[NET-NEXT PATCH 07/18] igb: add NAPI Rx queue support

Jeff Kirsher
2008-06-27T18:02:57Z

From: PJ Waskiewicz <peter.p.waskiewicz.jr@intel.com>

Update the NAPI implementation to use the new napi_struct infrstructure.
This removes the need of multiple net_device structs to implement a
multiqueue NAPI.

Signed-off-by: PJ Waskiewicz <peter.p.waskiewicz.jr.@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

drivers/net/igb/igb.h | 2 +
drivers/net/igb/igb_main.c | 148 ++++++++++++++++++--------------------------
2 files changed, 61 insertions(+), 89 deletions(-)

diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index 6b2e7d3..17eb84e 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -150,6 +150,7 @@ struct igb_ring {
u16 itr_register;
u16 cpu;

+ int queue_index;
unsigned int total_bytes;
unsigned int total_packets;

@@ -265,6 +266,7 @@ struct igb_adapter {
int msg_enable;
struct msix_entry *msix_entries;
u32 eims_enable_mask;
+ u32 eims_other;

/* to not mess up cache alignment, always add to the bottom */
unsigned long state;
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index a43186e..1f0703d 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -227,12 +227,11 @@ static int igb_alloc_queues(struct igb_adapter *adapter)
for (i = 0; i < adapter->num_rx_queues; i++) {
struct igb_ring *ring = &(adapter->rx_ring[i]);
ring->adapter = adapter;
+ ring->queue_index = i;
ring->itr_register = E1000_ITR;

- if (!ring->napi.poll)
- netif_napi_add(adapter->netdev, &ring->napi, igb_clean,
- adapter->napi.weight /
- adapter->num_rx_queues);
+ /* set a default napi handler for each rx_ring */
+ netif_napi_add(adapter->netdev, &ring->napi, igb_clean, 64);
}
return 0;
}
@@ -300,9 +299,6 @@ static void igb_configure_msix(struct igb_adapter *adapter)
array_wr32(E1000_MSIXBM(0), vector++,
E1000_EIMS_OTHER);

- /* disable IAM for ICR interrupt bits */
- wr32(E1000_IAM, 0);
-
tmp = rd32(E1000_CTRL_EXT);
/* enable MSI-X PBA support*/
tmp |= E1000_CTRL_EXT_PBA_CLR;
@@ -313,6 +309,7 @@ static void igb_configure_msix(struct igb_adapter *adapter)

wr32(E1000_CTRL_EXT, tmp);
adapter->eims_enable_mask |= E1000_EIMS_OTHER;
+ adapter->eims_other = E1000_EIMS_OTHER;

wrfl();
}
@@ -355,6 +352,9 @@ static int igb_request_msix(struct igb_adapter *adapter)
goto out;
ring->itr_register = E1000_EITR(0) + (vector << 2);
ring->itr_val = adapter->itr;
+ /* overwrite the poll routine for MSIX, we've already done
+ * netif_napi_add */
+ ring->napi.poll = &igb_clean_rx_ring_msix;
vector++;
}

@@ -363,9 +363,6 @@ static int igb_request_msix(struct igb_adapter *adapter)
if (err)
goto out;

- adapter->napi.poll = igb_clean_rx_ring_msix;
- for (i = 0; i < adapter->num_rx_queues; i++)
- adapter->rx_ring[i].napi.poll = adapter->napi.poll;
igb_configure_msix(adapter);
return 0;
out:
@@ -434,12 +431,8 @@ static int igb_request_irq(struct igb_adapter *adapter)

if (adapter->msix_entries) {
err = igb_request_msix(adapter);
- if (!err) {
- /* enable IAM, auto-mask,
- * DO NOT USE EIAM or IAM in legacy mode */
- wr32(E1000_IAM, IMS_ENABLE_MASK);
+ if (!err)
goto request_done;
- }
/* fall back to MSI */
igb_reset_interrupt_capability(adapter);
if (!pci_enable_msi(adapter->pdev))
@@ -448,7 +441,11 @@ static int igb_request_irq(struct igb_adapter *adapter)
igb_free_all_rx_resources(adapter);
adapter->num_rx_queues = 1;
igb_alloc_queues(adapter);
+ } else {
+ wr32(E1000_MSIXBM(0), (E1000_EICR_RX_QUEUE0 |
+ E1000_EIMS_OTHER));
}
+
if (adapter->msi_enabled) {
err = request_irq(adapter->pdev->irq, &igb_intr_msi, 0,
netdev->name, netdev);
@@ -500,9 +497,12 @@ static void igb_irq_disable(struct igb_adapter *adapter)
struct e1000_hw *hw = &adapter->hw;

if (adapter->msix_entries) {
+ wr32(E1000_EIAM, 0);
wr32(E1000_EIMC, ~0);
wr32(E1000_EIAC, 0);
}
+
+ wr32(E1000_IAM, 0);
wr32(E1000_IMC, ~0);
wrfl();
synchronize_irq(adapter->pdev->irq);
@@ -517,13 +517,14 @@ static void igb_irq_enable(struct igb_adapter *adapter)
struct e1000_hw *hw = &adapter->hw;

if (adapter->msix_entries) {
- wr32(E1000_EIMS,
- adapter->eims_enable_mask);
- wr32(E1000_EIAC,
- adapter->eims_enable_mask);
+ wr32(E1000_EIAC, adapter->eims_enable_mask);
+ wr32(E1000_EIAM, adapter->eims_enable_mask);
+ wr32(E1000_EIMS, adapter->eims_enable_mask);
wr32(E1000_IMS, E1000_IMS_LSC);
- } else
- wr32(E1000_IMS, IMS_ENABLE_MASK);
+ } else {
+ wr32(E1000_IMS, IMS_ENABLE_MASK);
+ wr32(E1000_IAM, IMS_ENABLE_MASK);
+ }
}

static void igb_update_mng_vlan(struct igb_adapter *adapter)
@@ -661,13 +662,10 @@ int igb_up(struct igb_adapter *adapter)

clear_bit(__IGB_DOWN, &adapter->state);

- napi_enable(&adapter->napi);
-
- if (adapter->msix_entries) {
- for (i = 0; i < adapter->num_rx_queues; i++)
- napi_enable(&adapter->rx_ring[i].napi);
+ for (i = 0; i < adapter->num_rx_queues; i++)
+ napi_enable(&adapter->rx_ring[i].napi);
+ if (adapter->msix_entries)
igb_configure_msix(adapter);
- }

/* Clear any pending interrupts. */
rd32(E1000_ICR);
@@ -704,11 +702,9 @@ void igb_down(struct igb_adapter *adapter)
wrfl();
msleep(10);

- napi_disable(&adapter->napi);
+ for (i = 0; i < adapter->num_rx_queues; i++)
+ napi_disable(&adapter->rx_ring[i].napi);

- if (adapter->msix_entries)
- for (i = 0; i < adapter->num_rx_queues; i++)
- napi_disable(&adapter->rx_ring[i].napi);
igb_irq_disable(adapter);

del_timer_sync(&adapter->watchdog_timer);
@@ -906,7 +902,6 @@ static int __devinit igb_probe(struct pci_dev *pdev,
igb_set_ethtool_ops(netdev);
netdev->tx_timeout = &igb_tx_timeout;
netdev->watchdog_timeo = 5 * HZ;
- netif_napi_add(netdev, &adapter->napi, igb_clean, 64);
netdev->vlan_rx_register = igb_vlan_rx_register;
netdev->vlan_rx_add_vid = igb_vlan_rx_add_vid;
netdev->vlan_rx_kill_vid = igb_vlan_rx_kill_vid;
@@ -1271,15 +1266,14 @@ static int igb_open(struct net_device *netdev)
/* From here on the code is the same as igb_up() */
clear_bit(__IGB_DOWN, &adapter->state);

- napi_enable(&adapter->napi);
- if (adapter->msix_entries)
- for (i = 0; i < adapter->num_rx_queues; i++)
- napi_enable(&adapter->rx_ring[i].napi);
-
- igb_irq_enable(adapter);
+ for (i = 0; i < adapter->num_rx_queues; i++)
+ napi_enable(&adapter->rx_ring[i].napi);

/* Clear any pending interrupts. */
rd32(E1000_ICR);
+
+ igb_irq_enable(adapter);
+
/* Fire a link status change interrupt to start the watchdog. */
wr32(E1000_ICS, E1000_ICS_LSC);

@@ -1507,8 +1501,6 @@ int igb_setup_rx_resources(struct igb_adapter *adapter,
rx_ring->pending_skb = NULL;

rx_ring->adapter = adapter;
- /* FIXME: do we want to setup ring->napi->poll here? */
- rx_ring->napi.poll = adapter->napi.poll;

return 0;

@@ -3007,26 +2999,19 @@ static irqreturn_t igb_msix_other(int irq, void *data)
struct net_device *netdev = data;
struct igb_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
- u32 eicr;
- /* disable interrupts from the "other" bit, avoid re-entry */
- wr32(E1000_EIMC, E1000_EIMS_OTHER);
-
- eicr = rd32(E1000_EICR);
+ u32 icr = rd32(E1000_ICR);

- if (eicr & E1000_EIMS_OTHER) {
- u32 icr = rd32(E1000_ICR);
- /* reading ICR causes bit 31 of EICR to be cleared */
- if (!(icr & E1000_ICR_LSC))
- goto no_link_interrupt;
- hw->mac.get_link_status = 1;
- /* guard against interrupt when we're going down */
- if (!test_bit(__IGB_DOWN, &adapter->state))
- mod_timer(&adapter->watchdog_timer, jiffies + 1);
- }
+ /* reading ICR causes bit 31 of EICR to be cleared */
+ if (!(icr & E1000_ICR_LSC))
+ goto no_link_interrupt;
+ hw->mac.get_link_status = 1;
+ /* guard against interrupt when we're going down */
+ if (!test_bit(__IGB_DOWN, &adapter->state))
+ mod_timer(&adapter->watchdog_timer, jiffies + 1);

no_link_interrupt:
wr32(E1000_IMS, E1000_IMS_LSC);
- wr32(E1000_EIMS, E1000_EIMS_OTHER);
+ wr32(E1000_EIMS, adapter->eims_other);

return IRQ_HANDLED;
}
@@ -3057,21 +3042,19 @@ static irqreturn_t igb_msix_rx(int irq, void *data)
struct igb_adapter *adapter = rx_ring->adapter;
struct e1000_hw *hw = &adapter->hw;

- if (!rx_ring->itr_val)
- wr32(E1000_EIMC, rx_ring->eims_value);
+ /* Write the ITR value calculated at the end of the
+ * previous interrupt.
+ */

- if (netif_rx_schedule_prep(adapter->netdev, &rx_ring->napi)) {
- rx_ring->total_bytes = 0;
- rx_ring->total_packets = 0;
- rx_ring->no_itr_adjust = 0;
- __netif_rx_schedule(adapter->netdev, &rx_ring->napi);
- } else {
- if (!rx_ring->no_itr_adjust) {
- igb_lower_rx_eitr(adapter, rx_ring);
- rx_ring->no_itr_adjust = 1;
- }
+ if (adapter->set_itr) {
+ wr32(rx_ring->itr_register,
+ 1000000000 / (rx_ring->itr_val * 256));
+ adapter->set_itr = 0;
}

+ if (netif_rx_schedule_prep(adapter->netdev, &rx_ring->napi))
+ __netif_rx_schedule(adapter->netdev, &rx_ring->napi);
+
return IRQ_HANDLED;
}

@@ -3085,7 +3068,6 @@ static irqreturn_t igb_intr_msi(int irq, void *data)
{
struct net_device *netdev = data;
struct igb_adapter *adapter = netdev_priv(netdev);
- struct napi_struct *napi = &adapter->napi;
struct e1000_hw *hw = &adapter->hw;
/* read ICR disables interrupts using IAM */
u32 icr = rd32(E1000_ICR);
@@ -3094,25 +3076,17 @@ static irqreturn_t igb_intr_msi(int irq, void *data)
* previous interrupt.
*/
if (adapter->set_itr) {
- wr32(E1000_ITR,
- 1000000000 / (adapter->itr * 256));
+ wr32(E1000_ITR, 1000000000 / (adapter->itr * 256));
adapter->set_itr = 0;
}

- /* read ICR disables interrupts using IAM */
if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
hw->mac.get_link_status = 1;
if (!test_bit(__IGB_DOWN, &adapter->state))
mod_timer(&adapter->watchdog_timer, jiffies + 1);
}

- if (netif_rx_schedule_prep(netdev, napi)) {
- adapter->tx_ring->total_bytes = 0;
- adapter->tx_ring->total_packets = 0;
- adapter->rx_ring->total_bytes = 0;
- adapter->rx_ring->total_packets = 0;
- __netif_rx_schedule(netdev, napi);
- }
+ netif_rx_schedule(netdev, &adapter->rx_ring[0].napi);

return IRQ_HANDLED;
}
@@ -3126,7 +3100,6 @@ static irqreturn_t igb_intr(int irq, void *data)
{
struct net_device *netdev = data;
struct igb_adapter *adapter = netdev_priv(netdev);
- struct napi_struct *napi = &adapter->napi;
struct e1000_hw *hw = &adapter->hw;
/* Interrupt Auto-Mask...upon reading ICR, interrupts are masked. No
* need for the IMC write */
@@ -3139,8 +3112,7 @@ static irqreturn_t igb_intr(int irq, void *data)
* previous interrupt.
*/
if (adapter->set_itr) {
- wr32(E1000_ITR,
- 1000000000 / (adapter->itr * 256));
+ wr32(E1000_ITR, 1000000000 / (adapter->itr * 256));
adapter->set_itr = 0;
}

@@ -3158,13 +3130,7 @@ static irqreturn_t igb_intr(int irq, void *data)
mod_timer(&adapter->watchdog_timer, jiffies + 1);
}

- if (netif_rx_schedule_prep(netdev, napi)) {
- adapter->tx_ring->total_bytes = 0;
- adapter->rx_ring->total_bytes = 0;
- adapter->tx_ring->total_packets = 0;
- adapter->rx_ring->total_packets = 0;
- __netif_rx_schedule(netdev, napi);
- }
+ netif_rx_schedule(netdev, &adapter->rx_ring[0].napi);

return IRQ_HANDLED;
}
@@ -3247,6 +3213,10 @@ quit_polling:
else if (mean_size > IGB_DYN_ITR_LENGTH_HIGH)
igb_lower_rx_eitr(adapter, rx_ring);
}
+
+ if (!test_bit(__IGB_DOWN, &adapter->state))
+ wr32(E1000_EIMS, rx_ring->eims_value);
+
return 0;
}