From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7568FCA101F for ; Fri, 12 Sep 2025 12:12:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=R4/EdeFuBETJuEZw4kec1kBMYDB1yN5f/2DiTTh54h8=; b=qWg5wBpLXaW9VgSNOjj7uftSIk xV3SwliqIgGxGKT6oMcqGK1kF8O3KAs90QWYumGy0myQFzVluKlzoE+nPgKnEr++vr4ytffUArLl/ afgn1BmmD8JW0e+PDKIG3qyA6II9d5f1zGjAsHbnQvPj1AbJD/drJ2wakHOFeJO6c9dpphLu6cEnr S4r+076BSwVA1WzJ0KT1/vVkJRvuXkUtUX34u4dKLvJzm7Pd/v1PHHlBGzuK7d/HKIdxtqdltWf5t idZp4WtAMQkZsMhh2w5bPCso57j8bqVbFuI+AjXp5Y+/qxrM53qEPney3FZ7EI9Iz3r5agcvgfjqW 9GBSqJOg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ux2dn-000000098zj-062r; Fri, 12 Sep 2025 12:12:35 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1ux2dj-000000098vp-2nt7 for linux-arm-kernel@lists.infradead.org; Fri, 12 Sep 2025 12:12:33 +0000 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4cNY916FLFz6L5pF; Fri, 12 Sep 2025 20:08:05 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 9A59B1402EA; Fri, 12 Sep 2025 20:12:22 +0800 (CST) Received: from localhost (10.203.177.15) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 12 Sep 2025 14:12:21 +0200 Date: Fri, 12 Sep 2025 13:12:19 +0100 From: Jonathan Cameron To: James Morse CC: , , , D Scott Phillips OS , , , , , , Jamie Iles , Xin Hao , , , , David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , , , Rob Herring , Rohit Mathew , "Rafael Wysocki" , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , "Will Deacon" , Greg Kroah-Hartman , Danilo Krummrich Subject: Re: [PATCH v2 18/29] arm_mpam: Register and enable IRQs Message-ID: <20250912131219.00000938@huawei.com> In-Reply-To: <20250910204309.20751-19-james.morse@arm.com> References: <20250910204309.20751-1-james.morse@arm.com> <20250910204309.20751-19-james.morse@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To frapeml500008.china.huawei.com (7.182.85.71) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250912_051231_997714_6D72C649 X-CRM114-Status: GOOD ( 29.39 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 10 Sep 2025 20:42:58 +0000 James Morse wrote: > Register and enable error IRQs. All the MPAM error interrupts indicate a > software bug, e.g. out of range partid. If the error interrupt is ever > signalled, attempt to disable MPAM. > > Only the irq handler accesses the ESR register, so no locking is needed. > The work to disable MPAM after an error needs to happen at process > context as it takes mutex. It also unregisters the interrupts, meaning > it can't be done from the threaded part of a threaded interrupt. > Instead, mpam_disable() gets scheduled. > > Enabling the IRQs in the MSC may involve cross calling to a CPU that > can access the MSC. > > Once the IRQ is requested, the mpam_disable() path can be called > asynchronously, which will walk structures sized by max_partid. Ensure > this size is fixed before the interrupt is requested. > > CC: Rohit Mathew > Tested-by: Rohit Mathew > Signed-off-by: James Morse A few comments inline. > @@ -1318,11 +1405,172 @@ static void mpam_enable_merge_features(struct list_head *all_classes_list) > } > } > > +static char *mpam_errcode_names[16] = { > + [0] = "No error", I think you had a bunch of defines for these in an earlier patch. Can we use that to index here instead of [0] etc. > + [1] = "PARTID_SEL_Range", > + [2] = "Req_PARTID_Range", > + [3] = "MSMONCFG_ID_RANGE", > + [4] = "Req_PMG_Range", > + [5] = "Monitor_Range", > + [6] = "intPARTID_Range", > + [7] = "Unexpected_INTERNAL", > + [8] = "Undefined_RIS_PART_SEL", > + [9] = "RIS_No_Control", > + [10] = "Undefined_RIS_MON_SEL", > + [11] = "RIS_No_Monitor", > + [12 ... 15] = "Reserved" > +}; > +static void mpam_unregister_irqs(void) > +{ > + int irq, idx; > + struct mpam_msc *msc; > + > + cpus_read_lock(); guard(cpus_read_lock)(); guard(srcu)(&mpam_srcu); > + /* take the lock as free_irq() can sleep */ > + idx = srcu_read_lock(&mpam_srcu); > + list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, > + srcu_read_lock_held(&mpam_srcu)) { > + irq = platform_get_irq_byname_optional(msc->pdev, "error"); > + if (irq <= 0) > + continue; > + > + if (test_and_clear_bit(MPAM_ERROR_IRQ_HW_ENABLED, &msc->error_irq_flags)) > + mpam_touch_msc(msc, mpam_disable_msc_ecr, msc); > + > + if (test_and_clear_bit(MPAM_ERROR_IRQ_REQUESTED, &msc->error_irq_flags)) { > + if (irq_is_percpu(irq)) { > + msc->reenable_error_ppi = 0; > + free_percpu_irq(irq, msc->error_dev_id); > + } else { > + devm_free_irq(&msc->pdev->dev, irq, msc); > + } > + } > + } > + srcu_read_unlock(&mpam_srcu, idx); > + cpus_read_unlock(); > +} > + > static void mpam_enable_once(void) > { > - mutex_lock(&mpam_list_lock); > - mpam_enable_merge_features(&mpam_classes); > - mutex_unlock(&mpam_list_lock); > + int err; > > /* > * Once the cpuhp callbacks have been changed, mpam_partid_max can no > @@ -1332,6 +1580,27 @@ static void mpam_enable_once(void) > partid_max_published = true; > spin_unlock(&partid_max_lock); > > + /* > + * If all the MSC have been probed, enabling the IRQs happens next. > + * That involves cross-calling to a CPU that can reach the MSC, and > + * the locks must be taken in this order: > + */ > + cpus_read_lock(); > + mutex_lock(&mpam_list_lock); > + mpam_enable_merge_features(&mpam_classes); > + > + err = mpam_register_irqs(); > + if (err) > + pr_warn("Failed to register irqs: %d\n", err); Perhaps move the print into the if (err) below? > + > + mutex_unlock(&mpam_list_lock); > + cpus_read_unlock(); > + > + if (err) { > + schedule_work(&mpam_broken_work); > + return; > + } > diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h > index 6e047fbd3512..f04a9ef189cf 100644 > --- a/drivers/resctrl/mpam_internal.h > +++ b/drivers/resctrl/mpam_internal.h > @@ -32,6 +32,10 @@ struct mpam_garbage { > struct platform_device *pdev; > }; > > +/* Bit positions for error_irq_flags */ > +#define MPAM_ERROR_IRQ_REQUESTED 0 > +#define MPAM_ERROR_IRQ_HW_ENABLED 1 If there aren't going to be load more of these (I've not really thought about whether there might) then using a bitmap for these seems to add complexity that we wouldn't see with bool error_irq_req; bool error_irq_hw_enabled; > + > struct mpam_msc { > /* member of mpam_all_msc */ > struct list_head all_msc_list; > @@ -46,6 +50,11 @@ struct mpam_msc { > struct pcc_mbox_chan *pcc_chan; > u32 nrdy_usec; > cpumask_t accessibility; > + bool has_extd_esr; > + > + int reenable_error_ppi; > + struct mpam_msc * __percpu *error_dev_id; > + > atomic_t online_refs; > > /* > @@ -54,6 +63,7 @@ struct mpam_msc { > */ > struct mutex probe_lock; > bool probed; > + unsigned long error_irq_flags; > u16 partid_max; > u8 pmg_max; > unsigned long ris_idxs;