2 * Copyright (c) 2016 Qualcomm Atheros, Inc
6 * Based on net/sched/sch_fq_codel.c
8 #ifndef __NET_SCHED_FQ_IMPL_H
9 #define __NET_SCHED_FQ_IMPL_H
13 /* functions that are embedded into includer */
15 static void fq_adjust_removal(struct fq *fq,
19 struct fq_tin *tin = flow->tin;
21 tin->backlog_bytes -= skb->len;
22 tin->backlog_packets--;
23 flow->backlog -= skb->len;
25 fq->memory_usage -= skb->truesize;
28 static void fq_rejigger_backlog(struct fq *fq, struct fq_flow *flow)
32 if (flow->backlog == 0) {
33 list_del_init(&flow->backlogchain);
37 list_for_each_entry_continue(i, &fq->backlogs, backlogchain)
38 if (i->backlog < flow->backlog)
41 list_move_tail(&flow->backlogchain,
46 static struct sk_buff *fq_flow_dequeue(struct fq *fq,
51 lockdep_assert_held(&fq->lock);
53 skb = __skb_dequeue(&flow->queue);
57 fq_adjust_removal(fq, flow, skb);
58 fq_rejigger_backlog(fq, flow);
63 static struct sk_buff *fq_tin_dequeue(struct fq *fq,
65 fq_tin_dequeue_t dequeue_func)
68 struct list_head *head;
71 lockdep_assert_held(&fq->lock);
74 head = &tin->new_flows;
75 if (list_empty(head)) {
76 head = &tin->old_flows;
81 flow = list_first_entry(head, struct fq_flow, flowchain);
83 if (flow->deficit <= 0) {
84 flow->deficit += fq->quantum;
85 list_move_tail(&flow->flowchain,
90 skb = dequeue_func(fq, tin, flow);
92 /* force a pass through old_flows to prevent starvation */
93 if ((head == &tin->new_flows) &&
94 !list_empty(&tin->old_flows)) {
95 list_move_tail(&flow->flowchain, &tin->old_flows);
97 list_del_init(&flow->flowchain);
103 flow->deficit -= skb->len;
104 tin->tx_bytes += skb->len;
110 static u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb)
112 u32 hash = skb_get_hash_perturb(skb, fq->perturbation);
114 return reciprocal_scale(hash, fq->flows_cnt);
117 static struct fq_flow *fq_flow_classify(struct fq *fq,
118 struct fq_tin *tin, u32 idx,
120 fq_flow_get_default_t get_default_func)
122 struct fq_flow *flow;
124 lockdep_assert_held(&fq->lock);
126 flow = &fq->flows[idx];
127 if (flow->tin && flow->tin != tin) {
128 flow = get_default_func(fq, tin, idx, skb);
139 static void fq_recalc_backlog(struct fq *fq,
141 struct fq_flow *flow)
145 if (list_empty(&flow->backlogchain))
146 list_add_tail(&flow->backlogchain, &fq->backlogs);
149 list_for_each_entry_continue_reverse(i, &fq->backlogs,
151 if (i->backlog > flow->backlog)
154 list_move(&flow->backlogchain, &i->backlogchain);
157 static void fq_tin_enqueue(struct fq *fq,
158 struct fq_tin *tin, u32 idx,
160 fq_skb_free_t free_func,
161 fq_flow_get_default_t get_default_func)
163 struct fq_flow *flow;
166 lockdep_assert_held(&fq->lock);
168 flow = fq_flow_classify(fq, tin, idx, skb, get_default_func);
171 flow->backlog += skb->len;
172 tin->backlog_bytes += skb->len;
173 tin->backlog_packets++;
174 fq->memory_usage += skb->truesize;
177 fq_recalc_backlog(fq, tin, flow);
179 if (list_empty(&flow->flowchain)) {
180 flow->deficit = fq->quantum;
181 list_add_tail(&flow->flowchain,
185 __skb_queue_tail(&flow->queue, skb);
186 oom = (fq->memory_usage > fq->memory_limit);
187 while (fq->backlog > fq->limit || oom) {
188 flow = list_first_entry_or_null(&fq->backlogs,
194 skb = fq_flow_dequeue(fq, flow);
198 free_func(fq, flow->tin, flow, skb);
200 flow->tin->overlimit++;
204 oom = (fq->memory_usage > fq->memory_limit);
209 static void fq_flow_filter(struct fq *fq,
210 struct fq_flow *flow,
211 fq_skb_filter_t filter_func,
213 fq_skb_free_t free_func)
215 struct fq_tin *tin = flow->tin;
216 struct sk_buff *skb, *tmp;
218 lockdep_assert_held(&fq->lock);
220 skb_queue_walk_safe(&flow->queue, skb, tmp) {
221 if (!filter_func(fq, tin, flow, skb, filter_data))
224 __skb_unlink(skb, &flow->queue);
225 fq_adjust_removal(fq, flow, skb);
226 free_func(fq, tin, flow, skb);
229 fq_rejigger_backlog(fq, flow);
232 static void fq_tin_filter(struct fq *fq,
234 fq_skb_filter_t filter_func,
236 fq_skb_free_t free_func)
238 struct fq_flow *flow;
240 lockdep_assert_held(&fq->lock);
242 list_for_each_entry(flow, &tin->new_flows, flowchain)
243 fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
244 list_for_each_entry(flow, &tin->old_flows, flowchain)
245 fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
248 static void fq_flow_reset(struct fq *fq,
249 struct fq_flow *flow,
250 fq_skb_free_t free_func)
254 while ((skb = fq_flow_dequeue(fq, flow)))
255 free_func(fq, flow->tin, flow, skb);
257 if (!list_empty(&flow->flowchain))
258 list_del_init(&flow->flowchain);
260 if (!list_empty(&flow->backlogchain))
261 list_del_init(&flow->backlogchain);
265 WARN_ON_ONCE(flow->backlog);
268 static void fq_tin_reset(struct fq *fq,
270 fq_skb_free_t free_func)
272 struct list_head *head;
273 struct fq_flow *flow;
276 head = &tin->new_flows;
277 if (list_empty(head)) {
278 head = &tin->old_flows;
279 if (list_empty(head))
283 flow = list_first_entry(head, struct fq_flow, flowchain);
284 fq_flow_reset(fq, flow, free_func);
287 WARN_ON_ONCE(tin->backlog_bytes);
288 WARN_ON_ONCE(tin->backlog_packets);
291 static void fq_flow_init(struct fq_flow *flow)
293 INIT_LIST_HEAD(&flow->flowchain);
294 INIT_LIST_HEAD(&flow->backlogchain);
295 __skb_queue_head_init(&flow->queue);
298 static void fq_tin_init(struct fq_tin *tin)
300 INIT_LIST_HEAD(&tin->new_flows);
301 INIT_LIST_HEAD(&tin->old_flows);
304 static int fq_init(struct fq *fq, int flows_cnt)
308 memset(fq, 0, sizeof(fq[0]));
309 INIT_LIST_HEAD(&fq->backlogs);
310 spin_lock_init(&fq->lock);
311 fq->flows_cnt = max_t(u32, flows_cnt, 1);
312 fq->perturbation = prandom_u32();
315 fq->memory_limit = 16 << 20; /* 16 MBytes */
317 fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
321 for (i = 0; i < fq->flows_cnt; i++)
322 fq_flow_init(&fq->flows[i]);
327 static void fq_reset(struct fq *fq,
328 fq_skb_free_t free_func)
332 for (i = 0; i < fq->flows_cnt; i++)
333 fq_flow_reset(fq, &fq->flows[i], free_func);