ioat: cleanup completion status reads

The cleanup path makes an effort to only perform an atomic read of the
64-bit completion address.  However in the 32-bit case it does not
matter if we read the upper-32 and lower-32 non-atomically because the
upper-32 will always be zero.

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 9f9edc2..5fd6e2d 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -96,14 +96,8 @@ struct ioat_chan_common {
 	struct ioatdma_device *device;
 	struct dma_chan common;
 
-	dma_addr_t completion_addr;
-	union {
-		u64 full; /* HW completion writeback */
-		struct {
-			u32 low;
-			u32 high;
-		};
-	} *completion_virt;
+	dma_addr_t completion_dma;
+	u64 *completion;
 	unsigned long last_compl_desc_addr_hw;
 	struct tasklet_struct cleanup_task;
 };