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2504ba9f | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d4b36210 | 2 | /* Copyright (C) 2013 Cisco Systems, Inc, 2013. |
d4b36210 VS |
3 | * |
4 | * Author: Vijay Subramanian <vijaynsu@cisco.com> | |
5 | * Author: Mythili Prabhu <mysuryan@cisco.com> | |
6 | * | |
7 | * ECN support is added by Naeem Khademi <naeemk@ifi.uio.no> | |
8 | * University of Oslo, Norway. | |
219e288e VS |
9 | * |
10 | * References: | |
24ed4900 | 11 | * RFC 8033: https://tools.ietf.org/html/rfc8033 |
d4b36210 VS |
12 | */ |
13 | ||
14 | #include <linux/module.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/types.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/skbuff.h> | |
20 | #include <net/pkt_sched.h> | |
21 | #include <net/inet_ecn.h> | |
22 | ||
57509003 | 23 | #define QUEUE_THRESHOLD 16384 |
d4b36210 | 24 | #define DQCOUNT_INVALID -1 |
3f7ae5f3 | 25 | #define MAX_PROB 0xffffffffffffffff |
d4b36210 VS |
26 | #define PIE_SCALE 8 |
27 | ||
28 | /* parameters used */ | |
29 | struct pie_params { | |
30 | psched_time_t target; /* user specified target delay in pschedtime */ | |
31 | u32 tupdate; /* timer frequency (in jiffies) */ | |
32 | u32 limit; /* number of packets that can be enqueued */ | |
219e288e | 33 | u32 alpha; /* alpha and beta are between 0 and 32 */ |
d4b36210 VS |
34 | u32 beta; /* and are used for shift relative to 1 */ |
35 | bool ecn; /* true if ecn is enabled */ | |
36 | bool bytemode; /* to scale drop early prob based on pkt size */ | |
37 | }; | |
38 | ||
39 | /* variables used */ | |
40 | struct pie_vars { | |
3f7ae5f3 | 41 | u64 prob; /* probability but scaled by u64 limit. */ |
d4b36210 VS |
42 | psched_time_t burst_time; |
43 | psched_time_t qdelay; | |
44 | psched_time_t qdelay_old; | |
45 | u64 dq_count; /* measured in bytes */ | |
46 | psched_time_t dq_tstamp; /* drain rate */ | |
95400b97 | 47 | u64 accu_prob; /* accumulated drop probability */ |
d4b36210 VS |
48 | u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */ |
49 | u32 qlen_old; /* in bytes */ | |
95400b97 | 50 | u8 accu_prob_overflows; /* overflows of accu_prob */ |
d4b36210 VS |
51 | }; |
52 | ||
53 | /* statistics gathering */ | |
54 | struct pie_stats { | |
55 | u32 packets_in; /* total number of packets enqueued */ | |
56 | u32 dropped; /* packets dropped due to pie_action */ | |
57 | u32 overlimit; /* dropped due to lack of space in queue */ | |
58 | u32 maxq; /* maximum queue size */ | |
59 | u32 ecn_mark; /* packets marked with ECN */ | |
60 | }; | |
61 | ||
62 | /* private data for the Qdisc */ | |
63 | struct pie_sched_data { | |
64 | struct pie_params params; | |
65 | struct pie_vars vars; | |
66 | struct pie_stats stats; | |
67 | struct timer_list adapt_timer; | |
cdeabbb8 | 68 | struct Qdisc *sch; |
d4b36210 VS |
69 | }; |
70 | ||
71 | static void pie_params_init(struct pie_params *params) | |
72 | { | |
73 | params->alpha = 2; | |
74 | params->beta = 20; | |
29daa855 | 75 | params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */ |
d4b36210 | 76 | params->limit = 1000; /* default of 1000 packets */ |
abde7920 | 77 | params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */ |
d4b36210 VS |
78 | params->ecn = false; |
79 | params->bytemode = false; | |
80 | } | |
81 | ||
82 | static void pie_vars_init(struct pie_vars *vars) | |
83 | { | |
84 | vars->dq_count = DQCOUNT_INVALID; | |
95400b97 | 85 | vars->accu_prob = 0; |
d4b36210 | 86 | vars->avg_dq_rate = 0; |
30a92ad7 MT |
87 | /* default of 150 ms in pschedtime */ |
88 | vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC); | |
95400b97 | 89 | vars->accu_prob_overflows = 0; |
d4b36210 VS |
90 | } |
91 | ||
92 | static bool drop_early(struct Qdisc *sch, u32 packet_size) | |
93 | { | |
94 | struct pie_sched_data *q = qdisc_priv(sch); | |
3f7ae5f3 MT |
95 | u64 rnd; |
96 | u64 local_prob = q->vars.prob; | |
d4b36210 VS |
97 | u32 mtu = psched_mtu(qdisc_dev(sch)); |
98 | ||
99 | /* If there is still burst allowance left skip random early drop */ | |
100 | if (q->vars.burst_time > 0) | |
101 | return false; | |
102 | ||
103 | /* If current delay is less than half of target, and | |
104 | * if drop prob is low already, disable early_drop | |
105 | */ | |
ac4a02c5 LM |
106 | if ((q->vars.qdelay < q->params.target / 2) && |
107 | (q->vars.prob < MAX_PROB / 5)) | |
d4b36210 VS |
108 | return false; |
109 | ||
110 | /* If we have fewer than 2 mtu-sized packets, disable drop_early, | |
111 | * similar to min_th in RED | |
112 | */ | |
113 | if (sch->qstats.backlog < 2 * mtu) | |
114 | return false; | |
115 | ||
116 | /* If bytemode is turned on, use packet size to compute new | |
117 | * probablity. Smaller packets will have lower drop prob in this case | |
118 | */ | |
119 | if (q->params.bytemode && packet_size <= mtu) | |
3f7ae5f3 | 120 | local_prob = (u64)packet_size * div_u64(local_prob, mtu); |
d4b36210 VS |
121 | else |
122 | local_prob = q->vars.prob; | |
123 | ||
95400b97 MT |
124 | if (local_prob == 0) { |
125 | q->vars.accu_prob = 0; | |
126 | q->vars.accu_prob_overflows = 0; | |
127 | } | |
128 | ||
129 | if (local_prob > MAX_PROB - q->vars.accu_prob) | |
130 | q->vars.accu_prob_overflows++; | |
131 | ||
132 | q->vars.accu_prob += local_prob; | |
133 | ||
134 | if (q->vars.accu_prob_overflows == 0 && | |
135 | q->vars.accu_prob < (MAX_PROB / 100) * 85) | |
136 | return false; | |
137 | if (q->vars.accu_prob_overflows == 8 && | |
138 | q->vars.accu_prob >= MAX_PROB / 2) | |
139 | return true; | |
140 | ||
3f7ae5f3 | 141 | prandom_bytes(&rnd, 8); |
95400b97 MT |
142 | if (rnd < local_prob) { |
143 | q->vars.accu_prob = 0; | |
144 | q->vars.accu_prob_overflows = 0; | |
d4b36210 | 145 | return true; |
95400b97 | 146 | } |
d4b36210 VS |
147 | |
148 | return false; | |
149 | } | |
150 | ||
520ac30f ED |
151 | static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, |
152 | struct sk_buff **to_free) | |
d4b36210 VS |
153 | { |
154 | struct pie_sched_data *q = qdisc_priv(sch); | |
155 | bool enqueue = false; | |
156 | ||
157 | if (unlikely(qdisc_qlen(sch) >= sch->limit)) { | |
158 | q->stats.overlimit++; | |
159 | goto out; | |
160 | } | |
161 | ||
162 | if (!drop_early(sch, skb->len)) { | |
163 | enqueue = true; | |
164 | } else if (q->params.ecn && (q->vars.prob <= MAX_PROB / 10) && | |
165 | INET_ECN_set_ce(skb)) { | |
166 | /* If packet is ecn capable, mark it if drop probability | |
167 | * is lower than 10%, else drop it. | |
168 | */ | |
169 | q->stats.ecn_mark++; | |
170 | enqueue = true; | |
171 | } | |
172 | ||
173 | /* we can enqueue the packet */ | |
174 | if (enqueue) { | |
175 | q->stats.packets_in++; | |
176 | if (qdisc_qlen(sch) > q->stats.maxq) | |
177 | q->stats.maxq = qdisc_qlen(sch); | |
178 | ||
179 | return qdisc_enqueue_tail(skb, sch); | |
180 | } | |
181 | ||
182 | out: | |
183 | q->stats.dropped++; | |
95400b97 MT |
184 | q->vars.accu_prob = 0; |
185 | q->vars.accu_prob_overflows = 0; | |
520ac30f | 186 | return qdisc_drop(skb, sch, to_free); |
d4b36210 VS |
187 | } |
188 | ||
189 | static const struct nla_policy pie_policy[TCA_PIE_MAX + 1] = { | |
190 | [TCA_PIE_TARGET] = {.type = NLA_U32}, | |
191 | [TCA_PIE_LIMIT] = {.type = NLA_U32}, | |
192 | [TCA_PIE_TUPDATE] = {.type = NLA_U32}, | |
193 | [TCA_PIE_ALPHA] = {.type = NLA_U32}, | |
194 | [TCA_PIE_BETA] = {.type = NLA_U32}, | |
195 | [TCA_PIE_ECN] = {.type = NLA_U32}, | |
196 | [TCA_PIE_BYTEMODE] = {.type = NLA_U32}, | |
197 | }; | |
198 | ||
2030721c AA |
199 | static int pie_change(struct Qdisc *sch, struct nlattr *opt, |
200 | struct netlink_ext_ack *extack) | |
d4b36210 VS |
201 | { |
202 | struct pie_sched_data *q = qdisc_priv(sch); | |
203 | struct nlattr *tb[TCA_PIE_MAX + 1]; | |
2ccccf5f | 204 | unsigned int qlen, dropped = 0; |
d4b36210 VS |
205 | int err; |
206 | ||
207 | if (!opt) | |
208 | return -EINVAL; | |
209 | ||
8cb08174 JB |
210 | err = nla_parse_nested_deprecated(tb, TCA_PIE_MAX, opt, pie_policy, |
211 | NULL); | |
d4b36210 VS |
212 | if (err < 0) |
213 | return err; | |
214 | ||
215 | sch_tree_lock(sch); | |
216 | ||
217 | /* convert from microseconds to pschedtime */ | |
218 | if (tb[TCA_PIE_TARGET]) { | |
219 | /* target is in us */ | |
220 | u32 target = nla_get_u32(tb[TCA_PIE_TARGET]); | |
221 | ||
222 | /* convert to pschedtime */ | |
223 | q->params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC); | |
224 | } | |
225 | ||
226 | /* tupdate is in jiffies */ | |
227 | if (tb[TCA_PIE_TUPDATE]) | |
ac4a02c5 LM |
228 | q->params.tupdate = |
229 | usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE])); | |
d4b36210 VS |
230 | |
231 | if (tb[TCA_PIE_LIMIT]) { | |
232 | u32 limit = nla_get_u32(tb[TCA_PIE_LIMIT]); | |
233 | ||
234 | q->params.limit = limit; | |
235 | sch->limit = limit; | |
236 | } | |
237 | ||
238 | if (tb[TCA_PIE_ALPHA]) | |
239 | q->params.alpha = nla_get_u32(tb[TCA_PIE_ALPHA]); | |
240 | ||
241 | if (tb[TCA_PIE_BETA]) | |
242 | q->params.beta = nla_get_u32(tb[TCA_PIE_BETA]); | |
243 | ||
244 | if (tb[TCA_PIE_ECN]) | |
245 | q->params.ecn = nla_get_u32(tb[TCA_PIE_ECN]); | |
246 | ||
247 | if (tb[TCA_PIE_BYTEMODE]) | |
248 | q->params.bytemode = nla_get_u32(tb[TCA_PIE_BYTEMODE]); | |
249 | ||
250 | /* Drop excess packets if new limit is lower */ | |
251 | qlen = sch->q.qlen; | |
252 | while (sch->q.qlen > sch->limit) { | |
ed760cb8 | 253 | struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); |
d4b36210 | 254 | |
2ccccf5f | 255 | dropped += qdisc_pkt_len(skb); |
25331d6c | 256 | qdisc_qstats_backlog_dec(sch, skb); |
db4879d9 | 257 | rtnl_qdisc_drop(skb, sch); |
d4b36210 | 258 | } |
2ccccf5f | 259 | qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped); |
d4b36210 VS |
260 | |
261 | sch_tree_unlock(sch); | |
262 | return 0; | |
263 | } | |
264 | ||
265 | static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) | |
266 | { | |
d4b36210 VS |
267 | struct pie_sched_data *q = qdisc_priv(sch); |
268 | int qlen = sch->qstats.backlog; /* current queue size in bytes */ | |
269 | ||
270 | /* If current queue is about 10 packets or more and dq_count is unset | |
271 | * we have enough packets to calculate the drain rate. Save | |
272 | * current time as dq_tstamp and start measurement cycle. | |
273 | */ | |
274 | if (qlen >= QUEUE_THRESHOLD && q->vars.dq_count == DQCOUNT_INVALID) { | |
275 | q->vars.dq_tstamp = psched_get_time(); | |
276 | q->vars.dq_count = 0; | |
277 | } | |
278 | ||
279 | /* Calculate the average drain rate from this value. If queue length | |
280 | * has receded to a small value viz., <= QUEUE_THRESHOLD bytes,reset | |
281 | * the dq_count to -1 as we don't have enough packets to calculate the | |
282 | * drain rate anymore The following if block is entered only when we | |
283 | * have a substantial queue built up (QUEUE_THRESHOLD bytes or more) | |
284 | * and we calculate the drain rate for the threshold here. dq_count is | |
285 | * in bytes, time difference in psched_time, hence rate is in | |
286 | * bytes/psched_time. | |
287 | */ | |
288 | if (q->vars.dq_count != DQCOUNT_INVALID) { | |
289 | q->vars.dq_count += skb->len; | |
290 | ||
291 | if (q->vars.dq_count >= QUEUE_THRESHOLD) { | |
292 | psched_time_t now = psched_get_time(); | |
293 | u32 dtime = now - q->vars.dq_tstamp; | |
294 | u32 count = q->vars.dq_count << PIE_SCALE; | |
295 | ||
296 | if (dtime == 0) | |
297 | return; | |
298 | ||
299 | count = count / dtime; | |
300 | ||
301 | if (q->vars.avg_dq_rate == 0) | |
302 | q->vars.avg_dq_rate = count; | |
303 | else | |
304 | q->vars.avg_dq_rate = | |
305 | (q->vars.avg_dq_rate - | |
306 | (q->vars.avg_dq_rate >> 3)) + (count >> 3); | |
307 | ||
308 | /* If the queue has receded below the threshold, we hold | |
309 | * on to the last drain rate calculated, else we reset | |
310 | * dq_count to 0 to re-enter the if block when the next | |
311 | * packet is dequeued | |
312 | */ | |
ac4a02c5 | 313 | if (qlen < QUEUE_THRESHOLD) { |
d4b36210 | 314 | q->vars.dq_count = DQCOUNT_INVALID; |
ac4a02c5 | 315 | } else { |
d4b36210 VS |
316 | q->vars.dq_count = 0; |
317 | q->vars.dq_tstamp = psched_get_time(); | |
318 | } | |
319 | ||
320 | if (q->vars.burst_time > 0) { | |
321 | if (q->vars.burst_time > dtime) | |
322 | q->vars.burst_time -= dtime; | |
323 | else | |
324 | q->vars.burst_time = 0; | |
325 | } | |
326 | } | |
327 | } | |
328 | } | |
329 | ||
330 | static void calculate_probability(struct Qdisc *sch) | |
331 | { | |
332 | struct pie_sched_data *q = qdisc_priv(sch); | |
333 | u32 qlen = sch->qstats.backlog; /* queue size in bytes */ | |
334 | psched_time_t qdelay = 0; /* in pschedtime */ | |
335 | psched_time_t qdelay_old = q->vars.qdelay; /* in pschedtime */ | |
3f7ae5f3 MT |
336 | s64 delta = 0; /* determines the change in probability */ |
337 | u64 oldprob; | |
338 | u64 alpha, beta; | |
339 | u32 power; | |
d4b36210 VS |
340 | bool update_prob = true; |
341 | ||
342 | q->vars.qdelay_old = q->vars.qdelay; | |
343 | ||
344 | if (q->vars.avg_dq_rate > 0) | |
345 | qdelay = (qlen << PIE_SCALE) / q->vars.avg_dq_rate; | |
346 | else | |
347 | qdelay = 0; | |
348 | ||
349 | /* If qdelay is zero and qlen is not, it means qlen is very small, less | |
350 | * than dequeue_rate, so we do not update probabilty in this round | |
351 | */ | |
352 | if (qdelay == 0 && qlen != 0) | |
353 | update_prob = false; | |
354 | ||
219e288e VS |
355 | /* In the algorithm, alpha and beta are between 0 and 2 with typical |
356 | * value for alpha as 0.125. In this implementation, we use values 0-32 | |
357 | * passed from user space to represent this. Also, alpha and beta have | |
358 | * unit of HZ and need to be scaled before they can used to update | |
3f7ae5f3 MT |
359 | * probability. alpha/beta are updated locally below by scaling down |
360 | * by 16 to come to 0-2 range. | |
d4b36210 | 361 | */ |
3f7ae5f3 MT |
362 | alpha = ((u64)q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; |
363 | beta = ((u64)q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; | |
364 | ||
365 | /* We scale alpha and beta differently depending on how heavy the | |
366 | * congestion is. Please see RFC 8033 for details. | |
367 | */ | |
368 | if (q->vars.prob < MAX_PROB / 10) { | |
369 | alpha >>= 1; | |
370 | beta >>= 1; | |
371 | ||
372 | power = 100; | |
373 | while (q->vars.prob < div_u64(MAX_PROB, power) && | |
374 | power <= 1000000) { | |
375 | alpha >>= 2; | |
376 | beta >>= 2; | |
377 | power *= 10; | |
378 | } | |
d4b36210 VS |
379 | } |
380 | ||
381 | /* alpha and beta should be between 0 and 32, in multiples of 1/16 */ | |
3f7ae5f3 MT |
382 | delta += alpha * (u64)(qdelay - q->params.target); |
383 | delta += beta * (u64)(qdelay - qdelay_old); | |
d4b36210 VS |
384 | |
385 | oldprob = q->vars.prob; | |
386 | ||
387 | /* to ensure we increase probability in steps of no more than 2% */ | |
3f7ae5f3 | 388 | if (delta > (s64)(MAX_PROB / (100 / 2)) && |
d4b36210 VS |
389 | q->vars.prob >= MAX_PROB / 10) |
390 | delta = (MAX_PROB / 100) * 2; | |
391 | ||
392 | /* Non-linear drop: | |
393 | * Tune drop probability to increase quickly for high delays(>= 250ms) | |
394 | * 250ms is derived through experiments and provides error protection | |
395 | */ | |
396 | ||
397 | if (qdelay > (PSCHED_NS2TICKS(250 * NSEC_PER_MSEC))) | |
398 | delta += MAX_PROB / (100 / 2); | |
399 | ||
400 | q->vars.prob += delta; | |
401 | ||
402 | if (delta > 0) { | |
403 | /* prevent overflow */ | |
404 | if (q->vars.prob < oldprob) { | |
405 | q->vars.prob = MAX_PROB; | |
406 | /* Prevent normalization error. If probability is at | |
407 | * maximum value already, we normalize it here, and | |
408 | * skip the check to do a non-linear drop in the next | |
409 | * section. | |
410 | */ | |
411 | update_prob = false; | |
412 | } | |
413 | } else { | |
414 | /* prevent underflow */ | |
415 | if (q->vars.prob > oldprob) | |
416 | q->vars.prob = 0; | |
417 | } | |
418 | ||
419 | /* Non-linear drop in probability: Reduce drop probability quickly if | |
420 | * delay is 0 for 2 consecutive Tupdate periods. | |
421 | */ | |
422 | ||
ac4a02c5 | 423 | if (qdelay == 0 && qdelay_old == 0 && update_prob) |
6c97da14 LM |
424 | /* Reduce drop probability to 98.4% */ |
425 | q->vars.prob -= q->vars.prob / 64u; | |
d4b36210 VS |
426 | |
427 | q->vars.qdelay = qdelay; | |
428 | q->vars.qlen_old = qlen; | |
429 | ||
430 | /* We restart the measurement cycle if the following conditions are met | |
431 | * 1. If the delay has been low for 2 consecutive Tupdate periods | |
432 | * 2. Calculated drop probability is zero | |
433 | * 3. We have atleast one estimate for the avg_dq_rate ie., | |
434 | * is a non-zero value | |
435 | */ | |
436 | if ((q->vars.qdelay < q->params.target / 2) && | |
437 | (q->vars.qdelay_old < q->params.target / 2) && | |
ac4a02c5 LM |
438 | q->vars.prob == 0 && |
439 | q->vars.avg_dq_rate > 0) | |
d4b36210 VS |
440 | pie_vars_init(&q->vars); |
441 | } | |
442 | ||
cdeabbb8 | 443 | static void pie_timer(struct timer_list *t) |
d4b36210 | 444 | { |
cdeabbb8 KC |
445 | struct pie_sched_data *q = from_timer(q, t, adapt_timer); |
446 | struct Qdisc *sch = q->sch; | |
d4b36210 VS |
447 | spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); |
448 | ||
449 | spin_lock(root_lock); | |
450 | calculate_probability(sch); | |
451 | ||
452 | /* reset the timer to fire after 'tupdate'. tupdate is in jiffies. */ | |
453 | if (q->params.tupdate) | |
454 | mod_timer(&q->adapt_timer, jiffies + q->params.tupdate); | |
455 | spin_unlock(root_lock); | |
d4b36210 VS |
456 | } |
457 | ||
e63d7dfd AA |
458 | static int pie_init(struct Qdisc *sch, struct nlattr *opt, |
459 | struct netlink_ext_ack *extack) | |
d4b36210 VS |
460 | { |
461 | struct pie_sched_data *q = qdisc_priv(sch); | |
462 | ||
463 | pie_params_init(&q->params); | |
464 | pie_vars_init(&q->vars); | |
465 | sch->limit = q->params.limit; | |
466 | ||
cdeabbb8 KC |
467 | q->sch = sch; |
468 | timer_setup(&q->adapt_timer, pie_timer, 0); | |
d4b36210 VS |
469 | |
470 | if (opt) { | |
2030721c | 471 | int err = pie_change(sch, opt, extack); |
d4b36210 VS |
472 | |
473 | if (err) | |
474 | return err; | |
475 | } | |
476 | ||
d5610902 | 477 | mod_timer(&q->adapt_timer, jiffies + HZ / 2); |
d4b36210 VS |
478 | return 0; |
479 | } | |
480 | ||
481 | static int pie_dump(struct Qdisc *sch, struct sk_buff *skb) | |
482 | { | |
483 | struct pie_sched_data *q = qdisc_priv(sch); | |
484 | struct nlattr *opts; | |
485 | ||
ae0be8de | 486 | opts = nla_nest_start_noflag(skb, TCA_OPTIONS); |
ac4a02c5 | 487 | if (!opts) |
d4b36210 VS |
488 | goto nla_put_failure; |
489 | ||
490 | /* convert target from pschedtime to us */ | |
491 | if (nla_put_u32(skb, TCA_PIE_TARGET, | |
ac4a02c5 | 492 | ((u32)PSCHED_TICKS2NS(q->params.target)) / |
d4b36210 VS |
493 | NSEC_PER_USEC) || |
494 | nla_put_u32(skb, TCA_PIE_LIMIT, sch->limit) || | |
ac4a02c5 LM |
495 | nla_put_u32(skb, TCA_PIE_TUPDATE, |
496 | jiffies_to_usecs(q->params.tupdate)) || | |
d4b36210 VS |
497 | nla_put_u32(skb, TCA_PIE_ALPHA, q->params.alpha) || |
498 | nla_put_u32(skb, TCA_PIE_BETA, q->params.beta) || | |
499 | nla_put_u32(skb, TCA_PIE_ECN, q->params.ecn) || | |
500 | nla_put_u32(skb, TCA_PIE_BYTEMODE, q->params.bytemode)) | |
501 | goto nla_put_failure; | |
502 | ||
503 | return nla_nest_end(skb, opts); | |
504 | ||
505 | nla_put_failure: | |
506 | nla_nest_cancel(skb, opts); | |
507 | return -1; | |
d4b36210 VS |
508 | } |
509 | ||
510 | static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d) | |
511 | { | |
512 | struct pie_sched_data *q = qdisc_priv(sch); | |
513 | struct tc_pie_xstats st = { | |
514 | .prob = q->vars.prob, | |
ac4a02c5 | 515 | .delay = ((u32)PSCHED_TICKS2NS(q->vars.qdelay)) / |
d4b36210 VS |
516 | NSEC_PER_USEC, |
517 | /* unscale and return dq_rate in bytes per sec */ | |
518 | .avg_dq_rate = q->vars.avg_dq_rate * | |
519 | (PSCHED_TICKS_PER_SEC) >> PIE_SCALE, | |
520 | .packets_in = q->stats.packets_in, | |
521 | .overlimit = q->stats.overlimit, | |
522 | .maxq = q->stats.maxq, | |
523 | .dropped = q->stats.dropped, | |
524 | .ecn_mark = q->stats.ecn_mark, | |
525 | }; | |
526 | ||
527 | return gnet_stats_copy_app(d, &st, sizeof(st)); | |
528 | } | |
529 | ||
530 | static struct sk_buff *pie_qdisc_dequeue(struct Qdisc *sch) | |
531 | { | |
ac4a02c5 | 532 | struct sk_buff *skb = qdisc_dequeue_head(sch); |
d4b36210 VS |
533 | |
534 | if (!skb) | |
535 | return NULL; | |
536 | ||
537 | pie_process_dequeue(sch, skb); | |
538 | return skb; | |
539 | } | |
540 | ||
541 | static void pie_reset(struct Qdisc *sch) | |
542 | { | |
543 | struct pie_sched_data *q = qdisc_priv(sch); | |
ac4a02c5 | 544 | |
d4b36210 VS |
545 | qdisc_reset_queue(sch); |
546 | pie_vars_init(&q->vars); | |
547 | } | |
548 | ||
549 | static void pie_destroy(struct Qdisc *sch) | |
550 | { | |
551 | struct pie_sched_data *q = qdisc_priv(sch); | |
ac4a02c5 | 552 | |
d4b36210 VS |
553 | q->params.tupdate = 0; |
554 | del_timer_sync(&q->adapt_timer); | |
555 | } | |
556 | ||
557 | static struct Qdisc_ops pie_qdisc_ops __read_mostly = { | |
558 | .id = "pie", | |
559 | .priv_size = sizeof(struct pie_sched_data), | |
560 | .enqueue = pie_qdisc_enqueue, | |
561 | .dequeue = pie_qdisc_dequeue, | |
562 | .peek = qdisc_peek_dequeued, | |
563 | .init = pie_init, | |
564 | .destroy = pie_destroy, | |
565 | .reset = pie_reset, | |
566 | .change = pie_change, | |
567 | .dump = pie_dump, | |
568 | .dump_stats = pie_dump_stats, | |
569 | .owner = THIS_MODULE, | |
570 | }; | |
571 | ||
572 | static int __init pie_module_init(void) | |
573 | { | |
574 | return register_qdisc(&pie_qdisc_ops); | |
575 | } | |
576 | ||
577 | static void __exit pie_module_exit(void) | |
578 | { | |
579 | unregister_qdisc(&pie_qdisc_ops); | |
580 | } | |
581 | ||
582 | module_init(pie_module_init); | |
583 | module_exit(pie_module_exit); | |
584 | ||
585 | MODULE_DESCRIPTION("Proportional Integral controller Enhanced (PIE) scheduler"); | |
586 | MODULE_AUTHOR("Vijay Subramanian"); | |
587 | MODULE_AUTHOR("Mythili Prabhu"); | |
588 | MODULE_LICENSE("GPL"); |