irqchip/gic-v3-its: Don't map the MSI page in its_irq_compose_msi_msg() (35ae7df2) · Commits · 戴 / test

its_irq_compose_msi_msg() may be called from non-preemptible context. However, on RT, iommu_dma_map_msi_msg requires to be called from a preemptible context. A recent change split iommu_dma_map_msi_msg() in two new functions: one that should be called in preemptible context, the other does not have any requirement. The GICv3 ITS driver is reworked to avoid executing preemptible code in non-preemptible context. This can be achieved by preparing the MSI mapping when allocating the MSI interrupt. Signed-off-by:

Julien Grall <julien.grall@arm.com> Reviewed-by:

Eric Auger <eric.auger@redhat.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com>

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

+6 −1

Original line number	Diff line number	Diff line
		@@ -1178,7 +1178,7 @@ static void its_irq_compose_msi_msg(struct irq_data d, struct msi_msg msg)
		msg->address_hi = upper_32_bits(addr);
		msg->data = its_get_event_id(d);

		iommu_dma_map_msi_msg(d->irq, msg);
		iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg);
		}

		static int its_irq_set_irqchip_state(struct irq_data *d,
		@@ -2563,6 +2563,7 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
		{
		msi_alloc_info_t *info = args;
		struct its_device *its_dev = info->scratchpad[0].ptr;
		struct its_node *its = its_dev->its;
		irq_hw_number_t hwirq;
		int err;
		int i;
		@@ -2571,6 +2572,10 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
		if (err)
		return err;

		err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev));
		if (err)
		return err;

		for (i = 0; i < nr_irqs; i++) {
		err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
		if (err)

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