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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 123E9C433F5 for ; Tue, 7 Dec 2021 20:54:29 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4J7sx01RJkz304j for ; Wed, 8 Dec 2021 07:54:28 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=MbREQLAm; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:40e1:4800::1; helo=sin.source.kernel.org; envelope-from=helgaas@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=MbREQLAm; dkim-atps=neutral Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4J7swC4R1Lz2ypX for ; Wed, 8 Dec 2021 07:53:47 +1100 (AEDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 16831CE1DFE; Tue, 7 Dec 2021 20:53:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3E3EC341C1; Tue, 7 Dec 2021 20:53:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638910419; bh=0olJYQ/vZXxNbmux0Wc5kCG7Q8xmQSGJ4EEGX5/7MKM=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=MbREQLAmpD8wPLYpCv9jTSrE00gvmkjU34dG8bCGSdkkOx5lA5r+o1g2zoGSx/C2b YIQIjqV/znJrCTHzH9zLIkNioxbfipIqhqype9Cd76anoG298O5tcN/hAXHTcgJr7E AQhUCxkGye8vXivrflomiTMP5ytmmN4IV5kZwS7+LEBV8ahxK0/RPJjGnSoav8YdLu Le2YSsXdQfJoyXe6klQp9YFPeJz/C9VdAwMAeftNu99ODwCGdjCd6c3CFrixrHlASA bFHldg7thBUs+vtbfN+tcSAWID3FMjm+GzEoLKnTtAPWT54ggSkOvfr4XTjRaQ/uf3 5wndBP5xrSsFw== Date: Tue, 7 Dec 2021 14:53:37 -0600 From: Bjorn Helgaas To: Thomas Gleixner Subject: Re: [patch V2 02/23] PCI/MSI: Fix pci_irq_vector()/pci_irq_get_affinity() Message-ID: <20211207205337.GA76377@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211206210223.929792157@linutronix.de> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hyperv@vger.kernel.org, linux-mips@vger.kernel.org, Paul Mackerras , sparclinux@vger.kernel.org, Wei Liu , Ashok Raj , x86@kernel.org, Christian Borntraeger , Megha Dey , Jason Gunthorpe , linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, ath11k@lists.infradead.org, Kevin Tian , Heiko Carstens , Alex Williamson , Cedric Le Goater , Kalle Valo , Juergen Gross , Thomas Bogendoerfer , Greg Kroah-Hartman , LKML , Marc Zygnier , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Dec 06, 2021 at 11:27:26PM +0100, Thomas Gleixner wrote: > pci_irq_vector() and pci_irq_get_affinity() use the list position to find the > MSI-X descriptor at a given index. That's correct for the normal case where > the entry number is the same as the list position. > > But it's wrong for cases where MSI-X was allocated with an entries array > describing sparse entry numbers into the hardware message descriptor > table. That's inconsistent at best. > > Make it always check the entry number because that's what the zero base > index really means. This change won't break existing users which use a > sparse entries array for allocation because these users retrieve the Linux > interrupt number from the entries array after allocation and none of them > uses pci_irq_vector() or pci_irq_get_affinity(). > > Fixes: aff171641d18 ("PCI: Provide sensible IRQ vector alloc/free routines") > Signed-off-by: Thomas Gleixner > Tested-by: Juergen Gross > Reviewed-by: Jason Gunthorpe Acked-by: Bjorn Helgaas > --- > V2: Fix typo in subject - Jason > --- > drivers/pci/msi.c | 26 ++++++++++++++++++-------- > 1 file changed, 18 insertions(+), 8 deletions(-) > > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -1187,19 +1187,24 @@ EXPORT_SYMBOL(pci_free_irq_vectors); > > /** > * pci_irq_vector - return Linux IRQ number of a device vector > - * @dev: PCI device to operate on > - * @nr: device-relative interrupt vector index (0-based). > + * @dev: PCI device to operate on > + * @nr: Interrupt vector index (0-based) > + * > + * @nr has the following meanings depending on the interrupt mode: > + * MSI-X: The index in the MSI-X vector table > + * MSI: The index of the enabled MSI vectors > + * INTx: Must be 0 > + * > + * Return: The Linux interrupt number or -EINVAl if @nr is out of range. > */ > int pci_irq_vector(struct pci_dev *dev, unsigned int nr) > { > if (dev->msix_enabled) { > struct msi_desc *entry; > - int i = 0; > > for_each_pci_msi_entry(entry, dev) { > - if (i == nr) > + if (entry->msi_attrib.entry_nr == nr) > return entry->irq; > - i++; > } > WARN_ON_ONCE(1); > return -EINVAL; > @@ -1223,17 +1228,22 @@ EXPORT_SYMBOL(pci_irq_vector); > * pci_irq_get_affinity - return the affinity of a particular MSI vector > * @dev: PCI device to operate on > * @nr: device-relative interrupt vector index (0-based). > + * > + * @nr has the following meanings depending on the interrupt mode: > + * MSI-X: The index in the MSI-X vector table > + * MSI: The index of the enabled MSI vectors > + * INTx: Must be 0 > + * > + * Return: A cpumask pointer or NULL if @nr is out of range > */ > const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr) > { > if (dev->msix_enabled) { > struct msi_desc *entry; > - int i = 0; > > for_each_pci_msi_entry(entry, dev) { > - if (i == nr) > + if (entry->msi_attrib.entry_nr == nr) > return &entry->affinity->mask; > - i++; > } > WARN_ON_ONCE(1); > return NULL; >