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 void
hfsc_adjust_levels(struct hfsc_class * cl)839 hfsc_adjust_levels(struct hfsc_class *cl)
840 {
841 struct hfsc_class *p;
842 unsigned int level;
843
844 do {
845 level = 0;
846 list_for_each_entry(p, &cl->children, siblings) {
847 if (p->level >= level)
848 level = p->level + 1;
849 }
850 cl->level = level;
851 } while ((cl = cl->cl_parent) != NULL);
852 }
853
854 static inline struct hfsc_class *
hfsc_find_class(u32 classid,struct Qdisc * sch)855 hfsc_find_class(u32 classid, struct Qdisc *sch)
856 {
857 struct hfsc_sched *q = qdisc_priv(sch);
858 struct Qdisc_class_common *clc;
859
860 clc = qdisc_class_find(&q->clhash, classid);
861 if (clc == NULL)
862 return NULL;
863 return container_of(clc, struct hfsc_class, cl_common);
864 }
865
866 static void
hfsc_change_rsc(struct hfsc_class * cl,struct tc_service_curve * rsc,u64 cur_time)867 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
868 u64 cur_time)
869 {
870 sc2isc(rsc, &cl->cl_rsc);
871 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
872 cl->cl_eligible = cl->cl_deadline;
873 if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
874 cl->cl_eligible.dx = 0;
875 cl->cl_eligible.dy = 0;
876 }
877 cl->cl_flags |= HFSC_RSC;
878 }
879
880 static void
hfsc_change_fsc(struct hfsc_class * cl,struct tc_service_curve * fsc)881 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
882 {
883 sc2isc(fsc, &cl->cl_fsc);
884 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
885 cl->cl_flags |= HFSC_FSC;
886 }
887
888 static void
hfsc_change_usc(struct hfsc_class * cl,struct tc_service_curve * usc,u64 cur_time)889 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
890 u64 cur_time)
891 {
892 sc2isc(usc, &cl->cl_usc);
893 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
894 cl->cl_flags |= HFSC_USC;
895 }
896
897 static void
hfsc_upgrade_rt(struct hfsc_class * cl)898 hfsc_upgrade_rt(struct hfsc_class *cl)
899 {
900 cl->cl_fsc = cl->cl_rsc;
901 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
902 cl->cl_flags |= HFSC_FSC;
903 }
904
905 static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
906 [TCA_HFSC_RSC] = { .len = sizeof(struct tc_service_curve) },
907 [TCA_HFSC_FSC] = { .len = sizeof(struct tc_service_curve) },
908 [TCA_HFSC_USC] = { .len = sizeof(struct tc_service_curve) },
909 };
910
911 static int
hfsc_change_class(struct Qdisc * sch,u32 classid,u32 parentid,struct nlattr ** tca,unsigned long * arg,struct netlink_ext_ack * extack)912 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
913 struct nlattr **tca, unsigned long *arg,
914 struct netlink_ext_ack *extack)
915 {
916 struct hfsc_sched *q = qdisc_priv(sch);
917 struct hfsc_class *cl = (struct hfsc_class *)*arg;
918 struct hfsc_class *parent = NULL;
919 struct nlattr *opt = tca[TCA_OPTIONS];
920 struct nlattr *tb[TCA_HFSC_MAX + 1];
921 struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
922 u64 cur_time;
923 int err;
924
925 if (opt == NULL)
926 return -EINVAL;
927
928 err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
929 NULL);
930 if (err < 0)
931 return err;
932
933 if (tb[TCA_HFSC_RSC]) {
934 rsc = nla_data(tb[TCA_HFSC_RSC]);
935 if (rsc->m1 == 0 && rsc->m2 == 0)
936 rsc = NULL;
937 }
938
939 if (tb[TCA_HFSC_FSC]) {
940 fsc = nla_data(tb[TCA_HFSC_FSC]);
941 if (fsc->m1 == 0 && fsc->m2 == 0)
942 fsc = NULL;
943 }
944
945 if (tb[TCA_HFSC_USC]) {
946 usc = nla_data(tb[TCA_HFSC_USC]);
947 if (usc->m1 == 0 && usc->m2 == 0)
948 usc = NULL;
949 }
950
951 if (cl != NULL) {
952 int old_flags;
953 int len = 0;
954
955 if (parentid) {
956 if (cl->cl_parent &&
957 cl->cl_parent->cl_common.classid != parentid)
958 return -EINVAL;
959 if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
960 return -EINVAL;
961 }
962 cur_time = psched_get_time();
963
964 if (tca[TCA_RATE]) {
965 err = gen_replace_estimator(&cl->bstats, NULL,
966 &cl->rate_est,
967 NULL,
968 true,
969 tca[TCA_RATE]);
970 if (err)
971 return err;
972 }
973
974 sch_tree_lock(sch);
975 old_flags = cl->cl_flags;
976
977 if (rsc != NULL)
978 hfsc_change_rsc(cl, rsc, cur_time);
979 if (fsc != NULL)
980 hfsc_change_fsc(cl, fsc);
981 if (usc != NULL)
982 hfsc_change_usc(cl, usc, cur_time);
983
984 if (cl->qdisc->q.qlen != 0)
985 len = qdisc_peek_len(cl->qdisc);
986 /* Check queue length again since some qdisc implementations
987 * (e.g., netem/codel) might empty the queue during the peek
988 * operation.
989 */
990 if (cl->qdisc->q.qlen != 0) {
991 if (cl->cl_flags & HFSC_RSC) {
992 if (old_flags & HFSC_RSC)
993 update_ed(cl, len);
994 else
995 init_ed(cl, len);
996 }
997
998 if (cl->cl_flags & HFSC_FSC) {
999 if (old_flags & HFSC_FSC)
1000 update_vf(cl, 0, cur_time);
1001 else
1002 init_vf(cl, len);
1003 }
1004 }
1005 sch_tree_unlock(sch);
1006
1007 return 0;
1008 }
1009
1010 if (parentid == TC_H_ROOT)
1011 return -EEXIST;
1012
1013 parent = &q->root;
1014 if (parentid) {
1015 parent = hfsc_find_class(parentid, sch);
1016 if (parent == NULL)
1017 return -ENOENT;
1018 }
1019
1020 if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1021 return -EINVAL;
1022 if (hfsc_find_class(classid, sch))
1023 return -EEXIST;
1024
1025 if (rsc == NULL && fsc == NULL)
1026 return -EINVAL;
1027
1028 cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1029 if (cl == NULL)
1030 return -ENOBUFS;
1031
1032 RB_CLEAR_NODE(&cl->el_node);
1033
1034 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1035 if (err) {
1036 kfree(cl);
1037 return err;
1038 }
1039
1040 if (tca[TCA_RATE]) {
1041 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1042 NULL, true, tca[TCA_RATE]);
1043 if (err) {
1044 tcf_block_put(cl->block);
1045 kfree(cl);
1046 return err;
1047 }
1048 }
1049
1050 if (rsc != NULL)
1051 hfsc_change_rsc(cl, rsc, 0);
1052 if (fsc != NULL)
1053 hfsc_change_fsc(cl, fsc);
1054 if (usc != NULL)
1055 hfsc_change_usc(cl, usc, 0);
1056
1057 cl->cl_common.classid = classid;
1058 cl->sched = q;
1059 cl->cl_parent = parent;
1060 cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1061 classid, NULL);
1062 if (cl->qdisc == NULL)
1063 cl->qdisc = &noop_qdisc;
1064 else
1065 qdisc_hash_add(cl->qdisc, true);
1066 INIT_LIST_HEAD(&cl->children);
1067 cl->vt_tree = RB_ROOT;
1068 cl->cf_tree = RB_ROOT;
1069
1070 sch_tree_lock(sch);
1071 /* Check if the inner class is a misconfigured 'rt' */
1072 if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) {
1073 NL_SET_ERR_MSG(extack,
1074 "Forced curve change on parent 'rt' to 'sc'");
1075 hfsc_upgrade_rt(parent);
1076 }
1077 qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1078 list_add_tail(&cl->siblings, &parent->children);
1079 if (parent->level == 0)
1080 qdisc_purge_queue(parent->qdisc);
1081 hfsc_adjust_levels(parent);
1082 sch_tree_unlock(sch);
1083
1084 qdisc_class_hash_grow(sch, &q->clhash);
1085
1086 *arg = (unsigned long)cl;
1087 return 0;
1088 }
1089
1090 static void
hfsc_destroy_class(struct Qdisc * sch,struct hfsc_class * cl)1091 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1092 {
1093 struct hfsc_sched *q = qdisc_priv(sch);
1094
1095 tcf_block_put(cl->block);
1096 qdisc_put(cl->qdisc);
1097 gen_kill_estimator(&cl->rate_est);
1098 if (cl != &q->root)
1099 kfree(cl);
1100 }
1101
1102 static int
hfsc_delete_class(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1103 hfsc_delete_class(struct Qdisc *sch, unsigned long arg,
1104 struct netlink_ext_ack *extack)
1105 {
1106 struct hfsc_sched *q = qdisc_priv(sch);
1107 struct hfsc_class *cl = (struct hfsc_class *)arg;
1108
1109 if (cl->level > 0 || qdisc_class_in_use(&cl->cl_common) ||
1110 cl == &q->root) {
1111 NL_SET_ERR_MSG(extack, "HFSC class in use");
1112 return -EBUSY;
1113 }
1114
1115 sch_tree_lock(sch);
1116
1117 list_del(&cl->siblings);
1118 hfsc_adjust_levels(cl->cl_parent);
1119
1120 qdisc_purge_queue(cl->qdisc);
1121 qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1122
1123 sch_tree_unlock(sch);
1124
1125 hfsc_destroy_class(sch, cl);
1126 return 0;
1127 }
1128
1129 static struct hfsc_class *
hfsc_classify(struct sk_buff * skb,struct Qdisc * sch,int * qerr)1130 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1131 {
1132 struct hfsc_sched *q = qdisc_priv(sch);
1133 struct hfsc_class *head, *cl;
1134 struct tcf_result res;
1135 struct tcf_proto *tcf;
1136 int result;
1137
1138 if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1139 (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1140 if (cl->level == 0)
1141 return cl;
1142
1143 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1144 head = &q->root;
1145 tcf = rcu_dereference_bh(q->root.filter_list);
1146 while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
1147 #ifdef CONFIG_NET_CLS_ACT
1148 switch (result) {
1149 case TC_ACT_QUEUED:
1150 case TC_ACT_STOLEN:
1151 case TC_ACT_TRAP:
1152 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1153 fallthrough;
1154 case TC_ACT_SHOT:
1155 return NULL;
1156 }
1157 #endif
1158 cl = (struct hfsc_class *)res.class;
1159 if (!cl) {
1160 cl = hfsc_find_class(res.classid, sch);
1161 if (!cl)
1162 break; /* filter selected invalid classid */
1163 if (cl->level >= head->level)
1164 break; /* filter may only point downwards */
1165 }
1166
1167 if (cl->level == 0)
1168 return cl; /* hit leaf class */
1169
1170 /* apply inner filter chain */
1171 tcf = rcu_dereference_bh(cl->filter_list);
1172 head = cl;
1173 }
1174
1175 /* classification failed, try default class */
1176 cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle),
1177 READ_ONCE(q->defcls)), sch);
1178 if (cl == NULL || cl->level > 0)
1179 return NULL;
1180
1181 return cl;
1182 }
1183
1184 static int
hfsc_graft_class(struct Qdisc * sch,unsigned long arg,struct Qdisc * new,struct Qdisc ** old,struct netlink_ext_ack * extack)1185 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1186 struct Qdisc **old, struct netlink_ext_ack *extack)
1187 {
1188 struct hfsc_class *cl = (struct hfsc_class *)arg;
1189
1190 if (cl->level > 0)
1191 return -EINVAL;
1192 if (new == NULL) {
1193 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1194 cl->cl_common.classid, NULL);
1195 if (new == NULL)
1196 new = &noop_qdisc;
1197 }
1198
1199 *old = qdisc_replace(sch, new, &cl->qdisc);
1200 return 0;
1201 }
1202
1203 static struct Qdisc *
hfsc_class_leaf(struct Qdisc * sch,unsigned long arg)1204 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1205 {
1206 struct hfsc_class *cl = (struct hfsc_class *)arg;
1207
1208 if (cl->level == 0)
1209 return cl->qdisc;
1210
1211 return NULL;
1212 }
1213
1214 static void
hfsc_qlen_notify(struct Qdisc * sch,unsigned long arg)1215 hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1216 {
1217 struct hfsc_class *cl = (struct hfsc_class *)arg;
1218
1219 /* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1220 * needs to be called explicitly to remove a class from vttree.
1221 */
1222 if (cl->cl_nactive)
1223 update_vf(cl, 0, 0);
1224 if (cl->cl_flags & HFSC_RSC)
1225 eltree_remove(cl);
1226 }
1227
1228 static unsigned long
hfsc_search_class(struct Qdisc * sch,u32 classid)1229 hfsc_search_class(struct Qdisc *sch, u32 classid)
1230 {
1231 return (unsigned long)hfsc_find_class(classid, sch);
1232 }
1233
1234 static unsigned long
hfsc_bind_tcf(struct Qdisc * sch,unsigned long parent,u32 classid)1235 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1236 {
1237 struct hfsc_class *p = (struct hfsc_class *)parent;
1238 struct hfsc_class *cl = hfsc_find_class(classid, sch);
1239
1240 if (cl != NULL) {
1241 if (p != NULL && p->level <= cl->level)
1242 return 0;
1243 qdisc_class_get(&cl->cl_common);
1244 }
1245
1246 return (unsigned long)cl;
1247 }
1248
1249 static void
hfsc_unbind_tcf(struct Qdisc * sch,unsigned long arg)1250 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1251 {
1252 struct hfsc_class *cl = (struct hfsc_class *)arg;
1253
1254 qdisc_class_put(&cl->cl_common);
1255 }
1256
hfsc_tcf_block(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1257 static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1258 struct netlink_ext_ack *extack)
1259 {
1260 struct hfsc_sched *q = qdisc_priv(sch);
1261 struct hfsc_class *cl = (struct hfsc_class *)arg;
1262
1263 if (cl == NULL)
1264 cl = &q->root;
1265
1266 return cl->block;
1267 }
1268
1269 static int
hfsc_dump_sc(struct sk_buff * skb,int attr,struct internal_sc * sc)1270 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1271 {
1272 struct tc_service_curve tsc;
1273
1274 tsc.m1 = sm2m(sc->sm1);
1275 tsc.d = dx2d(sc->dx);
1276 tsc.m2 = sm2m(sc->sm2);
1277 if (nla_put(skb, attr, sizeof(tsc), &tsc))
1278 goto nla_put_failure;
1279
1280 return skb->len;
1281
1282 nla_put_failure:
1283 return -1;
1284 }
1285
1286 static int
hfsc_dump_curves(struct sk_buff * skb,struct hfsc_class * cl)1287 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1288 {
1289 if ((cl->cl_flags & HFSC_RSC) &&
1290 (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1291 goto nla_put_failure;
1292
1293 if ((cl->cl_flags & HFSC_FSC) &&
1294 (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1295 goto nla_put_failure;
1296
1297 if ((cl->cl_flags & HFSC_USC) &&
1298 (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1299 goto nla_put_failure;
1300
1301 return skb->len;
1302
1303 nla_put_failure:
1304 return -1;
1305 }
1306
1307 static int
hfsc_dump_class(struct Qdisc * sch,unsigned long arg,struct sk_buff * skb,struct tcmsg * tcm)1308 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1309 struct tcmsg *tcm)
1310 {
1311 struct hfsc_class *cl = (struct hfsc_class *)arg;
1312 struct nlattr *nest;
1313
1314 tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1315 TC_H_ROOT;
1316 tcm->tcm_handle = cl->cl_common.classid;
1317 if (cl->level == 0)
1318 tcm->tcm_info = cl->qdisc->handle;
1319
1320 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1321 if (nest == NULL)
1322 goto nla_put_failure;
1323 if (hfsc_dump_curves(skb, cl) < 0)
1324 goto nla_put_failure;
1325 return nla_nest_end(skb, nest);
1326
1327 nla_put_failure:
1328 nla_nest_cancel(skb, nest);
1329 return -EMSGSIZE;
1330 }
1331
1332 static int
hfsc_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)1333 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1334 struct gnet_dump *d)
1335 {
1336 struct hfsc_class *cl = (struct hfsc_class *)arg;
1337 struct tc_hfsc_stats xstats;
1338 __u32 qlen;
1339
1340 qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1341 xstats.level = cl->level;
1342 xstats.period = cl->cl_vtperiod;
1343 xstats.work = cl->cl_total;
1344 xstats.rtwork = cl->cl_cumul;
1345
1346 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
1347 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1348 gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1349 return -1;
1350
1351 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1352 }
1353
1354
1355
1356 static void
hfsc_walk(struct Qdisc * sch,struct qdisc_walker * arg)1357 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1358 {
1359 struct hfsc_sched *q = qdisc_priv(sch);
1360 struct hfsc_class *cl;
1361 unsigned int i;
1362
1363 if (arg->stop)
1364 return;
1365
1366 for (i = 0; i < q->clhash.hashsize; i++) {
1367 hlist_for_each_entry(cl, &q->clhash.hash[i],
1368 cl_common.hnode) {
1369 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
1370 return;
1371 }
1372 }
1373 }
1374
1375 static void
hfsc_schedule_watchdog(struct Qdisc * sch)1376 hfsc_schedule_watchdog(struct Qdisc *sch)
1377 {
1378 struct hfsc_sched *q = qdisc_priv(sch);
1379 struct hfsc_class *cl;
1380 u64 next_time = 0;
1381
1382 cl = eltree_get_minel(q);
1383 if (cl)
1384 next_time = cl->cl_e;
1385 if (q->root.cl_cfmin != 0) {
1386 if (next_time == 0 || next_time > q->root.cl_cfmin)
1387 next_time = q->root.cl_cfmin;
1388 }
1389 if (next_time)
1390 qdisc_watchdog_schedule(&q->watchdog, next_time);
1391 }
1392
1393 static int
hfsc_init_qdisc(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1394 hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1395 struct netlink_ext_ack *extack)
1396 {
1397 struct hfsc_sched *q = qdisc_priv(sch);
1398 struct tc_hfsc_qopt *qopt;
1399 int err;
1400
1401 qdisc_watchdog_init(&q->watchdog, sch);
1402
1403 if (!opt || nla_len(opt) < sizeof(*qopt))
1404 return -EINVAL;
1405 qopt = nla_data(opt);
1406
1407 q->defcls = qopt->defcls;
1408 err = qdisc_class_hash_init(&q->clhash);
1409 if (err < 0)
1410 return err;
1411 q->eligible = RB_ROOT;
1412
1413 err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1414 if (err)
1415 return err;
1416
1417 gnet_stats_basic_sync_init(&q->root.bstats);
1418 q->root.cl_common.classid = sch->handle;
1419 q->root.sched = q;
1420 q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1421 sch->handle, NULL);
1422 if (q->root.qdisc == NULL)
1423 q->root.qdisc = &noop_qdisc;
1424 else
1425 qdisc_hash_add(q->root.qdisc, true);
1426 INIT_LIST_HEAD(&q->root.children);
1427 q->root.vt_tree = RB_ROOT;
1428 q->root.cf_tree = RB_ROOT;
1429
1430 qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1431 qdisc_class_hash_grow(sch, &q->clhash);
1432
1433 return 0;
1434 }
1435
1436 static int
hfsc_change_qdisc(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1437 hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1438 struct netlink_ext_ack *extack)
1439 {
1440 struct hfsc_sched *q = qdisc_priv(sch);
1441 struct tc_hfsc_qopt *qopt;
1442
1443 if (nla_len(opt) < sizeof(*qopt))
1444 return -EINVAL;
1445 qopt = nla_data(opt);
1446
1447 WRITE_ONCE(q->defcls, qopt->defcls);
1448
1449 return 0;
1450 }
1451
1452 static void
hfsc_reset_class(struct hfsc_class * cl)1453 hfsc_reset_class(struct hfsc_class *cl)
1454 {
1455 cl->cl_total = 0;
1456 cl->cl_cumul = 0;
1457 cl->cl_d = 0;
1458 cl->cl_e = 0;
1459 cl->cl_vt = 0;
1460 cl->cl_vtadj = 0;
1461 cl->cl_cvtmin = 0;
1462 cl->cl_cvtoff = 0;
1463 cl->cl_vtperiod = 0;
1464 cl->cl_parentperiod = 0;
1465 cl->cl_f = 0;
1466 cl->cl_myf = 0;
1467 cl->cl_cfmin = 0;
1468 cl->cl_nactive = 0;
1469
1470 cl->vt_tree = RB_ROOT;
1471 cl->cf_tree = RB_ROOT;
1472 qdisc_reset(cl->qdisc);
1473
1474 if (cl->cl_flags & HFSC_RSC)
1475 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1476 if (cl->cl_flags & HFSC_FSC)
1477 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1478 if (cl->cl_flags & HFSC_USC)
1479 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1480 }
1481
1482 static void
hfsc_reset_qdisc(struct Qdisc * sch)1483 hfsc_reset_qdisc(struct Qdisc *sch)
1484 {
1485 struct hfsc_sched *q = qdisc_priv(sch);
1486 struct hfsc_class *cl;
1487 unsigned int i;
1488
1489 for (i = 0; i < q->clhash.hashsize; i++) {
1490 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1491 hfsc_reset_class(cl);
1492 }
1493 q->eligible = RB_ROOT;
1494 qdisc_watchdog_cancel(&q->watchdog);
1495 }
1496
1497 static void
hfsc_destroy_qdisc(struct Qdisc * sch)1498 hfsc_destroy_qdisc(struct Qdisc *sch)
1499 {
1500 struct hfsc_sched *q = qdisc_priv(sch);
1501 struct hlist_node *next;
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 tcf_block_put(cl->block);
1508 cl->block = NULL;
1509 }
1510 }
1511 for (i = 0; i < q->clhash.hashsize; i++) {
1512 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1513 cl_common.hnode)
1514 hfsc_destroy_class(sch, cl);
1515 }
1516 qdisc_class_hash_destroy(&q->clhash);
1517 qdisc_watchdog_cancel(&q->watchdog);
1518 }
1519
1520 static int
hfsc_dump_qdisc(struct Qdisc * sch,struct sk_buff * skb)1521 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1522 {
1523 struct hfsc_sched *q = qdisc_priv(sch);
1524 unsigned char *b = skb_tail_pointer(skb);
1525 struct tc_hfsc_qopt qopt;
1526
1527 qopt.defcls = READ_ONCE(q->defcls);
1528 if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1529 goto nla_put_failure;
1530 return skb->len;
1531
1532 nla_put_failure:
1533 nlmsg_trim(skb, b);
1534 return -1;
1535 }
1536
1537 static int
hfsc_enqueue(struct sk_buff * skb,struct Qdisc * sch,struct sk_buff ** to_free)1538 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1539 {
1540 unsigned int len = qdisc_pkt_len(skb);
1541 struct hfsc_class *cl;
1542 int err;
1543 bool first;
1544
1545 cl = hfsc_classify(skb, sch, &err);
1546 if (cl == NULL) {
1547 if (err & __NET_XMIT_BYPASS)
1548 qdisc_qstats_drop(sch);
1549 __qdisc_drop(skb, to_free);
1550 return err;
1551 }
1552
1553 first = !cl->qdisc->q.qlen;
1554 err = qdisc_enqueue(skb, cl->qdisc, to_free);
1555 if (unlikely(err != NET_XMIT_SUCCESS)) {
1556 if (net_xmit_drop_count(err)) {
1557 cl->qstats.drops++;
1558 qdisc_qstats_drop(sch);
1559 }
1560 return err;
1561 }
1562
1563 sch->qstats.backlog += len;
1564 sch->q.qlen++;
1565
1566 if (first && !cl_in_el_or_vttree(cl)) {
1567 if (cl->cl_flags & HFSC_RSC)
1568 init_ed(cl, len);
1569 if (cl->cl_flags & HFSC_FSC)
1570 init_vf(cl, len);
1571 /*
1572 * If this is the first packet, isolate the head so an eventual
1573 * head drop before the first dequeue operation has no chance
1574 * to invalidate the deadline.
1575 */
1576 if (cl->cl_flags & HFSC_RSC)
1577 cl->qdisc->ops->peek(cl->qdisc);
1578
1579 }
1580
1581 return NET_XMIT_SUCCESS;
1582 }
1583
1584 static struct sk_buff *
hfsc_dequeue(struct Qdisc * sch)1585 hfsc_dequeue(struct Qdisc *sch)
1586 {
1587 struct hfsc_sched *q = qdisc_priv(sch);
1588 struct hfsc_class *cl;
1589 struct sk_buff *skb;
1590 u64 cur_time;
1591 unsigned int next_len;
1592 int realtime = 0;
1593
1594 if (sch->q.qlen == 0)
1595 return NULL;
1596
1597 cur_time = psched_get_time();
1598
1599 /*
1600 * if there are eligible classes, use real-time criteria.
1601 * find the class with the minimum deadline among
1602 * the eligible classes.
1603 */
1604 cl = eltree_get_mindl(q, cur_time);
1605 if (cl) {
1606 realtime = 1;
1607 } else {
1608 /*
1609 * use link-sharing criteria
1610 * get the class with the minimum vt in the hierarchy
1611 */
1612 cl = vttree_get_minvt(&q->root, cur_time);
1613 if (cl == NULL) {
1614 qdisc_qstats_overlimit(sch);
1615 hfsc_schedule_watchdog(sch);
1616 return NULL;
1617 }
1618 }
1619
1620 skb = qdisc_dequeue_peeked(cl->qdisc);
1621 if (skb == NULL) {
1622 qdisc_warn_nonwc("HFSC", cl->qdisc);
1623 return NULL;
1624 }
1625
1626 bstats_update(&cl->bstats, skb);
1627 update_vf(cl, qdisc_pkt_len(skb), cur_time);
1628 if (realtime)
1629 cl->cl_cumul += qdisc_pkt_len(skb);
1630
1631 if (cl->cl_flags & HFSC_RSC) {
1632 if (cl->qdisc->q.qlen != 0) {
1633 /* update ed */
1634 next_len = qdisc_peek_len(cl->qdisc);
1635 /* Check queue length again since some qdisc implementations
1636 * (e.g., netem/codel) might empty the queue during the peek
1637 * operation.
1638 */
1639 if (cl->qdisc->q.qlen != 0) {
1640 if (realtime)
1641 update_ed(cl, next_len);
1642 else
1643 update_d(cl, next_len);
1644 }
1645 } else {
1646 /* the class becomes passive */
1647 eltree_remove(cl);
1648 }
1649 }
1650
1651 qdisc_bstats_update(sch, skb);
1652 qdisc_qstats_backlog_dec(sch, skb);
1653 sch->q.qlen--;
1654
1655 return skb;
1656 }
1657
1658 static const struct Qdisc_class_ops hfsc_class_ops = {
1659 .change = hfsc_change_class,
1660 .delete = hfsc_delete_class,
1661 .graft = hfsc_graft_class,
1662 .leaf = hfsc_class_leaf,
1663 .qlen_notify = hfsc_qlen_notify,
1664 .find = hfsc_search_class,
1665 .bind_tcf = hfsc_bind_tcf,
1666 .unbind_tcf = hfsc_unbind_tcf,
1667 .tcf_block = hfsc_tcf_block,
1668 .dump = hfsc_dump_class,
1669 .dump_stats = hfsc_dump_class_stats,
1670 .walk = hfsc_walk
1671 };
1672
1673 static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1674 .id = "hfsc",
1675 .init = hfsc_init_qdisc,
1676 .change = hfsc_change_qdisc,
1677 .reset = hfsc_reset_qdisc,
1678 .destroy = hfsc_destroy_qdisc,
1679 .dump = hfsc_dump_qdisc,
1680 .enqueue = hfsc_enqueue,
1681 .dequeue = hfsc_dequeue,
1682 .peek = qdisc_peek_dequeued,
1683 .cl_ops = &hfsc_class_ops,
1684 .priv_size = sizeof(struct hfsc_sched),
1685 .owner = THIS_MODULE
1686 };
1687 MODULE_ALIAS_NET_SCH("hfsc");
1688
1689 static int __init
hfsc_init(void)1690 hfsc_init(void)
1691 {
1692 return register_qdisc(&hfsc_qdisc_ops);
1693 }
1694
1695 static void __exit
hfsc_cleanup(void)1696 hfsc_cleanup(void)
1697 {
1698 unregister_qdisc(&hfsc_qdisc_ops);
1699 }
1700
1701 MODULE_LICENSE("GPL");
1702 MODULE_DESCRIPTION("Hierarchical Fair Service Curve scheduler");
1703 module_init(hfsc_init);
1704 module_exit(hfsc_cleanup);
1705