From: Ian Munsie <redacted>

Some of the MSI IRQ code in pnv_pci_ioda_msi_setup() is generically useful so
split it out.

This will be used by some of the cxl PCIe code later.

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index df241b1..329164f 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c

@@ -1306,14 +1306,36 @@ static void pnv_ioda2_msi_eoi(struct irq_data *d)
 	icp_native_eoi(d);
 }
 
+
+static void set_msi_irq_chip(struct pnv_phb *phb, unsigned int virq)
+{
+	struct irq_data *idata;
+	struct irq_chip *ichip;
+
+	if (phb->type != PNV_PHB_IODA2)
+		return;
+
+	/*
+	 * Change the IRQ chip for the MSI interrupts on PHB3.
+	 * The corresponding IRQ chip should be populated for
+	 * the first time.