From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH v11 10/10] genirq/msi: use the MSI doorbell's IOVA when requested Date: Wed, 20 Jul 2016 11:09:28 +0200 (CEST) Message-ID: References: <1468933367-23159-1-git-send-email-eric.auger@redhat.com> <1468933367-23159-11-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <1468933367-23159-11-git-send-email-eric.auger@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Eric Auger Cc: eric.auger.pro@gmail.com, marc.zyngier@arm.com, christoffer.dall@linaro.org, andre.przywara@arm.com, robin.murphy@arm.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org, drjones@redhat.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, pbonzini@redhat.com, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, yehuday@marvell.com, Manish.Jaggi@caviumnetworks.com, robert.richter@caviumnetworks.com List-Id: iommu@lists.linux-foundation.org On Tue, 19 Jul 2016, Eric Auger wrote: First of all - valid for all patches: Subject: sys/subsys: Sentence starts with an uppercase letter Now for this particular one: genirq/msi: use the MSI doorbell's IOVA when requested > On MSI message composition we now use the MSI doorbell's IOVA in > place of the doorbell's PA in case the device is upstream to an > IOMMU that requires MSI addresses to be mapped. The doorbell's > allocation and mapping happened on an early stage (pci_enable_msi). This changelog is completely useless. At least I cannot figure out what that patch actually does. And the implementation is not self explaining either. > @@ -63,10 +63,18 @@ static int msi_compose(struct irq_data *irq_data, > { > int ret = 0; > > - if (erase) > + if (erase) { > memset(msg, 0, sizeof(*msg)); > - else > + } else { > + struct device *dev; > + > ret = irq_chip_compose_msi_msg(irq_data, msg); > + if (ret) > + return ret; > + > + dev = msi_desc_to_dev(irq_data_get_msi_desc(irq_data)); > + WARN_ON(iommu_msi_msg_pa_to_va(dev, msg)); What the heck is this call doing? And why is there only a WARN_ON and not a proper error return code handling? Thanks, tglx