powerpc/pseries/msi: Add an empty irq_write_msi_msg() handler

[sfrench/cifs-2.6.git] / arch / powerpc / platforms / pseries / msi.c

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index 1b305e4118622af70561daf8887b19ff2dcf101f..8627362f613ee51d931246731f7a85281ca2af3b 100644 (file)
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -507,12 +507,27 @@ static void pseries_msi_unmask(struct irq_data *d)
        irq_chip_unmask_parent(d);
 }
 
+static void pseries_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
+{
+       struct msi_desc *entry = irq_data_get_msi_desc(data);
+
+       /*
+        * Do not update the MSIx vector table. It's not strictly necessary
+        * because the table is initialized by the underlying hypervisor, PowerVM
+        * or QEMU/KVM. However, if the MSIx vector entry is cleared, any further
+        * activation will fail. This can happen in some drivers (eg. IPR) which
+        * deactivate an IRQ used for testing MSI support.
+        */
+       entry->msg = *msg;
+}
+
 static struct irq_chip pseries_pci_msi_irq_chip = {
        .name           = "pSeries-PCI-MSI",
        .irq_shutdown   = pseries_msi_shutdown,
        .irq_mask       = pseries_msi_mask,
        .irq_unmask     = pseries_msi_unmask,
        .irq_eoi        = irq_chip_eoi_parent,
+       .irq_write_msi_msg      = pseries_msi_write_msg,
 };
 
 static struct msi_domain_info pseries_msi_domain_info = {