From patchwork Wed Nov 11 16:51:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 7596861 Return-Path: X-Original-To: patchwork-linux-arm@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 732FB9F2F7 for ; Wed, 11 Nov 2015 16:55:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9A1382066E for ; Wed, 11 Nov 2015 16:55:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 85A5420667 for ; Wed, 11 Nov 2015 16:55:11 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZwYeE-0005GU-Fh; Wed, 11 Nov 2015 16:53:26 +0000 Received: from smtp02.citrix.com ([66.165.176.63]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZwYdP-0004d7-2t for linux-arm-kernel@lists.infradead.org; Wed, 11 Nov 2015 16:52:37 +0000 X-IronPort-AV: E=Sophos;i="5.20,276,1444694400"; d="scan'208";a="317443584" From: Stefano Stabellini To: Subject: [PATCH v3 5/6] xen/arm: introduce xen_read_wallclock Date: Wed, 11 Nov 2015 16:51:35 +0000 Message-ID: <1447260696-450-5-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151111_085235_612999_228405AB X-CRM114-Status: GOOD ( 11.80 ) X-Spam-Score: -4.6 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, Ian.Campbell@citrix.com, linux-arm-kernel@lists.infradead.org, Stefano Stabellini Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, 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 Read the wallclock from the shared info page at boot time. Signed-off-by: Stefano Stabellini --- Changes in v3: - use ktime_get_ns instead of calling into the arch_timer functions directly - read the wallclock from the late_initcall Changes in v2: - properly convert arch_timer ticker to nsec - use timespec64 interfaces - use sec_hi to get a 64-bit seconds value --- arch/arm/xen/enlighten.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 2f57ba3..eede8e9 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -28,6 +28,7 @@ #include #include #include +#include #include @@ -95,6 +96,30 @@ static unsigned long long xen_stolen_accounting(int cpu) return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline]; } +static void xen_read_wallclock(struct timespec64 *ts) +{ + u32 version; + u64 delta; + struct timespec64 now; + struct shared_info *s = HYPERVISOR_shared_info; + struct pvclock_wall_clock *wall_clock = &(s->wc); + + /* get wallclock at system boot */ + do { + version = wall_clock->version; + rmb(); /* fetch version before time */ + now.tv_sec = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec; + now.tv_nsec = wall_clock->nsec; + rmb(); /* fetch time before checking version */ + } while ((wall_clock->version & 1) || (version != wall_clock->version)); + + /* time since system boot */ + delta = ktime_get_ns(); + delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; + + *ts = ns_to_timespec64(delta); +} + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -303,6 +328,11 @@ static int __init xen_pm_init(void) pm_power_off = xen_power_off; arm_pm_restart = xen_restart; + if (!xen_initial_domain()) { + struct timespec64 ts; + xen_read_wallclock(&ts); + do_settimeofday64(&ts); + } return 0; }