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 7507DEDE9A4 for ; Thu, 14 Sep 2023 11:05:57 +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=kO0YwnpBHIs5OiKu5kDzBEHbHmXtJDo4OTQgCjllj/Y=; b=RzMoReRlRrVLQN kFyP3XjE1LlXWbmoSm3xnH95NvOG/4UZWTyeS6CnTDddkEsQZELrFkxo6AtR1NoedfjnWzB0m+Qls 8DGSKd0mTMFLVPOZsaBpIaa90ocSHplC/kOGYgXN+0/nB3qwOnhIotpdkbQ8hyV2Ph8uNvlcp6tXH i2ZCObNbgZQQ7m3gR6fccU9lknCjn2b3BxkdMml68NfId85SoCd2or/dNUXesPgu0KrezrLMvSXCe poY7u/mmaB6OkJL9H1ZahwkQvYzLRzQsQJLX3xYeJiMtNMKLIeInFlNPULW2cs8yeQPmjQMH1M+d/ UL5O9cMIO7sqvbyaYnWA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgkA8-0089St-1S; Thu, 14 Sep 2023 11:05:32 +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 1qgkA4-0089Ol-1d; Thu, 14 Sep 2023 11:05:30 +0000 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RmZF36jdgz6HJdP; Thu, 14 Sep 2023 19:03:35 +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 12:05:20 +0100 Date: Thu, 14 Sep 2023 12:05:19 +0100 From: Jonathan Cameron To: James Morse CC: , , , , , , , , , Salil Mehta , Russell King , Jean-Philippe Brucker , , Subject: Re: [RFC PATCH v2 03/35] drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden Message-ID: <20230914120519.0000247e@Huawei.com> In-Reply-To: <20230913163823.7880-4-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> <20230913163823.7880-4-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: lhrpeml100004.china.huawei.com (7.191.162.219) 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_040528_833652_E47360BD X-CRM114-Status: GOOD ( 22.99 ) 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 16:37:51 +0000 James Morse wrote: > Architectures often have extra per-cpu work that needs doing > before a CPU is registered, often to determine if a CPU is > hotpluggable. > > To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move > the cpu_register() call into arch_register_cpu(), which is made __weak > so architectures with extra work can override it. > This aligns with the way x86, ia64 and loongarch register hotplug CPUs > when they become present. Perhaps call out that you are also making cpu_devices visible outside of base/cpu.c Note it isn't obvious to me why you do that in this patch. I assume it will be needed later... Otherwise seems sensible to me. > > Signed-off-by: James Morse > --- > Changes since RFC: > * Dropped __init from x86/ia64 arch_register_cpu() > --- > arch/ia64/include/asm/cpu.h | 1 - > arch/ia64/kernel/topology.c | 2 +- > arch/loongarch/include/asm/cpu.h | 1 - > arch/x86/include/asm/cpu.h | 1 - > arch/x86/kernel/topology.c | 2 +- > drivers/base/cpu.c | 14 ++++++++++---- > include/linux/cpu.h | 5 +++++ > 7 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/arch/ia64/include/asm/cpu.h b/arch/ia64/include/asm/cpu.h > index db125df9e088..a3e690e685e5 100644 > --- a/arch/ia64/include/asm/cpu.h > +++ b/arch/ia64/include/asm/cpu.h > @@ -16,7 +16,6 @@ DECLARE_PER_CPU(struct ia64_cpu, cpu_devices); > DECLARE_PER_CPU(int, cpu_state); > > #ifdef CONFIG_HOTPLUG_CPU > -extern int arch_register_cpu(int num); > extern void arch_unregister_cpu(int); > #endif > > diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c > index 94a848b06f15..741863a187a6 100644 > --- a/arch/ia64/kernel/topology.c > +++ b/arch/ia64/kernel/topology.c > @@ -59,7 +59,7 @@ void __ref arch_unregister_cpu(int num) > } > EXPORT_SYMBOL(arch_unregister_cpu); > #else > -static int __init arch_register_cpu(int num) > +int __init arch_register_cpu(int num) > { > return register_cpu(&sysfs_cpus[num].cpu, num); > } > diff --git a/arch/loongarch/include/asm/cpu.h b/arch/loongarch/include/asm/cpu.h > index 7afe8cbb844e..b8568e637420 100644 > --- a/arch/loongarch/include/asm/cpu.h > +++ b/arch/loongarch/include/asm/cpu.h > @@ -130,7 +130,6 @@ enum cpu_type_enum { > > #if !defined(__ASSEMBLY__) > #ifdef CONFIG_HOTPLUG_CPU > -int arch_register_cpu(int num); > void arch_unregister_cpu(int cpu); > #endif > #endif /* ! __ASSEMBLY__ */ > diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h > index 3a233ebff712..96dc4665e87d 100644 > --- a/arch/x86/include/asm/cpu.h > +++ b/arch/x86/include/asm/cpu.h > @@ -28,7 +28,6 @@ struct x86_cpu { > }; > > #ifdef CONFIG_HOTPLUG_CPU > -extern int arch_register_cpu(int num); > extern void arch_unregister_cpu(int); > extern void soft_restart_cpu(void); > #endif > diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c > index ca004e2e4469..0bab03130033 100644 > --- a/arch/x86/kernel/topology.c > +++ b/arch/x86/kernel/topology.c > @@ -54,7 +54,7 @@ void arch_unregister_cpu(int num) > EXPORT_SYMBOL(arch_unregister_cpu); > #else /* CONFIG_HOTPLUG_CPU */ > > -static int __init arch_register_cpu(int num) > +int __init arch_register_cpu(int num) > { > return register_cpu(&per_cpu(cpu_devices, num).cpu, num); > } > diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c > index 34b48f660b6b..579064fda97b 100644 > --- a/drivers/base/cpu.c > +++ b/drivers/base/cpu.c > @@ -525,19 +525,25 @@ bool cpu_is_hotpluggable(unsigned int cpu) > EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); > > #ifdef CONFIG_GENERIC_CPU_DEVICES > -static DEFINE_PER_CPU(struct cpu, cpu_devices); > +DEFINE_PER_CPU(struct cpu, cpu_devices); > + > +int __weak arch_register_cpu(int cpu) > +{ > + return register_cpu(&per_cpu(cpu_devices, cpu), cpu); > +} > #endif > > static void __init cpu_dev_register_generic(void) > { > -#ifdef CONFIG_GENERIC_CPU_DEVICES > int i; > > + if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES)) > + return; > + > for_each_present_cpu(i) { > - if (register_cpu(&per_cpu(cpu_devices, i), i)) > + if (arch_register_cpu(i)) > panic("Failed to register CPU device"); > } > -#endif > } > > #ifdef CONFIG_GENERIC_CPU_VULNERABILITIES > diff --git a/include/linux/cpu.h b/include/linux/cpu.h > index 0abd60a7987b..a71691d7c2ca 100644 > --- a/include/linux/cpu.h > +++ b/include/linux/cpu.h > @@ -80,12 +80,17 @@ extern __printf(4, 5) > struct device *cpu_device_create(struct device *parent, void *drvdata, > const struct attribute_group **groups, > const char *fmt, ...); > +extern int arch_register_cpu(int cpu); > #ifdef CONFIG_HOTPLUG_CPU > extern void unregister_cpu(struct cpu *cpu); > extern ssize_t arch_cpu_probe(const char *, size_t); > extern ssize_t arch_cpu_release(const char *, size_t); > #endif > > +#ifdef CONFIG_GENERIC_CPU_DEVICES > +DECLARE_PER_CPU(struct cpu, cpu_devices); > +#endif > + > /* > * These states are not related to the core CPU hotplug mechanism. They are > * used by various (sub)architectures to track internal state _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel