diff options
| author | Giuseppe Cavallaro <peppe.cavallaro@st.com> | 2016-02-29 16:27:30 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-03-02 22:21:31 +0300 |
| commit | e3ad57c96715df2989ce6c18e58faf2913b305cb (patch) | |
| tree | 716a8f7f1662876b3006888c251fff7afc2e0896 /drivers/net/ethernet/stmicro/stmmac/ring_mode.c | |
| parent | 293e4365a1adb1d3747dcb7d12a52950e0e232a2 (diff) | |
| download | linux-e3ad57c96715df2989ce6c18e58faf2913b305cb.tar.xz | |
stmmac: review RX/TX ring management
This patch is to rework the ring management now optimized.
The indexes into the ring buffer are always incremented, and
the entry is accessed via doing a modulo to find the "real"
position in the ring.
It is inefficient, modulo is an expensive operation.
The formula [(entry + 1) & (size - 1)] is now adopted on
a ring that is power-of-2 in size.
Then, the number of elements cannot be set by command line but
it is fixed.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/ring_mode.c')
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/ring_mode.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c index 5dd50c6cda5b..4358a87fbc6e 100644 --- a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c +++ b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c @@ -31,8 +31,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) { struct stmmac_priv *priv = (struct stmmac_priv *)p; - unsigned int txsize = priv->dma_tx_size; - unsigned int entry = priv->cur_tx % txsize; + unsigned int entry = priv->cur_tx; struct dma_desc *desc; unsigned int nopaged_len = skb_headlen(skb); unsigned int bmax, len; @@ -62,7 +61,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) STMMAC_RING_MODE); wmb(); priv->tx_skbuff[entry] = NULL; - entry = (++priv->cur_tx) % txsize; + entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); if (priv->extend_desc) desc = (struct dma_desc *)(priv->dma_etx + entry); @@ -90,6 +89,8 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) STMMAC_RING_MODE); } + priv->cur_tx = entry; + return entry; } |