Hi Oliver,
On 7/28/20 7:50 PM, Oliver O'Halloran wrote:
On Wed, Jul 29, 2020 at 8:35 AM Gustavo Romero <grom...@linux.ibm.com> wrote:
Currently pnv_ioda_setup_bus_dma() is outside of a CONFIG_IOMMU_API guard
and if CONFIG_IOMMU_API=n the build can fail if the compiler sets
-Werror=unused-function, because pnv_ioda_setup_bus_dma() is only used in
functions guarded by a CONFIG_IOMMU_API guard.
That issue can be easily reproduced using the skiroot_defconfig. For other
configs, like powernv_defconfig, that issue is hidden by the fact that
if CONFIG_IOMMU_SUPPORT is enabled plus other common IOMMU options, like
CONFIG_OF_IOMMU, by default CONFIG_IOMMU_API is enabled as well. Hence, for
powernv_defconfig, it's necessary to set CONFIG_IOMMU_SUPPORT=n to make the
build fail, because CONFIG_PCI=y and pci-ioda.c is included in the build,
but since CONFIG_IOMMU_SUPPORT=n the CONFIG_IOMMU_API is disabled, breaking
the build.
This commit fixes that build issue by moving the pnv_ioda_setup_bus_dma()
inside a CONFIG_IOMMU_API guard, so when CONFIG_IOMMU_API is disabled that
function is not defined.
I think a fix for this is already in -next.
Indeed.
For the records, it's fixed in -next by:
commit e3417faec526cbf97773dca691dcd743f5bfeb64
Author: Oliver O'Halloran <ooh...@gmail.com>
Date: Sun Jul 5 23:35:57 2020 +1000
powerpc/powernv: Move pnv_ioda_setup_bus_dma under CONFIG_IOMMU_API
pnv_ioda_setup_bus_dma() is only used when a passed through PE is
returned to the host. If the kernel is built without IOMMU support
this is dead code. Move it under the #ifdef with the rest of the
IOMMU API support.
Reported-by: kernel test robot <l...@intel.com>
Signed-off-by: Oliver O'Halloran <ooh...@gmail.com>
Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Link: https://lore.kernel.org/r/20200705133557.443607-2-ooh...@gmail.com
Thanks.
Cheers,
Gustavo
