From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18ECE79C0 for ; Wed, 30 Nov 2022 18:42:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65F85C433D6; Wed, 30 Nov 2022 18:42:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669833769; bh=YYFfguAR0WLT78RoSoOuxno6o1fkXPZ4RaOq44hCWHs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I33UX2S4HfhOlicpI2/gH26XMMwaB58cg6IPwzYd355BrIsbMglk+WUIC4ylbxnHf sid9uzb86Lat5v0N7BUP75cQVb6hCAbyGR6OPyzUmPQSOwy7PgJnRNsdIxKIs4cmgn j4veqThmHMAdov4iqhnpIIx18c3eXoILAyEVP1wc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marek Szyprowski , Marc Zyngier , Thomas Gleixner , Luiz Capitulino Subject: [PATCH 5.15 195/206] genirq: Take the proposed affinity at face value if force==true Date: Wed, 30 Nov 2022 19:24:07 +0100 Message-Id: <20221130180537.979195798@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221130180532.974348590@linuxfoundation.org> References: <20221130180532.974348590@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Luiz Capitulino From: Marc Zyngier commit c48c8b829d2b966a6649827426bcdba082ccf922 upstream. Although setting the affinity of an interrupt to a set of CPUs that doesn't have any online CPU is generally frowned apon, there are a few limited cases where such affinity is set from a CPUHP notifier, setting the affinity to a CPU that isn't online yet. The saving grace is that this is always done using the 'force' attribute, which gives a hint that the affinity setting can be outside of the online CPU mask and the callsite set this flag with the knowledge that the underlying interrupt controller knows to handle it. This restores the expected behaviour on Marek's system. Fixes: 33de0aa4bae9 ("genirq: Always limit the affinity to online CPUs") Reported-by: Marek Szyprowski Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Marek Szyprowski Link: https://lore.kernel.org/r/4b7fc13c-887b-a664-26e8-45aed13f048a@samsung.com Link: https://lore.kernel.org/r/20220414140011.541725-1-maz@kernel.org Signed-off-by: Luiz Capitulino Signed-off-by: Greg Kroah-Hartman --- kernel/irq/manage.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -266,10 +266,16 @@ int irq_do_set_affinity(struct irq_data prog_mask = mask; } - /* Make sure we only provide online CPUs to the irqchip */ + /* + * Make sure we only provide online CPUs to the irqchip, + * unless we are being asked to force the affinity (in which + * case we do as we are told). + */ cpumask_and(&tmp_mask, prog_mask, cpu_online_mask); - if (!cpumask_empty(&tmp_mask)) + if (!force && !cpumask_empty(&tmp_mask)) ret = chip->irq_set_affinity(data, &tmp_mask, force); + else if (force) + ret = chip->irq_set_affinity(data, mask, force); else ret = -EINVAL;