From patchwork Mon Aug 9 12:37:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: William Breathitt Gray X-Patchwork-Id: 12426377 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 585C5C4338F for ; Mon, 9 Aug 2021 12:38:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F5C760F38 for ; Mon, 9 Aug 2021 12:38:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235468AbhHIMjM (ORCPT ); Mon, 9 Aug 2021 08:39:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235527AbhHIMjJ (ORCPT ); Mon, 9 Aug 2021 08:39:09 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F74CC061799; Mon, 9 Aug 2021 05:38:49 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id c16so16172780plh.7; Mon, 09 Aug 2021 05:38:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=501FGUGr+wDXj4ObY1nsPy9qx/iYl7JAzl3fYbbvm8A=; b=vFk+k/wjVuJo+igVsNhV6wdTtKMuXAnR2yr+MiHGWE3fKGc3Ml+t3vhdHW0+up/KQe 73jMtpNQmGzFUKwd6th60kFX9y49D85FMPbQ1X4CcAfYx0WEp0m101bCdLuqtMOZfVMs iphczO7cZNwFuUnQZJ9j2LwOnp/ONpHXTHWd/hO3t9cgC2ADZl6TBQNvA4+tqkB3apsF 1PLej3XK5eqBA2nX9d4CrrBVqaqwiPT6eMn5Rn0n7qDAYUdE3IZ4DQlmF5pc8InuPA1Z uIkg2vYBf0YNm+MorP2GqQrqVFXEKWRWiK+LM77wqPeiThsbA7R2ATlJAvLA8l9/7QTO UAfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=501FGUGr+wDXj4ObY1nsPy9qx/iYl7JAzl3fYbbvm8A=; b=iGuGT3XlJMp7uQFHU7kfXdqnyJMkyMH82StOry+hDKxGY6LhyIGehaBWvPZ+oJ6mK4 0rkYEkd2cDRXue6pkOXrFZXTteCNUobvirvxwzEE6AMfGcRDGUDWy/rnyofO3Z3Mymaw eUFNWnKrGdSHctGt6PyTwo26wRtKtHrQFJJsDCifkMokW4M8a2Hyxp7IA6wdulgJVLfD jDamjqapiFQLTvIza5mNLEbYhiUDmNsBwZ80QTOQU9STqNgRKNIZ6O6kTHOtF/ijVUgY +DKlIHLCtl33A9agg9KDzfgjwDjDzuZzg9+gHQc5VFm7wiQyEdWFU+d4LgMCh8VrmaGf wpTQ== X-Gm-Message-State: AOAM533WuABhfWNNEpF9gh2jjgMzFzrC7ETclJog2l21p5XirNgXQNud uaPLYrSFn9g6f/63+dYPjnQ= X-Google-Smtp-Source: ABdhPJwQDlKYj82TU8roh5g3IqMy+LnGDP83kJy0n1ymNIJYAj/6/mFdXBp7Gt8ROA1bBpiw+lEQWw== X-Received: by 2002:a65:63d7:: with SMTP id n23mr523128pgv.46.1628512729135; Mon, 09 Aug 2021 05:38:49 -0700 (PDT) Received: from localhost.localdomain ([156.146.35.76]) by smtp.gmail.com with ESMTPSA id e35sm22382177pjk.28.2021.08.09.05.38.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Aug 2021 05:38:48 -0700 (PDT) From: William Breathitt Gray To: jic23@kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com, kernel@pengutronix.de, a.fatoum@pengutronix.de, kamel.bouhara@bootlin.com, gwendal@chromium.org, alexandre.belloni@bootlin.com, david@lechnology.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, o.rempel@pengutronix.de, jarkko.nikula@linux.intel.com, William Breathitt Gray Subject: [PATCH v15 11/13] counter: Implement events_queue_size sysfs attribute Date: Mon, 9 Aug 2021 21:37:36 +0900 Message-Id: X-Mailer: git-send-email 2.32.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org The events_queue_size sysfs attribute provides a way for users to dynamically configure the Counter events queue size for the Counter character device interface. The size is in number of struct counter_event data structures. The number of elements will be rounded-up to a power of 2 due to a requirement of the kfifo_alloc function called during reallocation of the queue. Cc: Oleksij Rempel Signed-off-by: William Breathitt Gray --- Documentation/ABI/testing/sysfs-bus-counter | 8 ++++ drivers/counter/counter-sysfs.c | 45 +++++++++++++++++++++ 2 files changed, 53 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter index e0e99adb0ecc..84ebb1ed28ed 100644 --- a/Documentation/ABI/testing/sysfs-bus-counter +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -233,6 +233,14 @@ Description: shorter or equal to configured value are ignored. Value 0 means filter is disabled. +What: /sys/bus/counter/devices/counterX/events_queue_size +KernelVersion: 5.15 +Contact: linux-iio@vger.kernel.org +Description: + Size of the Counter events queue in number of struct + counter_event data structures. The number of elements will be + rounded-up to a power of 2. + What: /sys/bus/counter/devices/counterX/name KernelVersion: 5.2 Contact: linux-iio@vger.kernel.org diff --git a/drivers/counter/counter-sysfs.c b/drivers/counter/counter-sysfs.c index df1d75e0d7b8..d2d6495f73c5 100644 --- a/drivers/counter/counter-sysfs.c +++ b/drivers/counter/counter-sysfs.c @@ -3,11 +3,13 @@ * Generic Counter sysfs interface * Copyright (C) 2020 William Breathitt Gray */ +#include #include #include #include #include #include +#include #include #include #include @@ -785,12 +787,49 @@ static int counter_num_counts_read(struct counter_device *counter, u8 *val) return 0; } +static int counter_events_queue_size_read(struct counter_device *counter, + u64 *val) +{ + *val = kfifo_size(&counter->events); + return 0; +} + +static int counter_events_queue_size_write(struct counter_device *counter, + u64 val) +{ + DECLARE_KFIFO_PTR(events, struct counter_event); + int err = 0; + + /* Verify chrdev is not currently being used */ + if (test_and_set_bit_lock(0, counter->chrdev_lock)) + return -EBUSY; + + /* Allocate new events queue */ + err = kfifo_alloc(&events, val, GFP_KERNEL); + if (err) + goto exit_early; + + /* Swap in new events queue */ + kfifo_free(&counter->events); + counter->events.kfifo = events.kfifo; + +exit_early: + clear_bit_unlock(0, counter->chrdev_lock); + + return err; +} + static struct counter_comp counter_num_signals_comp = COUNTER_COMP_DEVICE_U8("num_signals", counter_num_signals_read, NULL); static struct counter_comp counter_num_counts_comp = COUNTER_COMP_DEVICE_U8("num_counts", counter_num_counts_read, NULL); +static struct counter_comp counter_events_queue_size_comp = + COUNTER_COMP_DEVICE_U64("events_queue_size", + counter_events_queue_size_read, + counter_events_queue_size_write); + static int counter_sysfs_attr_add(struct counter_device *const counter, struct counter_attribute_group *cattr_group) { @@ -829,6 +868,12 @@ static int counter_sysfs_attr_add(struct counter_device *const counter, if (err < 0) return err; + /* Create events_queue_size attribute */ + err = counter_attr_create(dev, cattr_group, + &counter_events_queue_size_comp, scope, NULL); + if (err < 0) + return err; + /* Create an attribute for each extension */ for (i = 0; i < counter->num_ext; i++) { ext = &counter->ext[i];