Re: [v8,5/7] PCI: mediatek-gen3: Add MSI support

[Marc Zyngier]

On 2021-03-11 00:05, Pali Rohár wrote:
> On Wednesday 24 February 2021 14:11:30 Jianjun Wang wrote:
> > +static int mtk_msi_bottom_domain_alloc(struct irq_domain *domain,
> > +				       unsigned int virq, unsigned int nr_irqs,
> > +				       void *arg)
> > +{
> > +	struct mtk_pcie_port *port = domain->host_data;
> > +	struct mtk_msi_set *msi_set;
> > +	int i, hwirq, set_idx;
> > +
> > +	mutex_lock(&port->lock);
> > +
> > +	hwirq = bitmap_find_free_region(port->msi_irq_in_use, 
> > PCIE_MSI_IRQS_NUM,
> > +					order_base_2(nr_irqs));
> > +
> > +	mutex_unlock(&port->lock);
> > +
> > +	if (hwirq < 0)
> > +		return -ENOSPC;
> > +
> > +	set_idx = hwirq / PCIE_MSI_IRQS_PER_SET;
> > +	msi_set = &port->msi_sets[set_idx];
> > +
> > +	for (i = 0; i < nr_irqs; i++)
> > +		irq_domain_set_info(domain, virq + i, hwirq + i,
> > +				    &mtk_msi_bottom_irq_chip, msi_set,
> > +				    handle_edge_irq, NULL, NULL);
> > +
> > +	return 0;
> > +}
> > +
> > +static void mtk_msi_bottom_domain_free(struct irq_domain *domain,
> > +				       unsigned int virq, unsigned int nr_irqs)
> > +{
> > +	struct mtk_pcie_port *port = domain->host_data;
> > +	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
> > +
> > +	mutex_lock(&port->lock);
> > +
> > +	bitmap_clear(port->msi_irq_in_use, data->hwirq, nr_irqs);
>
> Marc, should not be there bitmap_release_region() with order_base_2()?
>
> bitmap_release_region(port->msi_irq_in_use, data->hwirq, 
> order_base_2(nr_irqs));
>
> Because mtk_msi_bottom_domain_alloc() is allocating
> order_base_2(nr_irqs) interrupts, not only nr_irqs.

Indeed, good catch.

Thanks,

        M.
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