Hi Laurent, On 2012/12/17 2:25, Laurent Pinchart wrote: > Signed-off-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com> > --- > arch/arm/mach-shmobile/Kconfig | 6 ------ > arch/arm/mach-shmobile/Makefile | 3 --- > drivers/iommu/Kconfig | 6 ++++++ > drivers/iommu/Makefile | 1 + > .../ipmmu.c => drivers/iommu/shmobile-ipmmu.c | 0 > 5 files changed, 7 insertions(+), 9 deletions(-) > rename arch/arm/mach-shmobile/ipmmu.c => drivers/iommu/shmobile-ipmmu.c > (100%)
I agree that arch/arm is not a good place, but I'm not completely sure that ipmmu.c belongs in drivers/iommu. The reason is because of the PMB functionality provided by the IPMMU. The PMB provides a fixed address remapping capability that is completely unrelated to the IOMMU functionality. Since this remapping is done by writing the IPMMU registers directly, instead of via a page table it doesn't really fit in well with the IOMMU API (it also supports things like tiled/linear address translation, which require some other method to set up). Since the PMB and the IOMMU functions of the IPPMU share the same register address space, we would like to have one driver to handle the register accesses of both of these functions. That driver is ipmmu.c. So if ipmmu.c is in drivers/iommu, the entire IOMMU subsystem must be enabled in order to use the PMB functionality. So maybe it might be better to treat the IPMMU like a multifuction device, with a core driver (ipmmu.c) in one location and the function implementations in their own respective directories. Does drivers/mfd sound like a good place for it? Thanks, Damian. -- Damian Hobson-Garcia IGEL Co.,Ltd http://www.igel.co.jp -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
