This hashtable implementation is using hlist buckets to provide a simple
hashtable to prevent it from getting reimplemented all over the kernel.
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
include/linux/hashtable.h | 46 +++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 46 insertions(+), 0 deletions(-)
create mode 100644 include/linux/hashtable.h
diff --git a/include/linux/hashtable.h b/include/linux/hashtable.h
new file mode 100644
index 0000000..9b29fd1
--- /dev/null
+++ b/include/linux/hashtable.h
@@ -0,0 +1,46 @@
+#ifndef _LINUX_HASHTABLE_H
+#define _LINUX_HASHTABLE_H
+
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/hash.h>
+
+#define DEFINE_HASHTABLE(name, bits) \
+ struct hlist_head name[1 << bits];
+
+#define HASH_BITS(name) (order_base_2(ARRAY_SIZE(name)))
+#define HASH_SIZE(name) (1 << (HASH_BITS(name)))
+
+#define HASH_INIT(name) \
+({ \
+ int __i; \
+ for (__i = 0 ; __i < HASH_SIZE(name) ; __i++) \
+ INIT_HLIST_HEAD(&name[__i]); \
+})
+
+#define HASH_ADD(name, obj, key) \
+ hlist_add_head(obj, &name[ \
+ hash_long((unsigned long)key, HASH_BITS(name))]);
+
+#define HASH_GET(name, key, type, member, cmp_fn) \
+({ \
+ struct hlist_node *__node; \
+ typeof(key) __key = key; \
+ type *__obj = NULL; \
+ hlist_for_each_entry(__obj, __node, &name[ \
+ hash_long((unsigned long) __key, \
+ HASH_BITS(name))], member) \
+ if (cmp_fn(__obj, __key)) \
+ break; \
+ __obj; \
+})
+
+#define HASH_DEL(obj, member) \
+ hlist_del(&obj->member)
+
+#define HASH_FOR_EACH(bkt, node, name, obj, member) \
+ for (bkt = 0; bkt < HASH_SIZE(name); bkt++) \
+ hlist_for_each_entry(obj, node, &name[i], member)
+
+#endif
--
1.7.8.6
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