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[TG3]: Set minimal hw interrupt mitigation.
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Even though we do software interrupt mitigation
via NAPI, it still helps to have some minimal
hw assisted mitigation.

This helps, particularly, on systems where register
I/O overhead is much greater than the CPU horsepower.

For example, it helps on NUMA systems.  In such cases
the PIO overhead to disable interrupts for NAPI accounts
for the majority of the packet processing cost.  The
CPU is fast enough such that only a single packet is
processed by each NAPI poll call.

Thanks to Michael Chan for reviewing this patch.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed May 19, 2005
1 parent fac9b83 commit 15f9850
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Showing 2 changed files with 64 additions and 14 deletions.
72 changes: 59 additions & 13 deletions drivers/net/tg3.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2507,7 +2507,7 @@ static int tg3_setup_phy(struct tg3 *tp, int force_reset)
if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) {
if (netif_carrier_ok(tp->dev)) {
tw32(HOSTCC_STAT_COAL_TICKS,
DEFAULT_STAT_COAL_TICKS);
tp->coal.stats_block_coalesce_usecs);
} else {
tw32(HOSTCC_STAT_COAL_TICKS, 0);
}
Expand Down Expand Up @@ -5094,6 +5094,27 @@ static void tg3_set_bdinfo(struct tg3 *tp, u32 bdinfo_addr,
}

static void __tg3_set_rx_mode(struct net_device *);
static void tg3_set_coalesce(struct tg3 *tp, struct ethtool_coalesce *ec)
{
tw32(HOSTCC_RXCOL_TICKS, ec->rx_coalesce_usecs);
tw32(HOSTCC_TXCOL_TICKS, ec->tx_coalesce_usecs);
tw32(HOSTCC_RXMAX_FRAMES, ec->rx_max_coalesced_frames);
tw32(HOSTCC_TXMAX_FRAMES, ec->tx_max_coalesced_frames);
if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) {
tw32(HOSTCC_RXCOAL_TICK_INT, ec->rx_coalesce_usecs_irq);
tw32(HOSTCC_TXCOAL_TICK_INT, ec->tx_coalesce_usecs_irq);
}
tw32(HOSTCC_RXCOAL_MAXF_INT, ec->rx_max_coalesced_frames_irq);
tw32(HOSTCC_TXCOAL_MAXF_INT, ec->tx_max_coalesced_frames_irq);
if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) {
u32 val = ec->stats_block_coalesce_usecs;

if (!netif_carrier_ok(tp->dev))
val = 0;

tw32(HOSTCC_STAT_COAL_TICKS, val);
}
}

/* tp->lock is held. */
static int tg3_reset_hw(struct tg3 *tp)
Expand Down Expand Up @@ -5416,16 +5437,7 @@ static int tg3_reset_hw(struct tg3 *tp)
udelay(10);
}

tw32(HOSTCC_RXCOL_TICKS, 0);
tw32(HOSTCC_TXCOL_TICKS, LOW_TXCOL_TICKS);
tw32(HOSTCC_RXMAX_FRAMES, 1);
tw32(HOSTCC_TXMAX_FRAMES, LOW_RXMAX_FRAMES);
if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) {
tw32(HOSTCC_RXCOAL_TICK_INT, 0);
tw32(HOSTCC_TXCOAL_TICK_INT, 0);
}
tw32(HOSTCC_RXCOAL_MAXF_INT, 1);
tw32(HOSTCC_TXCOAL_MAXF_INT, 0);
tg3_set_coalesce(tp, &tp->coal);

/* set status block DMA address */
tw32(HOSTCC_STATUS_BLK_HOST_ADDR + TG3_64BIT_REG_HIGH,
Expand All @@ -5438,8 +5450,6 @@ static int tg3_reset_hw(struct tg3 *tp)
* the tg3_periodic_fetch_stats call there, and
* tg3_get_stats to see how this works for 5705/5750 chips.
*/
tw32(HOSTCC_STAT_COAL_TICKS,
DEFAULT_STAT_COAL_TICKS);
tw32(HOSTCC_STATS_BLK_HOST_ADDR + TG3_64BIT_REG_HIGH,
((u64) tp->stats_mapping >> 32));
tw32(HOSTCC_STATS_BLK_HOST_ADDR + TG3_64BIT_REG_LOW,
Expand Down Expand Up @@ -7284,6 +7294,14 @@ static void tg3_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
}
#endif

static int tg3_get_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
{
struct tg3 *tp = netdev_priv(dev);

memcpy(ec, &tp->coal, sizeof(*ec));
return 0;
}

static struct ethtool_ops tg3_ethtool_ops = {
.get_settings = tg3_get_settings,
.set_settings = tg3_set_settings,
Expand Down Expand Up @@ -7316,6 +7334,7 @@ static struct ethtool_ops tg3_ethtool_ops = {
.get_strings = tg3_get_strings,
.get_stats_count = tg3_get_stats_count,
.get_ethtool_stats = tg3_get_ethtool_stats,
.get_coalesce = tg3_get_coalesce,
};

static void __devinit tg3_get_eeprom_size(struct tg3 *tp)
Expand Down Expand Up @@ -9096,6 +9115,31 @@ static struct pci_dev * __devinit tg3_find_5704_peer(struct tg3 *tp)
return peer;
}

static void __devinit tg3_init_coal(struct tg3 *tp)
{
struct ethtool_coalesce *ec = &tp->coal;

memset(ec, 0, sizeof(*ec));
ec->cmd = ETHTOOL_GCOALESCE;
ec->rx_coalesce_usecs = LOW_RXCOL_TICKS;
ec->tx_coalesce_usecs = LOW_TXCOL_TICKS;
ec->rx_max_coalesced_frames = LOW_RXMAX_FRAMES;
ec->tx_max_coalesced_frames = LOW_TXMAX_FRAMES;
ec->rx_coalesce_usecs_irq = DEFAULT_RXCOAL_TICK_INT;
ec->tx_coalesce_usecs_irq = DEFAULT_TXCOAL_TICK_INT;
ec->rx_max_coalesced_frames_irq = DEFAULT_RXCOAL_MAXF_INT;
ec->tx_max_coalesced_frames_irq = DEFAULT_TXCOAL_MAXF_INT;
ec->stats_block_coalesce_usecs = DEFAULT_STAT_COAL_TICKS;

if (tp->coalesce_mode & (HOSTCC_MODE_CLRTICK_RXBD |
HOSTCC_MODE_CLRTICK_TXBD)) {
ec->rx_coalesce_usecs = LOW_RXCOL_TICKS_CLRTCKS;
ec->rx_coalesce_usecs_irq = DEFAULT_RXCOAL_TICK_INT_CLRTCKS;
ec->tx_coalesce_usecs = LOW_TXCOL_TICKS_CLRTCKS;
ec->tx_coalesce_usecs_irq = DEFAULT_TXCOAL_TICK_INT_CLRTCKS;
}
}

static int __devinit tg3_init_one(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
Expand Down Expand Up @@ -9341,6 +9385,8 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
/* flow control autonegotiation is default behavior */
tp->tg3_flags |= TG3_FLAG_PAUSE_AUTONEG;

tg3_init_coal(tp);

err = register_netdev(dev);
if (err) {
printk(KERN_ERR PFX "Cannot register net device, "
Expand Down
6 changes: 5 additions & 1 deletion drivers/net/tg3.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -876,10 +876,12 @@
#define HOSTCC_STATUS_ERROR_ATTN 0x00000004
#define HOSTCC_RXCOL_TICKS 0x00003c08
#define LOW_RXCOL_TICKS 0x00000032
#define LOW_RXCOL_TICKS_CLRTCKS 0x00000014
#define DEFAULT_RXCOL_TICKS 0x00000048
#define HIGH_RXCOL_TICKS 0x00000096
#define HOSTCC_TXCOL_TICKS 0x00003c0c
#define LOW_TXCOL_TICKS 0x00000096
#define LOW_TXCOL_TICKS_CLRTCKS 0x00000048
#define DEFAULT_TXCOL_TICKS 0x0000012c
#define HIGH_TXCOL_TICKS 0x00000145
#define HOSTCC_RXMAX_FRAMES 0x00003c10
Expand All @@ -892,8 +894,10 @@
#define HIGH_TXMAX_FRAMES 0x00000052
#define HOSTCC_RXCOAL_TICK_INT 0x00003c18
#define DEFAULT_RXCOAL_TICK_INT 0x00000019
#define DEFAULT_RXCOAL_TICK_INT_CLRTCKS 0x00000014
#define HOSTCC_TXCOAL_TICK_INT 0x00003c1c
#define DEFAULT_TXCOAL_TICK_INT 0x00000019
#define DEFAULT_TXCOAL_TICK_INT_CLRTCKS 0x00000014
#define HOSTCC_RXCOAL_MAXF_INT 0x00003c20
#define DEFAULT_RXCOAL_MAXF_INT 0x00000005
#define HOSTCC_TXCOAL_MAXF_INT 0x00003c24
Expand Down Expand Up @@ -2227,7 +2231,7 @@ struct tg3 {

#define SST_25VF0X0_PAGE_SIZE 4098


struct ethtool_coalesce coal;
};

#endif /* !(_T3_H) */

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