From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 143B83F8220; Fri, 11 Sep 2026 16:19:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789143557; cv=none; b=N0BsQcHPMrhQP/UfjX6wZ1QXkR1sLgKkaocC2nQwEmZXhNkv11lkUKgs5Wj7vm6gxBr5acEFuPYwZKX6pjNc2KX+a+XZ/S2inCw4kkbROEJN6qt5Vxk/Gmnjy9Qw5RRv5nXn3m0JZviNAz8JaRYgYSkmMPpcvLTdBFLORDLcdDQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789143557; c=relaxed/simple; bh=mVzTc977Tes6HFezCnL/znxLeac4LlKNCY7uhrr7GbI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=S3KyKbtU/FHdUilBfIIxWeIZx+LLk6wtX9E700WyC8wAclD7/QWYP9KMEVkDxB05N2oOsLtcBqMXcKsu+i9RnHoXy+NMnU905mJoT7mHmGcDMdNEcsFJcixMoS93vUhbHYcNay9n9h66U1YIdz/qdiRdon0y+XEWYk+WXhvW/34= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Es0VwMX2; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Es0VwMX2" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6858916F2; Fri, 11 Sep 2026 09:19:10 -0700 (PDT) Received: from [10.57.6.75] (unknown [10.57.6.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6986D3F7B4; Fri, 11 Sep 2026 09:19:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789143554; bh=mVzTc977Tes6HFezCnL/znxLeac4LlKNCY7uhrr7GbI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Es0VwMX2KsNRBpdLhVxZbG9MhbgbjQilQBqKWrj7gA82WtTHqIXRFCCac86kzCAno QyIhE5i2OCWIF6x3rpN/EPUC4b1t8k8MmHkulMWTrYrXryie307KyBrp8ctRNe0sHi Je2sgRzfoeRkC3iPFBixtYPPRpC+nUyyJqD1/JFA= Message-ID: Date: Fri, 11 Sep 2026 18:19:04 +0200 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 08/14] arm_mpam: propagate MSC access errors for interrupt control To: Ben Horgan , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , Lee Trager , Ritwick Sharma , Gavin Shan , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260911112835.714162-1-andre.przywara@arm.com> <20260911112835.714162-9-andre.przywara@arm.com> <89a13b60-a1fe-442f-ab0d-b0d37a118ad1@arm.com> Content-Language: en-GB From: Andre Przywara In-Reply-To: <89a13b60-a1fe-442f-ab0d-b0d37a118ad1@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Ben, On 9/11/26 16:26, Ben Horgan wrote: > Hi Andre, > > On 11/09/2026 12:28, Andre Przywara wrote: >> Allow the functions dealing with interrupt registration and enablement >> to check for and return errors, and propagate MSC read and write errors >> from the lower level up. >> This does not cover the IRQ handler yet, as this needs some more >> attention. >> >> Signed-off-by: Andre Przywara >> Reviewed-by: Srivathsa L Rao > > Commenting here as this is the last error propagation patch. I think we need a clean boundary for > the error propagation. As you said a while back I think we can propagate error for all non-static > functions from mpam_devices.c and the callers can discard the errors if appropriate. For instance, > mpam_reset_class_locked() should propagate any error. So I checked all non-static functions in mpam_devices.c: most either don't deal with MSCs at all, or already propagate errors. The two outliers are mpam_disable(), which must be "void", due to it being called via DECLARE_WORK, and mpam_reset_class_locked(), as you write above. The latter is a bit sad, because the caller is void, so any errors would be discarded there anyway, but for the sake of completeness we should indeed propagate here. And I guess it doesn't make sense to continue the vMSC or RIS list iterations after detecting the first error, but we just bail out immediately? Because any error would trigger mpam_disable() anyway? Cheers, Andre > > Thanks, > > Ben > >> --- >> drivers/resctrl/mpam_devices.c | 31 +++++++++++++++---------------- >> 1 file changed, 15 insertions(+), 16 deletions(-) >> >> diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c >> index 558efab75f911..eb26c25b9f970 100644 >> --- a/drivers/resctrl/mpam_devices.c >> +++ b/drivers/resctrl/mpam_devices.c >> @@ -1105,7 +1105,9 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) >> } >> >> /* Clear any stale errors */ >> - mpam_msc_clear_esr(msc); >> + ret = mpam_msc_clear_esr(msc); >> + if (ret) >> + return ret; >> >> spin_lock(&partid_max_lock); >> mpam_partid_max = min(mpam_partid_max, msc->partid_max); >> @@ -2668,9 +2670,7 @@ static int mpam_enable_msc_ecr(void *_msc) >> { >> struct mpam_msc *msc = _msc; >> >> - __mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN); >> - >> - return 0; >> + return __mpam_write_reg(msc, MPAMF_ECR, MPAMF_ECR_INTEN); >> } >> >> /* This can run in mpam_disable(), and the interrupt handler on the same CPU */ >> @@ -2678,9 +2678,7 @@ static int mpam_disable_msc_ecr(void *_msc) >> { >> struct mpam_msc *msc = _msc; >> >> - __mpam_write_reg(msc, MPAMF_ECR, 0); >> - >> - return 0; >> + return __mpam_write_reg(msc, MPAMF_ECR, 0); >> } >> >> static irqreturn_t __mpam_irq_handler(int irq, struct mpam_msc *msc) >> @@ -2777,11 +2775,13 @@ static int mpam_register_irqs(void) >> return err; >> } >> >> - mutex_lock(&msc->error_irq_lock); >> - msc->error_irq_req = true; >> - mpam_touch_msc(msc, mpam_enable_msc_ecr, msc); >> - msc->error_irq_hw_enabled = true; >> - mutex_unlock(&msc->error_irq_lock); >> + scoped_guard(mutex, &msc->error_irq_lock) { >> + msc->error_irq_req = true; >> + err = mpam_touch_msc(msc, mpam_enable_msc_ecr, msc); >> + if (err) >> + return err; >> + msc->error_irq_hw_enabled = true; >> + } >> } >> >> return 0; >> @@ -2800,10 +2800,10 @@ static void mpam_unregister_irqs(void) >> if (irq <= 0) >> continue; >> >> - mutex_lock(&msc->error_irq_lock); >> + guard(mutex)(&msc->error_irq_lock); >> if (msc->error_irq_hw_enabled) { >> - mpam_touch_msc(msc, mpam_disable_msc_ecr, msc); >> - msc->error_irq_hw_enabled = false; >> + if (!mpam_touch_msc(msc, mpam_disable_msc_ecr, msc)) >> + msc->error_irq_hw_enabled = false; >> } >> >> if (msc->error_irq_req) { >> @@ -2815,7 +2815,6 @@ static void mpam_unregister_irqs(void) >> } >> msc->error_irq_req = false; >> } >> - mutex_unlock(&msc->error_irq_lock); >> } >> } >> >