From patchwork Thu Nov 12 17:30:46 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 7604281 Return-Path: X-Original-To: patchwork-linux-arm@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 545E2BF90C for ; Thu, 12 Nov 2015 17:33:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 86C162070D for ; Thu, 12 Nov 2015 17:33:23 +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 AA898206B8 for ; Thu, 12 Nov 2015 17:33:22 +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 1Zwvic-0007Gq-8i; Thu, 12 Nov 2015 17:31:30 +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 1ZwviY-0007B7-37 for linux-arm-kernel@lists.infradead.org; Thu, 12 Nov 2015 17:31:26 +0000 X-IronPort-AV: E=Sophos;i="5.20,282,1444694400"; d="scan'208";a="317718779" From: Stefano Stabellini To: Subject: [PATCH v4 5/7] xen/arm: introduce xen_read_wallclock Date: Thu, 12 Nov 2015 17:30:46 +0000 Message-ID: <1447349448-22610-5-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-20151112_093126_387660_6FC742A9 X-CRM114-Status: GOOD ( 11.61 ) 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=-4.6 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 Acked-by: Arnd Bergmann --- Changes in v4: - simplify xen_read_wallclock 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 | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 2f57ba3..6ae4ef5 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -28,6 +28,7 @@ #include #include #include +#include #include @@ -95,6 +96,27 @@ 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; + struct timespec64 now, ts_monotonic; + 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 */ + ktime_get_ts64(&ts_monotonic); + *ts = timespec64_add(now, ts_monotonic); +} + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -303,6 +325,11 @@ 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; }