Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1436 commits)
  cassini: Use local-mac-address prom property for Cassini MAC address
  net: remove the duplicate #ifdef __KERNEL__
  net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
  netconsole: clarify stopping message
  netconsole: don't announce stopping if nothing happened
  cnic: Fix the type field in SPQ messages
  netfilter: fix export secctx error handling
  netfilter: fix the race when initializing nf_ct_expect_hash_rnd
  ipv4: IP defragmentation must be ECN aware
  net: r6040: Return proper error for r6040_init_one
  dcb: use after free in dcb_flushapp()
  dcb: unlock on error in dcbnl_ieee_get()
  net: ixp4xx_eth: Return proper error for eth_init_one
  include/linux/if_ether.h: Add #define ETH_P_LINK_CTL for HPNA and wlan local tunnel
  net: add POLLPRI to sock_def_readable()
  af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.
  net_sched: pfifo_head_drop problem
  mac80211: remove stray extern
  mac80211: implement off-channel TX using hw r-o-c offload
  mac80211: implement hardware offload for remain-on-channel
  ...

1 files changed, 61 insertions, 0 deletions

diff --git a/lib/average.c b/lib/average.c
new file mode 100644
index 0000000..5576c28
--- /dev/null
+++ b/lib/average.c
@@ -0,0 +1,61 @@
+/*
+ * lib/average.c
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/average.h>
+#include <linux/bug.h>
+#include <linux/log2.h>
+
+/**
+ * DOC: Exponentially Weighted Moving Average (EWMA)
+ *
+ * These are generic functions for calculating Exponentially Weighted Moving
+ * Averages (EWMA). We keep a structure with the EWMA parameters and a scaled
+ * up internal representation of the average value to prevent rounding errors.
+ * The factor for scaling up and the exponential weight (or decay rate) have to
+ * be specified thru the init fuction. The structure should not be accessed
+ * directly but only thru the helper functions.
+ */
+
+/**
+ * ewma_init() - Initialize EWMA parameters
+ * @avg: Average structure
+ * @factor: Factor to use for the scaled up internal value. The maximum value
+ *	of averages can be ULONG_MAX/(factor*weight). For performance reasons
+ *	factor has to be a power of 2.
+ * @weight: Exponential weight, or decay rate. This defines how fast the
+ *	influence of older values decreases. For performance reasons weight has
+ *	to be a power of 2.
+ *
+ * Initialize the EWMA parameters for a given struct ewma @avg.
+ */
+void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)
+{
+	WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));
+
+	avg->weight = ilog2(weight);
+	avg->factor = ilog2(factor);
+	avg->internal = 0;
+}
+EXPORT_SYMBOL(ewma_init);
+
+/**
+ * ewma_add() - Exponentially weighted moving average (EWMA)
+ * @avg: Average structure
+ * @val: Current value
+ *
+ * Add a sample to the average.
+ */
+struct ewma *ewma_add(struct ewma *avg, unsigned long val)
+{
+	avg->internal = avg->internal  ?
+		(((avg->internal << avg->weight) - avg->internal) +
+			(val << avg->factor)) >> avg->weight :
+		(val << avg->factor);
+	return avg;
+}
+EXPORT_SYMBOL(ewma_add);