Re: [PATCH V3 09/10] bnxt_en: Add TPH support in BNXT driver

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jul 17, 2024 at 03:55:10PM -0500, Wei Huang wrote:
> From: Manoj Panicker <manoj.panicker2@amd.com>
> 
> Implement TPH support in Broadcom BNXT device driver by invoking
> pcie_tph_set_st() function when interrupt affinity is changed.

*and* invoking pcie_tph_set_st() when setting up the IRQ in the first
place, I guess?

I guess this gives a significant performance benefit?  The series
includes "pci=nostmode" so the benefit can be quantified, so now I'm
curious about what you measured :)

> +static void bnxt_rtnl_lock_sp(struct bnxt *bp);
> +static void bnxt_rtnl_unlock_sp(struct bnxt *bp);

These duplicate declarations can't be right, can they?  OK for
work-in-progress, but it doesn't look like the final solution.

> +static void __bnxt_irq_affinity_notify(struct irq_affinity_notify *notify,
> +				       const cpumask_t *mask)
> +{
> +	struct bnxt_irq *irq;
> +
> +	irq = container_of(notify, struct bnxt_irq, affinity_notify);
> +	cpumask_copy(irq->cpu_mask, mask);
> +
> +	if (!pcie_tph_set_st(irq->bp->pdev, irq->msix_nr,
> +			     cpumask_first(irq->cpu_mask),
> +			     TPH_MEM_TYPE_VM, PCI_TPH_REQ_TPH_ONLY))
> +		netdev_dbg(irq->bp->dev, "error in setting steering tag\n");
> +
> +	if (netif_running(irq->bp->dev)) {
> +		rtnl_lock();
> +		bnxt_close_nic(irq->bp, false, false);
> +		bnxt_open_nic(irq->bp, false, false);
> +		rtnl_unlock();
> +	}
> +}