The function 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 patch split the function iommu_dma_map_msi_msg in 2 functions:
one that should be called in preemptible context, the other does
not have any requirement.
This patch reworks the GICv3 ITS driver to avoid executing preemptible
code in non-preemptible context by preparing the MSI mapping when
allocating the MSI interrupt.
Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 7577755bdcf4..1e8e01797d9b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1179,7 +1179,7 @@ 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(d->irq, msg);
}
static int its_irq_set_irqchip_state(struct irq_data *d,
@@ -2566,6 +2566,7 @@ 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;
@@ -2574,6 +2575,8 @@ 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));
+
for (i = 0; i < nr_irqs; i++) {
err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
if (err)
--
2.11.0
