iommu/arm-smmu: add devices attached to the SMMU to an IOMMU group

IOMMU groups are expected by certain users of the IOMMU API,
e.g. VFIO. Add new devices found by the SMMU driver to an IOMMU
group to satisfy those users.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index e46a88700b6824c735967118281c9f7feb6e41b0..879da20617fb328d22e713975204d77a9efbfb09 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1494,6 +1494,13 @@ static int arm_smmu_add_device(struct device *dev)
 {
        struct arm_smmu_device *child, *parent, *smmu;
        struct arm_smmu_master *master = NULL;
+       struct iommu_group *group;
+       int ret;
+
+       if (dev->archdata.iommu) {
+               dev_warn(dev, "IOMMU driver already assigned to device\n");
+               return -EINVAL;
+       }
 
        spin_lock(&arm_smmu_devices_lock);
        list_for_each_entry(parent, &arm_smmu_devices, list) {
@@ -1526,13 +1533,23 @@ static int arm_smmu_add_device(struct device *dev)
        if (!master)
                return -ENODEV;
 
+       group = iommu_group_alloc();
+       if (IS_ERR(group)) {
+               dev_err(dev, "Failed to allocate IOMMU group\n");
+               return PTR_ERR(group);
+       }
+
+       ret = iommu_group_add_device(group, dev);
+       iommu_group_put(group);
        dev->archdata.iommu = smmu;
-       return 0;
+
+       return ret;
 }
 
 static void arm_smmu_remove_device(struct device *dev)
 {
        dev->archdata.iommu = NULL;
+       iommu_group_remove_device(dev);
 }
 
 static struct iommu_ops arm_smmu_ops = {