gmac.c

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#endif /* CONFIG_PMAC_PBOOK */

/*
 * Handle a transmit timeout
 */
static void
gmac_tx_timeout(struct net_device *dev)
{
	struct gmac *gm = (struct gmac *) dev->priv;
	int i, timeout;
	unsigned long flags;
		
	printk (KERN_ERR "%s: transmit timed out, resetting\n", dev->name);

	spin_lock_irqsave(&gm->lock, flags);

	/* Stop chip */
	gmac_stop_dma(gm);
	/* Empty Tx ring of any remaining gremlins */
	gmac_tx_cleanup(dev, 1);
	/* Empty Rx ring of any remaining gremlins */
	for (i = 0; i < NRX; ++i) {
		if (gm->rx_buff[i] != 0) {
			dev_kfree_skb_irq(gm->rx_buff[i]);
			gm->rx_buff[i] = 0;
		}
	}
	/* Perform a software reset */
	GM_OUT(GM_RESET, GM_RESET_TX | GM_RESET_RX);
	for (timeout = 100; timeout > 0; --timeout) {
		mdelay(10);
		if ((GM_IN(GM_RESET) & (GM_RESET_TX | GM_RESET_RX)) == 0) {
			/* Mask out all chips interrupts */
			GM_OUT(GM_IRQ_MASK, 0xffffffff);
			break;
		}
	}
	if (!timeout)
		printk(KERN_ERR "%s reset chip failed !\n", dev->name);
	/* Create fresh rings */
	gmac_init_rings(gm, 1);
	/* re-initialize the MAC */
	gmac_mac_init(gm, dev->dev_addr);	
	/* re-initialize the multicast tables & promisc mode if any */
	gmac_set_multicast(dev);
	/* Restart PHY auto-poll */
	mii_interrupt(gm);
	/* Restart chip */
	gmac_start_dma(gm);
	
	spin_unlock_irqrestore(&gm->lock, flags);

	netif_wake_queue(dev);
}

/*
 * Add a packet to the transmit ring
 */
static int
gmac_xmit_start(struct sk_buff *skb, struct net_device *dev)
{
	struct gmac *gm = (struct gmac *) dev->priv;
	volatile struct gmac_dma_desc *dp;
	unsigned long flags;
	int i;

	spin_lock_irqsave(&gm->lock, flags);

	i = gm->next_tx;
	if (gm->tx_buff[i] != 0) {
		/* 
		 * Buffer is full, can't send this packet at the moment
		 * 
		 * Can this ever happen in 2.4 ?
		 */
		netif_stop_queue(dev);
		spin_unlock_irqrestore(&gm->lock, flags);
		return 1;
	}
	gm->next_tx = (i + 1) & (NTX - 1);
	gm->tx_buff[i] = skb;
	
	dp = &gm->txring[i];
	/* FIXME: Interrupt on all packet for now, change this to every N packet,
	 * with N to be adjusted
	 */
	dp->flags = TX_FL_INTERRUPT;
	dp->hi_addr = 0;
	st_le32(&dp->lo_addr, virt_to_bus(skb->data));
	mb();
	st_le32(&dp->size, TX_SZ_SOP | TX_SZ_EOP | skb->len);
	mb();

	GM_OUT(GM_TX_KICK, gm->next_tx);

	if (gm->tx_buff[gm->next_tx] != 0)
		netif_stop_queue(dev);

	spin_unlock_irqrestore(&gm->lock, flags);

	dev->trans_start = jiffies;

	return 0;
}

/*
 * Handle servicing of the transmit ring by deallocating used
 * Tx packets and restoring flow control when necessary
 */
static void
gmac_tx_cleanup(struct net_device *dev, int force_cleanup)
{
	struct gmac *gm = (struct gmac *) dev->priv;
	volatile struct gmac_dma_desc *dp;
	struct sk_buff *skb;
	int gone, i;

	i = gm->tx_gone;

	/* Note: If i==gone, we empty the entire ring. This works because
	 * if the ring was empty, we wouldn't have received the interrupt
	 */
	do {
		gone = GM_IN(GM_TX_COMP);
		skb = gm->tx_buff[i];
		if (skb == NULL)
			break;
		dp = &gm->txring[i];
		if (force_cleanup)
			++gm->stats.tx_errors;
		else {
			++gm->stats.tx_packets;
			gm->stats.tx_bytes += skb->len;
		}
		gm->tx_buff[i] = NULL;
		dev_kfree_skb_irq(skb);
		if (++i >= NTX)
			i = 0;
	} while (force_cleanup || i != gone);
	gm->tx_gone = i;

	if (!force_cleanup && netif_queue_stopped(dev) &&
	    (gm->tx_buff[gm->next_tx] == 0))
		netif_wake_queue(dev);
}

/*
 * Handle servicing of receive ring
 */
static void
gmac_receive(struct net_device *dev)
{
	struct gmac *gm = (struct gmac *) dev->priv;
	int i = gm->next_rx;
	volatile struct gmac_dma_desc *dp;
	struct sk_buff *skb, *new_skb;
	int len, flags, drop, last;
	unsigned char *data;
	u16 csum;

	last = -1;
	for (;;) {
		dp = &gm->rxring[i];
		/* Buffer not yet filled, no more Rx buffers to handle */
		if (ld_le32(&dp->size) & RX_SZ_OWN)
			break;
		/* Get packet length, flags, etc... */
		len = (ld_le32(&dp->size) >> 16) & 0x7fff;
		flags = ld_le32(&dp->flags);
		skb = gm->rx_buff[i];
		drop = 0;
		new_skb = NULL;
		csum = ld_le32(&dp->size) & RX_SZ_CKSUM_MASK;
		
		/* Handle errors */
		if ((len < ETH_ZLEN)||(flags & RX_FL_CRC_ERROR)||(!skb)) {
			++gm->stats.rx_errors;
			if (len < ETH_ZLEN)
				++gm->stats.rx_length_errors;
			if (flags & RX_FL_CRC_ERROR)
				++gm->stats.rx_crc_errors;
			if (!skb) {
				++gm->stats.rx_dropped;
				skb = gmac_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
				if (skb) {
					gm->rx_buff[i] = skb;
			    		skb->dev = dev;
			    		skb_put(skb, ETH_FRAME_LEN + RX_OFFSET);
			    		skb_reserve(skb, RX_OFFSET);
				}
			}
			drop = 1;
		} else {
			/* Large packet, alloc a new skb for the ring */
			if (len > RX_COPY_THRESHOLD) {
			    new_skb = gmac_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
			    if(!new_skb) {
			    	printk(KERN_INFO "%s: Out of SKBs in Rx, packet dropped !\n",
			    		dev->name);
			    	drop = 1;
			    	++gm->stats.rx_dropped;
			    	goto finish;
			    }

			    gm->rx_buff[i] = new_skb;
			    new_skb->dev = dev;
			    skb_put(new_skb, ETH_FRAME_LEN + RX_OFFSET);
			    skb_reserve(new_skb, RX_OFFSET);
			    skb_trim(skb, len);
			} else {
			    /* Small packet, copy it to a new small skb */
			    struct sk_buff *copy_skb = dev_alloc_skb(len + RX_OFFSET);

			    if(!copy_skb) {
				printk(KERN_INFO "%s: Out of SKBs in Rx, packet dropped !\n",
					dev->name);
				drop = 1;
				++gm->stats.rx_dropped;
			    	goto finish;
			    }

			    copy_skb->dev = dev;
			    skb_reserve(copy_skb, RX_OFFSET);
			    skb_put(copy_skb, len);
			    memcpy(copy_skb->data, skb->data, len);

			    new_skb = skb;
			    skb = copy_skb;
			}
		}
	finish:
		/* Need to drop packet ? */
		if (drop) {
			new_skb = skb;
			skb = NULL;
		}
		
		/* Put back ring entry */
		data = new_skb ? (new_skb->data - RX_OFFSET) : dummy_buf;
		dp->hi_addr = 0;
		st_le32(&dp->lo_addr, virt_to_bus(data));
		mb();
		st_le32(&dp->size, RX_SZ_OWN | ((RX_BUF_ALLOC_SIZE-RX_OFFSET) << RX_SZ_SHIFT));
		
		/* Got Rx packet ? */
		if (skb) {
			/* Yes, baby, keep that hot ;) */
			if(!(csum ^ 0xffff))
				skb->ip_summed = CHECKSUM_UNNECESSARY;
			else
				skb->ip_summed = CHECKSUM_NONE;
			skb->ip_summed = CHECKSUM_NONE;
			skb->protocol = eth_type_trans(skb, dev);
			netif_rx(skb);
			gm->stats.rx_bytes += skb->len;
			++gm->stats.rx_packets;
		}
		
		last = i;
		if (++i >= NRX)
			i = 0;
	}
	gm->next_rx = i;
	if (last >= 0) {
		mb();
		GM_OUT(GM_RX_KICK, last & 0xfffffffc);
	}
}

/*
 * Service chip interrupts
 */
static void
gmac_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = (struct net_device *) dev_id;
	struct gmac *gm = (struct gmac *) dev->priv;
	unsigned int status;

	status = GM_IN(GM_IRQ_STATUS);
	if (status & (GM_IRQ_BUS_ERROR | GM_IRQ_MIF))
		GM_OUT(GM_IRQ_ACK, status & (GM_IRQ_BUS_ERROR | GM_IRQ_MIF));
	
	if (status & (GM_IRQ_RX_TAG_ERR | GM_IRQ_BUS_ERROR)) {
		printk(KERN_ERR "%s: IRQ Error status: 0x%08x\n",
			dev->name, status);
	}
	
	if (status & GM_IRQ_MIF) {
		spin_lock(&gm->lock);
		mii_interrupt(gm);
		spin_unlock(&gm->lock);
	}
	
	if (status & GM_IRQ_RX_DONE) {
		spin_lock(&gm->lock);
		gmac_receive(dev);
		spin_unlock(&gm->lock);
	}
		
	if (status & (GM_IRQ_TX_INT_ME | GM_IRQ_TX_ALL)) {
		spin_lock(&gm->lock);
		gmac_tx_cleanup(dev, 0);
		spin_unlock(&gm->lock);
	}
}

/*
 * Retreive some error stats from chip and return them
 * to above layer
 */
static struct net_device_stats *
gmac_stats(struct net_device *dev)
{
	struct gmac *gm = (struct gmac *) dev->priv;
	struct net_device_stats *stats = &gm->stats;

	if (gm && gm->opened) {
		stats->rx_crc_errors += GM_IN(GM_MAC_RX_CRC_ERR_CTR);
		GM_OUT(GM_MAC_RX_CRC_ERR_CTR, 0);

		stats->rx_frame_errors += GM_IN(GM_MAC_RX_ALIGN_ERR_CTR);
		GM_OUT(GM_MAC_RX_ALIGN_ERR_CTR, 0);

		stats->rx_length_errors += GM_IN(GM_MAC_RX_LEN_ERR_CTR);
		GM_OUT(GM_MAC_RX_LEN_ERR_CTR, 0);

		stats->tx_aborted_errors += GM_IN(GM_MAC_EXCS_COLLISION_CTR);

		stats->collisions +=
			(GM_IN(GM_MAC_EXCS_COLLISION_CTR) +
			 GM_IN(GM_MAC_LATE_COLLISION_CTR));
		GM_OUT(GM_MAC_EXCS_COLLISION_CTR, 0);
		GM_OUT(GM_MAC_LATE_COLLISION_CTR, 0);
	}

	return stats;
}

static int __init
gmac_probe(void)
{
	struct device_node *gmac;

	/* We bump use count during probe since get_free_page can sleep
	 * which can be a race condition if module is unloaded at this
	 * point.
	 */
	MOD_INC_USE_COUNT;
	
	/*
	 * We don't use PCI scanning on pmac since the GMAC cell is disabled
	 * by default, and thus absent from kernel original PCI probing.
	 */
	for (gmac = find_compatible_devices("network", "gmac"); gmac != 0;
	     gmac = gmac->next)
		gmac_probe1(gmac);


	MOD_DEC_USE_COUNT;

	return 0;
}

static void
gmac_probe1(struct device_node *gmac)
{
	struct gmac *gm;
	unsigned long tx_descpage, rx_descpage;
	unsigned char *addr;
	struct net_device *dev;
	int i;

	if (gmac->n_addrs < 1 || gmac->n_intrs < 1) {
		printk(KERN_ERR "can't use GMAC %s: %d addrs and %d intrs\n",
		       gmac->full_name, gmac->n_addrs, gmac->n_intrs);
		return;
	}

	addr = get_property(gmac, "local-mac-address", NULL);
	if (addr == NULL) {
		printk(KERN_ERR "Can't get mac-address for GMAC %s\n",
		       gmac->full_name);
		return;
	}

	tx_descpage = get_free_page(GFP_KERNEL);
	if (tx_descpage == 0) {
		printk(KERN_ERR "GMAC: can't get a page for tx descriptors\n");
		return;
	}
	rx_descpage = get_free_page(GFP_KERNEL);
	if (rx_descpage == 0) {
		printk(KERN_ERR "GMAC: can't get a page for rx descriptors\n");
		free_page(tx_descpage);
		return;
	}

	dev = init_etherdev(NULL, sizeof(struct gmac));

	if (!dev) {
		printk(KERN_ERR "GMAC: init_etherdev failed, out of memory\n");
		free_page(tx_descpage);
		free_page(rx_descpage);
		return;
	}
	SET_MODULE_OWNER(dev);

	gm = dev->priv;
	dev->base_addr = gmac->addrs[0].address;
	gm->regs = (volatile unsigned int *)
		ioremap(gmac->addrs[0].address, 0x10000);
	dev->irq = gmac->intrs[0].line;
	gm->dev = dev;
	gm->of_node = gmac;

	spin_lock_init(&gm->lock);
	
	if (pci_device_from_OF_node(gmac, &gm->pci_bus, &gm->pci_devfn)) {
		gm->pci_bus = gm->pci_devfn = 0xff;
		printk(KERN_ERR "Can't locate GMAC PCI entry\n");
	}

	printk(KERN_INFO "%s: GMAC at", dev->name);
	for (i = 0; i < 6; ++i) {
		dev->dev_addr[i] = addr[i];
		printk("%c%.2x", (i? ':': ' '), addr[i]);
	}
	printk(", driver " GMAC_VERSION "\n");

	gm->tx_desc_page = tx_descpage;
	gm->rx_desc_page = rx_descpage;
	gm->rxring = (volatile struct gmac_dma_desc *) rx_descpage;
	gm->txring = (volatile struct gmac_dma_desc *) tx_descpage;

	gm->phy_addr = 0;
	gm->opened = 0;

	dev->open = gmac_open;
	dev->stop = gmac_close;
	dev->hard_start_xmit = gmac_xmit_start;
	dev->get_stats = gmac_stats;
	dev->set_multicast_list = &gmac_set_multicast;
	dev->tx_timeout = &gmac_tx_timeout;
	dev->watchdog_timeo = 5*HZ;

	ether_setup(dev);
	
	gm->next_gmac = gmacs;
	gmacs = dev;

#ifdef CONFIG_PMAC_PBOOK
	pmu_register_sleep_notifier(&gmac_sleep_notifier);
#endif
}

MODULE_AUTHOR("Paul Mackerras/Ben Herrenschmidt");
MODULE_DESCRIPTION("PowerMac GMAC driver.");

static void __exit gmac_cleanup_module(void)
{
	struct gmac *gm;
	struct net_device *dev;

	while ((dev = gmacs) != NULL) {
		gm = (struct gmac *) dev->priv;
		unregister_netdev(dev);
		free_page(gm->tx_desc_page);
		free_page(gm->rx_desc_page);
		gmacs = gm->next_gmac;
		kfree(dev);
	}
}

module_init(gmac_probe);
module_exit(gmac_cleanup_module);