From patchwork Mon Nov 30 22:50:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 334955 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 8E87AC64E7B for ; Mon, 30 Nov 2020 22:51:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C93C2076C for ; Mon, 30 Nov 2020 22:51:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="HoXKYA8h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387992AbgK3Wvn (ORCPT ); Mon, 30 Nov 2020 17:51:43 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:62479 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388675AbgK3Wvn (ORCPT ); Mon, 30 Nov 2020 17:51:43 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606776684; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=p01bbRRCTK64kdSbR9SeuHNenNLGRYge8zpK40f7Zh0=; b=HoXKYA8hqPhOZwiMW3yjlwsIFfFaETlBrDGUDZqDChx9OuV75uRs9NNp6OZTy4lx+asYWJ7R 5GtDB4RwK+J6MjZN0SGg4JZ1yok4gBugltzx+qhKWg57MkhSW/2Jn51m2L53juVpKreVz/ZG vsfJvUczOog+cGSib4bLHsjN20w= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI5ZDFmMiIsICJsaW51eC1wbUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n10.prod.us-east-1.postgun.com with SMTP id 5fc57749edac2724d81520aa (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 30 Nov 2020 22:50:49 GMT Sender: ilina=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B159CC433C6; Mon, 30 Nov 2020 22:50:48 +0000 (UTC) Received: from codeaurora.org (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: ilina) by smtp.codeaurora.org (Postfix) with ESMTPSA id AAB28C433ED; Mon, 30 Nov 2020 22:50:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AAB28C433ED Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org Cc: linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [PATCH v6 1/3] PM / Domains: add domain feature flag for next wakeup Date: Mon, 30 Nov 2020 15:50:37 -0700 Message-Id: <20201130225039.15981-2-ilina@codeaurora.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201130225039.15981-1-ilina@codeaurora.org> References: <20201130225039.15981-1-ilina@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org PM domains may support entering multiple power down states when the component devices and sub-domains are suspended. Also, they may specify the residency value for an idle state, only after which the idle state may provide power benefits. If the domain does not specify the residency for any of its idle states, the governor's choice is much simplified. Let's make this optional with the use of a PM domain feature flag. Signed-off-by: Lina Iyer --- Changes in v6: - New patch based on discussions on v5 of the series --- drivers/base/power/domain.c | 18 ++++++++++++++++++ include/linux/pm_domain.h | 28 ++++++++++++++++++++++------ 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 1b0c9ccbbe1f..1e6c0bf1c945 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1748,6 +1748,24 @@ int dev_pm_genpd_remove_notifier(struct device *dev) } EXPORT_SYMBOL_GPL(dev_pm_genpd_remove_notifier); +/** + * genpd_enable_next_wakeup - Enable genpd gov to use next_wakeup + * + * @genpd: The genpd to be updated + * @enable: Enable/disable genpd gov to use next wakeup + */ +void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, bool enable) +{ + genpd_lock(genpd); + if (enable) + genpd->flags |= GENPD_FLAG_GOV_NEXT_WAKEUP; + else + genpd->flags &= ~GENPD_FLAG_GOV_NEXT_WAKEUP; + genpd->next_wakeup = KTIME_MAX; + genpd_unlock(genpd); +} +EXPORT_SYMBOL_GPL(genpd_enable_next_wakeup); + static int genpd_add_subdomain(struct generic_pm_domain *genpd, struct generic_pm_domain *subdomain) { diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 2ca919ae8d36..1f359bd19f77 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -55,13 +55,19 @@ * * GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain * powered on except for system suspend. + * + * GENPD_FLAG_GOV_NEXT_WAKEUP: Enable the genpd governor to consider its + * components' next wakeup when determining the + * optimal idle state. This is setup only if the + * domain's idle state specifies a residency. */ -#define GENPD_FLAG_PM_CLK (1U << 0) -#define GENPD_FLAG_IRQ_SAFE (1U << 1) -#define GENPD_FLAG_ALWAYS_ON (1U << 2) -#define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) -#define GENPD_FLAG_CPU_DOMAIN (1U << 4) -#define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) +#define GENPD_FLAG_PM_CLK (1U << 0) +#define GENPD_FLAG_IRQ_SAFE (1U << 1) +#define GENPD_FLAG_ALWAYS_ON (1U << 2) +#define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) +#define GENPD_FLAG_CPU_DOMAIN (1U << 4) +#define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) +#define GENPD_FLAG_GOV_NEXT_WAKEUP (1U << 6) enum gpd_status { GENPD_STATE_ON = 0, /* PM domain is on */ @@ -205,6 +211,11 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev) return to_gpd_data(dev->power.subsys_data->domain_data); } +static inline bool genpd_may_use_next_wakeup(struct generic_pm_domain *genpd) +{ + return genpd->flags & GENPD_FLAG_GOV_NEXT_WAKEUP; +} + int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev); int pm_genpd_remove_device(struct device *dev); int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, @@ -217,6 +228,7 @@ int pm_genpd_remove(struct generic_pm_domain *genpd); int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state); int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); int dev_pm_genpd_remove_notifier(struct device *dev); +void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, bool enable); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -275,6 +287,10 @@ static inline int dev_pm_genpd_remove_notifier(struct device *dev) return -EOPNOTSUPP; } +static void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, + bool enable) +{ } + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif From patchwork Mon Nov 30 22:50:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 335496 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, 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 CA4C8C64E7B for ; Mon, 30 Nov 2020 22:51:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77C3020725 for ; Mon, 30 Nov 2020 22:51:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="xiyODCng" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbgK3Wvj (ORCPT ); Mon, 30 Nov 2020 17:51:39 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:42515 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729392AbgK3Wvi (ORCPT ); Mon, 30 Nov 2020 17:51:38 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606776681; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=HDl7UOGHxlMEeXUemp2TyRoeQg3MLQW/KGfzfmyonC4=; b=xiyODCngbJ36p7HFn6jVvHBDy5SzZnxYm3N6pzH4Z98L20MzpT9WNHCbsHyNgL5S7Klxlc+b oOdHsyYRFdjPPZ7zHdB+PWfvyB8Qn3mJE2eajA9vQtYubCKXNtxYt6VS35bypU9dqeSa/SAw IdEGCVANzHPhdn4MluW3e+11BHo= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI5ZDFmMiIsICJsaW51eC1wbUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 5fc5774a265512b1b2e7f3ee (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 30 Nov 2020 22:50:50 GMT Sender: ilina=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id E73A9C433ED; Mon, 30 Nov 2020 22:50:49 +0000 (UTC) Received: from codeaurora.org (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: ilina) by smtp.codeaurora.org (Postfix) with ESMTPSA id 7F727C43460; Mon, 30 Nov 2020 22:50:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 7F727C43460 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org Cc: linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [PATCH v6 2/3] PM / domains: inform PM domain of a device's next wakeup Date: Mon, 30 Nov 2020 15:50:38 -0700 Message-Id: <20201130225039.15981-3-ilina@codeaurora.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201130225039.15981-1-ilina@codeaurora.org> References: <20201130225039.15981-1-ilina@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Some devices may have a predictable interrupt pattern while executing usecases. An example would be the VSYNC interrupt associated with display devices. A 60 Hz display could cause a interrupt every 16 ms. If the device were in a PM domain, the domain would need to be powered up for device to resume and handle the interrupt. Entering a domain idle state saves power, only if the residency of the idle state is met. Without knowing the idle duration of the domain, the governor would just choose the deepest idle state that matches the QoS requirements. The domain might be powered off just as the device is expecting to wake up. If devices could inform PM frameworks of their next event, the parent PM domain's idle duration can be determined. So let's add the dev_pm_genpd_set_next_wakeup() API for the device to inform PM domains of the impending wakeup. This information will be the domain governor to determine the best idle state given the wakeup. Signed-off-by: Lina Iyer --- Changes in v6: - Update documentation Changes in v5: - Fix commit text as pointed by Ulf - Use -EOPNOTSUPP Changes in v4: - Use PM domain data to store next_wakeup - Drop runtime PM documentation Changes in v3: - Fix unwanted change Changes in v2: - Update documentation - Remove runtime PM enabled check - Update commit text --- drivers/base/power/domain.c | 41 +++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 8 ++++++++ 2 files changed, 49 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 1e6c0bf1c945..191539a8e06d 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -408,6 +408,46 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) } EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state); +/** + * dev_pm_genpd_set_next_wakeup - Notify PM framework of an impending wakeup. + * + * @dev: Device to handle + * @next: impending interrupt/wakeup for the device + * + * Allow devices to inform of the next wakeup. But, if the domain were already + * powered off, we will not wakeup the domain to recompute it's idle duration. + * Although devices are expected to update the next_wakeup after the end of + * their usecase as well, it is possible the devices themselves may not know + * about that. Stale @next will be ignored when powering off the domain. + */ +int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next) +{ + struct generic_pm_domain *genpd; + struct generic_pm_domain_data *gpd_data; + int ret = -EINVAL; + + genpd = dev_to_genpd_safe(dev); + if (!genpd) + return -ENODEV; + + if (WARN_ON(!dev->power.subsys_data || + !dev->power.subsys_data->domain_data)) + return ret; + + genpd_lock(genpd); + gpd_data = to_gpd_data(dev->power.subsys_data->domain_data); + if (ktime_before(ktime_get(), next)) { + gpd_data->next_wakeup = next; + genpd->flags |= GENPD_FLAG_GOV_NEXT_WAKEUP; + ret = 0; + } + genpd_unlock(genpd); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_genpd_set_next_wakeup); + + static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) { unsigned int state_idx = genpd->state_idx; @@ -1450,6 +1490,7 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev) gpd_data->td.constraint_changed = true; gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; + gpd_data->next_wakeup = KTIME_MAX; spin_lock_irq(&dev->power.lock); diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 1f359bd19f77..cc27d3d88849 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -9,6 +9,7 @@ #define _LINUX_PM_DOMAIN_H #include +#include #include #include #include @@ -197,6 +198,7 @@ struct generic_pm_domain_data { struct notifier_block *power_nb; int cpu; unsigned int performance_state; + ktime_t next_wakeup; void *data; }; @@ -229,6 +231,7 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state); int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); int dev_pm_genpd_remove_notifier(struct device *dev); void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, bool enable); +int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -291,6 +294,11 @@ static void genpd_enable_next_wakeup(struct generic_pm_domain *genpd, bool enable) { } +static inline int dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next) +{ + return -EOPNOTSUPP; +} + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif From patchwork Mon Nov 30 22:50:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lina Iyer X-Patchwork-Id: 335495 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, 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 702D2C64E90 for ; Mon, 30 Nov 2020 22:51:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16BB02076C for ; Mon, 30 Nov 2020 22:51:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="YYa5OkE9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388677AbgK3Wvv (ORCPT ); Mon, 30 Nov 2020 17:51:51 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:53144 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388131AbgK3Wvv (ORCPT ); Mon, 30 Nov 2020 17:51:51 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606776685; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=o1gOQc1/5k0lLJLcqySyZp12dZ1eIOKFqUM9lM67l/M=; b=YYa5OkE9Td90H90HgNhszcJfnAJLN1gRhciiWJsbpGHPTkROa0Hg+Y2iZsh2tnEv7rkVFHnS K2OE1DbxoyCDpJKnCvZqJNE1KybB3VyZnnwdNPSM49Sj19BuYGpmG1LTc6AMrxmxFpTcCICR Wi8OK/tGKKwQ6IHDzc7svbwSwwU= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI5ZDFmMiIsICJsaW51eC1wbUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-east-1.postgun.com with SMTP id 5fc5774b51762b1886abfb17 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 30 Nov 2020 22:50:51 GMT Sender: ilina=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 6A4A3C43460; Mon, 30 Nov 2020 22:50:50 +0000 (UTC) Received: from codeaurora.org (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: ilina) by smtp.codeaurora.org (Postfix) with ESMTPSA id 5360DC43462; Mon, 30 Nov 2020 22:50:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 5360DC43462 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=ilina@codeaurora.org From: Lina Iyer To: rjw@rjwysocki.net, ulf.hansson@linaro.org Cc: linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, Lina Iyer Subject: [PATCH v6 3/3] PM / Domains: use device's next wakeup to determine domain idle state Date: Mon, 30 Nov 2020 15:50:39 -0700 Message-Id: <20201130225039.15981-4-ilina@codeaurora.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201130225039.15981-1-ilina@codeaurora.org> References: <20201130225039.15981-1-ilina@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Currently, a PM domain's idle state is determined based on whether the QoS requirements are met. This may not save power, if the idle state residency requirements are not met. CPU PM domains use the next timer wakeup for the CPUs in the domain to determine the sleep duration of the domain. This is compared with the idle state residencies to determine the optimal idle state. For other PM domains, determining the sleep length is not that straight forward. But if the device's next_event is available, we can use that to determine the sleep duration of the PM domain. Let's update the domain governor logic to check for idle state residency based on the next wakeup of devices as well as QoS constraints. Signed-off-by: Lina Iyer --- Changes in v6: - Do not include power_on_latency_ns for next_wakeup determination. - Re-organize code to avoid multiple ktime_get() reads. - Check genpd flag if next_wakeup is useful for the domain. - Document why we ignore stale data Changes in v5: - Minor code changes suggested by Rafel Changes in v4: - Update to use next_wakeup from struct generic_pm_domain_data. Changes in v3: - None Changes in v2: - Fix state_idx type to hold negative value. - Update commit text. --- drivers/base/power/domain_governor.c | 102 ++++++++++++++++++++++++--- include/linux/pm_domain.h | 1 + 2 files changed, 94 insertions(+), 9 deletions(-) diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 490ed7deb99a..2afb7fa90d5d 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -117,6 +117,55 @@ static bool default_suspend_ok(struct device *dev) return td->cached_suspend_ok; } +static void update_domain_next_wakeup(struct generic_pm_domain *genpd, ktime_t now) +{ + ktime_t domain_wakeup = KTIME_MAX; + ktime_t next_wakeup; + struct pm_domain_data *pdd; + struct gpd_link *link; + + if (!genpd_may_use_next_wakeup(genpd)) + return; + + /* + * Devices that have a predictable wakeup pattern, may specify + * their next wakeup. Let's find the next wakeup from all the + * devices attached to this domain and from all the sub-domains. + * It is possible that component's a next wakeup may have become + * stale when we read that here. We will ignore to ensure the domain + * is able to enter its optimal idle state. + */ + list_for_each_entry(pdd, &genpd->dev_list, list_node) { + next_wakeup = to_gpd_data(pdd)->next_wakeup; + if (next_wakeup != KTIME_MAX && !ktime_before(next_wakeup, now)) + if (ktime_before(next_wakeup, domain_wakeup)) + domain_wakeup = next_wakeup; + } + + list_for_each_entry(link, &genpd->parent_links, parent_node) { + next_wakeup = link->child->next_wakeup; + if (next_wakeup != KTIME_MAX && !ktime_before(next_wakeup, now)) + if (ktime_before(next_wakeup, domain_wakeup)) + domain_wakeup = next_wakeup; + } + + genpd->next_wakeup = domain_wakeup; +} + +static bool next_wakeup_allows_state(struct generic_pm_domain *genpd, + unsigned int state, ktime_t now) +{ + ktime_t domain_wakeup = genpd->next_wakeup; + s64 idle_time_ns, min_sleep_ns; + + min_sleep_ns = genpd->states[state].power_off_latency_ns + + genpd->states[state].residency_ns; + + idle_time_ns = ktime_to_ns(ktime_sub(domain_wakeup, now)); + + return idle_time_ns >= min_sleep_ns; +} + static bool __default_power_down_ok(struct dev_pm_domain *pd, unsigned int state) { @@ -201,16 +250,41 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd, } /** - * default_power_down_ok - Default generic PM domain power off governor routine. + * _default_power_down_ok - Default generic PM domain power off governor routine. * @pd: PM domain to check. * * This routine must be executed under the PM domain's lock. */ -static bool default_power_down_ok(struct dev_pm_domain *pd) +static bool _default_power_down_ok(struct dev_pm_domain *pd, ktime_t now) { struct generic_pm_domain *genpd = pd_to_genpd(pd); + int state_idx = genpd->state_count - 1; struct gpd_link *link; + /* + * Find the next wakeup from devices that can determine their own wakeup + * to find when the domain would wakeup and do it for every device down + * the hierarchy. It is not worth while to sleep if the state's residency + * cannot be met. + */ + update_domain_next_wakeup(genpd, now); + if (genpd->next_wakeup != KTIME_MAX) { + /* Let's find out the deepest domain idle state, the devices prefer */ + while (state_idx >= 0) { + if (next_wakeup_allows_state(genpd, state_idx, now)) { + genpd->max_off_time_changed = true; + break; + } + state_idx--; + } + + if (state_idx < 0) { + state_idx = 0; + genpd->cached_power_down_ok = false; + goto done; + } + } + if (!genpd->max_off_time_changed) { genpd->state_idx = genpd->cached_power_down_state_idx; return genpd->cached_power_down_ok; @@ -228,21 +302,30 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) genpd->max_off_time_ns = -1; genpd->max_off_time_changed = false; genpd->cached_power_down_ok = true; - genpd->state_idx = genpd->state_count - 1; - /* Find a state to power down to, starting from the deepest. */ - while (!__default_power_down_ok(pd, genpd->state_idx)) { - if (genpd->state_idx == 0) { + /* + * Find a state to power down to, starting from the state + * determined by the next wakeup. + */ + while (!__default_power_down_ok(pd, state_idx)) { + if (state_idx == 0) { genpd->cached_power_down_ok = false; break; } - genpd->state_idx--; + state_idx--; } +done: + genpd->state_idx = state_idx; genpd->cached_power_down_state_idx = genpd->state_idx; return genpd->cached_power_down_ok; } +static bool default_power_down_ok(struct dev_pm_domain *pd) +{ + return _default_power_down_ok(pd, ktime_get()); +} + static bool always_on_power_down_ok(struct dev_pm_domain *domain) { return false; @@ -254,11 +337,12 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd) struct generic_pm_domain *genpd = pd_to_genpd(pd); struct cpuidle_device *dev; ktime_t domain_wakeup, next_hrtimer; + ktime_t now = ktime_get(); s64 idle_duration_ns; int cpu, i; /* Validate dev PM QoS constraints. */ - if (!default_power_down_ok(pd)) + if (!_default_power_down_ok(pd, now)) return false; if (!(genpd->flags & GENPD_FLAG_CPU_DOMAIN)) @@ -280,7 +364,7 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd) } /* The minimum idle duration is from now - until the next wakeup. */ - idle_duration_ns = ktime_to_ns(ktime_sub(domain_wakeup, ktime_get())); + idle_duration_ns = ktime_to_ns(ktime_sub(domain_wakeup, now)); if (idle_duration_ns <= 0) return false; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index cc27d3d88849..a41aea9d1c06 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -136,6 +136,7 @@ struct generic_pm_domain { unsigned int state); struct gpd_dev_ops dev_ops; s64 max_off_time_ns; /* Maximum allowed "suspended" time. */ + ktime_t next_wakeup; /* Maintained by the domain governor */ bool max_off_time_changed; bool cached_power_down_ok; bool cached_power_down_state_idx;