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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 019D3C35242 for ; Fri, 14 Feb 2020 23:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDE52206B6 for ; Fri, 14 Feb 2020 23:17:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="arZTtfq3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727458AbgBNXRK (ORCPT ); Fri, 14 Feb 2020 18:17:10 -0500 Received: from mail-yw1-f68.google.com ([209.85.161.68]:43177 "EHLO mail-yw1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbgBNXRK (ORCPT ); Fri, 14 Feb 2020 18:17:10 -0500 Received: by mail-yw1-f68.google.com with SMTP id f204so5001903ywc.10 for ; Fri, 14 Feb 2020 15:17:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=pyTRBMCVp91QtDenhmoQzqMCfGd84Vh8aWQ/JT+Qq5M=; b=arZTtfq3IuYFvYo4HsF0usZchn45O4hmIUeyrGFD/a5oAV5Xkt+NDc184e6GsSzXNu /3gVxkEfd4dp6kfe+8FkaL+zdU6LWhjf/sAyDl58QJGzHCopc7SzoygYknUGJ6P7d/xR S0dNSKpD1PbIebPkxz5NPbfkIVSHhFp8jTe61rUQJmb1RFij/Jjsrso7s7O1V9MLTC++ n/n/scvbt1Bc+VEKkMc39HOJutbPYGtU4rRl1ol+8euo+PXpDVFo/E76/FUq6NKU9R1P NQWmnfNKjCiF9F0XA2q++UvQif8XKWpESlzDdGV6+ZIpfhP7m1Z0cfWyDPxd1CTPx15C ZDKw== 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:user-agent; bh=pyTRBMCVp91QtDenhmoQzqMCfGd84Vh8aWQ/JT+Qq5M=; b=iqEkObf9b/5DcZOOCCzuuJc04XzwWwCJOmfN7ME1kRtitgpY7HWE0cwmXRp3g/r5df GXUIJJtXos/NV5tRvXsKZOPfTNmwAionXQMyXkW0RKEdKU/PVQRslG1gsGhOKX+WtGD+ d7h0GTAXBqHh/w/5keMKxzly/PWqAiUd3XeV/17Th7PC4qc25EiUyH+E4Td5kgDXi71M wB4UV8OR+320VIJtTUhZcalCpawOc4ur/BUHkS7FVKjd+EaOcqq73BqNSVBEGJtC0cSL 29vMyPpxYVnUxgboK1cgu26cJCdBqqSrVa76u/2uxVoe5T9arSGmwfKnNsYA+YwROrmd 2Yeg== X-Gm-Message-State: APjAAAW28IMRfRskXOnVR5bJDD3REWrZ3mkcNX//fMWJVIxQVjoSBGua TBaZ7udFkQWPTaY1pmlQCXikzg== X-Google-Smtp-Source: APXvYqztSlqL5qyucSaXldZIzGpZYX2jVlDz5jrdS7qSUp8e7UOzwZCvE3AoF5wpajH9JbVUGqBi4Q== X-Received: by 2002:a81:99c7:: with SMTP id q190mr4725618ywg.480.1581722229050; Fri, 14 Feb 2020 15:17:09 -0800 (PST) Received: from xps15 (S0106002369de4dac.cg.shawcable.net. [68.147.8.254]) by smtp.gmail.com with ESMTPSA id q130sm3171455ywg.52.2020.02.14.15.17.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Feb 2020 15:17:08 -0800 (PST) Date: Fri, 14 Feb 2020 16:17:06 -0700 From: Mathieu Poirier To: Mike Leach Cc: linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org, linux-doc@vger.kernel.org, suzuki.poulose@arm.com Subject: Re: [PATCH v4 3/6] coresight: Add generic sysfs link creation functions. Message-ID: <20200214231706.GD20024@xps15> References: <20200211105808.27884-1-mike.leach@linaro.org> <20200211105808.27884-4-mike.leach@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200211105808.27884-4-mike.leach@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, Feb 11, 2020 at 10:58:05AM +0000, Mike Leach wrote: > To allow the connections between coresight components to be represented > in sysfs, generic methods for creating sysfs links between two coresight > devices are added. > > Signed-off-by: Mike Leach > Reviewed-by: Suzuki K Poulose > --- > drivers/hwtracing/coresight/Makefile | 3 +- > drivers/hwtracing/coresight/coresight-priv.h | 4 + > drivers/hwtracing/coresight/coresight-sysfs.c | 124 ++++++++++++++++++ > include/linux/coresight.h | 20 +++ > 4 files changed, 150 insertions(+), 1 deletion(-) > create mode 100644 drivers/hwtracing/coresight/coresight-sysfs.c > > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile > index 0e3e72f0f510..19497d1d92bf 100644 > --- a/drivers/hwtracing/coresight/Makefile > +++ b/drivers/hwtracing/coresight/Makefile > @@ -2,7 +2,8 @@ > # > # Makefile for CoreSight drivers. > # > -obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o coresight-platform.o > +obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o \ > + coresight-platform.o coresight-sysfs.o > obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o \ > coresight-tmc-etf.o \ > coresight-tmc-etr.o > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index 1cad642f27aa..a4a658d46045 100644 > --- a/drivers/hwtracing/coresight/coresight-priv.h > +++ b/drivers/hwtracing/coresight/coresight-priv.h > @@ -153,6 +153,10 @@ struct coresight_device *coresight_get_sink_by_id(u32 id); > struct list_head *coresight_build_path(struct coresight_device *csdev, > struct coresight_device *sink); > void coresight_release_path(struct list_head *path); > +int coresight_add_sysfs_link(struct coresight_sysfs_link *info); > +void coresight_remove_sysfs_link(struct coresight_sysfs_link *info); > +int coresight_create_conns_sysfs_group(struct coresight_device *csdev); > +void coresight_remove_conns_sysfs_group(struct coresight_device *csdev); > > #ifdef CONFIG_CORESIGHT_SOURCE_ETM3X > extern int etm_readl_cp14(u32 off, unsigned int *val); > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c > new file mode 100644 > index 000000000000..17d565941e5e > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > @@ -0,0 +1,124 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2019, Linaro Limited, All rights reserved. > + * Author: Mike Leach > + */ > + > +#include > +#include > + > +#include "coresight-priv.h" > + > +/* > + * Connections group - links attribute. > + * Count of created links between coresight components in the group. > + */ > +static ssize_t nr_links_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct coresight_device *csdev = to_coresight_device(dev); > + > + return scnprintf(buf, PAGE_SIZE, "%d\n", csdev->nr_links); > +} > +static DEVICE_ATTR_RO(nr_links); > + > +static struct attribute *coresight_conns_attrs[] = { > + &dev_attr_nr_links.attr, > + NULL, > +}; > + > +static struct attribute_group coresight_conns_group = { > + .attrs = coresight_conns_attrs, > + .name = "connections", > +}; > + > +/* > + * Create connections group for CoreSight devices. > + * This group will then be used to collate the sysfs links between > + * devices. > + */ > +int coresight_create_conns_sysfs_group(struct coresight_device *csdev) > +{ > + int ret = 0; > + > + if (!csdev) > + return -EINVAL; > + > + ret = sysfs_create_group(&csdev->dev.kobj, &coresight_conns_group); > + if (ret) > + return ret; > + > + csdev->has_conns_grp = true; The only place coresight_create_conns_sysfs_group() is used is in coresight_register() where an error is returned to driver probe() functions if an error occurs. Have you found places where csdev->has_conns_grp is needed? If not please remove. > + return ret; > +} > + > +void coresight_remove_conns_sysfs_group(struct coresight_device *csdev) > +{ > + if (!csdev) > + return; > + > + if (csdev->has_conns_grp) { > + sysfs_remove_group(&csdev->dev.kobj, &coresight_conns_group); > + csdev->has_conns_grp = false; > + } > +} > + > +int coresight_add_sysfs_link(struct coresight_sysfs_link *info) > +{ > + int ret = 0; > + > + if (!info) > + return -EINVAL; > + if (!info->orig || !info->target || > + !info->orig_name || !info->target_name) > + return -EINVAL; > + if (!info->orig->has_conns_grp || !info->target->has_conns_grp) > + return -EINVAL; > + > + /* first link orig->target */ > + ret = sysfs_add_link_to_group(&info->orig->dev.kobj, > + coresight_conns_group.name, > + &info->target->dev.kobj, > + info->orig_name); > + if (ret) > + return ret; > + > + /* second link target->orig */ > + ret = sysfs_add_link_to_group(&info->target->dev.kobj, > + coresight_conns_group.name, > + &info->orig->dev.kobj, > + info->target_name); > + > + /* error in second link - remove first - otherwise inc counts */ > + if (ret) { > + sysfs_remove_link_from_group(&info->orig->dev.kobj, > + coresight_conns_group.name, > + info->orig_name); > + } else { > + info->orig->nr_links++; > + info->target->nr_links++; > + } > + > + return ret; > +} > + > +void coresight_remove_sysfs_link(struct coresight_sysfs_link *info) > +{ > + if (!info) > + return; > + if (!info->orig || !info->target || > + !info->orig_name || !info->target_name) > + return; > + > + sysfs_remove_link_from_group(&info->orig->dev.kobj, > + coresight_conns_group.name, > + info->orig_name); > + > + sysfs_remove_link_from_group(&info->target->dev.kobj, > + coresight_conns_group.name, > + info->target_name); > + > + info->orig->nr_links--; > + info->target->nr_links--; > +} > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index 193cc9dbf448..a2ec25e02ca9 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -148,6 +148,20 @@ struct coresight_connection { > struct coresight_device *child_dev; > }; > > +/** > + * struct coresight_sysfs_link - representation of a connection in sysfs. > + * @orig: Originating (master) coresight device for the link. > + * @orig_name: Name to use for the link orig->target. > + * @target: Target (slave) coresight device for the link. > + * @target_name: Name to use for the link target->orig. > + */ > +struct coresight_sysfs_link { > + struct coresight_device *orig; > + const char *orig_name; > + struct coresight_device *target; > + const char *target_name; > +}; > + > /** > * struct coresight_device - representation of a device as used by the framework > * @pdata: Platform data with device connections associated to this device. > @@ -165,6 +179,9 @@ struct coresight_connection { > * @ea: Device attribute for sink representation under PMU directory. > * @ect_dev: Associated cross trigger device. Not part of the trace data > * path or connections. > + * @nr_links: number of sysfs links created to other components from this > + * device. These will appear in the "connections" group. > + * @has_conns_grp: Have added a "connections" group for sysfs links. > */ > struct coresight_device { > struct coresight_platform_data *pdata; > @@ -180,6 +197,9 @@ struct coresight_device { > struct dev_ext_attribute *ea; > /* cross trigger handling */ > struct coresight_device *ect_dev; > + /* sysfs links between components */ > + int nr_links; > + bool has_conns_grp; > }; With the above: Reviewed-by: Mathieu Poirier > > /* > -- > 2.17.1 >