diff options
| author | Giuseppe Cavallaro <peppe.cavallaro@st.com> | 2016-02-29 14:27:30 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-03-02 14:21:31 -0500 |
| commit | e3ad57c96715df2989ce6c18e58faf2913b305cb (patch) | |
| tree | 716a8f7f1662876b3006888c251fff7afc2e0896 /drivers/net/ethernet/stmicro/stmmac/chain_mode.c | |
| parent | 293e4365a1adb1d3747dcb7d12a52950e0e232a2 (diff) | |
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/chain_mode.c')
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/chain_mode.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c index cf28daba4346..2763772ef1d4 100644 --- a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c +++ b/drivers/net/ethernet/stmicro/stmmac/chain_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 = priv->dma_tx + entry; unsigned int nopaged_len = skb_headlen(skb); unsigned int bmax; @@ -54,7 +53,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) while (len != 0) { priv->tx_skbuff[entry] = NULL; - entry = (++priv->cur_tx) % txsize; + entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); desc = priv->dma_tx + entry; if (len > bmax) { @@ -82,6 +81,9 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) len = 0; } } + + priv->cur_tx = entry; + return entry; } @@ -138,7 +140,7 @@ static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) */ p->des3 = (unsigned int)(priv->dma_rx_phy + (((priv->dirty_rx) + 1) % - priv->dma_rx_size) * + DMA_RX_SIZE) * sizeof(struct dma_desc)); } @@ -151,10 +153,9 @@ static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) * 1588-2002 time stamping is enabled, hence reinitialize it * to keep explicit chaining in the descriptor. */ - p->des3 = (unsigned int)(priv->dma_tx_phy + - (((priv->dirty_tx + 1) % - priv->dma_tx_size) * - sizeof(struct dma_desc))); + p->des3 = (unsigned int)((priv->dma_tx_phy + + ((priv->dirty_tx + 1) % DMA_TX_SIZE)) + * sizeof(struct dma_desc)); } const struct stmmac_mode_ops chain_mode_ops = { |