| Message ID | 20190129174728.6430-3-jglisse@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Device peer to peer (p2p) through vma | expand |
On 2019-01-29 10:47 a.m., jglisse@redhat.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > 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. This doesn't appear to be used in any of the further patches; so it's very confusing. I'm not sure a struct device wrapper is really necessary... Logan
On Tue, Jan 29, 2019 at 12:47:25PM -0500, jglisse@redhat.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > 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. There is no defintion of "peer to peer" in the driver/device model, so why should this be in the driver core at all? Especially as you only do this for PCI, why not just keep it in the PCI layer, that way you _know_ you are dealing with the right pointer types and there is no need to mess around with the driver core at all. thanks, greg k-h
On Tue, Jan 29, 2019 at 11:26:01AM -0700, Logan Gunthorpe wrote: > > > On 2019-01-29 10:47 a.m., jglisse@redhat.com wrote: > > From: Jérôme Glisse <jglisse@redhat.com> > > > > 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. > > This doesn't appear to be used in any of the further patches; so it's > very confusing. > > I'm not sure a struct device wrapper is really necessary... I wanted to allow other non pci device to join in the fun but yes right now i have only be doing this on pci devices. Jérôme
On Tue, Jan 29, 2019 at 08:46:05PM +0100, Greg Kroah-Hartman wrote: > On Tue, Jan 29, 2019 at 12:47:25PM -0500, jglisse@redhat.com wrote: > > From: Jérôme Glisse <jglisse@redhat.com> > > > > 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. > > There is no defintion of "peer to peer" in the driver/device model, so > why should this be in the driver core at all? > > Especially as you only do this for PCI, why not just keep it in the PCI > layer, that way you _know_ you are dealing with the right pointer types > and there is no need to mess around with the driver core at all. Ok i will drop the core device change. I wanted to allow other non PCI to join latter on (ie allow PCI device to export to non PCI device) but if that ever happen then we can update pci exporter at the same time we introduce non pci importer. Cheers, Jérôme
diff --git a/drivers/base/core.c b/drivers/base/core.c index 0073b09bb99f..56023b00e108 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -26,6 +26,7 @@ #include <linux/netdevice.h> #include <linux/sched/signal.h> #include <linux/sysfs.h> +#include <linux/pci-p2pdma.h> #include "base.h" #include "power/power.h" @@ -3167,3 +3168,22 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2) dev->of_node_reused = true; } EXPORT_SYMBOL_GPL(device_set_of_node_from_dev); + +/** + * device_test_p2p - test if two device can peer to peer to each other + * @devA: device A + * @devB: device B + * Returns: true if device can peer to peer to each other, false otherwise + */ +bool device_test_p2p(struct device *devA, struct device *devB) +{ + /* + * For now we only support PCIE peer to peer but other inter-connect + * can be added. + */ + if (pci_test_p2p(devA, devB)) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(device_test_p2p); diff --git a/include/linux/device.h b/include/linux/device.h index 6cb4640b6160..0d532d7f0779 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1250,6 +1250,7 @@ extern int device_online(struct device *dev); extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode); extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode); void device_set_of_node_from_dev(struct device *dev, const struct device *dev2); +bool device_test_p2p(struct device *devA, struct device *devB); static inline int dev_num_vf(struct device *dev) {