vfio: powerpc/spapr: Rework groups attaching

This is to make extended ownership and multiple groups support patches
simpler for review.

This should cause no behavioural change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 24 insertions, 16 deletions

diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index cf5d4a159ce9..e65bc73cc8a8 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -460,16 +460,21 @@ static int tce_iommu_attach_group(void *iommu_data,
                                 iommu_group_id(container->tbl->it_group),
                                 iommu_group_id(iommu_group));
                 ret = -EBUSY;
-        } else if (container->enabled) {
+                goto unlock_exit;
+        }
+
+        if (container->enabled) {
                 pr_err("tce_vfio: attaching group #%u to enabled container\n",
                                 iommu_group_id(iommu_group));
                 ret = -EBUSY;
-        } else {
-                ret = iommu_take_ownership(tbl);
-                if (!ret)
-                        container->tbl = tbl;
+                goto unlock_exit;
         }
 
+        ret = iommu_take_ownership(tbl);
+        if (!ret)
+                container->tbl = tbl;
+
+unlock_exit:
         mutex_unlock(&container->lock);
 
         return ret;
@@ -487,19 +492,22 @@ static void tce_iommu_detach_group(void *iommu_data,
                 pr_warn("tce_vfio: detaching group #%u, expected group is #%u\n",
                                 iommu_group_id(iommu_group),
                                 iommu_group_id(tbl->it_group));
-        } else {
-                if (container->enabled) {
-                        pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n",
-                                        iommu_group_id(tbl->it_group));
-                        tce_iommu_disable(container);
-                }
+                goto unlock_exit;
+        }
 
-                /* pr_debug("tce_vfio: detaching group #%u from iommu %p\n",
-                                iommu_group_id(iommu_group), iommu_group); */
-                container->tbl = NULL;
-                tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
-                iommu_release_ownership(tbl);
+        if (container->enabled) {
+                pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n",
+                                iommu_group_id(tbl->it_group));
+                tce_iommu_disable(container);
         }
+
+        /* pr_debug("tce_vfio: detaching group #%u from iommu %p\n",
+           iommu_group_id(iommu_group), iommu_group); */
+        container->tbl = NULL;
+        tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
+        iommu_release_ownership(tbl);
+
+unlock_exit:
         mutex_unlock(&container->lock);
 }