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,URIBL_BLOCKED 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 70269C43387 for ; Fri, 28 Dec 2018 15:37:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3458020869 for ; Fri, 28 Dec 2018 15:37:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="CJJtLhYn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732528AbeL1Pha (ORCPT ); Fri, 28 Dec 2018 10:37:30 -0500 Received: from mail-vs1-f67.google.com ([209.85.217.67]:35292 "EHLO mail-vs1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732018AbeL1Pha (ORCPT ); Fri, 28 Dec 2018 10:37:30 -0500 Received: by mail-vs1-f67.google.com with SMTP id e7so13171816vsc.2 for ; Fri, 28 Dec 2018 07:37:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YeoCcLIO6TBLl7FrMpKnuYcluO173e+MPWd9CDhxy/Y=; b=CJJtLhYnwGPturDSXtLn+1tZsCwTm8uY2tgJfviLACaoCGAsFFKazaWsqTziOZBi0Y 7AuPxLEEDfBdOZPHdcgaVFajfIM0Gqn8c9ACU8wdy3lCD7dzK9XzboBjfeJF15+WJcD0 /AgQcNMov2LQxMufo/0xdG5+lK++oARnlvV6U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YeoCcLIO6TBLl7FrMpKnuYcluO173e+MPWd9CDhxy/Y=; b=NjCjjGukAKinIShO1ZICtP0ApMa2qwVZKOH8nS9B6Zl3rMqMiZsFL491K88+OO76H/ pQ0XjttAvnxqq01xXPNZnn7a8nf0S6npb8A60HYg4u5Vsy9OLRdYvrxSpF1UVhJefLqt mFVwnRle8PcolhHIrx+S43RVRJ/VbTiiEi8WA7NbgztCaB5ynoefriGRe54aBAdV2seA XgRAD64FbwD6Zd8T+vEE+JpfSZNXBwHuCh5rxOHpLt/7MDk9HFMkbGveqrP55iBytetC 5TMPqjPGFU6jUBN+U2loftm6ARzgfYcWdOu24xs/XLppzp8/hIFXD9Bkv6hkYk+U0kh6 /Eag== X-Gm-Message-State: AA+aEWYY8aPo7C3xebFzhu2saQvdM+jaq2UL/1mxsBSCZyGDyA0Ut6MR UYTS4eiAKgt4rpFBndUTcHErBkmZDuhQDqgtxdNqfw== X-Google-Smtp-Source: AFSGD/UjQAa2h1RvbXMs7pyY62Lh+9nGDi3adnyLAAg/kB3UCIAXowF7RuELRup3Nv5wZ/Yij/SjtWYerB16zOPDNjI= X-Received: by 2002:a67:7685:: with SMTP id r127mr11255532vsc.35.1546011448292; Fri, 28 Dec 2018 07:37:28 -0800 (PST) MIME-Version: 1.0 References: <1545930550-9906-1-git-send-email-aisheng.dong@nxp.com> In-Reply-To: <1545930550-9906-1-git-send-email-aisheng.dong@nxp.com> From: Ulf Hansson Date: Fri, 28 Dec 2018 16:36:52 +0100 Message-ID: Subject: Re: [RFC PATCH 1/1] PM / Domains: Add multi PM domains support for attach_dev To: Aisheng Dong Cc: "linux-pm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "dongas86@gmail.com" , "kernel@pengutronix.de" , "shawnguo@kernel.org" , Fabio Estevam , dl-linux-imx , "rjw@rjwysocki.net" , "khilman@kernel.org" , "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 27 Dec 2018 at 18:14, Aisheng Dong wrote: > > Currently attach_dev() in power domain infrastructure still does > not support multi domains case as the struct device *dev passed > down from genpd_dev_pm_attach_by_id() is a virtual PD device, it > does not help for parsing the real device information from device > tree, e.g. Device/Power IDs, Clocks and it's unware of which real > power domain the device should attach. Thanks for working on this! I would appreciate if the changelog could clarify the problem a bit. Perhaps something along the lines of the below. "A genpd provider's ->attach_dev() callback may be invoked with a so called virtual device, which is created by genpd, at the point when a device is being attached to one of its corresponding multiple PM domains. In these cases, the genpd provider fails to look up any resource, by a clk_get() for example, for the virtual device in question. This is because, the virtual device that was created by genpd, does not have the virt_dev->of_node assigned." > > Extend the framework a bit to store the multi PM domains information > in per-device struct generic_pm_domain_data, then power domain driver > could retrieve it for necessary operations during attach_dev(). > > Two new APIs genpd_is_mpd_device() and dev_gpd_mpd_data() are also > introduced to ease the driver operation. > > Cc: "Rafael J. Wysocki" > Cc: Kevin Hilman > Cc: Ulf Hansson > Cc: Greg Kroah-Hartman > Signed-off-by: Dong Aisheng > --- > This patch is a follow-up work of the earlier discussion with Ulf Hansson > about the multi PM domains support for the attach_dev() function [1]. > After a bit more thinking, this is a less intrusive implementation with > the mininum impact on the exist function definitions and calling follows. > One known little drawback is that we have to use the device driver private > data (device.drvdata) to pass down the multi domains information in a > earlier time. However, as multi PD devices are created by domain framework, > this seems to be safe to use it in domain core code as device driver > is not likely going to use it. > Anyway, if any better ideas, please let me know. > > With the two new APIs, the using can be simply as: > static int xxx_attach_dev(struct generic_pm_domain *domain, > struct device *dev) > { > ... > if (genpd_is_mpd_device(dev)) { > mpd_data = dev_gpd_mpd_data(dev); > np = mpd_data->parent->of_node; > idx = mpd_data->index; > //dts parsing > ... > } > ... I think we can make this a lot less complicated. Just assign virt_dev->of_node = of_node_get(dev->of_node), somewhere in genpd_dev_pm_attach_by_id() and before calling __genpd_dev_pm_attach(). Doing that, would mean the genpd provider's ->attach_dev() callback, don't have to distinguish between virtual and non-virtual devices. Instead they should be able to look up resources in the same way as they did before. Kind regards Uffe > } > > [1] https://patchwork.kernel.org/patch/10658669/ > --- > drivers/base/power/domain.c | 31 +++++++++++++++++++++++++++++++ > include/linux/pm_domain.h | 23 +++++++++++++++++++++++ > 2 files changed, 54 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 7f38a92..1aa0918 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -1343,6 +1343,9 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, > gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; > gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; > > + if (genpd_is_mpd_device(dev)) > + gpd_data->mpd_data = dev_get_drvdata(dev); > + > spin_lock_irq(&dev->power.lock); > > if (dev->power.subsys_data->domain_data) { > @@ -2179,6 +2182,7 @@ EXPORT_SYMBOL_GPL(of_genpd_remove_last); > > static void genpd_release_dev(struct device *dev) > { > + kfree(dev->driver_data); > kfree(dev); > } > > @@ -2320,6 +2324,20 @@ int genpd_dev_pm_attach(struct device *dev) > EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); > > /** > + * genpd_is_mpd_device - Check if a device is associated with multi PM domains > + * @dev: Device to check. > + */ > + > +bool genpd_is_mpd_device(struct device *dev) > +{ > + if (!dev || (dev && !dev->bus)) > + return false; > + > + return dev->bus == &genpd_bus_type; > +}; > +EXPORT_SYMBOL_GPL(genpd_is_mpd_device); > + > +/** > * genpd_dev_pm_attach_by_id - Associate a device with one of its PM domains. > * @dev: The device used to lookup the PM domain. > * @index: The index of the PM domain. > @@ -2338,6 +2356,7 @@ EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); > struct device *genpd_dev_pm_attach_by_id(struct device *dev, > unsigned int index) > { > + struct pm_domain_mpd_data *mpd_data; > struct device *genpd_dev; > int num_domains; > int ret; > @@ -2366,6 +2385,18 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev, > return ERR_PTR(ret); > } > > + /* Allocate multi power domains data */ > + mpd_data = kzalloc(sizeof(*mpd_data), GFP_KERNEL); > + if (!mpd_data) { > + device_unregister(genpd_dev); > + return ERR_PTR(-ENOMEM); > + } > + > + mpd_data->parent = dev; > + mpd_data->index = index; > + > + dev_set_drvdata(genpd_dev, mpd_data); > + > /* Try to attach the device to the PM domain at the specified index. */ > ret = __genpd_dev_pm_attach(genpd_dev, dev->of_node, index, false); > if (ret < 1) { > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 3b5d728..106d4e7 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -144,6 +144,11 @@ struct gpd_timing_data { > bool cached_suspend_ok; > }; > > +struct pm_domain_mpd_data { > + struct device *parent; > + unsigned int index; > +}; > + > struct pm_domain_data { > struct list_head list_node; > struct device *dev; > @@ -151,6 +156,7 @@ struct pm_domain_data { > > struct generic_pm_domain_data { > struct pm_domain_data base; > + struct pm_domain_mpd_data *mpd_data; > struct gpd_timing_data td; > struct notifier_block nb; > unsigned int performance_state; > @@ -262,10 +268,17 @@ unsigned int of_genpd_opp_to_performance_state(struct device *dev, > struct device_node *np); > > int genpd_dev_pm_attach(struct device *dev); > +bool genpd_is_mpd_device(struct device *dev); > struct device *genpd_dev_pm_attach_by_id(struct device *dev, > unsigned int index); > struct device *genpd_dev_pm_attach_by_name(struct device *dev, > char *name); > + > +static inline struct pm_domain_mpd_data *dev_gpd_mpd_data(struct device *dev) > +{ > + return dev_gpd_data(dev)->mpd_data; > +} > + > #else /* !CONFIG_PM_GENERIC_DOMAINS_OF */ > static inline int of_genpd_add_provider_simple(struct device_node *np, > struct generic_pm_domain *genpd) > @@ -311,6 +324,11 @@ static inline int genpd_dev_pm_attach(struct device *dev) > return 0; > } > > +static bool genpd_is_mpd_device(struct device *dev) > +{ > + return false; > +} > + > static inline struct device *genpd_dev_pm_attach_by_id(struct device *dev, > unsigned int index) > { > @@ -323,6 +341,11 @@ static inline struct device *genpd_dev_pm_attach_by_name(struct device *dev, > return NULL; > } > > +static inline struct pm_domain_mpd_data *dev_gpd_mpd_data(struct device *dev) > +{ > + return ERR_PTR(-ENOSYS); > +} > + > static inline > struct generic_pm_domain *of_genpd_remove_last(struct device_node *np) > { > -- > 2.7.4 >