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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS 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 3237FC64EB1 for ; Fri, 7 Dec 2018 17:59:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9CA22082D for ; Fri, 7 Dec 2018 17:59:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="R8Jpelen" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9CA22082D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sifive.com 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 S1726280AbeLGR7A (ORCPT ); Fri, 7 Dec 2018 12:59:00 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:42426 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726083AbeLGR67 (ORCPT ); Fri, 7 Dec 2018 12:58:59 -0500 Received: by mail-pg1-f193.google.com with SMTP id d72so2035349pga.9 for ; Fri, 07 Dec 2018 09:58:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=date:subject:in-reply-to:cc:from:to:message-id:mime-version :content-transfer-encoding; bh=A7O+8UhdX6omDOFY0XLZhv+eaCAxPxhbfqQJ8TGsiCo=; b=R8JpelenRlbRKmrd41K0aiUWnHuUcHcMfxFAIw8n9rtEIvl7JoANB3W0u3IXSLdq/B dqZU76vaG59eynuUeT6af5araUkrjRQ8uUrmIe2uTMJa7tkvSfjN33K2eayD00EERH0/ 2hjgaiyqRFAA9qkYSVj1xd9K7C3JmNPDUXOKS3ltxdt4BAMpNha95vX4TS94nIoMpqWE syrH8IWd//bBJ+Mclkb3aHPAHEoop8yrfebazb2uQr/PgTMsZkPROnpxWb/Ar790vaXH 0k+u7BcNvk3lXUNAATL/Ryw6U9AMsrESpUUlMoO3NWwzIBuu0dZ1FPXcZ4Cpcm72LKqh T5JQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:subject:in-reply-to:cc:from:to:message-id :mime-version:content-transfer-encoding; bh=A7O+8UhdX6omDOFY0XLZhv+eaCAxPxhbfqQJ8TGsiCo=; b=kteZTKMJivPtSkpjDLW8CtcB+URS0UxJuvCgTHdPRnQVKJ1SwgZenYPudHeZmR8Edw g5oah0bhT8V08dqhtbS5DRIJ+XOGF+PVG+1sleLNvOHT/8ENW0Q3KBMVA10ZcMH9JkJ3 OIginXBR0EqNItsLLQvacy41t8vtSJUrlLEGHWe05j/Z8X2Uvx+sy0TVi0EVv2rh4b2y o0uE8YuBlGBH7kQQnf2Bt5TZ/LXwqxkvQ6BGeNfV8twjOUsb+YwlCeA+c79/Ooogi/kQ H5MO1xQzVCjovuwLyw+r68VsSH1isMrv+WTQMNSlvrP+zslM1ef1HUBOx3CyR18h4F/3 XJeg== X-Gm-Message-State: AA+aEWbbjVzaQO5Cf+fZdd9FePahyfhRbWJvc3ZoCC9iEkrh4/8u5J7q ccQnHhXmUsbJdXkhtn9wuGbcaQ== X-Google-Smtp-Source: AFSGD/UvUr6eHOVVNoCXD5NDhhmI5/TiXeQvRUzimKhg477Ui9bk4LnzDwc0phQHaY75lnIGWdygww== X-Received: by 2002:a63:31d0:: with SMTP id x199mr2798749pgx.10.1544205538165; Fri, 07 Dec 2018 09:58:58 -0800 (PST) Received: from localhost ([216.3.10.7]) by smtp.gmail.com with ESMTPSA id 69sm4707846pgg.86.2018.12.07.09.58.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Dec 2018 09:58:57 -0800 (PST) Date: Fri, 07 Dec 2018 09:58:57 -0800 (PST) X-Google-Original-Date: Fri, 07 Dec 2018 09:58:25 PST (-0800) Subject: Re: [PATCH v2 2/2] clocksource: riscv_timer: Provide sched_clock In-Reply-To: <20181204102952.21297-3-anup@brainfault.org> CC: daniel.lezcano@linaro.org, tglx@linutronix.de, aou@eecs.berkeley.edu, atish.patra@wdc.com, Christoph Hellwig , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, anup@brainfault.org From: Palmer Dabbelt To: anup@brainfault.org Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 04 Dec 2018 02:29:52 PST (-0800), anup@brainfault.org wrote: > Currently, we don't have a sched_clock registered for RISC-V systems. > This means Linux time keeping will use jiffies (running at HZ) as the > default sched_clock. > > To avoid this, we explicity provide sched_clock using RISC-V rdtime > instruction (similar to riscv_timer clocksource). > > Signed-off-by: Anup Patel > --- > drivers/clocksource/Kconfig | 2 +- > drivers/clocksource/riscv_timer.c | 9 +++++++++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > index 55c77e44bb2d..19649abd7c75 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -611,7 +611,7 @@ config ATCPIT100_TIMER > > config RISCV_TIMER > bool "Timer for the RISC-V platform" > - depends on RISCV > + depends on GENERIC_SCHED_CLOCK && RISCV > default y > select TIMER_PROBE > select TIMER_OF > diff --git a/drivers/clocksource/riscv_timer.c b/drivers/clocksource/riscv_timer.c > index 084e97dc10ed..431892200a08 100644 > --- a/drivers/clocksource/riscv_timer.c > +++ b/drivers/clocksource/riscv_timer.c > @@ -8,6 +8,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -49,6 +50,11 @@ static unsigned long long riscv_clocksource_rdtime(struct clocksource *cs) > return get_cycles64(); > } > > +static u64 riscv_sched_clock(void) > +{ > + return get_cycles64(); > +} > + > static DEFINE_PER_CPU(struct clocksource, riscv_clocksource) = { > .name = "riscv_clocksource", > .rating = 300, > @@ -97,6 +103,9 @@ static int __init riscv_timer_init_dt(struct device_node *n) > cs = per_cpu_ptr(&riscv_clocksource, cpuid); > clocksource_register_hz(cs, riscv_timebase); > > + sched_clock_register(riscv_sched_clock, > + BITS_PER_LONG, riscv_timebase); > + > error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING, > "clockevents/riscv/timer:starting", > riscv_timer_starting_cpu, riscv_timer_dying_cpu); Reviewed-by: Palmer Dabbelt