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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 AE004ECDFD0 for ; Fri, 14 Sep 2018 12:52:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E51E20882 for ; Fri, 14 Sep 2018 12:52:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E51E20882 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728382AbeINSGi (ORCPT ); Fri, 14 Sep 2018 14:06:38 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:49617 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728125AbeINSG1 (ORCPT ); Fri, 14 Sep 2018 14:06:27 -0400 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1g0nZs-0005wt-Ds; Fri, 14 Sep 2018 14:52:04 +0200 Message-Id: <20180914125119.081037164@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 14 Sep 2018 14:50:17 +0200 From: Thomas Gleixner To: LKML Cc: Andy Lutomirski , x86@kernel.org, Peter Zijlstra , Matt Rickard , Stephen Boyd , John Stultz , Florian Weimer , "K. Y. Srinivasan" , Vitaly Kuznetsov , devel@linuxdriverproject.org, virtualization@lists.linux-foundation.org, Paolo Bonzini , Arnd Bergmann , Juergen Gross Subject: [patch 11/11] x66/vdso: Add CLOCK_TAI support References: <20180914125006.349747096@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=x66-vdso--Add-CLOCK_TAI-support.patch Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the storage array in place it's now trivial to support CLOCK_TAI in the vdso. Instead of extending the array to accomodate CLOCK_TAI, make use of the fact that: - CLOCK ids are set in stone - CLOCK_THREAD_CPUTIME is never going to be supported in the VDSO so the array slot 3 is unused - CLOCK_TAI is id 11 which results in 3 when masked with 0x3 Add the mask to the basetime array lookup and set up the CLOCK_TAI base time in update_vsyscall(). The performance impact of the mask operation is within the noise. Signed-off-by: Thomas Gleixner --- arch/x86/entry/vdso/vclock_gettime.c | 2 +- arch/x86/entry/vsyscall/vsyscall_gtod.c | 4 ++++ arch/x86/include/asm/vgtod.h | 6 +++++- 3 files changed, 10 insertions(+), 2 deletions(-) --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -140,7 +140,7 @@ notrace static inline u64 vgetcyc(int mo notrace static int do_hres(clockid_t clk, struct timespec *ts) { - struct vgtod_ts *base = >od->basetime[clk]; + struct vgtod_ts *base = >od->basetime[clk & VGTOD_HRES_MASK]; u64 cycles, last, ns; unsigned int seq; --- a/arch/x86/entry/vsyscall/vsyscall_gtod.c +++ b/arch/x86/entry/vsyscall/vsyscall_gtod.c @@ -51,6 +51,10 @@ void update_vsyscall(struct timekeeper * base->sec = tk->xtime_sec; base->nsec = tk->tkr_mono.xtime_nsec; + base = &vdata->basetime[VGTOD_TAI]; + base->sec = tk->xtime_sec + (s64)tk->tai_offset; + base->nsec = tk->tkr_mono.xtime_nsec; + base = &vdata->basetime[CLOCK_MONOTONIC]; base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; nsec = tk->tkr_mono.xtime_nsec; --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -19,9 +19,13 @@ struct vgtod_ts { }; #define VGTOD_BASES (CLOCK_MONOTONIC_COARSE + 1) -#define VGTOD_HRES (BIT(CLOCK_REALTIME) | BIT(CLOCK_MONOTONIC)) +#define VGTOD_HRES (BIT(CLOCK_REALTIME) | BIT(CLOCK_MONOTONIC) | BIT(CLOCK_TAI)) #define VGTOD_COARSE (BIT(CLOCK_REALTIME_COARSE) | BIT(CLOCK_MONOTONIC_COARSE)) +/* Abuse CLOCK_THREAD_CPUTIME_ID for VGTOD CLOCK TAI */ +#define VGTOD_HRES_MASK 0x3 +#define VGTOD_TAI (CLOCK_TAI & VGTOD_HRES_MASK) + /* * vsyscall_gtod_data will be accessed by 32 and 64 bit code at the same time * so be carefull by modifying this structure.