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 6E7E2C3ABC3 for ; Tue, 13 May 2025 17:34:18 +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=VwNHHFkKkpugnXsLzIFZqwmrlvXoDWAFqw7h4dczRBU=; b=n4LcW2FnHm6CXXCuWY3xO7MwYv Wv84TlMCBwjMq9N3VLqP2g7fWQ34ZlIAvxTrJn6tzq82iQrW9qc+644umi+W9OEsydC9OkMVTRkXz CmbOu2nh9AAo9b6J5lrHhlc2A+wU+rmr+7nuway+JdZ40PCVBQB51WfytcCZUqL3Y8zBqE7B6F4NO 6yGJnuWLKgwmBRDgkuKCd40+ul22w+sHu+/RugSL+gjcHccTvKeAws1gPkOzcz+k3u/77xQCeM4Vf R+4EGZ/0aDHq5/x8KksSqnlsWir+ZAaBTLkniRkgWynu0wDtEKn+MoDeXF6wnZugHO3rxxnm9dutQ N3n7hxOQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEtW8-0000000D6u4-1dG0; Tue, 13 May 2025 17:34:12 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEtQe-0000000D5dD-0Svv for linux-arm-kernel@lists.infradead.org; Tue, 13 May 2025 17:28:32 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 6AE3D629FB; Tue, 13 May 2025 17:28:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11A5AC4AF0C; Tue, 13 May 2025 17:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747157311; bh=5BoSY6I4E3zhXcU/3IAaz838Ni4OzdDS8jPXJzV6qg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dm8fnhbb1HXn9Xj7HTUoE8BQAcuWlp0sNhyErxY9mHhVVE0lAMWqRBK5LDrxmjB0W BS5PshtG6OQFNM0XU9LNbzNgGHixp9rMcaBz1q/oJGMJSGReYcm8NwfdtY1/I6M4C7 m+hnhYBkHPddwowLFrZ9QmEsoGOvnPZsTG1FXaVfc4DHU/lC6x5dNiYAWVTvfbk3hw rILWiC4xmuFJ/brRqRagFPQKNRidwiQITQfBJnwg3Vzvwwf9d3yF8zKNZN0Gd4Gdj8 /StB4Cng0CwOX8TfoNfXeSYyA1ch6cQ0tTg1iWwdj10ajEWztRiu18loLqYfddn4Uv dXn5Kn/l5w7XQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1uEtQb-00EbRz-7F; Tue, 13 May 2025 18:28:29 +0100 From: Marc Zyngier To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org Cc: Thomas Gleixner , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Lorenzo Pieralisi , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Manivannan Sadhasivam , Bjorn Helgaas , Toan Le , Alyssa Rosenzweig , Thierry Reding , Jonathan Hunter Subject: [PATCH v2 6/9] irqchip/msi-lib: Honour the MSI_FLAG_NO_AFFINITY flag Date: Tue, 13 May 2025 18:28:16 +0100 Message-Id: <20250513172819.2216709-7-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250513172819.2216709-1-maz@kernel.org> References: <20250513172819.2216709-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, tglx@linutronix.de, andrew@lunn.ch, gregory.clement@bootlin.com, sebastian.hesselbarth@gmail.com, lpieralisi@kernel.org, kw@linux.com, manivannan.sadhasivam@linaro.org, bhelgaas@google.com, toan@os.amperecomputing.com, alyssa@rosenzweig.io, thierry.reding@gmail.com, jonathanh@nvidia.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false 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 Bad MSI implementations multiplex MSIs onto a single downstream interrupt, meaning they have no concept of individual affinity. The old MSI code did a reasonable job at this by honouring the MSI_FLAG_NO_AFFINITY, but the new shiny device MSI code doesn't. Teach it about the sad reality of existing hardware. Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-msi-lib.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-msi-lib.c b/drivers/irqchip/irq-msi-lib.c index 2a61c06c4da07..246c30205af40 100644 --- a/drivers/irqchip/irq-msi-lib.c +++ b/drivers/irqchip/irq-msi-lib.c @@ -105,8 +105,13 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain, * MSI message into the hardware which is the whole purpose of the * device MSI domain aside of mask/unmask which is provided e.g. by * PCI/MSI device domains. + * + * The exception to the rule is when the underlying domain + * tells you that affinity is not a thing -- for example when + * everything is muxed behind a single interrupt. */ - chip->irq_set_affinity = msi_domain_set_affinity; + if (!chip->irq_set_affinity && !(info->flags & MSI_FLAG_NO_AFFINITY)) + chip->irq_set_affinity = msi_domain_set_affinity; return true; } EXPORT_SYMBOL_GPL(msi_lib_init_dev_msi_info); -- 2.39.2