xiaomi-sm8450/android_kernel_xiaomi_sm8450
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[PATCH] chelsio: working NAPI

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This driver tries to enable/disable NAPI at runtime, but
does so in an unsafe manner, and the NAPI interrupt handling is
a mess. Replace it with a compile time selected NAPI implementation.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Stephen Hemminger
2006-12-08 11:08:33 -08:00
committed by Jeff Garzik
parent 0f0d84e52c
commit 7fe26a60e0
4 changed files with 66 additions and 82 deletions
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113
drivers/net/chelsio/sge.c
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@@ -1413,16 +1413,20 @@ static int sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
if (unlikely(adapter->vlan_grp && p->vlan_valid)) {
st->vlan_xtract++;
if (adapter->params.sge.polling)
#ifdef CONFIG_CHELSIO_T1_NAPI
vlan_hwaccel_receive_skb(skb, adapter->vlan_grp,
ntohs(p->vlan));
else
#else
vlan_hwaccel_rx(skb, adapter->vlan_grp,
ntohs(p->vlan));
} else if (adapter->params.sge.polling)
#endif
} else {
#ifdef CONFIG_CHELSIO_T1_NAPI
netif_receive_skb(skb);
else
#else
netif_rx(skb);
#endif
}
return 0;
}
@@ -1572,6 +1576,7 @@ static int process_responses(struct adapter *adapter, int budget)
return budget;
}
#ifdef CONFIG_CHELSIO_T1_NAPI
/*
* A simpler version of process_responses() that handles only pure (i.e.,
* non data-carrying) responses. Such respones are too light-weight to justify
@@ -1619,92 +1624,76 @@ static int process_pure_responses(struct adapter *adapter, struct respQ_e *e)
* or protection from interrupts as data interrupts are off at this point and
* other adapter interrupts do not interfere.
*/
static int t1_poll(struct net_device *dev, int *budget)
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);
*budget -= work_done;
dev->quota -= work_done;
if (work_done >= effective_budget)
return 1;
spin_lock_irq(&adapter->async_lock);
__netif_rx_complete(dev);
/*
* Because we don't atomically flush the following write it is
* possible that in very rare cases it can reach the device in a way
* that races with a new response being written plus an error interrupt
* causing the NAPI interrupt handler below to return unhandled status
* to the OS. To protect against this would require flushing the write
* and doing both the write and the flush with interrupts off. Way too
* expensive and unjustifiable given the rarity of the race.
*/
writel(adapter->sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
return 0;
}
writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,
adapter->regs + A_PL_ENABLE);
spin_unlock_irq(&adapter->async_lock);
/*
* Returns true if the device is already scheduled for polling.
*/
static inline int napi_is_scheduled(struct net_device *dev)
{
return test_bit(__LINK_STATE_RX_SCHED, &dev->state);
return 0;
}
/*
* NAPI version of the main interrupt handler.
*/
static irqreturn_t t1_interrupt_napi(int irq, void *data)
irqreturn_t t1_interrupt(int irq, void *data)
{
int handled;
struct adapter *adapter = data;
struct net_device *dev = adapter->sge->netdev;
struct sge *sge = adapter->sge;
struct respQ *q = &adapter->sge->respQ;
u32 cause;
int handled = 0;
/*
* Clear the SGE_DATA interrupt first thing. Normally the NAPI
* handler has control of the response queue and the interrupt handler
* can look at the queue reliably only once it knows NAPI is off.
* We can't wait that long to clear the SGE_DATA interrupt because we
* could race with t1_poll rearming the SGE interrupt, so we need to
* clear the interrupt speculatively and really early on.
*/
writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
cause = readl(adapter->regs + A_PL_CAUSE);
if (cause == 0 || cause == ~0)
return IRQ_NONE;
spin_lock(&adapter->async_lock);
if (!napi_is_scheduled(sge->netdev)) {
if (cause & F_PL_INTR_SGE_DATA) {
struct respQ *q = &adapter->sge->respQ;
struct respQ_e *e = &q->entries[q->cidx];
if (e->GenerationBit == q->genbit) {
if (e->DataValid ||
process_pure_responses(adapter, e)) {
if (likely(__netif_rx_schedule_prep(sge->netdev)))
__netif_rx_schedule(sge->netdev);
else if (net_ratelimit())
printk(KERN_INFO
"NAPI schedule failure!\n");
} else
writel(q->cidx, adapter->regs + A_SG_SLEEPING);
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;
}
/* no data, no NAPI needed */
netif_poll_enable(dev);
}
writel(q->cidx, adapter->regs + A_SG_SLEEPING);
} else
handled = t1_slow_intr_handler(adapter);
handled = 1;
goto unlock;
} else
writel(q->cidx, adapter->regs + A_SG_SLEEPING);
} else if (readl(adapter->regs + A_PL_CAUSE) & F_PL_INTR_SGE_DATA) {
printk(KERN_ERR "data interrupt while NAPI running\n");
}
handled = t1_slow_intr_handler(adapter);
if (!handled)
sge->stats.unhandled_irqs++;
unlock:
unlock:
spin_unlock(&adapter->async_lock);
return IRQ_RETVAL(handled != 0);
}
#else
/*
* Main interrupt handler, optimized assuming that we took a 'DATA'
* interrupt.
@@ -1720,7 +1709,7 @@ static irqreturn_t t1_interrupt_napi(int irq, void *data)
* 5. If we took an interrupt, but no valid respQ descriptors was found we
* let the slow_intr_handler run and do error handling.
*/
static irqreturn_t t1_interrupt(int irq, void *cookie)
irqreturn_t t1_interrupt(int irq, void *cookie)
{
int work_done;
struct respQ_e *e;
@@ -1752,11 +1741,7 @@ static irqreturn_t t1_interrupt(int irq, void *cookie)
spin_unlock(&adapter->async_lock);
return IRQ_RETVAL(work_done != 0);
}
irq_handler_t t1_select_intr_handler(adapter_t *adapter)
{
return adapter->params.sge.polling ? t1_interrupt_napi : t1_interrupt;
}
#endif
/*
* Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
@@ -2033,7 +2018,6 @@ static void sge_tx_reclaim_cb(unsigned long data)
*/
int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
{
sge->netdev->poll = t1_poll;
sge->fixed_intrtimer = p->rx_coalesce_usecs *
core_ticks_per_usec(sge->adapter);
writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
@@ -2234,7 +2218,6 @@ struct sge * __devinit t1_sge_create(struct adapter *adapter,
p->coalesce_enable = 0;
p->sample_interval_usecs = 0;
p->polling = 0;
return sge;
nomem_port: