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/* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#ifndef __BPF_LRU_LIST_H_
#define __BPF_LRU_LIST_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 inacitve 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 nr_scans;
bool percpu;
};
static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
{
/* ref is an approximation on access frequency. It does not
* have to be very accurate. Hence, no protection is used.
*/
if (!node->ref)
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);
void bpf_lru_promote(struct bpf_lru *lru, struct bpf_lru_node *node);
#endif