driver core: Add iommu_group tracking to struct device

IOMMU groups allow IOMMU drivers to represent DMA visibility
and isolation of devices.  Multiple devices may be grouped
together for the purposes of DMA.  Placing a pointer on
struct device enable easy access for things like streaming
DMA programming and drivers like VFIO.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 161d96241b1..d0e4d99405a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -36,6 +36,7 @@ struct subsys_private;
 struct bus_type;
 struct device_node;
 struct iommu_ops;
+struct iommu_group;
 
 struct bus_attribute {
         struct attribute        attr;
@@ -687,6 +688,7 @@ struct device {
         const struct attribute_group **groups;  /* optional groups */
 
         void    (*release)(struct device *dev);
+        struct iommu_group      *iommu_group;
 };
 
 /* Get the wakeup routines, which depend on struct device */