[PATCH V7 1/2] csky/dma: bugfix dma_sync_for_cpu/device

[Guo Ren]

ref: https://lkml.org/lkml/2018/5/18/1068

        map             for_cpu         for_device      unmap
TO_DEV  writeback       none            writeback       none
TO_CPU  invalidate      invalidate*     invalidate      invalidate*
BIDIR   writeback       invalidate      writeback       invalidate

Signed-off-by: Guo Ren <ren_...@c-sky.com>
---
 arch/csky/mm/dma-mapping.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
index 16c2087..30a2041 100644
--- a/arch/csky/mm/dma-mapping.c
+++ b/arch/csky/mm/dma-mapping.c
@@ -217,7 +217,8 @@ void arch_sync_dma_for_device(struct device *dev, 
phys_addr_t paddr,
                break;
        case DMA_FROM_DEVICE:
        case DMA_BIDIRECTIONAL:
-               BUG();
+               dma_wbinv_range(vaddr + offset, vaddr + offset + size);
+               break;
        default:
                BUG();
        }
@@ -240,7 +241,7 @@ void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t 
paddr,
 
        switch (dir) {
        case DMA_TO_DEVICE:
-               BUG();
+               break;
        case DMA_FROM_DEVICE:
        case DMA_BIDIRECTIONAL:
                dma_wbinv_range(vaddr + offset, vaddr + offset + size);
-- 
2.7.4