Date:   Wed, 8 Feb 2023 17:38:49 +0100
From:   Maciej Fijalkowski <maciej.fijalkowski@intel.com>
To:     Vladimir Oltean <vladimir.oltean@nxp.com>
CC:     <netdev@vger.kernel.org>, "David S. Miller" <davem@davemloft.net>,
        "Eric Dumazet" <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= <bjorn@kernel.org>,
        Magnus Karlsson <magnus.karlsson@intel.com>,
        Alexei Starovoitov <ast@kernel.org>,
        "Daniel Borkmann" <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        <bpf@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH net-next 11/11] net: enetc: add TX support for
 zero-copy XDP sockets
Message-ID: <Y+PQGblCxIRqsYbP@boxer>
References: <20230206100837.451300-1-vladimir.oltean@nxp.com>
 <20230206100837.451300-12-vladimir.oltean@nxp.com>
 <20230206101921.zmslsxfzdm6ovxf5@skbuf>
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20230206101921.zmslsxfzdm6ovxf5@skbuf>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?n1EPNKWoxXFO5Ng793Gsk9rO0+0XWWpembJjcIf+iBYy18YpWf1XkqgfSTMW?=
 =?us-ascii?Q?T6wTa0O72+po4RnDN/gQcfDhR2T/rwLNLV+G344QOaNd56sf6LkEvzqC79P8?=
 =?us-ascii?Q?ENijo6KE0MPtH3mrXhmlG+8IG5PkDInj8qTYTZ/SE++SpcZ9ynpYAnPJoxe8?=
 =?us-ascii?Q?DI7O++nN27wYu/JM+F31jSazETsXyXBFtXaMY7IuSoGaodBy/c5Hvpr/pAR2?=
 =?us-ascii?Q?BcZwetGTwW68e74ZEabBqI7fByZd9o1OGSHloLFbabGcniUptPV4A16vrXFW?=
 =?us-ascii?Q?b3qyTzm2Q5qAklS65/Z1Y+lvE+dx2GWfgw9XGE2wSyVNy7p69qMCeWSi0KM0?=
 =?us-ascii?Q?wE3DZ+QOFOrt/lEiXII8fpCFEEpBSCjJtJ1tApAHpBvtXd/+8VklA8SnQztk?=
 =?us-ascii?Q?3GVtqAbx7uZfc3CB3cVoX6HFrECIO8YVbuA+VvfmQWDtsRgVgGaFLd6FBqvk?=
 =?us-ascii?Q?8Bqf6bkSZ3v4fZ2N7aXDwtxc0wxufCGfzOPCK0vDxaEcsqx2qtnrs18/QBeV?=
 =?us-ascii?Q?88/hMZV8E9MMAT3g3zO0vetZxdXYAgOvSt+BPSej9rA489uZ1GQJloNfbiZR?=
 =?us-ascii?Q?iW0YYXdTf+hXG1Pq8G+c0vk424WbuLtAuPnjwA6HRplzutbewxlKRv6pFZqT?=
 =?us-ascii?Q?GFIT7WQLmrTuIA1UHZ8e2CXSreXsiu2UtIiVX3oxrRmgYfG20Jx61UyBeabw?=
 =?us-ascii?Q?c96WaSJc1GWv0wH8SayxZzHrE7cGDY2UV23W54En2dD+rNduvvj9qbw04ai7?=
 =?us-ascii?Q?oPktTNN1H+hwetevP4m5NcSlkTCeMgTZnD4o5GbmXM3LhF4LAql5Ro3aB6wq?=
 =?us-ascii?Q?B3rJlF1+jwoexQnkMTdYVoCVkW89myM3uj/811YJ1SZ1fd5gH0wkHg02Pzzm?=
 =?us-ascii?Q?koYJFqBN/rfaot44nf6TSxWduKLcWVTRUZBvdJG9LuwQW/fgixru1UIX3ZoV?=
 =?us-ascii?Q?bCyR+OlotlrO3fF1+RUDalbMgHf0AoDLQEN8iu5E+rrfxYh6PZMYIR0js2Dv?=
 =?us-ascii?Q?OMyosaA9FTeQWZ6m0YKfLTn6D5pVt1n13TpCrJLvC7IYFsh708eW7KSnPPrz?=
 =?us-ascii?Q?UOHeXwvcRvLzXJ0m6WH2hR4TwRbAeqCOshK41oaUaBUNZMKrW2Dp0WZJw7zQ?=
 =?us-ascii?Q?TchcQ9wteXXTpqC/0b+fGMMtsPEbStzrZ8rGqimgeDc1vL8idyns/uespOvs?=
 =?us-ascii?Q?97yBTAzleC6cYhVJ0dORhqSO/e/CzlV5yuVE2BJfukylMyalyFOwISErUoO1?=
 =?us-ascii?Q?MLM0uCutcso5x23PMlEukjAdYzEyz0l0nAjunvnQrBsVZXWF7l3LoNlQDIvp?=
 =?us-ascii?Q?gJuZjqKj/ITctmrTl4AhjA3R60BXgLJ4XVBlm9JprRoTG8kn0wt/lZwM3U/I?=
 =?us-ascii?Q?2qD6zWkWrOZRoLGYljrNBNHzzRzSPbOdUd6UxPMfE1JsgeKrQLvIjEE8D191?=
 =?us-ascii?Q?Bongi3aIde2Jff7ON8KaJsCsmuyVUyMtzYyOxB5t3K01RysfBSzxg4K4zC1z?=
 =?us-ascii?Q?rjy7rhr8AmQtIW9kYn1VTs+qrgY3yfoCa3Tcvu4gWpWQdSlJ6oJnt1lx5mkw?=
 =?us-ascii?Q?svsTP/wGae7GHJ0+HqceXkz+n9PJqn1C6gEsgkJFQGwt43IdDFzD4E8I5X4t?=
 =?us-ascii?Q?NrjGOhFzona+vfese3ZSql4=3D?=
X-MS-Exchange-CrossTenant-Network-Message-Id: f3709080-ebe8-4792-b6e2-08db09f2f903
X-MS-Exchange-CrossTenant-AuthSource: DM4PR11MB6117.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Feb 2023 16:38:56.9593
 (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: QmbGdQUVSNXqzf68B7BOiuHRGRGSqhAusE+TXdtLhLYOS3vb1aSr8LujCOpuWAfd2N0TnwuPCBbjqGvvheuIuzuj+0ResGIG0SB06EEdoRo=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1PR11MB5026
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, Feb 06, 2023 at 12:19:21PM +0200, Vladimir Oltean wrote:
> Yikes, ran git format-patch one patch too soon. There's also a hidden,
> bonus patch "12/11" below. Doesn't affect first 11 patches in any way,
> though. Here it is.
> 
> From f7f10232622309d66a7a1ae1932d0c081936d546 Mon Sep 17 00:00:00 2001
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> Date: Tue, 25 Oct 2022 02:32:24 +0300
> Subject: [RFC PATCH net-next 12/12] net: enetc: add support for XDP_TX
>  with zero-copy XDP sockets
> 
> Add support for the case when the BPF program attached to a ring with an
> XSK pool returns the XDP_TX verdict. The frame needs to go back on the
> interface it came from.
> 
> No dma_map or dma_sync_for_device is necessary, just a small impedance
> matching logic with the XDP_TX procedure we have in place for non-XSK,
> since the data structures are different (xdp_buff vs xdp_frame; cannot
> have multi-buffer with XSK).
> 
> In the TX confirmation routine, just release the RX buffer (as opposed
> to non-XSK XDP_TX). Recycling might be possible, but I haven't
> experimented with it.

ugh premature response on 10/11.

> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
>  drivers/net/ethernet/freescale/enetc/enetc.c | 35 ++++++++++++++++++--
>  drivers/net/ethernet/freescale/enetc/enetc.h |  1 +
>  2 files changed, 34 insertions(+), 2 deletions(-)