dmaengine/dw_dmac: Add 64 bit access width support for slave xfers on…

… mem side

64 bit transfers are possible on both sides in slave transfers (memory as well
as peripherals). This patch adds support for it memory side 64 bit transfers.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/dw_dmac.c

@@ -749,8 +749,14 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			mem = sg_phys(sg);
 			len = sg_dma_len(sg);
-			mem_width = 2;
-			if (unlikely(mem & 3 || len & 3))
+
+			if (!((mem | len) & 7))
+				mem_width = 3;
+			else if (!((mem | len) & 3))
+				mem_width = 2;
+			else if (!((mem | len) & 1))
+				mem_width = 1;
+			else
 				mem_width = 0;
 
 slave_sg_todev_fill_desc:
@@ -807,8 +813,14 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			mem = sg_phys(sg);
 			len = sg_dma_len(sg);
-			mem_width = 2;
-			if (unlikely(mem & 3 || len & 3))
+
+			if (!((mem | len) & 7))
+				mem_width = 3;
+			else if (!((mem | len) & 3))
+				mem_width = 2;
+			else if (!((mem | len) & 1))
+				mem_width = 1;
+			else
 				mem_width = 0;
 
 slave_sg_fromdev_fill_desc: