Move c_src dirs back to toplevel

[bcachefs-tools-debian] / include / linux / rhashtable-types.h

diff --git a/include/linux/rhashtable-types.h b/include/linux/rhashtable-types.h
new file mode 100644 (file)
index 0000000..57467cb
--- /dev/null
+++ b/include/linux/rhashtable-types.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Resizable, Scalable, Concurrent Hash Table
+ *
+ * Simple structures that might be needed in include
+ * files.
+ */
+
+#ifndef _LINUX_RHASHTABLE_TYPES_H
+#define _LINUX_RHASHTABLE_TYPES_H
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+struct rhash_head {
+       struct rhash_head __rcu         *next;
+};
+
+struct rhlist_head {
+       struct rhash_head               rhead;
+       struct rhlist_head __rcu        *next;
+};
+
+struct bucket_table;
+
+/**
+ * struct rhashtable_compare_arg - Key for the function rhashtable_compare
+ * @ht: Hash table
+ * @key: Key to compare against
+ */
+struct rhashtable_compare_arg {
+       struct rhashtable *ht;
+       const void *key;
+};
+
+typedef u32 (*rht_hashfn_t)(const void *data, u32 len, u32 seed);
+typedef u32 (*rht_obj_hashfn_t)(const void *data, u32 len, u32 seed);
+typedef int (*rht_obj_cmpfn_t)(struct rhashtable_compare_arg *arg,
+                              const void *obj);
+
+/**
+ * struct rhashtable_params - Hash table construction parameters
+ * @nelem_hint: Hint on number of elements, should be 75% of desired size
+ * @key_len: Length of key
+ * @key_offset: Offset of key in struct to be hashed
+ * @head_offset: Offset of rhash_head in struct to be hashed
+ * @max_size: Maximum size while expanding
+ * @min_size: Minimum size while shrinking
+ * @automatic_shrinking: Enable automatic shrinking of tables
+ * @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)
+ * @obj_hashfn: Function to hash object
+ * @obj_cmpfn: Function to compare key with object
+ */
+struct rhashtable_params {
+       u16                     nelem_hint;
+       u16                     key_len;
+       u16                     key_offset;
+       u16                     head_offset;
+       unsigned int            max_size;
+       u16                     min_size;
+       bool                    automatic_shrinking;
+       rht_hashfn_t            hashfn;
+       rht_obj_hashfn_t        obj_hashfn;
+       rht_obj_cmpfn_t         obj_cmpfn;
+};
+
+/**
+ * struct rhashtable - Hash table handle
+ * @tbl: Bucket table
+ * @key_len: Key length for hashfn
+ * @max_elems: Maximum number of elements in table
+ * @p: Configuration parameters
+ * @rhlist: True if this is an rhltable
+ * @run_work: Deferred worker to expand/shrink asynchronously
+ * @mutex: Mutex to protect current/future table swapping
+ * @lock: Spin lock to protect walker list
+ * @nelems: Number of elements in table
+ */
+struct rhashtable {
+       struct bucket_table __rcu       *tbl;
+       unsigned int                    key_len;
+       unsigned int                    max_elems;
+       struct rhashtable_params        p;
+       bool                            rhlist;
+       struct work_struct              run_work;
+       struct mutex                    mutex;
+       spinlock_t                      lock;
+       atomic_t                        nelems;
+};
+
+/**
+ * struct rhltable - Hash table with duplicate objects in a list
+ * @ht: Underlying rhtable
+ */
+struct rhltable {
+       struct rhashtable ht;
+};
+
+/**
+ * struct rhashtable_walker - Hash table walker
+ * @list: List entry on list of walkers
+ * @tbl: The table that we were walking over
+ */
+struct rhashtable_walker {
+       struct list_head list;
+       struct bucket_table *tbl;
+};
+
+/**
+ * struct rhashtable_iter - Hash table iterator
+ * @ht: Table to iterate through
+ * @p: Current pointer
+ * @list: Current hash list pointer
+ * @walker: Associated rhashtable walker
+ * @slot: Current slot
+ * @skip: Number of entries to skip in slot
+ */
+struct rhashtable_iter {
+       struct rhashtable *ht;
+       struct rhash_head *p;
+       struct rhlist_head *list;
+       struct rhashtable_walker walker;
+       unsigned int slot;
+       unsigned int skip;
+       bool end_of_table;
+};
+
+int rhashtable_init(struct rhashtable *ht,
+                   const struct rhashtable_params *params);
+int rhltable_init(struct rhltable *hlt,
+                 const struct rhashtable_params *params);
+
+#endif /* _LINUX_RHASHTABLE_TYPES_H */