1 files changed, 12 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d773dd440a45..88e3ec6e1d96 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1088,6 +1088,14 @@ int iommu_take_ownership(struct iommu_table *tbl)
         memset(tbl->it_map, 0xff, sz);
         iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size);
 
+        /*
+         * Disable iommu bypass, otherwise the user can DMA to all of
+         * our physical memory via the bypass window instead of just
+         * the pages that has been explicitly mapped into the iommu
+         */
+        if (tbl->set_bypass)
+                tbl->set_bypass(tbl, false);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(iommu_take_ownership);
@@ -1102,6 +1110,10 @@ void iommu_release_ownership(struct iommu_table *tbl)
         /* Restore bit#0 set by iommu_init_table() */
         if (tbl->it_offset == 0)
                 set_bit(0, tbl->it_map);
+
+        /* The kernel owns the device now, we can restore the iommu bypass */
+        if (tbl->set_bypass)
+                tbl->set_bypass(tbl, true);
 }
 EXPORT_SYMBOL_GPL(iommu_release_ownership);