[RFC v4 2/7] PCI: Allow msi domain set-up at host probing time

[Boqun Feng <boqun.feng@gmail.com>]

For GENERIC_MSI_IRQ_DOMAIN drivers, we can set up the msi domain via
dev_set_msi_domain() at probing time, and drivers can use this more
generic way to set up the msi domain for the host bridge.

This is the preparation for ARM64 Hyper-V PCI support.

Originally-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 drivers/pci/probe.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 60c50d4f156f..539b5139e376 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -829,11 +829,14 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
 {
 	struct irq_domain *d;
 
+	/* Default set by host bridge driver */
+	d = dev_get_msi_domain(bus->bridge);
 	/*
 	 * Any firmware interface that can resolve the msi_domain
 	 * should be called from here.
 	 */
-	d = pci_host_bridge_of_msi_domain(bus);
+	if (!d)
+		d = pci_host_bridge_of_msi_domain(bus);
 	if (!d)
 		d = pci_host_bridge_acpi_msi_domain(bus);
 
-- 
2.30.2