[PATCH 2/3] powerpc/pci: unmap legacy INTx interrupts of passthrough IO adapters

["Cédric Le Goater" <clg@kaod.org>]

When a passthrough IO adapter is removed from a pseries machine using
hash MMU and the XIVE interrupt mode, the POWER hypervisor, pHyp,
expects the guest OS to have cleared all page table entries related to
the adapter. If some are still present, the RTAS call which isolates
the PCI slot returns error 9001 "valid outstanding translations" and
the removal of the IO adapter fails.

INTx interrupt numbers need special care because Linux maps the
interrupts automatically in the Linux interrupt number space if they
are presented in the device tree node describing the IO adapter. These
interrupts are not un-mapped automatically and in case of an hot-plug
adapter, the PCI hot-plug layer needs to handle the cleanup to make
sure that all the page table entries of the XIVE ESB pages are
cleared.

Cc: "Oliver O'Halloran" <oohall@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/powerpc/kernel/pci-hotplug.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c
index bf83f76563a3..9e9c6befd7ea 100644
--- a/arch/powerpc/kernel/pci-hotplug.c
+++ b/arch/powerpc/kernel/pci-hotplug.c
@@ -57,6 +57,8 @@ void pcibios_release_device(struct pci_dev *dev)
 	struct pci_controller *phb = pci_bus_to_host(dev->bus);
 	struct pci_dn *pdn = pci_get_pdn(dev);
 
+	irq_dispose_mapping(dev->irq);
+
 	eeh_remove_device(dev);
 
 	if (phb->controller_ops.release_device)
-- 
2.25.4