From patchwork Mon Jan 23 04:41:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Viresh Kumar X-Patchwork-Id: 9531755 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3595F6020B for ; Mon, 23 Jan 2017 04:44:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 27B21279E0 for ; Mon, 23 Jan 2017 04:44:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1BD4527D5E; Mon, 23 Jan 2017 04:44:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 97AB3279E0 for ; Mon, 23 Jan 2017 04:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750834AbdAWEmK (ORCPT ); Sun, 22 Jan 2017 23:42:10 -0500 Received: from mail-pg0-f49.google.com ([74.125.83.49]:36467 "EHLO mail-pg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750730AbdAWEmH (ORCPT ); Sun, 22 Jan 2017 23:42:07 -0500 Received: by mail-pg0-f49.google.com with SMTP id t6so41347461pgt.3 for ; Sun, 22 Jan 2017 20:42:07 -0800 (PST) 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 :in-reply-to:references; bh=DmLR1pjlbs4CALqrv2DjGbuLOVno49NO9Aub0WCkhL4=; b=N8sg5vJALhwZjnGnMH8bdwHPkyWtd8wO3mscNQBt5ARtn2p4qjsKJVU2UK4Af+sZEW nvWs24fPpuXD0rxZMZwKiJGrOQqxnJyhG2RDF8KDwVvauaTptJ+Y3Rfuz+mib50E2MzG E1RFPESM0U53ctdH4dHSnEe5Itq+Tw6VcqddE= 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:in-reply-to:references; bh=DmLR1pjlbs4CALqrv2DjGbuLOVno49NO9Aub0WCkhL4=; b=H7R+OBu+ippeoucS4NULHCgRtOiPb1ggYlvhiSQFyDNg9QJruEqnjpyiK/017xkA3S 3qKyvoPWTqteqXjkuMh3yAAokuneGBDm5qbs739YO+2XC5MiKXkPk/sr4TdtHNW0E9Dn 1OcrOEE7mKpM//Pu86U4AK/i61BrQpzqHOdEYwf2fYJVAX4pVBFL/B0jPQN/VRyDNqxT 2AomTE4No9sJn25PG0UgacWBbIikeC3CLrUO/SCqgDFND/F4/uaSrubPxxDB4wSzhAI7 MlWlYt6HwNYAPHZjWe4A+sR6HOPHXIAPBg2GxGC+8lLy9aZ9R05BvBkTQ1tER7zv3JWP YPtg== X-Gm-Message-State: AIkVDXI2Op3lb84hWAFJ5JFcGhNzDFJzyoZGpaUmpUcv7pdNtfxvvPmGOC2Jwe4RbaVARwSI X-Received: by 10.99.129.193 with SMTP id t184mr30055365pgd.129.1485146527126; Sun, 22 Jan 2017 20:42:07 -0800 (PST) Received: from localhost ([122.171.65.82]) by smtp.gmail.com with ESMTPSA id 66sm32839682pgg.47.2017.01.22.20.42.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jan 2017 20:42:06 -0800 (PST) From: Viresh Kumar To: Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Guittot , Viresh Kumar Subject: [PATCH V2 02/12] PM / OPP: Add 'struct kref' to OPP table Date: Mon, 23 Jan 2017 10:11:42 +0530 Message-Id: <2739c3b223b586377f6fb6b0570f74afa81848e4.1485146406.git.viresh.kumar@linaro.org> X-Mailer: git-send-email 2.7.1.410.g6faf27b In-Reply-To: References: In-Reply-To: References: Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add kref to struct opp_table for easier accounting of the OPP table. Note that the new routine dev_pm_opp_get_opp_table() takes the reference from under the opp_table_lock, which guarantees that the OPP table doesn't get freed unless dev_pm_opp_put_opp_table() is called for the OPP table. Two separate release mechanisms are added: locked and unlocked. In unlocked version the routines aren't required to take/drop opp_table_lock as the callers have already done that. This is required to avoid breaking git bisect, otherwise we may get lockdeps between commits. Once all the users of OPP table are updated the unlocked version shall be removed. Signed-off-by: Viresh Kumar Reviewed-by: Stephen Boyd --- drivers/base/power/opp/core.c | 51 +++++++++++++++++++++++++++++++++++++++++-- drivers/base/power/opp/opp.h | 3 +++ include/linux/pm_opp.h | 10 +++++++++ 3 files changed, 62 insertions(+), 2 deletions(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index dcebd5efb6a1..ccc0d8913fd0 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -855,6 +855,7 @@ static struct opp_table *_allocate_opp_table(struct device *dev) srcu_init_notifier_head(&opp_table->srcu_head); INIT_LIST_HEAD(&opp_table->opp_list); mutex_init(&opp_table->lock); + kref_init(&opp_table->kref); /* Secure the device table modification */ list_add_rcu(&opp_table->node, &opp_tables); @@ -894,8 +895,36 @@ static void _kfree_device_rcu(struct rcu_head *head) kfree_rcu(opp_table, rcu_head); } -static void _free_opp_table(struct opp_table *opp_table) +void _get_opp_table_kref(struct opp_table *opp_table) { + kref_get(&opp_table->kref); +} + +struct opp_table *dev_pm_opp_get_opp_table(struct device *dev) +{ + struct opp_table *opp_table; + + /* Hold our table modification lock here */ + mutex_lock(&opp_table_lock); + + opp_table = _find_opp_table(dev); + if (!IS_ERR(opp_table)) { + _get_opp_table_kref(opp_table); + goto unlock; + } + + opp_table = _allocate_opp_table(dev); + +unlock: + mutex_unlock(&opp_table_lock); + + return opp_table; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table); + +static void _opp_table_kref_release_unlocked(struct kref *kref) +{ + struct opp_table *opp_table = container_of(kref, struct opp_table, kref); struct opp_device *opp_dev; /* Release clk */ @@ -916,6 +945,24 @@ static void _free_opp_table(struct opp_table *opp_table) _kfree_device_rcu); } +static void dev_pm_opp_put_opp_table_unlocked(struct opp_table *opp_table) +{ + kref_put(&opp_table->kref, _opp_table_kref_release_unlocked); +} + +static void _opp_table_kref_release(struct kref *kref) +{ + _opp_table_kref_release_unlocked(kref); + mutex_unlock(&opp_table_lock); +} + +void dev_pm_opp_put_opp_table(struct opp_table *opp_table) +{ + kref_put_mutex(&opp_table->kref, _opp_table_kref_release, + &opp_table_lock); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table); + /** * _remove_opp_table() - Removes a OPP table * @opp_table: OPP table to be removed. @@ -939,7 +986,7 @@ static void _remove_opp_table(struct opp_table *opp_table) if (opp_table->set_opp) return; - _free_opp_table(opp_table); + dev_pm_opp_put_opp_table_unlocked(opp_table); } void _opp_free(struct dev_pm_opp *opp) diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h index 105243b06373..aae4d8f480ef 100644 --- a/drivers/base/power/opp/opp.h +++ b/drivers/base/power/opp/opp.h @@ -131,6 +131,7 @@ enum opp_table_access { * @rcu_head: RCU callback head used for deferred freeing * @dev_list: list of devices that share these OPPs * @opp_list: table of opps + * @kref: for reference count of the table. * @lock: mutex protecting the opp_list. * @np: struct device_node pointer for opp's DT node. * @clock_latency_ns_max: Max clock latency in nanoseconds. @@ -164,6 +165,7 @@ struct opp_table { struct rcu_head rcu_head; struct list_head dev_list; struct list_head opp_list; + struct kref kref; struct mutex lock; struct device_node *np; @@ -192,6 +194,7 @@ struct opp_table { }; /* Routines internal to opp core */ +void _get_opp_table_kref(struct opp_table *opp_table); struct opp_table *_find_opp_table(struct device *dev); struct opp_table *_add_opp_table(struct device *dev); struct opp_device *_add_opp_dev(const struct device *dev, struct opp_table *opp_table); diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 66a02deeb03f..d867c6b25f9a 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -78,6 +78,9 @@ struct dev_pm_set_opp_data { #if defined(CONFIG_PM_OPP) +struct opp_table *dev_pm_opp_get_opp_table(struct device *dev); +void dev_pm_opp_put_opp_table(struct opp_table *opp_table); + unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp); unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp); @@ -126,6 +129,13 @@ int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) void dev_pm_opp_remove_table(struct device *dev); void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask); #else +static inline struct opp_table *dev_pm_opp_get_opp_table(struct device *dev) +{ + return ERR_PTR(-ENOTSUPP); +} + +static inline void dev_pm_opp_put_opp_table(struct opp_table *opp_table) {} + static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) { return 0;