From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755540Ab3AVHoU (ORCPT ); Tue, 22 Jan 2013 02:44:20 -0500 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:54438 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755516Ab3AVHoO (ORCPT ); Tue, 22 Jan 2013 02:44:14 -0500 From: "Srivatsa S. Bhat" Subject: [PATCH v5 33/45] 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 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 Date: Tue, 22 Jan 2013 13:12:17 +0530 Message-ID: <20130122074213.13822.71590.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.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: 13012207-4790-0000-0000-000006940976 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: Richard Kuo Cc: linux-hexagon@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/hexagon/kernel/smp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c index 8e095df..ec87de9 100644 --- a/arch/hexagon/kernel/smp.c +++ b/arch/hexagon/kernel/smp.c @@ -112,6 +112,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) unsigned long cpu; unsigned long retval; + get_online_cpus_atomic(); local_irq_save(flags); for_each_cpu(cpu, cpumask) { @@ -128,6 +129,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) } local_irq_restore(flags); + put_online_cpus_atomic(); } static struct irqaction ipi_intdesc = { @@ -241,9 +243,12 @@ 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) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp02.in.ibm.com (e28smtp02.in.ibm.com [122.248.162.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp02.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 380C02C06B3 for ; Tue, 22 Jan 2013 18:44:13 +1100 (EST) Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 22 Jan 2013 13:12:08 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id BDA84125804D for ; Tue, 22 Jan 2013 13:14:31 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r0M7i7Pd45088868 for ; Tue, 22 Jan 2013 13:14:07 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r0M7i23c012990 for ; Tue, 22 Jan 2013 07:44:07 GMT From: "Srivatsa S. Bhat" Subject: [PATCH v5 33/45] 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 Date: Tue, 22 Jan 2013 13:12:17 +0530 Message-ID: <20130122074213.13822.71590.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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: Richard Kuo Cc: linux-hexagon@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/hexagon/kernel/smp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c index 8e095df..ec87de9 100644 --- a/arch/hexagon/kernel/smp.c +++ b/arch/hexagon/kernel/smp.c @@ -112,6 +112,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) unsigned long cpu; unsigned long retval; + get_online_cpus_atomic(); local_irq_save(flags); for_each_cpu(cpu, cpumask) { @@ -128,6 +129,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) } local_irq_restore(flags); + put_online_cpus_atomic(); } static struct irqaction ipi_intdesc = { @@ -241,9 +243,12 @@ 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) From mboxrd@z Thu Jan 1 00:00:00 1970 From: srivatsa.bhat@linux.vnet.ibm.com (Srivatsa S. Bhat) Date: Tue, 22 Jan 2013 13:12:17 +0530 Subject: [PATCH v5 33/45] hexagon/smp: Use get/put_online_cpus_atomic() to prevent CPU offline In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> Message-ID: <20130122074213.13822.71590.stgit@srivatsabhat.in.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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: Richard Kuo Cc: linux-hexagon at vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/hexagon/kernel/smp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c index 8e095df..ec87de9 100644 --- a/arch/hexagon/kernel/smp.c +++ b/arch/hexagon/kernel/smp.c @@ -112,6 +112,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) unsigned long cpu; unsigned long retval; + get_online_cpus_atomic(); local_irq_save(flags); for_each_cpu(cpu, cpumask) { @@ -128,6 +129,7 @@ void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) } local_irq_restore(flags); + put_online_cpus_atomic(); } static struct irqaction ipi_intdesc = { @@ -241,9 +243,12 @@ 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)