[PATCH 2/7] genirq/msi: Limit level-triggered MSI to platform devices

[Marc Zyngier]

Nobody would be insane enough to try and use level triggered
MSIs on PCI, but let's make sure it doesn't happen. Also,
let's mandate that the irqchip backing the platform MSI domain
is providing an irq_set_type method (or the whole thing would
be a bit useless).

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
 drivers/base/platform-msi.c | 3 +++
 drivers/pci/msi.c           | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 8e22073aeeed..3b9694a6beaa 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -101,6 +101,9 @@ static void platform_msi_update_chip_ops(struct msi_domain_info *info)
 		chip->irq_set_affinity = msi_domain_set_affinity;
 	if (!chip->irq_write_msi_msg)
 		chip->irq_write_msi_msg = platform_msi_write_msg;
+	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
+		    !chip->irq_set_type))
+		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
 }
 
 static void platform_msi_free_descs(struct device *dev, int base, int nvec)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 30250631efe7..f45b74fcc059 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1434,6 +1434,9 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
 {
 	struct irq_domain *domain;
 
+	if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
+		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
+
 	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 		pci_msi_domain_update_dom_ops(info);
 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
-- 
2.14.2