Commit 73103975 authored by Julien Grall's avatar Julien Grall Committed by Marc Zyngier
Browse files

irqchip/gic-v3-mbi: Don't map the MSI page in mbi_compose_m{b, s}i_msg() 



The functions mbi_compose_m{b, s}i_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 patch 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 MSI 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: default avatarJulien Grall <julien.grall@arm.com>
[maz: only call iommu_dma_prepare_msi once, fix commit log accordingly]
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 2cb3b165

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

+8 −2
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ static void mbi_free_msi(struct mbi_range *mbi, unsigned int hwirq, 
static int mbi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

				   unsigned int nr_irqs, void *args)

{

	msi_alloc_info_t *info = args;

	struct mbi_range *mbi = NULL;

	int hwirq, offset, i, err = 0;
@@ -104,6 +105,11 @@ static int mbi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 


	hwirq = mbi->spi_start + offset;



	err = iommu_dma_prepare_msi(info->desc,

				    mbi_phys_base + GICD_SETSPI_NSR);

	if (err)

		return err;



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

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

		if (err)
@@ -142,7 +148,7 @@ static void mbi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
	msg[0].address_lo = lower_32_bits(mbi_phys_base + GICD_SETSPI_NSR);

	msg[0].data = data->parent_data->hwirq;



	iommu_dma_map_msi_msg(data->irq, msg);

	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);

}



#ifdef CONFIG_PCI_MSI
@@ -202,7 +208,7 @@ static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg) 
	msg[1].address_lo = lower_32_bits(mbi_phys_base + GICD_CLRSPI_NSR);

	msg[1].data = data->parent_data->hwirq;



	iommu_dma_map_msi_msg(data->irq, &msg[1]);

	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), &msg[1]);

}



/* Platform-MSI specific irqchip */

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