staging: fsl-dpaa2/eth: Compute needed headroom per frame

For non-linear skbs we build scatter-gather frames and allocate
a new buffer for the S/G table in which we reserve the required
headroom, so the actual skb headroom size doesn't matter.

Rather than use a one-size-fits-all approach, decide when to
enforce headroom requirements on a frame by frame basis.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ioana Radulescu 2017-12-08 06:47:57 -06:00 committed by Greg Kroah-Hartman
parent 2b7c86eb7b
commit 18c21467b2
2 changed files with 14 additions and 6 deletions

View file

@ -437,7 +437,8 @@ static int build_single_fd(struct dpaa2_eth_priv *priv,
struct sk_buff **skbh;
dma_addr_t addr;
buffer_start = PTR_ALIGN(skb->data - dpaa2_eth_needed_headroom(priv),
buffer_start = PTR_ALIGN(skb->data -
dpaa2_eth_needed_headroom(priv, skb),
DPAA2_ETH_TX_BUF_ALIGN);
/* Store a backpointer to the skb at the beginning of the buffer
@ -532,15 +533,17 @@ static netdev_tx_t dpaa2_eth_tx(struct sk_buff *skb, struct net_device *net_dev)
struct dpaa2_eth_drv_stats *percpu_extras;
struct dpaa2_eth_fq *fq;
u16 queue_mapping;
unsigned int needed_headroom;
int err, i;
percpu_stats = this_cpu_ptr(priv->percpu_stats);
percpu_extras = this_cpu_ptr(priv->percpu_extras);
if (skb_headroom(skb) < dpaa2_eth_needed_headroom(priv)) {
needed_headroom = dpaa2_eth_needed_headroom(priv, skb);
if (skb_headroom(skb) < needed_headroom) {
struct sk_buff *ns;
ns = skb_realloc_headroom(skb, dpaa2_eth_needed_headroom(priv));
ns = skb_realloc_headroom(skb, needed_headroom);
if (unlikely(!ns)) {
percpu_stats->tx_dropped++;
goto err_alloc_headroom;

View file

@ -364,9 +364,13 @@ static inline unsigned int dpaa2_eth_buf_raw_size(struct dpaa2_eth_priv *priv)
}
static inline
unsigned int dpaa2_eth_needed_headroom(struct dpaa2_eth_priv *priv)
unsigned int dpaa2_eth_needed_headroom(struct dpaa2_eth_priv *priv,
struct sk_buff *skb)
{
return priv->tx_data_offset + DPAA2_ETH_TX_BUF_ALIGN;
if (skb_is_nonlinear(skb))
return 0;
return DPAA2_ETH_SWA_SIZE + DPAA2_ETH_TX_BUF_ALIGN;
}
/* Extra headroom space requested to hardware, in order to make sure there's
@ -374,7 +378,8 @@ unsigned int dpaa2_eth_needed_headroom(struct dpaa2_eth_priv *priv)
*/
static inline unsigned int dpaa2_eth_rx_head_room(struct dpaa2_eth_priv *priv)
{
return dpaa2_eth_needed_headroom(priv) - DPAA2_ETH_RX_HWA_SIZE;
return priv->tx_data_offset + DPAA2_ETH_TX_BUF_ALIGN -
DPAA2_ETH_RX_HWA_SIZE;
}
static int dpaa2_eth_queue_count(struct dpaa2_eth_priv *priv)