1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ 2 /* Copyright (c) 2019 Mellanox Technologies. */ 3 4 #ifndef DIM_H 5 #define DIM_H 6 7 #include <linux/module.h> 8 9 #define DIM_NEVENTS 64 10 11 /* more than 10% difference */ 12 #define IS_SIGNIFICANT_DIFF(val, ref) \ 13 (((100UL * abs((val) - (ref))) / (ref)) > 10) 14 #define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) \ 15 & (BIT_ULL(bits) - 1)) 16 17 struct net_dim_cq_moder { 18 u16 usec; 19 u16 pkts; 20 u8 cq_period_mode; 21 }; 22 23 struct net_dim_sample { 24 ktime_t time; 25 u32 pkt_ctr; 26 u32 byte_ctr; 27 u16 event_ctr; 28 }; 29 30 struct dim_stats { 31 int ppms; /* packets per msec */ 32 int bpms; /* bytes per msec */ 33 int epms; /* events per msec */ 34 }; 35 36 struct net_dim { /* Dynamic Interrupt Moderation */ 37 u8 state; 38 struct dim_stats prev_stats; 39 struct net_dim_sample start_sample; 40 struct work_struct work; 41 u8 profile_ix; 42 u8 mode; 43 u8 tune_state; 44 u8 steps_right; 45 u8 steps_left; 46 u8 tired; 47 }; 48 49 enum { 50 NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0, 51 NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1, 52 NET_DIM_CQ_PERIOD_NUM_MODES 53 }; 54 55 enum { 56 NET_DIM_START_MEASURE, 57 NET_DIM_MEASURE_IN_PROGRESS, 58 NET_DIM_APPLY_NEW_PROFILE, 59 }; 60 61 enum { 62 DIM_PARKING_ON_TOP, 63 DIM_PARKING_TIRED, 64 DIM_GOING_RIGHT, 65 DIM_GOING_LEFT, 66 }; 67 68 enum { 69 DIM_STATS_WORSE, 70 DIM_STATS_SAME, 71 DIM_STATS_BETTER, 72 }; 73 74 enum { 75 DIM_STEPPED, 76 DIM_TOO_TIRED, 77 DIM_ON_EDGE, 78 }; 79 80 static inline bool dim_on_top(struct net_dim *dim) 81 { 82 switch (dim->tune_state) { 83 case DIM_PARKING_ON_TOP: 84 case DIM_PARKING_TIRED: 85 return true; 86 case DIM_GOING_RIGHT: 87 return (dim->steps_left > 1) && (dim->steps_right == 1); 88 default: /* DIM_GOING_LEFT */ 89 return (dim->steps_right > 1) && (dim->steps_left == 1); 90 } 91 } 92 93 static inline void dim_turn(struct net_dim *dim) 94 { 95 switch (dim->tune_state) { 96 case DIM_PARKING_ON_TOP: 97 case DIM_PARKING_TIRED: 98 break; 99 case DIM_GOING_RIGHT: 100 dim->tune_state = DIM_GOING_LEFT; 101 dim->steps_left = 0; 102 break; 103 case DIM_GOING_LEFT: 104 dim->tune_state = DIM_GOING_RIGHT; 105 dim->steps_right = 0; 106 break; 107 } 108 } 109 110 static inline void dim_park_on_top(struct net_dim *dim) 111 { 112 dim->steps_right = 0; 113 dim->steps_left = 0; 114 dim->tired = 0; 115 dim->tune_state = DIM_PARKING_ON_TOP; 116 } 117 118 static inline void dim_park_tired(struct net_dim *dim) 119 { 120 dim->steps_right = 0; 121 dim->steps_left = 0; 122 dim->tune_state = DIM_PARKING_TIRED; 123 } 124 125 static inline void 126 net_dim_sample(u16 event_ctr, u64 packets, u64 bytes, struct net_dim_sample *s) 127 { 128 s->time = ktime_get(); 129 s->pkt_ctr = packets; 130 s->byte_ctr = bytes; 131 s->event_ctr = event_ctr; 132 } 133 134 static inline void 135 dim_calc_stats(struct net_dim_sample *start, struct net_dim_sample *end, 136 struct dim_stats *curr_stats) 137 { 138 /* u32 holds up to 71 minutes, should be enough */ 139 u32 delta_us = ktime_us_delta(end->time, start->time); 140 u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr); 141 u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr, 142 start->byte_ctr); 143 144 if (!delta_us) 145 return; 146 147 curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us); 148 curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us); 149 curr_stats->epms = DIV_ROUND_UP(DIM_NEVENTS * USEC_PER_MSEC, 150 delta_us); 151 } 152 153 #endif /* DIM_H */ 154