1 files changed, 23 insertions, 8 deletions

diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 778b87b5a06c..d0244feb0301 100644
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -390,7 +390,22 @@ static void gve_tx_fill_seg_desc(union gve_tx_desc *seg_desc,
 	seg_desc->seg.seg_addr = cpu_to_be64(addr);
 }
 
-static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb)
+static void gve_dma_sync_for_device(struct device *dev, dma_addr_t *page_buses,
+				    u64 iov_offset, u64 iov_len)
+{
+	u64 last_page = (iov_offset + iov_len - 1) / PAGE_SIZE;
+	u64 first_page = iov_offset / PAGE_SIZE;
+	dma_addr_t dma;
+	u64 page;
+
+	for (page = first_page; page <= last_page; page++) {
+		dma = page_buses[page];
+		dma_sync_single_for_device(dev, dma, PAGE_SIZE, DMA_TO_DEVICE);
+	}
+}
+
+static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
+			  struct device *dev)
 {
 	int pad_bytes, hlen, hdr_nfrags, payload_nfrags, l4_hdr_offset;
 	union gve_tx_desc *pkt_desc, *seg_desc;
@@ -432,6 +447,9 @@ static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb)
 	skb_copy_bits(skb, 0,
 		      tx->tx_fifo.base + info->iov[hdr_nfrags - 1].iov_offset,
 		      hlen);
+	gve_dma_sync_for_device(dev, tx->tx_fifo.qpl->page_buses,
+				info->iov[hdr_nfrags - 1].iov_offset,
+				info->iov[hdr_nfrags - 1].iov_len);
 	copy_offset = hlen;
 
 	for (i = payload_iov; i < payload_nfrags + payload_iov; i++) {
@@ -445,6 +463,9 @@ static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb)
 		skb_copy_bits(skb, copy_offset,
 			      tx->tx_fifo.base + info->iov[i].iov_offset,
 			      info->iov[i].iov_len);
+		gve_dma_sync_for_device(dev, tx->tx_fifo.qpl->page_buses,
+					info->iov[i].iov_offset,
+					info->iov[i].iov_len);
 		copy_offset += info->iov[i].iov_len;
 	}
 
@@ -466,14 +487,10 @@ netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev)
 		 * may have added descriptors without ringing the doorbell.
 		 */
 
-		/* Ensure tx descs from a prior gve_tx are visible before
-		 * ringing doorbell.
-		 */
-		dma_wmb();
 		gve_tx_put_doorbell(priv, tx->q_resources, tx->req);
 		return NETDEV_TX_BUSY;
 	}
-	nsegs = gve_tx_add_skb(tx, skb);
+	nsegs = gve_tx_add_skb(tx, skb, &priv->pdev->dev);
 
 	netdev_tx_sent_queue(tx->netdev_txq, skb->len);
 	skb_tx_timestamp(skb);
@@ -484,8 +501,6 @@ netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev)
 	if (!netif_xmit_stopped(tx->netdev_txq) && netdev_xmit_more())
 		return NETDEV_TX_OK;
 
-	/* Ensure tx descs are visible before ringing doorbell */
-	dma_wmb();
 	gve_tx_put_doorbell(priv, tx->q_resources, tx->req);
 	return NETDEV_TX_OK;
 }