1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * Statically sized hash table implementation 2 * Statically sized hash table implementation
4 * (C) 2012 Sasha Levin <levinsasha928@gmail. 3 * (C) 2012 Sasha Levin <levinsasha928@gmail.com>
5 */ 4 */
6 5
7 #ifndef _LINUX_HASHTABLE_H 6 #ifndef _LINUX_HASHTABLE_H
8 #define _LINUX_HASHTABLE_H 7 #define _LINUX_HASHTABLE_H
9 8
10 #include <linux/list.h> 9 #include <linux/list.h>
11 #include <linux/types.h> 10 #include <linux/types.h>
12 #include <linux/kernel.h> 11 #include <linux/kernel.h>
13 #include <linux/hash.h> 12 #include <linux/hash.h>
14 #include <linux/rculist.h> 13 #include <linux/rculist.h>
15 14
16 #define DEFINE_HASHTABLE(name, bits) 15 #define DEFINE_HASHTABLE(name, bits) \
17 struct hlist_head name[1 << (bits)] = 16 struct hlist_head name[1 << (bits)] = \
18 { [0 ... ((1 << (bits) 17 { [0 ... ((1 << (bits)) - 1)] = HLIST_HEAD_INIT }
19 18
20 #define DEFINE_READ_MOSTLY_HASHTABLE(name, bit <<
21 struct hlist_head name[1 << (bits)] __ <<
22 { [0 ... ((1 << (bits) <<
23 <<
24 #define DECLARE_HASHTABLE(name, bits) 19 #define DECLARE_HASHTABLE(name, bits) \
25 struct hlist_head name[1 << (bits)] 20 struct hlist_head name[1 << (bits)]
26 21
27 #define HASH_SIZE(name) (ARRAY_SIZE(name)) 22 #define HASH_SIZE(name) (ARRAY_SIZE(name))
28 #define HASH_BITS(name) ilog2(HASH_SIZE(name)) 23 #define HASH_BITS(name) ilog2(HASH_SIZE(name))
29 24
30 /* Use hash_32 when possible to allow for fast 25 /* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */
31 #define hash_min(val, bits) 26 #define hash_min(val, bits) \
32 (sizeof(val) <= 4 ? hash_32(val, bits) 27 (sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits))
33 28
34 static inline void __hash_init(struct hlist_he 29 static inline void __hash_init(struct hlist_head *ht, unsigned int sz)
35 { 30 {
36 unsigned int i; 31 unsigned int i;
37 32
38 for (i = 0; i < sz; i++) 33 for (i = 0; i < sz; i++)
39 INIT_HLIST_HEAD(&ht[i]); 34 INIT_HLIST_HEAD(&ht[i]);
40 } 35 }
41 36
42 /** 37 /**
43 * hash_init - initialize a hash table 38 * hash_init - initialize a hash table
44 * @hashtable: hashtable to be initialized 39 * @hashtable: hashtable to be initialized
45 * 40 *
46 * Calculates the size of the hashtable from t 41 * Calculates the size of the hashtable from the given parameter, otherwise
47 * same as hash_init_size. 42 * same as hash_init_size.
48 * 43 *
49 * This has to be a macro since HASH_BITS() wi 44 * This has to be a macro since HASH_BITS() will not work on pointers since
50 * it calculates the size during preprocessing 45 * it calculates the size during preprocessing.
51 */ 46 */
52 #define hash_init(hashtable) __hash_init(hasht 47 #define hash_init(hashtable) __hash_init(hashtable, HASH_SIZE(hashtable))
53 48
54 /** 49 /**
55 * hash_add - add an object to a hashtable 50 * hash_add - add an object to a hashtable
56 * @hashtable: hashtable to add to 51 * @hashtable: hashtable to add to
57 * @node: the &struct hlist_node of the object 52 * @node: the &struct hlist_node of the object to be added
58 * @key: the key of the object to be added 53 * @key: the key of the object to be added
59 */ 54 */
60 #define hash_add(hashtable, node, key) 55 #define hash_add(hashtable, node, key) \
61 hlist_add_head(node, &hashtable[hash_m 56 hlist_add_head(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])
62 57
63 /** 58 /**
64 * hash_add_rcu - add an object to a rcu enabl 59 * hash_add_rcu - add an object to a rcu enabled hashtable
65 * @hashtable: hashtable to add to 60 * @hashtable: hashtable to add to
66 * @node: the &struct hlist_node of the object 61 * @node: the &struct hlist_node of the object to be added
67 * @key: the key of the object to be added 62 * @key: the key of the object to be added
68 */ 63 */
69 #define hash_add_rcu(hashtable, node, key) 64 #define hash_add_rcu(hashtable, node, key) \
70 hlist_add_head_rcu(node, &hashtable[ha 65 hlist_add_head_rcu(node, &hashtable[hash_min(key, HASH_BITS(hashtable))])
71 66
72 /** 67 /**
73 * hash_hashed - check whether an object is in 68 * hash_hashed - check whether an object is in any hashtable
74 * @node: the &struct hlist_node of the object 69 * @node: the &struct hlist_node of the object to be checked
75 */ 70 */
76 static inline bool hash_hashed(struct hlist_no 71 static inline bool hash_hashed(struct hlist_node *node)
77 { 72 {
78 return !hlist_unhashed(node); 73 return !hlist_unhashed(node);
79 } 74 }
80 75
81 static inline bool __hash_empty(struct hlist_h 76 static inline bool __hash_empty(struct hlist_head *ht, unsigned int sz)
82 { 77 {
83 unsigned int i; 78 unsigned int i;
84 79
85 for (i = 0; i < sz; i++) 80 for (i = 0; i < sz; i++)
86 if (!hlist_empty(&ht[i])) 81 if (!hlist_empty(&ht[i]))
87 return false; 82 return false;
88 83
89 return true; 84 return true;
90 } 85 }
91 86
92 /** 87 /**
93 * hash_empty - check whether a hashtable is e 88 * hash_empty - check whether a hashtable is empty
94 * @hashtable: hashtable to check 89 * @hashtable: hashtable to check
95 * 90 *
96 * This has to be a macro since HASH_BITS() wi 91 * This has to be a macro since HASH_BITS() will not work on pointers since
97 * it calculates the size during preprocessing 92 * it calculates the size during preprocessing.
98 */ 93 */
99 #define hash_empty(hashtable) __hash_empty(has 94 #define hash_empty(hashtable) __hash_empty(hashtable, HASH_SIZE(hashtable))
100 95
101 /** 96 /**
102 * hash_del - remove an object from a hashtabl 97 * hash_del - remove an object from a hashtable
103 * @node: &struct hlist_node of the object to 98 * @node: &struct hlist_node of the object to remove
104 */ 99 */
105 static inline void hash_del(struct hlist_node 100 static inline void hash_del(struct hlist_node *node)
106 { 101 {
107 hlist_del_init(node); 102 hlist_del_init(node);
108 } 103 }
109 104
110 /** 105 /**
111 * hash_del_rcu - remove an object from a rcu 106 * hash_del_rcu - remove an object from a rcu enabled hashtable
112 * @node: &struct hlist_node of the object to 107 * @node: &struct hlist_node of the object to remove
113 */ 108 */
114 static inline void hash_del_rcu(struct hlist_n 109 static inline void hash_del_rcu(struct hlist_node *node)
115 { 110 {
116 hlist_del_init_rcu(node); 111 hlist_del_init_rcu(node);
117 } 112 }
118 113
119 /** 114 /**
120 * hash_for_each - iterate over a hashtable 115 * hash_for_each - iterate over a hashtable
121 * @name: hashtable to iterate 116 * @name: hashtable to iterate
122 * @bkt: integer to use as bucket loop cursor 117 * @bkt: integer to use as bucket loop cursor
123 * @obj: the type * to use as a loop cursor fo 118 * @obj: the type * to use as a loop cursor for each entry
124 * @member: the name of the hlist_node within 119 * @member: the name of the hlist_node within the struct
125 */ 120 */
126 #define hash_for_each(name, bkt, obj, member) 121 #define hash_for_each(name, bkt, obj, member) \
127 for ((bkt) = 0, obj = NULL; obj == NUL 122 for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
128 (bkt)++)\ 123 (bkt)++)\
129 hlist_for_each_entry(obj, &nam 124 hlist_for_each_entry(obj, &name[bkt], member)
130 125
131 /** 126 /**
132 * hash_for_each_rcu - iterate over a rcu enab 127 * hash_for_each_rcu - iterate over a rcu enabled hashtable
133 * @name: hashtable to iterate 128 * @name: hashtable to iterate
134 * @bkt: integer to use as bucket loop cursor 129 * @bkt: integer to use as bucket loop cursor
135 * @obj: the type * to use as a loop cursor fo 130 * @obj: the type * to use as a loop cursor for each entry
136 * @member: the name of the hlist_node within 131 * @member: the name of the hlist_node within the struct
137 */ 132 */
138 #define hash_for_each_rcu(name, bkt, obj, memb 133 #define hash_for_each_rcu(name, bkt, obj, member) \
139 for ((bkt) = 0, obj = NULL; obj == NUL 134 for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
140 (bkt)++)\ 135 (bkt)++)\
141 hlist_for_each_entry_rcu(obj, 136 hlist_for_each_entry_rcu(obj, &name[bkt], member)
142 137
143 /** 138 /**
144 * hash_for_each_safe - iterate over a hashtab 139 * hash_for_each_safe - iterate over a hashtable safe against removal of
145 * hash entry 140 * hash entry
146 * @name: hashtable to iterate 141 * @name: hashtable to iterate
147 * @bkt: integer to use as bucket loop cursor 142 * @bkt: integer to use as bucket loop cursor
148 * @tmp: a &struct hlist_node used for tempora !! 143 * @tmp: a &struct used for temporary storage
149 * @obj: the type * to use as a loop cursor fo 144 * @obj: the type * to use as a loop cursor for each entry
150 * @member: the name of the hlist_node within 145 * @member: the name of the hlist_node within the struct
151 */ 146 */
152 #define hash_for_each_safe(name, bkt, tmp, obj 147 #define hash_for_each_safe(name, bkt, tmp, obj, member) \
153 for ((bkt) = 0, obj = NULL; obj == NUL 148 for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\
154 (bkt)++)\ 149 (bkt)++)\
155 hlist_for_each_entry_safe(obj, 150 hlist_for_each_entry_safe(obj, tmp, &name[bkt], member)
156 151
157 /** 152 /**
158 * hash_for_each_possible - iterate over all p 153 * hash_for_each_possible - iterate over all possible objects hashing to the
159 * same bucket 154 * same bucket
160 * @name: hashtable to iterate 155 * @name: hashtable to iterate
161 * @obj: the type * to use as a loop cursor fo 156 * @obj: the type * to use as a loop cursor for each entry
162 * @member: the name of the hlist_node within 157 * @member: the name of the hlist_node within the struct
163 * @key: the key of the objects to iterate ove 158 * @key: the key of the objects to iterate over
164 */ 159 */
165 #define hash_for_each_possible(name, obj, memb 160 #define hash_for_each_possible(name, obj, member, key) \
166 hlist_for_each_entry(obj, &name[hash_m 161 hlist_for_each_entry(obj, &name[hash_min(key, HASH_BITS(name))], member)
167 162
168 /** 163 /**
169 * hash_for_each_possible_rcu - iterate over a 164 * hash_for_each_possible_rcu - iterate over all possible objects hashing to the
170 * same bucket in an rcu enabled hashtable 165 * same bucket in an rcu enabled hashtable
>> 166 * in a rcu enabled hashtable
171 * @name: hashtable to iterate 167 * @name: hashtable to iterate
172 * @obj: the type * to use as a loop cursor fo 168 * @obj: the type * to use as a loop cursor for each entry
173 * @member: the name of the hlist_node within 169 * @member: the name of the hlist_node within the struct
174 * @key: the key of the objects to iterate ove 170 * @key: the key of the objects to iterate over
175 */ 171 */
176 #define hash_for_each_possible_rcu(name, obj, !! 172 #define hash_for_each_possible_rcu(name, obj, member, key) \
177 hlist_for_each_entry_rcu(obj, &name[ha 173 hlist_for_each_entry_rcu(obj, &name[hash_min(key, HASH_BITS(name))],\
178 member, ## cond) !! 174 member)
179 175
180 /** 176 /**
181 * hash_for_each_possible_rcu_notrace - iterat 177 * hash_for_each_possible_rcu_notrace - iterate over all possible objects hashing
182 * to the same bucket in an rcu enabled hashta 178 * to the same bucket in an rcu enabled hashtable in a rcu enabled hashtable
183 * @name: hashtable to iterate 179 * @name: hashtable to iterate
184 * @obj: the type * to use as a loop cursor fo 180 * @obj: the type * to use as a loop cursor for each entry
185 * @member: the name of the hlist_node within 181 * @member: the name of the hlist_node within the struct
186 * @key: the key of the objects to iterate ove 182 * @key: the key of the objects to iterate over
187 * 183 *
188 * This is the same as hash_for_each_possible_ 184 * This is the same as hash_for_each_possible_rcu() except that it does
189 * not do any RCU debugging or tracing. 185 * not do any RCU debugging or tracing.
190 */ 186 */
191 #define hash_for_each_possible_rcu_notrace(nam 187 #define hash_for_each_possible_rcu_notrace(name, obj, member, key) \
192 hlist_for_each_entry_rcu_notrace(obj, 188 hlist_for_each_entry_rcu_notrace(obj, \
193 &name[hash_min(key, HASH_BITS( 189 &name[hash_min(key, HASH_BITS(name))], member)
194 190
195 /** 191 /**
196 * hash_for_each_possible_safe - iterate over 192 * hash_for_each_possible_safe - iterate over all possible objects hashing to the
197 * same bucket safe against removals 193 * same bucket safe against removals
198 * @name: hashtable to iterate 194 * @name: hashtable to iterate
199 * @obj: the type * to use as a loop cursor fo 195 * @obj: the type * to use as a loop cursor for each entry
200 * @tmp: a &struct hlist_node used for tempora !! 196 * @tmp: a &struct used for temporary storage
201 * @member: the name of the hlist_node within 197 * @member: the name of the hlist_node within the struct
202 * @key: the key of the objects to iterate ove 198 * @key: the key of the objects to iterate over
203 */ 199 */
204 #define hash_for_each_possible_safe(name, obj, 200 #define hash_for_each_possible_safe(name, obj, tmp, member, key) \
205 hlist_for_each_entry_safe(obj, tmp,\ 201 hlist_for_each_entry_safe(obj, tmp,\
206 &name[hash_min(key, HASH_BITS( 202 &name[hash_min(key, HASH_BITS(name))], member)
207 203
208 204
209 #endif 205 #endif
210 206
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