/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
/* Copyright (c) 2019 Mellanox Technologies. */
#ifndef DIM_H
#define DIM_H
#include <linux/module.h>
#define NET_DIM_NEVENTS 64
/* more than 10% difference */
#define IS_SIGNIFICANT_DIFF(val, ref) \
(((100UL * abs((val) - (ref))) / (ref)) > 10)
#define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \
& (BIT_ULL(bits) - 1))
struct net_dim_cq_moder {
u16 usec;
u16 pkts;
u8 cq_period_mode;
};
struct net_dim_sample {
ktime_t time;
u32 pkt_ctr;
u32 byte_ctr;
u16 event_ctr;
};
struct net_dim_stats {
int ppms; /* packets per msec */
int bpms; /* bytes per msec */
int epms; /* events per msec */
};
struct net_dim { /* Dynamic Interrupt Moderation */
u8 state;
struct net_dim_stats prev_stats;
struct net_dim_sample start_sample;
struct work_struct work;
u8 profile_ix;
u8 mode;
u8 tune_state;
u8 steps_right;
u8 steps_left;
u8 tired;
};
enum {
NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0,
NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1,
NET_DIM_CQ_PERIOD_NUM_MODES
};
enum {
NET_DIM_START_MEASURE,
NET_DIM_MEASURE_IN_PROGRESS,
NET_DIM_APPLY_NEW_PROFILE,
};
enum {
NET_DIM_PARKING_ON_TOP,
NET_DIM_PARKING_TIRED,
NET_DIM_GOING_RIGHT,
NET_DIM_GOING_LEFT,
};
enum {
NET_DIM_STATS_WORSE,
NET_DIM_STATS_SAME,
NET_DIM_STATS_BETTER,
};
enum {
NET_DIM_STEPPED,
NET_DIM_TOO_TIRED,
NET_DIM_ON_EDGE,
};
static inline bool net_dim_on_top(struct net_dim *net_dim)
{
switch (net_dim->tune_state) {
case NET_DIM_PARKING_ON_TOP:
case NET_DIM_PARKING_TIRED:
return true;
case NET_DIM_GOING_RIGHT:
return (net_dim->steps_left > 1) && (net_dim->steps_right == 1);
default: /* NET_DIM_GOING_LEFT */
return (net_dim->steps_right > 1) && (net_dim->steps_left == 1);
}
}
static inline void net_dim_turn(struct net_dim *net_dim)
{
switch (net_dim->tune_state) {
case NET_DIM_PARKING_ON_TOP:
case NET_DIM_PARKING_TIRED:
break;
case NET_DIM_GOING_RIGHT:
net_dim->tune_state = NET_DIM_GOING_LEFT;
net_dim->steps_left = 0;
break;
case NET_DIM_GOING_LEFT:
net_dim->tune_state = NET_DIM_GOING_RIGHT;
net_dim->steps_right = 0;
break;
}
}
static inline void net_dim_park_on_top(struct net_dim *net_dim)
{
net_dim->steps_right = 0;
net_dim->steps_left = 0;
net_dim->tired = 0;
net_dim->tune_state = NET_DIM_PARKING_ON_TOP;
}
static inline void net_dim_park_tired(struct net_dim *net_dim)
{
net_dim->steps_right = 0;
net_dim->steps_left = 0;
net_dim->tune_state = NET_DIM_PARKING_TIRED;
}
static inline void
net_dim_sample(u16 event_ctr, u64 packets, u64 bytes, struct net_dim_sample *s)
{
s->time = ktime_get();
s->pkt_ctr = packets;
s->byte_ctr = bytes;
s->event_ctr = event_ctr;
}
static inline void
net_dim_calc_stats(struct net_dim_sample *start, struct net_dim_sample *end,
struct net_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);
if (!delta_us)
return;
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(NET_DIM_NEVENTS * USEC_PER_MSEC,
delta_us);
}
#endif /* DIM_H */
