From patchwork Tue Aug 23 21:46:52 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 1090022 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7NLlItu030844 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 23 Aug 2011 21:47:40 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QvyoN-0001wz-LX; Tue, 23 Aug 2011 21:47:07 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QvyoM-0004qP-UA; Tue, 23 Aug 2011 21:47:06 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QvyoI-0004oZ-2Z for linux-arm-kernel@lists.infradead.org; Tue, 23 Aug 2011 21:47:02 +0000 Received: from localhost.localdomain (e102144-lin.cambridge.arm.com [10.1.69.60]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id p7NLjb19026027; Tue, 23 Aug 2011 22:45:38 +0100 (BST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 8/8] ARM: stop: execute platform callback from cpu_stop code Date: Tue, 23 Aug 2011 22:46:52 +0100 Message-Id: <1314136012-20533-9-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 1.7.0.4 MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1314136012-20533-1-git-send-email-will.deacon@arm.com> References: <1314136012-20533-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110823_174702_367990_FA88FC3B X-CRM114-Status: GOOD ( 16.12 ) X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-2.8 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [217.140.96.50 listed in list.dnswl.org] -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: Will Deacon X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Tue, 23 Aug 2011 21:47:40 +0000 (UTC) Sending IPI_CPU_STOP to a CPU causes it to execute a busy cpu_relax loop forever. This makes it impossible to kexec successfully on an SMP system since the secondary CPUs do not reset. This patch adds a callback to platform_cpu_kill, defined when CONFIG_HOTPLUG_CPU=y, from the ipi_cpu_stop handling code. This function currently just returns 1 on all platforms that define it but allows them to do something more sophisticated in the future. Signed-off-by: Will Deacon --- arch/arm/Kconfig | 2 +- arch/arm/kernel/smp.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5ebc5d9..d2e9d42 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1849,7 +1849,7 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL && (!SMP || HOTPLUG_CPU) help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 96a7956..3f6e8d1 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -559,6 +559,10 @@ static void ipi_cpu_stop(unsigned int cpu) local_fiq_disable(); local_irq_disable(); +#ifdef CONFIG_HOTPLUG_CPU + platform_cpu_kill(cpu); +#endif + while (1) cpu_relax(); }