From: Yangchun Fu <yangchun@google.com>
To: netdev@vger.kernel.org
Cc: Yangchun Fu <yangchun@google.com>,
Catherine Sullivan <csully@google.com>
Subject: [PATCH net] gve: Fixes DMA synchronization.
Date: Mon, 28 Oct 2019 11:23:09 -0700 [thread overview]
Message-ID: <20191028182309.73313-1-yangchun@google.com> (raw)
Synces the DMA buffer properly in order for CPU and device to see
the most up-to-data data.
Signed-off-by: Yangchun Fu <yangchun@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
---
drivers/net/ethernet/google/gve/gve_rx.c | 2 ++
drivers/net/ethernet/google/gve/gve_tx.c | 26 ++++++++++++++++++++++--
2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/google/gve/gve_rx.c b/drivers/net/ethernet/google/gve/gve_rx.c
index 59564ac99d2a..edec61dfc868 100644
--- a/drivers/net/ethernet/google/gve/gve_rx.c
+++ b/drivers/net/ethernet/google/gve/gve_rx.c
@@ -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
diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 778b87b5a06c..d8342b7b9764 100644
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -390,7 +390,23 @@ 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 inline void gve_dma_sync_for_device(struct gve_priv *priv,
+ dma_addr_t *page_buses,
+ u64 iov_offset, u64 iov_len)
+{
+ u64 addr;
+ dma_addr_t dma;
+
+ for (addr = iov_offset; addr < iov_offset + iov_len;
+ addr += PAGE_SIZE) {
+ dma = page_buses[addr / PAGE_SIZE];
+ dma_sync_single_for_device(&priv->pdev->dev, dma, PAGE_SIZE,
+ DMA_TO_DEVICE);
+ }
+}
+
+static int gve_tx_add_skb(struct gve_tx_ring *tx, struct sk_buff *skb,
+ struct gve_priv *priv)
{
int pad_bytes, hlen, hdr_nfrags, payload_nfrags, l4_hdr_offset;
union gve_tx_desc *pkt_desc, *seg_desc;
@@ -432,6 +448,9 @@ 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(priv, 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 +464,9 @@ 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(priv, 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 +495,7 @@ 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);
netdev_tx_sent_queue(tx->netdev_txq, skb->len);
skb_tx_timestamp(skb);
--
2.24.0.rc0.303.g954a862665-goog
next reply other threads:[~2019-10-28 18:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 18:23 Yangchun Fu [this message]
2019-10-29 8:18 ` [PATCH net] gve: Fixes DMA synchronization Simon Horman
2019-10-30 21:50 ` Yangchun Fu
2019-10-30 0:41 ` David Miller
2019-10-30 21:51 ` Yangchun Fu
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