GTS);
	gfar_write(&priv->regs->dmactrl, tempval);

	/* Clear THLT/RHLT, so that the DMA starts polling now */
	gfar_write(&regs->tstat, TSTAT_CLEAR_THALT);
	gfar_write(&regs->rstat, RSTAT_CLEAR_RHALT);

	/* Unmask the interrupts we look for */
	gfar_write(&regs->imask, IMASK_DEFAULT);
}

/* Bring the controller up and running */
int startup_gfar(struct net_device *dev)
{
	struct txbd8 *txbdp;
	struct rxbd8 *rxbdp;
	dma_addr_t addr = 0;
	unsigned long vaddr;
	int i;
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	int err = 0;
	u32 rctrl = 0;
	u32 attrs = 0;

	gfar_write(&regs->imask, IMASK_INIT_CLEAR);

	/* Allocate memory for the buffer descriptors */
	vaddr = (unsigned long) dma_alloc_coherent(NULL,
			sizeof (struct txbd8) * priv->tx_ring_size +
			sizeof (struct rxbd8) * priv->rx_ring_size,
			&addr, GFP_KERNEL);

	if (vaddr == 0) {
		if (netif_msg_ifup(priv))
			printk(KERN_ERR "%s: Could not allocate buffer descriptors!\n",
					dev->name);
		return -ENOMEM;
	}

	priv->tx_bd_base = (struct txbd8 *) vaddr;

	/* enet DMA only understands physical addresses */
	gfar_write(&regs->tbase0, addr);

	/* Start the rx descriptor ring where the tx ring leaves off */
	addr = addr + sizeof (struct txbd8) * priv->tx_ring_size;
	vaddr = vaddr + sizeof (struct txbd8) * priv->tx_ring_size;
	priv->rx_bd_base = (struct rxbd8 *) vaddr;
	gfar_write(&regs->rbase0, addr);

	/* Setup the skbuff rings */
	priv->tx_skbuff =
	    (struct sk_buff **) kmalloc(sizeof (struct sk_buff *) *
					priv->tx_ring_size, GFP_KERNEL);

	if (NULL == priv->tx_skbuff) {
		if (netif_msg_ifup(priv))
			printk(KERN_ERR "%s: Could not allocate tx_skbuff\n",
					dev->name);
		err = -ENOMEM;
		goto tx_skb_fail;
	}

	for (i = 0; i < priv->tx_ring_size; i++)
		priv->tx_skbuff[i] = NULL;

	priv->rx_skbuff =
	    (struct sk_buff **) kmalloc(sizeof (struct sk_buff *) *
					priv->rx_ring_size, GFP_KERNEL);

	if (NULL == priv->rx_skbuff) {
		if (netif_msg_ifup(priv))
			printk(KERN_ERR "%s: Could not allocate rx_skbuff\n",
					dev->name);
		err = -ENOMEM;
		goto rx_skb_fail;
	}

	for (i = 0; i < priv->rx_ring_size; i++)
		priv->rx_skbuff[i] = NULL;

	/* Initialize some variables in our dev structure */
	priv->dirty_tx = priv->cur_tx = priv->tx_bd_base;
	priv->cur_rx = priv->rx_bd_base;
	priv->skb_curtx = priv->skb_dirtytx = 0;
	priv->skb_currx = 0;

	/* Initialize Transmit Descriptor Ring */
	txbdp = priv->tx_bd_base;
	for (i = 0; i < priv->tx_ring_size; i++) {
		txbdp->status = 0;
		txbdp->length = 0;
		txbdp->bufPtr = 0;
		txbdp++;
	}

	/* Set the last descriptor in the ring to indicate wrap */
	txbdp--;
	txbdp->status |= TXBD_WRAP;

	rxbdp = priv->rx_bd_base;
	for (i = 0; i < priv->rx_ring_size; i++) {
		struct sk_buff *skb = NULL;

		rxbdp->status = 0;

		skb = gfar_new_skb(dev, rxbdp);

		priv->rx_skbuff[i] = skb;

		rxbdp++;
	}

	/* Set the last descriptor in the ring to wrap */
	rxbdp--;
	rxbdp->status |= RXBD_WRAP;

	/* If the device has multiple interrupts, register for
	 * them.  Otherwise, only register for the one */
	if (priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
		/* Install our interrupt handlers for Error,
		 * Transmit, and Receive */
		if (request_irq(priv->interruptError, gfar_error,
				0, "enet_error", dev) < 0) {
			if (netif_msg_intr(priv))
				printk(KERN_ERR "%s: Can't get IRQ %d\n",
					dev->name, priv->interruptError);

			err = -1;
			goto err_irq_fail;
		}

		if (request_irq(priv->interruptTransmit, gfar_transmit,
				0, "enet_tx", dev) < 0) {
			if (netif_msg_intr(priv))
				printk(KERN_ERR "%s: Can't get IRQ %d\n",
					dev->name, priv->interruptTransmit);

			err = -1;

			goto tx_irq_fail;
		}

		if (request_irq(priv->interruptReceive, gfar_receive,
				0, "enet_rx", dev) < 0) {
			if (netif_msg_intr(priv))
				printk(KERN_ERR "%s: Can't get IRQ %d (receive0)\n",
						dev->name, priv->interruptReceive);

			err = -1;
			goto rx_irq_fail;
		}
	} else {
		if (request_irq(priv->interruptTransmit, gfar_interrupt,
				0, "gfar_interrupt", dev) < 0) {
			if (netif_msg_intr(priv))
				printk(KERN_ERR "%s: Can't get IRQ %d\n",
					dev->name, priv->interruptError);

			err = -1;
			goto err_irq_fail;
		}
	}

	phy_start(priv->phydev);

	/* Configure the coalescing support */
	if (priv->txcoalescing)
		gfar_write(&regs->txic,
			   mk_ic_value(priv->txcount, priv->txtime));
	else
		gfar_write(&regs->txic, 0);

	if (priv->rxcoalescing)
		gfar_write(&regs->rxic,
			   mk_ic_value(priv->rxcount, priv->rxtime));
	else
		gfar_write(&regs->rxic, 0);

	if (priv->rx_csum_enable)
		rctrl |= RCTRL_CHECKSUMMING;

	if (priv->extended_hash) {
		rctrl |= RCTRL_EXTHASH;

		gfar_clear_exact_match(dev);
		rctrl |= RCTRL_EMEN;
	}

	if (priv->vlan_enable)
		rctrl |= RCTRL_VLAN;

	if (priv->padding) {
		rctrl &= ~RCTRL_PAL_MASK;
		rctrl |= RCTRL_PADDING(priv->padding);
	}

	/* Init rctrl based on our settings */
	gfar_write(&priv->regs->rctrl, rctrl);

	if (dev->features & NETIF_F_IP_CSUM)
		gfar_write(&priv->regs->tctrl, TCTRL_INIT_CSUM);

	/* Set the extraction length and index */
	attrs = ATTRELI_EL(priv->rx_stash_size) |
		ATTRELI_EI(priv->rx_stash_index);

	gfar_write(&priv->regs->attreli, attrs);

	/* Start with defaults, and add stashing or locking
	 * depending on the approprate variables */
	attrs = ATTR_INIT_SETTINGS;

	if (priv->bd_stash_en)
		attrs |= ATTR_BDSTASH;

	if (priv->rx_stash_size != 0)
		attrs |= ATTR_BUFSTASH;

	gfar_write(&priv->regs->attr, attrs);

	gfar_write(&priv->regs->fifo_tx_thr, priv->fifo_threshold);
	gfar_write(&priv->regs->fifo_tx_starve, priv->fifo_starve);
	gfar_write(&priv->regs->fifo_tx_starve_shutoff, priv->fifo_starve_off);

	/* Start the controller */
	gfar_start(dev);

	return 0;

rx_irq_fail:
	free_irq(priv->interruptTransmit, dev);
tx_irq_fail:
	free_irq(priv->interruptError, dev);
err_irq_fail:
rx_skb_fail:
	free_skb_resources(priv);
tx_skb_fail:
	dma_free_coherent(NULL,
			sizeof(struct txbd8)*priv->tx_ring_size
			+ sizeof(struct rxbd8)*priv->rx_ring_size,
			priv->tx_bd_base,
			gfar_read(&regs->tbase0));

	return err;
}

/* Called when something needs to use the ethernet device */
/* Returns 0 for success. */
static int gfar_enet_open(struct net_device *dev)
{
#ifdef CONFIG_GFAR_NAPI
	struct gfar_private *priv = netdev_priv(dev);
#endif
	int err;

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

	/* Initialize a bunch of registers */
	init_registers(dev);

	gfar_set_mac_address(dev);

	err = init_phy(dev);

	if(err) {
#ifdef CONFIG_GFAR_NAPI
		napi_disable(&priv->napi);
#endif
		return err;
	}

	err = startup_gfar(dev);
	if (err) {
#ifdef CONFIG_GFAR_NAPI
		napi_disable(&priv->napi);
#endif
		return err;
	}

	netif_start_queue(dev);

	return err;
}

static inline struct txfcb *gfar_add_fcb(struct sk_buff *skb, struct txbd8 *bdp)
{
	struct txfcb *fcb = (struct txfcb *)skb_push (skb, GMAC_FCB_LEN);

	memset(fcb, 0, GMAC_FCB_LEN);

	return fcb;
}

static inline void gfar_tx_checksum(struct sk_buff *skb, struct txfcb *fcb)
{
	u8 flags = 0;

	/* If we're here, it's a IP packet with a TCP or UDP
	 * payload.  We set it to checksum, using a pseudo-header
	 * we provide
	 */
	flags = TXFCB_DEFAULT;

	/* Tell the controller what the protocol is */
	/* And provide the already calculated phcs */
	if (ip_hdr(skb)->protocol == IPPROTO_UDP) {
		flags |= TXFCB_UDP;
		fcb->phcs = udp_hdr(skb)->check;
	} else
		fcb->phcs = tcp_hdr(skb)->check;

	/* l3os is the distance between the start of the
	 * frame (skb->data) and the start of the IP hdr.
	 * l4os is the distance between the start of the
	 * l3 hdr and the l4 hdr */
	fcb->l3os = (u16)(skb_network_offset(skb) - GMAC_FCB_LEN);
	fcb->l4os = skb_network_header_len(skb);

	fcb->flags = flags;
}