Subject: [PATCH 2/2] iommu: Implement a dummy bus_set_iommu()

From: [email-masked] (Joerg Roedel)
Date: Wed, 22 Oct 2014 16:29:22 +0200

On Wed, Oct 15, 2014 at 11:10:44AM +0200, Thierry Reding wrote:
> It seems like I never got back to you on this. The reason here is that
> for Tegra the IOMMU is part of a larger IP block. The IP block is
> primarily a memory controller with a bunch of configuration knobs for
> arbitration, prioritization and whatnot. A smaller part of the device
> does the IOMMU translation. Therefore the IOMMU implementation would
> be part of a larger driver, and having this dummy would reduce the
> amount of #ifdefs required.
> 
> bus_set_iommu() is also the only function in include/linux/iommu.h that
> doesn't have a dummy, so it seemed like a natural thing to do.
> 
> That said, I can work around this being absent for !IOMMU_API.

Or you make this "larger driver" just depend on IOMMU_API? Otherwise you
need the #ifdefs anyway to not carry around the iommu-ops functions in
the driver without having the iommu core enabled, no?

	Joerg