kernel/bpf/bpf_lru_list.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /* Copyright (c) 2016 Facebook
   3  */
   4 #ifndef __BPF_LRU_LIST_H_
   5 #define __BPF_LRU_LIST_H_
   6
   7 #include <linux/list.h>
   8 #include <linux/spinlock_types.h>
   9
  10 #define NR_BPF_LRU_LIST_T       (3)
  11 #define NR_BPF_LRU_LIST_COUNT   (2)
  12 #define NR_BPF_LRU_LOCAL_LIST_T (2)
  13 #define BPF_LOCAL_LIST_T_OFFSET NR_BPF_LRU_LIST_T
  14
  15 enum bpf_lru_list_type {
  16         BPF_LRU_LIST_T_ACTIVE,
  17         BPF_LRU_LIST_T_INACTIVE,
  18         BPF_LRU_LIST_T_FREE,
  19         BPF_LRU_LOCAL_LIST_T_FREE,
  20         BPF_LRU_LOCAL_LIST_T_PENDING,
  21 };
  22
  23 struct bpf_lru_node {
  24         struct list_head list;
  25         u16 cpu;
  26         u8 type;
  27         u8 ref;
  28 };
  29
  30 struct bpf_lru_list {
  31         struct list_head lists[NR_BPF_LRU_LIST_T];
  32         unsigned int counts[NR_BPF_LRU_LIST_COUNT];
  33         /* The next inactive list rotation starts from here */
  34         struct list_head *next_inactive_rotation;
  35
  36         raw_spinlock_t lock ____cacheline_aligned_in_smp;
  37 };
  38
  39 struct bpf_lru_locallist {
  40         struct list_head lists[NR_BPF_LRU_LOCAL_LIST_T];
  41         u16 next_steal;
  42         raw_spinlock_t lock;
  43 };
  44
  45 struct bpf_common_lru {
  46         struct bpf_lru_list lru_list;
  47         struct bpf_lru_locallist __percpu *local_list;
  48 };
  49
  50 typedef bool (*del_from_htab_func)(void *arg, struct bpf_lru_node *node);
  51
  52 struct bpf_lru {
  53         union {
  54                 struct bpf_common_lru common_lru;
  55                 struct bpf_lru_list __percpu *percpu_lru;
  56         };
  57         del_from_htab_func del_from_htab;
  58         void *del_arg;
  59         unsigned int hash_offset;
  60         unsigned int nr_scans;
  61         bool percpu;
  62 };
  63
  64 static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
  65 {
  66         /* ref is an approximation on access frequency.  It does not
  67          * have to be very accurate.  Hence, no protection is used.
  68          */
  69         if (!node->ref)
  70                 node->ref = 1;
  71 }
  72
  73 int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
  74                  del_from_htab_func del_from_htab, void *delete_arg);
  75 void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
  76                       u32 elem_size, u32 nr_elems);
  77 void bpf_lru_destroy(struct bpf_lru *lru);
  78 struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash);
  79 void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node);
  80 void bpf_lru_promote(struct bpf_lru *lru, struct bpf_lru_node *node);
  81
  82 #endif