From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756209Ab3BRMnw (ORCPT ); Mon, 18 Feb 2013 07:43:52 -0500 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:54128 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853Ab3BRMnt (ORCPT ); Mon, 18 Feb 2013 07:43:49 -0500 From: "Srivatsa S. Bhat" Subject: [PATCH v6 25/46] staging: octeon: 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 Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, fweisbec@gmail.com, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, walken@google.com, vincent.guittot@linaro.org Date: Mon, 18 Feb 2013 18:11:39 +0530 Message-ID: <20130218124139.26245.43948.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> References: <20130218123714.26245.61816.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-Content-Scanned: Fidelis XPS MAILER x-cbid: 13021812-1618-0000-0000-0000035BC435 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 preempt_disable() or local_irq_disable() 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: Greg Kroah-Hartman Cc: David Daney Signed-off-by: Srivatsa S. Bhat --- drivers/staging/octeon/ethernet-rx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/octeon/ethernet-rx.c b/drivers/staging/octeon/ethernet-rx.c index 34afc16..8588b4d 100644 --- a/drivers/staging/octeon/ethernet-rx.c +++ b/drivers/staging/octeon/ethernet-rx.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #ifdef CONFIG_XFRM @@ -97,6 +98,7 @@ static void cvm_oct_enable_one_cpu(void) return; /* ... if a CPU is available, Turn on NAPI polling for that CPU. */ + get_online_cpus_atomic(); for_each_online_cpu(cpu) { if (!cpu_test_and_set(cpu, core_state.cpu_state)) { v = smp_call_function_single(cpu, cvm_oct_enable_napi, @@ -106,6 +108,7 @@ static void cvm_oct_enable_one_cpu(void) break; } } + put_online_cpus_atomic(); } static void cvm_oct_no_more_work(void)