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| author |   Ioana Radulescu <ruxandra.radulescu@nxp.com> | 2017-12-08 06:47:58 -0600 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-08 16:33:29 +0100 |
| commit | c163685fc886037b83e27cfc1d9efffd00e7a5bf (patch) | |
| tree | a89a51222e5d060a53565e83cc6e79ff56fd8ca0 /drivers/staging/fsl-dpaa2/ethernet | |
| parent | staging: fsl-dpaa2/eth: Compute needed headroom per frame (diff) | |
| download | linux-dev-c163685fc886037b83e27cfc1d9efffd00e7a5bf.tar.xz linux-dev-c163685fc886037b83e27cfc1d9efffd00e7a5bf.zip | |
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')
| -rw-r--r-- | drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c | 14 | ||||
| -rw-r--r-- | drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h | 2 |
2 files changed, 11 insertions, 5 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 diff --git a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h index 4ea41d85c231..d68ac386dd0a 100644 --- a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h +++ b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h @@ -370,7 +370,7 @@ unsigned int dpaa2_eth_needed_headroom(struct dpaa2_eth_priv *priv, if (skb_is_nonlinear(skb)) return 0; - return DPAA2_ETH_SWA_SIZE + DPAA2_ETH_TX_BUF_ALIGN; + return DPAA2_ETH_SWA_SIZE; } /* Extra headroom space requested to hardware, in order to make sure there's |