Remove master device from the IOMMU. This will be helpful when removing the
overlay nodes using dynamic programming during run time.
Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
---
Changes from v10:
Add comment regarding return values of iommu_remove_dt_device().
Add ASSERT to check if is_protected is removed or not.
Changes from v7:
Add check if IOMMU is enabled.
Fix indentation of fail.
---
---
xen/drivers/passthrough/device_tree.c | 43 +++++++++++++++++++++++++++
xen/include/xen/iommu.h | 10 +++++++
2 files changed, 53 insertions(+)
diff --git a/xen/drivers/passthrough/device_tree.c
b/xen/drivers/passthrough/device_tree.c
index 687c61e7da..80f6efc606 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -127,6 +127,49 @@ int iommu_release_dt_devices(struct domain *d)
return 0;
}
+int iommu_remove_dt_device(struct dt_device_node *np)
+{
+ const struct iommu_ops *ops = iommu_get_ops();
+ struct device *dev = dt_to_dev(np);
+ int rc;
+
+ if ( !iommu_enabled )
+ return 1;
+
+ if ( !ops )
+ return -EOPNOTSUPP;
+
+ spin_lock(&dtdevs_lock);
+
+ if ( iommu_dt_device_is_assigned_locked(np) )
+ {
+ rc = -EBUSY;
+ goto fail;
+ }
+
+ if ( !ops->remove_device )
+ {
+ rc = -EOPNOTSUPP;
+ goto fail;
+ }
+
+ /*
+ * De-register the device from the IOMMU driver.
+ * The driver is responsible for removing is_protected flag.
+ */
+ rc = ops->remove_device(0, dev);
+
+ if ( !rc )
+ {
+ ASSERT(!dt_device_is_protected(np));
+ iommu_fwspec_free(dev);
+ }
+
+ fail:
+ spin_unlock(&dtdevs_lock);
+ return rc;
+}
+
int iommu_add_dt_device(struct dt_device_node *np)
{
const struct iommu_ops *ops = iommu_get_ops();
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index a18b68e247..84bd77395e 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -235,6 +235,16 @@ int iommu_add_dt_device(struct dt_device_node *np);
int iommu_do_dt_domctl(struct xen_domctl *domctl, struct domain *d,
XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl);
+/*
+ * Helper to remove master device from the IOMMU.
+ *
+ * Return values:
+ * 0 : device is de-registerd from IOMMU.
+ * <0 : error while removing the device from IOMMU.
+ * >0 : IOMMU is not enabled/present or device is not connected to it.
+ */
+int iommu_remove_dt_device(struct dt_device_node *np);
+
#endif /* HAS_DEVICE_TREE */
struct page_info;
--
2.17.1
