core.c

来自「linux 内核源代码」· C语言 代码 · 共 2,457 行 · 第 1/5 页

static void emac_clean_tx_ring(struct emac_instance *dev)
{
	int i;

	for (i = 0; i < NUM_TX_BUFF; ++i) {
		if (dev->tx_skb[i]) {
			dev_kfree_skb(dev->tx_skb[i]);
			dev->tx_skb[i] = NULL;
			if (dev->tx_desc[i].ctrl & MAL_TX_CTRL_READY)
				++dev->estats.tx_dropped;
		}
		dev->tx_desc[i].ctrl = 0;
		dev->tx_desc[i].data_ptr = 0;
	}
}

static void emac_clean_rx_ring(struct emac_instance *dev)
{
	int i;

	for (i = 0; i < NUM_RX_BUFF; ++i)
		if (dev->rx_skb[i]) {
			dev->rx_desc[i].ctrl = 0;
			dev_kfree_skb(dev->rx_skb[i]);
			dev->rx_skb[i] = NULL;
			dev->rx_desc[i].data_ptr = 0;
		}

	if (dev->rx_sg_skb) {
		dev_kfree_skb(dev->rx_sg_skb);
		dev->rx_sg_skb = NULL;
	}
}

static inline int emac_alloc_rx_skb(struct emac_instance *dev, int slot,
				    gfp_t flags)
{
	struct sk_buff *skb = alloc_skb(dev->rx_skb_size, flags);
	if (unlikely(!skb))
		return -ENOMEM;

	dev->rx_skb[slot] = skb;
	dev->rx_desc[slot].data_len = 0;

	skb_reserve(skb, EMAC_RX_SKB_HEADROOM + 2);
	dev->rx_desc[slot].data_ptr =
	    dma_map_single(&dev->ofdev->dev, skb->data - 2, dev->rx_sync_size,
			   DMA_FROM_DEVICE) + 2;
	wmb();
	dev->rx_desc[slot].ctrl = MAL_RX_CTRL_EMPTY |
	    (slot == (NUM_RX_BUFF - 1) ? MAL_RX_CTRL_WRAP : 0);

	return 0;
}

static void emac_print_link_status(struct emac_instance *dev)
{
	if (netif_carrier_ok(dev->ndev))
		printk(KERN_INFO "%s: link is up, %d %s%s\n",
		       dev->ndev->name, dev->phy.speed,
		       dev->phy.duplex == DUPLEX_FULL ? "FDX" : "HDX",
		       dev->phy.pause ? ", pause enabled" :
		       dev->phy.asym_pause ? ", asymmetric pause enabled" : "");
	else
		printk(KERN_INFO "%s: link is down\n", dev->ndev->name);
}

/* Process ctx, rtnl_lock semaphore */
static int emac_open(struct net_device *ndev)
{
	struct emac_instance *dev = netdev_priv(ndev);
	int err, i;

	DBG(dev, "open" NL);

	/* Setup error IRQ handler */
	err = request_irq(dev->emac_irq, emac_irq, 0, "EMAC", dev);
	if (err) {
		printk(KERN_ERR "%s: failed to request IRQ %d\n",
		       ndev->name, dev->emac_irq);
		return err;
	}

	/* Allocate RX ring */
	for (i = 0; i < NUM_RX_BUFF; ++i)
		if (emac_alloc_rx_skb(dev, i, GFP_KERNEL)) {
			printk(KERN_ERR "%s: failed to allocate RX ring\n",
			       ndev->name);
			goto oom;
		}

	dev->tx_cnt = dev->tx_slot = dev->ack_slot = dev->rx_slot = 0;
	clear_bit(MAL_COMMAC_RX_STOPPED, &dev->commac.flags);
	dev->rx_sg_skb = NULL;

	mutex_lock(&dev->link_lock);
	dev->opened = 1;

	/* Start PHY polling now.
	 */
	if (dev->phy.address >= 0) {
		int link_poll_interval;
		if (dev->phy.def->ops->poll_link(&dev->phy)) {
			dev->phy.def->ops->read_link(&dev->phy);
			netif_carrier_on(dev->ndev);
			link_poll_interval = PHY_POLL_LINK_ON;
		} else {
			netif_carrier_off(dev->ndev);
			link_poll_interval = PHY_POLL_LINK_OFF;
		}
		dev->link_polling = 1;
		wmb();
		schedule_delayed_work(&dev->link_work, link_poll_interval);
		emac_print_link_status(dev);
	} else
		netif_carrier_on(dev->ndev);

	emac_configure(dev);
	mal_poll_add(dev->mal, &dev->commac);
	mal_enable_tx_channel(dev->mal, dev->mal_tx_chan);
	mal_set_rcbs(dev->mal, dev->mal_rx_chan, emac_rx_size(ndev->mtu));
	mal_enable_rx_channel(dev->mal, dev->mal_rx_chan);
	emac_tx_enable(dev);
	emac_rx_enable(dev);
	emac_netif_start(dev);

	mutex_unlock(&dev->link_lock);

	return 0;
 oom:
	emac_clean_rx_ring(dev);
	free_irq(dev->emac_irq, dev);

	return -ENOMEM;
}

/* BHs disabled */
#if 0
static int emac_link_differs(struct emac_instance *dev)
{
	u32 r = in_be32(&dev->emacp->mr1);

	int duplex = r & EMAC_MR1_FDE ? DUPLEX_FULL : DUPLEX_HALF;
	int speed, pause, asym_pause;

	if (r & EMAC_MR1_MF_1000)
		speed = SPEED_1000;
	else if (r & EMAC_MR1_MF_100)
		speed = SPEED_100;
	else
		speed = SPEED_10;

	switch (r & (EMAC_MR1_EIFC | EMAC_MR1_APP)) {
	case (EMAC_MR1_EIFC | EMAC_MR1_APP):
		pause = 1;
		asym_pause = 0;
		break;
	case EMAC_MR1_APP:
		pause = 0;
		asym_pause = 1;
		break;
	default:
		pause = asym_pause = 0;
	}
	return speed != dev->phy.speed || duplex != dev->phy.duplex ||
	    pause != dev->phy.pause || asym_pause != dev->phy.asym_pause;
}
#endif

static void emac_link_timer(struct work_struct *work)
{
	struct emac_instance *dev =
		container_of((struct delayed_work *)work,
			     struct emac_instance, link_work);
	int link_poll_interval;

	mutex_lock(&dev->link_lock);
	DBG2(dev, "link timer" NL);

	if (!dev->opened)
		goto bail;

	if (dev->phy.def->ops->poll_link(&dev->phy)) {
		if (!netif_carrier_ok(dev->ndev)) {
			/* Get new link parameters */
			dev->phy.def->ops->read_link(&dev->phy);

			netif_carrier_on(dev->ndev);
			emac_netif_stop(dev);
			emac_full_tx_reset(dev);
			emac_netif_start(dev);
			emac_print_link_status(dev);
		}
		link_poll_interval = PHY_POLL_LINK_ON;
	} else {
		if (netif_carrier_ok(dev->ndev)) {
			netif_carrier_off(dev->ndev);
			netif_tx_disable(dev->ndev);
			emac_reinitialize(dev);
			emac_print_link_status(dev);
		}
		link_poll_interval = PHY_POLL_LINK_OFF;
	}
	schedule_delayed_work(&dev->link_work, link_poll_interval);
 bail:
	mutex_unlock(&dev->link_lock);
}

static void emac_force_link_update(struct emac_instance *dev)
{
	netif_carrier_off(dev->ndev);
	smp_rmb();
	if (dev->link_polling) {
		cancel_rearming_delayed_work(&dev->link_work);
		if (dev->link_polling)
			schedule_delayed_work(&dev->link_work,  PHY_POLL_LINK_OFF);
	}
}

/* Process ctx, rtnl_lock semaphore */
static int emac_close(struct net_device *ndev)
{
	struct emac_instance *dev = netdev_priv(ndev);

	DBG(dev, "close" NL);

	if (dev->phy.address >= 0) {
		dev->link_polling = 0;
		cancel_rearming_delayed_work(&dev->link_work);
	}
	mutex_lock(&dev->link_lock);
	emac_netif_stop(dev);
	dev->opened = 0;
	mutex_unlock(&dev->link_lock);

	emac_rx_disable(dev);
	emac_tx_disable(dev);
	mal_disable_rx_channel(dev->mal, dev->mal_rx_chan);
	mal_disable_tx_channel(dev->mal, dev->mal_tx_chan);
	mal_poll_del(dev->mal, &dev->commac);

	emac_clean_tx_ring(dev);
	emac_clean_rx_ring(dev);

	free_irq(dev->emac_irq, dev);

	return 0;
}

static inline u16 emac_tx_csum(struct emac_instance *dev,
			       struct sk_buff *skb)
{
	if (emac_has_feature(dev, EMAC_FTR_HAS_TAH &&
			     skb->ip_summed == CHECKSUM_PARTIAL)) {
		++dev->stats.tx_packets_csum;
		return EMAC_TX_CTRL_TAH_CSUM;
	}
	return 0;
}

static inline int emac_xmit_finish(struct emac_instance *dev, int len)
{
	struct emac_regs __iomem *p = dev->emacp;
	struct net_device *ndev = dev->ndev;

	/* Send the packet out. If the if makes a significant perf
	 * difference, then we can store the TMR0 value in "dev"
	 * instead
	 */
	if (emac_has_feature(dev, EMAC_FTR_EMAC4))
		out_be32(&p->tmr0, EMAC4_TMR0_XMIT);
	else
		out_be32(&p->tmr0, EMAC_TMR0_XMIT);

	if (unlikely(++dev->tx_cnt == NUM_TX_BUFF)) {
		netif_stop_queue(ndev);
		DBG2(dev, "stopped TX queue" NL);
	}

	ndev->trans_start = jiffies;
	++dev->stats.tx_packets;
	dev->stats.tx_bytes += len;

	return 0;
}

/* Tx lock BH */
static int emac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	struct emac_instance *dev = netdev_priv(ndev);
	unsigned int len = skb->len;
	int slot;

	u16 ctrl = EMAC_TX_CTRL_GFCS | EMAC_TX_CTRL_GP | MAL_TX_CTRL_READY |
	    MAL_TX_CTRL_LAST | emac_tx_csum(dev, skb);

	slot = dev->tx_slot++;
	if (dev->tx_slot == NUM_TX_BUFF) {
		dev->tx_slot = 0;
		ctrl |= MAL_TX_CTRL_WRAP;
	}

	DBG2(dev, "xmit(%u) %d" NL, len, slot);

	dev->tx_skb[slot] = skb;
	dev->tx_desc[slot].data_ptr = dma_map_single(&dev->ofdev->dev,
						     skb->data, len,
						     DMA_TO_DEVICE);
	dev->tx_desc[slot].data_len = (u16) len;
	wmb();
	dev->tx_desc[slot].ctrl = ctrl;

	return emac_xmit_finish(dev, len);
}

#ifdef CONFIG_IBM_NEW_EMAC_TAH
static inline int emac_xmit_split(struct emac_instance *dev, int slot,
				  u32 pd, int len, int last, u16 base_ctrl)
{
	while (1) {
		u16 ctrl = base_ctrl;
		int chunk = min(len, MAL_MAX_TX_SIZE);
		len -= chunk;

		slot = (slot + 1) % NUM_TX_BUFF;

		if (last && !len)
			ctrl |= MAL_TX_CTRL_LAST;
		if (slot == NUM_TX_BUFF - 1)
			ctrl |= MAL_TX_CTRL_WRAP;

		dev->tx_skb[slot] = NULL;
		dev->tx_desc[slot].data_ptr = pd;
		dev->tx_desc[slot].data_len = (u16) chunk;
		dev->tx_desc[slot].ctrl = ctrl;
		++dev->tx_cnt;

		if (!len)
			break;

		pd += chunk;
	}
	return slot;
}

/* Tx lock BH disabled (SG version for TAH equipped EMACs) */
static int emac_start_xmit_sg(struct sk_buff *skb, struct net_device *ndev)
{
	struct emac_instance *dev = netdev_priv(ndev);
	int nr_frags = skb_shinfo(skb)->nr_frags;
	int len = skb->len, chunk;
	int slot, i;
	u16 ctrl;
	u32 pd;

	/* This is common "fast" path */
	if (likely(!nr_frags && len <= MAL_MAX_TX_SIZE))
		return emac_start_xmit(skb, ndev);

	len -= skb->data_len;

	/* Note, this is only an *estimation*, we can still run out of empty
	 * slots because of the additional fragmentation into
	 * MAL_MAX_TX_SIZE-sized chunks
	 */
	if (unlikely(dev->tx_cnt + nr_frags + mal_tx_chunks(len) > NUM_TX_BUFF))
		goto stop_queue;

	ctrl = EMAC_TX_CTRL_GFCS | EMAC_TX_CTRL_GP | MAL_TX_CTRL_READY |
	    emac_tx_csum(dev, skb);
	slot = dev->tx_slot;

	/* skb data */
	dev->tx_skb[slot] = NULL;
	chunk = min(len, MAL_MAX_TX_SIZE);
	dev->tx_desc[slot].data_ptr = pd =
	    dma_map_single(&dev->ofdev->dev, skb->data, len, DMA_TO_DEVICE);
	dev->tx_desc[slot].data_len = (u16) chunk;
	len -= chunk;
	if (unlikely(len))
		slot = emac_xmit_split(dev, slot, pd + chunk, len, !nr_frags,
				       ctrl);
	/* skb fragments */
	for (i = 0; i < nr_frags; ++i) {
		struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i];
		len = frag->size;

		if (unlikely(dev->tx_cnt + mal_tx_chunks(len) >= NUM_TX_BUFF))
			goto undo_frame;

		pd = dma_map_page(&dev->ofdev->dev, frag->page, frag->page_offset, len,
				  DMA_TO_DEVICE);

		slot = emac_xmit_split(dev, slot, pd, len, i == nr_frags - 1,
				       ctrl);
	}

	DBG2(dev, "xmit_sg(%u) %d - %d" NL, skb->len, dev->tx_slot, slot);

	/* Attach skb to the last slot so we don't release it too early */
	dev->tx_skb[slot] = skb;

	/* Send the packet out */
	if (dev->tx_slot == NUM_TX_BUFF - 1)
		ctrl |= MAL_TX_CTRL_WRAP;
	wmb();
	dev->tx_desc[dev->tx_slot].ctrl = ctrl;
	dev->tx_slot = (slot + 1) % NUM_TX_BUFF;

	return emac_xmit_finish(dev, skb->len);

 undo_frame:
	/* Well, too bad. Our previous estimation was overly optimistic.
	 * Undo everything.
	 */
	while (slot != dev->tx_slot) {
		dev->tx_desc[slot].ctrl = 0;
		--dev->tx_cnt;
		if (--slot < 0)
			slot = NUM_TX_BUFF - 1;
	}
	++dev->estats.tx_undo;

 stop_queue:
	netif_stop_queue(ndev);
	DBG2(dev, "stopped TX queue" NL);
	return 1;
}
#else
# define emac_start_xmit_sg	emac_start_xmit
#endif	/* !defined(CONFIG_IBM_NEW_EMAC_TAH) */

/* Tx lock BHs */
static void emac_parse_tx_error(struct emac_instance *dev, u16 ctrl)
{
	struct emac_error_stats *st = &dev->estats;

	DBG(dev, "BD TX error %04x" NL, ctrl);

	++st->tx_bd_errors;
	if (ctrl & EMAC_TX_ST_BFCS)
		++st->tx_bd_bad_fcs;
	if (ctrl & EMAC_TX_ST_LCS)
		++st->tx_bd_carrier_loss;
	if (ctrl & EMAC_TX_ST_ED)
		++st->tx_bd_excessive_deferral;
	if (ctrl & EMAC_TX_ST_EC)
		++st->tx_bd_excessive_collisions;
	if (ctrl & EMAC_TX_ST_LC)
		++st->tx_bd_late_collision;
	if (ctrl & EMAC_TX_ST_MC)
		++st->tx_bd_multple_collisions;
	if (ctrl & EMAC_TX_ST_SC)
		++st->tx_bd_single_collision;
	if (ctrl & EMAC_TX_ST_UR)
		++st->tx_bd_underrun;
	if (ctrl & EMAC_TX_ST_SQE)
		++st->tx_bd_sqe;
}

static void emac_poll_tx(void *param)
{
	struct emac_instance *dev = param;
	u32 bad_mask;

	DBG2(dev, "poll_tx, %d %d" NL, dev->tx_cnt, dev->ack_slot);

	if (emac_has_feature(dev, EMAC_FTR_HAS_TAH))
		bad_mask = EMAC_IS_BAD_TX_TAH;
	else
		bad_mask = EMAC_IS_BAD_TX;

	netif_tx_lock_bh(dev->ndev);
	if (dev->tx_cnt) {
		u16 ctrl;
		int slot = dev->ack_slot, n = 0;
	again:
		ctrl = dev->tx_desc[slot].ctrl;
		if (!(ctrl & MAL_TX_CTRL_READY)) {
			struct sk_buff *skb = dev->tx_skb[slot];
			++n;

			if (skb) {
				dev_kfree_skb(skb);
				dev->tx_skb[slot] = NULL;
			}
			slot = (slot + 1) % NUM_TX_BUFF;

			if (unlikely(ctrl & bad_mask))
				emac_parse_tx_error(dev, ctrl);

			if (--dev->tx_cnt)