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

Pull networking updates from David Miller:

 1) Unified UDP encapsulation offload methods for drivers, from
    Alexander Duyck.

 2) Make DSA binding more sane, from Andrew Lunn.

 3) Support QCA9888 chips in ath10k, from Anilkumar Kolli.

 4) Several workqueue usage cleanups, from Bhaktipriya Shridhar.

 5) Add XDP (eXpress Data Path), essentially running BPF programs on RX
    packets as soon as the device sees them, with the option to mirror
    the packet on TX via the same interface.  From Brenden Blanco and
    others.

 6) Allow qdisc/class stats dumps to run lockless, from Eric Dumazet.

 7) Add VLAN support to b53 and bcm_sf2, from Florian Fainelli.

 8) Simplify netlink conntrack entry layout, from Florian Westphal.

 9) Add ipv4 forwarding support to mlxsw spectrum driver, from Ido
    Schimmel, Yotam Gigi, and Jiri Pirko.

10) Add SKB array infrastructure and convert tun and macvtap over to it.
    From Michael S Tsirkin and Jason Wang.

11) Support qdisc packet injection in pktgen, from John Fastabend.

12) Add neighbour monitoring framework to TIPC, from Jon Paul Maloy.

13) Add NV congestion control support to TCP, from Lawrence Brakmo.

14) Add GSO support to SCTP, from Marcelo Ricardo Leitner.

15) Allow GRO and RPS to function on macsec devices, from Paolo Abeni.

16) Support MPLS over IPV4, from Simon Horman.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits)
  xgene: Fix build warning with ACPI disabled.
  be2net: perform temperature query in adapter regardless of its interface state
  l2tp: Correctly return -EBADF from pppol2tp_getname.
  net/mlx5_core/health: Remove deprecated create_singlethread_workqueue
  net: ipmr/ip6mr: update lastuse on entry change
  macsec: ensure rx_sa is set when validation is disabled
  tipc: dump monitor attributes
  tipc: add a function to get the bearer name
  tipc: get monitor threshold for the cluster
  tipc: make cluster size threshold for monitoring configurable
  tipc: introduce constants for tipc address validation
  net: neigh: disallow transition to NUD_STALE if lladdr is unchanged in neigh_update()
  MAINTAINERS: xgene: Add driver and documentation path
  Documentation: dtb: xgene: Add MDIO node
  dtb: xgene: Add MDIO node
  drivers: net: xgene: ethtool: Use phy_ethtool_gset and sset
  drivers: net: xgene: Use exported functions
  drivers: net: xgene: Enable MDIO driver
  drivers: net: xgene: Add backward compatibility
  drivers: net: phy: xgene: Add MDIO driver
  ...

1 files changed, 85 insertions, 55 deletions

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index ad535a854e5c..e21f7cc5ae4d 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -69,6 +69,7 @@ EXPORT_SYMBOL_GPL(can_len2dlc);
 
 #ifdef CONFIG_CAN_CALC_BITTIMING
 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
+#define CAN_CALC_SYNC_SEG 1
 
 /*
  * Bit-timing calculation derived from:
@@ -83,98 +84,126 @@ EXPORT_SYMBOL_GPL(can_len2dlc);
  * registers of the CAN controller. You can find more information
  * in the header file linux/can/netlink.h.
  */
-static int can_update_spt(const struct can_bittiming_const *btc,
-			  int sampl_pt, int tseg, int *tseg1, int *tseg2)
+static int can_update_sample_point(const struct can_bittiming_const *btc,
+			  unsigned int sample_point_nominal, unsigned int tseg,
+			  unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
+			  unsigned int *sample_point_error_ptr)
 {
-	*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
-	if (*tseg2 < btc->tseg2_min)
-		*tseg2 = btc->tseg2_min;
-	if (*tseg2 > btc->tseg2_max)
-		*tseg2 = btc->tseg2_max;
-	*tseg1 = tseg - *tseg2;
-	if (*tseg1 > btc->tseg1_max) {
-		*tseg1 = btc->tseg1_max;
-		*tseg2 = tseg - *tseg1;
+	unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
+	unsigned int sample_point, best_sample_point = 0;
+	unsigned int tseg1, tseg2;
+	int i;
+
+	for (i = 0; i <= 1; i++) {
+		tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
+		tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
+		tseg1 = tseg - tseg2;
+		if (tseg1 > btc->tseg1_max) {
+			tseg1 = btc->tseg1_max;
+			tseg2 = tseg - tseg1;
+		}
+
+		sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
+		sample_point_error = abs(sample_point_nominal - sample_point);
+
+		if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
+			best_sample_point = sample_point;
+			best_sample_point_error = sample_point_error;
+			*tseg1_ptr = tseg1;
+			*tseg2_ptr = tseg2;
+		}
 	}
-	return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
+
+	if (sample_point_error_ptr)
+		*sample_point_error_ptr = best_sample_point_error;
+
+	return best_sample_point;
 }
 
 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 			      const struct can_bittiming_const *btc)
 {
 	struct can_priv *priv = netdev_priv(dev);
-	long best_error = 1000000000, error = 0;
-	int best_tseg = 0, best_brp = 0, brp = 0;
-	int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
-	int spt_error = 1000, spt = 0, sampl_pt;
-	long rate;
+	unsigned int bitrate;			/* current bitrate */
+	unsigned int bitrate_error;		/* difference between current and nominal value */
+	unsigned int best_bitrate_error = UINT_MAX;
+	unsigned int sample_point_error;	/* difference between current and nominal value */
+	unsigned int best_sample_point_error = UINT_MAX;
+	unsigned int sample_point_nominal;	/* nominal sample point */
+	unsigned int best_tseg = 0;		/* current best value for tseg */
+	unsigned int best_brp = 0;		/* current best value for brp */
+	unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
 	u64 v64;
 
 	/* Use CiA recommended sample points */
 	if (bt->sample_point) {
-		sampl_pt = bt->sample_point;
+		sample_point_nominal = bt->sample_point;
 	} else {
 		if (bt->bitrate > 800000)
-			sampl_pt = 750;
+			sample_point_nominal = 750;
 		else if (bt->bitrate > 500000)
-			sampl_pt = 800;
+			sample_point_nominal = 800;
 		else
-			sampl_pt = 875;
+			sample_point_nominal = 875;
 	}
 
 	/* tseg even = round down, odd = round up */
 	for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
 	     tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
-		tsegall = 1 + tseg / 2;
+		tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
+
 		/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
 		brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
-		/* chose brp step which is possible in system */
+
+		/* choose brp step which is possible in system */
 		brp = (brp / btc->brp_inc) * btc->brp_inc;
 		if ((brp < btc->brp_min) || (brp > btc->brp_max))
 			continue;
-		rate = priv->clock.freq / (brp * tsegall);
-		error = bt->bitrate - rate;
+
+		bitrate = priv->clock.freq / (brp * tsegall);
+		bitrate_error = abs(bt->bitrate - bitrate);
+
 		/* tseg brp biterror */
-		if (error < 0)
-			error = -error;
-		if (error > best_error)
+		if (bitrate_error > best_bitrate_error)
 			continue;
-		best_error = error;
-		if (error == 0) {
-			spt = can_update_spt(btc, sampl_pt, tseg / 2,
-					     &tseg1, &tseg2);
-			error = sampl_pt - spt;
-			if (error < 0)
-				error = -error;
-			if (error > spt_error)
-				continue;
-			spt_error = error;
-		}
+
+		/* reset sample point error if we have a better bitrate */
+		if (bitrate_error < best_bitrate_error)
+			best_sample_point_error = UINT_MAX;
+
+		can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
+		if (sample_point_error > best_sample_point_error)
+			continue;
+
+		best_sample_point_error = sample_point_error;
+		best_bitrate_error = bitrate_error;
 		best_tseg = tseg / 2;
 		best_brp = brp;
-		if (error == 0)
+
+		if (bitrate_error == 0 && sample_point_error == 0)
 			break;
 	}
 
-	if (best_error) {
+	if (best_bitrate_error) {
 		/* Error in one-tenth of a percent */
-		error = (best_error * 1000) / bt->bitrate;
-		if (error > CAN_CALC_MAX_ERROR) {
+		v64 = (u64)best_bitrate_error * 1000;
+		do_div(v64, bt->bitrate);
+		bitrate_error = (u32)v64;
+		if (bitrate_error > CAN_CALC_MAX_ERROR) {
 			netdev_err(dev,
-				   "bitrate error %ld.%ld%% too high\n",
-				   error / 10, error % 10);
+				   "bitrate error %d.%d%% too high\n",
+				   bitrate_error / 10, bitrate_error % 10);
 			return -EDOM;
-		} else {
-			netdev_warn(dev, "bitrate error %ld.%ld%%\n",
-				    error / 10, error % 10);
 		}
+		netdev_warn(dev, "bitrate error %d.%d%%\n",
+			    bitrate_error / 10, bitrate_error % 10);
 	}
 
 	/* real sample point */
-	bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
-					  &tseg1, &tseg2);
+	bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
+					  &tseg1, &tseg2, NULL);
 
-	v64 = (u64)best_brp * 1000000000UL;
+	v64 = (u64)best_brp * 1000 * 1000 * 1000;
 	do_div(v64, priv->clock.freq);
 	bt->tq = (u32)v64;
 	bt->prop_seg = tseg1 / 2;
@@ -182,9 +211,9 @@ static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	bt->phase_seg2 = tseg2;
 
 	/* check for sjw user settings */
-	if (!bt->sjw || !btc->sjw_max)
+	if (!bt->sjw || !btc->sjw_max) {
 		bt->sjw = 1;
-	else {
+	} else {
 		/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
 		if (bt->sjw > btc->sjw_max)
 			bt->sjw = btc->sjw_max;
@@ -194,8 +223,9 @@ static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	}
 
 	bt->brp = best_brp;
-	/* real bit-rate */
-	bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
+
+	/* real bitrate */
+	bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
 
 	return 0;
 }