Commit 3de00b89 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik

chelsio: NAPI speed improvement

Speedup and cleanup the receive processing by eliminating the
mmio read and a lock round trip.
Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 4d22de3e
......@@ -1559,6 +1559,14 @@ static int process_responses(struct adapter *adapter, int budget)
return budget;
}
static inline int responses_pending(const struct adapter *adapter)
{
const struct respQ *Q = &adapter->sge->respQ;
const struct respQ_e *e = &Q->entries[Q->cidx];
return (e->GenerationBit == Q->genbit);
}
#ifdef CONFIG_CHELSIO_T1_NAPI
/*
* A simpler version of process_responses() that handles only pure (i.e.,
......@@ -1568,13 +1576,16 @@ static int process_responses(struct adapter *adapter, int budget)
* which the caller must ensure is a valid pure response. Returns 1 if it
* encounters a valid data-carrying response, 0 otherwise.
*/
static int process_pure_responses(struct adapter *adapter, struct respQ_e *e)
static int process_pure_responses(struct adapter *adapter)
{
struct sge *sge = adapter->sge;
struct respQ *q = &sge->respQ;
struct respQ_e *e = &q->entries[q->cidx];
unsigned int flags = 0;
unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
if (e->DataValid)
return 1;
do {
flags |= e->Qsleeping;
......@@ -1610,23 +1621,20 @@ static int process_pure_responses(struct adapter *adapter, struct respQ_e *e)
int t1_poll(struct net_device *dev, int *budget)
{
struct adapter *adapter = dev->priv;
int effective_budget = min(*budget, dev->quota);
int work_done = process_responses(adapter, effective_budget);
int work_done;
work_done = process_responses(adapter, min(*budget, dev->quota));
*budget -= work_done;
dev->quota -= work_done;
if (work_done >= effective_budget)
if (unlikely(responses_pending(adapter)))
return 1;
spin_lock_irq(&adapter->async_lock);
__netif_rx_complete(dev);
netif_rx_complete(dev);
writel(adapter->sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,
adapter->regs + A_PL_ENABLE);
spin_unlock_irq(&adapter->async_lock);
return 0;
}
/*
......@@ -1635,44 +1643,33 @@ int t1_poll(struct net_device *dev, int *budget)
irqreturn_t t1_interrupt(int irq, void *data)
{
struct adapter *adapter = data;
struct net_device *dev = adapter->sge->netdev;
struct sge *sge = adapter->sge;
u32 cause;
int handled = 0;
cause = readl(adapter->regs + A_PL_CAUSE);
if (cause == 0 || cause == ~0)
return IRQ_NONE;
int handled;
spin_lock(&adapter->async_lock);
if (cause & F_PL_INTR_SGE_DATA) {
struct respQ *q = &adapter->sge->respQ;
struct respQ_e *e = &q->entries[q->cidx];
if (likely(responses_pending(adapter))) {
struct net_device *dev = sge->netdev;
handled = 1;
writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
if (e->GenerationBit == q->genbit &&
__netif_rx_schedule_prep(dev)) {
if (e->DataValid || process_pure_responses(adapter, e)) {
/* mask off data IRQ */
writel(adapter->slow_intr_mask,
adapter->regs + A_PL_ENABLE);
__netif_rx_schedule(sge->netdev);
goto unlock;
if (__netif_rx_schedule_prep(dev)) {
if (process_pure_responses(adapter))
__netif_rx_schedule(dev);
else {
/* no data, no NAPI needed */
writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
netif_poll_enable(dev); /* undo schedule_prep */
}
/* no data, no NAPI needed */
netif_poll_enable(dev);
}
writel(q->cidx, adapter->regs + A_SG_SLEEPING);
} else
handled = t1_slow_intr_handler(adapter);
return IRQ_HANDLED;
}
spin_lock(&adapter->async_lock);
handled = t1_slow_intr_handler(adapter);
spin_unlock(&adapter->async_lock);
if (!handled)
sge->stats.unhandled_irqs++;
unlock:
spin_unlock(&adapter->async_lock);
return IRQ_RETVAL(handled != 0);
}
......@@ -1695,17 +1692,13 @@ irqreturn_t t1_interrupt(int irq, void *data)
irqreturn_t t1_interrupt(int irq, void *cookie)
{
int work_done;
struct respQ_e *e;
struct adapter *adapter = cookie;
struct respQ *Q = &adapter->sge->respQ;
spin_lock(&adapter->async_lock);
e = &Q->entries[Q->cidx];
prefetch(e);
writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
if (likely(e->GenerationBit == Q->genbit))
if (likely(responses_pending(adapter))
work_done = process_responses(adapter, -1);
else
work_done = t1_slow_intr_handler(adapter);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment