On Tue, Jan 29, 2019 at 12:47 PM <jglisse@xxxxxxxxxx> wrote: > > From: Jérôme Glisse <jglisse@xxxxxxxxxx> > > device_test_p2p() return true if two devices can peer to peer to > each other. We add a generic function as different inter-connect > can support peer to peer and we want to genericaly test this no > matter what the inter-connect might be. However this version only > support PCIE for now. > What about something like these patches: https://cgit.freedesktop.org/~deathsimple/linux/commit/?h=p2p&id=4fab9ff69cb968183f717551441b475fabce6c1c https://cgit.freedesktop.org/~deathsimple/linux/commit/?h=p2p&id=f90b12d41c277335d08c9dab62433f27c0fadbe5 They are a bit more thorough. Alex > Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx> > Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Cc: Christian Koenig <christian.koenig@xxxxxxx> > Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-pci@xxxxxxxxxxxxxxx > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Joerg Roedel <jroedel@xxxxxxx> > Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > --- > drivers/pci/p2pdma.c | 27 +++++++++++++++++++++++++++ > include/linux/pci-p2pdma.h | 6 ++++++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index c52298d76e64..620ac60babb5 100644 > --- a/drivers/pci/p2pdma.c > +++ b/drivers/pci/p2pdma.c > @@ -797,3 +797,30 @@ ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, > return sprintf(page, "%s\n", pci_name(p2p_dev)); > } > EXPORT_SYMBOL_GPL(pci_p2pdma_enable_show); > + > +bool pci_test_p2p(struct device *devA, struct device *devB) > +{ > + struct pci_dev *pciA, *pciB; > + bool ret; > + int tmp; > + > + /* > + * For now we only support PCIE peer to peer but other inter-connect > + * can be added. > + */ > + pciA = find_parent_pci_dev(devA); > + pciB = find_parent_pci_dev(devB); > + if (pciA == NULL || pciB == NULL) { > + ret = false; > + goto out; > + } > + > + tmp = upstream_bridge_distance(pciA, pciB, NULL); > + ret = tmp < 0 ? false : true; > + > +out: > + pci_dev_put(pciB); > + pci_dev_put(pciA); > + return false; > +} > +EXPORT_SYMBOL_GPL(pci_test_p2p); > diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h > index bca9bc3e5be7..7671cc499a08 100644 > --- a/include/linux/pci-p2pdma.h > +++ b/include/linux/pci-p2pdma.h > @@ -36,6 +36,7 @@ int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, > bool *use_p2pdma); > ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, > bool use_p2pdma); > +bool pci_test_p2p(struct device *devA, struct device *devB); > #else /* CONFIG_PCI_P2PDMA */ > static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, > size_t size, u64 offset) > @@ -97,6 +98,11 @@ static inline ssize_t pci_p2pdma_enable_show(char *page, > { > return sprintf(page, "none\n"); > } > + > +static inline bool pci_test_p2p(struct device *devA, struct device *devB) > +{ > + return false; > +} > #endif /* CONFIG_PCI_P2PDMA */ > > > -- > 2.17.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel
