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authorNeilBrown <neilb@suse.com>2018-06-18 12:52:50 +1000
committerDavid S. Miller <davem@davemloft.net>2018-06-22 13:43:27 +0900
commit0eb71a9da5796851fa87ddc1a534066c0fe54055 (patch)
tree2e6a006f82122ffc983e89f74b5b702ae75799b9 /include/linux/rhashtable-types.h
parentcbab901296232b1247b46e6e127103d2f738d783 (diff)
rhashtable: split rhashtable.h
Due to the use of rhashtables in net namespaces, rhashtable.h is included in lots of the kernel, so a small changes can required a large recompilation. This makes development painful. This patch splits out rhashtable-types.h which just includes the major type declarations, and does not include (non-trivial) inline code. rhashtable.h is no longer included by anything in the include/ directory. Common include files only include rhashtable-types.h so a large recompilation is only triggered when that changes. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/rhashtable-types.h')
-rw-r--r--include/linux/rhashtable-types.h139
1 files changed, 139 insertions, 0 deletions
diff --git a/include/linux/rhashtable-types.h b/include/linux/rhashtable-types.h
new file mode 100644
index 000000000000..9740063ff13b
--- /dev/null
+++ b/include/linux/rhashtable-types.h
@@ -0,0 +1,139 @@
+/* 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
+ * @locks_mul: Number of bucket locks to allocate per cpu (default: 32)
+ * @automatic_shrinking: Enable automatic shrinking of tables
+ * @nulls_base: Base value to generate nulls marker
+ * @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;
+ u8 locks_mul;
+ u32 nulls_base;
+ 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 */