From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB42DD41; Tue, 28 Nov 2023 07:12:03 -0800 (PST) Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4SfmBn0tR3z6D8Wd; Tue, 28 Nov 2023 23:11:45 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 1E0A5140A9C; Tue, 28 Nov 2023 23:12:02 +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; Tue, 28 Nov 2023 15:12:01 +0000 Date: Tue, 28 Nov 2023 15:12:00 +0000 From: Jonathan Cameron To: Russell King CC: , , , , , , , , , , , , , Salil Mehta , Jean-Philippe Brucker , , , James Morse , Catalin Marinas , Will Deacon Subject: Re: [PATCH RFC 13/22] arm64: setup: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu() Message-ID: <20231128151200.0000737c@Huawei.com> In-Reply-To: <20231128150854.00005370@Huawei.com> References: <20231128150854.00005370@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500005.china.huawei.com (7.191.163.240) To lhrpeml500005.china.huawei.com (7.191.163.240) On Tue, 28 Nov 2023 15:08:54 +0000 Jonathan Cameron wrote: > On Tue, 07 Nov 2023 10:30:25 +0000 > Russell King wrote: > > > From: James Morse > > > > To allow ACPI's _STA value to hide CPUs that are present, but not > > available to online right now due to VMM or firmware policy, the > > register_cpu() call needs to be made by the ACPI machinery when ACPI > > is in use. This allows it to hide CPUs that are unavailable from sysfs. > > > > Switching to GENERIC_CPU_DEVICES is an intermediate step to allow all > > five ACPI architectures to be modified at once. > > > > Switch over to GENERIC_CPU_DEVICES, and provide an arch_register_cpu() > > that populates the hotpluggable flag. arch_register_cpu() is also the > > interface the ACPI machinery expects. > > > > The struct cpu in struct cpuinfo_arm64 is never used directly, remove > > it to use the one GENERIC_CPU_DEVICES provides. > > > > This changes the CPUs visible in sysfs from possible to present, but > > on arm64 smp_prepare_cpus() ensures these are the same. > > > > This patch also has the effect of moving the registration of CPUs from > > subsys to driver core initialisation, prior to any initcalls running. > > > > Signed-off-by: James Morse > > Reviewed-by: Russell King (Oracle) > > Signed-off-by: Russell King (Oracle) > > Given this series adds an arch_cpu_is_hotpluggable() callback we probably > want something in this patch description to say why this > isn't using that, but instead overriding arch_register_cpu() > As per comment on next patch I'm fine with this slight dance. Reviewed-by: Jonathan Cameron