drivers/vfio: Fix EEH build error

The VFIO related components could be built as dynamic modules.
Unfortunately, CONFIG_EEH can't be configured to "m". The patch
fixes the build errors when configuring VFIO related components
as dynamic modules as follows:

  CC [M]  drivers/vfio/vfio_iommu_spapr_tce.o
In file included from drivers/vfio/vfio.c:33:0:
include/linux/vfio.h:101:43: warning: ‘struct pci_dev’ declared \
inside parameter list [enabled by default]
   :
  WRAP    arch/powerpc/boot/zImage.pseries
  WRAP    arch/powerpc/boot/zImage.maple
  WRAP    arch/powerpc/boot/zImage.pmac
  WRAP    arch/powerpc/boot/zImage.epapr
  MODPOST 1818 modules
ERROR: ".vfio_spapr_iommu_eeh_ioctl" [drivers/vfio/vfio_iommu_spapr_tce.ko]\
undefined!
ERROR: ".vfio_spapr_pci_eeh_open" [drivers/vfio/pci/vfio-pci.ko] undefined!
ERROR: ".vfio_spapr_pci_eeh_release" [drivers/vfio/pci/vfio-pci.ko] undefined!

Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
drivers/vfio: Allow EEH to be built as module

This adds necessary declarations to the SPAPR VFIO EEH module,
otherwise multiple dynamic linker errors reported:

vfio_spapr_eeh: Unknown symbol eeh_pe_set_option (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_configure (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_reset (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_get_state (err 0)
vfio_spapr_eeh: Unknown symbol eeh_iommu_group_to_pe (err 0)
vfio_spapr_eeh: Unknown symbol eeh_dev_open (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_set_option (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_configure (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_reset (err 0)
vfio_spapr_eeh: Unknown symbol eeh_pe_get_state (err 0)
vfio_spapr_eeh: Unknown symbol eeh_iommu_group_to_pe (err 0)
vfio_spapr_eeh: Unknown symbol eeh_dev_open (err 0)

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
drivers/vfio: Enable VFIO if EEH is not supported

The existing vfio_pci_open() fails upon error returned from
vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
support which this patch brings back.

The patch fixes the issue by dropping the return value of
vfio_spapr_pci_eeh_open().

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>