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authorAuke Kok <auke-jan.h.kok@intel.com>2008-04-23 11:09:08 -0700
committerJeff Garzik <jgarzik@redhat.com>2008-04-25 02:07:12 -0400
commitde5b3077da8275e87196a1e34c5535f5279c5e1a (patch)
tree6e98ea368a62f8a0350da5a758188cd180086383
parent7c25769f88ff0b186766d6a9f9390a2e9fd4670f (diff)
downloadblackbird-op-linux-de5b3077da8275e87196a1e34c5535f5279c5e1a.tar.gz
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e1000e: Add interrupt moderation run-time ethtool interface
The ethtool -c / -C interface can now be used to modify the irq moderation algorithm. This change does not require an adapter reset and can thus be used at all times. The adapter only supports changing/reading rx-usecs which has special values for 0, 1 and 3: 0 - no irq moderation whatsoever 1 - normal moderation favoring regular mixed traffic (default) 3 - best attempt at low latency possible at cost of CPU For values between 10 and 10000 the rx-usecs defines "the minimum time between successive irqs" in usec, unlike the module parameter. Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
-rw-r--r--drivers/net/e1000e/e1000.h3
-rw-r--r--drivers/net/e1000e/ethtool.c43
2 files changed, 46 insertions, 0 deletions
diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h
index 4d3d1c2991c9..79a426feffb7 100644
--- a/drivers/net/e1000e/e1000.h
+++ b/drivers/net/e1000e/e1000.h
@@ -70,6 +70,9 @@ struct e1000_info;
#define E1000_MAX_RXD 4096
#define E1000_MIN_RXD 80
+#define E1000_MIN_ITR_USECS 10 /* 100000 irq/sec */
+#define E1000_MAX_ITR_USECS 10000 /* 100 irq/sec */
+
/* Early Receive defines */
#define E1000_ERT_2048 0x100
diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index c894a6f03bb4..ce045acce63e 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -1770,6 +1770,47 @@ static int e1000_phys_id(struct net_device *netdev, u32 data)
return 0;
}
+static int e1000_get_coalesce(struct net_device *netdev,
+ struct ethtool_coalesce *ec)
+{
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+
+ if (adapter->itr_setting <= 3)
+ ec->rx_coalesce_usecs = adapter->itr_setting;
+ else
+ ec->rx_coalesce_usecs = 1000000 / adapter->itr_setting;
+
+ return 0;
+}
+
+static int e1000_set_coalesce(struct net_device *netdev,
+ struct ethtool_coalesce *ec)
+{
+ struct e1000_adapter *adapter = netdev_priv(netdev);
+ struct e1000_hw *hw = &adapter->hw;
+
+ if ((ec->rx_coalesce_usecs > E1000_MAX_ITR_USECS) ||
+ ((ec->rx_coalesce_usecs > 3) &&
+ (ec->rx_coalesce_usecs < E1000_MIN_ITR_USECS)) ||
+ (ec->rx_coalesce_usecs == 2))
+ return -EINVAL;
+
+ if (ec->rx_coalesce_usecs <= 3) {
+ adapter->itr = 20000;
+ adapter->itr_setting = ec->rx_coalesce_usecs;
+ } else {
+ adapter->itr = (1000000 / ec->rx_coalesce_usecs);
+ adapter->itr_setting = adapter->itr & ~3;
+ }
+
+ if (adapter->itr_setting != 0)
+ ew32(ITR, 1000000000 / (adapter->itr * 256));
+ else
+ ew32(ITR, 0);
+
+ return 0;
+}
+
static int e1000_nway_reset(struct net_device *netdev)
{
struct e1000_adapter *adapter = netdev_priv(netdev);
@@ -1845,6 +1886,8 @@ static const struct ethtool_ops e1000_ethtool_ops = {
.phys_id = e1000_phys_id,
.get_ethtool_stats = e1000_get_ethtool_stats,
.get_sset_count = e1000e_get_sset_count,
+ .get_coalesce = e1000_get_coalesce,
+ .set_coalesce = e1000_set_coalesce,
};
void e1000e_set_ethtool_ops(struct net_device *netdev)
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