1 /* 2 * cn_queue.c 3 * 4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru> 5 * All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 */ 22 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/list.h> 26 #include <linux/workqueue.h> 27 #include <linux/spinlock.h> 28 #include <linux/slab.h> 29 #include <linux/skbuff.h> 30 #include <linux/suspend.h> 31 #include <linux/connector.h> 32 #include <linux/delay.h> 33 34 void cn_queue_wrapper(struct work_struct *work) 35 { 36 struct cn_callback_entry *cbq = 37 container_of(work, struct cn_callback_entry, work); 38 struct cn_callback_data *d = &cbq->data; 39 40 d->callback(d->callback_priv); 41 42 d->destruct_data(d->ddata); 43 d->ddata = NULL; 44 45 kfree(d->free); 46 } 47 48 static struct cn_callback_entry *cn_queue_alloc_callback_entry(char *name, struct cb_id *id, void (*callback)(void *)) 49 { 50 struct cn_callback_entry *cbq; 51 52 cbq = kzalloc(sizeof(*cbq), GFP_KERNEL); 53 if (!cbq) { 54 printk(KERN_ERR "Failed to create new callback queue.\n"); 55 return NULL; 56 } 57 58 snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name); 59 memcpy(&cbq->id.id, id, sizeof(struct cb_id)); 60 cbq->data.callback = callback; 61 62 INIT_WORK(&cbq->work, &cn_queue_wrapper); 63 return cbq; 64 } 65 66 static void cn_queue_free_callback(struct cn_callback_entry *cbq) 67 { 68 flush_workqueue(cbq->pdev->cn_queue); 69 70 kfree(cbq); 71 } 72 73 int cn_cb_equal(struct cb_id *i1, struct cb_id *i2) 74 { 75 return ((i1->idx == i2->idx) && (i1->val == i2->val)); 76 } 77 78 int cn_queue_add_callback(struct cn_queue_dev *dev, char *name, struct cb_id *id, void (*callback)(void *)) 79 { 80 struct cn_callback_entry *cbq, *__cbq; 81 int found = 0; 82 83 cbq = cn_queue_alloc_callback_entry(name, id, callback); 84 if (!cbq) 85 return -ENOMEM; 86 87 atomic_inc(&dev->refcnt); 88 cbq->pdev = dev; 89 90 spin_lock_bh(&dev->queue_lock); 91 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) { 92 if (cn_cb_equal(&__cbq->id.id, id)) { 93 found = 1; 94 break; 95 } 96 } 97 if (!found) 98 list_add_tail(&cbq->callback_entry, &dev->queue_list); 99 spin_unlock_bh(&dev->queue_lock); 100 101 if (found) { 102 atomic_dec(&dev->refcnt); 103 cn_queue_free_callback(cbq); 104 return -EINVAL; 105 } 106 107 cbq->nls = dev->nls; 108 cbq->seq = 0; 109 cbq->group = cbq->id.id.idx; 110 111 return 0; 112 } 113 114 void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id) 115 { 116 struct cn_callback_entry *cbq, *n; 117 int found = 0; 118 119 spin_lock_bh(&dev->queue_lock); 120 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) { 121 if (cn_cb_equal(&cbq->id.id, id)) { 122 list_del(&cbq->callback_entry); 123 found = 1; 124 break; 125 } 126 } 127 spin_unlock_bh(&dev->queue_lock); 128 129 if (found) { 130 cn_queue_free_callback(cbq); 131 atomic_dec(&dev->refcnt); 132 } 133 } 134 135 struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls) 136 { 137 struct cn_queue_dev *dev; 138 139 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 140 if (!dev) 141 return NULL; 142 143 snprintf(dev->name, sizeof(dev->name), "%s", name); 144 atomic_set(&dev->refcnt, 0); 145 INIT_LIST_HEAD(&dev->queue_list); 146 spin_lock_init(&dev->queue_lock); 147 148 dev->nls = nls; 149 dev->netlink_groups = 0; 150 151 dev->cn_queue = create_workqueue(dev->name); 152 if (!dev->cn_queue) { 153 kfree(dev); 154 return NULL; 155 } 156 157 return dev; 158 } 159 160 void cn_queue_free_dev(struct cn_queue_dev *dev) 161 { 162 struct cn_callback_entry *cbq, *n; 163 164 flush_workqueue(dev->cn_queue); 165 destroy_workqueue(dev->cn_queue); 166 167 spin_lock_bh(&dev->queue_lock); 168 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) 169 list_del(&cbq->callback_entry); 170 spin_unlock_bh(&dev->queue_lock); 171 172 while (atomic_read(&dev->refcnt)) { 173 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", 174 dev->name, atomic_read(&dev->refcnt)); 175 msleep(1000); 176 } 177 178 kfree(dev); 179 dev = NULL; 180 } 181