From patchwork Mon Mar 23 13:50:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qais Yousef X-Patchwork-Id: 11453035 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CDAAB92A for ; Mon, 23 Mar 2020 13:52:04 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A78C02074D for ; Mon, 23 Mar 2020 13:52:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LDh2wLuP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A78C02074D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=80T1CupzbeXCAOCoCJAn0GRSik9efg7IbZgFo28fDrQ=; b=LDh2wLuPDS8rHs17fWGV3tnpFE 2yDDc7qMbojeXVu9/2EbohYX5+g0WTB06vNstc05GBFVW5OTki+4jhaM3pRiQlUOMOkdWenvTYxis TRSAUirgieDGmYg4vgCfDzQcvZ73b3Nz3504FIxM/gYFjZYsnqVxDclmhdTTvTsXeJD0rcRKoM1H8 uXMryvi8zCBrPnKJqIzMf7iNnqtObnpHaINTCDz2OwqMj3mxlR7HtgyMwN1iqQ3EX3fcL0v/DUJkp xY+sbqTxfL0HyK8jLaK/LAY7vJsTD/xT9odCrWr0lXIIdhEVGOqUJGjsIzib7MdT2i3YXOiUjKlAH 7jjayTZQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGNUl-0002de-7s; Mon, 23 Mar 2020 13:51:59 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGNUH-00029h-Dz for linux-arm-kernel@lists.infradead.org; Mon, 23 Mar 2020 13:51:31 +0000 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 EDC941FB; Mon, 23 Mar 2020 06:51:28 -0700 (PDT) Received: from e107158-lin.cambridge.arm.com (e107158-lin.cambridge.arm.com [10.1.195.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6EFA53F52E; Mon, 23 Mar 2020 06:51:26 -0700 (PDT) From: Qais Yousef To: Thomas Gleixner Subject: [PATCH v4 02/17] smp: Create a new function to shutdown nonboot cpus Date: Mon, 23 Mar 2020 13:50:55 +0000 Message-Id: <20200323135110.30522-3-qais.yousef@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200323135110.30522-1-qais.yousef@arm.com> References: <20200323135110.30522-1-qais.yousef@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200323_065129_608890_20F5BBF1 X-CRM114-Status: GOOD ( 16.15 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, "Rafael J. Wysocki" , Catalin Marinas , Greg Kroah-Hartman , "Peter Zijlstra \(Intel\)" , Jiri Kosina , Daniel Lezcano , linux-kernel@vger.kernel.org, Nicholas Piggin , Ingo Molnar , Eiichi Tsukata , Nadav Amit , Josh Poimboeuf , Russell King , Will Deacon , Qais Yousef , linux-arm-kernel@lists.infradead.org, Zhenzhong Duan MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This function will be used later in machine_shutdown() for some archs. disable_nonboot_cpus() is not safe to use when doing machine_down(), because it relies on freeze_secondary_cpus() which in turn is a suspend/resume related freeze and could abort if the logic detects any pending activities that can prevent finishing the offlining process. Signed-off-by: Qais Yousef CC: Thomas Gleixner CC: Josh Poimboeuf CC: "Peter Zijlstra (Intel)" CC: Jiri Kosina CC: Nicholas Piggin CC: Daniel Lezcano CC: Ingo Molnar CC: Eiichi Tsukata CC: Zhenzhong Duan CC: Nadav Amit CC: Greg Kroah-Hartman CC: "Rafael J. Wysocki" CC: Tony Luck CC: Fenghua Yu CC: Russell King CC: Catalin Marinas CC: Will Deacon CC: linux-arm-kernel@lists.infradead.org CC: linux-ia64@vger.kernel.org CC: linux-kernel@vger.kernel.org --- include/linux/cpu.h | 2 ++ kernel/cpu.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index cf8cf38dca43..64a246e9c8db 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -120,6 +120,7 @@ extern void cpu_hotplug_enable(void); void clear_tasks_mm_cpumask(int cpu); int cpu_down(unsigned int cpu); int remove_cpu(unsigned int cpu); +extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); #else /* CONFIG_HOTPLUG_CPU */ @@ -131,6 +132,7 @@ static inline int cpus_read_trylock(void) { return true; } static inline void lockdep_assert_cpus_held(void) { } static inline void cpu_hotplug_disable(void) { } static inline void cpu_hotplug_enable(void) { } +static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } #endif /* !CONFIG_HOTPLUG_CPU */ /* Wrappers which go away once all code is converted */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 069802f7010f..03c727195b65 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1069,6 +1069,48 @@ int remove_cpu(unsigned int cpu) } EXPORT_SYMBOL_GPL(remove_cpu); +void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) +{ + unsigned int cpu; + int error; + + cpu_maps_update_begin(); + + /* + * Make certain the cpu I'm about to reboot on is online. + * + * This is inline to what migrate_to_reboot_cpu() already do. + */ + if (!cpu_online(primary_cpu)) + primary_cpu = cpumask_first(cpu_online_mask); + + for_each_online_cpu(cpu) { + if (cpu == primary_cpu) + continue; + + error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE); + if (error) { + pr_err("Failed to offline CPU%d - error=%d", + cpu, error); + break; + } + } + + /* + * Ensure all but the reboot CPU are offline. + */ + BUG_ON(num_online_cpus() > 1); + + /* + * Make sure the CPUs won't be enabled by someone else after this + * point. Kexec will reboot to a new kernel shortly resetting + * everything along the way. + */ + cpu_hotplug_disabled++; + + cpu_maps_update_done(); +} + #else #define takedown_cpu NULL #endif /*CONFIG_HOTPLUG_CPU*/