Re: [PATCH v3 3/6] iommu: Improve iommu_iotlb_gather helpers

[Nadav Amit <nadav.amit@gmail.com>]

> On Jun 15, 2021, at 12:05 PM, Nadav Amit <nadav.amit@gmail.com> wrote:
> 
> 
> 
>> On Jun 15, 2021, at 3:42 AM, Robin Murphy <robin.murphy@arm.com> wrote:
>> 
>> On 2021-06-07 19:25, Nadav Amit wrote:
>>> From: Robin Murphy <robin.murphy@arm.com>
>>> The Mediatek driver is not the only one which might want a basic
>>> address-based gathering behaviour, so although it's arguably simple
>>> enough to open-code, let's factor it out for the sake of cleanliness.
>>> Let's also take this opportunity to document the intent of these
>>> helpers for clarity.
>>> Cc: Joerg Roedel <joro@8bytes.org>
>>> Cc: Will Deacon <will@kernel.org>
>>> Cc: Jiajun Cao <caojiajun@vmware.com>
>>> Cc: Robin Murphy <robin.murphy@arm.com>
>>> Cc: Lu Baolu <baolu.lu@linux.intel.com>
>>> Cc: iommu@lists.linux-foundation.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> 
>> Nit: missing your signoff.
>> 
>>> ---
>>> Changes from Robin's version:
>>> * Added iommu_iotlb_gather_add_range() stub !CONFIG_IOMMU_API
>> 
>> Out of curiosity, is there any config in which a stub is actually needed? Unlike iommu_iotlb_gather_init(), I would have thought that these helpers should only ever be called by driver code which already depends on IOMMU_API.
> 
> Indeed, this was only done as a defensive step.
> 
> I will remove it. I see no reason for it. Sorry for ruining your patch.

And remove the stub for iommu_iotlb_gather_is_disjoint() as well.