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 39D71C4828F for ; Fri, 2 Feb 2024 16:47:28 +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:MIME-Version:References:In-Reply-To: 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=uy6bYIouadjkGnVVcL7jxlzPQhjLgUXhPoPNh+hZ9oI=; b=1PMKjs/0pIETbz eCDT/apkqSQBYdpXt/+et5yotDKgbUi3fwsq7A2jydLY/+yZM0Mm5bNTWI8dZuLNkTajbUw49fsOS fPHVqEoPR6jTYDYwZhKHmY+TqXRJfpA6NTGeJc7kXjnFe5+JLgHR1rT8qqSUu/xfMl5g79TjfV76+ WRXbqG9swYNc5KkpYq/KpBd6CjGDiPYsvjQyB/hB836zR6iylfjTc1CCQkxGmkIOcxs9ReoT9wIE7 sYjEhge+H3g+YUtzYK6XvR283+IepvvbWP80ABMUKIjR2hlS3T2j9FilwUNIv53rrGwrM5fEDz9W8 Uptno7YD7uwpylJ/Pj5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVwhA-0000000CP7B-0f3A; Fri, 02 Feb 2024 16:47:16 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVwh7-0000000CP5I-1D73; Fri, 02 Feb 2024 16:47:14 +0000 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4TRM6d5P4Bz6K7G4; Sat, 3 Feb 2024 00:43:53 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 822581400CD; Sat, 3 Feb 2024 00:47:03 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Fri, 2 Feb 2024 16:47:02 +0000 Date: Fri, 2 Feb 2024 16:47:02 +0000 From: Jonathan Cameron To: "Russell King (Oracle)" CC: , , , , , , , , , , , , , , Salil Mehta , Jean-Philippe Brucker , , , James Morse , "Rafael J. Wysocki" Subject: Re: [PATCH RFC v4 11/15] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Message-ID: <20240202164702.00001c5b@Huawei.com> In-Reply-To: References: Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240202_084713_514261_81666C87 X-CRM114-Status: GOOD ( 17.95 ) 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 Wed, 31 Jan 2024 16:50:32 +0000 Russell King (Oracle) wrote: > From: James Morse > > To support virtual CPU hotplug, ACPI has added an 'online capable' bit > to the MADT GICC entries. This indicates a disabled CPU entry may not > be possible to online via PSCI until firmware has set enabled bit in > _STA. > > This means that a "usable" GIC is one that is marked as either enabled, > or online capable. Therefore, change acpi_gicc_is_usable() to check both > bits. However, we need to change the test in gic_acpi_match_gicc() back > to testing just the enabled bit so the count of enabled distributors is > correct. > > What about the redistributor in the GICC entry? ACPI doesn't want to say. > Assume the worst: When a redistributor is described in the GICC entry, > but the entry is marked as disabled at boot, assume the redistributor > is inaccessible. > > The GICv3 driver doesn't support late online of redistributors, so this > means the corresponding CPU can't be brought online either. Clear the > possible and present bits. > > Systems that want CPU hotplug in a VM can ensure their redistributors > are always-on, and describe them that way with a GICR entry in the MADT. > > When mapping redistributors found via GICC entries, handle the case > where the arch code believes the CPU is present and possible, but it > does not have an accessible redistributor. Print a warning and clear > the present and possible bits. > > Signed-off-by: James Morse > Signed-off-by: Russell King (Oracle) Reviewed-by: Jonathan Cameron _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel