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authorIoana Radulescu <ruxandra.radulescu@nxp.com>2017-12-08 06:47:58 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-08 16:33:29 +0100
commitc163685fc886037b83e27cfc1d9efffd00e7a5bf (patch)
treea89a51222e5d060a53565e83cc6e79ff56fd8ca0 /drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c
parent18c21467b2162107891f15ce1da4350b4e7016a3 (diff)
downloadlinux-c163685fc886037b83e27cfc1d9efffd00e7a5bf.tar.bz2
staging: fsl-dpaa2/eth: Make Tx buffer alignment optional
Aligning the Tx buffers at 64B is a performance optimization recommendation, not a hard requirement. Make optional the alignment of Tx FD buffers, without enforcing a reallocation in case there is not enough headroom for it. On Rx, we keep allocating buffers with enough headroom to allow Tx alignment of forwarded frames. Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c')
-rw-r--r--drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c
index 8edb7c10f978..7f3e4fae6bb9 100644
--- a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c
+++ b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c
@@ -433,13 +433,19 @@ static int build_single_fd(struct dpaa2_eth_priv *priv,
struct dpaa2_fd *fd)
{
struct device *dev = priv->net_dev->dev.parent;
- u8 *buffer_start;
+ u8 *buffer_start, *aligned_start;
struct sk_buff **skbh;
dma_addr_t addr;
- buffer_start = PTR_ALIGN(skb->data -
- dpaa2_eth_needed_headroom(priv, skb),
- DPAA2_ETH_TX_BUF_ALIGN);
+ buffer_start = skb->data - dpaa2_eth_needed_headroom(priv, skb);
+
+ /* If there's enough room to align the FD address, do it.
+ * It will help hardware optimize accesses.
+ */
+ aligned_start = PTR_ALIGN(buffer_start - DPAA2_ETH_TX_BUF_ALIGN,
+ DPAA2_ETH_TX_BUF_ALIGN);
+ if (aligned_start >= skb->head)
+ buffer_start = aligned_start;
/* Store a backpointer to the skb at the beginning of the buffer
* (in the private data area) such that we can release it