Merge tag 'batman-adv-for-davem' of git://git.open-mesh.org/linux-merge

[mirror_ubuntu-zesty-kernel.git] / include / net / sch_generic.h

#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 <net/gen_stats.h>
#include <net/rtnetlink.h>

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

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_THROTTLED,
};

/*
 * following bits are only changed while qdisc lock is held
 */
enum qdisc___state_t {
        __QDISC___STATE_RUNNING = 1,
};

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

struct Qdisc {
        int                     (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
        struct sk_buff *        (*dequeue)(struct Qdisc *dev);
        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)
        u32                     limit;
        const struct Qdisc_ops  *ops;
        struct qdisc_size_table __rcu *stab;
        struct list_head        list;
        u32                     handle;
        u32                     parent;
        int                     (*reshape_fail)(struct sk_buff *skb,
                                        struct Qdisc *q);

        void                    *u32_node;

        /* This field is deprecated, but it is still used by CBQ
         * and it will live until better solution will be invented.
         */
        struct Qdisc            *__parent;
        struct netdev_queue     *dev_queue;

        struct gnet_stats_rate_est64    rate_est;
        struct Qdisc            *next_sched;
        struct sk_buff          *gso_skb;
        /*
         * For performance sake on SMP, we put highly modified fields at the end
         */
        unsigned long           state;
        struct sk_buff_head     q;
        struct gnet_stats_basic_packed bstats;
        unsigned int            __state;
        struct gnet_stats_queue qstats;
        struct rcu_head         rcu_head;
        int                     padded;
        atomic_t                refcnt;

        spinlock_t              busylock ____cacheline_aligned_in_smp;
};

static inline bool qdisc_is_running(const struct Qdisc *qdisc)
{
        return (qdisc->__state & __QDISC___STATE_RUNNING) ? true : false;
}

static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
        if (qdisc_is_running(qdisc))
                return false;
        qdisc->__state |= __QDISC___STATE_RUNNING;
        return true;
}

static inline void qdisc_run_end(struct Qdisc *qdisc)
{
        qdisc->__state &= ~__QDISC___STATE_RUNNING;
}

static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
{
        return test_bit(__QDISC_STATE_THROTTLED, &qdisc->state) ? true : false;
}

static inline void qdisc_throttled(struct Qdisc *qdisc)
{
        set_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
}

static inline void qdisc_unthrottled(struct Qdisc *qdisc)
{
        clear_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
}

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

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

        /* Filter manipulation */
        struct tcf_proto **     (*tcf_chain)(struct Qdisc *, unsigned long);
        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 *);
};

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

        int                     (*enqueue)(struct sk_buff *, struct Qdisc *);
        struct sk_buff *        (*dequeue)(struct Qdisc *);
        struct sk_buff *        (*peek)(struct Qdisc *);
        unsigned int            (*drop)(struct Qdisc *);

        int                     (*init)(struct Qdisc *, struct nlattr *arg);
        void                    (*reset)(struct Qdisc *);
        void                    (*destroy)(struct Qdisc *);
        int                     (*change)(struct Qdisc *, struct nlattr *arg);
        void                    (*attach)(struct Qdisc *);

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

        struct module           *owner;
};


struct tcf_result {
        unsigned long   class;
        u32             classid;
};

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*);

        unsigned long           (*get)(struct tcf_proto*, u32 handle);
        void                    (*put)(struct tcf_proto*, unsigned long);
        int                     (*change)(struct net *net, struct sk_buff *,
                                        struct tcf_proto*, unsigned long,
                                        u32 handle, struct nlattr **,
                                        unsigned long *, bool);
        int                     (*delete)(struct tcf_proto*, unsigned long);
        void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);

        /* rtnetlink specific */
        int                     (*dump)(struct net*, struct tcf_proto*, unsigned long,
                                        struct sk_buff *skb, struct tcmsg*);

        struct module           *owner;
};

struct tcf_proto {
        /* Fast access part */
        struct tcf_proto        *next;
        void                    *root;
        int                     (*classify)(struct sk_buff *,
                                            const struct tcf_proto *,
                                            struct tcf_result *);
        __be16                  protocol;

        /* All the rest */
        u32                     prio;
        u32                     classid;
        struct Qdisc            *q;
        void                    *data;
        const struct tcf_proto_ops      *ops;
};

struct qdisc_skb_cb {
        unsigned int            pkt_len;
        u16                     slave_dev_queue_mapping;
        u16                     _pad;
        unsigned char           data[24];
};

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) < offsetof(struct qdisc_skb_cb, data) + sz);
        BUILD_BUG_ON(sizeof(qcb->data) < sz);
}

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

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

/* The qdisc root lock is a mechanism by which to top level
 * of a qdisc tree can be locked from any qdisc node in the
 * forest.  This allows changing the configuration of some
 * aspect of the qdisc tree while blocking out asynchronous
 * qdisc access in the packet processing paths.
 *
 * It is only legal to do this when the root will not change
 * on us.  Otherwise we'll potentially lock the wrong qdisc
 * root.  This is enforced by holding the RTNL semaphore, which
 * all users of this lock accessor must do.
 */
static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
{
        struct Qdisc *root = qdisc_root(qdisc);

        ASSERT_RTNL();
        return qdisc_lock(root);
}

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(const struct Qdisc *q)
{
        spin_lock_bh(qdisc_root_sleeping_lock(q));
}

static inline void sch_tree_unlock(const struct Qdisc *q)
{
        spin_unlock_bh(qdisc_root_sleeping_lock(q));
}

#define tcf_tree_lock(tp)       sch_tree_lock((tp)->q)
#define tcf_tree_unlock(tp)     sch_tree_unlock((tp)->q)

extern struct Qdisc noop_qdisc;
extern struct Qdisc_ops noop_qdisc_ops;
extern struct Qdisc_ops pfifo_fast_ops;
extern struct Qdisc_ops mq_qdisc_ops;
extern const struct Qdisc_ops *default_qdisc_ops;

struct Qdisc_class_common {
        u32                     classid;
        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;

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

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 *);

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_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
                          const struct Qdisc_ops *ops);
struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
                                const struct Qdisc_ops *ops, u32 parentid);
void __qdisc_calculate_pkt_len(struct sk_buff *skb,
                               const struct qdisc_size_table *stab);
void tcf_destroy(struct tcf_proto *tp);
void tcf_destroy_chain(struct tcf_proto **fl);

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

        for (; i < dev->num_tx_queues; i++) {
                qdisc = netdev_get_tx_queue(dev, i)->qdisc;
                if (qdisc) {
                        spin_lock_bh(qdisc_lock(qdisc));
                        qdisc_reset(qdisc);
                        spin_unlock_bh(qdisc_lock(qdisc));
                }
        }
}

static inline void qdisc_reset_all_tx(struct net_device *dev)
{
        qdisc_reset_all_tx_gt(dev, 0);
}

/* Are all TX queues of the device empty?  */
static inline bool qdisc_all_tx_empty(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);
                const struct Qdisc *q = txq->qdisc;

                if (q->q.qlen)
                        return false;
        }
        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 (txq->qdisc != txq->qdisc_sleeping)
                        return true;
        }
        return false;
}

/* 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 (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;
}

/* 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)
{
        qdisc_calculate_pkt_len(skb, sch);
        return sch->enqueue(skb, sch);
}

static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
{
        qdisc_skb_cb(skb)->pkt_len = skb->len;
        return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
}


static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
                                 const struct sk_buff *skb)
{
        bstats->bytes += qdisc_pkt_len(skb);
        bstats->packets += skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1;
}

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

static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
                                       struct sk_buff_head *list)
{
        __skb_queue_tail(list, skb);
        sch->qstats.backlog += qdisc_pkt_len(skb);

        return NET_XMIT_SUCCESS;
}

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

static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
                                                   struct sk_buff_head *list)
{
        struct sk_buff *skb = __skb_dequeue(list);

        if (likely(skb != NULL)) {
                sch->qstats.backlog -= qdisc_pkt_len(skb);
                qdisc_bstats_update(sch, skb);
        }

        return skb;
}

static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
{
        return __qdisc_dequeue_head(sch, &sch->q);
}

static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
                                              struct sk_buff_head *list)
{
        struct sk_buff *skb = __skb_dequeue(list);

        if (likely(skb != NULL)) {
                unsigned int len = qdisc_pkt_len(skb);
                sch->qstats.backlog -= len;
                kfree_skb(skb);
                return len;
        }

        return 0;
}

static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
{
        return __qdisc_queue_drop_head(sch, &sch->q);
}

static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
                                                   struct sk_buff_head *list)
{
        struct sk_buff *skb = __skb_dequeue_tail(list);

        if (likely(skb != NULL))
                sch->qstats.backlog -= qdisc_pkt_len(skb);

        return skb;
}

static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
{
        return __qdisc_dequeue_tail(sch, &sch->q);
}

static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
{
        return skb_peek(&sch->q);
}

/* generic pseudo peek method for non-work-conserving qdisc */
static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
{
        /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
        if (!sch->gso_skb) {
                sch->gso_skb = sch->dequeue(sch);
                if (sch->gso_skb)
                        /* it's still part of the queue */
                        sch->q.qlen++;
        }

        return sch->gso_skb;
}

/* 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 = sch->gso_skb;

        if (skb) {
                sch->gso_skb = NULL;
                sch->q.qlen--;
        } else {
                skb = sch->dequeue(sch);
        }

        return skb;
}

static inline void __qdisc_reset_queue(struct Qdisc *sch,
                                       struct sk_buff_head *list)
{
        /*
         * We do not know the backlog in bytes of this list, it
         * is up to the caller to correct it
         */
        __skb_queue_purge(list);
}

static inline void qdisc_reset_queue(struct Qdisc *sch)
{
        __qdisc_reset_queue(sch, &sch->q);
        sch->qstats.backlog = 0;
}

static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
                                              struct sk_buff_head *list)
{
        struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);

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

        return 0;
}

static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
{
        return __qdisc_queue_drop(sch, &sch->q);
}

static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
{
        kfree_skb(skb);
        sch->qstats.drops++;

        return NET_XMIT_DROP;
}

static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
{
        sch->qstats.drops++;

#ifdef CONFIG_NET_CLS_ACT
        if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
                goto drop;

        return NET_XMIT_SUCCESS;

drop:
#endif
        kfree_skb(skb);
        return NET_XMIT_DROP;
}

/* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
   long it will take to send a packet given its size.
 */
static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
{
        int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
        if (slot < 0)
                slot = 0;
        slot >>= rtab->rate.cell_log;
        if (slot > 255)
                return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
        return rtab->data[slot];
}

#ifdef CONFIG_NET_CLS_ACT
static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask,
                                            int action)
{
        struct sk_buff *n;

        n = skb_clone(skb, gfp_mask);

        if (n) {
                n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
                n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
                n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
        }
        return n;
}
#endif

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

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

        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->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
}

#endif