Re: [net-next, 08/10] bng_en: Add irq allocation support

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 18/06/2025 15:47, Vikas Gupta wrote:
> Add irq allocation functions. This will help
> to allocate IRQs to both netdev and RoCE aux devices.
> 
> Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
> Reviewed-by: Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
> Reviewed-by: Rajashekar Hudumula <rajashekar.hudumula@broadcom.com>
> ---
>   drivers/net/ethernet/broadcom/bnge/bnge.h     |  3 +
>   .../net/ethernet/broadcom/bnge/bnge_resc.c    | 69 +++++++++++++++++++
>   .../net/ethernet/broadcom/bnge/bnge_resc.h    | 13 ++++
>   3 files changed, 85 insertions(+)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnge/bnge.h b/drivers/net/ethernet/broadcom/bnge/bnge.h
> index b58d8fc6f258..3c161b1a9b62 100644
> --- a/drivers/net/ethernet/broadcom/bnge/bnge.h
> +++ b/drivers/net/ethernet/broadcom/bnge/bnge.h
> @@ -172,6 +172,9 @@ struct bnge_dev {
>   #define BNGE_SUPPORTS_TPA(bd)	((bd)->max_tpa_v2)
>   
>   	u8                      num_tc;
> +
> +	struct bnge_irq		*irq_tbl;
> +	u16			irqs_acquired;
>   };
>   
>   static inline bool bnge_is_roce_en(struct bnge_dev *bd)
> diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_resc.c b/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
> index 68e094474822..84f91e05a2b0 100644
> --- a/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
> +++ b/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
> @@ -326,3 +326,72 @@ int bnge_reserve_rings(struct bnge_dev *bd)
>   
>   	return rc;
>   }
> +
> +int bnge_alloc_irqs(struct bnge_dev *bd)
> +{
> +	u16 aux_msix, tx_cp, num_entries;
> +	u16 irqs_demand, max, min = 1;
> +	int i, rc = 0;

This assignment is not needed. Error paths re-assign proper error code
while normal flow re-assigns rc to the return value of
bnge_adjust_rings()

> +
> +	irqs_demand = bnge_nqs_demand(bd);
> +	max = bnge_get_max_func_irqs(bd);
> +	if (irqs_demand > max)
> +		irqs_demand = max;
> +
> +	if (!(bd->flags & BNGE_EN_SHARED_CHNL))
> +		min = 2;
> +
> +	irqs_demand = pci_alloc_irq_vectors(bd->pdev, min, irqs_demand,
> +					    PCI_IRQ_MSIX);
> +	aux_msix = bnge_aux_get_msix(bd);
> +	if (irqs_demand < 0 || irqs_demand < aux_msix) {
> +		rc = -ENODEV;
> +		goto err_free_irqs;
> +	}
> +
> +	num_entries = irqs_demand;
> +	if (pci_msix_can_alloc_dyn(bd->pdev))
> +		num_entries = max;
> +	bd->irq_tbl = kcalloc(num_entries, sizeof(*bd->irq_tbl), GFP_KERNEL);
> +	if (!bd->irq_tbl) {
> +		rc = -ENOMEM;
> +		goto err_free_irqs;
> +	}
> +
> +	for (i = 0; i < irqs_demand; i++)
> +		bd->irq_tbl[i].vector = pci_irq_vector(bd->pdev, i);
> +
> +	bd->irqs_acquired = irqs_demand;
> +	/* Reduce rings based upon num of vectors allocated.
> +	 * We dont need to consider NQs as they have been calculated
> +	 * and must be more than irqs_demand.
> +	 */
> +	rc = bnge_adjust_rings(bd, &bd->rx_nr_rings,
> +			       &bd->tx_nr_rings,
> +			       irqs_demand - aux_msix, min == 1);
> +	if (rc)
> +		goto err_free_irqs;
> +
> +	tx_cp = bnge_num_tx_to_cp(bd, bd->tx_nr_rings);
> +	bd->nq_nr_rings = (min == 1) ?
> +		max_t(u16, tx_cp, bd->rx_nr_rings) :
> +		tx_cp + bd->rx_nr_rings;
> +
> +	/* Readjust tx_nr_rings_per_tc */
> +	if (!bd->num_tc)
> +		bd->tx_nr_rings_per_tc = bd->tx_nr_rings;
> +
> +	return 0;
> +
> +err_free_irqs:
> +	dev_err(bd->dev, "Failed to allocate IRQs err = %d\n", rc);
> +	bnge_free_irqs(bd);
> +	return rc;
> +}

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