From mboxrd@z Thu Jan 1 00:00:00 1970 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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 18FB4C433DB for ; Sat, 30 Jan 2021 05:13:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD66064DE2 for ; Sat, 30 Jan 2021 05:13:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233660AbhA3FM6 (ORCPT ); Sat, 30 Jan 2021 00:12:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229619AbhA3FA1 (ORCPT ); Sat, 30 Jan 2021 00:00:27 -0500 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8EC2C061573; Fri, 29 Jan 2021 20:59:42 -0800 (PST) Received: by mail-pf1-x42a.google.com with SMTP id m6so7537259pfk.1; Fri, 29 Jan 2021 20:59:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=iuWsF8GDl/hi9MxuXzy2n4gX9Xml0dieu92Tb2P0Obw=; b=uuAZ7w9gMS/po3hziG54J7JhVOhSPc9YguELWtu4lK2bZIBX1QQHUlgf8TfbqITj+W +X+I/w+67aHJClZC/822/6x3fYwgBvw61vF9dzhyJrxTPuRGG1Nlc8/T1aZsuT2aU/u5 pfcT72QnFyByl1pftmipjHpIGilcjirPJ76LYLqVcLRiTyatBfAyqAFBg5rI4VqBR660 QNCIb8Z+osMJ1XZYYuCgiel8pgG3HASC8VlubOLBXtOE0FfTFVvJsom4zocaWLNPGCJN ZlOIeqkc4Y7GXPNO4Q/lxT3DcVEfZ4Dhe/auKmkOlunOB+uLfSmtyI/urM3IpYX49kz6 96Ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=iuWsF8GDl/hi9MxuXzy2n4gX9Xml0dieu92Tb2P0Obw=; b=HZN1wxVd52CramPKt7Va9KuvPexzVye6g74dJB6NOvuCnNlgchnQBh92rey4OyLqC7 Kg+b5I1Ao0RUjebv53+Jzueeq61Uit2x3lW4lhCAcwqFEEbyyOA+8TA9eKuTeoANF6pp 21BhunUZIXpnrg5Gqtow3Ym3Yc8AlBqULWdgp+m5mGhLxzZ+ubr5/j+TCUIft1gOSkcY 3yEGaGbDEn/RQE6w4oUuAxVdMqQEcWgyebR27z8EuI2j36tEVECz7Jb8tz+EJetvAULq R0JzodWAAQqjSY97dczJRr5zXOpNvJeu6A7VDWEWVXcmaA/hl40A4+WQfr9AIoM+FXKT HgKQ== X-Gm-Message-State: AOAM530dNj/AEOricZtx+5K29cI9v7zosRRc1Gm6T2og594jkuUU56eN r3iQbWfIixO8N916xRWc0Z4= X-Google-Smtp-Source: ABdhPJwKSxuQV6xtbs3H20e4fo5ykBo6wQEM2X4e8TrZUG+ZaQQVEgQZpBjCyI1pZchR5sLW4mv+rA== X-Received: by 2002:a63:33c4:: with SMTP id z187mr7777053pgz.312.1611982782449; Fri, 29 Jan 2021 20:59:42 -0800 (PST) Received: from shinobu (113x33x126x33.ap113.ftth.ucom.ne.jp. [113.33.126.33]) by smtp.gmail.com with ESMTPSA id l2sm9463930pju.25.2021.01.29.20.59.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Jan 2021 20:59:41 -0800 (PST) Date: Sat, 30 Jan 2021 13:59:31 +0900 From: William Breathitt Gray To: David Lechner Cc: jic23@kernel.org, kernel@pengutronix.de, linux-stm32@st-md-mailman.stormreply.com, a.fatoum@pengutronix.de, kamel.bouhara@bootlin.com, gwendal@chromium.org, alexandre.belloni@bootlin.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, syednwaris@gmail.com, patrick.havelange@essensium.com, fabrice.gasnier@st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, Dan Carpenter Subject: Re: [PATCH v7 3/5] counter: Add character device interface Message-ID: References: <57bc509273bf288d74835e6ebdaebf27b4991888.1608935587.git.vilhelm.gray@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ELMJ14pDjrGcIjMp" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ELMJ14pDjrGcIjMp Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Dec 30, 2020 at 03:36:35PM -0600, David Lechner wrote: > On 12/25/20 6:15 PM, William Breathitt Gray wrote: >=20 > > diff --git a/include/uapi/linux/counter.h b/include/uapi/linux/counter.h > > new file mode 100644 > > index 000000000000..7585dc9db19d > > --- /dev/null > > +++ b/include/uapi/linux/counter.h > > @@ -0,0 +1,123 @@ > > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > > +/* > > + * Userspace ABI for Counter character devices > > + * Copyright (C) 2020 William Breathitt Gray > > + */ > > +#ifndef _UAPI_COUNTER_H_ > > +#define _UAPI_COUNTER_H_ > > + > > +#include > > +#include > > + > > +/* Component type definitions */ > > +enum counter_component_type { > > + COUNTER_COMPONENT_NONE, > > + COUNTER_COMPONENT_SIGNAL, > > + COUNTER_COMPONENT_COUNT, > > + COUNTER_COMPONENT_FUNCTION, > > + COUNTER_COMPONENT_SYNAPSE_ACTION, > > + COUNTER_COMPONENT_EXTENSION, > > +}; > > + > > +/* Component scope definitions */ > > +enum counter_scope { >=20 > Do we need COUNTER_SCOPE_NONE to go with COUNTER_COMPONENT_NONE? COUNTER_COMPONENT_NONE alone should be fine because it already indicates that the 'component' member of the struct counter_watch is to be ignored (i.e. type, scope, etc. will not be evaluated and that section of code is bypassed). > > + COUNTER_SCOPE_DEVICE, > > + COUNTER_SCOPE_SIGNAL, > > + COUNTER_SCOPE_COUNT, > > +}; > > + > > +/** > > + * struct counter_component - Counter component identification > > + * @type: component type (Count, extension, etc.) >=20 > Instead of "Count, extension, etc.", it could be more helpful > to say one of enum counter_component_type. Ack. > > + * @scope: component scope (Device, Count, or Signal) >=20 > Same here. @scope must be one of enum counter_scope. Ack. > > + * @parent: parent component identification number > > + * @id: component identification number >=20 > It could be helpful to say that these id numbers match > the X/Y/Z in the sysfs paths as described in the sysfs > ABI. Ack. > > + */ > > +struct counter_component { > > + __u8 type; > > + __u8 scope; > > + __u8 parent; > > + __u8 id; > > +}; > > + > > +/* Event type definitions */ > > +enum counter_event_type { > > + COUNTER_EVENT_OVERFLOW, > > + COUNTER_EVENT_UNDERFLOW, > > + COUNTER_EVENT_OVERFLOW_UNDERFLOW, > > + COUNTER_EVENT_THRESHOLD, > > + COUNTER_EVENT_INDEX, > > +}; > > + > > +/** > > + * struct counter_watch - Counter component watch configuration > > + * @component: component to watch when event triggers > > + * @event: event that triggers >=20 > It would be helpful to say that @event must be one of > enum counter_event_type. Ack. > > + * @channel: event channel >=20 > It would be useful to say that @channel should be 0 unless > a component has more than one event of the same type. I'll make this clearer. > > + */ > > +struct counter_watch { > > + struct counter_component component; > > + __u8 event; > > + __u8 channel; > > +}; > > + > > +/* ioctl commands */ > > +#define COUNTER_CLEAR_WATCHES_IOCTL _IO(0x3E, 0x00) > > +#define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x01, struct counter_watch) > > +#define COUNTER_LOAD_WATCHES_IOCTL _IO(0x3E, 0x02) > > + > > +/** > > + * struct counter_event - Counter event data > > + * @timestamp: best estimate of time of event occurrence, in nanosecon= ds > > + * @value: component value > > + * @watch: component watch configuration > > + * @errno: system error number > > + */ > > +struct counter_event { > > + __aligned_u64 timestamp; > > + __aligned_u64 value; > > + struct counter_watch watch; > > + __u8 errno; >=20 > There are error codes larger than 255. Probably better > make this __u32. Are error codes larger than 255 actually useful in this case? I noticed the exit() function will only return the least significant byte of status to the parent: https://man7.org/linux/man-pages/man3/exit.3.html William Breathitt Gray --ELMJ14pDjrGcIjMp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEk5I4PDJ2w1cDf/bghvpINdm7VJIFAmAU57MACgkQhvpINdm7 VJJRZRAApPY7C5W6wFI/RES8FynKQPvVbA8y2f9aCWjF2ir1uxdCF/vQQXNDxa46 O06eBUhB6NWeXG8bKWvCnQ+84mBbnH+v9wlXiX0NbYUhQ44kKSVcJ26n+78Vj5l0 tJTPLtIgtQktPuu8Uuqtzxh4LAvSd/vn2exidqqLfpsF3EwucLRQa/++j+/uXUTu fPp0zi9sLUUcohSDAgf404mllaRTyeivwHyqRoztLUN/QDWI42UakQYGmg1gRItu v3UHxYKh+mFpfWM28fJQXvqsErUZQpEfu3zwddn3rVSLpW/9Ja28NCPfIqR0dlhB 19OhtYT0MmfLpmuR+E+2M0ht41F2gJadXp7+/c8dZ3LsnOM7eqKZlH8/mgTlLRmm tphEIh/uAIN8jm7SACr2bH4VbjoTRfug56k5X25APg4TEYmRvrEBXlkOU7hOAKvx UA+7c5ql0QpeGRNQtztn7Cxt6agQNoZScmQ6y3wc2pWfC+dOZwiw/A+u1BrhrQ0Y gfFwZ2A/X8Q+oevhNzmwPq/zqiEyr60gmLPvt2RzznnjkzyCPq3EceHKe5DGGEA1 Vzo6UIaAihwYAB1nivmVg7wzMRnMf/mdTzkLjBrlkoZ6aGZBQV0BJAvXaYOsToV4 7SRyLCgmHi9e758Vdo6CH4B/k9wRoOQ0da6epTmoYDkp9u0hsTE= =zNAQ -----END PGP SIGNATURE----- --ELMJ14pDjrGcIjMp-- From mboxrd@z Thu Jan 1 00:00:00 1970 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=-5.7 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 5881FC433E0 for ; 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[113.33.126.33]) by smtp.gmail.com with ESMTPSA id l2sm9463930pju.25.2021.01.29.20.59.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Jan 2021 20:59:41 -0800 (PST) Date: Sat, 30 Jan 2021 13:59:31 +0900 From: William Breathitt Gray To: David Lechner Subject: Re: [PATCH v7 3/5] counter: Add character device interface Message-ID: References: <57bc509273bf288d74835e6ebdaebf27b4991888.1608935587.git.vilhelm.gray@gmail.com> MIME-Version: 1.0 In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210129_235945_164555_21859D1C X-CRM114-Status: GOOD ( 22.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kamel.bouhara@bootlin.com, gwendal@chromium.org, a.fatoum@pengutronix.de, mcoquelin.stm32@gmail.com, linux-iio@vger.kernel.org, patrick.havelange@essensium.com, alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de, Dan Carpenter , fabrice.gasnier@st.com, syednwaris@gmail.com, linux-stm32@st-md-mailman.stormreply.com, jic23@kernel.org, alexandre.torgue@st.com Content-Type: multipart/mixed; boundary="===============0864207882739807141==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============0864207882739807141== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ELMJ14pDjrGcIjMp" Content-Disposition: inline --ELMJ14pDjrGcIjMp Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Dec 30, 2020 at 03:36:35PM -0600, David Lechner wrote: > On 12/25/20 6:15 PM, William Breathitt Gray wrote: >=20 > > diff --git a/include/uapi/linux/counter.h b/include/uapi/linux/counter.h > > new file mode 100644 > > index 000000000000..7585dc9db19d > > --- /dev/null > > +++ b/include/uapi/linux/counter.h > > @@ -0,0 +1,123 @@ > > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > > +/* > > + * Userspace ABI for Counter character devices > > + * Copyright (C) 2020 William Breathitt Gray > > + */ > > +#ifndef _UAPI_COUNTER_H_ > > +#define _UAPI_COUNTER_H_ > > + > > +#include > > +#include > > + > > +/* Component type definitions */ > > +enum counter_component_type { > > + COUNTER_COMPONENT_NONE, > > + COUNTER_COMPONENT_SIGNAL, > > + COUNTER_COMPONENT_COUNT, > > + COUNTER_COMPONENT_FUNCTION, > > + COUNTER_COMPONENT_SYNAPSE_ACTION, > > + COUNTER_COMPONENT_EXTENSION, > > +}; > > + > > +/* Component scope definitions */ > > +enum counter_scope { >=20 > Do we need COUNTER_SCOPE_NONE to go with COUNTER_COMPONENT_NONE? COUNTER_COMPONENT_NONE alone should be fine because it already indicates that the 'component' member of the struct counter_watch is to be ignored (i.e. type, scope, etc. will not be evaluated and that section of code is bypassed). > > + COUNTER_SCOPE_DEVICE, > > + COUNTER_SCOPE_SIGNAL, > > + COUNTER_SCOPE_COUNT, > > +}; > > + > > +/** > > + * struct counter_component - Counter component identification > > + * @type: component type (Count, extension, etc.) >=20 > Instead of "Count, extension, etc.", it could be more helpful > to say one of enum counter_component_type. Ack. > > + * @scope: component scope (Device, Count, or Signal) >=20 > Same here. @scope must be one of enum counter_scope. Ack. > > + * @parent: parent component identification number > > + * @id: component identification number >=20 > It could be helpful to say that these id numbers match > the X/Y/Z in the sysfs paths as described in the sysfs > ABI. Ack. > > + */ > > +struct counter_component { > > + __u8 type; > > + __u8 scope; > > + __u8 parent; > > + __u8 id; > > +}; > > + > > +/* Event type definitions */ > > +enum counter_event_type { > > + COUNTER_EVENT_OVERFLOW, > > + COUNTER_EVENT_UNDERFLOW, > > + COUNTER_EVENT_OVERFLOW_UNDERFLOW, > > + COUNTER_EVENT_THRESHOLD, > > + COUNTER_EVENT_INDEX, > > +}; > > + > > +/** > > + * struct counter_watch - Counter component watch configuration > > + * @component: component to watch when event triggers > > + * @event: event that triggers >=20 > It would be helpful to say that @event must be one of > enum counter_event_type. Ack. > > + * @channel: event channel >=20 > It would be useful to say that @channel should be 0 unless > a component has more than one event of the same type. I'll make this clearer. > > + */ > > +struct counter_watch { > > + struct counter_component component; > > + __u8 event; > > + __u8 channel; > > +}; > > + > > +/* ioctl commands */ > > +#define COUNTER_CLEAR_WATCHES_IOCTL _IO(0x3E, 0x00) > > +#define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x01, struct counter_watch) > > +#define COUNTER_LOAD_WATCHES_IOCTL _IO(0x3E, 0x02) > > + > > +/** > > + * struct counter_event - Counter event data > > + * @timestamp: best estimate of time of event occurrence, in nanosecon= ds > > + * @value: component value > > + * @watch: component watch configuration > > + * @errno: system error number > > + */ > > +struct counter_event { > > + __aligned_u64 timestamp; > > + __aligned_u64 value; > > + struct counter_watch watch; > > + __u8 errno; >=20 > There are error codes larger than 255. Probably better > make this __u32. Are error codes larger than 255 actually useful in this case? I noticed the exit() function will only return the least significant byte of status to the parent: https://man7.org/linux/man-pages/man3/exit.3.html William Breathitt Gray --ELMJ14pDjrGcIjMp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEk5I4PDJ2w1cDf/bghvpINdm7VJIFAmAU57MACgkQhvpINdm7 VJJRZRAApPY7C5W6wFI/RES8FynKQPvVbA8y2f9aCWjF2ir1uxdCF/vQQXNDxa46 O06eBUhB6NWeXG8bKWvCnQ+84mBbnH+v9wlXiX0NbYUhQ44kKSVcJ26n+78Vj5l0 tJTPLtIgtQktPuu8Uuqtzxh4LAvSd/vn2exidqqLfpsF3EwucLRQa/++j+/uXUTu fPp0zi9sLUUcohSDAgf404mllaRTyeivwHyqRoztLUN/QDWI42UakQYGmg1gRItu v3UHxYKh+mFpfWM28fJQXvqsErUZQpEfu3zwddn3rVSLpW/9Ja28NCPfIqR0dlhB 19OhtYT0MmfLpmuR+E+2M0ht41F2gJadXp7+/c8dZ3LsnOM7eqKZlH8/mgTlLRmm tphEIh/uAIN8jm7SACr2bH4VbjoTRfug56k5X25APg4TEYmRvrEBXlkOU7hOAKvx UA+7c5ql0QpeGRNQtztn7Cxt6agQNoZScmQ6y3wc2pWfC+dOZwiw/A+u1BrhrQ0Y gfFwZ2A/X8Q+oevhNzmwPq/zqiEyr60gmLPvt2RzznnjkzyCPq3EceHKe5DGGEA1 Vzo6UIaAihwYAB1nivmVg7wzMRnMf/mdTzkLjBrlkoZ6aGZBQV0BJAvXaYOsToV4 7SRyLCgmHi9e758Vdo6CH4B/k9wRoOQ0da6epTmoYDkp9u0hsTE= =zNAQ -----END PGP SIGNATURE----- --ELMJ14pDjrGcIjMp-- --===============0864207882739807141== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============0864207882739807141==--