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: 13075072 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DCB69C4332F for ; Fri, 16 Dec 2022 14:58:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230232AbiLPO6L (ORCPT ); Fri, 16 Dec 2022 09:58:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiLPO6K (ORCPT ); Fri, 16 Dec 2022 09:58:10 -0500 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2B115D6AB for ; Fri, 16 Dec 2022 06:58:09 -0800 (PST) Received: by mail-lf1-x12b.google.com with SMTP id p36so3784844lfa.12 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=gPORZC/IcV+slqZxJ7bBvARG5q8zudHPUslPmjNISVumD6hoXZLfKJD7chwOqelTTG dLnDRNtX9TzzFyJppW8yWEtlB5RvEytH7A9qQN+cH0CKtywFgzA3NvknJm7L7mNru8IH fzEsFfnrkUJpQVsTbNjTTgLLhdqr3tqnarXmJaXggOW4RbqOmrrzgbExbMyAa0cUukhz gG/GPvVhEu0V4j6FTIHDqEAR4oacPo0jct/Udv3eT7IQ9LAd3AogOyDNYLL8T/pDBlln zBXWeD7FHxg+UfZ000z7EmeR7/nHDiv4aVqE7H39MJfKCaB+rCW3DwoAOsa0BYSc42R4 ZUfw== X-Gm-Message-State: ANoB5pmSQ+MZU0zJ4sJDzf2pqE8mYFhxcoi+GmQs3RvZQxZRNU3R1Qa8 y4jX4/i7gzgcdfKRWr0RPoBtqQ== X-Google-Smtp-Source: AA0mqf5zVAxsQWpDKAT+cihDzTutK+yPkquZd6gx5FEZQi1/4SqpZkDMvO905N9BPjowSzn5q4YqQw== 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 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org 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; + }; }; }; From patchwork Fri Dec 16 14:58:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 13075073 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3563AC001B2 for ; Fri, 16 Dec 2022 14:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231146AbiLPO6M (ORCPT ); Fri, 16 Dec 2022 09:58:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiLPO6M (ORCPT ); Fri, 16 Dec 2022 09:58:12 -0500 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF4C65E08A for ; Fri, 16 Dec 2022 06:58:10 -0800 (PST) Received: by mail-lf1-x12e.google.com with SMTP id c1so3818488lfi.7 for ; Fri, 16 Dec 2022 06:58:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=XI5FWBUPx6OMJbv7hDR0vpuygKMiyn48qRmwgBRrpyg=; b=EjIV/9MO/jyr60HiahpHnsgbaMKKNPGZzbZkILX054s2tSkZjbR+YPU3MsrCaoowzB 0GHQhPSElmgbkTB3ztBmRq5YmW6je+CGusNx7M4GiA28XsgEoVfeoHg0FEfK9w8egsiU WAS7wpOw1xqETJhgx/dMIviVsyA94i8R+XgdMJqWg6LFJZtYReRadI/gLlzhVV+k9qPx lg0EMKE3+n2p32hXqJK81sBxrgjSv/r3laKdi57M+qDU8EfAFVq1QENe0DGANercJGLp aDIP5OHbnkuf21y86i65QKribqVIlXU4KjJWx5WSy6mIFt9t78xFKTnk0cOS16VGE7lq eskg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=XI5FWBUPx6OMJbv7hDR0vpuygKMiyn48qRmwgBRrpyg=; b=BbnZhyvAhu+vIjaDu4kpD9Qp3K2SHfQ6Rm7mycXVEijNebOauIzPrRLRRbWSWpSPci STeDrYQ82aObKgX1DkvV860YFQ8tDtmgRPpQxwblD80KqftuU3A80h3O8QtW3Sn4xHRZ s6HVzEJR2BuHIxzF9v8PHmBqgzTSQuxouOmFoYQVsn61qw0r3qg2RhqcZXgdxPDroNaa ewKUK0qmJrPb1QbrjLmQ19g20TP+kGjb4HEmHW8xwBbO6Vpcrup8JMKraNr66ConC3mr BvrnGvDMc9DKXKnGEjT9EU8x23YtOVp9ABYHy16uRTrXC3RJqrClKu8AvUZR7n1aDcsT Gs6A== X-Gm-Message-State: ANoB5plRh1mRYjOfFmt3nDaexw3MKa20PTHZUHnfu8t7biXRJHbxO3tw 2Slm/gZtRetlYHBj4tsS/mxWEg== X-Google-Smtp-Source: AA0mqf7o2LPOY0FvSHAVIjM0eT7KSIcxGgoOk4WtpFSZ1GwSLmN7A174rFc/lccav32QpexwxxNkgw== X-Received: by 2002:a05:6512:3042:b0:4a4:68b7:d642 with SMTP id b2-20020a056512304200b004a468b7d642mr11799574lfb.41.1671202689138; Fri, 16 Dec 2022 06:58:09 -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.179.2022.12.16.06.58.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Dec 2022 06:58:08 -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 2/2] cpuidle: psci: Mark as PREEMPT_RT safe Date: Fri, 16 Dec 2022 15:58:02 +0100 Message-Id: <20221216145802.102374-2-krzysztof.kozlowski@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221216145802.102374-1-krzysztof.kozlowski@linaro.org> References: <20221216145802.102374-1-krzysztof.kozlowski@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The PSCI cpuidle power domain in power_off callback uses __this_cpu_write() so it is PREEMPT_RT safe. This allows to use it in Realtime kernels and solves errors like: BUG: scheduling while atomic: swapper/2/0/0x00000002 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x68/0x84 dump_stack+0x18/0x34 __schedule_bug+0x60/0x80 __schedule+0x628/0x800 schedule_rtlock+0x28/0x5c rtlock_slowlock_locked+0x360/0xd30 rt_spin_lock+0x88/0xb0 genpd_lock_nested_spin+0x1c/0x30 genpd_power_off.part.0.isra.0+0x20c/0x2a0 genpd_runtime_suspend+0x150/0x2bc __rpm_callback+0x48/0x170 rpm_callback+0x6c/0x7c rpm_suspend+0x108/0x660 __pm_runtime_suspend+0x4c/0x8c __psci_enter_domain_idle_state.constprop.0+0x54/0xe0 psci_enter_domain_idle_state+0x18/0x2c cpuidle_enter_state+0x8c/0x4e0 cpuidle_enter+0x38/0x50 do_idle+0x248/0x2f0 cpu_startup_entry+0x24/0x30 secondary_start_kernel+0x130/0x154 __secondary_switched+0xb0/0xb4 Cc: Adrien Thierry Cc: Brian Masney Signed-off-by: Krzysztof Kozlowski --- drivers/cpuidle/cpuidle-psci-domain.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c index 821984947ed9..5cb78e754b27 100644 --- a/drivers/cpuidle/cpuidle-psci-domain.c +++ b/drivers/cpuidle/cpuidle-psci-domain.c @@ -62,7 +62,8 @@ static int psci_pd_init(struct device_node *np, bool use_osi) if (!pd_provider) goto free_pd; - pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN; + pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_RT_SAFE | \ + GENPD_FLAG_CPU_DOMAIN; /* Allow power off when OSI has been successfully enabled. */ if (use_osi)