AMD/IOMMU: disable previously enabled IOMMUs upon init failure

If any IOMMUs were successfully initialized before encountering failure,
the successfully enabled ones should be disabled again before cleaning
up their resources.

Move disable_iommu() next to enable_iommu() to avoid a forward
declaration, and take the opportunity to remove stray blank lines ahead
of both functions' final closing braces.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Brian Woods <brian.woods@amd.com>

xen/drivers/passthrough/amd/iommu_init.c

@@ -909,7 +909,35 @@ static void enable_iommu(struct amd_iommu *iommu)
 
     iommu->enabled = 1;
     spin_unlock_irqrestore(&iommu->lock, flags);
+}
 
+static void disable_iommu(struct amd_iommu *iommu)
+{
+    unsigned long flags;
+
+    spin_lock_irqsave(&iommu->lock, flags);
+
+    if ( !iommu->enabled )
+    {
+        spin_unlock_irqrestore(&iommu->lock, flags);
+        return;
+    }
+
+    amd_iommu_msi_enable(iommu, IOMMU_CONTROL_DISABLED);
+    set_iommu_command_buffer_control(iommu, IOMMU_CONTROL_DISABLED);
+    set_iommu_event_log_control(iommu, IOMMU_CONTROL_DISABLED);
+
+    if ( amd_iommu_has_feature(iommu, IOMMU_EXT_FEATURE_PPRSUP_SHIFT) )
+        set_iommu_ppr_log_control(iommu, IOMMU_CONTROL_DISABLED);
+
+    if ( amd_iommu_has_feature(iommu, IOMMU_EXT_FEATURE_GTSUP_SHIFT) )
+        set_iommu_guest_translation_control(iommu, IOMMU_CONTROL_DISABLED);
+
+    set_iommu_translation_control(iommu, IOMMU_CONTROL_DISABLED);
+
+    iommu->enabled = 0;
+
+    spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
 static void __init deallocate_buffer(void *buf, uint32_t sz)
@@ -1046,6 +1074,7 @@ static void __init amd_iommu_init_cleanup(void)
         list_del(&iommu->list);
         if ( iommu->enabled )
         {
+            disable_iommu(iommu);
             deallocate_ring_buffer(&iommu->cmd_buffer);
             deallocate_ring_buffer(&iommu->event_log);
             deallocate_ring_buffer(&iommu->ppr_log);
@@ -1297,36 +1326,6 @@ error_out:
     return rc;
 }
 
-static void disable_iommu(struct amd_iommu *iommu)
-{
-    unsigned long flags;
-
-    spin_lock_irqsave(&iommu->lock, flags);
-
-    if ( !iommu->enabled )
-    {
-        spin_unlock_irqrestore(&iommu->lock, flags); 
-        return;
-    }
-
-    amd_iommu_msi_enable(iommu, IOMMU_CONTROL_DISABLED);
-    set_iommu_command_buffer_control(iommu, IOMMU_CONTROL_DISABLED);
-    set_iommu_event_log_control(iommu, IOMMU_CONTROL_DISABLED);
-
-    if ( amd_iommu_has_feature(iommu, IOMMU_EXT_FEATURE_PPRSUP_SHIFT) )
-        set_iommu_ppr_log_control(iommu, IOMMU_CONTROL_DISABLED);
-
-    if ( amd_iommu_has_feature(iommu, IOMMU_EXT_FEATURE_GTSUP_SHIFT) )
-        set_iommu_guest_translation_control(iommu, IOMMU_CONTROL_DISABLED);
-
-    set_iommu_translation_control(iommu, IOMMU_CONTROL_DISABLED);
-
-    iommu->enabled = 0;
-
-    spin_unlock_irqrestore(&iommu->lock, flags);
-
-}
-
 static void invalidate_all_domain_pages(void)
 {
     struct domain *d;