[PATCH v2 4/7] irqchip: Have CONFIG_IRQ_MSI_IOMMU be selected by irqchips that need it

[Thomas Gleixner]

On Wed, Feb 19 2025 at 17:31, Nicolin Chen wrote:

> From: Jason Gunthorpe <jgg at nvidia.com>
>
> Currently, IRQ_MSI_IOMMU is selected if DMA_IOMMU is available to provide
> an implementation for iommu_dma_prepare/compose_msi_msg(). However, it'll
> make more sense for irqchips that call prepare/compose to select it, and
> that will trigger all the additional code and data to be compiled into
> the kernel.
>
> If IRQ_MSI_IOMMU is selected with no IOMMU side implementation, then the
> prepare/compose() will be NOP stubs.
>
> If IRQ_MSI_IOMMU is not selected by an irqchip, then the related code on
> the iommu side is compiled out.
>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>

Reviewed-by: Thomas Gleixner <tglx at linutronix.de>

I don't think I have conflicting changes here, so the MSI/IRQ related
changes can be routed through the IOMMU tree along with the rest.

Thanks,

        tglx