From patchwork Tue Nov 7 10:30:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 13448461 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 34CE0C001B2 for ; Tue, 7 Nov 2023 10:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234145AbjKGKcg (ORCPT ); Tue, 7 Nov 2023 05:32:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234162AbjKGKcB (ORCPT ); Tue, 7 Nov 2023 05:32:01 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDA921FC0; Tue, 7 Nov 2023 02:30:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=m3xZZLoBnSq7UmzJgGvVrvaxRH67D0JzR/58Y1dSI2A=; b=KOfg7Erft+/myd21Gc1g4bsxYO qb3Z5q2vWEWZ5VRsdxLIuLg2Vfp5SRajsKhOOqbok/JeJUX9zMWuZT4aOq8iaGgY4LwR3yGhtNgWU HNsb3S1jcGaDpX1V+dVaWPriMA+IZwzKFC9+qK8CsB22Ljjo6SvH8prK/HRrOKG+TVQRZsHbjik3i tMl6NH34TEfJF807OjGakQO/fFUBybkolqtpMpuXxfmpvIJCYSi9HFcQ6pqHeS+cI35BnXuI9IukU LJwYTl+LzCfsFoInxenz2nZKh4bLcQ1IVJjmfbsqNJDgQcVPvj/E6ZdmdlNuL77RA/jpTnfA6EXrL rpg0YC0A==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:55722 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1r0JM9-0000JR-0l; Tue, 07 Nov 2023 10:30:49 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1r0JMB-00CTyJ-08; Tue, 07 Nov 2023 10:30:51 +0000 In-Reply-To: References: From: Russell King (Oracle) 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, x86@kernel.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org Cc: Salil Mehta , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com, James Morse , Huacai Chen , WANG Xuerui Subject: [PATCH RFC 18/22] LoongArch: Switch over to GENERIC_CPU_DEVICES MIME-Version: 1.0 Content-Disposition: inline Message-Id: Sender: Russell King Date: Tue, 07 Nov 2023 10:30:51 +0000 Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org From: James Morse 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. This is a subtle change. Originally: - on boot, topology_init() would have marked present CPUs that io_master() is true for as hotplug-incapable. - if a CPU is hotplugged that is an io_master(), it can later be hot-unplugged. The new behaviour is that any CPU that io_master() is true for will now always be marked as hotplug-incapable, thus even if it was hotplugged, it can no longer be hot-unplugged. 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 Signed-off-by: Russell King (Oracle) Reviewed-by: Gavin Shan Reviewed-by: Jonathan Cameron --- Changes since RFC v2: * Explain the change in behaviour in the patch description (highlighted by Jonathan Cameron - thanks.) Add note about initialisation order change. --- 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 64620e90c12c..632de780a490 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 ae860fe81536..7dfb46c68f58 100644 --- a/arch/loongarch/kernel/topology.c +++ b/arch/loongarch/kernel/topology.c @@ -10,20 +10,13 @@ #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; - 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); } void arch_unregister_cpu(int cpu) @@ -34,21 +27,3 @@ void arch_unregister_cpu(int cpu) unregister_cpu(c); } #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);