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Commit c163685f authored by Ioana Radulescu's avatar Ioana Radulescu Committed by Greg Kroah-Hartman
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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: default avatarIoana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 18c21467

drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.c

+10 −4
Original line number Diff line number Diff line
@@ -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),

	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

drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h

+1 −1
Original line number Diff line number Diff line
@@ -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