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
   8 bool 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 }
  20 EXPORT_SYMBOL(dim_on_top);
  21
  22 void 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 }
  38 EXPORT_SYMBOL(dim_turn);
  39
  40 void 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 }
  47 EXPORT_SYMBOL(dim_park_on_top);
  48
  49 void 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 }
  55 EXPORT_SYMBOL(dim_park_tired);
  56
  57 void 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 }
  83 EXPORT_SYMBOL(dim_calc_stats);