gianfar.c

Powerpc网络处理器MPC85xx增强型三速以太控制器驱动程序

		if (bdp->status & RXBD_WRAP)
			bdp = priv->rx_bd_base;
		else
			bdp++;

		/* update to point at the next skb */
		priv->skb_currx =
		    (priv->skb_currx +
		     1) & RX_RING_MOD_MASK(priv->rx_ring_size);

	}

	/* Update the current rxbd pointer to be the next one */
	priv->cur_rx = bdp;

	return howmany;
}

#ifdef CONFIG_GFAR_NAPI
static int gfar_poll(struct net_device *dev, int *budget)
{
	int howmany;
	struct gfar_private *priv = netdev_priv(dev);
	int rx_work_limit = *budget;
	unsigned long int flags;  

	if (rx_work_limit > dev->quota)
		rx_work_limit = dev->quota;
    //取*budget 和dev->quota中的较小值
    // *budget : MAX number of packets that the current CPU can receive from all interface
    // dev->quota: per interface value usually = dev->weight 
	howmany = gfar_clean_rx_ring(dev, rx_work_limit);

	dev->quota -= howmany;
	rx_work_limit -= howmany;
	*budget -= howmany;

	/* Lock priv */
	spin_lock_irqsave(&priv->txlock, flags);
	gfar_clean_tx_ring(dev);
	spin_unlock_irqrestore(&priv->txlock, flags);

	if (rx_work_limit > 0) { 
		netif_rx_complete(dev); 
		//将NIC从queue->poll_list 中删除

		/* Clear the halt bit in RSTAT */
		gfar_write(&priv->regs->rstat, RSTAT_CLEAR_RHALT);

		gfar_write(&priv->regs->imask, IMASK_DEFAULT);
        // 重新打开收发中断
		/* If we are coalescing interrupts, update the timer */
		/* Otherwise, clear it */
		if (likely(priv->rxcoalescing)) {
			gfar_write(&priv->regs->rxic, 0);
			gfar_write(&priv->regs->rxic,
				   mk_ic_value(priv->rxcount, priv->rxtime));
		}
	}

	/* Return 1 if there's more work to do */
	return (rx_work_limit > 0) ? 0 : 1;
}
#endif

#ifdef CONFIG_NET_POLL_CONTROLLER
/*
 * Polling 'interrupt' - used by things like netconsole to send skbs
 * without having to re-enable interrupts. It's not called while
 * the interrupt routine is executing.
 */
static void gfar_netpoll(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);

	/* If the device has multiple interrupts, run tx/rx */
	if (priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
		disable_irq(priv->interruptTransmit);
		disable_irq(priv->interruptReceive);
		disable_irq(priv->interruptError);
		gfar_interrupt(priv->interruptTransmit, dev);
		enable_irq(priv->interruptError);
		enable_irq(priv->interruptReceive);
		enable_irq(priv->interruptTransmit);
	} else {
		disable_irq(priv->interruptTransmit);
		gfar_interrupt(priv->interruptTransmit, dev);
		enable_irq(priv->interruptTransmit);
	}
}
#endif

/* The interrupt handler for devices with one interrupt */
static irqreturn_t gfar_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct gfar_private *priv = netdev_priv(dev);

	/* Save ievent for future reference */
	u32 events = gfar_read(&priv->regs->ievent);

	/* Check for reception */
	if (events & IEVENT_RX_MASK)
		gfar_receive(irq, dev_id);

	/* Check for transmit completion */
	if (events & IEVENT_TX_MASK)
		gfar_transmit(irq, dev_id);

	/* Check for errors */
	if (events & IEVENT_ERR_MASK)
		gfar_error(irq, dev_id);

	return IRQ_HANDLED;
}

/* Called every time the controller might need to be made
 * aware of new link state.  The PHY code conveys this
 * information through variables in the phydev structure, and this
 * function converts those variables into the appropriate
 * register values, and can bring down the device if needed.
 */
static void adjust_link(struct net_device *dev)
{
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	unsigned long flags;
	struct phy_device *phydev = priv->phydev;
	int new_state = 0;

	spin_lock_irqsave(&priv->txlock, flags);
	if (phydev->link) {
		u32 tempval = gfar_read(&regs->maccfg2);
		u32 ecntrl = gfar_read(&regs->ecntrl);

		/* Now we make sure that we can be in full duplex mode.
		 * If not, we operate in half-duplex mode. */
		if (phydev->duplex != priv->oldduplex) {
			new_state = 1;
			if (!(phydev->duplex))
				tempval &= ~(MACCFG2_FULL_DUPLEX);
			else
				tempval |= MACCFG2_FULL_DUPLEX;

			priv->oldduplex = phydev->duplex;
		}

		if (phydev->speed != priv->oldspeed) {
			new_state = 1;
			switch (phydev->speed) {
			case 1000:
				tempval =
				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_GMII);
				break;
			case 100:
			case 10:
				tempval =
				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_MII);

				/* Reduced mode distinguishes
				 * between 10 and 100 */
				if (phydev->speed == SPEED_100)
					ecntrl |= ECNTRL_R100;
				else
					ecntrl &= ~(ECNTRL_R100);
				break;
			default:
				if (netif_msg_link(priv))
					printk(KERN_WARNING
						"%s: Ack!  Speed (%d) is not 10/100/1000!\n",
						dev->name, phydev->speed);
				break;
			}

			priv->oldspeed = phydev->speed;
		}

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

		if (!priv->oldlink) {
			new_state = 1;
			priv->oldlink = 1;
			netif_schedule(dev);
		}
	} else if (priv->oldlink) {
		new_state = 1;
		priv->oldlink = 0;
		priv->oldspeed = 0;
		priv->oldduplex = -1;
	}

	if (new_state && netif_msg_link(priv))
		phy_print_status(phydev);

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

/* Update the hash table based on the current list of multicast
 * addresses we subscribe to.  Also, change the promiscuity of
 * the device based on the flags (this function is called
 * whenever dev->flags is changed */
static void gfar_set_multi(struct net_device *dev)
{
	struct dev_mc_list *mc_ptr;
	struct gfar_private *priv = netdev_priv(dev);
	struct gfar __iomem *regs = priv->regs;
	u32 tempval;

	if(dev->flags & IFF_PROMISC) {
		/* Set RCTRL to PROM */
		tempval = gfar_read(&regs->rctrl);
		tempval |= RCTRL_PROM;
		gfar_write(&regs->rctrl, tempval);
	} else {
		/* Set RCTRL to not PROM */
		tempval = gfar_read(&regs->rctrl);
		tempval &= ~(RCTRL_PROM);
		gfar_write(&regs->rctrl, tempval);
	}

	if(dev->flags & IFF_ALLMULTI) {
		/* Set the hash to rx all multicast frames */
		gfar_write(&regs->igaddr0, 0xffffffff);
		gfar_write(&regs->igaddr1, 0xffffffff);
		gfar_write(&regs->igaddr2, 0xffffffff);
		gfar_write(&regs->igaddr3, 0xffffffff);
		gfar_write(&regs->igaddr4, 0xffffffff);
		gfar_write(&regs->igaddr5, 0xffffffff);
		gfar_write(&regs->igaddr6, 0xffffffff);
		gfar_write(&regs->igaddr7, 0xffffffff);
		gfar_write(&regs->gaddr0, 0xffffffff);
		gfar_write(&regs->gaddr1, 0xffffffff);
		gfar_write(&regs->gaddr2, 0xffffffff);
		gfar_write(&regs->gaddr3, 0xffffffff);
		gfar_write(&regs->gaddr4, 0xffffffff);
		gfar_write(&regs->gaddr5, 0xffffffff);
		gfar_write(&regs->gaddr6, 0xffffffff);
		gfar_write(&regs->gaddr7, 0xffffffff);
	} else {
		int em_num;
		int idx;

		/* zero out the hash */
		gfar_write(&regs->igaddr0, 0x0);
		gfar_write(&regs->igaddr1, 0x0);
		gfar_write(&regs->igaddr2, 0x0);
		gfar_write(&regs->igaddr3, 0x0);
		gfar_write(&regs->igaddr4, 0x0);
		gfar_write(&regs->igaddr5, 0x0);
		gfar_write(&regs->igaddr6, 0x0);
		gfar_write(&regs->igaddr7, 0x0);
		gfar_write(&regs->gaddr0, 0x0);
		gfar_write(&regs->gaddr1, 0x0);
		gfar_write(&regs->gaddr2, 0x0);
		gfar_write(&regs->gaddr3, 0x0);
		gfar_write(&regs->gaddr4, 0x0);
		gfar_write(&regs->gaddr5, 0x0);
		gfar_write(&regs->gaddr6, 0x0);
		gfar_write(&regs->gaddr7, 0x0);

		/* If we have extended hash tables, we need to
		 * clear the exact match registers to prepare for
		 * setting them */
		if (priv->extended_hash) {
			em_num = GFAR_EM_NUM + 1;
			gfar_clear_exact_match(dev);
			idx = 1;
		} else {
			idx = 0;
			em_num = 0;
		}

		if(dev->mc_count == 0)
			return;

		/* Parse the list, and set the appropriate bits */
		for(mc_ptr = dev->mc_list; mc_ptr; mc_ptr = mc_ptr->next) {
			if (idx < em_num) {
				gfar_set_mac_for_addr(dev, idx,
						mc_ptr->dmi_addr);
				idx++;
			} else
				gfar_set_hash_for_addr(dev, mc_ptr->dmi_addr);
		}
	}

	return;
}


/* Clears each of the exact match registers to zero, so they
 * don't interfere with normal reception */
static void gfar_clear_exact_match(struct net_device *dev)
{
	int idx;
	u8 zero_arr[MAC_ADDR_LEN] = {0,0,0,0,0,0};

	for(idx = 1;idx < GFAR_EM_NUM + 1;idx++)
		gfar_set_mac_for_addr(dev, idx, (u8 *)zero_arr);
}

/* Set the appropriate hash bit for the given addr */
/* The algorithm works like so:
 * 1) Take the Destination Address (ie the multicast address), and
 * do a CRC on it (little endian), and reverse the bits of the
 * result.
 * 2) Use the 8 most significant bits as a hash into a 256-entry
 * table.  The table is controlled through 8 32-bit registers:
 * gaddr0-7.  gaddr0's MSB is entry 0, and gaddr7's LSB is
 * gaddr7.  This means that the 3 most significant bits in the
 * hash index which gaddr register to use, and the 5 other bits
 * indicate which bit (assuming an IBM numbering scheme, which
 * for PowerPC (tm) is usually the case) in the register holds
 * the entry. */
static void gfar_set_hash_for_addr(struct net_device *dev, u8 *addr)
{
	u32 tempval;
	struct gfar_private *priv = netdev_priv(dev);
	u32 result = ether_crc(MAC_ADDR_LEN, addr);
	int width = priv->hash_width;
	u8 whichbit = (result >> (32 - width)) & 0x1f;
	u8 whichreg = result >> (32 - width + 5);
	u32 value = (1 << (31-whichbit));

	tempval = gfar_read(priv->hash_regs[whichreg]);
	tempval |= value;
	gfar_write(priv->hash_regs[whichreg], tempval);

	return;
}


/* There are multiple MAC Address register pairs on some controllers
 * This function sets the numth pair to a given address
 */
static void gfar_set_mac_for_addr(struct net_device *dev, int num, u8 *addr)
{
	struct gfar_private *priv = netdev_priv(dev);
	int idx;
	char tmpbuf[MAC_ADDR_LEN];
	u32 tempval;
	u32 __iomem *macptr = &priv->regs->macstnaddr1;

	macptr += num*2;

	/* Now copy it into the mac registers backwards, cuz */
	/* little endian is silly */
	for (idx = 0; idx < MAC_ADDR_LEN; idx++)
		tmpbuf[MAC_ADDR_LEN - 1 - idx] = addr[idx];

	gfar_write(macptr, *((u32 *) (tmpbuf)));

	tempval = *((u32 *) (tmpbuf + 4));

	gfar_write(macptr+1, tempval);
}

/* GFAR error interrupt handler */
static irqreturn_t gfar_error(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct gfar_private *priv = netdev_priv(dev);

	/* Save ievent for future reference */
	u32 events = gfar_read(&priv->regs->ievent);

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

	/* Magic Packet is not an error. */
	if ((priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_MAGIC_PACKET) &&
	    (events & IEVENT_MAG))
		events &= ~IEVENT_MAG;

	/* Hmm... */
	if (netif_msg_rx_err(priv) || netif_msg_tx_err(priv))
		printk(KERN_DEBUG "%s: error interrupt (ievent=0x%08x imask=0x%08x)\n",
		       dev->name, events, gfar_read(&priv->regs->imask));

	/* Update the error counters */
	if (events & IEVENT_TXE) {
		priv->stats.tx_errors++;

		if (events & IEVENT_LC)
			priv->stats.tx_window_errors++;
		if (events & IEVENT_CRL)
			priv->stats.tx_aborted_errors++;
		if (events & IEVENT_XFUN) {
			if (netif_msg_tx_err(priv))
				printk(KERN_DEBUG "%s: TX FIFO underrun, "
				       "packet dropped.\n", dev->name);
			priv->stats.tx_dropped++;
			priv->extra_stats.tx_underrun++;

			/* Reactivate the Tx Queues */
			gfar_write(&priv->regs->tstat, TSTAT_CLEAR_THALT);
		}
		if (netif_msg_tx_err(priv))
			printk(KERN_DEBUG "%s: Transmit Error\n", dev->name);
	}
	if (events & IEVENT_BSY) {
		priv->stats.rx_errors++;
		priv->extra_stats.rx_bsy++;

		gfar_receive(irq, dev_id);

#ifndef CONFIG_GFAR_NAPI
		/* Clear the halt bit in RSTAT */
		gfar_write(&priv->regs->rstat, RSTAT_CLEAR_RHALT);
#endif

		if (netif_msg_rx_err(priv))
			printk(KERN_DEBUG "%s: busy error (rstat: %x)\n",
			       dev->name, gfar_read(&priv->regs->rstat));
	}
	if (events & IEVENT_BABR) {
		priv->stats.rx_errors++;
		priv->extra_stats.rx_babr++;

		if (netif_msg_rx_err(priv))
			printk(KERN_DEBUG "%s: babbling RX error\n", dev->name);
	}
	if (events & IEVENT_EBERR) {
		priv->extra_stats.eberr++;
		if (netif_msg_rx_err(priv))
			printk(KERN_DEBUG "%s: bus error\n", dev->name);
	}
	if ((events & IEVENT_RXC) && netif_msg_rx_status(priv))
		printk(KERN_DEBUG "%s: control frame\n", dev->name);

	if (events & IEVENT_BABT) {
		priv->extra_stats.tx_babt++;
		if (netif_msg_tx_err(priv))
			printk(KERN_DEBUG "%s: babbling TX error\n", dev->name);
	}
	return IRQ_HANDLED;
}

/* Structure for a device driver */
static struct platform_driver gfar_driver = {
	.probe = gfar_probe,
	.remove = gfar_remove,
	.suspend = gfar_suspend,
	.resume = gfar_resume,
	.driver	= {
		.name = "fsl-gianfar",
	},
};

static int __init gfar_init(void)
{
	int err = gfar_mdio_init();

	if (err)
		return err;

	err = platform_driver_register(&gfar_driver);

	if (err)
		gfar_mdio_exit();

	return err;
}

static void __exit gfar_exit(void)
{
	platform_driver_unregister(&gfar_driver);
	gfar_mdio_exit();
}

module_init(gfar_init);
module_exit(gfar_exit);