1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/bpf/bpf_lru_list.h b/kernel/bpf/bpf_lru_list.h
new file mode 100644
index 000000000..7d4f89b7c
--- /dev/null
+++ b/kernel/bpf/bpf_lru_list.h
@@ -0,0 +1,85 @@
+/* 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