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8#ifndef __NET_SCHED_FQ_IMPL_H
9#define __NET_SCHED_FQ_IMPL_H
10
11#include <net/fq.h>
12
13
14
15static 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--;
32 fq->memory_usage -= skb->truesize;
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
50static 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
60begin:
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
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
97static 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
124static void fq_recalc_backlog(struct fq *fq,
125 struct fq_tin *tin,
126 struct fq_flow *flow)
127{
128 struct fq_flow *i;
129
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);
140}
141
142static 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++;
158 fq->memory_usage += skb->truesize;
159 fq->backlog++;
160
161 fq_recalc_backlog(fq, tin, flow);
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
171 if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) {
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++;
186 if (fq->memory_usage > fq->memory_limit)
187 fq->overmemory++;
188 }
189}
190
191static 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
211static 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
234static 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
241static 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
247static 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;
258 fq->memory_limit = 16 << 20;
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
270static 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
283
