1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (c) 2016 Qualcomm Atheros, Inc 4 * 5 * Based on net/sched/sch_fq_codel.c 6 */ 7 #ifndef __NET_SCHED_FQ_IMPL_H 8 #define __NET_SCHED_FQ_IMPL_H 9 10 #include <net/fq.h> 11 12 /* functions that are embedded into includer */ 13 14 15 static void 16 __fq_adjust_removal(struct fq *fq, struct fq_flow *flow, unsigned int packets, 17 unsigned int bytes, unsigned int truesize) 18 { 19 struct fq_tin *tin = flow->tin; 20 int idx; 21 22 tin->backlog_bytes -= bytes; 23 tin->backlog_packets -= packets; 24 flow->backlog -= bytes; 25 fq->backlog -= packets; 26 fq->memory_usage -= truesize; 27 28 if (flow->backlog) 29 return; 30 31 if (flow == &tin->default_flow) { 32 list_del_init(&tin->tin_list); 33 return; 34 } 35 36 idx = flow - fq->flows; 37 __clear_bit(idx, fq->flows_bitmap); 38 } 39 40 static void fq_adjust_removal(struct fq *fq, 41 struct fq_flow *flow, 42 struct sk_buff *skb) 43 { 44 __fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize); 45 } 46 47 static struct sk_buff *fq_flow_dequeue(struct fq *fq, 48 struct fq_flow *flow) 49 { 50 struct sk_buff *skb; 51 52 lockdep_assert_held(&fq->lock); 53 54 skb = __skb_dequeue(&flow->queue); 55 if (!skb) 56 return NULL; 57 58 fq_adjust_removal(fq, flow, skb); 59 60 return skb; 61 } 62 63 static int fq_flow_drop(struct fq *fq, struct fq_flow *flow, 64 fq_skb_free_t free_func) 65 { 66 unsigned int packets = 0, bytes = 0, truesize = 0; 67 struct fq_tin *tin = flow->tin; 68 struct sk_buff *skb; 69 int pending; 70 71 lockdep_assert_held(&fq->lock); 72 73 pending = min_t(int, 32, skb_queue_len(&flow->queue) / 2); 74 do { 75 skb = __skb_dequeue(&flow->queue); 76 if (!skb) 77 break; 78 79 packets++; 80 bytes += skb->len; 81 truesize += skb->truesize; 82 free_func(fq, tin, flow, skb); 83 } while (packets < pending); 84 85 __fq_adjust_removal(fq, flow, packets, bytes, truesize); 86 87 return packets; 88 } 89 90 static struct sk_buff *fq_tin_dequeue(struct fq *fq, 91 struct fq_tin *tin, 92 fq_tin_dequeue_t dequeue_func) 93 { 94 struct fq_flow *flow; 95 struct list_head *head; 96 struct sk_buff *skb; 97 98 lockdep_assert_held(&fq->lock); 99 100 begin: 101 head = &tin->new_flows; 102 if (list_empty(head)) { 103 head = &tin->old_flows; 104 if (list_empty(head)) 105 return NULL; 106 } 107 108 flow = list_first_entry(head, struct fq_flow, flowchain); 109 110 if (flow->deficit <= 0) { 111 flow->deficit += fq->quantum; 112 list_move_tail(&flow->flowchain, 113 &tin->old_flows); 114 goto begin; 115 } 116 117 skb = dequeue_func(fq, tin, flow); 118 if (!skb) { 119 /* force a pass through old_flows to prevent starvation */ 120 if ((head == &tin->new_flows) && 121 !list_empty(&tin->old_flows)) { 122 list_move_tail(&flow->flowchain, &tin->old_flows); 123 } else { 124 list_del_init(&flow->flowchain); 125 flow->tin = NULL; 126 } 127 goto begin; 128 } 129 130 flow->deficit -= skb->len; 131 tin->tx_bytes += skb->len; 132 tin->tx_packets++; 133 134 return skb; 135 } 136 137 static u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb) 138 { 139 u32 hash = skb_get_hash(skb); 140 141 return reciprocal_scale(hash, fq->flows_cnt); 142 } 143 144 static struct fq_flow *fq_flow_classify(struct fq *fq, 145 struct fq_tin *tin, u32 idx, 146 struct sk_buff *skb) 147 { 148 struct fq_flow *flow; 149 150 lockdep_assert_held(&fq->lock); 151 152 flow = &fq->flows[idx]; 153 if (flow->tin && flow->tin != tin) { 154 flow = &tin->default_flow; 155 tin->collisions++; 156 fq->collisions++; 157 } 158 159 if (!flow->tin) 160 tin->flows++; 161 162 return flow; 163 } 164 165 static struct fq_flow *fq_find_fattest_flow(struct fq *fq) 166 { 167 struct fq_tin *tin; 168 struct fq_flow *flow = NULL; 169 u32 len = 0; 170 int i; 171 172 for_each_set_bit(i, fq->flows_bitmap, fq->flows_cnt) { 173 struct fq_flow *cur = &fq->flows[i]; 174 unsigned int cur_len; 175 176 cur_len = cur->backlog; 177 if (cur_len <= len) 178 continue; 179 180 flow = cur; 181 len = cur_len; 182 } 183 184 list_for_each_entry(tin, &fq->tin_backlog, tin_list) { 185 unsigned int cur_len = tin->default_flow.backlog; 186 187 if (cur_len <= len) 188 continue; 189 190 flow = &tin->default_flow; 191 len = cur_len; 192 } 193 194 return flow; 195 } 196 197 static void fq_tin_enqueue(struct fq *fq, 198 struct fq_tin *tin, u32 idx, 199 struct sk_buff *skb, 200 fq_skb_free_t free_func) 201 { 202 struct fq_flow *flow; 203 struct sk_buff *next; 204 bool oom; 205 206 lockdep_assert_held(&fq->lock); 207 208 flow = fq_flow_classify(fq, tin, idx, skb); 209 210 if (!flow->backlog) { 211 if (flow != &tin->default_flow) 212 __set_bit(idx, fq->flows_bitmap); 213 else if (list_empty(&tin->tin_list)) 214 list_add(&tin->tin_list, &fq->tin_backlog); 215 } 216 217 flow->tin = tin; 218 skb_list_walk_safe(skb, skb, next) { 219 skb_mark_not_on_list(skb); 220 flow->backlog += skb->len; 221 tin->backlog_bytes += skb->len; 222 tin->backlog_packets++; 223 fq->memory_usage += skb->truesize; 224 fq->backlog++; 225 __skb_queue_tail(&flow->queue, skb); 226 } 227 228 if (list_empty(&flow->flowchain)) { 229 flow->deficit = fq->quantum; 230 list_add_tail(&flow->flowchain, 231 &tin->new_flows); 232 } 233 234 oom = (fq->memory_usage > fq->memory_limit); 235 while (fq->backlog > fq->limit || oom) { 236 flow = fq_find_fattest_flow(fq); 237 if (!flow) 238 return; 239 240 if (!fq_flow_drop(fq, flow, free_func)) 241 return; 242 243 flow->tin->overlimit++; 244 fq->overlimit++; 245 if (oom) { 246 fq->overmemory++; 247 oom = (fq->memory_usage > fq->memory_limit); 248 } 249 } 250 } 251 252 static void fq_flow_filter(struct fq *fq, 253 struct fq_flow *flow, 254 fq_skb_filter_t filter_func, 255 void *filter_data, 256 fq_skb_free_t free_func) 257 { 258 struct fq_tin *tin = flow->tin; 259 struct sk_buff *skb, *tmp; 260 261 lockdep_assert_held(&fq->lock); 262 263 skb_queue_walk_safe(&flow->queue, skb, tmp) { 264 if (!filter_func(fq, tin, flow, skb, filter_data)) 265 continue; 266 267 __skb_unlink(skb, &flow->queue); 268 fq_adjust_removal(fq, flow, skb); 269 free_func(fq, tin, flow, skb); 270 } 271 } 272 273 static void fq_tin_filter(struct fq *fq, 274 struct fq_tin *tin, 275 fq_skb_filter_t filter_func, 276 void *filter_data, 277 fq_skb_free_t free_func) 278 { 279 struct fq_flow *flow; 280 281 lockdep_assert_held(&fq->lock); 282 283 list_for_each_entry(flow, &tin->new_flows, flowchain) 284 fq_flow_filter(fq, flow, filter_func, filter_data, free_func); 285 list_for_each_entry(flow, &tin->old_flows, flowchain) 286 fq_flow_filter(fq, flow, filter_func, filter_data, free_func); 287 } 288 289 static void fq_flow_reset(struct fq *fq, 290 struct fq_flow *flow, 291 fq_skb_free_t free_func) 292 { 293 struct fq_tin *tin = flow->tin; 294 struct sk_buff *skb; 295 296 while ((skb = fq_flow_dequeue(fq, flow))) 297 free_func(fq, tin, flow, skb); 298 299 if (!list_empty(&flow->flowchain)) { 300 list_del_init(&flow->flowchain); 301 if (list_empty(&tin->new_flows) && 302 list_empty(&tin->old_flows)) 303 list_del_init(&tin->tin_list); 304 } 305 306 flow->tin = NULL; 307 308 WARN_ON_ONCE(flow->backlog); 309 } 310 311 static void fq_tin_reset(struct fq *fq, 312 struct fq_tin *tin, 313 fq_skb_free_t free_func) 314 { 315 struct list_head *head; 316 struct fq_flow *flow; 317 318 for (;;) { 319 head = &tin->new_flows; 320 if (list_empty(head)) { 321 head = &tin->old_flows; 322 if (list_empty(head)) 323 break; 324 } 325 326 flow = list_first_entry(head, struct fq_flow, flowchain); 327 fq_flow_reset(fq, flow, free_func); 328 } 329 330 WARN_ON_ONCE(!list_empty(&tin->tin_list)); 331 WARN_ON_ONCE(tin->backlog_bytes); 332 WARN_ON_ONCE(tin->backlog_packets); 333 } 334 335 static void fq_flow_init(struct fq_flow *flow) 336 { 337 INIT_LIST_HEAD(&flow->flowchain); 338 __skb_queue_head_init(&flow->queue); 339 } 340 341 static void fq_tin_init(struct fq_tin *tin) 342 { 343 INIT_LIST_HEAD(&tin->new_flows); 344 INIT_LIST_HEAD(&tin->old_flows); 345 INIT_LIST_HEAD(&tin->tin_list); 346 fq_flow_init(&tin->default_flow); 347 } 348 349 static int fq_init(struct fq *fq, int flows_cnt) 350 { 351 int i; 352 353 memset(fq, 0, sizeof(fq[0])); 354 spin_lock_init(&fq->lock); 355 INIT_LIST_HEAD(&fq->tin_backlog); 356 fq->flows_cnt = max_t(u32, flows_cnt, 1); 357 fq->quantum = 300; 358 fq->limit = 8192; 359 fq->memory_limit = 16 << 20; /* 16 MBytes */ 360 361 fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL); 362 if (!fq->flows) 363 return -ENOMEM; 364 365 fq->flows_bitmap = bitmap_zalloc(fq->flows_cnt, GFP_KERNEL); 366 if (!fq->flows_bitmap) { 367 kvfree(fq->flows); 368 fq->flows = NULL; 369 return -ENOMEM; 370 } 371 372 for (i = 0; i < fq->flows_cnt; i++) 373 fq_flow_init(&fq->flows[i]); 374 375 return 0; 376 } 377 378 static void fq_reset(struct fq *fq, 379 fq_skb_free_t free_func) 380 { 381 int i; 382 383 for (i = 0; i < fq->flows_cnt; i++) 384 fq_flow_reset(fq, &fq->flows[i], free_func); 385 386 kvfree(fq->flows); 387 fq->flows = NULL; 388 389 bitmap_free(fq->flows_bitmap); 390 fq->flows_bitmap = NULL; 391 } 392 393 #endif 394