Commit 3e508034 authored by Lennert Buytenhek's avatar Lennert Buytenhek Committed by David S. Miller
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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: default avatarLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6bdf576e

drivers/net/mv643xx_eth.c

+103 −30
Original line number Diff line number Diff line
@@ -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;

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