From patchwork Mon Aug 12 18:49:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11090659 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 184B813B1 for ; Mon, 12 Aug 2019 18:51:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04E49285A8 for ; Mon, 12 Aug 2019 18:51:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ED12A285CD; Mon, 12 Aug 2019 18:51:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 762AC285B8 for ; Mon, 12 Aug 2019 18:51:54 +0000 (UTC) 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=VsUhldTcKOw7fUQK3vd+8P0kNXRSVKl9xIVYqZV4Swg=; b=UiecvZE98eSWOtJVwZ/GD0cPDc DpqeOMMUiMTAOrimxEqRDtp/iWTdA6Nimkv8+BYMKWwgbBIA2NDHUn2+GkaXjGjO//zPJLdWAIEMQ SRYr4IL9L8gmoKpoxwsgw2W+aRHdEwb8FmPwIV/QU9kfeoL3LdbihOGB+yDWOTF2MowbKd63CULdV 3+W1NSHfJgG1j/gb9bZQ6ViiLm9WxMC7xoAW+tod0N3vcf6Zi1sFykkbBYEzyhCxUZQPI0ASJ/izy 2uEPcOpCpLe2P0yzKxDHbmqFo1oU6BuS9820gOOFm77nxh0ACwtn1CT7BcrBp81GVjEUOVYHiyUSD ljSZOvhQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hxFQ9-0006fZ-OK; Mon, 12 Aug 2019 18:51:53 +0000 Received: from inva021.nxp.com ([92.121.34.21]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hxFON-000429-1S for linux-arm-kernel@lists.infradead.org; Mon, 12 Aug 2019 18:50:05 +0000 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id C269E2006A1; Mon, 12 Aug 2019 20:50:01 +0200 (CEST) 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 A7DE32006AE; Mon, 12 Aug 2019 20:50:01 +0200 (CEST) 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 A0E00205ED; Mon, 12 Aug 2019 20:50:00 +0200 (CEST) From: Leonard Crestez To: Stephen Boyd , MyungJoo Ham , Kyungmin Park , Rob Herring Subject: [PATCH 6/7] PM / devfreq: imx-ddrc: Measure bandwidth with perf Date: Mon, 12 Aug 2019 21:49:50 +0300 Message-Id: <6d8762453bf6020b8f1ec8c06bb5713a3d3d635e.1565633880.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-20190812_115003_380434_05555A9C X-CRM114-Status: GOOD ( 16.95 ) 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: Dong Aisheng , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Abel Vesa , Saravana Kannan , Anson Huang , linux-arm-kernel@lists.infradead.org, Viresh Kumar , Michael Turquette , linux-pm@vger.kernel.org, linux-imx@nxp.com, Krzysztof Kozlowski , Chanwoo Choi , Will Deacon , Alexandre Bailon , kernel@pengutronix.de, Fabio Estevam , Mark Rutland , Shawn Guo , Georgi Djakov , devicetree@vger.kernel.org, Jacky Bai MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 | 136 ++++++++++++++++++++++++++++++++++++- 1 file changed, 134 insertions(+), 2 deletions(-) diff --git a/drivers/devfreq/imx-ddrc.c b/drivers/devfreq/imx-ddrc.c index e46a1e711bc6..d7f27cdce697 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 @@ -81,10 +84,22 @@ 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) { @@ -233,17 +248,117 @@ static int imx_ddrc_get_cur_freq(struct device *dev, unsigned long *freq) static int imx_ddrc_get_dev_status(struct device *dev, 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) / (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) / (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) + return -EINVAL; + + dev_info(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); struct arm_smccc_res res; int index; @@ -291,10 +406,13 @@ static int imx_ddrc_init_freq_info(struct device *dev) 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); + return dev_pm_opp_of_remove_table(dev); } static int imx_ddrc_probe(struct platform_device *pdev) { @@ -342,10 +460,22 @@ static int imx_ddrc_probe(struct platform_device *pdev) priv->profile.get_dev_status = imx_ddrc_get_dev_status; priv->profile.exit = imx_ddrc_exit; priv->profile.get_cur_freq = imx_ddrc_get_cur_freq; priv->profile.initial_freq = clk_get_rate(priv->dram_core); + /* Handle devfreq-events */ + 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) { + dev_warn(dev, "failed to init perf events: %d\n", ret); + goto err; + } + gov = DEVFREQ_GOV_SIMPLE_ONDEMAND; + } + priv->devfreq = devm_devfreq_add_device(dev, &priv->profile, gov, NULL); if (IS_ERR(priv->devfreq)) { ret = PTR_ERR(priv->devfreq); dev_err(dev, "failed to add devfreq device: %d\n", ret); @@ -353,10 +483,12 @@ 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[] = {