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Message-ID: <1449650274-14896-11-git-send-email-peppe.cavallaro@st.com>
Date: Wed, 9 Dec 2015 09:37:46 +0100
From: Giuseppe Cavallaro <peppe.cavallaro@...com>
To: <netdev@...r.kernel.org>
CC: <alexandre.torgue@...com>, Fabrice Gasnier <fabrice.gasnier@...com>
Subject: [PATCH (net-next.git) 10/18] stmmac: optimize tx clean function
From: Fabrice Gasnier <fabrice.gasnier@...com>
This patch "inline" get_tx_owner and get_ls routines. It Results in a
unique read to tdes0, instead of three, to check TX_OWN and LS bits,
and other status bits.
It helps improve driver TX path by removing two uncached read/writes
inside TX clean loop for enhanced descriptors but not for normal ones
because the des1 must be read in any case.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@...com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@...com>
---
drivers/net/ethernet/stmicro/stmmac/common.h | 8 ++++++
drivers/net/ethernet/stmicro/stmmac/enh_desc.c | 12 +++++++-
drivers/net/ethernet/stmicro/stmmac/norm_desc.c | 13 ++++++++-
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 27 ++++++++++-----------
4 files changed, 42 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index e58d81c..fb01e94 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -241,6 +241,14 @@ enum rx_frame_status {
dma_own = 0x8,
};
+/* Tx status */
+enum tx_frame_status {
+ tx_done = 0x0,
+ tx_not_ls = 0x1,
+ tx_err = 0x2,
+ tx_dma_own = 0x4,
+};
+
enum dma_irq_status {
tx_hard_error = 0x1,
tx_hard_error_bump_tc = 0x2,
diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
index 1c9a520..b672e51 100644
--- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
@@ -31,7 +31,15 @@ static int enh_desc_get_tx_status(void *data, struct stmmac_extra_stats *x,
{
struct net_device_stats *stats = (struct net_device_stats *)data;
unsigned int tdes0 = p->des0;
- int ret = 0;
+ int ret = tx_done;
+
+ /* Get tx owner first */
+ if (unlikely(tdes0 & ETDES0_OWN))
+ return tx_dma_own;
+
+ /* Verify tx error by looking at the last segment. */
+ if (likely(!(tdes0 & ETDES0_LAST_SEGMENT)))
+ return tx_not_ls;
if (unlikely(tdes0 & ETDES0_ERROR_SUMMARY)) {
if (unlikely(tdes0 & ETDES0_JABBER_TIMEOUT))
@@ -71,7 +79,7 @@ static int enh_desc_get_tx_status(void *data, struct stmmac_extra_stats *x,
dwmac_dma_flush_tx_fifo(ioaddr);
}
- ret = -1;
+ ret = tx_err;
}
if (unlikely(tdes0 & ETDES0_DEFERRED))
diff --git a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
index df2603e..9ccae3c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
@@ -31,7 +31,16 @@ static int ndesc_get_tx_status(void *data, struct stmmac_extra_stats *x,
{
struct net_device_stats *stats = (struct net_device_stats *)data;
unsigned int tdes0 = p->des0;
- int ret = 0;
+ unsigned int tdes1 = p->des1;
+ int ret = tx_done;
+
+ /* Get tx owner first */
+ if (unlikely(tdes0 & TDES0_OWN))
+ return tx_dma_own;
+
+ /* Verify tx error by looking at the last segment. */
+ if (likely(!(tdes1 & TDES1_LAST_SEGMENT)))
+ return tx_not_ls;
if (unlikely(tdes0 & TDES0_ERROR_SUMMARY)) {
if (unlikely(tdes0 & TDES0_UNDERFLOW_ERROR)) {
@@ -54,7 +63,7 @@ static int ndesc_get_tx_status(void *data, struct stmmac_extra_stats *x,
collisions = (tdes0 & TDES0_COLLISION_COUNT_MASK) >> 3;
stats->collisions += collisions;
}
- ret = -1;
+ ret = tx_err;
}
if (tdes0 & TDES0_VLAN_FRAME)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2f2f607..e51eee3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1333,32 +1333,31 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
priv->xstats.tx_clean++;
while (entry != priv->cur_tx) {
- int last;
struct sk_buff *skb = priv->tx_skbuff[entry];
struct dma_desc *p;
+ int status;
if (priv->extend_desc)
p = (struct dma_desc *)(priv->dma_etx + entry);
else
p = priv->dma_tx + entry;
- /* Check if the descriptor is owned by the DMA. */
- if (priv->hw->desc->get_tx_owner(p))
- break;
-
- /* Verify tx error by looking at the last segment. */
- last = priv->tx_skbuff_dma[entry].last_segment;
- if (likely(last)) {
- int tx_error =
- priv->hw->desc->tx_status(&priv->dev->stats,
+ status = priv->hw->desc->tx_status(&priv->dev->stats,
&priv->xstats, p,
priv->ioaddr);
- if (likely(tx_error == 0)) {
+ /* Check if the descriptor is owned by the DMA */
+ if (unlikely(status & tx_dma_own))
+ break;
+
+ /* Just consider the last segment and ...*/
+ if (likely(!(status & tx_not_ls))) {
+ /* ... verify the status error condition */
+ if (unlikely(status & tx_err)) {
+ priv->dev->stats.tx_errors++;
+ } else {
priv->dev->stats.tx_packets++;
priv->xstats.tx_pkt_n++;
- } else
- priv->dev->stats.tx_errors++;
-
+ }
stmmac_get_tx_hwtstamp(priv, entry, skb);
}
if (netif_msg_tx_done(priv))
--
1.7.4.4
--
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