From patchwork Thu Nov 5 17:09:43 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 7562861 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 C0BDE9F2F7 for ; Thu, 5 Nov 2015 17:13:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DF1992080D for ; Thu, 5 Nov 2015 17:13:10 +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 EFFFB20836 for ; Thu, 5 Nov 2015 17:13:09 +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 1ZuO3U-0001hb-8M; Thu, 05 Nov 2015 17:10:32 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZuO3Q-0000vg-TP for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2015 17:10:30 +0000 X-IronPort-AV: E=Sophos;i="5.20,248,1444694400"; d="scan'208";a="310621938" From: Stefano Stabellini To: Subject: [PATCH 1/3] xen/arm: introduce xen_read_wallclock Date: Thu, 5 Nov 2015 17:09:43 +0000 Message-ID: <1446743385-12848-1-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: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151105_091029_197424_525DE3ED X-CRM114-Status: GOOD ( 11.75 ) X-Spam-Score: -6.9 (------) 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: 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=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 --- arch/arm/Kconfig | 1 + arch/arm/xen/enlighten.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 60be104..a9de420 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1852,6 +1852,7 @@ config XEN depends on CPU_V7 && !CPU_V6 depends on !GENERIC_ATOMIC64 depends on MMU + depends on HAVE_ARM_ARCH_TIMER select ARCH_DMA_ADDR_T_64BIT select ARM_PSCI select SWIOTLB_XEN diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 15621b1..f07383d 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -28,6 +28,8 @@ #include #include #include +#include +#include #include @@ -95,6 +97,32 @@ static unsigned long long xen_stolen_accounting(int cpu) return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline]; } +static void xen_read_wallclock(struct timespec *ts) +{ + u32 version; + u64 delta; + struct timespec 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 = wall_clock->sec; + now.tv_nsec = wall_clock->nsec; + rmb(); /* fetch time before checking version */ + } while ((wall_clock->version & 1) || (version != wall_clock->version)); + + delta = arch_timer_read_counter(); /* time since system boot */ + delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; + + now.tv_nsec = do_div(delta, NSEC_PER_SEC); + now.tv_sec = delta; + + set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); +} + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -218,6 +246,7 @@ static int __init xen_guest_init(void) struct shared_info *shared_info_page = NULL; struct resource res; phys_addr_t grant_frames; + struct timespec ts; if (!xen_domain()) return 0; @@ -291,6 +320,8 @@ static int __init xen_guest_init(void) pv_time_ops.steal_clock = xen_stolen_accounting; static_key_slow_inc(¶virt_steal_enabled); + xen_read_wallclock(&ts); + do_settimeofday(&ts); return 0; }