--- /dev/null
+/*
+ * net/sched/sch_cbq.c Class-Based Queueing discipline.
+ *
+ * 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.
+ *
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+
+
+/* Class-Based Queueing (CBQ) algorithm.
+ =======================================
+
+ Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
+ Management Models for Packet Networks",
+ IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
+
+ [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
+
+ [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
+ Parameters", 1996
+
+ [4] Sally Floyd and Michael Speer, "Experimental Results
+ for Class-Based Queueing", 1998, not published.
+
+ -----------------------------------------------------------------------
+
+ Algorithm skeleton was taken from NS simulator cbq.cc.
+ If someone wants to check this code against the LBL version,
+ he should take into account that ONLY the skeleton was borrowed,
+ the implementation is different. Particularly:
+
+ --- The WRR algorithm is different. Our version looks more
+ reasonable (I hope) and works when quanta are allowed to be
+ less than MTU, which is always the case when real time classes
+ have small rates. Note, that the statement of [3] is
+ incomplete, delay may actually be estimated even if class
+ per-round allotment is less than MTU. Namely, if per-round
+ allotment is W*r_i, and r_1+...+r_k = r < 1
+
+ delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
+
+ In the worst case we have IntServ estimate with D = W*r+k*MTU
+ and C = MTU*r. The proof (if correct at all) is trivial.
+
+
+ --- It seems that cbq-2.0 is not very accurate. At least, I cannot
+ interpret some places, which look like wrong translations
+ from NS. Anyone is advised to find these differences
+ and explain to me, why I am wrong 8).
+
+ --- Linux has no EOI event, so that we cannot estimate true class
+ idle time. Workaround is to consider the next dequeue event
+ as sign that previous packet is finished. This is wrong because of
+ internal device queueing, but on a permanently loaded link it is true.
+ Moreover, combined with clock integrator, this scheme looks
+ very close to an ideal solution. */
+
+struct cbq_sched_data;
+
+
+struct cbq_class {
+ struct Qdisc_class_common common;
+ struct cbq_class *next_alive; /* next class with backlog in this priority band */
+
+/* Parameters */
+ unsigned char priority; /* class priority */
+ unsigned char priority2; /* priority to be used after overlimit */
+ unsigned char ewma_log; /* time constant for idle time calculation */
+ unsigned char ovl_strategy;
+#ifdef CONFIG_NET_CLS_ACT
+ unsigned char police;
+#endif
+
+ u32 defmap;
+
+ /* Link-sharing scheduler parameters */
+ long maxidle; /* Class parameters: see below. */
+ long offtime;
+ long minidle;
+ u32 avpkt;
+ struct qdisc_rate_table *R_tab;
+
+ /* Overlimit strategy parameters */
+ void (*overlimit)(struct cbq_class *cl);
+ psched_tdiff_t penalty;
+
+ /* General scheduler (WRR) parameters */
+ long allot;
+ long quantum; /* Allotment per WRR round */
+ long weight; /* Relative allotment: see below */
+
+ struct Qdisc *qdisc; /* Ptr to CBQ discipline */
+ struct cbq_class *split; /* Ptr to split node */
+ struct cbq_class *share; /* Ptr to LS parent in the class tree */
+ struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
+ struct cbq_class *borrow; /* NULL if class is bandwidth limited;
+ parent otherwise */
+ struct cbq_class *sibling; /* Sibling chain */
+ struct cbq_class *children; /* Pointer to children chain */
+
+ struct Qdisc *q; /* Elementary queueing discipline */
+
+
+/* Variables */
+ unsigned char cpriority; /* Effective priority */
+ unsigned char delayed;
+ unsigned char level; /* level of the class in hierarchy:
+ 0 for leaf classes, and maximal
+ level of children + 1 for nodes.
+ */
+
+ psched_time_t last; /* Last end of service */
+ psched_time_t undertime;
+ long avgidle;
+ long deficit; /* Saved deficit for WRR */
+ psched_time_t penalized;
+ struct gnet_stats_basic_packed bstats;
+ struct gnet_stats_queue qstats;
+ struct gnet_stats_rate_est64 rate_est;
+ struct tc_cbq_xstats xstats;
+
+ struct tcf_proto __rcu *filter_list;
+
+ int refcnt;
+ int filters;
+
+ struct cbq_class *defaults[TC_PRIO_MAX + 1];
+};
+
+struct cbq_sched_data {
+ struct Qdisc_class_hash clhash; /* Hash table of all classes */
+ int nclasses[TC_CBQ_MAXPRIO + 1];
+ unsigned int quanta[TC_CBQ_MAXPRIO + 1];
+
+ struct cbq_class link;
+
+ unsigned int activemask;
+ struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
+ with backlog */
+
+#ifdef CONFIG_NET_CLS_ACT
+ struct cbq_class *rx_class;
+#endif
+ struct cbq_class *tx_class;
+ struct cbq_class *tx_borrowed;
+ int tx_len;
+ psched_time_t now; /* Cached timestamp */
+ unsigned int pmask;
+
+ struct hrtimer delay_timer;
+ struct qdisc_watchdog watchdog; /* Watchdog timer,
+ started when CBQ has
+ backlog, but cannot
+ transmit just now */
+ psched_tdiff_t wd_expires;
+ int toplevel;
+ u32 hgenerator;
+};
+
+
+#define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
+
+static inline struct cbq_class *
+cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
+{
+ struct Qdisc_class_common *clc;
+
+ clc = qdisc_class_find(&q->clhash, classid);
+ if (clc == NULL)
+ return NULL;
+ return container_of(clc, struct cbq_class, common);
+}
+
+#ifdef CONFIG_NET_CLS_ACT
+
+static struct cbq_class *
+cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
+{
+ struct cbq_class *cl;
+
+ for (cl = this->tparent; cl; cl = cl->tparent) {
+ struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
+
+ if (new != NULL && new != this)
+ return new;
+ }
+ return NULL;
+}
+
+#endif
+
+/* Classify packet. The procedure is pretty complicated, but
+ * it allows us to combine link sharing and priority scheduling
+ * transparently.
+ *
+ * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
+ * so that it resolves to split nodes. Then packets are classified
+ * by logical priority, or a more specific classifier may be attached
+ * to the split node.
+ */
+
+static struct cbq_class *
+cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *head = &q->link;
+ struct cbq_class **defmap;
+ struct cbq_class *cl = NULL;
+ u32 prio = skb->priority;
+ struct tcf_proto *fl;
+ struct tcf_result res;
+
+ /*
+ * Step 1. If skb->priority points to one of our classes, use it.
+ */
+ if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
+ (cl = cbq_class_lookup(q, prio)) != NULL)
+ return cl;
+
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ for (;;) {
+ int result = 0;
+ defmap = head->defaults;
+
+ fl = rcu_dereference_bh(head->filter_list);
+ /*
+ * Step 2+n. Apply classifier.
+ */
+ result = tc_classify_compat(skb, fl, &res);
+ if (!fl || result < 0)
+ goto fallback;
+
+ cl = (void *)res.class;
+ if (!cl) {
+ if (TC_H_MAJ(res.classid))
+ cl = cbq_class_lookup(q, res.classid);
+ else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
+ cl = defmap[TC_PRIO_BESTEFFORT];
+
+ if (cl == NULL)
+ goto fallback;
+ }
+ if (cl->level >= head->level)
+ goto fallback;
+#ifdef CONFIG_NET_CLS_ACT
+ switch (result) {
+ case TC_ACT_QUEUED:
+ case TC_ACT_STOLEN:
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+ case TC_ACT_SHOT:
+ return NULL;
+ case TC_ACT_RECLASSIFY:
+ return cbq_reclassify(skb, cl);
+ }
+#endif
+ if (cl->level == 0)
+ return cl;
+
+ /*
+ * Step 3+n. If classifier selected a link sharing class,
+ * apply agency specific classifier.
+ * Repeat this procdure until we hit a leaf node.
+ */
+ head = cl;
+ }
+
+fallback:
+ cl = head;
+
+ /*
+ * Step 4. No success...
+ */
+ if (TC_H_MAJ(prio) == 0 &&
+ !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
+ !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
+ return head;
+
+ return cl;
+}
+
+/*
+ * A packet has just been enqueued on the empty class.
+ * cbq_activate_class adds it to the tail of active class list
+ * of its priority band.
+ */
+
+static inline void cbq_activate_class(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ int prio = cl->cpriority;
+ struct cbq_class *cl_tail;
+
+ cl_tail = q->active[prio];
+ q->active[prio] = cl;
+
+ if (cl_tail != NULL) {
+ cl->next_alive = cl_tail->next_alive;
+ cl_tail->next_alive = cl;
+ } else {
+ cl->next_alive = cl;
+ q->activemask |= (1<<prio);
+ }
+}
+
+/*
+ * Unlink class from active chain.
+ * Note that this same procedure is done directly in cbq_dequeue*
+ * during round-robin procedure.
+ */
+
+static void cbq_deactivate_class(struct cbq_class *this)
+{
+ struct cbq_sched_data *q = qdisc_priv(this->qdisc);
+ int prio = this->cpriority;
+ struct cbq_class *cl;
+ struct cbq_class *cl_prev = q->active[prio];
+
+ do {
+ cl = cl_prev->next_alive;
+ if (cl == this) {
+ cl_prev->next_alive = cl->next_alive;
+ cl->next_alive = NULL;
+
+ if (cl == q->active[prio]) {
+ q->active[prio] = cl_prev;
+ if (cl == q->active[prio]) {
+ q->active[prio] = NULL;
+ q->activemask &= ~(1<<prio);
+ return;
+ }
+ }
+ return;
+ }
+ } while ((cl_prev = cl) != q->active[prio]);
+}
+
+static void
+cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
+{
+ int toplevel = q->toplevel;
+
+ if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) {
+ psched_time_t now = psched_get_time();
+
+ do {
+ if (cl->undertime < now) {
+ q->toplevel = cl->level;
+ return;
+ }
+ } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
+ }
+}
+
+static int
+cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ int uninitialized_var(ret);
+ struct cbq_class *cl = cbq_classify(skb, sch, &ret);
+
+#ifdef CONFIG_NET_CLS_ACT
+ q->rx_class = cl;
+#endif
+ if (cl == NULL) {
+ if (ret & __NET_XMIT_BYPASS)
+ qdisc_qstats_drop(sch);
+ kfree_skb(skb);
+ return ret;
+ }
+
+#ifdef CONFIG_NET_CLS_ACT
+ cl->q->__parent = sch;
+#endif
+ ret = qdisc_enqueue(skb, cl->q);
+ if (ret == NET_XMIT_SUCCESS) {
+ sch->q.qlen++;
+ cbq_mark_toplevel(q, cl);
+ if (!cl->next_alive)
+ cbq_activate_class(cl);
+ return ret;
+ }
+
+ if (net_xmit_drop_count(ret)) {
+ qdisc_qstats_drop(sch);
+ cbq_mark_toplevel(q, cl);
+ cl->qstats.drops++;
+ }
+ return ret;
+}
+
+/* Overlimit actions */
+
+/* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */
+
+static void cbq_ovl_classic(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ psched_tdiff_t delay = cl->undertime - q->now;
+
+ if (!cl->delayed) {
+ delay += cl->offtime;
+
+ /*
+ * Class goes to sleep, so that it will have no
+ * chance to work avgidle. Let's forgive it 8)
+ *
+ * BTW cbq-2.0 has a crap in this
+ * place, apparently they forgot to shift it by cl->ewma_log.
+ */
+ if (cl->avgidle < 0)
+ delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
+ if (cl->avgidle < cl->minidle)
+ cl->avgidle = cl->minidle;
+ if (delay <= 0)
+ delay = 1;
+ cl->undertime = q->now + delay;
+
+ cl->xstats.overactions++;
+ cl->delayed = 1;
+ }
+ if (q->wd_expires == 0 || q->wd_expires > delay)
+ q->wd_expires = delay;
+
+ /* Dirty work! We must schedule wakeups based on
+ * real available rate, rather than leaf rate,
+ * which may be tiny (even zero).
+ */
+ if (q->toplevel == TC_CBQ_MAXLEVEL) {
+ struct cbq_class *b;
+ psched_tdiff_t base_delay = q->wd_expires;
+
+ for (b = cl->borrow; b; b = b->borrow) {
+ delay = b->undertime - q->now;
+ if (delay < base_delay) {
+ if (delay <= 0)
+ delay = 1;
+ base_delay = delay;
+ }
+ }
+
+ q->wd_expires = base_delay;
+ }
+}
+
+/* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when
+ * they go overlimit
+ */
+
+static void cbq_ovl_rclassic(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ struct cbq_class *this = cl;
+
+ do {
+ if (cl->level > q->toplevel) {
+ cl = NULL;
+ break;
+ }
+ } while ((cl = cl->borrow) != NULL);
+
+ if (cl == NULL)
+ cl = this;
+ cbq_ovl_classic(cl);
+}
+
+/* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */
+
+static void cbq_ovl_delay(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ psched_tdiff_t delay = cl->undertime - q->now;
+
+ if (test_bit(__QDISC_STATE_DEACTIVATED,
+ &qdisc_root_sleeping(cl->qdisc)->state))
+ return;
+
+ if (!cl->delayed) {
+ psched_time_t sched = q->now;
+ ktime_t expires;
+
+ delay += cl->offtime;
+ if (cl->avgidle < 0)
+ delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
+ if (cl->avgidle < cl->minidle)
+ cl->avgidle = cl->minidle;
+ cl->undertime = q->now + delay;
+
+ if (delay > 0) {
+ sched += delay + cl->penalty;
+ cl->penalized = sched;
+ cl->cpriority = TC_CBQ_MAXPRIO;
+ q->pmask |= (1<<TC_CBQ_MAXPRIO);
+
+ expires = ns_to_ktime(PSCHED_TICKS2NS(sched));
+ if (hrtimer_try_to_cancel(&q->delay_timer) &&
+ ktime_to_ns(ktime_sub(
+ hrtimer_get_expires(&q->delay_timer),
+ expires)) > 0)
+ hrtimer_set_expires(&q->delay_timer, expires);
+ hrtimer_restart(&q->delay_timer);
+ cl->delayed = 1;
+ cl->xstats.overactions++;
+ return;
+ }
+ delay = 1;
+ }
+ if (q->wd_expires == 0 || q->wd_expires > delay)
+ q->wd_expires = delay;
+}
+
+/* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */
+
+static void cbq_ovl_lowprio(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+
+ cl->penalized = q->now + cl->penalty;
+
+ if (cl->cpriority != cl->priority2) {
+ cl->cpriority = cl->priority2;
+ q->pmask |= (1<<cl->cpriority);
+ cl->xstats.overactions++;
+ }
+ cbq_ovl_classic(cl);
+}
+
+/* TC_CBQ_OVL_DROP: penalize class by dropping */
+
+static void cbq_ovl_drop(struct cbq_class *cl)
+{
+ if (cl->q->ops->drop)
+ if (cl->q->ops->drop(cl->q))
+ cl->qdisc->q.qlen--;
+ cl->xstats.overactions++;
+ cbq_ovl_classic(cl);
+}
+
+static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
+ psched_time_t now)
+{
+ struct cbq_class *cl;
+ struct cbq_class *cl_prev = q->active[prio];
+ psched_time_t sched = now;
+
+ if (cl_prev == NULL)
+ return 0;
+
+ do {
+ cl = cl_prev->next_alive;
+ if (now - cl->penalized > 0) {
+ cl_prev->next_alive = cl->next_alive;
+ cl->next_alive = NULL;
+ cl->cpriority = cl->priority;
+ cl->delayed = 0;
+ cbq_activate_class(cl);
+
+ if (cl == q->active[prio]) {
+ q->active[prio] = cl_prev;
+ if (cl == q->active[prio]) {
+ q->active[prio] = NULL;
+ return 0;
+ }
+ }
+
+ cl = cl_prev->next_alive;
+ } else if (sched - cl->penalized > 0)
+ sched = cl->penalized;
+ } while ((cl_prev = cl) != q->active[prio]);
+
+ return sched - now;
+}
+
+static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
+{
+ struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
+ delay_timer);
+ struct Qdisc *sch = q->watchdog.qdisc;
+ psched_time_t now;
+ psched_tdiff_t delay = 0;
+ unsigned int pmask;
+
+ now = psched_get_time();
+
+ pmask = q->pmask;
+ q->pmask = 0;
+
+ while (pmask) {
+ int prio = ffz(~pmask);
+ psched_tdiff_t tmp;
+
+ pmask &= ~(1<<prio);
+
+ tmp = cbq_undelay_prio(q, prio, now);
+ if (tmp > 0) {
+ q->pmask |= 1<<prio;
+ if (tmp < delay || delay == 0)
+ delay = tmp;
+ }
+ }
+
+ if (delay) {
+ ktime_t time;
+
+ time = ktime_set(0, 0);
+ time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
+ hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
+ }
+
+ qdisc_unthrottled(sch);
+ __netif_schedule(qdisc_root(sch));
+ return HRTIMER_NORESTART;
+}
+
+#ifdef CONFIG_NET_CLS_ACT
+static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
+{
+ struct Qdisc *sch = child->__parent;
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = q->rx_class;
+
+ q->rx_class = NULL;
+
+ if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) {
+ int ret;
+
+ cbq_mark_toplevel(q, cl);
+
+ q->rx_class = cl;
+ cl->q->__parent = sch;
+
+ ret = qdisc_enqueue(skb, cl->q);
+ if (ret == NET_XMIT_SUCCESS) {
+ sch->q.qlen++;
+ if (!cl->next_alive)
+ cbq_activate_class(cl);
+ return 0;
+ }
+ if (net_xmit_drop_count(ret))
+ qdisc_qstats_drop(sch);
+ return 0;
+ }
+
+ qdisc_qstats_drop(sch);
+ return -1;
+}
+#endif
+
+/*
+ * It is mission critical procedure.
+ *
+ * We "regenerate" toplevel cutoff, if transmitting class
+ * has backlog and it is not regulated. It is not part of
+ * original CBQ description, but looks more reasonable.
+ * Probably, it is wrong. This question needs further investigation.
+ */
+
+static inline void
+cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
+ struct cbq_class *borrowed)
+{
+ if (cl && q->toplevel >= borrowed->level) {
+ if (cl->q->q.qlen > 1) {
+ do {
+ if (borrowed->undertime == PSCHED_PASTPERFECT) {
+ q->toplevel = borrowed->level;
+ return;
+ }
+ } while ((borrowed = borrowed->borrow) != NULL);
+ }
+#if 0
+ /* It is not necessary now. Uncommenting it
+ will save CPU cycles, but decrease fairness.
+ */
+ q->toplevel = TC_CBQ_MAXLEVEL;
+#endif
+ }
+}
+
+static void
+cbq_update(struct cbq_sched_data *q)
+{
+ struct cbq_class *this = q->tx_class;
+ struct cbq_class *cl = this;
+ int len = q->tx_len;
+ psched_time_t now;
+
+ q->tx_class = NULL;
+ /* Time integrator. We calculate EOS time
+ * by adding expected packet transmission time.
+ */
+ now = q->now + L2T(&q->link, len);
+
+ for ( ; cl; cl = cl->share) {
+ long avgidle = cl->avgidle;
+ long idle;
+
+ cl->bstats.packets++;
+ cl->bstats.bytes += len;
+
+ /*
+ * (now - last) is total time between packet right edges.
+ * (last_pktlen/rate) is "virtual" busy time, so that
+ *
+ * idle = (now - last) - last_pktlen/rate
+ */
+
+ idle = now - cl->last;
+ if ((unsigned long)idle > 128*1024*1024) {
+ avgidle = cl->maxidle;
+ } else {
+ idle -= L2T(cl, len);
+
+ /* true_avgidle := (1-W)*true_avgidle + W*idle,
+ * where W=2^{-ewma_log}. But cl->avgidle is scaled:
+ * cl->avgidle == true_avgidle/W,
+ * hence:
+ */
+ avgidle += idle - (avgidle>>cl->ewma_log);
+ }
+
+ if (avgidle <= 0) {
+ /* Overlimit or at-limit */
+
+ if (avgidle < cl->minidle)
+ avgidle = cl->minidle;
+
+ cl->avgidle = avgidle;
+
+ /* Calculate expected time, when this class
+ * will be allowed to send.
+ * It will occur, when:
+ * (1-W)*true_avgidle + W*delay = 0, i.e.
+ * idle = (1/W - 1)*(-true_avgidle)
+ * or
+ * idle = (1 - W)*(-cl->avgidle);
+ */
+ idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
+
+ /*
+ * That is not all.
+ * To maintain the rate allocated to the class,
+ * we add to undertime virtual clock,
+ * necessary to complete transmitted packet.
+ * (len/phys_bandwidth has been already passed
+ * to the moment of cbq_update)
+ */
+
+ idle -= L2T(&q->link, len);
+ idle += L2T(cl, len);
+
+ cl->undertime = now + idle;
+ } else {
+ /* Underlimit */
+
+ cl->undertime = PSCHED_PASTPERFECT;
+ if (avgidle > cl->maxidle)
+ cl->avgidle = cl->maxidle;
+ else
+ cl->avgidle = avgidle;
+ }
+ if ((s64)(now - cl->last) > 0)
+ cl->last = now;
+ }
+
+ cbq_update_toplevel(q, this, q->tx_borrowed);
+}
+
+static inline struct cbq_class *
+cbq_under_limit(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ struct cbq_class *this_cl = cl;
+
+ if (cl->tparent == NULL)
+ return cl;
+
+ if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
+ cl->delayed = 0;
+ return cl;
+ }
+
+ do {
+ /* It is very suspicious place. Now overlimit
+ * action is generated for not bounded classes
+ * only if link is completely congested.
+ * Though it is in agree with ancestor-only paradigm,
+ * it looks very stupid. Particularly,
+ * it means that this chunk of code will either
+ * never be called or result in strong amplification
+ * of burstiness. Dangerous, silly, and, however,
+ * no another solution exists.
+ */
+ cl = cl->borrow;
+ if (!cl) {
+ this_cl->qstats.overlimits++;
+ this_cl->overlimit(this_cl);
+ return NULL;
+ }
+ if (cl->level > q->toplevel)
+ return NULL;
+ } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
+
+ cl->delayed = 0;
+ return cl;
+}
+
+static inline struct sk_buff *
+cbq_dequeue_prio(struct Qdisc *sch, int prio)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl_tail, *cl_prev, *cl;
+ struct sk_buff *skb;
+ int deficit;
+
+ cl_tail = cl_prev = q->active[prio];
+ cl = cl_prev->next_alive;
+
+ do {
+ deficit = 0;
+
+ /* Start round */
+ do {
+ struct cbq_class *borrow = cl;
+
+ if (cl->q->q.qlen &&
+ (borrow = cbq_under_limit(cl)) == NULL)
+ goto skip_class;
+
+ if (cl->deficit <= 0) {
+ /* Class exhausted its allotment per
+ * this round. Switch to the next one.
+ */
+ deficit = 1;
+ cl->deficit += cl->quantum;
+ goto next_class;
+ }
+
+ skb = cl->q->dequeue(cl->q);
+
+ /* Class did not give us any skb :-(
+ * It could occur even if cl->q->q.qlen != 0
+ * f.e. if cl->q == "tbf"
+ */
+ if (skb == NULL)
+ goto skip_class;
+
+ cl->deficit -= qdisc_pkt_len(skb);
+ q->tx_class = cl;
+ q->tx_borrowed = borrow;
+ if (borrow != cl) {
+#ifndef CBQ_XSTATS_BORROWS_BYTES
+ borrow->xstats.borrows++;
+ cl->xstats.borrows++;
+#else
+ borrow->xstats.borrows += qdisc_pkt_len(skb);
+ cl->xstats.borrows += qdisc_pkt_len(skb);
+#endif
+ }
+ q->tx_len = qdisc_pkt_len(skb);
+
+ if (cl->deficit <= 0) {
+ q->active[prio] = cl;
+ cl = cl->next_alive;
+ cl->deficit += cl->quantum;
+ }
+ return skb;
+
+skip_class:
+ if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
+ /* Class is empty or penalized.
+ * Unlink it from active chain.
+ */
+ cl_prev->next_alive = cl->next_alive;
+ cl->next_alive = NULL;
+
+ /* Did cl_tail point to it? */
+ if (cl == cl_tail) {
+ /* Repair it! */
+ cl_tail = cl_prev;
+
+ /* Was it the last class in this band? */
+ if (cl == cl_tail) {
+ /* Kill the band! */
+ q->active[prio] = NULL;
+ q->activemask &= ~(1<<prio);
+ if (cl->q->q.qlen)
+ cbq_activate_class(cl);
+ return NULL;
+ }
+
+ q->active[prio] = cl_tail;
+ }
+ if (cl->q->q.qlen)
+ cbq_activate_class(cl);
+
+ cl = cl_prev;
+ }
+
+next_class:
+ cl_prev = cl;
+ cl = cl->next_alive;
+ } while (cl_prev != cl_tail);
+ } while (deficit);
+
+ q->active[prio] = cl_prev;
+
+ return NULL;
+}
+
+static inline struct sk_buff *
+cbq_dequeue_1(struct Qdisc *sch)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+ unsigned int activemask;
+
+ activemask = q->activemask & 0xFF;
+ while (activemask) {
+ int prio = ffz(~activemask);
+ activemask &= ~(1<<prio);
+ skb = cbq_dequeue_prio(sch, prio);
+ if (skb)
+ return skb;
+ }
+ return NULL;
+}
+
+static struct sk_buff *
+cbq_dequeue(struct Qdisc *sch)
+{
+ struct sk_buff *skb;
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ psched_time_t now;
+
+ now = psched_get_time();
+
+ if (q->tx_class)
+ cbq_update(q);
+
+ q->now = now;
+
+ for (;;) {
+ q->wd_expires = 0;
+
+ skb = cbq_dequeue_1(sch);
+ if (skb) {
+ qdisc_bstats_update(sch, skb);
+ sch->q.qlen--;
+ qdisc_unthrottled(sch);
+ return skb;
+ }
+
+ /* All the classes are overlimit.
+ *
+ * It is possible, if:
+ *
+ * 1. Scheduler is empty.
+ * 2. Toplevel cutoff inhibited borrowing.
+ * 3. Root class is overlimit.
+ *
+ * Reset 2d and 3d conditions and retry.
+ *
+ * Note, that NS and cbq-2.0 are buggy, peeking
+ * an arbitrary class is appropriate for ancestor-only
+ * sharing, but not for toplevel algorithm.
+ *
+ * Our version is better, but slower, because it requires
+ * two passes, but it is unavoidable with top-level sharing.
+ */
+
+ if (q->toplevel == TC_CBQ_MAXLEVEL &&
+ q->link.undertime == PSCHED_PASTPERFECT)
+ break;
+
+ q->toplevel = TC_CBQ_MAXLEVEL;
+ q->link.undertime = PSCHED_PASTPERFECT;
+ }
+
+ /* No packets in scheduler or nobody wants to give them to us :-(
+ * Sigh... start watchdog timer in the last case.
+ */
+
+ if (sch->q.qlen) {
+ qdisc_qstats_overlimit(sch);
+ if (q->wd_expires)
+ qdisc_watchdog_schedule(&q->watchdog,
+ now + q->wd_expires);
+ }
+ return NULL;
+}
+
+/* CBQ class maintanance routines */
+
+static void cbq_adjust_levels(struct cbq_class *this)
+{
+ if (this == NULL)
+ return;
+
+ do {
+ int level = 0;
+ struct cbq_class *cl;
+
+ cl = this->children;
+ if (cl) {
+ do {
+ if (cl->level > level)
+ level = cl->level;
+ } while ((cl = cl->sibling) != this->children);
+ }
+ this->level = level + 1;
+ } while ((this = this->tparent) != NULL);
+}
+
+static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
+{
+ struct cbq_class *cl;
+ unsigned int h;
+
+ if (q->quanta[prio] == 0)
+ return;
+
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
+ /* BUGGGG... Beware! This expression suffer of
+ * arithmetic overflows!
+ */
+ if (cl->priority == prio) {
+ cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
+ q->quanta[prio];
+ }
+ if (cl->quantum <= 0 ||
+ cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
+ pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
+ cl->common.classid, cl->quantum);
+ cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
+ }
+ }
+ }
+}
+
+static void cbq_sync_defmap(struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+ struct cbq_class *split = cl->split;
+ unsigned int h;
+ int i;
+
+ if (split == NULL)
+ return;
+
+ for (i = 0; i <= TC_PRIO_MAX; i++) {
+ if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
+ split->defaults[i] = NULL;
+ }
+
+ for (i = 0; i <= TC_PRIO_MAX; i++) {
+ int level = split->level;
+
+ if (split->defaults[i])
+ continue;
+
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ struct cbq_class *c;
+
+ hlist_for_each_entry(c, &q->clhash.hash[h],
+ common.hnode) {
+ if (c->split == split && c->level < level &&
+ c->defmap & (1<<i)) {
+ split->defaults[i] = c;
+ level = c->level;
+ }
+ }
+ }
+ }
+}
+
+static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
+{
+ struct cbq_class *split = NULL;
+
+ if (splitid == 0) {
+ split = cl->split;
+ if (!split)
+ return;
+ splitid = split->common.classid;
+ }
+
+ if (split == NULL || split->common.classid != splitid) {
+ for (split = cl->tparent; split; split = split->tparent)
+ if (split->common.classid == splitid)
+ break;
+ }
+
+ if (split == NULL)
+ return;
+
+ if (cl->split != split) {
+ cl->defmap = 0;
+ cbq_sync_defmap(cl);
+ cl->split = split;
+ cl->defmap = def & mask;
+ } else
+ cl->defmap = (cl->defmap & ~mask) | (def & mask);
+
+ cbq_sync_defmap(cl);
+}
+
+static void cbq_unlink_class(struct cbq_class *this)
+{
+ struct cbq_class *cl, **clp;
+ struct cbq_sched_data *q = qdisc_priv(this->qdisc);
+
+ qdisc_class_hash_remove(&q->clhash, &this->common);
+
+ if (this->tparent) {
+ clp = &this->sibling;
+ cl = *clp;
+ do {
+ if (cl == this) {
+ *clp = cl->sibling;
+ break;
+ }
+ clp = &cl->sibling;
+ } while ((cl = *clp) != this->sibling);
+
+ if (this->tparent->children == this) {
+ this->tparent->children = this->sibling;
+ if (this->sibling == this)
+ this->tparent->children = NULL;
+ }
+ } else {
+ WARN_ON(this->sibling != this);
+ }
+}
+
+static void cbq_link_class(struct cbq_class *this)
+{
+ struct cbq_sched_data *q = qdisc_priv(this->qdisc);
+ struct cbq_class *parent = this->tparent;
+
+ this->sibling = this;
+ qdisc_class_hash_insert(&q->clhash, &this->common);
+
+ if (parent == NULL)
+ return;
+
+ if (parent->children == NULL) {
+ parent->children = this;
+ } else {
+ this->sibling = parent->children->sibling;
+ parent->children->sibling = this;
+ }
+}
+
+static unsigned int cbq_drop(struct Qdisc *sch)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl, *cl_head;
+ int prio;
+ unsigned int len;
+
+ for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) {
+ cl_head = q->active[prio];
+ if (!cl_head)
+ continue;
+
+ cl = cl_head;
+ do {
+ if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
+ sch->q.qlen--;
+ if (!cl->q->q.qlen)
+ cbq_deactivate_class(cl);
+ return len;
+ }
+ } while ((cl = cl->next_alive) != cl_head);
+ }
+ return 0;
+}
+
+static void
+cbq_reset(struct Qdisc *sch)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl;
+ int prio;
+ unsigned int h;
+
+ q->activemask = 0;
+ q->pmask = 0;
+ q->tx_class = NULL;
+ q->tx_borrowed = NULL;
+ qdisc_watchdog_cancel(&q->watchdog);
+ hrtimer_cancel(&q->delay_timer);
+ q->toplevel = TC_CBQ_MAXLEVEL;
+ q->now = psched_get_time();
+
+ for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
+ q->active[prio] = NULL;
+
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
+ qdisc_reset(cl->q);
+
+ cl->next_alive = NULL;
+ cl->undertime = PSCHED_PASTPERFECT;
+ cl->avgidle = cl->maxidle;
+ cl->deficit = cl->quantum;
+ cl->cpriority = cl->priority;
+ }
+ }
+ sch->q.qlen = 0;
+}
+
+
+static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
+{
+ if (lss->change & TCF_CBQ_LSS_FLAGS) {
+ cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
+ cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
+ }
+ if (lss->change & TCF_CBQ_LSS_EWMA)
+ cl->ewma_log = lss->ewma_log;
+ if (lss->change & TCF_CBQ_LSS_AVPKT)
+ cl->avpkt = lss->avpkt;
+ if (lss->change & TCF_CBQ_LSS_MINIDLE)
+ cl->minidle = -(long)lss->minidle;
+ if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
+ cl->maxidle = lss->maxidle;
+ cl->avgidle = lss->maxidle;
+ }
+ if (lss->change & TCF_CBQ_LSS_OFFTIME)
+ cl->offtime = lss->offtime;
+ return 0;
+}
+
+static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
+{
+ q->nclasses[cl->priority]--;
+ q->quanta[cl->priority] -= cl->weight;
+ cbq_normalize_quanta(q, cl->priority);
+}
+
+static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
+{
+ q->nclasses[cl->priority]++;
+ q->quanta[cl->priority] += cl->weight;
+ cbq_normalize_quanta(q, cl->priority);
+}
+
+static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
+{
+ struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
+
+ if (wrr->allot)
+ cl->allot = wrr->allot;
+ if (wrr->weight)
+ cl->weight = wrr->weight;
+ if (wrr->priority) {
+ cl->priority = wrr->priority - 1;
+ cl->cpriority = cl->priority;
+ if (cl->priority >= cl->priority2)
+ cl->priority2 = TC_CBQ_MAXPRIO - 1;
+ }
+
+ cbq_addprio(q, cl);
+ return 0;
+}
+
+static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
+{
+ switch (ovl->strategy) {
+ case TC_CBQ_OVL_CLASSIC:
+ cl->overlimit = cbq_ovl_classic;
+ break;
+ case TC_CBQ_OVL_DELAY:
+ cl->overlimit = cbq_ovl_delay;
+ break;
+ case TC_CBQ_OVL_LOWPRIO:
+ if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO ||
+ ovl->priority2 - 1 <= cl->priority)
+ return -EINVAL;
+ cl->priority2 = ovl->priority2 - 1;
+ cl->overlimit = cbq_ovl_lowprio;
+ break;
+ case TC_CBQ_OVL_DROP:
+ cl->overlimit = cbq_ovl_drop;
+ break;
+ case TC_CBQ_OVL_RCLASSIC:
+ cl->overlimit = cbq_ovl_rclassic;
+ break;
+ default:
+ return -EINVAL;
+ }
+ cl->penalty = ovl->penalty;
+ return 0;
+}
+
+#ifdef CONFIG_NET_CLS_ACT
+static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
+{
+ cl->police = p->police;
+
+ if (cl->q->handle) {
+ if (p->police == TC_POLICE_RECLASSIFY)
+ cl->q->reshape_fail = cbq_reshape_fail;
+ else
+ cl->q->reshape_fail = NULL;
+ }
+ return 0;
+}
+#endif
+
+static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
+{
+ cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
+ return 0;
+}
+
+static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
+ [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
+ [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
+ [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
+ [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
+ [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
+ [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
+ [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
+};
+
+static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tb[TCA_CBQ_MAX + 1];
+ struct tc_ratespec *r;
+ int err;
+
+ err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL)
+ return -EINVAL;
+
+ r = nla_data(tb[TCA_CBQ_RATE]);
+
+ if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL)
+ return -EINVAL;
+
+ err = qdisc_class_hash_init(&q->clhash);
+ if (err < 0)
+ goto put_rtab;
+
+ q->link.refcnt = 1;
+ q->link.sibling = &q->link;
+ q->link.common.classid = sch->handle;
+ q->link.qdisc = sch;
+ q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+ sch->handle);
+ if (!q->link.q)
+ q->link.q = &noop_qdisc;
+
+ q->link.priority = TC_CBQ_MAXPRIO - 1;
+ q->link.priority2 = TC_CBQ_MAXPRIO - 1;
+ q->link.cpriority = TC_CBQ_MAXPRIO - 1;
+ q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC;
+ q->link.overlimit = cbq_ovl_classic;
+ q->link.allot = psched_mtu(qdisc_dev(sch));
+ q->link.quantum = q->link.allot;
+ q->link.weight = q->link.R_tab->rate.rate;
+
+ q->link.ewma_log = TC_CBQ_DEF_EWMA;
+ q->link.avpkt = q->link.allot/2;
+ q->link.minidle = -0x7FFFFFFF;
+
+ qdisc_watchdog_init(&q->watchdog, sch);
+ hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
+ q->delay_timer.function = cbq_undelay;
+ q->toplevel = TC_CBQ_MAXLEVEL;
+ q->now = psched_get_time();
+
+ cbq_link_class(&q->link);
+
+ if (tb[TCA_CBQ_LSSOPT])
+ cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
+
+ cbq_addprio(q, &q->link);
+ return 0;
+
+put_rtab:
+ qdisc_put_rtab(q->link.R_tab);
+ return err;
+}
+
+static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+
+ if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
+ goto nla_put_failure;
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_cbq_lssopt opt;
+
+ opt.flags = 0;
+ if (cl->borrow == NULL)
+ opt.flags |= TCF_CBQ_LSS_BOUNDED;
+ if (cl->share == NULL)
+ opt.flags |= TCF_CBQ_LSS_ISOLATED;
+ opt.ewma_log = cl->ewma_log;
+ opt.level = cl->level;
+ opt.avpkt = cl->avpkt;
+ opt.maxidle = cl->maxidle;
+ opt.minidle = (u32)(-cl->minidle);
+ opt.offtime = cl->offtime;
+ opt.change = ~0;
+ if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
+ goto nla_put_failure;
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_cbq_wrropt opt;
+
+ memset(&opt, 0, sizeof(opt));
+ opt.flags = 0;
+ opt.allot = cl->allot;
+ opt.priority = cl->priority + 1;
+ opt.cpriority = cl->cpriority + 1;
+ opt.weight = cl->weight;
+ if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
+ goto nla_put_failure;
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_cbq_ovl opt;
+
+ opt.strategy = cl->ovl_strategy;
+ opt.priority2 = cl->priority2 + 1;
+ opt.pad = 0;
+ opt.penalty = cl->penalty;
+ if (nla_put(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt))
+ goto nla_put_failure;
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_cbq_fopt opt;
+
+ if (cl->split || cl->defmap) {
+ opt.split = cl->split ? cl->split->common.classid : 0;
+ opt.defmap = cl->defmap;
+ opt.defchange = ~0;
+ if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
+ goto nla_put_failure;
+ }
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+#ifdef CONFIG_NET_CLS_ACT
+static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_cbq_police opt;
+
+ if (cl->police) {
+ opt.police = cl->police;
+ opt.__res1 = 0;
+ opt.__res2 = 0;
+ if (nla_put(skb, TCA_CBQ_POLICE, sizeof(opt), &opt))
+ goto nla_put_failure;
+ }
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+#endif
+
+static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
+{
+ if (cbq_dump_lss(skb, cl) < 0 ||
+ cbq_dump_rate(skb, cl) < 0 ||
+ cbq_dump_wrr(skb, cl) < 0 ||
+ cbq_dump_ovl(skb, cl) < 0 ||
+#ifdef CONFIG_NET_CLS_ACT
+ cbq_dump_police(skb, cl) < 0 ||
+#endif
+ cbq_dump_fopt(skb, cl) < 0)
+ return -1;
+ return 0;
+}
+
+static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+ if (cbq_dump_attr(skb, &q->link) < 0)
+ goto nla_put_failure;
+ return nla_nest_end(skb, nest);
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -1;
+}
+
+static int
+cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+
+ q->link.xstats.avgidle = q->link.avgidle;
+ return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
+}
+
+static int
+cbq_dump_class(struct Qdisc *sch, unsigned long arg,
+ struct sk_buff *skb, struct tcmsg *tcm)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+ struct nlattr *nest;
+
+ if (cl->tparent)
+ tcm->tcm_parent = cl->tparent->common.classid;
+ else
+ tcm->tcm_parent = TC_H_ROOT;
+ tcm->tcm_handle = cl->common.classid;
+ tcm->tcm_info = cl->q->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+ if (cbq_dump_attr(skb, cl) < 0)
+ goto nla_put_failure;
+ return nla_nest_end(skb, nest);
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -1;
+}
+
+static int
+cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
+ struct gnet_dump *d)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ cl->xstats.avgidle = cl->avgidle;
+ cl->xstats.undertime = 0;
+
+ if (cl->undertime != PSCHED_PASTPERFECT)
+ cl->xstats.undertime = cl->undertime - q->now;
+
+ if (gnet_stats_copy_basic(d, NULL, &cl->bstats) < 0 ||
+ gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
+ gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)
+ return -1;
+
+ return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
+}
+
+static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+ struct Qdisc **old)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ if (new == NULL) {
+ new = qdisc_create_dflt(sch->dev_queue,
+ &pfifo_qdisc_ops, cl->common.classid);
+ if (new == NULL)
+ return -ENOBUFS;
+ } else {
+#ifdef CONFIG_NET_CLS_ACT
+ if (cl->police == TC_POLICE_RECLASSIFY)
+ new->reshape_fail = cbq_reshape_fail;
+#endif
+ }
+ sch_tree_lock(sch);
+ *old = cl->q;
+ cl->q = new;
+ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
+ qdisc_reset(*old);
+ sch_tree_unlock(sch);
+
+ return 0;
+}
+
+static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ return cl->q;
+}
+
+static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ if (cl->q->q.qlen == 0)
+ cbq_deactivate_class(cl);
+}
+
+static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = cbq_class_lookup(q, classid);
+
+ if (cl) {
+ cl->refcnt++;
+ return (unsigned long)cl;
+ }
+ return 0;
+}
+
+static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+
+ WARN_ON(cl->filters);
+
+ tcf_destroy_chain(&cl->filter_list);
+ qdisc_destroy(cl->q);
+ qdisc_put_rtab(cl->R_tab);
+ gen_kill_estimator(&cl->bstats, &cl->rate_est);
+ if (cl != &q->link)
+ kfree(cl);
+}
+
+static void cbq_destroy(struct Qdisc *sch)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct hlist_node *next;
+ struct cbq_class *cl;
+ unsigned int h;
+
+#ifdef CONFIG_NET_CLS_ACT
+ q->rx_class = NULL;
+#endif
+ /*
+ * Filters must be destroyed first because we don't destroy the
+ * classes from root to leafs which means that filters can still
+ * be bound to classes which have been destroyed already. --TGR '04
+ */
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode)
+ tcf_destroy_chain(&cl->filter_list);
+ }
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
+ common.hnode)
+ cbq_destroy_class(sch, cl);
+ }
+ qdisc_class_hash_destroy(&q->clhash);
+}
+
+static void cbq_put(struct Qdisc *sch, unsigned long arg)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ if (--cl->refcnt == 0) {
+#ifdef CONFIG_NET_CLS_ACT
+ spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
+ struct cbq_sched_data *q = qdisc_priv(sch);
+
+ spin_lock_bh(root_lock);
+ if (q->rx_class == cl)
+ q->rx_class = NULL;
+ spin_unlock_bh(root_lock);
+#endif
+
+ cbq_destroy_class(sch, cl);
+ }
+}
+
+static int
+cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
+ unsigned long *arg)
+{
+ int err;
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = (struct cbq_class *)*arg;
+ struct nlattr *opt = tca[TCA_OPTIONS];
+ struct nlattr *tb[TCA_CBQ_MAX + 1];
+ struct cbq_class *parent;
+ struct qdisc_rate_table *rtab = NULL;
+
+ if (opt == NULL)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy);
+ if (err < 0)
+ return err;
+
+ if (cl) {
+ /* Check parent */
+ if (parentid) {
+ if (cl->tparent &&
+ cl->tparent->common.classid != parentid)
+ return -EINVAL;
+ if (!cl->tparent && parentid != TC_H_ROOT)
+ return -EINVAL;
+ }
+
+ if (tb[TCA_CBQ_RATE]) {
+ rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
+ tb[TCA_CBQ_RTAB]);
+ if (rtab == NULL)
+ return -EINVAL;
+ }
+
+ if (tca[TCA_RATE]) {
+ err = gen_replace_estimator(&cl->bstats, NULL,
+ &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
+ if (err) {
+ qdisc_put_rtab(rtab);
+ return err;
+ }
+ }
+
+ /* Change class parameters */
+ sch_tree_lock(sch);
+
+ if (cl->next_alive != NULL)
+ cbq_deactivate_class(cl);
+
+ if (rtab) {
+ qdisc_put_rtab(cl->R_tab);
+ cl->R_tab = rtab;
+ }
+
+ if (tb[TCA_CBQ_LSSOPT])
+ cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
+
+ if (tb[TCA_CBQ_WRROPT]) {
+ cbq_rmprio(q, cl);
+ cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
+ }
+
+ if (tb[TCA_CBQ_OVL_STRATEGY])
+ cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
+
+#ifdef CONFIG_NET_CLS_ACT
+ if (tb[TCA_CBQ_POLICE])
+ cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
+#endif
+
+ if (tb[TCA_CBQ_FOPT])
+ cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
+
+ if (cl->q->q.qlen)
+ cbq_activate_class(cl);
+
+ sch_tree_unlock(sch);
+
+ return 0;
+ }
+
+ if (parentid == TC_H_ROOT)
+ return -EINVAL;
+
+ if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL ||
+ tb[TCA_CBQ_LSSOPT] == NULL)
+ return -EINVAL;
+
+ rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]);
+ if (rtab == NULL)
+ return -EINVAL;
+
+ if (classid) {
+ err = -EINVAL;
+ if (TC_H_MAJ(classid ^ sch->handle) ||
+ cbq_class_lookup(q, classid))
+ goto failure;
+ } else {
+ int i;
+ classid = TC_H_MAKE(sch->handle, 0x8000);
+
+ for (i = 0; i < 0x8000; i++) {
+ if (++q->hgenerator >= 0x8000)
+ q->hgenerator = 1;
+ if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
+ break;
+ }
+ err = -ENOSR;
+ if (i >= 0x8000)
+ goto failure;
+ classid = classid|q->hgenerator;
+ }
+
+ parent = &q->link;
+ if (parentid) {
+ parent = cbq_class_lookup(q, parentid);
+ err = -EINVAL;
+ if (parent == NULL)
+ goto failure;
+ }
+
+ err = -ENOBUFS;
+ cl = kzalloc(sizeof(*cl), GFP_KERNEL);
+ if (cl == NULL)
+ goto failure;
+
+ if (tca[TCA_RATE]) {
+ err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
+ if (err) {
+ kfree(cl);
+ goto failure;
+ }
+ }
+
+ cl->R_tab = rtab;
+ rtab = NULL;
+ cl->refcnt = 1;
+ cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
+ if (!cl->q)
+ cl->q = &noop_qdisc;
+ cl->common.classid = classid;
+ cl->tparent = parent;
+ cl->qdisc = sch;
+ cl->allot = parent->allot;
+ cl->quantum = cl->allot;
+ cl->weight = cl->R_tab->rate.rate;
+
+ sch_tree_lock(sch);
+ cbq_link_class(cl);
+ cl->borrow = cl->tparent;
+ if (cl->tparent != &q->link)
+ cl->share = cl->tparent;
+ cbq_adjust_levels(parent);
+ cl->minidle = -0x7FFFFFFF;
+ cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
+ cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
+ if (cl->ewma_log == 0)
+ cl->ewma_log = q->link.ewma_log;
+ if (cl->maxidle == 0)
+ cl->maxidle = q->link.maxidle;
+ if (cl->avpkt == 0)
+ cl->avpkt = q->link.avpkt;
+ cl->overlimit = cbq_ovl_classic;
+ if (tb[TCA_CBQ_OVL_STRATEGY])
+ cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY]));
+#ifdef CONFIG_NET_CLS_ACT
+ if (tb[TCA_CBQ_POLICE])
+ cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE]));
+#endif
+ if (tb[TCA_CBQ_FOPT])
+ cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
+ sch_tree_unlock(sch);
+
+ qdisc_class_hash_grow(sch, &q->clhash);
+
+ *arg = (unsigned long)cl;
+ return 0;
+
+failure:
+ qdisc_put_rtab(rtab);
+ return err;
+}
+
+static int cbq_delete(struct Qdisc *sch, unsigned long arg)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = (struct cbq_class *)arg;
+ unsigned int qlen;
+
+ if (cl->filters || cl->children || cl == &q->link)
+ return -EBUSY;
+
+ sch_tree_lock(sch);
+
+ qlen = cl->q->q.qlen;
+ qdisc_reset(cl->q);
+ qdisc_tree_decrease_qlen(cl->q, qlen);
+
+ if (cl->next_alive)
+ cbq_deactivate_class(cl);
+
+ if (q->tx_borrowed == cl)
+ q->tx_borrowed = q->tx_class;
+ if (q->tx_class == cl) {
+ q->tx_class = NULL;
+ q->tx_borrowed = NULL;
+ }
+#ifdef CONFIG_NET_CLS_ACT
+ if (q->rx_class == cl)
+ q->rx_class = NULL;
+#endif
+
+ cbq_unlink_class(cl);
+ cbq_adjust_levels(cl->tparent);
+ cl->defmap = 0;
+ cbq_sync_defmap(cl);
+
+ cbq_rmprio(q, cl);
+ sch_tree_unlock(sch);
+
+ BUG_ON(--cl->refcnt == 0);
+ /*
+ * This shouldn't happen: we "hold" one cops->get() when called
+ * from tc_ctl_tclass; the destroy method is done from cops->put().
+ */
+
+ return 0;
+}
+
+static struct tcf_proto __rcu **cbq_find_tcf(struct Qdisc *sch,
+ unsigned long arg)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ if (cl == NULL)
+ cl = &q->link;
+
+ return &cl->filter_list;
+}
+
+static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
+ u32 classid)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *p = (struct cbq_class *)parent;
+ struct cbq_class *cl = cbq_class_lookup(q, classid);
+
+ if (cl) {
+ if (p && p->level <= cl->level)
+ return 0;
+ cl->filters++;
+ return (unsigned long)cl;
+ }
+ return 0;
+}
+
+static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
+{
+ struct cbq_class *cl = (struct cbq_class *)arg;
+
+ cl->filters--;
+}
+
+static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ struct cbq_sched_data *q = qdisc_priv(sch);
+ struct cbq_class *cl;
+ unsigned int h;
+
+ if (arg->stop)
+ return;
+
+ for (h = 0; h < q->clhash.hashsize; h++) {
+ hlist_for_each_entry(cl, &q->clhash.hash[h], 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 const struct Qdisc_class_ops cbq_class_ops = {
+ .graft = cbq_graft,
+ .leaf = cbq_leaf,
+ .qlen_notify = cbq_qlen_notify,
+ .get = cbq_get,
+ .put = cbq_put,
+ .change = cbq_change_class,
+ .delete = cbq_delete,
+ .walk = cbq_walk,
+ .tcf_chain = cbq_find_tcf,
+ .bind_tcf = cbq_bind_filter,
+ .unbind_tcf = cbq_unbind_filter,
+ .dump = cbq_dump_class,
+ .dump_stats = cbq_dump_class_stats,
+};
+
+static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
+ .next = NULL,
+ .cl_ops = &cbq_class_ops,
+ .id = "cbq",
+ .priv_size = sizeof(struct cbq_sched_data),
+ .enqueue = cbq_enqueue,
+ .dequeue = cbq_dequeue,
+ .peek = qdisc_peek_dequeued,
+ .drop = cbq_drop,
+ .init = cbq_init,
+ .reset = cbq_reset,
+ .destroy = cbq_destroy,
+ .change = NULL,
+ .dump = cbq_dump,
+ .dump_stats = cbq_dump_stats,
+ .owner = THIS_MODULE,
+};
+
+static int __init cbq_module_init(void)
+{
+ return register_qdisc(&cbq_qdisc_ops);
+}
+static void __exit cbq_module_exit(void)
+{
+ unregister_qdisc(&cbq_qdisc_ops);
+}
+module_init(cbq_module_init)
+module_exit(cbq_module_exit)
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff