powerpc/powernv: Add iommu DMA bypass support for IODA2

[platform/adaptation/renesas_rcar/renesas_kernel.git] / arch / powerpc / kernel / iommu.c

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d773dd4..88e3ec6 100644 (file)
--- 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);