Message-ID: <917b1d52-54c2-ea8b-5382-dbd8ce71a76c@linux.intel.com>
Date:   Wed, 1 Mar 2023 20:24:10 -0800
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Subject: Re: [PATCH v2 0/2] Add support to enable ATS on VFs independently
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To:     Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
        linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev,
        joro@8bytes.org, bhelgaas@google.com, robin.murphy@arm.com,
        will@kernel.org
Cc:     jean-philippe@linaro.org, darren@os.amperecomputing.com,
        scott@os.amperecomputing.com
References: <20230228042137.1941024-1-gankulkarni@os.amperecomputing.com>
From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
In-Reply-To: <20230228042137.1941024-1-gankulkarni@os.amperecomputing.com>
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On 2/27/23 8:21 PM, Ganapatrao Kulkarni wrote:
> As discussed in [1], adding a helper function to configure the STU of an
> ATS capability. Function pci_ats_stu_configure() can be called to program
> the STU while enumerating the PF, to support scenarios like PF is not
> enabled with ATS, whereas VFs can enable it.
> 
> In SMMU-V3 driver, calling pci_ats_stu_configure() to confgiure the STU
> while enumerating a PF in passthrough mode.

It looks like you are fixing this issue only for your platform. Is there any
way to generically program PF STU? May be from pci_ats_init()?

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer