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 C9A17EDE9A4 for ; Thu, 14 Sep 2023 11:48:02 +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=Gog77s6udXgFJNlMJJWTHM/XvMZAao2nzaV/RvVWjC4=; b=B4EVX/eFQ5/ARz PVOm6mauykaMBG8To9HrYRowNobEdp0TpdyzXWGmnzAAOYS6tuZQOJ/38h3MSR6aRruKykIMaEmkK LRkhasx7qPoo310ncfpsDUJ7JhFGtZs8yo3NfP2ut2B0pV8gMQHM80OAkVPHOCZ/KzIWUqLWspKFO TgVvAMddwtHe3JrHxzKJxi4ROSJlQRuJD38sF+AMb5Z9QRz29B4LIxuXj8+VH28BuWwkuBRaqsdLV FNmKt17yMm7LMA+zfmaEn5OZtanxgXPphsopg683S1O782ruFaD2/fFbL2LZOiUW4I0cS2qGWlx/y CvsF1zH4QeznNOL8rXfw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgkon-008GO1-1p; Thu, 14 Sep 2023 11:47:33 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qgkok-008GMi-1O; Thu, 14 Sep 2023 11:47:32 +0000 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Rmb6D5jBWz67cSL; Thu, 14 Sep 2023 19:42:44 +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 15.1.2507.31; Thu, 14 Sep 2023 12:47:25 +0100 Date: Thu, 14 Sep 2023 12:47:24 +0100 From: Jonathan Cameron To: James Morse CC: , , , , , , , , , Salil Mehta , Russell King , Jean-Philippe Brucker , , Subject: Re: [RFC PATCH v2 09/35] LoongArch: Switch over to GENERIC_CPU_DEVICES Message-ID: <20230914124724.000027f3@Huawei.com> In-Reply-To: <20230913163823.7880-10-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> <20230913163823.7880-10-james.morse@arm.com> 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: lhrpeml100006.china.huawei.com (7.191.160.224) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230914_044730_747286_5163249F X-CRM114-Status: GOOD ( 22.36 ) 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, 13 Sep 2023 16:37:57 +0000 James Morse wrote: > Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be > overridden by the arch code, switch over to this to allow common code > to choose when the register_cpu() call is made. > > This allows topology_init() to be removed. > > This is an intermediate step to the logic being moved to drivers/acpi, > where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. > > Signed-off-by: James Morse > --- > arch/loongarch/Kconfig | 1 + > arch/loongarch/kernel/topology.c | 29 ++--------------------------- > 2 files changed, 3 insertions(+), 27 deletions(-) > > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > index 2bddd202470e..5bed51adc68c 100644 > --- a/arch/loongarch/Kconfig > +++ b/arch/loongarch/Kconfig > @@ -72,6 +72,7 @@ config LOONGARCH > select GENERIC_CLOCKEVENTS > select GENERIC_CMOS_UPDATE > select GENERIC_CPU_AUTOPROBE > + select GENERIC_CPU_DEVICES > select GENERIC_ENTRY > select GENERIC_GETTIMEOFDAY > select GENERIC_IOREMAP if !ARCH_IOREMAP > diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c > index caa7cd859078..8e4441c1ff39 100644 > --- a/arch/loongarch/kernel/topology.c > +++ b/arch/loongarch/kernel/topology.c > @@ -7,20 +7,13 @@ > #include > #include > > -static DEFINE_PER_CPU(struct cpu, cpu_devices); > - > #ifdef CONFIG_HOTPLUG_CPU > int arch_register_cpu(int cpu) > { > - int ret; > struct cpu *c = &per_cpu(cpu_devices, cpu); > > - c->hotpluggable = 1; This is a bit subtle. Can loongarch hotplug a CPU that is also io_master(cpu)? I have no idea if there is a subtle difference between. 1) CPUs present at boot where if they are an io_master they are not allowed to be hot removed. 2) CPUs that turn up (hotplugged) later which are an io_master and by original code can be removed. My guess is that no io_master CPU can be hotplugged in making this irrelevant and your code correct as the =1 is just a micro optimizatoin. If we can confirm that, a one line addition to the patch description would be great. Otherwise LGTM > - ret = register_cpu(c, cpu); > - if (ret < 0) > - pr_warn("register_cpu %d failed (%d)\n", cpu, ret); > - > - return ret; > + c->hotpluggable = !io_master(cpu); > + return register_cpu(c, cpu); > } > EXPORT_SYMBOL(arch_register_cpu); > > @@ -33,21 +26,3 @@ void arch_unregister_cpu(int cpu) > } > EXPORT_SYMBOL(arch_unregister_cpu); > #endif > - > -static int __init topology_init(void) > -{ > - int i, ret; > - > - for_each_present_cpu(i) { > - struct cpu *c = &per_cpu(cpu_devices, i); > - > - c->hotpluggable = !io_master(i); > - ret = register_cpu(c, i); > - if (ret < 0) > - pr_warn("topology_init: register_cpu %d failed (%d)\n", i, ret); > - } > - > - return 0; > -} > - > -subsys_initcall(topology_init); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel