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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 277BBCDB465 for ; Tue, 17 Oct 2023 00:48:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233590AbjJQAs0 (ORCPT ); Mon, 16 Oct 2023 20:48:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233549AbjJQAs0 (ORCPT ); Mon, 16 Oct 2023 20:48:26 -0400 Received: from out30-97.freemail.mail.aliyun.com (out30-97.freemail.mail.aliyun.com [115.124.30.97]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7785492; Mon, 16 Oct 2023 17:48:23 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0VuKn2PK_1697503699; Received: from 30.240.113.74(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VuKn2PK_1697503699) by smtp.aliyun-inc.com; Tue, 17 Oct 2023 08:48:20 +0800 Message-ID: <83e7bb45-7776-4cfa-a3ed-050faaa1e72c@linux.alibaba.com> Date: Tue, 17 Oct 2023 08:48:17 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 3/4] drivers/perf: add DesignWare PCIe PMU driver Content-Language: en-US To: Bjorn Helgaas Cc: chengyou@linux.alibaba.com, kaishen@linux.alibaba.com, yangyicong@huawei.com, will@kernel.org, Jonathan.Cameron@huawei.com, baolin.wang@linux.alibaba.com, robin.murphy@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, rdunlap@infradead.org, mark.rutland@arm.com, zhuo.song@linux.alibaba.com, renyu.zj@linux.alibaba.com References: <20231016143805.GA1207929@bhelgaas> From: Shuai Xue In-Reply-To: <20231016143805.GA1207929@bhelgaas> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 2023/10/16 22:38, Bjorn Helgaas wrote: > On Mon, Oct 16, 2023 at 11:00:13AM +0800, Shuai Xue wrote: >> On 2023/10/14 00:30, Bjorn Helgaas wrote: >>> On Fri, Oct 13, 2023 at 11:46:44AM +0800, Shuai Xue wrote: >>>> On 2023/10/13 00:25, Bjorn Helgaas wrote: >>>>> On Thu, Oct 12, 2023 at 11:28:55AM +0800, Shuai Xue wrote: >>>>>> This commit adds the PCIe Performance Monitoring Unit (PMU) >>>>>> driver support for T-Head Yitian SoC chip. Yitian is based on >>>>>> the Synopsys PCI Express Core controller IP which provides >>>>>> statistics feature. The PMU is not a PCIe Root Complex >>>>>> integrated End Point(RCiEP) device but only register counters >>>>>> provided by each PCIe Root Port. > >> @@ -447,10 +447,10 @@ static int dwc_pcie_pmu_event_add(struct perf_event *event, int flags) >> u32 ctrl; >> >> /* Only one counter and it is in use */ >> - if (pcie_pmu->event) >> + if (pcie_pmu->event[type]) >> return -ENOSPC; >> >> - pcie_pmu->event = event; >> + pcie_pmu->event[type] = event; > > OK, makes good sense (probably update the comment also, e.g., "one > counter of each type"). Yes, will do that. > >> } >>> If so, I might word this as: >>> >>> Each Root Port contains one counter that can be used for either: >>> >>> - Time-Based Analysis (RX/TX data throughput and time spent in >>> each low-power LTSSM state) or >>> >>> - Event counting (error and non-error events for a specified lane) >>> >>> There is no interrupt for counter overflow. >> >> Based on above, I change the word to: >> >> To facilitate collection of statistics the controller provides the >> following two features for each Root Port: >> >> - one 64-bit counter for Time Based Analysis (RX/TX data throughput and >> time spent in each low-power LTSSM state) and >> - one 32-bit counter for Event counting (error and non-error events for >> a specified lane) >> >> Note: There is no interrupt for counter overflow. > > Beautiful, that's very clear. > Thank you for quick feedback. I will send a new version latter. Best Regards. Shuai