diff mbox series

[iwl-next,1/1] igc: Improve XDP_SETUP_PROG process

Message ID 20241204120233.3148482-1-yoong.siang.song@intel.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [iwl-next,1/1] igc: Improve XDP_SETUP_PROG process | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Song, Yoong Siang Dec. 4, 2024, 12:02 p.m. UTC
Improve XDP_SETUP_PROG process by avoiding unnecessary link down/up event
and hardware device reset.

Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h      |   2 +
 drivers/net/ethernet/intel/igc/igc_main.c | 138 ++++++++++++++++++++++
 drivers/net/ethernet/intel/igc/igc_xdp.c  |   4 +-
 3 files changed, 142 insertions(+), 2 deletions(-)

Comments

Vinicius Costa Gomes Dec. 5, 2024, 12:38 a.m. UTC | #1
Song Yoong Siang <yoong.siang.song@intel.com> writes:

> Improve XDP_SETUP_PROG process by avoiding unnecessary link down/up event
> and hardware device reset.
>

Some examples of problems that these hardware resets are causing would
be good.

> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
> ---

The duplication of code doesn't look that good. Initialization is
tricky, it seems to make it easy to update one place and forget to
update the other.

A couple of ideas:
 - separate the code into functions that can be used from the "usual"
 igc_open()/igc_close() flow;
 - it seems that igc_close()/igc_open() are too big a hammer for
 installing a new XDP program: what do we really need? (my mental model
 is: 1. stop new traffic from going into any queue; 2. wait for any
 packets "in progress"; 3. install the program; 4. resume operations;
 what else?)

>  drivers/net/ethernet/intel/igc/igc.h      |   2 +
>  drivers/net/ethernet/intel/igc/igc_main.c | 138 ++++++++++++++++++++++
>  drivers/net/ethernet/intel/igc/igc_xdp.c  |   4 +-
>  3 files changed, 142 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
> index eac0f966e0e4..b1e46fcaae1a 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -341,6 +341,8 @@ void igc_up(struct igc_adapter *adapter);
>  void igc_down(struct igc_adapter *adapter);
>  int igc_open(struct net_device *netdev);
>  int igc_close(struct net_device *netdev);
> +void igc_xdp_open(struct net_device *netdev);
> +void igc_xdp_close(struct net_device *netdev);
>  int igc_setup_tx_resources(struct igc_ring *ring);
>  int igc_setup_rx_resources(struct igc_ring *ring);
>  void igc_free_tx_resources(struct igc_ring *ring);
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index 27872bdea9bd..098529a80b88 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -6145,6 +6145,144 @@ int igc_close(struct net_device *netdev)
>  	return 0;
>  }
>  
> +void igc_xdp_open(struct net_device *netdev)
> +{
> +	struct igc_adapter *adapter = netdev_priv(netdev);
> +	struct pci_dev *pdev = adapter->pdev;
> +	struct igc_hw *hw = &adapter->hw;
> +	int err = 0;
> +	int i = 0;
> +
> +	/* disallow open during test */
> +	if (test_bit(__IGC_TESTING, &adapter->state))
> +		return;
> +
> +	pm_runtime_get_sync(&pdev->dev);
> +
> +	igc_ptp_reset(adapter);
> +
> +	/* allocate transmit descriptors */
> +	err = igc_setup_all_tx_resources(adapter);
> +	if (err)
> +		goto err_setup_tx;
> +
> +	/* allocate receive descriptors */
> +	err = igc_setup_all_rx_resources(adapter);
> +	if (err)
> +		goto err_setup_rx;
> +
> +	igc_setup_tctl(adapter);
> +	igc_setup_rctl(adapter);
> +	igc_configure_tx(adapter);
> +	igc_configure_rx(adapter);
> +	igc_rx_fifo_flush_base(&adapter->hw);
> +
> +	/* call igc_desc_unused which always leaves
> +	 * at least 1 descriptor unused to make sure
> +	 * next_to_use != next_to_clean
> +	 */
> +	for (i = 0; i < adapter->num_rx_queues; i++) {
> +		struct igc_ring *ring = adapter->rx_ring[i];
> +
> +		if (ring->xsk_pool)
> +			igc_alloc_rx_buffers_zc(ring, igc_desc_unused(ring));
> +		else
> +			igc_alloc_rx_buffers(ring, igc_desc_unused(ring));
> +	}
> +
> +	err = igc_request_irq(adapter);
> +	if (err)
> +		goto err_req_irq;
> +
> +	clear_bit(__IGC_DOWN, &adapter->state);
> +
> +	for (i = 0; i < adapter->num_q_vectors; i++)
> +		napi_enable(&adapter->q_vector[i]->napi);
> +
> +	/* Clear any pending interrupts. */
> +	rd32(IGC_ICR);
> +	igc_irq_enable(adapter);
> +
> +	pm_runtime_put(&pdev->dev);
> +
> +	netif_tx_start_all_queues(netdev);
> +	netif_carrier_on(netdev);
> +
> +	return;
> +
> +err_req_irq:
> +	igc_release_hw_control(adapter);
> +	igc_power_down_phy_copper_base(&adapter->hw);
> +	igc_free_all_rx_resources(adapter);
> +err_setup_rx:
> +	igc_free_all_tx_resources(adapter);
> +err_setup_tx:
> +	igc_reset(adapter);
> +	pm_runtime_put(&pdev->dev);
> +}
> +
> +void igc_xdp_close(struct net_device *netdev)
> +{
> +	struct igc_adapter *adapter = netdev_priv(netdev);
> +	struct pci_dev *pdev = adapter->pdev;
> +	struct igc_hw *hw = &adapter->hw;
> +	u32 tctl, rctl;
> +	int i = 0;
> +
> +	WARN_ON(test_bit(__IGC_RESETTING, &adapter->state));
> +
> +	pm_runtime_get_sync(&pdev->dev);
> +
> +	set_bit(__IGC_DOWN, &adapter->state);
> +
> +	igc_ptp_suspend(adapter);
> +
> +	if (pci_device_is_present(pdev)) {
> +		/* disable receives in the hardware */
> +		rctl = rd32(IGC_RCTL);
> +		wr32(IGC_RCTL, rctl & ~IGC_RCTL_EN);
> +		/* flush and sleep below */
> +	}
> +	/* set trans_start so we don't get spurious watchdogs during reset */
> +	netif_trans_update(netdev);
> +
> +	netif_carrier_off(netdev);
> +	netif_tx_stop_all_queues(netdev);
> +
> +	if (pci_device_is_present(pdev)) {
> +		/* disable transmits in the hardware */
> +		tctl = rd32(IGC_TCTL);
> +		tctl &= ~IGC_TCTL_EN;
> +		wr32(IGC_TCTL, tctl);
> +		/* flush both disables and wait for them to finish */
> +		wrfl();
> +		usleep_range(10000, 20000);
> +
> +		igc_irq_disable(adapter);
> +	}
> +
> +	for (i = 0; i < adapter->num_q_vectors; i++) {
> +		if (adapter->q_vector[i]) {
> +			napi_synchronize(&adapter->q_vector[i]->napi);
> +			napi_disable(&adapter->q_vector[i]->napi);
> +		}
> +	}
> +
> +	del_timer_sync(&adapter->watchdog_timer);
> +	del_timer_sync(&adapter->phy_info_timer);
> +
> +	igc_disable_all_tx_rings_hw(adapter);
> +	igc_clean_all_tx_rings(adapter);
> +	igc_clean_all_rx_rings(adapter);
> +
> +	igc_free_irq(adapter);
> +
> +	igc_free_all_tx_resources(adapter);
> +	igc_free_all_rx_resources(adapter);
> +
> +	pm_runtime_put_sync(&pdev->dev);
> +}
> +
>  /**
>   * igc_ioctl - Access the hwtstamp interface
>   * @netdev: network interface device structure
> diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
> index 869815f48ac1..f1d6ab56ab54 100644
> --- a/drivers/net/ethernet/intel/igc/igc_xdp.c
> +++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
> @@ -25,7 +25,7 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
>  
>  	need_update = !!adapter->xdp_prog != !!prog;
>  	if (if_running && need_update)
> -		igc_close(dev);
> +		igc_xdp_close(dev);
>  
>  	old_prog = xchg(&adapter->xdp_prog, prog);
>  	if (old_prog)
> @@ -37,7 +37,7 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
>  		xdp_features_clear_redirect_target(dev);
>  
>  	if (if_running && need_update)
> -		igc_open(dev);
> +		igc_xdp_open(dev);
>  
>  	return 0;
>  }
> -- 
> 2.34.1
>
>

Cheers,
Song, Yoong Siang Dec. 5, 2024, 2:45 a.m. UTC | #2
On Thursday, December 5, 2024 8:38 AM, Gomes, Vinicius <vinicius.gomes@intel.com> wrote:
>Song Yoong Siang <yoong.siang.song@intel.com> writes:
>
>> Improve XDP_SETUP_PROG process by avoiding unnecessary link down/up event
>> and hardware device reset.
>>
>
>Some examples of problems that these hardware resets are causing would
>be good.
>

Sure, maybe I can give an example of "before" and "after" behavior
on ptp4l clock sync log in commit msg in next submission.

>> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
>> ---
>
>The duplication of code doesn't look that good. Initialization is
>tricky, it seems to make it easy to update one place and forget to
>update the other.
>

The original idea of this patch is to avoid huge changes on
igc_open/igc_close functions. But I agree with you that
duplication of code is challenging to maintain. I will create
common function whenever necessary in next submission.

>A couple of ideas:
> - separate the code into functions that can be used from the "usual"
> igc_open()/igc_close() flow;
> - it seems that igc_close()/igc_open() are too big a hammer for
> installing a new XDP program: what do we really need? (my mental model
> is: 1. stop new traffic from going into any queue; 2. wait for any
> packets "in progress"; 3. install the program; 4. resume operations;
> what else?)

I think will need to reallocate DMA resource, if user enable XDP pool first,
then only setup XDP prog. Maybe I can reuse the reset sequence in
igc_xdp_enable_pool(). I will study further.

[...]
>
>Cheers,
>--
>Vinicius

Thanks & Regards
Siang
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index eac0f966e0e4..b1e46fcaae1a 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -341,6 +341,8 @@  void igc_up(struct igc_adapter *adapter);
 void igc_down(struct igc_adapter *adapter);
 int igc_open(struct net_device *netdev);
 int igc_close(struct net_device *netdev);
+void igc_xdp_open(struct net_device *netdev);
+void igc_xdp_close(struct net_device *netdev);
 int igc_setup_tx_resources(struct igc_ring *ring);
 int igc_setup_rx_resources(struct igc_ring *ring);
 void igc_free_tx_resources(struct igc_ring *ring);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 27872bdea9bd..098529a80b88 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6145,6 +6145,144 @@  int igc_close(struct net_device *netdev)
 	return 0;
 }
 
+void igc_xdp_open(struct net_device *netdev)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct pci_dev *pdev = adapter->pdev;
+	struct igc_hw *hw = &adapter->hw;
+	int err = 0;
+	int i = 0;
+
+	/* disallow open during test */
+	if (test_bit(__IGC_TESTING, &adapter->state))
+		return;
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	igc_ptp_reset(adapter);
+
+	/* allocate transmit descriptors */
+	err = igc_setup_all_tx_resources(adapter);
+	if (err)
+		goto err_setup_tx;
+
+	/* allocate receive descriptors */
+	err = igc_setup_all_rx_resources(adapter);
+	if (err)
+		goto err_setup_rx;
+
+	igc_setup_tctl(adapter);
+	igc_setup_rctl(adapter);
+	igc_configure_tx(adapter);
+	igc_configure_rx(adapter);
+	igc_rx_fifo_flush_base(&adapter->hw);
+
+	/* call igc_desc_unused which always leaves
+	 * at least 1 descriptor unused to make sure
+	 * next_to_use != next_to_clean
+	 */
+	for (i = 0; i < adapter->num_rx_queues; i++) {
+		struct igc_ring *ring = adapter->rx_ring[i];
+
+		if (ring->xsk_pool)
+			igc_alloc_rx_buffers_zc(ring, igc_desc_unused(ring));
+		else
+			igc_alloc_rx_buffers(ring, igc_desc_unused(ring));
+	}
+
+	err = igc_request_irq(adapter);
+	if (err)
+		goto err_req_irq;
+
+	clear_bit(__IGC_DOWN, &adapter->state);
+
+	for (i = 0; i < adapter->num_q_vectors; i++)
+		napi_enable(&adapter->q_vector[i]->napi);
+
+	/* Clear any pending interrupts. */
+	rd32(IGC_ICR);
+	igc_irq_enable(adapter);
+
+	pm_runtime_put(&pdev->dev);
+
+	netif_tx_start_all_queues(netdev);
+	netif_carrier_on(netdev);
+
+	return;
+
+err_req_irq:
+	igc_release_hw_control(adapter);
+	igc_power_down_phy_copper_base(&adapter->hw);
+	igc_free_all_rx_resources(adapter);
+err_setup_rx:
+	igc_free_all_tx_resources(adapter);
+err_setup_tx:
+	igc_reset(adapter);
+	pm_runtime_put(&pdev->dev);
+}
+
+void igc_xdp_close(struct net_device *netdev)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct pci_dev *pdev = adapter->pdev;
+	struct igc_hw *hw = &adapter->hw;
+	u32 tctl, rctl;
+	int i = 0;
+
+	WARN_ON(test_bit(__IGC_RESETTING, &adapter->state));
+
+	pm_runtime_get_sync(&pdev->dev);
+
+	set_bit(__IGC_DOWN, &adapter->state);
+
+	igc_ptp_suspend(adapter);
+
+	if (pci_device_is_present(pdev)) {
+		/* disable receives in the hardware */
+		rctl = rd32(IGC_RCTL);
+		wr32(IGC_RCTL, rctl & ~IGC_RCTL_EN);
+		/* flush and sleep below */
+	}
+	/* set trans_start so we don't get spurious watchdogs during reset */
+	netif_trans_update(netdev);
+
+	netif_carrier_off(netdev);
+	netif_tx_stop_all_queues(netdev);
+
+	if (pci_device_is_present(pdev)) {
+		/* disable transmits in the hardware */
+		tctl = rd32(IGC_TCTL);
+		tctl &= ~IGC_TCTL_EN;
+		wr32(IGC_TCTL, tctl);
+		/* flush both disables and wait for them to finish */
+		wrfl();
+		usleep_range(10000, 20000);
+
+		igc_irq_disable(adapter);
+	}
+
+	for (i = 0; i < adapter->num_q_vectors; i++) {
+		if (adapter->q_vector[i]) {
+			napi_synchronize(&adapter->q_vector[i]->napi);
+			napi_disable(&adapter->q_vector[i]->napi);
+		}
+	}
+
+	del_timer_sync(&adapter->watchdog_timer);
+	del_timer_sync(&adapter->phy_info_timer);
+
+	igc_disable_all_tx_rings_hw(adapter);
+	igc_clean_all_tx_rings(adapter);
+	igc_clean_all_rx_rings(adapter);
+
+	igc_free_irq(adapter);
+
+	igc_free_all_tx_resources(adapter);
+	igc_free_all_rx_resources(adapter);
+
+	pm_runtime_put_sync(&pdev->dev);
+}
+
 /**
  * igc_ioctl - Access the hwtstamp interface
  * @netdev: network interface device structure
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
index 869815f48ac1..f1d6ab56ab54 100644
--- a/drivers/net/ethernet/intel/igc/igc_xdp.c
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
@@ -25,7 +25,7 @@  int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 
 	need_update = !!adapter->xdp_prog != !!prog;
 	if (if_running && need_update)
-		igc_close(dev);
+		igc_xdp_close(dev);
 
 	old_prog = xchg(&adapter->xdp_prog, prog);
 	if (old_prog)
@@ -37,7 +37,7 @@  int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 		xdp_features_clear_redirect_target(dev);
 
 	if (if_running && need_update)
-		igc_open(dev);
+		igc_xdp_open(dev);
 
 	return 0;
 }