From patchwork Wed Apr 6 14:17:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 8762791 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B50EE9F3D1 for ; Wed, 6 Apr 2016 14:20:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C5C5A20212 for ; Wed, 6 Apr 2016 14:20:18 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CB8E620123 for ; Wed, 6 Apr 2016 14:20:14 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1anoHO-0001A9-KI; Wed, 06 Apr 2016 14:17:58 +0000 Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1anoHN-00018a-64 for xen-devel@lists.xenproject.org; Wed, 06 Apr 2016 14:17:57 +0000 Received: from [193.109.254.147] by server-15.bemta-14.messagelabs.com id C2/55-02980-49A15075; Wed, 06 Apr 2016 14:17:56 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrOLMWRWlGSWpSXmKPExsVyuP0Ov+5kKdZ wgynTjS2+b5nM5MDocfjDFZYAxijWzLyk/IoE1oyz16czF/RIVxw795GpgfGJWBcjJ4eEgJHE 24n/mLoYuTiEBBYySrxY9ZsdJMEmoCqx4fopVhBbRMBRYnXbUlaQImaBGcwSDV17mUASwgJhE ndat4MVsQA1XOr6ChbnFbCTmNnSzQyxQU7i+szpYHFOAXuJZzdvgsWFQGqaN7BNYORewMiwil GjOLWoLLVI19BUL6koMz2jJDcxM0fX0NBELze1uDgxPTUnMalYLzk/dxMj0MP1DAyMOxj/nvY 8xCjJwaQkyuspwRouxJeUn1KZkVicEV9UmpNafIhRhoNDSYJ3iiRQTrAoNT21Ii0zBxhqMGkJ Dh4lEd5EkDRvcUFibnFmOkTqFKOilDjvRJCEAEgiozQPrg0W3pcYZaWEeRkZGBiEeApSi3IzS 1DlXzGKczAqCfMWgkzhycwrgZv+CmgxE9DiemEmkMUliQgpqQbGqwsWhHFF3Jiy7BzDLg3ORt V7c2RC61UzzsSGVx3ivNMtFKJlVfxhpV5euPUzIVH7C5rvw2Kz1lxYcqhBvEvr2Y2IS39Lfvx cxtH+2W2/Yusu1yq3vzLi7lckZN3TGb0NfbO/pBydePpx9fTArj7nC3f9+e8t3Rl9fFewc91B cZ8W8SvXJ2YosRRnJBpqMRcVJwIAOJkh5GoCAAA= X-Env-Sender: jgross@suse.com X-Msg-Ref: server-8.tower-27.messagelabs.com!1459952275!32233778!1 X-Originating-IP: [195.135.220.15] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 8.28; banners=-,-,- X-VirusChecked: Checked Received: (qmail 24166 invoked from network); 6 Apr 2016 14:17:55 -0000 Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by server-8.tower-27.messagelabs.com with DHE-RSA-CAMELLIA256-SHA encrypted SMTP; 6 Apr 2016 14:17:55 -0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B27A2ADB0; Wed, 6 Apr 2016 14:17:51 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Date: Wed, 6 Apr 2016 16:17:43 +0200 Message-Id: <1459952266-3687-4-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1459952266-3687-1-git-send-email-jgross@suse.com> References: <1459952266-3687-1-git-send-email-jgross@suse.com> Cc: Juergen Gross , jeremy@goop.org, jdelvare@suse.com, peterz@infradead.org, hpa@zytor.com, akataria@vmware.com, x86@kernel.org, rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, chrisw@sous-sol.org, mingo@redhat.com, david.vrabel@citrix.com, Douglas_Warzecha@dell.com, pali.rohar@gmail.com, boris.ostrovsky@oracle.com, tglx@linutronix.de, linux@roeck-us.net Subject: [Xen-devel] [PATCH v5 3/6] smp: add function to execute a function synchronously on a cpu X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On some hardware models (e.g. Dell Studio 1555 laptop) some hardware related functions (e.g. SMIs) are to be executed on physical cpu 0 only. Instead of open coding such a functionality multiple times in the kernel add a service function for this purpose. This will enable the possibility to take special measures in virtualized environments like Xen, too. Signed-off-by: Juergen Gross Acked-by: Peter Zijlstra (Intel) --- V5: rename and reshuffle parameters of smp_call_on_cpu() as requested by Peter Zijlstra test target cpu to be online as requested by Peter Zijlstra V4: change return value in case of illegal cpu as requested by Peter Zijlstra make pinning of vcpu an option as suggested by Peter Zijlstra V2: instead of manipulating the allowed set of cpus use cpu specific workqueue as requested by Peter Zijlstra --- include/linux/smp.h | 3 +++ kernel/smp.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/up.c | 17 +++++++++++++++++ 3 files changed, 70 insertions(+) diff --git a/include/linux/smp.h b/include/linux/smp.h index c441407..4f1c475 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -196,4 +196,7 @@ extern void arch_enable_nonboot_cpus_end(void); void smp_setup_processor_id(void); +int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, + bool phys); + #endif /* __LINUX_SMP_H */ diff --git a/kernel/smp.c b/kernel/smp.c index 9388064..f671948 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -740,3 +740,53 @@ void wake_up_all_idle_cpus(void) preempt_enable(); } EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); + +/** + * smp_call_on_cpu - Call a function on a specific cpu + * + * Used to call a function on a specific cpu and wait for it to return. + * Optionally make sure the call is done on a specified physical cpu via vcpu + * pinning in order to support virtualized environments. + */ +struct smp_call_on_cpu_struct { + struct work_struct work; + struct completion done; + int (*func)(void *); + void *data; + int ret; + int cpu; +}; + +static void smp_call_on_cpu_callback(struct work_struct *work) +{ + struct smp_call_on_cpu_struct *sscs; + + sscs = container_of(work, struct smp_call_on_cpu_struct, work); + if (sscs->cpu >= 0) + hypervisor_pin_vcpu(sscs->cpu); + sscs->ret = sscs->func(sscs->data); + if (sscs->cpu >= 0) + hypervisor_pin_vcpu(-1); + + complete(&sscs->done); +} + +int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) +{ + struct smp_call_on_cpu_struct sscs = { + .work = __WORK_INITIALIZER(sscs.work, smp_call_on_cpu_callback), + .done = COMPLETION_INITIALIZER_ONSTACK(sscs.done), + .func = func, + .data = par, + .cpu = phys ? cpu : -1, + }; + + if (cpu >= nr_cpu_ids || !cpu_online(cpu)) + return -ENXIO; + + queue_work_on(cpu, system_wq, &sscs.work); + wait_for_completion(&sscs.done); + + return sscs.ret; +} +EXPORT_SYMBOL_GPL(smp_call_on_cpu); diff --git a/kernel/up.c b/kernel/up.c index 3ccee2b..ee81ac9 100644 --- a/kernel/up.c +++ b/kernel/up.c @@ -83,3 +83,20 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), preempt_enable(); } EXPORT_SYMBOL(on_each_cpu_cond); + +int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) +{ + int ret; + + if (cpu != 0) + return -ENXIO; + + if (phys) + hypervisor_pin_vcpu(0); + ret = func(par); + if (phys) + hypervisor_pin_vcpu(-1); + + return ret; +} +EXPORT_SYMBOL_GPL(smp_call_on_cpu);