An aliasing PCI bridge is another case where we should flag the
corresponding allocation as "proxied", as MSIs are coming with
the bridge's RID, and not the originating device's.
Signed-off-by: Marc Zyngier <m...@kernel.org>
---
drivers/irqchip/irq-gic-v3-its-pci-msi.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 87711e0f8014..ad2810c017ed 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -67,11 +67,16 @@ static int its_pci_msi_prepare(struct irq_domain *domain,
struct device *dev,
/*
* If pdev is downstream of any aliasing bridges, take an upper
* bound of how many other vectors could map to the same DevID.
+ * Also tell the ITS that the signalling will come from a proxy
+ * device, and that special allocation rules apply.
*/
pci_for_each_dma_alias(pdev, its_get_pci_alias, &alias_dev);
- if (alias_dev != pdev && alias_dev->subordinate)
- pci_walk_bus(alias_dev->subordinate, its_pci_msi_vec_count,
- &alias_count);
+ if (alias_dev != pdev) {
+ if (alias_dev->subordinate)
+ pci_walk_bus(alias_dev->subordinate,
+ its_pci_msi_vec_count, &alias_count);
+ info->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE;
+ }
/* ITS specific DeviceID, as the core ITS ignores dev. */
info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
--
2.28.0
