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 1B2E9C79FA1 for ; Mon, 7 Sep 2026 16:41:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IrTLbOTuuMQ4L6f9zvoUGhlf4wkNs5/PIEKC6sIRKzw=; b=KxfMD5CcnYMZEOXeRi8hiDsxJt mVXOrIpohQnEoFIytmiCKKsZnUFBFbplH/IVENwdrqkqI6CATRip3S8yiXNayrghURrhcydXXpmqF pkr1/OUvaNGWzP1+RRyDP35zfeUf5aGyjvXztqrgdrHVLFDHKjVwKleaZJh42spb5KMC3lIO2FyXo iurwrAbgbqKvAjFiIKEkmli97igy4KKzkrm92M4WTMnflWs8bCfhcZBxmRmihfOA+n3NRkRFmYcec 9vpasmxZyMV6h8JY6UnFDCa98Xo0FQWmbDitRCA73tzNpSVGVcJRXkkAfdFaA5cQuToCB4GM345FJ N1XbP2JA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3cPE-00000007Ldn-0f2l; Mon, 07 Sep 2026 16:41:16 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3cP5-00000007LSq-2rcC for linux-arm-kernel@lists.infradead.org; Mon, 07 Sep 2026 16:41:07 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 2622D60261; Mon, 7 Sep 2026 16:41:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8351E1F00A3F; Mon, 7 Sep 2026 16:41:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788799266; bh=IrTLbOTuuMQ4L6f9zvoUGhlf4wkNs5/PIEKC6sIRKzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Cl6u/ywB2DKdlUfB00LGseaWWQeZTgxCSacs6+G9B2GLgrcRdNqVSfBdgAGDki+cP pRVU96/X2jGIRvB24yRvH7MGvvgLZTne8ceL3es+phtgtgaFn4ylSIgtvJ2mNdN8hM IpZwPAENDmZ5ZkL2k3en4xblqBTjDtOU8SSO4RdVIgAKHGHwVmMau1gVQXLzLxrMIb ev8n+hrFdyud9E7/79AoKY0LUtAVy3lfM1Dgn7Ir3QVGm8QAFgkn4/9yRxKWA7SKm0 l7qslGovC2LRdlg9leogMDNSvgxU5cZfHzjBDKzb+Vd4FZCAaSlLLd96RVyvlPodd9 idk9CX2H4Jujg== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Will Deacon , Thomas Gleixner , Catalin Marinas , Borislav Petkov , Lorenzo Pieralisi , Jinjie Ruan , Mark Rutland , David Woodhouse , Peter Zijlstra , Marc Zyngier Subject: [PATCH 11/19] arm64: smp: Use generic HOTPLUG_SPLIT_STARTUP machinery for CPU onlining Date: Mon, 7 Sep 2026 17:40:14 +0100 Message-ID: <20260907164024.17164-12-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260907164024.17164-1-will@kernel.org> References: <20260907164024.17164-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In preparation for enabling parallel bringup of secondary CPUs on arm64, take the baby step of moving from HOTPLUG_CORE_SYNC_FULL to HOTPLUG_SPLIT_STARTUP. Rework the cpu_die_early() path to use a private cpumask, otherwise clearing the incoming CPU from the present mask in the 'kick' stage will prevent the hotplug stage machine from progressing and arch_cpuhp_cleanup_kick_cpu() will not be called. Signed-off-by: Will Deacon --- arch/arm64/Kconfig | 2 +- arch/arm64/include/asm/smp.h | 1 + arch/arm64/kernel/smp.c | 9 +++++---- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 89d1f0f2269c..fd8cf792b7fd 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -230,7 +230,7 @@ config ARM64 select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES select HAVE_KRETPROBES - select HOTPLUG_CORE_SYNC_FULL + select HOTPLUG_SPLIT_STARTUP select HOTPLUG_SMT if HOTPLUG_CPU select IRQ_DOMAIN select IRQ_FORCED_THREADING diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h index fe343c30d620..7b986a6a765b 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -89,6 +89,7 @@ asmlinkage void secondary_start_kernel(void); struct secondary_data { struct task_struct *task; long status; + cpumask_t cpu_died_early_mask; }; extern struct secondary_data secondary_data; diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 00362ed6e1ab..c5e9d5d5e003 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -62,7 +62,7 @@ * so we need some other way of telling a new secondary core * where to place its SVC stack */ -struct secondary_data secondary_data; +struct secondary_data secondary_data = {}; /* Number of CPUs which aren't online, but looping in kernel text. */ static int cpus_stuck_in_kernel; @@ -108,7 +108,7 @@ static int boot_secondary(unsigned int cpu, struct task_struct *idle) return -EOPNOTSUPP; } -int __cpu_up(unsigned int cpu, struct task_struct *idle) +int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *idle) { int ret; @@ -146,6 +146,8 @@ void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu, bool is_alive) cpus_stuck_in_kernel++; break; case CPU_KILL_ME: + if (cpumask_test_cpu(cpu, &secondary_data.cpu_died_early_mask)) + set_cpu_present(cpu, false); if (!op_cpu_kill(cpu)) { pr_crit("CPU%u: died during early boot\n", cpu); break; @@ -406,8 +408,7 @@ void __noreturn cpu_die_early(void) pr_crit("CPU%d: will not boot\n", cpu); - /* Mark this CPU absent */ - set_cpu_present(cpu, 0); + cpumask_set_cpu(cpu, &secondary_data.cpu_died_early_mask); if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) { update_cpu_boot_status(CPU_KILL_ME); -- 2.55.0.979.g7e5102b832-goog