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Subject: Re: [PATCH v3 3/6] iommu: Improve iommu_iotlb_gather helpers
From:   Nadav Amit <nadav.amit@gmail.com>
In-Reply-To: <07969028-d807-cad1-2a01-8efc87390157@arm.com>
Date:   Tue, 15 Jun 2021 12:05:11 -0700
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Jiajun Cao <caojiajun@vmware.com>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
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Message-Id: <25B4DBA5-72A3-4122-8678-AF3500F5023E@gmail.com>
References: <20210607182541.119756-1-namit@vmware.com>
 <20210607182541.119756-4-namit@vmware.com>
 <07969028-d807-cad1-2a01-8efc87390157@arm.com>
To:     Robin Murphy <robin.murphy@arm.com>
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> On Jun 15, 2021, at 3:42 AM, Robin Murphy <robin.murphy@arm.com> =
wrote:
>=20
> 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>
>=20
> Nit: missing your signoff.
>=20
>> ---
>> Changes from Robin's version:
>> * Added iommu_iotlb_gather_add_range() stub !CONFIG_IOMMU_API
>=20
> 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.