Commit 741106f7 authored by Tony Nguyen's avatar Tony Nguyen
Browse files

ice: Improve MSI-X fallback logic 



Currently if the driver is unable to get all the MSI-X vectors it wants, it
falls back to the minimum configuration which equates to a single Tx/Rx
traffic queue pair. Instead of using the minimum configuration, if given
more vectors than the minimum, utilize those vectors for additional traffic
queues after accounting for other interrupts.

Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: default avatarTony Brelinski <tonyx.brelinski@intel.com>
parent fe6cd890

drivers/net/ethernet/intel/ice/ice_main.c

+25 −15
Original line number Diff line number Diff line
@@ -3391,39 +3391,41 @@ static int ice_init_pf(struct ice_pf *pf) 
 */

static int ice_ena_msix_range(struct ice_pf *pf)

{

	int v_left, v_actual, v_other, v_budget = 0;

	struct device *dev = ice_pf_to_dev(pf);

	int v_left, v_actual, v_budget = 0;

	int needed, err, i;



	v_left = pf->hw.func_caps.common_cap.num_msix_vectors;



	/* reserve one vector for miscellaneous handler */

	needed = 1;

	/* reserve for LAN miscellaneous handler */

	needed = ICE_MIN_LAN_OICR_MSIX;

	if (v_left < needed)

		goto no_hw_vecs_left_err;

	v_budget += needed;

	v_left -= needed;



	/* reserve vectors for LAN traffic */

	needed = min_t(int, num_online_cpus(), v_left);

	/* reserve for flow director */

	if (test_bit(ICE_FLAG_FD_ENA, pf->flags)) {

		needed = ICE_FDIR_MSIX;

		if (v_left < needed)

			goto no_hw_vecs_left_err;

	pf->num_lan_msix = needed;

		v_budget += needed;

		v_left -= needed;

	}



	/* reserve one vector for flow director */

	if (test_bit(ICE_FLAG_FD_ENA, pf->flags)) {

		needed = ICE_FDIR_MSIX;

	/* total used for non-traffic vectors */

	v_other = v_budget;



	/* reserve vectors for LAN traffic */

	needed = min_t(int, num_online_cpus(), v_left);

	if (v_left < needed)

		goto no_hw_vecs_left_err;

	pf->num_lan_msix = needed;

	v_budget += needed;

	v_left -= needed;

	}



	pf->msix_entries = devm_kcalloc(dev, v_budget,

					sizeof(*pf->msix_entries), GFP_KERNEL);



	if (!pf->msix_entries) {

		err = -ENOMEM;

		goto exit_err;
@@ -3435,7 +3437,6 @@ static int ice_ena_msix_range(struct ice_pf *pf) 
	/* actually reserve the vectors */

	v_actual = pci_enable_msix_range(pf->pdev, pf->msix_entries,

					 ICE_MIN_MSIX, v_budget);



	if (v_actual < 0) {

		dev_err(dev, "unable to reserve MSI-X vectors\n");

		err = v_actual;
@@ -3452,7 +3453,16 @@ static int ice_ena_msix_range(struct ice_pf *pf) 
			err = -ERANGE;

			goto msix_err;

		} else {

			int v_traffic = v_actual - v_other;



			if (v_actual == ICE_MIN_MSIX ||

			    v_traffic < ICE_MIN_LAN_TXRX_MSIX)

				pf->num_lan_msix = ICE_MIN_LAN_TXRX_MSIX;

			else

				pf->num_lan_msix = v_traffic;



			dev_notice(dev, "Enabled %d MSI-X vectors for LAN traffic.\n",

				   pf->num_lan_msix);

		}

	}