On Mon, 16 Sep 2019, Greg Kroah-Hartman wrote:
> > Upstream commit e4849aff1e16 ("MIPS: SiByte: Enable swiotlb for SWARM,
> > LittleSur and BigSur") results in build failures in v4.4.y and v4.14.y.
> >
> > make bigsur_defconfig:
> >
> > warning: (SIBYTE_SWARM && SIBYTE_SENTOSA && SIBYTE_BIGSUR && SWIOTLB_XEN && AMD_IOMMU) selects SWIOTLB which has unmet direct dependencies (CAVIUM_OCTEON_SOC || MACH_LOONGSON64 && CPU_LOONGSON3 || NLM_XLP_BOARD || NLM_XLR_BOARD)
> > warning: (SIBYTE_SWARM && SIBYTE_SENTOSA && SIBYTE_BIGSUR && SWIOTLB_XEN && AMD_IOMMU) selects SWIOTLB which has unmet direct dependencies (CAVIUM_OCTEON_SOC || MACH_LOONGSON64 && CPU_LOONGSON3 || NLM_XLP_BOARD || NLM_XLR_BOARD)
> >
> > and the actual build:
> >
> > lib/swiotlb.o: In function `swiotlb_tbl_map_single':
> > (.text+0x1c0): undefined reference to `iommu_is_span_boundary'
> > Makefile:1021: recipe for target 'vmlinux' failed
> >
> > Please revert.
>
> Shouldn't I also revert it in 4.9.y?
NB there's certainly a dependency of some kind between this series and
Christoph's swiotlb rework, which preceded it just a little, so I'm not at
all surprised it can't be backported to the beginning of time without also
pulling a pile of other changes.
Thank you both for taking care of this revert.
Maciej
