Commit b6596985 authored by Joe Damato's avatar Joe Damato Committed by Jakub Kicinski
Browse files

igc: Link queues to NAPI instances 



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: default avatarJoe Damato <jdamato@fastly.com>
Reviewed-by: default avatarVitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: default avatarAvigail Dahan <avigailx.dahan@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250106221929.956999-15-anthony.l.nguyen@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1a63399c

drivers/net/ethernet/intel/igc/igc.h

+2 −0
Original line number Diff line number Diff line
@@ -337,6 +337,8 @@ 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_up(struct igc_adapter *adapter);

void igc_down(struct igc_adapter *adapter);

int igc_open(struct net_device *netdev);

drivers/net/ethernet/intel/igc/igc_main.c

+47 −9
Original line number Diff line number Diff line
@@ -4942,6 +4942,22 @@ static int igc_sw_init(struct igc_adapter *adapter) 
	return 0;

}



void igc_set_queue_napi(struct igc_adapter *adapter, int vector,

			struct napi_struct *napi)

{

	struct igc_q_vector *q_vector = adapter->q_vector[vector];



	if (q_vector->rx.ring)

		netif_queue_set_napi(adapter->netdev,

				     q_vector->rx.ring->queue_index,

				     NETDEV_QUEUE_TYPE_RX, napi);



	if (q_vector->tx.ring)

		netif_queue_set_napi(adapter->netdev,

				     q_vector->tx.ring->queue_index,

				     NETDEV_QUEUE_TYPE_TX, napi);

}



/**

 * igc_up - Open the interface and prepare it to handle traffic

 * @adapter: board private structure
@@ -4949,6 +4965,7 @@ 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 */
@@ -4956,8 +4973,11 @@ 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);
@@ -5186,6 +5206,7 @@ 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_set_queue_napi(adapter, i, NULL);

			napi_disable(&adapter->q_vector[i]->napi);

		}

	}
@@ -6015,6 +6036,7 @@ 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;
@@ -6050,8 +6072,11 @@ 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);
@@ -7296,7 +7321,7 @@ static void igc_deliver_wake_packet(struct net_device *netdev) 
	netif_rx(skb);

}



static int igc_resume(struct device *dev)

static int __igc_resume(struct device *dev, bool rpm)

{

	struct pci_dev *pdev = to_pci_dev(dev);

	struct net_device *netdev = pci_get_drvdata(pdev);
@@ -7339,7 +7364,11 @@ static int igc_resume(struct device *dev) 
	wr32(IGC_WUS, ~0);



	if (netif_running(netdev)) {

		if (!rpm)

			rtnl_lock();

		err = __igc_open(netdev, true);

		if (!rpm)

			rtnl_unlock();

		if (!err)

			netif_device_attach(netdev);

	}
@@ -7347,9 +7376,14 @@ static int igc_resume(struct device *dev) 
	return err;

}



static int igc_resume(struct device *dev)

{

	return __igc_resume(dev, false);

}



static int igc_runtime_resume(struct device *dev)

{

	return igc_resume(dev);

	return __igc_resume(dev, true);

}



static int igc_suspend(struct device *dev)
@@ -7394,14 +7428,18 @@ static pci_ers_result_t igc_io_error_detected(struct pci_dev *pdev, 
	struct net_device *netdev = pci_get_drvdata(pdev);

	struct igc_adapter *adapter = netdev_priv(netdev);



	rtnl_lock();

	netif_device_detach(netdev);



	if (state == pci_channel_io_perm_failure)

	if (state == pci_channel_io_perm_failure) {

		rtnl_unlock();

		return PCI_ERS_RESULT_DISCONNECT;

	}



	if (netif_running(netdev))

		igc_down(adapter);

	pci_disable_device(pdev);

	rtnl_unlock();



	/* Request a slot reset. */

	return PCI_ERS_RESULT_NEED_RESET;
@@ -7412,7 +7450,7 @@ static pci_ers_result_t igc_io_error_detected(struct pci_dev *pdev, 
 *  @pdev: Pointer to PCI device

 *

 *  Restart the card from scratch, as if from a cold-boot. Implementation

 *  resembles the first-half of the igc_resume routine.

 *  resembles the first-half of the __igc_resume routine.

 **/

static pci_ers_result_t igc_io_slot_reset(struct pci_dev *pdev)

{
@@ -7451,7 +7489,7 @@ static pci_ers_result_t igc_io_slot_reset(struct pci_dev *pdev) 
 *

 *  This callback is called when the error recovery driver tells us that

 *  its OK to resume normal operation. Implementation resembles the

 *  second-half of the igc_resume routine.

 *  second-half of the __igc_resume routine.

 */

static void igc_io_resume(struct pci_dev *pdev)

{

drivers/net/ethernet/intel/igc/igc_xdp.c

+2 −0
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ static int igc_xdp_enable_pool(struct igc_adapter *adapter, 
		napi_disable(napi);

	}



	igc_set_queue_napi(adapter, queue_id, NULL);

	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);

	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
@@ -135,6 +136,7 @@ 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);