[PATCH v3 5/7] irqchip/ls-scfg-msi: Don't map the MSI page in ls_scfg_msi_compose_msg()

Julien Grall
2019-05-01T13:58:22Z

ls_scfg_msi_compose_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 FreeScale SCFG MSI driver is reworked to avoid executing preemptible
code in non-preemptible context. This can be achieved by preparing the
MSI maping when allocating the MSI interrupt.

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

---
Changes in v2:
- Rework the commit message to use imperative mood
---
drivers/irqchip/irq-ls-scfg-msi.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-ls-scfg-msi.c b/drivers/irqchip/irq-ls-scfg-msi.c
index c671b3212010..669d29105772 100644
--- a/drivers/irqchip/irq-ls-scfg-msi.c
+++ b/drivers/irqchip/irq-ls-scfg-msi.c
@@ -100,7 +100,7 @@ static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
msg->data |= cpumask_first(mask);
}

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

static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
@@ -141,6 +141,7 @@ static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
unsigned int nr_irqs,
void *args)
{
+ msi_alloc_info_t *info = args;
struct ls_scfg_msi *msi_data = domain->host_data;
int pos, err = 0;

@@ -157,6 +158,10 @@ static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
if (err)
return err;

+ err = iommu_dma_prepare_msi(info->desc, msi_data->msiir_addr);
+ if (err)
+ return err;
+
irq_domain_set_info(domain, virq, pos,
&ls_scfg_msi_parent_chip, msi_data,
handle_simple_irq, NULL, NULL);
--
2.11.0