[PATCH 10/10] ACPI: IORT: Allow COMPILE_TEST of IORT

[Lorenzo Pieralisi]

On Tue, Nov 28, 2023 at 08:48:06PM -0400, Jason Gunthorpe wrote:
> The arm-smmu driver can COMPILE_TEST on x86, so expand this to also
> enable the IORT code so it can be COMPILE_TEST'd too.
> 
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>  drivers/acpi/Kconfig        | 2 --
>  drivers/acpi/Makefile       | 2 +-
>  drivers/acpi/arm64/Kconfig  | 1 +
>  drivers/acpi/arm64/Makefile | 2 +-
>  drivers/iommu/Kconfig       | 1 +
>  5 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index f819e760ff195a..3b7f77b227d13a 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -541,9 +541,7 @@ config ACPI_PFRUT
>  	  To compile the drivers as modules, choose M here:
>  	  the modules will be called pfr_update and pfr_telemetry.
>  
> -if ARM64
>  source "drivers/acpi/arm64/Kconfig"
> -endif
>  
>  config ACPI_PPTT
>  	bool
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index eaa09bf52f1760..4e77ae37b80726 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -127,7 +127,7 @@ obj-y				+= pmic/
>  video-objs			+= acpi_video.o video_detect.o
>  obj-y				+= dptf/
>  
> -obj-$(CONFIG_ARM64)		+= arm64/
> +obj-y				+= arm64/
>  
>  obj-$(CONFIG_ACPI_VIOT)		+= viot.o
>  
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> index b3ed6212244c1e..537d49d8ace69e 100644
> --- a/drivers/acpi/arm64/Kconfig
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -11,6 +11,7 @@ config ACPI_GTDT
>  
>  config ACPI_AGDI
>  	bool "Arm Generic Diagnostic Dump and Reset Device Interface"
> +	depends on ARM64
>  	depends on ARM_SDE_INTERFACE
>  	help
>  	  Arm Generic Diagnostic Dump and Reset Device Interface (AGDI) is
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> index 143debc1ba4a9d..71d0e635599390 100644
> --- a/drivers/acpi/arm64/Makefile
> +++ b/drivers/acpi/arm64/Makefile
> @@ -4,4 +4,4 @@ obj-$(CONFIG_ACPI_IORT) 	+= iort.o
>  obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
>  obj-$(CONFIG_ACPI_APMT) 	+= apmt.o
>  obj-$(CONFIG_ARM_AMBA)		+= amba.o
> -obj-y				+= dma.o init.o
> +obj-$(CONFIG_ARM64)		+= dma.o init.o
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 7673bb82945b6c..309378e76a9bc9 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -318,6 +318,7 @@ config ARM_SMMU
>  	select IOMMU_API
>  	select IOMMU_IO_PGTABLE_LPAE
>  	select ARM_DMA_USE_IOMMU if ARM
> +	select ACPI_IORT if ACPI
>  	help
>  	  Support for implementations of the ARM System MMU architecture
>  	  versions 1 and 2.
> -- 

I don't think it should be done this way. Is the goal compile testing
IORT code ? If so, why are we forcing it through the SMMU (only because
it can be compile tested while eg SMMUv3 driver can't ?) menu entry ?

This looks a bit artificial (and it is unclear from the Kconfig
file why only that driver selects IORT, it looks like eg the SMMUv3
does not have the same dependency - there is also the SMMUv3 perf
driver to consider).

Maybe we can move IORT code into drivers/acpi and add a silent config
option there with a dependency on ARM64 || COMPILE_TEST.

Don't know but at least it is clearer. As for the benefits of compile
testing IORT code - yes the previous patch is a warning to fix but
I am not so sure about the actual benefits.

Thanks,
Lorenzo