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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  * Copyright (c) 2003 Patrick McHardy, <kaber@trash.net>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
  * of the License, or (at your option) any later version.
  *
  * 2003-10-17 - Ported from altq
  */
 /*
  * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
  *
  * Permission to use, copy, modify, and distribute this software and
  * its documentation is hereby granted (including for commercial or
  * for-profit use), provided that both the copyright notice and this
  * permission notice appear in all copies of the software, derivative
  * works, or modified versions, and any portions thereof.
  *
  * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
  * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
  * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * Carnegie Mellon encourages (but does not require) users of this
  * software to return any improvements or extensions that they make,
  * and to grant Carnegie Mellon the rights to redistribute these
  * changes without encumbrance.
  */
 /*
  * H-FSC is described in Proceedings of SIGCOMM'97,
  * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
  * Real-Time and Priority Service"
  * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
  *
  * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
  * when a class has an upperlimit, the fit-time is computed from the
  * upperlimit service curve.  the link-sharing scheduler does not schedule
  * a class whose fit-time exceeds the current time.
  */
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/compiler.h>
 #include <linux/spinlock.h>
 #include <linux/skbuff.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include <linux/init.h>
 #include <linux/rtnetlink.h>
 #include <linux/pkt_sched.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
 #include <net/pkt_cls.h>
 #include <asm/div64.h>
 
 /*
  * kernel internal service curve representation:
  *   coordinates are given by 64 bit unsigned integers.
  *   x-axis: unit is clock count.
  *   y-axis: unit is byte.
  *
  *   The service curve parameters are converted to the internal
  *   representation. The slope values are scaled to avoid overflow.
  *   the inverse slope values as well as the y-projection of the 1st
  *   segment are kept in order to avoid 64-bit divide operations
  *   that are expensive on 32-bit architectures.
  */
 
 struct internal_sc {
     u64 sm1;    /* scaled slope of the 1st segment */
     u64 ism1;   /* scaled inverse-slope of the 1st segment */
     u64 dx; /* the x-projection of the 1st segment */
     u64 dy; /* the y-projection of the 1st segment */
     u64 sm2;    /* scaled slope of the 2nd segment */
     u64 ism2;   /* scaled inverse-slope of the 2nd segment */
 };
 
 /* runtime service curve */
 struct runtime_sc {
     u64 x;  /* current starting position on x-axis */
     u64 y;  /* current starting position on y-axis */
     u64 sm1;    /* scaled slope of the 1st segment */
     u64 ism1;   /* scaled inverse-slope of the 1st segment */
     u64 dx; /* the x-projection of the 1st segment */
     u64 dy; /* the y-projection of the 1st segment */
     u64 sm2;    /* scaled slope of the 2nd segment */
     u64 ism2;   /* scaled inverse-slope of the 2nd segment */
 };
 
 enum hfsc_class_flags {
     HFSC_RSC = 0x1,
     HFSC_FSC = 0x2,
     HFSC_USC = 0x4
 };
 
 struct hfsc_class {
     struct Qdisc_class_common cl_common;
 
     struct gnet_stats_basic_sync bstats;
     struct gnet_stats_queue qstats;
     struct net_rate_estimator __rcu *rate_est;
     struct tcf_proto __rcu *filter_list; /* filter list */
     struct tcf_block *block;
     unsigned int    filter_cnt; /* filter count */
     unsigned int    level;      /* class level in hierarchy */
 
     struct hfsc_sched *sched;   /* scheduler data */
     struct hfsc_class *cl_parent;   /* parent class */
     struct list_head siblings;  /* sibling classes */
     struct list_head children;  /* child classes */
     struct Qdisc    *qdisc;     /* leaf qdisc */
 
     struct rb_node el_node;     /* qdisc's eligible tree member */
     struct rb_root vt_tree;     /* active children sorted by cl_vt */
     struct rb_node vt_node;     /* parent's vt_tree member */
     struct rb_root cf_tree;     /* active children sorted by cl_f */
     struct rb_node cf_node;     /* parent's cf_heap member */
 
     u64 cl_total;       /* total work in bytes */
     u64 cl_cumul;       /* cumulative work in bytes done by
                        real-time criteria */
 
     u64 cl_d;           /* deadline*/
     u64 cl_e;           /* eligible time */
     u64 cl_vt;          /* virtual time */
     u64 cl_f;           /* time when this class will fit for
                        link-sharing, max(myf, cfmin) */
     u64 cl_myf;         /* my fit-time (calculated from this
                        class's own upperlimit curve) */
     u64 cl_cfmin;       /* earliest children's fit-time (used
                        with cl_myf to obtain cl_f) */
     u64 cl_cvtmin;      /* minimal virtual time among the
                        children fit for link-sharing
                        (monotonic within a period) */
     u64 cl_vtadj;       /* intra-period cumulative vt
                        adjustment */
     u64 cl_cvtoff;      /* largest virtual time seen among
                        the children */
 
     struct internal_sc cl_rsc;  /* internal real-time service curve */
     struct internal_sc cl_fsc;  /* internal fair service curve */
     struct internal_sc cl_usc;  /* internal upperlimit service curve */
     struct runtime_sc cl_deadline;  /* deadline curve */
     struct runtime_sc cl_eligible;  /* eligible curve */
     struct runtime_sc cl_virtual;   /* virtual curve */
     struct runtime_sc cl_ulimit;    /* upperlimit curve */
 
     u8      cl_flags;   /* which curves are valid */
     u32     cl_vtperiod;    /* vt period sequence number */
     u32     cl_parentperiod;/* parent's vt period sequence number*/
     u32     cl_nactive; /* number of active children */
 };
 
 struct hfsc_sched {
     u16 defcls;             /* default class id */
     struct hfsc_class root;         /* root class */
     struct Qdisc_class_hash clhash;     /* class hash */
     struct rb_root eligible;        /* eligible tree */
     struct qdisc_watchdog watchdog;     /* watchdog timer */
 };
 
 #define HT_INFINITY 0xffffffffffffffffULL   /* infinite time value */
 
 
 /*
  * eligible tree holds backlogged classes being sorted by their eligible times.
  * there is one eligible tree per hfsc instance.
  */
 
 static void
 eltree_insert(struct hfsc_class *cl)
 {
     struct rb_node **p = &cl->sched->eligible.rb_node;
     struct rb_node *parent = NULL;
     struct hfsc_class *cl1;
 
     while (*p != NULL) {
         parent = *p;
         cl1 = rb_entry(parent, struct hfsc_class, el_node);
         if (cl->cl_e >= cl1->cl_e)
             p = &parent->rb_right;
         else
             p = &parent->rb_left;
     }
     rb_link_node(&cl->el_node, parent, p);
     rb_insert_color(&cl->el_node, &cl->sched->eligible);
 }
 
 static inline void
 eltree_remove(struct hfsc_class *cl)
 {
     rb_erase(&cl->el_node, &cl->sched->eligible);
 }
 
 static inline void
 eltree_update(struct hfsc_class *cl)
 {
     eltree_remove(cl);
     eltree_insert(cl);
 }
 
 /* find the class with the minimum deadline among the eligible classes */
 static inline struct hfsc_class *
 eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
 {
     struct hfsc_class *p, *cl = NULL;
     struct rb_node *n;
 
     for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
         p = rb_entry(n, struct hfsc_class, el_node);
         if (p->cl_e > cur_time)
             break;
         if (cl == NULL || p->cl_d < cl->cl_d)
             cl = p;
     }
     return cl;
 }
 
 /* find the class with minimum eligible time among the eligible classes */
 static inline struct hfsc_class *
 eltree_get_minel(struct hfsc_sched *q)
 {
     struct rb_node *n;
 
     n = rb_first(&q->eligible);
     if (n == NULL)
         return NULL;
     return rb_entry(n, struct hfsc_class, el_node);
 }
 
 /*
  * vttree holds holds backlogged child classes being sorted by their virtual
  * time. each intermediate class has one vttree.
  */
 static void
 vttree_insert(struct hfsc_class *cl)
 {
     struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
     struct rb_node *parent = NULL;
     struct hfsc_class *cl1;
 
     while (*p != NULL) {
         parent = *p;
         cl1 = rb_entry(parent, struct hfsc_class, vt_node);
         if (cl->cl_vt >= cl1->cl_vt)
             p = &parent->rb_right;
         else
             p = &parent->rb_left;
     }
     rb_link_node(&cl->vt_node, parent, p);
     rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
 }
 
 static inline void
 vttree_remove(struct hfsc_class *cl)
 {
     rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
 }
 
 static inline void
 vttree_update(struct hfsc_class *cl)
 {
     vttree_remove(cl);
     vttree_insert(cl);
 }
 
 static inline struct hfsc_class *
 vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
 {
     struct hfsc_class *p;
     struct rb_node *n;
 
     for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
         p = rb_entry(n, struct hfsc_class, vt_node);
         if (p->cl_f <= cur_time)
             return p;
     }
     return NULL;
 }
 
 /*
  * get the leaf class with the minimum vt in the hierarchy
  */
 static struct hfsc_class *
 vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
 {
     /* if root-class's cfmin is bigger than cur_time nothing to do */
     if (cl->cl_cfmin > cur_time)
         return NULL;
 
     while (cl->level > 0) {
         cl = vttree_firstfit(cl, cur_time);
         if (cl == NULL)
             return NULL;
         /*
          * update parent's cl_cvtmin.
          */
         if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
             cl->cl_parent->cl_cvtmin = cl->cl_vt;
     }
     return cl;
 }
 
 static void
 cftree_insert(struct hfsc_class *cl)
 {
     struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
     struct rb_node *parent = NULL;
     struct hfsc_class *cl1;
 
     while (*p != NULL) {
         parent = *p;
         cl1 = rb_entry(parent, struct hfsc_class, cf_node);
         if (cl->cl_f >= cl1->cl_f)
             p = &parent->rb_right;
         else
             p = &parent->rb_left;
     }
     rb_link_node(&cl->cf_node, parent, p);
     rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
 }
 
 static inline void
 cftree_remove(struct hfsc_class *cl)
 {
     rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
 }
 
 static inline void
 cftree_update(struct hfsc_class *cl)
 {
     cftree_remove(cl);
     cftree_insert(cl);
 }
 
 /*
  * service curve support functions
  *
  *  external service curve parameters
  *  m: bps
  *  d: us
  *  internal service curve parameters
  *  sm: (bytes/psched_us) << SM_SHIFT
  *  ism: (psched_us/byte) << ISM_SHIFT
  *  dx: psched_us
  *
  * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
  *
  * sm and ism are scaled in order to keep effective digits.
  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
  * digits in decimal using the following table.
  *
  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
  *  ------------+-------------------------------------------------------
  *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
  *
  *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
  *
  * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
  */
 #define SM_SHIFT    (30 - PSCHED_SHIFT)
 #define ISM_SHIFT   (8 + PSCHED_SHIFT)
 
 #define SM_MASK     ((1ULL << SM_SHIFT) - 1)
 #define ISM_MASK    ((1ULL << ISM_SHIFT) - 1)
 
 static inline u64
 seg_x2y(u64 x, u64 sm)
 {
     u64 y;
 
     /*
      * compute
      *  y = x * sm >> SM_SHIFT
      * but divide it for the upper and lower bits to avoid overflow
      */
     y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
     return y;
 }
 
 static inline u64
 seg_y2x(u64 y, u64 ism)
 {
     u64 x;
 
     if (y == 0)
         x = 0;
     else if (ism == HT_INFINITY)
         x = HT_INFINITY;
     else {
         x = (y >> ISM_SHIFT) * ism
             + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
     }
     return x;
 }
 
 /* Convert m (bps) into sm (bytes/psched us) */
 static u64
 m2sm(u32 m)
 {
     u64 sm;
 
     sm = ((u64)m << SM_SHIFT);
     sm += PSCHED_TICKS_PER_SEC - 1;
     do_div(sm, PSCHED_TICKS_PER_SEC);
     return sm;
 }
 
 /* convert m (bps) into ism (psched us/byte) */
 static u64
 m2ism(u32 m)
 {
     u64 ism;
 
     if (m == 0)
         ism = HT_INFINITY;
     else {
         ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
         ism += m - 1;
         do_div(ism, m);
     }
     return ism;
 }
 
 /* convert d (us) into dx (psched us) */
 static u64
 d2dx(u32 d)
 {
     u64 dx;
 
     dx = ((u64)d * PSCHED_TICKS_PER_SEC);
     dx += USEC_PER_SEC - 1;
     do_div(dx, USEC_PER_SEC);
     return dx;
 }
 
 /* convert sm (bytes/psched us) into m (bps) */
 static u32
 sm2m(u64 sm)
 {
     u64 m;
 
     m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
     return (u32)m;
 }
 
 /* convert dx (psched us) into d (us) */
 static u32
 dx2d(u64 dx)
 {
     u64 d;
 
     d = dx * USEC_PER_SEC;
     do_div(d, PSCHED_TICKS_PER_SEC);
     return (u32)d;
 }
 
 static void
 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
 {
     isc->sm1  = m2sm(sc->m1);
     isc->ism1 = m2ism(sc->m1);
     isc->dx   = d2dx(sc->d);
     isc->dy   = seg_x2y(isc->dx, isc->sm1);
     isc->sm2  = m2sm(sc->m2);
     isc->ism2 = m2ism(sc->m2);
 }
 
 /*
  * initialize the runtime service curve with the given internal
  * service curve starting at (x, y).
  */
 static void
 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 {
     rtsc->x    = x;
     rtsc->y    = y;
     rtsc->sm1  = isc->sm1;
     rtsc->ism1 = isc->ism1;
     rtsc->dx   = isc->dx;
     rtsc->dy   = isc->dy;
     rtsc->sm2  = isc->sm2;
     rtsc->ism2 = isc->ism2;
 }
 
 /*
  * calculate the y-projection of the runtime service curve by the
  * given x-projection value
  */
 static u64
 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
 {
     u64 x;
 
     if (y < rtsc->y)
         x = rtsc->x;
     else if (y <= rtsc->y + rtsc->dy) {
         /* x belongs to the 1st segment */
         if (rtsc->dy == 0)
             x = rtsc->x + rtsc->dx;
         else
             x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
     } else {
         /* x belongs to the 2nd segment */
         x = rtsc->x + rtsc->dx
             + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
     }
     return x;
 }
 
 static u64
 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
 {
     u64 y;
 
     if (x <= rtsc->x)
         y = rtsc->y;
     else if (x <= rtsc->x + rtsc->dx)
         /* y belongs to the 1st segment */
         y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
     else
         /* y belongs to the 2nd segment */
         y = rtsc->y + rtsc->dy
             + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
     return y;
 }
 
 /*
  * update the runtime service curve by taking the minimum of the current
  * runtime service curve and the service curve starting at (x, y).
  */
 static void
 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 {
     u64 y1, y2, dx, dy;
     u32 dsm;
 
     if (isc->sm1 <= isc->sm2) {
         /* service curve is convex */
         y1 = rtsc_x2y(rtsc, x);
         if (y1 < y)
             /* the current rtsc is smaller */
             return;
         rtsc->x = x;
         rtsc->y = y;
         return;
     }
 
     /*
      * service curve is concave
      * compute the two y values of the current rtsc
      *  y1: at x
      *  y2: at (x + dx)
      */
     y1 = rtsc_x2y(rtsc, x);
     if (y1 <= y) {
         /* rtsc is below isc, no change to rtsc */
         return;
     }
 
     y2 = rtsc_x2y(rtsc, x + isc->dx);
     if (y2 >= y + isc->dy) {
         /* rtsc is above isc, replace rtsc by isc */
         rtsc->x = x;
         rtsc->y = y;
         rtsc->dx = isc->dx;
         rtsc->dy = isc->dy;
         return;
     }
 
     /*
      * the two curves intersect
      * compute the offsets (dx, dy) using the reverse
      * function of seg_x2y()
      *  seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
      */
     dx = (y1 - y) << SM_SHIFT;
     dsm = isc->sm1 - isc->sm2;
     do_div(dx, dsm);
     /*
      * check if (x, y1) belongs to the 1st segment of rtsc.
      * if so, add the offset.
      */
     if (rtsc->x + rtsc->dx > x)
         dx += rtsc->x + rtsc->dx - x;
     dy = seg_x2y(dx, isc->sm1);
 
     rtsc->x = x;
     rtsc->y = y;
     rtsc->dx = dx;
     rtsc->dy = dy;
 }
 
 static void
 init_ed(struct hfsc_class *cl, unsigned int next_len)
 {
     u64 cur_time = psched_get_time();
 
     /* update the deadline curve */
     rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 
     /*
      * update the eligible curve.
      * for concave, it is equal to the deadline curve.
      * for convex, it is a linear curve with slope m2.
      */
     cl->cl_eligible = cl->cl_deadline;
     if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
         cl->cl_eligible.dx = 0;
         cl->cl_eligible.dy = 0;
     }
 
     /* compute e and d */
     cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
     cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 
     eltree_insert(cl);
 }
 
 static void
 update_ed(struct hfsc_class *cl, unsigned int next_len)
 {
     cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
     cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 
     eltree_update(cl);
 }
 
 static inline void
 update_d(struct hfsc_class *cl, unsigned int next_len)
 {
     cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 }
 
 static inline void
 update_cfmin(struct hfsc_class *cl)
 {
     struct rb_node *n = rb_first(&cl->cf_tree);
     struct hfsc_class *p;
 
     if (n == NULL) {
         cl->cl_cfmin = 0;
         return;
     }
     p = rb_entry(n, struct hfsc_class, cf_node);
     cl->cl_cfmin = p->cl_f;
 }
 
 static void
 init_vf(struct hfsc_class *cl, unsigned int len)
 {
     struct hfsc_class *max_cl;
     struct rb_node *n;
     u64 vt, f, cur_time;
     int go_active;
 
     cur_time = 0;
     go_active = 1;
     for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
         if (go_active && cl->cl_nactive++ == 0)
             go_active = 1;
         else
             go_active = 0;
 
         if (go_active) {
             n = rb_last(&cl->cl_parent->vt_tree);
             if (n != NULL) {
                 max_cl = rb_entry(n, struct hfsc_class, vt_node);
                 /*
                  * set vt to the average of the min and max
                  * classes.  if the parent's period didn't
                  * change, don't decrease vt of the class.
                  */
                 vt = max_cl->cl_vt;
                 if (cl->cl_parent->cl_cvtmin != 0)
                     vt = (cl->cl_parent->cl_cvtmin + vt)/2;
 
                 if (cl->cl_parent->cl_vtperiod !=
                     cl->cl_parentperiod || vt > cl->cl_vt)
                     cl->cl_vt = vt;
             } else {
                 /*
                  * first child for a new parent backlog period.
                  * initialize cl_vt to the highest value seen
                  * among the siblings. this is analogous to
                  * what cur_time would provide in realtime case.
                  */
                 cl->cl_vt = cl->cl_parent->cl_cvtoff;
                 cl->cl_parent->cl_cvtmin = 0;
             }
 
             /* update the virtual curve */
             rtsc_min(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
             cl->cl_vtadj = 0;
 
             cl->cl_vtperiod++;  /* increment vt period */
             cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
             if (cl->cl_parent->cl_nactive == 0)
                 cl->cl_parentperiod++;
             cl->cl_f = 0;
 
             vttree_insert(cl);
             cftree_insert(cl);
 
             if (cl->cl_flags & HFSC_USC) {
                 /* class has upper limit curve */
                 if (cur_time == 0)
                     cur_time = psched_get_time();
 
                 /* update the ulimit curve */
                 rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
                      cl->cl_total);
                 /* compute myf */
                 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
                               cl->cl_total);
             }
         }
 
         f = max(cl->cl_myf, cl->cl_cfmin);
         if (f != cl->cl_f) {
             cl->cl_f = f;
             cftree_update(cl);
         }
         update_cfmin(cl->cl_parent);
     }
 }
 
 static void
 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
 {
     u64 f; /* , myf_bound, delta; */
     int go_passive = 0;
 
     if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
         go_passive = 1;
 
     for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
         cl->cl_total += len;
 
         if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
             continue;
 
         if (go_passive && --cl->cl_nactive == 0)
             go_passive = 1;
         else
             go_passive = 0;
 
         /* update vt */
         cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) + cl->cl_vtadj;
 
         /*
          * if vt of the class is smaller than cvtmin,
          * the class was skipped in the past due to non-fit.
          * if so, we need to adjust vtadj.
          */
         if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
             cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
             cl->cl_vt = cl->cl_parent->cl_cvtmin;
         }
 
         if (go_passive) {
             /* no more active child, going passive */
 
             /* update cvtoff of the parent class */
             if (cl->cl_vt > cl->cl_parent->cl_cvtoff)
                 cl->cl_parent->cl_cvtoff = cl->cl_vt;
 
             /* remove this class from the vt tree */
             vttree_remove(cl);
 
             cftree_remove(cl);
             update_cfmin(cl->cl_parent);
 
             continue;
         }
 
         /* update the vt tree */
         vttree_update(cl);
 
         /* update f */
         if (cl->cl_flags & HFSC_USC) {
             cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
 #if 0
             cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
                                   cl->cl_total);
             /*
              * This code causes classes to stay way under their
              * limit when multiple classes are used at gigabit
              * speed. needs investigation. -kaber
              */
             /*
              * if myf lags behind by more than one clock tick
              * from the current time, adjust myfadj to prevent
              * a rate-limited class from going greedy.
              * in a steady state under rate-limiting, myf
              * fluctuates within one clock tick.
              */
             myf_bound = cur_time - PSCHED_JIFFIE2US(1);
             if (cl->cl_myf < myf_bound) {
                 delta = cur_time - cl->cl_myf;
                 cl->cl_myfadj += delta;
                 cl->cl_myf += delta;
             }
 #endif
         }
 
         f = max(cl->cl_myf, cl->cl_cfmin);
         if (f != cl->cl_f) {
             cl->cl_f = f;
             cftree_update(cl);
             update_cfmin(cl->cl_parent);
         }
     }
 }
 
 static unsigned int
 qdisc_peek_len(struct Qdisc *sch)
 {
     struct sk_buff *skb;
     unsigned int len;
 
     skb = sch->ops->peek(sch);
     if (unlikely(skb == NULL)) {
         qdisc_warn_nonwc("qdisc_peek_len", sch);
         return 0;
     }
     len = qdisc_pkt_len(skb);
 
     return len;
 }
 
 static void
 hfsc_adjust_levels(struct hfsc_class *cl)
 {
     struct hfsc_class *p;
     unsigned int level;
 
     do {
         level = 0;
         list_for_each_entry(p, &cl->children, siblings) {
             if (p->level >= level)
                 level = p->level + 1;
         }
         cl->level = level;
     } while ((cl = cl->cl_parent) != NULL);
 }
 
 static inline struct hfsc_class *
 hfsc_find_class(u32 classid, struct Qdisc *sch)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct Qdisc_class_common *clc;
 
     clc = qdisc_class_find(&q->clhash, classid);
     if (clc == NULL)
         return NULL;
     return container_of(clc, struct hfsc_class, cl_common);
 }
 
 static void
 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
         u64 cur_time)
 {
     sc2isc(rsc, &cl->cl_rsc);
     rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
     cl->cl_eligible = cl->cl_deadline;
     if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
         cl->cl_eligible.dx = 0;
         cl->cl_eligible.dy = 0;
     }
     cl->cl_flags |= HFSC_RSC;
 }
 
 static void
 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
 {
     sc2isc(fsc, &cl->cl_fsc);
     rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
     cl->cl_flags |= HFSC_FSC;
 }
 
 static void
 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
         u64 cur_time)
 {
     sc2isc(usc, &cl->cl_usc);
     rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
     cl->cl_flags |= HFSC_USC;
 }
 
 static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
     [TCA_HFSC_RSC]  = { .len = sizeof(struct tc_service_curve) },
     [TCA_HFSC_FSC]  = { .len = sizeof(struct tc_service_curve) },
     [TCA_HFSC_USC]  = { .len = sizeof(struct tc_service_curve) },
 };
 
 static int
 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
           struct nlattr **tca, unsigned long *arg,
           struct netlink_ext_ack *extack)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl = (struct hfsc_class *)*arg;
     struct hfsc_class *parent = NULL;
     struct nlattr *opt = tca[TCA_OPTIONS];
     struct nlattr *tb[TCA_HFSC_MAX + 1];
     struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
     u64 cur_time;
     int err;
 
     if (opt == NULL)
         return -EINVAL;
 
     err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
                       NULL);
     if (err < 0)
         return err;
 
     if (tb[TCA_HFSC_RSC]) {
         rsc = nla_data(tb[TCA_HFSC_RSC]);
         if (rsc->m1 == 0 && rsc->m2 == 0)
             rsc = NULL;
     }
 
     if (tb[TCA_HFSC_FSC]) {
         fsc = nla_data(tb[TCA_HFSC_FSC]);
         if (fsc->m1 == 0 && fsc->m2 == 0)
             fsc = NULL;
     }
 
     if (tb[TCA_HFSC_USC]) {
         usc = nla_data(tb[TCA_HFSC_USC]);
         if (usc->m1 == 0 && usc->m2 == 0)
             usc = NULL;
     }
 
     if (cl != NULL) {
         int old_flags;
 
         if (parentid) {
             if (cl->cl_parent &&
                 cl->cl_parent->cl_common.classid != parentid)
                 return -EINVAL;
             if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
                 return -EINVAL;
         }
         cur_time = psched_get_time();
 
         if (tca[TCA_RATE]) {
             err = gen_replace_estimator(&cl->bstats, NULL,
                             &cl->rate_est,
                             NULL,
                             true,
                             tca[TCA_RATE]);
             if (err)
                 return err;
         }
 
         sch_tree_lock(sch);
         old_flags = cl->cl_flags;
 
         if (rsc != NULL)
             hfsc_change_rsc(cl, rsc, cur_time);
         if (fsc != NULL)
             hfsc_change_fsc(cl, fsc);
         if (usc != NULL)
             hfsc_change_usc(cl, usc, cur_time);
 
         if (cl->qdisc->q.qlen != 0) {
             int len = qdisc_peek_len(cl->qdisc);
 
             if (cl->cl_flags & HFSC_RSC) {
                 if (old_flags & HFSC_RSC)
                     update_ed(cl, len);
                 else
                     init_ed(cl, len);
             }
 
             if (cl->cl_flags & HFSC_FSC) {
                 if (old_flags & HFSC_FSC)
                     update_vf(cl, 0, cur_time);
                 else
                     init_vf(cl, len);
             }
         }
         sch_tree_unlock(sch);
 
         return 0;
     }
 
     if (parentid == TC_H_ROOT)
         return -EEXIST;
 
     parent = &q->root;
     if (parentid) {
         parent = hfsc_find_class(parentid, sch);
         if (parent == NULL)
             return -ENOENT;
     }
 
     if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
         return -EINVAL;
     if (hfsc_find_class(classid, sch))
         return -EEXIST;
 
     if (rsc == NULL && fsc == NULL)
         return -EINVAL;
 
     cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
     if (cl == NULL)
         return -ENOBUFS;
 
     err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
     if (err) {
         kfree(cl);
         return err;
     }
 
     if (tca[TCA_RATE]) {
         err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
                     NULL, true, tca[TCA_RATE]);
         if (err) {
             tcf_block_put(cl->block);
             kfree(cl);
             return err;
         }
     }
 
     if (rsc != NULL)
         hfsc_change_rsc(cl, rsc, 0);
     if (fsc != NULL)
         hfsc_change_fsc(cl, fsc);
     if (usc != NULL)
         hfsc_change_usc(cl, usc, 0);
 
     cl->cl_common.classid = classid;
     cl->sched     = q;
     cl->cl_parent = parent;
     cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
                       classid, NULL);
     if (cl->qdisc == NULL)
         cl->qdisc = &noop_qdisc;
     else
         qdisc_hash_add(cl->qdisc, true);
     INIT_LIST_HEAD(&cl->children);
     cl->vt_tree = RB_ROOT;
     cl->cf_tree = RB_ROOT;
 
     sch_tree_lock(sch);
     qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
     list_add_tail(&cl->siblings, &parent->children);
     if (parent->level == 0)
         qdisc_purge_queue(parent->qdisc);
     hfsc_adjust_levels(parent);
     sch_tree_unlock(sch);
 
     qdisc_class_hash_grow(sch, &q->clhash);
 
     *arg = (unsigned long)cl;
     return 0;
 }
 
 static void
 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
 
     tcf_block_put(cl->block);
     qdisc_put(cl->qdisc);
     gen_kill_estimator(&cl->rate_est);
     if (cl != &q->root)
         kfree(cl);
 }
 
 static int
 hfsc_delete_class(struct Qdisc *sch, unsigned long arg,
           struct netlink_ext_ack *extack)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
         return -EBUSY;
 
     sch_tree_lock(sch);
 
     list_del(&cl->siblings);
     hfsc_adjust_levels(cl->cl_parent);
 
     qdisc_purge_queue(cl->qdisc);
     qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
 
     sch_tree_unlock(sch);
 
     hfsc_destroy_class(sch, cl);
     return 0;
 }
 
 static struct hfsc_class *
 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *head, *cl;
     struct tcf_result res;
     struct tcf_proto *tcf;
     int result;
 
     if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
         (cl = hfsc_find_class(skb->priority, sch)) != NULL)
         if (cl->level == 0)
             return cl;
 
     *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
     head = &q->root;
     tcf = rcu_dereference_bh(q->root.filter_list);
     while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
         switch (result) {
         case TC_ACT_QUEUED:
         case TC_ACT_STOLEN:
         case TC_ACT_TRAP:
             *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
             fallthrough;
         case TC_ACT_SHOT:
             return NULL;
         }
 #endif
         cl = (struct hfsc_class *)res.class;
         if (!cl) {
             cl = hfsc_find_class(res.classid, sch);
             if (!cl)
                 break; /* filter selected invalid classid */
             if (cl->level >= head->level)
                 break; /* filter may only point downwards */
         }
 
         if (cl->level == 0)
             return cl; /* hit leaf class */
 
         /* apply inner filter chain */
         tcf = rcu_dereference_bh(cl->filter_list);
         head = cl;
     }
 
     /* classification failed, try default class */
     cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
     if (cl == NULL || cl->level > 0)
         return NULL;
 
     return cl;
 }
 
 static int
 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
          struct Qdisc **old, struct netlink_ext_ack *extack)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     if (cl->level > 0)
         return -EINVAL;
     if (new == NULL) {
         new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
                     cl->cl_common.classid, NULL);
         if (new == NULL)
             new = &noop_qdisc;
     }
 
     *old = qdisc_replace(sch, new, &cl->qdisc);
     return 0;
 }
 
 static struct Qdisc *
 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     if (cl->level == 0)
         return cl->qdisc;
 
     return NULL;
 }
 
 static void
 hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     /* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
      * needs to be called explicitly to remove a class from vttree.
      */
     update_vf(cl, 0, 0);
     if (cl->cl_flags & HFSC_RSC)
         eltree_remove(cl);
 }
 
 static unsigned long
 hfsc_search_class(struct Qdisc *sch, u32 classid)
 {
     return (unsigned long)hfsc_find_class(classid, sch);
 }
 
 static unsigned long
 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
 {
     struct hfsc_class *p = (struct hfsc_class *)parent;
     struct hfsc_class *cl = hfsc_find_class(classid, sch);
 
     if (cl != NULL) {
         if (p != NULL && p->level <= cl->level)
             return 0;
         cl->filter_cnt++;
     }
 
     return (unsigned long)cl;
 }
 
 static void
 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     cl->filter_cnt--;
 }
 
 static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
                     struct netlink_ext_ack *extack)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl = (struct hfsc_class *)arg;
 
     if (cl == NULL)
         cl = &q->root;
 
     return cl->block;
 }
 
 static int
 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
 {
     struct tc_service_curve tsc;
 
     tsc.m1 = sm2m(sc->sm1);
     tsc.d  = dx2d(sc->dx);
     tsc.m2 = sm2m(sc->sm2);
     if (nla_put(skb, attr, sizeof(tsc), &tsc))
         goto nla_put_failure;
 
     return skb->len;
 
  nla_put_failure:
     return -1;
 }
 
 static int
 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
 {
     if ((cl->cl_flags & HFSC_RSC) &&
         (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
         goto nla_put_failure;
 
     if ((cl->cl_flags & HFSC_FSC) &&
         (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
         goto nla_put_failure;
 
     if ((cl->cl_flags & HFSC_USC) &&
         (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
         goto nla_put_failure;
 
     return skb->len;
 
  nla_put_failure:
     return -1;
 }
 
 static int
 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
         struct tcmsg *tcm)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
     struct nlattr *nest;
 
     tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
                       TC_H_ROOT;
     tcm->tcm_handle = cl->cl_common.classid;
     if (cl->level == 0)
         tcm->tcm_info = cl->qdisc->handle;
 
     nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
     if (nest == NULL)
         goto nla_put_failure;
     if (hfsc_dump_curves(skb, cl) < 0)
         goto nla_put_failure;
     return nla_nest_end(skb, nest);
 
  nla_put_failure:
     nla_nest_cancel(skb, nest);
     return -EMSGSIZE;
 }
 
 static int
 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
     struct gnet_dump *d)
 {
     struct hfsc_class *cl = (struct hfsc_class *)arg;
     struct tc_hfsc_stats xstats;
     __u32 qlen;
 
     qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
     xstats.level   = cl->level;
     xstats.period  = cl->cl_vtperiod;
     xstats.work    = cl->cl_total;
     xstats.rtwork  = cl->cl_cumul;
 
     if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
         gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
         gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
         return -1;
 
     return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
 }
 
 
 
 static void
 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl;
     unsigned int i;
 
     if (arg->stop)
         return;
 
     for (i = 0; i < q->clhash.hashsize; i++) {
         hlist_for_each_entry(cl, &q->clhash.hash[i],
                      cl_common.hnode) {
             if (arg->count < arg->skip) {
                 arg->count++;
                 continue;
             }
             if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
                 arg->stop = 1;
                 return;
             }
             arg->count++;
         }
     }
 }
 
 static void
 hfsc_schedule_watchdog(struct Qdisc *sch)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl;
     u64 next_time = 0;
 
     cl = eltree_get_minel(q);
     if (cl)
         next_time = cl->cl_e;
     if (q->root.cl_cfmin != 0) {
         if (next_time == 0 || next_time > q->root.cl_cfmin)
             next_time = q->root.cl_cfmin;
     }
     if (next_time)
         qdisc_watchdog_schedule(&q->watchdog, next_time);
 }
 
 static int
 hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
         struct netlink_ext_ack *extack)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct tc_hfsc_qopt *qopt;
     int err;
 
     qdisc_watchdog_init(&q->watchdog, sch);
 
     if (!opt || nla_len(opt) < sizeof(*qopt))
         return -EINVAL;
     qopt = nla_data(opt);
 
     q->defcls = qopt->defcls;
     err = qdisc_class_hash_init(&q->clhash);
     if (err < 0)
         return err;
     q->eligible = RB_ROOT;
 
     err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
     if (err)
         return err;
 
     gnet_stats_basic_sync_init(&q->root.bstats);
     q->root.cl_common.classid = sch->handle;
     q->root.sched   = q;
     q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
                       sch->handle, NULL);
     if (q->root.qdisc == NULL)
         q->root.qdisc = &noop_qdisc;
     else
         qdisc_hash_add(q->root.qdisc, true);
     INIT_LIST_HEAD(&q->root.children);
     q->root.vt_tree = RB_ROOT;
     q->root.cf_tree = RB_ROOT;
 
     qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
     qdisc_class_hash_grow(sch, &q->clhash);
 
     return 0;
 }
 
 static int
 hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
           struct netlink_ext_ack *extack)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct tc_hfsc_qopt *qopt;
 
     if (opt == NULL || nla_len(opt) < sizeof(*qopt))
         return -EINVAL;
     qopt = nla_data(opt);
 
     sch_tree_lock(sch);
     q->defcls = qopt->defcls;
     sch_tree_unlock(sch);
 
     return 0;
 }
 
 static void
 hfsc_reset_class(struct hfsc_class *cl)
 {
     cl->cl_total        = 0;
     cl->cl_cumul        = 0;
     cl->cl_d            = 0;
     cl->cl_e            = 0;
     cl->cl_vt           = 0;
     cl->cl_vtadj        = 0;
     cl->cl_cvtmin       = 0;
     cl->cl_cvtoff       = 0;
     cl->cl_vtperiod     = 0;
     cl->cl_parentperiod = 0;
     cl->cl_f            = 0;
     cl->cl_myf          = 0;
     cl->cl_cfmin        = 0;
     cl->cl_nactive      = 0;
 
     cl->vt_tree = RB_ROOT;
     cl->cf_tree = RB_ROOT;
     qdisc_reset(cl->qdisc);
 
     if (cl->cl_flags & HFSC_RSC)
         rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
     if (cl->cl_flags & HFSC_FSC)
         rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
     if (cl->cl_flags & HFSC_USC)
         rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
 }
 
 static void
 hfsc_reset_qdisc(struct Qdisc *sch)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl;
     unsigned int i;
 
     for (i = 0; i < q->clhash.hashsize; i++) {
         hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
             hfsc_reset_class(cl);
     }
     q->eligible = RB_ROOT;
     qdisc_watchdog_cancel(&q->watchdog);
     sch->qstats.backlog = 0;
     sch->q.qlen = 0;
 }
 
 static void
 hfsc_destroy_qdisc(struct Qdisc *sch)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hlist_node *next;
     struct hfsc_class *cl;
     unsigned int i;
 
     for (i = 0; i < q->clhash.hashsize; i++) {
         hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
             tcf_block_put(cl->block);
             cl->block = NULL;
         }
     }
     for (i = 0; i < q->clhash.hashsize; i++) {
         hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
                       cl_common.hnode)
             hfsc_destroy_class(sch, cl);
     }
     qdisc_class_hash_destroy(&q->clhash);
     qdisc_watchdog_cancel(&q->watchdog);
 }
 
 static int
 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     unsigned char *b = skb_tail_pointer(skb);
     struct tc_hfsc_qopt qopt;
 
     qopt.defcls = q->defcls;
     if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
         goto nla_put_failure;
     return skb->len;
 
  nla_put_failure:
     nlmsg_trim(skb, b);
     return -1;
 }
 
 static int
 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
 {
     unsigned int len = qdisc_pkt_len(skb);
     struct hfsc_class *cl;
     int err;
     bool first;
 
     cl = hfsc_classify(skb, sch, &err);
     if (cl == NULL) {
         if (err & __NET_XMIT_BYPASS)
             qdisc_qstats_drop(sch);
         __qdisc_drop(skb, to_free);
         return err;
     }
 
     first = !cl->qdisc->q.qlen;
     err = qdisc_enqueue(skb, cl->qdisc, to_free);
     if (unlikely(err != NET_XMIT_SUCCESS)) {
         if (net_xmit_drop_count(err)) {
             cl->qstats.drops++;
             qdisc_qstats_drop(sch);
         }
         return err;
     }
 
     if (first) {
         if (cl->cl_flags & HFSC_RSC)
             init_ed(cl, len);
         if (cl->cl_flags & HFSC_FSC)
             init_vf(cl, len);
         /*
          * If this is the first packet, isolate the head so an eventual
          * head drop before the first dequeue operation has no chance
          * to invalidate the deadline.
          */
         if (cl->cl_flags & HFSC_RSC)
             cl->qdisc->ops->peek(cl->qdisc);
 
     }
 
     sch->qstats.backlog += len;
     sch->q.qlen++;
 
     return NET_XMIT_SUCCESS;
 }
 
 static struct sk_buff *
 hfsc_dequeue(struct Qdisc *sch)
 {
     struct hfsc_sched *q = qdisc_priv(sch);
     struct hfsc_class *cl;
     struct sk_buff *skb;
     u64 cur_time;
     unsigned int next_len;
     int realtime = 0;
 
     if (sch->q.qlen == 0)
         return NULL;
 
     cur_time = psched_get_time();
 
     /*
      * if there are eligible classes, use real-time criteria.
      * find the class with the minimum deadline among
      * the eligible classes.
      */
     cl = eltree_get_mindl(q, cur_time);
     if (cl) {
         realtime = 1;
     } else {
         /*
          * use link-sharing criteria
          * get the class with the minimum vt in the hierarchy
          */
         cl = vttree_get_minvt(&q->root, cur_time);
         if (cl == NULL) {
             qdisc_qstats_overlimit(sch);
             hfsc_schedule_watchdog(sch);
             return NULL;
         }
     }
 
     skb = qdisc_dequeue_peeked(cl->qdisc);
     if (skb == NULL) {
         qdisc_warn_nonwc("HFSC", cl->qdisc);
         return NULL;
     }
 
     bstats_update(&cl->bstats, skb);
     update_vf(cl, qdisc_pkt_len(skb), cur_time);
     if (realtime)
         cl->cl_cumul += qdisc_pkt_len(skb);
 
     if (cl->cl_flags & HFSC_RSC) {
         if (cl->qdisc->q.qlen != 0) {
             /* update ed */
             next_len = qdisc_peek_len(cl->qdisc);
             if (realtime)
                 update_ed(cl, next_len);
             else
                 update_d(cl, next_len);
         } else {
             /* the class becomes passive */
             eltree_remove(cl);
         }
     }
 
     qdisc_bstats_update(sch, skb);
     qdisc_qstats_backlog_dec(sch, skb);
     sch->q.qlen--;
 
     return skb;
 }
 
 static const struct Qdisc_class_ops hfsc_class_ops = {
     .change     = hfsc_change_class,
     .delete     = hfsc_delete_class,
     .graft      = hfsc_graft_class,
     .leaf       = hfsc_class_leaf,
     .qlen_notify    = hfsc_qlen_notify,
     .find       = hfsc_search_class,
     .bind_tcf   = hfsc_bind_tcf,
     .unbind_tcf = hfsc_unbind_tcf,
     .tcf_block  = hfsc_tcf_block,
     .dump       = hfsc_dump_class,
     .dump_stats = hfsc_dump_class_stats,
     .walk       = hfsc_walk
 };
 
 static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
     .id     = "hfsc",
     .init       = hfsc_init_qdisc,
     .change     = hfsc_change_qdisc,
     .reset      = hfsc_reset_qdisc,
     .destroy    = hfsc_destroy_qdisc,
     .dump       = hfsc_dump_qdisc,
     .enqueue    = hfsc_enqueue,
     .dequeue    = hfsc_dequeue,
     .peek       = qdisc_peek_dequeued,
     .cl_ops     = &hfsc_class_ops,
     .priv_size  = sizeof(struct hfsc_sched),
     .owner      = THIS_MODULE
 };
 
 static int __init
 hfsc_init(void)
 {
     return register_qdisc(&hfsc_qdisc_ops);
 }
 
 static void __exit
 hfsc_cleanup(void)
 {
     unregister_qdisc(&hfsc_qdisc_ops);
 }
 
 MODULE_LICENSE("GPL");
 module_init(hfsc_init);
 module_exit(hfsc_cleanup);

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