From patchwork Mon Aug 29 06:48:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 9303113 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EF02D6077C for ; Mon, 29 Aug 2016 06:52:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F38EA287B1 for ; Mon, 29 Aug 2016 06:52:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E83EA287EA; Mon, 29 Aug 2016 06:52:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id DF04028797 for ; Mon, 29 Aug 2016 06:52:10 +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 1beGOC-00020a-CT; Mon, 29 Aug 2016 06:49:48 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1beGOA-0001zu-Os for xen-devel@lists.xenproject.org; Mon, 29 Aug 2016 06:49:46 +0000 Received: from [85.158.143.35] by server-2.bemta-6.messagelabs.com id C3/BE-13744-A0BD3C75; Mon, 29 Aug 2016 06:49:46 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrGLMWRWlGSWpSXmKPExsVyuP0Ovy7n7cP hBnf3qlh83zKZyYHR4/CHKywBjFGsmXlJ+RUJrBkLJmkW3JOueH9pJ2MD42rxLkZODgkBI4m3 E/8xdTFycQgJLGSUmHZ1IzNIgk1AVWLD9VOsILaIgKPE6ralrCBFzAIzmCUauvYygSSEBcIk+ i8dZwSxWYAazkx5xQJi8wrYS5xa9p8ZYoOcxPWZ08HqOQUcJH5ubQCLCwHVbL90jWUCI/cCRo ZVjBrFqUVlqUW6hoZ6SUWZ6RkluYmZObqGBmZ6uanFxYnpqTmJScV6yfm5mxiB/mUAgh2Mn5Y FHGKU5GBSEuW9I3IwXIgvKT+lMiOxOCO+qDQntfgQowwHh5IEr+fNw+FCgkWp6akVaZk5wECD SUtw8CiJ8IaApHmLCxJzizPTIVKnGBWlxHmngSQEQBIZpXlwbbDgvsQoKyXMywh0iBBPQWpRb mYJqvwrRnEORiVh3ikgU3gy80rgpr8CWswEtJjh9X6QxSWJCCmpBsYjZtMNN8n3bg5tVZJbHv Nojegc+bSAFavrWB41v1vMLWouOrv8n8CSq/9Uttgsj/cPuMFY+kv6+8ME/euCswRMZL3uVp9 QiUiYc/X4lNNHuz7P4ImJOXBxrW+sq+HaFh3Btfr1uU2cxxiePlUKZ1mi9eC73IWkE1Izf3TP frz60/SZi7t3l9crsRRnJBpqMRcVJwIA+xWQG2kCAAA= X-Env-Sender: jgross@suse.com X-Msg-Ref: server-12.tower-21.messagelabs.com!1472453385!30597490!1 X-Originating-IP: [195.135.220.15] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 8.84; banners=-,-,- X-VirusChecked: Checked Received: (qmail 26032 invoked from network); 29 Aug 2016 06:49:45 -0000 Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by server-12.tower-21.messagelabs.com with DHE-RSA-CAMELLIA256-SHA encrypted SMTP; 29 Aug 2016 06:49:45 -0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 09057AAD1; Mon, 29 Aug 2016 06:49:42 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Date: Mon, 29 Aug 2016 08:48:44 +0200 Message-Id: <1472453327-19050-4-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1472453327-19050-1-git-send-email-jgross@suse.com> References: <1472453327-19050-1-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 v6 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-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 --- 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 eccae469..8e0cb7a 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -196,6 +196,9 @@ 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); + /* SMP core functions */ int smpcfd_prepare_cpu(unsigned int cpu); int smpcfd_dead_cpu(unsigned int cpu); diff --git a/kernel/smp.c b/kernel/smp.c index 4274ca5..f4f6137 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -725,3 +725,53 @@ 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);