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Date: Fri, 13 Feb 2009 01:07:09 +0100
From: Lennert Buytenhek <buytenh@...tstofly.org>
To: jeff@...zik.org, netdev@...r.kernel.org
Cc: nico@....org
Subject: [PATCH 2/6] mv643xx_eth: rework interrupt coalescing, and export via ethtool
This patch:
- increases the precision of the receive/transmit interrupt
coalescing register value computations by using 64bit temporaries;
- adds functions to read the current hardware coalescing register
values and convert them back to usecs;
- exports the {get,set} {rx,tx} coal methods via the standard
ethtool coalescing interface.
Signed-off-by: Lennert Buytenhek <buytenh@...vell.com>
---
drivers/net/mv643xx_eth.c | 133 +++++++++++++++++++++++++++++++++++----------
1 files changed, 103 insertions(+), 30 deletions(-)
diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 7a67181..4a92d99 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -1221,6 +1221,85 @@ static void mib_counters_timer_wrapper(unsigned long _mp)
}
+/* interrupt coalescing *****************************************************/
+/*
+ * Hardware coalescing parameters are set in units of 64 t_clk
+ * cycles. I.e.:
+ *
+ * coal_delay_in_usec = 64000000 * register_value / t_clk_rate
+ *
+ * register_value = coal_delay_in_usec * t_clk_rate / 64000000
+ *
+ * In the ->set*() methods, we round the computed register value
+ * to the nearest integer.
+ */
+static unsigned int get_rx_coal(struct mv643xx_eth_private *mp)
+{
+ u32 val = rdlp(mp, SDMA_CONFIG);
+ u64 temp;
+
+ if (mp->shared->extended_rx_coal_limit)
+ temp = ((val & 0x02000000) >> 10) | ((val & 0x003fff80) >> 7);
+ else
+ temp = (val & 0x003fff00) >> 8;
+
+ temp *= 64000000;
+ do_div(temp, mp->shared->t_clk);
+
+ return (unsigned int)temp;
+}
+
+static void set_rx_coal(struct mv643xx_eth_private *mp, unsigned int usec)
+{
+ u64 temp;
+ u32 val;
+
+ temp = (u64)usec * mp->shared->t_clk;
+ temp += 31999999;
+ do_div(temp, 64000000);
+
+ val = rdlp(mp, SDMA_CONFIG);
+ if (mp->shared->extended_rx_coal_limit) {
+ if (temp > 0xffff)
+ temp = 0xffff;
+ val &= ~0x023fff80;
+ val |= (temp & 0x8000) << 10;
+ val |= (temp & 0x7fff) << 7;
+ } else {
+ if (temp > 0x3fff)
+ temp = 0x3fff;
+ val &= ~0x003fff00;
+ val |= (temp & 0x3fff) << 8;
+ }
+ wrlp(mp, SDMA_CONFIG, val);
+}
+
+static unsigned int get_tx_coal(struct mv643xx_eth_private *mp)
+{
+ u64 temp;
+
+ temp = (rdlp(mp, TX_FIFO_URGENT_THRESHOLD) & 0x3fff0) >> 4;
+ temp *= 64000000;
+ do_div(temp, mp->shared->t_clk);
+
+ return (unsigned int)temp;
+}
+
+static void set_tx_coal(struct mv643xx_eth_private *mp, unsigned int usec)
+{
+ u64 temp;
+
+ temp = (u64)usec * mp->shared->t_clk;
+ temp += 31999999;
+ do_div(temp, 64000000);
+
+ if (temp > 0x3fff)
+ temp = 0x3fff;
+
+ wrlp(mp, TX_FIFO_URGENT_THRESHOLD, temp << 4);
+}
+
+
/* ethtool ******************************************************************/
struct mv643xx_eth_stats {
char stat_string[ETH_GSTRING_LEN];
@@ -1384,6 +1463,28 @@ static u32 mv643xx_eth_get_link(struct net_device *dev)
return !!netif_carrier_ok(dev);
}
+static int
+mv643xx_eth_get_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
+{
+ struct mv643xx_eth_private *mp = netdev_priv(dev);
+
+ ec->rx_coalesce_usecs = get_rx_coal(mp);
+ ec->tx_coalesce_usecs = get_tx_coal(mp);
+
+ return 0;
+}
+
+static int
+mv643xx_eth_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
+{
+ struct mv643xx_eth_private *mp = netdev_priv(dev);
+
+ set_rx_coal(mp, ec->rx_coalesce_usecs);
+ set_tx_coal(mp, ec->tx_coalesce_usecs);
+
+ return 0;
+}
+
static void mv643xx_eth_get_strings(struct net_device *dev,
uint32_t stringset, uint8_t *data)
{
@@ -1438,6 +1539,8 @@ static const struct ethtool_ops mv643xx_eth_ethtool_ops = {
.get_drvinfo = mv643xx_eth_get_drvinfo,
.nway_reset = mv643xx_eth_nway_reset,
.get_link = mv643xx_eth_get_link,
+ .get_coalesce = mv643xx_eth_get_coalesce,
+ .set_coalesce = mv643xx_eth_set_coalesce,
.set_sg = ethtool_op_set_sg,
.get_strings = mv643xx_eth_get_strings,
.get_ethtool_stats = mv643xx_eth_get_ethtool_stats,
@@ -2053,36 +2156,6 @@ static void port_start(struct mv643xx_eth_private *mp)
}
}
-static void set_rx_coal(struct mv643xx_eth_private *mp, unsigned int delay)
-{
- unsigned int coal = ((mp->shared->t_clk / 1000000) * delay) / 64;
- u32 val;
-
- val = rdlp(mp, SDMA_CONFIG);
- if (mp->shared->extended_rx_coal_limit) {
- if (coal > 0xffff)
- coal = 0xffff;
- val &= ~0x023fff80;
- val |= (coal & 0x8000) << 10;
- val |= (coal & 0x7fff) << 7;
- } else {
- if (coal > 0x3fff)
- coal = 0x3fff;
- val &= ~0x003fff00;
- val |= (coal & 0x3fff) << 8;
- }
- wrlp(mp, SDMA_CONFIG, val);
-}
-
-static void set_tx_coal(struct mv643xx_eth_private *mp, unsigned int delay)
-{
- unsigned int coal = ((mp->shared->t_clk / 1000000) * delay) / 64;
-
- if (coal > 0x3fff)
- coal = 0x3fff;
- wrlp(mp, TX_FIFO_URGENT_THRESHOLD, (coal & 0x3fff) << 4);
-}
-
static void mv643xx_eth_recalc_skb_size(struct mv643xx_eth_private *mp)
{
int skb_size;
--
1.5.6.4
--
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