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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 DE1AEC433DF for ; Thu, 28 May 2020 01:37:09 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A6C33207BC for ; Thu, 28 May 2020 01:37:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="V6NsbR2r" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A6C33207BC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hisilicon.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Qp8bOHsifbFR1LhpF7LY24sGrQZrkb4vu2GX8MyVZtU=; b=V6NsbR2rIdmnMN 6hnsAQ4wcb/NBUPPYvmIHvqfju0M+gQvHHgaPNvTMJZODnXfGPOX4qAAnma8edSwpH11BQjmAl6cO j7quYnSDt1R/EpWAZkSE3qBfYJNTPNp7kn3Adm4ex7tLckHtWrEeLh0iSPf+Pz9wmsvJ9x1BB7/Y3 bxYLQl1hAtO5akK96+4TW1aZxAZ5KcloNZj6ef0j3n/gMOZWcmu7nkqtgNsyt5S1idg7GIdRtXekd yTlnaq3VRi0uXuFKqXI4x2+cbEDELK9neX9+F7As1as8UHFTnQUEkWVP3MnZ297HQQI/jOVXbD37E 6KG0iB7fFoAfoKMgrtgQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1je7To-0000SB-DS; Thu, 28 May 2020 01:37:08 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1je7S8-0007e7-3w for linux-arm-kernel@lists.infradead.org; Thu, 28 May 2020 01:35:28 +0000 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 4A5E2CDD85FBA056B940; Thu, 28 May 2020 09:35:19 +0800 (CST) Received: from [127.0.0.1] (10.74.221.148) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.487.0; Thu, 28 May 2020 09:35:12 +0800 Subject: Re: [PATCH V1 RESEND 1/3] perf/imx_ddr: Add system PMU identifier for userspace To: John Garry , Will Deacon , "Rob Herring" References: <20200512073115.14177-1-qiangqing.zhang@nxp.com> <20200512073115.14177-2-qiangqing.zhang@nxp.com> <20200519185125.GB453195@bogus> <20200520073304.GA23534@willie-the-truck> <20200521130415.GB5949@willie-the-truck> <51aa7cbc-0ce2-b96d-b056-fcc6013ccecf@huawei.com> From: Shaokun Zhang Message-ID: <36a5bf0c-fcf5-ad74-b5ee-1b4502705aec@hisilicon.com> Date: Thu, 28 May 2020 09:35:13 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <51aa7cbc-0ce2-b96d-b056-fcc6013ccecf@huawei.com> X-Originating-IP: [10.74.221.148] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200527_183524_347043_964953A1 X-CRM114-Status: GOOD ( 13.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Joakim Zhang , "linux-kernel@vger.kernel.org" , NXP Linux Team , Shawn Guo , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On 2020/5/27 22:34, John Garry wrote: >>>>> >>>>> I also really dislike this. What's the preferred way to identify the SoC >>>>> from userspace? >>>> >>>> /proc/cpuinfo? ;) >>> >>> The *SoC*! >>> >>>> For an non-firmware specific case, I'd say soc_device should be. I'd >>>> guess ACPI systems don't use it and for them it's dmidecode typically. >>>> The other problem I have with soc_device is it is optional. >>> >> >> Hi Will, >> >>> John -- what do you think about using soc_device to expose this information, >>> with ACPI systems using DMI data instead? >> >> Generally I don't think that DMI is reliable, and I saw this as the least preferred choice. I'm looking at the sysfs DMI info for my dev board, and I don't even see anything like a SoC identifier. >> >> As for the event_source device sysfs identifier file, it would not always contain effectively the same as the SoC ID. >> >> Certain PMUs which I'm interested in plan to have probe-able identification info available in future. >> > > BTW, Shaokun now tells me that the HiSi uncore PMU HW have such registers to identify the implementation. I didn't know. > Right, we have this register which shows the PMU version. Thanks, Shaokun > So we could add that identifier file for those PMUs as proof-of-concept, exposing that register. > > As for other PMUs which I'm interested in, again, future versions should have such registers to self-identify. > > So using something derived from the DT compat string would hopefully be the uncommon case. > > Cheers, > John > > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel