dmaengine: consolidate tx_status functions

Now that we have the completed cookie in the dma_chan structure, we
can consolidate the tx_status functions by providing a function to set
the txstate structure and returning the DMA status.  We also provide
a separate helper to set the residue for cookies which are still in
progress.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index b0517c8..97e100c 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -729,13 +729,15 @@
 {
 	struct ioat_chan_common *chan = to_chan_common(c);
 	struct ioatdma_device *device = chan->device;
+	enum dma_status ret;
 
-	if (ioat_tx_status(c, cookie, txstate) == DMA_SUCCESS)
-		return DMA_SUCCESS;
+	ret = dma_cookie_status(c, cookie, txstate);
+	if (ret == DMA_SUCCESS)
+		return ret;
 
 	device->cleanup_fn((unsigned long) c);
 
-	return ioat_tx_status(c, cookie, txstate);
+	return dma_cookie_status(c, cookie, txstate);
 }
 
 static void ioat1_dma_start_null_desc(struct ioat_dma_chan *ioat)
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 9653b6b..c7888bc 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -142,27 +142,6 @@
 	return container_of(chan, struct ioat_dma_chan, base);
 }
 
-/**
- * ioat_tx_status - poll the status of an ioat transaction
- * @c: channel handle
- * @cookie: transaction identifier
- * @txstate: if set, updated with the transaction state
- */
-static inline enum dma_status
-ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
-		 struct dma_tx_state *txstate)
-{
-	dma_cookie_t last_used;
-	dma_cookie_t last_complete;
-
-	last_used = c->cookie;
-	last_complete = c->completed_cookie;
-
-	dma_set_tx_state(txstate, last_complete, last_used, 0);
-
-	return dma_async_is_complete(cookie, last_complete, last_used);
-}
-
 /* wrapper around hardware descriptor format + additional software fields */
 
 /**
diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index 1bda46c..145eda2 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -410,13 +410,15 @@
 		struct dma_tx_state *txstate)
 {
 	struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+	enum dma_status ret;
 
-	if (ioat_tx_status(c, cookie, txstate) == DMA_SUCCESS)
-		return DMA_SUCCESS;
+	ret = dma_cookie_status(c, cookie, txstate);
+	if (ret == DMA_SUCCESS)
+		return ret;
 
 	ioat3_cleanup(ioat);
 
-	return ioat_tx_status(c, cookie, txstate);
+	return dma_cookie_status(c, cookie, txstate);
 }
 
 static struct dma_async_tx_descriptor *