Commit de337ee3 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

irqchip/gic-v2m: Add PCI Multi-MSI support 



We'd never implemented Multi-MSI support with GICv2m, because
it is weird and clunky, and you'd think people would rather use
MSI-X.

Turns out there is still plenty of devices out there that rely
on Multi-MSI. Oh well, let's teach that trick to the v2m widget,
it is not a big deal anyway.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 95a25625

drivers/irqchip/irq-gic-v2m.c

+22 −24
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static struct irq_chip gicv2m_msi_irq_chip = { 


static struct msi_domain_info gicv2m_msi_domain_info = {

	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |

		   MSI_FLAG_PCI_MSIX),

		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),

	.chip	= &gicv2m_msi_irq_chip,

};
@@ -155,18 +155,12 @@ static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain, 
	return 0;

}



static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq)

static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,

			       int nr_irqs)

{

	int pos;



	pos = hwirq - v2m->spi_start;

	if (pos < 0 || pos >= v2m->nr_spis) {

		pr_err("Failed to teardown msi. Invalid hwirq %d\n", hwirq);

		return;

	}



	spin_lock(&v2m_lock);

	__clear_bit(pos, v2m->bm);

	bitmap_release_region(v2m->bm, hwirq - v2m->spi_start,

			      get_count_order(nr_irqs));

	spin_unlock(&v2m_lock);

}
@@ -174,13 +168,13 @@ static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 
				   unsigned int nr_irqs, void *args)

{

	struct v2m_data *v2m = NULL, *tmp;

	int hwirq, offset, err = 0;

	int hwirq, offset, i, err = 0;



	spin_lock(&v2m_lock);

	list_for_each_entry(tmp, &v2m_nodes, entry) {

		offset = find_first_zero_bit(tmp->bm, tmp->nr_spis);

		if (offset < tmp->nr_spis) {

			__set_bit(offset, tmp->bm);

		offset = bitmap_find_free_region(tmp->bm, tmp->nr_spis,

						 get_count_order(nr_irqs));

		if (offset >= 0) {

			v2m = tmp;

			break;

		}
@@ -192,16 +186,21 @@ static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 


	hwirq = v2m->spi_start + offset;



	err = gicv2m_irq_gic_domain_alloc(domain, virq, hwirq);

	if (err) {

		gicv2m_unalloc_msi(v2m, hwirq);

		return err;

	}

	for (i = 0; i < nr_irqs; i++) {

		err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i);

		if (err)

			goto fail;



	irq_domain_set_hwirq_and_chip(domain, virq, hwirq,

		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,

					      &gicv2m_irq_chip, v2m);

	}



	return 0;



fail:

	irq_domain_free_irqs_parent(domain, virq, nr_irqs);

	gicv2m_unalloc_msi(v2m, hwirq, get_count_order(nr_irqs));

	return err;

}



static void gicv2m_irq_domain_free(struct irq_domain *domain,
@@ -210,8 +209,7 @@ static void gicv2m_irq_domain_free(struct irq_domain *domain, 
	struct irq_data *d = irq_domain_get_irq_data(domain, virq);

	struct v2m_data *v2m = irq_data_get_irq_chip_data(d);



	BUG_ON(nr_irqs != 1);

	gicv2m_unalloc_msi(v2m, d->hwirq);

	gicv2m_unalloc_msi(v2m, d->hwirq, nr_irqs);

	irq_domain_free_irqs_parent(domain, virq, nr_irqs);

}

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