From patchwork Fri Feb 14 23:27:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 212843 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3357C3F68F for ; Fri, 14 Feb 2020 23:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAD372086A for ; Fri, 14 Feb 2020 23:27:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="wIWeAYgn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727963AbgBNX1s (ORCPT ); Fri, 14 Feb 2020 18:27:48 -0500 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:1035 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727649AbgBNX1s (ORCPT ); Fri, 14 Feb 2020 18:27:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581722867; x=1613258867; h=date:from:to:subject:message-id:references:mime-version: in-reply-to; bh=w2YudPijii+dzE2cW4maD6E6FQY1WRpU8HmwPnvoM5k=; b=wIWeAYgn40YOrYt2FC6c5BTIphd+RIWYLpUy4SbFnDl1Cp9drlyhvVc6 N6VynUKymRW5+/IXaVCtxQa6ACgoS7pFMti42jWpUJ9wV9sdUlKLIfV9c JA7UZLw1SXo1k6n10q7e3xqgNSG/14gZHHn0S6xD+tF38IR+IZUBgLjbu 0=; IronPort-SDR: 4QzLk7agU2cCkHMRbCkf+yxdh7O3HX/h13ILndMQD5DBXAC5QIGb3xBDBxJz+ZI2EvA/bpTqBv mUC+a3+dOYhg== X-IronPort-AV: E=Sophos;i="5.70,442,1574121600"; d="scan'208";a="26558954" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1d-74cf8b49.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 14 Feb 2020 23:27:45 +0000 Received: from EX13MTAUEB002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-74cf8b49.us-east-1.amazon.com (Postfix) with ESMTPS id 9E2B3C0845; Fri, 14 Feb 2020 23:27:38 +0000 (UTC) Received: from EX13D08UEB001.ant.amazon.com (10.43.60.245) by EX13MTAUEB002.ant.amazon.com (10.43.60.12) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 14 Feb 2020 23:27:25 +0000 Received: from EX13MTAUEB002.ant.amazon.com (10.43.60.12) by EX13D08UEB001.ant.amazon.com (10.43.60.245) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 14 Feb 2020 23:27:25 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.60.234) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Fri, 14 Feb 2020 23:27:19 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id F07DD4028E; Fri, 14 Feb 2020 23:27:18 +0000 (UTC) Date: Fri, 14 Feb 2020 23:27:18 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 10/12] xen: Introduce wrapper for save/restore sched clock offset Message-ID: <305f20fbf503b637b1a08b7bec543f49271a725a.1581721799.git.anchalag@amazon.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Introduce wrappers for save/restore xen_sched_clock_offset to be used by PM hibernation code to avoid system instability during resume. Signed-off-by: Anchal Agarwal --- arch/x86/xen/time.c | 15 +++++++++++++-- arch/x86/xen/xen-ops.h | 2 ++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 8cf632dda605..eeb6d3d2eaab 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -379,12 +379,23 @@ static const struct pv_time_ops xen_time_ops __initconst = { static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; static u64 xen_clock_value_saved; +/*This is needed to maintain a monotonic clock value during PM hibernation */ +void xen_save_sched_clock_offset(void) +{ + xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; +} + +void xen_restore_sched_clock_offset(void) +{ + xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; +} + void xen_save_time_memory_area(void) { struct vcpu_register_time_memory_area t; int ret; - xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; + xen_save_sched_clock_offset(); if (!xen_clock) return; @@ -426,7 +437,7 @@ void xen_restore_time_memory_area(void) out: /* Need pvclock_resume() before using xen_clocksource_read(). */ pvclock_resume(); - xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; + xen_restore_sched_clock_offset(); } static void xen_setup_vsyscall_time_info(void) diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index d84c357994bd..9f49124df033 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -72,6 +72,8 @@ void xen_save_time_memory_area(void); void xen_restore_time_memory_area(void); void xen_init_time_ops(void); void xen_hvm_init_time_ops(void); +void xen_save_sched_clock_offset(void); +void xen_restore_sched_clock_offset(void); irqreturn_t xen_debug_interrupt(int irq, void *dev_id);