Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2016 Qualcomm Atheros, Inc |
| 3 | * |
| 4 | * GPL v2 |
| 5 | * |
| 6 | * Based on net/sched/sch_fq_codel.c |
| 7 | */ |
| 8 | #ifndef __NET_SCHED_FQ_IMPL_H |
| 9 | #define __NET_SCHED_FQ_IMPL_H |
| 10 | |
| 11 | #include <net/fq.h> |
| 12 | |
| 13 | /* functions that are embedded into includer */ |
| 14 | |
| 15 | static struct sk_buff *fq_flow_dequeue(struct fq *fq, |
| 16 | struct fq_flow *flow) |
| 17 | { |
| 18 | struct fq_tin *tin = flow->tin; |
| 19 | struct fq_flow *i; |
| 20 | struct sk_buff *skb; |
| 21 | |
| 22 | lockdep_assert_held(&fq->lock); |
| 23 | |
| 24 | skb = __skb_dequeue(&flow->queue); |
| 25 | if (!skb) |
| 26 | return NULL; |
| 27 | |
| 28 | tin->backlog_bytes -= skb->len; |
| 29 | tin->backlog_packets--; |
| 30 | flow->backlog -= skb->len; |
| 31 | fq->backlog--; |
Toke Høiland-Jørgensen | 097b065 | 2016-09-23 21:59:09 +0200 | [diff] [blame^] | 32 | fq->memory_usage -= skb->truesize; |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 33 | |
| 34 | if (flow->backlog == 0) { |
| 35 | list_del_init(&flow->backlogchain); |
| 36 | } else { |
| 37 | i = flow; |
| 38 | |
| 39 | list_for_each_entry_continue(i, &fq->backlogs, backlogchain) |
| 40 | if (i->backlog < flow->backlog) |
| 41 | break; |
| 42 | |
| 43 | list_move_tail(&flow->backlogchain, |
| 44 | &i->backlogchain); |
| 45 | } |
| 46 | |
| 47 | return skb; |
| 48 | } |
| 49 | |
| 50 | static struct sk_buff *fq_tin_dequeue(struct fq *fq, |
| 51 | struct fq_tin *tin, |
| 52 | fq_tin_dequeue_t dequeue_func) |
| 53 | { |
| 54 | struct fq_flow *flow; |
| 55 | struct list_head *head; |
| 56 | struct sk_buff *skb; |
| 57 | |
| 58 | lockdep_assert_held(&fq->lock); |
| 59 | |
| 60 | begin: |
| 61 | head = &tin->new_flows; |
| 62 | if (list_empty(head)) { |
| 63 | head = &tin->old_flows; |
| 64 | if (list_empty(head)) |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | flow = list_first_entry(head, struct fq_flow, flowchain); |
| 69 | |
| 70 | if (flow->deficit <= 0) { |
| 71 | flow->deficit += fq->quantum; |
| 72 | list_move_tail(&flow->flowchain, |
| 73 | &tin->old_flows); |
| 74 | goto begin; |
| 75 | } |
| 76 | |
| 77 | skb = dequeue_func(fq, tin, flow); |
| 78 | if (!skb) { |
| 79 | /* force a pass through old_flows to prevent starvation */ |
| 80 | if ((head == &tin->new_flows) && |
| 81 | !list_empty(&tin->old_flows)) { |
| 82 | list_move_tail(&flow->flowchain, &tin->old_flows); |
| 83 | } else { |
| 84 | list_del_init(&flow->flowchain); |
| 85 | flow->tin = NULL; |
| 86 | } |
| 87 | goto begin; |
| 88 | } |
| 89 | |
| 90 | flow->deficit -= skb->len; |
| 91 | tin->tx_bytes += skb->len; |
| 92 | tin->tx_packets++; |
| 93 | |
| 94 | return skb; |
| 95 | } |
| 96 | |
| 97 | static struct fq_flow *fq_flow_classify(struct fq *fq, |
| 98 | struct fq_tin *tin, |
| 99 | struct sk_buff *skb, |
| 100 | fq_flow_get_default_t get_default_func) |
| 101 | { |
| 102 | struct fq_flow *flow; |
| 103 | u32 hash; |
| 104 | u32 idx; |
| 105 | |
| 106 | lockdep_assert_held(&fq->lock); |
| 107 | |
| 108 | hash = skb_get_hash_perturb(skb, fq->perturbation); |
| 109 | idx = reciprocal_scale(hash, fq->flows_cnt); |
| 110 | flow = &fq->flows[idx]; |
| 111 | |
| 112 | if (flow->tin && flow->tin != tin) { |
| 113 | flow = get_default_func(fq, tin, idx, skb); |
| 114 | tin->collisions++; |
| 115 | fq->collisions++; |
| 116 | } |
| 117 | |
| 118 | if (!flow->tin) |
| 119 | tin->flows++; |
| 120 | |
| 121 | return flow; |
| 122 | } |
| 123 | |
Michal Kazior | b43e719 | 2016-04-27 12:59:13 +0200 | [diff] [blame] | 124 | static void fq_recalc_backlog(struct fq *fq, |
| 125 | struct fq_tin *tin, |
| 126 | struct fq_flow *flow) |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 127 | { |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 128 | struct fq_flow *i; |
| 129 | |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 130 | if (list_empty(&flow->backlogchain)) |
| 131 | list_add_tail(&flow->backlogchain, &fq->backlogs); |
| 132 | |
| 133 | i = flow; |
| 134 | list_for_each_entry_continue_reverse(i, &fq->backlogs, |
| 135 | backlogchain) |
| 136 | if (i->backlog > flow->backlog) |
| 137 | break; |
| 138 | |
| 139 | list_move(&flow->backlogchain, &i->backlogchain); |
Michal Kazior | b43e719 | 2016-04-27 12:59:13 +0200 | [diff] [blame] | 140 | } |
| 141 | |
| 142 | static void fq_tin_enqueue(struct fq *fq, |
| 143 | struct fq_tin *tin, |
| 144 | struct sk_buff *skb, |
| 145 | fq_skb_free_t free_func, |
| 146 | fq_flow_get_default_t get_default_func) |
| 147 | { |
| 148 | struct fq_flow *flow; |
| 149 | |
| 150 | lockdep_assert_held(&fq->lock); |
| 151 | |
| 152 | flow = fq_flow_classify(fq, tin, skb, get_default_func); |
| 153 | |
| 154 | flow->tin = tin; |
| 155 | flow->backlog += skb->len; |
| 156 | tin->backlog_bytes += skb->len; |
| 157 | tin->backlog_packets++; |
Toke Høiland-Jørgensen | 097b065 | 2016-09-23 21:59:09 +0200 | [diff] [blame^] | 158 | fq->memory_usage += skb->truesize; |
Michal Kazior | b43e719 | 2016-04-27 12:59:13 +0200 | [diff] [blame] | 159 | fq->backlog++; |
| 160 | |
| 161 | fq_recalc_backlog(fq, tin, flow); |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 162 | |
| 163 | if (list_empty(&flow->flowchain)) { |
| 164 | flow->deficit = fq->quantum; |
| 165 | list_add_tail(&flow->flowchain, |
| 166 | &tin->new_flows); |
| 167 | } |
| 168 | |
| 169 | __skb_queue_tail(&flow->queue, skb); |
| 170 | |
Toke Høiland-Jørgensen | 097b065 | 2016-09-23 21:59:09 +0200 | [diff] [blame^] | 171 | if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) { |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 172 | flow = list_first_entry_or_null(&fq->backlogs, |
| 173 | struct fq_flow, |
| 174 | backlogchain); |
| 175 | if (!flow) |
| 176 | return; |
| 177 | |
| 178 | skb = fq_flow_dequeue(fq, flow); |
| 179 | if (!skb) |
| 180 | return; |
| 181 | |
| 182 | free_func(fq, flow->tin, flow, skb); |
| 183 | |
| 184 | flow->tin->overlimit++; |
| 185 | fq->overlimit++; |
Toke Høiland-Jørgensen | 097b065 | 2016-09-23 21:59:09 +0200 | [diff] [blame^] | 186 | if (fq->memory_usage > fq->memory_limit) |
| 187 | fq->overmemory++; |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 188 | } |
| 189 | } |
| 190 | |
| 191 | static void fq_flow_reset(struct fq *fq, |
| 192 | struct fq_flow *flow, |
| 193 | fq_skb_free_t free_func) |
| 194 | { |
| 195 | struct sk_buff *skb; |
| 196 | |
| 197 | while ((skb = fq_flow_dequeue(fq, flow))) |
| 198 | free_func(fq, flow->tin, flow, skb); |
| 199 | |
| 200 | if (!list_empty(&flow->flowchain)) |
| 201 | list_del_init(&flow->flowchain); |
| 202 | |
| 203 | if (!list_empty(&flow->backlogchain)) |
| 204 | list_del_init(&flow->backlogchain); |
| 205 | |
| 206 | flow->tin = NULL; |
| 207 | |
| 208 | WARN_ON_ONCE(flow->backlog); |
| 209 | } |
| 210 | |
| 211 | static void fq_tin_reset(struct fq *fq, |
| 212 | struct fq_tin *tin, |
| 213 | fq_skb_free_t free_func) |
| 214 | { |
| 215 | struct list_head *head; |
| 216 | struct fq_flow *flow; |
| 217 | |
| 218 | for (;;) { |
| 219 | head = &tin->new_flows; |
| 220 | if (list_empty(head)) { |
| 221 | head = &tin->old_flows; |
| 222 | if (list_empty(head)) |
| 223 | break; |
| 224 | } |
| 225 | |
| 226 | flow = list_first_entry(head, struct fq_flow, flowchain); |
| 227 | fq_flow_reset(fq, flow, free_func); |
| 228 | } |
| 229 | |
| 230 | WARN_ON_ONCE(tin->backlog_bytes); |
| 231 | WARN_ON_ONCE(tin->backlog_packets); |
| 232 | } |
| 233 | |
| 234 | static void fq_flow_init(struct fq_flow *flow) |
| 235 | { |
| 236 | INIT_LIST_HEAD(&flow->flowchain); |
| 237 | INIT_LIST_HEAD(&flow->backlogchain); |
| 238 | __skb_queue_head_init(&flow->queue); |
| 239 | } |
| 240 | |
| 241 | static void fq_tin_init(struct fq_tin *tin) |
| 242 | { |
| 243 | INIT_LIST_HEAD(&tin->new_flows); |
| 244 | INIT_LIST_HEAD(&tin->old_flows); |
| 245 | } |
| 246 | |
| 247 | static int fq_init(struct fq *fq, int flows_cnt) |
| 248 | { |
| 249 | int i; |
| 250 | |
| 251 | memset(fq, 0, sizeof(fq[0])); |
| 252 | INIT_LIST_HEAD(&fq->backlogs); |
| 253 | spin_lock_init(&fq->lock); |
| 254 | fq->flows_cnt = max_t(u32, flows_cnt, 1); |
| 255 | fq->perturbation = prandom_u32(); |
| 256 | fq->quantum = 300; |
| 257 | fq->limit = 8192; |
Toke Høiland-Jørgensen | 097b065 | 2016-09-23 21:59:09 +0200 | [diff] [blame^] | 258 | fq->memory_limit = 16 << 20; /* 16 MBytes */ |
Michal Kazior | 557fc4a | 2016-04-22 14:20:13 +0200 | [diff] [blame] | 259 | |
| 260 | fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL); |
| 261 | if (!fq->flows) |
| 262 | return -ENOMEM; |
| 263 | |
| 264 | for (i = 0; i < fq->flows_cnt; i++) |
| 265 | fq_flow_init(&fq->flows[i]); |
| 266 | |
| 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | static void fq_reset(struct fq *fq, |
| 271 | fq_skb_free_t free_func) |
| 272 | { |
| 273 | int i; |
| 274 | |
| 275 | for (i = 0; i < fq->flows_cnt; i++) |
| 276 | fq_flow_reset(fq, &fq->flows[i], free_func); |
| 277 | |
| 278 | kfree(fq->flows); |
| 279 | fq->flows = NULL; |
| 280 | } |
| 281 | |
| 282 | #endif |