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

Pull networking updates from David Miller:

 1) The addition of nftables.  No longer will we need protocol aware
    firewall filtering modules, it can all live in userspace.

    At the core of nftables is a, for lack of a better term, virtual
    machine that executes byte codes to inspect packet or metadata
    (arriving interface index, etc.) and make verdict decisions.

    Besides support for loading packet contents and comparing them, the
    interpreter supports lookups in various datastructures as
    fundamental operations.  For example sets are supports, and
    therefore one could create a set of whitelist IP address entries
    which have ACCEPT verdicts attached to them, and use the appropriate
    byte codes to do such lookups.

    Since the interpreted code is composed in userspace, userspace can
    do things like optimize things before giving it to the kernel.

    Another major improvement is the capability of atomically updating
    portions of the ruleset.  In the existing netfilter implementation,
    one has to update the entire rule set in order to make a change and
    this is very expensive.

    Userspace tools exist to create nftables rules using existing
    netfilter rule sets, but both kernel implementations will need to
    co-exist for quite some time as we transition from the old to the
    new stuff.

    Kudos to Patrick McHardy, Pablo Neira Ayuso, and others who have
    worked so hard on this.

 2) Daniel Borkmann and Hannes Frederic Sowa made several improvements
    to our pseudo-random number generator, mostly used for things like
    UDP port randomization and netfitler, amongst other things.

    In particular the taus88 generater is updated to taus113, and test
    cases are added.

 3) Support 64-bit rates in HTB and TBF schedulers, from Eric Dumazet
    and Yang Yingliang.

 4) Add support for new 577xx tigon3 chips to tg3 driver, from Nithin
    Sujir.

 5) Fix two fatal flaws in TCP dynamic right sizing, from Eric Dumazet,
    Neal Cardwell, and Yuchung Cheng.

 6) Allow IP_TOS and IP_TTL to be specified in sendmsg() ancillary
    control message data, much like other socket option attributes.
    From Francesco Fusco.

 7) Allow applications to specify a cap on the rate computed
    automatically by the kernel for pacing flows, via a new
    SO_MAX_PACING_RATE socket option.  From Eric Dumazet.

 8) Make the initial autotuned send buffer sizing in TCP more closely
    reflect actual needs, from Eric Dumazet.

 9) Currently early socket demux only happens for TCP sockets, but we
    can do it for connected UDP sockets too.  Implementation from Shawn
    Bohrer.

10) Refactor inet socket demux with the goal of improving hash demux
    performance for listening sockets.  With the main goals being able
    to use RCU lookups on even request sockets, and eliminating the
    listening lock contention.  From Eric Dumazet.

11) The bonding layer has many demuxes in it's fast path, and an RCU
    conversion was started back in 3.11, several changes here extend the
    RCU usage to even more locations.  From Ding Tianhong and Wang
    Yufen, based upon suggestions by Nikolay Aleksandrov and Veaceslav
    Falico.

12) Allow stackability of segmentation offloads to, in particular, allow
    segmentation offloading over tunnels.  From Eric Dumazet.

13) Significantly improve the handling of secret keys we input into the
    various hash functions in the inet hashtables, TCP fast open, as
    well as syncookies.  From Hannes Frederic Sowa.  The key fundamental
    operation is "net_get_random_once()" which uses static keys.

    Hannes even extended this to ipv4/ipv6 fragmentation handling and
    our generic flow dissector.

14) The generic driver layer takes care now to set the driver data to
    NULL on device removal, so it's no longer necessary for drivers to
    explicitly set it to NULL any more.  Many drivers have been cleaned
    up in this way, from Jingoo Han.

15) Add a BPF based packet scheduler classifier, from Daniel Borkmann.

16) Improve CRC32 interfaces and generic SKB checksum iterators so that
    SCTP's checksumming can more cleanly be handled.  Also from Daniel
    Borkmann.

17) Add a new PMTU discovery mode, IP_PMTUDISC_INTERFACE, which forces
    using the interface MTU value.  This helps avoid PMTU attacks,
    particularly on DNS servers.  From Hannes Frederic Sowa.

18) Use generic XPS for transmit queue steering rather than internal
    (re-)implementation in virtio-net.  From Jason Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits)
  random32: add test cases for taus113 implementation
  random32: upgrade taus88 generator to taus113 from errata paper
  random32: move rnd_state to linux/random.h
  random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized
  random32: add periodic reseeding
  random32: fix off-by-one in seeding requirement
  PHY: Add RTL8201CP phy_driver to realtek
  xtsonic: add missing platform_set_drvdata() in xtsonic_probe()
  macmace: add missing platform_set_drvdata() in mace_probe()
  ethernet/arc/arc_emac: add missing platform_set_drvdata() in arc_emac_probe()
  ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh
  vlan: Implement vlan_dev_get_egress_qos_mask as an inline.
  ixgbe: add warning when max_vfs is out of range.
  igb: Update link modes display in ethtool
  netfilter: push reasm skb through instead of original frag skbs
  ip6_output: fragment outgoing reassembled skb properly
  MAINTAINERS: mv643xx_eth: take over maintainership from Lennart
  net_sched: tbf: support of 64bit rates
  ixgbe: deleting dfwd stations out of order can cause null ptr deref
  ixgbe: fix build err, num_rx_queues is only available with CONFIG_RPS
  ...

1 files changed, 27 insertions, 47 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00link.c b/drivers/net/wireless/rt2x00/rt2x00link.c
index 8368aab86f28..c2b3b6629188 100644
--- a/drivers/net/wireless/rt2x00/rt2x00link.c
+++ b/drivers/net/wireless/rt2x00/rt2x00link.c
@@ -35,50 +35,28 @@
  */
 #define DEFAULT_RSSI		-128
 
-/*
- * Helper struct and macro to work with moving/walking averages.
- * When adding a value to the average value the following calculation
- * is needed:
- *
- *        avg_rssi = ((avg_rssi * 7) + rssi) / 8;
- *
- * The advantage of this approach is that we only need 1 variable
- * to store the average in (No need for a count and a total).
- * But more importantly, normal average values will over time
- * move less and less towards newly added values this results
- * that with link tuning, the device can have a very good RSSI
- * for a few minutes but when the device is moved away from the AP
- * the average will not decrease fast enough to compensate.
- * The walking average compensates this and will move towards
- * the new values correctly allowing a effective link tuning,
- * the speed of the average moving towards other values depends
- * on the value for the number of samples. The higher the number
- * of samples, the slower the average will move.
- * We use two variables to keep track of the average value to
- * compensate for the rounding errors. This can be a significant
- * error (>5dBm) if the factor is too low.
- */
-#define AVG_SAMPLES	8
-#define AVG_FACTOR	1000
-#define MOVING_AVERAGE(__avg, __val) \
-({ \
-	struct avg_val __new; \
-	__new.avg_weight = \
-	    (__avg).avg_weight  ? \
-		((((__avg).avg_weight * ((AVG_SAMPLES) - 1)) + \
-		  ((__val) * (AVG_FACTOR))) / \
-		 (AVG_SAMPLES)) : \
-		((__val) * (AVG_FACTOR)); \
-	__new.avg = __new.avg_weight / (AVG_FACTOR); \
-	__new; \
-})
+/* Constants for EWMA calculations. */
+#define RT2X00_EWMA_FACTOR	1024
+#define RT2X00_EWMA_WEIGHT	8
+
+static inline int rt2x00link_get_avg_rssi(struct ewma *ewma)
+{
+	unsigned long avg;
+
+	avg = ewma_read(ewma);
+	if (avg)
+		return -avg;
+
+	return DEFAULT_RSSI;
+}
 
 static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
 {
 	struct link_ant *ant = &rt2x00dev->link.ant;
 
-	if (ant->rssi_ant.avg && rt2x00dev->link.qual.rx_success)
-		return ant->rssi_ant.avg;
+	if (rt2x00dev->link.qual.rx_success)
+		return rt2x00link_get_avg_rssi(&ant->rssi_ant);
+
 	return DEFAULT_RSSI;
 }
 
@@ -100,8 +78,8 @@ static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
 
 static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
 {
-	rt2x00dev->link.ant.rssi_ant.avg = 0;
-	rt2x00dev->link.ant.rssi_ant.avg_weight = 0;
+	ewma_init(&rt2x00dev->link.ant.rssi_ant, RT2X00_EWMA_FACTOR,
+		  RT2X00_EWMA_WEIGHT);
 }
 
 static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
@@ -249,12 +227,12 @@ void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
 	/*
 	 * Update global RSSI
 	 */
-	link->avg_rssi = MOVING_AVERAGE(link->avg_rssi, rxdesc->rssi);
+	ewma_add(&link->avg_rssi, -rxdesc->rssi);
 
 	/*
 	 * Update antenna RSSI
 	 */
-	ant->rssi_ant = MOVING_AVERAGE(ant->rssi_ant, rxdesc->rssi);
+	ewma_add(&ant->rssi_ant, -rxdesc->rssi);
 }
 
 void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
@@ -309,6 +287,8 @@ void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
 	 */
 	rt2x00dev->link.count = 0;
 	memset(qual, 0, sizeof(*qual));
+	ewma_init(&rt2x00dev->link.avg_rssi, RT2X00_EWMA_FACTOR,
+		  RT2X00_EWMA_WEIGHT);
 
 	/*
 	 * Restore the VGC level as stored in the registers,
@@ -363,17 +343,17 @@ static void rt2x00link_tuner(struct work_struct *work)
 	 * collect the RSSI data we could use this. Otherwise we
 	 * must fallback to the default RSSI value.
 	 */
-	if (!link->avg_rssi.avg || !qual->rx_success)
+	if (!qual->rx_success)
 		qual->rssi = DEFAULT_RSSI;
 	else
-		qual->rssi = link->avg_rssi.avg;
+		qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);
 
 	/*
 	 * Check if link tuning is supported by the hardware, some hardware
 	 * do not support link tuning at all, while other devices can disable
 	 * the feature from the EEPROM.
 	 */
-	if (test_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags))
+	if (rt2x00_has_cap_link_tuning(rt2x00dev))
 		rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);
 
 	/*
@@ -513,7 +493,7 @@ static void rt2x00link_vcocal(struct work_struct *work)
 void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
 {
 	INIT_DELAYED_WORK(&rt2x00dev->link.agc_work, rt2x00link_agc);
-	if (test_bit(CAPABILITY_VCO_RECALIBRATION, &rt2x00dev->cap_flags))
+	if (rt2x00_has_cap_vco_recalibration(rt2x00dev))
 		INIT_DELAYED_WORK(&rt2x00dev->link.vco_work, rt2x00link_vcocal);
 	INIT_DELAYED_WORK(&rt2x00dev->link.watchdog_work, rt2x00link_watchdog);
 	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner);