LXR linux/lib/dim/dim.c

   1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2/*
   3 * Copyright (c) 2019, Mellanox Technologies inc.  All rights reserved.
   4 */
   5
   6#include <linux/dim.h>
   7
   8bool dim_on_top(struct dim *dim)
   9{
  10        switch (dim->tune_state) {
  11        case DIM_PARKING_ON_TOP:
  12        case DIM_PARKING_TIRED:
  13                return true;
  14        case DIM_GOING_RIGHT:
  15                return (dim->steps_left > 1) && (dim->steps_right == 1);
  16        default: /* DIM_GOING_LEFT */
  17                return (dim->steps_right > 1) && (dim->steps_left == 1);
  18        }
  19}
  20EXPORT_SYMBOL(dim_on_top);
  21
  22void dim_turn(struct dim *dim)
  23{
  24        switch (dim->tune_state) {
  25        case DIM_PARKING_ON_TOP:
  26        case DIM_PARKING_TIRED:
  27                break;
  28        case DIM_GOING_RIGHT:
  29                dim->tune_state = DIM_GOING_LEFT;
  30                dim->steps_left = 0;
  31                break;
  32        case DIM_GOING_LEFT:
  33                dim->tune_state = DIM_GOING_RIGHT;
  34                dim->steps_right = 0;
  35                break;
  36        }
  37}
  38EXPORT_SYMBOL(dim_turn);
  39
  40void dim_park_on_top(struct dim *dim)
  41{
  42        dim->steps_right  = 0;
  43        dim->steps_left   = 0;
  44        dim->tired        = 0;
  45        dim->tune_state   = DIM_PARKING_ON_TOP;
  46}
  47EXPORT_SYMBOL(dim_park_on_top);
  48
  49void dim_park_tired(struct dim *dim)
  50{
  51        dim->steps_right  = 0;
  52        dim->steps_left   = 0;
  53        dim->tune_state   = DIM_PARKING_TIRED;
  54}
  55EXPORT_SYMBOL(dim_park_tired);
  56
  57void dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
  58                    struct dim_stats *curr_stats)
  59{
  60        /* u32 holds up to 71 minutes, should be enough */
  61        u32 delta_us = ktime_us_delta(end->time, start->time);
  62        u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
  63        u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr,
  64                             start->byte_ctr);
  65        u32 ncomps = BIT_GAP(BITS_PER_TYPE(u32), end->comp_ctr,
  66                             start->comp_ctr);
  67
  68        if (!delta_us)
  69                return;
  70
  71        curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us);
  72        curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us);
  73        curr_stats->epms = DIV_ROUND_UP(DIM_NEVENTS * USEC_PER_MSEC,
  74                                        delta_us);
  75        curr_stats->cpms = DIV_ROUND_UP(ncomps * USEC_PER_MSEC, delta_us);
  76        if (curr_stats->epms != 0)
  77                curr_stats->cpe_ratio = DIV_ROUND_DOWN_ULL(
  78                        curr_stats->cpms * 100, curr_stats->epms);
  79        else
  80                curr_stats->cpe_ratio = 0;
  81
  82}
  83EXPORT_SYMBOL(dim_calc_stats);
  84