Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9cfeeb57 authored by Yangchun Fu's avatar Yangchun Fu Committed by David S. Miller
Browse files

gve: Fixes DMA synchronization. 



Synces the DMA buffer properly in order for CPU and device to see
the most up-to-data data.

Signed-off-by: default avatarYangchun Fu <yangchun@google.com>
Reviewed-by: default avatarCatherine Sullivan <csully@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a904a069

drivers/net/ethernet/google/gve/gve_rx.c

+2 −0
Original line number Diff line number Diff line
@@ -289,6 +289,8 @@ static bool gve_rx(struct gve_rx_ring *rx, struct gve_rx_desc *rx_desc, 


	len = be16_to_cpu(rx_desc->len) - GVE_RX_PAD;

	page_info = &rx->data.page_info[idx];

	dma_sync_single_for_cpu(&priv->pdev->dev, rx->data.qpl->page_buses[idx],

				PAGE_SIZE, DMA_FROM_DEVICE);



	/* gvnic can only receive into registered segments. If the buffer

	 * can't be recycled, our only choice is to copy the data out of

drivers/net/ethernet/google/gve/gve_tx.c

+22 −2
Original line number Diff line number Diff line
@@ -390,7 +390,21 @@ 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)

{

	dma_addr_t dma;

	u64 addr;



	for (addr = iov_offset; addr < iov_offset + iov_len;

	     addr += PAGE_SIZE) {

		dma = page_buses[addr / PAGE_SIZE];

		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 +446,9 @@ 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 +462,9 @@ 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;

	}
@@ -473,7 +493,7 @@ netdev_tx_t gve_tx(struct sk_buff *skb, struct net_device *dev) 
		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);