From patchwork Thu Oct 31 21:50:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11221945 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BE4D5913 for ; Thu, 31 Oct 2019 21:52:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 876862087F for ; Thu, 31 Oct 2019 21:52:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KSADOjvO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 876862087F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nxp.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=O1AW2kT6obJlZXLDEmxWRfFLrUyo7zYdEtw+iZTUVHc=; b=KSADOjvOsRr9mlxzSiP7GV09RP Oy/HmgaLx0SWsRoyPJCPhdh2U2kKo04csAqcGR/2mUQ/ZfoJAri3pdtEkItzhERqEdOndV6P9Xbck sS8m5ENQZeUnbHIab+DEdB+ASeDSgbmc2t/8RpSoPCiUnqTHXVhpAPAtvEaNoQdpulyjd8eTsu4yT ycQZoBmDrM4JrFStMF3UbKcmM8to5Tzz0ZSmw7Up+4UBwaFsKUQOsosIDlkGbOOrBEeBTC6S3jVyW leIAlSGkyXTdc4WT7lNjT0oZ+lXnZw6Nhg0JeQdKb9cimOQoYEtRPSe4PcbiSVC/2zZgyIfeTcdoY bsf6OP9Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQIMX-0006NM-9w; Thu, 31 Oct 2019 21:52:13 +0000 Received: from inva021.nxp.com ([92.121.34.21]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQIL1-0005Hp-1r for linux-arm-kernel@lists.infradead.org; Thu, 31 Oct 2019 21:50:41 +0000 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id B7DC920056E; Thu, 31 Oct 2019 22:50:37 +0100 (CET) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 9C26C2001E6; Thu, 31 Oct 2019 22:50:37 +0100 (CET) Received: from fsr-ub1864-112.ea.freescale.net (fsr-ub1864-112.ea.freescale.net [10.171.82.98]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 8DA2D20605; Thu, 31 Oct 2019 22:50:36 +0100 (CET) From: Leonard Crestez To: Stephen Boyd , MyungJoo Ham , Kyungmin Park , Rob Herring Subject: [PATCH v3 5/6] PM / devfreq: imx-ddrc: Measure bandwidth with perf Date: Thu, 31 Oct 2019 23:50:26 +0200 Message-Id: <259544688d43fbe66290d1b4f06826f57c8f18a0.1572558427.git.leonard.crestez@nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191031_145039_421380_A03E584D X-CRM114-Status: GOOD ( 17.62 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [92.121.34.21 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 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: Mark Rutland , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Jacky Bai , Viresh Kumar , Michael Turquette , Angus Ainslie , Alexandre Bailon , linux-clk@vger.kernel.org, Abel Vesa , Saravana Kannan , Krzysztof Kozlowski , Chanwoo Choi , Matthias Kaehlcke , linux-imx@nxp.com, devicetree@vger.kernel.org, linux-pm@vger.kernel.org, Martin Kepplinger , linux-arm-kernel@lists.infradead.org, Dong Aisheng , Anson Huang , "Rafael J. Wysocki" , kernel@pengutronix.de, Fabio Estevam , Shawn Guo , Georgi Djakov MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org The imx8m ddrc has a performance monitoring block attached which can be used to measure bandwidth usage and automatically adjust frequency. There is already a perf driver for that block so instead of implementing a devfreq events driver use the in-kernel perf API to implement get_dev_status directly. Signed-off-by: Leonard Crestez --- drivers/devfreq/imx-ddrc.c | 146 ++++++++++++++++++++++++++++++++++++- 1 file changed, 143 insertions(+), 3 deletions(-) diff --git a/drivers/devfreq/imx-ddrc.c b/drivers/devfreq/imx-ddrc.c index 3ce51614ecab..c74dec7fbfe4 100644 --- a/drivers/devfreq/imx-ddrc.c +++ b/drivers/devfreq/imx-ddrc.c @@ -11,10 +11,13 @@ #include #include #include #include +#include +#include + #define IMX_SIP_DDR_DVFS 0xc2000004 /* Values starting from 0 switch to specific frequency */ #define IMX_SIP_DDR_FREQ_SET_HIGH 0x00 @@ -80,10 +83,22 @@ struct imx_ddrc { struct clk *dram_alt; struct clk *dram_apb; int freq_count; struct imx_ddrc_freq freq_table[IMX_DDRC_MAX_FREQ_COUNT]; + + /* For measuring load with perf events: */ + struct platform_device *pmu_pdev; + struct pmu *pmu; + + struct perf_event_attr rd_event_attr; + struct perf_event_attr wr_event_attr; + struct perf_event *rd_event; + struct perf_event *wr_event; + + u64 last_rd_val, last_rd_ena, last_rd_run; + u64 last_wr_val, last_wr_ena, last_wr_run; }; static struct imx_ddrc_freq *imx_ddrc_find_freq(struct imx_ddrc *priv, unsigned long rate) { @@ -247,19 +262,128 @@ static int imx_ddrc_get_cur_freq(struct device *dev, unsigned long *freq) return 0; } static int imx_ddrc_get_dev_status(struct device *dev, - struct devfreq_dev_status *stat) + struct devfreq_dev_status *stat) { struct imx_ddrc *priv = dev_get_drvdata(dev); - stat->busy_time = 0; - stat->total_time = 0; stat->current_frequency = clk_get_rate(priv->dram_core); + if (priv->rd_event && priv->wr_event) { + u64 rd_delta, rd_val, rd_ena, rd_run; + u64 wr_delta, wr_val, wr_ena, wr_run; + + rd_val = perf_event_read_value(priv->rd_event, + &rd_ena, &rd_run); + wr_val = perf_event_read_value(priv->wr_event, + &wr_ena, &wr_run); + + rd_delta = (rd_val - priv->last_rd_val) * + (rd_ena - priv->last_rd_ena); + do_div(rd_delta, rd_run - priv->last_rd_run); + priv->last_rd_val = rd_val; + priv->last_rd_ena = rd_ena; + priv->last_rd_run = rd_run; + + wr_delta = (wr_val - priv->last_wr_val) * + (wr_ena - priv->last_wr_ena); + do_div(wr_delta, wr_run - priv->last_wr_run); + priv->last_wr_val = wr_val; + priv->last_wr_ena = wr_ena; + priv->last_wr_run = wr_run; + + /* magic numbers, possibly wrong */ + stat->busy_time = 4 * (rd_delta + wr_delta); + stat->total_time = stat->current_frequency; + } else { + stat->busy_time = 0; + stat->total_time = 0; + } + + return 0; +} + +static int imx_ddrc_perf_disable(struct imx_ddrc *priv) +{ + /* release and set to NULL */ + if (!IS_ERR_OR_NULL(priv->rd_event)) + perf_event_release_kernel(priv->rd_event); + if (!IS_ERR_OR_NULL(priv->wr_event)) + perf_event_release_kernel(priv->wr_event); + priv->rd_event = NULL; + priv->wr_event = NULL; + + return 0; +} + +static int imx_ddrc_perf_enable(struct imx_ddrc *priv) +{ + int ret; + + priv->rd_event_attr.size = sizeof(priv->rd_event_attr); + priv->rd_event_attr.type = priv->pmu->type; + priv->rd_event_attr.config = 0x2a; + + priv->rd_event = perf_event_create_kernel_counter( + &priv->rd_event_attr, 0, NULL, NULL, NULL); + if (IS_ERR(priv->rd_event)) { + ret = PTR_ERR(priv->rd_event); + goto err; + } + + priv->wr_event_attr.size = sizeof(priv->wr_event_attr); + priv->wr_event_attr.type = priv->pmu->type; + priv->wr_event_attr.config = 0x2b; + + priv->wr_event = perf_event_create_kernel_counter( + &priv->wr_event_attr, 0, NULL, NULL, NULL); + if (IS_ERR(priv->wr_event)) { + ret = PTR_ERR(priv->wr_event); + goto err; + } + return 0; + +err: + imx_ddrc_perf_disable(priv); + return ret; +} + +static int imx_ddrc_init_events(struct device *dev, + struct device_node *events_node) +{ + struct imx_ddrc *priv = dev_get_drvdata(dev); + struct device_driver *driver; + + /* + * We need pmu->type for perf_event_attr but there is no API for + * mapping device_node to pmu. Fetch private data for imx-ddr-pmu and + * cast that to a struct pmu instead. + */ + priv->pmu_pdev = of_find_device_by_node(events_node); + if (!priv->pmu_pdev) + return -EPROBE_DEFER; + driver = priv->pmu_pdev->dev.driver; + if (!driver) + return -EPROBE_DEFER; + if (strcmp(driver->name, "imx-ddr-pmu")) { + dev_warn(dev, "devfreq-events node %pOF has unexpected driver %s\n", + events_node, driver->name); + return -ENODEV; + } + + priv->pmu = platform_get_drvdata(priv->pmu_pdev); + if (!priv->pmu) { + dev_err(dev, "devfreq-events device missing private data\n"); + return -EINVAL; + } + + dev_dbg(dev, "events from pmu %s\n", priv->pmu->name); + + return imx_ddrc_perf_enable(priv); } static int imx_ddrc_init_freq_info(struct device *dev) { struct imx_ddrc *priv = dev_get_drvdata(dev); @@ -340,10 +464,15 @@ static int imx_ddrc_check_opps(struct device *dev) return 0; } static void imx_ddrc_exit(struct device *dev) { + struct imx_ddrc *priv = dev_get_drvdata(dev); + + imx_ddrc_perf_disable(priv); + platform_device_put(priv->pmu_pdev); + dev_pm_opp_of_remove_table(dev); } static int imx_ddrc_probe(struct platform_device *pdev) { @@ -363,10 +492,19 @@ static int imx_ddrc_probe(struct platform_device *pdev) if (ret) { dev_err(dev, "failed to init firmware freq info: %d\n", ret); return ret; } + events_node = of_parse_phandle(dev->of_node, "devfreq-events", 0); + if (events_node) { + ret = imx_ddrc_init_events(dev, events_node); + of_node_put(events_node); + if (ret) + goto err; + gov = DEVFREQ_GOV_SIMPLE_ONDEMAND; + } + priv->dram_core = devm_clk_get(dev, "dram_core"); priv->dram_pll = devm_clk_get(dev, "dram_pll"); priv->dram_alt = devm_clk_get(dev, "dram_alt"); priv->dram_apb = devm_clk_get(dev, "dram_apb"); if (IS_ERR(priv->dram_core) || @@ -404,10 +542,12 @@ static int imx_ddrc_probe(struct platform_device *pdev) } return 0; err: + imx_ddrc_perf_disable(priv); + platform_device_put(priv->pmu_pdev); dev_pm_opp_of_remove_table(dev); return ret; } static const struct of_device_id imx_ddrc_of_match[] = {