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Commit 8208d170 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size 



The way we allocate events works fine in most cases, except
when multiple PCI devices share an ITS-visible DevID, and that
one of them is trying to use MultiMSI allocation.

In that case, our allocation is not guaranteed to be zero-based
anymore, and we have to make sure we allocate it on a boundary
that is compatible with the PCI Multi-MSI constraints.

Fix this by allocating the full region upfront instead of iterating
over the number of MSIs. MSI-X are always allocated one by one,
so this shouldn't change anything on that front.

Fixes: b48ac83d ("irqchip: GICv3: ITS: MSI support")
Cc: stable@vger.kernel.org
Reported-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 8fa4e55b

drivers/irqchip/irq-gic-v3-its.c

+13 −12
Original line number Diff line number Diff line
@@ -2399,13 +2399,14 @@ static void its_free_device(struct its_device *its_dev) 
	kfree(its_dev);

}



static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)

static int its_alloc_device_irq(struct its_device *dev, int nvecs, irq_hw_number_t *hwirq)

{

	int idx;



	idx = find_first_zero_bit(dev->event_map.lpi_map,

				  dev->event_map.nr_lpis);

	if (idx == dev->event_map.nr_lpis)

	idx = bitmap_find_free_region(dev->event_map.lpi_map,

				      dev->event_map.nr_lpis,

				      get_count_order(nvecs));

	if (idx < 0)

		return -ENOSPC;



	*hwirq = dev->event_map.lpi_base + idx;
@@ -2501,21 +2502,21 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 
	int err;

	int i;



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

		err = its_alloc_device_irq(its_dev, &hwirq);

	err = its_alloc_device_irq(its_dev, nr_irqs, &hwirq);

	if (err)

		return err;



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

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

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

		if (err)

			return err;



		irq_domain_set_hwirq_and_chip(domain, virq + i,

					      hwirq, &its_irq_chip, its_dev);

					      hwirq + i, &its_irq_chip, its_dev);

		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq + i)));

		pr_debug("ID:%d pID:%d vID:%d\n",

			 (int)(hwirq - its_dev->event_map.lpi_base),

			 (int) hwirq, virq + i);

			 (int)(hwirq + i - its_dev->event_map.lpi_base),

			 (int)(hwirq + i), virq + i);

	}



	return 0;