From patchwork Fri Mar 6 12:47:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11423815 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0B67792A for ; Fri, 6 Mar 2020 12:49:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA1B42084E for ; Fri, 6 Mar 2020 12:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727366AbgCFMtX (ORCPT ); Fri, 6 Mar 2020 07:49:23 -0500 Received: from mail.baikalelectronics.com ([87.245.175.226]:35752 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727387AbgCFMtW (ORCPT ); Fri, 6 Mar 2020 07:49:22 -0500 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 228448030794; Fri, 6 Mar 2020 12:49:21 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id msL3ZZHxO_QW; Fri, 6 Mar 2020 15:49:20 +0300 (MSK) From: To: Thomas Bogendoerfer CC: Serge Semin , Serge Semin , Alexey Malahov , Paul Burton , Ralf Baechle , , Subject: [PATCH 21/22] mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU Date: Fri, 6 Mar 2020 15:47:04 +0300 In-Reply-To: <20200306124705.6595-1-Sergey.Semin@baikalelectronics.ru> References: <20200306124705.6595-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Message-Id: <20200306124921.228448030794@mail.baikalelectronics.ru> Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Serge Semin Due to being embedded into the CPU cores MIPS count/compare timer frequency is changed together with the CPU clocks alteration. In case if frequency really changes the kernel clockevent framework must be notified, otherwise the kernel timers won't work correctly. Fix this by calling clockevents_update_freq() for each r4k clockevent handlers registered per available CPUs. Traditionally MIPS r4k-clock are clocked with CPU frequency divided by 2. But this isn't true for some of the platforms. Due to this we have to save the basic CPU frequency, so then use it to scale the initial timer frequency (mips_hpt_frequency) and pass the updated value further to the clockevent framework. Signed-off-by: Serge Semin Signed-off-by: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Paul Burton Cc: Ralf Baechle --- arch/mips/kernel/cevt-r4k.c | 44 +++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c index dd6a18bc10ab..f24377c1e8d7 100644 --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c @@ -8,6 +8,7 @@ */ #include #include +#include #include #include #include @@ -250,6 +251,49 @@ unsigned int __weak get_c0_compare_int(void) return MIPS_CPU_IRQ_BASE + cp0_compare_irq; } +#ifdef CONFIG_CPU_FREQ + +static unsigned long mips_ref_freq; + +static int cpufreq_callback(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct cpufreq_freqs *freq = data; + struct clock_event_device *cd; + unsigned long rate; + int cpu; + + if (!mips_ref_freq) + mips_ref_freq = freq->old; + + if (val == CPUFREQ_POSTCHANGE) { + rate = cpufreq_scale(mips_hpt_frequency, mips_ref_freq, + freq->new); + + for_each_cpu(cpu, freq->policy->cpus) { + cd = &per_cpu(mips_clockevent_device, cpu); + + clockevents_update_freq(cd, rate); + } + } + + return 0; +} + +static struct notifier_block cpufreq_notifier = { + .notifier_call = cpufreq_callback, +}; + +static int __init register_cpufreq_notifier(void) +{ + return cpufreq_register_notifier(&cpufreq_notifier, + CPUFREQ_TRANSITION_NOTIFIER); + +} +core_initcall(register_cpufreq_notifier); + +#endif /* !CONFIG_CPU_FREQ */ + int r4k_clockevent_init(void) { unsigned int cpu = smp_processor_id();