[PATCH v2 1/2] iommu/amd-vi: allow disable_iommu() against non-initialized IOMMUs

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Introduce a force option to disable_iommu() that allows it to disable the
IOMMU, even when ->enabled is not set.  While there remove the unlikely(),
this is not a hot path anyway.

No functional change, as there are no current callers that pass force ==
true.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/drivers/passthrough/amd/iommu_init.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/xen/drivers/passthrough/amd/iommu_init.c 
b/xen/drivers/passthrough/amd/iommu_init.c
index d77dd8511288..76ae78e5ea53 100644
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -929,13 +929,13 @@ static void enable_iommu(struct amd_iommu *iommu)
         amd_iommu_flush_all_caches(iommu);
 }
 
-static void disable_iommu(struct amd_iommu *iommu)
+static void disable_iommu(struct amd_iommu *iommu, bool force)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&iommu->lock, flags);
 
-    if ( unlikely(!iommu->enabled) )
+    if ( !iommu->enabled && !force )
         goto out;
 
     if ( !iommu->ctrl.int_cap_xt_en )
@@ -1139,7 +1139,7 @@ static void __init amd_iommu_init_cleanup(void)
         iommu->ctrl.int_cap_xt_en = 0;
 
         if ( iommu->enabled )
-            disable_iommu(iommu);
+            disable_iommu(iommu, false);
         else if ( iommu->mmio_base )
             writeq(iommu->ctrl.raw,
                    iommu->mmio_base + IOMMU_CONTROL_MMIO_OFFSET);
@@ -1584,7 +1584,7 @@ void cf_check amd_iommu_crash_shutdown(void)
     struct amd_iommu *iommu;
 
     for_each_amd_iommu ( iommu )
-        disable_iommu(iommu);
+        disable_iommu(iommu, false);
 }
 
 void cf_check amd_iommu_resume(void)
@@ -1598,7 +1598,7 @@ void cf_check amd_iommu_resume(void)
         * To make sure that iommus have not been touched 
         * before re-enablement
         */
-        disable_iommu(iommu);
+        disable_iommu(iommu, false);
         enable_iommu(iommu);
         if ( !iommu->features.flds.ia_sup )
             invalidate_all = false;
-- 
2.53.0