[PATCH V2 2/2] include: linux: Update gather only if it's not NULL

[Ashish Mhetre <amhetre@nvidia.com>]

Gather can be NULL when unmap is called for freeing old table while
mapping. If it's NULL then there is no need to add page for syncing
the TLB.

Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
---
 include/linux/iommu.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4d47f2c33311..2a28c1ef8517 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -928,6 +928,9 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain,
 					       struct iommu_iotlb_gather *gather,
 					       unsigned long iova, size_t size)
 {
+	if (!gather)
+		return;
+
 	/*
 	 * If the new page is disjoint from the current range or is mapped at
 	 * a different granularity, then sync the TLB so that the gather
-- 
2.25.1