Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751301AbaKFFGr (ORCPT ); Thu, 6 Nov 2014 00:06:47 -0500 Received: from mga02.intel.com ([134.134.136.20]:31767 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751051AbaKFFGo (ORCPT ); Thu, 6 Nov 2014 00:06:44 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,691,1406617200"; d="scan'208";a="484954527" Message-ID: <545B01DC.5060107@linux.intel.com> Date: Thu, 06 Nov 2014 13:06:36 +0800 From: Jiang Liu Organization: Intel User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Yijing Wang , Bjorn Helgaas CC: Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Randy Dunlap , Yinghai Lu , Borislav Petkov , Grant Likely , Marc Zyngier , Yingjoe Chen , Matthias Brugger , Alexander Gordeev , Konrad Rzeszutek Wilk , Andrew Morton , Tony Luck , Joerg Roedel , Greg Kroah-Hartman , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [Patch Part2 v4 21/31] PCI/MSI: enhance PCI MSI core to support hierarchy irqdomain References: <1415102525-9898-1-git-send-email-jiang.liu@linux.intel.com> <1415102525-9898-22-git-send-email-jiang.liu@linux.intel.com> <20141105230952.GH6168@google.com> <545AD5B3.60009@huawei.com> In-Reply-To: <545AD5B3.60009@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/11/6 9:58, Yijing Wang wrote: >>> >>> @@ -1098,3 +1099,128 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, >>> return nvec; >>> } >>> EXPORT_SYMBOL(pci_enable_msix_range); >>> + >>> +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN >> >> Space, not tab. >> >>> +static inline irq_hw_number_t >>> +msi_get_hwirq(struct pci_dev *pdev, struct msi_desc *msidesc) >> >> The convention in this file is "struct pci_dev *dev". And "struct msi_desc >> *desc" (or maybe "*entry"). Try to converge things, not diverge them. >> >>> +{ >>> + 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; >> >> Where does this bit layout come from? Is this defined in the spec >> somewhere? A reference would help. > > Currently, more and more Non-PCI device use MSI(or similar MSI mechanism), like DMAR fault irq > and HPET FSB irq. And we have to add additional code to support the MSI capability. > So I hope we can decouple MSI code and PCI code, then we can unify all MSI(or Message Based interrupt) > in one framework. Hi Yijing, I have a following patch to share more code among MSI/DMAR/HPET, which is one step forward as you suggested. Will send out that patch set soon. Regards! Gerry > > Thanks! > Yijing. > >> >>> +} >>> + >>> +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) >> >> if (ret < 0) >> return ret; >> >> and un-indent the mainline code below. Then it's obvious that this is the >> normal case, not the error case. >> >>> + for (i = 0; i < nr_irqs; i++) { >>> + irq_domain_set_hwirq_and_chip(domain, virq + i, >>> + hwirq + i, &msi_chip, (void *)(long)i); >>> + __irq_set_handler(virq + i, handle_edge_irq, 0, "edge"); >>> + } >>> + >>> + return ret; >>> +} >>> + >>> +static void msi_domain_free(struct irq_domain *domain, unsigned int virq, >>> + unsigned int nr_irqs) >>> +{ >>> + int i; >>> + >>> + for (i = 0; i < nr_irqs; i++) { >>> + struct msi_desc *msidesc = irq_get_msi_desc(virq); >>> + >>> + if (msidesc) >>> + msidesc->irq = 0; >>> + } >>> + irq_domain_free_irqs_top(domain, virq, nr_irqs); >>> +} >>> + >>> +static int msi_domain_activate(struct irq_domain *domain, >>> + struct irq_data *irq_data) >>> +{ >>> + int ret = 0; >>> + struct msi_msg msg; >>> + >>> + /* >>> + * irq_data->chip_data is MSI/MSIx offset. >> >> "MSI-X", as you wrote on the next line. >> >>> + * MSI-X message is written per-IRQ, the offset is always 0. >>> + * MSI message denotes a contiguous group of IRQs, written for 0th IRQ. >>> + */ >>> + if (!irq_data->chip_data) { >> >> if (irq_data->chip_data) >> return 0; >> >> and un-indent the mainline code below, and drop the "ret = 0" init above. >> >>> + ret = irq_chip_compose_msi_msg(irq_data, &msg); >>> + if (ret == 0) >> >> if (ret) >> return ret; >> >>> + write_msi_msg(irq_data->irq, &msg); >>> + } >>> + >>> + return ret; >> return 0; >>> +} >>> + >>> +static int msi_domain_deactivate(struct irq_domain *domain, >>> + struct irq_data *irq_data) >>> +{ >>> + struct msi_msg msg; >>> + >>> + if (irq_data->chip_data) { >>> + memset(&msg, 0, sizeof(msg)); >>> + write_msi_msg(irq_data->irq, &msg); >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static struct irq_domain_ops msi_domain_ops = { >>> + .alloc = msi_domain_alloc, >>> + .free = msi_domain_free, >>> + .activate = msi_domain_activate, >>> + .deactivate = msi_domain_deactivate, >>> +}; >>> + >>> +struct irq_domain *msi_create_irq_domain(struct irq_domain *parent) >>> +{ >>> + struct irq_domain *domain; >>> + >>> + domain = irq_domain_add_tree(NULL, &msi_domain_ops, NULL); >>> + if (domain) >> >> if (!domain) >> return NULL; >> >> and un-indent this: >> >>> + domain->parent = parent; >>> + >>> + return domain; >>> +} >>> + >>> +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)); >>> + virq = irq_domain_alloc_irqs(domain, msidesc->nvec_used, >>> + node, arg); >>> + if (virq < 0) { >>> + /* Special handling for pci_enable_msi_range(). */ >>> + return (type == PCI_CAP_ID_MSI && >>> + msidesc->nvec_used > 1) ? 1 : -ENOSPC; >> >> I think "if" would be easier to read than this ternary expression. >> >>> + } >>> + for (i = 0; i < msidesc->nvec_used; i++) >>> + irq_set_msi_desc_off(virq + i, i, msidesc); >>> + } >>> + >>> + list_for_each_entry(msidesc, &dev->msi_list, list) >>> + if (msidesc->nvec_used == 1) >>> + dev_dbg(&dev->dev, "irq %d for MSI/MSI-X\n", virq); >>> + else >>> + dev_dbg(&dev->dev, "irq [%d-%d] for MSI/MSI-X\n", >>> + virq, virq + msidesc->nvec_used - 1); >>> + >>> + return 0; >>> +} >>> +#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ >>> diff --git a/include/linux/msi.h b/include/linux/msi.h >>> index 44f4746d033b..05dcd425f82b 100644 >>> --- a/include/linux/msi.h >>> +++ b/include/linux/msi.h >>> @@ -75,4 +75,15 @@ struct msi_chip { >>> void (*teardown_irq)(struct msi_chip *chip, unsigned int irq); >>> }; >>> >>> +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN >> >> Use a space here, not a tab. >> >>> +extern struct irq_chip msi_chip; >> >> I don't think "msi_chip" is a good name. "Chip" only hints that it's a >> semiconductor integrated circuit; it doesn't say anything about what it >> does. I've suggested "msi_controller" elsewhere. >> >> Why does this need to be exported? And why should there be only one in a >> system? >> >>> +extern struct irq_domain *msi_create_irq_domain(struct irq_domain *parent); >>> +extern int msi_irq_domain_alloc_irqs(struct irq_domain *domain, int type, >>> + struct pci_dev *dev, void *arg); >>> + >>> +extern irq_hw_number_t arch_msi_irq_domain_get_hwirq(void *arg); >>> +extern void arch_msi_irq_domain_set_hwirq(void *arg, irq_hw_number_t hwirq); >> >> Look at the rest of the file and notice that the existing code does not use >> "extern" on function declarations. >> >>> +#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ >> >> Use a space here (not a tab), like the #endif just below. >> >>> #endif /* LINUX_MSI_H */ >>> -- >>> 1.7.10.4 >>> >> >> . >> > > -- 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/