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Subject[PATCH net-next-2.6 v9 04/20] pch_can: Improve rx processing
Date
Replace complex "goto" to "do~while".
For easy to read/understand, it divides a rx function into some functions.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
drivers/net/can/pch_can.c | 158 +++++++++++++++++++++++----------------------
1 files changed, 82 insertions(+), 76 deletions(-)
diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 210957f..d646fbc 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -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;

- /* 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);
+ 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, obj_num);

- /* Reading the MCONT register. */
- reg = ioread32(&priv->regs->ifregs[0].mcont);
- reg &= 0xffff;
+ /* Reading the MCONT register. */
+ reg = ioread32(&priv->regs->ifregs[0].mcont);
+
+ if (reg & PCH_IF_MCONT_EOB)
+ break;

- for (k = int_stat; !(reg & PCH_IF_MCONT_EOB); k++) {
/* 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;
--
1.6.0.6


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