Re: [PATCH v8 2/7] iommu/arm-smmu-qcom-debug: Add support for TBUs

[Georgi Djakov]

Hi Will,

On 1.05.24 17:34, Will Deacon wrote:
> Hi Georgi,
>
> On Wed, Apr 17, 2024 at 06:37:26AM -0700, Georgi Djakov wrote:
> > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom-debug.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom-debug.c
> > index bb89d49adf8d..eff7ca94ec8d 100644
> > --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom-debug.c
> > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom-debug.c
>
> ...
>
> > +static const struct of_device_id qcom_tbu_of_match[] = {
> > +	{ .compatible = "qcom,sc7280-tbu" },
> > +	{ .compatible = "qcom,sdm845-tbu" },
> > +	{ }
> > +};
> > +
> > +static struct platform_driver qcom_tbu_driver = {
> > +	.driver = {
> > +		.name           = "qcom_tbu",
> > +		.of_match_table = qcom_tbu_of_match,
> > +	},
> > +	.probe = qcom_tbu_probe,
> > +};
> > +builtin_platform_driver(qcom_tbu_driver);
>
> I just noticed that this breaks a modular build of the arm-smmu driver
> because we now have two init functions for the module:
>
>    ld.lld: error: duplicate symbol: init_module
>    >>> defined at arm-smmu.c
>    >>>            drivers/iommu/arm/arm-smmu/arm-smmu.o:(init_module)
>    >>> defined at arm-smmu-qcom-debug.c
>    >>>            drivers/iommu/arm/arm-smmu/arm-smmu-qcom-debug.o:(.init.text+0x4)
>
> I think you should initialise the TBU debug feature by calling into it
> manually from qcom_smmu_impl_init().
>
> Please can you send a patch to fix that? For now, I'll bodge it so that
> the qcom debug stuff doesn't build as a module (see below).

Тhanks for sorting that out and apologies for missing it. We are at rc6 now and
i am afraid that i won't be able to validate my patch until next week (Easter
holidays here). I'll definitely send the rework when I get back.

BR,
Georgi

> Cheers,
>
> Will
>
> --->8
>
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 032bfd681307..66325210c8c9 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -376,7 +376,7 @@ config ARM_SMMU_QCOM
>
>   config ARM_SMMU_QCOM_DEBUG
>          bool "ARM SMMU QCOM implementation defined debug support"
> -       depends on ARM_SMMU_QCOM
> +       depends on ARM_SMMU_QCOM=y
>          help
>            Support for implementation specific debug features in ARM SMMU
>            hardware found in QTI platforms. This include support for