From nobody Sun Sep 14 20:10:57 2025 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 191A6C32793 for ; Wed, 18 Jan 2023 12:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229834AbjARMRs (ORCPT ); Wed, 18 Jan 2023 07:17:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230301AbjARMQW (ORCPT ); Wed, 18 Jan 2023 07:16:22 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16D0187665; Wed, 18 Jan 2023 03:38:05 -0800 (PST) Date: Wed, 18 Jan 2023 11:38:03 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1674041883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IKOeI6CJeABbZr5jjK4xgH28Q+CRnseRGHAeKjim1sE=; b=2MkPdvl5Hkuy70hsqyLwLqopja5ec10Mmw50F0PetxysQUITiAKSCMgjCIXaGjMRQJpfn6 zpbiLI6J/GtZVh1SjoH3PRNxbHhr3SBU4MjqOgesyjmiUUmuCNYLsb4PqMggU2z2e7nXKC q53HDIdZeaArF2q93eCxGSk+6nEH3Swmsf7OJ3Bcrf2BPiRRIzTgr1eGMWFDFqL3fWyNs8 5xWv8s4m/Dc/teC0HqDCHbmfoz0SwR3ej8FgtCQJU3tbWUzrssxZ2W22qaiL9w+3OjUcMu hMP1OZ5XiMBZsxxlZHKzjm0fstEIz6jm9bcNvY3DMVT1hhu3ip5OZbs+AewPhA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1674041883; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IKOeI6CJeABbZr5jjK4xgH28Q+CRnseRGHAeKjim1sE=; b=FDArWEg2kSBUNlfiDXRnZKUg0qHAT0aPBNJq+XP6Xr5lqNLd9VzGHvGuh99zXBGnwOLupo 7yiccxMRSrOEGoCw== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] cpuidle, arm64: Fix the ARM64 cpuidle logic Cc: Mark Rutland , Peter Zijlstra , Ingo Molnar , Sudeep Holla , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: MIME-Version: 1.0 Message-ID: <167404188327.4906.4923868760332054149.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 19235e47279894b033a3ec5cf2732de634862b3a Gitweb: https://git.kernel.org/tip/19235e47279894b033a3ec5cf2732de63= 4862b3a Author: Peter Zijlstra AuthorDate: Tue, 17 Jan 2023 11:26:29 +01:00 Committer: Ingo Molnar CommitterDate: Wed, 18 Jan 2023 12:27:17 +01:00 cpuidle, arm64: Fix the ARM64 cpuidle logic The recent cpuidle changes started triggering RCU splats on Juno development boards: | =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D | WARNING: suspicious RCU usage | ----------------------------- | include/trace/events/ipi.h:19 suspicious rcu_dereference_check() usage! Fix cpuidle on ARM64: - ... by introducing a new 'is_rcu' flag to the cpuidle helpers & make ARM64 use it, as ARM64 wants to keep RCU active longer and wants to do the ct_cpuidle_enter()/exit() dance itself. - Also update the PSCI driver accordingly. - This also removes the last known RCU_NONIDLE() user as a bonus. Reported-by: Mark Rutland Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Tested-by: Sudeep Holla Tested-by: Mark Rutland Reviewed-by: Mark Rutland Link: https://lore.kernel.org/r/Y8Z31UbzG3LJgAXE@hirez.programming.kicks-as= s.net -- --- arch/arm64/kernel/cpuidle.c | 4 ++-- arch/arm64/kernel/suspend.c | 12 +++++++++++- drivers/cpuidle/cpuidle-psci.c | 6 +----- drivers/firmware/psci/psci.c | 11 +++++++++++ include/linux/cpuidle.h | 22 +++++++++++++++------- 5 files changed, 40 insertions(+), 15 deletions(-) diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c index 41974a1..42e19ff 100644 --- a/arch/arm64/kernel/cpuidle.c +++ b/arch/arm64/kernel/cpuidle.c @@ -67,10 +67,10 @@ __cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_= lpi_state *lpi) u32 state =3D lpi->address; =20 if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags)) - return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(psci_cpu_suspend_enter, + return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(psci_cpu_suspend_enter, lpi->index, state); else - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, + return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter, lpi->index, state); } #endif diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index e7163f3..0fbdf5f 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -104,6 +105,10 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned = long)) * From this point debug exceptions are disabled to prevent * updates to mdscr register (saved and restored along with * general purpose registers) from kernel debuggers. + * + * Strictly speaking the trace_hardirqs_off() here is superfluous, + * hardirqs should be firmly off by now. This really ought to use + * something like raw_local_daif_save(). */ flags =3D local_daif_save(); =20 @@ -120,6 +125,8 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned l= ong)) */ arm_cpuidle_save_irq_context(&context); =20 + ct_cpuidle_enter(); + if (__cpu_suspend_enter(&state)) { /* Call the suspend finisher */ ret =3D fn(arg); @@ -133,8 +140,11 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned = long)) */ if (!ret) ret =3D -EOPNOTSUPP; + + ct_cpuidle_exit(); } else { - RCU_NONIDLE(__cpu_suspend_exit()); + ct_cpuidle_exit(); + __cpu_suspend_exit(); } =20 arm_cpuidle_restore_irq_context(&context); diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 4fc4e03..312a34e 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -69,16 +69,12 @@ static __cpuidle int __psci_enter_domain_idle_state(str= uct cpuidle_device *dev, else pm_runtime_put_sync_suspend(pd_dev); =20 - ct_cpuidle_enter(); - state =3D psci_get_domain_state(); if (!state) state =3D states[idx]; =20 ret =3D psci_cpu_suspend_enter(state) ? -1 : idx; =20 - ct_cpuidle_exit(); - if (s2idle) dev_pm_genpd_resume(pd_dev); else @@ -192,7 +188,7 @@ static __cpuidle int psci_enter_idle_state(struct cpuid= le_device *dev, { u32 *state =3D __this_cpu_read(psci_cpuidle_data.psci_states); =20 - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state[idx= ]); + return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter, idx, state= [idx]); } =20 static const struct of_device_id psci_idle_state_match[] =3D { diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index e7bcfca..f3a044f 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -462,11 +462,22 @@ int psci_cpu_suspend_enter(u32 state) if (!psci_power_state_loses_context(state)) { struct arm_cpuidle_irq_context context; =20 + ct_cpuidle_enter(); arm_cpuidle_save_irq_context(&context); ret =3D psci_ops.cpu_suspend(state, 0); arm_cpuidle_restore_irq_context(&context); + ct_cpuidle_exit(); } else { + /* + * ARM64 cpu_suspend() wants to do ct_cpuidle_*() itself. + */ + if (!IS_ENABLED(CONFIG_ARM64)) + ct_cpuidle_enter(); + ret =3D cpu_suspend(state, psci_suspend_finisher); + + if (!IS_ENABLED(CONFIG_ARM64)) + ct_cpuidle_exit(); } =20 return ret; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 630c879..3183aeb 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -307,7 +307,7 @@ extern s64 cpuidle_governor_latency_req(unsigned int cp= u); #define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \ idx, \ state, \ - is_retention) \ + is_retention, is_rcu) \ ({ \ int __ret =3D 0; \ \ @@ -319,9 +319,11 @@ extern s64 cpuidle_governor_latency_req(unsigned int c= pu); if (!is_retention) \ __ret =3D cpu_pm_enter(); \ if (!__ret) { \ - ct_cpuidle_enter(); \ + if (!is_rcu) \ + ct_cpuidle_enter(); \ __ret =3D low_level_idle_enter(state); \ - ct_cpuidle_exit(); \ + if (!is_rcu) \ + ct_cpuidle_exit(); \ if (!is_retention) \ cpu_pm_exit(); \ } \ @@ -330,15 +332,21 @@ extern s64 cpuidle_governor_latency_req(unsigned int = cpu); }) =20 #define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \ - __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0) + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0, 0) =20 #define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \ - __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1) + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1, 0) =20 #define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \ - __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0) + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 0) + +#define CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(low_level_idle_enter, idx, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0, 1) =20 #define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, s= tate) \ - __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1) + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 0) + +#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(low_level_idle_enter, id= x, state) \ + __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1, 1) =20 #endif /* _LINUX_CPUIDLE_H */