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557fc4a0 MK |
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--; | |
097b065b | 32 | fq->memory_usage -= skb->truesize; |
557fc4a0 MK |
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 | ||
b43e7199 MK |
124 | static 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 | ||
557fc4a0 MK |
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; | |
557fc4a0 MK |
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++; | |
097b065b | 158 | fq->memory_usage += skb->truesize; |
557fc4a0 MK |
159 | fq->backlog++; |
160 | ||
b43e7199 | 161 | fq_recalc_backlog(fq, tin, flow); |
557fc4a0 MK |
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 | ||
097b065b | 171 | if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) { |
557fc4a0 MK |
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++; | |
097b065b THJ |
186 | if (fq->memory_usage > fq->memory_limit) |
187 | fq->overmemory++; | |
557fc4a0 MK |
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; | |
097b065b | 258 | fq->memory_limit = 16 << 20; /* 16 MBytes */ |
557fc4a0 MK |
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 |