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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2E600C433E0 for ; Thu, 18 Jun 2020 09:20:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0675F20EDD for ; Thu, 18 Jun 2020 09:20:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729093AbgFRJUK (ORCPT ); Thu, 18 Jun 2020 05:20:10 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2324 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728995AbgFRJUJ (ORCPT ); Thu, 18 Jun 2020 05:20:09 -0400 Received: from lhreml724-chm.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id F2C18BCA44432416FAA3; Thu, 18 Jun 2020 10:20:07 +0100 (IST) Received: from [127.0.0.1] (10.210.165.247) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1913.5; Thu, 18 Jun 2020 10:20:07 +0100 Subject: Re: [PATCH] drivers/perf: hisi: Add identifier sysfs file To: Shaokun Zhang , , CC: , , , , References: <1592399111-134786-1-git-send-email-john.garry@huawei.com> <089b4276-a247-5d39-4227-32629d3ee888@hisilicon.com> From: John Garry Message-ID: <086e0fd0-590b-8a95-5ac9-9d585e8a3342@huawei.com> Date: Thu, 18 Jun 2020 10:18:42 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <089b4276-a247-5d39-4227-32629d3ee888@hisilicon.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.210.165.247] X-ClientProxiedBy: lhreml701-chm.china.huawei.com (10.201.108.50) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/06/2020 02:40, Shaokun Zhang wrote: >> } >> >> + hha_pmu->identifier = readl(hha_pmu->base + HHA_VERSION); > Since we are now refactoring the PMU framework, the PMU version offset > is always the same except DDRC PMU and other uncore PMU modules will > also use this, how about we do it as the common code: > > #define HISI_PMU_VERSION_REG 0x1CF0 > int hisi_uncore_pmu_version(struct hisi_pmu *hisi_pmu) > { > return readl(hisi_pmu->base + HISI_PMU_VERSION_REG); > } > EXPORT_SYMBOL_GPL(hisi_uncore_pmu_version); Hi Shaokun, Some points to make: - It's hardly worth having a separate function to do this 1-line readl() call, especially since it not even generic (DDRC is different) - We would have to export it (or put in a common header file with static inline keywords) - less exports are good - with factoring out common code, it's good to reduce total code - this change would increase it, AFAICS - This is HW specific. The driver is currently layered such that all HW specific stuff is in the HW driver (like hisi_uncore_ddrc_pmu.c), and not library code (hisi_uncore_pmu.c). I don't see why you want to mix that, like you're proposing in the framework revision you proposed internally. Thanks, John > > hha_pmu->identifier = hisi_uncore_pmu_version(hha_pmu); > we can remove the duplicated PMU version register definition in each module. > > Thanks, > Shaokun > >> + >> return 0; >> } >> >> @@ -320,10 +323,23 @@ static const struct attribute_group hisi_hha_pmu_cpumask_attr_group = { >> .attrs = hisi_hha_pmu_cpumask_attrs, >> };