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 bool 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 false;
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 return true;
83 }
84 EXPORT_SYMBOL(dim_calc_stats);
85
86 MODULE_DESCRIPTION("Dynamic Interrupt Moderation (DIM) library");
87 MODULE_LICENSE("Dual BSD/GPL");
88
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