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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 EFD11C43387 for ; Wed, 16 Jan 2019 10:29:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C077D206C2 for ; Wed, 16 Jan 2019 10:29:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392028AbfAPK3c (ORCPT ); Wed, 16 Jan 2019 05:29:32 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:44880 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731556AbfAPK3c (ORCPT ); Wed, 16 Jan 2019 05:29:32 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B3F3D80D; Wed, 16 Jan 2019 02:29:31 -0800 (PST) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3BDE3F5AF; Wed, 16 Jan 2019 02:29:28 -0800 (PST) Subject: Re: [PATCH 2/7] coresight: perf: Add "sinks" group to PMU directory To: mathieu.poirier@linaro.org, acme@kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org Cc: mingo@redhat.com, tglx@linutronix.de, alexander.shishkin@linux.intel.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, will.deacon@arm.com, mark.rutland@arm.com, jolsa@redhat.com, namhyung@kernel.org, adrian.hunter@intel.com, ast@kernel.org, hpa@zytor.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20190115230742.13730-1-mathieu.poirier@linaro.org> <20190115230742.13730-3-mathieu.poirier@linaro.org> From: Suzuki K Poulose Message-ID: <9819f0ad-d735-6c50-ffca-90f08153aad2@arm.com> Date: Wed, 16 Jan 2019 10:29:26 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20190115230742.13730-3-mathieu.poirier@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/01/2019 23:07, Mathieu Poirier wrote: > Add a "sinks" directory entry so that users can see all the sinks > available in the system in a single place. Individual sink are added > as they are registered with the coresight bus. > > Signed-off-by: Mathieu Poirier > --- > .../hwtracing/coresight/coresight-etm-perf.c | 43 +++++++++++++++++++ > .../hwtracing/coresight/coresight-etm-perf.h | 1 + > drivers/hwtracing/coresight/coresight.c | 17 ++++++++ > 3 files changed, 61 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > index f21eb28b6782..292bd409a68c 100644 > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -43,8 +44,18 @@ static const struct attribute_group etm_pmu_format_group = { > .attrs = etm_config_formats_attr, > }; > > +static struct attribute *etm_config_sinks_attr[] = { > + NULL, > +}; > + > +static const struct attribute_group etm_pmu_sinks_group = { > + .name = "sinks", > + .attrs = etm_config_sinks_attr, > +}; > + > static const struct attribute_group *etm_pmu_attr_groups[] = { > &etm_pmu_format_group, > + &etm_pmu_sinks_group, > NULL, > }; > > @@ -479,6 +490,38 @@ int etm_perf_symlink(struct coresight_device *csdev, bool link) > return 0; > } > > +static ssize_t etm_perf_sink_name_show(struct device *dev, > + struct device_attribute *dattr, > + char *buf) > +{ > + /* See function coresight_sink_by_id() to know where this is used */ > + u32 hash = hashlen_hash(hashlen_string(NULL, dattr->attr.name)); > + > + return scnprintf(buf, PAGE_SIZE, "%x\n", hash); > +} > + > +int etm_perf_symlink_sink(struct coresight_device *csdev) > +{ > + struct device *pmu_dev = etm_pmu.dev; > + struct device *pdev = csdev->dev.parent; > + struct device_attribute *dev_attr; > + > + if (csdev->type != CORESIGHT_DEV_TYPE_SINK && > + csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) > + return -EINVAL; > + > + if (!etm_perf_up) > + return -EPROBE_DEFER; > + > + dev_attr = kzalloc(sizeof(*dev_attr), GFP_KERNEL); > + dev_attr->attr.name = kstrdup(dev_name(pdev), GFP_KERNEL); > + dev_attr->attr.mode = 0444; > + dev_attr->show = etm_perf_sink_name_show; I would have added the attribute to the csdev (say, sink_attr), and add that to the group, so that it is easier to remove the attribute when the sink device is removed from the system (when we get there). It would be good to have something in place to remove the attribute. Otherwise, the overall approach looks fine to me. Suzuki