From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752858Ab3FWNtQ (ORCPT ); Sun, 23 Jun 2013 09:49:16 -0400 Received: from e28smtp06.in.ibm.com ([122.248.162.6]:52725 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752237Ab3FWNtL (ORCPT ); Sun, 23 Jun 2013 09:49:11 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH 34/45] hexagon/smp: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Kuo , Thomas Gleixner , linux-hexagon@vger.kernel.org Date: Sun, 23 Jun 2013 19:15:49 +0530 Message-ID: <20130623134545.19094.46020.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> References: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062313-9574-0000-0000-0000086AA908 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Richard Kuo Cc: Thomas Gleixner Cc: linux-hexagon@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/hexagon/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c index 0e364ca..30d4318 100644 --- a/arch/hexagon/kernel/smp.c +++ b/arch/hexagon/kernel/smp.c @@ -241,9 +241,12 @@ void smp_send_reschedule(int cpu) void smp_send_stop(void) { struct cpumask targets; + + get_online_cpus_atomic(); cpumask_copy(&targets, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &targets); send_ipi(&targets, IPI_CPU_STOP); + put_online_cpus_atomic(); } void arch_send_call_function_single_ipi(int cpu)