From patchwork Wed Sep 13 16:37:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 722425 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 759BACA553B for ; Wed, 13 Sep 2023 16:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230394AbjIMQjJ (ORCPT ); Wed, 13 Sep 2023 12:39:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230327AbjIMQjD (ORCPT ); Wed, 13 Sep 2023 12:39:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 488B419A7; Wed, 13 Sep 2023 09:38:59 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 45A3FFEC; Wed, 13 Sep 2023 09:39:36 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4A8B83F5A1; Wed, 13 Sep 2023 09:38:57 -0700 (PDT) From: James Morse To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev Cc: x86@kernel.org, Salil Mehta , Russell King , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com Subject: [RFC PATCH v2 03/35] drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden Date: Wed, 13 Sep 2023 16:37:51 +0000 Message-Id: <20230913163823.7880-4-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230913163823.7880-1-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org 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. Signed-off-by: James Morse Reviewed-by: Russell King (Oracle) --- 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