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 BDBCACF31B7 for ; Wed, 19 Nov 2025 12:25:37 +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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=iaNGvwojjwDFcj0h0OSPs/v0aav4Dsn+Wh3vQvbEoZU=; b=4J39wl2gnjYytO3kqH5JVyexA4 8DhqifkctjZOgWtwBr4POCPf1EvLZESSUX8tqM6iZEC+Am0+MRRmyDjBW/JPxtQcjR2GUTe4Jy6TV lOk39uYO11WbggWWYROfmuEsh8TM1feWsCnireG4P1A6wXHhH4KLI2C3UBSuOWP4ZvIVzh8F7tDqu XTCoas0kOHnl+WOhOlu3AK8z02Oi+uavOxLHrSbCQuCmkErG13VrvguyKLNtW9ihDTuElZMugvNHL T3/hNTE6kVKnZLUC2XHTtiB+QzErTMxfmSDT8iLg43bTbdaj2W0rmzTRvOkTTSoPek76+qPkStSv3 KSplcaEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLhFX-00000003886-3A4E; Wed, 19 Nov 2025 12:25:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLhFO-0000000380A-42lI for linux-arm-kernel@lists.infradead.org; Wed, 19 Nov 2025 12:25:20 +0000 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 D8F0C1BC0; Wed, 19 Nov 2025 04:25:10 -0800 (PST) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 424763F740; Wed, 19 Nov 2025 04:25:13 -0800 (PST) From: Ben Horgan To: james.morse@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, bobo.shaobowang@huawei.com, carl@os.amperecomputing.com, catalin.marinas@arm.com, dakr@kernel.org, dave.martin@arm.com, david@redhat.com, dfustini@baylibre.com, fenghuay@nvidia.com, gregkh@linuxfoundation.org, gshan@redhat.com, guohanjun@huawei.com, jeremy.linton@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, peternewman@google.com, quic_jiles@quicinc.com, rafael@kernel.org, robh@kernel.org, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, sudeep.holla@arm.com, tan.shaopeng@fujitsu.com, will@kernel.org, xhao@linux.alibaba.com, reinette.chatre@intel.com, Ben Horgan , Shaopeng Tan , Zeng Heng Subject: [PATCH v6 20/34] arm_mpam: Extend reset logic to allow devices to be reset any time Date: Wed, 19 Nov 2025 12:22:50 +0000 Message-ID: <20251119122305.302149-21-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251119122305.302149-1-ben.horgan@arm.com> References: <20251119122305.302149-1-ben.horgan@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251119_042519_132214_A2A021EB X-CRM114-Status: GOOD ( 15.01 ) 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 From: James Morse cpuhp callbacks aren't the only time the MSC configuration may need to be reset. Resctrl has an API call to reset a class. If an MPAM error interrupt arrives it indicates the driver has misprogrammed an MSC. The safest thing to do is reset all the MSCs and disable MPAM. Add a helper to reset RIS via their class. Call this from mpam_disable(), which can be scheduled from the error interrupt handler. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Ben Horgan Reviewed-by: Gavin Shan Reviewed-by: Fenghua Yu Reviewed-by: Shaopeng Tan Tested-by: Fenghua Yu Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Carl Worth Tested-by: Gavin Shan Tested-by: Zeng Heng Tested-by: Hanjun Guo Signed-off-by: Ben Horgan --- drivers/resctrl/mpam_devices.c | 57 ++++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 7941b093396e..7943d174b3f4 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -808,15 +808,13 @@ static void mpam_reset_ris_partid(struct mpam_msc_ris *ris, u16 partid) /* * Called via smp_call_on_cpu() to prevent migration, while still being - * pre-emptible. + * pre-emptible. Caller must hold mpam_srcu. */ static int mpam_reset_ris(void *arg) { u16 partid, partid_max; struct mpam_msc_ris *ris = arg; - WARN_ON_ONCE(!srcu_read_lock_held((&mpam_srcu))); - if (ris->in_reset_state) return 0; @@ -1337,8 +1335,55 @@ static void mpam_enable_once(void) mpam_partid_max + 1, mpam_pmg_max + 1); } +static void mpam_reset_component_locked(struct mpam_component *comp) +{ + struct mpam_vmsc *vmsc; + + lockdep_assert_cpus_held(); + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(vmsc, &comp->vmsc, comp_list, + srcu_read_lock_held(&mpam_srcu)) { + struct mpam_msc *msc = vmsc->msc; + struct mpam_msc_ris *ris; + + list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list, + srcu_read_lock_held(&mpam_srcu)) { + if (!ris->in_reset_state) + mpam_touch_msc(msc, mpam_reset_ris, ris); + ris->in_reset_state = true; + } + } +} + +static void mpam_reset_class_locked(struct mpam_class *class) +{ + struct mpam_component *comp; + + lockdep_assert_cpus_held(); + + guard(srcu)(&mpam_srcu); + list_for_each_entry_srcu(comp, &class->components, class_list, + srcu_read_lock_held(&mpam_srcu)) + mpam_reset_component_locked(comp); +} + +static void mpam_reset_class(struct mpam_class *class) +{ + cpus_read_lock(); + mpam_reset_class_locked(class); + cpus_read_unlock(); +} + +/* + * Called in response to an error IRQ. + * All of MPAMs errors indicate a software bug, restore any modified + * controls to their reset values. + */ void mpam_disable(struct work_struct *ignored) { + int idx; + struct mpam_class *class; struct mpam_msc *msc, *tmp; mutex_lock(&mpam_cpuhp_state_lock); @@ -1348,6 +1393,12 @@ void mpam_disable(struct work_struct *ignored) } mutex_unlock(&mpam_cpuhp_state_lock); + idx = srcu_read_lock(&mpam_srcu); + list_for_each_entry_srcu(class, &mpam_classes, classes_list, + srcu_read_lock_held(&mpam_srcu)) + mpam_reset_class(class); + srcu_read_unlock(&mpam_srcu, idx); + mutex_lock(&mpam_list_lock); list_for_each_entry_safe(msc, tmp, &mpam_all_msc, all_msc_list) mpam_msc_destroy(msc); -- 2.43.0