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ixgbe: use EIAM to automask MSI-X 

when disabling interrupts, driver was writing with IO, this is no
necessary because on ixgbe parts the hardware can "oneshot"
disable and clear the interrupt.  So on 82598/82599 use of EIAM
should avoid one posted write per interrupt when in MSI-X mode.
This should improve performance and seems to in my limited
testing, reduce CPU utilization VERY slightly.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesse Brandeburg 2009-12-03 11:33:54 +00:00 committed by David S. Miller
parent 7ca3bc582c
commit 9b471446cb
1 changed files with 19 additions and 6 deletions
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25
drivers/net/ixgbe/ixgbe_main.c
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@ -1329,8 +1329,7 @@ static irqreturn_t ixgbe_msix_clean_tx(int irq, void *data)
r_idx + 1);
}
/* disable interrupts on this vector only */
ixgbe_irq_disable_queues(adapter, ((u64)1 << q_vector->v_idx));
/* EIAM disabled interrupts (on this vector) for us */
napi_schedule(&q_vector->napi);
return IRQ_HANDLED;
@ -1362,7 +1361,7 @@ static irqreturn_t ixgbe_msix_clean_rx(int irq, void *data)
return IRQ_HANDLED;
/* disable interrupts on this vector only */
ixgbe_irq_disable_queues(adapter, ((u64)1 << q_vector->v_idx));
/* EIAM disabled interrupts (on this vector) for us */
napi_schedule(&q_vector->napi);
return IRQ_HANDLED;
@ -1397,8 +1396,7 @@ static irqreturn_t ixgbe_msix_clean_many(int irq, void *data)
r_idx + 1);
}
/* disable interrupts on this vector only */
ixgbe_irq_disable_queues(adapter, ((u64)1 << q_vector->v_idx));
/* EIAM disabled interrupts (on this vector) for us */
napi_schedule(&q_vector->napi);
return IRQ_HANDLED;
@ -2716,7 +2714,22 @@ static int ixgbe_up_complete(struct ixgbe_adapter *adapter)
IXGBE_WRITE_REG(hw, IXGBE_GPIE, gpie);
}
if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED)) {
if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED) {
/*
* use EIAM to auto-mask when MSI-X interrupt is asserted
* this saves a register write for every interrupt
*/
switch (hw->mac.type) {
case ixgbe_mac_82598EB:
IXGBE_WRITE_REG(hw, IXGBE_EIAM, IXGBE_EICS_RTX_QUEUE);
break;
default:
case ixgbe_mac_82599EB:
IXGBE_WRITE_REG(hw, IXGBE_EIAM_EX(0), 0xFFFFFFFF);
IXGBE_WRITE_REG(hw, IXGBE_EIAM_EX(1), 0xFFFFFFFF);
break;
}
} else {
/* legacy interrupts, use EIAM to auto-mask when reading EICR,
* specifically only auto mask tx and rx interrupts */
IXGBE_WRITE_REG(hw, IXGBE_EIAM, IXGBE_EICS_RTX_QUEUE);