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
57bool dim_calc_stats(const struct dim_sample *start,
58 const struct dim_sample *end,
59 struct dim_stats *curr_stats)
60{
61 /* u32 holds up to 71 minutes, should be enough */
62 u32 delta_us = ktime_us_delta(later: end->time, earlier: start->time);
63 u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
64 u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr,
65 start->byte_ctr);
66 u32 ncomps = BIT_GAP(BITS_PER_TYPE(u32), end->comp_ctr,
67 start->comp_ctr);
68
69 if (!delta_us)
70 return false;
71
72 curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us);
73 curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us);
74 curr_stats->epms = DIV_ROUND_UP(DIM_NEVENTS * USEC_PER_MSEC,
75 delta_us);
76 curr_stats->cpms = DIV_ROUND_UP(ncomps * USEC_PER_MSEC, delta_us);
77 if (curr_stats->epms != 0)
78 curr_stats->cpe_ratio = DIV_ROUND_DOWN_ULL(
79 curr_stats->cpms * 100, curr_stats->epms);
80 else
81 curr_stats->cpe_ratio = 0;
82
83 return true;
84}
85EXPORT_SYMBOL(dim_calc_stats);
86
87MODULE_DESCRIPTION("Dynamic Interrupt Moderation (DIM) library");
88MODULE_LICENSE("Dual BSD/GPL");
89