powerpc/pseries/pci: Add support of MSI domains to PHB hotplug

Simply allocate or release the MSI domains when a PHB is inserted in
or removed from the machine.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-11-clg@kaod.org

arch/powerpc/platforms/pseries/msi.c

@@ -733,6 +733,16 @@ int pseries_msi_allocate_domains(struct pci_controller *phb)
 	return __pseries_msi_allocate_domains(phb, count);
 }
 
+void pseries_msi_free_domains(struct pci_controller *phb)
+{
+	if (phb->msi_domain)
+		irq_domain_remove(phb->msi_domain);
+	if (phb->dev_domain)
+		irq_domain_remove(phb->dev_domain);
+	if (phb->fwnode)
+		irq_domain_free_fwnode(phb->fwnode);
+}
+
 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
 {
 	/* No LSI -> leave MSIs (if any) configured */

arch/powerpc/platforms/pseries/pci_dlpar.c

@@ -33,6 +33,8 @@ struct pci_controller *init_phb_dynamic(struct device_node *dn)
 
 	pci_devs_phb_init_dynamic(phb);
 
+	pseries_msi_allocate_domains(phb);
+
 	/* Create EEH devices for the PHB */
 	eeh_phb_pe_create(phb);
 
@@ -74,6 +76,8 @@ int remove_phb_dynamic(struct pci_controller *phb)
 		}
 	}
 
+	pseries_msi_free_domains(phb);
+
 	/* Remove the PCI bus and unregister the bridge device from sysfs */
 	phb->bus = NULL;
 	pci_remove_bus(b);

arch/powerpc/platforms/pseries/pseries.h

@@ -86,6 +86,7 @@ int pseries_root_bridge_prepare(struct pci_host_bridge *bridge);
 
 extern struct pci_controller_ops pseries_pci_controller_ops;
 int pseries_msi_allocate_domains(struct pci_controller *phb);
+void pseries_msi_free_domains(struct pci_controller *phb);
 
 unsigned long pseries_memory_block_size(void);