Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752688AbaKFKCv (ORCPT ); Thu, 6 Nov 2014 05:02:51 -0500 Received: from www.linutronix.de ([62.245.132.108]:41637 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670AbaKFKCn (ORCPT ); Thu, 6 Nov 2014 05:02:43 -0500 Date: Thu, 6 Nov 2014 11:01:47 +0100 (CET) From: Thomas Gleixner To: Jiang Liu cc: Benjamin Herrenschmidt , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Bjorn Helgaas , Randy Dunlap , Yinghai Lu , Borislav Petkov , Grant Likely , Marc Zyngier , Yingjoe Chen , Matthias Brugger , Yijing Wang , Alexander Gordeev , Konrad Rzeszutek Wilk , Andrew Morton , Tony Luck , Joerg Roedel , Greg Kroah-Hartman , Suravee Suthikulanit , x86@kernel.org, LKML , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, LAK Subject: Re: [Patch Part2 v4 21/31] PCI/MSI: enhance PCI MSI core to support hierarchy irqdomain In-Reply-To: <1415102525-9898-22-git-send-email-jiang.liu@linux.intel.com> Message-ID: References: <1415102525-9898-1-git-send-email-jiang.liu@linux.intel.com> <1415102525-9898-22-git-send-email-jiang.liu@linux.intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 4 Nov 2014, Jiang Liu wrote: > +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN > +static inline irq_hw_number_t > +msi_get_hwirq(struct pci_dev *pdev, struct msi_desc *msidesc) > +{ > + return (irq_hw_number_t)msidesc->msi_attrib.entry_nr | > + PCI_DEVID(pdev->bus->number, pdev->devfn) << 11 | > + (pci_domain_nr(pdev->bus) & 0xFFFFFFFF) << 27; > +} > + > +static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq, > + unsigned int nr_irqs, void *arg) > +{ > + int i, ret; > + irq_hw_number_t hwirq = arch_msi_irq_domain_get_hwirq(arg); > + > + if (irq_find_mapping(domain, hwirq) > 0) > + return -EEXIST; > + > + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg); > + if (ret >= 0) > + for (i = 0; i < nr_irqs; i++) { > + irq_domain_set_hwirq_and_chip(domain, virq + i, > + hwirq + i, &msi_chip, (void *)(long)i); I think msi_chip being a global unique thing is problematic. It does not allow multi platform kernels to select a chip at boot time and it does not allow per domain chip implementations when you have multiple msi domains. Aside of that msi_chip is a pretty bad name for a global. The solution is rather simple and msi is wide spread enough to justify that. struct irqdomain_msi_data { struct irq_chip *irq_chip; }; We make that a struct so we can accomodate for other special things which might be domain rather than architecture specific. One obvious use case would be to hold the arch_msi_irq_domain_get/set_hwirq callbacks. struct irq_domain *msi_create_irq_domain(struct irq_domain *parent, struct irqdomain_msi_data *data) { struct irq_domain *domain; domain = irq_domain_add_tree(NULL, &msi_domain_ops, NULL); if (domain) { domain->parent = parent; domain->msi_data = data; } return domain; } Now the above becomes: struct irq_chip *msi_chip = domain->msi_data->irq_chip; irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, msi_chip, (void *)(long)i); > +int msi_irq_domain_alloc_irqs(struct irq_domain *domain, int type, > + struct pci_dev *dev, void *arg) > +{ > + int i, virq; > + struct msi_desc *msidesc; > + int node = dev_to_node(&dev->dev); > + > + list_for_each_entry(msidesc, &dev->msi_list, list) { > + arch_msi_irq_domain_set_hwirq(arg, msi_get_hwirq(dev, msidesc)); The arch_xxx callbacks want to be documented. It's not obvious what they are supposed to do. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/