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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CF3E7C001DB for ; Fri, 4 Aug 2023 01:39:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=69pdIXrOx3QUi5uCONKZOMoTiMZ6CY1L2MbKsLvRuJw=; b=ZpTUqOpnuZWnTQ GgDXpkxGYmvIgmKTxNFUNTzpt5bFnYvUqssxvu03gnXJIAO/2ZaUTp/F9w1I/K0e0wYc9OS2hrw6J 7rOyiTClUXxjyTW6RE1KiGtkkHhz4fFKnQV+hVwe2tfZWK6L4RUsOml5w8tMjyIJrP5QPBQYTJK3U 67cTCu96PAOfltot0qnw2htcOUzutVvSiED0IARvLaViGQpkFJzup4UAkFyU6vZUKooX/ZoMkcry3 eQX8xoU3X2Mp3Se6xM3TLMjeWDKiHhdVfAvP8E7etTKuQS8ARJblXhFVsweKlJFatI3qjfGRNEzKK VkGuzNNUPhgXgvOrzBmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qRjmf-00BGEG-31; Fri, 04 Aug 2023 01:39:17 +0000 Received: from out30-119.freemail.mail.aliyun.com ([115.124.30.119]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qRjmd-00BGBz-0F for linux-arm-kernel@lists.infradead.org; Fri, 04 Aug 2023 01:39:16 +0000 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R791e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0Vp-Qx-N_1691113145; Received: from 30.240.114.112(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0Vp-Qx-N_1691113145) by smtp.aliyun-inc.com; Fri, 04 Aug 2023 09:39:07 +0800 Message-ID: <10176239-78c1-e276-e74f-a6e79b9c0751@linux.alibaba.com> Date: Fri, 4 Aug 2023 09:39:03 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.13.1 Subject: Re: [PATCH v6 3/4] drivers/perf: add DesignWare PCIe PMU driver Content-Language: en-US To: Yicong Yang , Jonathan Cameron Cc: yangyicong@hisilicon.com, chengyou@linux.alibaba.com, kaishen@linux.alibaba.com, helgaas@kernel.org, will@kernel.org, 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 References: <20230606074938.97724-1-xueshuai@linux.alibaba.com> <20230606074938.97724-4-xueshuai@linux.alibaba.com> <31e2b012-3a29-d063-842d-e3f7736816e7@huawei.com> <20230727103929.00000544@Huawei.com> <12958abe-4bdb-8532-bf67-8e772ed2a9dd@linux.alibaba.com> From: Shuai Xue In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230803_183915_298618_FB113FCF X-CRM114-Status: GOOD ( 23.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2023/8/1 19:46, Yicong Yang wrote: > On 2023/7/28 20:41, Shuai Xue wrote: >> >> >> On 2023/7/27 17:39, Jonathan Cameron wrote: >>> On Tue, 6 Jun 2023 23:14:07 +0800 >>> Yicong Yang wrote: >>> >>>> On 2023/6/6 15:49, 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. >>>>> >>>>> To facilitate collection of statistics the controller provides the >>>>> following two features for each Root Port: >>>>> >>>>> - Time Based Analysis (RX/TX data throughput and time spent in each >>>>> low-power LTSSM state) >>>>> - Event counters (Error and Non-Error for lanes) >>>>> >>>>> Note, only one counter for each type and does not overflow interrupt. >>>>> >>>>> This driver adds PMU devices for each PCIe Root Port. And the PMU device is >>>>> named based the BDF of Root Port. For example, >>>>> >>>>> 30:03.0 PCI bridge: Device 1ded:8000 (rev 01) >>>>> >>>>> the PMU device name for this Root Port is dwc_rootport_3018. >>>>> >>>>> Example usage of counting PCIe RX TLP data payload (Units of 16 bytes):: >>>>> >>>>> $# perf stat -a -e dwc_rootport_3018/Rx_PCIe_TLP_Data_Payload/ >>>>> >>>>> average RX bandwidth can be calculated like this: >>>>> >>>>> PCIe TX Bandwidth = PCIE_TX_DATA * 16B / Measure_Time_Window >>>>> >>>>> Signed-off-by: Shuai Xue >>>>> Reported-by: kernel test robot >>>>> Link: https://lore.kernel.org/oe-kbuild-all/202305170639.XU3djFZX-lkp@intel.com/ >>>>> Reviewed-by: Baolin Wang >>> >>> I'll review on top to avoid any duplication with Yicong. >> >> Thank you! It also served as a reminder that I missed Yicong's email. It appears >> that Thunderbird mistakenly moved his email to the junk folder, resulting in me >> overlooking it. >> >>> >>> Note I've cropped the stuff neither of us commented on so it's >>> easier to spot the feedback. >> >> Thank you for noting that. My feedback is replied inline. >> >>> >>> Jonathan >>> >>>>> --- >>>>> drivers/perf/Kconfig | 7 + >>>>> drivers/perf/Makefile | 1 + >>>>> drivers/perf/dwc_pcie_pmu.c | 706 ++++++++++++++++++++++++++++++++++++ >>>>> 3 files changed, 714 insertions(+) >>>>> create mode 100644 drivers/perf/dwc_pcie_pmu.c >>>>> >>>>> diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig >>>>> index 711f82400086..6ff3921d7a62 100644 >>>>> --- a/drivers/perf/Kconfig >>>>> +++ b/drivers/perf/Kconfig >>>>> @@ -209,6 +209,13 @@ config MARVELL_CN10K_DDR_PMU >>>>> Enable perf support for Marvell DDR Performance monitoring >>>>> event on CN10K platform. >>>>> >>>>> +config DWC_PCIE_PMU >>>>> + tristate "Enable Synopsys DesignWare PCIe PMU Support" >>>>> + depends on (ARM64 && PCI) >>>>> + help >>>>> + Enable perf support for Synopsys DesignWare PCIe PMU Performance >>>>> + monitoring event on Yitian 710 platform. >>> >>> The documentation kind of implies this isn't platform specific. >>> If some parts are (such as which events exist) then you may want to push >>> that to userspace / perftool with appropriate matching against specific SoC. >>> >>> If it is generic, then change this text to "event on platform including the Yitian 710." >> >> It is generic without any platform specific, so I will change it as you expected. >> >>> >>>>> + >>>>> source "drivers/perf/arm_cspmu/Kconfig" >>>>> >>>>> source "drivers/perf/amlogic/Kconfig" >>> >>>>> new file mode 100644 >>>>> index 000000000000..8bfcf6e0662d >>>>> --- /dev/null >>>>> +++ b/drivers/perf/dwc_pcie_pmu.c >>>>> @@ -0,0 +1,706 @@ >>> >>> ... >>> >>>>> + >>>>> +struct dwc_pcie_pmu { >>>>> + struct pci_dev *pdev; /* Root Port device */ >>>> >>>> If the root port removed after the probe of this PCIe PMU driver, we'll access the NULL >>>> pointer. I didn't see you hold the root port to avoid the removal. >> >> Do you mean that I should have a reference count of rootport by pci_dev_get() when allocating >> pcie_pmu? >> >> pcie_pmu->pdev = pci_dev_get(); > > It could be one option, but will block the removal of device from userspace. Another option > is to register a PCI bus notifier then on removal/added the driver can get notified and handle > it, for example, remove the related PMU on the removal of the root ports. I see, but can root port be removed from userspace? I check the hotplug slot interface, no root port is available to power off. Thank you. Best Regards, Shuai _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel