// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB/* * Copyright (c) 2019, Mellanox Technologies inc.  All rights reserved. */ #include <linux/dim.h> static int rdma_dim_step(struct dim *dim){	if (dim->tune_state == DIM_GOING_RIGHT) {		if (dim->profile_ix == (RDMA_DIM_PARAMS_NUM_PROFILES - 1))			return DIM_ON_EDGE;		dim->profile_ix++;		dim->steps_right++;	}	if (dim->tune_state == DIM_GOING_LEFT) {		if (dim->profile_ix == 0)			return DIM_ON_EDGE;		dim->profile_ix--;		dim->steps_left++;	} 	return DIM_STEPPED;} static int rdma_dim_stats_compare(struct dim_stats *curr,				  struct dim_stats *prev){	/* first stat */	if (!prev->cpms)		return DIM_STATS_SAME; 	if (IS_SIGNIFICANT_DIFF(curr->cpms, prev->cpms))		return (curr->cpms > prev->cpms) ? DIM_STATS_BETTER :						DIM_STATS_WORSE; 	if (IS_SIGNIFICANT_DIFF(curr->cpe_ratio, prev->cpe_ratio))		return (curr->cpe_ratio > prev->cpe_ratio) ? DIM_STATS_BETTER :						DIM_STATS_WORSE; 	return DIM_STATS_SAME;} static bool rdma_dim_decision(struct dim_stats *curr_stats, struct dim *dim){	int prev_ix = dim->profile_ix;	u8 state = dim->tune_state;	int stats_res;	int step_res; 	if (state != DIM_PARKING_ON_TOP && state != DIM_PARKING_TIRED) {		stats_res = rdma_dim_stats_compare(curr_stats,						   &dim->prev_stats); 		switch (stats_res) {		case DIM_STATS_SAME:			if (curr_stats->cpe_ratio <= 50 * prev_ix)				dim->profile_ix = 0;			break;		case DIM_STATS_WORSE:			dim_turn(dim);			fallthrough;		case DIM_STATS_BETTER:			step_res = rdma_dim_step(dim);			if (step_res == DIM_ON_EDGE)				dim_turn(dim);			break;		}	} 	dim->prev_stats = *curr_stats; 	return dim->profile_ix != prev_ix;} void rdma_dim(struct dim *dim, u64 completions){	struct dim_sample *curr_sample = &dim->measuring_sample;	struct dim_stats curr_stats;	u32 nevents; 	dim_update_sample_with_comps(curr_sample->event_ctr + 1, 0, 0,				     curr_sample->comp_ctr + completions,				     &dim->measuring_sample); 	switch (dim->state) {	case DIM_MEASURE_IN_PROGRESS:		nevents = curr_sample->event_ctr - dim->start_sample.event_ctr;		if (nevents < DIM_NEVENTS)			break;		if (!dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats))			break;		if (rdma_dim_decision(&curr_stats, dim)) {			dim->state = DIM_APPLY_NEW_PROFILE;			schedule_work(&dim->work);			break;		}		fallthrough;	case DIM_START_MEASURE:		dim->state = DIM_MEASURE_IN_PROGRESS;		dim_update_sample_with_comps(curr_sample->event_ctr, 0, 0,					     curr_sample->comp_ctr,					     &dim->start_sample);		break;	case DIM_APPLY_NEW_PROFILE:		break;	}}EXPORT_SYMBOL(rdma_dim);