mt76: add unlikely() for dma_mapping_error() check

In the tx/rx fastpath, the funciton dma_map_single() rarely fails. This adds unlikely() optimization to this error check conditional. Signed-off-by: Ryder Lee <[email protected]> Signed-off-by: Felix Fietkau <[email protected]>
syb999 · Apr 25, 2019 · edb2a00 · edb2a00
1 parent 334b4ce
commit edb2a00
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/dma.c b/dma.c
@@ -270,7 +270,7 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid,
 
 	addr = dma_map_single(dev->dev, skb->data, skb->len,
 			      DMA_TO_DEVICE);
-	if (dma_mapping_error(dev->dev, addr))
+	if (unlikely(dma_mapping_error(dev->dev, addr)))
 		return -ENOMEM;
 
 	buf.addr = addr;
@@ -307,7 +307,7 @@ mt76_dma_tx_queue_skb(struct mt76_dev *dev, enum mt76_txq_id qid,
 
 	len = skb_headlen(skb);
 	addr = dma_map_single(dev->dev, skb->data, len, DMA_TO_DEVICE);
-	if (dma_mapping_error(dev->dev, addr))
+	if (unlikely(dma_mapping_error(dev->dev, addr)))
 		goto free;
 
 	tx_info.buf[n].addr = t->dma_addr;
@@ -321,7 +321,7 @@ mt76_dma_tx_queue_skb(struct mt76_dev *dev, enum mt76_txq_id qid,
 
 		addr = dma_map_single(dev->dev, iter->data, iter->len,
 				      DMA_TO_DEVICE);
-		if (dma_mapping_error(dev->dev, addr))
+		if (unlikely(dma_mapping_error(dev->dev, addr)))
 			goto unmap;
 
 		tx_info.buf[n].addr = addr;
@@ -379,7 +379,7 @@ mt76_dma_rx_fill(struct mt76_dev *dev, struct mt76_queue *q)
 			break;
 
 		addr = dma_map_single(dev->dev, buf, len, DMA_FROM_DEVICE);
-		if (dma_mapping_error(dev->dev, addr)) {
+		if (unlikely(dma_mapping_error(dev->dev, addr))) {
 			skb_free_frag(buf);
 			break;
 		}