/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_DST_OPS_H
#define _NET_DST_OPS_H
#include <linux/types.h>
#include <linux/percpu_counter.h>
#include <linux/cache.h>

struct dst_entry;
struct kmem_cachep;
struct net_device;
struct sk_buff;
struct sock;
struct net;

struct dst_ops {
        unsigned short          family;
        unsigned int            gc_thresh;

        void                    (*gc)(struct dst_ops *ops);
        struct dst_entry *      (*check)(struct dst_entry *, __u32 cookie);
        unsigned int            (*default_advmss)(const struct dst_entry *);
        unsigned int            (*mtu)(const struct dst_entry *);
        u32 *                   (*cow_metrics)(struct dst_entry *, unsigned long);
        void                    (*destroy)(struct dst_entry *);
        void                    (*ifdown)(struct dst_entry *,
                                          struct net_device *dev);
        void                    (*negative_advice)(struct sock *sk, struct dst_entry *);
        void                    (*link_failure)(struct sk_buff *);
        void                    (*update_pmtu)(struct dst_entry *dst, struct sock *sk,
                                               struct sk_buff *skb, u32 mtu,
                                               bool confirm_neigh);
        void                    (*redirect)(struct dst_entry *dst, struct sock *sk,
                                            struct sk_buff *skb);
        int                     (*local_out)(struct net *net, struct sock *sk, struct sk_buff *skb);
        struct neighbour *      (*neigh_lookup)(const struct dst_entry *dst,
                                                struct sk_buff *skb,
                                                const void *daddr);
        void                    (*confirm_neigh)(const struct dst_entry *dst,
                                                 const void *daddr);

        struct kmem_cache       *kmem_cachep;

        struct percpu_counter   pcpuc_entries ____cacheline_aligned_in_smp;
};

static inline int dst_entries_get_fast(struct dst_ops *dst)
{
        return percpu_counter_read_positive(&dst->pcpuc_entries);
}

static inline int dst_entries_get_slow(struct dst_ops *dst)
{
        return percpu_counter_sum_positive(&dst->pcpuc_entries);
}

#define DST_PERCPU_COUNTER_BATCH 32
static inline void dst_entries_add(struct dst_ops *dst, int val)
{
        percpu_counter_add_batch(&dst->pcpuc_entries, val,
                                 DST_PERCPU_COUNTER_BATCH);
}

static inline int dst_entries_init(struct dst_ops *dst)
{
        return percpu_counter_init(&dst->pcpuc_entries, 0, GFP_KERNEL);
}

static inline void dst_entries_destroy(struct dst_ops *dst)
{
        percpu_counter_destroy(&dst->pcpuc_entries);
}

#endif