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Commit 48544cc2 authored by Masakazu Mokuno's avatar Masakazu Mokuno Committed by Jeff Garzik
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ps3: tx descriptor handling cleanup 



gelic: TX descriptor handling cleanup

        - Emitted return value of NETDEV_TX_LOCKED when DMA map or kick
          failure.
          Now it would free the skb, update drop packet statistics
          and return OK. Requested from Jeff Garzik.
        - Enable tx queue if number of free descriptors are more than 2
        - Fixed descriptor leak if dma map for second descriptor failed
        - Stopped calling xmit handler from interrupt handler in order
          to recheck tx queue.  Instead, call appropriate helper functions.

Signed-off-by: default avatarMasakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent ea6992aa

drivers/net/ps3_gelic_net.c

+71 −53
Original line number Diff line number Diff line
@@ -408,22 +408,25 @@ static void gelic_net_release_tx_chain(struct gelic_net_card *card, int stop) 
			break;



		case GELIC_NET_DESCR_COMPLETE:

			if (tx_chain->tail->skb) {

				card->netdev_stats.tx_packets++;

				card->netdev_stats.tx_bytes +=

					tx_chain->tail->skb->len;

			}

			break;



		case GELIC_NET_DESCR_CARDOWNED:

			/* pending tx request */

		default:

			/* any other value (== GELIC_NET_DESCR_NOT_IN_USE) */

			if (!stop)

				goto out;

		}

		gelic_net_release_tx_descr(card, tx_chain->tail);

		release = 1;

		release ++;

	}

out:

	if (!stop && release)

	if (!stop && (2 < release))

		netif_wake_queue(card->netdev);

}
@@ -660,19 +663,21 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, 
{

	dma_addr_t buf[2];

	unsigned int vlan_len;

	struct gelic_net_descr *sec_descr = descr->next;



	if (skb->len < GELIC_NET_VLAN_POS)

		return -EINVAL;



	memcpy(&descr->vlan, skb->data, GELIC_NET_VLAN_POS);

	vlan_len = GELIC_NET_VLAN_POS;

	memcpy(&descr->vlan, skb->data, vlan_len);

	if (card->vlan_index != -1) {

		/* internal vlan tag used */

		descr->vlan.h_vlan_proto = htons(ETH_P_8021Q); /* vlan 0x8100*/

		descr->vlan.h_vlan_TCI = htons(card->vlan_id[card->vlan_index]);

		vlan_len = GELIC_NET_VLAN_POS + VLAN_HLEN; /* VLAN_HLEN=4 */

	} else

		vlan_len = GELIC_NET_VLAN_POS; /* no vlan tag */

		vlan_len += VLAN_HLEN; /* added for above two lines */

	}



	/* first descr */

	/* map data area */

	buf[0] = dma_map_single(ctodev(card), &descr->vlan,

			     vlan_len, DMA_TO_DEVICE);
@@ -683,20 +688,6 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, 
		return -ENOMEM;

	}



	descr->buf_addr = buf[0];

	descr->buf_size = vlan_len;

	descr->skb = skb; /* not used */

	descr->data_status = 0;

	gelic_net_set_txdescr_cmdstat(descr, skb, 1); /* not the frame end */



	/* second descr */

	card->tx_chain.head = card->tx_chain.head->next;

	descr->next_descr_addr = descr->next->bus_addr;

	descr = descr->next;

	if (gelic_net_get_descr_status(descr) != GELIC_NET_DESCR_NOT_IN_USE)

		/* XXX will be removed */

		dev_err(ctodev(card), "descr is not free!\n");



	buf[1] = dma_map_single(ctodev(card), skb->data + GELIC_NET_VLAN_POS,

			     skb->len - GELIC_NET_VLAN_POS,

			     DMA_TO_DEVICE);
@@ -711,13 +702,24 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, 
		return -ENOMEM;

	}



	descr->buf_addr = buf[1];

	descr->buf_size = skb->len - GELIC_NET_VLAN_POS;

	descr->skb = skb;

	/* first descr */

	descr->buf_addr = buf[0];

	descr->buf_size = vlan_len;

	descr->skb = NULL; /* not used */

	descr->data_status = 0;

	descr->next_descr_addr = 0; /* terminate hw descr */

	gelic_net_set_txdescr_cmdstat(descr, skb, 0);

	descr->next_descr_addr = descr->next->bus_addr;

	gelic_net_set_txdescr_cmdstat(descr, skb, 1); /* not the frame end */



	/* second descr */

	sec_descr->buf_addr = buf[1];

	sec_descr->buf_size = skb->len - GELIC_NET_VLAN_POS;

	sec_descr->skb = skb;

	sec_descr->data_status = 0;

	sec_descr->next_descr_addr = 0; /* terminate hw descr */

	gelic_net_set_txdescr_cmdstat(sec_descr, skb, 0);



	/* bump free descriptor pointer */

	card->tx_chain.head = sec_descr->next;

	return 0;

}
@@ -730,7 +732,7 @@ static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card, 
static int gelic_net_kick_txdma(struct gelic_net_card *card,

				struct gelic_net_descr *descr)

{

	int status = -ENXIO;

	int status = 0;

	int count = 10;



	if (card->tx_dma_progress)
@@ -764,47 +766,62 @@ static int gelic_net_kick_txdma(struct gelic_net_card *card, 
static int gelic_net_xmit(struct sk_buff *skb, struct net_device *netdev)

{

	struct gelic_net_card *card = netdev_priv(netdev);

	struct gelic_net_descr *descr = NULL;

	struct gelic_net_descr *descr;

	int result;

	unsigned long flags;



	spin_lock_irqsave(&card->tx_dma_lock, flags);



	gelic_net_release_tx_chain(card, 0);

	if (!skb)

		goto kick;



	descr = gelic_net_get_next_tx_descr(card);

	if (!descr) {

		/*

		 * no more descriptors free

		 */

		netif_stop_queue(netdev);

		spin_unlock_irqrestore(&card->tx_dma_lock, flags);

		return NETDEV_TX_BUSY;

	}

	result = gelic_net_prepare_tx_descr_v(card, descr, skb);



	if (result)

		goto error;



	card->tx_chain.head = card->tx_chain.head->next;



	if (descr->prev)

	result = gelic_net_prepare_tx_descr_v(card, descr, skb);

	if (result) {

		/*

		 * DMA map failed.  As chanses are that failure

		 * would continue, just release skb and return

		 */

		card->netdev_stats.tx_dropped++;

		dev_kfree_skb_any(skb);

		spin_unlock_irqrestore(&card->tx_dma_lock, flags);

		return NETDEV_TX_OK;

	}

	/*

	 * link this prepared descriptor to previous one

	 * to achieve high performance

	 */

	descr->prev->next_descr_addr = descr->bus_addr;

kick:

	/*

	 * as hardware descriptor is modified in the above lines,

	 * ensure that the hardware sees it

	 */

	wmb();

	if (gelic_net_kick_txdma(card, card->tx_chain.tail))

		goto error;



	if (gelic_net_kick_txdma(card, descr)) {

		/*

		 * kick failed.

		 * release descriptors which were just prepared

		 */

		card->netdev_stats.tx_dropped++;

		gelic_net_release_tx_descr(card, descr);

		gelic_net_release_tx_descr(card, descr->next);

		card->tx_chain.tail = descr->next->next;

		dev_info(ctodev(card), "%s: kick failure\n", __func__);

	} else {

		/* OK, DMA started/reserved */

		netdev->trans_start = jiffies;

	spin_unlock_irqrestore(&card->tx_dma_lock, flags);

	return NETDEV_TX_OK;

	}



error:

	card->netdev_stats.tx_dropped++;

	spin_unlock_irqrestore(&card->tx_dma_lock, flags);

	return NETDEV_TX_LOCKED;

	return NETDEV_TX_OK;

}



/**
@@ -1025,9 +1042,10 @@ static irqreturn_t gelic_net_interrupt(int irq, void *ptr) 
	if (status & GELIC_NET_TXINT) {

		spin_lock_irqsave(&card->tx_dma_lock, flags);

		card->tx_dma_progress = 0;

		gelic_net_release_tx_chain(card, 0);

		/* kick outstanding tx descriptor if any */

		gelic_net_kick_txdma(card, card->tx_chain.tail);

		spin_unlock_irqrestore(&card->tx_dma_lock, flags);

		/* start pending DMA */

		gelic_net_xmit(NULL, netdev);

	}

	return IRQ_HANDLED;

}