2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008 The Board of Trustees of The Leland
4 * Stanford Junior University
12 #include <linux/slab.h>
13 #include <linux/vmalloc.h>
15 #include <linux/highmem.h>
16 #include <asm/pgtable.h>
18 static void *kmem_alloc(size_t);
19 static void *kmem_zalloc(size_t);
20 static void kmem_free(void *, size_t);
22 struct sw_table_hash {
26 unsigned int bucket_mask; /* Number of buckets minus 1. */
27 struct sw_flow **buckets;
30 static struct sw_flow **find_bucket(struct sw_table *swt,
31 const struct sw_flow_key *key)
33 struct sw_table_hash *th = (struct sw_table_hash *) swt;
34 unsigned int crc = crc32_calculate(&th->crc32, key, sizeof *key);
35 return &th->buckets[crc & th->bucket_mask];
38 static struct sw_flow *table_hash_lookup(struct sw_table *swt,
39 const struct sw_flow_key *key)
41 struct sw_flow *flow = *find_bucket(swt, key);
42 return flow && flow_keys_equal(&flow->key, key) ? flow : NULL;
45 static int table_hash_insert(struct sw_table *swt, struct sw_flow *flow)
47 struct sw_table_hash *th = (struct sw_table_hash *) swt;
48 struct sw_flow **bucket;
51 if (flow->key.wildcards != 0)
54 bucket = find_bucket(swt, &flow->key);
55 if (*bucket == NULL) {
57 rcu_assign_pointer(*bucket, flow);
60 struct sw_flow *old_flow = *bucket;
61 if (!flow_keys_equal(&old_flow->key, &flow->key)) {
62 rcu_assign_pointer(*bucket, flow);
63 flow_deferred_free(old_flow);
72 /* Caller must update n_flows. */
73 static int do_delete(struct sw_flow **bucket, struct sw_flow *flow)
75 rcu_assign_pointer(*bucket, NULL);
76 flow_deferred_free(flow);
80 /* Returns number of deleted flows. We can ignore the priority
81 * argument, since all exact-match entries are the same (highest)
83 static int table_hash_delete(struct sw_table *swt,
84 const struct sw_flow_key *key,
85 uint16_t priority, int strict)
87 struct sw_table_hash *th = (struct sw_table_hash *) swt;
88 unsigned int count = 0;
90 if (key->wildcards == 0) {
91 struct sw_flow **bucket = find_bucket(swt, key);
92 struct sw_flow *flow = *bucket;
93 if (flow && flow_keys_equal(&flow->key, key))
94 count = do_delete(bucket, flow);
98 for (i = 0; i <= th->bucket_mask; i++) {
99 struct sw_flow **bucket = &th->buckets[i];
100 struct sw_flow *flow = *bucket;
101 if (flow && flow_del_matches(&flow->key, key, strict))
102 count += do_delete(bucket, flow);
105 th->n_flows -= count;
109 static int table_hash_timeout(struct datapath *dp, struct sw_table *swt)
111 struct sw_table_hash *th = (struct sw_table_hash *) swt;
115 mutex_lock(&dp_mutex);
116 for (i = 0; i <= th->bucket_mask; i++) {
117 struct sw_flow **bucket = &th->buckets[i];
118 struct sw_flow *flow = *bucket;
120 int reason = flow_timeout(flow);
122 count += do_delete(bucket, flow);
123 dp_send_flow_expired(dp, flow, reason);
127 th->n_flows -= count;
128 mutex_unlock(&dp_mutex);
133 static void table_hash_destroy(struct sw_table *swt)
135 struct sw_table_hash *th = (struct sw_table_hash *) swt;
137 for (i = 0; i <= th->bucket_mask; i++)
139 flow_free(th->buckets[i]);
140 kmem_free(th->buckets, (th->bucket_mask + 1) * sizeof *th->buckets);
144 static int table_hash_iterate(struct sw_table *swt,
145 const struct sw_flow_key *key,
146 struct sw_table_position *position,
147 int (*callback)(struct sw_flow *, void *private),
150 struct sw_table_hash *th = (struct sw_table_hash *) swt;
152 if (position->private[0] > th->bucket_mask)
155 if (key->wildcards == 0) {
156 struct sw_flow *flow;
159 flow = table_hash_lookup(swt, key);
163 error = callback(flow, private);
165 position->private[0] = -1;
170 for (i = position->private[0]; i <= th->bucket_mask; i++) {
171 struct sw_flow *flow = th->buckets[i];
172 if (flow && flow_matches_1wild(&flow->key, key)) {
173 int error = callback(flow, private);
175 position->private[0] = i;
183 static void table_hash_stats(struct sw_table *swt,
184 struct sw_table_stats *stats)
186 struct sw_table_hash *th = (struct sw_table_hash *) swt;
187 stats->name = "hash";
188 stats->n_flows = th->n_flows;
189 stats->max_flows = th->bucket_mask + 1;
190 stats->n_matched = swt->n_matched;
193 struct sw_table *table_hash_create(unsigned int polynomial,
194 unsigned int n_buckets)
196 struct sw_table_hash *th;
197 struct sw_table *swt;
199 th = kzalloc(sizeof *th, GFP_KERNEL);
203 BUG_ON(n_buckets & (n_buckets - 1));
204 th->buckets = kmem_zalloc(n_buckets * sizeof *th->buckets);
205 if (th->buckets == NULL) {
206 printk("failed to allocate %u buckets\n", n_buckets);
210 th->bucket_mask = n_buckets - 1;
213 swt->lookup = table_hash_lookup;
214 swt->insert = table_hash_insert;
215 swt->delete = table_hash_delete;
216 swt->timeout = table_hash_timeout;
217 swt->destroy = table_hash_destroy;
218 swt->iterate = table_hash_iterate;
219 swt->stats = table_hash_stats;
221 crc32_init(&th->crc32, polynomial);
227 /* Double-hashing table. */
229 struct sw_table_hash2 {
231 struct sw_table *subtable[2];
234 static struct sw_flow *table_hash2_lookup(struct sw_table *swt,
235 const struct sw_flow_key *key)
237 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
240 for (i = 0; i < 2; i++) {
241 struct sw_flow *flow = *find_bucket(t2->subtable[i], key);
242 if (flow && flow_keys_equal(&flow->key, key))
248 static int table_hash2_insert(struct sw_table *swt, struct sw_flow *flow)
250 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
252 if (table_hash_insert(t2->subtable[0], flow))
254 return table_hash_insert(t2->subtable[1], flow);
257 static int table_hash2_delete(struct sw_table *swt,
258 const struct sw_flow_key *key,
259 uint16_t priority, int strict)
261 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
262 return (table_hash_delete(t2->subtable[0], key, priority, strict)
263 + table_hash_delete(t2->subtable[1], key, priority, strict));
266 static int table_hash2_timeout(struct datapath *dp, struct sw_table *swt)
268 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
269 return (table_hash_timeout(dp, t2->subtable[0])
270 + table_hash_timeout(dp, t2->subtable[1]));
273 static void table_hash2_destroy(struct sw_table *swt)
275 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
276 table_hash_destroy(t2->subtable[0]);
277 table_hash_destroy(t2->subtable[1]);
281 static int table_hash2_iterate(struct sw_table *swt,
282 const struct sw_flow_key *key,
283 struct sw_table_position *position,
284 int (*callback)(struct sw_flow *, void *),
287 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
290 for (i = position->private[1]; i < 2; i++) {
291 int error = table_hash_iterate(t2->subtable[i], key, position,
296 position->private[0] = 0;
297 position->private[1]++;
302 static void table_hash2_stats(struct sw_table *swt,
303 struct sw_table_stats *stats)
305 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
306 struct sw_table_stats substats[2];
309 for (i = 0; i < 2; i++)
310 table_hash_stats(t2->subtable[i], &substats[i]);
311 stats->name = "hash2";
312 stats->n_flows = substats[0].n_flows + substats[1].n_flows;
313 stats->max_flows = substats[0].max_flows + substats[1].max_flows;
314 stats->n_matched = swt->n_matched;
317 struct sw_table *table_hash2_create(unsigned int poly0, unsigned int buckets0,
318 unsigned int poly1, unsigned int buckets1)
321 struct sw_table_hash2 *t2;
322 struct sw_table *swt;
324 t2 = kzalloc(sizeof *t2, GFP_KERNEL);
328 t2->subtable[0] = table_hash_create(poly0, buckets0);
329 if (t2->subtable[0] == NULL)
332 t2->subtable[1] = table_hash_create(poly1, buckets1);
333 if (t2->subtable[1] == NULL)
334 goto out_free_subtable0;
337 swt->lookup = table_hash2_lookup;
338 swt->insert = table_hash2_insert;
339 swt->delete = table_hash2_delete;
340 swt->timeout = table_hash2_timeout;
341 swt->destroy = table_hash2_destroy;
342 swt->iterate = table_hash2_iterate;
343 swt->stats = table_hash2_stats;
348 table_hash_destroy(t2->subtable[0]);
354 /* From fs/xfs/linux-2.4/kmem.c. */
357 kmem_alloc(size_t size)
361 #ifdef KMALLOC_MAX_SIZE
362 if (size > KMALLOC_MAX_SIZE)
365 ptr = kmalloc(size, GFP_KERNEL);
369 printk("openflow: used vmalloc for %lu bytes\n",
370 (unsigned long)size);
376 kmem_zalloc(size_t size)
378 void *ptr = kmem_alloc(size);
380 memset(ptr, 0, size);
385 kmem_free(void *ptr, size_t size)
387 if (((unsigned long)ptr < VMALLOC_START) ||
388 ((unsigned long)ptr >= VMALLOC_END)) {