The current implementation in the igb_xsk_wakeup expects
the Rx and Tx queues to share the same irq. This would lead
to triggering of incorrect irq in split irq configuration.
This patch addresses this issue which could impact environments
with 2 active cpu cores
or when the number of queues is reduced to 2 or less
cat /proc/interrupts | grep eno2
167: 0 0 0 0 IR-PCI-MSIX-0000:08:00.0
0-edge eno2
168: 0 0 0 0 IR-PCI-MSIX-0000:08:00.0
1-edge eno2-rx-0
169: 0 0 0 0 IR-PCI-MSIX-0000:08:00.0
2-edge eno2-rx-1
170: 0 0 0 0 IR-PCI-MSIX-0000:08:00.0
3-edge eno2-tx-0
171: 0 0 0 0 IR-PCI-MSIX-0000:08:00.0
4-edge eno2-tx-1
Furthermore it uses the flags input argument to trigger either rx, tx or
both rx and tx irqs as specified in the ndo_xsk_wakeup api documentation
Fixes: 80f6ccf9f116 ("igb: Introduce XSK data structures and helpers")
Signed-off-by: Vivek Behera <[email protected]>
Reviewed-by: Aleksandr Loktionov <[email protected]>
Suggested-by: Maciej Fijalkowski <[email protected]>
Acked-by: Maciej Fijalkowski <[email protected]>
---
v1:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v2:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v3:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v4:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v5:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v6:
https://lore.kernel.org/intel-wired-lan/[email protected]/
v7:
https://lore.kernel.org/intel-wired-lan/[email protected]/
changelog:
v1
- Initial description of the Bug and fixes made in the patch
v1 -> v2
- Handling of RX and TX Wakeup in igc_xsk_wakeup for a split IRQ configuration
- Review suggestions by Aleksander: Modified sequence to complete all
error checks for rx and tx before updating napi states and triggering irqs
- Corrected trigger of TX and RX interrupts over E1000_ICS (non msix use case)
- Added define for Tx interrupt trigger bit mask for E1000_ICS
v2 -> v3
- Included applicable feedback and suggestions from igc patch
- Fixed logic in updating eics value when both TX and RX need wakeup
v3 -> v4
- Added comments to explain trigerring of both TX and RX with active queue pairs
- Fixed check of xsk pools in if statement
v4 -> v5
- Introduced a simplified logic for sequential check for RX and TX
v5 -> v6
- Further simplifications suggested by Maciej
- Included review suggestions from reviewers
v6 -> v7
- Removed redundant braces
- Updated comment block to improve explanation of implemented logic
v7 -> v8
- Added acked-by tag
---
drivers/net/ethernet/intel/igb/igb_xsk.c | 38 +++++++++++++++++++-----
1 file changed, 30 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_xsk.c
b/drivers/net/ethernet/intel/igb/igb_xsk.c
index 30ce5fbb5b77..ce4a7b58cad2 100644
--- a/drivers/net/ethernet/intel/igb/igb_xsk.c
+++ b/drivers/net/ethernet/intel/igb/igb_xsk.c
@@ -524,6 +524,16 @@ bool igb_xmit_zc(struct igb_ring *tx_ring, struct
xsk_buff_pool *xsk_pool)
return nb_pkts < budget;
}
+static u32 igb_sw_irq_prep(struct igb_q_vector *q_vector)
+{
+ u32 eics = 0;
+
+ if (!napi_if_scheduled_mark_missed(&q_vector->napi))
+ eics = q_vector->eims_value;
+
+ return eics;
+}
+
int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
{
struct igb_adapter *adapter = netdev_priv(dev);
@@ -542,20 +552,32 @@ int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32
flags)
ring = adapter->tx_ring[qid];
- if (test_bit(IGB_RING_FLAG_TX_DISABLED, &ring->flags))
- return -ENETDOWN;
-
if (!READ_ONCE(ring->xsk_pool))
return -EINVAL;
- if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
+ if (flags & XDP_WAKEUP_TX) {
+ if (test_bit(IGB_RING_FLAG_TX_DISABLED, &ring->flags))
+ return -ENETDOWN;
+
+ eics |= igb_sw_irq_prep(ring->q_vector);
+ }
+
+ if (flags & XDP_WAKEUP_RX) {
+ /* If IGB_FLAG_QUEUE_PAIRS is active, the q_vector
+ * and NAPI is shared between RX and TX.
+ * If NAPI is already running it would be marked as missed
+ * from the TX path, making this RX call a NOP
+ */
+ ring = adapter->rx_ring[qid];
+ eics |= igb_sw_irq_prep(ring->q_vector);
+ }
+
+ if (eics) {
/* Cause software interrupt */
- if (adapter->flags & IGB_FLAG_HAS_MSIX) {
- eics |= ring->q_vector->eims_value;
+ if (adapter->flags & IGB_FLAG_HAS_MSIX)
wr32(E1000_EICS, eics);
- } else {
+ else
wr32(E1000_ICS, E1000_ICS_RXDMT0);
- }
}
return 0;
--
2.34.1
