linux/lib/dim/dim.c
Caleb Sander Mateos a865276872 dim: make dim_calc_stats() inputs const pointers
Make the start and end arguments to dim_calc_stats() const pointers
to clarify that the function does not modify their values.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Arthur Kiyanovski <akiyano@amazon.com>
Link: https://patch.msgid.link/20241031002326.3426181-1-csander@purestorage.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-03 12:35:57 -08:00

89 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
* Copyright (c) 2019, Mellanox Technologies inc. All rights reserved.
*/
#include <linux/dim.h>
bool dim_on_top(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
return true;
case DIM_GOING_RIGHT:
return (dim->steps_left > 1) && (dim->steps_right == 1);
default: /* DIM_GOING_LEFT */
return (dim->steps_right > 1) && (dim->steps_left == 1);
}
}
EXPORT_SYMBOL(dim_on_top);
void dim_turn(struct dim *dim)
{
switch (dim->tune_state) {
case DIM_PARKING_ON_TOP:
case DIM_PARKING_TIRED:
break;
case DIM_GOING_RIGHT:
dim->tune_state = DIM_GOING_LEFT;
dim->steps_left = 0;
break;
case DIM_GOING_LEFT:
dim->tune_state = DIM_GOING_RIGHT;
dim->steps_right = 0;
break;
}
}
EXPORT_SYMBOL(dim_turn);
void dim_park_on_top(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tired = 0;
dim->tune_state = DIM_PARKING_ON_TOP;
}
EXPORT_SYMBOL(dim_park_on_top);
void dim_park_tired(struct dim *dim)
{
dim->steps_right = 0;
dim->steps_left = 0;
dim->tune_state = DIM_PARKING_TIRED;
}
EXPORT_SYMBOL(dim_park_tired);
bool dim_calc_stats(const struct dim_sample *start,
const struct dim_sample *end,
struct dim_stats *curr_stats)
{
/* u32 holds up to 71 minutes, should be enough */
u32 delta_us = ktime_us_delta(end->time, start->time);
u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr,
start->byte_ctr);
u32 ncomps = BIT_GAP(BITS_PER_TYPE(u32), end->comp_ctr,
start->comp_ctr);
if (!delta_us)
return false;
curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us);
curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us);
curr_stats->epms = DIV_ROUND_UP(DIM_NEVENTS * USEC_PER_MSEC,
delta_us);
curr_stats->cpms = DIV_ROUND_UP(ncomps * USEC_PER_MSEC, delta_us);
if (curr_stats->epms != 0)
curr_stats->cpe_ratio = DIV_ROUND_DOWN_ULL(
curr_stats->cpms * 100, curr_stats->epms);
else
curr_stats->cpe_ratio = 0;
return true;
}
EXPORT_SYMBOL(dim_calc_stats);
MODULE_DESCRIPTION("Dynamic Interrupt Moderation (DIM) library");
MODULE_LICENSE("Dual BSD/GPL");