swiotlb: factor out copy to/from device

Impact: generalize IO bounce memcpys

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 4 deletions

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index d8b09051c455..a0b4039e2880 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -312,6 +312,15 @@ static int is_swiotlb_buffer(char *addr)
         return addr >= io_tlb_start && addr < io_tlb_end;
 }
 
+static void
+__sync_single(char *buffer, char *dma_addr, size_t size, int dir)
+{
+        if (dir == DMA_TO_DEVICE)
+                memcpy(dma_addr, buffer, size);
+        else
+                memcpy(buffer, dma_addr, size);
+}
+
 /*
  * Allocates bounce buffer and returns its kernel virtual address.
  */
@@ -413,7 +422,7 @@ found:
         for (i = 0; i < nslots; i++)
                 io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
         if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
-                memcpy(dma_addr, buffer, size);
+                __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
 
         return dma_addr;
 }
@@ -437,7 +446,7 @@ unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
                  * bounce... copy the data back into the original buffer * and
                  * delete the bounce buffer.
                  */
-                memcpy(buffer, dma_addr, size);
+                __sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
 
         /*
          * Return the buffer to the free list by setting the corresponding
@@ -477,13 +486,13 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
         switch (target) {
         case SYNC_FOR_CPU:
                 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
-                        memcpy(buffer, dma_addr, size);
+                        __sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
                 else
                         BUG_ON(dir != DMA_TO_DEVICE);
                 break;
         case SYNC_FOR_DEVICE:
                 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
-                        memcpy(dma_addr, buffer, size);
+                        __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
                 else
                         BUG_ON(dir != DMA_FROM_DEVICE);
                 break;