powerpc/powernv/pci: Customize the MSI EOI handler to support PHB3

PHB3s need an extra OPAL call to EOI the interrupt. The call takes an
OPAL HW IRQ number but it is translated into a vector number in OPAL.
Here, we directly use the vector number of the in-the-middle "PNV-MSI"
domain instead of grabbing the OPAL HW IRQ number in the XICS parent
domain.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-22-clg@kaod.org

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -2169,12 +2169,33 @@ static void pnv_msi_compose_msg(struct irq_data *d, struct msi_msg *msg)
 			entry->msi_attrib.is_64 ? "64" : "32", d->hwirq, rc);
 }
 
+/*
+ * The IRQ data is mapped in the MSI domain in which HW IRQ numbers
+ * correspond to vector numbers.
+ */
+static void pnv_msi_eoi(struct irq_data *d)
+{
+	struct pci_controller *hose = irq_data_get_irq_chip_data(d);
+	struct pnv_phb *phb = hose->private_data;
+
+	if (phb->model == PNV_PHB_MODEL_PHB3) {
+		/*
+		 * The EOI OPAL call takes an OPAL HW IRQ number but
+		 * since it is translated into a vector number in
+		 * OPAL, use that directly.
+		 */
+		WARN_ON_ONCE(opal_pci_msi_eoi(phb->opal_id, d->hwirq));
+	}
+
+	irq_chip_eoi_parent(d);
+}
+
 static struct irq_chip pnv_msi_irq_chip = {
 	.name			= "PNV-MSI",
 	.irq_shutdown		= pnv_msi_shutdown,
 	.irq_mask		= irq_chip_mask_parent,
 	.irq_unmask		= irq_chip_unmask_parent,
-	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_eoi		= pnv_msi_eoi,
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 	.irq_compose_msi_msg	= pnv_msi_compose_msg,
 };