/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_SCHED_GENERIC_H
#define __NET_SCHED_GENERIC_H

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/pkt_sched.h>
#include <linux/pkt_cls.h>
#include <linux/percpu.h>
#include <linux/dynamic_queue_limits.h>
#include <linux/list.h>
#include <linux/refcount.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/atomic.h>
#include <linux/hashtable.h>
#include <net/gen_stats.h>
#include <net/rtnetlink.h>
#include <net/flow_offload.h>
#include <linux/xarray.h>

struct Qdisc_ops;
struct qdisc_walker;
struct tcf_walker;
struct module;
struct bpf_flow_keys;

struct qdisc_rate_table {
        struct tc_ratespec rate;
        u32             data[256];
        struct qdisc_rate_table *next;
        int             refcnt;
};

enum qdisc_state_t {
        __QDISC_STATE_SCHED,
        __QDISC_STATE_DEACTIVATED,
        __QDISC_STATE_MISSED,
        __QDISC_STATE_DRAINING,
};

#define QDISC_STATE_MISSED      BIT(__QDISC_STATE_MISSED)
#define QDISC_STATE_DRAINING    BIT(__QDISC_STATE_DRAINING)

#define QDISC_STATE_NON_EMPTY   (QDISC_STATE_MISSED | \
                                        QDISC_STATE_DRAINING)

struct qdisc_size_table {
        struct rcu_head         rcu;
        struct list_head        list;
        struct tc_sizespec      szopts;
        int                     refcnt;
        u16                     data[];
};

/* similar to sk_buff_head, but skb->prev pointer is undefined. */
struct qdisc_skb_head {
        struct sk_buff  *head;
        struct sk_buff  *tail;
        __u32           qlen;
        spinlock_t      lock;
};

struct Qdisc {
        int                     (*enqueue)(struct sk_buff *skb,
                                           struct Qdisc *sch,
                                           struct sk_buff **to_free);
        struct sk_buff *        (*dequeue)(struct Qdisc *sch);
        unsigned int            flags;
#define TCQ_F_BUILTIN           1
#define TCQ_F_INGRESS           2
#define TCQ_F_CAN_BYPASS        4
#define TCQ_F_MQROOT            8
#define TCQ_F_ONETXQUEUE        0x10 /* dequeue_skb() can assume all skbs are for
                                      * q->dev_queue : It can test
                                      * netif_xmit_frozen_or_stopped() before
                                      * dequeueing next packet.
                                      * Its true for MQ/MQPRIO slaves, or non
                                      * multiqueue device.
                                      */
#define TCQ_F_WARN_NONWC        (1 << 16)
#define TCQ_F_CPUSTATS          0x20 /* run using percpu statistics */
#define TCQ_F_NOPARENT          0x40 /* root of its hierarchy :
                                      * qdisc_tree_decrease_qlen() should stop.
                                      */
#define TCQ_F_INVISIBLE         0x80 /* invisible by default in dump */
#define TCQ_F_NOLOCK            0x100 /* qdisc does not require locking */
#define TCQ_F_OFFLOADED         0x200 /* qdisc is offloaded to HW */
#define TCQ_F_DEQUEUE_DROPS     0x400 /* ->dequeue() can drop packets in q->to_free */

        u32                     limit;
        const struct Qdisc_ops  *ops;
        struct qdisc_size_table __rcu *stab;
        struct hlist_node       hash;
        u32                     handle;
        u32                     parent;

        struct netdev_queue     *dev_queue;

        struct net_rate_estimator __rcu *rate_est;
        struct gnet_stats_basic_sync __percpu *cpu_bstats;
        struct gnet_stats_queue __percpu *cpu_qstats;
        int                     pad;
        refcount_t              refcnt;

        /* Cache line potentially dirtied in dequeue() or __netif_reschedule(). */
        __cacheline_group_begin(Qdisc_read_mostly) ____cacheline_aligned;
                struct sk_buff_head     gso_skb;
                struct Qdisc            *next_sched;
                struct sk_buff_head     skb_bad_txq;
        __cacheline_group_end(Qdisc_read_mostly);

        /* Fields dirtied in dequeue() fast path. */
        __cacheline_group_begin(Qdisc_write) ____cacheline_aligned;
                struct qdisc_skb_head   q;
                unsigned long           state;
                struct gnet_stats_basic_sync bstats;
                bool                    running; /* must be written under qdisc spinlock */

                /* Note : we only change qstats.backlog in fast path. */
                struct gnet_stats_queue qstats;

                struct sk_buff          *to_free;
        __cacheline_group_end(Qdisc_write);


        atomic_long_t           defer_count ____cacheline_aligned_in_smp;
        struct llist_head       defer_list;

        spinlock_t              seqlock;

        struct rcu_head         rcu;
        netdevice_tracker       dev_tracker;
        struct lock_class_key   root_lock_key;
        /* private data */
        long privdata[] ____cacheline_aligned;
};

static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
{
        if (qdisc->flags & TCQ_F_BUILTIN)
                return;
        refcount_inc(&qdisc->refcnt);
}

static inline bool qdisc_refcount_dec_if_one(struct Qdisc *qdisc)
{
        if (qdisc->flags & TCQ_F_BUILTIN)
                return true;
        return refcount_dec_if_one(&qdisc->refcnt);
}

/* Intended to be used by unlocked users, when concurrent qdisc release is
 * possible.
 */

static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
{
        if (qdisc->flags & TCQ_F_BUILTIN)
                return qdisc;
        if (refcount_inc_not_zero(&qdisc->refcnt))
                return qdisc;
        return NULL;
}

/* For !TCQ_F_NOLOCK qdisc: callers must either call this within a qdisc
 * root_lock section, or provide their own memory barriers -- ordering
 * against qdisc_run_begin/end() atomic bit operations.
 */
static inline bool qdisc_is_running(struct Qdisc *qdisc)
{
        if (qdisc->flags & TCQ_F_NOLOCK)
                return spin_is_locked(&qdisc->seqlock);
        return READ_ONCE(qdisc->running);
}

static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc)
{
        return !(READ_ONCE(qdisc->state) & QDISC_STATE_NON_EMPTY);
}

static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
{
        return q->flags & TCQ_F_CPUSTATS;
}

static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
{
        if (qdisc_is_percpu_stats(qdisc))
                return nolock_qdisc_is_empty(qdisc);
        return !READ_ONCE(qdisc->q.qlen);
}

/* For !TCQ_F_NOLOCK qdisc, qdisc_run_begin/end() must be invoked with
 * the qdisc root lock acquired.
 */
static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
        if (qdisc->flags & TCQ_F_NOLOCK) {
                if (spin_trylock(&qdisc->seqlock))
                        return true;

                /* No need to insist if the MISSED flag was already set.
                 * Note that test_and_set_bit() also gives us memory ordering
                 * guarantees wrt potential earlier enqueue() and below
                 * spin_trylock(), both of which are necessary to prevent races
                 */
                if (test_and_set_bit(__QDISC_STATE_MISSED, &qdisc->state))
                        return false;

                /* Try to take the lock again to make sure that we will either
                 * grab it or the CPU that still has it will see MISSED set
                 * when testing it in qdisc_run_end()
                 */
                return spin_trylock(&qdisc->seqlock);
        }
        if (READ_ONCE(qdisc->running))
                return false;
        WRITE_ONCE(qdisc->running, true);
        return true;
}

static inline struct sk_buff *qdisc_run_end(struct Qdisc *qdisc)
{
        struct sk_buff *to_free = NULL;

        if (qdisc->flags & TCQ_F_NOLOCK) {
                spin_unlock(&qdisc->seqlock);

                /* spin_unlock() only has store-release semantic. The unlock
                 * and test_bit() ordering is a store-load ordering, so a full
                 * memory barrier is needed here.
                 */
                smp_mb();

                if (unlikely(test_bit(__QDISC_STATE_MISSED,
                                      &qdisc->state)))
                        __netif_schedule(qdisc);
                return NULL;
        }

        if (qdisc->flags & TCQ_F_DEQUEUE_DROPS) {
                to_free = qdisc->to_free;
                if (to_free)
                        qdisc->to_free = NULL;
        }
        WRITE_ONCE(qdisc->running, false);
        return to_free;
}

static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
{
        return qdisc->flags & TCQ_F_ONETXQUEUE;
}

static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
{
        return netdev_queue_dql_avail(txq);
}

struct Qdisc_class_ops {
        unsigned int            flags;
        /* Child qdisc manipulation */
        struct netdev_queue *   (*select_queue)(struct Qdisc *, struct tcmsg *);
        int                     (*graft)(struct Qdisc *, unsigned long cl,
                                        struct Qdisc *, struct Qdisc **,
                                        struct netlink_ext_ack *extack);
        struct Qdisc *          (*leaf)(struct Qdisc *, unsigned long cl);
        void                    (*qlen_notify)(struct Qdisc *, unsigned long);

        /* Class manipulation routines */
        unsigned long           (*find)(struct Qdisc *, u32 classid);
        int                     (*change)(struct Qdisc *, u32, u32,
                                        struct nlattr **, unsigned long *,
                                        struct netlink_ext_ack *);
        int                     (*delete)(struct Qdisc *, unsigned long,
                                          struct netlink_ext_ack *);
        void                    (*walk)(struct Qdisc *, struct qdisc_walker * arg);

        /* Filter manipulation */
        struct tcf_block *      (*tcf_block)(struct Qdisc *sch,
                                             unsigned long arg,
                                             struct netlink_ext_ack *extack);
        unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
                                        u32 classid);
        void                    (*unbind_tcf)(struct Qdisc *, unsigned long);

        /* rtnetlink specific */
        int                     (*dump)(struct Qdisc *, unsigned long,
                                        struct sk_buff *skb, struct tcmsg*);
        int                     (*dump_stats)(struct Qdisc *, unsigned long,
                                        struct gnet_dump *);
};

/* Qdisc_class_ops flag values */

/* Implements API that doesn't require rtnl lock */
enum qdisc_class_ops_flags {
        QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
};

struct Qdisc_ops {
        struct Qdisc_ops        *next;
        const struct Qdisc_class_ops    *cl_ops;
        char                    id[IFNAMSIZ];
        int                     priv_size;
        unsigned int            static_flags;

        int                     (*enqueue)(struct sk_buff *skb,
                                           struct Qdisc *sch,
                                           struct sk_buff **to_free);
        struct sk_buff *        (*dequeue)(struct Qdisc *);
        struct sk_buff *        (*peek)(struct Qdisc *);

        int                     (*init)(struct Qdisc *sch, struct nlattr *arg,
                                        struct netlink_ext_ack *extack);
        void                    (*reset)(struct Qdisc *);
        void                    (*destroy)(struct Qdisc *);
        int                     (*change)(struct Qdisc *sch,
                                          struct nlattr *arg,
                                          struct netlink_ext_ack *extack);
        void                    (*attach)(struct Qdisc *sch);
        int                     (*change_tx_queue_len)(struct Qdisc *, unsigned int);
        void                    (*change_real_num_tx)(struct Qdisc *sch,
                                                      unsigned int new_real_tx);

        int                     (*dump)(struct Qdisc *, struct sk_buff *);
        int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);

        void                    (*ingress_block_set)(struct Qdisc *sch,
                                                     u32 block_index);
        void                    (*egress_block_set)(struct Qdisc *sch,
                                                    u32 block_index);
        u32                     (*ingress_block_get)(struct Qdisc *sch);
        u32                     (*egress_block_get)(struct Qdisc *sch);

        struct module           *owner;
};

struct tcf_result {
        union {
                struct {
                        unsigned long   class;
                        u32             classid;
                };
                const struct tcf_proto *goto_tp;
        };
};

struct tcf_chain;

struct tcf_proto_ops {
        struct list_head        head;
        char                    kind[IFNAMSIZ];

        int                     (*classify)(struct sk_buff *,
                                            const struct tcf_proto *,
                                            struct tcf_result *);
        int                     (*init)(struct tcf_proto*);
        void                    (*destroy)(struct tcf_proto *tp, bool rtnl_held,
                                           struct netlink_ext_ack *extack);

        void*                   (*get)(struct tcf_proto*, u32 handle);
        void                    (*put)(struct tcf_proto *tp, void *f);
        int                     (*change)(struct net *net, struct sk_buff *,
                                        struct tcf_proto*, unsigned long,
                                        u32 handle, struct nlattr **,
                                        void **, u32,
                                        struct netlink_ext_ack *);
        int                     (*delete)(struct tcf_proto *tp, void *arg,
                                          bool *last, bool rtnl_held,
                                          struct netlink_ext_ack *);
        bool                    (*delete_empty)(struct tcf_proto *tp);
        void                    (*walk)(struct tcf_proto *tp,
                                        struct tcf_walker *arg, bool rtnl_held);
        int                     (*reoffload)(struct tcf_proto *tp, bool add,
                                             flow_setup_cb_t *cb, void *cb_priv,
                                             struct netlink_ext_ack *extack);
        void                    (*hw_add)(struct tcf_proto *tp,
                                          void *type_data);
        void                    (*hw_del)(struct tcf_proto *tp,
                                          void *type_data);
        void                    (*bind_class)(void *, u32, unsigned long,
                                              void *, unsigned long);
        void *                  (*tmplt_create)(struct net *net,
                                                struct tcf_chain *chain,
                                                struct nlattr **tca,
                                                struct netlink_ext_ack *extack);
        void                    (*tmplt_destroy)(void *tmplt_priv);
        void                    (*tmplt_reoffload)(struct tcf_chain *chain,
                                                   bool add,
                                                   flow_setup_cb_t *cb,
                                                   void *cb_priv);
        struct tcf_exts *       (*get_exts)(const struct tcf_proto *tp,
                                            u32 handle);

        /* rtnetlink specific */
        int                     (*dump)(struct net*, struct tcf_proto*, void *,
                                        struct sk_buff *skb, struct tcmsg*,
                                        bool);
        int                     (*terse_dump)(struct net *net,
                                              struct tcf_proto *tp, void *fh,
                                              struct sk_buff *skb,
                                              struct tcmsg *t, bool rtnl_held);
        int                     (*tmplt_dump)(struct sk_buff *skb,
                                              struct net *net,
                                              void *tmplt_priv);

        struct module           *owner;
        int                     flags;
};

/* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
 * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
 * conditions can occur when filters are inserted/deleted simultaneously.
 */
enum tcf_proto_ops_flags {
        TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
};

struct tcf_proto {
        /* Fast access part */
        struct tcf_proto __rcu  *next;
        void __rcu              *root;

        /* called under RCU BH lock*/
        int                     (*classify)(struct sk_buff *,
                                            const struct tcf_proto *,
                                            struct tcf_result *);
        __be16                  protocol;

        /* All the rest */
        u32                     prio;
        void                    *data;
        const struct tcf_proto_ops      *ops;
        struct tcf_chain        *chain;
        /* Lock protects tcf_proto shared state and can be used by unlocked
         * classifiers to protect their private data.
         */
        spinlock_t              lock;
        bool                    deleting;
        bool                    counted;
        bool                    usesw;
        refcount_t              refcnt;
        struct rcu_head         rcu;
        struct hlist_node       destroy_ht_node;
};

struct qdisc_skb_cb {
        unsigned int            pkt_len;
        u16                     pkt_segs;
        u16                     tc_classid;
#define QDISC_CB_PRIV_LEN 20
        unsigned char           data[QDISC_CB_PRIV_LEN];

        u16                     slave_dev_queue_mapping;
        u8                      post_ct:1;
        u8                      post_ct_snat:1;
        u8                      post_ct_dnat:1;
};

typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);

struct tcf_chain {
        /* Protects filter_chain. */
        struct mutex filter_chain_lock;
        struct tcf_proto __rcu *filter_chain;
        struct list_head list;
        struct tcf_block *block;
        u32 index; /* chain index */
        unsigned int refcnt;
        unsigned int action_refcnt;
        bool explicitly_created;
        bool flushing;
        const struct tcf_proto_ops *tmplt_ops;
        void *tmplt_priv;
        struct rcu_head rcu;
};

struct tcf_block {
        struct xarray ports; /* datapath accessible */
        /* Lock protects tcf_block and lifetime-management data of chains
         * attached to the block (refcnt, action_refcnt, explicitly_created).
         */
        struct mutex lock;
        struct list_head chain_list;
        u32 index; /* block index for shared blocks */
        u32 classid; /* which class this block belongs to */
        refcount_t refcnt;
        struct net *net;
        struct Qdisc *q;
        struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
        struct flow_block flow_block;
        struct list_head owner_list;
        bool keep_dst;
        atomic_t useswcnt;
        atomic_t offloadcnt; /* Number of oddloaded filters */
        unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
        unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
        struct {
                struct tcf_chain *chain;
                struct list_head filter_chain_list;
        } chain0;
        struct rcu_head rcu;
        DECLARE_HASHTABLE(proto_destroy_ht, 7);
        struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
};

struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index);

static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
{
        return lockdep_is_held(&chain->filter_chain_lock);
}

static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
{
        return lockdep_is_held(&tp->lock);
}

#define tcf_chain_dereference(p, chain)                                 \
        rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))

#define tcf_proto_dereference(p, tp)                                    \
        rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))

static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
{
        struct qdisc_skb_cb *qcb;

        BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
        BUILD_BUG_ON(sizeof(qcb->data) < sz);
}

static inline int qdisc_qlen(const struct Qdisc *q)
{
        return q->q.qlen;
}

static inline int qdisc_qlen_sum(const struct Qdisc *q)
{
        __u32 qlen = q->qstats.qlen;
        int i;

        if (qdisc_is_percpu_stats(q)) {
                for_each_possible_cpu(i)
                        qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
        } else {
                qlen += q->q.qlen;
        }

        return qlen;
}

static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
{
        return (struct qdisc_skb_cb *)skb->cb;
}

static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
{
        return &qdisc->q.lock;
}

static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
{
        struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);

        return q;
}

static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
{
        return rcu_dereference_bh(qdisc->dev_queue->qdisc);
}

static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
{
        return rcu_dereference_rtnl(qdisc->dev_queue->qdisc_sleeping);
}

static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
{
        struct Qdisc *root = qdisc_root_sleeping(qdisc);

        ASSERT_RTNL();
        return qdisc_lock(root);
}

static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
{
        return qdisc->dev_queue->dev;
}

static inline void sch_tree_lock(struct Qdisc *q)
{
        if (q->flags & TCQ_F_MQROOT)
                spin_lock_bh(qdisc_lock(q));
        else
                spin_lock_bh(qdisc_root_sleeping_lock(q));
}

static inline void sch_tree_unlock(struct Qdisc *q)
{
        if (q->flags & TCQ_F_MQROOT)
                spin_unlock_bh(qdisc_lock(q));
        else
                spin_unlock_bh(qdisc_root_sleeping_lock(q));
}

extern struct Qdisc noop_qdisc;
extern struct Qdisc_ops noop_qdisc_ops;
extern struct Qdisc_ops pfifo_fast_ops;
extern const u8 sch_default_prio2band[TC_PRIO_MAX + 1];
extern struct Qdisc_ops mq_qdisc_ops;
extern struct Qdisc_ops noqueue_qdisc_ops;
extern const struct Qdisc_ops *default_qdisc_ops;
static inline const struct Qdisc_ops *
get_default_qdisc_ops(const struct net_device *dev, int ntx)
{
        return ntx < dev->real_num_tx_queues ?
                        default_qdisc_ops : &pfifo_fast_ops;
}

struct Qdisc_class_common {
        u32                     classid;
        unsigned int            filter_cnt;
        struct hlist_node       hnode;
};

struct Qdisc_class_hash {
        struct hlist_head       *hash;
        unsigned int            hashsize;
        unsigned int            hashmask;
        unsigned int            hashelems;
};

static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
{
        id ^= id >> 8;
        id ^= id >> 4;
        return id & mask;
}

static inline struct Qdisc_class_common *
qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
{
        struct Qdisc_class_common *cl;
        unsigned int h;

        if (!id)
                return NULL;

        h = qdisc_class_hash(id, hash->hashmask);
        hlist_for_each_entry(cl, &hash->hash[h], hnode) {
                if (cl->classid == id)
                        return cl;
        }
        return NULL;
}

static inline bool qdisc_class_in_use(const struct Qdisc_class_common *cl)
{
        return cl->filter_cnt > 0;
}

static inline void qdisc_class_get(struct Qdisc_class_common *cl)
{
        unsigned int res;

        if (check_add_overflow(cl->filter_cnt, 1, &res))
                WARN(1, "Qdisc class overflow");

        cl->filter_cnt = res;
}

static inline void qdisc_class_put(struct Qdisc_class_common *cl)
{
        unsigned int res;

        if (check_sub_overflow(cl->filter_cnt, 1, &res))
                WARN(1, "Qdisc class underflow");

        cl->filter_cnt = res;
}

static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
{
        u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;

        return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
}

int qdisc_class_hash_init(struct Qdisc_class_hash *);
void qdisc_class_hash_insert(struct Qdisc_class_hash *,
                             struct Qdisc_class_common *);
void qdisc_class_hash_remove(struct Qdisc_class_hash *,
                             struct Qdisc_class_common *);
void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
void qdisc_class_hash_destroy(struct Qdisc_class_hash *);

int dev_qdisc_change_tx_queue_len(struct net_device *dev);
void dev_qdisc_change_real_num_tx(struct net_device *dev,
                                  unsigned int new_real_tx);
void dev_init_scheduler(struct net_device *dev);
void dev_shutdown(struct net_device *dev);
void dev_activate(struct net_device *dev);
void dev_deactivate(struct net_device *dev);
void dev_deactivate_many(struct list_head *head);
struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
                              struct Qdisc *qdisc);
void qdisc_reset(struct Qdisc *qdisc);
void qdisc_destroy(struct Qdisc *qdisc);
void qdisc_put(struct Qdisc *qdisc);
void qdisc_put_unlocked(struct Qdisc *qdisc);
void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);

static inline void dev_reset_queue(struct net_device *dev,
                                   struct netdev_queue *dev_queue,
                                   void *_unused)
{
        struct Qdisc *qdisc;
        bool nolock;

        qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
        if (!qdisc)
                return;

        nolock = qdisc->flags & TCQ_F_NOLOCK;

        if (nolock)
                spin_lock_bh(&qdisc->seqlock);
        spin_lock_bh(qdisc_lock(qdisc));

        qdisc_reset(qdisc);

        spin_unlock_bh(qdisc_lock(qdisc));
        if (nolock) {
                clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
                clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
                spin_unlock_bh(&qdisc->seqlock);
        }
}

#ifdef CONFIG_NET_SCHED
int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
                              void *type_data);
void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
                                struct Qdisc *new, struct Qdisc *old,
                                enum tc_setup_type type, void *type_data,
                                struct netlink_ext_ack *extack);
#else
static inline int
qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
                          void *type_data)
{
        q->flags &= ~TCQ_F_OFFLOADED;
        return 0;
}

static inline void
qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
                           struct Qdisc *new, struct Qdisc *old,
                           enum tc_setup_type type, void *type_data,
                           struct netlink_ext_ack *extack)
{
}
#endif
void qdisc_offload_query_caps(struct net_device *dev,
                              enum tc_setup_type type,
                              void *caps, size_t caps_len);
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
                          const struct Qdisc_ops *ops,
                          struct netlink_ext_ack *extack);
void qdisc_free(struct Qdisc *qdisc);
struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
                                const struct Qdisc_ops *ops, u32 parentid,
                                struct netlink_ext_ack *extack);
void __qdisc_calculate_pkt_len(struct sk_buff *skb,
                               const struct qdisc_size_table *stab);
int skb_do_redirect(struct sk_buff *);

static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
{
#ifdef CONFIG_NET_XGRESS
        return skb->tc_at_ingress;
#else
        return false;
#endif
}

static inline bool skb_skip_tc_classify(struct sk_buff *skb)
{
#ifdef CONFIG_NET_CLS_ACT
        if (skb->tc_skip_classify) {
                skb->tc_skip_classify = 0;
                return true;
        }
#endif
        return false;
}

/* Reset all TX qdiscs greater than index of a device.  */
static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
{
        struct Qdisc *qdisc;
        bool nolock;

        for (; i < dev->num_tx_queues; i++) {
                qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
                if (qdisc) {
                        nolock = qdisc->flags & TCQ_F_NOLOCK;

                        if (nolock)
                                spin_lock_bh(&qdisc->seqlock);
                        spin_lock_bh(qdisc_lock(qdisc));
                        qdisc_reset(qdisc);
                        spin_unlock_bh(qdisc_lock(qdisc));
                        if (nolock) {
                                clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
                                clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
                                spin_unlock_bh(&qdisc->seqlock);
                        }
                }
        }
}

/* Are all TX queues of the device empty?  */
static inline bool qdisc_all_tx_empty(const struct net_device *dev)
{
        unsigned int i;

        rcu_read_lock();
        for (i = 0; i < dev->num_tx_queues; i++) {
                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
                const struct Qdisc *q = rcu_dereference(txq->qdisc);

                if (!qdisc_is_empty(q)) {
                        rcu_read_unlock();
                        return false;
                }
        }
        rcu_read_unlock();
        return true;
}

/* Are any of the TX qdiscs changing?  */
static inline bool qdisc_tx_changing(const struct net_device *dev)
{
        unsigned int i;

        for (i = 0; i < dev->num_tx_queues; i++) {
                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);

                if (rcu_access_pointer(txq->qdisc) !=
                    rcu_access_pointer(txq->qdisc_sleeping))
                        return true;
        }
        return false;
}

/* "noqueue" qdisc identified by not having any enqueue, see noqueue_init() */
static inline bool qdisc_txq_has_no_queue(const struct netdev_queue *txq)
{
        struct Qdisc *qdisc = rcu_access_pointer(txq->qdisc);

        return qdisc->enqueue == NULL;
}

/* Is the device using the noop qdisc on all queues?  */
static inline bool qdisc_tx_is_noop(const struct net_device *dev)
{
        unsigned int i;

        for (i = 0; i < dev->num_tx_queues; i++) {
                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
                if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
                        return false;
        }
        return true;
}

static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
{
        return qdisc_skb_cb(skb)->pkt_len;
}

static inline unsigned int qdisc_pkt_segs(const struct sk_buff *skb)
{
        u32 pkt_segs = qdisc_skb_cb(skb)->pkt_segs;

        DEBUG_NET_WARN_ON_ONCE(pkt_segs !=
                        (skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1));
        return pkt_segs;
}

/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
enum net_xmit_qdisc_t {
        __NET_XMIT_STOLEN = 0x00010000,
        __NET_XMIT_BYPASS = 0x00020000,
};

#ifdef CONFIG_NET_CLS_ACT
#define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
#else
#define net_xmit_drop_count(e)  (1)
#endif

static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
                                           const struct Qdisc *sch)
{
#ifdef CONFIG_NET_SCHED
        struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);

        if (stab)
                __qdisc_calculate_pkt_len(skb, stab);
#endif
}

static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
                                struct sk_buff **to_free)
{
        return sch->enqueue(skb, sch, to_free);
}

static inline void _bstats_update(struct gnet_stats_basic_sync *bstats,
                                  __u64 bytes, __u64 packets)
{
        u64_stats_update_begin(&bstats->syncp);
        u64_stats_add(&bstats->bytes, bytes);
        u64_stats_add(&bstats->packets, packets);
        u64_stats_update_end(&bstats->syncp);
}

static inline void bstats_update(struct gnet_stats_basic_sync *bstats,
                                 const struct sk_buff *skb)
{
        _bstats_update(bstats, qdisc_pkt_len(skb), qdisc_pkt_segs(skb));
}

static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
                                           const struct sk_buff *skb)
{
        bstats_update(this_cpu_ptr(sch->cpu_bstats), skb);
}

static inline void qdisc_bstats_update(struct Qdisc *sch,
                                       const struct sk_buff *skb)
{
        bstats_update(&sch->bstats, skb);
}

static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
                                            const struct sk_buff *skb)
{
        sch->qstats.backlog -= qdisc_pkt_len(skb);
}

static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
                                                const struct sk_buff *skb)
{
        this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
}

static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
                                            const struct sk_buff *skb)
{
        sch->qstats.backlog += qdisc_pkt_len(skb);
}

static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
                                                const struct sk_buff *skb)
{
        this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
}

static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
{
        this_cpu_inc(sch->cpu_qstats->qlen);
}

static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
{
        this_cpu_dec(sch->cpu_qstats->qlen);
}

static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
{
        this_cpu_inc(sch->cpu_qstats->requeues);
}

static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
{
        sch->qstats.drops += count;
}

static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
{
        qstats->drops++;
}

static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
{
        qstats->overlimits++;
}

static inline void qdisc_qstats_drop(struct Qdisc *sch)
{
        qstats_drop_inc(&sch->qstats);
}

static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
{
        this_cpu_inc(sch->cpu_qstats->drops);
}

static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
{
        sch->qstats.overlimits++;
}

static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
{
        __u32 qlen = qdisc_qlen_sum(sch);

        return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
}

static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
                                             __u32 *backlog)
{
        struct gnet_stats_queue qstats = { 0 };

        gnet_stats_add_queue(&qstats, sch->cpu_qstats, &sch->qstats);
        *qlen = qstats.qlen + qdisc_qlen(sch);
        *backlog = qstats.backlog;
}

static inline void qdisc_purge_queue(struct Qdisc *sch)
{
        __u32 qlen, backlog;

        qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
        qdisc_reset(sch);
        qdisc_tree_reduce_backlog(sch, qlen, backlog);
}

static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
                                        struct qdisc_skb_head *qh)
{
        struct sk_buff *last = qh->tail;

        if (last) {
                skb->next = NULL;
                last->next = skb;
                qh->tail = skb;
        } else {
                qh->tail = skb;
                qh->head = skb;
        }
        qh->qlen++;
}

static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
{
        __qdisc_enqueue_tail(skb, &sch->q);
        qdisc_qstats_backlog_inc(sch, skb);
        return NET_XMIT_SUCCESS;
}

static inline void __qdisc_enqueue_head(struct sk_buff *skb,
                                        struct qdisc_skb_head *qh)
{
        skb->next = qh->head;

        if (!qh->head)
                qh->tail = skb;
        qh->head = skb;
        qh->qlen++;
}

static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
{
        struct sk_buff *skb = qh->head;

        if (likely(skb != NULL)) {
                qh->head = skb->next;
                qh->qlen--;
                if (qh->head == NULL)
                        qh->tail = NULL;
                skb->next = NULL;
        }

        return skb;
}

static inline struct sk_buff *qdisc_dequeue_internal(struct Qdisc *sch, bool direct)
{
        struct sk_buff *skb;

        skb = __skb_dequeue(&sch->gso_skb);
        if (skb) {
                sch->q.qlen--;
                qdisc_qstats_backlog_dec(sch, skb);
                return skb;
        }
        if (direct) {
                skb = __qdisc_dequeue_head(&sch->q);
                if (skb)
                        qdisc_qstats_backlog_dec(sch, skb);
                return skb;
        } else {
                return sch->dequeue(sch);
        }
}

static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
{
        struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);

        if (likely(skb != NULL)) {
                qdisc_qstats_backlog_dec(sch, skb);
                qdisc_bstats_update(sch, skb);
        }

        return skb;
}

struct tc_skb_cb {
        struct qdisc_skb_cb qdisc_cb;
        u32 drop_reason;

        u16 zone; /* Only valid if qdisc_skb_cb(skb)->post_ct = true */
        u16 mru;
};

static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
{
        struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;

        BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));
        return cb;
}

static inline enum skb_drop_reason
tcf_get_drop_reason(const struct sk_buff *skb)
{
        return tc_skb_cb(skb)->drop_reason;
}

static inline void tcf_set_drop_reason(const struct sk_buff *skb,
                                       enum skb_drop_reason reason)
{
        tc_skb_cb(skb)->drop_reason = reason;
}

static inline void tcf_kfree_skb_list(struct sk_buff *skb)
{
        while (unlikely(skb)) {
                struct sk_buff *next = skb->next;

                prefetch(next);
                kfree_skb_reason(skb, tcf_get_drop_reason(skb));
                skb = next;
        }
}

static inline void qdisc_dequeue_drop(struct Qdisc *q, struct sk_buff *skb,
                                      enum skb_drop_reason reason)
{
        DEBUG_NET_WARN_ON_ONCE(!(q->flags & TCQ_F_DEQUEUE_DROPS));
        DEBUG_NET_WARN_ON_ONCE(q->flags & TCQ_F_NOLOCK);

        tcf_set_drop_reason(skb, reason);
        skb->next = q->to_free;
        q->to_free = skb;
}

/* Instead of calling kfree_skb() while root qdisc lock is held,
 * queue the skb for future freeing at end of __dev_xmit_skb()
 */
static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
{
        skb->next = *to_free;
        *to_free = skb;
}

static inline void __qdisc_drop_all(struct sk_buff *skb,
                                    struct sk_buff **to_free)
{
        if (skb->prev)
                skb->prev->next = *to_free;
        else
                skb->next = *to_free;
        *to_free = skb;
}

static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
                                                   struct qdisc_skb_head *qh,
                                                   struct sk_buff **to_free)
{
        struct sk_buff *skb = __qdisc_dequeue_head(qh);

        if (likely(skb != NULL)) {
                unsigned int len = qdisc_pkt_len(skb);

                qdisc_qstats_backlog_dec(sch, skb);
                __qdisc_drop(skb, to_free);
                return len;
        }

        return 0;
}

static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
{
        const struct qdisc_skb_head *qh = &sch->q;

        return qh->head;
}

/* generic pseudo peek method for non-work-conserving qdisc */
static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
{
        struct sk_buff *skb = skb_peek(&sch->gso_skb);

        /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
        if (!skb) {
                skb = sch->dequeue(sch);

                if (skb) {
                        __skb_queue_head(&sch->gso_skb, skb);
                        /* it's still part of the queue */
                        qdisc_qstats_backlog_inc(sch, skb);
                        sch->q.qlen++;
                }
        }

        return skb;
}

static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
                                                 struct sk_buff *skb)
{
        if (qdisc_is_percpu_stats(sch)) {
                qdisc_qstats_cpu_backlog_dec(sch, skb);
                qdisc_bstats_cpu_update(sch, skb);
                qdisc_qstats_cpu_qlen_dec(sch);
        } else {
                qdisc_qstats_backlog_dec(sch, skb);
                qdisc_bstats_update(sch, skb);
                sch->q.qlen--;
        }
}

static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
                                                 unsigned int pkt_len)
{
        if (qdisc_is_percpu_stats(sch)) {
                qdisc_qstats_cpu_qlen_inc(sch);
                this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
        } else {
                sch->qstats.backlog += pkt_len;
                sch->q.qlen++;
        }
}

/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
{
        struct sk_buff *skb = skb_peek(&sch->gso_skb);

        if (skb) {
                skb = __skb_dequeue(&sch->gso_skb);
                if (qdisc_is_percpu_stats(sch)) {
                        qdisc_qstats_cpu_backlog_dec(sch, skb);
                        qdisc_qstats_cpu_qlen_dec(sch);
                } else {
                        qdisc_qstats_backlog_dec(sch, skb);
                        sch->q.qlen--;
                }
        } else {
                skb = sch->dequeue(sch);
        }

        return skb;
}

static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
{
        /*
         * We do not know the backlog in bytes of this list, it
         * is up to the caller to correct it
         */
        ASSERT_RTNL();
        if (qh->qlen) {
                rtnl_kfree_skbs(qh->head, qh->tail);

                qh->head = NULL;
                qh->tail = NULL;
                qh->qlen = 0;
        }
}

static inline void qdisc_reset_queue(struct Qdisc *sch)
{
        __qdisc_reset_queue(&sch->q);
}

static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
                                          struct Qdisc **pold)
{
        struct Qdisc *old;

        sch_tree_lock(sch);
        old = *pold;
        *pold = new;
        if (old != NULL)
                qdisc_purge_queue(old);
        sch_tree_unlock(sch);

        return old;
}

static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
{
        rtnl_kfree_skbs(skb, skb);
        qdisc_qstats_drop(sch);
}

static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
                                 struct sk_buff **to_free)
{
        __qdisc_drop(skb, to_free);
        qdisc_qstats_cpu_drop(sch);

        return NET_XMIT_DROP;
}

static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
                             struct sk_buff **to_free)
{
        __qdisc_drop(skb, to_free);
        qdisc_qstats_drop(sch);

        return NET_XMIT_DROP;
}

static inline int qdisc_drop_reason(struct sk_buff *skb, struct Qdisc *sch,
                                    struct sk_buff **to_free,
                                    enum skb_drop_reason reason)
{
        tcf_set_drop_reason(skb, reason);
        return qdisc_drop(skb, sch, to_free);
}

static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
                                 struct sk_buff **to_free)
{
        __qdisc_drop_all(skb, to_free);
        qdisc_qstats_drop(sch);

        return NET_XMIT_DROP;
}

struct psched_ratecfg {
        u64     rate_bytes_ps; /* bytes per second */
        u32     mult;
        u16     overhead;
        u16     mpu;
        u8      linklayer;
        u8      shift;
};

static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
                                unsigned int len)
{
        len += r->overhead;

        if (len < r->mpu)
                len = r->mpu;

        if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
                return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;

        return ((u64)len * r->mult) >> r->shift;
}

void psched_ratecfg_precompute(struct psched_ratecfg *r,
                               const struct tc_ratespec *conf,
                               u64 rate64);

static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
                                          const struct psched_ratecfg *r)
{
        memset(res, 0, sizeof(*res));

        /* legacy struct tc_ratespec has a 32bit @rate field
         * Qdisc using 64bit rate should add new attributes
         * in order to maintain compatibility.
         */
        res->rate = min_t(u64, r->rate_bytes_ps, ~0U);

        res->overhead = r->overhead;
        res->mpu = r->mpu;
        res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
}

struct psched_pktrate {
        u64     rate_pkts_ps; /* packets per second */
        u32     mult;
        u8      shift;
};

static inline u64 psched_pkt2t_ns(const struct psched_pktrate *r,
                                  unsigned int pkt_num)
{
        return ((u64)pkt_num * r->mult) >> r->shift;
}

void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64);

/* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
 * The fast path only needs to access filter list and to update stats
 */
struct mini_Qdisc {
        struct tcf_proto *filter_list;
        struct tcf_block *block;
        struct gnet_stats_basic_sync __percpu *cpu_bstats;
        struct gnet_stats_queue __percpu *cpu_qstats;
        unsigned long rcu_state;
};

static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
                                                const struct sk_buff *skb)
{
        bstats_update(this_cpu_ptr(miniq->cpu_bstats), skb);
}

static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
{
        this_cpu_inc(miniq->cpu_qstats->drops);
}

struct mini_Qdisc_pair {
        struct mini_Qdisc miniq1;
        struct mini_Qdisc miniq2;
        struct mini_Qdisc __rcu **p_miniq;
};

void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
                          struct tcf_proto *tp_head);
void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
                          struct mini_Qdisc __rcu **p_miniq);
void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
                                struct tcf_block *block);

static inline bool mini_qdisc_pair_inited(struct mini_Qdisc_pair *miniqp)
{
        return !!miniqp->p_miniq;
}

void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx);

int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));

/* Make sure qdisc is no longer in SCHED state. */
static inline void qdisc_synchronize(const struct Qdisc *q)
{
        while (test_bit(__QDISC_STATE_SCHED, &q->state))
                msleep(1);
}

#endif