From patchwork Thu Jun 27 19:58:01 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Srivatsa S. Bhat" X-Patchwork-Id: 255209 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id C31572C21DA for ; Fri, 28 Jun 2013 06:22:38 +1000 (EST) Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp09.au.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A43B02C08CD for ; Fri, 28 Jun 2013 06:01:39 +1000 (EST) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 28 Jun 2013 16:57:48 +1000 Received: from d23dlp02.au.ibm.com (202.81.31.213) by e23smtp09.au.ibm.com (202.81.31.206) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 28 Jun 2013 16:57:46 +1000 Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [9.190.235.152]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id CA0C32BB0051 for ; Fri, 28 Jun 2013 06:01:34 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5RJkXEp61210740 for ; Fri, 28 Jun 2013 05:46:33 +1000 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5RK1WYa020139 for ; Fri, 28 Jun 2013 06:01:34 +1000 Received: from srivatsabhat.in.ibm.com ([9.79.209.72]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r5RK1FZt019174; Fri, 28 Jun 2013 06:01:25 +1000 From: "Srivatsa S. Bhat" Subject: [PATCH v3 32/45] blackfin/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, David.Laight@aculab.com Date: Fri, 28 Jun 2013 01:28:01 +0530 Message-ID: <20130627195801.29830.77286.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> References: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062806-3568-0000-0000-000003D834E7 Cc: linux-arch@vger.kernel.org, Bob Liu , Mike Frysinger , nikunj@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, Steven Miao , linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, wangyun@linux.vnet.ibm.com, "Srivatsa S. Bhat" , netdev@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, Thomas Gleixner , linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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: Mike Frysinger Cc: Bob Liu Cc: Steven Miao Cc: Thomas Gleixner Cc: uclinux-dist-devel@blackfin.uclinux.org Signed-off-by: Srivatsa S. Bhat --- arch/blackfin/mach-common/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c index 1bc2ce6..11496cd 100644 --- a/arch/blackfin/mach-common/smp.c +++ b/arch/blackfin/mach-common/smp.c @@ -238,13 +238,13 @@ void smp_send_stop(void) { cpumask_t callmap; - preempt_disable(); + get_online_cpus_atomic(); cpumask_copy(&callmap, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &callmap); if (!cpumask_empty(&callmap)) send_ipi(&callmap, BFIN_IPI_CPU_STOP); - preempt_enable(); + put_online_cpus_atomic(); return; }