From patchwork Thu May 21 00:34:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11561843 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 57F4B13B1 for ; Thu, 21 May 2020 00:35:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AD252075F for ; Thu, 21 May 2020 00:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727837AbgEUAfj (ORCPT ); Wed, 20 May 2020 20:35:39 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:33048 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727798AbgEUAfg (ORCPT ); Wed, 20 May 2020 20:35:36 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id E97E38030791; Thu, 21 May 2020 00:35:33 +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 w9zTcyg2r2ci; Thu, 21 May 2020 03:35:33 +0300 (MSK) From: Serge Semin To: Thomas Bogendoerfer CC: Serge Semin , Serge Semin , Alexey Malahov , Paul Burton , Ralf Baechle , Greg Kroah-Hartman , Arnd Bergmann , Rob Herring , , afzal mohammed , , Subject: [PATCH v3 14/14] mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU Date: Thu, 21 May 2020 03:34:43 +0300 Message-ID: <20200521003443.11385-15-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200521003443.11385-1-Sergey.Semin@baikalelectronics.ru> References: <20200521003443.11385-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org 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 Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Paul Burton Cc: Ralf Baechle Cc: Greg Kroah-Hartman Cc: Arnd Bergmann Cc: Rob Herring Cc: devicetree@vger.kernel.org --- Changelog v3: - Add r4k_ prefix to the cpufreq change notifier methods. --- 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 17a9cbb8b3df..995ad9e69ded 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 r4k_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 r4k_cpufreq_notifier = { + .notifier_call = r4k_cpufreq_callback, +}; + +static int __init r4k_register_cpufreq_notifier(void) +{ + return cpufreq_register_notifier(&r4k_cpufreq_notifier, + CPUFREQ_TRANSITION_NOTIFIER); + +} +core_initcall(r4k_register_cpufreq_notifier); + +#endif /* !CONFIG_CPU_FREQ */ + int r4k_clockevent_init(void) { unsigned long flags = IRQF_PERCPU | IRQF_TIMER | IRQF_SHARED;