kernel/bpf/bpf_lru_list.h

root/kernel/bpf/bpf_lru_list.h
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2016 Facebook
 */
#ifndef __BPF_LRU_LIST_H_
#define __BPF_LRU_LIST_H_

#include <linux/cache.h>
#include <linux/list.h>
#include <linux/spinlock_types.h>

#define NR_BPF_LRU_LIST_T       (3)
#define NR_BPF_LRU_LIST_COUNT   (2)
#define NR_BPF_LRU_LOCAL_LIST_T (2)
#define BPF_LOCAL_LIST_T_OFFSET NR_BPF_LRU_LIST_T

enum bpf_lru_list_type {
        BPF_LRU_LIST_T_ACTIVE,
        BPF_LRU_LIST_T_INACTIVE,
        BPF_LRU_LIST_T_FREE,
        BPF_LRU_LOCAL_LIST_T_FREE,
        BPF_LRU_LOCAL_LIST_T_PENDING,
};

struct bpf_lru_node {
        struct list_head list;
        u16 cpu;
        u8 type;
        u8 ref;
};

struct bpf_lru_list {
        struct list_head lists[NR_BPF_LRU_LIST_T];
        unsigned int counts[NR_BPF_LRU_LIST_COUNT];
        /* The next inactive list rotation starts from here */
        struct list_head *next_inactive_rotation;

        raw_spinlock_t lock ____cacheline_aligned_in_smp;
};

struct bpf_lru_locallist {
        struct list_head lists[NR_BPF_LRU_LOCAL_LIST_T];
        u16 next_steal;
        raw_spinlock_t lock;
};

struct bpf_common_lru {
        struct bpf_lru_list lru_list;
        struct bpf_lru_locallist __percpu *local_list;
};

typedef bool (*del_from_htab_func)(void *arg, struct bpf_lru_node *node);

struct bpf_lru {
        union {
                struct bpf_common_lru common_lru;
                struct bpf_lru_list __percpu *percpu_lru;
        };
        del_from_htab_func del_from_htab;
        void *del_arg;
        unsigned int hash_offset;
        unsigned int target_free;
        unsigned int nr_scans;
        bool percpu;
};

static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
{
        if (!READ_ONCE(node->ref))
                WRITE_ONCE(node->ref, 1);
}

int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
                 del_from_htab_func del_from_htab, void *delete_arg);
void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
                      u32 elem_size, u32 nr_elems);
void bpf_lru_destroy(struct bpf_lru *lru);
struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash);
void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node);

#endif
Linux
