[RFC PATCH 1/4] iommu: build iova.c for any IOMMU

[thunder.leizhen@huawei.com (leizhen)]

On 2014/11/26 1:27, Robin Murphy wrote:
> In preparation for sharing the IOVA allocator, build it for all
> IOMMU API users.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/iommu/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index 16edef7..9f7910b 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -1,4 +1,4 @@
> -obj-$(CONFIG_IOMMU_API) += iommu.o
> +obj-$(CONFIG_IOMMU_API) += iommu.o iova.o

I'm not a maintainer, so just code review comment.

I don't known whether or not you will apply iova to all iommu drivers. But if only x86 and arm/arm64,
it's no good to force other iommu drivers to include iova.o, because they have not used it yet.

Maybe it's good to define a new config, like CONFIG_IOMMU_IOVA.

config INTEL_IOMMU
	select IOMMU_IOVA

config ARM_SMMU
	select IOMMU_IOVA

obj-$(CONFIG_IOMMU_IOVA) += iova.o

>  obj-$(CONFIG_IOMMU_API) += iommu-traces.o
>  obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
>  obj-$(CONFIG_OF_IOMMU)	+= of_iommu.o
> @@ -7,7 +7,7 @@ obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
>  obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o
>  obj-$(CONFIG_ARM_SMMU) += arm-smmu.o
>  obj-$(CONFIG_DMAR_TABLE) += dmar.o
> -obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
> +obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o
>  obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
>  obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
>  obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
>