From patchwork Thu May 27 08:45:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 449351 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5091C4707F for ; Thu, 27 May 2021 08:49:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3BF761222 for ; Thu, 27 May 2021 08:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235786AbhE0Iuh (ORCPT ); Thu, 27 May 2021 04:50:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235721AbhE0IuT (ORCPT ); Thu, 27 May 2021 04:50:19 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 435FFC06135D for ; Thu, 27 May 2021 01:48:30 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lmBgq-0002QB-JZ for netdev@vger.kernel.org; Thu, 27 May 2021 10:48:28 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id ED04A62D423 for ; Thu, 27 May 2021 08:45:38 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id D82B862D3DE; Thu, 27 May 2021 08:45:34 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 543047b9; Thu, 27 May 2021 08:45:34 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Oliver Hartkopp , Marc Kleine-Budde Subject: [net-next 04/21] can: uapi: introduce CANFD_FDF flag for mixed content in struct canfd_frame Date: Thu, 27 May 2021 10:45:15 +0200 Message-Id: <20210527084532.1384031-5-mkl@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210527084532.1384031-1-mkl@pengutronix.de> References: <20210527084532.1384031-1-mkl@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Oliver Hartkopp The struct can_frame and struct canfd_frame intentionally share the same layout to be able to write CAN frame content into a CAN FD frame structure. When this is done the former differentiation via CAN_MTU / CANFD_MTU is lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of using struct canfd_frame for mixed CAN/CAN FD content (dual use). N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside of struct canfd_frame therefore the CANFD_FDF flag is disregarded by Linux. Link: https://lore.kernel.org/r/20170411134343.3089-1-socketcan@hartkopp.net Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/uapi/linux/can.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index ac5d7a31671f..90801ada2bbe 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -135,9 +135,18 @@ struct can_frame { * controller only the CANFD_BRS bit is relevant for real CAN controllers when * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make * sense for virtual CAN interfaces to test applications with echoed frames. + * + * The struct can_frame and struct canfd_frame intentionally share the same + * layout to be able to write CAN frame content into a CAN FD frame structure. + * When this is done the former differentiation via CAN_MTU / CANFD_MTU gets + * lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of + * using struct canfd_frame for mixed CAN / CAN FD content (dual use). + * N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside of + * struct canfd_frame therefore the CANFD_FDF flag is disregarded by Linux. */ #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */ #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */ +#define CANFD_FDF 0x04 /* mark CAN FD for dual use of struct canfd_frame */ /** * struct canfd_frame - CAN flexible data rate frame structure