1 /*
2 * Copyright (c) 2003 Patrick McHardy, <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * 2003-10-17 - Ported from altq
10 */
11 /*
12 * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
13 *
14 * Permission to use, copy, modify, and distribute this software and
15 * its documentation is hereby granted (including for commercial or
16 * for-profit use), provided that both the copyright notice and this
17 * permission notice appear in all copies of the software, derivative
18 * works, or modified versions, and any portions thereof.
19 *
20 * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
21 * WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON PROVIDES THIS
22 * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
32 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
33 * DAMAGE.
34 *
35 * Carnegie Mellon encourages (but does not require) users of this
36 * software to return any improvements or extensions that they make,
37 * and to grant Carnegie Mellon the rights to redistribute these
38 * changes without encumbrance.
39 */
40 /*
41 * H-FSC is described in Proceedings of SIGCOMM'97,
42 * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
43 * Real-Time and Priority Service"
44 * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
45 *
46 * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
47 * when a class has an upperlimit, the fit-time is computed from the
48 * upperlimit service curve. the link-sharing scheduler does not schedule
49 * a class whose fit-time exceeds the current time.
50 */
51
52 #include <linux/kernel.h>
53 #include <linux/module.h>
54 #include <linux/types.h>
55 #include <linux/errno.h>
56 #include <linux/compiler.h>
57 #include <linux/spinlock.h>
58 #include <linux/skbuff.h>
59 #include <linux/string.h>
60 #include <linux/slab.h>
61 #include <linux/list.h>
62 #include <linux/rbtree.h>
63 #include <linux/init.h>
64 #include <linux/rtnetlink.h>
65 #include <linux/pkt_sched.h>
66 #include <net/netlink.h>
67 #include <net/pkt_sched.h>
68 #include <net/pkt_cls.h>
69 #include <asm/div64.h>
70
71 /*
72 * kernel internal service curve representation:
73 * coordinates are given by 64 bit unsigned integers.
74 * x-axis: unit is clock count.
75 * y-axis: unit is byte.
76 *
77 * The service curve parameters are converted to the internal
78 * representation. The slope values are scaled to avoid overflow.
79 * the inverse slope values as well as the y-projection of the 1st
80 * segment are kept in order to avoid 64-bit divide operations
81 * that are expensive on 32-bit architectures.
82 */
83
84 struct internal_sc {
85 u64 sm1; /* scaled slope of the 1st segment */
86 u64 ism1; /* scaled inverse-slope of the 1st segment */
87 u64 dx; /* the x-projection of the 1st segment */
88 u64 dy; /* the y-projection of the 1st segment */
89 u64 sm2; /* scaled slope of the 2nd segment */
90 u64 ism2; /* scaled inverse-slope of the 2nd segment */
91 };
92
93 /* runtime service curve */
94 struct runtime_sc {
95 u64 x; /* current starting position on x-axis */
96 u64 y; /* current starting position on y-axis */
97 u64 sm1; /* scaled slope of the 1st segment */
98 u64 ism1; /* scaled inverse-slope of the 1st segment */
99 u64 dx; /* the x-projection of the 1st segment */
100 u64 dy; /* the y-projection of the 1st segment */
101 u64 sm2; /* scaled slope of the 2nd segment */
102 u64 ism2; /* scaled inverse-slope of the 2nd segment */
103 };
104
105 enum hfsc_class_flags {
106 HFSC_RSC = 0x1,
107 HFSC_FSC = 0x2,
108 HFSC_USC = 0x4
109 };
110
111 struct hfsc_class {
112 struct Qdisc_class_common cl_common;
113
114 struct gnet_stats_basic_sync bstats;
115 struct gnet_stats_queue qstats;
116 struct net_rate_estimator __rcu *rate_est;
117 struct tcf_proto __rcu *filter_list; /* filter list */
118 struct tcf_block *block;
119 unsigned int level; /* class level in hierarchy */
120
121 struct hfsc_sched *sched; /* scheduler data */
122 struct hfsc_class *cl_parent; /* parent class */
123 struct list_head siblings; /* sibling classes */
124 struct list_head children; /* child classes */
125 struct Qdisc *qdisc; /* leaf qdisc */
126
127 struct rb_node el_node; /* qdisc's eligible tree member */
128 struct rb_root vt_tree; /* active children sorted by cl_vt */
129 struct rb_node vt_node; /* parent's vt_tree member */
130 struct rb_root cf_tree; /* active children sorted by cl_f */
131 struct rb_node cf_node; /* parent's cf_heap member */
132
133 u64 cl_total; /* total work in bytes */
134 u64 cl_cumul; /* cumulative work in bytes done by
135 real-time criteria */
136
137 u64 cl_d; /* deadline*/
138 u64 cl_e; /* eligible time */
139 u64 cl_vt; /* virtual time */
140 u64 cl_f; /* time when this class will fit for
141 link-sharing, max(myf, cfmin) */
142 u64 cl_myf; /* my fit-time (calculated from this
143 class's own upperlimit curve) */
144 u64 cl_cfmin; /* earliest children's fit-time (used
145 with cl_myf to obtain cl_f) */
146 u64 cl_cvtmin; /* minimal virtual time among the
147 children fit for link-sharing
148 (monotonic within a period) */
149 u64 cl_vtadj; /* intra-period cumulative vt
150 adjustment */
151 u64 cl_cvtoff; /* largest virtual time seen among
152 the children */
153
154 struct internal_sc cl_rsc; /* internal real-time service curve */
155 struct internal_sc cl_fsc; /* internal fair service curve */
156 struct internal_sc cl_usc; /* internal upperlimit service curve */
157 struct runtime_sc cl_deadline; /* deadline curve */
158 struct runtime_sc cl_eligible; /* eligible curve */
159 struct runtime_sc cl_virtual; /* virtual curve */
160 struct runtime_sc cl_ulimit; /* upperlimit curve */
161
162 u8 cl_flags; /* which curves are valid */
163 u32 cl_vtperiod; /* vt period sequence number */
164 u32 cl_parentperiod;/* parent's vt period sequence number*/
165 u32 cl_nactive; /* number of active children */
166 };
167
168 struct hfsc_sched {
169 u16 defcls; /* default class id */
170 struct hfsc_class root; /* root class */
171 struct Qdisc_class_hash clhash; /* class hash */
172 struct rb_root eligible; /* eligible tree */
173 struct qdisc_watchdog watchdog; /* watchdog timer */
174 };
175
176 #define HT_INFINITY 0xffffffffffffffffULL /* infinite time value */
177
cl_in_el_or_vttree(struct hfsc_class * cl)178 static bool cl_in_el_or_vttree(struct hfsc_class *cl)
179 {
180 return ((cl->cl_flags & HFSC_FSC) && cl->cl_nactive) ||
181 ((cl->cl_flags & HFSC_RSC) && !RB_EMPTY_NODE(&cl->el_node));
182 }
183
184 /*
185 * eligible tree holds backlogged classes being sorted by their eligible times.
186 * there is one eligible tree per hfsc instance.
187 */
188
189 static void
eltree_insert(struct hfsc_class * cl)190 eltree_insert(struct hfsc_class *cl)
191 {
192 struct rb_node **p = &cl->sched->eligible.rb_node;
193 struct rb_node *parent = NULL;
194 struct hfsc_class *cl1;
195
196 while (*p != NULL) {
197 parent = *p;
198 cl1 = rb_entry(parent, struct hfsc_class, el_node);
199 if (cl->cl_e >= cl1->cl_e)
200 p = &parent->rb_right;
201 else
202 p = &parent->rb_left;
203 }
204 rb_link_node(&cl->el_node, parent, p);
205 rb_insert_color(&cl->el_node, &cl->sched->eligible);
206 }
207
208 static inline void
eltree_remove(struct hfsc_class * cl)209 eltree_remove(struct hfsc_class *cl)
210 {
211 if (!RB_EMPTY_NODE(&cl->el_node)) {
212 rb_erase(&cl->el_node, &cl->sched->eligible);
213 RB_CLEAR_NODE(&cl->el_node);
214 }
215 }
216
217 static inline void
eltree_update(struct hfsc_class * cl)218 eltree_update(struct hfsc_class *cl)
219 {
220 eltree_remove(cl);
221 eltree_insert(cl);
222 }
223
224 /* find the class with the minimum deadline among the eligible classes */
225 static inline struct hfsc_class *
eltree_get_mindl(struct hfsc_sched * q,u64 cur_time)226 eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
227 {
228 struct hfsc_class *p, *cl = NULL;
229 struct rb_node *n;
230
231 for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
232 p = rb_entry(n, struct hfsc_class, el_node);
233 if (p->cl_e > cur_time)
234 break;
235 if (cl == NULL || p->cl_d < cl->cl_d)
236 cl = p;
237 }
238 return cl;
239 }
240
241 /* find the class with minimum eligible time among the eligible classes */
242 static inline struct hfsc_class *
eltree_get_minel(struct hfsc_sched * q)243 eltree_get_minel(struct hfsc_sched *q)
244 {
245 struct rb_node *n;
246
247 n = rb_first(&q->eligible);
248 if (n == NULL)
249 return NULL;
250 return rb_entry(n, struct hfsc_class, el_node);
251 }
252
253 /*
254 * vttree holds holds backlogged child classes being sorted by their virtual
255 * time. each intermediate class has one vttree.
256 */
257 static void
vttree_insert(struct hfsc_class * cl)258 vttree_insert(struct hfsc_class *cl)
259 {
260 struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
261 struct rb_node *parent = NULL;
262 struct hfsc_class *cl1;
263
264 while (*p != NULL) {
265 parent = *p;
266 cl1 = rb_entry(parent, struct hfsc_class, vt_node);
267 if (cl->cl_vt >= cl1->cl_vt)
268 p = &parent->rb_right;
269 else
270 p = &parent->rb_left;
271 }
272 rb_link_node(&cl->vt_node, parent, p);
273 rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
274 }
275
276 static inline void
vttree_remove(struct hfsc_class * cl)277 vttree_remove(struct hfsc_class *cl)
278 {
279 rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
280 }
281
282 static inline void
vttree_update(struct hfsc_class * cl)283 vttree_update(struct hfsc_class *cl)
284 {
285 vttree_remove(cl);
286 vttree_insert(cl);
287 }
288
289 static inline struct hfsc_class *
vttree_firstfit(struct hfsc_class * cl,u64 cur_time)290 vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
291 {
292 struct hfsc_class *p;
293 struct rb_node *n;
294
295 for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
296 p = rb_entry(n, struct hfsc_class, vt_node);
297 if (p->cl_f <= cur_time)
298 return p;
299 }
300 return NULL;
301 }
302
303 /*
304 * get the leaf class with the minimum vt in the hierarchy
305 */
306 static struct hfsc_class *
vttree_get_minvt(struct hfsc_class * cl,u64 cur_time)307 vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
308 {
309 /* if root-class's cfmin is bigger than cur_time nothing to do */
310 if (cl->cl_cfmin > cur_time)
311 return NULL;
312
313 while (cl->level > 0) {
314 cl = vttree_firstfit(cl, cur_time);
315 if (cl == NULL)
316 return NULL;
317 /*
318 * update parent's cl_cvtmin.
319 */
320 if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
321 cl->cl_parent->cl_cvtmin = cl->cl_vt;
322 }
323 return cl;
324 }
325
326 static void
cftree_insert(struct hfsc_class * cl)327 cftree_insert(struct hfsc_class *cl)
328 {
329 struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
330 struct rb_node *parent = NULL;
331 struct hfsc_class *cl1;
332
333 while (*p != NULL) {
334 parent = *p;
335 cl1 = rb_entry(parent, struct hfsc_class, cf_node);
336 if (cl->cl_f >= cl1->cl_f)
337 p = &parent->rb_right;
338 else
339 p = &parent->rb_left;
340 }
341 rb_link_node(&cl->cf_node, parent, p);
342 rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
343 }
344
345 static inline void
cftree_remove(struct hfsc_class * cl)346 cftree_remove(struct hfsc_class *cl)
347 {
348 rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
349 }
350
351 static inline void
cftree_update(struct hfsc_class * cl)352 cftree_update(struct hfsc_class *cl)
353 {
354 cftree_remove(cl);
355 cftree_insert(cl);
356 }
357
358 /*
359 * service curve support functions
360 *
361 * external service curve parameters
362 * m: bps
363 * d: us
364 * internal service curve parameters
365 * sm: (bytes/psched_us) << SM_SHIFT
366 * ism: (psched_us/byte) << ISM_SHIFT
367 * dx: psched_us
368 *
369 * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
370 *
371 * sm and ism are scaled in order to keep effective digits.
372 * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
373 * digits in decimal using the following table.
374 *
375 * bits/sec 100Kbps 1Mbps 10Mbps 100Mbps 1Gbps
376 * ------------+-------------------------------------------------------
377 * bytes/1.024us 12.8e-3 128e-3 1280e-3 12800e-3 128000e-3
378 *
379 * 1.024us/byte 78.125 7.8125 0.78125 0.078125 0.0078125
380 *
381 * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
382 */
383 #define SM_SHIFT (30 - PSCHED_SHIFT)
384 #define ISM_SHIFT (8 + PSCHED_SHIFT)
385
386 #define SM_MASK ((1ULL << SM_SHIFT) - 1)
387 #define ISM_MASK ((1ULL << ISM_SHIFT) - 1)
388
389 static inline u64
seg_x2y(u64 x,u64 sm)390 seg_x2y(u64 x, u64 sm)
391 {
392 u64 y;
393
394 /*
395 * compute
396 * y = x * sm >> SM_SHIFT
397 * but divide it for the upper and lower bits to avoid overflow
398 */
399 y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
400 return y;
401 }
402
403 static inline u64
seg_y2x(u64 y,u64 ism)404 seg_y2x(u64 y, u64 ism)
405 {
406 u64 x;
407
408 if (y == 0)
409 x = 0;
410 else if (ism == HT_INFINITY)
411 x = HT_INFINITY;
412 else {
413 x = (y >> ISM_SHIFT) * ism
414 + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
415 }
416 return x;
417 }
418
419 /* Convert m (bps) into sm (bytes/psched us) */
420 static u64
m2sm(u32 m)421 m2sm(u32 m)
422 {
423 u64 sm;
424
425 sm = ((u64)m << SM_SHIFT);
426 sm += PSCHED_TICKS_PER_SEC - 1;
427 do_div(sm, PSCHED_TICKS_PER_SEC);
428 return sm;
429 }
430
431 /* convert m (bps) into ism (psched us/byte) */
432 static u64
m2ism(u32 m)433 m2ism(u32 m)
434 {
435 u64 ism;
436
437 if (m == 0)
438 ism = HT_INFINITY;
439 else {
440 ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
441 ism += m - 1;
442 do_div(ism, m);
443 }
444 return ism;
445 }
446
447 /* convert d (us) into dx (psched us) */
448 static u64
d2dx(u32 d)449 d2dx(u32 d)
450 {
451 u64 dx;
452
453 dx = ((u64)d * PSCHED_TICKS_PER_SEC);
454 dx += USEC_PER_SEC - 1;
455 do_div(dx, USEC_PER_SEC);
456 return dx;
457 }
458
459 /* convert sm (bytes/psched us) into m (bps) */
460 static u32
sm2m(u64 sm)461 sm2m(u64 sm)
462 {
463 u64 m;
464
465 m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
466 return (u32)m;
467 }
468
469 /* convert dx (psched us) into d (us) */
470 static u32
dx2d(u64 dx)471 dx2d(u64 dx)
472 {
473 u64 d;
474
475 d = dx * USEC_PER_SEC;
476 do_div(d, PSCHED_TICKS_PER_SEC);
477 return (u32)d;
478 }
479
480 static void
sc2isc(struct tc_service_curve * sc,struct internal_sc * isc)481 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
482 {
483 isc->sm1 = m2sm(sc->m1);
484 isc->ism1 = m2ism(sc->m1);
485 isc->dx = d2dx(sc->d);
486 isc->dy = seg_x2y(isc->dx, isc->sm1);
487 isc->sm2 = m2sm(sc->m2);
488 isc->ism2 = m2ism(sc->m2);
489 }
490
491 /*
492 * initialize the runtime service curve with the given internal
493 * service curve starting at (x, y).
494 */
495 static void
rtsc_init(struct runtime_sc * rtsc,struct internal_sc * isc,u64 x,u64 y)496 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
497 {
498 rtsc->x = x;
499 rtsc->y = y;
500 rtsc->sm1 = isc->sm1;
501 rtsc->ism1 = isc->ism1;
502 rtsc->dx = isc->dx;
503 rtsc->dy = isc->dy;
504 rtsc->sm2 = isc->sm2;
505 rtsc->ism2 = isc->ism2;
506 }
507
508 /*
509 * calculate the y-projection of the runtime service curve by the
510 * given x-projection value
511 */
512 static u64
rtsc_y2x(struct runtime_sc * rtsc,u64 y)513 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
514 {
515 u64 x;
516
517 if (y < rtsc->y)
518 x = rtsc->x;
519 else if (y <= rtsc->y + rtsc->dy) {
520 /* x belongs to the 1st segment */
521 if (rtsc->dy == 0)
522 x = rtsc->x + rtsc->dx;
523 else
524 x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
525 } else {
526 /* x belongs to the 2nd segment */
527 x = rtsc->x + rtsc->dx
528 + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
529 }
530 return x;
531 }
532
533 static u64
rtsc_x2y(struct runtime_sc * rtsc,u64 x)534 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
535 {
536 u64 y;
537
538 if (x <= rtsc->x)
539 y = rtsc->y;
540 else if (x <= rtsc->x + rtsc->dx)
541 /* y belongs to the 1st segment */
542 y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
543 else
544 /* y belongs to the 2nd segment */
545 y = rtsc->y + rtsc->dy
546 + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
547 return y;
548 }
549
550 /*
551 * update the runtime service curve by taking the minimum of the current
552 * runtime service curve and the service curve starting at (x, y).
553 */
554 static void
rtsc_min(struct runtime_sc * rtsc,struct internal_sc * isc,u64 x,u64 y)555 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
556 {
557 u64 y1, y2, dx, dy;
558 u32 dsm;
559
560 if (isc->sm1 <= isc->sm2) {
561 /* service curve is convex */
562 y1 = rtsc_x2y(rtsc, x);
563 if (y1 < y)
564 /* the current rtsc is smaller */
565 return;
566 rtsc->x = x;
567 rtsc->y = y;
568 return;
569 }
570
571 /*
572 * service curve is concave
573 * compute the two y values of the current rtsc
574 * y1: at x
575 * y2: at (x + dx)
576 */
577 y1 = rtsc_x2y(rtsc, x);
578 if (y1 <= y) {
579 /* rtsc is below isc, no change to rtsc */
580 return;
581 }
582
583 y2 = rtsc_x2y(rtsc, x + isc->dx);
584 if (y2 >= y + isc->dy) {
585 /* rtsc is above isc, replace rtsc by isc */
586 rtsc->x = x;
587 rtsc->y = y;
588 rtsc->dx = isc->dx;
589 rtsc->dy = isc->dy;
590 return;
591 }
592
593 /*
594 * the two curves intersect
595 * compute the offsets (dx, dy) using the reverse
596 * function of seg_x2y()
597 * seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
598 */
599 dx = (y1 - y) << SM_SHIFT;
600 dsm = isc->sm1 - isc->sm2;
601 do_div(dx, dsm);
602 /*
603 * check if (x, y1) belongs to the 1st segment of rtsc.
604 * if so, add the offset.
605 */
606 if (rtsc->x + rtsc->dx > x)
607 dx += rtsc->x + rtsc->dx - x;
608 dy = seg_x2y(dx, isc->sm1);
609
610 rtsc->x = x;
611 rtsc->y = y;
612 rtsc->dx = dx;
613 rtsc->dy = dy;
614 }
615
616 static void
init_ed(struct hfsc_class * cl,unsigned int next_len)617 init_ed(struct hfsc_class *cl, unsigned int next_len)
618 {
619 u64 cur_time = psched_get_time();
620
621 /* update the deadline curve */
622 rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
623
624 /*
625 * update the eligible curve.
626 * for concave, it is equal to the deadline curve.
627 * for convex, it is a linear curve with slope m2.
628 */
629 cl->cl_eligible = cl->cl_deadline;
630 if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
631 cl->cl_eligible.dx = 0;
632 cl->cl_eligible.dy = 0;
633 }
634
635 /* compute e and d */
636 cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
637 cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
638
639 eltree_insert(cl);
640 }
641
642 static void
update_ed(struct hfsc_class * cl,unsigned int next_len)643 update_ed(struct hfsc_class *cl, unsigned int next_len)
644 {
645 cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
646 cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
647
648 eltree_update(cl);
649 }
650
651 static inline void
update_d(struct hfsc_class * cl,unsigned int next_len)652 update_d(struct hfsc_class *cl, unsigned int next_len)
653 {
654 cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
655 }
656
657 static inline void
update_cfmin(struct hfsc_class * cl)658 update_cfmin(struct hfsc_class *cl)
659 {
660 struct rb_node *n = rb_first(&cl->cf_tree);
661 struct hfsc_class *p;
662
663 if (n == NULL) {
664 cl->cl_cfmin = 0;
665 return;
666 }
667 p = rb_entry(n, struct hfsc_class, cf_node);
668 cl->cl_cfmin = p->cl_f;
669 }
670
671 static void
init_vf(struct hfsc_class * cl,unsigned int len)672 init_vf(struct hfsc_class *cl, unsigned int len)
673 {
674 struct hfsc_class *max_cl;
675 struct rb_node *n;
676 u64 vt, f, cur_time;
677 int go_active;
678
679 cur_time = 0;
680 go_active = 1;
681 for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
682 if (go_active && cl->cl_nactive++ == 0)
683 go_active = 1;
684 else
685 go_active = 0;
686
687 if (go_active) {
688 n = rb_last(&cl->cl_parent->vt_tree);
689 if (n != NULL) {
690 max_cl = rb_entry(n, struct hfsc_class, vt_node);
691 /*
692 * set vt to the average of the min and max
693 * classes. if the parent's period didn't
694 * change, don't decrease vt of the class.
695 */
696 vt = max_cl->cl_vt;
697 if (cl->cl_parent->cl_cvtmin != 0)
698 vt = (cl->cl_parent->cl_cvtmin + vt)/2;
699
700 if (cl->cl_parent->cl_vtperiod !=
701 cl->cl_parentperiod || vt > cl->cl_vt)
702 cl->cl_vt = vt;
703 } else {
704 /*
705 * first child for a new parent backlog period.
706 * initialize cl_vt to the highest value seen
707 * among the siblings. this is analogous to
708 * what cur_time would provide in realtime case.
709 */
710 cl->cl_vt = cl->cl_parent->cl_cvtoff;
711 cl->cl_parent->cl_cvtmin = 0;
712 }
713
714 /* update the virtual curve */
715 rtsc_min(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
716 cl->cl_vtadj = 0;
717
718 cl->cl_vtperiod++; /* increment vt period */
719 cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
720 if (cl->cl_parent->cl_nactive == 0)
721 cl->cl_parentperiod++;
722 cl->cl_f = 0;
723
724 vttree_insert(cl);
725 cftree_insert(cl);
726
727 if (cl->cl_flags & HFSC_USC) {
728 /* class has upper limit curve */
729 if (cur_time == 0)
730 cur_time = psched_get_time();
731
732 /* update the ulimit curve */
733 rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
734 cl->cl_total);
735 /* compute myf */
736 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
737 cl->cl_total);
738 }
739 }
740
741 f = max(cl->cl_myf, cl->cl_cfmin);
742 if (f != cl->cl_f) {
743 cl->cl_f = f;
744 cftree_update(cl);
745 }
746 update_cfmin(cl->cl_parent);
747 }
748 }
749
750 static void
update_vf(struct hfsc_class * cl,unsigned int len,u64 cur_time)751 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
752 {
753 u64 f; /* , myf_bound, delta; */
754 int go_passive = 0;
755
756 if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
757 go_passive = 1;
758
759 for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
760 cl->cl_total += len;
761
762 if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
763 continue;
764
765 if (go_passive && --cl->cl_nactive == 0)
766 go_passive = 1;
767 else
768 go_passive = 0;
769
770 /* update vt */
771 cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) + cl->cl_vtadj;
772
773 /*
774 * if vt of the class is smaller than cvtmin,
775 * the class was skipped in the past due to non-fit.
776 * if so, we need to adjust vtadj.
777 */
778 if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
779 cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
780 cl->cl_vt = cl->cl_parent->cl_cvtmin;
781 }
782
783 if (go_passive) {
784 /* no more active child, going passive */
785
786 /* update cvtoff of the parent class */
787 if (cl->cl_vt > cl->cl_parent->cl_cvtoff)
788 cl->cl_parent->cl_cvtoff = cl->cl_vt;
789
790 /* remove this class from the vt tree */
791 vttree_remove(cl);
792
793 cftree_remove(cl);
794 update_cfmin(cl->cl_parent);
795
796 continue;
797 }
798
799 /* update the vt tree */
800 vttree_update(cl);
801
802 /* update f */
803 if (cl->cl_flags & HFSC_USC) {
804 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
805 #if 0
806 cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
807 cl->cl_total);
808 /*
809 * This code causes classes to stay way under their
810 * limit when multiple classes are used at gigabit
811 * speed. needs investigation. -kaber
812 */
813 /*
814 * if myf lags behind by more than one clock tick
815 * from the current time, adjust myfadj to prevent
816 * a rate-limited class from going greedy.
817 * in a steady state under rate-limiting, myf
818 * fluctuates within one clock tick.
819 */
820 myf_bound = cur_time - PSCHED_JIFFIE2US(1);
821 if (cl->cl_myf < myf_bound) {
822 delta = cur_time - cl->cl_myf;
823 cl->cl_myfadj += delta;
824 cl->cl_myf += delta;
825 }
826 #endif
827 }
828
829 f = max(cl->cl_myf, cl->cl_cfmin);
830 if (f != cl->cl_f) {
831 cl->cl_f = f;
832 cftree_update(cl);
833 update_cfmin(cl->cl_parent);
834 }
835 }
836 }
837
838 static unsigned int
qdisc_peek_len(struct Qdisc * sch)839 qdisc_peek_len(struct Qdisc *sch)
840 {
841 struct sk_buff *skb;
842 unsigned int len;
843
844 skb = sch->ops->peek(sch);
845 if (unlikely(skb == NULL)) {
846 qdisc_warn_nonwc("qdisc_peek_len", sch);
847 return 0;
848 }
849 len = qdisc_pkt_len(skb);
850
851 return len;
852 }
853
854 static void
hfsc_adjust_levels(struct hfsc_class * cl)855 hfsc_adjust_levels(struct hfsc_class *cl)
856 {
857 struct hfsc_class *p;
858 unsigned int level;
859
860 do {
861 level = 0;
862 list_for_each_entry(p, &cl->children, siblings) {
863 if (p->level >= level)
864 level = p->level + 1;
865 }
866 cl->level = level;
867 } while ((cl = cl->cl_parent) != NULL);
868 }
869
870 static inline struct hfsc_class *
hfsc_find_class(u32 classid,struct Qdisc * sch)871 hfsc_find_class(u32 classid, struct Qdisc *sch)
872 {
873 struct hfsc_sched *q = qdisc_priv(sch);
874 struct Qdisc_class_common *clc;
875
876 clc = qdisc_class_find(&q->clhash, classid);
877 if (clc == NULL)
878 return NULL;
879 return container_of(clc, struct hfsc_class, cl_common);
880 }
881
882 static void
hfsc_change_rsc(struct hfsc_class * cl,struct tc_service_curve * rsc,u64 cur_time)883 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
884 u64 cur_time)
885 {
886 sc2isc(rsc, &cl->cl_rsc);
887 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
888 cl->cl_eligible = cl->cl_deadline;
889 if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
890 cl->cl_eligible.dx = 0;
891 cl->cl_eligible.dy = 0;
892 }
893 cl->cl_flags |= HFSC_RSC;
894 }
895
896 static void
hfsc_change_fsc(struct hfsc_class * cl,struct tc_service_curve * fsc)897 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
898 {
899 sc2isc(fsc, &cl->cl_fsc);
900 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
901 cl->cl_flags |= HFSC_FSC;
902 }
903
904 static void
hfsc_change_usc(struct hfsc_class * cl,struct tc_service_curve * usc,u64 cur_time)905 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
906 u64 cur_time)
907 {
908 sc2isc(usc, &cl->cl_usc);
909 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
910 cl->cl_flags |= HFSC_USC;
911 }
912
913 static void
hfsc_upgrade_rt(struct hfsc_class * cl)914 hfsc_upgrade_rt(struct hfsc_class *cl)
915 {
916 cl->cl_fsc = cl->cl_rsc;
917 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
918 cl->cl_flags |= HFSC_FSC;
919 }
920
921 static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
922 [TCA_HFSC_RSC] = { .len = sizeof(struct tc_service_curve) },
923 [TCA_HFSC_FSC] = { .len = sizeof(struct tc_service_curve) },
924 [TCA_HFSC_USC] = { .len = sizeof(struct tc_service_curve) },
925 };
926
927 static int
hfsc_change_class(struct Qdisc * sch,u32 classid,u32 parentid,struct nlattr ** tca,unsigned long * arg,struct netlink_ext_ack * extack)928 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
929 struct nlattr **tca, unsigned long *arg,
930 struct netlink_ext_ack *extack)
931 {
932 struct hfsc_sched *q = qdisc_priv(sch);
933 struct hfsc_class *cl = (struct hfsc_class *)*arg;
934 struct hfsc_class *parent = NULL;
935 struct nlattr *opt = tca[TCA_OPTIONS];
936 struct nlattr *tb[TCA_HFSC_MAX + 1];
937 struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
938 u64 cur_time;
939 int err;
940
941 if (opt == NULL)
942 return -EINVAL;
943
944 err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
945 NULL);
946 if (err < 0)
947 return err;
948
949 if (tb[TCA_HFSC_RSC]) {
950 rsc = nla_data(tb[TCA_HFSC_RSC]);
951 if (rsc->m1 == 0 && rsc->m2 == 0)
952 rsc = NULL;
953 }
954
955 if (tb[TCA_HFSC_FSC]) {
956 fsc = nla_data(tb[TCA_HFSC_FSC]);
957 if (fsc->m1 == 0 && fsc->m2 == 0)
958 fsc = NULL;
959 }
960
961 if (tb[TCA_HFSC_USC]) {
962 usc = nla_data(tb[TCA_HFSC_USC]);
963 if (usc->m1 == 0 && usc->m2 == 0)
964 usc = NULL;
965 }
966
967 if (cl != NULL) {
968 int old_flags;
969 int len = 0;
970
971 if (parentid) {
972 if (cl->cl_parent &&
973 cl->cl_parent->cl_common.classid != parentid)
974 return -EINVAL;
975 if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
976 return -EINVAL;
977 }
978 cur_time = psched_get_time();
979
980 if (tca[TCA_RATE]) {
981 err = gen_replace_estimator(&cl->bstats, NULL,
982 &cl->rate_est,
983 NULL,
984 true,
985 tca[TCA_RATE]);
986 if (err)
987 return err;
988 }
989
990 sch_tree_lock(sch);
991 old_flags = cl->cl_flags;
992
993 if (rsc != NULL)
994 hfsc_change_rsc(cl, rsc, cur_time);
995 if (fsc != NULL)
996 hfsc_change_fsc(cl, fsc);
997 if (usc != NULL)
998 hfsc_change_usc(cl, usc, cur_time);
999
1000 if (cl->qdisc->q.qlen != 0)
1001 len = qdisc_peek_len(cl->qdisc);
1002 /* Check queue length again since some qdisc implementations
1003 * (e.g., netem/codel) might empty the queue during the peek
1004 * operation.
1005 */
1006 if (cl->qdisc->q.qlen != 0) {
1007 if (cl->cl_flags & HFSC_RSC) {
1008 if (old_flags & HFSC_RSC)
1009 update_ed(cl, len);
1010 else
1011 init_ed(cl, len);
1012 }
1013
1014 if (cl->cl_flags & HFSC_FSC) {
1015 if (old_flags & HFSC_FSC)
1016 update_vf(cl, 0, cur_time);
1017 else
1018 init_vf(cl, len);
1019 }
1020 }
1021 sch_tree_unlock(sch);
1022
1023 return 0;
1024 }
1025
1026 if (parentid == TC_H_ROOT)
1027 return -EEXIST;
1028
1029 parent = &q->root;
1030 if (parentid) {
1031 parent = hfsc_find_class(parentid, sch);
1032 if (parent == NULL)
1033 return -ENOENT;
1034 }
1035
1036 if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1037 return -EINVAL;
1038 if (hfsc_find_class(classid, sch))
1039 return -EEXIST;
1040
1041 if (rsc == NULL && fsc == NULL)
1042 return -EINVAL;
1043
1044 cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1045 if (cl == NULL)
1046 return -ENOBUFS;
1047
1048 RB_CLEAR_NODE(&cl->el_node);
1049
1050 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1051 if (err) {
1052 kfree(cl);
1053 return err;
1054 }
1055
1056 if (tca[TCA_RATE]) {
1057 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1058 NULL, true, tca[TCA_RATE]);
1059 if (err) {
1060 tcf_block_put(cl->block);
1061 kfree(cl);
1062 return err;
1063 }
1064 }
1065
1066 if (rsc != NULL)
1067 hfsc_change_rsc(cl, rsc, 0);
1068 if (fsc != NULL)
1069 hfsc_change_fsc(cl, fsc);
1070 if (usc != NULL)
1071 hfsc_change_usc(cl, usc, 0);
1072
1073 cl->cl_common.classid = classid;
1074 cl->sched = q;
1075 cl->cl_parent = parent;
1076 cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1077 classid, NULL);
1078 if (cl->qdisc == NULL)
1079 cl->qdisc = &noop_qdisc;
1080 else
1081 qdisc_hash_add(cl->qdisc, true);
1082 INIT_LIST_HEAD(&cl->children);
1083 cl->vt_tree = RB_ROOT;
1084 cl->cf_tree = RB_ROOT;
1085
1086 sch_tree_lock(sch);
1087 /* Check if the inner class is a misconfigured 'rt' */
1088 if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) {
1089 NL_SET_ERR_MSG(extack,
1090 "Forced curve change on parent 'rt' to 'sc'");
1091 hfsc_upgrade_rt(parent);
1092 }
1093 qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1094 list_add_tail(&cl->siblings, &parent->children);
1095 if (parent->level == 0)
1096 qdisc_purge_queue(parent->qdisc);
1097 hfsc_adjust_levels(parent);
1098 sch_tree_unlock(sch);
1099
1100 qdisc_class_hash_grow(sch, &q->clhash);
1101
1102 *arg = (unsigned long)cl;
1103 return 0;
1104 }
1105
1106 static void
hfsc_destroy_class(struct Qdisc * sch,struct hfsc_class * cl)1107 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1108 {
1109 struct hfsc_sched *q = qdisc_priv(sch);
1110
1111 tcf_block_put(cl->block);
1112 qdisc_put(cl->qdisc);
1113 gen_kill_estimator(&cl->rate_est);
1114 if (cl != &q->root)
1115 kfree(cl);
1116 }
1117
1118 static int
hfsc_delete_class(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1119 hfsc_delete_class(struct Qdisc *sch, unsigned long arg,
1120 struct netlink_ext_ack *extack)
1121 {
1122 struct hfsc_sched *q = qdisc_priv(sch);
1123 struct hfsc_class *cl = (struct hfsc_class *)arg;
1124
1125 if (cl->level > 0 || qdisc_class_in_use(&cl->cl_common) ||
1126 cl == &q->root) {
1127 NL_SET_ERR_MSG(extack, "HFSC class in use");
1128 return -EBUSY;
1129 }
1130
1131 sch_tree_lock(sch);
1132
1133 list_del(&cl->siblings);
1134 hfsc_adjust_levels(cl->cl_parent);
1135
1136 qdisc_purge_queue(cl->qdisc);
1137 qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1138
1139 sch_tree_unlock(sch);
1140
1141 hfsc_destroy_class(sch, cl);
1142 return 0;
1143 }
1144
1145 static struct hfsc_class *
hfsc_classify(struct sk_buff * skb,struct Qdisc * sch,int * qerr)1146 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1147 {
1148 struct hfsc_sched *q = qdisc_priv(sch);
1149 struct hfsc_class *head, *cl;
1150 struct tcf_result res;
1151 struct tcf_proto *tcf;
1152 int result;
1153
1154 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1155 (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1156 if (cl->level == 0)
1157 return cl;
1158
1159 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1160 head = &q->root;
1161 tcf = rcu_dereference_bh(q->root.filter_list);
1162 while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
1163 #ifdef CONFIG_NET_CLS_ACT
1164 switch (result) {
1165 case TC_ACT_QUEUED:
1166 case TC_ACT_STOLEN:
1167 case TC_ACT_TRAP:
1168 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1169 fallthrough;
1170 case TC_ACT_SHOT:
1171 return NULL;
1172 }
1173 #endif
1174 cl = (struct hfsc_class *)res.class;
1175 if (!cl) {
1176 cl = hfsc_find_class(res.classid, sch);
1177 if (!cl)
1178 break; /* filter selected invalid classid */
1179 if (cl->level >= head->level)
1180 break; /* filter may only point downwards */
1181 }
1182
1183 if (cl->level == 0)
1184 return cl; /* hit leaf class */
1185
1186 /* apply inner filter chain */
1187 tcf = rcu_dereference_bh(cl->filter_list);
1188 head = cl;
1189 }
1190
1191 /* classification failed, try default class */
1192 cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle),
1193 READ_ONCE(q->defcls)), sch);
1194 if (cl == NULL || cl->level > 0)
1195 return NULL;
1196
1197 return cl;
1198 }
1199
1200 static int
hfsc_graft_class(struct Qdisc * sch,unsigned long arg,struct Qdisc * new,struct Qdisc ** old,struct netlink_ext_ack * extack)1201 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1202 struct Qdisc **old, struct netlink_ext_ack *extack)
1203 {
1204 struct hfsc_class *cl = (struct hfsc_class *)arg;
1205
1206 if (cl->level > 0)
1207 return -EINVAL;
1208 if (new == NULL) {
1209 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1210 cl->cl_common.classid, NULL);
1211 if (new == NULL)
1212 new = &noop_qdisc;
1213 }
1214
1215 *old = qdisc_replace(sch, new, &cl->qdisc);
1216 return 0;
1217 }
1218
1219 static struct Qdisc *
hfsc_class_leaf(struct Qdisc * sch,unsigned long arg)1220 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1221 {
1222 struct hfsc_class *cl = (struct hfsc_class *)arg;
1223
1224 if (cl->level == 0)
1225 return cl->qdisc;
1226
1227 return NULL;
1228 }
1229
1230 static void
hfsc_qlen_notify(struct Qdisc * sch,unsigned long arg)1231 hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1232 {
1233 struct hfsc_class *cl = (struct hfsc_class *)arg;
1234
1235 /* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1236 * needs to be called explicitly to remove a class from vttree.
1237 */
1238 if (cl->cl_nactive)
1239 update_vf(cl, 0, 0);
1240 if (cl->cl_flags & HFSC_RSC)
1241 eltree_remove(cl);
1242 }
1243
1244 static unsigned long
hfsc_search_class(struct Qdisc * sch,u32 classid)1245 hfsc_search_class(struct Qdisc *sch, u32 classid)
1246 {
1247 return (unsigned long)hfsc_find_class(classid, sch);
1248 }
1249
1250 static unsigned long
hfsc_bind_tcf(struct Qdisc * sch,unsigned long parent,u32 classid)1251 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1252 {
1253 struct hfsc_class *p = (struct hfsc_class *)parent;
1254 struct hfsc_class *cl = hfsc_find_class(classid, sch);
1255
1256 if (cl != NULL) {
1257 if (p != NULL && p->level <= cl->level)
1258 return 0;
1259 qdisc_class_get(&cl->cl_common);
1260 }
1261
1262 return (unsigned long)cl;
1263 }
1264
1265 static void
hfsc_unbind_tcf(struct Qdisc * sch,unsigned long arg)1266 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1267 {
1268 struct hfsc_class *cl = (struct hfsc_class *)arg;
1269
1270 qdisc_class_put(&cl->cl_common);
1271 }
1272
hfsc_tcf_block(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1273 static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1274 struct netlink_ext_ack *extack)
1275 {
1276 struct hfsc_sched *q = qdisc_priv(sch);
1277 struct hfsc_class *cl = (struct hfsc_class *)arg;
1278
1279 if (cl == NULL)
1280 cl = &q->root;
1281
1282 return cl->block;
1283 }
1284
1285 static int
hfsc_dump_sc(struct sk_buff * skb,int attr,struct internal_sc * sc)1286 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1287 {
1288 struct tc_service_curve tsc;
1289
1290 tsc.m1 = sm2m(sc->sm1);
1291 tsc.d = dx2d(sc->dx);
1292 tsc.m2 = sm2m(sc->sm2);
1293 if (nla_put(skb, attr, sizeof(tsc), &tsc))
1294 goto nla_put_failure;
1295
1296 return skb->len;
1297
1298 nla_put_failure:
1299 return -1;
1300 }
1301
1302 static int
hfsc_dump_curves(struct sk_buff * skb,struct hfsc_class * cl)1303 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1304 {
1305 if ((cl->cl_flags & HFSC_RSC) &&
1306 (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1307 goto nla_put_failure;
1308
1309 if ((cl->cl_flags & HFSC_FSC) &&
1310 (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1311 goto nla_put_failure;
1312
1313 if ((cl->cl_flags & HFSC_USC) &&
1314 (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1315 goto nla_put_failure;
1316
1317 return skb->len;
1318
1319 nla_put_failure:
1320 return -1;
1321 }
1322
1323 static int
hfsc_dump_class(struct Qdisc * sch,unsigned long arg,struct sk_buff * skb,struct tcmsg * tcm)1324 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1325 struct tcmsg *tcm)
1326 {
1327 struct hfsc_class *cl = (struct hfsc_class *)arg;
1328 struct nlattr *nest;
1329
1330 tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1331 TC_H_ROOT;
1332 tcm->tcm_handle = cl->cl_common.classid;
1333 if (cl->level == 0)
1334 tcm->tcm_info = cl->qdisc->handle;
1335
1336 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1337 if (nest == NULL)
1338 goto nla_put_failure;
1339 if (hfsc_dump_curves(skb, cl) < 0)
1340 goto nla_put_failure;
1341 return nla_nest_end(skb, nest);
1342
1343 nla_put_failure:
1344 nla_nest_cancel(skb, nest);
1345 return -EMSGSIZE;
1346 }
1347
1348 static int
hfsc_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)1349 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1350 struct gnet_dump *d)
1351 {
1352 struct hfsc_class *cl = (struct hfsc_class *)arg;
1353 struct tc_hfsc_stats xstats;
1354 __u32 qlen;
1355
1356 qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1357 xstats.level = cl->level;
1358 xstats.period = cl->cl_vtperiod;
1359 xstats.work = cl->cl_total;
1360 xstats.rtwork = cl->cl_cumul;
1361
1362 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
1363 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1364 gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1365 return -1;
1366
1367 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1368 }
1369
1370
1371
1372 static void
hfsc_walk(struct Qdisc * sch,struct qdisc_walker * arg)1373 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1374 {
1375 struct hfsc_sched *q = qdisc_priv(sch);
1376 struct hfsc_class *cl;
1377 unsigned int i;
1378
1379 if (arg->stop)
1380 return;
1381
1382 for (i = 0; i < q->clhash.hashsize; i++) {
1383 hlist_for_each_entry(cl, &q->clhash.hash[i],
1384 cl_common.hnode) {
1385 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
1386 return;
1387 }
1388 }
1389 }
1390
1391 static void
hfsc_schedule_watchdog(struct Qdisc * sch)1392 hfsc_schedule_watchdog(struct Qdisc *sch)
1393 {
1394 struct hfsc_sched *q = qdisc_priv(sch);
1395 struct hfsc_class *cl;
1396 u64 next_time = 0;
1397
1398 cl = eltree_get_minel(q);
1399 if (cl)
1400 next_time = cl->cl_e;
1401 if (q->root.cl_cfmin != 0) {
1402 if (next_time == 0 || next_time > q->root.cl_cfmin)
1403 next_time = q->root.cl_cfmin;
1404 }
1405 if (next_time)
1406 qdisc_watchdog_schedule(&q->watchdog, next_time);
1407 }
1408
1409 static int
hfsc_init_qdisc(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1410 hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1411 struct netlink_ext_ack *extack)
1412 {
1413 struct hfsc_sched *q = qdisc_priv(sch);
1414 struct tc_hfsc_qopt *qopt;
1415 int err;
1416
1417 qdisc_watchdog_init(&q->watchdog, sch);
1418
1419 if (!opt || nla_len(opt) < sizeof(*qopt))
1420 return -EINVAL;
1421 qopt = nla_data(opt);
1422
1423 q->defcls = qopt->defcls;
1424 err = qdisc_class_hash_init(&q->clhash);
1425 if (err < 0)
1426 return err;
1427 q->eligible = RB_ROOT;
1428
1429 err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1430 if (err)
1431 return err;
1432
1433 gnet_stats_basic_sync_init(&q->root.bstats);
1434 q->root.cl_common.classid = sch->handle;
1435 q->root.sched = q;
1436 q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1437 sch->handle, NULL);
1438 if (q->root.qdisc == NULL)
1439 q->root.qdisc = &noop_qdisc;
1440 else
1441 qdisc_hash_add(q->root.qdisc, true);
1442 INIT_LIST_HEAD(&q->root.children);
1443 q->root.vt_tree = RB_ROOT;
1444 q->root.cf_tree = RB_ROOT;
1445
1446 qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1447 qdisc_class_hash_grow(sch, &q->clhash);
1448
1449 return 0;
1450 }
1451
1452 static int
hfsc_change_qdisc(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1453 hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1454 struct netlink_ext_ack *extack)
1455 {
1456 struct hfsc_sched *q = qdisc_priv(sch);
1457 struct tc_hfsc_qopt *qopt;
1458
1459 if (nla_len(opt) < sizeof(*qopt))
1460 return -EINVAL;
1461 qopt = nla_data(opt);
1462
1463 WRITE_ONCE(q->defcls, qopt->defcls);
1464
1465 return 0;
1466 }
1467
1468 static void
hfsc_reset_class(struct hfsc_class * cl)1469 hfsc_reset_class(struct hfsc_class *cl)
1470 {
1471 cl->cl_total = 0;
1472 cl->cl_cumul = 0;
1473 cl->cl_d = 0;
1474 cl->cl_e = 0;
1475 cl->cl_vt = 0;
1476 cl->cl_vtadj = 0;
1477 cl->cl_cvtmin = 0;
1478 cl->cl_cvtoff = 0;
1479 cl->cl_vtperiod = 0;
1480 cl->cl_parentperiod = 0;
1481 cl->cl_f = 0;
1482 cl->cl_myf = 0;
1483 cl->cl_cfmin = 0;
1484 cl->cl_nactive = 0;
1485
1486 cl->vt_tree = RB_ROOT;
1487 cl->cf_tree = RB_ROOT;
1488 qdisc_reset(cl->qdisc);
1489
1490 if (cl->cl_flags & HFSC_RSC)
1491 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1492 if (cl->cl_flags & HFSC_FSC)
1493 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1494 if (cl->cl_flags & HFSC_USC)
1495 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1496 }
1497
1498 static void
hfsc_reset_qdisc(struct Qdisc * sch)1499 hfsc_reset_qdisc(struct Qdisc *sch)
1500 {
1501 struct hfsc_sched *q = qdisc_priv(sch);
1502 struct hfsc_class *cl;
1503 unsigned int i;
1504
1505 for (i = 0; i < q->clhash.hashsize; i++) {
1506 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1507 hfsc_reset_class(cl);
1508 }
1509 q->eligible = RB_ROOT;
1510 qdisc_watchdog_cancel(&q->watchdog);
1511 }
1512
1513 static void
hfsc_destroy_qdisc(struct Qdisc * sch)1514 hfsc_destroy_qdisc(struct Qdisc *sch)
1515 {
1516 struct hfsc_sched *q = qdisc_priv(sch);
1517 struct hlist_node *next;
1518 struct hfsc_class *cl;
1519 unsigned int i;
1520
1521 for (i = 0; i < q->clhash.hashsize; i++) {
1522 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
1523 tcf_block_put(cl->block);
1524 cl->block = NULL;
1525 }
1526 }
1527 for (i = 0; i < q->clhash.hashsize; i++) {
1528 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1529 cl_common.hnode)
1530 hfsc_destroy_class(sch, cl);
1531 }
1532 qdisc_class_hash_destroy(&q->clhash);
1533 qdisc_watchdog_cancel(&q->watchdog);
1534 }
1535
1536 static int
hfsc_dump_qdisc(struct Qdisc * sch,struct sk_buff * skb)1537 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1538 {
1539 struct hfsc_sched *q = qdisc_priv(sch);
1540 unsigned char *b = skb_tail_pointer(skb);
1541 struct tc_hfsc_qopt qopt;
1542
1543 qopt.defcls = READ_ONCE(q->defcls);
1544 if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1545 goto nla_put_failure;
1546 return skb->len;
1547
1548 nla_put_failure:
1549 nlmsg_trim(skb, b);
1550 return -1;
1551 }
1552
1553 static int
hfsc_enqueue(struct sk_buff * skb,struct Qdisc * sch,struct sk_buff ** to_free)1554 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1555 {
1556 unsigned int len = qdisc_pkt_len(skb);
1557 struct hfsc_class *cl;
1558 int err;
1559 bool first;
1560
1561 cl = hfsc_classify(skb, sch, &err);
1562 if (cl == NULL) {
1563 if (err & __NET_XMIT_BYPASS)
1564 qdisc_qstats_drop(sch);
1565 __qdisc_drop(skb, to_free);
1566 return err;
1567 }
1568
1569 first = !cl->qdisc->q.qlen;
1570 err = qdisc_enqueue(skb, cl->qdisc, to_free);
1571 if (unlikely(err != NET_XMIT_SUCCESS)) {
1572 if (net_xmit_drop_count(err)) {
1573 cl->qstats.drops++;
1574 qdisc_qstats_drop(sch);
1575 }
1576 return err;
1577 }
1578
1579 sch->qstats.backlog += len;
1580 sch->q.qlen++;
1581
1582 if (first && !cl_in_el_or_vttree(cl)) {
1583 if (cl->cl_flags & HFSC_RSC)
1584 init_ed(cl, len);
1585 if (cl->cl_flags & HFSC_FSC)
1586 init_vf(cl, len);
1587 /*
1588 * If this is the first packet, isolate the head so an eventual
1589 * head drop before the first dequeue operation has no chance
1590 * to invalidate the deadline.
1591 */
1592 if (cl->cl_flags & HFSC_RSC)
1593 cl->qdisc->ops->peek(cl->qdisc);
1594
1595 }
1596
1597 return NET_XMIT_SUCCESS;
1598 }
1599
1600 static struct sk_buff *
hfsc_dequeue(struct Qdisc * sch)1601 hfsc_dequeue(struct Qdisc *sch)
1602 {
1603 struct hfsc_sched *q = qdisc_priv(sch);
1604 struct hfsc_class *cl;
1605 struct sk_buff *skb;
1606 u64 cur_time;
1607 unsigned int next_len;
1608 int realtime = 0;
1609
1610 if (sch->q.qlen == 0)
1611 return NULL;
1612
1613 cur_time = psched_get_time();
1614
1615 /*
1616 * if there are eligible classes, use real-time criteria.
1617 * find the class with the minimum deadline among
1618 * the eligible classes.
1619 */
1620 cl = eltree_get_mindl(q, cur_time);
1621 if (cl) {
1622 realtime = 1;
1623 } else {
1624 /*
1625 * use link-sharing criteria
1626 * get the class with the minimum vt in the hierarchy
1627 */
1628 cl = vttree_get_minvt(&q->root, cur_time);
1629 if (cl == NULL) {
1630 qdisc_qstats_overlimit(sch);
1631 hfsc_schedule_watchdog(sch);
1632 return NULL;
1633 }
1634 }
1635
1636 skb = qdisc_dequeue_peeked(cl->qdisc);
1637 if (skb == NULL) {
1638 qdisc_warn_nonwc("HFSC", cl->qdisc);
1639 return NULL;
1640 }
1641
1642 bstats_update(&cl->bstats, skb);
1643 update_vf(cl, qdisc_pkt_len(skb), cur_time);
1644 if (realtime)
1645 cl->cl_cumul += qdisc_pkt_len(skb);
1646
1647 if (cl->cl_flags & HFSC_RSC) {
1648 if (cl->qdisc->q.qlen != 0) {
1649 /* update ed */
1650 next_len = qdisc_peek_len(cl->qdisc);
1651 /* Check queue length again since some qdisc implementations
1652 * (e.g., netem/codel) might empty the queue during the peek
1653 * operation.
1654 */
1655 if (cl->qdisc->q.qlen != 0) {
1656 if (realtime)
1657 update_ed(cl, next_len);
1658 else
1659 update_d(cl, next_len);
1660 }
1661 } else {
1662 /* the class becomes passive */
1663 eltree_remove(cl);
1664 }
1665 }
1666
1667 qdisc_bstats_update(sch, skb);
1668 qdisc_qstats_backlog_dec(sch, skb);
1669 sch->q.qlen--;
1670
1671 return skb;
1672 }
1673
1674 static const struct Qdisc_class_ops hfsc_class_ops = {
1675 .change = hfsc_change_class,
1676 .delete = hfsc_delete_class,
1677 .graft = hfsc_graft_class,
1678 .leaf = hfsc_class_leaf,
1679 .qlen_notify = hfsc_qlen_notify,
1680 .find = hfsc_search_class,
1681 .bind_tcf = hfsc_bind_tcf,
1682 .unbind_tcf = hfsc_unbind_tcf,
1683 .tcf_block = hfsc_tcf_block,
1684 .dump = hfsc_dump_class,
1685 .dump_stats = hfsc_dump_class_stats,
1686 .walk = hfsc_walk
1687 };
1688
1689 static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1690 .id = "hfsc",
1691 .init = hfsc_init_qdisc,
1692 .change = hfsc_change_qdisc,
1693 .reset = hfsc_reset_qdisc,
1694 .destroy = hfsc_destroy_qdisc,
1695 .dump = hfsc_dump_qdisc,
1696 .enqueue = hfsc_enqueue,
1697 .dequeue = hfsc_dequeue,
1698 .peek = qdisc_peek_dequeued,
1699 .cl_ops = &hfsc_class_ops,
1700 .priv_size = sizeof(struct hfsc_sched),
1701 .owner = THIS_MODULE
1702 };
1703 MODULE_ALIAS_NET_SCH("hfsc");
1704
1705 static int __init
hfsc_init(void)1706 hfsc_init(void)
1707 {
1708 return register_qdisc(&hfsc_qdisc_ops);
1709 }
1710
1711 static void __exit
hfsc_cleanup(void)1712 hfsc_cleanup(void)
1713 {
1714 unregister_qdisc(&hfsc_qdisc_ops);
1715 }
1716
1717 MODULE_LICENSE("GPL");
1718 MODULE_DESCRIPTION("Hierarchical Fair Service Curve scheduler");
1719 module_init(hfsc_init);
1720 module_exit(hfsc_cleanup);
1721