Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1697 insertions, 0 deletions

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
new file mode 100644
index 000000000..b18ec1f6d
--- /dev/null
+++ b/net/sched/sch_hfsc.c
@@ -0,0 +1,1697 @@
+/*
+ * 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_packed 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_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
+{
+	unsigned int len = cl->qdisc->q.qlen;
+	unsigned int backlog = cl->qdisc->qstats.backlog;
+
+	qdisc_reset(cl->qdisc);
+	qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
+}
+
+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(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,
+						    qdisc_root_sleeping_running(sch),
+						    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,
+					qdisc_root_sleeping_running(sch),
+					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)
+		hfsc_purge_queue(sch, parent);
+	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 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);
+
+	hfsc_purge_queue(sch, cl);
+	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, 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;
+			/* fall through */
+		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(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;
+
+	cl->qstats.backlog = cl->qdisc->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(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||
+	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
+	    gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->qdisc->q.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;
+
+	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)
+{
+	struct hfsc_class *cl;
+	int uninitialized_var(err);
+
+	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;
+	}
+
+	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 (cl->qdisc->q.qlen == 1) {
+		unsigned int len = qdisc_pkt_len(skb);
+
+		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);
+
+	}
+
+	qdisc_qstats_backlog_inc(sch, skb);
+	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);