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Commit 1d5b4b27 authored by Tomoya's avatar Tomoya Committed by David S. Miller
Browse files

pch_can: Improve rx processing 



Replace complex "goto" to "do~while".
For easy to read/understand, it divides a rx function into some functions.

Signed-off-by: default avatarTomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8ac9702b

drivers/net/can/pch_can.c

+82 −76
Original line number Diff line number Diff line
@@ -698,83 +698,110 @@ static irqreturn_t pch_can_interrupt(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static int pch_can_rx_normal(struct net_device *ndev, u32 int_stat)

static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)

{

	if (obj_id < PCH_FIFO_THRESH) {

		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL |

			  PCH_CMASK_ARB, &priv->regs->ifregs[0].cmask);



		/* Clearing the Dir bit. */

		pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);



		/* Clearing NewDat & IntPnd */

		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,

				  PCH_IF_MCONT_INTPND);

		pch_can_check_if_busy(&priv->regs->ifregs[0].creq, obj_id);

	} else if (obj_id > PCH_FIFO_THRESH) {

		pch_can_int_clr(priv, obj_id);

	} else if (obj_id == PCH_FIFO_THRESH) {

		int cnt;

		for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)

			pch_can_int_clr(priv, cnt + 1);

	}

}



static void pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)

{

	struct pch_can_priv *priv = netdev_priv(ndev);

	struct net_device_stats *stats = &(priv->ndev->stats);

	struct sk_buff *skb;

	struct can_frame *cf;



	netdev_dbg(priv->ndev, "Msg Obj is overwritten.\n");

	pch_can_bit_clear(&priv->regs->ifregs[0].mcont,

			  PCH_IF_MCONT_MSGLOST);

	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,

		  &priv->regs->ifregs[0].cmask);

	pch_can_check_if_busy(&priv->regs->ifregs[0].creq, obj_id);



	skb = alloc_can_err_skb(ndev, &cf);

	if (!skb)

		return;



	cf->can_id |= CAN_ERR_CRTL;

	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;

	stats->rx_over_errors++;

	stats->rx_errors++;



	netif_receive_skb(skb);

}



static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)

{

	u32 reg;

	canid_t id;

	u32 ide;

	u32 rtr;

	int i, k;

	int rcv_pkts = 0;

	struct sk_buff *skb;

	struct can_frame *cf;

	struct pch_can_priv *priv = netdev_priv(ndev);

	struct net_device_stats *stats = &(priv->ndev->stats);

	int i;

	u32 id2;

	u16 data_reg;



	do {

		/* Reading the messsage object from the Message RAM */

		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);

	pch_can_check_if_busy(&priv->regs->ifregs[0].creq, int_stat);

		pch_can_check_if_busy(&priv->regs->ifregs[0].creq, obj_num);



		/* Reading the MCONT register. */

		reg = ioread32(&priv->regs->ifregs[0].mcont);

	reg &= 0xffff;



	for (k = int_stat; !(reg & PCH_IF_MCONT_EOB); k++) {

		if (reg & PCH_IF_MCONT_EOB)

			break;



		/* If MsgLost bit set. */

		if (reg & PCH_IF_MCONT_MSGLOST) {

			dev_err(&priv->ndev->dev, "Msg Obj is overwritten.\n");

			pch_can_bit_clear(&priv->regs->ifregs[0].mcont,

					  PCH_IF_MCONT_MSGLOST);

			iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,

				  &priv->regs->ifregs[0].cmask);

			pch_can_check_if_busy(&priv->regs->ifregs[0].creq, k);



			skb = alloc_can_err_skb(ndev, &cf);

			if (!skb)

				return -ENOMEM;



			priv->can.can_stats.error_passive++;

			priv->can.state = CAN_STATE_ERROR_PASSIVE;

			cf->can_id |= CAN_ERR_CRTL;

			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;

			cf->data[2] |= CAN_ERR_PROT_OVERLOAD;

			stats->rx_packets++;

			stats->rx_bytes += cf->can_dlc;



			netif_receive_skb(skb);

			pch_can_rx_msg_lost(ndev, obj_num);

			rcv_pkts++;

			goto RX_NEXT;

			quota--;

			obj_num++;

			continue;

		} else if (!(reg & PCH_IF_MCONT_NEWDAT)) {

			obj_num++;

			continue;

		}

		if (!(reg & PCH_IF_MCONT_NEWDAT))

			goto RX_NEXT;



		skb = alloc_can_skb(priv->ndev, &cf);

		if (!skb)

			return -ENOMEM;



		/* Get Received data */

		ide = ((ioread32(&priv->regs->ifregs[0].id2)) & PCH_ID2_XTD) >>

									     14;

		if (ide) {

		id2 = ioread32(&priv->regs->ifregs[0].id2);

		if (id2 & PCH_ID2_XTD) {

			id = (ioread32(&priv->regs->ifregs[0].id1) & 0xffff);

			id |= (((ioread32(&priv->regs->ifregs[0].id2)) &

					    0x1fff) << 16);

			cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;

			id |= (((id2) & 0x1fff) << 16);

			cf->can_id = id | CAN_EFF_FLAG;

		} else {

			id = (((ioread32(&priv->regs->ifregs[0].id2)) &

						     (CAN_SFF_MASK << 2)) >> 2);

			cf->can_id = (id & CAN_SFF_MASK);

			id = (id2 >> 2) & CAN_SFF_MASK;

			cf->can_id = id;

		}



		rtr = (ioread32(&priv->regs->ifregs[0].id2) &  PCH_ID2_DIR);

		if (rtr) {

			cf->can_dlc = 0;

		if (id2 & PCH_ID2_DIR)

			cf->can_id |= CAN_RTR_FLAG;

		} else {

			cf->can_dlc =

			      ((ioread32(&priv->regs->ifregs[0].mcont)) & 0x0f);

		}



		cf->can_dlc = get_can_dlc((ioread32(&priv->regs->

						    ifregs[0].mcont)) & 0xF);



		for (i = 0; i < cf->can_dlc; i += 2) {

			data_reg = ioread16(&priv->regs->ifregs[0].data[i / 2]);
@@ -785,33 +812,12 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 int_stat) 
		netif_receive_skb(skb);

		rcv_pkts++;

		stats->rx_packets++;

		quota--;

		stats->rx_bytes += cf->can_dlc;



		if (k < PCH_FIFO_THRESH) {

			iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL |

				  PCH_CMASK_ARB, &priv->regs->ifregs[0].cmask);



			/* Clearing the Dir bit. */

			pch_can_bit_clear(&priv->regs->ifregs[0].id2,

					  PCH_ID2_DIR);



			/* Clearing NewDat & IntPnd */

			pch_can_bit_clear(&priv->regs->ifregs[0].mcont,

					  PCH_IF_MCONT_INTPND);

			pch_can_check_if_busy(&priv->regs->ifregs[0].creq, k);

		} else if (k > PCH_FIFO_THRESH) {

			pch_can_int_clr(priv, k);

		} else if (k == PCH_FIFO_THRESH) {

			int cnt;

			for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)

				pch_can_int_clr(priv, cnt+1);

		}

RX_NEXT:

		/* Reading the messsage object from the Message RAM */

		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);

		pch_can_check_if_busy(&priv->regs->ifregs[0].creq, k);

		reg = ioread32(&priv->regs->ifregs[0].mcont);

	}

		pch_fifo_thresh(priv, obj_num);

		obj_num++;

	} while (quota > 0);



	return rcv_pkts;

}
@@ -869,7 +875,7 @@ static int pch_can_rx_poll(struct napi_struct *napi, int quota) 
		goto end;



	if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {

		rcv_pkts += pch_can_rx_normal(ndev, int_stat);

		rcv_pkts += pch_can_rx_normal(ndev, int_stat, quota);

		quota -= rcv_pkts;

		if (quota < 0)

			goto end;