From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Dutile Subject: Re: [PATCH v2 6/7] intel-iommu: Make use of DMA quirks and ACS checks in IOMMU groups Date: Thu, 31 May 2012 15:47:49 -0400 Message-ID: <4FC7CAE5.7020306@redhat.com> References: <20120530201424.31527.33142.stgit@bling.home> <20120530201942.31527.51604.stgit@bling.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120530201942.31527.51604.stgit-xdHQ/5r00wBBDLzU/O5InQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Alex Williamson Cc: aik-sLpHqDYs0B2HXe+LvDLADg@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, liuj97-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org List-Id: iommu@lists.linux-foundation.org On 05/30/2012 04:19 PM, Alex Williamson wrote: > Work around broken devices and adhere to ACS support when determining > IOMMU grouping. > > Signed-off-by: Alex Williamson > --- > > drivers/iommu/intel-iommu.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 4a43452..ebf2b31 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -4090,6 +4090,14 @@ static int intel_iommu_domain_has_cap(struct iommu_domain *domain, > return 0; > } > > +static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to) > +{ > + pci_dev_put(*from); > + *from = to; > +} > + > +#define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF) > + > static int intel_iommu_add_device(struct device *dev) > { > struct pci_dev *pdev = to_pci_dev(dev); > @@ -4112,6 +4120,23 @@ static int intel_iommu_add_device(struct device *dev) > } else > dma_pdev = pci_dev_get(pdev); > > + swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev)); > + > + if (dma_pdev->multifunction&& > + !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) > + swap_pci_ref(&dma_pdev, > + pci_get_slot(dma_pdev->bus, > + PCI_DEVFN(PCI_SLOT(dma_pdev->devfn), > + 0))); > + > + while (!pci_is_root_bus(dma_pdev->bus)) { > + if (pci_acs_path_enabled(dma_pdev->bus->self, > + NULL, REQ_ACS_FLAGS)) > + break; > + > + swap_pci_ref(&dma_pdev, pci_dev_get(dma_pdev->bus->self)); > + } > + I'm having deja-vu on this patch.... .... why not just make the above two patches as two functions in drivers/iommu/iommu.c, one exported for these two modules (and maybe others someday...), e.g., iommu_pdev_put()) which [intel-,amd-]iommu.c call ? > group = iommu_group_get(&dma_pdev->dev); > pci_dev_put(dma_pdev); > if (!group) { >