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[PKT_SCHED]: GRED: Cleanup equalize flag and add new WRED mode detection
[linux-2.6/btrfs-unstable.git] / net / sched / sch_gred.c
blob4ced47bf60890f1713f8b78906534eb513570062
1 /*
2 * net/sched/sch_gred.c Generic Random Early Detection queue.
3 *
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 *
10 * Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002
11 *
12 * 991129: - Bug fix with grio mode
13 * - a better sing. AvgQ mode with Grio(WRED)
14 * - A finer grained VQ dequeue based on sugestion
15 * from Ren Liu
16 * - More error checks
17 *
18 *
19 *
20 * For all the glorious comments look at Alexey's sch_red.c
21 */
22
23 #include <linux/config.h>
24 #include <linux/module.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/bitops.h>
28 #include <linux/types.h>
29 #include <linux/kernel.h>
30 #include <linux/sched.h>
31 #include <linux/string.h>
32 #include <linux/mm.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/in.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/if_ether.h>
39 #include <linux/inet.h>
40 #include <linux/netdevice.h>
41 #include <linux/etherdevice.h>
42 #include <linux/notifier.h>
43 #include <net/ip.h>
44 #include <net/route.h>
45 #include <linux/skbuff.h>
46 #include <net/sock.h>
47 #include <net/pkt_sched.h>
48
49 #if 1 /* control */
50 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
51 #else
52 #define DPRINTK(format,args...)
53 #endif
54
55 #if 0 /* data */
56 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
57 #else
58 #define D2PRINTK(format,args...)
59 #endif
60
61 struct gred_sched_data;
62 struct gred_sched;
63
64 struct gred_sched_data
65 {
66 /* Parameters */
67 u32 limit; /* HARD maximal queue length */
68 u32 qth_min; /* Min average length threshold: A scaled */
69 u32 qth_max; /* Max average length threshold: A scaled */
70 u32 DP; /* the drop pramaters */
71 char Wlog; /* log(W) */
72 char Plog; /* random number bits */
73 u32 Scell_max;
74 u32 Rmask;
75 u32 bytesin; /* bytes seen on virtualQ so far*/
76 u32 packetsin; /* packets seen on virtualQ so far*/
77 u32 backlog; /* bytes on the virtualQ */
78 u32 forced; /* packets dropped for exceeding limits */
79 u32 early; /* packets dropped as a warning */
80 u32 other; /* packets dropped by invoking drop() */
81 u32 pdrop; /* packets dropped because we exceeded physical queue limits */
82 char Scell_log;
83 u8 Stab[256];
84 u8 prio; /* the prio of this vq */
85
86 /* Variables */
87 unsigned long qave; /* Average queue length: A scaled */
88 int qcount; /* Packets since last random number generation */
89 u32 qR; /* Cached random number */
90
91 psched_time_t qidlestart; /* Start of idle period */
92 };
93
94 enum {
95 GRED_WRED_MODE = 1,
96 };
97
98 struct gred_sched
99 {
100 struct gred_sched_data *tab[MAX_DPs];
101 unsigned long flags;
102 u32 DPs;
103 u32 def;
104 u8 initd;
105 u8 grio;
106 };
107
108 static inline int gred_wred_mode(struct gred_sched *table)
109 {
110 return test_bit(GRED_WRED_MODE, &table->flags);
111 }
112
113 static inline void gred_enable_wred_mode(struct gred_sched *table)
114 {
115 __set_bit(GRED_WRED_MODE, &table->flags);
116 }
117
118 static inline void gred_disable_wred_mode(struct gred_sched *table)
119 {
120 __clear_bit(GRED_WRED_MODE, &table->flags);
121 }
122
123 static inline int gred_wred_mode_check(struct Qdisc *sch)
124 {
125 struct gred_sched *table = qdisc_priv(sch);
126 int i;
127
128 /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
129 for (i = 0; i < table->DPs; i++) {
130 struct gred_sched_data *q = table->tab[i];
131 int n;
132
133 if (q == NULL)
134 continue;
135
136 for (n = 0; n < table->DPs; n++)
137 if (table->tab[n] && table->tab[n] != q &&
138 table->tab[n]->prio == q->prio)
139 return 1;
140 }
141
142 return 0;
143 }
144
145 static int
146 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
147 {
148 psched_time_t now;
149 struct gred_sched_data *q=NULL;
150 struct gred_sched *t= qdisc_priv(sch);
151 unsigned long qave=0;
152 int i=0;
153
154 if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
155 D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
156 goto do_enqueue;
157 }
158
159
160 if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
161 printk("GRED: setting to default (%d)\n ",t->def);
162 if (!(q=t->tab[t->def])) {
163 DPRINTK("GRED: setting to default FAILED! dropping!! "
164 "(%d)\n ", t->def);
165 goto drop;
166 }
167 /* fix tc_index? --could be controvesial but needed for
168 requeueing */
169 skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
170 }
171
172 D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
173 "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
174 sch->qstats.backlog);
175 /* sum up all the qaves of prios <= to ours to get the new qave*/
176 if (!gred_wred_mode(t) && t->grio) {
177 for (i=0;i<t->DPs;i++) {
178 if ((!t->tab[i]) || (i==q->DP))
179 continue;
180
181 if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
182 qave +=t->tab[i]->qave;
183 }
184
185 }
186
187 q->packetsin++;
188 q->bytesin+=skb->len;
189
190 if (gred_wred_mode(t)) {
191 qave=0;
192 q->qave=t->tab[t->def]->qave;
193 q->qidlestart=t->tab[t->def]->qidlestart;
194 }
195
196 if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
197 long us_idle;
198 PSCHED_GET_TIME(now);
199 us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
200 PSCHED_SET_PASTPERFECT(q->qidlestart);
201
202 q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
203 } else {
204 if (gred_wred_mode(t)) {
205 q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
206 } else {
207 q->qave += q->backlog - (q->qave >> q->Wlog);
208 }
209
210 }
211
212
213 if (gred_wred_mode(t))
214 t->tab[t->def]->qave=q->qave;
215
216 if ((q->qave+qave) < q->qth_min) {
217 q->qcount = -1;
218 enqueue:
219 if (q->backlog + skb->len <= q->limit) {
220 q->backlog += skb->len;
221 do_enqueue:
222 __skb_queue_tail(&sch->q, skb);
223 sch->qstats.backlog += skb->len;
224 sch->bstats.bytes += skb->len;
225 sch->bstats.packets++;
226 return 0;
227 } else {
228 q->pdrop++;
229 }
230
231 drop:
232 kfree_skb(skb);
233 sch->qstats.drops++;
234 return NET_XMIT_DROP;
235 }
236 if ((q->qave+qave) >= q->qth_max) {
237 q->qcount = -1;
238 sch->qstats.overlimits++;
239 q->forced++;
240 goto drop;
241 }
242 if (++q->qcount) {
243 if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
244 goto enqueue;
245 q->qcount = 0;
246 q->qR = net_random()&q->Rmask;
247 sch->qstats.overlimits++;
248 q->early++;
249 goto drop;
250 }
251 q->qR = net_random()&q->Rmask;
252 goto enqueue;
253 }
254
255 static int
256 gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
257 {
258 struct gred_sched_data *q;
259 struct gred_sched *t= qdisc_priv(sch);
260 q= t->tab[(skb->tc_index&0xf)];
261 /* error checking here -- probably unnecessary */
262 PSCHED_SET_PASTPERFECT(q->qidlestart);
263
264 __skb_queue_head(&sch->q, skb);
265 sch->qstats.backlog += skb->len;
266 sch->qstats.requeues++;
267 q->backlog += skb->len;
268 return 0;
269 }
270
271 static struct sk_buff *
272 gred_dequeue(struct Qdisc* sch)
273 {
274 struct sk_buff *skb;
275 struct gred_sched_data *q;
276 struct gred_sched *t= qdisc_priv(sch);
277
278 skb = __skb_dequeue(&sch->q);
279 if (skb) {
280 sch->qstats.backlog -= skb->len;
281 q= t->tab[(skb->tc_index&0xf)];
282 if (q) {
283 q->backlog -= skb->len;
284 if (!q->backlog && !gred_wred_mode(t))
285 PSCHED_GET_TIME(q->qidlestart);
286 } else {
287 D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
288 }
289 return skb;
290 }
291
292 if (gred_wred_mode(t)) {
293 q= t->tab[t->def];
294 if (!q)
295 D2PRINTK("no default VQ set: Results will be "
296 "screwed up\n");
297 else
298 PSCHED_GET_TIME(q->qidlestart);
299 }
300
301 return NULL;
302 }
303
304 static unsigned int gred_drop(struct Qdisc* sch)
305 {
306 struct sk_buff *skb;
307
308 struct gred_sched_data *q;
309 struct gred_sched *t= qdisc_priv(sch);
310
311 skb = __skb_dequeue_tail(&sch->q);
312 if (skb) {
313 unsigned int len = skb->len;
314 sch->qstats.backlog -= len;
315 sch->qstats.drops++;
316 q= t->tab[(skb->tc_index&0xf)];
317 if (q) {
318 q->backlog -= len;
319 q->other++;
320 if (!q->backlog && !gred_wred_mode(t))
321 PSCHED_GET_TIME(q->qidlestart);
322 } else {
323 D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
324 }
325
326 kfree_skb(skb);
327 return len;
328 }
329
330 q=t->tab[t->def];
331 if (!q) {
332 D2PRINTK("no default VQ set: Results might be screwed up\n");
333 return 0;
334 }
335
336 PSCHED_GET_TIME(q->qidlestart);
337 return 0;
338
339 }
340
341 static void gred_reset(struct Qdisc* sch)
342 {
343 int i;
344 struct gred_sched_data *q;
345 struct gred_sched *t= qdisc_priv(sch);
346
347 __skb_queue_purge(&sch->q);
348
349 sch->qstats.backlog = 0;
350
351 for (i=0;i<t->DPs;i++) {
352 q= t->tab[i];
353 if (!q)
354 continue;
355 PSCHED_SET_PASTPERFECT(q->qidlestart);
356 q->qave = 0;
357 q->qcount = -1;
358 q->backlog = 0;
359 q->other=0;
360 q->forced=0;
361 q->pdrop=0;
362 q->early=0;
363 }
364 }
365
366 static int gred_change(struct Qdisc *sch, struct rtattr *opt)
367 {
368 struct gred_sched *table = qdisc_priv(sch);
369 struct gred_sched_data *q;
370 struct tc_gred_qopt *ctl;
371 struct tc_gred_sopt *sopt;
372 struct rtattr *tb[TCA_GRED_STAB];
373 struct rtattr *tb2[TCA_GRED_DPS];
374
375 if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
376 return -EINVAL;
377
378 if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
379 rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
380
381 if (tb2[TCA_GRED_DPS-1] == 0)
382 return -EINVAL;
383
384 sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
385 table->DPs=sopt->DPs;
386 table->def=sopt->def_DP;
387
388 if (sopt->grio) {
389 table->grio = 1;
390 gred_disable_wred_mode(table);
391 if (gred_wred_mode_check(sch))
392 gred_enable_wred_mode(table);
393 } else {
394 table->grio = 0;
395 gred_disable_wred_mode(table);
396 }
397
398 table->initd=0;
399 /* probably need to clear all the table DP entries as well */
400 return 0;
401 }
402
403
404 if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
405 RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
406 RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
407 return -EINVAL;
408
409 ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
410 if (ctl->DP > MAX_DPs-1 ) {
411 /* misbehaving is punished! Put in the default drop probability */
412 DPRINTK("\nGRED: DP %u not in the proper range fixed. New DP "
413 "set to default at %d\n",ctl->DP,table->def);
414 ctl->DP=table->def;
415 }
416
417 if (table->tab[ctl->DP] == NULL) {
418 table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data),
419 GFP_KERNEL);
420 if (NULL == table->tab[ctl->DP])
421 return -ENOMEM;
422 memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data)));
423 }
424 q= table->tab[ctl->DP];
425
426 if (table->grio) {
427 if (ctl->prio <=0) {
428 if (table->def && table->tab[table->def]) {
429 DPRINTK("\nGRED: DP %u does not have a prio"
430 "setting default to %d\n",ctl->DP,
431 table->tab[table->def]->prio);
432 q->prio=table->tab[table->def]->prio;
433 } else {
434 DPRINTK("\nGRED: DP %u does not have a prio"
435 " setting default to 8\n",ctl->DP);
436 q->prio=8;
437 }
438 } else {
439 q->prio=ctl->prio;
440 }
441 } else {
442 q->prio=8;
443 }
444
445
446 q->DP=ctl->DP;
447 q->Wlog = ctl->Wlog;
448 q->Plog = ctl->Plog;
449 q->limit = ctl->limit;
450 q->Scell_log = ctl->Scell_log;
451 q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
452 q->Scell_max = (255<<q->Scell_log);
453 q->qth_min = ctl->qth_min<<ctl->Wlog;
454 q->qth_max = ctl->qth_max<<ctl->Wlog;
455 q->qave=0;
456 q->backlog=0;
457 q->qcount = -1;
458 q->other=0;
459 q->forced=0;
460 q->pdrop=0;
461 q->early=0;
462
463 PSCHED_SET_PASTPERFECT(q->qidlestart);
464 memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
465
466 if (table->grio) {
467 gred_disable_wred_mode(table);
468 if (gred_wred_mode_check(sch))
469 gred_enable_wred_mode(table);
470 }
471
472 if (!table->initd) {
473 table->initd=1;
474 /*
475 the first entry also goes into the default until
476 over-written
477 */
478
479 if (table->tab[table->def] == NULL) {
480 table->tab[table->def]=
481 kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL);
482 if (NULL == table->tab[table->def])
483 return -ENOMEM;
484
485 memset(table->tab[table->def], 0,
486 (sizeof(struct gred_sched_data)));
487 }
488 q= table->tab[table->def];
489 q->DP=table->def;
490 q->Wlog = ctl->Wlog;
491 q->Plog = ctl->Plog;
492 q->limit = ctl->limit;
493 q->Scell_log = ctl->Scell_log;
494 q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
495 q->Scell_max = (255<<q->Scell_log);
496 q->qth_min = ctl->qth_min<<ctl->Wlog;
497 q->qth_max = ctl->qth_max<<ctl->Wlog;
498
499 if (table->grio)
500 q->prio=table->tab[ctl->DP]->prio;
501 else
502 q->prio=8;
503
504 q->qcount = -1;
505 PSCHED_SET_PASTPERFECT(q->qidlestart);
506 memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
507 }
508 return 0;
509
510 }
511
512 static int gred_init(struct Qdisc *sch, struct rtattr *opt)
513 {
514 struct gred_sched *table = qdisc_priv(sch);
515 struct tc_gred_sopt *sopt;
516 struct rtattr *tb[TCA_GRED_STAB];
517 struct rtattr *tb2[TCA_GRED_DPS];
518
519 if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
520 return -EINVAL;
521
522 if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
523 rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
524
525 if (tb2[TCA_GRED_DPS-1] == 0)
526 return -EINVAL;
527
528 sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
529 table->DPs=sopt->DPs;
530 table->def=sopt->def_DP;
531 table->grio=sopt->grio;
532 table->initd=0;
533 return 0;
534 }
535
536 DPRINTK("\n GRED_INIT error!\n");
537 return -EINVAL;
538 }
539
540 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
541 {
542 unsigned long qave;
543 struct rtattr *rta;
544 struct tc_gred_qopt *opt = NULL ;
545 struct tc_gred_qopt *dst;
546 struct gred_sched *table = qdisc_priv(sch);
547 struct gred_sched_data *q;
548 int i;
549 unsigned char *b = skb->tail;
550
551 rta = (struct rtattr*)b;
552 RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
553
554 opt=kmalloc(sizeof(struct tc_gred_qopt)*MAX_DPs, GFP_KERNEL);
555
556 if (opt == NULL) {
557 DPRINTK("gred_dump:failed to malloc for %Zd\n",
558 sizeof(struct tc_gred_qopt)*MAX_DPs);
559 goto rtattr_failure;
560 }
561
562 memset(opt, 0, (sizeof(struct tc_gred_qopt))*table->DPs);
563
564 if (!table->initd) {
565 DPRINTK("NO GRED Queues setup!\n");
566 }
567
568 for (i=0;i<MAX_DPs;i++) {
569 dst= &opt[i];
570 q= table->tab[i];
571
572 if (!q) {
573 /* hack -- fix at some point with proper message
574 This is how we indicate to tc that there is no VQ
575 at this DP */
576
577 dst->DP=MAX_DPs+i;
578 continue;
579 }
580
581 dst->limit=q->limit;
582 dst->qth_min=q->qth_min>>q->Wlog;
583 dst->qth_max=q->qth_max>>q->Wlog;
584 dst->DP=q->DP;
585 dst->backlog=q->backlog;
586 if (q->qave) {
587 if (gred_wred_mode(table)) {
588 q->qidlestart=table->tab[table->def]->qidlestart;
589 q->qave=table->tab[table->def]->qave;
590 }
591 if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
592 long idle;
593 psched_time_t now;
594 PSCHED_GET_TIME(now);
595 idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
596 qave = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
597 dst->qave = qave >> q->Wlog;
598
599 } else {
600 dst->qave = q->qave >> q->Wlog;
601 }
602 } else {
603 dst->qave = 0;
604 }
605
606
607 dst->Wlog = q->Wlog;
608 dst->Plog = q->Plog;
609 dst->Scell_log = q->Scell_log;
610 dst->other = q->other;
611 dst->forced = q->forced;
612 dst->early = q->early;
613 dst->pdrop = q->pdrop;
614 dst->prio = q->prio;
615 dst->packets=q->packetsin;
616 dst->bytesin=q->bytesin;
617 }
618
619 RTA_PUT(skb, TCA_GRED_PARMS, sizeof(struct tc_gred_qopt)*MAX_DPs, opt);
620 rta->rta_len = skb->tail - b;
621
622 kfree(opt);
623 return skb->len;
624
625 rtattr_failure:
626 if (opt)
627 kfree(opt);
628 DPRINTK("gred_dump: FAILURE!!!!\n");
629
630 /* also free the opt struct here */
631 skb_trim(skb, b - skb->data);
632 return -1;
633 }
634
635 static void gred_destroy(struct Qdisc *sch)
636 {
637 struct gred_sched *table = qdisc_priv(sch);
638 int i;
639
640 for (i = 0;i < table->DPs; i++) {
641 if (table->tab[i])
642 kfree(table->tab[i]);
643 }
644 }
645
646 static struct Qdisc_ops gred_qdisc_ops = {
647 .next = NULL,
648 .cl_ops = NULL,
649 .id = "gred",
650 .priv_size = sizeof(struct gred_sched),
651 .enqueue = gred_enqueue,
652 .dequeue = gred_dequeue,
653 .requeue = gred_requeue,
654 .drop = gred_drop,
655 .init = gred_init,
656 .reset = gred_reset,
657 .destroy = gred_destroy,
658 .change = gred_change,
659 .dump = gred_dump,
660 .owner = THIS_MODULE,
661 };
662
663 static int __init gred_module_init(void)
664 {
665 return register_qdisc(&gred_qdisc_ops);
666 }
667 static void __exit gred_module_exit(void)
668 {
669 unregister_qdisc(&gred_qdisc_ops);
670 }
671 module_init(gred_module_init)
672 module_exit(gred_module_exit)
673 MODULE_LICENSE("GPL");
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