[RFC net-next v2 2/2] igc: Link queues to NAPI instances
From: Joe Damato
Date: Mon Oct 14 2024 - 17:31:16 EST
Link queues to NAPI instances via netdev-genl API so that users can
query this information with netlink. Handle a few cases in the driver:
1. Link/unlink the NAPIs when XDP is enabled/disabled
2. Handle IGC_FLAG_QUEUE_PAIRS enabled and disabled
Example output when IGC_FLAG_QUEUE_PAIRS is enabled:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'tx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'}]
Since IGC_FLAG_QUEUE_PAIRS is enabled, you'll note that the same NAPI ID
is present for both rx and tx queues at the same index, for example
index 0:
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
To test IGC_FLAG_QUEUE_PAIRS disabled, a test system was booted using
the grub command line option "maxcpus=2" to force
igc_set_interrupt_capability to disable IGC_FLAG_QUEUE_PAIRS.
Example output when IGC_FLAG_QUEUE_PAIRS is disabled:
$ lscpu | grep "On-line CPU"
On-line CPU(s) list: 0,2
$ ethtool -l enp86s0 | tail -5
Current hardware settings:
RX: n/a
TX: n/a
Other: 1
Combined: 2
$ cat /proc/interrupts | grep enp
144: [...] enp86s0
145: [...] enp86s0-rx-0
146: [...] enp86s0-rx-1
147: [...] enp86s0-tx-0
148: [...] enp86s0-tx-1
1 "other" IRQ, and 2 IRQs for each of RX and Tx, so we expect netlink to
report 4 IRQs with unique NAPI IDs:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump napi-get --json='{"ifindex": 2}'
[{'id': 8196, 'ifindex': 2, 'irq': 148},
{'id': 8195, 'ifindex': 2, 'irq': 147},
{'id': 8194, 'ifindex': 2, 'irq': 146},
{'id': 8193, 'ifindex': 2, 'irq': 145}]
Now we examine which queues these NAPIs are associated with, expecting
that since IGC_FLAG_QUEUE_PAIRS is disabled each RX and TX queue will
have its own NAPI instance:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'}]
Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
---
v2:
- Update commit message to include tests for IGC_FLAG_QUEUE_PAIRS
disabled
- Refactored code to move napi queue mapping and unmapping to helper
functions igc_set_queue_napi and igc_unset_queue_napi
- Adjust the code to handle IGC_FLAG_QUEUE_PAIRS disabled
- Call helpers to map/unmap queues to NAPIs in igc_up, __igc_open,
igc_xdp_enable_pool, and igc_xdp_disable_pool
drivers/net/ethernet/intel/igc/igc.h | 3 ++
drivers/net/ethernet/intel/igc/igc_main.c | 58 +++++++++++++++++++++--
drivers/net/ethernet/intel/igc/igc_xdp.c | 2 +
3 files changed, 59 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index eac0f966e0e4..7b1c9ea60056 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -337,6 +337,9 @@ struct igc_adapter {
struct igc_led_classdev *leds;
};
+void igc_set_queue_napi(struct igc_adapter *adapter, int q_idx,
+ struct napi_struct *napi);
+void igc_unset_queue_napi(struct igc_adapter *adapter, int q_idx);
void igc_up(struct igc_adapter *adapter);
void igc_down(struct igc_adapter *adapter);
int igc_open(struct net_device *netdev);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 7964bbedb16c..59c00acfa0ed 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -4948,6 +4948,47 @@ static int igc_sw_init(struct igc_adapter *adapter)
return 0;
}
+void igc_set_queue_napi(struct igc_adapter *adapter, int q_idx,
+ struct napi_struct *napi)
+{
+ if (adapter->flags & IGC_FLAG_QUEUE_PAIRS) {
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_RX, napi);
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_TX, napi);
+ } else {
+ if (q_idx < adapter->num_rx_queues) {
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_RX, napi);
+ } else {
+ q_idx -= adapter->num_rx_queues;
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_TX, napi);
+ }
+ }
+}
+
+void igc_unset_queue_napi(struct igc_adapter *adapter, int q_idx)
+{
+ struct net_device *netdev = adapter->netdev;
+
+ if (adapter->flags & IGC_FLAG_QUEUE_PAIRS) {
+ netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_RX,
+ NULL);
+ netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_TX,
+ NULL);
+ } else {
+ if (q_idx < adapter->num_rx_queues) {
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_RX, NULL);
+ } else {
+ q_idx -= adapter->num_rx_queues;
+ netif_queue_set_napi(adapter->netdev, q_idx,
+ NETDEV_QUEUE_TYPE_TX, NULL);
+ }
+ }
+}
+
/**
* igc_up - Open the interface and prepare it to handle traffic
* @adapter: board private structure
@@ -4955,6 +4996,7 @@ static int igc_sw_init(struct igc_adapter *adapter)
void igc_up(struct igc_adapter *adapter)
{
struct igc_hw *hw = &adapter->hw;
+ struct napi_struct *napi;
int i = 0;
/* hardware has been reset, we need to reload some things */
@@ -4962,8 +5004,11 @@ void igc_up(struct igc_adapter *adapter)
clear_bit(__IGC_DOWN, &adapter->state);
- for (i = 0; i < adapter->num_q_vectors; i++)
- napi_enable(&adapter->q_vector[i]->napi);
+ for (i = 0; i < adapter->num_q_vectors; i++) {
+ napi = &adapter->q_vector[i]->napi;
+ napi_enable(napi);
+ igc_set_queue_napi(adapter, i, napi);
+ }
if (adapter->msix_entries)
igc_configure_msix(adapter);
@@ -5192,6 +5237,7 @@ void igc_down(struct igc_adapter *adapter)
for (i = 0; i < adapter->num_q_vectors; i++) {
if (adapter->q_vector[i]) {
napi_synchronize(&adapter->q_vector[i]->napi);
+ igc_unset_queue_napi(adapter, i);
napi_disable(&adapter->q_vector[i]->napi);
}
}
@@ -6021,6 +6067,7 @@ static int __igc_open(struct net_device *netdev, bool resuming)
struct igc_adapter *adapter = netdev_priv(netdev);
struct pci_dev *pdev = adapter->pdev;
struct igc_hw *hw = &adapter->hw;
+ struct napi_struct *napi;
int err = 0;
int i = 0;
@@ -6056,8 +6103,11 @@ static int __igc_open(struct net_device *netdev, bool resuming)
clear_bit(__IGC_DOWN, &adapter->state);
- for (i = 0; i < adapter->num_q_vectors; i++)
- napi_enable(&adapter->q_vector[i]->napi);
+ for (i = 0; i < adapter->num_q_vectors; i++) {
+ napi = &adapter->q_vector[i]->napi;
+ napi_enable(napi);
+ igc_set_queue_napi(adapter, i, napi);
+ }
/* Clear any pending interrupts. */
rd32(IGC_ICR);
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
index e27af72aada8..886f04b8c394 100644
--- a/drivers/net/ethernet/intel/igc/igc_xdp.c
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
@@ -84,6 +84,7 @@ static int igc_xdp_enable_pool(struct igc_adapter *adapter,
napi_disable(napi);
}
+ igc_unset_queue_napi(adapter, queue_id);
set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
@@ -133,6 +134,7 @@ static int igc_xdp_disable_pool(struct igc_adapter *adapter, u16 queue_id)
xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
+ igc_set_queue_napi(adapter, queue_id, napi);
if (needs_reset) {
napi_enable(napi);
--
2.25.1