Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751288AbaKFB7F (ORCPT ); Wed, 5 Nov 2014 20:59:05 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:36936 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbaKFB7B (ORCPT ); Wed, 5 Nov 2014 20:59:01 -0500 Message-ID: <545AD5B3.60009@huawei.com> Date: Thu, 6 Nov 2014 09:58:11 +0800 From: Yijing Wang User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Bjorn Helgaas , Jiang Liu 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 , , , , , 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> In-Reply-To: <20141105230952.GH6168@google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.27.212] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> >> @@ -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. 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 >> > > . > -- Thanks! 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