Re: [PATCH v2 03/10] iommu/arm-smmu-v3: Look for existing iotlb tag in smmu_domain->invs

On Mon, Jan 26, 2026 at 05:03:01PM -0400, Jason Gunthorpe wrote:

On Wed, Jan 21, 2026 at 05:24:21PM -0800, Nicolin Chen wrote:

quoted

Once arm_smmu_attach_prepare() installs an iotlb tag to smmu_domain->invs,
arm_smmu_domain_get_iotlb_tag() callers should get the tag from the array.

Only the arm_smmu_domain_get_iotlb_tag() caller for new_smmu_domain in the
arm_smmu_attach_prepare_invs() will be allowed to allocate a new tag.

It would be nicer to have two functions 'alloc' and 'find' instead of
the bool. Alloc would call find.

Yea, that just came to me as well after seeing Will's comments
in another thread.

Nicolin