From mboxrd@z Thu Jan 1 00:00:00 1970 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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 46517C352A4 for ; Fri, 7 Feb 2020 13:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2307221775 for ; Fri, 7 Feb 2020 13:26:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727465AbgBGN0D (ORCPT ); Fri, 7 Feb 2020 08:26:03 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:40773 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726874AbgBGNZ6 (ORCPT ); Fri, 7 Feb 2020 08:25:58 -0500 Received: from p5b06da22.dip0.t-ipconnect.de ([91.6.218.34] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j03da-0003gz-Ri; Fri, 07 Feb 2020 14:25:39 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 068D0100F5A; Fri, 7 Feb 2020 13:25:38 +0000 (GMT) Message-Id: <20200207124402.530143168@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 07 Feb 2020 13:38:50 +0100 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, John Stultz , Vincenzo Frascino , Andy Lutomirski , Christophe Leroy , Paolo Bonzini , Juergen Gross , Michael Kelley , Sasha Levin , Ralf Baechle , Paul Burton , James Hogan , Russell King , Catalin Marinas , Will Deacon , Mark Rutland , Marc Zyngier , Andrei Vagin Subject: [patch V2 03/17] lib/vdso: Allow the high resolution parts to be compiled out References: <20200207123847.339896630@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner If the architecture knows at compile time that there is no VDSO capable clocksource supported it makes sense to optimize the guts of the high resolution parts of the VDSO out at build time. Add a helper function to check whether the VDSO should be high resolution capable and provide a stub which can be overridden by an architecture. Signed-off-by: Thomas Gleixner --- lib/vdso/gettimeofday.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -38,6 +38,13 @@ u64 vdso_calc_delta(u64 cycles, u64 last } #endif +#ifndef __arch_vdso_hres_capable +static inline bool __arch_vdso_hres_capable(void) +{ + return true; +} +#endif + #ifdef CONFIG_TIME_NS static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk, struct __kernel_timespec *ts) @@ -101,6 +108,10 @@ static __always_inline int do_hres(const u64 cycles, last, sec, ns; u32 seq; + /* Allows to compile the high resolution parts out */ + if (!__arch_vdso_hres_capable()) + return -1; + do { /* * Open coded to handle VCLOCK_TIMENS. Time namespace