omap: i2c: add a timeout to the busy waiting
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / staging / batman-adv / originator.c
blob29c241119a3b146aed9339070cea30cde79bcfa4
1 /*
2 * Copyright (C) 2009 B.A.T.M.A.N. contributors:
4 * Marek Lindner, Simon Wunderlich
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA
22 /* increase the reference counter for this originator */
24 #include "main.h"
25 #include "originator.h"
26 #include "hash.h"
27 #include "translation-table.h"
28 #include "routing.h"
30 static DECLARE_DELAYED_WORK(purge_orig_wq, purge_orig);
32 static void start_purge_timer(void)
34 queue_delayed_work(bat_event_workqueue, &purge_orig_wq, 1 * HZ);
37 int originator_init(void)
39 unsigned long flags;
40 if (orig_hash)
41 return 1;
43 spin_lock_irqsave(&orig_hash_lock, flags);
44 orig_hash = hash_new(128, compare_orig, choose_orig);
46 if (!orig_hash)
47 goto err;
49 spin_unlock_irqrestore(&orig_hash_lock, flags);
50 start_purge_timer();
51 return 1;
53 err:
54 spin_unlock_irqrestore(&orig_hash_lock, flags);
55 return 0;
58 void originator_free(void)
60 unsigned long flags;
62 if (!orig_hash)
63 return;
65 cancel_delayed_work_sync(&purge_orig_wq);
67 spin_lock_irqsave(&orig_hash_lock, flags);
68 hash_delete(orig_hash, free_orig_node);
69 orig_hash = NULL;
70 spin_unlock_irqrestore(&orig_hash_lock, flags);
73 struct neigh_node *
74 create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node,
75 uint8_t *neigh, struct batman_if *if_incoming)
77 struct neigh_node *neigh_node;
79 bat_dbg(DBG_BATMAN, "Creating new last-hop neighbor of originator\n");
81 neigh_node = kzalloc(sizeof(struct neigh_node), GFP_ATOMIC);
82 if (!neigh_node)
83 return NULL;
85 INIT_LIST_HEAD(&neigh_node->list);
87 memcpy(neigh_node->addr, neigh, ETH_ALEN);
88 neigh_node->orig_node = orig_neigh_node;
89 neigh_node->if_incoming = if_incoming;
91 list_add_tail(&neigh_node->list, &orig_node->neigh_list);
92 return neigh_node;
95 void free_orig_node(void *data)
97 struct list_head *list_pos, *list_pos_tmp;
98 struct neigh_node *neigh_node;
99 struct orig_node *orig_node = (struct orig_node *)data;
101 /* for all neighbors towards this originator ... */
102 list_for_each_safe(list_pos, list_pos_tmp, &orig_node->neigh_list) {
103 neigh_node = list_entry(list_pos, struct neigh_node, list);
105 list_del(list_pos);
106 kfree(neigh_node);
109 hna_global_del_orig(orig_node, "originator timed out");
111 kfree(orig_node->bcast_own);
112 kfree(orig_node->bcast_own_sum);
113 kfree(orig_node);
116 /* this function finds or creates an originator entry for the given
117 * address if it does not exits */
118 struct orig_node *get_orig_node(uint8_t *addr)
120 struct orig_node *orig_node;
121 struct hashtable_t *swaphash;
122 int size;
124 orig_node = ((struct orig_node *)hash_find(orig_hash, addr));
126 if (orig_node != NULL)
127 return orig_node;
129 bat_dbg(DBG_BATMAN, "Creating new originator: %pM \n", addr);
131 orig_node = kzalloc(sizeof(struct orig_node), GFP_ATOMIC);
132 if (!orig_node)
133 return NULL;
135 INIT_LIST_HEAD(&orig_node->neigh_list);
137 memcpy(orig_node->orig, addr, ETH_ALEN);
138 orig_node->router = NULL;
139 orig_node->batman_if = NULL;
140 orig_node->hna_buff = NULL;
142 size = num_ifs * sizeof(TYPE_OF_WORD) * NUM_WORDS;
144 orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
145 if (!orig_node->bcast_own)
146 goto free_orig_node;
148 size = num_ifs * sizeof(uint8_t);
149 orig_node->bcast_own_sum = kzalloc(size, GFP_ATOMIC);
150 if (!orig_node->bcast_own_sum)
151 goto free_bcast_own;
153 if (hash_add(orig_hash, orig_node) < 0)
154 goto free_bcast_own_sum;
156 if (orig_hash->elements * 4 > orig_hash->size) {
157 swaphash = hash_resize(orig_hash, orig_hash->size * 2);
159 if (swaphash == NULL)
160 printk(KERN_ERR
161 "batman-adv:Couldn't resize orig hash table \n");
162 else
163 orig_hash = swaphash;
166 return orig_node;
167 free_bcast_own_sum:
168 kfree(orig_node->bcast_own_sum);
169 free_bcast_own:
170 kfree(orig_node->bcast_own);
171 free_orig_node:
172 kfree(orig_node);
173 return NULL;
176 static bool purge_orig_neighbors(struct orig_node *orig_node,
177 struct neigh_node **best_neigh_node)
179 struct list_head *list_pos, *list_pos_tmp;
180 struct neigh_node *neigh_node;
181 bool neigh_purged = false;
183 *best_neigh_node = NULL;
186 /* for all neighbors towards this originator ... */
187 list_for_each_safe(list_pos, list_pos_tmp, &orig_node->neigh_list) {
188 neigh_node = list_entry(list_pos, struct neigh_node, list);
190 if (time_after(jiffies,
191 (neigh_node->last_valid +
192 ((PURGE_TIMEOUT * HZ) / 1000)))) {
194 bat_dbg(DBG_BATMAN, "neighbor timeout: originator %pM, neighbor: %pM, last_valid %lu\n", orig_node->orig, neigh_node->addr, (neigh_node->last_valid / HZ));
196 neigh_purged = true;
197 list_del(list_pos);
198 kfree(neigh_node);
199 } else {
200 if ((*best_neigh_node == NULL) ||
201 (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
202 *best_neigh_node = neigh_node;
205 return neigh_purged;
209 static bool purge_orig_node(struct orig_node *orig_node)
211 struct neigh_node *best_neigh_node;
213 if (time_after(jiffies,
214 (orig_node->last_valid +
215 ((2 * PURGE_TIMEOUT * HZ) / 1000)))) {
217 bat_dbg(DBG_BATMAN,
218 "Originator timeout: originator %pM, last_valid %lu\n",
219 orig_node->orig, (orig_node->last_valid / HZ));
220 return true;
221 } else {
222 if (purge_orig_neighbors(orig_node, &best_neigh_node))
223 update_routes(orig_node, best_neigh_node,
224 orig_node->hna_buff,
225 orig_node->hna_buff_len);
227 return false;
230 void purge_orig(struct work_struct *work)
232 HASHIT(hashit);
233 struct orig_node *orig_node;
234 unsigned long flags;
236 spin_lock_irqsave(&orig_hash_lock, flags);
238 /* for all origins... */
239 while (hash_iterate(orig_hash, &hashit)) {
240 orig_node = hashit.bucket->data;
241 if (purge_orig_node(orig_node)) {
242 hash_remove_bucket(orig_hash, &hashit);
243 free_orig_node(orig_node);
247 spin_unlock_irqrestore(&orig_hash_lock, flags);
249 start_purge_timer();