Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   "Wu, Hao" <hao.wu@intel.com>
To:     "matthew.gerlach@linux.intel.com" <matthew.gerlach@linux.intel.com>,
        "Xu, Yilun" <yilun.xu@intel.com>,
        "Weight, Russell H" <russell.h.weight@intel.com>,
        "Muddebihal, Basheer Ahmed" <basheer.ahmed.muddebihal@intel.com>,
        "trix@redhat.com" <trix@redhat.com>,
        "mdf@kernel.org" <mdf@kernel.org>,
        "corbet@lwn.net" <corbet@lwn.net>,
        "linux-fpga@vger.kernel.org" <linux-fpga@vger.kernel.org>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Williams, Dan J" <dan.j.williams@intel.com>,
        "Raj, Ashok" <ashok.raj@intel.com>,
        "Zhang, Tianfei" <tianfei.zhang@intel.com>
Subject: RE: [PATCH v2 1/2] Documentation: fpga: dfl: add PCI Identification
 documentation
Thread-Topic: [PATCH v2 1/2] Documentation: fpga: dfl: add PCI Identification
 documentation
Thread-Index: AQHYLpZT7Z7itnhgnUS70d9Sjf19Wqy5mIFQ
Date:   Fri, 11 Mar 2022 04:16:51 +0000
Message-ID: <DM6PR11MB3819DB0E648AB7A2B85E1FD9850C9@DM6PR11MB3819.namprd11.prod.outlook.com>
References: <20220303003534.3307971-1-matthew.gerlach@linux.intel.com>
 <20220303003534.3307971-2-matthew.gerlach@linux.intel.com>
In-Reply-To: <20220303003534.3307971-2-matthew.gerlach@linux.intel.com>
Accept-Language: en-US
Content-Language: en-US
dlp-product: dlpe-windows
dlp-reaction: no-action
dlp-version: 11.6.401.20
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?MrtXHH6UMM6QWMb4qXxPZkJ0XnGPPcerU7uO7C310+WHjVYg/yWxZLTsRdhG?=
 =?us-ascii?Q?bfTuKSfRYDRKJLl6GUXrANu2nMcTqcfsz82rWoQ9It77Rl+3pSu/9OEyyDN+?=
 =?us-ascii?Q?hN8y12si5SDUjGOz8Jelng/IKzvayYwei6PXLUxVTIA+MVjKEC3Z6LW0ke4V?=
 =?us-ascii?Q?m5Mi91Jmrk/ee0Oitie8EkkTPeNBzX1aUNKOmTPamySKC0MTYx2AEu28N2QH?=
 =?us-ascii?Q?OymYH8/ufYqlv5tIcVSzIpwNlbtFmQpQuv2hqhJjnf6IcxYc2iZY+RMJdPoL?=
 =?us-ascii?Q?OS1IRmEHVmgEaF3A34/Oh9eZQfusDchKREpo2YKlinuPeAwfiTidFykHRdhk?=
 =?us-ascii?Q?4CX1UiqS3YFmbn6PfNKV0+cGhvBTJLSXakERYnjVeZyuid03O74tq4yoA836?=
 =?us-ascii?Q?+lfWi5OiLdm/TJOB0GJxDYTnhHc5AsmOff8mhpvfBVSe9uEyVRnFDXI/wOGP?=
 =?us-ascii?Q?qzYZFMruL9GyU8BcQ/62Ov0DWAysT+dPu7ZyGaN34bfir96I3z9GBUhBZdxW?=
 =?us-ascii?Q?wA1JOGMZtUb5cxmR/isoK7xtu0C+UsomqHiFrwAsuRjRj3H56klec9vfIq4b?=
 =?us-ascii?Q?OvIyvtSXxh4DqjmJ2JKMCB8VIwiidLdyWajBGCBx7I/G3J2w8yceHMTjPyKY?=
 =?us-ascii?Q?mb7VI3Vc9INYBbdIK8YUcSkyR9AZQOTPHRHunGouTKfIM+VqowRtGXSfwyp5?=
 =?us-ascii?Q?wT91tdgVsCKNaYEIvvisWYkA8pNclK5x8rbBY3XMNtjlEJCX1b9jG5vVmO01?=
 =?us-ascii?Q?PHNNPiCpG65q/CGnDAAfVdWRyENzVWf0Jt/h16Ke0KotKgJoG/DtFla5y0iv?=
 =?us-ascii?Q?JqgPZHfEJFNQ3u7PwNpUGBLs5p1yhkARW6sZAtHOgrm3RK6k+kkE47YZ+B90?=
 =?us-ascii?Q?poXhzhSbsbHWi6lmhhQtGPaon3ctVGDBhg4lmffbj2ltF6b9fRDZVw9KnbWR?=
 =?us-ascii?Q?Cazunzq3lxVXdAfl0R//8Ni63Yc92of5nAv9131xlIWHp4rJGGUenCFmohAq?=
 =?us-ascii?Q?50kTv6Qz66n8ZfD3OKRLHkTDWOIWvKu6VQI4aPe4GJsVbsL+5gwvxZktGOFi?=
 =?us-ascii?Q?7BPg03SD++FiR1kfqpXcYoz0PxUFTpd3YZKz4ijPTvSS7g6WLeoJo++5n2zP?=
 =?us-ascii?Q?aWjpcF7ubRnRVLOOGzQnyzpNSsMCCTXAiPLTSrk1rrYLRT0H/nGQTvwERpVP?=
 =?us-ascii?Q?cEppKPig7QMdF3U6K2d/noijrytptxOPTo97qz2/Yth4AFI8SHcL5UQi1W4f?=
 =?us-ascii?Q?s5fpu5fY5H/z83boX9mbFkvQ6zKukPpqs+P734pMZbQ3rajKrY8WzolGIol2?=
 =?us-ascii?Q?FO83ny3IkPFeqezEvKfiy0eGlxTTwsDNBAPFPhnrDKIlr9RIn5lM/NNKfjYt?=
 =?us-ascii?Q?/4qeh+Qi/W61wPdCaLah1UdQ5slGRAvcJAaL8Yfw8UjKCTYN63MCIXRP5xaM?=
 =?us-ascii?Q?6OBh0wJK2jb9Tk3hLGKBhVKOYc2NZQH6oUmOL5zttSBPPLpJl9aLA3/wzEhS?=
 =?us-ascii?Q?C2FMHXe3Qp2LTSc8N/7/3YGBTnzbDIyBBwCU9wh/Y3OmL/BEiqDWciKUWCC8?=
 =?us-ascii?Q?SpQ7sSUUBrUPjlw8UNL9JYvAE1whD6QfNqLUyKeuX/E+Lk7CyIwtvCrGFmvf?=
 =?us-ascii?Q?NrKdv53sSsu0bRdedc25DHQ=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: DM6PR11MB3819.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: b291fca9-eba2-415b-7783-08da0315f7c8
X-MS-Exchange-CrossTenant-originalarrivaltime: 11 Mar 2022 04:16:51.2028
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: nyIqWJDxAcCVQ25B343FyeiNYomPcahdv2wdDpKF4GWdjdqIJc0f9/zYP/L5i4f/TK/BgSp6H3CiixDmWYk65Q==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR11MB1559
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,
        SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> Subject: [PATCH v2 1/2] Documentation: fpga: dfl: add PCI Identification
> documentation
>=20
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>=20
> Add documentation on identifying FPGA based PCI cards prompted
> by discussion on the linux-fpga@vger.kernel.org mailing list.
>=20
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> ---
> v2: Introduced in v2.
> ---
>  Documentation/fpga/dfl.rst | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>=20
> diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> index ef9eec71f6f3..5fb2ca8e76d7 100644
> --- a/Documentation/fpga/dfl.rst
> +++ b/Documentation/fpga/dfl.rst
> @@ -502,6 +502,26 @@ Developer only needs to provide a sub feature driver
> with matched feature id.
>  FME Partial Reconfiguration Sub Feature driver (see drivers/fpga/dfl-fme=
-pr.c)
>  could be a reference.
>=20
> +PCI Device Identification
> +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D
> +Since FPGA based PCI cards can be reconfigured to a perform a completely
> +new function at runtime, properly identifying such cards and binding the
> +correct driver can be challenging. In many use cases, deployed FPGA base=
d
> +PCI cards are essentially static and the PCI Product ID and Vendor ID pa=
ir
> +is sufficient to identify the card.  The DFL framework helps with the
> +dynamic case of deployed FPGA cards changing at run time by providing
> +more detailed information about card discoverable at runtime.
> +
> +At one level, the DFL on a PCI card describes the function of the card.
> +However, the same DFL could be instantiated on different physical cards.
> +Conversely, different DFLs could be instantiated on the same physical ca=
rd.
> +Practical management of a cloud containing a heterogeneous set of such c=
ards
> +requires a PCI level of card identification. While the PCI Product ID an=
d
> +Vendor ID may be sufficient to bind the dfl-pci driver, it is expected
> +that FPGA PCI cards would advertise suitable Subsystem ID and Subsystem
> +Vendor ID values. PCI Vital Product Data (VPD) can also be used for
> +more granular information about the board.

I think PCI Device/Card Identification is out of scope of DFL. DFL is anoth=
er
level concept, it can't help to identify which card it is. There is no addi=
tional
requirement to users, they can choose any method they want, and they=20
don't have to reuse dfl-pci for their own cards.

> +
>  Location of DFLs on a PCI Device
>  =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D
>  The original method for finding a DFL on a PCI device assumed the start =
of the
> --
> 2.25.1