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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD7DDC4332F for ; Thu, 29 Sep 2022 21:08:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229845AbiI2VIA (ORCPT ); Thu, 29 Sep 2022 17:08:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229839AbiI2VH6 (ORCPT ); Thu, 29 Sep 2022 17:07:58 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6FCC1B95C0; Thu, 29 Sep 2022 14:07:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1664485678; x=1696021678; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XhYF8rZOoKFacUMCVB3oEurglWDcnVMOCVxLu6rDayk=; b=Wa99g0E8brNVegeiwEngfvQuXivXd6WP2sNbTp7MKDaRNk9pB3oZLQT/ pDydJI0gq4Fu36+5N3dS7lS+tSLHtgrEx68BzBlmsdekb5ZIDFmgJVyFw B2DgIWe+8CHAVzKpQ/R4HQO10wIY5wK1po4sj43fj9oS8BRhKfSV8PU+j A=; X-IronPort-AV: E=Sophos;i="5.93,356,1654560000"; d="scan'208";a="264663810" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-pdx-2c-90419278.us-west-2.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2022 21:07:57 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2c-90419278.us-west-2.amazon.com (Postfix) with ESMTPS id E4AF945E7E; Thu, 29 Sep 2022 21:07:56 +0000 (UTC) Received: from EX19D012UWB002.ant.amazon.com (10.13.138.53) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Thu, 29 Sep 2022 21:07:54 +0000 Received: from EX13MTAUEB002.ant.amazon.com (10.43.60.12) by EX19D012UWB002.ant.amazon.com (10.13.138.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.1118.12; Thu, 29 Sep 2022 21:07:54 +0000 Received: from dev-dsk-risbhat-2b-8bdc64cd.us-west-2.amazon.com (10.189.73.169) by mail-relay.amazon.com (10.43.60.234) with Microsoft SMTP Server id 15.0.1497.38 via Frontend Transport; Thu, 29 Sep 2022 21:07:53 +0000 Received: by dev-dsk-risbhat-2b-8bdc64cd.us-west-2.amazon.com (Postfix, from userid 22673075) id 25801286C; Thu, 29 Sep 2022 21:07:52 +0000 (UTC) From: Rishabh Bhatnagar To: CC: , , , , , , , Robert Hodaszi , Marc Zyngier , Rishabh Bhatnagar Subject: [PATCH 3/6] genirq: Delay deactivation in free_irq() Date: Thu, 29 Sep 2022 21:06:48 +0000 Message-ID: <20220929210651.12308-4-risbhat@amazon.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220929210651.12308-1-risbhat@amazon.com> References: <20220929210651.12308-1-risbhat@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Gleixner commit 4001d8e8762f57d418b66e4e668601791900a1dd upstream. When interrupts are shutdown, they are immediately deactivated in the irqdomain hierarchy. While this looks obviously correct there is a subtle issue: There might be an interrupt in flight when free_irq() is invoking the shutdown. This is properly handled at the irq descriptor / primary handler level, but the deactivation might completely disable resources which are required to acknowledge the interrupt. Split the shutdown code and deactivate the interrupt after synchronization in free_irq(). Fixup all other usage sites where this is not an issue to invoke the combined shutdown_and_deactivate() function instead. This still might be an issue if the interrupt in flight servicing is delayed on a remote CPU beyond the invocation of synchronize_irq(), but that cannot be handled at that level and needs to be handled in the synchronize_irq() context. Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains") Reported-by: Robert Hodaszi Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.de Signed-off-by: Rishabh Bhatnagar --- kernel/irq/autoprobe.c | 6 +++--- kernel/irq/chip.c | 6 ++++++ kernel/irq/cpuhotplug.c | 2 +- kernel/irq/internals.h | 1 + kernel/irq/manage.c | 10 ++++++++++ 5 files changed, 21 insertions(+), 4 deletions(-) diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index befa671fba64..39ff9ab34e82 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -92,7 +92,7 @@ unsigned long probe_irq_on(void) /* It triggered already - consider it spurious. */ if (!(desc->istate & IRQS_WAITING)) { desc->istate &= ~IRQS_AUTODETECT; - irq_shutdown(desc); + irq_shutdown_and_deactivate(desc); } else if (i < 32) mask |= 1 << i; @@ -129,7 +129,7 @@ unsigned int probe_irq_mask(unsigned long val) mask |= 1 << i; desc->istate &= ~IRQS_AUTODETECT; - irq_shutdown(desc); + irq_shutdown_and_deactivate(desc); } raw_spin_unlock_irq(&desc->lock); } @@ -171,7 +171,7 @@ int probe_irq_off(unsigned long val) nr_of_irqs++; } desc->istate &= ~IRQS_AUTODETECT; - irq_shutdown(desc); + irq_shutdown_and_deactivate(desc); } raw_spin_unlock_irq(&desc->lock); } diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 317fc759de76..1936d86db883 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -293,6 +293,12 @@ void irq_shutdown(struct irq_desc *desc) } irq_state_clr_started(desc); } +} + + +void irq_shutdown_and_deactivate(struct irq_desc *desc) +{ + irq_shutdown(desc); /* * This must be called even if the interrupt was never started up, * because the activation can happen before the interrupt is diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index 9eb09aef0313..a9f931217a1b 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -115,7 +115,7 @@ static bool migrate_one_irq(struct irq_desc *desc) */ if (irqd_affinity_is_managed(d)) { irqd_set_managed_shutdown(d); - irq_shutdown(desc); + irq_shutdown_and_deactivate(desc); return false; } affinity = cpu_online_mask; diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 5230c47fc43e..3de3821ab5fe 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -78,6 +78,7 @@ extern void __enable_irq(struct irq_desc *desc); extern int irq_startup(struct irq_desc *desc, bool resend, bool force); extern void irq_shutdown(struct irq_desc *desc); +extern void irq_shutdown_and_deactivate(struct irq_desc *desc); extern void irq_enable(struct irq_desc *desc); extern void irq_disable(struct irq_desc *desc); extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 722aeaae92b1..4e4fc7879307 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -1604,6 +1605,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) /* If this was the last handler, shut down the IRQ line: */ if (!desc->action) { irq_settings_clr_disable_unlazy(desc); + /* Only shutdown. Deactivate after synchronize_hardirq() */ irq_shutdown(desc); } @@ -1673,6 +1675,14 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) * require it to deallocate resources over the slow bus. */ chip_bus_lock(desc); + /* + * There is no interrupt on the fly anymore. Deactivate it + * completely. + */ + raw_spin_lock_irqsave(&desc->lock, flags); + irq_domain_deactivate_irq(&desc->irq_data); + raw_spin_unlock_irqrestore(&desc->lock, flags); + irq_release_resources(desc); chip_bus_sync_unlock(desc); irq_remove_timings(desc); -- 2.37.1