stmmac: add is_jumbo field to dma data

Optimize tx_clean by avoiding a des3 read in stmmac_clean_desc3().

In ring mode, TX, des3 seems only used when xmit a jumbo frame.
In case of normal descriptors, it may also be used for time
stamping.
Clean it in the above two case, without reading it.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
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>

diff --git a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
index 355eafb..dacb654 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
+++ b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
@@ -152,7 +152,8 @@ static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
        struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
        unsigned int entry = priv->dirty_tx;
 
-       if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc)
+       if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc &&
+           priv->hwts_tx_en)
                /* NOTE: Device will overwrite des3 with timestamp value if
                 * 1588-2002 time stamping is enabled, hence reinitialize it
                 * to keep explicit chaining in the descriptor.

diff --git a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
index cfc2f24..c648774 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
+++ b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c
@@ -57,6 +57,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
 
                priv->tx_skbuff_dma[entry].buf = desc->des2;
                priv->tx_skbuff_dma[entry].len = bmax;
+               priv->tx_skbuff_dma[entry].is_jumbo = true;
 
                desc->des3 = desc->des2 + BUF_SIZE_4KiB;
                priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
@@ -76,6 +77,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
                        return -1;
                priv->tx_skbuff_dma[entry].buf = desc->des2;
                priv->tx_skbuff_dma[entry].len = len;
+               priv->tx_skbuff_dma[entry].is_jumbo = true;
 
                desc->des3 = desc->des2 + BUF_SIZE_4KiB;
                priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
@@ -89,6 +91,7 @@ static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum)
                        return -1;
                priv->tx_skbuff_dma[entry].buf = desc->des2;
                priv->tx_skbuff_dma[entry].len = nopaged_len;
+               priv->tx_skbuff_dma[entry].is_jumbo = true;
                desc->des3 = desc->des2 + BUF_SIZE_4KiB;
                priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum,
                                                STMMAC_RING_MODE);
@@ -126,7 +129,13 @@ static void stmmac_init_desc3(struct dma_desc *p)
 
 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
 {
-       if (unlikely(p->des3))
+       struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
+       unsigned int entry = priv->dirty_tx;
+
+       /* des3 is only used for jumbo frames tx or time stamping */
+       if (unlikely(priv->tx_skbuff_dma[entry].is_jumbo ||
+                    (priv->tx_skbuff_dma[entry].last_segment &&
+                     !priv->extend_desc && priv->hwts_tx_en)))
                p->des3 = 0;
 }
 

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 0436918..0d01f3e 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -47,6 +47,7 @@ struct stmmac_tx_info {
        bool map_as_page;
        unsigned len;
        bool last_segment;
+       bool is_jumbo;
 };
 
 struct stmmac_priv {

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index feae0de..0194a8f 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1361,6 +1361,7 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
                }
                priv->hw->mode->clean_desc3(priv, p);
                priv->tx_skbuff_dma[entry].last_segment = false;
+               priv->tx_skbuff_dma[entry].is_jumbo = false;
 
                if (likely(skb != NULL)) {
                        pkts_compl++;