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/cache.h>
8 #include <linux/list.h>
9 #include <linux/spinlock_types.h>
10
11 #define NR_BPF_LRU_LIST_T (3)
12 #define NR_BPF_LRU_LIST_COUNT (2)
13 #define NR_BPF_LRU_LOCAL_LIST_T (2)
14 #define BPF_LOCAL_LIST_T_OFFSET NR_BPF_LRU_LIST_T
15
16 enum bpf_lru_list_type {
17 BPF_LRU_LIST_T_ACTIVE,
18 BPF_LRU_LIST_T_INACTIVE,
19 BPF_LRU_LIST_T_FREE,
20 BPF_LRU_LOCAL_LIST_T_FREE,
21 BPF_LRU_LOCAL_LIST_T_PENDING,
22 };
23
24 struct bpf_lru_node {
25 struct list_head list;
26 u16 cpu;
27 u8 type;
28 u8 ref;
29 };
30
31 struct bpf_lru_list {
32 struct list_head lists[NR_BPF_LRU_LIST_T];
33 unsigned int counts[NR_BPF_LRU_LIST_COUNT];
34 /* The next inactive list rotation starts from here */
35 struct list_head *next_inactive_rotation;
36
37 raw_spinlock_t lock ____cacheline_aligned_in_smp;
38 };
39
40 struct bpf_lru_locallist {
41 struct list_head lists[NR_BPF_LRU_LOCAL_LIST_T];
42 u16 next_steal;
43 raw_spinlock_t lock;
44 };
45
46 struct bpf_common_lru {
47 struct bpf_lru_list lru_list;
48 struct bpf_lru_locallist __percpu *local_list;
49 };
50
51 typedef bool (*del_from_htab_func)(void *arg, struct bpf_lru_node *node);
52
53 struct bpf_lru {
54 union {
55 struct bpf_common_lru common_lru;
56 struct bpf_lru_list __percpu *percpu_lru;
57 };
58 del_from_htab_func del_from_htab;
59 void *del_arg;
60 unsigned int hash_offset;
61 unsigned int nr_scans;
62 bool percpu;
63 };
64
bpf_lru_node_set_ref(struct bpf_lru_node * node)65 static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
66 {
67 /* ref is an approximation on access frequency. It does not
68 * have to be very accurate. Hence, no protection is used.
69 */
70 if (!node->ref)
71 node->ref = 1;
72 }
73
74 int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
75 del_from_htab_func del_from_htab, void *delete_arg);
76 void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
77 u32 elem_size, u32 nr_elems);
78 void bpf_lru_destroy(struct bpf_lru *lru);
79 struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash);
80 void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node);
81 void bpf_lru_promote(struct bpf_lru *lru, struct bpf_lru_node *node);
82
83 #endif
84