Commit bea86103 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
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[PATCH] sky2: fix NAPI and receive handling 



Speed up the receive and interrupt processing and eliminate a
couple of race conditions from NAPI code.

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent d571b694

drivers/net/sky2.c

+30 −33
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ 


#define RX_LE_SIZE	    	256

#define RX_LE_BYTES		(RX_LE_SIZE*sizeof(struct sky2_rx_le))

#define RX_MAX_PENDING		(RX_LE_SIZE/2 - 1)

#define RX_MAX_PENDING		(RX_LE_SIZE/2 - 2)

#define RX_DEF_PENDING		128

#define RX_COPY_THRESHOLD	256
@@ -690,7 +690,7 @@ static inline void sky2_put_idx(struct sky2_hw *hw, unsigned q, 
setnew:

		sky2_write16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX), idx);

	}

	*last = sky2_read16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX));

	*last = idx;

}
@@ -723,15 +723,6 @@ static inline void sky2_rx_add(struct sky2_port *sky2, struct ring_info *re) 
	le->opcode = OP_PACKET | HW_OWNER;

}



/* Tell receiver about new buffers. */

static inline void rx_set_put(struct net_device *dev)

{

	struct sky2_port *sky2 = netdev_priv(dev);



	if (sky2->rx_last_put != sky2->rx_put)

		sky2_put_idx(sky2->hw, rxqaddr[sky2->port], sky2->rx_put,

			     &sky2->rx_last_put, RX_LE_SIZE);

}



/* Tell chip where to start receive checksum.

 * Actually has two checksums, but set both same to avoid possible byte
@@ -1616,6 +1607,10 @@ static struct sk_buff *sky2_receive(struct sky2_port *sky2, 
	re->skb->ip_summed = CHECKSUM_NONE;

	sky2_rx_add(sky2, re);



	/* Tell receiver about new buffers. */

	sky2_put_idx(sky2->hw, rxqaddr[sky2->port], sky2->rx_put,

		     &sky2->rx_last_put, RX_LE_SIZE);



	return skb;



error:
@@ -1664,16 +1659,26 @@ static int sky2_poll(struct net_device *dev0, int *budget) 
	hwidx = sky2_read16(hw, STAT_PUT_IDX);

	BUG_ON(hwidx >= STATUS_RING_SIZE);

 	rmb();

	while (hw->st_idx != hwidx && work_done < to_do) {



	do {

		struct sky2_status_le *le = hw->st_le + hw->st_idx;

		struct sky2_port *sky2;

		struct sk_buff *skb;

		u32 status;

		u16 length;



		BUG_ON(le->link >= hw->ports);

		if (!hw->dev[le->link])

			goto skip;

		/* Are we done yet? */

		if (hw->st_idx == hwidx) {

			sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);

			hwidx = sky2_read16(hw, STAT_PUT_IDX);

			if (hwidx == hw->st_idx)

				break;

		}



		hw->st_idx = (hw->st_idx + 1) % STATUS_RING_SIZE;

		prefetch(&hw->st_le[hw->st_idx]);



		BUG_ON(le->link >= hw->ports || !hw->dev[le->link]);



		sky2 = netdev_priv(hw->dev[le->link]);

		status = le32_to_cpu(le->status);
@@ -1692,6 +1697,7 @@ static int sky2_poll(struct net_device *dev0, int *budget) 
			} else

#endif

				netif_receive_skb(skb);

			++work_done;

			break;



#ifdef SKY2_VLAN_TAG_USED
@@ -1722,22 +1728,11 @@ static int sky2_poll(struct net_device *dev0, int *budget) 
			break;

		}



	skip:

		hw->st_idx = (hw->st_idx + 1) % STATUS_RING_SIZE;

		if (hw->st_idx == hwidx) {

			hwidx = sky2_read16(hw, STAT_PUT_IDX);

			rmb();

		}

	}

		le->opcode = 0;	/* paranoia */

	} while (work_done < to_do);



	mmiowb();



	if (hw->dev[0])

		rx_set_put(hw->dev[0]);



	if (hw->dev[1])

		rx_set_put(hw->dev[1]);



	*budget -= work_done;

	dev0->quota -= work_done;

	if (work_done < to_do) {
@@ -1750,10 +1745,10 @@ static int sky2_poll(struct net_device *dev0, int *budget) 
			sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);

		}



		netif_rx_complete(dev0);

		hw->intr_mask |= Y2_IS_STAT_BMU;

		sky2_write32(hw, B0_IMSK, hw->intr_mask);

		sky2_read32(hw, B0_IMSK);

		netif_rx_complete(dev0);

	}



	return work_done >= to_do;
@@ -1880,6 +1875,7 @@ static void sky2_phy_intr(struct sky2_hw *hw, unsigned port) 
static irqreturn_t sky2_intr(int irq, void *dev_id, struct pt_regs *regs)

{

	struct sky2_hw *hw = dev_id;

	struct net_device *dev0 = hw->dev[0];

	u32 status;



	status = sky2_read32(hw, B0_Y2_SP_ISRC2);
@@ -1890,12 +1886,13 @@ static irqreturn_t sky2_intr(int irq, void *dev_id, struct pt_regs *regs) 
		sky2_hw_intr(hw);



	/* Do NAPI for Rx and Tx status */

	if ((status & Y2_IS_STAT_BMU) && netif_rx_schedule_test(hw->dev[0])) {

		sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);



	if (status & Y2_IS_STAT_BMU) {

		hw->intr_mask &= ~Y2_IS_STAT_BMU;

		sky2_write32(hw, B0_IMSK, hw->intr_mask);

		__netif_rx_schedule(hw->dev[0]);

		prefetch(&hw->st_le[hw->st_idx]);



		if (netif_rx_schedule_test(dev0))

			__netif_rx_schedule(dev0);

	}



	if (status & Y2_IS_IRQ_PHY1)