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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 CE4A3C48BE5 for ; Wed, 16 Jun 2021 06:48:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7F41611CE for ; Wed, 16 Jun 2021 06:48:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231610AbhFPGu0 (ORCPT ); Wed, 16 Jun 2021 02:50:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231490AbhFPGuX (ORCPT ); Wed, 16 Jun 2021 02:50:23 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71FC4C061760 for ; Tue, 15 Jun 2021 23:48:18 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id v12so612655plo.10 for ; Tue, 15 Jun 2021 23:48:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=G2o9MLJnJsw+6A1+/Voo6W0MsEPUjxURc0icFdbia4A=; b=o3ZGRm+0PhR57FZeE69PXo3qtAMRcOMhbEPnUNPCmO6a3bopp2N37v+kmO19XhecJk d3fAwvpax0VF0gdRK99Gg4WeuW8tMXK7i/gICzuT6F+LczfGHLkIDT840edL0ZLQBuDq YCpzFBNxvRYhinwex9s/GmHopX+OQ7YH2HlsKvPIbmpp0ICcVQm/fzAo3DUcy3JkN0TV MwKlKRz8wqfI4Vv82WBDRXlMTO93AKiAYh5Bx2YPL/ValHsZQ9U7fINE4lqsxaIczaDo tcjkTMqK0LBuaT+RcZkqhbcpFfEFCbYlDiBOf2q1jktpKcLMXiGdXDUy0yezAqW15yO+ QgJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=G2o9MLJnJsw+6A1+/Voo6W0MsEPUjxURc0icFdbia4A=; b=Q7FS0qnZmVHnfbkox4F2TgB2Hpp4DPpyr7eVt7ltvnqsrt3XoP0CYjX+sBQBpQmHUv upGrCG5G2qSE6d9UMA636Cky0l/8ROdd7FWlAJZ31NUNU/ph5unuyCFlwCBrq0V0PCdU 6UwNd4hw1dAMYW6vmqHboOz1SppXUwkRSAYpbHQszjwX0kJUAooD1UFtRbAt9uR0Z47z wzASI8qxdJlCNeiJH0847638DWkaCm1B4V/NH1gwuIc4kv/TeLQF+5CJj4voYhH1+Wi+ fILOuBrkVXFSWQt75J51pTRnXKcaHfwEhikTLf6H6NGAXIg1Bmqe7BJHwo7N6hyi9jwk exsA== X-Gm-Message-State: AOAM533s/lxH0M4UjU1XR7GCW4qnK6rvkv9cJM7OyXCEuMkpOFVEgAC2 vgIYbhoVuByggWAUJKH1jUDLOc0Z5RBhPw== X-Google-Smtp-Source: ABdhPJxpzad74jam2+j2zJsuqJEtQzcp85IAyX1hiOrexHl514pCD7fFd/TmWVot90x4+5TugFFUsw== X-Received: by 2002:a17:902:b609:b029:118:8a66:6963 with SMTP id b9-20020a170902b609b02901188a666963mr7854149pls.65.1623826097975; Tue, 15 Jun 2021 23:48:17 -0700 (PDT) Received: from localhost ([136.185.134.182]) by smtp.gmail.com with ESMTPSA id d8sm1127995pfq.198.2021.06.15.23.48.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Jun 2021 23:48:17 -0700 (PDT) From: Viresh Kumar To: Rafael Wysocki , Ionela Voinescu , Viresh Kumar , Jonathan Corbet Cc: linux-pm@vger.kernel.org, Vincent Guittot , Qian Cai , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 1/3] cpufreq: Add start_cpu() and stop_cpu() callbacks Date: Wed, 16 Jun 2021 12:18:07 +0530 Message-Id: <2ffbaf079a21c2810c402cb5bba4e9c14c4a0ff4.1623825725.git.viresh.kumar@linaro.org> X-Mailer: git-send-email 2.31.1.272.g89b43f80a514 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On CPU hot-unplug, the cpufreq core doesn't call any driver specific callback unless all the CPUs of a policy went away, in which case we call stop_cpu() callback. For the CPPC cpufreq driver, we need to perform per-cpu init/exit work which that can't be performed from policy specific init()/exit() callbacks. This patch adds a new callback, start_cpu() and modifies the stop_cpu() callback, to perform such CPU specific work. These routines are called whenever a CPU is added or removed from a policy. Note that this also moves the setting of policy->cpus to online CPUs only, outside of rwsem as we needed to call start_cpu() for online CPUs only. This shouldn't have any side effects. Signed-off-by: Viresh Kumar --- Documentation/cpu-freq/cpu-drivers.rst | 7 +++++-- drivers/cpufreq/cpufreq.c | 19 +++++++++++++++---- include/linux/cpufreq.h | 5 ++++- 3 files changed, 24 insertions(+), 7 deletions(-) diff --git a/Documentation/cpu-freq/cpu-drivers.rst b/Documentation/cpu-freq/cpu-drivers.rst index a697278ce190..15cfe42b4075 100644 --- a/Documentation/cpu-freq/cpu-drivers.rst +++ b/Documentation/cpu-freq/cpu-drivers.rst @@ -71,8 +71,11 @@ And optionally .exit - A pointer to a per-policy cleanup function called during CPU_POST_DEAD phase of cpu hotplug process. - .stop_cpu - A pointer to a per-policy stop function called during - CPU_DOWN_PREPARE phase of cpu hotplug process. + .start_cpu - A pointer to a per-policy per-cpu start function called + during CPU online phase. + + .stop_cpu - A pointer to a per-policy per-cpu stop function called + during CPU offline phase. .suspend - A pointer to a per-policy suspend function which is called with interrupts disabled and _after_ the governor is stopped for the diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 802abc925b2a..128dfb1b0cdf 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1119,6 +1119,10 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp cpumask_set_cpu(cpu, policy->cpus); + /* Do CPU specific initialization if required */ + if (cpufreq_driver->start_cpu) + cpufreq_driver->start_cpu(policy, cpu); + if (has_target()) { ret = cpufreq_start_governor(policy); if (ret) @@ -1375,13 +1379,19 @@ static int cpufreq_online(unsigned int cpu) cpumask_copy(policy->related_cpus, policy->cpus); } - down_write(&policy->rwsem); /* * affected cpus must always be the one, which are online. We aren't * managing offline cpus here. */ cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); + /* Do CPU specific initialization if required */ + if (cpufreq_driver->start_cpu) { + for_each_cpu(j, policy->cpus) + cpufreq_driver->start_cpu(policy, j); + } + + down_write(&policy->rwsem); if (new_policy) { for_each_cpu(j, policy->related_cpus) { per_cpu(cpufreq_cpu_data, j) = policy; @@ -1581,6 +1591,10 @@ static int cpufreq_offline(unsigned int cpu) policy->cpu = cpumask_any(policy->cpus); } + /* Do CPU specific de-initialization if required */ + if (cpufreq_driver->stop_cpu) + cpufreq_driver->stop_cpu(policy, cpu); + /* Start governor again for active policy */ if (!policy_is_inactive(policy)) { if (has_target()) { @@ -1597,9 +1611,6 @@ static int cpufreq_offline(unsigned int cpu) policy->cdev = NULL; } - if (cpufreq_driver->stop_cpu) - cpufreq_driver->stop_cpu(policy); - if (has_target()) cpufreq_exit_governor(policy); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 353969c7acd3..c281b3df4e2f 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -371,7 +371,10 @@ struct cpufreq_driver { int (*online)(struct cpufreq_policy *policy); int (*offline)(struct cpufreq_policy *policy); int (*exit)(struct cpufreq_policy *policy); - void (*stop_cpu)(struct cpufreq_policy *policy); + + /* CPU specific start/stop */ + void (*start_cpu)(struct cpufreq_policy *policy, unsigned int cpu); + void (*stop_cpu)(struct cpufreq_policy *policy, unsigned int cpu); int (*suspend)(struct cpufreq_policy *policy); int (*resume)(struct cpufreq_policy *policy); -- 2.31.1.272.g89b43f80a514