[PATCH v4] iommu/rockchip: Add missing set_platform_dma_ops callback

[Heiko Stübner]

Am Freitag, 31. März 2023, 11:51:54 CEST schrieb Steven Price:
> Similar to exynos, we need a set_platform_dma_ops() callback for proper
> operation on ARM 32 bit after recent changes in the IOMMU framework
> (detach ops removal). But also the use of a NULL domain is confusing.
> 
> Rework the code to add support for IOMMU_DOMAIN_IDENTITY and a singleton
> rk_identity_domain which is assigned to domain when using an identity
> mapping rather than "detaching". This makes the code easier to reason about.
> 
> Signed-off-by: Steven Price <steven.price at arm.com>

My knowledge of IOMMU magic is not that deep. Nevertheless I do believe
to mostly understand the change and the splats on my rk3288-pinky are gone
now with this patch:

Acked-by: Heiko Stuebner <heiko at sntech.de>
Tested-by: Heiko Stuebner <heiko at sntech.de>