ARM: PL08x: consolidate common txd initialization

Consolidate code which allocates and initializes txds.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/amba-pl08x.c

@@ -1363,6 +1363,18 @@ static int pl08x_prep_channel_resources(struct pl08x_dma_chan *plchan,
 	return 0;
 }
 
+static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan)
+{
+	struct pl08x_txd *txd = kzalloc(sizeof(struct pl08x_txd), GFP_NOWAIT);
+
+	if (txd) {
+		dma_async_tx_descriptor_init(&txd->tx, &plchan->chan);
+		txd->tx.tx_submit = pl08x_tx_submit;
+		INIT_LIST_HEAD(&txd->node);
+	}
+	return txd;
+}
+
 /*
  * Initialize a descriptor to be used by memcpy submit
  */
@@ -1375,14 +1387,13 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
 	struct pl08x_txd *txd;
 	int ret;
 
-	txd = kzalloc(sizeof(struct pl08x_txd), GFP_NOWAIT);
+	txd = pl08x_get_txd(plchan);
 	if (!txd) {
 		dev_err(&pl08x->adev->dev,
 			"%s no memory for descriptor\n", __func__);
 		return NULL;
 	}
 
-	dma_async_tx_descriptor_init(&txd->tx, chan);
 	txd->direction = DMA_NONE;
 	txd->srcbus.addr = src;
 	txd->dstbus.addr = dest;
@@ -1391,12 +1402,8 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
 	txd->cd = &pl08x->pd->memcpy_channel;
 	/* Both to be incremented or the code will break */
 	txd->cd->cctl |= PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR;
-	txd->tx.tx_submit = pl08x_tx_submit;
-	txd->tx.callback = NULL;
-	txd->tx.callback_param = NULL;
 	txd->len = len;
 
-	INIT_LIST_HEAD(&txd->node);
 	ret = pl08x_prep_channel_resources(plchan, txd);
 	if (ret)
 		return NULL;
@@ -1430,14 +1437,12 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
 	dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
 		__func__, sgl->length, plchan->name);
 
-	txd = kzalloc(sizeof(struct pl08x_txd), GFP_NOWAIT);
+	txd = pl08x_get_txd(plchan);
 	if (!txd) {
 		dev_err(&pl08x->adev->dev, "%s no txd\n", __func__);
 		return NULL;
 	}
 
-	dma_async_tx_descriptor_init(&txd->tx, chan);
-
 	if (direction != plchan->runtime_direction)
 		dev_err(&pl08x->adev->dev, "%s DMA setup does not match "
 			"the direction configured for the PrimeCell\n",
@@ -1467,11 +1472,7 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
 		return NULL;
 	}
 	txd->cd = plchan->cd;
-	txd->tx.tx_submit = pl08x_tx_submit;
-	txd->tx.callback = NULL;
-	txd->tx.callback_param = NULL;
 	txd->len = sgl->length;
-	INIT_LIST_HEAD(&txd->node);
 
 	ret = pl08x_prep_channel_resources(plchan, txd);
 	if (ret)