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.
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/base/core.c | 20 ++++++++++++++++++++
include/linux/device.h | 1 +
2 files changed, 21 insertions(+)
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)
{
--
2.17.2
