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 {
27 unsigned int bucket_mask; /* Number of buckets minus 1. */
28 struct sw_flow **buckets;
31 static struct sw_flow **find_bucket(struct sw_table *swt,
32 const struct sw_flow_key *key)
34 struct sw_table_hash *th = (struct sw_table_hash *) swt;
35 unsigned int crc = crc32_calculate(&th->crc32, key, sizeof *key);
36 return &th->buckets[crc & th->bucket_mask];
39 static struct sw_flow *table_hash_lookup(struct sw_table *swt,
40 const struct sw_flow_key *key)
42 struct sw_flow *flow = *find_bucket(swt, key);
43 return flow && !memcmp(&flow->key, key, sizeof *key) ? flow : NULL;
46 static int table_hash_insert(struct sw_table *swt, struct sw_flow *flow)
48 struct sw_table_hash *th = (struct sw_table_hash *) swt;
49 struct sw_flow **bucket;
50 unsigned long int flags;
53 if (flow->key.wildcards != 0)
56 spin_lock_irqsave(&th->lock, flags);
57 bucket = find_bucket(swt, &flow->key);
58 if (*bucket == NULL) {
59 atomic_inc(&th->n_flows);
60 rcu_assign_pointer(*bucket, flow);
63 struct sw_flow *old_flow = *bucket;
64 if (!memcmp(&old_flow->key, &flow->key, sizeof flow->key)
65 && flow_del(old_flow)) {
66 rcu_assign_pointer(*bucket, flow);
67 flow_deferred_free(old_flow);
73 spin_unlock_irqrestore(&th->lock, flags);
77 /* Caller must update n_flows. */
78 static int do_delete(struct sw_flow **bucket, struct sw_flow *flow)
81 rcu_assign_pointer(*bucket, NULL);
82 flow_deferred_free(flow);
88 /* Returns number of deleted flows. */
89 static int table_hash_delete(struct sw_table *swt,
90 const struct sw_flow_key *key, int strict)
92 struct sw_table_hash *th = (struct sw_table_hash *) swt;
93 unsigned int count = 0;
95 if (key->wildcards == 0) {
96 struct sw_flow **bucket = find_bucket(swt, key);
97 struct sw_flow *flow = *bucket;
98 if (flow && !memcmp(&flow->key, key, sizeof *key))
99 count = do_delete(bucket, flow);
103 for (i = 0; i <= th->bucket_mask; i++) {
104 struct sw_flow **bucket = &th->buckets[i];
105 struct sw_flow *flow = *bucket;
106 if (flow && flow_del_matches(&flow->key, key, strict))
107 count += do_delete(bucket, flow);
111 atomic_sub(count, &th->n_flows);
115 static int table_hash_timeout(struct datapath *dp, struct sw_table *swt)
117 struct sw_table_hash *th = (struct sw_table_hash *) swt;
121 for (i = 0; i <= th->bucket_mask; i++) {
122 struct sw_flow **bucket = &th->buckets[i];
123 struct sw_flow *flow = *bucket;
124 if (flow && flow_timeout(flow)) {
125 count += do_delete(bucket, flow);
126 if (dp->flags & OFPC_SEND_FLOW_EXP)
127 dp_send_flow_expired(dp, flow);
132 atomic_sub(count, &th->n_flows);
136 static void table_hash_destroy(struct sw_table *swt)
138 struct sw_table_hash *th = (struct sw_table_hash *) swt;
140 for (i = 0; i <= th->bucket_mask; i++)
142 flow_free(th->buckets[i]);
143 kmem_free(th->buckets, (th->bucket_mask + 1) * sizeof *th->buckets);
147 static int table_hash_iterate(struct sw_table *swt,
148 const struct sw_flow_key *key,
149 struct sw_table_position *position,
150 int (*callback)(struct sw_flow *, void *private),
153 struct sw_table_hash *th = (struct sw_table_hash *) swt;
155 if (position->private[0] > th->bucket_mask)
158 if (key->wildcards == 0) {
159 struct sw_flow *flow = table_hash_lookup(swt, key);
160 position->private[0] = -1;
161 return flow ? callback(flow, private) : 0;
165 for (i = position->private[0]; i <= th->bucket_mask; i++) {
166 struct sw_flow *flow = th->buckets[i];
167 if (flow && flow_matches(key, &flow->key)) {
168 int error = callback(flow, private);
170 position->private[0] = i + 1;
178 static void table_hash_stats(struct sw_table *swt,
179 struct sw_table_stats *stats)
181 struct sw_table_hash *th = (struct sw_table_hash *) swt;
182 stats->name = "hash";
183 stats->n_flows = atomic_read(&th->n_flows);
184 stats->max_flows = th->bucket_mask + 1;
187 struct sw_table *table_hash_create(unsigned int polynomial,
188 unsigned int n_buckets)
190 struct sw_table_hash *th;
191 struct sw_table *swt;
193 th = kmalloc(sizeof *th, GFP_KERNEL);
197 BUG_ON(n_buckets & (n_buckets - 1));
198 th->buckets = kmem_zalloc(n_buckets * sizeof *th->buckets);
199 if (th->buckets == NULL) {
200 printk("failed to allocate %u buckets\n", n_buckets);
204 th->bucket_mask = n_buckets - 1;
207 swt->lookup = table_hash_lookup;
208 swt->insert = table_hash_insert;
209 swt->delete = table_hash_delete;
210 swt->timeout = table_hash_timeout;
211 swt->destroy = table_hash_destroy;
212 swt->iterate = table_hash_iterate;
213 swt->stats = table_hash_stats;
215 spin_lock_init(&th->lock);
216 crc32_init(&th->crc32, polynomial);
217 atomic_set(&th->n_flows, 0);
222 /* Double-hashing table. */
224 struct sw_table_hash2 {
226 struct sw_table *subtable[2];
229 static struct sw_flow *table_hash2_lookup(struct sw_table *swt,
230 const struct sw_flow_key *key)
232 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
235 for (i = 0; i < 2; i++) {
236 struct sw_flow *flow = *find_bucket(t2->subtable[i], key);
237 if (flow && !memcmp(&flow->key, key, sizeof *key))
243 static int table_hash2_insert(struct sw_table *swt, struct sw_flow *flow)
245 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
247 if (table_hash_insert(t2->subtable[0], flow))
249 return table_hash_insert(t2->subtable[1], flow);
252 static int table_hash2_delete(struct sw_table *swt,
253 const struct sw_flow_key *key, int strict)
255 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
256 return (table_hash_delete(t2->subtable[0], key, strict)
257 + table_hash_delete(t2->subtable[1], key, strict));
260 static int table_hash2_timeout(struct datapath *dp, struct sw_table *swt)
262 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
263 return (table_hash_timeout(dp, t2->subtable[0])
264 + table_hash_timeout(dp, t2->subtable[1]));
267 static void table_hash2_destroy(struct sw_table *swt)
269 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
270 table_hash_destroy(t2->subtable[0]);
271 table_hash_destroy(t2->subtable[1]);
275 static int table_hash2_iterate(struct sw_table *swt,
276 const struct sw_flow_key *key,
277 struct sw_table_position *position,
278 int (*callback)(struct sw_flow *, void *),
281 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
284 for (i = position->private[1]; i < 2; i++) {
285 int error = table_hash_iterate(t2->subtable[i], key, position,
290 position->private[0] = 0;
291 position->private[1]++;
296 static void table_hash2_stats(struct sw_table *swt,
297 struct sw_table_stats *stats)
299 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
300 struct sw_table_stats substats[2];
303 for (i = 0; i < 2; i++)
304 table_hash_stats(t2->subtable[i], &substats[i]);
305 stats->name = "hash2";
306 stats->n_flows = substats[0].n_flows + substats[1].n_flows;
307 stats->max_flows = substats[0].max_flows + substats[1].max_flows;
310 struct sw_table *table_hash2_create(unsigned int poly0, unsigned int buckets0,
311 unsigned int poly1, unsigned int buckets1)
314 struct sw_table_hash2 *t2;
315 struct sw_table *swt;
317 t2 = kmalloc(sizeof *t2, GFP_KERNEL);
321 t2->subtable[0] = table_hash_create(poly0, buckets0);
322 if (t2->subtable[0] == NULL)
325 t2->subtable[1] = table_hash_create(poly1, buckets1);
326 if (t2->subtable[1] == NULL)
327 goto out_free_subtable0;
330 swt->lookup = table_hash2_lookup;
331 swt->insert = table_hash2_insert;
332 swt->delete = table_hash2_delete;
333 swt->timeout = table_hash2_timeout;
334 swt->destroy = table_hash2_destroy;
335 swt->iterate = table_hash2_iterate;
336 swt->stats = table_hash2_stats;
341 table_hash_destroy(t2->subtable[0]);
347 /* From fs/xfs/linux-2.4/kmem.c. */
350 kmem_alloc(size_t size)
354 #ifdef KMALLOC_MAX_SIZE
355 if (size > KMALLOC_MAX_SIZE)
358 ptr = kmalloc(size, GFP_KERNEL);
362 printk("openflow: used vmalloc for %lu bytes\n",
363 (unsigned long)size);
369 kmem_zalloc(size_t size)
371 void *ptr = kmem_alloc(size);
373 memset(ptr, 0, size);
378 kmem_free(void *ptr, size_t size)
380 if (((unsigned long)ptr < VMALLOC_START) ||
381 ((unsigned long)ptr >= VMALLOC_END)) {