1 files changed, 335 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c
new file mode 100644
index 000000000000..1fffe48a93cc
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx_am.c
@@ -0,0 +1,335 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "en.h"
+
+/* Adaptive moderation profiles */
+#define MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE 256
+#define MLX5E_RX_AM_DEF_PROFILE_CQE 1
+#define MLX5E_RX_AM_DEF_PROFILE_EQE 1
+#define MLX5E_PARAMS_AM_NUM_PROFILES 5
+
+/* All profiles sizes must be MLX5E_PARAMS_AM_NUM_PROFILES */
+#define MLX5_AM_EQE_PROFILES { \
+	{1,   MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
+	{8,   MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
+	{64,  MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
+	{128, MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
+	{256, MLX5E_AM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \
+}
+
+#define MLX5_AM_CQE_PROFILES { \
+	{2,  256},             \
+	{8,  128},             \
+	{16, 64},              \
+	{32, 64},              \
+	{64, 64}               \
+}
+
+static const struct mlx5e_cq_moder
+profile[MLX5_CQ_PERIOD_NUM_MODES][MLX5E_PARAMS_AM_NUM_PROFILES] = {
+	MLX5_AM_EQE_PROFILES,
+	MLX5_AM_CQE_PROFILES,
+};
+
+static inline struct mlx5e_cq_moder mlx5e_am_get_profile(u8 cq_period_mode, int ix)
+{
+	return profile[cq_period_mode][ix];
+}
+
+struct mlx5e_cq_moder mlx5e_am_get_def_profile(u8 rx_cq_period_mode)
+{
+	int default_profile_ix;
+
+	if (rx_cq_period_mode == MLX5_CQ_PERIOD_MODE_START_FROM_CQE)
+		default_profile_ix = MLX5E_RX_AM_DEF_PROFILE_CQE;
+	else /* MLX5_CQ_PERIOD_MODE_START_FROM_EQE */
+		default_profile_ix = MLX5E_RX_AM_DEF_PROFILE_EQE;
+
+	return profile[rx_cq_period_mode][default_profile_ix];
+}
+
+/* Adaptive moderation logic */
+enum {
+	MLX5E_AM_START_MEASURE,
+	MLX5E_AM_MEASURE_IN_PROGRESS,
+	MLX5E_AM_APPLY_NEW_PROFILE,
+};
+
+enum {
+	MLX5E_AM_PARKING_ON_TOP,
+	MLX5E_AM_PARKING_TIRED,
+	MLX5E_AM_GOING_RIGHT,
+	MLX5E_AM_GOING_LEFT,
+};
+
+enum {
+	MLX5E_AM_STATS_WORSE,
+	MLX5E_AM_STATS_SAME,
+	MLX5E_AM_STATS_BETTER,
+};
+
+enum {
+	MLX5E_AM_STEPPED,
+	MLX5E_AM_TOO_TIRED,
+	MLX5E_AM_ON_EDGE,
+};
+
+static bool mlx5e_am_on_top(struct mlx5e_rx_am *am)
+{
+	switch (am->tune_state) {
+	case MLX5E_AM_PARKING_ON_TOP:
+	case MLX5E_AM_PARKING_TIRED:
+		WARN_ONCE(true, "mlx5e_am_on_top: PARKING\n");
+		return true;
+	case MLX5E_AM_GOING_RIGHT:
+		return (am->steps_left > 1) && (am->steps_right == 1);
+	default: /* MLX5E_AM_GOING_LEFT */
+		return (am->steps_right > 1) && (am->steps_left == 1);
+	}
+}
+
+static void mlx5e_am_turn(struct mlx5e_rx_am *am)
+{
+	switch (am->tune_state) {
+	case MLX5E_AM_PARKING_ON_TOP:
+	case MLX5E_AM_PARKING_TIRED:
+		WARN_ONCE(true, "mlx5e_am_turn: PARKING\n");
+		break;
+	case MLX5E_AM_GOING_RIGHT:
+		am->tune_state = MLX5E_AM_GOING_LEFT;
+		am->steps_left = 0;
+		break;
+	case MLX5E_AM_GOING_LEFT:
+		am->tune_state = MLX5E_AM_GOING_RIGHT;
+		am->steps_right = 0;
+		break;
+	}
+}
+
+static int mlx5e_am_step(struct mlx5e_rx_am *am)
+{
+	if (am->tired == (MLX5E_PARAMS_AM_NUM_PROFILES * 2))
+		return MLX5E_AM_TOO_TIRED;
+
+	switch (am->tune_state) {
+	case MLX5E_AM_PARKING_ON_TOP:
+	case MLX5E_AM_PARKING_TIRED:
+		WARN_ONCE(true, "mlx5e_am_step: PARKING\n");
+		break;
+	case MLX5E_AM_GOING_RIGHT:
+		if (am->profile_ix == (MLX5E_PARAMS_AM_NUM_PROFILES - 1))
+			return MLX5E_AM_ON_EDGE;
+		am->profile_ix++;
+		am->steps_right++;
+		break;
+	case MLX5E_AM_GOING_LEFT:
+		if (am->profile_ix == 0)
+			return MLX5E_AM_ON_EDGE;
+		am->profile_ix--;
+		am->steps_left++;
+		break;
+	}
+
+	am->tired++;
+	return MLX5E_AM_STEPPED;
+}
+
+static void mlx5e_am_park_on_top(struct mlx5e_rx_am *am)
+{
+	am->steps_right  = 0;
+	am->steps_left   = 0;
+	am->tired        = 0;
+	am->tune_state   = MLX5E_AM_PARKING_ON_TOP;
+}
+
+static void mlx5e_am_park_tired(struct mlx5e_rx_am *am)
+{
+	am->steps_right  = 0;
+	am->steps_left   = 0;
+	am->tune_state   = MLX5E_AM_PARKING_TIRED;
+}
+
+static void mlx5e_am_exit_parking(struct mlx5e_rx_am *am)
+{
+	am->tune_state = am->profile_ix ? MLX5E_AM_GOING_LEFT :
+					  MLX5E_AM_GOING_RIGHT;
+	mlx5e_am_step(am);
+}
+
+static int mlx5e_am_stats_compare(struct mlx5e_rx_am_stats *curr,
+				  struct mlx5e_rx_am_stats *prev)
+{
+	int diff;
+
+	if (!prev->ppms)
+		return curr->ppms ? MLX5E_AM_STATS_BETTER :
+				    MLX5E_AM_STATS_SAME;
+
+	diff = curr->ppms - prev->ppms;
+	if (((100 * abs(diff)) / prev->ppms) > 10) /* more than 10% diff */
+		return (diff > 0) ? MLX5E_AM_STATS_BETTER :
+				    MLX5E_AM_STATS_WORSE;
+
+	if (!prev->epms)
+		return curr->epms ? MLX5E_AM_STATS_WORSE :
+				    MLX5E_AM_STATS_SAME;
+
+	diff = curr->epms - prev->epms;
+	if (((100 * abs(diff)) / prev->epms) > 10) /* more than 10% diff */
+		return (diff < 0) ? MLX5E_AM_STATS_BETTER :
+				    MLX5E_AM_STATS_WORSE;
+
+	return MLX5E_AM_STATS_SAME;
+}
+
+static bool mlx5e_am_decision(struct mlx5e_rx_am_stats *curr_stats,
+			      struct mlx5e_rx_am *am)
+{
+	int prev_state = am->tune_state;
+	int prev_ix = am->profile_ix;
+	int stats_res;
+	int step_res;
+
+	switch (am->tune_state) {
+	case MLX5E_AM_PARKING_ON_TOP:
+		stats_res = mlx5e_am_stats_compare(curr_stats, &am->prev_stats);
+		if (stats_res != MLX5E_AM_STATS_SAME)
+			mlx5e_am_exit_parking(am);
+		break;
+
+	case MLX5E_AM_PARKING_TIRED:
+		am->tired--;
+		if (!am->tired)
+			mlx5e_am_exit_parking(am);
+		break;
+
+	case MLX5E_AM_GOING_RIGHT:
+	case MLX5E_AM_GOING_LEFT:
+		stats_res = mlx5e_am_stats_compare(curr_stats, &am->prev_stats);
+		if (stats_res != MLX5E_AM_STATS_BETTER)
+			mlx5e_am_turn(am);
+
+		if (mlx5e_am_on_top(am)) {
+			mlx5e_am_park_on_top(am);
+			break;
+		}
+
+		step_res = mlx5e_am_step(am);
+		switch (step_res) {
+		case MLX5E_AM_ON_EDGE:
+			mlx5e_am_park_on_top(am);
+			break;
+		case MLX5E_AM_TOO_TIRED:
+			mlx5e_am_park_tired(am);
+			break;
+		}
+
+		break;
+	}
+
+	if ((prev_state     != MLX5E_AM_PARKING_ON_TOP) ||
+	    (am->tune_state != MLX5E_AM_PARKING_ON_TOP))
+		am->prev_stats = *curr_stats;
+
+	return am->profile_ix != prev_ix;
+}
+
+static void mlx5e_am_sample(struct mlx5e_rq *rq,
+			    struct mlx5e_rx_am_sample *s)
+{
+	s->time	     = ktime_get();
+	s->pkt_ctr   = rq->stats.packets;
+	s->event_ctr = rq->cq.event_ctr;
+}
+
+#define MLX5E_AM_NEVENTS 64
+
+static void mlx5e_am_calc_stats(struct mlx5e_rx_am_sample *start,
+				struct mlx5e_rx_am_sample *end,
+				struct mlx5e_rx_am_stats *curr_stats)
+{
+	/* u32 holds up to 71 minutes, should be enough */
+	u32 delta_us = ktime_us_delta(end->time, start->time);
+	unsigned int npkts = end->pkt_ctr - start->pkt_ctr;
+
+	if (!delta_us) {
+		WARN_ONCE(true, "mlx5e_am_calc_stats: delta_us=0\n");
+		return;
+	}
+
+	curr_stats->ppms =            (npkts * USEC_PER_MSEC) / delta_us;
+	curr_stats->epms = (MLX5E_AM_NEVENTS * USEC_PER_MSEC) / delta_us;
+}
+
+void mlx5e_rx_am_work(struct work_struct *work)
+{
+	struct mlx5e_rx_am *am = container_of(work, struct mlx5e_rx_am,
+					      work);
+	struct mlx5e_rq *rq = container_of(am, struct mlx5e_rq, am);
+	struct mlx5e_cq_moder cur_profile = profile[am->mode][am->profile_ix];
+
+	mlx5_core_modify_cq_moderation(rq->priv->mdev, &rq->cq.mcq,
+				       cur_profile.usec, cur_profile.pkts);
+
+	am->state = MLX5E_AM_START_MEASURE;
+}
+
+void mlx5e_rx_am(struct mlx5e_rq *rq)
+{
+	struct mlx5e_rx_am *am = &rq->am;
+	struct mlx5e_rx_am_sample end_sample;
+	struct mlx5e_rx_am_stats curr_stats;
+	u16 nevents;
+
+	switch (am->state) {
+	case MLX5E_AM_MEASURE_IN_PROGRESS:
+		nevents = rq->cq.event_ctr - am->start_sample.event_ctr;
+		if (nevents < MLX5E_AM_NEVENTS)
+			break;
+		mlx5e_am_sample(rq, &end_sample);
+		mlx5e_am_calc_stats(&am->start_sample, &end_sample,
+				    &curr_stats);
+		if (mlx5e_am_decision(&curr_stats, am)) {
+			am->state = MLX5E_AM_APPLY_NEW_PROFILE;
+			schedule_work(&am->work);
+			break;
+		}
+		/* fall through */
+	case MLX5E_AM_START_MEASURE:
+		mlx5e_am_sample(rq, &am->start_sample);
+		am->state = MLX5E_AM_MEASURE_IN_PROGRESS;
+		break;
+	case MLX5E_AM_APPLY_NEW_PROFILE:
+		break;
+	}
+}