From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933033AbcEXVEl (ORCPT ); Tue, 24 May 2016 17:04:41 -0400 Received: from mail.kernel.org ([198.145.29.136]:60995 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752581AbcEXVEj (ORCPT ); Tue, 24 May 2016 17:04:39 -0400 Date: Tue, 24 May 2016 16:04:34 -0500 From: Bjorn Helgaas To: Yongji Xie Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux-foundation.org, alex.williamson@redhat.com, bhelgaas@google.com, aik@ozlabs.ru, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, joro@8bytes.org, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, eric.auger@linaro.org, will.deacon@arm.com, gwshan@linux.vnet.ibm.com, David.Laight@ACULAB.COM, alistair@popple.id.au, ruscur@russell.cc Subject: Re: [PATCH 3/5] PCI: Set PCI_BUS_FLAGS_MSI_REMAP if MSI controller supports IRQ remapping Message-ID: <20160524210434.GB16463@localhost> References: <1461761010-5452-1-git-send-email-xyjxie@linux.vnet.ibm.com> <1461761010-5452-4-git-send-email-xyjxie@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461761010-5452-4-git-send-email-xyjxie@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 27, 2016 at 08:43:28PM +0800, Yongji Xie wrote: > On ARM HW the capability of IRQ remapping is abstracted on > MSI controller side. MSI_FLAG_IRQ_REMAPPING is used to advertise > this [1]. > > To have a universal flag to test this capability for different > archs on PCI side, we set PCI_BUS_FLAGS_MSI_REMAP for PCI buses > when MSI_FLAG_IRQ_REMAPPING is set. > > [1] http://www.spinics.net/lists/kvm/msg130256.html > > Signed-off-by: Yongji Xie > --- > drivers/pci/msi.c | 12 ++++++++++++ > drivers/pci/probe.c | 3 +++ > include/linux/msi.h | 6 +++++- > 3 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index a080f44..1661cdf 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -1134,6 +1134,18 @@ void *msi_desc_to_pci_sysdata(struct msi_desc *desc) > } > EXPORT_SYMBOL_GPL(msi_desc_to_pci_sysdata); > > +void pci_bus_check_msi_remapping(struct pci_bus *bus, > + struct irq_domain *domain) > +{ > +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN > + struct msi_domain_info *info; > + > + info = msi_get_domain_info(domain); > + if (info->flags & MSI_FLAG_IRQ_REMAPPING) > + bus->bus_flags |= PCI_BUS_FLAGS_MSI_REMAP; > +#endif > +} Functions named "check_foo" are a pet peeve of mine because the name doesn't tell us anything about what the function *does*. In this case, we know it checks something about MSI remapping, but we don't know whether we're checking whether it's enabled, disabled, or some other property. I'd prefer something like: int pci_bus_msi_isolated(struct pci_bus *bus, struct irq_domain *domain) { struct msi_domain_info *info; if (!domain) return 0; info = msi_get_domain_info(domain); if (info->flags & MSI_FLAG_IRQ_REMAPPING) return 1; return 0; } void pci_set_bus_msi_domain(struct pci_bus *bus) { ... if (b == bus && pci_bus_msi_isolated(bus, d)) bus->bus_flags |= PCI_BUS_FLAGS_MSI_REMAP; > #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN > /** > * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 6d7ab9b..25cf1b1 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -696,6 +696,9 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus) > if (!d) > d = pci_host_bridge_msi_domain(b); > > + if (d && b == bus) > + pci_bus_check_msi_remapping(bus, d); > + > dev_set_msi_domain(&bus->dev, d); > } > > diff --git a/include/linux/msi.h b/include/linux/msi.h > index 03eda72..b4c649e 100644 > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -15,6 +15,8 @@ extern int pci_msi_ignore_mask; > struct irq_data; > struct msi_desc; > struct pci_dev; > +struct pci_bus; > +struct irq_domain; > struct platform_msi_priv_data; > void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg); > void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg); > @@ -155,6 +157,9 @@ void arch_restore_msi_irqs(struct pci_dev *dev); > void default_teardown_msi_irqs(struct pci_dev *dev); > void default_restore_msi_irqs(struct pci_dev *dev); > > +void pci_bus_check_msi_remapping(struct pci_bus *bus, > + struct irq_domain *domain); > + > struct msi_controller { > struct module *owner; > struct device *dev; > @@ -173,7 +178,6 @@ struct msi_controller { > #include > #include > > -struct irq_domain; > struct irq_domain_ops; > struct irq_chip; > struct device_node; > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html