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,
35 offsetof(struct sw_flow_key, wildcards));
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 && flow_keys_equal(&flow->key, 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;
52 if (flow->key.wildcards != 0)
55 bucket = find_bucket(swt, &flow->key);
56 if (*bucket == NULL) {
58 rcu_assign_pointer(*bucket, flow);
61 struct sw_flow *old_flow = *bucket;
62 if (flow_keys_equal(&old_flow->key, &flow->key)) {
63 /* Keep stats from the original flow */
64 flow->init_time = old_flow->init_time;
65 flow->packet_count = old_flow->packet_count;
66 flow->byte_count = old_flow->byte_count;
68 rcu_assign_pointer(*bucket, flow);
69 flow_deferred_free(old_flow);
78 /* Caller must update n_flows. */
79 static int do_delete(struct sw_flow **bucket, struct sw_flow *flow)
81 rcu_assign_pointer(*bucket, NULL);
82 flow_deferred_free(flow);
86 /* Returns number of deleted flows. We can ignore the priority
87 * argument, since all exact-match entries are the same (highest)
89 static int table_hash_delete(struct sw_table *swt,
90 const struct sw_flow_key *key,
91 uint16_t priority, int strict)
93 struct sw_table_hash *th = (struct sw_table_hash *) swt;
94 unsigned int count = 0;
96 if (key->wildcards == 0) {
97 struct sw_flow **bucket = find_bucket(swt, key);
98 struct sw_flow *flow = *bucket;
99 if (flow && flow_keys_equal(&flow->key, key))
100 count = do_delete(bucket, flow);
104 for (i = 0; i <= th->bucket_mask; i++) {
105 struct sw_flow **bucket = &th->buckets[i];
106 struct sw_flow *flow = *bucket;
107 if (flow && flow_del_matches(&flow->key, key, strict))
108 count += do_delete(bucket, flow);
111 th->n_flows -= count;
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 mutex_lock(&dp_mutex);
122 for (i = 0; i <= th->bucket_mask; i++) {
123 struct sw_flow **bucket = &th->buckets[i];
124 struct sw_flow *flow = *bucket;
126 int reason = flow_timeout(flow);
128 count += do_delete(bucket, flow);
129 dp_send_flow_expired(dp, flow, reason);
133 th->n_flows -= count;
134 mutex_unlock(&dp_mutex);
139 static void table_hash_destroy(struct sw_table *swt)
141 struct sw_table_hash *th = (struct sw_table_hash *) swt;
143 for (i = 0; i <= th->bucket_mask; i++)
145 flow_free(th->buckets[i]);
146 kmem_free(th->buckets, (th->bucket_mask + 1) * sizeof *th->buckets);
150 static int table_hash_iterate(struct sw_table *swt,
151 const struct sw_flow_key *key,
152 struct sw_table_position *position,
153 int (*callback)(struct sw_flow *, void *private),
156 struct sw_table_hash *th = (struct sw_table_hash *) swt;
158 if (position->private[0] > th->bucket_mask)
161 if (key->wildcards == 0) {
162 struct sw_flow *flow;
165 flow = table_hash_lookup(swt, key);
169 error = callback(flow, private);
171 position->private[0] = -1;
176 for (i = position->private[0]; i <= th->bucket_mask; i++) {
177 struct sw_flow *flow = th->buckets[i];
178 if (flow && flow_matches_1wild(&flow->key, key)) {
179 int error = callback(flow, private);
181 position->private[0] = i;
189 static void table_hash_stats(struct sw_table *swt,
190 struct sw_table_stats *stats)
192 struct sw_table_hash *th = (struct sw_table_hash *) swt;
193 stats->name = "hash";
194 stats->wildcards = 0; /* No wildcards are supported. */
195 stats->n_flows = th->n_flows;
196 stats->max_flows = th->bucket_mask + 1;
197 stats->n_matched = swt->n_matched;
200 struct sw_table *table_hash_create(unsigned int polynomial,
201 unsigned int n_buckets)
203 struct sw_table_hash *th;
204 struct sw_table *swt;
206 th = kzalloc(sizeof *th, GFP_KERNEL);
210 BUG_ON(n_buckets & (n_buckets - 1));
211 th->buckets = kmem_zalloc(n_buckets * sizeof *th->buckets);
212 if (th->buckets == NULL) {
213 printk("failed to allocate %u buckets\n", n_buckets);
217 th->bucket_mask = n_buckets - 1;
220 swt->lookup = table_hash_lookup;
221 swt->insert = table_hash_insert;
222 swt->delete = table_hash_delete;
223 swt->timeout = table_hash_timeout;
224 swt->destroy = table_hash_destroy;
225 swt->iterate = table_hash_iterate;
226 swt->stats = table_hash_stats;
228 crc32_init(&th->crc32, polynomial);
234 /* Double-hashing table. */
236 struct sw_table_hash2 {
238 struct sw_table *subtable[2];
241 static struct sw_flow *table_hash2_lookup(struct sw_table *swt,
242 const struct sw_flow_key *key)
244 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
247 for (i = 0; i < 2; i++) {
248 struct sw_flow *flow = *find_bucket(t2->subtable[i], key);
249 if (flow && flow_keys_equal(&flow->key, key))
255 static int table_hash2_insert(struct sw_table *swt, struct sw_flow *flow)
257 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
259 if (table_hash_insert(t2->subtable[0], flow))
261 return table_hash_insert(t2->subtable[1], flow);
264 static int table_hash2_delete(struct sw_table *swt,
265 const struct sw_flow_key *key,
266 uint16_t priority, int strict)
268 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
269 return (table_hash_delete(t2->subtable[0], key, priority, strict)
270 + table_hash_delete(t2->subtable[1], key, priority, strict));
273 static int table_hash2_timeout(struct datapath *dp, struct sw_table *swt)
275 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
276 return (table_hash_timeout(dp, t2->subtable[0])
277 + table_hash_timeout(dp, t2->subtable[1]));
280 static void table_hash2_destroy(struct sw_table *swt)
282 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
283 table_hash_destroy(t2->subtable[0]);
284 table_hash_destroy(t2->subtable[1]);
288 static int table_hash2_iterate(struct sw_table *swt,
289 const struct sw_flow_key *key,
290 struct sw_table_position *position,
291 int (*callback)(struct sw_flow *, void *),
294 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
297 for (i = position->private[1]; i < 2; i++) {
298 int error = table_hash_iterate(t2->subtable[i], key, position,
303 position->private[0] = 0;
304 position->private[1]++;
309 static void table_hash2_stats(struct sw_table *swt,
310 struct sw_table_stats *stats)
312 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
313 struct sw_table_stats substats[2];
316 for (i = 0; i < 2; i++)
317 table_hash_stats(t2->subtable[i], &substats[i]);
318 stats->name = "hash2";
319 stats->wildcards = 0; /* No wildcards are supported. */
320 stats->n_flows = substats[0].n_flows + substats[1].n_flows;
321 stats->max_flows = substats[0].max_flows + substats[1].max_flows;
322 stats->n_matched = swt->n_matched;
325 struct sw_table *table_hash2_create(unsigned int poly0, unsigned int buckets0,
326 unsigned int poly1, unsigned int buckets1)
329 struct sw_table_hash2 *t2;
330 struct sw_table *swt;
332 t2 = kzalloc(sizeof *t2, GFP_KERNEL);
336 t2->subtable[0] = table_hash_create(poly0, buckets0);
337 if (t2->subtable[0] == NULL)
340 t2->subtable[1] = table_hash_create(poly1, buckets1);
341 if (t2->subtable[1] == NULL)
342 goto out_free_subtable0;
345 swt->lookup = table_hash2_lookup;
346 swt->insert = table_hash2_insert;
347 swt->delete = table_hash2_delete;
348 swt->timeout = table_hash2_timeout;
349 swt->destroy = table_hash2_destroy;
350 swt->iterate = table_hash2_iterate;
351 swt->stats = table_hash2_stats;
356 table_hash_destroy(t2->subtable[0]);
362 /* From fs/xfs/linux-2.4/kmem.c. */
365 kmem_alloc(size_t size)
369 #ifdef KMALLOC_MAX_SIZE
370 if (size > KMALLOC_MAX_SIZE)
373 ptr = kmalloc(size, GFP_KERNEL);
377 printk("openflow: used vmalloc for %lu bytes\n",
378 (unsigned long)size);
384 kmem_zalloc(size_t size)
386 void *ptr = kmem_alloc(size);
388 memset(ptr, 0, size);
393 kmem_free(void *ptr, size_t size)
395 if (((unsigned long)ptr < VMALLOC_START) ||
396 ((unsigned long)ptr >= VMALLOC_END)) {