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 1B4CEC0015E for ; Fri, 11 Aug 2023 11:01:12 +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:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5Sir+kXoUfkKWloEm3P8n9XEpiV3Y0M511j/0Xw8k8A=; b=olVwX8lnKN9Mz6 SWakdb7szR/mv0NVOS1kbtYPyubbUlHaNQAud9X+GdtKDIvt/oXL/hSSVZCIoQJZZ9iJru2xHNrsX 0vi/8mSXyt9xQOHad848LYqnwTiD1S9yQ6EoTG/im8GWCIYdSXkGAeVJHfxkNqiXFhnzaUlRKURVL Jwu7vr+rxEUTyr5cpyEJiNCJVFTMFg0M8R8c9cxiaRqenV2BduTHk3pavNpSlGf63xhggSyG7oBuZ d8qJ7ZUtobciO8hBItx3s8WFn24AmovXeqTM+vkJEm+IjgSVywJJTC2sL1UQliHh+w8MBb2PEIxol qwu6rUxxbWKvEFhFE8jQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qUPsr-00AMEJ-0U; Fri, 11 Aug 2023 11:00:45 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qUPsp-00AMD0-04 for linux-arm-kernel@lists.infradead.org; Fri, 11 Aug 2023 11:00:44 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9B6BD637CB; Fri, 11 Aug 2023 11:00:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0FA1C433C7; Fri, 11 Aug 2023 11:00:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691751641; bh=cEl3r7yAOwX5FZhvE8h8dANr7BWBZOnBqQkPPztJWWg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P7VIrpBJDV8YKFzsSTb1f7n2xn7z/xmYC64AOowEBRU556a/Nb+o2s8IUPWiUUKac wmr5yyTIOr6K4fWFlu7A7m7H8QuwjTElFtenW8itMf87UDgpqQeqBRuTmIJb4o4fn9 8nWfEX0jLndE0t4RT2Vr8dZHXeeWqHE9pwSbQxU7wY1XWannD9i4PkB2lDOzI/b0+l a7S00IYScp3LBkpG0WEUZ0mBi9d5to96oArk4MsUYon1F6qidebn60n7Fe49nCd9LF kd2BgNpl9YRLT/faw/R+iITtAXHhF8LKRY3WNMQ7tKgXJxN4YX5lhayiKQhpfEMshU MGKhcNqz338Dw== Date: Fri, 11 Aug 2023 12:00:35 +0100 From: Will Deacon To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com, yangyicong@huawei.com, Sami Mujawar , Catalin Marinas , Mark Rutland , Mike Leach , Leo Yan , Alexander Shishkin , James Clark , coresight@lists.linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V4 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device() Message-ID: <20230811110035.GA6993@willie-the-truck> References: <20230808082247.383405-1-anshuman.khandual@arm.com> <20230808082247.383405-2-anshuman.khandual@arm.com> <9d22520a-3450-0e75-59a2-035209f239e6@arm.com> <20230811101201.GA6827@willie-the-truck> <7920ce3b-15ee-c8d8-a7c0-59009620073c@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7920ce3b-15ee-c8d8-a7c0-59009620073c@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230811_040043_149549_7319A207 X-CRM114-Status: GOOD ( 23.53 ) 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 Fri, Aug 11, 2023 at 03:55:43PM +0530, Anshuman Khandual wrote: > > > On 8/11/23 15:42, Will Deacon wrote: > > On Fri, Aug 11, 2023 at 02:13:42PM +0530, Anshuman Khandual wrote: > >> On 8/8/23 13:52, Anshuman Khandual wrote: > >>> + /* > >>> + * Sanity check all the GICC tables for the same interrupt > >>> + * number. For now, only support homogeneous ACPI machines. > >>> + */ > >>> + for_each_possible_cpu(cpu) { > >>> + struct acpi_madt_generic_interrupt *gicc; > >>> + > >>> + gicc = acpi_cpu_get_madt_gicc(cpu); > >>> + if (gicc->header.length < len) > >>> + return gsi ? -ENXIO : 0; > >>> + > >>> + this_gsi = parse_gsi(gicc); > >>> + if (!this_gsi) > >>> + return gsi ? -ENXIO : 0; > >>> + > >>> + this_hetid = find_acpi_cpu_topology_hetero_id(cpu); > >>> + if (!gsi) { > >>> + hetid = this_hetid; > >>> + gsi = this_gsi; > >>> + } else if (hetid != this_hetid || gsi != this_gsi) { > >>> + pr_warn("ACPI: %s: must be homogeneous\n", pdev->name); > >>> + return -ENXIO; > >>> + } > >>> + } > >> > >> As discussed on the previous version i.e V3 thread, will move the > >> 'this_gsi' check after parse_gsi(), inside if (!gsi) conditional > >> block. This will treat subsequent cpu parse_gsi()'s failure as a > >> mismatch thus triggering the pr_warn() message. > >> > >> diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c > >> index 845683ca7c64..6eae772d6298 100644 > >> --- a/drivers/perf/arm_pmu_acpi.c > >> +++ b/drivers/perf/arm_pmu_acpi.c > >> @@ -98,11 +98,11 @@ arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len, > >> return gsi ? -ENXIO : 0; > >> > >> this_gsi = parse_gsi(gicc); > >> - if (!this_gsi) > >> - return gsi ? -ENXIO : 0; > >> - > >> this_hetid = find_acpi_cpu_topology_hetero_id(cpu); > >> if (!gsi) { > >> + if (!this_gsi) > >> + return 0; > > > > Why do you need this hunk? > > Otherwise '0' gsi on all cpus would just clear the above homogeneity > test, and end up in acpi_register_gsi() making it fail, but with the > following warning before returning with -ENXIO. > > irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH); > if (irq < 0) { > pr_warn("ACPI: %s Unable to register interrupt: %d\n", pdev->name, gsi); > return -ENXIO; > } Ah gotcha, thanks. > Is this behaviour better than returning 0 after detecting '0' gsi in > the first cpu to avoid the above mentioned scenario ? Although 0 gsi > followed by non-zero ones will still end up warning about a mismatch. Can we move the check _after_ the loop, then? That way, we still detect mismatches but we'll quietly return 0 if nobody has an interrupt. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel