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TOMOYO Linux Cross Reference
Linux/net/sched/sch_hfsc.c

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  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         unsigned int    refcnt;         /* usage count */
114 
115         struct gnet_stats_basic_packed bstats;
116         struct gnet_stats_queue qstats;
117         struct gnet_stats_rate_est64 rate_est;
118         unsigned int    level;          /* class level in hierarchy */
119         struct tcf_proto __rcu *filter_list; /* filter list */
120         unsigned int    filter_cnt;     /* filter count */
121 
122         struct hfsc_sched *sched;       /* scheduler data */
123         struct hfsc_class *cl_parent;   /* parent class */
124         struct list_head siblings;      /* sibling classes */
125         struct list_head children;      /* child classes */
126         struct Qdisc    *qdisc;         /* leaf qdisc */
127 
128         struct rb_node el_node;         /* qdisc's eligible tree member */
129         struct rb_root vt_tree;         /* active children sorted by cl_vt */
130         struct rb_node vt_node;         /* parent's vt_tree member */
131         struct rb_root cf_tree;         /* active children sorted by cl_f */
132         struct rb_node cf_node;         /* parent's cf_heap member */
133         struct list_head dlist;         /* drop list member */
134 
135         u64     cl_total;               /* total work in bytes */
136         u64     cl_cumul;               /* cumulative work in bytes done by
137                                            real-time criteria */
138 
139         u64     cl_d;                   /* deadline*/
140         u64     cl_e;                   /* eligible time */
141         u64     cl_vt;                  /* virtual time */
142         u64     cl_f;                   /* time when this class will fit for
143                                            link-sharing, max(myf, cfmin) */
144         u64     cl_myf;                 /* my fit-time (calculated from this
145                                            class's own upperlimit curve) */
146         u64     cl_myfadj;              /* my fit-time adjustment (to cancel
147                                            history dependence) */
148         u64     cl_cfmin;               /* earliest children's fit-time (used
149                                            with cl_myf to obtain cl_f) */
150         u64     cl_cvtmin;              /* minimal virtual time among the
151                                            children fit for link-sharing
152                                            (monotonic within a period) */
153         u64     cl_vtadj;               /* intra-period cumulative vt
154                                            adjustment */
155         u64     cl_vtoff;               /* inter-period cumulative vt offset */
156         u64     cl_cvtmax;              /* max child's vt in the last period */
157         u64     cl_cvtoff;              /* cumulative cvtmax of all periods */
158         u64     cl_pcvtoff;             /* parent's cvtoff at initialization
159                                            time */
160 
161         struct internal_sc cl_rsc;      /* internal real-time service curve */
162         struct internal_sc cl_fsc;      /* internal fair service curve */
163         struct internal_sc cl_usc;      /* internal upperlimit service curve */
164         struct runtime_sc cl_deadline;  /* deadline curve */
165         struct runtime_sc cl_eligible;  /* eligible curve */
166         struct runtime_sc cl_virtual;   /* virtual curve */
167         struct runtime_sc cl_ulimit;    /* upperlimit curve */
168 
169         unsigned long   cl_flags;       /* which curves are valid */
170         unsigned long   cl_vtperiod;    /* vt period sequence number */
171         unsigned long   cl_parentperiod;/* parent's vt period sequence number*/
172         unsigned long   cl_nactive;     /* number of active children */
173 };
174 
175 struct hfsc_sched {
176         u16     defcls;                         /* default class id */
177         struct hfsc_class root;                 /* root class */
178         struct Qdisc_class_hash clhash;         /* class hash */
179         struct rb_root eligible;                /* eligible tree */
180         struct list_head droplist;              /* active leaf class list (for
181                                                    dropping) */
182         struct qdisc_watchdog watchdog;         /* watchdog timer */
183 };
184 
185 #define HT_INFINITY     0xffffffffffffffffULL   /* infinite time value */
186 
187 
188 /*
189  * eligible tree holds backlogged classes being sorted by their eligible times.
190  * there is one eligible tree per hfsc instance.
191  */
192 
193 static void
194 eltree_insert(struct hfsc_class *cl)
195 {
196         struct rb_node **p = &cl->sched->eligible.rb_node;
197         struct rb_node *parent = NULL;
198         struct hfsc_class *cl1;
199 
200         while (*p != NULL) {
201                 parent = *p;
202                 cl1 = rb_entry(parent, struct hfsc_class, el_node);
203                 if (cl->cl_e >= cl1->cl_e)
204                         p = &parent->rb_right;
205                 else
206                         p = &parent->rb_left;
207         }
208         rb_link_node(&cl->el_node, parent, p);
209         rb_insert_color(&cl->el_node, &cl->sched->eligible);
210 }
211 
212 static inline void
213 eltree_remove(struct hfsc_class *cl)
214 {
215         rb_erase(&cl->el_node, &cl->sched->eligible);
216 }
217 
218 static inline void
219 eltree_update(struct hfsc_class *cl)
220 {
221         eltree_remove(cl);
222         eltree_insert(cl);
223 }
224 
225 /* find the class with the minimum deadline among the eligible classes */
226 static inline struct hfsc_class *
227 eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
228 {
229         struct hfsc_class *p, *cl = NULL;
230         struct rb_node *n;
231 
232         for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
233                 p = rb_entry(n, struct hfsc_class, el_node);
234                 if (p->cl_e > cur_time)
235                         break;
236                 if (cl == NULL || p->cl_d < cl->cl_d)
237                         cl = p;
238         }
239         return cl;
240 }
241 
242 /* find the class with minimum eligible time among the eligible classes */
243 static inline struct hfsc_class *
244 eltree_get_minel(struct hfsc_sched *q)
245 {
246         struct rb_node *n;
247 
248         n = rb_first(&q->eligible);
249         if (n == NULL)
250                 return NULL;
251         return rb_entry(n, struct hfsc_class, el_node);
252 }
253 
254 /*
255  * vttree holds holds backlogged child classes being sorted by their virtual
256  * time. each intermediate class has one vttree.
257  */
258 static void
259 vttree_insert(struct hfsc_class *cl)
260 {
261         struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
262         struct rb_node *parent = NULL;
263         struct hfsc_class *cl1;
264 
265         while (*p != NULL) {
266                 parent = *p;
267                 cl1 = rb_entry(parent, struct hfsc_class, vt_node);
268                 if (cl->cl_vt >= cl1->cl_vt)
269                         p = &parent->rb_right;
270                 else
271                         p = &parent->rb_left;
272         }
273         rb_link_node(&cl->vt_node, parent, p);
274         rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
275 }
276 
277 static inline void
278 vttree_remove(struct hfsc_class *cl)
279 {
280         rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
281 }
282 
283 static inline void
284 vttree_update(struct hfsc_class *cl)
285 {
286         vttree_remove(cl);
287         vttree_insert(cl);
288 }
289 
290 static inline struct hfsc_class *
291 vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
292 {
293         struct hfsc_class *p;
294         struct rb_node *n;
295 
296         for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
297                 p = rb_entry(n, struct hfsc_class, vt_node);
298                 if (p->cl_f <= cur_time)
299                         return p;
300         }
301         return NULL;
302 }
303 
304 /*
305  * get the leaf class with the minimum vt in the hierarchy
306  */
307 static struct hfsc_class *
308 vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
309 {
310         /* if root-class's cfmin is bigger than cur_time nothing to do */
311         if (cl->cl_cfmin > cur_time)
312                 return NULL;
313 
314         while (cl->level > 0) {
315                 cl = vttree_firstfit(cl, cur_time);
316                 if (cl == NULL)
317                         return NULL;
318                 /*
319                  * update parent's cl_cvtmin.
320                  */
321                 if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
322                         cl->cl_parent->cl_cvtmin = cl->cl_vt;
323         }
324         return cl;
325 }
326 
327 static void
328 cftree_insert(struct hfsc_class *cl)
329 {
330         struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
331         struct rb_node *parent = NULL;
332         struct hfsc_class *cl1;
333 
334         while (*p != NULL) {
335                 parent = *p;
336                 cl1 = rb_entry(parent, struct hfsc_class, cf_node);
337                 if (cl->cl_f >= cl1->cl_f)
338                         p = &parent->rb_right;
339                 else
340                         p = &parent->rb_left;
341         }
342         rb_link_node(&cl->cf_node, parent, p);
343         rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
344 }
345 
346 static inline void
347 cftree_remove(struct hfsc_class *cl)
348 {
349         rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
350 }
351 
352 static inline void
353 cftree_update(struct hfsc_class *cl)
354 {
355         cftree_remove(cl);
356         cftree_insert(cl);
357 }
358 
359 /*
360  * service curve support functions
361  *
362  *  external service curve parameters
363  *      m: bps
364  *      d: us
365  *  internal service curve parameters
366  *      sm: (bytes/psched_us) << SM_SHIFT
367  *      ism: (psched_us/byte) << ISM_SHIFT
368  *      dx: psched_us
369  *
370  * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
371  *
372  * sm and ism are scaled in order to keep effective digits.
373  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
374  * digits in decimal using the following table.
375  *
376  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
377  *  ------------+-------------------------------------------------------
378  *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
379  *
380  *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
381  *
382  * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
383  */
384 #define SM_SHIFT        (30 - PSCHED_SHIFT)
385 #define ISM_SHIFT       (8 + PSCHED_SHIFT)
386 
387 #define SM_MASK         ((1ULL << SM_SHIFT) - 1)
388 #define ISM_MASK        ((1ULL << ISM_SHIFT) - 1)
389 
390 static inline u64
391 seg_x2y(u64 x, u64 sm)
392 {
393         u64 y;
394 
395         /*
396          * compute
397          *      y = x * sm >> SM_SHIFT
398          * but divide it for the upper and lower bits to avoid overflow
399          */
400         y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
401         return y;
402 }
403 
404 static inline u64
405 seg_y2x(u64 y, u64 ism)
406 {
407         u64 x;
408 
409         if (y == 0)
410                 x = 0;
411         else if (ism == HT_INFINITY)
412                 x = HT_INFINITY;
413         else {
414                 x = (y >> ISM_SHIFT) * ism
415                     + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
416         }
417         return x;
418 }
419 
420 /* Convert m (bps) into sm (bytes/psched us) */
421 static u64
422 m2sm(u32 m)
423 {
424         u64 sm;
425 
426         sm = ((u64)m << SM_SHIFT);
427         sm += PSCHED_TICKS_PER_SEC - 1;
428         do_div(sm, PSCHED_TICKS_PER_SEC);
429         return sm;
430 }
431 
432 /* convert m (bps) into ism (psched us/byte) */
433 static u64
434 m2ism(u32 m)
435 {
436         u64 ism;
437 
438         if (m == 0)
439                 ism = HT_INFINITY;
440         else {
441                 ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
442                 ism += m - 1;
443                 do_div(ism, m);
444         }
445         return ism;
446 }
447 
448 /* convert d (us) into dx (psched us) */
449 static u64
450 d2dx(u32 d)
451 {
452         u64 dx;
453 
454         dx = ((u64)d * PSCHED_TICKS_PER_SEC);
455         dx += USEC_PER_SEC - 1;
456         do_div(dx, USEC_PER_SEC);
457         return dx;
458 }
459 
460 /* convert sm (bytes/psched us) into m (bps) */
461 static u32
462 sm2m(u64 sm)
463 {
464         u64 m;
465 
466         m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
467         return (u32)m;
468 }
469 
470 /* convert dx (psched us) into d (us) */
471 static u32
472 dx2d(u64 dx)
473 {
474         u64 d;
475 
476         d = dx * USEC_PER_SEC;
477         do_div(d, PSCHED_TICKS_PER_SEC);
478         return (u32)d;
479 }
480 
481 static void
482 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
483 {
484         isc->sm1  = m2sm(sc->m1);
485         isc->ism1 = m2ism(sc->m1);
486         isc->dx   = d2dx(sc->d);
487         isc->dy   = seg_x2y(isc->dx, isc->sm1);
488         isc->sm2  = m2sm(sc->m2);
489         isc->ism2 = m2ism(sc->m2);
490 }
491 
492 /*
493  * initialize the runtime service curve with the given internal
494  * service curve starting at (x, y).
495  */
496 static void
497 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
498 {
499         rtsc->x    = x;
500         rtsc->y    = y;
501         rtsc->sm1  = isc->sm1;
502         rtsc->ism1 = isc->ism1;
503         rtsc->dx   = isc->dx;
504         rtsc->dy   = isc->dy;
505         rtsc->sm2  = isc->sm2;
506         rtsc->ism2 = isc->ism2;
507 }
508 
509 /*
510  * calculate the y-projection of the runtime service curve by the
511  * given x-projection value
512  */
513 static u64
514 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
515 {
516         u64 x;
517 
518         if (y < rtsc->y)
519                 x = rtsc->x;
520         else if (y <= rtsc->y + rtsc->dy) {
521                 /* x belongs to the 1st segment */
522                 if (rtsc->dy == 0)
523                         x = rtsc->x + rtsc->dx;
524                 else
525                         x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
526         } else {
527                 /* x belongs to the 2nd segment */
528                 x = rtsc->x + rtsc->dx
529                     + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
530         }
531         return x;
532 }
533 
534 static u64
535 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
536 {
537         u64 y;
538 
539         if (x <= rtsc->x)
540                 y = rtsc->y;
541         else if (x <= rtsc->x + rtsc->dx)
542                 /* y belongs to the 1st segment */
543                 y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
544         else
545                 /* y belongs to the 2nd segment */
546                 y = rtsc->y + rtsc->dy
547                     + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
548         return y;
549 }
550 
551 /*
552  * update the runtime service curve by taking the minimum of the current
553  * runtime service curve and the service curve starting at (x, y).
554  */
555 static void
556 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
557 {
558         u64 y1, y2, dx, dy;
559         u32 dsm;
560 
561         if (isc->sm1 <= isc->sm2) {
562                 /* service curve is convex */
563                 y1 = rtsc_x2y(rtsc, x);
564                 if (y1 < y)
565                         /* the current rtsc is smaller */
566                         return;
567                 rtsc->x = x;
568                 rtsc->y = y;
569                 return;
570         }
571 
572         /*
573          * service curve is concave
574          * compute the two y values of the current rtsc
575          *      y1: at x
576          *      y2: at (x + dx)
577          */
578         y1 = rtsc_x2y(rtsc, x);
579         if (y1 <= y) {
580                 /* rtsc is below isc, no change to rtsc */
581                 return;
582         }
583 
584         y2 = rtsc_x2y(rtsc, x + isc->dx);
585         if (y2 >= y + isc->dy) {
586                 /* rtsc is above isc, replace rtsc by isc */
587                 rtsc->x = x;
588                 rtsc->y = y;
589                 rtsc->dx = isc->dx;
590                 rtsc->dy = isc->dy;
591                 return;
592         }
593 
594         /*
595          * the two curves intersect
596          * compute the offsets (dx, dy) using the reverse
597          * function of seg_x2y()
598          *      seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
599          */
600         dx = (y1 - y) << SM_SHIFT;
601         dsm = isc->sm1 - isc->sm2;
602         do_div(dx, dsm);
603         /*
604          * check if (x, y1) belongs to the 1st segment of rtsc.
605          * if so, add the offset.
606          */
607         if (rtsc->x + rtsc->dx > x)
608                 dx += rtsc->x + rtsc->dx - x;
609         dy = seg_x2y(dx, isc->sm1);
610 
611         rtsc->x = x;
612         rtsc->y = y;
613         rtsc->dx = dx;
614         rtsc->dy = dy;
615 }
616 
617 static void
618 init_ed(struct hfsc_class *cl, unsigned int next_len)
619 {
620         u64 cur_time = psched_get_time();
621 
622         /* update the deadline curve */
623         rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
624 
625         /*
626          * update the eligible curve.
627          * for concave, it is equal to the deadline curve.
628          * for convex, it is a linear curve with slope m2.
629          */
630         cl->cl_eligible = cl->cl_deadline;
631         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
632                 cl->cl_eligible.dx = 0;
633                 cl->cl_eligible.dy = 0;
634         }
635 
636         /* compute e and d */
637         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
638         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
639 
640         eltree_insert(cl);
641 }
642 
643 static void
644 update_ed(struct hfsc_class *cl, unsigned int next_len)
645 {
646         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
647         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
648 
649         eltree_update(cl);
650 }
651 
652 static inline void
653 update_d(struct hfsc_class *cl, unsigned int next_len)
654 {
655         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
656 }
657 
658 static inline void
659 update_cfmin(struct hfsc_class *cl)
660 {
661         struct rb_node *n = rb_first(&cl->cf_tree);
662         struct hfsc_class *p;
663 
664         if (n == NULL) {
665                 cl->cl_cfmin = 0;
666                 return;
667         }
668         p = rb_entry(n, struct hfsc_class, cf_node);
669         cl->cl_cfmin = p->cl_f;
670 }
671 
672 static void
673 init_vf(struct hfsc_class *cl, unsigned int len)
674 {
675         struct hfsc_class *max_cl;
676         struct rb_node *n;
677         u64 vt, f, cur_time;
678         int go_active;
679 
680         cur_time = 0;
681         go_active = 1;
682         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
683                 if (go_active && cl->cl_nactive++ == 0)
684                         go_active = 1;
685                 else
686                         go_active = 0;
687 
688                 if (go_active) {
689                         n = rb_last(&cl->cl_parent->vt_tree);
690                         if (n != NULL) {
691                                 max_cl = rb_entry(n, struct hfsc_class, vt_node);
692                                 /*
693                                  * set vt to the average of the min and max
694                                  * classes.  if the parent's period didn't
695                                  * change, don't decrease vt of the class.
696                                  */
697                                 vt = max_cl->cl_vt;
698                                 if (cl->cl_parent->cl_cvtmin != 0)
699                                         vt = (cl->cl_parent->cl_cvtmin + vt)/2;
700 
701                                 if (cl->cl_parent->cl_vtperiod !=
702                                     cl->cl_parentperiod || vt > cl->cl_vt)
703                                         cl->cl_vt = vt;
704                         } else {
705                                 /*
706                                  * first child for a new parent backlog period.
707                                  * add parent's cvtmax to cvtoff to make a new
708                                  * vt (vtoff + vt) larger than the vt in the
709                                  * last period for all children.
710                                  */
711                                 vt = cl->cl_parent->cl_cvtmax;
712                                 cl->cl_parent->cl_cvtoff += vt;
713                                 cl->cl_parent->cl_cvtmax = 0;
714                                 cl->cl_parent->cl_cvtmin = 0;
715                                 cl->cl_vt = 0;
716                         }
717 
718                         cl->cl_vtoff = cl->cl_parent->cl_cvtoff -
719                                                         cl->cl_pcvtoff;
720 
721                         /* update the virtual curve */
722                         vt = cl->cl_vt + cl->cl_vtoff;
723                         rtsc_min(&cl->cl_virtual, &cl->cl_fsc, vt,
724                                                       cl->cl_total);
725                         if (cl->cl_virtual.x == vt) {
726                                 cl->cl_virtual.x -= cl->cl_vtoff;
727                                 cl->cl_vtoff = 0;
728                         }
729                         cl->cl_vtadj = 0;
730 
731                         cl->cl_vtperiod++;  /* increment vt period */
732                         cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
733                         if (cl->cl_parent->cl_nactive == 0)
734                                 cl->cl_parentperiod++;
735                         cl->cl_f = 0;
736 
737                         vttree_insert(cl);
738                         cftree_insert(cl);
739 
740                         if (cl->cl_flags & HFSC_USC) {
741                                 /* class has upper limit curve */
742                                 if (cur_time == 0)
743                                         cur_time = psched_get_time();
744 
745                                 /* update the ulimit curve */
746                                 rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
747                                          cl->cl_total);
748                                 /* compute myf */
749                                 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
750                                                       cl->cl_total);
751                                 cl->cl_myfadj = 0;
752                         }
753                 }
754 
755                 f = max(cl->cl_myf, cl->cl_cfmin);
756                 if (f != cl->cl_f) {
757                         cl->cl_f = f;
758                         cftree_update(cl);
759                 }
760                 update_cfmin(cl->cl_parent);
761         }
762 }
763 
764 static void
765 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
766 {
767         u64 f; /* , myf_bound, delta; */
768         int go_passive = 0;
769 
770         if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
771                 go_passive = 1;
772 
773         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
774                 cl->cl_total += len;
775 
776                 if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
777                         continue;
778 
779                 if (go_passive && --cl->cl_nactive == 0)
780                         go_passive = 1;
781                 else
782                         go_passive = 0;
783 
784                 if (go_passive) {
785                         /* no more active child, going passive */
786 
787                         /* update cvtmax of the parent class */
788                         if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
789                                 cl->cl_parent->cl_cvtmax = cl->cl_vt;
790 
791                         /* remove this class from the vt tree */
792                         vttree_remove(cl);
793 
794                         cftree_remove(cl);
795                         update_cfmin(cl->cl_parent);
796 
797                         continue;
798                 }
799 
800                 /*
801                  * update vt and f
802                  */
803                 cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
804                             - cl->cl_vtoff + cl->cl_vtadj;
805 
806                 /*
807                  * if vt of the class is smaller than cvtmin,
808                  * the class was skipped in the past due to non-fit.
809                  * if so, we need to adjust vtadj.
810                  */
811                 if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
812                         cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
813                         cl->cl_vt = cl->cl_parent->cl_cvtmin;
814                 }
815 
816                 /* update the vt tree */
817                 vttree_update(cl);
818 
819                 if (cl->cl_flags & HFSC_USC) {
820                         cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
821                                                               cl->cl_total);
822 #if 0
823                         /*
824                          * This code causes classes to stay way under their
825                          * limit when multiple classes are used at gigabit
826                          * speed. needs investigation. -kaber
827                          */
828                         /*
829                          * if myf lags behind by more than one clock tick
830                          * from the current time, adjust myfadj to prevent
831                          * a rate-limited class from going greedy.
832                          * in a steady state under rate-limiting, myf
833                          * fluctuates within one clock tick.
834                          */
835                         myf_bound = cur_time - PSCHED_JIFFIE2US(1);
836                         if (cl->cl_myf < myf_bound) {
837                                 delta = cur_time - cl->cl_myf;
838                                 cl->cl_myfadj += delta;
839                                 cl->cl_myf += delta;
840                         }
841 #endif
842                 }
843 
844                 f = max(cl->cl_myf, cl->cl_cfmin);
845                 if (f != cl->cl_f) {
846                         cl->cl_f = f;
847                         cftree_update(cl);
848                         update_cfmin(cl->cl_parent);
849                 }
850         }
851 }
852 
853 static void
854 set_active(struct hfsc_class *cl, unsigned int len)
855 {
856         if (cl->cl_flags & HFSC_RSC)
857                 init_ed(cl, len);
858         if (cl->cl_flags & HFSC_FSC)
859                 init_vf(cl, len);
860 
861         list_add_tail(&cl->dlist, &cl->sched->droplist);
862 }
863 
864 static void
865 set_passive(struct hfsc_class *cl)
866 {
867         if (cl->cl_flags & HFSC_RSC)
868                 eltree_remove(cl);
869 
870         list_del(&cl->dlist);
871 
872         /*
873          * vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
874          * needs to be called explicitly to remove a class from vttree.
875          */
876 }
877 
878 static unsigned int
879 qdisc_peek_len(struct Qdisc *sch)
880 {
881         struct sk_buff *skb;
882         unsigned int len;
883 
884         skb = sch->ops->peek(sch);
885         if (skb == NULL) {
886                 qdisc_warn_nonwc("qdisc_peek_len", sch);
887                 return 0;
888         }
889         len = qdisc_pkt_len(skb);
890 
891         return len;
892 }
893 
894 static void
895 hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
896 {
897         unsigned int len = cl->qdisc->q.qlen;
898         unsigned int backlog = cl->qdisc->qstats.backlog;
899 
900         qdisc_reset(cl->qdisc);
901         qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
902 }
903 
904 static void
905 hfsc_adjust_levels(struct hfsc_class *cl)
906 {
907         struct hfsc_class *p;
908         unsigned int level;
909 
910         do {
911                 level = 0;
912                 list_for_each_entry(p, &cl->children, siblings) {
913                         if (p->level >= level)
914                                 level = p->level + 1;
915                 }
916                 cl->level = level;
917         } while ((cl = cl->cl_parent) != NULL);
918 }
919 
920 static inline struct hfsc_class *
921 hfsc_find_class(u32 classid, struct Qdisc *sch)
922 {
923         struct hfsc_sched *q = qdisc_priv(sch);
924         struct Qdisc_class_common *clc;
925 
926         clc = qdisc_class_find(&q->clhash, classid);
927         if (clc == NULL)
928                 return NULL;
929         return container_of(clc, struct hfsc_class, cl_common);
930 }
931 
932 static void
933 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
934                 u64 cur_time)
935 {
936         sc2isc(rsc, &cl->cl_rsc);
937         rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
938         cl->cl_eligible = cl->cl_deadline;
939         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
940                 cl->cl_eligible.dx = 0;
941                 cl->cl_eligible.dy = 0;
942         }
943         cl->cl_flags |= HFSC_RSC;
944 }
945 
946 static void
947 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
948 {
949         sc2isc(fsc, &cl->cl_fsc);
950         rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
951         cl->cl_flags |= HFSC_FSC;
952 }
953 
954 static void
955 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
956                 u64 cur_time)
957 {
958         sc2isc(usc, &cl->cl_usc);
959         rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
960         cl->cl_flags |= HFSC_USC;
961 }
962 
963 static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
964         [TCA_HFSC_RSC]  = { .len = sizeof(struct tc_service_curve) },
965         [TCA_HFSC_FSC]  = { .len = sizeof(struct tc_service_curve) },
966         [TCA_HFSC_USC]  = { .len = sizeof(struct tc_service_curve) },
967 };
968 
969 static int
970 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
971                   struct nlattr **tca, unsigned long *arg)
972 {
973         struct hfsc_sched *q = qdisc_priv(sch);
974         struct hfsc_class *cl = (struct hfsc_class *)*arg;
975         struct hfsc_class *parent = NULL;
976         struct nlattr *opt = tca[TCA_OPTIONS];
977         struct nlattr *tb[TCA_HFSC_MAX + 1];
978         struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
979         u64 cur_time;
980         int err;
981 
982         if (opt == NULL)
983                 return -EINVAL;
984 
985         err = nla_parse_nested(tb, TCA_HFSC_MAX, opt, hfsc_policy);
986         if (err < 0)
987                 return err;
988 
989         if (tb[TCA_HFSC_RSC]) {
990                 rsc = nla_data(tb[TCA_HFSC_RSC]);
991                 if (rsc->m1 == 0 && rsc->m2 == 0)
992                         rsc = NULL;
993         }
994 
995         if (tb[TCA_HFSC_FSC]) {
996                 fsc = nla_data(tb[TCA_HFSC_FSC]);
997                 if (fsc->m1 == 0 && fsc->m2 == 0)
998                         fsc = NULL;
999         }
1000 
1001         if (tb[TCA_HFSC_USC]) {
1002                 usc = nla_data(tb[TCA_HFSC_USC]);
1003                 if (usc->m1 == 0 && usc->m2 == 0)
1004                         usc = NULL;
1005         }
1006 
1007         if (cl != NULL) {
1008                 if (parentid) {
1009                         if (cl->cl_parent &&
1010                             cl->cl_parent->cl_common.classid != parentid)
1011                                 return -EINVAL;
1012                         if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
1013                                 return -EINVAL;
1014                 }
1015                 cur_time = psched_get_time();
1016 
1017                 if (tca[TCA_RATE]) {
1018                         spinlock_t *lock = qdisc_root_sleeping_lock(sch);
1019 
1020                         err = gen_replace_estimator(&cl->bstats, NULL,
1021                                                     &cl->rate_est,
1022                                                     lock,
1023                                                     tca[TCA_RATE]);
1024                         if (err)
1025                                 return err;
1026                 }
1027 
1028                 sch_tree_lock(sch);
1029                 if (rsc != NULL)
1030                         hfsc_change_rsc(cl, rsc, cur_time);
1031                 if (fsc != NULL)
1032                         hfsc_change_fsc(cl, fsc);
1033                 if (usc != NULL)
1034                         hfsc_change_usc(cl, usc, cur_time);
1035 
1036                 if (cl->qdisc->q.qlen != 0) {
1037                         if (cl->cl_flags & HFSC_RSC)
1038                                 update_ed(cl, qdisc_peek_len(cl->qdisc));
1039                         if (cl->cl_flags & HFSC_FSC)
1040                                 update_vf(cl, 0, cur_time);
1041                 }
1042                 sch_tree_unlock(sch);
1043 
1044                 return 0;
1045         }
1046 
1047         if (parentid == TC_H_ROOT)
1048                 return -EEXIST;
1049 
1050         parent = &q->root;
1051         if (parentid) {
1052                 parent = hfsc_find_class(parentid, sch);
1053                 if (parent == NULL)
1054                         return -ENOENT;
1055         }
1056 
1057         if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1058                 return -EINVAL;
1059         if (hfsc_find_class(classid, sch))
1060                 return -EEXIST;
1061 
1062         if (rsc == NULL && fsc == NULL)
1063                 return -EINVAL;
1064 
1065         cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1066         if (cl == NULL)
1067                 return -ENOBUFS;
1068 
1069         if (tca[TCA_RATE]) {
1070                 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1071                                         qdisc_root_sleeping_lock(sch),
1072                                         tca[TCA_RATE]);
1073                 if (err) {
1074                         kfree(cl);
1075                         return err;
1076                 }
1077         }
1078 
1079         if (rsc != NULL)
1080                 hfsc_change_rsc(cl, rsc, 0);
1081         if (fsc != NULL)
1082                 hfsc_change_fsc(cl, fsc);
1083         if (usc != NULL)
1084                 hfsc_change_usc(cl, usc, 0);
1085 
1086         cl->cl_common.classid = classid;
1087         cl->refcnt    = 1;
1088         cl->sched     = q;
1089         cl->cl_parent = parent;
1090         cl->qdisc = qdisc_create_dflt(sch->dev_queue,
1091                                       &pfifo_qdisc_ops, classid);
1092         if (cl->qdisc == NULL)
1093                 cl->qdisc = &noop_qdisc;
1094         INIT_LIST_HEAD(&cl->children);
1095         cl->vt_tree = RB_ROOT;
1096         cl->cf_tree = RB_ROOT;
1097 
1098         sch_tree_lock(sch);
1099         qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1100         list_add_tail(&cl->siblings, &parent->children);
1101         if (parent->level == 0)
1102                 hfsc_purge_queue(sch, parent);
1103         hfsc_adjust_levels(parent);
1104         cl->cl_pcvtoff = parent->cl_cvtoff;
1105         sch_tree_unlock(sch);
1106 
1107         qdisc_class_hash_grow(sch, &q->clhash);
1108 
1109         *arg = (unsigned long)cl;
1110         return 0;
1111 }
1112 
1113 static void
1114 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1115 {
1116         struct hfsc_sched *q = qdisc_priv(sch);
1117 
1118         tcf_destroy_chain(&cl->filter_list);
1119         qdisc_destroy(cl->qdisc);
1120         gen_kill_estimator(&cl->bstats, &cl->rate_est);
1121         if (cl != &q->root)
1122                 kfree(cl);
1123 }
1124 
1125 static int
1126 hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1127 {
1128         struct hfsc_sched *q = qdisc_priv(sch);
1129         struct hfsc_class *cl = (struct hfsc_class *)arg;
1130 
1131         if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1132                 return -EBUSY;
1133 
1134         sch_tree_lock(sch);
1135 
1136         list_del(&cl->siblings);
1137         hfsc_adjust_levels(cl->cl_parent);
1138 
1139         hfsc_purge_queue(sch, cl);
1140         qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1141 
1142         BUG_ON(--cl->refcnt == 0);
1143         /*
1144          * This shouldn't happen: we "hold" one cops->get() when called
1145          * from tc_ctl_tclass; the destroy method is done from cops->put().
1146          */
1147 
1148         sch_tree_unlock(sch);
1149         return 0;
1150 }
1151 
1152 static struct hfsc_class *
1153 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1154 {
1155         struct hfsc_sched *q = qdisc_priv(sch);
1156         struct hfsc_class *head, *cl;
1157         struct tcf_result res;
1158         struct tcf_proto *tcf;
1159         int result;
1160 
1161         if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1162             (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1163                 if (cl->level == 0)
1164                         return cl;
1165 
1166         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1167         head = &q->root;
1168         tcf = rcu_dereference_bh(q->root.filter_list);
1169         while (tcf && (result = tc_classify(skb, tcf, &res, false)) >= 0) {
1170 #ifdef CONFIG_NET_CLS_ACT
1171                 switch (result) {
1172                 case TC_ACT_QUEUED:
1173                 case TC_ACT_STOLEN:
1174                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1175                 case TC_ACT_SHOT:
1176                         return NULL;
1177                 }
1178 #endif
1179                 cl = (struct hfsc_class *)res.class;
1180                 if (!cl) {
1181                         cl = hfsc_find_class(res.classid, sch);
1182                         if (!cl)
1183                                 break; /* filter selected invalid classid */
1184                         if (cl->level >= head->level)
1185                                 break; /* filter may only point downwards */
1186                 }
1187 
1188                 if (cl->level == 0)
1189                         return cl; /* hit leaf class */
1190 
1191                 /* apply inner filter chain */
1192                 tcf = rcu_dereference_bh(cl->filter_list);
1193                 head = cl;
1194         }
1195 
1196         /* classification failed, try default class */
1197         cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1198         if (cl == NULL || cl->level > 0)
1199                 return NULL;
1200 
1201         return cl;
1202 }
1203 
1204 static int
1205 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1206                  struct Qdisc **old)
1207 {
1208         struct hfsc_class *cl = (struct hfsc_class *)arg;
1209 
1210         if (cl->level > 0)
1211                 return -EINVAL;
1212         if (new == NULL) {
1213                 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1214                                         cl->cl_common.classid);
1215                 if (new == NULL)
1216                         new = &noop_qdisc;
1217         }
1218 
1219         *old = qdisc_replace(sch, new, &cl->qdisc);
1220         return 0;
1221 }
1222 
1223 static struct Qdisc *
1224 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1225 {
1226         struct hfsc_class *cl = (struct hfsc_class *)arg;
1227 
1228         if (cl->level == 0)
1229                 return cl->qdisc;
1230 
1231         return NULL;
1232 }
1233 
1234 static void
1235 hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1236 {
1237         struct hfsc_class *cl = (struct hfsc_class *)arg;
1238 
1239         if (cl->qdisc->q.qlen == 0) {
1240                 update_vf(cl, 0, 0);
1241                 set_passive(cl);
1242         }
1243 }
1244 
1245 static unsigned long
1246 hfsc_get_class(struct Qdisc *sch, u32 classid)
1247 {
1248         struct hfsc_class *cl = hfsc_find_class(classid, sch);
1249 
1250         if (cl != NULL)
1251                 cl->refcnt++;
1252 
1253         return (unsigned long)cl;
1254 }
1255 
1256 static void
1257 hfsc_put_class(struct Qdisc *sch, unsigned long arg)
1258 {
1259         struct hfsc_class *cl = (struct hfsc_class *)arg;
1260 
1261         if (--cl->refcnt == 0)
1262                 hfsc_destroy_class(sch, cl);
1263 }
1264 
1265 static unsigned long
1266 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1267 {
1268         struct hfsc_class *p = (struct hfsc_class *)parent;
1269         struct hfsc_class *cl = hfsc_find_class(classid, sch);
1270 
1271         if (cl != NULL) {
1272                 if (p != NULL && p->level <= cl->level)
1273                         return 0;
1274                 cl->filter_cnt++;
1275         }
1276 
1277         return (unsigned long)cl;
1278 }
1279 
1280 static void
1281 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1282 {
1283         struct hfsc_class *cl = (struct hfsc_class *)arg;
1284 
1285         cl->filter_cnt--;
1286 }
1287 
1288 static struct tcf_proto __rcu **
1289 hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
1290 {
1291         struct hfsc_sched *q = qdisc_priv(sch);
1292         struct hfsc_class *cl = (struct hfsc_class *)arg;
1293 
1294         if (cl == NULL)
1295                 cl = &q->root;
1296 
1297         return &cl->filter_list;
1298 }
1299 
1300 static int
1301 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1302 {
1303         struct tc_service_curve tsc;
1304 
1305         tsc.m1 = sm2m(sc->sm1);
1306         tsc.d  = dx2d(sc->dx);
1307         tsc.m2 = sm2m(sc->sm2);
1308         if (nla_put(skb, attr, sizeof(tsc), &tsc))
1309                 goto nla_put_failure;
1310 
1311         return skb->len;
1312 
1313  nla_put_failure:
1314         return -1;
1315 }
1316 
1317 static int
1318 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1319 {
1320         if ((cl->cl_flags & HFSC_RSC) &&
1321             (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1322                 goto nla_put_failure;
1323 
1324         if ((cl->cl_flags & HFSC_FSC) &&
1325             (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1326                 goto nla_put_failure;
1327 
1328         if ((cl->cl_flags & HFSC_USC) &&
1329             (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1330                 goto nla_put_failure;
1331 
1332         return skb->len;
1333 
1334  nla_put_failure:
1335         return -1;
1336 }
1337 
1338 static int
1339 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1340                 struct tcmsg *tcm)
1341 {
1342         struct hfsc_class *cl = (struct hfsc_class *)arg;
1343         struct nlattr *nest;
1344 
1345         tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1346                                           TC_H_ROOT;
1347         tcm->tcm_handle = cl->cl_common.classid;
1348         if (cl->level == 0)
1349                 tcm->tcm_info = cl->qdisc->handle;
1350 
1351         nest = nla_nest_start(skb, TCA_OPTIONS);
1352         if (nest == NULL)
1353                 goto nla_put_failure;
1354         if (hfsc_dump_curves(skb, cl) < 0)
1355                 goto nla_put_failure;
1356         return nla_nest_end(skb, nest);
1357 
1358  nla_put_failure:
1359         nla_nest_cancel(skb, nest);
1360         return -EMSGSIZE;
1361 }
1362 
1363 static int
1364 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1365         struct gnet_dump *d)
1366 {
1367         struct hfsc_class *cl = (struct hfsc_class *)arg;
1368         struct tc_hfsc_stats xstats;
1369 
1370         cl->qstats.backlog = cl->qdisc->qstats.backlog;
1371         xstats.level   = cl->level;
1372         xstats.period  = cl->cl_vtperiod;
1373         xstats.work    = cl->cl_total;
1374         xstats.rtwork  = cl->cl_cumul;
1375 
1376         if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
1377             gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
1378             gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->qdisc->q.qlen) < 0)
1379                 return -1;
1380 
1381         return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1382 }
1383 
1384 
1385 
1386 static void
1387 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1388 {
1389         struct hfsc_sched *q = qdisc_priv(sch);
1390         struct hfsc_class *cl;
1391         unsigned int i;
1392 
1393         if (arg->stop)
1394                 return;
1395 
1396         for (i = 0; i < q->clhash.hashsize; i++) {
1397                 hlist_for_each_entry(cl, &q->clhash.hash[i],
1398                                      cl_common.hnode) {
1399                         if (arg->count < arg->skip) {
1400                                 arg->count++;
1401                                 continue;
1402                         }
1403                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1404                                 arg->stop = 1;
1405                                 return;
1406                         }
1407                         arg->count++;
1408                 }
1409         }
1410 }
1411 
1412 static void
1413 hfsc_schedule_watchdog(struct Qdisc *sch)
1414 {
1415         struct hfsc_sched *q = qdisc_priv(sch);
1416         struct hfsc_class *cl;
1417         u64 next_time = 0;
1418 
1419         cl = eltree_get_minel(q);
1420         if (cl)
1421                 next_time = cl->cl_e;
1422         if (q->root.cl_cfmin != 0) {
1423                 if (next_time == 0 || next_time > q->root.cl_cfmin)
1424                         next_time = q->root.cl_cfmin;
1425         }
1426         WARN_ON(next_time == 0);
1427         qdisc_watchdog_schedule(&q->watchdog, next_time);
1428 }
1429 
1430 static int
1431 hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
1432 {
1433         struct hfsc_sched *q = qdisc_priv(sch);
1434         struct tc_hfsc_qopt *qopt;
1435         int err;
1436 
1437         if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1438                 return -EINVAL;
1439         qopt = nla_data(opt);
1440 
1441         q->defcls = qopt->defcls;
1442         err = qdisc_class_hash_init(&q->clhash);
1443         if (err < 0)
1444                 return err;
1445         q->eligible = RB_ROOT;
1446         INIT_LIST_HEAD(&q->droplist);
1447 
1448         q->root.cl_common.classid = sch->handle;
1449         q->root.refcnt  = 1;
1450         q->root.sched   = q;
1451         q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1452                                           sch->handle);
1453         if (q->root.qdisc == NULL)
1454                 q->root.qdisc = &noop_qdisc;
1455         INIT_LIST_HEAD(&q->root.children);
1456         q->root.vt_tree = RB_ROOT;
1457         q->root.cf_tree = RB_ROOT;
1458 
1459         qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1460         qdisc_class_hash_grow(sch, &q->clhash);
1461 
1462         qdisc_watchdog_init(&q->watchdog, sch);
1463 
1464         return 0;
1465 }
1466 
1467 static int
1468 hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt)
1469 {
1470         struct hfsc_sched *q = qdisc_priv(sch);
1471         struct tc_hfsc_qopt *qopt;
1472 
1473         if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1474                 return -EINVAL;
1475         qopt = nla_data(opt);
1476 
1477         sch_tree_lock(sch);
1478         q->defcls = qopt->defcls;
1479         sch_tree_unlock(sch);
1480 
1481         return 0;
1482 }
1483 
1484 static void
1485 hfsc_reset_class(struct hfsc_class *cl)
1486 {
1487         cl->cl_total        = 0;
1488         cl->cl_cumul        = 0;
1489         cl->cl_d            = 0;
1490         cl->cl_e            = 0;
1491         cl->cl_vt           = 0;
1492         cl->cl_vtadj        = 0;
1493         cl->cl_vtoff        = 0;
1494         cl->cl_cvtmin       = 0;
1495         cl->cl_cvtmax       = 0;
1496         cl->cl_cvtoff       = 0;
1497         cl->cl_pcvtoff      = 0;
1498         cl->cl_vtperiod     = 0;
1499         cl->cl_parentperiod = 0;
1500         cl->cl_f            = 0;
1501         cl->cl_myf          = 0;
1502         cl->cl_myfadj       = 0;
1503         cl->cl_cfmin        = 0;
1504         cl->cl_nactive      = 0;
1505 
1506         cl->vt_tree = RB_ROOT;
1507         cl->cf_tree = RB_ROOT;
1508         qdisc_reset(cl->qdisc);
1509 
1510         if (cl->cl_flags & HFSC_RSC)
1511                 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1512         if (cl->cl_flags & HFSC_FSC)
1513                 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1514         if (cl->cl_flags & HFSC_USC)
1515                 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1516 }
1517 
1518 static void
1519 hfsc_reset_qdisc(struct Qdisc *sch)
1520 {
1521         struct hfsc_sched *q = qdisc_priv(sch);
1522         struct hfsc_class *cl;
1523         unsigned int i;
1524 
1525         for (i = 0; i < q->clhash.hashsize; i++) {
1526                 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1527                         hfsc_reset_class(cl);
1528         }
1529         q->eligible = RB_ROOT;
1530         INIT_LIST_HEAD(&q->droplist);
1531         qdisc_watchdog_cancel(&q->watchdog);
1532         sch->qstats.backlog = 0;
1533         sch->q.qlen = 0;
1534 }
1535 
1536 static void
1537 hfsc_destroy_qdisc(struct Qdisc *sch)
1538 {
1539         struct hfsc_sched *q = qdisc_priv(sch);
1540         struct hlist_node *next;
1541         struct hfsc_class *cl;
1542         unsigned int i;
1543 
1544         for (i = 0; i < q->clhash.hashsize; i++) {
1545                 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1546                         tcf_destroy_chain(&cl->filter_list);
1547         }
1548         for (i = 0; i < q->clhash.hashsize; i++) {
1549                 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1550                                           cl_common.hnode)
1551                         hfsc_destroy_class(sch, cl);
1552         }
1553         qdisc_class_hash_destroy(&q->clhash);
1554         qdisc_watchdog_cancel(&q->watchdog);
1555 }
1556 
1557 static int
1558 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1559 {
1560         struct hfsc_sched *q = qdisc_priv(sch);
1561         unsigned char *b = skb_tail_pointer(skb);
1562         struct tc_hfsc_qopt qopt;
1563 
1564         qopt.defcls = q->defcls;
1565         if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1566                 goto nla_put_failure;
1567         return skb->len;
1568 
1569  nla_put_failure:
1570         nlmsg_trim(skb, b);
1571         return -1;
1572 }
1573 
1574 static int
1575 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1576 {
1577         struct hfsc_class *cl;
1578         int uninitialized_var(err);
1579 
1580         cl = hfsc_classify(skb, sch, &err);
1581         if (cl == NULL) {
1582                 if (err & __NET_XMIT_BYPASS)
1583                         qdisc_qstats_drop(sch);
1584                 kfree_skb(skb);
1585                 return err;
1586         }
1587 
1588         err = qdisc_enqueue(skb, cl->qdisc);
1589         if (unlikely(err != NET_XMIT_SUCCESS)) {
1590                 if (net_xmit_drop_count(err)) {
1591                         cl->qstats.drops++;
1592                         qdisc_qstats_drop(sch);
1593                 }
1594                 return err;
1595         }
1596 
1597         if (cl->qdisc->q.qlen == 1)
1598                 set_active(cl, qdisc_pkt_len(skb));
1599 
1600         qdisc_qstats_backlog_inc(sch, skb);
1601         sch->q.qlen++;
1602 
1603         return NET_XMIT_SUCCESS;
1604 }
1605 
1606 static struct sk_buff *
1607 hfsc_dequeue(struct Qdisc *sch)
1608 {
1609         struct hfsc_sched *q = qdisc_priv(sch);
1610         struct hfsc_class *cl;
1611         struct sk_buff *skb;
1612         u64 cur_time;
1613         unsigned int next_len;
1614         int realtime = 0;
1615 
1616         if (sch->q.qlen == 0)
1617                 return NULL;
1618 
1619         cur_time = psched_get_time();
1620 
1621         /*
1622          * if there are eligible classes, use real-time criteria.
1623          * find the class with the minimum deadline among
1624          * the eligible classes.
1625          */
1626         cl = eltree_get_mindl(q, cur_time);
1627         if (cl) {
1628                 realtime = 1;
1629         } else {
1630                 /*
1631                  * use link-sharing criteria
1632                  * get the class with the minimum vt in the hierarchy
1633                  */
1634                 cl = vttree_get_minvt(&q->root, cur_time);
1635                 if (cl == NULL) {
1636                         qdisc_qstats_overlimit(sch);
1637                         hfsc_schedule_watchdog(sch);
1638                         return NULL;
1639                 }
1640         }
1641 
1642         skb = qdisc_dequeue_peeked(cl->qdisc);
1643         if (skb == NULL) {
1644                 qdisc_warn_nonwc("HFSC", cl->qdisc);
1645                 return NULL;
1646         }
1647 
1648         bstats_update(&cl->bstats, skb);
1649         update_vf(cl, qdisc_pkt_len(skb), cur_time);
1650         if (realtime)
1651                 cl->cl_cumul += qdisc_pkt_len(skb);
1652 
1653         if (cl->qdisc->q.qlen != 0) {
1654                 if (cl->cl_flags & HFSC_RSC) {
1655                         /* update ed */
1656                         next_len = qdisc_peek_len(cl->qdisc);
1657                         if (realtime)
1658                                 update_ed(cl, next_len);
1659                         else
1660                                 update_d(cl, next_len);
1661                 }
1662         } else {
1663                 /* the class becomes passive */
1664                 set_passive(cl);
1665         }
1666 
1667         qdisc_unthrottled(sch);
1668         qdisc_bstats_update(sch, skb);
1669         qdisc_qstats_backlog_dec(sch, skb);
1670         sch->q.qlen--;
1671 
1672         return skb;
1673 }
1674 
1675 static unsigned int
1676 hfsc_drop(struct Qdisc *sch)
1677 {
1678         struct hfsc_sched *q = qdisc_priv(sch);
1679         struct hfsc_class *cl;
1680         unsigned int len;
1681 
1682         list_for_each_entry(cl, &q->droplist, dlist) {
1683                 if (cl->qdisc->ops->drop != NULL &&
1684                     (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) {
1685                         if (cl->qdisc->q.qlen == 0) {
1686                                 update_vf(cl, 0, 0);
1687                                 set_passive(cl);
1688                         } else {
1689                                 list_move_tail(&cl->dlist, &q->droplist);
1690                         }
1691                         cl->qstats.drops++;
1692                         qdisc_qstats_drop(sch);
1693                         sch->qstats.backlog -= len;
1694                         sch->q.qlen--;
1695                         return len;
1696                 }
1697         }
1698         return 0;
1699 }
1700 
1701 static const struct Qdisc_class_ops hfsc_class_ops = {
1702         .change         = hfsc_change_class,
1703         .delete         = hfsc_delete_class,
1704         .graft          = hfsc_graft_class,
1705         .leaf           = hfsc_class_leaf,
1706         .qlen_notify    = hfsc_qlen_notify,
1707         .get            = hfsc_get_class,
1708         .put            = hfsc_put_class,
1709         .bind_tcf       = hfsc_bind_tcf,
1710         .unbind_tcf     = hfsc_unbind_tcf,
1711         .tcf_chain      = hfsc_tcf_chain,
1712         .dump           = hfsc_dump_class,
1713         .dump_stats     = hfsc_dump_class_stats,
1714         .walk           = hfsc_walk
1715 };
1716 
1717 static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1718         .id             = "hfsc",
1719         .init           = hfsc_init_qdisc,
1720         .change         = hfsc_change_qdisc,
1721         .reset          = hfsc_reset_qdisc,
1722         .destroy        = hfsc_destroy_qdisc,
1723         .dump           = hfsc_dump_qdisc,
1724         .enqueue        = hfsc_enqueue,
1725         .dequeue        = hfsc_dequeue,
1726         .peek           = qdisc_peek_dequeued,
1727         .drop           = hfsc_drop,
1728         .cl_ops         = &hfsc_class_ops,
1729         .priv_size      = sizeof(struct hfsc_sched),
1730         .owner          = THIS_MODULE
1731 };
1732 
1733 static int __init
1734 hfsc_init(void)
1735 {
1736         return register_qdisc(&hfsc_qdisc_ops);
1737 }
1738 
1739 static void __exit
1740 hfsc_cleanup(void)
1741 {
1742         unregister_qdisc(&hfsc_qdisc_ops);
1743 }
1744 
1745 MODULE_LICENSE("GPL");
1746 module_init(hfsc_init);
1747 module_exit(hfsc_cleanup);
1748 

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