From patchwork Fri Dec 16 14:58:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 33973 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:e747:0:0:0:0:0 with SMTP id c7csp1014109wrn; Fri, 16 Dec 2022 07:02:10 -0800 (PST) X-Google-Smtp-Source: AA0mqf4tTmYD89I5mh8Me7MNk9Xef+QtE6xcrRE5R5vqYcmV/RGBx1UZ5s4Uxls1h2V2jGz9czOQ X-Received: by 2002:a05:6a00:88c:b0:56b:f51d:820a with SMTP id q12-20020a056a00088c00b0056bf51d820amr40400666pfj.7.1671202930460; Fri, 16 Dec 2022 07:02:10 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1671202930; cv=none; d=google.com; s=arc-20160816; b=uy960nqvwCGIY0kZttTEFuDkPowm4M+DnvboaOzJhK3W9yodpYUos3RGUgRNa3R3Lq XjCylUymwCF6RX6JIegOrDSUi2Dia8Jll2kHqBaGRdyeviDKs/uZ404Jw9100OW3x15n jLEgedFVUOsjr/+ygCOEI9YkMYfPnam9Qe2OjGwMsgQVtUBLffaQvHOCCi5qcDpcMhYA qhHeWMPsf0fM+xY2ZO5rNbtIdRteXmCMqQe2/hcnHhOEcWZ7Zz95eSbJdhDybJpO1YD7 wvC+Fp9Rbx962Zwxwv1ynAjCR+S2BzMwUWJszmt+v9pQY/j3JgtiBLTXBom/dAb+7gPP ZcSA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=qnQ8WVqn39lloqLDzY0u45TgwEZ131RficcHAU+KQ+E=; b=euqXBRhsw70NYNnlGZg6t1LRDdTEOf5wjvgAF0upu0m8xnNA0IMV4BjrIqVVK+aYrR y28yWPuDSfHhVRG3aG4ldfkHIDqaINDEBc8YeVHUA/Ad1RtrCjsrmCToVZElmf7/q4Fj OpJto8tXO0hVH11R4xOYYZnIJHkjQCC6K23czlopPicPin7fXxMOpIVu9jiWjToMBHJN E1Is04qw+qYUPXwJ96HQMuyo/6DMxC0S6I7AB+74meowURiziaMjMc32ojVfG6Kl4yaQ 4NxD5zOSmZ61mzzgkUK2OKLuSU3zpz/NSlt5c7ZoMg+VhboL1S6tpoga7YQq7nlmCXm5 PQqg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=oeFrpbC9; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id h15-20020a056a001a4f00b0057374ca3be1si2827713pfv.151.2022.12.16.07.01.54; Fri, 16 Dec 2022 07:02:09 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=oeFrpbC9; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231143AbiLPO6M (ORCPT + 99 others); Fri, 16 Dec 2022 09:58:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229680AbiLPO6K (ORCPT ); Fri, 16 Dec 2022 09:58:10 -0500 Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A48A05D6BB for ; Fri, 16 Dec 2022 06:58:09 -0800 (PST) Received: by mail-lf1-x12d.google.com with SMTP id m29so3602936lfo.11 for ; Fri, 16 Dec 2022 06:58:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=qnQ8WVqn39lloqLDzY0u45TgwEZ131RficcHAU+KQ+E=; b=oeFrpbC9q5PPAqJO+kaJZzPL/fa2Oy9hVNpADsk/a8586GWPaS1aCP5E7xjAKGysDA u9aJDkLjv5XtEcv+PyCVB2tKVfbcCaWGGl90UHXLsBUV9JbaMOhDCJK5nVL28Ogh9FT6 8EH3i8jPcclhrjL/7QtkKfZ9Z1lQpEq1oEgF7dsL7ljqit9fRlajx09JAriSqqj2kQ50 lgCAuRBHTUlI+u1m752A7ICLwBXy8xPK1HTkVqNbxWCQ+X08LjDEVoTuJHJgdgIZr8Zr 0hqHwcbROUkSAzBNkVy7AJwHjxdM8sJAWwlFV1wOr52xphNz8+l4UcUGYMfb66MR1rc9 x2/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=qnQ8WVqn39lloqLDzY0u45TgwEZ131RficcHAU+KQ+E=; b=BX5BJ5tZatnJrPVQmjGX539kjGIPVBCWCzlOC6DQBmnsQNi5tfwaXMorSsX6X9tukT xwmYbdz5q5bgU4ig86XnQV9IBa/xfLAnIGD8S8NBkRPxszAd0pdDv8Vq+WmeAJrLrFqB jyamoGZNntFmBBAe+xjYPlpef6ejYGJtY3FZkjTIfv6aREmAeq03CsGGhMqdna7ZddSC NWrvC0tAua5Hz9f3qLzxO8L3Ng0IW0a4SOUdyelIWNPI51leugMWvpjAueVhWxdqgExo Z47ncd77vEa0jxAAhx5xV35+fATolDxHLduBaylE67HTR+9yUe/a7HhrRbIJdej9CC9X SfvQ== X-Gm-Message-State: ANoB5pm3SaYKhVB6KLwCG4mXxMoNOAuUrv8WvFWZWJ7VO+A5TjMNthCd 8jdaaJKTVA0ghHzyRzHwt03/Cg== X-Received: by 2002:a05:6512:2102:b0:4b5:6c36:79a4 with SMTP id q2-20020a056512210200b004b56c3679a4mr8644808lfr.65.1671202688023; Fri, 16 Dec 2022 06:58:08 -0800 (PST) Received: from krzk-bin.NAT.warszawa.vectranet.pl (088156142067.dynamic-2-waw-k-3-2-0.vectranet.pl. [88.156.142.67]) by smtp.gmail.com with ESMTPSA id c18-20020ac25f72000000b004b59b43ec61sm238491lfc.179.2022.12.16.06.58.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Dec 2022 06:58:07 -0800 (PST) From: Krzysztof Kozlowski To: "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , Pavel Machek , Len Brown , Greg Kroah-Hartman , Daniel Lezcano , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Krzysztof Kozlowski , Adrien Thierry , Brian Masney Subject: [PATCH RFC 1/2] PM: domains: Add GENPD_FLAG_RT_SAFE for PREEMPT_RT Date: Fri, 16 Dec 2022 15:58:01 +0100 Message-Id: <20221216145802.102374-1-krzysztof.kozlowski@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1752383282907689626?= X-GMAIL-MSGID: =?utf-8?q?1752383282907689626?= Realtime kernels with PREEMPT_RT must use raw_spinlock_t, so add a flag allowing a power domain provider to indicate it is RT safe. The flag is supposed to be used with existing GENPD_FLAG_IRQ_SAFE. Cc: Adrien Thierry Cc: Brian Masney Signed-off-by: Krzysztof Kozlowski --- Independently from Adrien, I encountered the same problem around genpd when using PREEMPT_RT kernel. Previous patch by Adrien: https://lore.kernel.org/all/20220615203605.1068453-1-athierry@redhat.com/ --- drivers/base/power/domain.c | 51 +++++++++++++++++++++++++++++++++++-- include/linux/pm_domain.h | 13 ++++++++++ 2 files changed, 62 insertions(+), 2 deletions(-) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index a539d6bc6fe0..478862ae478a 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -119,6 +119,48 @@ static const struct genpd_lock_ops genpd_spin_ops = { .unlock = genpd_unlock_spin, }; +static void genpd_lock_rawspin(struct generic_pm_domain *genpd) + __acquires(&genpd->rslock) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&genpd->rslock, flags); + genpd->rlock_flags = flags; +} + +static void genpd_lock_nested_rawspin(struct generic_pm_domain *genpd, + int depth) + __acquires(&genpd->rslock) +{ + unsigned long flags; + + raw_spin_lock_irqsave_nested(&genpd->rslock, flags, depth); + genpd->rlock_flags = flags; +} + +static int genpd_lock_interruptible_rawspin(struct generic_pm_domain *genpd) + __acquires(&genpd->rslock) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&genpd->rslock, flags); + genpd->rlock_flags = flags; + return 0; +} + +static void genpd_unlock_rawspin(struct generic_pm_domain *genpd) + __releases(&genpd->rslock) +{ + raw_spin_unlock_irqrestore(&genpd->rslock, genpd->rlock_flags); +} + +static const struct genpd_lock_ops genpd_rawspin_ops = { + .lock = genpd_lock_rawspin, + .lock_nested = genpd_lock_nested_rawspin, + .lock_interruptible = genpd_lock_interruptible_rawspin, + .unlock = genpd_unlock_rawspin, +}; + #define genpd_lock(p) p->lock_ops->lock(p) #define genpd_lock_nested(p, d) p->lock_ops->lock_nested(p, d) #define genpd_lock_interruptible(p) p->lock_ops->lock_interruptible(p) @@ -2048,8 +2090,13 @@ static void genpd_free_data(struct generic_pm_domain *genpd) static void genpd_lock_init(struct generic_pm_domain *genpd) { if (genpd->flags & GENPD_FLAG_IRQ_SAFE) { - spin_lock_init(&genpd->slock); - genpd->lock_ops = &genpd_spin_ops; + if (genpd->flags & GENPD_FLAG_RT_SAFE) { + raw_spin_lock_init(&genpd->rslock); + genpd->lock_ops = &genpd_rawspin_ops; + } else { + spin_lock_init(&genpd->slock); + genpd->lock_ops = &genpd_spin_ops; + } } else { mutex_init(&genpd->mlock); genpd->lock_ops = &genpd_mtx_ops; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index c6cda024ff99..6b0f9de2be1c 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -61,6 +61,14 @@ * GENPD_FLAG_MIN_RESIDENCY: Enable the genpd governor to consider its * components' next wakeup when determining the * optimal idle state. + * + * GENPD_FLAG_RT_SAFE: When used with GENPD_FLAG_IRQ_SAFE, this informs + * genpd that its backend callbacks, ->power_on|off(), + * do not use other spinlocks. They might use + * raw_spinlocks or other pre-emption-disable + * methods, all of which are PREEMPT_RT safe. Note + * that, a genpd having this flag set, requires its + * masterdomains to also have it set. */ #define GENPD_FLAG_PM_CLK (1U << 0) #define GENPD_FLAG_IRQ_SAFE (1U << 1) @@ -69,6 +77,7 @@ #define GENPD_FLAG_CPU_DOMAIN (1U << 4) #define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5) #define GENPD_FLAG_MIN_RESIDENCY (1U << 6) +#define GENPD_FLAG_RT_SAFE (1U << 7) enum gpd_status { GENPD_STATE_ON = 0, /* PM domain is on */ @@ -164,6 +173,10 @@ struct generic_pm_domain { spinlock_t slock; unsigned long lock_flags; }; + struct { + raw_spinlock_t rslock; + unsigned long rlock_flags; + }; }; };