From patchwork Tue Mar 29 13:44:10 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joao Martins X-Patchwork-Id: 8687311 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 7EED0C0553 for ; Tue, 29 Mar 2016 13:47:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A140A202AE for ; Tue, 29 Mar 2016 13:47:22 +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 B811020154 for ; Tue, 29 Mar 2016 13:47:21 +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 1aktwm-0007Rg-8O; Tue, 29 Mar 2016 13:44:40 +0000 Received: from mail6.bemta6.messagelabs.com ([85.158.143.247]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aktwl-0007R1-6z for xen-devel@lists.xen.org; Tue, 29 Mar 2016 13:44:39 +0000 Received: from [85.158.143.35] by server-3.bemta-6.messagelabs.com id 9A/E8-07120-6C68AF65; Tue, 29 Mar 2016 13:44:38 +0000 X-Env-Sender: joao.m.martins@oracle.com X-Msg-Ref: server-10.tower-21.messagelabs.com!1459259076!6299624!1 X-Originating-IP: [156.151.31.81] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMTU2LjE1MS4zMS44MSA9PiAyODgzMzk=\n X-StarScan-Received: X-StarScan-Version: 8.11; banners=-,-,- X-VirusChecked: Checked Received: (qmail 46000 invoked from network); 29 Mar 2016 13:44:37 -0000 Received: from userp1040.oracle.com (HELO userp1040.oracle.com) (156.151.31.81) by server-10.tower-21.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 29 Mar 2016 13:44:37 -0000 Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id u2TDiXeP012484 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 29 Mar 2016 13:44:33 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0021.oracle.com (8.13.8/8.13.8) with ESMTP id u2TDiWTY013246 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 29 Mar 2016 13:44:33 GMT Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id u2TDiWwS007402; Tue, 29 Mar 2016 13:44:32 GMT Received: from localhost.localdomain (/193.126.154.29) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 29 Mar 2016 06:44:32 -0700 From: Joao Martins To: xen-devel@lists.xen.org Date: Tue, 29 Mar 2016 14:44:10 +0100 Message-Id: <1459259051-4943-6-git-send-email-joao.m.martins@oracle.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1459259051-4943-1-git-send-email-joao.m.martins@oracle.com> References: <1459259051-4943-1-git-send-email-joao.m.martins@oracle.com> X-Source-IP: userv0021.oracle.com [156.151.31.71] Cc: Andrew Cooper , Joao Martins , Keir Fraser , Jan Beulich Subject: [Xen-devel] [PATCH v2 5/6] x86/time: refactor read_platform_stime() 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 To fetch the last read from the clocksource which was used to calculate system_time. In the case of clocksource=tsc we will use it to set tsc_timestamp. Signed-off-by: Joao Martins Reviewed-by: Andrew Cooper Reviewed-by: Konrad Rzeszutek Wilk --- Cc: Keir Fraser Cc: Jan Beulich Cc: Andrew Cooper Changes since v1: - Add missing spaces between brackets - Move plt_stamp_counter to read_platform_stime() - Add signature change in time_calibration_std_rendezvous() --- xen/arch/x86/time.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 9cadfcb..123aa42 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -568,16 +568,19 @@ static void plt_overflow(void *unused) set_timer(&plt_overflow_timer, NOW() + plt_overflow_period); } -static s_time_t read_platform_stime(void) +static s_time_t read_platform_stime(u64 *stamp) { - u64 count; + u64 plt_stamp_counter, count; s_time_t stime; ASSERT(!local_irq_is_enabled()); spin_lock(&platform_timer_lock); - count = plt_stamp64 + ((plt_src.read_counter() - plt_stamp) & plt_mask); + plt_stamp_counter = plt_src.read_counter(); + count = plt_stamp64 + ((plt_stamp_counter - plt_stamp) & plt_mask); stime = __read_platform_stime(count); + if ( stamp ) + *stamp = plt_stamp_counter; spin_unlock(&platform_timer_lock); return stime; @@ -727,7 +730,7 @@ void cstate_restore_tsc(void) if ( boot_cpu_has(X86_FEATURE_NONSTOP_TSC) ) return; - write_tsc(stime2tsc(read_platform_stime())); + write_tsc(stime2tsc(read_platform_stime(NULL))); } /*************************************************************************** @@ -1046,7 +1049,7 @@ int cpu_frequency_change(u64 freq) local_irq_disable(); /* Platform time /first/, as we may be delayed by platform_timer_lock. */ - t->stime_master_stamp = read_platform_stime(); + t->stime_master_stamp = read_platform_stime(NULL); /* TSC-extrapolated time may be bogus after frequency change. */ /*t->stime_local_stamp = get_s_time();*/ t->stime_local_stamp = t->stime_master_stamp; @@ -1364,7 +1367,7 @@ static void time_calibration_tsc_rendezvous(void *_r) if ( r->master_stime == 0 ) { - r->master_stime = read_platform_stime(); + r->master_stime = read_platform_stime(NULL); r->master_tsc_stamp = rdtsc(); } atomic_inc(&r->semaphore); @@ -1409,7 +1412,7 @@ static void time_calibration_std_rendezvous(void *_r) { while ( atomic_read(&r->semaphore) != (total_cpus - 1) ) cpu_relax(); - r->master_stime = read_platform_stime(); + r->master_stime = read_platform_stime(NULL); mb(); /* write r->master_stime /then/ signal */ atomic_inc(&r->semaphore); } @@ -1456,7 +1459,7 @@ void init_percpu_time(void) local_irq_save(flags); t->local_tsc_stamp = rdtsc(); - now = read_platform_stime(); + now = read_platform_stime(NULL); local_irq_restore(flags); t->stime_master_stamp = now;